Title of Invention	CHANNEL CODING METHOD OF VARIABLE LENGTH INFORMATION USING BLOCK CODE
Abstract	A channel coding method of variable length information using block code is disclosed. A method for channel-coding information bits using a code generation matrix including 32 rows and A columns corresponding to length of the mformation bits includes, channel-coding the information bits having "A" length using basis sequences having 32-bit length corresponding to columns of the code generation matrix, and outputting the channel-coded result as an output sequence. If"A" is higher than 10, the code generation matrix is generated when (A-10) additional basis sequences were added as columm- directional sequences to a first or second matrix. The first matrix is a TFCI code generation matrix composed of 32 rows and 10 columns used for TFCI coding. The second matrix is made when at least one of an inter-row location or an mter-column location of the first matrix was changed. The additional basis sequences satisfy a value 10 of a mmimum Hammmg distance.

Title of Invention

CHANNEL CODING METHOD OF VARIABLE LENGTH INFORMATION USING BLOCK CODE

Abstract

A channel coding method of variable length information using block code is disclosed. A method for channel-coding information bits using a code generation matrix including 32 rows and A columns corresponding to length of the mformation bits includes, channel-coding the information bits having "A" length using basis sequences having 32-bit length corresponding to columns of the code generation matrix, and outputting the channel-coded result as an output sequence. If"A" is higher than 10, the code generation matrix is generated when (A-10) additional basis sequences were added as columm- directional sequences to a first or second matrix. The first matrix is a TFCI code generation matrix composed of 32 rows and 10 columns used for TFCI coding. The second matrix is made when at least one of an inter-row location or an mter-column location of the first matrix was changed. The additional basis sequences satisfy a value 10 of a mmimum Hammmg distance.

Full Text	[description] [Invention Title] CHANNEL CODING METHOD OF VARIABLE LENGTH INFORMATION USING BLOCK CODE [Technical Field] The present invention relates to a coding method for a mobile communication system, and more particularly to a method for effectively performing a channel-coding process on variable length information using a block code. [Background Art] For the convenience of description and better understanding of the present invention, some concepts requisite for the present invention from among several basic coding theories will hereinafter be described in detail. Generally, a general binary error correction code is denoted by [n, k, d] , where "n" is the number of bits of coded codewords, "k" is the number of information bits created prior to the coding process, and "d" is a minimum distance between codewords. In this case, only the binary code has been considered for the above-mentioned binary error correction code, such that a number of possible codeword points in code space is denoted by 2", and a total number of coded codewords is denoted by 2". Also, if the minimum distance is not substantially considered to be important, the aforementioned binary error correction code may also be denoted by [n, k] . If there is no mention of the above error correction code in this application, it should be noted that individual values of "n", "k", and "d" be set to the above-mentioned values. In this case, the above-mentioned error correction code should not be confused with a matrix-type block code composed of X number of rows (i.e., X rows) and Y number of columns (i.e., Y columns). In the meantime, the coding rate R is defined as a specific value acquired when the number of information bits is divided by the number of bits of each codeword. In other words, the coding rate R is denoted by "k/n", i.e., R = k/n. Next, the Hamming distance will hereinafter be described in detail. If two binary codes having the same number of bits include some bits having different bit values, the above- mentioned Hamming distance is indicative of the number of the above bits having the different bit values. Generally, if the Hamming distance "d" is denoted by d=2a+l, "a" number of errors can be corrected. For example, if one of two codewords is 101011 and the other one is 110010, the Hamming distance between the two codewords is 3. In the meantime, the term "minimum distance" for use in the coding theory is indicative of a minimum value between two arbitrary codewords contained in a code. The minimum distance is considered to be one of criteria to evaluate the performance of a code. The longer the distance between the codewords generated by the coding process, the lower the probability of misdetecting a corresponding codeword to be another codeword; as a result, the coding performance becomes better. Performance of a total code is estimated by a minimum distance between codewords having the worst performance. In conclusion, if a minimum distance of a specific code is maximized, this specific code may have a superior performance. In the next-generation mobile communication system, control information transmits system constituent information and transmission channel information, such that it is considered to be very important information to determine a system performance. Generally, this control information has a short length to use a relatively small amount of system resources. The above-mentioned control information is coded by the coding technique having very resistant to a channel error, and is then transmitted. A variety of coding schemes for the above control information have been considered in the 3GPP mobile communication system, for example, a short-length block code based on a Reed-Muller (RM) code, a tail-biting convolution code, and a repetition code of a complex code. In the meantime, the control information for use in the 3GPP LTE system acting as an improved format of the above-mentioned mobile communication system is coded by means of block codes, such that the block-coded control information is then transmitted. In more detail, if the length of a transmission (Tx) information bit is "A", the channel-coding process is performed by a block code composed of 20 rows and A columns (i.e., (20,A) block code) during the transmission of a specific channel (e.g.. Physical Uplink Control Channel (PUCCH)), and the channel-coding result is then transmitted. In the 3GPP LTE system, uplink control information is transmitted over the PUCCH and a PUSCH (i.e., a physical uplink shared channel). The control information transmitted over the PUSCH is channel-coded by a block code composed of 32 rows and A columns (i.e., (32, A) block code), such that the channel-coded control information is then transmitted. In the meantime, the (32, A) block code may have various formats. It is difficult for the user to search for an optimum format after checking individual coding performances of the variable-length information bits associated with all block codes. iDisclosurel [Technical Problem! Accordingly, the present invention is directed to a channel coding method of variable-length information using a block code that substantially obviates one or more problems due to limitations and disadvantages of the related art. An object of the present invention is to provide an effective (32,A) block coding method of variable-length information. In other words, under the condition that the length of an information bit is changed in various ways and the bit length of a coded codeword is also changed in various ways, the present invention provides the (32,A) block coding method for effectively supporting the combination of variable bit lengths. In the meantime, the number of coded bits may be equal to or less than 32, and the number of information bits may be changed in various ways. Therefore, according to the following embodiments of the present invention, the present invention provides a method for effectively using only some necessary parts of all the proposed block codes associated with the number of specific-length information bits or the number of specific-length coding bits. On the contrary, if the coding with a length longer than the above specific length is needed, the present invention allows the block code based on the above specific length to be repeated, such that it performs a long-length coding. iTechnical Solution] To achieve these objects and other advantages and in accordance with the purpose of the invention, as embodied and broadly described herein, a method for channel-coding information bits using a code generation matrix which includes 32 rows and A columns corresponding to a length of the information bits, the method comprising: channel-coding the information bits having the length of A using basis sequences having a 32-bit length corresponding to individual columns of the code generation matrix, and outputting the channel-coded result as an output secjuence, in which if the A value is higher than "10", the code generation matrix is generated when (A-10) number of additional basis sequences from among several additional basis sequences were added as column-directional sequences to a first or second matrix, in which the first matrix corresponds to a Transport Format Combination Indicator (TFCI) code generation matrix information composed of 32 rows and 10 columns used for coding TFCI information, the second matrix is made when at least one of an inter-row location or an inter-column location of the first matrix was changed, and the additional basis sequences satisfy a predetermined condition in which a value of a minimum Hamming distance is 10. Preferably, the additional basis sequence includes 10 number of "0" values. Preferably, the second matrix is made when at least one of an inter-row location or an inter-column location of the first matrix was changed, and includes lower 12 rows to be deleted to generate a third matrix, such that the third matrix corresponds to another code generation matrix for Physical Uplink Control CHannel (PUCCH) transmission. In another aspect of the present invention, there is provided a method for channel-coding information bits using a code generation matrix which includes 32 rows and A columns corresponding to a length of the information bits, the method comprising: channel-coding the information bits having the length of A using basis sequences having a 32- bit length corresponding to individual columns of the code generation matrix, and outputting the channel-coded result as an output sequence, in which if the A value is higher than "10", the code generation matrix is generated when (A- 10) number of additional basis sequences from among several additional basis sequences were added as column-directional sequences to a first or second matrix, in which the second matrix is made when at least one of an inter-row location or an inter-column location of the first matrix was changed, the first matrix is represented by the following Table, [Table] , and the several additional basis sequences are equal to [1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 1, 1, 0, 0, 0, 1, 0, 1, 0, 1, 0, 1, 1, 1, 0, 0], [1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1. 1, 1, 1, 0, 0, 0, 0, 1, 1, 1, 1, 0, 1, 0, 0, 0, 0, 1, 0], [0, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 1, 0, 1, 0, 1, 1, 0, 0, 0, 1, 1, 0], and [0, 0, 1, 1, 1, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 1, 1, 0, 0, 1, 0, 1, 0, 0, 1], respectively. In another aspect of the present invention, there is provided a method for channel-coding information bits using a code generation matrix which includes 32 rows and A columns corresponding to a length of the information bits, the method comprising: channel-coding the information bits having the length of A using basis sequences having a 32- bit length corresponding to individual columns of the code generation matrix, and outputting the channel-coded result 10 as an output sequence, in which the code generation matrix corresponds to a tenth matrix having 32 rows and A columns, in which a fourth matrix corresponds to a matrix composed of 20 rows and A columns in which A number of basis sequences were sequentially selected from a left side of a fifth matrix represented by the following table [Table] , and a sixth matrix is a matrix made when at least one of an inter-row location or an inter-column location of the fourth matrix was changed, and a seventh matrix is a matrix made when additional 12 bits were added to each of basis sequences of the fourth or the sixth matrix, in which 11 the seventh matrix corresponds to a matrix composed of 32 rows and A columns in which A number of basis sequences were sequentially selected from a left side of a eighth matrix represented by the following table [Table] , and a ninth matrix generated when at least one inter-row or inter-column location of the seventh matrix was changed, and the tenth matrix is a code generation 12 matrix generated when basis sequences corresponding to the A number of the basis sequences from a left side of the seventh or the ninth matrix were selected. Preferably, if the A value is equal to or less than "14", a predetermined number of column-directional sequences corresponding to the A length on the basis of a left side of column-directional sequences of a eleventh matrix sequentially correspond to the basis sequences of the code generation matrix, in which the eleventh matrix is represented by the following Table. [Table] Preferably, if the A value is equal to or less than "11", a predetermined number of column-directional sequences corresponding to the A length on the basis of a left side of column-directional sequences of a twelfth matrix sequentially correspond to the basis sequences of the code generation matrix, in which the twelfth matrix is represented by the following Table. [Table] Preferably, the method further comprises: if the number of bits (i.e., a bit number) of the output sequence is at least 32 (i.e., at least 32 bits), repeating each basis sequence of the code generation matrix a predetermined number of times, and performing a channel coding process using a specific part having a predetermined length corresponding to the bit number of the output sequence from among the repeated basis sequence. Preferably, if the bit number of the output sequence is higher than 32 (i.e., 32 bits), the output sequence is acquired when the channel-coded result is cyclically repeated. Preferably, the information bit corresponds to at least one of Channel Quality Information (CQI) and a Preceding Matrix Index (PMI). Preferably, the output sequence is transmitted over a Physical Uplink Shared Channel (PUSCH). It is to be understood that both the foregoing general description and the following detailed description of the present invention are exemplary and explanatory and are intended to provide further explanation of the wo 2009/082147 PCT/KR2008/007576 15 invention as claimed. [Advantageous Effects] According to the above-mentioned embodiments of the present invention, the present invention reuses a code generation matrix used for TFCI (Transport Format Combination Indicator) information coding of a conventional 3GPP system and/or the (20,A) code generation matrix for PUCCH transmission, such that it can easily implement the (32,k) block coding. As a result, a minimum- distance between the generated codewords increases, resulting in an increased system performance. [Description of Drawings] The accompanying drawings, which are included to provide a further understanding of the invention, illustrate embodiments of the invention and together with the description serve to explain the principle of the invention. In the drawings: FIG. 1 is a conceptual diagram illustrating a method for generating the (32,14) block code using the (32,10) block code used for a conventional TFCI wo 2009/082147 PCT/KR2008/007576 16 information coding and the (20,14) code used for PUCCH transmission according to the present invention; and FIG. 2 is a graph illustrating minimum-distance performances acquired when the (40, k) block code, the (52,k) block code, and the (54,k) block code are generated on the condition that the (20,k) block code and the (32,k) block code are used as base codes. [Best Mode] Reference will now be made in detail to the preferred embodiments of the present invention, examples of which are illustrated in the accompanying drawings. Wherever possible, the same reference numbers will be used throughout the drawings to refer to the same or like parts. Prior to describing the present invention, it should be noted that most terras disclosed in the present invention correspond to general terms well known in the art, but some terms have been selected by the applicant as necessary and will hereinafter be disclosed in the following description of the present invention. Therefore, it is preferable that the terms defined by the applicant be understood on the basis of their meanings in the present invention. For example, although the following description relates to a detailed example applied to the 3GPP LTE (3rd Generation wo 2009/082147 PCT/KR2008/007576 17 Partnership Project Long Term Evolution) system, the present invention can also be applied to not only the above 3GPP LTE system but also other arbitrary communication systems which need to perform the channel coding process on variable-length control information using the block code. For the convenience of description and better understanding of the present invention, general structures and devices well known in the art will be omitted or be denoted by a block diagram or a flow chart. Wherever possible, the same reference numbers will be used throughout the drawings to refer to the same or like parts. Firstly, items to be commonly considered by the present invention will hereinafter be described in detail. The [n,k] code is a specific code in which the number of coding bits is "n" and the number of information bits is "k". In this case, if there is no mention in a generation matrix of each code, this generation matrix is represented by a basic-sequence-type table. In fact, the coding method is similar to that of a TFCI code of the 3GPP release 99. In other words, the information bits are sequentially allocated to the left-sided basis sequence, and a sequence corresponding to the product of the basis sequence and the information bit is added by binary operations (i.e.. wo 2009/082147 PCT/KR2008/007576 18 Exclusive OR sum) corresponding to the number of information bits, such that a coding bit is generated. If the code is represented according to the above- mentioned method, although the number of information bits (hereinafter referred to as "information bit number") is variable, the present invention has an advantage in that it can perform the coding process of data on the basis of a matrix-type basis sequence table. The present invention is able to support a variety of information bit numbers using the above-mentioned advantages. Therefore, a basis sequence table or a code generation matrix is represented in consideration of a maximum-sized information bit number. If the maximum number of information bits needed for the actual application is less than the following proposed size, it is preferable that a table having no basis sequence for at least a corresponding maximum bit number (i.e., a corresponding maximum number of bits) be used. In the meantime, the operation of replacing a generation code of "0" with another generation code of "1" according to the coding theory has no influence on the code characteristics. Therefore, although the value of "0" is replaced with the other value of "1" in the basis sequence table, the replaced result may indicate the same code feature. Also, although the order of coding bits is wo 2009/082147 PCT/KR2008/007576 19 replaced with another order according to the coding theory, the replaced result may also indicate the same code feature. Therefore, although the row location is replaced with another row location in the basis sequence table, the replaced result may also indicate the same code feature. The basis sequence proposed by the following embodiments is designed to have a variable number of information bits (i.e., a variable information-bit number), and is also designed to have a variable number of coding bits (i.e., a variable coding bit number). Therefore, in the case of devising the inventive concept of the present invention, a specific code in which a specific column is deleted from a specific basis sequence table was pre- considered. For example, if a basis sequence table is denoted by a specific format such as (32,14), the (20,11)- format basis sequence table is one of application examples of the above (32,14)-format basis sequence table. In more detail, if 12 columns are successively deleted from the bottom of the (32,14)-format basis sequence table, and 3 rows are deleted from the right of the (32,14)-format basis sequence table, the above-mentioned (20,11)- format basis sequence table can be acquired. In brief, the row and column of the basis sequence table according to the present invention have been decided on the basis of the largest wo 2009/082147 PCT/KR2008/007576 20 size. In the case of the small-sized row and column, the rows and columns of the largest-sized basis sequence table are sequentially deleted from the right or the bottom of the above table, such that the deleted result is used. Needless to say, as previously stated above, although the row location may be replaced with the column location in the smaller-sized basis sequence table, or although the location of "0" is replaced with the other location of "1" in the basis sequence table, the above replaced results may have the same codes. For the convenience of description and better understanding of the present invention, in the case of indicating the order of any data of the present invention, the information bits sequentially proceed in the direction from the left column to the right column in the above basis sequence table. The coding bits sequentially proceed in the direction from the uppermost row to the lowermost row in the above basis sequence table. The term "basis sequence table" may also be called "Code generation matrix" or other terms as necessary. In the meantime, it is preferable that a specific- pattern basis sequence for use in a specific channel estimation method be unavailable. In this case, a specific table, from which a specific basis sequence based on a wo 2009/082147 PCT/KR2008/007576 21 system type is removed, may be selected from various tables proposed by the following embodiments. From the viewpoint of the coding process, a corresponding basis sequence may always be considered to be "0", such that the same coding performance is made, but only the number of information bits is reduced. Therefore, according to the basis sequence table proposed by the following embodiments, a specific basis sequence table having no specific basis sequence or a code generation matrix has already been considered in the case of designing the present invention. According to the above-mentioned one aspect of the present invention, the present invention provides the (32,A)-format block coding method. In more detail, the present invention provides the (32,14)-format block coding method in consideration of the maximum length (i.e., 14 bits) of information bits. However, it should be noted that only some basis sequences from among the (32,14)- format code generation matrix be used according to the information-bit length as previously stated above. Although a variety of methods can be used for the above-mentioned purposes, the following embodiments provide a code design method capable of maintaining a maximum common point with conventional codes using the conventional wo 2009/082147 PCT/KR2008/007576 22 block codes. In more detail, the conventional codes provide a first method of using the (32,10)-format block code for the TFCI-information coding used in the 3GPP release 99 and a second method of using the (20,14)-format block code for PUCCH transmission. In this case, the above-mentioned (20,14)-format block code has been disclosed in United States Provisional Application No. 51/016,492 used as priority of the present invention, entitled "GENERATION METHOD OF VARIOUS SHORT LENGTH BLOCK CODES WITH NESTED STRUCTURE BY PUNCTURING A BASE CODE" filed by the same applicant as the present invention, which is incorporated herein by reference. Detailed descriptions of the (32,10)-foinmat block code and the (20,14)-format block code will hereinafter be described in detail. The (32,10)-format block code for the TFCI information coding and the (20,14)-format block code for PUCCH transmission will hereinafter be described in detail. (32,10) TFCI Block Code and (20,14) Block Code The (20,14) block code for use in this embodiment will be generated as follows. Firstly, (20,10) block code is generated from the (32,10)-structured TFCI code generation matrix, and 4 basis sequences are added to the (20,10) block code, such that the (20,14) block code is wo 2009/082147 PCT/KR2008/007576 23 generated. The (20,10) block code is based on the (32,10)-code generation matrix used for the channel coding of TFCI (Transport Format Combination Indicator) information in the 3GPP Rel' 99. As a result, the (20,10) bloc}c code can be designed to be punctured according to the length of a codeword to be coded. The reuse of the (32,10) TFCI information code has a variety of advantages. For example, the TFCI information code has been designed on the basis of the Reed-Muller (RM) code, such that the punctured TFCI code may have a modified Reed-Muller (RM) code structure. This Reed-Muller (RM) - based code has an advantage in that it can be quickly decoded by a fast Hadamard transform method during the decoding process. For another example, the TFCI coding method supports a variable-length information bit and a variable-length coding bit. In this way, the information- bit length or the coding-bit length can be changed in various ways, such that requirements for CQI transmission of the 3GPP LTE can be well satisfied. The following Table 1 shows the (32,10)-code generation matrix used for the channel coding of TFCI information in the 3GPP Rel' 99. In this case, the (32,10)-code generation matrix generates a specific 24 codeword which has the length of 32 bits and the value of dniin=12. [Table 1] 5 Generally, as well known in the art, although the inter-row location or the inter-column location is replaced with other locations in the block code, there is no 25 difference in performance between the generated codewords. The following Table 2 shows a specific block code, which is equivalent to the (32,10) block code used for the aforementioned TFCI-information coding using the above- mentioned advantage. [Table 2] As can be seen from the block code shown in Table 2, the row- and column- locations of the (32,10) code used for the TFCI coding are changed to other locations, and locations between some columns (or locations between some rows on the basis of the TFCI information code) are exchanged with each other. In other words, according to this embodiment of the present invention, 12 rows in either the (32,10)-format TFCI information code (Table 1) or its equivalent matrix (Table 2) may be punctured, or 2 0 rows are selected from wo 2009/082147 PCT/KR2008/007576 26 the the (32,10)-format TFCI information code (Table 1) or its equivalent matrix (Table 2), such that the (20,10) block code is configured. In this case, from the viewpoint of the block code of Table 2, 12 columns may be punctured, and 20 columns may be selected. There is no difference in mode performance between the first case of using Table 1 and the second case of using Table 2. For the convenience of description and better understanding of the present invention, it is assumed that the present invention uses the equivalent format (See Table 2) of the TFCI information code if there is no mention in the above-mentioned description. In the meantime, the (32,10) code used for coding the TFCI information has been generated on the basis of the Reed-Muller (RM) code. In this case, in order to implement an error correction performance, it is very important for the above (32,10) code to search for a puncturing pattern which enables a codeword to have the longest distance (c/^„) . Compared with this embodiment, an exhaustive search capable of searching for an optimum puncturing pattern in a generation matrix of the (32,10) code used for TFCI coding will hereinafter be described in detail. Provided that the number of columns of a generation matrix to be punctured in the (32x10) matrix (also denoted by (3210) matrix) is set wo 2009/082147 PCT/KR2008/007576 27 to "p", the number of all available puncturing patterns is denoted by . In this case, is indicative of the number of cases, each of which selects the p columns from among 32 columns. For example, if the value of "p" is 12 (p>=12), there are different (10x20) generation matrixes (i.e., = 225,792,840 number of (10x20) generation matrixes), 10-bit information (i.e., 2"' = 1,024 number of information segments) is coded into a codeword of 20 bits. A minimum Hamming distance ( d^„ ) between codewords generated by individual matrixes is calculated, such that a generation matrix having the highest value is found in the above minimum Hamming distance {d^^). If a puncturing pattern is used to make the generation matrix having the maximum ( d„„ ] value, this puncturing pattern is considered to be the last pattern to be finally found. However, the generation of the optimum (20,10) block code on the basis of the above steps requires a large number of calculations, resulting in greater inconvenience of use. Therefore, this embodiment of the present invention adds specific restriction conditions to the process for deciding the puncturing pattern, such that it reduces the wo 2009/082147 PCT/KR2008/007576 28 range of a searching space for acquiring an optimum ( „„ ) value. Next, a method for more effectively searching for a generation matrix of the (20,10) code which generates a codeword having d^=cl will hereinafter be described in detail. Provided that a target { rf„, ) value is denoted by d, the Hamming weight »v(g\|(Hj,.ji,[/]) of each row vector gioty2o[i] (I^'^IO) of the (20,10)-code generation matrix has some requirements shown in the following Equation 1. [Equation 1] f=0,l,--,10 ;¦ 6(There are all ones in this row vector) For example, if the value of d is 6 (d=5) , Equation 1 can be represented by the following Equation 2. [Equation 2] Therefore, if the above restriction of Equation 2 is added to individual row vectors gioby2o\i] of the (1020) matrix generated from the above-mentioned exhaustive search process, the added result can reduce the number (N« ) of searching spaces capable of searching for a generation matrix generating a codeword having d^„=6 . Generally, wo 2009/082147 PCT/KR2008/007576 29 based on various cited references, it is well known in the art that a maximum { d^„ ) value of the (20,10) code is 6, and its detailed description has been disclosed in "The Theory of Error-Correcting Codes (by F.J. MacWilliams and N.J.A. Sloane)". Therefore, the condition of d^=6 is applied to the condition of Equation 1, such that 360 patterns indicating an optimum performance can be found. The above 360 puncturing patterns have been disclosed in Appendix "A" of United States Provisional Application No. 61/016,492, entitled "GENERATION METHOD OF VARIOUS SHORT LENGTH BLOCK CODES WITH NESTED STRUCTURE BY PUNCTURING A BASE CODE" filed by the same applicant as the present invention. Specifically, indexes of punctured columns based on Table 2 have been disclosed in the Appendix "A" . For the convenience of description, the above-mentioned indexes will herein be omitted. The following pattern from among the above 360 puncturing patterns will hereinafter be described as an example. The following Table 3 shows a specific pattern, which indicates the distribution of a specific Hamming weight from among the 360 patterns. [Table 3] The puncturing patterns shown in Table 3 correspond to the sixth index of Table A. 2 of the Appendix "A" of United States Provisional Application No. 61/015,492. In this case, the value "0" of Table 3 indicates that a column corresponding to the location of "0" is punctured. The value "1" of Table 3 indicates that a column corresponding to the location of "1" is not punctured but selected for the (20,10) block code. In the case where the puncturing pattern of Table 3 is applied to Table 2, the result is shown as the following Table 4. [Table 4] In this case, compared with Table 2, row- and column- directions of Table 4 are changed, but Table 4 has the same meaning as Table 2. 12 punctured rows from among individual row- directional sequences are shown at the right side of Table 4. As a result, the generated (20,10) block code can be represented by Table 4. [Table 5] In the meantime, there is a little difference between the order of rows of Table 4 or Table 5 and the matrix order of the 3GPP-based TFCI coding. As described above, although the location of each row is changed to another location according to the above-mentioned coding theory, there is no difference in performance between generated codewords. If the row order of Table 4 or Table 5 is adjusted in the same manner as in the TFCI code matrix, the following Table 6 is acquired. [Table 6] As described above, only the row order of Table 6 is different from that of Table 4, but the remaining features of Table 6 are exactly equal to those of Table 4. The representation method of Table 6 has an advantage in that the last 2-bits be punctured during the puncturing time from the (20,10) code to the (18,10) code. Next, a method for extending the above-mentioned (20,10) code to a maximum of the (20,14) code will hereinafter be described in detail. As for the (20, A) block code according to this embodiment, it is assumed that a CQl value indicating channel quality information (CQI) of the 3GPP LTE system be applied to the channel coding method for PUCCH transmission. Also, in the case of generating the (20,10) code, the bit number of the CQI information of the 3GPP LTE system can be decided in the range from 4 bits to 10 bits, such that it wo 2009/082147 PCT/KR2008/007576 34 can be maximally extended to the (20,10) block code. However, in the case of the MIMO system, the bit number of the CQI information may be higher than 10 bits as necessary. However, a transmission (Tx) amount of actual CQI is decided according to a CQI generation method. For the coding process, the present invention may consider a method for supporting all the information bit numbers ranging from 4 bits to 14 bits. Therefore, the (20,14) block coding method will hereinafter be described, which is capable of supporting a maximum of 14 bits by adding a column corresponding to the information bit number to the above (20,10) block code. In order to search for the added column during the exhaustive search, a large number of calculations must be carried out. Therefore, the execution of the exhaustive search in all the cases may be ineffective or undesirable. In this step, it should be noted that the sixth column of Table 6 is set to "1" and is used as a basis sequence. Therefore, if the added column must satisfy the minimum distance "d", a minimum number of "0" must be equal to or higher than "d". In this example, the number of "0" is equal to a minimum distance between codewords. In more detail, a difference between the added column and the old sixth column composed of "1" is indicative of a distance 35 between two codewords, such that the number of "0" contained in the added column is equal to the distance between codewords. Generally, a maximum of a minimum distance available for the (20,10) code is 6. In the present invention, a minimum of a maximum distance available for the (20,11) code corresponding to an extended version of the (20,10) code is 4. In more detail, the maximum-/minimum- distance characteristics based on various information bit numbers of the 20-bit codeword can be represented by Table 7. [Table 7] Therefore, this embodiment of the present invention provides a column adding method, which allows the maximum- /minimum- distance of the added column to be "4" . According to this column adding method, a column having at least four "0" values is added to the added column. In order to minimize the number of searching times, it is assumed that the added column of this embodiment includes 4 number of "0" values (i.e., four "0" values). In this way, if the added column includes the four "O" values and 16 number of "1" values, this added column can be configured in various ways. A representative example of 36 the added column is shovm in the following Table 8. If the (20,10) code of Table 6 is extended to the (20,14) code. Table 8 can be acquired. [Table 8] With reference to Table 8, the four added columns are indicative of four columns located at the right side. In each added column, "0" is denoted by a bold line. Based on the above-mentioned facts, a method for modifying or optimizing Table 8 will hereinafter be described in detail. According to this embodiment, the sixth column of Table 8, i.e., all bits of the column Mj.,5, is set to "1", such that the sixth column is considered to be a basis sequence. This basis sequence greatly contributes to all codewords of a corresponding bit. Therefore, from the viewpoint of the corresponding bit, the use of the basis sequence having many weights may be desirable. However, several bits in all codewords are exclusive-OR (XOR) operated, such that their combination result must be considered. Thus, in order to reduce the number of the combination cases, the basis sequence in which each of all bits has the value of "1" moves to the frontmost column, resulting in the increase of a contribution rate. In this way, if data is coded under a small number of bits {i.e., a small bit number), the present invention may consider the above method for moving the basis sequence in which each of all bits is "1" to the frontmost column, and the moved result is represented by the following Table 9. [Table 9] with reference to Table 9, a sixth sequence (i.e., each bit of the sixth sequence has the value of "1") from among the original column- directional basis secjuence moves to the location of a first basis sequence, and the order of other sequences is not changed to another order. In the following description, it is assumed that the (20,14) block code structure for PUCCH transmission uses the block code of Table 9. If the number of information bits for PUCCH transmission is limited to a maximum of 13 bits or less, the basis sequence located at the rightmost part of Table 9 may be omitted as necessary, and the omitted result can be represented by the following Table 10. [Table 10] Next, based on the above-mentioned description, a method for generating the (n,)c) block code (where n^32 and k^l4) will hereinafter be described in detail. (n, k) BLOCK CODE (n A block code having a maximum size of (32,14) will hereinafter be described in detail. In other words, according to this embodiment, a maximum size of the coding bit number is 32, and a maximum size of the information bit number is 14. The coding design can be implemented in various ways, but a coding method according to this embodiment must be designed to search for a maximum number of common points with conventional codes. In order to generate the (32,14) block code, the present invention considers the (20,14) block code {See Table 9) acquired from the (32,10) TFCI block code of the 3GPP Release 99, and at the same time considers the above- wo 2009/082147 PCT/KR2008/007576 40 mentioned (32,10) TFCI block code. In order to generate the (32,14) block code using the (20,14) block code and the (32,10) TFCI block code, a »TBD" (To be defined) part of FIG. 1 needs to be additionally defined. FIG. 1 is a conceptual diagram illustrating a method for generating the (32,14) block code using the (32,10) block code used for a conventional TFCI information coding and the (20,14) code used for PUCCH transmission according to the present invention. Referring to FIG. 1, if the (32,10) block code 101 used for the TFCI information coding and the (20,14) block code 102 are used to generate the (32,14) block code 104, the TBD part 103 must be additionally defined. In one aspect of any one of block codes, the above- mentioned definition can be analyzed in various ways. Namely, the (32,14) block code 104 according to this embodiment is generated when four basis sequences (corresponding to the combination part between the 102a part and the 103 part of FIG. 1) is added to the right side of the conventional (32,10) block code. In another aspect of the above block codes, 12 row-directional sequences (corresponding to the combination part between the 101a part and the 103 part of FIG. 1) are added to either the block code of Table 9 or its equivalent 41 (20,14) block code 102, such that the (32,14) block code 104 may also be generated. In this case, the conventional TFCI information code shown in Table 1 and its equivalent code can also be used as the (32,10) block code 101. The block code of Table 9 and its equivalent code can also be used as the (20,14) block code 102. In this case, if the inter-row location and/or the inter-column location of the conventional block code are/is changed to others, the above equivalent code is made. Preferably, if the code is designed, the designed code must allow the TBD 103 to have the best performance at a minimum distance. Generally, according to various information-bit lengths and various coding-bit lengths, the following minimum-distance performances are acquired as shown in Table 11. [Table 11) With reference to Table 11, in the case of the (32,A) block coding, if "A" is higher than "10", a maximum value of a minimum Hamming distance of the basis sequence is limited to "10". wo 2009/082147 PCT/KR2008/007576 42 Therefore, according to a preferred embodiment of the present invention, the TBD part 103 of FIG. 1 along with the 102a part of the (20,14) block code 102 must allow a maximum value of the minimum Hamming distance of each basis sequence (corresponding to the combination part between the 102a part and the 103 part of FIG. 1) to be "10". In this case, the 102a part corresponds to the information bits of more than 10 bits. In more detail, if the number of additional basis sequences is 1 or 2 (i.e., if if "A" is 11 or 12), this means that one or two basis sequences are added to allow a minimum Hamming distance of each basis sequence to be "10". If the number of additional basis sequences is 3 or 4 (i.e., if "A" is 13 or 14), this means that three or four basis sequences are added to allow a minimum Hamming distance of each basis sequence to be "8". The (32,10) block code for TFCI information coding includes a basis sequence in which each of all components is "1", such that each of the additional basis sequences may include 10 number of "0" values. In other words, if the (20,14) block code is used as the block code of Table 9, individual basis sequences corresponding to the 102a part of FIG. 1 include 4 number of "0" values, such that the basis sequence part 43 corresponding to the TBD part may include 6 number of "0" values. An example for satisfying the above-mentioned condition is shown in the following Table 12. [Table 12] As can be seen from Table 12, if 12 rows from the bottom of Table 12 are deleted, the (20,14) code for PUCCH transmission is formed. If 14 rows from the bottom of Table 12 are deleted, the (18,14) code is formed. Variable application of the information bit can be easily implemented, and as many basis sequences of Table 12 as the number of corresponding information bits are acquired from Table 12, such that the acquired basis sequences are used for the coding process. If a maximum number of information bits (i.e., a maximum information-bit number) of FIG. 12 is less than 14 (i.e., 14 bits), basis sequences as many as the predetermined number unnecessary for the basis-sequence table such as Table 9 may be deleted from the right column. This means that basis sequences as many as the number of information bits required for the (32,10) block code may be added. For example, provided that a maximum information- bit number is limited to 11 bits, the following (32,11) block code of Table 13 can be used. [Table 13] In the meantime, a method for arranging the (32,k) block code in consideration of the (16,k) block code will hereinafter be described in detail. A method for generating an optimum code of the (32, k) block code of Table 12 or Table 13 is as follows. In the case of generating the (20,k) or (18,k) block code, if the remaining rows from the lowest row are deleted, the above optimum code of the (32, k) block code can be generated. However, if the (16,k) block code is needed, much consideration is needed. Therefore, according to this embodiment of the present invention, the row order of the above (32, k) block code is changed in consideration of the (16, k) block code. If the (16,k) block code is needed, although some rows from the lowest row of the (32, k) block code are deleted and used, the 46 present invention is able to generate a necessary code. A representative example is shown in the following Table 14. [Table 14] In Table 14, during the code conversion from the (32, k) code to the (20, k) code, if 12 rows are deleted from Table 14 on the basis of the lowest row, an optimum code is generated. If 14 rows are deleted from Table 14 on the basis of the lowest row, the (18, k) code is wo 2009/082147 PCT/KR20O8/007576 47 generated. If 16 rows are deleted from Table 14 on the basis of the lowest row, the (16,k) code is generated. In the meantime, based on the above-mentioned description, if a codeword of more than 32 bits is needed, the following channel coding method can be carried out. IF CODEWORD OF MORE THAN 32 BITS IS NEEDED: If the codeword of more than 32 bits is needed, the present invention provides a method for generating the long-length (n,k) code by repeating the above basis sequence on the basis of the (32, k) or (20, k) code used as a base code. The (32,k) or (20,k) code can be easily generated on the basis of Table 12 or Table 14. In the meantime, in order to assign a stronger or higher error correction capability to a transmission (Tx) bit, the present invention may increase the number of coding bits (i.e., the coding bit number) . In this case, it is preferable that a new code corresponding to the increased number of coding bits be generated, but it is very difficult for a code designer to design a new code whenever the number of coding bits increases. Therefore, one of simple generation methods is to repeat the base code by a desired length. If the desired length is not accurately wo 2009/082147 PCT/KR2008/007576 48 represented by an integer multiple of the base code, the base code is repeated by at least the desired length, and as many base codes as the number of excessive bits may be removed. In this case, although the present invention is able to search for an optimum puncturing pattern every time, the present invention can substantially consider a simple puncturing method based on a rate matching block. In this case, the present invention may consider the (32, k) or (20, k) code as the base code. For the convenience of description, the present invention considers only a specific case in which a desired length has the size of an integer multiple of the base code. In the remaining cases, it is assumed that the present invention is able to acquire a necessary code using the puncturing method. Also, the present invention is able to use a variety of "k" values. In this case, for the convenience of description, it is assumed that a maximum size of 'k" is set to 14. Although there is no mention of the smaller size of less than 14 in the present invention, it is well known to those skilled in the art that a basis sequence corresponding to a corresponding length be selected and used. For example, if the (64,14) code is needed, the (32,14) code can be repeated only two times. If the wo 2009/082147 PCT/KR2008/007576 49 (40,14) code is needed, the (20,14) code can be repeated only two times. Also, the (32,14) code and the (20,14) code are simultaneously considered as the base code, such that the (32,14) code and the (20,14) code are sequentially attached to configure the (52,14) code. In conclusion, the combination of available codes may be determined to be the {a32+b20,14) code (where 'a" or "b" is an integer number of at least "0". If the last necessary coding bit number is not denoted by an integer multiple of the base code, the base code is repeated to be longer than the desired length, unnecessary parts may be severed from the end part of the longer-sized code or may be punctured using the rate matching blocks. In the meantime, according to another aspect of the present invention, after the order of information bits has been reversed, the base code may then be repeated. As described above, if the base code is continuously repeated, minimum-distance characteristics of the base code are maintained without any change, such that the resultant minimum-distance characteristics are repeated. Therefore, if the code having an original minimum distance of 4 is repeated two times, the minimum wo 2009/082147 PCT/KR2008/007576 50 distance is increased by two times, such that the minimum distance of the resultant code reaches "8". However, provided that any variation is applied to the information bit during the above repetition, although the information bit which forms a codeword having a minimum distance is used, a codeword generated by another information bit changed by the above repetition is able to form another codeword having the distance longer than the above-mentioned minimum distance. If the minimum distance is not repeated according to the above-mentioned principles, a code can be designed such that the minimum- distance characteristics can be larger than those of a simple multiple. The present invention can consider a variety of methods for changing the information bit. For example, in order to change the above-mentioned information bit, a method for using a reverse version of a bit unit, and a method for allowing the information bit to pass through a random sequence such as a PN sequence can be used in the present invention. Also, the present invention may assign different information-bit variations to individual repetition times, such that the information bit is differently changed whenever the repetition occurs. However, in this case. wo 2009/082147 PCT/KR2008/007576 51 the complexity of a transmission/reception end increases. If the repetition is performed several times, the present invention may not change the information bit in the first time, and may change the information bit in the next time. In more detail, in the case of repeating the code according to this embodiment, the information bit is not changed at the even-th repetition, but is changed at the odd-th repetition. In other words, the present invention controls the information-bit variation to be toggled whenever the repetition occurs. For example, under the condition that the (20,k) code and the (32, k) code are used as the base codes, the (40, k) code, the (52, k) code, and the (64, k) code can be generated according to the present invention. A detailed description thereof will hereinafter be described. FIG. 2 is a graph illustrating minimum-distance performances acquired when the (40,k) block code, the (52,k) block code, and the (64,k) block code are generated on the condition that the (20,k) block code and the (32, k) block code are used as base codes. Referring to FIG. 2, " (40,k)_20+20" indicates that the (2 0, k) code acting as the base code is repeated two times. "(20,k)_20rev" indicates that the information bit is reversed from the (2 0, k) code acting as the base code. wo 2009/082147 PCT/KI12008/007576 52 " (32, k)_32rev" can be analyzed in the same method as the above-mentioned method. "(40,k)_20+20rev" indicates that the (20,k) code used as the base code was repeated two times, an information bit was changed according to the toggle method at the first repetition time, and the information bit was then reversed at the second repetition time. In this way, " (64, k)_32+32rev" can also be analyzed in the same method as the above. In the meantime, "(52,k)_20+32rev" indicates that the (32, k) and (20, k) codes were selected as base codes, each of the selected base codes was repeated only once, and the (32,k) code acting as the second base code was bit-reversed and the information bit was then applied to the bit-reverse result. In FIG. 2, if the value of k is denoted by k^4, the "(40,k)_20" code has a low performance less than that of the (32, k) code. Therefore, it can be recognized that the operation of using the (3 2,k) code with less number of coding bits has a good performance higher than that of the operation of repeating the (20, k) code two times. In other words, the repetition of (32, k) code with less number of coding bits has a high performance superior to that of the repetition of (20,k) code. Therefore, the preferred embodiment of the present invention provides a method for wo 2009/082147 PCT/KR2008/007576 53 repeatedly using the (32,k) code during the coding process for a long-length coding bit. In other words, according to this embodiment of the present invention, provided that the (32,k) code was selected as the base code, the bit number (i.e., the number of bits) of the last output sequence was equal to or higher than 32 (i.e., 32 bits), and an integer multiple of the base code was not implemented, the (3 2, k) code is repeated to be longer than a desired length, and unnecessary parts (i.e., corresponding to the bit number of the needed output sequence) are severed from the end of the repeated result. The above-mentioned embodiment can be analyzed as follows. In more detail, if the length of the needed output sequence is at least 32 bits, it can be recognized that the coded result of the (32,k) block code was cyclically repeated to acquire the above output sequence. Namely, provided that the 32-bit-length codeword, which has been channel-coded by the (32,k) block code, is represented by /bo,A\|,(!'2.^3'-->^B-i (where B=32) , and the output sequence longer than the length of 32 bits (e.g., the bit length of "Q") is represented by relationship between the output sequence and the channel- coded 32-bit-length codeword can be represented by the wo 2009/082147 PCT/KR2008/007576 54 following Equation 3. [Equation 3] 9/=^((modfi) where i = 0, 1, 2, ..., 0-1 As can be seen from Equation 3, the output sequence component having the index "i" corresponds to a codeword component which has an index corresponding to the modulo- operation result value. In this case, the modulo-operation result value is acquired when the index "i" was modulo- operated with the "B" value of 32. If the Q value is higher than 32, the output sequence is acquired when the channel-coded sequence was cyclically repeated. This also means that the (32, k) code was repeated a predetermined number of times and the part corresponding to the length of a necessary codeword was selected and used. As well known to those skilled in the art, the above-mentioned operation results have been substantially equal to each other, but they have been analyzed in different ways. In the meantime, as can be seen from FIG. 2, the performance of the " (52,k)_20+32rev" code is equal to or higher than that of the " (52, k)_20+32" code, and the performance of the (40, k)_20+20rev" code is equal to or higher than that of " (40,k)_20+20". Therefore, in order to improve the minimum-distance characteristics, the wo 2009/082147 PCT/KR2008/007576 55 information bit is repeated without any change at the first repetition time, and is then reversed at the next repetition time. Finally, if the last information bit number is not denoted by an integer multiple of the base code, the base code is repeated to be longer than a desired length, and unnecessary parts can be severed from the end part of the repeated result, or can be punctured by the rate matching block method. In the meantime, the above-mentioned method for performing the bit reversion of the information bit according to the toggle scheme can also be applied to not only the repetition of the above-mentioned base code but also other repetitions of various base codes. For example, when the repetitive coding of the simplex code of ACK/NACK control information is performed, the information bit is coded without any change at the first repetition time, and the bit-reversion information bit of the ACK/NACK control information is then coded at the second repetition time. It should be noted that most terminology disclosed in the present invention is defined in consideration of functions of the present invention, and can be differently determined according to intention of those skilled in the art or usual practices. Therefore, it is preferable that wo 2009/082147 PCT/KR2008/007576 56 the above-mentioned terminology be understood on the basis of all contents disclosed in the present invention. It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or scope of the invention. Thus, it is intended that the present invention cover the modifications and variations of this invention provided they come within the scope of the appended claims and their equivalents. That is, the present invention is not limited to only the embodiments described herein and includes the widest range equivalent to principles and features disclosed herein. [industrial Applicability] As apparent from the above description, the channel coding method according to the present invention can be easily applied to the other channel coding of the 3GPP LTE system which transmits CQI/PMI information to an uplink via a PUSCH channel. However, the above-mentioned methods are not limited to only the above 3GPP LTE system, but they can also be applied to a variety of communication schemes, each of which performs the block coding on variable-length information. What is claimed is: Claim 1. A method for channel-coding first type information bits using one or more basis sequences for a code matrix which includes 32 rows and A columns, hereinafter called as basis sequences for (32, A) code, the A corresponding to a length of the first type information bits, the method comprising: channel-coding the first type information bits having the length A using the basis sequences for (32, A) code; and outputting the channel-coded result as an output sequence, v\;herein A number of the basis sequences for (32, A) code are selected from the following Table 1, when A is a natural number not more than 14. 21aim 2 The r.'.ethod according to claim 1, wherein one or more basis sequences for a code matrix which includes 2 0 rows and B columns, hereinafter called as basis sequences for (20, B) code, are selected from a table including only 20 rows of the table 1 from an upper side, wherein 3 is a natural number not more than 14, and wherein the basis sequences for (20, B) code are used for channel coding second type information bits. Claim 3 The method according to claim 2, wherein the table 1 is generated to have a maximum value of minimum Hamming distance between the basis sequences for (20, B) code. Claim 4 The method according to claim 2, wherein the table 1 is generated to have a maximum value of a minimum Hamming distance between the basis sequences for (32, A) code. Claim 5 The method according to claim 1, wherein the first type information bits are at least one of Channel Quality Information, hereinafter called as CQI, and a Preceding Matrix Index, hereinafter called as PMI. Claim 6 The method according to claim 2, wherein the second type information bits are control information bits transmitted through a Physical Uplink Control Channel, hereinafter called as PUCCH. Claim 7 The method according to claim 1, wherein the basis sequences for (32, A) code which correspond to 11'", 12'", 13"" and 14th bits of the first type information bits include 10 "0" values. claim 8 The method according to claim 1, wherein the basis sequences for (32, A) code are selected from the following Table 2, when A. is a natural nur.ber not more than 11, A channel coding method of variable length information using block code is disclosed. A method for channel-coding information bits using a code generation matrix including 32 rows and A columns corresponding to length of the mformation bits includes, channel-coding the information bits having 'A' length using basis sequences having 32-bit length corresponding to columns of the code generation matrix, and outputting the channel-coded result as an output sequence. If'A' is higher than 10, the code generation matrix is generated when (A-10) additional basis sequences were added as columm- directional sequences to a first or second matrix. The first matrix is a TFCI code generation matrix composed of 32 rows and 10 columns used for TFCI coding. The second matrix is made when at least one of an inter-row location or an mter-column location of the first matrix was changed. The additional basis sequences satisfy a value 10 of a mmimum Hammmg distance.

Full Text

[description]
[Invention Title]
CHANNEL CODING METHOD OF VARIABLE LENGTH INFORMATION
USING BLOCK CODE
[Technical Field]
The present invention relates to a coding method for
a mobile communication system, and more particularly to a
method for effectively performing a channel-coding process
on variable length information using a block code.
[Background Art]
For the convenience of description and better
understanding of the present invention, some concepts
requisite for the present invention from among several
basic coding theories will hereinafter be described in
detail.
Generally, a general binary error correction code
is denoted by [n, k, d] , where "n" is the number of bits
of coded codewords, "k" is the number of information bits
created prior to the coding process, and "d" is a minimum
distance between codewords. In this case, only the binary
code has been considered for the above-mentioned binary
error correction code, such that a number of possible
codeword points in code space is denoted by 2", and a
total number of coded codewords is denoted by 2". Also,
if the minimum distance is not substantially considered
to be important, the aforementioned binary error
correction code may also be denoted by [n, k] . If there
is no mention of the above error correction code in this
application, it should be noted that individual values of
"n", "k", and "d" be set to the above-mentioned values.
In this case, the above-mentioned error correction
code should not be confused with a matrix-type block code
composed of X number of rows (i.e., X rows) and Y number
of columns (i.e., Y columns).
In the meantime, the coding rate R is defined as a
specific value acquired when the number of information
bits is divided by the number of bits of each codeword.
In other words, the coding rate R is denoted by "k/n",
i.e., R = k/n.
Next, the Hamming distance will hereinafter be
described in detail.
If two binary codes having the same number of bits
include some bits having different bit values, the above-
mentioned Hamming distance is indicative of the number of
the above bits having the different bit values. Generally,
if the Hamming distance "d" is denoted by d=2a+l, "a"
number of errors can be corrected. For example, if one of
two codewords is 101011 and the other one is 110010, the
Hamming distance between the two codewords is 3.
In the meantime, the term "minimum distance" for
use in the coding theory is indicative of a minimum value
between two arbitrary codewords contained in a code. The
minimum distance is considered to be one of criteria to
evaluate the performance of a code. The longer the
distance between the codewords generated by the coding
process, the lower the probability of misdetecting a
corresponding codeword to be another codeword; as a
result, the coding performance becomes better.
Performance of a total code is estimated by a minimum
distance between codewords having the worst performance.
In conclusion, if a minimum distance of a specific code
is maximized, this specific code may have a superior
performance.
In the next-generation mobile communication system,
control information transmits system constituent
information and transmission channel information, such
that it is considered to be very important information to
determine a system performance. Generally, this control
information has a short length to use a relatively small
amount of system resources. The above-mentioned control
information is coded by the coding technique having very
resistant to a channel error, and is then transmitted. A
variety of coding schemes for the above control
information have been considered in the 3GPP mobile
communication system, for example, a short-length block
code based on a Reed-Muller (RM) code, a tail-biting
convolution code, and a repetition code of a complex code.
In the meantime, the control information for use in
the 3GPP LTE system acting as an improved format of the
above-mentioned mobile communication system is coded by
means of block codes, such that the block-coded control
information is then transmitted. In more detail, if the
length of a transmission (Tx) information bit is "A", the
channel-coding process is performed by a block code
composed of 20 rows and A columns (i.e., (20,A) block
code) during the transmission of a specific channel (e.g..
Physical Uplink Control Channel (PUCCH)), and the
channel-coding result is then transmitted. In the 3GPP
LTE system, uplink control information is transmitted
over the PUCCH and a PUSCH (i.e., a physical uplink
shared channel). The control information transmitted over
the PUSCH is channel-coded by a block code composed of 32
rows and A columns (i.e., (32, A) block code), such that
the channel-coded control information is then transmitted.
In the meantime, the (32, A) block code may have
various formats. It is difficult for the user to search
for an optimum format after checking individual coding
performances of the variable-length information bits
associated with all block codes.
iDisclosurel
[Technical Problem!
Accordingly, the present invention is directed to a
channel coding method of variable-length information using
a block code that substantially obviates one or more
problems due to limitations and disadvantages of the
related art.
An object of the present invention is to provide an
effective (32,A) block coding method of variable-length
information. In other words, under the condition that the
length of an information bit is changed in various ways and
the bit length of a coded codeword is also changed in
various ways, the present invention provides the (32,A)
block coding method for effectively supporting the
combination of variable bit lengths.
In the meantime, the number of coded bits may be
equal to or less than 32, and the number of information
bits may be changed in various ways. Therefore, according
to the following embodiments of the present invention, the
present invention provides a method for effectively using
only some necessary parts of all the proposed block codes
associated with the number of specific-length information
bits or the number of specific-length coding bits. On the
contrary, if the coding with a length longer than the above
specific length is needed, the present invention allows the
block code based on the above specific length to be
repeated, such that it performs a long-length coding.
iTechnical Solution]
To achieve these objects and other advantages and in
accordance with the purpose of the invention, as embodied
and broadly described herein, a method for channel-coding
information bits using a code generation matrix which
includes 32 rows and A columns corresponding to a length of
the information bits, the method comprising: channel-coding
the information bits having the length of A using basis
sequences having a 32-bit length corresponding to
individual columns of the code generation matrix, and
outputting the channel-coded result as an output secjuence,
in which if the A value is higher than "10", the code
generation matrix is generated when (A-10) number of
additional basis sequences from among several additional
basis sequences were added as column-directional sequences
to a first or second matrix, in which the first matrix
corresponds to a Transport Format Combination Indicator
(TFCI) code generation matrix information composed of 32
rows and 10 columns used for coding TFCI information, the
second matrix is made when at least one of an inter-row
location or an inter-column location of the first matrix
was changed, and the additional basis sequences satisfy a
predetermined condition in which a value of a minimum
Hamming distance is 10.
Preferably, the additional basis sequence includes
10 number of "0" values.
Preferably, the second matrix is made when at least
one of an inter-row location or an inter-column location of
the first matrix was changed, and includes lower 12 rows to
be deleted to generate a third matrix, such that the third
matrix corresponds to another code generation matrix for
Physical Uplink Control CHannel (PUCCH) transmission.
In another aspect of the present invention, there is
provided a method for channel-coding information bits using
a code generation matrix which includes 32 rows and A
columns corresponding to a length of the information bits,
the method comprising: channel-coding the information bits
having the length of A using basis sequences having a 32-
bit length corresponding to individual columns of the code
generation matrix, and outputting the channel-coded result
as an output sequence, in which if the A value is higher
than "10", the code generation matrix is generated when (A-
10) number of additional basis sequences from among several
additional basis sequences were added as column-directional
sequences to a first or second matrix, in which the second
matrix is made when at least one of an inter-row location
or an inter-column location of the first matrix was changed,
the first matrix is represented by the following Table,
[Table]
, and the several additional basis sequences are
equal to
[1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 1,
1, 0, 0, 0, 1, 0, 1, 0, 1, 0, 1, 1, 1, 0, 0],
[1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1. 1, 1, 1, 0,
0, 0, 0, 1, 1, 1, 1, 0, 1, 0, 0, 0, 0, 1, 0],
[0, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
1, 0, 0, 1, 0, 1, 0, 1, 1, 0, 0, 0, 1, 1, 0], and
[0, 0, 1, 1, 1, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
1, 1, 1, 1, 0, 1, 1, 0, 0, 1, 0, 1, 0, 0, 1], respectively.
In another aspect of the present invention, there is
provided a method for channel-coding information bits using
a code generation matrix which includes 32 rows and A
columns corresponding to a length of the information bits,
the method comprising: channel-coding the information bits
having the length of A using basis sequences having a 32-
bit length corresponding to individual columns of the code
generation matrix, and outputting the channel-coded result
10
as an output sequence, in which the code generation matrix
corresponds to a tenth matrix having 32 rows and A columns,
in which a fourth matrix corresponds to a matrix composed
of 20 rows and A columns in which A number of basis
sequences were sequentially selected from a left side of a
fifth matrix represented by the following table
[Table]
, and a sixth matrix is a matrix made when at least
one of an inter-row location or an inter-column location of
the fourth matrix was changed, and a seventh matrix is a
matrix made when additional 12 bits were added to each of
basis sequences of the fourth or the sixth matrix, in which
11
the seventh matrix corresponds to a matrix composed of 32
rows and A columns in which A number of basis sequences
were sequentially selected from a left side of a eighth
matrix represented by the following table
[Table]
, and a ninth matrix generated when at least one
inter-row or inter-column location of the seventh matrix
was changed, and the tenth matrix is a code generation
12
matrix generated when basis sequences corresponding to the
A number of the basis sequences from a left side of the
seventh or the ninth matrix were selected.
Preferably, if the A value is equal to or less than
"14", a predetermined number of column-directional
sequences corresponding to the A length on the basis of a
left side of column-directional sequences of a eleventh
matrix sequentially correspond to the basis sequences of
the code generation matrix, in which the eleventh matrix is
represented by the following Table.
[Table]
Preferably, if the A value is equal to or less than
"11", a predetermined number of column-directional
sequences corresponding to the A length on the basis of a
left side of column-directional sequences of a twelfth
matrix sequentially correspond to the basis sequences of
the code generation matrix, in which the twelfth matrix is
represented by the following Table.
[Table]
Preferably, the method further comprises: if the
number of bits (i.e., a bit number) of the output sequence
is at least 32 (i.e., at least 32 bits), repeating each
basis sequence of the code generation matrix a
predetermined number of times, and performing a channel
coding process using a specific part having a predetermined
length corresponding to the bit number of the output
sequence from among the repeated basis sequence.
Preferably, if the bit number of the output sequence
is higher than 32 (i.e., 32 bits), the output sequence is
acquired when the channel-coded result is cyclically
repeated.
Preferably, the information bit corresponds to at
least one of Channel Quality Information (CQI) and a
Preceding Matrix Index (PMI).
Preferably, the output sequence is transmitted over
a Physical Uplink Shared Channel (PUSCH).
It is to be understood that both the foregoing
general description and the following detailed description
of the present invention are exemplary and explanatory and
are intended to provide further explanation of the
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15
invention as claimed.
[Advantageous Effects]
According to the above-mentioned embodiments of the
present invention, the present invention reuses a code
generation matrix used for TFCI (Transport Format
Combination Indicator) information coding of a conventional
3GPP system and/or the (20,A) code generation matrix for
PUCCH transmission, such that it can easily implement the
(32,k) block coding. As a result, a minimum- distance
between the generated codewords increases, resulting in an
increased system performance.
[Description of Drawings]
The accompanying drawings, which are included to
provide a further understanding of the invention,
illustrate embodiments of the invention and together with
the description serve to explain the principle of the
invention.
In the drawings:
FIG. 1 is a conceptual diagram illustrating a
method for generating the (32,14) block code using the
(32,10) block code used for a conventional TFCI
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information coding and the (20,14) code used for PUCCH
transmission according to the present invention; and
FIG. 2 is a graph illustrating minimum-distance
performances acquired when the (40, k) block code, the
(52,k) block code, and the (54,k) block code are
generated on the condition that the (20,k) block code and
the (32,k) block code are used as base codes.
[Best Mode]
Reference will now be made in detail to the
preferred embodiments of the present invention, examples of
which are illustrated in the accompanying drawings.
Wherever possible, the same reference numbers will be used
throughout the drawings to refer to the same or like parts.
Prior to describing the present invention, it should
be noted that most terras disclosed in the present invention
correspond to general terms well known in the art, but some
terms have been selected by the applicant as necessary and
will hereinafter be disclosed in the following description
of the present invention. Therefore, it is preferable that
the terms defined by the applicant be understood on the
basis of their meanings in the present invention. For
example, although the following description relates to a
detailed example applied to the 3GPP LTE (3rd Generation
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17
Partnership Project Long Term Evolution) system, the
present invention can also be applied to not only the above
3GPP LTE system but also other arbitrary communication
systems which need to perform the channel coding process on
variable-length control information using the block code.
For the convenience of description and better
understanding of the present invention, general structures
and devices well known in the art will be omitted or be
denoted by a block diagram or a flow chart. Wherever
possible, the same reference numbers will be used
throughout the drawings to refer to the same or like parts.
Firstly, items to be commonly considered by the
present invention will hereinafter be described in detail.
The [n,k] code is a specific code in which the
number of coding bits is "n" and the number of information
bits is "k".
In this case, if there is no mention in a generation
matrix of each code, this generation matrix is represented
by a basic-sequence-type table. In fact, the coding method
is similar to that of a TFCI code of the 3GPP release 99.
In other words, the information bits are sequentially
allocated to the left-sided basis sequence, and a sequence
corresponding to the product of the basis sequence and the
information bit is added by binary operations (i.e..
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18
Exclusive OR sum) corresponding to the number of
information bits, such that a coding bit is generated.
If the code is represented according to the above-
mentioned method, although the number of information bits
(hereinafter referred to as "information bit number") is
variable, the present invention has an advantage in that it
can perform the coding process of data on the basis of a
matrix-type basis sequence table. The present invention is
able to support a variety of information bit numbers using
the above-mentioned advantages. Therefore, a basis
sequence table or a code generation matrix is represented
in consideration of a maximum-sized information bit number.
If the maximum number of information bits needed for the
actual application is less than the following proposed size,
it is preferable that a table having no basis sequence for
at least a corresponding maximum bit number (i.e., a
corresponding maximum number of bits) be used.
In the meantime, the operation of replacing a
generation code of "0" with another generation code of "1"
according to the coding theory has no influence on the code
characteristics. Therefore, although the value of "0" is
replaced with the other value of "1" in the basis sequence
table, the replaced result may indicate the same code
feature. Also, although the order of coding bits is
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19
replaced with another order according to the coding theory,
the replaced result may also indicate the same code feature.
Therefore, although the row location is replaced with
another row location in the basis sequence table, the
replaced result may also indicate the same code feature.
The basis sequence proposed by the following
embodiments is designed to have a variable number of
information bits (i.e., a variable information-bit number),
and is also designed to have a variable number of coding
bits (i.e., a variable coding bit number). Therefore, in
the case of devising the inventive concept of the present
invention, a specific code in which a specific column is
deleted from a specific basis sequence table was pre-
considered. For example, if a basis sequence table is
denoted by a specific format such as (32,14), the (20,11)-
format basis sequence table is one of application examples
of the above (32,14)-format basis sequence table. In more
detail, if 12 columns are successively deleted from the
bottom of the (32,14)-format basis sequence table, and 3
rows are deleted from the right of the (32,14)-format basis
sequence table, the above-mentioned (20,11)- format basis
sequence table can be acquired. In brief, the row and
column of the basis sequence table according to the present
invention have been decided on the basis of the largest
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20
size. In the case of the small-sized row and column, the
rows and columns of the largest-sized basis sequence table
are sequentially deleted from the right or the bottom of
the above table, such that the deleted result is used.
Needless to say, as previously stated above, although the
row location may be replaced with the column location in
the smaller-sized basis sequence table, or although the
location of "0" is replaced with the other location of "1"
in the basis sequence table, the above replaced results may
have the same codes.
For the convenience of description and better
understanding of the present invention, in the case of
indicating the order of any data of the present invention,
the information bits sequentially proceed in the direction
from the left column to the right column in the above basis
sequence table. The coding bits sequentially proceed in
the direction from the uppermost row to the lowermost row
in the above basis sequence table. The term "basis
sequence table" may also be called "Code generation matrix"
or other terms as necessary.
In the meantime, it is preferable that a specific-
pattern basis sequence for use in a specific channel
estimation method be unavailable. In this case, a specific
table, from which a specific basis sequence based on a
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21
system type is removed, may be selected from various tables
proposed by the following embodiments. From the viewpoint
of the coding process, a corresponding basis sequence may
always be considered to be "0", such that the same coding
performance is made, but only the number of information
bits is reduced.
Therefore, according to the basis sequence table
proposed by the following embodiments, a specific basis
sequence table having no specific basis sequence or a code
generation matrix has already been considered in the case
of designing the present invention.
According to the above-mentioned one aspect of the
present invention, the present invention provides the
(32,A)-format block coding method. In more detail, the
present invention provides the (32,14)-format block coding
method in consideration of the maximum length (i.e., 14
bits) of information bits. However, it should be noted
that only some basis sequences from among the (32,14)-
format code generation matrix be used according to the
information-bit length as previously stated above.
Although a variety of methods can be used for the
above-mentioned purposes, the following embodiments provide
a code design method capable of maintaining a maximum
common point with conventional codes using the conventional
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block codes. In more detail, the conventional codes
provide a first method of using the (32,10)-format block
code for the TFCI-information coding used in the 3GPP
release 99 and a second method of using the (20,14)-format
block code for PUCCH transmission. In this case, the
above-mentioned (20,14)-format block code has been
disclosed in United States Provisional Application No.
51/016,492 used as priority of the present invention,
entitled "GENERATION METHOD OF VARIOUS SHORT LENGTH BLOCK
CODES WITH NESTED STRUCTURE BY PUNCTURING A BASE CODE"
filed by the same applicant as the present invention, which
is incorporated herein by reference. Detailed descriptions
of the (32,10)-foinmat block code and the (20,14)-format
block code will hereinafter be described in detail.
The (32,10)-format block code for the TFCI
information coding and the (20,14)-format block code for
PUCCH transmission will hereinafter be described in detail.
(32,10) TFCI Block Code and (20,14) Block Code
The (20,14) block code for use in this embodiment
will be generated as follows. Firstly, (20,10) block code
is generated from the (32,10)-structured TFCI code
generation matrix, and 4 basis sequences are added to the
(20,10) block code, such that the (20,14) block code is
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23
generated.
The (20,10) block code is based on the (32,10)-code
generation matrix used for the channel coding of TFCI
(Transport Format Combination Indicator) information in the
3GPP Rel' 99. As a result, the (20,10) bloc}c code can be
designed to be punctured according to the length of a
codeword to be coded.
The reuse of the (32,10) TFCI information code has a
variety of advantages. For example, the TFCI information
code has been designed on the basis of the Reed-Muller (RM)
code, such that the punctured TFCI code may have a modified
Reed-Muller (RM) code structure. This Reed-Muller (RM) -
based code has an advantage in that it can be quickly
decoded by a fast Hadamard transform method during the
decoding process. For another example, the TFCI coding
method supports a variable-length information bit and a
variable-length coding bit. In this way, the information-
bit length or the coding-bit length can be changed in
various ways, such that requirements for CQI transmission
of the 3GPP LTE can be well satisfied.
The following Table 1 shows the (32,10)-code
generation matrix used for the channel coding of TFCI
information in the 3GPP Rel' 99. In this case, the
(32,10)-code generation matrix generates a specific
24
codeword which has the length of 32 bits and the value of
dniin=12.
[Table 1]
5 Generally, as well known in the art, although the
inter-row location or the inter-column location is replaced
with other locations in the block code, there is no
25
difference in performance between the generated codewords.
The following Table 2 shows a specific block code, which is
equivalent to the (32,10) block code used for the
aforementioned TFCI-information coding using the above-
mentioned advantage.
[Table 2]
As can be seen from the block code shown in Table 2,
the row- and column- locations of the (32,10) code used for
the TFCI coding are changed to other locations, and
locations between some columns (or locations between some
rows on the basis of the TFCI information code) are
exchanged with each other.
In other words, according to this embodiment of the
present invention, 12 rows in either the (32,10)-format
TFCI information code (Table 1) or its equivalent matrix
(Table 2) may be punctured, or 2 0 rows are selected from
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26
the the (32,10)-format TFCI information code (Table 1) or
its equivalent matrix (Table 2), such that the (20,10)
block code is configured. In this case, from the viewpoint
of the block code of Table 2, 12 columns may be punctured,
and 20 columns may be selected. There is no difference in
mode performance between the first case of using Table 1
and the second case of using Table 2. For the convenience
of description and better understanding of the present
invention, it is assumed that the present invention uses
the equivalent format (See Table 2) of the TFCI information
code if there is no mention in the above-mentioned
description.
In the meantime, the (32,10) code used for coding
the TFCI information has been generated on the basis of the
Reed-Muller (RM) code. In this case, in order to implement
an error correction performance, it is very important for
the above (32,10) code to search for a puncturing pattern
which enables a codeword to have the longest distance (c/^„) .
Compared with this embodiment, an exhaustive search
capable of searching for an optimum puncturing pattern in a
generation matrix of the (32,10) code used for TFCI coding
will hereinafter be described in detail. Provided that the
number of columns of a generation matrix to be punctured in
the (32x10) matrix (also denoted by (32*10) matrix) is set
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27
to "p", the number of all available puncturing patterns is
denoted by . In this case, is indicative of the
number of cases, each of which selects the p columns from
among 32 columns.
For example, if the value of "p" is 12 (p>=12), there
are different (10x20) generation matrixes (i.e.,
= 225,792,840 number of (10x20) generation matrixes), 10-bit
information (i.e., 2"' = 1,024 number of information segments)
is coded into a codeword of 20 bits. A minimum Hamming
distance ( d^„ ) between codewords generated by individual
matrixes is calculated, such that a generation matrix
having the highest value is found in the above minimum
Hamming distance {d^^). If a puncturing pattern is used to
make the generation matrix having the maximum ( d„„ ] value,
this puncturing pattern is considered to be the last
pattern to be finally found. However, the generation of
the optimum (20,10) block code on the basis of the above
steps requires a large number of calculations, resulting in
greater inconvenience of use.
Therefore, this embodiment of the present invention
adds specific restriction conditions to the process for
deciding the puncturing pattern, such that it reduces the
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28
range of a searching space for acquiring an optimum ( „„ )
value.
Next, a method for more effectively searching for a
generation matrix of the (20,10) code which generates a
codeword having d^=cl will hereinafter be described in
detail. Provided that a target { rf„, ) value is denoted by d,
the Hamming weight »v(g|(Hj,.ji,[/]) of each row vector
gioty2o[i] (I^'^IO) of the (20,10)-code generation matrix has
some requirements shown in the following Equation 1.
[Equation 1]
f=0,l,--,10
;¦ * 6(There are all ones in this row vector)
For example, if the value of d is 6 (d=5) , Equation
1 can be represented by the following Equation 2.
[Equation 2]
Therefore, if the above restriction of Equation 2 is
added to individual row vectors gioby2o\i] of the (10*20)
matrix generated from the above-mentioned exhaustive search
process, the added result can reduce the number (N« )
of searching spaces capable of searching for a generation
matrix generating a codeword having d^„=6 . Generally,
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29
based on various cited references, it is well known in the
art that a maximum { d^„ ) value of the (20,10) code is 6,
and its detailed description has been disclosed in "The
Theory of Error-Correcting Codes (by F.J. MacWilliams and
N.J.A. Sloane)". Therefore, the condition of d^=6 is
applied to the condition of Equation 1, such that 360
patterns indicating an optimum performance can be found.
The above 360 puncturing patterns have been
disclosed in Appendix "A" of United States Provisional
Application No. 61/016,492, entitled "GENERATION METHOD OF
VARIOUS SHORT LENGTH BLOCK CODES WITH NESTED STRUCTURE BY
PUNCTURING A BASE CODE" filed by the same applicant as the
present invention. Specifically, indexes of punctured
columns based on Table 2 have been disclosed in the
Appendix "A" . For the convenience of description, the
above-mentioned indexes will herein be omitted.
The following pattern from among the above 360
puncturing patterns will hereinafter be described as an
example.
The following Table 3 shows a specific pattern,
which indicates the distribution of a specific Hamming
weight from among the 360 patterns.
[Table 3]
The puncturing patterns shown in Table 3 correspond
to the sixth index of Table A. 2 of the Appendix "A" of
United States Provisional Application No. 61/015,492. In
this case, the value "0" of Table 3 indicates that a column
corresponding to the location of "0" is punctured. The
value "1" of Table 3 indicates that a column corresponding
to the location of "1" is not punctured but selected for
the (20,10) block code.
In the case where the puncturing pattern of Table 3
is applied to Table 2, the result is shown as the following
Table 4.
[Table 4]
In this case, compared with Table 2, row- and
column- directions of Table 4 are changed, but Table 4 has
the same meaning as Table 2. 12 punctured rows from among
individual row- directional sequences are shown at the
right side of Table 4. As a result, the generated (20,10)
block code can be represented by Table 4.
[Table 5]
In the meantime, there is a little difference
between the order of rows of Table 4 or Table 5 and the
matrix order of the 3GPP-based TFCI coding. As described
above, although the location of each row is changed to
another location according to the above-mentioned coding
theory, there is no difference in performance between
generated codewords. If the row order of Table 4 or Table
5 is adjusted in the same manner as in the TFCI code matrix,
the following Table 6 is acquired.
[Table 6]
As described above, only the row order of Table 6 is
different from that of Table 4, but the remaining features
of Table 6 are exactly equal to those of Table 4. The
representation method of Table 6 has an advantage in that
the last 2-bits be punctured during the puncturing time
from the (20,10) code to the (18,10) code.
Next, a method for extending the above-mentioned
(20,10) code to a maximum of the (20,14) code will
hereinafter be described in detail.
As for the (20, A) block code according to this
embodiment, it is assumed that a CQl value indicating
channel quality information (CQI) of the 3GPP LTE system be
applied to the channel coding method for PUCCH transmission.
Also, in the case of generating the (20,10) code, the bit
number of the CQI information of the 3GPP LTE system can be
decided in the range from 4 bits to 10 bits, such that it
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34
can be maximally extended to the (20,10) block code.
However, in the case of the MIMO system, the bit number of
the CQI information may be higher than 10 bits as necessary.
However, a transmission (Tx) amount of actual CQI is
decided according to a CQI generation method. For the
coding process, the present invention may consider a method
for supporting all the information bit numbers ranging from
4 bits to 14 bits.
Therefore, the (20,14) block coding method will
hereinafter be described, which is capable of supporting a
maximum of 14 bits by adding a column corresponding to the
information bit number to the above (20,10) block code.
In order to search for the added column during the
exhaustive search, a large number of calculations must be
carried out. Therefore, the execution of the exhaustive
search in all the cases may be ineffective or undesirable.
In this step, it should be noted that the sixth
column of Table 6 is set to "1" and is used as a basis
sequence. Therefore, if the added column must satisfy the
minimum distance "d", a minimum number of "0" must be equal
to or higher than "d". In this example, the number of "0"
is equal to a minimum distance between codewords. In more
detail, a difference between the added column and the old
sixth column composed of "1" is indicative of a distance
35
between two codewords, such that the number of "0"
contained in the added column is equal to the distance
between codewords.
Generally, a maximum of a minimum distance available
for the (20,10) code is 6. In the present invention, a
minimum of a maximum distance available for the (20,11)
code corresponding to an extended version of the (20,10)
code is 4. In more detail, the maximum-/minimum- distance
characteristics based on various information bit numbers of
the 20-bit codeword can be represented by Table 7.
[Table 7]
Therefore, this embodiment of the present invention
provides a column adding method, which allows the maximum-
/minimum- distance of the added column to be "4" .
According to this column adding method, a column having at
least four "0" values is added to the added column.
In order to minimize the number of searching times,
it is assumed that the added column of this embodiment
includes 4 number of "0" values (i.e., four "0" values).
In this way, if the added column includes the four "O"
values and 16 number of "1" values, this added column can
be configured in various ways. A representative example of
36
the added column is shovm in the following Table 8. If the
(20,10) code of Table 6 is extended to the (20,14) code.
Table 8 can be acquired.
[Table 8]
With reference to Table 8, the four added columns
are indicative of four columns located at the right side.
In each added column, "0" is denoted by a bold line.
Based on the above-mentioned facts, a method for
modifying or optimizing Table 8 will hereinafter be
described in detail.
According to this embodiment, the sixth column of
Table 8, i.e., all bits of the column Mj.,5, is set to "1",
such that the sixth column is considered to be a basis
sequence. This basis sequence greatly contributes to all
codewords of a corresponding bit. Therefore, from the
viewpoint of the corresponding bit, the use of the basis
sequence having many weights may be desirable.
However, several bits in all codewords are
exclusive-OR (XOR) operated, such that their combination
result must be considered. Thus, in order to reduce the
number of the combination cases, the basis sequence in
which each of all bits has the value of "1" moves to the
frontmost column, resulting in the increase of a
contribution rate. In this way, if data is coded under a
small number of bits {i.e., a small bit number), the
present invention may consider the above method for moving
the basis sequence in which each of all bits is "1" to the
frontmost column, and the moved result is represented by
the following Table 9.
[Table 9]
with reference to Table 9, a sixth sequence (i.e.,
each bit of the sixth sequence has the value of "1") from
among the original column- directional basis secjuence moves
to the location of a first basis sequence, and the order of
other sequences is not changed to another order.
In the following description, it is assumed that the
(20,14) block code structure for PUCCH transmission uses
the block code of Table 9. If the number of information
bits for PUCCH transmission is limited to a maximum of 13
bits or less, the basis sequence located at the rightmost
part of Table 9 may be omitted as necessary, and the
omitted result can be represented by the following Table 10.
[Table 10]
Next, based on the above-mentioned description, a
method for generating the (n,)c) block code (where n^32 and
k^l4) will hereinafter be described in detail.
(n, k) BLOCK CODE (n A block code having a maximum size of (32,14) will
hereinafter be described in detail. In other words,
according to this embodiment, a maximum size of the coding
bit number is 32, and a maximum size of the information bit
number is 14. The coding design can be implemented in
various ways, but a coding method according to this
embodiment must be designed to search for a maximum number
of common points with conventional codes.
In order to generate the (32,14) block code, the
present invention considers the (20,14) block code {See
Table 9) acquired from the (32,10) TFCI block code of the
3GPP Release 99, and at the same time considers the above-
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40
mentioned (32,10) TFCI block code. In order to generate
the (32,14) block code using the (20,14) block code and the
(32,10) TFCI block code, a »TBD" (To be defined) part of
FIG. 1 needs to be additionally defined.
FIG. 1 is a conceptual diagram illustrating a
method for generating the (32,14) block code using the
(32,10) block code used for a conventional TFCI
information coding and the (20,14) code used for PUCCH
transmission according to the present invention.
Referring to FIG. 1, if the (32,10) block code 101
used for the TFCI information coding and the (20,14)
block code 102 are used to generate the (32,14) block
code 104, the TBD part 103 must be additionally defined.
In one aspect of any one of block codes, the above-
mentioned definition can be analyzed in various ways.
Namely, the (32,14) block code 104 according to this
embodiment is generated when four basis sequences
(corresponding to the combination part between the 102a
part and the 103 part of FIG. 1) is added to the right
side of the conventional (32,10) block code. In another
aspect of the above block codes, 12 row-directional
sequences (corresponding to the combination part between
the 101a part and the 103 part of FIG. 1) are added to
either the block code of Table 9 or its equivalent
41
(20,14) block code 102, such that the (32,14) block code
104 may also be generated.
In this case, the conventional TFCI information
code shown in Table 1 and its equivalent code can also be
used as the (32,10) block code 101. The block code of
Table 9 and its equivalent code can also be used as the
(20,14) block code 102. In this case, if the inter-row
location and/or the inter-column location of the
conventional block code are/is changed to others, the
above equivalent code is made.
Preferably, if the code is designed, the designed
code must allow the TBD 103 to have the best performance
at a minimum distance. Generally, according to various
information-bit lengths and various coding-bit lengths,
the following minimum-distance performances are acquired
as shown in Table 11.
[Table 11)
With reference to Table 11, in the case of the
(32,A) block coding, if "A" is higher than "10", a
maximum value of a minimum Hamming distance of the basis
sequence is limited to "10".
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42
Therefore, according to a preferred embodiment of
the present invention, the TBD part 103 of FIG. 1 along
with the 102a part of the (20,14) block code 102 must
allow a maximum value of the minimum Hamming distance of
each basis sequence (corresponding to the combination
part between the 102a part and the 103 part of FIG. 1) to
be "10". In this case, the 102a part corresponds to the
information bits of more than 10 bits. In more detail, if
the number of additional basis sequences is 1 or 2 (i.e.,
if if "A" is 11 or 12), this means that one or two basis
sequences are added to allow a minimum Hamming distance
of each basis sequence to be "10". If the number of
additional basis sequences is 3 or 4 (i.e., if "A" is 13
or 14), this means that three or four basis sequences are
added to allow a minimum Hamming distance of each basis
sequence to be "8". The (32,10) block code for TFCI
information coding includes a basis sequence in which
each of all components is "1", such that each of the
additional basis sequences may include 10 number of "0"
values. In other words, if the (20,14) block code is used
as the block code of Table 9, individual basis sequences
corresponding to the 102a part of FIG. 1 include 4 number
of "0" values, such that the basis sequence part
43
corresponding to the TBD part may include 6 number of "0"
values.
An example for satisfying the above-mentioned
condition is shown in the following Table 12.
[Table 12]
As can be seen from Table 12, if 12 rows from the
bottom of Table 12 are deleted, the (20,14) code for
PUCCH transmission is formed. If 14 rows from the bottom
of Table 12 are deleted, the (18,14) code is formed.
Variable application of the information bit can be easily
implemented, and as many basis sequences of Table 12 as
the number of corresponding information bits are acquired
from Table 12, such that the acquired basis sequences are
used for the coding process. If a maximum number of
information bits (i.e., a maximum information-bit number)
of FIG. 12 is less than 14 (i.e., 14 bits), basis
sequences as many as the predetermined number unnecessary
for the basis-sequence table such as Table 9 may be
deleted from the right column. This means that basis
sequences as many as the number of information bits
required for the (32,10) block code may be added.
For example, provided that a maximum information-
bit number is limited to 11 bits, the following (32,11)
block code of Table 13 can be used.
[Table 13]
In the meantime, a method for arranging the (32,k)
block code in consideration of the (16,k) block code will
hereinafter be described in detail.
A method for generating an optimum code of the
(32, k) block code of Table 12 or Table 13 is as follows.
In the case of generating the (20,k) or (18,k) block code,
if the remaining rows from the lowest row are deleted,
the above optimum code of the (32, k) block code can be
generated. However, if the (16,k) block code is needed,
much consideration is needed. Therefore, according to
this embodiment of the present invention, the row order
of the above (32, k) block code is changed in
consideration of the (16, k) block code. If the (16,k)
block code is needed, although some rows from the lowest
row of the (32, k) block code are deleted and used, the
46
present invention is able to generate a necessary code. A
representative example is shown in the following Table 14.
[Table 14]
In Table 14, during the code conversion from the
(32, k) code to the (20, k) code, if 12 rows are deleted
from Table 14 on the basis of the lowest row, an optimum
code is generated. If 14 rows are deleted from Table 14
on the basis of the lowest row, the (18, k) code is
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47
generated. If 16 rows are deleted from Table 14 on the
basis of the lowest row, the (16,k) code is generated.
In the meantime, based on the above-mentioned
description, if a codeword of more than 32 bits is needed,
the following channel coding method can be carried out.
IF CODEWORD OF MORE THAN 32 BITS IS NEEDED:
If the codeword of more than 32 bits is needed, the
present invention provides a method for generating the
long-length (n,k) code by repeating the above basis
sequence on the basis of the (32, k) or (20, k) code used
as a base code.
The (32,k) or (20,k) code can be easily generated
on the basis of Table 12 or Table 14. In the meantime, in
order to assign a stronger or higher error correction
capability to a transmission (Tx) bit, the present
invention may increase the number of coding bits (i.e.,
the coding bit number) . In this case, it is preferable
that a new code corresponding to the increased number of
coding bits be generated, but it is very difficult for a
code designer to design a new code whenever the number of
coding bits increases. Therefore, one of simple
generation methods is to repeat the base code by a
desired length. If the desired length is not accurately
wo 2009/082147 PCT/KR2008/007576
48
represented by an integer multiple of the base code, the
base code is repeated by at least the desired length, and
as many base codes as the number of excessive bits may be
removed. In this case, although the present invention is
able to search for an optimum puncturing pattern every
time, the present invention can substantially consider a
simple puncturing method based on a rate matching block.
In this case, the present invention may consider
the (32, k) or (20, k) code as the base code. For the
convenience of description, the present invention
considers only a specific case in which a desired length
has the size of an integer multiple of the base code. In
the remaining cases, it is assumed that the present
invention is able to acquire a necessary code using the
puncturing method. Also, the present invention is able to
use a variety of "k" values. In this case, for the
convenience of description, it is assumed that a maximum
size of 'k" is set to 14. Although there is no mention of
the smaller size of less than 14 in the present invention,
it is well known to those skilled in the art that a basis
sequence corresponding to a corresponding length be
selected and used.
For example, if the (64,14) code is needed, the
(32,14) code can be repeated only two times. If the
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49
(40,14) code is needed, the (20,14) code can be repeated
only two times. Also, the (32,14) code and the (20,14)
code are simultaneously considered as the base code, such
that the (32,14) code and the (20,14) code are
sequentially attached to configure the (52,14) code.
In conclusion, the combination of available codes
may be determined to be the {a*32+b*20,14) code (where '*a"
or "b" is an integer number of at least "0".
If the last necessary coding bit number is not
denoted by an integer multiple of the base code, the base
code is repeated to be longer than the desired length,
unnecessary parts may be severed from the end part of the
longer-sized code or may be punctured using the rate
matching blocks.
In the meantime, according to another aspect of the
present invention, after the order of information bits
has been reversed, the base code may then be repeated.
As described above, if the base code is
continuously repeated, minimum-distance characteristics
of the base code are maintained without any change, such
that the resultant minimum-distance characteristics are
repeated. Therefore, if the code having an original
minimum distance of 4 is repeated two times, the minimum
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50
distance is increased by two times, such that the minimum
distance of the resultant code reaches "8".
However, provided that any variation is applied to
the information bit during the above repetition, although
the information bit which forms a codeword having a
minimum distance is used, a codeword generated by another
information bit changed by the above repetition is able
to form another codeword having the distance longer than
the above-mentioned minimum distance. If the minimum
distance is not repeated according to the above-mentioned
principles, a code can be designed such that the minimum-
distance characteristics can be larger than those of a
simple multiple.
The present invention can consider a variety of
methods for changing the information bit. For example, in
order to change the above-mentioned information bit, a
method for using a reverse version of a bit unit, and a
method for allowing the information bit to pass through a
random sequence such as a PN sequence can be used in the
present invention.
Also, the present invention may assign different
information-bit variations to individual repetition times,
such that the information bit is differently changed
whenever the repetition occurs. However, in this case.
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51
the complexity of a transmission/reception end increases.
If the repetition is performed several times, the present
invention may not change the information bit in the first
time, and may change the information bit in the next time.
In more detail, in the case of repeating the code
according to this embodiment, the information bit is not
changed at the even-th repetition, but is changed at the
odd-th repetition. In other words, the present invention
controls the information-bit variation to be toggled
whenever the repetition occurs.
For example, under the condition that the (20,k)
code and the (32, k) code are used as the base codes, the
(40, k) code, the (52, k) code, and the (64, k) code can be
generated according to the present invention. A detailed
description thereof will hereinafter be described.
FIG. 2 is a graph illustrating minimum-distance
performances acquired when the (40,k) block code, the
(52,k) block code, and the (64,k) block code are
generated on the condition that the (20,k) block code and
the (32, k) block code are used as base codes.
Referring to FIG. 2, " (40,k)_20+20" indicates that
the (2 0, k) code acting as the base code is repeated two
times. "(20,k)_20rev" indicates that the information bit is
reversed from the (2 0, k) code acting as the base code.
wo 2009/082147 PCT/KI12008/007576
52
" (32, k)_32rev" can be analyzed in the same method as the
above-mentioned method.
"(40,k)_20+20rev" indicates that the (20,k) code
used as the base code was repeated two times, an
information bit was changed according to the toggle method
at the first repetition time, and the information bit was
then reversed at the second repetition time. In this way,
" (64, k)_32+32rev" can also be analyzed in the same method
as the above. In the meantime, "(52,k)_20+32rev" indicates
that the (32, k) and (20, k) codes were selected as base
codes, each of the selected base codes was repeated only
once, and the (32,k) code acting as the second base code
was bit-reversed and the information bit was then applied
to the bit-reverse result.
In FIG. 2, if the value of k is denoted by k^4, the
"(40,k)_20" code has a low performance less than that of
the (32, k) code. Therefore, it can be recognized that the
operation of using the (3 2,k) code with less number of
coding bits has a good performance higher than that of the
operation of repeating the (20, k) code two times. In other
words, the repetition of (32, k) code with less number of
coding bits has a high performance superior to that of the
repetition of (20,k) code. Therefore, the preferred
embodiment of the present invention provides a method for
wo 2009/082147 PCT/KR2008/007576
53
repeatedly using the (32,k) code during the coding process
for a long-length coding bit. In other words, according to
this embodiment of the present invention, provided that the
(32,k) code was selected as the base code, the bit number
(i.e., the number of bits) of the last output sequence was
equal to or higher than 32 (i.e., 32 bits), and an integer
multiple of the base code was not implemented, the (3 2, k)
code is repeated to be longer than a desired length, and
unnecessary parts (i.e., corresponding to the bit number of
the needed output sequence) are severed from the end of the
repeated result.
The above-mentioned embodiment can be analyzed as
follows. In more detail, if the length of the needed
output sequence is at least 32 bits, it can be recognized
that the coded result of the (32,k) block code was
cyclically repeated to acquire the above output sequence.
Namely, provided that the 32-bit-length codeword, which has
been channel-coded by the (32,k) block code, is represented
by /bo,A|,(!'2.^3'-->^B-i (where B=32) , and the output sequence
longer than the length of 32 bits (e.g., the bit length of
"Q") is represented by relationship between the output sequence and the channel-
coded 32-bit-length codeword can be represented by the
wo 2009/082147 PCT/KR2008/007576
54
following Equation 3.
[Equation 3]
9/=^((modfi) where i = 0, 1, 2, ..., 0-1
As can be seen from Equation 3, the output sequence
component having the index "i" corresponds to a codeword
component which has an index corresponding to the modulo-
operation result value. In this case, the modulo-operation
result value is acquired when the index "i" was modulo-
operated with the "B" value of 32. If the Q value is
higher than 32, the output sequence is acquired when the
channel-coded sequence was cyclically repeated. This also
means that the (32, k) code was repeated a predetermined
number of times and the part corresponding to the length of
a necessary codeword was selected and used. As well known
to those skilled in the art, the above-mentioned operation
results have been substantially equal to each other, but
they have been analyzed in different ways.
In the meantime, as can be seen from FIG. 2, the
performance of the " (52,k)_20+32rev" code is equal to or
higher than that of the " (52, k)_20+32" code, and the
performance of the (40, k)_20+20rev" code is equal to or
higher than that of " (40,k)_20+20". Therefore, in order to
improve the minimum-distance characteristics, the
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55
information bit is repeated without any change at the first
repetition time, and is then reversed at the next
repetition time.
Finally, if the last information bit number is not
denoted by an integer multiple of the base code, the base
code is repeated to be longer than a desired length, and
unnecessary parts can be severed from the end part of the
repeated result, or can be punctured by the rate matching
block method.
In the meantime, the above-mentioned method for
performing the bit reversion of the information bit
according to the toggle scheme can also be applied to not
only the repetition of the above-mentioned base code but
also other repetitions of various base codes. For example,
when the repetitive coding of the simplex code of ACK/NACK
control information is performed, the information bit is
coded without any change at the first repetition time, and
the bit-reversion information bit of the ACK/NACK control
information is then coded at the second repetition time.
It should be noted that most terminology disclosed
in the present invention is defined in consideration of
functions of the present invention, and can be differently
determined according to intention of those skilled in the
art or usual practices. Therefore, it is preferable that
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56
the above-mentioned terminology be understood on the basis
of all contents disclosed in the present invention. It
will be apparent to those skilled in the art that various
modifications and variations can be made in the present
invention without departing from the spirit or scope of the
invention. Thus, it is intended that the present invention
cover the modifications and variations of this invention
provided they come within the scope of the appended claims
and their equivalents.
That is, the present invention is not limited to only
the embodiments described herein and includes the widest
range equivalent to principles and features disclosed
herein.
[industrial Applicability]
As apparent from the above description, the channel
coding method according to the present invention can be
easily applied to the other channel coding of the 3GPP LTE
system which transmits CQI/PMI information to an uplink via
a PUSCH channel. However, the above-mentioned methods are
not limited to only the above 3GPP LTE system, but they can
also be applied to a variety of communication schemes, each
of which performs the block coding on variable-length
information.
What is claimed is:
Claim 1. A method for channel-coding first type information bits
using one or more basis sequences for a code matrix which includes
32 rows and A columns, hereinafter called as basis sequences for
(32, A) code, the A corresponding to a length of the first type
information bits, the method comprising:
channel-coding the first type information bits having the
length A using the basis sequences for (32, A) code; and
outputting the channel-coded result as an output sequence,
v\;herein A number of the basis sequences for (32, A) code are
selected from
the following Table 1, when A is a natural number not more
than 14.
21aim 2 The r.'.ethod according to claim 1, wherein one or more basis
sequences for a code matrix which includes 2 0 rows and B columns,
hereinafter called as basis sequences for (20, B) code, are selected
from a table including only 20 rows of the table 1 from an upper
side, wherein 3 is a natural number not more than 14, and
wherein the basis sequences for (20, B) code are used for
channel coding second type information bits.
Claim 3 The method according to claim 2, wherein the table 1 is
generated to have a maximum value of minimum Hamming distance
between the basis sequences for (20, B) code.
Claim 4 The method according to claim 2, wherein the table 1 is
generated to have a maximum value of a minimum Hamming distance
between the basis sequences for (32, A) code.
Claim 5 The method according to claim 1, wherein the first type
information bits are at least one of Channel Quality Information,
hereinafter called as CQI, and a Preceding Matrix Index, hereinafter
called as PMI.
Claim 6 The method according to claim 2, wherein the second type
information bits are control information bits transmitted through a
Physical Uplink Control Channel, hereinafter called as PUCCH.
Claim 7 The method according to claim 1, wherein the basis
sequences for (32, A) code which correspond to 11'", 12'", 13"" and
14th bits of the first type information bits include 10 "0" values.
claim 8 The method according to claim 1, wherein the basis
sequences for (32, A) code are selected from the following Table 2,
when A. is a natural nur.ber not more than 11,

A channel coding method of variable
length information using block code is disclosed. A
method for channel-coding information bits using a code
generation matrix including 32 rows and A columns corresponding
to length of the mformation bits includes, channel-coding
the information bits having 'A' length using basis
sequences having 32-bit length corresponding to
columns of the code generation matrix, and outputting the
channel-coded result as an output sequence. If'A' is higher
than 10, the code generation matrix is generated when
(A-10) additional basis sequences were added as columm-
directional sequences to a first or second matrix. The first
matrix is a TFCI code generation matrix composed of 32
rows and 10 columns used for TFCI coding. The second
matrix is made when at least one of an inter-row location
or an mter-column location of the first matrix was
changed. The additional basis sequences satisfy a value 10
of a mmimum Hammmg distance.

Documents:

http://ipindiaonline.gov.in/patentsearch/GrantedSearch/viewdoc.aspx?id=5X9+ZxLtTVOjJe+8eq7DEQ==&loc=wDBSZCsAt7zoiVrqcFJsRw==

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Patent Number

279998

Indian Patent Application Number

1233/KOLNP/2010

PG Journal Number

06/2017

Publication Date

10-Feb-2017

Grant Date

06-Feb-2017

Date of Filing

06-Apr-2010

Name of Patentee

LG ELECTRONICS INC.

Applicant Address

20, YEOUIDO-DONG, YEONGDEUNGPO-GU, SEOUL 150-721 REPUBLIC OF KOREA

Inventors:

#	Inventor's Name	Inventor's Address
1	YU, NAM YUL	LG INSTITUTE, HOGYE 1(IL)-DONG, DONGAN-GU, ANYANG-SI, GYEONGGI-DO 431-080 REPUBLIC OF KOREA
2	ROH, DONG WOOK	LG INSTITUTE, HOGYE 1(IL)-DONG, DONGAN-GU, ANYANG-SI, GYEONGGI-DO 431-080 REPUBLIC OF KOREA
3	KIM, KI JUN	LG INSTITUTE, HOGYE 1(IL)-DONG, DONGAN-GU, ANYANG-SI, GYEONGGI-DO 431-080 REPUBLIC OF KOREA
4	AHN, JOON KUI	LG INSTITUTE, HOGYE 1(IL)-DONG, DONGAN-GU, ANYANG-SI, GYEONGGI-DO 431-080 REPUBLIC OF KOREA
5	LEE, DAE WON	LG INSTITUTE, HOGYE 1(IL)-DONG, DONGAN-GU, ANYANG-SI, GYEONGGI-DO 431-080 REPUBLIC OF KOREA
6	CHO, JUNG HYUN	LG INSTITUTE, HOGYE 1(IL)-DONG, DONGAN-GU, ANYANG-SI, GYEONGGI-DO 431-080 REPUBLIC OF KOREA
7	NOH, YU JIN	LG INSTITUTE, HOGYE 1(IL)-DONG, DONGAN-GU, ANYANG-SI, GYEONGGI-DO 431-080 REPUBLIC OF KOREA

PCT International Classification Number

H03M 13/27

PCT International Application Number

PCT/KR2008/007576

PCT International Filing date

2008-12-22

PCT Conventions:

#	PCT Application Number	Date of Convention	Priority Country
1	61/021,337	2008-01-16	U.S.A.
2	61/028,016	2008-02-12	U.S.A.
3	61/016,492	2007-12-24	U.S.A.
4	10-2008-0074682	2008-07-30	U.S.A.