Title of Invention

SYSTEM AND METHOD TO SEND ACK/NACK WITHIN ASSIGNMENT MESSAGE FOR REVERSE LINK TRAFFIC IN A COMMUNICATION SYSTEM

Abstract

The invention describes an improved method and system to send ACK/NACK for high rate packet data transmission. According to this, ACK/NACK is encoded within the assignment message on a Forward Shared Signaling Channel (F-SSCH), which in turn saves the bandwidth separately reserved for ACK/NACK transmission and also the transmit power that would be required to send the ACK/NACK transmission and also the transmit power that would be required to send the ACK/NACK bits.

Full Text

FIELD OF THE INVENTION The present invention, in general relates to the field of communication. In HRPD Rev C specification forward shared signaling channel (F-SSCH) carries the Link assignments messages (LAM'S) for the forward and reverse traffic. F-SSCH also carries the acknowledgement of the reverse traffic. In case of non persistent assignment, the assignment is given to the AT when the assignment duration expires. The duration of the assignment is defined such that it expires, when the packet is successfully decoded or the maximum number of retransmission has expired. The art given here describes a way to improve upon encoding done for N (ACK) and assignment on F-SSCH. More particularly the invention relates to system and method to send ack / nack within assignment message for reverse link traffic in a communication system. DESCRIPTION OF PRIOR ART The prior applications related to the said invention are: 1. Framework proposal for LBC mode of Rev C C30-20060627- 054_KHLMNQRSUZJ-BC_FDD_Framework. 2. C802.20-06-04 Technical Specification. SUMMARY OF INVENTION It is observed in the harmonized proposal for the HRPD rev C and 802.20; the F- SSCH used during the RL traffic has a scope of improvement. There are 2 types of assignment Persistent and Non persistent. In case of non persistent assignment when duration of the assignment is finished, there is a need to give the RL assignment to the AT. At the same time AN needs to transmit the N(ACK) also for the RL traffic. For this purpose the F-SSCH is used. This has encoded block segment for assignment purpose and N(ACK) segment for the ACK/NACK purpose. 3 modulation symbols are used to transmit an ACK. NACK is not transmitted as the ON/OFF keying mechanism is used for this purpose. As assignment and ACK both are going to the same AT, there is a possibility to encode the N(ACK) within the assignment block. This will save the ACK node reserved for this purpose as well the transmit power needed to transmit the ACK bits. These saved sub carriers can be used for some other purpose (control or user data depending on the scheduling). Only one bit will be used for this purpose in the assignment block, while 9 bits were needed to transmit if N(ACK) segment is used. If N(ACK) is coded in assignment block less number of bits ( and hence the modulation symbols/sub carriers ) as well as less power will be needed to transmit the N(ACK). BRIEF DESCRIPTION OF ACCOMPANYING DRAWINGS Figure 1 depicts F-SSCH assignment blocks for RLAM and FLAM as specified in Harmonized proposal. Figure 2 depicts RL H-ARQ transmission timing with FDD eight interlace. Figure 3 depicts New Assignment Message having ACK-bit within the message Figure 4 depicts New Assignment Messages having New Block types. Figure 5 depicts RL H-ARQ transmission with New Assignment Messages. BRIEF DESCRIPTION OF INVENTION As specified in the harmonized proposals, the Shared Signaling Channel (F- SSCH) shall be present in each FL PHY Frame and shall includes four segments populated over hop-ports that are specified by the SS MAC Protocol. These 4 segments are called Encoded Block Segment, Acknowledgement Segment, Power Control Segment, and Fast OSI Segment. Encoded Block Segment of F-SSCH carries assignments for FL and RL traffic Resources. A selection of FL signaling messages (called "Link Assignment Message (LAM)") is shown in FIGURE 1. Columns of this table indicate different fields while rows correspond to different signaling blocks. Every cell in the table indicates multiplicity of a given field. A 3-bit block type field allows the AT to identify the type of block and therefore interpret the subsequent fields. The set of information bits of every block is extended by a 16-bit CRC to enable reliable detection. Acknowledgement Segment of F-SSCH carries acknowledgement bits for RL traffic. This segment is used to acknowledge RL H-ARQ transmissions and therefore is present in every FL PHY frame to acknowledge the associated RL PHY frame. Each acknowledgement (ACK) is a one bit message (which needs 3 modulation symbols to carry). NACK bits are encoded using on/off keying so that the absence of ACK transmission implies negative acknowledgement. Reverse link power control segment carries CQI erasure indicator bits that are used to indicate RL channel quality. Additionally, it can also carry optional power control bits for ATs that are being served on the reverse link by this sector. Fast OSI Segment is an optional segment which is used to provide other sector interference indication to an AT from sectors in its active set. In HRPD Rev-C proposal, the RL traffic mechanism is shown in the FIGURE 3 with FDD eight interlace timeline. For the RL traffic as seen in the FIGURE 2, non persistent assignment message is given at the 0th interlace then AT transmits the data packet at the 2nd interlace, 8th interlace it gives the Assignment message as well as the acknowledgement for the data packet received. Then at the 11th interlace either new data packet or the retransmitted data packet of the previous data packet is sent based on the ACK/NACK. In this method of resource assignment and ack encoding, there is a possibility to encode the N(ACK) within the assignment message. This will save the ACK node reserved for this purpose as well as power needed to transmit ACK bit. These saved sub carriers can be used for some other purpose (control or user data depending on the scheduling). Only one bit will be used for this purpose in the assignment block, while 9 bits were needed to transmit if N(ACK) segment is used. In an embodiment the new assignment message is given as shown in FIGURE 3. In this method a new one bit field is introduced in the existing link assignment messages (RLAM and FLAM both. FLAM can be used when there is forward link traffic for the same AT). This is field is shown as ACK-Bit. When ACK-bit is set to T, it shows the acknowledgement and when ACK-Bit is set to '0' it shows Negative Acknowledgement (or vice versa can be chosen). In FIGURE 5 the RL traffic of an AT with new assignment message is shown. Here First time at the 0th interlace the assignment message is given for the Data. At the 8th interlace, when the assignment is to be given to this AT in RL transfer, then new assignment message RLAM (FIGURE 3) is given, which contains assignment as well as the Acknowledgement (using ACK -Bit field). If at the 8th interlace the assignment is not given to AT in RL transfer then the ACK/NACK for this AT should be given in the ACK/NACK segment, as specified in the harmonised proposal. In another embodiment the new assignment message is shown in FIGURE 4. In this method, reserved Block Types should be used to specify the new assignment messages. This method does not require any new bit within the assignment. When AT decodes the Block Type field of the assignment message, it comes to know of the ACK/NACK based on the block type field. In FIGURE 5 the RL traffic of an AT with new assignment message is shown. Here First time at the 0th interlace the assignment message is given for the Data. At the 8th interlace, when the assignment is to be given to this AT in RL transfer, then new assignment message ACK/NACK-RLAM (FIGURE 4) is given, which contains assignment as well as the Acknowledgement (using reserved block type field). If at the 8th interlace the assignment is not given to AT in RL transfer then the ACK/NACK for this AT should be given in the ACK/NACK segment , as specified in the harmonised proposal. In short the present invention consists of the following features: 1. Giving the ACK within the assignment block in F-SSCH. 2. Saving the Sub carriers reserved for the ACK/NACK transmission by encoding the ACK/NACK within the assignment block. 3. Saving the transmit power needed to send the ACK bits in the ACK segment of the F-SSCH, by placing the ACK/NACK within encoded block segment or any other relevant place. 4. Saving the encoding of a segment or a part of segment, by encoding it into another segment within F-SSCH to reduce the redundant bits. 5. Saving the processing and decode time by doing the claim 4. ADVANTAGES 1. It saves the Nodes used for sending the ACK/NACK. For example to send one ack 3 modulation (9 bits mapped to 3 8-PSK symbols) symbols are needed. With the New art the modulation symbols needed to transmit the ack, will be much less than 3 sub carriers needed to transmit the 3 modulation symbols. Also saved sub carriers can be used for the purpose of the sending any other signaling data or the user data. AN shoud define a way to use these saved sub carriers. 2. Less power will be needed to transmit the ACK within the assignment segment, than the Ack segment. For over all system the power saved will be considerable to transmit the F-SSCH in the forward direction. 3. AT need not decode the ACK segment when ack is given within the assignment. This ACK decode processing, and time to decode the ACK can be saved in AT. GLOSSARY OF TERMS AND DEFINITIONS THEREOF HRPD High Rate Packet Data RL Reverse Link FL Forward Link RLAB Reverse Link Assignment Block FLAB Forward Link Assignment Block NS-RLAB Non Persistent Reverse Link Assignment Block NS-FLAB Non Persistent Forward Link Assignment Block AT Access Terminal AN Access Network F-SSCH Forward Shared Signaling Channel ACK Acknowledgement NACK Negative Acknowledgement We Claim, 1. A method to send ACK / NACK within assignment message for reverse link traffic in a communication system wherein ACK/NACK is encoded within the assignment message on a Forward Shared Signaling Channel (F-SSCH), which in turn saves the bandwidth separately reserved for ACK/NACK transmission and saves the transmit power that would be required to send the ACK/NACK bits. 2. A method as claimed in claim 1 wherein the said method further involves the step of giving the ACK within the assignment block in F-SSCH. 3. A method as claimed in claim 1 wherein the method involves the step of saving the Sub carriers reserved for the ACK/NACK transmission by encoding the ACK/NACK within the assignment block. 4. A method as claimed in claim 1 wherein the said method involves the step of saving the transmit power needed to send the ACK bits in the ACK segment of the F-SSCH, by placing the ACK/NACK within encoded block segment or in a relevant place. 5. A method as claimed in claim 1 wherein the said method involves saving the encoding of a segment or a part of segment, by encoding it into another segment within F-SSCH to reduce the redundant bits. 6. A method as claimed in claim 1 wherein, the Forward Shared Signaling Channel (F- SSCH) is present in an FL PHY Frame and includes segments populated over hop-ports that are specified by the SS MAC Protocol. 7. A method as claimed in claim 6 wherein the segments are Encoded Block Segment, Acknowledgement Segment, Power Control Segment, and Fast OSI Segment. 8. A method as claimed in claim 7 wherein Encoded Block Segment of F-SSCH carries assignments for FL and RL traffic Resources. 9. A method as claimed in claim 7 wherein Acknowledgement Segment of F-SSCH carries acknowledgement bits for RL traffic and is present in every FL PHY frame to acknowledge the associated RL PHY frame. 10. A method as claimed in claim 9 wherein an acknowledgement (ACK) is a one bit message and NACK bits are encoded using on/off keying. 11. A method as claimed in claim 7 wherein power control segment carries CQI erasure indicator bits that are used to indicate RL channel quality and additionally, carries optional power control bits for ATs that are being served on the reverse link. 12. A method as claimed in claim 7 wherein Fast OSI Segment is optional segment and provide other sector interference indication to an AT from sectors in its active set. 13. A system to send ACK / NACK within assignment message for reverse link traffic in a communication system wherein ACK/NACK is encoded within the assignment message on a Forward Shared Signaling Channel (F-SSCH), which in turn saves the bandwidth separately reserved for ACK/NACK transmission and saves the transmit power that would be required to send the ACK/NACK bits. 14. A method to send ACK / NACK within assignment message for reverse link traffic in a communication system substantially described particularly with reference to the accompanying drawings. 15. A system to send ACK / NACK within assignment message for reverse link traffic in a communication system substantially described particularly with reference to the accompanying drawings.

Documents:

1521-CHE-2006 AMENDED PAGES OF SPECIFICATION 26-02-2013.pdf

1521-CHE-2006 AMENDED CLAIMS 26-02-2013.pdf

1521-CHE-2006 EXAMINATION REPORT REPLY RECEIVED 26-02-2013.pdf

1521-CHE-2006 FORM-1 26-02-2013.pdf

1521-CHE-2006 FORM-13 26-02-2013.pdf

1521-CHE-2006 FORM-3 26-02-2013.pdf

1521-CHE-2006 OTHER PATENT DOCUMENT 26-02-2013.pdf

1521-CHE-2006 POWER OF ATTORNEY 26-02-2013.pdf

1521-CHE-2006 ABSTRACT.pdf

1521-CHE-2006 CLAIMS.pdf

1521-CHE-2006 CORRESPONDENCE OTHERS.pdf

1521-CHE-2006 FORM-1.pdf

1521-CHE-2006 FORM-13 13-12-2013.pdf

1521-CHE-2006 FORM-18.pdf

1521-CHE-2006 FORM-5.pdf

1521-CHE-2006 FORM-13 17-12-2013.pdf

1521-che-2006-correspondnece-others.pdf

1521-che-2006-description(provisional).pdf

1521-che-2006-drawings.pdf

1521-che-2006-form 1.pdf

1521-che-2006-form 26.pdf