Title of Invention

AN IMPROVED GLOBAL POSITIONING SYSTEM RECEIVER

Abstract

An Improved Global Positioning System Receiver that comprises of a single digital signal processor to perform correlation processing and navigation processing, facilitating easy channel configuration according to user requirements on channel configuration, and also makes it possible to change the sampling frequency in the software to interface with different manufacturers of radio frequency down converter, characterized in that, the inclusion of correlator and navigation processing is performed by a single programmable digital signal processor chip, a sampling clock that directly connects the digital signal processor to the radio frequency down converter.

Full Text

Background: Global Positioning System (GPS) receives are primarily used for navigation purpose. The device outputs position, speed and other vital navigation information. The receiver needs an antenna along with a hardware unit comprising of Radio Frequency (RF) down converter, Correlator and a Navigation Processor. The receiver gets satellite signals from the antenna; down converts in RF down converter and processes the signal in the Correlator. The measurement and correlation values from the Correlator are transmitted to a navigation processor (Digital Signal Processor or any other micro controller) for further processing. Position and other navigation information are computed in navigation processor and transmitted out in a standard format which can be used by the system integrators to develop various applications around these GPS receivers like Fleet Management System, Traffic telematics etc. Every new application conceived in these fields invariably involves the integration of GS sensor technology with one or more of the technologies from among cellular telephony, data modems, speech recognition, speech synthesis, audio/video compression, internet access etc. The GPS receiver under the invention has been designed to make steamless integration of multiple technologies feasible without any compromise in performance levels and without the need for a customized hardware. Status of the Prior Art: The traditional Global Positioning System receiver requires following hardware units for its functioning: a. Antenna b. RF down converter c. Hardware Correlator d. Navigation processor. The existing GPS Receivers are designed around a hardware correlator. The correlator is used to acquire and track the satellite signals. The correlator resides is an /Application Specific Integrated Circuit, which is a hardware chip that is customised to the needs of the correlator. The number of gates required in the Application Specific Integrated Circuit depends on the complexity of the correlator. For eg:- the number of gates required for a 12 channel correlator is about 200 000 which is twice the gates requied for a 6 channel correlator. The traditional Global Positioning System receiver uses a specific Radio Frequency down converter for a specific correlator. Problems with the Prior Art: The correlator in the traditional GPS receivers, based on the Application Specific Integrated Circuit has several drawbacks. • It requires the usage of 4 hardware units. This makes the Global Positioning System receiver a costly device, which also consumes a lot of power. • As the complexity of the correlator increases, the cost of the Application Specific Integrated Circuit increases. Thus increasing the cost of the Global Positioning System receiver as well as the power consumption. • The performance of the receiver depends mainly on the correlator. Since the correlator resides in an Application Specific Integrated Circuit, which is a customised hardware chip, it is very difficult to implement new signal processing algorithms in the correlator. This makes the traditional GPS receiver inflexible. • Since the correlator is in hardware, of the RF down converter is changed, it is very difficult to change the correlator. This makes the interface of the correlator with "all" types of RF down converter difficult and contributes to the flexibility of the system. How the invention seeks to solve the problem: In the improved Global Positioning System receiver, the correlator is included within the navigation processing unit which resides in a programmable Digital Signal Processor (DSP) chip. The invention eliminates the need of Hardware correlator, thereby making it easy to implement new signal processing algorithms. Also, the Correlator design can be easily changed in the software to interface with "any" type of RF down converter. This makes the system very flexible. As there is no hardware Correlator, the cost as well as the power consumption of the GPS receiver is reduced considerably. What features achieve this problem solving: • Under the Improved Global Positioning System receiver, the programmable DSP processor is used to realise the correlator function and Navigation processor, thereby eliminating the usage of the hardware correlator. • Under the improved Global Positioning System receiver, a sampling clock is directly connected from DSP to the. RF down converter, making it possible to change the sampling frequency in the software to interface with "any" type of RF down converter. How the present invention constitutes an improvement over what is already known: In the improved Global Positioning System receiver, the channel configuration becomes easy. It makes it easy to alter the number of instructions consumed by the programmable Digital Signal Processor. Based on the requirement, the channels can be easily programmed. This further reduces power consumption. Brittf Description of Aocompanying Drawings: The invention is regarding the inclusion of correlation and navigation functions within the navigation processing unit which resides in a programmable Digital Signal Processor chip. It also directly connects a sampling clock from DSP to the RF down converter, making it possible to change the sampling frequency in the software to interface with "any" type of Radio Frequency down converter. Explanation to tha drawings; Niunaral 1 is the Radio Frequency down converter that is connected to the Programmable Digital Signal Processor. Numeral 2 of the device is the Reference Frequency Crystal that is connected to the radio Frequency Down converter. Numeral 3 is the programmable Digital Signal Processor that is connected to Real Time Clock, Radio Frequency down converter. Serial Electricity Erasable Programmable Read only memory. Numeral 4 of the device is the Real Time Clock. Numeral 5 of the device is the Battery. Numeral 6 of the device is the Serial Electricity Erasable Programmable Read Only Memory connected to the programmable Digital Signal Processor, Numeral 7 of the device is the Byte Electrically Programmable Read Only Memory A RS232 driver connected to the programmable Digital Signal Processor, Numeral 8 of the device is The RS232 driver. In the accompanying drawing sheet 2, the chart of the functional constituents of the device. Numeral 9 is the correlator that interfaces with the hardware. Numeral 10 is the correlator manager responsible for giving outputs for Range and Doppler measurements. Numeral 11 is the Channel Manager, that controls the correlator manager. Numeral 12 is the Measurement Data processor for short listed satellites. Numeral 13 is the Satellite date Base manager that collects ephemeris and almanac data Numeral 14 is the Host communication that interfaces with Hosts such as PC. Numeral 15 is the User Computation module that gets measurements and outputs the position. Numeral 16 is the Satellite Position Computation Module that computes the satellite position required to compute user position. Numeral 17 is the Satellite Visibility Computation that generates Visible list required by Channel Manager. Numeral 18 Non Violate Memory Manager that interfaces with Non Violate Memory for storing some important parameters. Statement of Invention: This invention provides for an improved Global Positioning System Receiver that comprises of a single digital signal processor to perform correlation processing and navigation processing, facilitating easy channel configuration according to user requirements on channel configuration and also it possible to change the sampling frttquency in the software to interface with different manufacturers of radio frequency down converter, characterised in that the inclusion of correlator and navigation processing is performed by a single programmable digital signal processor chip, a sampling clock that directly connects the digital signal processor to the radio frequency down converter. WE CLAIM: 1. An Improved Global Positioning System Receiver that comprises of a single digital signal processor to perform correlation processing and navigation processing, facilitating easy channel configuration according to user requirements on channel configuration, and also makes it possible to change the sampling frequency in the software to interface with different manufacturers of radio frequency down converter, characterized in that, the inclusion of correlator and navigation processing is performed by a single programmable digital signal processor chip, a sampling clock that directly connects the digital signal processor to the radio frequency down converter. 2. An improved Global Positioning System Receiver as claimed in claim 1 wherein the correlator is an unique software eliminating need for a hardware. 3. An Improved Global Positioning System Receiver as claimed in claim 1 wherein the software correlator can receive and track signals from upto 12 satellites simultaneously. 4. An improved Global Positioning System Receiver as claimed in claim 1 wherein the change in sampling frequency is accommodated by connecting the digital signal chip processor directly to radio frequency down converter. 5. An improved Global Positioning System Receiver as illustrated in the accompanying drawings and as substantially herein described.

Documents:

0907-mas-1999 abstract-duplicate.pdf

0907-mas-1999 abstract.pdf

0907-mas-1999 claims-duplicate.pdf

0907-mas-1999 claims.pdf

0907-mas-1999 correspondence-others.pdf

0907-mas-1999 correspondence-po.pdf

0907-mas-1999 description (complete)-duplicate.pdf

0907-mas-1999 description (complete).pdf

0907-mas-1999 description (provisional).pdf

0907-mas-1999 drawings-duplicate.pdf

0907-mas-1999 drawings.pdf

0907-mas-1999 form-1.pdf

0907-mas-1999 form-19.pdf

0907-mas-1999 form-26.pdf

0907-mas-1999 form-4.pdf

0907-mas-1999 form-5.pdf

0907-mas-1999 form-6.pdf

0907-mas-1999 others.pdf