GNSS Software Radio Receiver Development Platform Developed

GNSS receivers on the market today commonly used GNSS Receiver chips and CPUdesign based on digital signal processing, The design of this receiver chips internalparameters fixed and hardware architecture not easy change, the cost is high, the circuitstructure poor flexibility, not easy to expand. In some special uses of the GNSS receiver, suchas to be compatible with multiple satellite navigation and positioning system signal in GNSSreceiver, often need to change the design parameters and upgrading of different signalprocessing algorithm to improve the performance of the receiver, Using a dedicated chipGNSS receiver is difficult to adapt the special applications. Along with large scale fieldprogrammable logic gate array (FPGA) and high speed digital signal processor (DSP) insoftware radio receiver the widely application, based on the design thought of software radioGNSS receiving function effectively solve the hardware GNSS receiver poor flexibility, noteasy to expand.This paper is the FPGA and DSP, modular development of GNSS receivers based onsoftware radio development platform. Main research include the following content:First design the system solutions for GNSS software radio receiver development platform.On the basis of the system program resource analysis, determined the device type; Completedbased on FPGA+DSP GNSS software radio receiver development platform hardware design;developed platform support for GPS, GLONASS, Galileo, and BD the four systems in any ofthe three RF front-end,support realize a total of72channels correlator, support theachievement of the multi-constellation GNSS receiver.Second，realized the GNSS software radio receiver development platform of thecomponent. Completed the system clock, and the power supply system design; FPGA moduleincludes AS configuration circuit, JTAG debugging circuit, SRAM circuit, serial ports, RFcircuit and USB interface circuit; DSP modules including Flash circuit, SDRAM circuit,debugging circuit and reset circuit; The EMIF interface timing analysis, completed the EMIFregisters configuration, realize the DSP and FPGA interface circuit, completed the GNSSsoftware radio receiver hardware circuit development.Third，The single-channel GPS correlator based on DSP Builder design modules. Thecarrier implements the module under the NCO, complex phase rotation frequency, code NCO,C/A code generator, code five is a module, carrier NCO, C/A code generator and carried out adetailed analysis of frequency control, the carrier tracking frequency accuracy up to9mHZ,code precision of phase error for one-thirty second chip. Last，Completed development of GNSS receivers based on software radio developmentplatform for hardware testing and system speed. Results showed that the development ofstable and reliable platform, can achieve positioning correctly, meet the system requirements.