Design Of GNSS Receiver Hardware Platform Based On ZYNQ Architecture

As a space-based wireless navigation system,Global Navigation Satellite System(GNSS)has the ability of all-weather,global,continuous and high-precision three-dimensional positioning,speed measurement and time measurement,which is widely used in civil and military fields.The user receiver is an indispensable equipment in the application of satellite navigation technology.The user realizes the utilization of satellite resources through the receiver.This paper designs a GNSS receiver hardware platform based on ZYNQ architecture,which can support the signal access and processing of GPS,Beidou,GLONASS,and Galileo satellite navigation systems.It has the advantages of miniaturization,light weight and low cost.The baseband digital signal processing module and the navigation and positioning solution module of the hardware platform are integrated in the XC7Z02CLG400 chip of the ZYNQ series.The chip integrates dual core ARM Processor and FPGA,which can realize both hardware programming and software programming.Therefore,the hardware platform can be integrated with other hardware to form a practical product,and can also be used for the demonstration and verification of the algorithm scheme.Firstly,this paper studies the GNSS signal system.Based on the detailed analysis of the satellite signal characteristics of each frequency band,it summarizes the composition of the user receiver and the functions performed by each part,which provides the basis for the determination of the scheme and the subsequent functional test of the receiver hardware platform to correctly and reasonably configure the RF front-end.Secondly,the requirements and design requirements of the receiver hardware platform are analyzed,and the scheme of the receiver hardware platform is designed according to the analysis results.In the design of hardware platform,the RF front-end uses four MAX2771 chips to realize the RF front-end circuit of multi satellite signal input;the baseband digital signal processing module and navigation solution module are integrated in a microprocessor,and all components are industrial devices.In the design of power module,the requirements of core processor and RF front-end chip are fully considered.Different types of voltage stabilizing chips are used to design different output power circuits and control the starting sequence of power circuits.The storage device of receiver hardware platform includes flash and DDR3 SDRAM.Flash circuit is used to store ephemeris and solidify program,which provides hardware conditions for receiver hot start and installation of operating system.DDR3 SDRAM part of the circuit uses two DDR3 chips to form a 32 bit data interface circuit,which improves the speed of the receiver navigation solution.Thirdly,according to the designed circuit schematic,the design of high-speed 10 layer PCB is completed.In the design process,the influences of electromagnetic interference,electromagnetic compatibility,signal integrity and power integrity on the performance of printed circuit board shall be fully considered.A reasonable stack structure shall be designed,and the polar Si 9000 software shall be used for the design of characteristic impedance.After reasonable layout,wiring,and negative layer division,the receiver printed circuit board design was completed.Finally,the hardware platform of the receiver is debugged and tested to verify the correctness and practicability of the project and work results.First of all,test and debug the working voltage,peripheral communication interface and data storage of the receiver.After the hardware debugging of the receiver,the thesis carries out the if data acquisition experiment to verify the correctness of the design of the RF front-end circuit of the receiver,and through the simulation verification,the collected satellite data can be used for navigation and positioning;then the hardware platform of the receiver is tested and the positioning results are output through the upper computer software,and the results show that the hardware platform of the receiver meets the working requirements.