Simulation And Test Verification Of Galileo Satellite Navigation Signal Based On GPU

The introduction of emerging signal system enhances the acquisition and tracking performance of Galileo satellite navigation signals,making Galileo system become the hotspot in the field of satellite navigation.Galileo satellite navigation signal simulator with great research value can provide flexible and stable runtime debugging environment for Galileo receiver and promote performance testing of the emerging signaling system.This paper focuses on Galileo E1 band signal simulation algorithm and GPU parallel acceleration research,the main work includes:1.Based on the vector signal generator,completing the system design of Galileo signal simulator and dividing the Galileo signal simulator into two parts: signal generation and signal playback.The collaborative CPU+GPU approach is adopted to speed up the generation of signal files.Signal mapping and sampling rate conversion are realized through FPGA programming.2.Galileo IF signal simulation algorithm is designed in this paper.Based on the analysis of the internal IF signal model of the receiver,the main error source in signal transmission process is discussed,and the exact transmission delay is calculated at the sampling time;the code phase and carrier phase at any time are calculated by the time delay fitting algorithm,and doppler frequency offset is simulated by non-linear correspondence;Galileo I/NAV type navigation message is constructed based on Rinex file,and CBOC modulation is generated according to code offset at the sampling time.3.For the characteristics that Galileo signal simulation algorithm is computationally intensive and contains a large number of parallel processing flows,a Galileo signal generation acceleration algorithm based on GPU is proposed.The algorithm is based on CUDA architecture.The time slicing algorithm is adopted on the GPU side to complete the thread task allocation in the time dimension.The read-write separation algorithm with double buffer is used on the CPU side to accelerate the signal file generation.Finally,the parallel algorithm is compared with the serial algorithm and the efficiency of the acceleration algorithm is verified.4.Playing and testing the signal with the help of vector signal generator hardware platform.FPGA-based signal processing algorithm is implemented.The software and hardware receiver are respectively used to verify the signal.By comparing the tracking and positioning result with the simulation theoretical value,the accuracy of the Galileo signal simulation is verified.