Simulation And Test Verification Of GNSS Satellite Navigation Signal Based On CUDA

Due to the widely use of the technology of navigation,demand on navigation equipment has become increasingly high.GNSS satellite navigation simulation system includes various kinds of complex scene modeling,which can provide flexible and stable testing environment for GNSS receiver.It can also accelerate the research on the related product and promote the development of the navigation industry.This paper focuses on the design of GNSS simulation interaction program and the research on the implement of CUDA parallel acceleration for navigation signal simulation algorithm.The main work includes:1.Completing the design of GNSS signal simulation system and dividing the simulator into two parts,host computer monitoring and signal generation.Establishing three main functional models: signal configuration,trajectory generation and database,in the host computer program.The functions of scene modeling,trajectory generation,visualization and data management are realized.2.GNSS IF signal simulation algorithm is designed,using GLONASS L1 signal as an example.Main error sources are discussed based on the analysis of the intermediate frequency signal model.The transmission delay is calculated at the sampling rate,while the code phase and carrier phase at any time are calculated by the time delay fitting algorithm.The doppler frequency offset is simulated by nonlinear correspondence.3.A signal generation acceleration algorithm based on CUDA is implemented,for the computation-intensive part in the process of GNSS signal simulation.The time slicing algorithm is adopted on the GPU-end,while the read-write separation scheme with double buffer is used on CPUend to speed up the signal generation.Memory allocation strategy is optimized,on the basis of CUDA memory hierarchy,for the further improvement.At last,by contrast with the simulation using the parallel algorithm and the serial,the efficiency of the acceleration algorithm is verified.4.The generated signal was tested with software and hardware receiver separately.The signal was analyzed according to the acquiring,tracking and solving results.Finally,playing and testing the signal with the vector signal generation hardware platform,then comparing the positioning result with the theoretical value.The feasibility of this scheme is verified.