低轨卫星捕获算法的优化与FPGA实现OA

The LEO(low earth orbit)satellite communication-navigation integrated system integrated with BDS(BeiDou navigation satellite system)can effectively improve the navigation-positioning and communication capabilities of China's satellite system.However,the high-speed motion of the LEO satellite terminal leads to greater Doppler frequency offset,which increases the difficulty of signal acquisition.In order to capture communication-navigation integrated signals fast and accurately,this paper takes the signals with greater Doppler frequency offset caused by high dynamics of LEO satellites as the research object,and verifies the optimization effect of PMF-FFT(partial matched filter-fast Fourier transform)algorithm combined with zero padding method and windowing method by the Matlab.The optimized structure can increase the capture peak value by 64.7%.Then the traditional PMF-FFT acquisition algorithm is optimized by determining the window function and the number of zero padding.The FFT module is improved to make it reconfigurable to adapt to the different number of zeros.In this paper,Verilog HDL is used to implement the optimized PMF-FFT algorithm.The correctness and effectiveness of the optimized algorithm have been confirmed by simulation waveform and experimental results from Vivado.To sum up,the proposed algorithm has more advantages in the field of UAV aerial object detection.It provides theoretical support for LEO satellite acquisition.