高动态环境下GPS信号捕获研究

高动态环境信号的捕获是GPS接收机的关键技术,接收机处于高速运动的状态使GPS信号产生相位延迟和多普勒频移，增加了信号的捕获难度。分析了滑动相关捕获和基于FFT捕获两种算法,给出了基于FFT捕获算法的FPGA实现架构，并采用GPS信号仿真器对该设计的可行性进行了捕获验证。结果表明：在导航星相对载体的速度为1 000m/s，加速度为5g的情况下，基于FFT捕获算法可以实现信号的可靠捕获。

Research on GPS Signal Acquisition Algorithm in High Dynamic environment

Signal capture in dynamic environment is the key technology of the Global Positioning System（ GPS） receiver. The phase delay of GPS signal and doppler frequency shift are produced by the receiver within a state of high speed movement, and the signal capture difficulty is increased. Two algorithms including FFT capturing and sliding relative to capture are analyzed. The FPGA implementation architecture based on FFT capturing algorithm is given,and the GPS signal simulator is adopted to verify the feasibility of the design which can capture signal. The results show that capture based on FFT algorithm can realize reliable signal capture in the navigation astrology for carrier rate of 1000 m/s and acceleration of 5g cases.