Dynamic GPS receiver carrier-wave Doppler analysis and loop tracking performance test

Against the problem that the ordinary GPS receiver can not work normally under the dynamic conditions of the cannon-launched guided ammunition, this paper adopts SPIRENT satellite signal simulator to analyze the carrier-wave Doppler frequency and its variation rate under several dynamic conditions, and generate the satellite signal under different dynamic status conditions of the carrier. A software receiver is utilized to perform the test to analyze on the performances of the tracking loop adopting the second-order and third-order phase-locked loops (PLL), the second-order PLL assisted by the first-order frequency-locked loop (FLL), and the third-order PLL assisted by the second-order FLL. It shows that when the acceleration is 40g, only PLL will lose lock, while the PLL assisted by the FLL tracks normally. However, in ballistic environment, the second-order PLL assisted by the first-order FLL tracks normally by one channel, the third-order PLL assisted by the second-order FLL tracks normally by two channels. This paper puts forward an improvement proposal for the carrier-wave tracking loop.