A new multipath estimation method for GPS signals

An integration and frequency analysis based method was put forwarded suitable for estimating close-in GPS multipath parameters of code and carrier in low SNR (signal to noise ratio) environment. With the proposed method, the robustness of the algorithm under various SNR was obtained. The paper built the multipath model and noise model, and proposed the SNR enhancement method based on integration. Later the relationship between the sampling rate and the multipath resolution was deduced. The relationship between integration time and SNR enhancement was also deduced. Simulations validated the correctness of theoretical derivations and the low SNR multipath estimation method for both carrier and code parameters based on frequency analysis and integration. It is shown that the mew method can distinguish multipath of 0.05 C/A chips delay and estimate parameters of code and carrier in -20 dB SNR in case of 20.46 MHz sampling rate with L=30.