一种基于压缩采样与相关幅值估计的GPS抗多径方法

A Method for GPS Multipath Mitigation Based on the Compressed Sampling and the Auto-correlation Function Amplitude Estimation

该文提出一种基于Teager-Kaiser(TK)算子压缩采样与相关幅值估计的GPS抗多径方法。首先通过TK算子对接收信号相关曲线压缩采样以获得初步的多径时延和幅度估计;然后根据所得时延和幅度以及C/A码自相关函数曲线的特征,构造出与各时延位置相对应的多径信号相关曲线,并通过对接收信号相关曲线的重构,获得对各多径信号幅度和时延的进一步估计;最后根据重构估计出的结果,得到相应直达信号(LOS)的幅度和时延估计信息,从而实现GPS接收机抗多径的目的。不同情况下的仿真结果表明,该方法抗多径性能要优于常规GPS接收机中的窄相关器,同时,考虑到TK算子时延采样取整可能带来的影响,在进行一个采样点修正的情况下,其性能可接近于高分辨率多相关器。

A method for GPS multipath mitigation is proposed. The general process of the proposed method is that first initial estimations of time delay and amplitude of each multipath are obtained by compressed sampling of the received signal with Teager-Kaiser （TK） operator, and then further estimations of the initial estimated results are got by reconstructing the received signal＇s auto-correlation curve. Finally, more precise estimates of amplitude and time delay of the Line-Of-Sight （LOS） signal can be acquired from the previous reconstruction results, and thus the goal of GPS multipath mitigation is achieved. The simulation results under different conditions show that the proposed method outperforms the narrow correlator which is often used in a conventional GPS receiver, and it can also achieve a superior performance as the high resolution correlator can when one sample interval modification is done on the TK time delay estimation results.