Evaluation of Multipath Mitigation Technique using Software GPS Receiver

The effect of multipath is especially serious in urban area where buildings reflect GPS signal. Multipath brings about the performance degradation on many GPS applications because the presence of multipath causes the diminution of pseudorange measurement accuracy in turn position accuracy. In this paper, a multipath mitigation named weighted correlation method is implemented on software GPS receiver, in which the asymmetric correlation function is compensated by modifying the late correlation value. Asymmetry compensation is obtained as weighted sum of two correlators which have different early-late chip spaces. This structure is adopted to lessen the computation load lower keeping up performance similar to that. The performance of implemented multipath mitigation technique is evaluated using GPS signal and multipath signal generated by GPS signal generator and software GPS receiver. The test results show that the weighted correlation method gives better performance than the standard correlator and the narrow correlator.