Evaluation of Weighted Correlator for Multipath Mitigation in GPS Receiver

Shin, Mi-Young; Jang, Han-Jin; Suh, Sang-Hyun; Park, Chan-Sik; Hwang, Dong-Hwan; Lee, Sang-Jeong

Journal of Navigation and Port Research 2007;31(5):409-414.
Published online June 30, 2007.

GPS 수신기의 다중경로 오차 제거를 위한 가중 상관기의 성능평가

신미영, 장한진, 서상현, 박찬식, 황동환, 이상정

Evaluation of Weighted Correlator for Multipath Mitigation in GPS Receiver

Mi-Young Shin, Han-Jin Jang, Sang-Hyun Suh, Chan-Sik Park, Dong-Hwan Hwang, Sang-Jeong Lee

Abstract

The effect of multipath is especially serious in urban area and sea surface where buildings and water 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 weighted correlator and the narrow correlator.

Key Words: 소프트웨어 GPS 수신기; Software GPS receiver;Multipath mitigation;Correlator-based methods;Asymmetric correlation function