Study on Multipath Model of BDS/GPS Signal in Urban Canyon

Abstract

With the rapid development and application of GNSS (Global Navigation Satellite System) high precision positioning technology, multipath signal model, especially in urban canyon environment, has received much attention in academic and industrial circles. In order to get multipath model in the real urban canyon environment, the real GNSS IF signal data is collected in Shanghai typical urban canyon area. Code phase delay, carrier phase changing rate and power attenuation are selected as the multipath characteristic parameters. Then, multipath delay model, multipath power attenuation model, multipath life time model, multipath fading frequency model and multipath occurrence probability model are established by using these parameters. The independent statistic models of GEO and NGEO satellites are analyzed and compared respectively, because GEO satellites which motion is very slow is used in Beidou constellation. In addition, the difference of the statistical characteristics with different satellite elevation angle is analyzed, because multipath characteristics are sensitive to the satellite position. In this paper, statistical models of multipath characteristic parameters in urban canyon environment is studied by analyzing real signal data, which provides important reference for multipath mitigation algorithm and navigation system design.