Multipath mitigation using LMS adaptive filtering for GPS applications

Global Positioning System (GPS) is a satellite based all weather navigation system. Its positional accuracy is limited by several errors including multipath. Estimation and mitigation of multipath improves the positional accuracy. The objective of this paper is to analyze the effect of multipath at the GPS receiver antenna site and suggest a suitable technique to mitigate it for static applications. An adaptive filter is considered to mitigate the error, which uses Least Mean Square (LMS) adaption algorithm. The results are encouraging and the multipath error is reduced by 99.8% for L1 and 99.7% for L2. This technique can be used to identify better location for installing base station for Differential GPS applications.