Progress In Electromagnetics Research M
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By K. Yedukondalu, A. D. Sarma, and S. S. Vemuri

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Estimation and mitigation of multipath error improves the positional accuracy of GPS. The objective of this paper is to estimate the effect of multipath interference at the receiver antenna based on both code and carrier phase measurements using Code minus Carrier (CMC) technique, and suggest a suitable method to mitigate it for static applications. Different adaptive filters such as Least Mean Squares (LMS) and various Recursive Least Squares (RLS) are considered to mitigate the error. The estimated multipath error for a typical signal is 0.8 m and 2.1 m on L1 and L2 carriers, respectively. The results due to adaptive filtering methods are encouraging and significant reduction of error (cm level) is observed. It is found that, when compared with experimental static dual frequency GPS receiver data, LMS and RLS filters give better error minimization on L1 and L2, respectively.

K. Yedukondalu, A. D. Sarma, and S. S. Vemuri, "Estimation and Mitigation of GPS Multipath Interference Using Adaptive Filtering," Progress In Electromagnetics Research M, Vol. 21, 133-148, 2011.

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