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Tuyển tập báo cáo các nghiên cứu khoa học quốc tế ngành hóa học dành cho các bạn yêu hóa học tham khảo đề tài: Research Article An Adaptive Multipath Mitigation Filter for GNSS Applications | Hindawi Publishing Corporation EURASIP Journal on Advances in Signal Processing Volume 2008 Article ID 214815 10 pages doi 10.1155 2008 214815 Research Article An Adaptive Multipath Mitigation Filter for GNSS Applications Chung-Liang Chang and Jyh-Ching Juang Department of Electrical Engineering National Cheng Kung University Tainan 70101 Taiwan Correspondence should be addressed to Chung-Liang Chang ngj567.liang@msa.hinet.net Received 27 June 2007 Revised 15 November 2007 Accepted 5 January 2008 Recommended by Jonathon Chambers Global navigation satellite system GNSS is designed to serve both civilian and military applications. However the GNSS performance suffers from several errors such as ionosphere delay troposphere delay ephemeris error and receiver noise and multipath. Among these errors the multipath is one of the most unpredictable error sources in high-accuracy navigation. This paper applies a modified adaptive filter to reduce code and carrier multipath errors in GPS. The filter employs a tap-delay line with an Adaline network to estimate the direction and the delayed-signal parameters. Then the multipath effect is mitigated by subtracting the estimated multipath effects from the processed correlation function. The hardware complexity of the method is also compared with other existing methods. Simulation results show that the proposed method using field data has a significant reduction in multipath error especially in short-delay multipath scenarios. Copyright 2008 C.-L. Chang and J.-C. Juang. This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use distribution and reproduction in any medium provided the original work is properly cited. 1. BACKGROUND AND MOTIVATION In recent years the Global navigation satellite system GNSS has been extensively used in navigation services to provide users with information of positioning accuracy and integrity. However the performance of GNSS in navigation .