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 Code Tracking Algorithms for Mitigating Multipath Effects in Fading Channels for Satellite-Based Positioning | Hindawi Publishing Corporation EURASIP Journal on Advances in Signal Processing Volume 2008 Article ID 863629 17 pages doi 2008 863629 Research Article Code Tracking Algorithms for Mitigating Multipath Effects in Fading Channels for Satellite-Based Positioning Mohammad Zahidul H. Bhuiyan Elena Simona Lohan and Markku Renfors Institute of Communications Engineering Tampere University of Technology . Box 553 33101 Tampere Finland Correspondence should be addressed to Elena Simona Lohan Received 28 February 2007 Accepted 30 September 2007 Recommended by Richard J. Barton The ever-increasing public interest in location and positioning services has originated a demand for higher performance global navigation satellite systems GNSSs . In order to achieve this incremental performance the estimation of line-of-sight LOS delay with high accuracy is a prerequisite for all GNSSs. The delay lock loops DLLs and their enhanced variants . feedback code tracking loops are the structures of choice for the commercial GNSS receivers but their performance in severe multipath scenarios is still rather limited. In addition the new satellite positioning system proposals specify the use of a new modulation the binary offset carrier BOC modulation which triggers a new challenge in the code tracking stage. Therefore in order to meet this emerging challenge and to improve the accuracy of the delay estimation in severe multipath scenarios this paper analyzes feedback as well as feedforward code tracking algorithms and proposes the peak tracking PT methods which are combinations of both feedback and feedforward structures and utilize the inherent advantages of both structures. We propose and analyze here two variants of PT algorithm PT with second-order differentiation Diff2 and PT with Teager Kaiser TK operator which will be denoted herein as PT Diff2 and PT TK respectively. In addition to the proposal of the PT methods the authors propose also an .
