An Efficient Code-Timing Estimator for DS-CDMA Systems over Resolvable Multipath Channels

Liu, Jianhua; Li, Jian

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EURASIP Journal on Applied Signal Processing
Volume 2005 (2005), Issue 5, Pages 670-682
doi:10.1155/ASP.2005.670

An Efficient Code-Timing Estimator for DS-CDMA Systems over Resolvable Multipath Channels

Jianhua Liu¹ and Jian Li²

¹College of Engineering, Embry-Riddle Aeronautical University, 600 S. Clyde Morris Boulevard, Daytona Beach 32114, FL, USA
²Department of Electrical and Computer Engineering, University of Florida, P.O. Box 116130, Gainesville 32611-6130, FL, USA

Received 31 July 2003; Revised 26 March 2004

Copyright © 2005 Jianhua Liu and Jian Li. 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.

Abstract

We consider the problem of training-based code-timing estimation for the asynchronous direct-sequence code-division multiple-access (DS-CDMA) system. We propose a modified large-sample maximum-likelihood (MLSML) estimator that can be used for the code-timing estimation for the DS-CDMA systems over the resolvable multipath channels in closed form. Simulation results show that MLSML can be used to provide a high correct acquisition probability and a high estimation accuracy. Simulation results also show that MLSML can have very good near-far resistant capability due to employing a data model similar to that for adaptive array processing where strong interferences can be suppressed.