Open Access

A Chip-Level BSOR-Based Linear GSIC Multiuser Detector for Long-Code CDMA Systems

EURASIP Journal on Wireless Communications and Networking20082007:025945

https://doi.org/10.1155/2007/25945

Received: 7 March 2007

Accepted: 10 October 2007

Published: 2 January 2008

Abstract

We introduce a chip-level linear group-wise successive interference cancellation (GSIC) multiuser structure that is asymptotically equivalent to block successive over-relaxation (BSOR) iteration, which is known to outperform the conventional block Gauss-Seidel iteration by an order of magnitude in terms of convergence speed. The main advantage of the proposed scheme is that it uses directly the spreading codes instead of the cross-correlation matrix and thus does not require the calculation of the cross-correlation matrix (requires floating point operations (flops), where is the processing gain and is the number of users) which reduces significantly the overall computational complexity. Thus it is suitable for long-code CDMA systems such as IS-95 and UMTS where the cross-correlation matrix is changing every symbol. We study the convergence behavior of the proposed scheme using two approaches and prove that it converges to the decorrelator detector if the over-relaxation factor is in the interval ]0, 2[. Simulation results are in excellent agreement with theory.

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Authors’ Affiliations

(1)
Electrical Engineering Department, King Fahd University of Petroleum and Minerals
(2)
Department of Electronics, Faculty of Engineering, University of Batna

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Copyright

© A. Bentrcia et al. 2007

This article is published under license to BioMed Central Ltd. 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.