Skip to content


  • Research Article
  • Open Access

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

EURASIP Journal on Wireless Communications and Networking20082007:025945

  • Received: 7 March 2007
  • Accepted: 10 October 2007
  • Published:


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.


  • Information System
  • Computational Complexity
  • Excellent Agreement
  • System Application
  • Convergence Speed


Authors’ Affiliations

Electrical Engineering Department, King Fahd University of Petroleum and Minerals, P.O.Box 1387, Dhahran, 31261, Saudi Arabia
Department of Electronics, Faculty of Engineering, University of Batna, Batna, 05000, Algeria


  1. Andrews JG: Interference cancellation for cellular systems: a contemporary overview. IEEE Wireless Communications 2005,12(2):19-29. 10.1109/MWC.2005.1421925View ArticleGoogle Scholar
  2. Buehrer RM, Correal-Mendoza NS, Woerner BD: A simulation comparison of multi-user receivers for cellular CDMA. IEEE Transactions on Vehicular Technology 2000,49(4):1065-1085. 10.1109/25.875213View ArticleGoogle Scholar
  3. Jamal K, Dahlman E: Multi-stage serial interference cancellation for DS-CDMA. Proceedings of the IEEE 46th Vehicular Technology Conference (VTC '96), April 1996, Atlanta, Ga, USA 2: 671-675.View ArticleGoogle Scholar
  4. Rasmussen LK, Lim TJ, Johansson A: A matrix-algebraic approach to successive interference cancellation in CDMA. IEEE Transactions on Communications 2000,48(1):145-151. 10.1109/26.818882View ArticleGoogle Scholar
  5. Guo D, Rasmussen LK, Sun S, Lim TJ: A matrix-algebraic approach to linear parallel interference cancellation in CDMA. IEEE Transactions on Communications 2000,48(1):152-161. 10.1109/26.818883View ArticleGoogle Scholar
  6. Johansson A-L, Rasmussen LK: Linear group-wise successive interference cancellation in CDMA. Proceedings of the IEEE 5th International Symposium on Spread Spectrum Techniques & Applications (ISSSTA '98) , September 1998, Sun City, South Africa 1: 121-126.Google Scholar
  7. Bentrcia A, Zerguine A, Sheikh AU, Benyoucef M: A new linear group-wise SIC multiuser detector. IEEE Communications Letters 2007,11(2):176-178.View ArticleGoogle Scholar
  8. Kapur A, Varanasi MK: Multiuser detection for overloaded CDMA systems. IEEE Transactions on Information Theory 2003,49(7):1728-1742. 10.1109/TIT.2003.813562MathSciNetView ArticleMATHGoogle Scholar
  9. Varga RS: Matrix Iterative Analysis. 2nd edition. Springer, Berlin, Germaany; 2000.View ArticleMATHGoogle Scholar
  10. Grant A, Schlegel C: Convergence of linear interference cancellation multiuser receivers. IEEE Transactions on Communications 2001,49(10):1824-1834. 10.1109/26.957404View ArticleMATHGoogle Scholar
  11. Junti M: Multiuser demodulation for DS-CDMA systems in fading channels, Ph.D. thesis. Department of Electrical Engineering, Oulu University, Oulu, Finland; 1998.Google Scholar
  12. Bentrcia A, Zerguine A, Sheikh AU: The effect of users' grouping on the convergence behavior of the linear group-wise SIC. Proceedings of the IEEE Region 10 Annual International Conference (TENCON '04), November 2004, Chiang Mai, Thailand 2: B501-B504.Google Scholar


© 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.