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 Accurate Bit Error Rate Calculation for Asynchronous Chaos-Based DS-CDMA over Multipath Channel | Hindawi Publishing Corporation EURASIP Journal on Advances in Signal Processing Volume 2009 Article ID 571307 12 pages doi 2009 571307 Research Article Accurate Bit Error Rate Calculation for Asynchronous Chaos-Based DS-CDMA over Multipath Channel Georges Kaddoum 1 2 Daniel Roviras 3 Pascal Charge 2 and Daniele Fournier-Prunaret2 1IRIT Laboratory University of Toulouse 2 rue Charles Camichel 31071 Toulouse cedex France 2LATTIS Laboratory University of Toulouse 135 avenue de Rangueil 31077 Toulouse cedex 4 France 3LAETITIA Laboratory CNAM Paris 292 rue Saint-Martin 75003 Paris France Correspondence should be addressed to Georges Kaddoum gkaddoum@ Received 21 January 2009 Revised 26 June 2009 Accepted 23 July 2009 Recommended by Kutluyil Dogancay An accurate approach to compute the bit error rate expression for multiuser chaosbased DS-CDMA system is presented in this paper. For more realistic communication system a slow fading multipath channel is considered. A simple RAKE receiver structure is considered. Based on the bit energy distribution this approach compared to others computation methods existing in literature gives accurate results with low computation charge. Perfect estimation of the channel coefficients with the associated delays and chaos synchronization is assumed. The bit error rate is derived in terms of the bit energy distribution the number of paths the noise variance and the number of users. Results are illustrated by theoretical calculations and numerical simulations which point out the accuracy of our approach. Copyright 2009 Georges Kaddoum et al. 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. Introduction Communication using chaos has attracted a great deal of attention from many researchers for more than a decade. Motivations of these studies remain to the .