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: Spectral Efficiency of CDMA Downlink Cellular Networks with Matched Filter | Hindawi Publishing Corporation EURASIP Journal on Wireless Communications and Networking Volume 2006 Article ID 74081 Pages 1-10 DOI WCN 2006 74081 Spectral Efficiency of CDMA Downlink Cellular Networks with Matched Filter Nicolas Bonneau 1 Merouane Debbah 2 and Eitan Altman1 1 MAESTRO INRIA Sophia Antipolis 2004 Route des Lucioles . 93 06902 Sophia Antipolis France 2 Mobile Communications Group Institut Eurecom 2229 Route des Cretes 193 06904 Sophia Antipolis France Received 20 May 2005 Revised 13 October 2005 Accepted 8 December 2005 Recommended for Publication by Chia-Chin Chong In this contribution the performance of a downlink code division multiple access CDMA system with orthogonal spreading and multicell interference is analyzed. A useful framework is provided in order to determine the optimal base station coverage for wireless frequency selective channels with dense networks where each user is equipped with a matched filter. Using asymptotic arguments explicit expressions of the spectral efficiency are obtained and provide a simple expression of the network spectral efficiency based only on a few meaningful parameters. Contrarily to a common misconception which asserts that to increase spectral efficiency in a CDMA network one has to increase the number of cells we show that depending on the path loss and the fading channel statistics the code orthogonal gain due to the synchronization of all the users at the base station can compensate and even compete in some cases with the drawbacks due to intercell interference. The results are especially realistic and useful for the design of dense networks. Copyright 2006 Nicolas Bonneau 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 An important problem that arises in the design of CDMA systems concerns the deployment
