tailieunhanh - Báo cáo hóa học: " Joint Downlink Power Control and Multicode Receivers for Downlink Transmissions in High Speed UMTS"

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: Joint Downlink Power Control and Multicode Receivers for Downlink Transmissions in High Speed UMTS | Hindawi Publishing Corporation EURASIP Journal on Wireless Communications and Networking Volume 2006 Article ID 79148 Pages 1-10 DOI WCN 2006 79148 Joint Downlink Power Control and Multicode Receivers for Downlink Transmissions in High Speed UMTS Bessem Sayadi Stefan Ataman and Inbar Fijalkow ETIS ENSEA University of Clergy-Pontoise CNRS 6 Avenue du Ponceau 95014 Clergy-Pontoise France Received 30 September 2005 Revised 28 February 2006 Accepted 19 May 2006 We propose to combine the gains of a downlink power control and a joint multicode detection for an HSDPA link. We propose an iterative algorithm that controls both the transmitted code powers and the joint multicode receiver filter coefficients for the high-speed multicode user. At each iteration the receiver filter coefficients of the multicode user are first updated in order to reduce the intercode interferences and then the transmitted code powers are updated too. In this way each spreading code of the multicode scheme creates the minimum possible interference to others while satisfying the quality of service requirement. The main goals of the proposed algorithm are on one hand to decrease intercode interference and on the other hand to increase the system capacity. Analysis for the rake receiver joint multicode zero forcing ZF receiver and joint multicode MMSE receiver is presented. Simulation is used to show the convergence of the proposed algorithm to a fixed point power vector where the multicode user satisfies its signal-to-interference ratio SIR target on each code. The results show the convergence behavior for the different receivers as the number of codes increases. A significant gain in transmitted base station power is obtained. Copyright 2006 Bessem Sayadi 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 As .