tailieunhanh - Báo cáo hóa học: " Research Article Practical Radio Link Resource Allocation for Fair QoS-Provision on OFDMA Downlink with Partial Channel-State Information"

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 Practical Radio Link Resource Allocation for Fair QoS-Provision on OFDMA Downlink with Partial Channel-State Information | Hindawi Publishing Corporation EURASIP Journal on Advances in Signal Processing Volume 2009 Article ID 602856 16 pages doi 2009 602856 Research Article Practical Radio Link Resource Allocation for Fair QoS-Provision on OFDMA Downlink with Partial Channel-State Information Ayman Alsawah and Inbar Fijalkow ETIS CNRS ENSEA University Cergy-Pontoise 6 Avenue du Ponceau 95000 Cergy-Pontoise France Correspondence should be addressed to Ayman Alsawah Received 13 February 2008 Revised 6 June 2008 Accepted 22 July 2008 Recommended by Shinsuke Hara We address the problem of resource allocation on the downlink of an OFDMA single-cell system under fairness constraints with limited channel state information CSI . Target QoS corresponds to a minimum user data rate a target bit-error rate and a maximum BER-outage probability. The channel model includes path-loss shadowing and fading. The only available CSI is the channel average gain of each user. This partial CSI defines a shadowed path-loss that yields a modified user distribution. Resource allocation is based on the shadowed user distribution that we characterize analytically. Thus under the target QoS we provide the optimal resource allocation that maximizes the user rate. Compared to full-CSI-based allocation schemes our solution offers a significant complexity and feedback reduction. Finally the performance of our method is compared to other existing methods and the robustness of its outage performance to CSI errors is shown. Copyright 2009 A. Alsawah and I. Fijalkow. 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 In cellular systems service providers are interested in offering a given quality of service QoS to all users regardless of their locations in the cell. This leads to the challenging problem of resource .