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: Adaptive Downlink Resource Allocation Strategies for Real-Time Data Services in OFDM Cellular Systems | Hindawi Publishing Corporation EURASIP Journal on Wireless Communications and Networking Volume 2006 Article ID 17526 Pages 1-11 DOI WCN 2006 17526 Adaptive Downlink Resource Allocation Strategies for Real-Time Data Services in OFDM Cellular Systems Navid Damji and Tho Le-Ngoc Department ofECE McGill University 3480 University street Montreal Quebec Canada H3A 2A7 Received 1 October 2005 Revised 25 February 2006 Accepted 21 March 2006 This paper presents a detailed performance analysis of adaptive downlink resource allocation based on users instantaneous channel responses using power minimization PM and bandwidth constrained power minimization BCPM strategies. This study shows that in cellular systems where interference is a dominant factor the link outage performance of a resource allocation strategy varies significantly depending on the user channel parameters. In particular both analytical and simulation results indicate that the PM strategy outperforms BCPM in a mild shadowing environment. However in severe shadowing conditions this trend is reversed. This assessment holds true for both flat and frequency-selective fading. Copyright 2006 N. Damji and T. Le-Ngoc . 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 The next generation of mobile communications is envisioned to offer a multitude of services that are available and accessible anywhere and anytime. With the introduction of new multirate multi-QoS services the future networks should be designed for economic packet data transfers 1 . These services are highly asymmetrical and require high transmission bandwidth on the downlink. However due to the limitations of the available frequency spectrum its efficient use is crucial to the success of the next generation wireless networks. Novel access methods coupled with adaptive .
