tailieunhanh - Báo cáo hóa học: " Research Article Cross-Layer Admission Control Policy for CDMA Beamforming Systems"

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 Cross-Layer Admission Control Policy for CDMA Beamforming Systems | Hindawi Publishing Corporation EURASIP Journal on Wireless Communications and Networking Volume 2007 Article ID 14562 15 pages doi 2007 14562 Research Article Cross-Layer Admission Control Policy for CDMA Beamforming Systems Wei Sheng and Steven D. Blostein Department of Electrical and Computer Engineering Queen s University Walter Light Hall 19 Union Street Kingston Ontario Canada K7L 3N6 Received 31 October 2006 Revised 24 June 2007 Accepted 1 August 2007 Recommended by Robert W. Heath Jr. A novel admission control AC policy is proposed for the uplink of a cellular CDMA beamforming system. An approximated power control feasibility condition PCFC required by a cross-layer AC policy is derived. This approximation however increases outage probability in the physical layer. A truncated automatic retransmission request ARQ scheme is then employed to mitigate the outage problem. In this paper we investigate the joint design of an AC policy and an ARQ-based outage mitigation algorithm in a cross-layer context. This paper provides a framework for joint AC design among physical data-link and network layers. This enables multiple quality-of-service QoS requirements to be more flexibly used to optimize system performance. Numerical examples show that by appropriately choosing ARQ parameters the proposed AC policy can achieve a significant performance gain in terms of reduced outage probability and increased system throughput while simultaneously guaranteeing all the QoS requirements. Copyright 2007 W. Sheng and S. D. Blostein. 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 a code division multiple access CDMA system quality-of-service QoS requirements rely on interference mitigation schemes and resource management such as power control multiuser detection and admission control AC 13 . .