tailieunhanh - Báo cáo hóa học: " Research Article Fading-Aware Packet Scheduling Algorithm in OFDM-MIMO 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 Fading-Aware Packet Scheduling Algorithm in OFDM-MIMO Systems | Hindawi Publishing Corporation EURASIP Journal on Wireless Communications and Networking Volume 2007 Article ID 95917 10 pages doi 2007 95917 Research Article Fading-Aware Packet Scheduling Algorithm in OFDM-MIMO Systems Zhifeng Diao1 and Victor O. K. Li2 1 Department of Electrical Engineering Arizona State University Tempe AZ 85287 USA 2 Department of Electrical and Electronic Engineering The University of Hong Kong Pokfulam Hong Kong Received 26 June 2006 Revised 9 December 2006 Accepted 1 February 2007 Recommended by Athina Petropulu To maximize system throughput and guarantee the quality of service QoS of multimedia traffic in orthogonal frequency division multiplexing OFDM systems with smart antennas a new packet scheduler is introduced to consider QoS requirements packet location in the frame and modulation level. In the frequency domain several consecutive subchannels are grouped as a frequency subband. Each subband in a frame can be used to transmit a packet and can be reused by several users in a multiple-input and multiple-output MIMO systems. In this paper we consider the adaptive packet scheduling algorithms design for OFDM SDMA system. Based on the BER requirements all traffics are divided into classes. Based on such classification a dynamic packet scheduler is proposed which greatly improves system capacity and can guarantee QoS requirements. Adaptive modulation is also applied in the scheduler. Then the complexity analysis of these algorithms is given. When compared with existing schedulers our scheduler achieves higher system capacity with much reduced complexity. The use of adaptive modulation further enhances the system capacity. Simulation results demonstrate that as the traffic load increases the new scheduler has much better performance in system throughput average delay and packet loss rate. Copyright 2007 Z. Diao and V. O. K. Li. This is an open access article distributed under the Creative Commons Attribution License which permits .