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 Employing Coordinated Transmit and Receive Beamforming in Clustering Double-Directional Radio Channel | Hindawi Publishing Corporation EURASIP Journal on Wireless Communications and Networking Volume 2007 Article ID 57175 10 pages doi 2007 57175 Research Article Employing Coordinated Transmit and Receive Beamforming in Clustering Double-Directional Radio Channel Chen Sun 1 Makoto Taromaru 1 and Takashi Ohira2 1 ATR Wave Engineering Laboratories 2-2-2 Hikaridai Keihanna Science City Kyoto 619-0288 Japan 2 Department of Information and Computer Sciences Toyohashi University of Technology 1-1 Hibariga-oka Toyohashi 441-8580 Japan Received 31 October 2006 Accepted 1 August 2007 Recommended by Robert W. Heath Jr. A novel beamforming BF system that employs two switched beam antennas SBAs at both ends of the wireless link in an indoor double-directional radio channel DDRC is proposed. The distributed directivity gain DDG and beam pattern correlation in DDRC are calculated. The channel capacity of the BF system is obtained from an analytical model. Using the channel capacity and outage capacity as performance measures we show that the DDG of the BF system directly increases the average signal-to-noise ratio SNR of the wireless link thus achieving a direct increase of the ergodic channel capacity. By jointly switching between different pairs of transmit Tx and receive Rx directional beam patterns towards different wave clusters the system provides diversity gain to combat against multipath fading thus reducing the outage probability of the random channel capacity. Furthermore the performance of the BF system is compared with that of a multiple-input multiple-output MIMO system that is set up using linear antenna arrays. Results show that in a low-SNR environment the BF system outperforms the MIMO system in the same clustering DDRC. Copyright 2007 Chen Sun 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 .
