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 On the Asymptotic Optimality of Opportunistic Norm-Based User Selection with Hard SINR Constraint | Hindawi Publishing Corporation EURASIP Journal on Advances in Signal Processing Volume 2009 Article ID 475273 12 pages doi 2009 475273 Research Article On the Asymptotic Optimality of Opportunistic Norm-Based User Selection with Hard SINR Constraint Xi Zhang 1 Eduard A. Jorswieck 2 Bjorn Ottersten EURASIP Member 1 and Arogyasvsami Paulraj3 1 Signal Processing Laboratory ACCESS Linnaeus Center Royal Institute of Technology KTH 10044 Stockholm SE Sweden 2 Communications Laboratory Faculty of Electrical Engineering and Information Technology Dresden University of Technology 01062 Dresden Germany 3 Information Systems Laboratory Stanford University CA 94305 USA Correspondence should be addressed to Xi Zhang Received 30 November 2008 Revised 2 April 2009 Accepted 10 June 2009 Recommended by Ana Perez-Neira Recently user selection algorithms in combination with linear precoding have been proposed that achieve the same scaling as the sum capacity of the MIMO broadcast channel. Robust opportunistic beamforming which only requires partial channel state information for user selection further reduces feedback requirements. In this work we study the optimality of the opportunistic norm-based user selection system in conjunction with hard SINR requirements under max-min fair beamforming transmit power minimization. It is shown that opportunistic norm-based user selection is asymptotically optimal as the number of transmit antennas goes to infinity when only two users are selected in high SNR regime. The asymptotic performance of opportunistic norm-based user selection is also studied when the number of users goes to infinity. When a limited number of transmit antennas and or median range of users are available only insignificant performance degradation is observed in simulations with an ideal channel model or based on measurement data. Copyright 2009 Xi Zhang et al. This is an open access article distributed under the Creative Commons Attribution .