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 Optimal Multiuser Zero Forcing with Per-Antenna Power Constraints for Network MIMO Coordination | Hindawi Publishing Corporation EURASIP Journal on Wireless Communications and Networking Volume 2011 Article ID 190461 12 pages doi 2011 190461 Research Article Optimal Multiuser Zero Forcing with Per-Antenna Power Constraints for Network MIMO Coordination Saeed Kaviani and Witold A. Krzymien Electrical Computer Engineeering University of Alberta and TRLabs Edmonton AB Canada T6G 2V4 Correspondence should be addressed to Witold A. Krzymien wak@ Received 31 October 2010 Accepted 12 February 2011 Academic Editor Rodrigo C. De Lamare Copyright 2011 S. Kaviani and W. A. Krzymien. 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. We consider a multicell multiple-input multiple-output MIMO coordinated downlink transmission also known as network MIMO under per-antenna power constraints. We investigate a simple multiuser zero-forcing ZF linear precoding technique known as block diagonalization BD for network MIMO. The optimal form of BD with per-antenna power constraints is proposed. It involves a novel approach of optimizing the precoding matrices over the entire null space of other users transmissions. An iterative gradient descent method is derived by solving the dual of the throughput maximization problem which finds the optimal precoding matrices globally and efficiently. The comprehensive simulations illustrate several network MIMO coordination advantages when the optimal BD scheme is used. Its achievable throughput is compared with the capacity region obtained through the recently established duality concept under per-antenna power constraints. 1. Introduction While the potential capacity gains in point-to-point 1 2 and multiuser 3 multiple-input multiple-output MIMO wireless systems are significant in cellular networks this increase is very limited due to intra- and intercell .
