Tham khảo luận văn - đề án 'báo cáo hóa học: " research article feedback reduction in uplink mimo ofdm systems by chunk optimization"', luận văn - báo cáo phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | Hindawi Publishing Corporation EURASIP Journal on Advances in Signal Processing Volume 2008 Article ID 597072 14 pages doi 2008 597072 Research Article Feedback Reduction in Uplink MIMO OFDM Systems by Chunk Optimization Eduard Jorswieck 1 Aydin Sezgin 2 Bjorn Ottersten 1 and Arogyaswami Paulraj2 1 ACCESS Linnaeus Center Electrical Engineering KTH - Royal Institute of Technology 100 44 Stockholm Sweden 2 Information Systems Laboratory Stanford University CA 94305 USA Correspondence should be addressed to Eduard Jorswieck Received 12 June 2007 Revised 12 September 2007 Accepted 19 November 2007 Recommended by Ana Perez-Neira The performance of multiuser MIMO systems can be significantly increased by channel-aware scheduling and signal processing at the transmitters based on channel state information. In the multipleantenna uplink multicarrier scenario the base station decides centrally on the optimal signal processing and spectral power allocation as well as scheduling. An interesting challenge is the reduction of the overhead in order to inform the mobiles about their transmit strategies. In this work we propose to reduce the feedback by chunk processing and quantization. We maximize the weighted sum rate of a MIMO OFDM MAC under individual power constraints and chunk size constraints. An efficient iterative algorithm is developed and convergence is proved. The feedback overhead as a function of the chunk size is considered in the rate computation and the optimal chunk size is determined by numerical simulations for various channel models. Finally the issues of finite modulation and coding schemes as well as quantization of the precoding matrices are addressed. Copyright 2008 Eduard Jorswieck 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 cited. 1. INTRODUCTION The .
