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 Problem of Bandwidth Partitioning in FDD Block-Fading Single-User MISO/SIMO Systems | Hindawi Publishing Corporation EURASIP Journal on Advances in Signal Processing Volume 2008 Article ID 735929 13 pages doi 2008 735929 Research Article On the Problem of Bandwidth Partitioning in FDD Block-Fading Single-User MISO SIMO Systems Michel T. IvrlaC and Josef A. Nossek Lehrstuhlfur Netzwerktheorie und Signalverarbeitung Technische Universitat Munchen 80290 Munchen Germany Correspondence should be addressed to Michel T. Ivrlac ivrlac@ Received 6 November 2007 Revised 2 April 2008 Accepted 26 June 2008 Recommended by Sven Erik Nordholm We report on our research activity on the problem of how to optimally partition the available bandwidth of frequency division duplex multi-input single-output communication systems into subbands for the uplink the downlink and the feedback. In the downlink the transmitter applies coherent beamforming based on quantized channel information which is obtained by feedback from the receiver. As feedback takes away resources from the uplink which could otherwise be used to transfer payload data it is highly desirable to reserve the right amount of uplink resources for the feedback. Under the assumption of random vector quantization and a frequency flat independent and identically distributed block-fading channel we derive closed-form expressions for both the feedback quantization and bandwidth partitioning which j ointly maximize the sum of the average payload data rates of the downlink and the uplink. While we do introduce some approximations to facilitate mathematical tractability the analytical solution is asymptotically exact as the number of antennas approaches infinity while for systems with few antennas it turns out to be a fairly accurate approximation. In this way the obtained results are meaningful for practical communication systems which usually can only employ a few antennas. Copyright 2008 M. T. Ivrlac and J. A. Nossek. This is an open access article distributed under the Creative Commons Attribution .
