Random Beamforming with Systematic Beam Selection
AuthorsJörg Wagner, Ying-Chang Liang, and Rui Zhang
ReferenceThe 17th Annual IEEE International Symposium on Personal, Indoor and Mobile Radio Communications (PIMRC ), Helsinki, Finland, Sept. 2006.
AbstractIn this paper, we propose a new random beamforming scheme for multiuser multiple-input single-output block fading channels, e.g., a wireless downlink in a cellular communication system. Unlike previous methods it achieves spatial multiplexing gain over the complete range of realistic signal-to-noise ratios (SNRs) even for moderate user numbers. The main shortcoming of the random beamforming schemes for multiple data-streams proposed so far is their interference limitation, especially under medium and high SNR. The key to mitigate this problem in our scheme is to allow feedback of each user's channel gain in each random beam. This information suffices to determine the sum-rate maximizing subset of beams and users at the base station. In this sense, our scheme, referred to as orthonormal random beamforming with systematic beam selection, can be considered as optimal among all random beamforming schemes that do not make use of additional preprocessing at the transmitter (apart from power normalization). It achieves a significant performance gain compared to previous schemes particularly for realistic SNR values.
Download this document:
Copyright Notice: © 2006 IEEE. Personal use of this material is permitted. However, permission to reprint/republish this material for advertising or promotional purposes or for creating new collective works for resale or redistribution to servers or lists, or to reuse any copyrighted component of this work in other works must be obtained from the IEEE.
This material is presented to ensure timely dissemination of scholarly and technical work. Copyright and all rights therein are retained by authors or by other copyright holders. All persons copying this information are expected to adhere to the terms and constraints invoked by each author's copyright. In most cases, these works may not be reposted without the explicit permission of the copyright holder.