Unified Analysis of Linear Block Precoding for Distributed Antenna Systems

Abstract

Block transmission with cyclic prefix is a promising technique to realize high-speed data rates in frequency selective fading channels. Many popular linear precoding schemes, including orthogonal frequency-division multiplexing (OFDM), single-carrier (SC) block transmission, and time-reversal (TR), can be interpreted as such a block transmission. This paper presents a unified performance analysis which shows how the optimal precoding strategy depends on the receiver type and the optimization criterion (capacity and mean-square error). We analyze three variants of TR methods (based on maximum-ratio combining, equal-gain combining and selective combining) and two-types of pre-equalization methods (zero-forcing and minimum mean-square error). As one application of our framework, we derive optimal power control for OFDM in the presence of interference limitation for distributed antenna systems; we find that without power control, OFDM does not have any capacity advantage over SC transmissions. When comparing SC and TR, we find that for single-antenna systems at high SNRs, SC has a capacity advantage; however, TR performs better in the low SNR regime. For multiple-antenna systems, TR always provides higher capacity, and the capacity of TR can approach that of optimal precoders with a number of distributed antennas. Globecom 2009This work may not be copied or reproduced in whole or in part for any commercial purpose. Permission to copy in whole or in part without payment of fee is granted for nonprofit educational and research purposes provided that all such whole or partial copies include the following: a notice that such copying is by permission of Mitsubishi Electric Research Laboratories, Inc.; an acknowledgment of the authors and individual contributions to the work; and all applicable portions of the copyright notice. Copying, reproduction, or republishing for any other purpose shall require a license with payment of fee to Mitsubishi Electric Research Laboratories, Inc. All rights reserved. Abstract-Block transmission with cyclic prefix is a promising technique to realize high-speed data rates in frequency selective fading channels. Many popular linear precoding schemes, including orthogonal frequency-division multiplexing (OFDM), single-carrier (SC) block transmission, and time-reversal (TR), can be interpreted as such a block transmission. This paper presents a unified performance analysis which shows how the optimal precoding strategy depends on the receiver type and the optimization criterion (capacity and mean-square error). We analyze three variants of TR methods (based on maximum-ratio combining, equal-gain combining and selective combining) and two-types of pre-equalization methods (zero-forcing and minimum mean-square error). As one application of our framework, we derive optimal power control for OFDM in the presence of interference limitation for distributed antenna systems; we find that without power control, OFDM does not have any capacity advantage over SC transmissions. When comparing SC ...