Universal space-time codes from two-dimensional trellis codes

Abstract

In the absence of accurate channel probability distribution information or in broadcast scenarios, code design for consistent channel-by-channel performance, rather than average performance, may be desirable. Root and Varaiya's compound channel theorem promises the existence of universal codes that operate with a consistent proximity to channel mutual information on any instance of the compound linear vector Gaussian channel that is similar to the capacity gap of an AWGN-specific code with similar complexity on the AWGN channel. This study presents single-dimensional trellis codes such that when multiplexed over two, three and four transmit antennas, provide universal performance over the compound linear vector Gaussian channel. As a result of their channel-by-channel consistency, the universal trellis codes presented here deliver comparable or in some cases superior frame-error-rate and bit-error-rate performance under quasistatic Rayleigh fading to trellis codes of similar complexity that are designed specifically for the quasistatic Rayleigh fading scenario.