Stratified diagonal layered space-time architectures: signal processing and information theoretic aspects
We consider a multielement antenna system that uses M transmit and N receive antennas [an (M,N) wireless link] impaired by additive white Gaussian noise in a quasistatic flat-fading channel environment. The transmitter, which is subject to a power constraint, does not know the random outcome of the matrix channel but does know the channel statistics. The link operates under a probability of outage constraint. We present a novel architecture using stratified space-time diagonals to express a message for efficient communications. The special message arrangement, which is termed stratified-diagonal-BLAST (SD-BLAST), enables receiver signal processing that substantially mutes self interference caused by multipath without incurring waste of space-time. We investigate the proposed communication structure in important downlink categories, showing that, in theory, the message architecture is optimally efficient for all (M, 1) systems and extremely efficient when M/spl Gt/N. We quantify the capacity performance of SD-BLAST using empirically generated complementary cumulative distribution functions (CCDFs) for (16, 5), (8, 3), and (4, 2) systems to exhibit near optimal performance most especially for the (16, 5) system.