Iterative QR Detection for BLAST

We study an iterative detection algorithm of an uncoded multi-transmitter multi-receiver system. The main data stream is demultiplexed into M substreams, and each substream is modulated independently then transmitted by its dedicated antenna. The receiver disposes of N ≥ M antennas. Over each receive antenna the signal is a superposition of the M substreams affected by independent fades and disturbed by AWGN. The detection algorithm is based on the QR decomposition of the channel transfer matrix which is then used to perform hard or soft inter-substream interference cancellation. Comparisons are done with the V-BLAST optimal order (OPT) detection algorithm. The proposed algorithm is 4 to 8 times less complex than the V-BLAST OPT, and maintains comparable performance. 1