Iterative Post-Successive Interference Cancellation in V-BLAST Systems

In the conventional Vertical Bell Laboratory Layered Space-Time (V-BLAST) receiver with successive interference cancellation (SIC) decoding, the diversity order for the first detected symbol is the lowest, hence its error probability dominates the overall average error probability. In this paper, a new SIC scheme is presented, called iterative post SIC (IP-SIC) that can increase the diversity order to a fixed desired value for all substreams, thereby significantly reduce the overall average error probability. The key to the technique is that after the interference from all substreams is subtracted from the received vector (the resulting vector will be referred to as the modified received vector), the detected symbol times its channel vector is added to the modified received vector one at a time and the substream is detected again. Important features of the proposed approach are the increase in diversity order and the flexibility of balancing the increase in diversity order and the suppression of remaining interference. The latter feature can be used to further reduce the average error probability. The performance and computational complexity of the proposed scheme are analyzed.