Groupwise successive interference cancellation for MIMO communication systems

This paper proposes a modified detection scheme which reduces the performance gap between the V-BLAST MMSE detection algorithm and the maximum likelihood (ML) detection. In V-BLAST detection algorithm error propagation due to unreliable decision feedback severely limits the system performance. Here, we propose a new detection scheme that reduces the destructive effect of error propagation to a great extent. In our proposed detection algorithm, we have used ML detection to jointly estimate two strongest sub-streams of the transmitted data. For this purpose, we find an optimum beam-forming matrix to minimize the power of cumulative noise and the interfering sub-streams. It is shown that the proposed scheme outperforms the conventional V-BLAST MMSE algorithm with moderate increase in computational complexity. Nevertheless, our study shows that the complexity of our proposed algorithm is almost negligible compared to maximum likelihood detection.