Low-complexity MIMO detection: A mixture of ZF, ML and SIC

For multiple-input multiple-output (MIMO) spatial multiplexing systems, it is known that the maximum likelihood (ML) detector can achieve the optimal error-rate performance at the cost of high computational complexity, while the zero-forcing (ZF) detector and its variation with successive interference cancelation (SIC) attain low complexity with degraded performance. In this paper, we propose a new low-complexity MIMO detector which smartly includes ZF, ML and SIC for processing. The required computational complexity of this special mixture can be lower than that of the ordered SIC-ZF method in many cases. Importantly, simulation results show that this proposed low-complexity detector can significantly outperform the ordered SIC-ZF method in terms of the bit-error rate (BER), and own a diversity gain quite similar to that of the ML detector.