A Low Complexity Soft-output QRD-M Algorithm For MIMO-OFDM Systems

In this paper, a low-complexity soft-output QRD-M detection algorithm is proposed for high-throughput Multiple-input multiple-output (MIMO) systems. By employing novel expansion and sorting scheme, the proposed algorithm can greatly reduce the numbers of the fundamental operations during the tree search process, especially the comparison operations which play a key role in the QRD-M detector' computational complexity. Furthermore, the proposed algorithm can yield the Log-likelihood ratio (LLR) values of the coded bits without any additional likelihood function or an appropriate constant. Simulation results show that the proposed algorithm can achieve a near-ML detection performance under TGn channel Models.