Signal position-based adaptive QR decompositionbased M detection algorithm for multiple-input multiple-output systems

The QR decomposition-based M (QRD-M) algorithm is a suboptimal detection algorithm that achieves near-maximum-likelihood detection (MLD) performance with low complexity. Some conventional QRD-M algorithms that directly determine the number of surviving paths have simple structures and are consequently cost effective and easy to implement. However, it is possible that surviving paths are chosen that have unnecessarily low reliability. The authors propose an algorithm, termed signal position-based QRD-M, to solve this problem using position estimation of the received signal. The position estimation process is accomplished using the most reliable candidate symbol to minimise additional processing. Computer simulations demonstrated that the proposed algorithm can achieve near-MLD performance with lower complexity than the fixed QRD-M algorithm.