A Sphere Decoding Algorithm for MIMO Channels

Multi-input multi-output (MIMO) transmission has become a popular technique to increase spectral efficiency. Meanwhile, the design of cost-effective receivers for MIMO channels remains a challenging task. Maximum-likelihood (ML) detector can achieve superb performance, yet the computational complexity is enormously high. Receivers based on sphere decoding (SD) reach the performance of ML detectors, and potentially a great deal of computational cost can be saved. In this paper, a practical sphere-decoding algorithm is proposed. It utilizes a simple and effective way to set the initial radius which plays a decisive role in determining the computational complexity. Furthermore, a pseudo-antenna augmentation scheme is employed such that SD can be applied where the number of receive antennas is less than that of transmit antennas; thus enhance the applicability of this powerful algorithm