A fast geometric decoding algorithm for MIMO systems

One of the practical challenges of Wireless communications over Multiple-input Multiple-output (MIMO) channels is to reduce the complexity of the decoding algorithm without sacrifice in performance degradation. Geometric decoding (GD) is an emerging technique which can offer substantially lower complexity while maintaining about the same error rate as that of Maximum likelihood (ML) decoding. In this paper we propose a fast GD algorithm which uses a hyper ellipsoid to reduce the searching region. Simulation results on different MIMO systems transmitting 64QAM show that the proposed GD algorithm can achieve about the same error-rate performance as an ML decoder, yet having less than 5% of the decoding complexity of an ML decoder.