Low complexity QRD-M algorithm based on LR-aided decoding for MIMO-OFDM systems

In this paper, an efficient Multiple-input multiple-output (MIMO) detection scheme with low complexity is proposed. The proposed scheme has a feature of combined a QRD-M, which is the M-algorithm combined with QR decomposition, with a complex lattice reduction (LR)-aided detection scheme. For the first T stages, the QRD-M detection is executed. And then, the complex LR-aided detection is executed for last N_t - T stages. Simulation results show that the proposed detection scheme provides comparable performance to the QRD-M detection. And this scheme can significantly reduce the computational complexity compared with the QRD-M, because the complexity for the QRDM is limited by the newly adopted parameter T. The value of T is determined by required system performance. Moreover, to detect the symbols accurately which experienced bad channel, reverse ordering is applied to the proposed scheme. In the case of reverse ordering, the proposed scheme can achieve more improved performance.