Improved 2-Step QRM-ML Block Signal Detection for Single-Carrier Transmission

A new 2-step maximum likelihood block signal detection employing QR decomposition and M-algorithm (QRM-MLBD) is proposed to further reduce the computational complexity while keeping a good bit error rate (BER) performance for the single-carrier (SC) transmission in a frequency-selective fading channel. Prior to QRM-MLBD, a computationally efficient minimum mean square error based frequency-domain equalization (MMSE-FDE) is performed to discard the symbol candidates in the tree based on the soft decision results of MMSE-FDE. We evaluate, by computer simulation, the BER performance achievable by the proposed improved 2-step QRM-MLBD and show that the proposed scheme can reduce the computational complexity compared to the previously proposed conventional 2-step QRM-MLBD while keeping the same BER performance.