Low complexity sequence detection for MIMO ISI channel with decision feedback MLSE

A reduced complexity decision feedback maximum likelihood sequence estimation (DF-MLSE) for MIMO frequency selective fading channels has been proposed. The BER performance of the proposed algorithm is the same as for the standard MLSE, yet computational complexity is significantly reduced. For a typical MIMO system with 4 transmitter antennas and 4 receiver antennas the computational complexity reduction is 20-fold. The complexity reduction in previously proposed receivers is even higher at the cost of 2 dB SNR loss for the same BER performance as for the standard MLSE. Unlike previous approaches we are taking advantage of the a priori knowledge hidden in the time domain received signal structure to produce receivers with the same BER performance as the standard MLSE detector and significantly lower computational cost.