Generalized Approximate Message Passing Based Turbo Frequency Domain Equalization for Single Carrier Broadband MIMO Systems

The design of soft-input soft-output Frequency Domain Equalizer (FDE) is explored by using message passing methods for MIMO Single Carrier-Cyclic Prefix (SC-CP) systems. A novel low-complexity MIMO Turbo frequency domain equalization scheme is proposed based on the Generalized Approximate Message Passing (GAMP) algorithm. This new message passing MIMO equalization approach can circumvent the problem of MIMO matrix inversion on each frequency bin involved in the conventional MIMO FDE, while retaining the merits of frequency domain equalization due to SC-CP transmission. Thus, it has a complexity that grows linearly with the number of receive antennas. Simulation results show that the proposed MIMO equalization algorithm can significantly outperform the conventional counterpart in the terms of Bit Error Rate (BER) performance.