Frequency-domain SC/MMSE iterative equalizer with MF approximation in LDPC-coded MIMO transmissions

Abstract

Multiple-input multiple-output (MIMO) transmission systems, exploiting multiple antennas at both Tx and Rx sides, have potential to dramatically increase the spectral efficiency in rich-scattering wireless links. At the receiver, the so-called space-time equalizer can adaptively deal with dispersive channels and jointly decode multiplexed signals. Recently, low-density parity-check (LDPC) codes have drawn lots of attention for achieving excellent error-correction performance by means of the low-complexity belief propagation (BP) algorithm. This paper explores an iterative space-time equalizer employing soft cancellation followed by frequency-domain linear filtering, and evaluates the error-rate performance in LDPC-coded MIMO transmissions over time-varying frequency-selective fading channels.