Turbo MIMO equalization and decoding in fast fading mobile coded OFDM

Abstract

Data detection of coded multiple-input multipleoutput (MIMO) orthogonal frequency division multiplexing (OFDM) in fast time-varying channels are considered. Maintaining high performance with manageable complexity relies on iterative soft-in soft-out equalization and decoding. This paper derives the optimum front-end demodulation structure by extending Ungerboeck equalizer formulation to a MIMO intercarrier interference (ICI) channel. Utilizing the fact that ICI energy is clustered in adjacent subcarriers, frequency domain equalization is made localized. This paper further proposes a computational efficient linear minimum mean square error (LMMSE) based equalization method: recursive sliding-window (SW) SIC-LMMSE equalizer. Simulation results are reported for the iterative receivers with application to the mobile worldwide interoperability for microwave access (WiMAX).