Low complexity turbo equalization for mobile MIMO OFDM systems

Abstract

Turbo equalization schemes based on minimum mean square error (MMSE) criteria available in the literature for multiple-input multiple-output (MIMO) systems are computationally expensive as they require a relatively large matrix inversion. In this paper, we propose a low complexity turbo-equalization scheme with successive interference cancellation for the equalization of rapidly time varying multi-path channels for orthogonal frequency division multiplexing (OFDM) based MIMO receiver systems (TE-SIC-MIMO). TE-SIC-MIMO leverages on the soft feedback symbol estimate to remove the inter-carrier interference(ICI) and co-antenna interference (CAI) from the received data thus turning the system matrix into an easily invertable form. Numerical simulation results show that TE-SIC-MIMO performs better than other schemes of comparable computation complexity at signal to noise ratios (SNR) of practical interest.