Design optimization of iterative receivers

In this paper, we consider design optimization of low-density parity-check (LDPC) coded multiple-input multiple-output (MIMO) orthogonal frequency division multiplexing (OFDM) systems for high data rate wireless transmission. First, starting from the maximum-likelihood (ML) principle, we devise a novel expectation-maximization (EM)-based scheme for joint estimation of carrier frequency-offset (CFO) and channel coefficients in MIMO-OFDM systems. Based on simulation results, the performance of joint estimator is quite satisfying. Then, this CFO estimator is incorporated into the initialization step of the turbo receiver. Experimental results show the effectiveness of our receiver design in combating CFO over unknown frequency selective fading channels.