Joint Frequency Offset and Channel Estimation in Frequency Selective MIMO Correlated Fading Channels

In this paper, we address the problem of frequency offset and channel gains estimation for correlated multi-input multi-output (MIMO) channels. The channel is assumed to be frequency-selective and block fading with both spatial and multipath correlations. A maximum-likelihood (ML) frequency offset (FO) estimator is proposed by using the Baysian approach and the mean and variance of the FO estimation are derived. To evaluate the performance of the FO estimator, its Cramer-Rao lower bound (CRLB) is also developed. Based on the FO estimate, we derive the linear minimum mean square error (LMMSE) channel estimator and analytically investigate the effect of frequency offset estimation error on the mean square error (MSE) performance of the channel estimator. Finally, the performances of the FO and channel estimation are evaluated by simulation results.