MIMO OFDM Frequency Offset Estimator with Low Computational Complexity

This paper addresses a low complexity frequency offset estimator for multiple-input multiple-output (MIMO) orthogonal frequency division multiplexing (OFDM) systems over frequency selective fading channels. By exploiting the good correlation property of the training sequences, which are constructed from the Chu sequence, carrier frequency offset (CFO) estimation is obtained with great complexity reduction through factor decomposition for the derivative of the cost function. The CFO estimate's variance and Cramer-Rao bound (CRB) are developed to optimize the parameter of the simplified estimator and also to evaluate the estimation performance. Simulation results verify the good performance of the training-assisted CFO estimator.