Simplified Frequency Offset Estimation for MIMO OFDM Systems

This paper addresses a simplified 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 through factor decomposition for the derivative of the cost function with great complexity reduction. The mean square error (MSE) of the CFO estimation is derived to optimize the key parameter of the simplified estimator as well as to evaluate the estimator performance. Simulation results confirm the good performance of the training-assisted CFO estimator.