Training Aided Frequency Offset Estimation for MIMO OFDM Systems via Polynomial Rooting

In this paper, we investigate training aided frequency offset estimation for multiple-input multiple-output (MIMO) orthogonal frequency division multiplexing (OFDM) systems via polynomial rooting over frequency selective fading channels. By designing the training sequences properly, both integer and fractional carrier frequency offsets (CFO) can be estimated from the polynomials corresponding to the cost function. Moreover, we show through analysis that rooting the cost function is equivalent to rooting the first-order derivative of the cost function in the considered MIMO case. Simulation results verify the good performance of our new CFO estimator and the corresponding analytical results.