Blind Closed-Form Carrier Frequency Offset Estimation for OFDM With Multi-Antenna Receiver

In this paper, we propose a new blind closed-form carrier frequency offset (CFO) estimator for orthogonal frequency-division multiplexing (OFDM) with a multiantenna receiver. A cost function is carefully designed for CFO estimation by using the multiple observations from the receive antennas. We prove that this cost function can be exactly expressed as a cosine function even with the effect of noise. As a result, the CFO estimate can be then obtained in closed form without any searching procedure. The proposed estimator supports fully loaded transmissions, and thus, the spectral efficiency can be saved. As compared with the existing blind maximum-likelihood (ML) estimator for multiantenna receiver, the proposed estimator can achieve comparable estimation performance with only a significantly reduced computational burden. The numerical results are provided to corroborate the proposed studies.