A polynomial-rooting algorithm for CFO estimation in slow fading OFDM

This study proposes a polynomial-rooting algorithm to estimate the carrier-frequency-offset (CFO) of a slow fading orthogonal frequency division multiplexing (OFDM) system. The proposed algorithm uses an inter-carrier-interference self-cancellation (ICI-SC) scheme to precode data symbols at the transmitter. This study derives the time coherency of the precoded OFDM signal, which enables the proposed algorithm to estimate the CFO through array signal processing techniques. The proposed algorithm first constructs snapshot vectors using the receive time samples at specific positions. This snapshot vector is CFO-directed because of the coherent property of the precoded signal. Using the second order statistics of the snapshot vector, the proposed approach estimates the CFO through a polynomial-rooting algorithm.