An SNR-Assisted Decision-Directed RCFO Estimation Algorithm for Wireless OFDM Systems

An effect of decision errors on the decision-directed (DD) algorithm for residual carrier frequency offset (RCFO) estimation is analyzed, and a new signal-to-noise ratio (SNR)-assisted DD algorithm is proposed to estimate the RCFO in wireless orthogonal frequency-division multiplexing (OFDM) systems. In the algorithm, the received data on the subchannels with high SNRs are employed in the cross-correlation operation between the adjacent OFDM symbols, and the data of the cross correlation on the subchannels are hard decided. With these decisions and the SNR-weighted factors on the subchannels, the new algorithm estimates the RCFO in high accuracy. The simulation results indicate that the proposed scheme achieves a much better performance than the conventional DD schemes.