A high accuracy DC offset estimation scheme for OFDM based WLAN

A high accuracy direct current offset (DCO) estimator after the coarse DCO cancellation in OFDM systems is proposed based on the structure of received OFDM preamble signal in Wireless LAN (WLAN). The simulation results show that the proposed DCO estimator is able to achieve robust performance even under severe carrier frequency offset (CFO) and DCO situation. Moreover, the performance of proposed algorithm does not vary with the magnitude of DCO, and it is not vulnerable to the normalized CFO. The DCO mean square error (MSE) versus SNR of proposed algorithm is in good agreement with the analytic result, and it can provide 5dB improvement over the Yih's estimator in performance.