An Improved PTA Method to Estimate the Residual Carrier Frequency Offset in Wireless OFDM Systems

An improved pilot tone aided (PTA) method to estimate the residual frequency offset (RCFO) is proposed for wireless orthogonal frequency division multiplexing (OFDM) systems. Based on the estimated SNRs of the subchannels, the cross-correlation data between adjacent OFDM symbols on the sub-channels with high quality transmissions are selected, and hard decided. The hard decisions and data on the pilot tones are used to estimate the residual frequency offset on the corresponding sub-channels respectively. Each of the estimated RCFOs is weighted by the SNR on the corresponding subchannel and combined to improve the RCFO estimation performance. The simulation results indicate that the proposed scheme achieves much better performance than the available PTA schemes.