An OFDM timing recovery scheme with inherent delay-spread estimation

A new method for timing recovery and delay-spread estimation in OFDM systems is proposed. The method uses the correlation between the cyclic extension and data portion of the received OFDM symbols to estimate timing. Although cyclic extension based timing estimation methods have been proposed earlier, the present scheme is unique in the way the correlation is computed and used to estimate timing. The method identifies the complete range of ISI-free sampling positions available in an OFDM symbol, instead of identifying just one of them randomly. Further, the delay-spread information provided by the method can be used to improve the BER performance of the system by adjusting the frequency-domain interpolation filter bandwidth.