Timing phase estimator overcoming Rayleigh fading for OFDM systems

A timing offset estimator robust to a Rayleigh fading channel and a fast Fourier transform (FFT) window selection algorithm that can remove inter symbol interference (ISI) are proposed for an orthogonal frequency division multiplexing (OFDM) system. Conventional algorithms using the scattered pilots for timing offset estimation only use phase information, whereas the proposed algorithm utilizes both phase and amplitude information. The use of amplitude information in the proposed algorithm means that the influence of distorted pilots due to fading becomes insignificant when estimating a timing offset. As a result, the proposed algorithm is robust to multipath fading channels and produces a superior performance with less computational complexity compared to conventional algorithms. The proposed FFT window selection algorithm based on the cyclic extension property of the OFDM structure can remove the ISI problems caused by multipath fading channels, thereby significantly improving the receiver performance without any additional computational requirements. The paper uses the DVB-T standard to evaluate the algorithms.