Low complexity fine timing synchronization method and system for stimi

A fine timing synchronization system for synchronizing a fast Fourier transform (FFT) unit of an orthogonal frequency division multiplexing (OFDM) receiver to accurately receive an OFDM signal, the OFDM signal comprising a transmission identification, synchronization symbols and at least one OFDM symbol, the system comprising:

• an equalizer having an input for receiving a signal and an output, the signal comprising a channel frequency response and a synchronization sequence having been generated by an FFT operation of a coarse timing synchronization unit, wherein the equalizer is configured to remove the synchronization sequence from the signal to obtain the CFR;
• a correlation estimator coupled to the output of the equalizer for calculating a correlation coefficient of the correlation between the CFR applied to a number of carriers and the CFR applied to the number of carriers with different window shifts, the largest window shift corresponding to a downsampling factor indicated by the lowest correlation coefficient greater than a threshold;
• a downsampler coupled to the output of the correlation estimator for obtaining the downsampling factor and coupled to the output of the equalizer for downsampling the CFR by the downsampling factor;
• an inverse FFT unit coupled to the output of the downsampler for performing an inverse fast Fourier transform on the downsampled CFR with a reduced number of calculations reduced by the downsampling factor, wherein the downsampled CFR is transformed into a channel impulse response (CIR) in the time domain;
• and
• a fine timing synchronization position unit coupled to the output of the inverse FFT unit for determining a fine timing synchronization position from the CIR, the fine timing synchronization position unit configured to provide an accurate channel power delay profile to determine window size and position of the FFT unit within the OFDM receiver, wherein the fine timing synchronization position is provided to the FFT unit within the OFDM receiver to accurately receive the at least one OFDM symbol of the OFDM signal.