Symbol timing and frequency synchronizing device for OFDM signals and method thereof

摘要

The frequency and symbol timing synchronization apparatus and method of an orthogonal frequency division multiplexing (OFDM) signal is disclosed. The frequency and symbol timing synchronization apparatus at least to receive data including the three sync symbol constructed by at least the same sync signal is performed for the reception data and the autocorrelation delays by an amount predetermined delay, performs normalization by normalizing and the auto-correlation unit for outputting an auto-correlation value, a normalized autocorrelation value and a predetermined and comparator for comparing the threshold value, a normalized auto-correlation value is the peak for detecting a predetermined threshold value or larger intervals as flat (flat) section and a flat detector and the flat section estimating a frequency offset within the frequency to obtain a frequency offset value offset estimation, frequency offset compensation using the frequency offset value, perform the frequency offset compensation on a received signal portion, the frequency offset using the compensated signal and the reference signal is performed to cross-correlation, and performs normalization by normalizing Cross-correlation unit for outputting correlation difference value, and the cross-correlation value is detected, a point where the maximum and includes a symbol timing synchronization performing symbol timing synchronization by performing symbol timing estimation. Symbol timing and frequency synchronization method of the present invention has the fine frequency synchronization due to allow the sample error in size can be possible, because by using the compensation signal to the frequency offset obtained symbol timing synchronization to reduce the symbol timing error .