A frequency and symbol timing synchronization apparatus for orthogonal
frequency division multiplexed (OFDM) signals, and a method performed by the apparatus are provided. This apparatus includes an autocorrelation unit, a
comparator, a peak
flat detector, a
frequency offset estimator, a
frequency offset compensation unit, a cross correlation unit and a symbol timing synchronization unit. The autocorrelation unit receives data including a
synchronizing symbol made up of at least three identical
synchronizing signals, delays the received data by a predetermined
delay amount, performs autocorrelation between the received data and the delayed data, normalizes an autocorrelated value, and outputs a normalized autocorrelated value. The
comparator compares the normalized autocorrelated value with a predetermined threshold value. The peak
flat detector detects as a flat section a section where the normalized autocorrelated value is equal to or greater than the threshold value. The
frequency offset estimator estimates a frequency offset within the flat section to obtain a frequency offset value. The frequency offset compensation unit compensates for the frequency offset of a received
signal using the frequency offset value. The cross correlation unit performs cross correlation using a frequency offset-compensated
signal and a reference
signal, and normalizes the cross-correlated value to output a normalized cross-correlated value. The symbol timing synchronization unit detects a point where the cross-correlated value is maximum, and performs symbol timing
estimation, thereby performing symbol timing synchronization. In the symbol timing and frequency synchronization apparatus and method, accurate frequency synchronization can be achieved because a
large sample error can be allowed. Also, a symbol
timing error can be reduced since symbol timing synchronization is achieved using a frequency offset-compensated signal.