A SYNCRONOUS APPARATUS AND METHOD FOR TIMMING OFFSET CORRECTION IN OFDM-FDMA/CDMA/TDMA SYSTEM

摘要

A synchronizing apparatus and a method for improving timing correction performance in an OFDM(Orthogonal Frequency Division Multiplexing)-FDMA(Orthogonal Frequency Division Multiple Access)/CDMA(Code Division Multiple Access)/TDMA(Time Division Multiple Access) system are provided to obtain a timing metric for generating a peak at an exact symbol timing location by using a preamble structure where patterns are repeated three times at a time domain after IFFT(Inverse Fast Fourier Transform) during symbol timing correction of a downlink preamble, thereby preventing performance deterioration of a traffic channel caused by synchronization errors. An auto-correlator(110) calculates an auto correlation value between a received signal and a signal that the received signal is delayed as much as Np. A power detector(120) calculates a power size of the received signal in order to normalize the auto-correlation value. A timing metric/normalization unit(130) divides the auto-correlation value by the power size of the received signal and normalizes the divided value to obtain timing metric. A peak detector(140) corrects a frame start location and an initial symbol timing by searching the maximum value of the timing metric by measuring a frame as moving from an arbitrary start point as much as a sample.