Patent ID: 6836518
Filing Date: 2004-12-28
Classification: H04L

Abstract:
A synchronization control method used in a demodulating unit, to which orthogonal frequency division multiplexed (OFDM) signal is applied, said OFDM signal including a null interval, predetermined sync symbol and a data symbol at a predetermined intervals, comprising the steps of:receiving said OFDM signal; detecting a power value of the received OFDM signal; comparing the detected power value with a first threshold value, said first threshold value being generated from an average power of said received OFDM signal; detecting said null interval based on a result of said comparison between said detected power value and said first threshold value; executing arithmetic calculations in a plurality of arithmetic calculation windows for obtaining correlation values between said received OFDM signal and a predetermined sync symbol pattern; applying a predetermined reduction to correlation values corresponding to a predetermined part of said correlation values so that the reduced correlation values of said corresponding part do not exceed a predetermined value; detecting a maximum value from said correlation values obtained in said arithmetic calculations and said reduced correction values; and detecting information of a position of said predetermined sync symbol of said OFDM signal based on a timing of said maximum value and said null interval for demodulating said received OFDM signal in said demodulating unit.