Patent ID: 6731702
Filing Date: 2004-05-04
Classification: H04L

Abstract:
A null symbol position detecting method for receiving a signal and detecting a null symbol position from the received signal, wherein a unit transmission frame of the received signal has at least a null symbol at a beginning of said unit transmission frame and a plurality of transmission symbols following said null symbol, each of said plurality of transmission symbols having a guard band and a valid symbol, wherein information included in a period of said guard band is made equal to information included in said valid symbol, and wherein a length of a period of said null symbol is different than a length of a period of each of said plurality of transmission symbols, said method comprising the steps of:computing a correlation value between said received signal and a signal obtained by delaying said received signal by a time equal to a period of said valid symbol; computing a moving average for a period equal to said period of said guard band for said correlation value between said received signal and a signal obtained by delaying said received signal by a time equal to a period of said valid symbol; and detecting said null symbol position based on a variation in correlation value during a period in which the computed moving average peaks.