Patent ID: 8483330

Claim:
A method of identifying a symbol for further processing in a received signal representing a physical medium wherein the received signal may travel over more than one path, wherein the received signal comprises a continuous sequence of symbols φ 1 , φ 2 , . . . φ n , each represented by a sequence of samples X 0 , X 2 , . . . X n−1 , and wherein the symbols have a guard period GP of duration T gp at the beginning thereof, each guard period containing a cyclic prefix with the same subsequence of samples as a tail end portion of the associated symbol, the method comprising:— delaying the received signal by a fixed number of samples; computing the correlation of the received signal with the delayed signal; computing the summation of said correlation over a window of duration T i , wherein T i >T gp ; sliding said window over the correlation to find a characteristic point or region; and deriving the start of each symbol for further processing from said characteristic point or region, wherein the channel impulse response is less than the guard period T gp , and said characteristic point or region is a substantially top-flat region, and wherein the start of the symbol for further processing is derived by locating a point within said top-flat region and clear of the boundaries thereof and subtracting therefrom a fixed time value to find a point free of inter-symbol interference and clear of the boundaries where inter-symbol interference occurs.