Patent ID: 7684313

Claim:
A method of determining an FFT window location for reception of an OFDM signal received over a transmission channel, the OFDM signal including a plurality of symbols each having a guard interval, the method comprising acts of: a) determining, according to a correlation process, a location of maximum correlation in a first symbol of the plurality of symbols; b) determining an initial location of the FFT window; c) determining a plurality of permissible echo location options based upon the initial location of the FFT window and a pulse estimation response process, different than the correlation process; d) selecting a permissible echo location option from the plurality of permissible echo location options that corresponds most closely to the location of maximum correlation; and e) adjusting the initial location of the FFT window so that the adjusted FFT window location includes substantially all of a useful symbol length of the first symbol while a maximum number of echoes are included within the guard interval of the first symbol; wherein the acts (a) through (e) are performed on a digital signal processor-based FFT window synchronization module; and wherein the act (a) includes acts of: calculating, over a first window that is the guard interval in length and disposed in a first position, a first sum of a correlation between samples of the first symbol that are spaced apart from each other by the useful symbol length of the first symbol for each of the samples of the first symbol that are within the first window; moving the first window along the useful symbol length of the first symbol to a next position; and repeating the acts of calculating over the first window and moving the first window as the first window is moved along the useful length of the first symbol to generate a plurality of first sums corresponding to each first window position.