Patent ID: 7319659
Filing Date: 2008-01-15
Classification: H04L

Abstract:
1. A method for processing an RF OFDM signal transmitted from an OFDM transmitter, comprising the steps of: receiving and converting the RF OFDM signal into an IF OFDM signal; converting the IF OFDM signal into a digital OFDM signal; detecting a transmission mode and guard interval length of the OFDM signal, comprising steps of: delaying the OFDM signal for a first and second number of samples according to the transmission mode to be detected; multiplying the two delayed signals by coefficient signals, and deriving a sum of the two products; deriving an error signal by subtracting the sum of the two products from the OFDM signal; extracting amplitudes of the coefficient signals, and accordingly deriving step size signals for controlling a convergent rate and an amount of fluctuation of the coefficient signals; updating the coefficient signals according to the error signal and step size signals with least-mean-squared (LMS) algorithm; detecting edges of the amplitudes of the coefficient signals; and determining the guard interval length and transmission mode according to the detected edges; implementing digital processing of the OFDM signal in time domain and frequency domain; and implementing channel decoding and de-interleaving of the OFDM signal.