Patent ID: 7337109

Claim:
A multiple step-sized levels adaptive method for time scaling to synthesize an S 3 [n] signal from an S 1 [n] signal and an S 2 [n] signal, the method comprising: (a) calculating a temporary magnitude of a cross-correlation function of the S 1 [n] signal and the S 2 [n] signal according to a temporary index; (b) comparing the temporary magnitude with a threshold value; (c) if the temporary magnitude is smaller than the threshold value, calculating a first reference magnitude of the cross-correlation function of the S 1 [n] signal and the S 2 [n] signal according to a first reference index lagging the temporary index by a first determined number, or calculating a second reference magnitude of the cross-correlation function of the S 1 [n] signal and the S 2 [n] signal according to a second reference index lagging the temporary index by a second number; and (d) synthesizing the S 3 [n] signal by weighting the S 1 [n] signal and adding the weighted S 1 [n] signal to an S 4 [n] signal that lags the S 2 [n] by a maximum index corresponding to a largest magnitude among all of the magnitudes calculated in step (c), wherein the S 1 [n] signal has N 1 elements while the S 2 [n] signal has N 2 elements, and the S 3 [n] signal =the S 1 [n] signal, where 0<=n<the maximum index; =(N 1 −n)/(N 1 −the maximum index)*S 1 [n]+(n−the maximum index)/(N 1 −the maximum index)*S 4 [n−the maximum index], where the maximum index <=n<N 1 ; =S 4 [n−the maximum index], where N 1 <=n<=N 2 −the maximum index.