Patent ID: 7239674
Filing Date: 2007-07-03
Classification: H04L

Abstract:
1. A method of recovering a carrier frequency from an input signal, wherein the signal has 2 N possible phase states, N={0, 1, 2, . . . }, the method comprising the steps of: (a) filtering the input signal with a bandpass filter around an intermediate frequency of the signal; (b) determining a limit amplitude value by— (c) limiting any positive and negative amplitude swings of the filtered signal of step (a) to the limit amplitude value; (d) filtering the signal resulting from the preceding steps, and (e) squaring the signal resulting from step (d); (f) repeating steps (d) and (e) N−1 times; (g) transforming the signal resulting from step (f); (h) determining a peak frequency response of the signal resulting from step (g) between about 2 (i) dividing the peak frequency response by 2