| 摘要 |
PROBLEM TO BE SOLVED: To provide a method for estimating the carrier frequency of a digital signal which has N-pieces of states showing N-pieces of marks and which is phase-modulated. SOLUTION: The method includes prefiltering of a received signal, multiplication of the phase of the received signal by a number N, calculation of the Fourier transformation of the received signal having the phase multiplied by N and the decision of a frequency by which Fourier transformation becomes a maximum value. For deciding the value of the frequency corresponding to the maximum value of the Fourier transformation, the maximum value of the derivative of the square of the absolute value of the Fourier transformation and the value of the frequency for which the derivative becomes zero are decided. |
