| 摘要 |
The invention relates to a method of and a circuit for digitally demodulating a suppressed-carrier amplitude-modulated signal, of two carriers having the same frequencies Fs in a phase-quadrature relationship, and having a sinusoidal reference signal which is in synchronism with said modulated signal. The method consists in determining the initial angular phase shift alpha r, between the reference signal and the sampling signal of the frequency Fe by determining the peak amplitude, as well as the sign of the reference signal and the sign of its derivative for a given sampling instant tn+m. The successive values alpha r+k phi of the angular phase shifts relative to said modulated signal are thereafter determined by successively adding the phase shift <IMAGE> The amplitudes of the modulated signal of the two quadrature sub-carriers are determined with the aid of tables containing the values of cos ( alpha r+k phi ) and sin ( alpha r+k phi ).
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