| 摘要 |
PURPOSE:To stabilize the center frequency of a continuous phase modulation (MSK) signal, by controlling inversion of the polarity of an in-phase component (orthogonal component) of a modulation output in accordance with an even phase point (odd phase point) obtained from an information data, and controlling the center frequency of a frequency modulator by its signal. CONSTITUTION:Digital information generated in an information source 1 is given to a voltage controlling oscillator 3 through a waveform generator 2, and an MSK signal having frequency of omega0+ or -pi/2T is generated. The outputted MSK signal is led to a multiplier 4 together with a signal of the center frequency omega0 from a reference oscillator 8, and an orthogonal component of the outputted MSK signal is derived. The derived orthogonal component is sampled by the timing showing an even phase point in a sample holding circuit 7, and is sent to an inversion controlling circuit 7. An operating circuit 10 adds and subtracts the digital information generated in the information source 1, outputs phase point information to a logical gate 11, and the gate 11 sends a noninversion and inversion control signal to the inversion controlling circuit 7 in accordance with ''0'' and a (pi) phase point. |
