| 摘要 |
PURPOSE:To generate a waveform superimposing FSk modulating wave equivalently with a simple constitution, by performing frequency modulation to a local oscillator for frequency conversion with a waveform superimposing signal, in a waveform superimposing FSK transmitter of an offset waveform superimposing system. CONSTITUTION:An input data to be transmitted at a terminal 11 is modulated at an FSK modulator 1 and given to a superimposing waveform oscillator 2, where a superimposing waveform signal is generated. This signal is applied to a phase shifter 3 and adjusted to a prescribed relation of phase and applied to a local oscillator 7, where a local oscillating frequency frequency-modulated according to the superimposing waveform signal is obtained. An output FSK- modulated at a mixer 8 with the inputted data is frequency-modulated with the output of the oscillator 7 and given to a band pass filter 9, allowing to obtain a signal in waveform superimposing FSK modulation at a transmission frequency. |
