| 摘要 |
PURPOSE:To attain the insertion of a new data in a repeater, by summing a phase-inverted carrier to a carrier applied with FM modulation, and cancelling the modulated component. CONSTITUTION:A carrier FM-modulated with an SC signal is given to a line after n-phase modulation. After a reception signal is converted into an intermediate frequency signal at a repeater, the SC signal is demodulated. The demodulated SC signal is reversed in phase, and the resulted signal is added to a new SC signal at an adder 40. An oscillator 42 is FM-modulated with the synthesized signal and the obtained signal is synthesized with the intermediate frequency signal. As a result, an obtained output signal is transmitted from an antenna 43. This output signal has no component of the old SC signal and has the component of the new SC signal only. |
