| 摘要 |
PURPOSE:To eliminate the frequency variance between transmission and reception to ensure a good demodulation, by transmitting the residual carrier component with a superposition on a voice channel and a control channel and using the residual carrier component for a demodulating injection carrier. CONSTITUTION:At the transmitter side, the residual carrier components of low levels are transmitted simultaneously with a superposition on a voice channel and a control channel. At the receiver side, the arrived signal is amplified by an RF amplifier 1 and then converted into an intermediate frequency through a mixer 2 and the 1st local oscillator 8. This signal is applied to a demodulator 5 through a crystal filter 3 and an IF amplifier 4 as well as to a narrow band carrier filter 10. Thus the residual carrier of the IF band is extracted and amplified through an amplifier 11 to be injected to the demodulator 5. The lincompex signal is demodulated to the AF band by the demodulator 5 and then separated into the voice channel and the control channel by a branching filter 6, and the both signals are synthesized to reproduce an aural signal. |
