| 摘要 |
<p>Method for producing, within the receiver, a reference signal, wherein its amplitude is a function of the attenuation of the transmitted useful signal, said signal responding, within automatically controlled amplification circuits, to the same amplification laws than the useful signal, so as to derive gain control for the circuits as a function of the amplified level of said signal. The device comprises an amplitude modulator (5) for processing a pilot signal (6) through the continuous conponent of the received signal, an adder (3) for adding the modulated signal to the useful signal so as to transmit the resulting signal to the amplification circuits (7), a pilot signal filter (8) and a synchronous detection (9, 10) at the output of said filter in order to derive the gain control level from said amplification circuits (7). The method of the invention is for use in optical fibre and coaxial cable transmission.</p> |
