| 摘要 |
A digital communication system for transmitting and receiving a hybrid optical and RF communication signal. The system includes a hybrid transmitter that incorporates an optical transmitter, an RF transmitter, and a transmitter control unit that controls both transmitters. Similarly, a hybrid receiver includes an optical receiver and an RF receiver, both connected to a receiver control unit. When an optical carrier signal is transmitted to the optical receiver by the optical transmitter, the transmitter control unit causes the RF transmitter to transmit an RF synchronization signal along with the carrier to provide a timing base for the digital pulses carried by the optical signal. The receiver control unit uses the timing parameters from the RF signal to reconstruct the received optical carrier signal that may have deteriorated during the transmission due to ambient optical noise, attenuation or obstructing objects. The RF synchronization signal does not carry modulated data, and is thus a narrow bandwidth signal that occupies a small spectrum that may be shared by many such hybrid communication systems in a small area.
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