COMMUNICATION SYSTEM USING RADIOFREQUENCY SPECTRUM

摘要

PURPOSE: To provide a system for limiting the broadcasting of information to respective subscribers by the distribution system of coaxial cables by wavelength or frequency demultiplexing the spectrum of radio frequency signals to a downstream side by surface acoustic waves and distributing the demultiplexed signals to a downstream side point. CONSTITUTION: A head end station HE1 transmits an optical carrier provided with the spectrum including plural radio frequency sub carriers through an optical fiber feeder FF1 to an optical fiber node FN1 . The photodiode receiver OPR1 of the node FN1 detects the spectrum SP1 of the RF sub carrier. For the spectrum SP1 , the respective high pass part and low pass part of the spectrum SP1 are sent through an amplifier AM1 , an HPFHF1 and an LPFLF1 to a router coupler RO1 . The coupler RO1 demultiplexes the spectrum of the sub carriers to the individual sub carriers. The different pairs of the sub carriers appear at the output ports OP1 -OPN of the router RO1 and transmission to the downstream side and an upstream side is made possible. The sub carriers are distributed through the coaxial cables CC1 -CCN to the subscribers SU1 -SUN.