SUPERPOSED COMMUNICATION APPARATUS, AND COMMUNICATION SYSTEM

摘要

PROBLEM TO BE SOLVED: To stably receive a signal for high-speed communication superposed on a signal for low-speed communication even if high-speed communication is carried out by using an existing low-speed communication wiring topology. SOLUTION: In a communication system wherein communication using signals of different protocols is carried out, a superposed communication part 2 of a superposed communication device 1 transmits and receives a superposed signal wherein a signal of a second protocol is superposed on a signal of a first protocol. The signal of the first protocol is a signal to be transmitted through a communication wire W. The signal of the second protocol has a frequency higher than that of the signal of the first protocol and is superposed on the signal of the first protocol. A receiving part 21 of the superposed communication part 2 extracts the signal of the second protocol from the superposed signal by using a band pass filter 22. The cutoff frequency of the band pass filter 22 is changed by a cut-off frequency changing part 24. COPYRIGHT: (C)2010,JPO&INPIT