Multiple communication of CATV

CATV has multiple communications that divide the cable transmission band The coaxial cable can transmit signals of many channels at the same time, but there are not many wires separated from each other in the coaxial cable. In fact, there is only one thin wire. This method of transmitting multiple channels with one wire is called frequency division multiplexing (FDM). Each frequency band transmitted in this cable can be regarded as an independent signal transmission route. After these divided frequency bands transmit the sound and video signals, if the receiving place receives all the signals, the signals of each channel will be mixed together and cannot be used. Therefore, it is necessary to filter the radio wave through the filter to select the desired frequency band, then pick up the image and sound signals from the filtered frequency band, and amplify the signal through an amplifier to make it reappear on the TV picture. Therefore, multiple communication is an important characteristic of CATV.