MULTIICHANNEL MOBILE STATION UNIT

摘要

PURPOSE:To make a circuit simple and small-size by converting different base band frequencies into the same occupied frequency band in the terminal station unit which can perform multiplex communication. CONSTITUTION:Multiplex signals of channels CH1-24 are branched by branching circuit DV1. When CH1-12 are denoted as the A group, the A group has base band 12-60kHz converted to the same 60-108kHz as CH13-24 by demodulator DM1. This base band is further demodulated to 0-4kHz by demodulators DM2 and DM3 and is sent to terminal telephone set TEL through service trunk TRK. Channels are selected by interlocking switch RS. Since many channels are near to one another, zone designation signals are given to terminals to prevent radio interference with other mobile stations in the fixed station side, and signals based on them are generated by fixed station designation signal transmission circuit SG and are transmitted from trunk TRK together with moldulation signals.