| 摘要 |
PURPOSE:To eliminate limitations of the manipulation and installation place of a telephone set while eliminating the need for a signal transmission line between a radio equipment and the telephone set, by applying radio transmission to information transmission between a mobile radio equipment and the telephone set. CONSTITUTION:Plural mobile radio equipments 20 share plural radio channels and a mobile radio system carrying communication out among radio telephone sets 21 by using an angle-modulated analog signal is constituted; and some or all of the modulating function, demodulating function, filter function of removing a disturbing wave, function of selecting an assigned radio channel, and control-signal transmitting and receiving function that radio equipment 20 has come into effect through digital signal processing. Transmitting-receiving branching filter 23 is provided connecting with digital modulator 22 and digital demodulator 31 of this radio equipment 20 and then coupled with base-station telephone set 11 via antenna 24 in the mobile station and antenna 25 of the telephone set. To telephone set 11, A/D converter 29 connected to transmitting-receiving branching filter 26, digital demodulator 27, D/A converter 28, and digital modulator 30 is connected. |
