| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a combined modulation method by which a millimeter wave band signal and a low frequency band signal can be efficiently multiplexed and which is simpler than a conventional method and reduces costs, and to provide a method for demultiplexing optical signals subjected to combined modulation and combined modulation type radio base station. <P>SOLUTION: The method of for subjecting optical signals to combined modulation is composed of: a central control station 2 provided with radio modulation/demodulation parts 3, 4; a radio base station 1 provided with antenna parts 13, 14; and an optical fiber 6 for connecting both stations 1, 2. When a fiber radio communication system which multiplexes a plurality of radio signals of different frequencies is utilized to optically transmit the multiplexed signal, the intensity of input light to an optical modulator 5 is modulated by using one radio signal in advance, and the intensity of the input light whose intensity is modulated is further modulated by using another radio signal in the optical modulator 5, so that the plurality of signals are multiplexed and then optically transmitted. <P>COPYRIGHT: (C)2005,JPO&NCIPI |
