| 摘要 |
PROBLEM TO BE SOLVED: To reduced the cost of a radio base station(BS) and to simplify its configuration by receiving a downlink sub carrier multiplexed(SCM) signal at the same time with transfer to an uplink from a receiving radio terminal in the BS and inserting and withdrawing an optical signal. SOLUTION: A control station(CS) 7 transmits a downlink SCM optical signal and continuous light for an uplink. In a transmitter of the CS 7, a data signal in an IF band is upconverted into a millimeter wave band by a millimeter wave local signal and subsequently applied to an optical modulator. A continuous light output of a laser beam light source whose wavelength is different is transmitted to a BS 8 by a different millimeter wave signal. In the uplink, the SCM optical signal branched by a wavelength demultiplexer in each wavelength, and subsequently, only an SCM optical signal with a specific wavelength is received and demodulated by a photodetector. Thus, a downlink SCM signal is received at the same time with the transfer to the uplink from a receiving radio terminal in the BC 8, and the optical signal is inserted and pulled down. |
