Patent ID: 7043271

Claim:
A radio communication system comprising a base station for performing radio communication with a radio communication terminal; and a control station connected to the base station via an optical transmission line, said base station comprising: a variable direction array antenna which comprises a plurality of antenna elements and which can change directivity in accordance with a position of said radio communication terminal; a base station side frequency conversion unit configured to subject received signals received from said radio communication terminal via said plurality of antenna elements to frequency conversion to different bands; a sub-carrier multiplexing signal generation unit configured to combine a plurality of signals subjected to the frequency conversion by said base station side frequency conversion unit to generate a sub-carrier multiplexing signal; and a base station side transmission means configured to transmit optical signals generated by conducting optical modulation with respect to said sub-carrier multiplexing signal to said control station via said optical transmission line, said control station comprising: a first optical/electric conversion unit configured to convert the optical signal transmitted from said base station into an electric signal; a first branching unit configured to branch the electric signal to the signals received by the plurality of antennas; control station side frequency conversion unit configured to perform the frequency conversion to obtain the signals of the same frequency band for each of the branched signals; a beam calculation unit configured to obtain a weighting coefficient to control directivity of said plurality of antenna elements; a weighting unit configured to perform weighting with respect to the branched signals of which frequencies have been converted by said control station side frequency conversion unit based on said weighting coefficient; a combiner unit configured to combine the weighted signals; and a received signal generation unit configured to demodulate the combined signals to generate a received signal.