| 摘要 |
PROBLEM TO BE SOLVED: To save power and reduce interference amount. SOLUTION: A 120 deg.-beam antenna 33 and an antenna means, comprising two 60 deg.-beams 27 and 28 consisting of antennas 31 and 32 and a hybrid 34 of which antenna means substantially covers the service area thereof are installed. The movement speed of a mobile station is determined from the fading pitch of radio waves received from the mobile station, and whether the mobile station is present in the direction of the beam 27 or in the direction of the beam 28 is detected from the phase difference between signals received through ports 34a and 34b of the hybrid 34 by a device 54. The result of the detection is made reference to. If the movement speed is equal to or greater than a prescribed value, a control device 26 allocates one of transmitter-receivers 37-1 to 37-L, that can perform transmission from the 120 deg.-beam antenna 33. If the movement speed is less than the specified value, the control device allocates one among transmitter-receivers 48-1 to 48-N or 43-1 to 43-M, that can transmit from the antenna beam 27 or 28, depending on the direction of the mobile station. |
