| 摘要 |
PURPOSE:To remarkably improve S/N at the output of a base band receiver of a master station and to considerably expand the service area by always sending a reference signal from a master station to a slave station and allowing the slave station receiving the signal to control the base band signal transmission power of its own station in response to the reception intensity. CONSTITUTION:A reference receiver 1 of the slave station receives a reference signal sent from the master station via a reception antenna 4 and the transmission output level of the base band transmitter 1 is controlled in response to the reception intensity of the input reference signal. A transmission output level controller 24 generates an AGC voltage to apply automatic control to the gain of a transmission power amplifier 13 of the base band transmitter 1 in response to the inputted envelope level thereby controlling the level of the base band signal. The AGC voltage is regulated to a quantity preset corresponding to the reference signal reception intensity so that it is large when the slave station exists near the master station and it is sufficiently small when the slave station is located sufficiently remotely from the master station. |
