AUTOMATIC GAIN CONTROL TRANSMISSION SYSTEM FORECASTING TRANSMISSION LOSS

摘要

PURPOSE:To improve the stability of a receiving signal in the fixed stations side by forecasting the transmission loss on a basis of the gain of a receiving amplifier in a mobile station for a pilot signal originated from the fixed station and controlling the level of the receiving signal in the mobile station. CONSTITUTION:The output of an antenna coil 5 is led to an amplifier 7 through a receiving signal branching filter 6, and the output is allowed to pass an automatic gain controller 8 consisting of a pilot signal extracting band-pass filter, an amplifier, a diode, etc., and the output of the amplifier 7 is controlled by the output of this controller 8, thus forming an automatic gain control circuit of the receiving signal. In case of transmission from the mobile station side to the fixed station, the receiving level in the fixed station is stabilized because a transmitting amplifier 19 is controlled by the output of the automatic gain controller 8 of said receiving signal.