| 摘要 |
PROBLEM TO BE SOLVED: To reduce the power consumption of a mobile communication unit, such as a cordless telephone set or a portable telephone set by controlling the transmission power of the communication unit depending on a distance away from a master station or a base station, and to activate the communication unit by a required minimum transmission power at all times. SOLUTION: An intermediate frequency amplifier(IF AMP) 12 at a receiver side of the mobile communication unit retrieves an idle channel at call connection and outputs a reception signal strength indicator RSSI signal which is proportional to the reception signal strength to detect a state of outside of a speech zone after a call is set up. A transmitter side power amplifier(PA) consists of an automatic gain control power amplifier(AGC PA) 17 and the gain of this automatic gain control power amplifier(AGC PA) 17 is automatically controlled by the RSSI signal. When the reception signal strength is high, the RSSI signal is also high in proportion thereto and causes the gain of the automatic gain control power amplifier(AGC PA) 17 to decrease. |
