TRANSMISSION POWER CONTROLLER

PURPOSE:To control transmission power at a high speed to reduce interference onto another station and to reduce power consumption. CONSTITUTION:The fluctuation of a reception level is detected by a reception level fluctuation detection section 23, and when number of times of the reception level reaching a level or below within a prescribed time exceeds a reference value, a discrimination section 24 controls switches 29, 31 to calculate P1=P2-(V2-Vt) at a transmission power calculation section 18, where P2 is a transmission power of an opposite station obtained from a demodulation output of the reception signal, V2 is a reception level from a detection section 16 and Vt is a required minimum reception level, a modulation section 19 is modulated by a signal representing the P1 to control a power amplifier 21 so that the transmission power is P1. The opposite station is controlled similarly and the transmission power is controlled corresponding to the reception level fluctuation at a high speed by the open loop control. When the reception level fluctuation is less than the reference value, the switches 29, 31 are controlled, a received addition/subtraction request value alpha and a preceding transmission power P1' are added as P1=P1'+alpha, an amplifier 21 is controlled so that the transmission power is equal to the P1, beta=Vt-V2 is calculated by an adder section 28 and the value betais used as an adder/subtractor request value and the modulation section 19 is controlled for the purpose of modulation transmission.