Transmission power controlling method and base station apparatus

A base station apparatus for a mobile communication wireless network, comprising:

• a plurality of transmitter circuits for respective user terminals;
• a plurality of transmitter circuits for common lines;
• a transmission power limiting circuit;
• and
• a radio frequency circuit, wherein:
• output signals from the transmitter circuits for respective user terminals and for common lines are added up to one output signal;
• total downlink transmission power of the added-up output signal is cut at the transmission power limiting circuit so as to be less than or equal to a specified maximum value of total downlink transmission power;
• the resultant signal is output to the radio frequency circuit;
• a value of the total downlink transmission power is notified in each time slot from the transmission power limiting circuit to the respective transmitter circuits for respective user terminals;
• and
• a value of downlink transmission power is set at the respective transmitter circuits for respective user terminals in accordance with a received transmit power control bit and the notified value of the total downlink transmission power.