RADIO BASE STATION APPARATUS, MOBILE TERMINAL APPARATUS AND TRANSMISSION POWER CONTROL METHOD

摘要

In order to make transmission power control of a PDCCH signal in an appropriate manner in a communication system having a system band formed with a plurality of fundamental frequency blocks, the present invention provides a radio base station apparatus having: a transmitting section configured to transmit downlink control channel signals for respective fundamental frequency blocks to a mobile terminal apparatus; and a receiving section configured to receive retransmission response signals that are transmitted in a predetermined fundamental frequency block from the mobile terminal apparatus. In the transmitting section, a transmission power control section (211) is provided to control transmission power of the downlink control channel signals based on the number of transmissions N of a downlink control channel signal transmitted from the transmitting section during a predetermined time period and information about the number of transmissions of a predetermined retransmission response signal transmitted from the mobile terminal apparatus in response to each of downlink shared channel signals associated with the downlink control channel signals transmitted during the predetermined time period.