Patent ID: 7603116

Claim:
A radio base station apparatus which is used in a mobile radio communication system in which a plurality of radio terminals are simultaneously call-connected and the number of radio terminals which can be connected varies depending on an amount of interference, and exchanges baseband transmission/reception signals with an external radio device which performs radio communication with the radio terminals, characterized by comprising: a plurality of channel circuits which are respectively provided for radio channels used in the mobile radio communication system, convert transmission data, which are to be transmitted to radio terminals call-connected through the radio channels, into baseband transmission signals, output the signals to the external radio device with arbitrary transmission power, and output baseband reception signals from the external radio device as reception data from the radio terminals; loopback test means for testing a transmission function or a reception function of an arbitrary channel circuit by looping back a predetermined test signal, inside the apparatus, which is output from a transmitting-side channel circuit, of said channel circuits, which serves as a transmitting side in a loopback test, and by receiving the test signal through a receiving-side channel circuit of said channel circuits which serves as a receiving side in the loopback test; and a control unit which determines transmission power for the test signal in accordance with the number of call connections of a radio terminal call-connected to said apparatus in the loopback test, and indicates the transmission power to said transmitting-side channel circuit.