Patent ID: 8838162

Claim:
A power control method that controls communication power to be used for cognitive radio communication, the power control method comprises: an estimating step of estimating a target value of an SNR (SN ratio) based on control information relating to interference; and an adjusting step of adjusting the communication power based on the target value of the SNR estimated by the estimating step: wherein a radio communication system that performs the cognitive radio communication includes a base station for the cognitive radio communication, a first radio communication device that can perform radio communication, and a second radio communication device that can perform the radio communication, the first radio communication device includes a radio receiver, the second radio communication device includes a radio transmitter, the power control method further comprises a transmitting step of transmitting the control information relating to the interference to the radio receiver of the first radio communication device by the base station, in the estimating step, the radio receiver of the first radio communication device estimates the target value of the SNR based on the control information and notifies the radio transmitter of the second radio communication device of a command including the target value of the SNR, in the adjusting step, the radio transmitter of second radio communication device adjusts transmission power to transmit a radio signal to the second radio communication device based on the target value of the SNR, and the first radio communication device performs the cognitive radio communication with the transmission power between the second radio communication device and the first radio communication device.