Patent ID: 8326336

Claim:
A Cognitive Radio (CR) apparatus for performing communication in a CR network, comprising: a communication unit configured to measure a channel estimation signal, transmit measured channel state information to a master device, and, when a Quiet Period (QP) of a reference channel arrives, make a communication channel transition to a candidate channel and perform communication through the candidate channel; and a channel information management unit configured to receive and manage the channel state information measured by the communication unit and channel information comprising the candidate channel, into which a channel transition is to be made during the QP of the reference channel, received from the master device and control channel transition of the communication unit based on the channel information, wherein channel state of the candidate channel is measured by using a channel estimation signal transmitted through the candidate channel during the QP, wherein the candidate channel is selected to the communication channel transition for the QP based on the channel state of the candidate channel.