Aspects of the present invention relate to a communication method and apparatus in a cognitive radio (CR) environment, the method including: receiving an uplink signal that is repeatedly transmitted via at least one candidate channel that is not being used; determining whether the receiving of the uplink signal is due to an existence of an incumbent user using a CR channel of the target cell; and changing the CR channel of the target cell when the receiving of the uplink signal is due to the existence of the incumbent user using the CR channel of the target cell.