The present invention relates to a cognitive radio-based wireless communication system and to an air interface method in a physical layer and a data link layer, which constitute a cognitive radio-based next-generation wireless communication system.The air interface method for wireless communication in the cognitive radio-based wireless communication system of the present invention is provided in the cognitive radio-based wireless communication system including a base station system and a plurality of mobile station systems. The base station system and a certain mobile station system communicate with each other using an overlay method that uses a spectrum hole. The base station system and the mobile station system switch from the overlay method to an underlay method to communicate with each other when a paying user having high priority performs communication using the spectrum hole.