A method for and apparatus for performing resource allocation in a wireless communication system is provided. The apparatus includes receiving a configuration of an entire system bandwidth including a predefined system bandwidth and a carrier segment in which is allocated in not available region for the predefined system bandwidth; checking an indication to indicate whether the entire system bandwidth is available or not for the UE, and information for the entire system bandwidth in the configuration; and receiving a reference signal and a control signal at subframes determined based on the indication and the information.