There is provided a transmitting apparatus in a broadband wireless communication system in which a control channel generator generates a control channel that includes an user information and a resource group information allocated to the user based on position and number of at least one predetermined resource unit included in the resource group which consists of at least one predetermined resource unit and a channel generator for allocating the data to resources according to the control channel, and a method thereof. Also, there is provided a receiving apparatus in response to the transmitting apparatus and a method thereof.