A resource allocation control unit is provided between the despreading process unit and the channel decoding process unit of a radio base station receiver, and a resource for a channel decoding process is allocated only when there is actually user communication data in a communication service that is not of a continuous data communication under control of the resource allocation control unit. Thereby, the number of resources of the channel decoding process unit is smaller than the number of resources for despreading processes corresponding to the number of users that can receive the services simultaneously.