A receiver apparatus in a multi-user communication system and a control method are provided. The receiver apparatus includes a multi-user detector for creating a soft decision value by using multiple received signals and priori information output from a prior iteration, and a channel decoder for performing local iterative decoding on the soft decision value created by the multi-user detector, and updating the soft decision value. The receiver apparatus also includes a global decoding controller for checking the soft decision value updated by the channel decoder, and controlling whether or not to perform global iterative decoding. Accordingly, it is possible to minimize a processing time delay and to reduce the complexity through an interference cancellation processing for multiple user signals and an iterative decoding processing, and also it is possible to minimize the decoding delays of user signals by processing soft decision values for multiple user signals as many as a predetermined number of decoding iterations before terminating.