First aperiodic zero power channel state information reference signal configuration information of a serving cell can be transmitted. Second aperiodic zero power channel state information reference signal configuration information of the serving cell can be transmitted. Downlink control information can be transmitted in a subframe of the serving cell. The downlink control information can include an aperiodic zero power channel state information reference signal indicator bit field that indicates a selection of one of at least the first aperiodic zero power channel state information reference signal configuration, the second aperiodic zero power channel state information reference signal configuration, and no aperiodic zero power channel state information reference signal in the subframe.