Method and apparatus for signaling aperiodic channel state indication reference signals for LTE operation

An apparatus comprising:

• a controller that controls operations of the apparatus;
• and
• a transceiver that
• receives first aperiodic zero power channel state information reference signal configuration information of a serving cell,
• receives second aperiodic zero power channel state information reference signal configuration information of the serving cell, and
• receives downlink control information on a physical control channel in a subframe of the serving cell, where the downlink control information includes an aperiodic zero power channel state information reference signal indicator bit field that indicates a selection of one out 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.