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

A method in a base station comprising:

• transmitting, from the base station to a user equipment, downlink control information containing a channel state information request on a physical control channel in a subframe of a first serving cell, the channel state information request directing the user equipment to perform channel state information measurements for at least one aperiodic channel state information reference signal of a second serving cell, where the downlink control information includes an indication of resources for the aperiodic channel state information reference signal in a subframe of the second serving cell;
• and
• receiving, from the user equipment, in another subframe, a message containing the requested channel state information.

An apparatus comprising:

• a controller that controls operations of the apparatus;
• and
• a transceiver that transmits, to a user equipment, downlink control information containing a channel state information request on a physical control channel in a subframe of a first serving cell, the channel state information request directing the user equipment to perform channel state information measurements for at least one aperiodic channel state information reference signal of a second serving cell, where the downlink control information includes an indication of resources for the aperiodic channel state information reference signal in a subframe of the second serving cell, and where the transceiver receives, from the user equipment, in another subframe, a message containing the requested channel state information.