Channel State Information Feedback Design in Advanced Wireless Communication Systems

An apparatus in a user equipment (UE) configured to provide feedback in a wireless communication system, the apparatus comprising:

• a receiver configured to receive a first set of channel state information reference signal (CSI-RS) and a second set of CSI-RS;
• a controller configured to calculate a channel quality indicator (CQI) using a received power of the first set of CSI-RS and a channel matrix estimated based on the second set of CSI-RS;
• and
• a transmitter configured to send feedback based on the calculated CQI.

A method for providing feedback by a user equipment (UE) in a wireless communication system, the method comprising:

• measuring signals received on a plurality of channel state information reference signal (CSI-RS) ports;
• selecting a plurality of combinations of the CSI-RS ports;
• applying a plurality of precoding matrixes to each of the selected combinations of CSI-RS ports;
• calculating channel quality indicator (CQI) values for each of the applications of precoding matrixes to each of the selected combinations of CSI-RS ports;
• selecting a selected port number (SPN), a selected port index (SPI), a precoding matrix indicator (PMI) corresponding to one of the plurality of precoding matrixes, and a rank indicator (RI) that yields a highest CQI from among the calculated CQI values, wherein the SPN is a number of selected CSI-RS ports and is equal to the RI, and wherein the SPI includes indices of the selected CSI-RS ports;
• and
• sending feedback indicating the SPI, the highest CQI value, the PMI, and at least one of the SPN or the RI.

An apparatus in a user equipment (UE) configured to provide feedback in a wireless communication system, the apparatus comprising:

• a controller configured to measure signals received on a plurality of channel state information reference signal (CSI-RS) ports;
• select a plurality of combinations of the CSI-RS ports;
• apply a plurality of precoding matrixes to each of the selected combinations of CSI-RS ports;
• calculate channel quality indicator (CQI) values for each of the applications of precoding matrixes to each of the selected combinations of CSI-RS ports selection;
• and select a selected port number (SPN), a selected port index (SPI), a precoding matrix indicator (PMI) corresponding to one of the plurality of precoding matrixes, and a rank indicator (RI) that yields a highest CQI from among the calculated CQI values, wherein the SPN is a number of selected CSI-RS ports and is equal to the RI, and wherein the SPI includes indices of the selected CSI-RS ports;
• and
• a transmitter configured to send feedback indicating the SPI, the CQI, the PMI and at least one of the SPN or the RI.