Enhanced CSI feedback for FD-MIMO

An apparatus configured for wireless communication, the apparatus comprising:

• at least one processor;
• and
• a memory coupled to the at least one processor,
• wherein the at least one processor is configured to:
• receive, at a user equipment (UE), a feedback configuration signal that configures a single channel state information (CSI) process identifying azimuth and elevation CSI reference signal (CSI-RS) ports;
• transmit, by the UE, a precoding matrix indicator (PMI) report, wherein the PMI report includes a first PMI associated with the azimuth CSI-RS ports and a second PMI associated with the elevation CSI-RS ports, and a low rank indicator, wherein at least one of the first PMI and the second PMI is assigned a low rank, and wherein the low rank indicator denotes which of the first PMI or the second PMI is assigned the low rank;
• and
• transmit, by the UE, a CSI report with measurements based on the azimuth and elevation CSI-RS ports.

An apparatus for wireless communication, comprising:

• means for receiving, at a user equipment (UE), a feedback configuration signal that configures a single channel state information (CSI) process identifying azimuth and elevation CSI reference signal (CSI-RS) ports;
• means for transmitting, by the UE, a precoding matrix indicator (PMI) report, wherein the PMI report includes a first PMI associated with the azimuth CSI-RS ports and a second PMI associated with the elevation CSI-RS ports, and a low rank indicator, wherein at least one of the first PMI and the second PMI is assigned a low rank, and wherein the low rank indicator denotes which of the first PMI or the second PMI is assigned the low rank;
• and
• means for transmitting, by the UE, a CSI report with measurements based on the azimuth and elevation CSI-RS ports.