Method and apparatus for resource-based CSI acquisition in advanced wireless communication systems

A base station in a wireless communication system, the base station comprising:

• a transceiver configured to:
• transmit, to a user equipment (UE) configuration information for a channel state information reference signal (CSI-RS) resource set comprising CSI-RS resources, the CSI-RS resources grouped into a first group and a second group;
• and
• receive, from the UE, a CSI report including a CSI reference signal resource indicator (CRI) corresponding to at least two CSI-RS resources associated with a CSI,
• wherein the CSI report includes a rank indicator (RI) field,
• wherein the RI field corresponds to two RIs for the CSI associated with the at least two CSI-RS resources,
• wherein the RI field corresponds to a rank combination (RI1, RI2), the (RI1, RI2) being one of (1,1), (2,1), (2,1), (2,2),
• wherein the at least two CSI-RS resources are from the CSI-RS resource set,
• wherein the CSI associated with the at least two CSI-RS resources is identified based on a resource pair that consists of one resource from the first group and one resource from the second group, and
• wherein the CRI corresponds to the resource pair for the CSI associated with the at least two CSI-RS resources.

A method of a user equipment (UE) in a wireless communication system, the method comprising:

• receiving, from a base station, configuration information for a channel state information reference signal (CSI-RS) resource set comprising CSI-RS resources, the CSI-RS resources grouped into a first group and a second group;
• identifying CSI associated with at least two CSI-RS resources from the CSI-RS resource set;
• determining a CSI report to include a CSI reference signal resource indicator (CRI) corresponding to the at least two CSI-RS resources associated with the identified CSI, wherein the CSI report includes a rank indicator (RI) field, wherein the RI field corresponds to two RIs for the CSI associated with the at least two CSI-RS resources, and wherein the RI field corresponds to a rank combination (RI1, RI2), the (RI1, RI2) being one of (1,1), (2,1), (2,1), (2,2);
• and
• transmitting, to the base station, the determined CSI report,
• wherein the CSI associated with the at least two CSI-RS resources is identified based on a resource pair that consists of one resource from the first group and one resource from the second group, and
• wherein the CRI corresponds to the resource pair for the CSI associated with the at least two CSI-RS resources.