Channel state information reference signals for wireless communications

A method of a base station (BS) in a wireless communication system, the method comprising:

• identifying first information corresponding to a number of antenna ports associated with transmissions of channel state information-reference signals (CSI-RSs);
• identifying, based on channel coherence information, a first size of code division multiplexing (CDM) groups associated with the number of antenna ports and a first shape of the CDM groups;
• identifying, based on the first size and the first shape of the CDM groups, second information from the first information;
• identifying, based on the second information, a starting subcarrier (SC) index and a starting symbol index for a resource allocation;
• identifying, based on the number of antenna ports associated with a CSI-RS transmission and a predetermined frequency domain granularity of channel state information, a size of resource block (RB) cluster for the resource allocation;
• and
• transmitting, to a user equipment (UE), resource configuration information indicating at least one of the size of RB cluster, the first size of the CDM groups, the first shape of the CDM groups, the starting SC index, and the starting symbol index.

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

• a transceiver configured to receive, from a base station (BS), resource configuration information indicating at least one of a size of resource bock (RB) cluster, a first size of code division multiplexing (CDM) groups, a first shape of the CDM groups, a starting subcarrier (SC) index, and a starting symbol index;
• and
• a processor operably coupled to the transceiver, the processor configured to:
• identify the size of RB cluster for a resource allocation, the size of RB cluster is associated with a number of antenna ports for a channel state information-reference signal (CSI-RS) transmission and a predetermined frequency domain granularity of channel state information,
• identify the first size of CDM groups associated with the number of antenna ports and the first shape of the CDM groups, wherein the first size of CDM groups is determined in accordance with channel coherence information, and
• identify the starting SC index and the starting symbol index for the resource allocation,
• wherein:
• the number of antenna ports associated with transmissions of CSI-RSs corresponds to first information and second information is identified from the first information based on the first size and the first shape of the CDM groups, and
• the starting SC index and the starting symbol index are determined based on the second information.