Transmitting channel state information reference signals in new radio

An apparatus for wireless communications in a user equipment, comprising:

• a processor configured to:
• receive an indication of a configuration of channel state information reference signals (CSI-RSs) from a transmission reception point (TRP), wherein the configuration indicates a set of resource elements (REs) to be used for CSI-RSs and a first mapping of CSI-RS ports to the set of REs, wherein the configuration further indicates the orthogonal cover codes (OCCs) used for transmitting the CSI-RSs,
• wherein the set of REs comprises one or more RE groups, wherein a RE group of the one or more RE groups comprises two or more localized REs within one orthogonal frequency division multiplexing (OFDM) symbol, wherein the two or more localized REs are adjacent to each other in the frequency domain, and
• wherein the mapped CSI-RS ports are separated by orthogonal cover codes (OCCs) applied to the one or more RE groups in frequency domain only;
• process CSI-RSs based on the indicated configuration to determine channel state information, wherein the configuration indicates a combination of one OFDM symbol CSI-RSs with a first numerology having a first subcarrier spacing and two OFDM symbols CSI-RSs with a second numerology having a second subcarrier spacing;
• and
• report the channel state information to the TRP;
• and
• a memory coupled with the processor.

A method for wireless communications by a user equipment, comprising:

• receiving an indication of a configuration of channel state information reference signals (CSI-RSs) from a transmission reception point (TRP), wherein the configuration indicates a set of resource elements (REs) to be used for CSI-RSs and a first mapping of CSI-RS ports to the set of REs, wherein the configuration further indicates orthogonal cover codes (OCCs) used for transmitting the CSI-RSs,
• wherein the set of REs comprises one or more RE groups, wherein a RE group of the one or more RE groups comprises two or more localized REs within one orthogonal frequency division multiplexing (OFDM) symbol, wherein the two or more localized REs are adjacent to each other in the frequency domain, and
• wherein the mapped CSI-RS ports are separated by orthogonal cover codes (OCCs) applied to the one or more RE groups in frequency domain only;
• processing CSI-RSs based on the indicated configuration to determine channel state information, wherein the configuration indicates a combination of one OFDM symbol CSI-RSs with a first numerology having a first subcarrier spacing and two OFDM symbols CSI-RSs with a second numerology having a second subcarrier spacing;
• and
• reporting the channel state information to the TRP.

An apparatus for wireless communications in a base station, comprising:

• a processor configured to:
• determine a configuration of channel state information reference signals (CSI-RSs), wherein the configuration indicates a set of resource elements (REs) to be used for CSI-RSs and a first mapping of CSI-RS ports to the set of REs, wherein the configuration further indicates the orthogonal cover codes (OCCs) used for transmitting the CSI-RSs,
• wherein the set of REs comprises one or more RE groups, wherein a RE group of the one or more RE groups comprises two or more localized REs within one orthogonal frequency division multiplexing (OFDM) symbol, wherein the two or more localized REs are adjacent to each other in the frequency domain, and
• wherein the mapped CSI-RS ports are separated by orthogonal cover codes (OCCs) applied to the one or more RE groups in frequency domain only;
• send an indication of the configuration of the CSI-RSs;
• and
• transmit the CSI-RSs according to the determined configuration, wherein the configuration indicates a combination of one OFDM symbol CSI-RSs with a first numerology having a first subcarrier spacing and two OFDM symbols CSI-RSs with a second numerology having a second subcarrier spacing;
• and
• a memory coupled with the processor.