Demodulation reference signal (DMRS) combining for single DMRS configurations

A method of wireless communication by a base station, the method comprising:

• receiving an indication from a user equipment (UE) indicating that the UE is capable of combining demodulation reference signals (DMRSs) across scheduling periods;
• determining, based at least in part on the received indication, that DMRS combining for demodulating a downlink data channel in a slot or subslot is supported across the slot or subslot and a subsequent adjacent slot or subslot;
• selecting one of a plurality of DMRS configurations for demodulating the downlink data channel in the slot or subslot, the plurality of DMRS configurations indicating whether the DMRS combining is supported across the slot or subslot and the subsequent adjacent slot or subslot, wherein the plurality of DMRS configurations comprises a configuration that is capable of indicating to the UE that a single DMRS is configured in the slot or subslot and is to be combined with a DMRS in a subsequent adjacent slot or subslot to demodulate the downlink data channel, and wherein the indication that the single DMRS is to be combined with the DMRS in the subsequent adjacent slot or subslot further indicates to the UE that channel estimation is to be delayed until reception of the DMRS in the subsequent adjacent slot or subslot;
• and
• transmitting the selected one of the plurality of DMRS configurations.

An apparatus for wireless communication performed by a user equipment (UE), the apparatus comprising:

• a memory;
• and
• at least one processor operatively coupled to the memory, wherein the memory and the at least one processor are configured to cause the UE to:
• transmit an indication to a base station indicating that the UE is capable of combining demodulation reference signals (DMRS) across scheduling periods;
• receive, from the base station based at least in part on the indication, signaling indicating one of a plurality of DMRS configurations for demodulating a downlink data channel in a slot or subslot, the plurality of DMRS configurations indicating whether DMRS combining is supported across the slot or subslot and a subsequent adjacent slot or subslot, wherein the plurality of DMRS configurations comprises a configuration that indicates to the UE that a single DMRS is configured in the slot or subslot and is to be combined with a DMRS in a subsequent adjacent slot or subslot to demodulate the downlink data channel:
• delay, based at least in part on the reception of the signaling indicating one of the plurality of DMRS configurations, channel estimation until reception of the DMRS in the subsequent adjacent slot or subslot;
• and
• demodulate the downlink data channel based on the indicated one of the plurality of DMRS configurations and the delay of the channel estimation.

An apparatus for wireless communication by a base station, the apparatus comprising:

• a memory;
• and
• at least one processor operatively coupled to the memory, wherein the memory and the at least one processor are configured to cause the base station to:
• receive an indication from a user equipment (UE) indicating that the UE is capable of combining demodulation reference signals (DMRSs) across scheduling periods;
• determine, based at least in part on the received indication, that DMRS combining for demodulating a downlink data channel in a slot or subslot is supported across the slot or subslot and a subsequent adjacent slot or subslot;
• select one of a plurality of DMRS configurations for demodulating the downlink data channel in the slot or subslot, the plurality of DMRS configurations indicating whether the DMRS combining is supported across the slot or subslot and the subsequent adjacent slot or subslot, wherein the plurality of DMRS configurations comprises a configuration that is capable of indicating to the UE that a single DMRS is configured in the slot or subslot and is to be combined with a DMRS in a subsequent adjacent slot or subslot to demodulate the downlink data channel, and wherein the indication that the single DMRS is to be combined with the DMRS in the subsequent adjacent slot or subslot further indicates to the UE that channel estimation is to be delayed until reception of the DMRS in the subsequent adjacent slot or subslot;
• and
• transmit the selected one of the plurality of DMRS configurations.