Physical uplink control channel with adaptive demodulation reference signal density
A base station transmits to a user equipment (UE), an indication of an adjustment to at least one of a density or a location of one or more demodulation reference signals (DMRS) for at least one physical uplink control channel (PUCCH) format. The base station monitors for PUCCH based on the adjustment to the density or the location of the DMRS indicated to the UE. A UE receives, from the base station an indication of an adjustment to at least one of a density or a location of one or more DMRS for at least one PUCCH forma and transmits, to the base station, a PUCCH based on the indication of the adjustment to at least one of the density or the location of the one or more DMRS.
1. An apparatus for wireless communication of a base station, comprising:
memory; and
at least one processor coupled to the memory and configured to:
transmit, to a user equipment (UE), an indication of an adjustment to at least one of a density or a location of one or more demodulation reference signals (DMRS) in subcarriers for at least one physical uplink control channel (PUCCH) format; and
monitor for PUCCH based on the adjustment to the density or the location of the DMRS indicated to the UE.
2. The apparatus of claim 1 , wherein the at least one processor is further configured to:
receive at least one of channel state information (CSI) feedback or an uplink transmission from the UE, the adjustment to the at least one of the density or the location of the DMRS for the at least one PUCCH format being based on the CSI feedback of the uplink transmission from the UE.
3. The apparatus of claim 1 , wherein the at least one PUCCH format is a short PUCCH format including PUCCH format 2 or PUCCH format 0 having a length of two or fewer symbols, and wherein the one or more DMRS is included in each symbol.
4. The apparatus of claim 1 , wherein the adjustment to at least one of the density or the location of the one or more DMRS corresponds to a length adjustment of the at least one PUCCH format.
5. The apparatus of claim 1 , wherein the adjustment to the density of the one or more DMRS corresponds to an increase or a decrease in a number of subcarriers per symbol.
6. The apparatus of claim 5 , wherein the number is increased or decreased based on at least one of a coverage enhancement indication or an acknowledgement (ACK) to a physical downlink shared channel (PDSCH).
7. The apparatus of claim 1 , wherein at least one of the density or the location of the one or more DMRS corresponds to one or more DMRS patterns.
8. The apparatus of claim 7 , wherein the one or more DMRS patterns are associated with a contiguous set of orthogonal frequency division multiplexing (OFDM) symbols.
9. The apparatus of claim 1 , wherein the at least one processor is further configured to:
receive, from the UE, the PUCCH based on the indication of the adjustment to at least one of the density or the location of the one or more DMRS.
10. The apparatus of claim 1 , wherein the adjustment of the at least one of the density or the location of the one or more DMRS is further based on at least one of an uplink channel measurement, a signal-to-interference plus noise ratio (SINR), or a hybrid automatic repeat request (HARQ) process.
11. The apparatus of claim 1 , wherein the indication corresponds to one of a set of reconfigurations for the at least one PUCCH format.
12. The apparatus of claim 1 , wherein the indication is transmitted via at least one of UE-specific downlink control information (DCI), group-common DCI, or a medium access control (MAC) control element (MAC-CE).
13. The apparatus of claim 1 , wherein the adjustment to at least one of the density or the location of the one or more DMRS is indicated based on a preconfigured adjustment or a predefined adjustment.
14. The apparatus of claim 1 , further comprising:
at least one of an antenna or a transceiver coupled to the at least one processor.
15. A method of wireless communication of a base station, comprising:
transmitting, to a user equipment (UE), an indication of an adjustment to at least one of a density or a location of one or more demodulation reference signals (DMRS) in subcarriers for at least one physical uplink control channel (PUCCH) format; and
monitoring for PUCCH based on the adjustment to the density or the location of the DMRS indicated to the UE.
16. An apparatus of wireless communication of a user equipment (UE), comprising:
memory; and
at least one processor coupled to the memory and configured to:
receive, from a base station, an indication of an adjustment to at least one of a density or a location of one or more demodulation reference signals (DMRS) in subcarriers for at least one physical uplink control channel (PUCCH) format; and
transmit, to the base station, a PUCCH based on the indication of the adjustment to at least one of the density or the location of the one or more DMRS.
17. The apparatus of claim 16 , wherein the at least one processor is further configured to:
transmit, to the base station, at least one of channel state information (CSI) feedback or an uplink transmission, the adjustment to the at least one of the density or the location of the one or more DMRS for the at least one PUCCH format being based on the CSI feedback or the uplink transmission.
18. The apparatus of claim 16 , wherein the at least one PUCCH format is a short PUCCH format including PUCCH format 2 or PUCCH format 0 having a length of two or fewer symbols, and wherein the one or more DMRS is included in each symbol.
19. The apparatus of claim 16 , wherein the adjustment to at least one of the density or the location of the one or more DMRS corresponds to a length adjustment of the at least one PUCCH format.
20. The apparatus of claim 16 , wherein the adjustment to the density of the one or more DMRS corresponds to an increase or a decrease in a number of subcarriers per symbol.
21. The apparatus of claim 20 , wherein the number is increased or decreased based on at least one of a coverage enhancement indication or an acknowledgement (ACK) to a physical downlink shared channel (PDSCH).
22. The apparatus of claim 16 , wherein at least one of the density or the location of the one or more DMRS corresponds to one or more DMRS patterns.
23. The apparatus of claim 22 , wherein the one or more DMRS patterns are associated with a contiguous set of orthogonal frequency division multiplexing (OFDM) symbols.
24. The apparatus of claim 16 , wherein the adjustment to at least one of the density or the location of the one or more DMRS is based on at least one of an uplink channel measurement, a signal-to-interference plus noise ratio (SINR), or a hybrid automatic repeat request (HARQ) process.
25. The apparatus of claim 16 , wherein the indication corresponds to one of a set of reconfigurations for the at least one PUCCH format.
26. The apparatus of claim 16 , wherein the indication is received via at least one of UE-specific downlink control information (DCI), group-common DCI, or a medium access control (MAC) control element (MAC-CE).
27. The apparatus of claim 16 , wherein the adjustment to at least one of the density or the location of the one or more DMRS is indicated based on a preconfigured adjustment or a predefined adjustment.
28. The apparatus of claim 16 , further comprising:
at least one of an antenna or a transceiver coupled to the at least one processor.
29. A method of wireless communication of a user equipment (UE), comprising:
receiving, from a base station, an indication of an adjustment to at least one of a density or a location of one or more demodulation reference signals (DMRS) in subcarriers for at least one physical uplink control channel (PUCCH) format; and
transmitting to the base station a PUCCH based on the indication of the adjustment to at least one of the density or the location of the one or more DMRS.