Sounding reference signal port enhancements for uplink transmissions
Methods, systems, and devices for wireless communications are described. A user equipment (UE) may receive, from a network entity, control signaling that includes sounding reference signal (SRS) configuration information associated with an increased quantity of SRS ports. The SRS configuration information may include a quantity of symbols via which to transmit SRSs, a frequency resource comb for each respective symbol, and a threshold quantity of cyclic shifts. The UE may map a first subset of SRS ports to a first symbol and map a second subset of SRS ports to a second symbol. The UE may transmit, and the network entity receive, the SRSs using the first subset of SRS ports via the first symbol according to a first frequency resource comb and respective cyclic shifts and using the second subset of SRS ports via the second symbol according to a second frequency resource comb and respective cyclic shifts.
1 . An apparatus for wireless communications at a user equipment (UE), comprising:
at least one processor; and
one or more memories coupled with the at least one processor, the one or more memories storing instructions executable by the at least one processor, directly or after compilation, to cause the UE to:
receive control signaling comprising sounding reference signal configuration information associated with a plurality of sounding reference signal ports at the UE, the sounding reference signal configuration information indicating a quantity of symbols via which to transmit sounding reference signals and indicating a respective frequency resource pattern for each respective symbol of the quantity of symbols, each respective frequency resource pattern being one of a quantity of frequency resource patterns;
map a first subset of sounding reference signal ports of the plurality of sounding reference signal ports to a first symbol of the quantity of symbols and a second subset of sounding reference signal ports of the plurality of sounding reference signal ports to a second symbol of the quantity of symbols; and
transmit sounding reference signaling using the first subset of sounding reference signal ports via the first symbol according to a first frequency resource pattern of the quantity of frequency resource patterns according to the mapping and using the second subset of sounding reference signal ports via the second symbol according to a second frequency resource pattern of the quantity of frequency resource patterns according to the mapping.
2 . The apparatus of claim 1 , wherein the instructions are further executable by the at least one processor, directly or after compilation, to cause the UE to:
receive control signaling comprising an indication of a threshold quantity of cyclic shifts for the quantity of symbols;
map each sounding reference signal port of the first subset of sounding reference signal ports to a respective cyclic shift based at least in part on the threshold quantity of cyclic shifts and a respective sounding reference signal port index; and
map each sounding reference signal port of the second subset of sounding reference signal ports to a respective cyclic shift based at least in part on the threshold quantity of cyclic shifts and a respective sounding reference signal port index.
3 . The apparatus of claim 2 , wherein the instructions to transmit the sounding reference signaling are executable by the at least one processor, directly or after compilation, to cause the UE to:
sound each sounding reference signal port of the first subset of sounding reference signal ports and each sounding reference signal port of the second subset of sounding reference signal ports according to the respective cyclic shifts.
4 . The apparatus of claim 2 , wherein the instructions are further executable by the at least one processor, directly or after compilation, to cause the UE to:
divide the plurality of sounding reference signal ports into the first subset of sounding reference signal ports and the second subset of sounding reference signal ports, the first subset of sounding reference signal ports being associated with a first set of port indices, and the second subset of sounding reference signal ports being associated with a second set of port indices; and
set the second set of port indices equal to the first set of port indices, wherein mapping each sounding reference signal port of the first subset of sounding reference signal ports to a respective cyclic shift and mapping each sounding reference signal port of the second subset of sounding reference signal ports to a respective cyclic shift is based at least in part on setting the second set of port indices equal to the first set of port indices.
5 . The apparatus of claim 1 , wherein the instructions to mapping are executable by the at least one processor, directly or after compilation, to cause the UE to:
map each sounding reference signal port of the first subset of sounding reference signal ports to the first frequency resource pattern and each sounding reference signal port of the second subset of sounding reference signal ports to the second frequency resource pattern.
6 . The apparatus of claim 5 , wherein a first offset, a first pattern, or both associated with the first frequency resource pattern is different than a second offset, a second pattern, or both associated with the second frequency resource pattern.
7 . The apparatus of claim 1 , wherein the instructions to mapping are executable by the at least one processor, directly or after compilation, to cause the UE to:
map a third subset of sounding reference signal ports of the plurality of sounding reference signal ports to a third symbol of the quantity of symbols; and
transmit sounding reference signaling using the third subset of sounding reference signal ports via the third symbol according to a third frequency resource pattern of the quantity of frequency resource patterns.
8 . The apparatus of claim 1 , wherein the control signaling is received as a radio resource control message.
9 . An apparatus for wireless communications at a network entity, comprising:
at least one processor; and
one or more memories coupled with the at least one processor, the one or more memories storing instructions executable by the at least one processor, directly or after compilation, to cause the network entity to:
output control signaling comprising sounding reference signal configuration information associated with a plurality of sounding reference signal ports at a user equipment (UE), the sounding reference signal configuration information indicating a quantity of symbols via which the UE is to transmit sounding reference signals, and indicating a respective frequency resource pattern for each respective symbol of the quantity of symbols, each respective frequency resource pattern being one of a quantity of frequency resource patterns;
obtain sounding reference signaling associated with a first subset of sounding reference signal ports via a first symbol according to a first frequency resource pattern of the quantity of frequency resource patterns; and
obtain sounding reference signaling associated with a second subset of sounding reference signal ports via a second symbol according to a second frequency resource pattern of the quantity of frequency resource patterns.
10 . The apparatus of claim 9 , wherein the instructions are further executable by the at least one processor, directly or after compilation, to cause the network entity to:
output control signaling comprising an indication of a threshold quantity of cyclic shifts for the quantity of symbols.
11 . The apparatus of claim 10 , wherein the instructions to obtain the sounding reference signaling are executable by the at least one processor, directly or after compilation, to cause the network entity to:
obtain the sounding reference signaling from the plurality of sounding reference signal ports, each sounding reference signal port mapped to a respective cyclic shift based at least in part on the threshold quantity of cyclic shifts.
12 . The apparatus of claim 9 , wherein the instructions are further executable by the at least one processor, directly or after compilation, to cause the network entity to:
map each sounding reference signal port of the first subset of sounding reference signal ports to the first frequency resource pattern and each sounding reference signal port of the second subset of sounding reference signal ports to the second frequency resource pattern, wherein obtaining the sounding reference signaling is based at least in part on the mapping.
13 . The apparatus of claim 9 , wherein the instructions are further executable by the at least one processor, directly or after compilation, to cause the network entity to:
perform channel measurements based at least in part on obtaining the sounding reference signaling associated with the first subset of sounding reference signal ports and the second subset of sounding reference signal ports.
14 . The apparatus of claim 9 , wherein a first offset, a first pattern, or both associated with the first frequency resource pattern is different than a second offset, a second pattern, or both associated with the second frequency resource pattern.
15 . The apparatus of claim 9 , wherein the control signaling is output as a radio resource control message.
16 . A method for wireless communications at a user equipment (UE), comprising:
receiving control signaling comprising sounding reference signal configuration information associated with a plurality of sounding reference signal ports at the UE, the sounding reference signal configuration information indicating a quantity of symbols via which to transmit sounding reference signals and indicating a respective frequency resource pattern for each respective symbol of the quantity of symbols, each respective frequency resource pattern being one of a quantity of frequency resource patterns;
mapping a first subset of sounding reference signal ports of the plurality of sounding reference signal ports to a first symbol of the quantity of symbols and a second subset of sounding reference signal ports of the plurality of sounding reference signal ports to a second symbol of the quantity of symbols; and
transmitting sounding reference signaling using the first subset of sounding reference signal ports via the first symbol according to a first frequency resource pattern of the quantity of frequency resource patterns according to the mapping and using the second subset of sounding reference signal ports via the second symbol according to a second frequency resource pattern of the quantity of frequency resource patterns according to the mapping.
17 . The method of claim 16 , further comprising:
receiving control signaling comprising an indication of a threshold quantity of cyclic shifts for the quantity of symbols;
mapping each sounding reference signal port of the first subset of sounding reference signal ports to a respective cyclic shift based at least in part on the threshold quantity of cyclic shifts and a respective sounding reference signal port index; and
mapping each sounding reference signal port of the second subset of sounding reference signal ports to a respective cyclic shift based at least in part on the threshold quantity of cyclic shifts and a respective sounding reference signal port index.
18 . The method of claim 17 , wherein transmitting the sounding reference signaling comprises:
sounding each sounding reference signal port of the first subset of sounding reference signal ports and each sounding reference signal port of the second subset of sounding reference signal ports according to the respective cyclic shifts.
19 . The method of claim 17 , further comprising:
dividing the plurality of sounding reference signal ports into the first subset of sounding reference signal ports and the second subset of sounding reference signal ports, the first subset of sounding reference signal ports being associated with a first set of port indices, and the second subset of sounding reference signal ports being associated with a second set of port indices; and
setting the second set of port indices equal to the first set of port indices, wherein mapping each sounding reference signal port of the first subset of sounding reference signal ports to a respective cyclic shift and mapping each sounding reference signal port of the second subset of sounding reference signal ports to a respective cyclic shift is based at least in part on setting the second set of port indices equal to the first set of port indices.
20 . The method of claim 16 , wherein the mapping comprises:
mapping each sounding reference signal port of the first subset of sounding reference signal ports to the first frequency resource pattern and each sounding reference signal port of the second subset of sounding reference signal ports to the second frequency resource pattern.
21 . The method of claim 20 , wherein a first offset, a first pattern, or both associated with the first frequency resource pattern is different than a second offset, a second pattern, or both associated with the second frequency resource pattern.
22 . The method of claim 16 , wherein the mapping comprises:
mapping a third subset of sounding reference signal ports of the plurality of sounding reference signal ports to a third symbol of the quantity of symbols; and
transmitting sounding reference signaling using the third subset of sounding reference signal ports via the third symbol according to a third frequency resource pattern of the quantity of frequency resource patterns.
23 . The method of claim 16 , wherein the control signaling is received as a radio resource control message.
24 . A method for wireless communications at a network entity, comprising:
outputting control signaling comprising sounding reference signal configuration information associated with a plurality of sounding reference signal ports at a user equipment (UE), the sounding reference signal configuration information indicating a quantity of symbols via which the UE is to transmit sounding reference signals, and indicating a respective frequency resource pattern for each respective symbol of the quantity of symbols, each respective frequency resource pattern being one of a quantity of frequency resource patterns;
obtaining sounding reference signaling associated with a first subset of sounding reference signal ports via a first symbol according to a first frequency resource pattern of the quantity of frequency resource patterns; and
obtaining sounding reference signaling associated with a second subset of sounding reference signal ports via a second symbol according to a second frequency resource pattern of the quantity of frequency resource patterns.
25 . The method of claim 24 , further comprising:
outputting control signaling comprising an indication of a threshold quantity of cyclic shifts for the quantity of symbols.
26 . The method of claim 25 , wherein obtaining the sounding reference signaling comprises:
obtaining the sounding reference signaling from the plurality of sounding reference signal ports, each sounding reference signal port mapped to a respective cyclic shift based at least in part on the threshold quantity of cyclic shifts.
27 . The method of claim 24 , further comprising:
mapping each sounding reference signal port of the first subset of sounding reference signal ports to the first frequency resource pattern and each sounding reference signal port of the second subset of sounding reference signal ports to the second frequency resource pattern, wherein obtaining the sounding reference signaling is based at least in part on the mapping.
28 . The method of claim 24 , further comprising:
performing channel measurements based at least in part on obtaining the sounding reference signaling associated with the first subset of sounding reference signal ports and the second subset of sounding reference signal ports.
29 . The method of claim 24 , wherein a first offset, a first pattern, or both associated with the first frequency resource pattern is different than a second offset, a second pattern, or both associated with the second frequency resource pattern.
30 . The method of claim 24 , wherein the control signaling is output as a radio resource control message.