Techniques for interference measurement reporting for receiver-assisted channel access
Methods, systems, and devices for wireless communications are described for receiver-assisted channel access in shared radio frequency spectrum. A receiver, such as a user equipment (UE) may transmit a measurement report to a transmitter, such as an access network entity, that indicates channel occupancy as measured at the receiver. In some cases, the receiver may identify resources for signal measurement and reporting that are configured by the transmitter, and provide an interference measurement report based on the signal measurements. The interference measurement report may indicate whether a channel is occupied, or an occupancy level of the channel. Resources may be configured for multiple beams, with the interference measurement report including interference measurements for the multiple beams. Further, the signal resources may provide resources for a listen-before-talk (LBT) procedure, through signal resource sets that span multiple slots.
1 . A method for wireless communication at a user equipment (UE), comprising:
receiving, from an access network entity, an indication to provide an interference measurement report based at least in part on one or more signals configured for multiple beams for contention-based receiver-assisted channel access, wherein the contention-based receiver-assisted channel access indicates a channel availability or a channel occupation of an associated channel bandwidth of the one or more signals;
receiving the one or more signals transmitted by the access network entity via the one or more beams as part of the contention-based receiver-assisted channel access; and
transmitting, to the access network entity, the interference measurement report based at least in part on one or more interference levels of the one or more received signals, the one or more interference levels associated with a wideband interference measurement for the contention-based channel access across a channel bandwidth of a communications channel between the UE and the access network entity, wherein the one or more interference levels indicate the channel availability or the channel occupation of the associated channel bandwidth of the one or more signals.
2 . The method of claim 1 , wherein the one or more interference levels are measured from one or more reference signals transmitted by the access network entity.
3 . The method of claim 1 , wherein the wideband interference measurement across the channel bandwidth of the communications channel indicates channel occupation for the contention-based receiver-assisted channel access.
4 . The method of claim 1 , further comprising:
measuring a received signal strength of each of a plurality of resource elements of the one or more signals; and
summing the received signal strength measurements to generate a received signal strength indicator (RSSI) that is provided in the interference measurement report.
5 . The method of claim 4 , wherein the measuring further comprises:
measuring the one or more signals for a plurality of beams based at least in part on a plurality of transmission configuration indicator (TCI) states that are provided by the network access entity.
6 . The method of claim 1 , wherein the transmitting the interference measurement report comprises:
reporting a plurality of measurements for a plurality of beams, wherein each beam of the plurality of beams is associated with a configured resource of a signal resource set.
7 . The method of claim 1 , further comprising:
comparing the one or more measured interference levels associated with a first signal of the one or more signals to one or more threshold values; and
setting a channel occupation status of the associated channel bandwidth based at least in part on the comparing, and wherein the channel occupation status is provided with the interference measurement report.
8 . The method of claim 7 , wherein two or more threshold values are configured by radio resource control (RRC) signaling, in an activation downlink control information (DCI), or any combinations thereof.
9 . The method of claim 1 , further comprising:
receiving, from the access network entity, a measurement report configuration that indicates resources for the one or more signals.
10 . The method of claim 9 , wherein the resources for the one or more signals include resources for interference measurements over reference signals that have zero power.
11 . The method of claim 9 , wherein the measurement report configuration further indicates beam information for the one or more beams.
12 . The method of claim 11 , wherein the beam information is included in the measurement report configuration in a beam indication field for one or more types of reference signals.
13 . The method of claim 11 , wherein the beam information is derived based at least in part on a reference signal spatial quasi-colocation (QCL), or QCL Type D, for one or more interference measurement resources.
14 . The method of claim 11 , wherein the beam information is provided in one or more explicit information fields, or is derived from a beam associated with one or more synchronization signals, reference signals, beam selection signals, or control signals.
15 . The method of claim 1 , wherein the one or more signals are each transmitted in a plurality of resource elements that span the associated channel bandwidth of the associated signal.
16 . The method of claim 1 , wherein the one or more signals provide for time domain multiplexed interference measurements prior to performing a fast Fourier transform (FFT) on signal resources.
17 . The method of claim 1 , wherein the one or more signals span time resources associated with a listen-before-talk (LBT) procedure associated with the contention-based receiver-assisted channel access.
18 . The method of claim 17 , wherein each signal of the one or more signals are configured with a number of repetitions at symbol-level granularity and an offset relative to a starting symbol to provide resources that span time resources associated with the LBT procedure.
19 . The method of claim 17 , wherein each signal of the one or more signals are configured in plurality of resource sets associated with a plurality of symbols that span time resources associated with the LBT procedure.
20 . A method for wireless communication at an access network entity, comprising:
transmitting, to a user equipment (UE), an indication to provide an interference measurement report based at least in part on one or more signals configured for multiple beams for contention-based receiver-assisted channel access, wherein the contention-based receiver-assisted channel access indicates a channel availability or a channel occupation of an associated channel bandwidth of the one or more signals;
transmitting, via the one or more beams and as part of the contention-based receiver-assisted channel access, the one or more signals to the UE in a set of resources that span a channel bandwidth of a communications channel between the UE and the access network entity; and
receiving, from the UE, the interference measurement report that indicates, for the one or more signals, measured interference levels at the UE, the measured interference levels associated with a wideband interference measurement for the contention-based channel access across a channel bandwidth of the communications channel, wherein the measured interference levels indicate the channel availability or the channel occupation of the associated channel bandwidth of the one or more signals.
21 . The method of claim 20 , wherein the wideband interference measurement across the channel bandwidth of the communications channel indicates channel occupation for the contention-based receiver-assisted channel access.
22 . The method of claim 20 , wherein the interference measurement report indicates a received signal strength indicator (RSSI) for the one or more signals for the associated channel bandwidth.
23 . The method of claim 22 , further comprising:
configuring the UE with a plurality of transmission configuration indicator (TCI) states for a plurality of beams, and wherein the indication to provide the interference measurement report indicates one or more of the plurality of TCI states.
24 . An apparatus for wireless communication at a user equipment (UE), comprising:
a processor;
memory coupled with the processor, and instructions stored in the memory and executable by the processor to cause the apparatus to:
receive, from an access network entity, an indication to provide an interference measurement report based at least in part on one or more signals configured for multiple beams for contention-based receiver-assisted channel access, wherein the contention-based receiver-assisted channel access indicates a channel availability or a channel occupation of an associated channel bandwidth of the one or more signals;
receive the one or more signals transmitted by the access network entity via the one or more beams as part of the contention-based receiver-assisted channel access;
identify one or more interference levels of the one or more signals, wherein the one or more interference levels indicate channel occupation of an associated channel bandwidth of the one or more signals; and
transmit, to the access network entity, the interference measurement report based at least in part on one or more interference levels of the one or more received signals, the one or more interference levels associated with a wideband interference measurement for the contention-based channel access across a channel bandwidth of a communications channel between the UE and the access network entity, wherein the one or more interference levels indicate the channel availability or the channel occupation of the associated channel bandwidth of the one or more signals.
25 . The apparatus of claim 24 , wherein the wideband interference measurement across the channel bandwidth of the communications channel indicates channel occupation for the contention-based receiver-assisted channel access.
26 . The apparatus of claim 24 , wherein the one or more interference levels are measured from one or more reference signals transmitted by the access network entity.
27 . The apparatus of claim 24 , wherein the instructions are executable by the processor to further cause the apparatus to:
measure a received signal strength of each of a plurality of resource elements of the one or more signals; and
sum the received signal strength measurements to generate a received signal strength indicator (RSSI) that is provided in the interference measurement report.
28 . The apparatus of claim 27 , wherein, to measure the received signal strength, the instructions are executable by the processor to further cause the apparatus to:
measure the one or more signals for a plurality of beams based at least in part on a plurality of transmission configuration indicator (TCI) states that are provided by the network access entity.
29 . The apparatus of claim 24 , wherein, to transmit the interference measurement report, the instructions are executable by the processor to further cause the apparatus to:
report a plurality of measurements for a plurality of beams, wherein each beam of the plurality of beams is associated with a configured resource of a signal resource set.
30 . An apparatus for wireless communication at an access network entity, comprising:
a processor;
memory coupled with the processor; and
instructions stored in the memory and executable by the processor to cause the apparatus to:
transmit, to a user equipment (UE), an indication to provide an interference measurement report based at least in part on one or more signals configured for multiple beams for contention-based receiver-assisted channel access, wherein the contention-based receiver-assisted channel access indicates a channel availability or a channel occupation of an associated channel bandwidth of the one or more signals;
transmit, via the one or more beams and as part of the contention-based receiver-assisted channel access, the one or more signals to the UE in a set of resources that span a channel bandwidth of a communications channel between the UE and the access network entity; and
receive, from the UE, the interference measurement report that indicates, for the one or more signals, measured interference levels at the UE, the measured interference levels associated with a wideband interference measurement for the contention-based channel access across a channel bandwidth of the communications channel, wherein the measured interference levels indicate the channel availability or the channel occupation of the associated channel bandwidth of the one or more signals.