Terminal device and base station involved in directional listen-before-talk
By incorporating spatial information in DCI formats to indicate beam availability, the inefficiencies in 5G NR systems' directional beamforming are addressed, optimizing channel access and reducing interference in unlicensed frequency bands.
Patent Information
- Application Number
- JP2024540799
- Authority / Receiving Office
- JP · JP
- Patent Type
- Applications
- Current Assignee / Owner
- Priority Date
- 2022-01-07
- Filing Date
- 2022-12-06
- Publication Date
- 2025-01-24
AI Technical Summary
In 5G NR systems operating in unlicensed frequency bands, directional beamforming complicates channel access procedures, leading to inefficiencies in downlink and uplink transmissions due to the lack of spatial information in current DCI formats, resulting in unnecessary monitoring and potential interference.
The proposed solution involves providing spatial information through DCI formats to indicate the availability of beams, allowing UEs to determine whether to monitor downlink control channels or perform uplink transmissions based on beam availability, thereby optimizing LBT operations and reducing unnecessary channel access attempts.
This approach enhances the efficiency of channel access by minimizing unnecessary monitoring and interference, improving power consumption and coexistence with other systems in unlicensed bands.
Smart Images
Figure 2025502046000001_ABST
Abstract
Claims
1. A terminal device, A transceiver, in operation, receiving configuration or scheduling information indicating time resources on a frequency band applicable for a Listen Before Talk (LBT) operation for monitoring a downlink control channel or for performing an uplink transmission, and indicating association of the time resources with a first beam, and receiving Downlink Control Information (DCI) indicating an availability status of a second beam among a plurality of second beams in a time interval on the frequency band, wherein the first beam is at least partially covered by the second beam; a circuit for, during operation, determining, based on the DCI, the availability status of the second beam in the time resource and whether the time resource is within the time interval, and determining whether to monitor the downlink control channel or perform the uplink transmission in the time resource according to a result of determining the availability status of the second beam and whether the time resource is within the time interval; A terminal device comprising:
2. If the circuitry determines that the second beam is unavailable within the time interval and the time resource is within the time interval, the circuitry, in operation, skips monitoring the downlink control channel or performing the uplink transmission during the time resource. The terminal device according to claim 1 .
3. The transceiver, in operation, receives a first search space set group for monitoring the downlink control channel within a channel occupation time (COT) of a base station serving the terminal device, or a first LBT type configuration for performing the uplink transmission within the COT, and a second search space set group for monitoring the downlink control channel outside the COT, or a second LBT type configuration for performing the uplink transmission; When the circuit determines that the second beam is available within the time interval and the time resource is within the time interval, the circuit, in operation, controls the transceiver to monitor the downlink control channel in the first search space set group within the time resource or perform LBT for the uplink transmission according to the first LBT type within the time resource. The terminal device according to claim 1 or 2.
4. If the circuit determines that the availability status of the second beam is unknown within the time interval, the circuit, in operation, controls the transceiver to monitor the downlink control channel in the second search space set group or perform an LBT for the uplink transmission according to the second LBT type. The terminal device according to claim 3.
5. the second beam is represented by a transmission configuration indicator (TCI) state ID, and the circuit, in operation, determines that the first beam is covered by the second beam if a TCI state ID of the downlink control channel or a TCI state ID of the uplink transmission is the same as the TCI state ID representing the second beam. The terminal device according to any one of claims 1 to 4.
6. In operation, the transceiver receives a mapping configuration indicating a mapping of each of a plurality of synchronization signal block (SSB) beam indexes to one or more first beams including the first beam, the mapping configuration being specific to the terminal device, and each of the plurality of second beams being represented by a respective SSB beam index; the DCI indicating an availability status for an SSB beam index among the plurality of SSB beam indexes representing the second beam; and determining, in operation, that the first beam is covered by the second beam if the mapping configuration indicates a mapping of the first beam to the SSB beam index representing the second beam. The terminal device according to any one of claims 1 to 4.
7. the DCI includes a first field indicating the availability status of each of a plurality of second beams including the second beam; The terminal device according to any one of claims 1 to 6.
8. the DCI includes a second field indicating a duration of the time interval for each second beam of the plurality of second beams indicated as available by the first field; The terminal device according to claim 7.
9. the second field indicating the duration and start time of the time interval for each second beam of the plurality of second beams indicated as available by the first field; The terminal device according to claim 8.
10. the DCI includes a third field indicating whether the second beam indicated as available by the first field is time division multiplexed, the third field having a length of 1 bit; The terminal device according to claim 8.
11. The DCI includes a fourth field indicating a time division multiplexing pattern among a plurality of time division multiplexing patterns known to the terminal device, and the second beam indicated as available by the first field is time division multiplexed according to the fourth field. The terminal device according to claim 7.
12. the DCI includes, for each second beam among the plurality of second beams indicated as available by the first field, a slot format indication (SFI) indicating, for each symbol in a slot, the availability status of the second beam; The terminal device according to claim 7.
13. A base station, a transceiver configured to transmit configuration or scheduling information, during operation, indicating time resources on a frequency band applicable for listen-before-talk (LBT) operation for monitoring a downlink control channel or for performing an uplink transmission, and indicating an association of the time resources with a first beam; a circuit that, in operation, determines an availability status of a second beam of a plurality of second beams in a time interval including the time resource on the frequency band by a listen-before-talk (LBT) operation, the first beam being at least partially covered by the second beam; Equipped with wherein the transceiver, in operation, transmits downlink control information (DCI) indicating the availability status of the second beam in the time interval on the frequency band; and wherein the circuitry, in operation, controls the transceiver to transmit the downlink control channel or receive the uplink transmission according to the availability status of the second beam in the time interval on the frequency band. Base station.
14. A communication method performed by a terminal device, comprising: receiving configuration or scheduling information indicating time resources on a frequency band applicable for a listen-before-talk (LBT) operation for monitoring a downlink control channel or for performing an uplink transmission, and indicating an association of the time resources with a first beam; receiving downlink control information (DCI) indicating an availability status of a second beam of a plurality of second beams in a time interval on the frequency band, the first beam being at least partially covered by the second beam; determining, based on the DCI, the availability status of the second beam in the time resource and whether the time resource is within the time interval; determining whether to monitor the downlink control channel or perform the uplink transmission in the time resource according to the availability status of the second beam and a result of determining whether the time resource is within the time interval; A communication method comprising:
15. 1. A communication method performed by a base station, comprising: transmitting configuration or scheduling information indicating time resources on a frequency band applicable for a listen-before-talk (LBT) operation for monitoring a downlink control channel or for performing an uplink transmission, and indicating an association of the time resources with a first beam; determining an availability status of a second beam of a plurality of second beams in a time interval including the time resource on the frequency band by a listen-before-talk (LBT) operation, the first beam being at least partially covered by the second beam; transmitting Downlink Control Information (DCI) indicating the availability status of the second beam in the time interval on the frequency band; controlling transmission of the downlink control channel or reception of the uplink transmission according to the availability status of the second beam in the time interval on the frequency band; A communication method comprising:
16. In operation, the terminal device performs the following steps: receiving configuration or scheduling information indicating time resources on a frequency band applicable for a listen-before-talk (LBT) operation for monitoring a downlink control channel or for performing an uplink transmission, and indicating an association of the time resources with a first beam; receiving downlink control information (DCI) indicating an availability status of a second beam of a plurality of second beams in a time interval on the frequency band, the first beam being at least partially covered by the second beam; determining, based on the DCI, the availability status of the second beam in the time resource and whether the time resource is within the time interval; determining whether to monitor the downlink control channel or perform the uplink transmission in the time resource according to the availability status of the second beam and a result of determining whether the time resource is within the time interval; An integrated circuit that performs the steps of
17. In operation, the base station is configured to perform the following steps: transmitting configuration or scheduling information indicating time resources on a frequency band applicable for a listen-before-talk (LBT) operation for monitoring a downlink control channel or for performing an uplink transmission, and indicating an association of the time resources with a first beam; determining an availability status of a second beam of a plurality of second beams in a time interval including the time resource on the frequency band via a listen-before-talk (LBT) operation, the first beam being at least partially covered by the second beam; transmitting Downlink Control Information (DCI) indicating the availability status of the second beam in a time interval on the frequency band; controlling transmission of the downlink control channel or reception of the uplink transmission according to the availability status of the second beam in the time interval on the frequency band; An integrated circuit that performs the steps of
Citation Information
Patent Citations
TR38.913