CN-115918198-B - Terminal, wireless communication method, base station and system

Abstract

The terminal according to one embodiment of the present disclosure includes a control unit configured to determine a size of an SRS resource indicator (SRS Resource Indicator (SRI)) field for indicating downlink control information for codebook-based transmission, when more than 2 Sounding REFERENCE SIGNAL (SRS) resources are set for the codebook-based transmission or when more than 4 SRS resources are set for non-codebook-based transmission, and a transmission unit configured to perform the transmission based on the SRS resources indicated by the SRI field. According to one aspect of the present disclosure, the spatial relationship of SRS can be appropriately specified.

Inventors

• MATSUMURA YUSUKE
• NAGATA AKIRA
• GUO SHAOZHEN
• WANG JING
• HOU XIAOLIN

Assignees

• 株式会社NTT都科摩

Dates

Publication Date

20260508

Application Date

20200124

Claims (7)

1. 1. A terminal, comprising: A reception unit that receives a MAC (Medium Access Control (MAC)) control element that is a medium access control element that indicates a transmission setting indicator state, i.e., TCI (Transmission Configuration Indication state) state, for a reference signal resource for measurement, i.e., SRS (Sounding REFERENCE SIGNAL) resource; a control unit configured to determine a size of SRI (SRS Resource Indicator) field, which is an SRS resource indicator field in downlink control information indicating codebook-based transmission or non-codebook-based transmission, when more than 2 SRS resources are set for codebook-based transmission or when more than 4 SRS resources are set for non-codebook-based transmission, and And a transmitting unit configured to perform the instructed codebook-based transmission or non-codebook-based transmission based on the SRS resource indicated by the SRI field and indicated in the TCI state by the MAC control element.
2. 2. The terminal of claim 1, wherein, In the case where the TCI state of the SRS resource for the specific cell is updated by the MAC control element and the specific cell is included in the set list, the control unit updates the TCI state of the SRS resource for the other cell included in the list to the TCI state of the SRS resource for the specific cell.
3. 3. The terminal according to claim 1 or 2, wherein, The control unit specifies an SRS resource set based on an SRS resource set indicator field included in the downlink control information and specifies the SRS resources within the SRS resource set based on the SRI field.
4. 4. The terminal according to claim 1 or 2, wherein, In the case where more than 4 SRS resources are set in one SRS resource set with respect to the transmission of the non-codebook, the control section determines the size of the SRI field in the downlink control information.
5. 5. A wireless communication method for a terminal includes: A step of receiving a MAC (Medium Access Control (MAC)) control element that is a medium access control element and that represents a transmission setting indicator state, i.e., TCI (Transmission Configuration Indication state) state, for a reference signal resource for measurement, i.e., SRS (Sounding REFERENCE SIGNAL) resource; A step of determining the size of SRI (SRS Resource Indicator) field, which is an SRS resource indicator field in downlink control information indicating codebook-based transmission or non-codebook-based transmission, in the case where more than 2 SRS resources are set for codebook-based transmission or in the case where more than 4 SRS resources are set for non-codebook-based transmission, and The step of indicating the codebook-based transmission or non-codebook-based transmission is performed based on the SRS resource indicated by the SRI field and indicated by the MAC control element in the TCI state.
6. 6. A base station, comprising: A transmission unit configured to transmit a MAC (Medium Access Control (MAC)) control element, which is a medium access control element, to a terminal, the MAC control element indicating a TCI (Transmission Configuration Indication state) state, which is a transmission setting indicator state for an SRS (Sounding REFERENCE SIGNAL) resource, which is a reference signal resource for measurement; A control unit configured to determine a size of a SRI (SRS Resource Indicator) field, which is an SRS resource indicator field in downlink control information indicating codebook-based transmission or non-codebook-based transmission, in a case where more than 2 SRS resources are set to the terminal for codebook-based transmission or in a case where more than 4 SRS resources are set to the terminal for non-codebook-based transmission, and And a transmitting unit configured to perform the instructed codebook-based transmission or non-codebook-based transmission based on the SRS resource indicated by the SRI field and indicated in the TCI state by the MAC control element.
7. 7. A system comprising a terminal according to any of claims 1 to 4 and a base station according to claim 6.

Description

Terminal, wireless communication method, base station and system Technical Field The present disclosure relates to a terminal, a wireless communication method, a base station, and a system in a next generation mobile communication system. Background In a universal mobile telecommunications system (Universal Mobile Telecommunications System (UMTS)) network, long term evolution (Long Term Evolution (LTE)) is standardized for the purpose of further high-speed data rates, low latency, and the like (non-patent document 1). Further, for the purpose of further large capacity, high altitude, and the like of LTE (third generation partnership project (Third Generation Partnership Project (3 GPP)) Release (rel.)) versions 8 and 9, LTE-Advanced (3 GPP rel.10-14) is standardized. Subsequent systems of LTE (e.g., also referred to as fifth generation mobile communication system (5 th generation mobile communication system (5G)), 5g+ (plus), new Radio (NR)), 3gpp rel.15 later, and the like have also been studied. Prior art literature Non-patent literature Non-patent document 1：3GPP TS 36.300 V8.12.0 "Evolved Universal Terrestrial Radio Access （E-UTRA） and Evolved Universal Terrestrial Radio Access Network （E-UTRAN）; Overall description; Stage 2 （Release 8）",2010, month 4 Disclosure of Invention Problems to be solved by the invention In a future wireless communication system (e.g., NR), a User terminal (User Equipment (UE)) controls transmission processing (e.g., at least one of transmission, mapping, precoding, modulation, coding) of a channel, a signal, etc. of an uplink based on a spatial relationship (spatial relationship). In rel.15 NR, setting information of measurement reference signal (Sounding REFERENCE SIGNAL (SRS)) resources set to a UE includes spatial relationship information (may also be referred to as Spatial Relation Information (SRI)). That is, SRS resources are linked and set one-to-one with a spatial relationship. However, in NR of rel.16 and beyond, it is required to dynamically change the spatial relationship with respect to SRS. Accordingly, it is an object of the present disclosure to provide a terminal, a wireless communication method, and a base station capable of appropriately specifying a spatial relationship of SRS. Means for solving the problems The terminal according to one embodiment of the present disclosure includes a control unit configured to determine a size of an SRS resource indicator (SRS Resource Indicator (SRI)) field for indicating downlink control information for codebook-based transmission, when more than 2 Sounding REFERENCE SIGNAL (SRS) resources are set for the codebook-based transmission or when more than 4 SRS resources are set for non-codebook-based transmission, and a transmission unit configured to perform the transmission based on the SRS resources indicated by the SRI field. Effects of the invention According to one aspect of the present disclosure, the spatial relationship of SRS can be appropriately specified. Drawings Fig. 1 is a diagram showing an example of spatial relationship information of SRS. Fig. 2 is a diagram showing an example of an SRI instruction for codebook-based transmission in embodiment 1.1. Fig. 3 is a diagram showing an example of an SRI instruction for non-codebook based transmission and L max =1 in embodiment 1.1. Fig. 4 is a diagram showing an example of an SRI instruction for non-codebook based transmission and L max =2 in embodiment 1.1. Fig. 5A and 5B are diagrams showing an example of the reduction in the size of the SRI field in embodiment 1.1. Fig. 6A and 6B are diagrams showing an example of SRS resource IDs set to a plurality of SRS resource sets in embodiment 1.2. Fig. 7 is a diagram showing an example of an SRI instruction for codebook-based transmission in the case where the SRS resource ID is unique across a plurality of SRS resource sets. Fig. 8A and 8B are diagrams showing an example of an SRI instruction for codebook-based transmission in the case where the SRS resource ID is shared across a plurality of SRS resource sets. Fig. 9A to 9C are diagrams showing an example of the correspondence between SRI fields and SRSI fields. Fig. 10A and 10B are diagrams showing an example of a decrease in the SRSI field size in embodiment 1.2. Fig. 11 is a diagram showing an example of setting information of spatial relationships of SRS according to the second embodiment. Fig. 12A and 12B are diagrams showing an example of a MAC CE for spatial relationship update of a P-SRS according to the third embodiment. Fig. 13 is a diagram showing an example of a schematic configuration of a radio communication system according to an embodiment. Fig. 14 is a diagram showing an example of a configuration of a base station according to an embodiment. Fig. 15 is a diagram showing an example of a configuration of a user terminal according to an embodiment. Fig. 16 is a diagram showing an example of a hardware configuration of a base station and a user terminal