Wireless Terminal Spatial Relation Selection for Quick Beam Switching

Solution Overview

Problem

The number of candidates for configuring spatial relations in uplink transmission in future radio communication systems is limited, leading to delays and resource consumption during reconfiguration, which affects the performance of UL transmission.

Innovation Solution

A method for determining spatial relations for UL transmission by utilizing default spatial relations, spatial relations configured through RRC, MAC CE, or DCI, and spatial relations corresponding to PUCCH resources, allowing quick beam switching without RRC reconfiguration.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If the number of spatial relation candidates is increased to improve UL transmission control flexibility, then the adaptability is improved, but the device complexity and reconfiguration time increase

Engineering Contradiction:

ImproveUL transmission control flexibilityVSAvoidreconfiguration complexity

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent segments the spatial relation configuration into multiple stages: RRC configuration establishes a pool of candidate spatial relations, MAC CE activates specific candidates, and DCI selects the actual spatial relation for transmission. This segmentation allows the system to maintain flexibility while managing complexity through hierarchical control

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent performs preliminary action by pre-configuring multiple candidate spatial relations through RRC signaling before actual UL transmission. This allows the terminal to have ready-made spatial relation options available, enabling quick selection and switching without time-consuming reconfiguration during active transmission

Inventive Principle:

Principle #10Preliminary action

2Adaptability or versatility

If the number of spatial relation candidates is increased to improve UL transmission control flexibility, then the adaptability is improved, but the loss of time during reconfiguration increases

Engineering Contradiction:

ImproveUL transmission control flexibilityVSAvoidreconfiguration delay

Core Design Contradiction:

Adaptability or versatilityVSLoss of time

Solution Approach 1:

The patent performs preliminary action by pre-configuring multiple candidate spatial relations through RRC signaling before actual UL transmission. This allows the terminal to have ready-made spatial relation options available, enabling quick selection and switching without time-consuming reconfiguration during active transmission

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent implements dynamic spatial relation selection where the terminal can switch between pre-configured spatial relation candidates based on current channel conditions and transmission requirements. The MAC CE and DCI mechanisms enable dynamic activation and selection without requiring full RRC reconfiguration, reducing time loss while maintaining adaptability

Inventive Principle:

Principle #15Dynamics

3Adaptability or versatility

If the number of spatial relation candidates is increased to improve UL transmission control flexibility, then the adaptability is improved, but the use of energy and resource consumption increase

Engineering Contradiction:

ImproveUL transmission control flexibilityVSAvoidreconfiguration resource consumption

Core Design Contradiction:

Adaptability or versatilityVSUse of energy by moving object

Solution Approach 1:

The patent segments the spatial relation configuration into multiple stages: RRC configuration establishes a pool of candidate spatial relations, MAC CE activates specific candidates, and DCI selects the actual spatial relation for transmission. This segmentation allows the system to maintain flexibility while managing complexity through hierarchical control

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent applies partial action by configuring a limited pool of candidate spatial relations through RRC rather than all possible spatial relations. The MAC CE and DCI then select from this partial set, reducing the overall signaling overhead and resource consumption while maintaining sufficient flexibility for practical UL transmission control

Inventive Principle:

Principle #16Partial or excessive action

Data Source

PatentEP4024936B1Terminal and wireless communication method

Publication Date: 2025.10.01 NTT DOCOMO INC

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AI summary

A terminal according to one aspect of the present disclosure includes a control section that, in a case that downlink control information (DCI) for scheduling a physical uplink shared channel (PUSCH) is a DCI format that does not contain indication of a spatial relation, determines one of a first reference signal and a second reference signal as a certain spatial relation, the first reference signal related to quasi-co-location (QCL) of certain downlink transmission or a spatial relation of certain uplink transmission, the second reference signal being indicated by information that is received; and a transmitting section that transmits the PUSCH in accordance with the certain spatial relation. According to one aspect of the present disclosure, UL transmission can be appropriately controlled.