Terminal SRS Spatial Relation Switching via MAC CE

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Solution Overview

Problem

In future radio communication systems like NR, the dynamic change of spatial relations for Sounding Reference Signals (SRS) is required but not supported in Rel-15 NR, limiting the flexibility of uplink channel and signal transmission processing.

Innovation Solution

The proposed solution involves configuring spatial relations for SRS resources using RRC signaling and MAC CE to allow dynamic changes, enabling flexible control of uplink beams and signals through MAC CE-activated spatial relations.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If spatial relation configuration for SRS resources is fixed in Rel-15 NR, then system simplicity is maintained, but dynamic adaptability for uplink transmission is limited

Engineering Contradiction:
Improvedynamic adaptabilityVSAvoidconfiguration complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent applies dynamics by transitioning from a fixed spatial relation configuration to a dynamic configuration where spatial relations can be changed. This is achieved by introducing a mechanism to update spatial relation information for SRS resources, allowing the system to adapt to changing transmission requirements while maintaining a manageable configuration structure.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent changes the parameter of spatial relation configuration from static to dynamic. By enabling updates to spatial relation information through standardized procedures, the system can modify transmission parameters without requiring complete reconfiguration, thus improving adaptability while controlling complexity.

Inventive Principle:
Principle #35Parameter changes

2Adaptability or versatility

If dynamic spatial relation changes are implemented for SRS, then transmission flexibility is improved, but configuration complexity increases

Engineering Contradiction:
Improvetransmission flexibilityVSAvoidconfiguration complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent segments the spatial relation configuration into manageable components. By dividing the configuration into distinct elements that can be independently updated, the system achieves transmission flexibility while reducing the complexity of managing overall configuration changes through standardized update procedures.

Inventive Principle:
Principle #1Segmentation

3Adaptability or versatility

If one-to-one association between SRS resources and spatial relations is maintained, then configuration simplicity is preserved, but dynamic reconfiguration capability is reduced

Engineering Contradiction:
Improvedynamic reconfiguration capabilityVSAvoidconfiguration structure
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent introduces dynamics to the one-to-one association model by enabling updates to spatial relation information. This allows the system to maintain the simplicity of one-to-one mapping while achieving dynamic reconfiguration capability through standardized update procedures that modify existing associations rather than creating complex many-to-many relationships.

Inventive Principle:
Principle #15Dynamics

Data Source

PatentEP3989656B1Terminal and wireless communication method
Publication Date: 2025.09.10 NTT DOCOMO INC
  • EP3989656B1 patent drawingFigure 1
  • EP3989656B1 patent drawingFigure 2
  • EP3989656B1 patent drawingFigure 3A~3D

AI summary

A terminal according to one aspect of the present disclosure includes a receiving section that receives a Medium Access Control (MAC) control element for activating spatial relation information (SRI) related to a Sounding Reference Signal (SRS) resource set, and a control section that applies the SRI indicated by the MAC control element to a plurality of SRS resources in the SRS resource set, when the SRS resource set corresponds to a specific usage. According to one aspect of the present disclosure, a spatial relation for an SRS can be appropriately specified.