Terminal CSI Reporting for Multi-TRP Coherent Joint Transmission

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Solution Overview

Problem

Existing radio communication systems lack clear definitions for channel state information (CSI) and codebook configurations in coherent joint transmission (CJT) using multiple transmission/reception points (TRPs) or panels, leading to potential deterioration in communication throughput and quality.

Innovation Solution

A terminal is equipped with a receiving section to receive configurations of candidate values for spatial domain basis vectors and a control section to determine appropriate CSI/codebook combinations for CJT, enabling precise CSI reporting.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If clear definitions for CSI and codebook in CJT are not provided, then system complexity is reduced, but communication throughput and quality deteriorate

Engineering Contradiction:
Improvecommunication throughputVSAvoidsystem complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The patent applies parameter changes by systematically defining multiple parameters for CSI reporting in CJT scenarios, including codebook configuration parameters, spatial domain basis vector parameters, and reporting parameter combinations. These parameter definitions enable precise control of CSI reporting behavior while maintaining manageable system complexity through structured parameter management.

Inventive Principle:
Principle #35Parameter changes

2Reliability

If detailed CSI/codebook configuration is implemented, then communication quality improves, but configuration complexity increases

Engineering Contradiction:
Improvecommunication qualityVSAvoidconfiguration complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent segments the CSI reporting configuration into distinct components: codebook configuration parameters, spatial domain basis vector parameters, and reporting parameter combinations. Each segment is independently defined and can be configured separately, allowing detailed control of communication quality while managing configuration complexity through modular organization.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent introduces dynamic parameter combinations that allow the terminal to adaptively select and report different parameter sets based on channel conditions and CJT configuration. This dynamic approach enables high communication quality through precise CSI reporting while reducing configuration complexity by allowing flexible parameter selection rather than requiring all parameters to be fixed.

Inventive Principle:
Principle #15Dynamics

3Productivity

If CSI reporting for multi-TRP/CJT is not clearly defined, then ease of operation is maintained, but communication performance deteriorates

Engineering Contradiction:
Improvecommunication performanceVSAvoidoperation simplicity
Core Design Contradiction:
ProductivityVSEase of operation

Solution Approach 1:

The patent enables the terminal to autonomously determine and report appropriate CSI parameter combinations based on received CJT configurations and channel conditions. The terminal self-configures the CSI reporting by selecting from defined parameter sets, eliminating the need for complex manual configuration while ensuring optimal communication performance through adaptive parameter selection.

Inventive Principle:
Principle #25Self-service

Data Source

PatentEP4622128A1Terminal, wireless communication method, and base station
Publication Date: 2025.09.24 NTT DOCOMO INC
  • EP4622128A1 patent drawingFigure 1
  • EP4622128A1 patent drawingFigure 2
  • EP4622128A1 patent drawingFigure 3A~3B

AI summary

A terminal according to one aspect of the present disclosure includes: a receiving section that receives a configuration of a plurality of combinations of candidate values for a parameter related to numbers of spatial domain basis vectors for N transmission/reception points; and a control section that controls reporting of one combination based on the plurality of combinations, based on the configuration.