Mobile Terminal CSI Reporting with Assumed PDSCH Precoding Under Movement

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

The reporting of channel state information (CSI) in next-generation mobile communication systems, particularly for user terminals moving at middle speeds, is not adequately addressed, leading to potential deterioration in communication throughput and quality.

Innovation Solution

A terminal equipped with a transmitting section and a control section that assumes a specific precoding matrix or vector for PDSCH transmission in CSI calculation, enhancing CSI reporting to account for movement-related influences.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If conventional CSI reporting methods are used without considering movement influence, then the system complexity remains low, but communication throughput and quality deteriorate for moving terminals

Engineering Contradiction:
Improvecommunication throughputVSAvoidCSI reporting complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The terminal performs CQI calculation based on assumed PDSCH transmission using a specific precoding matrix or vector before actual PDSCH reception. This preliminary CQI calculation accounts for movement-related channel variations, enabling more accurate CSI reporting that adapts to terminal motion without requiring complex real-time measurements during movement transitions

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The invention changes the parameter assumptions in CQI calculation by assuming specific precoding matrices or vectors for PDSCH transmission. This parameter change allows the CSI report to reflect movement-induced channel state variations, improving communication throughput for moving terminals while maintaining manageable system complexity through standardized assumption rules

Inventive Principle:
Principle #35Parameter changes

2Reliability

If CSI reporting does not account for movement influence, then the reporting method remains simple, but communication quality deteriorates

Engineering Contradiction:
Improvecommunication qualityVSAvoidCSI reporting method complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The terminal calculates CQI in advance based on assumed PDSCH transmission characteristics that account for movement effects. This preliminary calculation ensures that CSI reports reflect current channel conditions for moving terminals, improving communication reliability without requiring complex real-time adaptation mechanisms during actual transmission

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The terminal provides feedback through CSI reports that incorporate movement-related channel state information derived from assumed PDSCH transmission. This feedback mechanism enables the base station to adapt transmissions to moving terminal conditions, improving communication quality while maintaining systematic feedback procedures

Inventive Principle:
Principle #23Feedback

Data Source

PatentEP4597856A1Terminal, wireless communication method, and base station
Publication Date: 2025.08.06 NTT DOCOMO INC
  • EP4597856A1 patent drawingFigure 1
  • EP4597856A1 patent drawingFigure 2
  • EP4597856A1 patent drawingFigure 3A~3B

AI summary

A terminal according to one aspect of the present disclosure includes a transmitting section that transmits a channel state information (CSI) report, and a control section that, when the CSI report includes at least one channel quality indicator (CQI), assumes that a specific precoding matrix or a vector of a specific PDSCH symbol is applied to physical downlink shared channel (PDSCH) transmission for CQI calculation. According to one aspect of the present disclosure, the CSI report related to influence on movement can be appropriately performed.