NR-U CSI Feedback Scheduling Under Variable Interference

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Solution Overview

Problem

Existing cellular networks face challenges in efficiently utilizing unlicensed spectrum for NR-based access, particularly in managing channel-state information (CSI) measurements and transmissions in environments with varying interference levels.

Innovation Solution

Implementing wireless transmit/receive units (WTRUs) capable of transmitting DCI, CSI-RS, and CSI reports to optimize channel access and reporting mechanisms, including aperiodic and periodic/semi-persistent scheduling, to enhance NR unlicensed access in both sub6 and above6 bands.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If aperiodic and periodic/semi-persistent scheduling is implemented for CSI transmissions, then the efficiency and reliability of NR unlicensed access is improved, but the device complexity increases

Engineering Contradiction:
Improvereliability of NR unlicensed accessVSAvoiddevice complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent implements dynamic scheduling mechanisms where CSI transmissions can switch between aperiodic and periodic/semi-persistent modes based on channel conditions and traffic requirements. This dynamic approach allows the system to adapt to varying interference levels in unlicensed spectrum, improving reliability while managing device complexity through conditional logic rather than fixed complex structures.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent changes transmission parameters such as scheduling timing, resource allocation, and CSI reporting configurations based on channel state and interference measurements. By dynamically adjusting these parameters, the system achieves improved reliability in unlicensed access without requiring permanently complex device architectures, as the complexity is activated only when needed.

Inventive Principle:
Principle #35Parameter changes

2Productivity

If channel-state information measurements are optimized for varying interference levels, then the utilization of unlicensed spectrum is improved, but the measurement precision requirements increase

Engineering Contradiction:
Improveutilization of unlicensed spectrumVSAvoidmeasurement precision
Core Design Contradiction:
ProductivityVSMeasurement precision

Solution Approach 1:

The patent implements feedback mechanisms where channel-state information is continuously measured and reported back to the network. This feedback loop allows the system to adapt to varying interference levels in unlicensed spectrum, improving overall utilization while distributing the measurement precision requirements across multiple reporting instances rather than demanding extreme precision in every single measurement.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The patent employs periodic CSI measurements and reporting, particularly through semi-persistent scheduling. This periodic approach allows the system to capture channel variations over time, improving spectrum utilization through accumulated measurements while reducing the burden on any single measurement's precision requirement.

Inventive Principle:
Principle #19Periodic action

Data Source

PatentEP3834346B1CSI feedback in NR-u
Publication Date: 2026.01.14 INTERDIGITAL PATENT HOLDINGS INC
  • EP3834346B1 patent drawingFigure 1A
  • EP3834346B1 patent drawingFigure 1B
  • EP3834346B1 patent drawingFigure 1C

AI summary

Systems, methods, and instrumentalities are described herein that may be used for transmission of one or more DCI, CSI-RS and/or CSI reports. A wireless transmit/receive unit (WTRU) may receive a DCI that includes information indicating two channel state information reference signal (CSI-RS) resources and four CSI reporting resources. Each CSI-RS resource may be associated with two CSI reporting resources. The WTRU may monitor a first CSI-RS resource for a CSI-RS. If the WTRU does not identify the CSI-RS in the first CSI-RS resource, the WTRU may monitor a second CSI-RS resource for the CSI-RS. The WTRU may receive the CSI-RS on the first CSI-RS resource or the second CSI-RS resource. The WTRU may determine availabilities of the first and/or the second CSI reporting resource associated with the CSI-RS resource on which the WTRU received the CSI-RS. The WTRU may transmit a CSI report on an available CSI reporting resource.