NR Duplex Subband Sensing for Cross-Link Interference Mitigation

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing wireless communication systems face challenges in managing cross-link interference (CLI) in duplex operations, which affect radio interface efficiency and coverage, particularly in environments with multiple wireless devices operating simultaneously.

Innovation Solution

Implementing sensing-based interference mitigation techniques to detect and manage CLI, utilizing directional sensing and cross division duplex (XDD) methods to optimize signal transmission and reception.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If wireless devices operate simultaneously in duplex mode to increase data traffic capacity, then network throughput and resource utilization improve, but cross-link interference between uplink and downlink signals worsens

Engineering Contradiction:
Improvedata traffic capacityVSAvoidcross-link interference
Core Design Contradiction:
ProductivityVSObject-affected harmful factors

Solution Approach 1:

The patent segments the frequency spectrum into multiple subbands and assigns different duplex modes to different subbands. This allows simultaneous uplink and downlink operations in different frequency portions while reducing overall interference. The base station and UE independently determine CLI measurements for each subband and switch transmission directions subband-by-subband based on interference conditions.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent implements dynamic subband-wise full-duplex operation where the duplex mode (uplink or downlink) can change dynamically per subband based on real-time CLI measurements. The base station and UE continuously monitor interference levels and adaptively switch between TDD and FDD modes in different subbands to optimize performance while managing interference.

Inventive Principle:
Principle #15Dynamics

2Reliability

If directional sensing and XDD methods are implemented to mitigate CLI, then radio interface efficiency improves, but system complexity and measurement overhead increase

Engineering Contradiction:
Improveradio interface efficiencyVSAvoidsensing system complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent enables the base station and UE to autonomously perform CLI measurements and determine appropriate duplex modes without requiring complex centralized coordination. Each device independently measures CLI on different subbands, determines interference conditions, and switches transmission directions based on local measurements, reducing overall system complexity while maintaining effectiveness.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The patent implements preliminary CLI measurement and assessment before switching duplex modes. The base station configures CLI measurement resources, and devices perform measurements in advance to determine whether subband switching is needed, allowing proactive interference mitigation rather than reactive responses.

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentEP4497214B1Sensing-based interference mitigation in NR duplex
Publication Date: 2026.04.01 INTERDIGITAL PATENT HOLDINGS INC
  • EP4497214B1 patent drawingFigure 1A
  • EP4497214B1 patent drawingFigure 1B
  • EP4497214B1 patent drawingFigure 1C

AI summary

A wireless transmit/receive unit (WTRU) may include a processor that is configured to receive configuration information indicating a plurality of sub-bands for cross-link interference (CLI) measurements and respective resources for performing CLI measurements for each of the plurality of sub-bands. The processor may receive a downlink control information (DCI) indicating resources associated with a first reference sub-band. The processor may perform a CLI measurement for the first reference sub-band using one or more resources for performing CLI measurements for the first sub-band. The processor may perform a CLI measurement for at least one other sub-band of the plurality of sub-bands using the respective resources for CLI measurements of the at least one other sub-band based on determining that the CLI measurement for the first sub-band is greater than a threshold. The processor may send an indication that the CLI measurement for the sub-band is greater than the threshold.