Uplink Reference Signal Resource Configuration for Cross-Link Interference

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Solution Overview

Problem

Cross-link interference (CLI) in wireless communication systems, particularly in 5G networks with high frequency unpaired spectrum, limits the flexibility of resource utilization in time division duplexing (TDD) configurations, leading to interference between uplink and downlink communications.

Innovation Solution

Configuring user equipment (UE) to transmit uplink reference signals over resources also used by another access point for downlink signals or interference measurement, with orthogonal frequency and spatial arrangements to mitigate CLI, enabling accurate interference measurement and reporting.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If dynamic TDD is used to provide flexibility for configuring resources, then resource utilization flexibility is improved, but cross-link interference occurs between uplink and downlink communications

Engineering Contradiction:
Improveresource configuration flexibilityVSAvoidcross-link interference
Core Design Contradiction:
Adaptability or versatilityVSObject-generated harmful factors

Solution Approach 1:

The patent segments the resource configuration process into two independent parts: downlink resource configuration (including reference signals and IMR) and uplink resource configuration. By separating these configurations, the system can independently optimize each direction without causing interference, thus resolving the contradiction between flexibility and interference.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent applies preliminary action by having the first access point receive downlink resource configuration information from the second access point before configuring uplink resources. This advance knowledge allows the first access point to proactively avoid allocating uplink resources that would cause CLI, thereby preventing interference before it occurs.

Inventive Principle:
Principle #10Preliminary action

2Device complexity

If uplink reference signal transmission is configured without considering downlink resource usage, then device complexity is reduced, but interference measurement accuracy deteriorates

Engineering Contradiction:
Improveconfiguration complexityVSAvoidinterference measurement accuracy
Core Design Contradiction:
Device complexityVSMeasurement precision

Solution Approach 1:

The patent introduces an intermediary mechanism where downlink resource configuration information acts as a mediator between the two access points. This intermediary information enables coordinated resource allocation without requiring complex direct communication or coordination protocols, thus maintaining low device complexity while achieving accurate interference measurement.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Object-generated harmful factors

If orthogonal frequency and spatial arrangements are used to mitigate CLI, then interference mitigation performance is improved, but device complexity increases

Engineering Contradiction:
ImproveCLI mitigation performanceVSAvoidresource arrangement complexity
Core Design Contradiction:
Object-generated harmful factorsVSDevice complexity

Solution Approach 1:

The patent applies dynamics by making the resource arrangement adaptive rather than fixed. The system dynamically selects between orthogonal frequency arrangements and orthogonal spatial arrangements based on current network conditions and interference patterns. This dynamic approach achieves effective CLI mitigation while avoiding the complexity of implementing both arrangements simultaneously.

Inventive Principle:
Principle #15Dynamics

Data Source

PatentEP4283915B1Configuring reference signal transmission in wireless communications
Publication Date: 2025.08.20 QUALCOMM INC
  • EP4283915B1 patent drawingFigure 1
  • EP4283915B1 patent drawingFigure 2
  • EP4283915B1 patent drawingFigure 3

AI summary

Aspects herein describe transmitting reference signals in wireless communications. An indication of resources over which to transmit an uplink reference signal can be received from an access point, where the resources are at least partially used by another device to transmit a downlink reference signal or a second uplink reference signal. The uplink reference signal can be transmitted over the resources.