Network Device Self-Interference Avoidance in Dual Connectivity

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Solution Overview

Problem

In communication technologies, particularly in LTE and 5G NR systems, self-interference occurs due to harmonic interference between different frequency bands, affecting signal transmission quality in Dual Connectivity (DC) and carrier aggregation systems.

Innovation Solution

A method where a first network device detects self-interference and transmits interference avoidance indication information to a second network device, allowing it to communicate with the user equipment (UE) through specific time-domain and frequency-domain resources, thereby preventing self-interference and improving signal quality.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If dual connectivity is implemented with LTE 1.8GHz uplink and NR 3.5GHz downlink, then network capacity and coverage are improved, but self-interference occurs due to second harmonic interference from uplink to downlink

Engineering Contradiction:
Improvenetwork capacityVSAvoidself-interference
Core Design Contradiction:
ProductivityVSObject-affected harmful factors

Solution Approach 1:

The patent segments the time-domain resources into different uplink and downlink slots, creating specific patterns (e.g., TDD-UL-DL configuration) that separate interfering uplink transmissions from vulnerable downlink receptions. This temporal segmentation prevents the second harmonic interference from affecting downlink signals while maintaining dual connectivity functionality.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent implements periodic interference avoidance patterns where specific uplink and downlink slots are regularly alternated according to predefined configurations. This periodic structure ensures that downlink receptions occur during time periods when uplink transmissions (and their harmonic interference) are absent, thereby systematically preventing self-interference while maintaining network productivity.

Inventive Principle:
Principle #19Periodic action

2Productivity

If carrier aggregation is implemented with 1.8GHz uplink and 3.5GHz downlink, then spectral efficiency is improved, but secondary harmonic interference degrades downlink reception quality

Engineering Contradiction:
Improvespectral efficiencyVSAvoiddownlink reception quality
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The patent applies time-domain segmentation to carrier aggregation scenarios, dividing the aggregated carriers into specific uplink and downlink time resources. By configuring certain slots as uplink-only or downlink-only within the carrier aggregation framework, the patent prevents secondary harmonic interference from degrading downlink reception while maintaining the spectral efficiency benefits of carrier aggregation.

Inventive Principle:
Principle #1Segmentation

3Productivity

If SUL carrier at 1.8GHz is used with NR carrier at 3.5GHz, then uplink coverage is improved, but secondary harmonic interference affects downlink reception

Engineering Contradiction:
Improveuplink coverageVSAvoiddownlink reception quality
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The patent implements periodic time-domain patterns for SUL carriers where uplink transmissions on the 1.8GHz SUL carrier are scheduled in specific slots that are periodically alternated with downlink slots on the 3.5GHz carrier. This periodic action ensures that secondary harmonic interference from SUL uplink transmissions does not coincide with downlink receptions, thereby maintaining both uplink coverage improvement and downlink reception reliability.

Inventive Principle:
Principle #19Periodic action

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

Effectively prevents self-interference by dynamically adjusting communication resources, enhancing signal transmission quality in dual connectivity and carrier aggregation scenarios.

Implementation Method 1

a downlink reception signal at a frequency of 3.5GHz for the UE may be adversely affected by a second harmonic interference generated by the uplink signal at a frequency of 1.8GHz

Methodology Applied
Scientific EffectSecond harmonic generation: Second Harmonic Generation

Implementation Method 2

the downlink reception signal at a frequency of 3.5GHz for the UE may be adversely affected by the secondary harmonic interference generated by the uplink signal at a frequency of 1.8GHz

Methodology Applied
Scientific EffectSecondary harmonic generation: Second Harmonic Generation

Data Source

PatentEP3706489B1Method for evading signal interference and network device
Publication Date: 2024.06.26 VIVO MOBILE COMM CO LTD
  • EP3706489B1 patent drawingFigure 1~2
  • EP3706489B1 patent drawingFigure 3
  • EP3706489B1 patent drawingFigure 4

AI summary

The present disclosure provides a signal interference avoidance method and a network device, so as to prevent the occurrence of a self-interference for a UE. The signal interference avoidance method includes, when the self-interference occurs for the UE connected concurrently to a first network device and a second network device, transmitting first interference avoidance indication information to the second network device. The first interference avoidance indication information is used to enable the second network device to communicate with the UE through a first time-domain resource and/or a first frequency-domain resource. The first interference avoidance indication information includes identification information about the UE. According to the present disclosure, it is able to effectively prevent the occurrence of the self-interference for the UE, thereby to improve the signal transmission quality.