Base Station TDD Coordination for LTE-NR Intermodulation Mitigation

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Solution Overview

Problem

The coexistence of LTE and NR systems in mobile telecommunications systems leads to interference issues, particularly when LTE operates in FDD mode and NR operates in TDD mode, causing intermodulation products that desensitize the UE receiver and impact LTE performance.

Innovation Solution

Implementing a mechanism for exchanging time division duplexing configurations between LTE and NR base stations via X2 and/or Xn interfaces, allowing dynamic adjustment of subframe patterns and power control to mitigate interference, and enhancing MDT measurement logging to indicate coexistence issues.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If LTE and NR systems operate simultaneously in overlapping frequencies, then network coverage and service capability are improved, but interference and intermodulation products increase causing receiver desensitization

Engineering Contradiction:

Improvenetwork coverage and service capabilityVSAvoidinterference and intermodulation products

Core Design Contradiction:

Adaptability or versatilityVSObject-affected harmful factors

Solution Approach 1:

The patent segments the time domain by introducing a virtual subframe structure that divides each radio frame into multiple virtual subframes. This allows separate scheduling and resource allocation for LTE and NR transmissions, preventing their simultaneous occurrence and eliminating intermodulation interference while maintaining both network services

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent implements periodic time-division multiplexing where LTE and NR transmissions are scheduled in alternating periodic intervals. The network node periodically switches between LTE and NR subframe configurations, ensuring that each system has dedicated time slots free from the other's interference

Inventive Principle:

Principle #19Periodic action

2Object-affected harmful factors

If dynamic subframe configuration is implemented for interference mitigation, then interference reduction is achieved, but signaling overhead and system complexity increase

Engineering Contradiction:

ImproveinterferenceVSAvoidsignaling overhead and system complexity

Core Design Contradiction:

Object-affected harmful factorsVSDevice complexity

Solution Approach 1:

The patent creates a universal virtual subframe structure that serves both LTE and NR systems simultaneously. This unified framework allows a single set of signaling mechanisms to manage both networks, reducing overall signaling overhead compared to separate management systems while enabling dynamic interference mitigation

Inventive Principle:

Principle #6Universality (Multi-functionality)

Solution Approach 2:

The patent pre-configures virtual subframe structures and scheduling patterns in advance based on predicted interference conditions. By preparing resource allocation schemes beforehand and using semi-static configuration, the system reduces the need for frequent dynamic signaling while maintaining effective interference mitigation

Inventive Principle:

Principle #10Preliminary action

Data Source

PatentEP3689016B1Base station and user equipment

Publication Date: 2025.12.17 SONY GROUP CORP

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AI summary

The present disclosure provides a new radio base station for a mobile telecommunications system. The new radio base station has a circuitry configured to communicate with at least one user equipment and at least one LTE base station and to establish a new radio cell. The circuitry is further configured to transmit a time division duplexing configuration of the new radio cell to the LTE base station for identifying, based on the received time division duplexing configuration, a coexistence and intermodulation influence on an LTE receiver of the at least one user equipment.