Adaptive TDD Configuration for Interference Mitigation

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Solution Overview

Problem

Current wireless communication systems, particularly in LTE technology, face challenges in efficiently managing downlink and uplink communications in TDD configurations, leading to interference issues between serving cells and neighbor cells, which affects network performance and capacity.

Innovation Solution

The implementation of adaptive TDD configurations that adjust downlink and uplink resource allocations based on cell loading and interference detection, using techniques such as energy detection of CRS tones and CSI-RS tones to identify mismatched subframes, and applying enhanced inter-cell interference coordination mechanisms to mitigate interference.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If TDD configurations are adjusted to increase downlink capacity, then downlink throughput is improved, but uplink interference from neighboring cells increases

Engineering Contradiction:
Improvedownlink throughputVSAvoiduplink interference
Core Design Contradiction:
ProductivityVSObject-affected harmful factors

Solution Approach 1:

The patent implements dynamic TDD configuration adjustment where the eNodeB can change uplink-downlink subframe assignments in real-time based on detected interference conditions and traffic demands. This allows the system to adaptively optimize downlink capacity while preventing uplink interference by switching to configurations that avoid simultaneous uplink transmission in neighboring cells when interference is detected.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system employs interference detection mechanisms that monitor uplink interference levels and provide feedback to the TDD configuration manager. Based on this feedback, the eNodeB adjusts TDD configurations to mitigate interference while maintaining high downlink throughput, creating a closed-loop control system that balances capacity and interference.

Inventive Principle:
Principle #23Feedback

2Productivity

If TDD configurations are adjusted to increase uplink capacity, then uplink throughput is improved, but downlink interference from neighboring cells increases

Engineering Contradiction:
Improveuplink throughputVSAvoiddownlink interference
Core Design Contradiction:
ProductivityVSObject-affected harmful factors

Solution Approach 1:

The patent enables dynamic adjustment of TDD configurations to optimize uplink capacity by increasing uplink subframe assignments when traffic demands require it. The system monitors downlink interference conditions and dynamically switches configurations to avoid scenarios where uplink transmissions in neighboring cells cause interference to downlink receptions, thus improving uplink throughput while controlling downlink interference.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system uses downlink interference detection feedback to guide TDD configuration adjustments. When downlink interference from neighboring cells is detected, the system modifies uplink-downlink subframe assignments to reduce the impact on downlink performance while maintaining high uplink capacity, creating adaptive optimization based on real-time interference conditions.

Inventive Principle:
Principle #23Feedback

3Device complexity

If fixed TDD configurations are used, then system complexity is reduced, but adaptability to varying traffic conditions deteriorates

Engineering Contradiction:
Improveconfiguration management complexityVSAvoidtraffic condition adaptability
Core Design Contradiction:
Device complexityVSAdaptability or versatility

Solution Approach 1:

The patent implements dynamic TDD configuration management that automatically adjusts uplink-downlink subframe assignments based on real-time traffic conditions, interference levels, and network state. This dynamic approach replaces fixed configurations with adaptive configurations that automatically optimize for current conditions, significantly improving traffic adaptability while the system manages the increased complexity through automated algorithms and standardized procedures.

Inventive Principle:
Principle #15Dynamics

Data Source

PatentEP2845433B1Interference mitigation based on adaptive time division duplexing (TDD) configurations
Publication Date: 2021.06.09 QUALCOMM INC
  • EP2845433B1 patent drawingFigure 1
  • EP2845433B1 patent drawingFigure 2
  • EP2845433B1 patent drawingFigure 3

AI summary

A method for mitigating interference in a wireless network includes an eNodeB and/or a UE identifying interference. The eNodeB may identify the interfering TDD configurations based on a downlink signal of a neighboring eNodeB received during an uplink timeslot for a UE associated with the eNodeB. Likewise, the UE may identify an interfering UE based on an uplink signal received during a downlink timeslot for an eNodeB associated with the UE. The eNodeB performs interference management based at least in part on the identified interference. HARQ transmissions are rescheduled from non-anchor subframe potentially not common to a set of TDD configurations to anchor subframe common to the set of TDD configurations.