Multicell Link Direction Alignment for Wireless Networks

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Solution Overview

Problem

Dynamic allocation of air interface resources in wireless communication systems can lead to misalignment in link direction among neighboring cells, increasing the probability of cross-link interference and transmission failures.

Innovation Solution

A network node determines uplink/downlink ratios for flexible subframes using a look-up-table to optimize link direction assignments, reducing interference by assigning optimal link directions for each subframe in both the cell and its neighboring cells.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If dynamic allocation of air interface resources is used to adapt to traffic situations, then resource utilization efficiency is improved, but link direction misalignment occurs among neighboring cells

Engineering Contradiction:
Improveresource utilization efficiencyVSAvoidlink direction alignment
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The network node receives feedback information from neighboring cells about their uplink/downlink configurations and uses this feedback to determine optimal link direction assignments that align with neighbors, thereby maintaining reliability while preserving dynamic resource allocation benefits

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The system dynamically changes the link direction parameter (uplink/downlink configuration) of flexible subframes based on traffic conditions and neighboring cell states, allowing adaptation to varying traffic situations while coordinating with neighbors to prevent misalignment

Inventive Principle:
Principle #35Parameter changes

2Adaptability or versatility

If dynamic link direction assignment is implemented, then cross-link interference increases, but transmission reliability deteriorates

Engineering Contradiction:
Improvelink direction flexibilityVSAvoidcross-link interference
Core Design Contradiction:
Adaptability or versatilityVSObject-affected harmful factors

Solution Approach 1:

The network node determines the link direction of flexible subframes in advance based on predicted traffic patterns and neighboring cell configurations, preventing cross-link interference before it occurs by proactively assigning non-conflicting directions

Inventive Principle:
Principle #9Preliminary anti-action

Solution Approach 2:

The system uses feedback from neighboring cells about their current and future link directions to adjust flexible subframe assignments, enabling coordinated resource allocation that adapts to changing conditions while avoiding interference through informed decision-making

Inventive Principle:
Principle #23Feedback

Data Source

PatentEP3824688B1Multicell link direction alignment
Publication Date: 2023.10.04 NOKIA TECHNOLOGIES OY
  • EP3824688B1 patent drawingFigure 1~2
  • EP3824688B1 patent drawingFigure 3~5
  • EP3824688B1 patent drawingFigure 6~8

AI summary

To minimize a number of uplink/downlink conflicts when at least some of the subframes within a transmission frame may be flexible allocated either to uplink or to downlink, a network node, which is configured to provide wireless access to user devices in a cell, is configured to determine in the cell and its neighboring cells uplink/downlink ratios of at least the flexible subframes, and based on the uplink/downlink ratios, determine, from a look-up-table, optimal link direction assignments at least for the flexible subframes, and to cause transmissions using the optimal link direction assignments.