Root Sequence Index Allocation Using Interference Conflict Ranking

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Solution Overview

Problem

Existing wireless communication networks face interference issues due to conflicts between root sequence indices (RSIs) allocated to different cells, leading to failures in random access procedures and suboptimal network performance.

Innovation Solution

A method to detect and resolve RSI conflicts by determining conflict ranks based on expected interference levels, allocating RSIs to cells with minimal interference, and optimizing RSI allocation using a network configuration system to ensure efficient use of RSIs across cells with varying ranges.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If root sequence indices are allocated to multiple cells without conflict detection, then network configuration is simple and fast, but interference occurs between random access signals of different cells

Engineering Contradiction:
Improverandom access success rateVSAvoidRSI allocation complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The system performs preliminary detection of RSI conflicts and determination of conflict ranks before final RSI allocation. By proactively identifying potential interference issues and ranking cells by their expected interference levels, the system resolves conflicts in advance, ensuring reliable random access without requiring complex real-time interference management during operation.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The system uses feedback from conflict detection results to dynamically adjust RSI allocations. By monitoring which RSIs cause conflicts and how severe the interference is (conflict rank), the system iteratively optimizes the allocation to minimize interference while maintaining simplicity in the allocation process.

Inventive Principle:
Principle #23Feedback

2Object-affected harmful factors

If root sequence indices are changed to avoid conflicts, then interference is reduced, but the allocation process becomes more complex

Engineering Contradiction:
Improveinterference levelVSAvoidallocation process complexity
Core Design Contradiction:
Object-affected harmful factorsVSDevice complexity

Solution Approach 1:

The system changes the parameter of RSI selection by introducing conflict rank as a new dimension for decision-making. Instead of arbitrarily selecting non-conflicting RSIs, the system ranks available RSIs based on their expected interference levels and selects those with the lowest conflict ranks, systematically reducing interference while maintaining a structured allocation process.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The system applies different allocation strategies to different cells based on their local characteristics. By determining conflict ranks specific to each cell's environment and interference profile, the system tailors the RSI allocation to local conditions, reducing interference where it matters most while keeping the overall process manageable.

Inventive Principle:
Principle #3Local quality

3Manufacturing precision

If comprehensive conflict detection is performed across all cells, then RSI allocation accuracy is improved, but processing time increases

Engineering Contradiction:
ImproveRSI allocation accuracyVSAvoidprocessing time
Core Design Contradiction:
Manufacturing precisionVSLoss of time

Solution Approach 1:

The system segments the comprehensive conflict detection process into manageable parts by evaluating cells in groups or prioritizing based on their importance and interference potential. By dividing the network into segments for conflict analysis and using hierarchical conflict rank determination, the system achieves accurate RSI allocation without requiring exhaustive simultaneous analysis of all cells.

Inventive Principle:
Principle #1Segmentation

Data Source

PatentEP4523443B1Root sequence index determination based on expected interference with other cells
Publication Date: 2026.02.11 ELISA OYJ
  • EP4523443B1 patent drawingFigure 1~2
  • EP4523443B1 patent drawingFigure 3
  • EP4523443B1 patent drawingFigure 4

AI summary

Example embodiments may relate to determining root sequence indices (RSI) for a cell. A computer- implemented method may comprise: obtaining a first set of N1 RSIs allocated to a first cell; obtaining a plurality of RSI sets allocated to a plurality of second cells; determining an RSI conflict; determining a conflict rank for the plurality of second cells, wherein the conflict rank is indicative of a level of expected interference with the first cell; determining a plurality of RSI lists associated with the plurality of second cells; selecting an RSI list, which is indicative of a set of N1 RSIs not allocated to any of the plurality of second cells, and which is associated with a cell having a conflict rank indicative of a lowest level of expected interference; and allocating the set of N1 RSIs not allocated to any of the plurality of second cells to the first cell.