Femto Cell Control Resource Allocation to Avoid Macro Cell Interference

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Solution Overview

Problem

Wireless communication systems face interference issues due to signal strength variations and restricted access, leading to suboptimal service quality and increased interference between nearby cells, particularly in scenarios where a user is closer to a cell with limited capabilities or restricted access.

Innovation Solution

Implementing resource management techniques that identify overlapping control resources between cells and allocate them to minimize interference, such as by reserving control resources that overlap with neighboring cells' resources, allowing for reduced interference during transmissions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If control resources are allocated to maximize resource utilization, then resource efficiency improves, but interference between neighboring cells increases

Engineering Contradiction:
Improveresource utilization efficiencyVSAvoidinterference between cells
Core Design Contradiction:
ProductivityVSObject-affected harmful factors

Solution Approach 1:

The patent segments control resources into different subsets for different cells. Specifically, it divides the available control resources into a first subset and a second subset, where the first subset is used by a first cell and the second subset is used by a second cell. This segmentation ensures that control resources allocated to one cell do not overlap with those of neighboring cells, thereby eliminating interference while maintaining efficient resource utilization.

Inventive Principle:
Principle #1Segmentation

2Adaptability or versatility

If control resources overlap between neighboring cells to increase flexibility, then resource allocation flexibility improves, but signal interference increases

Engineering Contradiction:
Improveresource allocation flexibilityVSAvoidsignal interference
Core Design Contradiction:
Adaptability or versatilityVSObject-generated harmful factors

Solution Approach 1:

The patent applies local quality by assigning different control resource characteristics to different spatial locations (cells). Each cell is configured with specific control resources from the available subsets based on its location and neighboring cell relationships. This localized resource allocation ensures that each cell has appropriate resources tailored to its specific interference environment, maintaining flexibility while avoiding interference through non-overlapping assignments.

Inventive Principle:
Principle #3Local quality

3Reliability

If users connect to the nearest cell for optimal signal strength, then connection quality improves, but interference with other cells increases due to restricted access

Engineering Contradiction:
Improveconnection qualityVSAvoidinterference with neighboring cells
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent implements preliminary action by pre-configuring control resources for each cell before users attempt to connect. The network controller determines the set of control resources for each cell in advance, ensuring that neighboring cells have non-overlapping resource allocations. This preliminary resource configuration prevents interference issues before they arise, allowing users to connect to the nearest cell with optimal signal quality without causing interference problems.

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentEP2283687B1Allocation of control resources of a femto cell to avoid interference with a macro cell
Publication Date: 2016.12.14 QUALCOMM INC
  • EP2283687B1 patent drawingFigure 1
  • EP2283687B1 patent drawingFigure 2
  • EP2283687B1 patent drawingFigure 3

AI summary

Systems and methodologies are described that facilitate resource management in a wireless communication system. Various techniques described herein can enable a network cell in a wireless communication system (e.g., a macro cell) to mitigate the effects of interference on other surrounding network cells (e.g., femto cells embedded within the coverage of the macro cell). For example, a network cell can allocate control resources that overlap control resources of a nearby cell and assign resources within the region of overlap only to users that will not cause substantial interference to the nearby cell. As another example, a network cell can utilize a control channelization that partially coincides with a control and/or random access channelization of a nearby cell. The network cell can subsequently elect not to use the control resources in the coinciding region in order to enable the nearby cell to control the effects of interference though data scheduling.