D2D Interference Management via Expected Level Broadcasting

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Solution Overview

Problem

In hybrid cellular and Device-to-Device (D2D) networks, interference management is challenging due to the sharing of resources between cellular and ad-hoc portions, leading to performance degradation and increased interference, especially when D2D communications reuse frequencies allocated to cellular users.

Innovation Solution

A node determines and broadcasts expected interference levels for resource blocks, allowing UEs to make informed decisions on resource allocation and transmission power to minimize interference, using tables and interference calculations based on UE characteristics and quality of service requirements, enabling autonomous interference management with limited signaling overhead.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If D2D communications reuse frequencies allocated to cellular users, then data transfer rates and system bandwidth are improved, but interference between cellular and D2D portions increases

Engineering Contradiction:
Improvedata transfer rateVSAvoidinterference
Core Design Contradiction:
ProductivityVSObject-generated harmful factors

Solution Approach 1:

The node performs preliminary actions by determining expected interference levels for each resource block before D2D communications begin. The node calculates these interference levels based on measured time-variant interference, UE characteristics, and QoS requirements, then broadcasts this information to UEs so they can make informed resource selection decisions in advance, preventing interference issues before they occur.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The system implements feedback mechanisms where the node continuously monitors actual interference levels and compares them against expected values. When discrepancies are detected, the node updates the expected interference levels and rebroadcasts this information, enabling dynamic adaptation to changing network conditions and maintaining optimal resource allocation.

Inventive Principle:
Principle #23Feedback

2Adaptability or versatility

If resources are shared between cellular and ad-hoc portions, then system versatility is improved, but interference management complexity increases

Engineering Contradiction:
Improvesystem versatilityVSAvoidinterference management complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The node serves as an intermediary that simplifies the complex task of shared resource management. It collects interference measurements, calculates expected interference levels for each resource block, and broadcasts this information to UEs. This intermediary function abstracts the complexity from individual UEs, allowing them to make simple decisions based on provided guidance while the node handles the complex calculations and coordination.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Loss of energy

If autonomous interference management is implemented by UEs, then signaling overhead is reduced, but measurement and decision making complexity at UE level increases

Engineering Contradiction:
Improvesignaling overheadVSAvoidUE decision making complexity
Core Design Contradiction:
Loss of energyVSDevice complexity

Solution Approach 1:

The node transforms complex interference management into a parameter-based system by calculating and broadcasting expected interference levels as quantitative parameters for each resource block. UEs then make autonomous decisions by simply comparing these parameters against their requirements, converting complex multi-factor decision making into a straightforward parameter comparison that reduces both signaling overhead and UE complexity.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP2425670B1Methods, apparatuses and computer program product for managing device-to-device interference
Publication Date: 2016.07.20 NOKIA TECHNOLOGIES OY
  • EP2425670B1 patent drawingFigure 1
  • EP2425670B1 patent drawingFigure 2a~2d
  • EP2425670B1 patent drawingFigure 3a~3b

AI summary

Various methods for managing device-to-device interference are provided. One example method includes receiving an expected interference level for a resource block, where the expected interference level is represented by data indicative of interference associated with the resource block due to device-to-device communications using the resource block. The example method further includes selecting the resource block for a device-to-device communications session based at least in part on the expected interference level for the resource block. Similar and related example methods and example apparatuses are also provided.