Dynamic CRS Interference Cancellation Switching in Heterogeneous Networks

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Solution Overview

Problem

Wireless communication networks face interference issues due to transmissions from neighboring base stations, which degrade performance on both downlink and uplink, and existing methods like interference cancelation and puncturing have limitations in effectively managing these interferences.

Innovation Solution

A method and apparatus that dynamically switch between common reference signal interference cancelation (CRS IC) and resource element (RE) puncturing based on measured interference parameters, using cooperative resource partitioning between serving and non-serving Node Bs to identify and mitigate interference in subframes.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If interference cancelation techniques are used, then interference reduction is achieved, but computational complexity increases

Engineering Contradiction:
ImproveinterferenceVSAvoidcomputational complexity
Core Design Contradiction:
Object-affected harmful factorsVSDevice complexity

Solution Approach 1:

The patent changes the parameter of interference measurement by introducing a specific metric that combines signal strength and interference level. This allows the system to dynamically adjust between CRS IC and puncturing based on the measured parameter, resolving the contradiction by providing a systematic way to select the appropriate interference mitigation technique rather than always using the more complex CRS IC

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent implements dynamic switching between two interference mitigation techniques (CRS IC and puncturing) based on real-time measurements. The system transitions from a static approach to a dynamic one where the chosen technique adapts to current channel conditions, reducing computational complexity when interference is low while maintaining effectiveness when interference is high

Inventive Principle:
Principle #15Dynamics

2Device complexity

If resource element puncturing is used, then computational complexity is reduced, but interference reduction effectiveness decreases

Engineering Contradiction:
Improvecomputational complexityVSAvoidinterference reduction effectiveness
Core Design Contradiction:
Device complexityVSObject-affected harmful factors

Solution Approach 1:

The system dynamically selects between puncturing and CRS IC based on measured interference parameters. When interference levels exceed a threshold, the system switches to CRS IC for effective interference reduction. When interference is below the threshold, it uses puncturing to maintain lower computational complexity, thus resolving the contradiction adaptively

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent introduces a measurement parameter that quantifies interference severity, which serves as the basis for selecting the appropriate mitigation technique. This parameter-driven approach ensures that puncturing is only used when interference levels justify the simpler processing, maintaining effectiveness while optimizing complexity

Inventive Principle:
Principle #35Parameter changes

3Object-affected harmful factors

If cooperative resource partitioning is implemented, then interference management is improved, but network coordination complexity increases

Engineering Contradiction:
Improveinterference managementVSAvoidnetwork coordination complexity
Core Design Contradiction:
Object-affected harmful factorsVSDevice complexity

Solution Approach 1:

The patent segments the network coordination function by having each node independently measure and report interference parameters to the serving node, which then makes the switching decision. This segmentation reduces overall network coordination complexity by distributing the measurement function while centralizing the decision-making function

Inventive Principle:
Principle #1Segmentation

4Object-affected harmful factors

If dynamic switching between techniques is implemented, then interference mitigation effectiveness is improved, but system complexity increases

Engineering Contradiction:
Improveinterference mitigation effectivenessVSAvoidsystem complexity
Core Design Contradiction:
Object-affected harmful factorsVSDevice complexity

Solution Approach 1:

The patent implements dynamic switching between CRS IC and puncturing based on real-time measurement of interference parameters. The system transitions from static interference mitigation to a dynamic approach where the chosen technique adapts to current conditions, improving overall effectiveness while maintaining manageable complexity through automated decision-making

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system performs self-service by automatically measuring interference parameters and selecting the appropriate mitigation technique without requiring manual configuration or complex external control. The serving node autonomously makes switching decisions based on reported measurements, reducing the need for complex network-wide coordination

Inventive Principle:
Principle #25Self-service

Data Source

PatentEP2625833B1Dynamic switching between common reference signal interference cancelation and resource element puncturing in a co-channel heterogeneous network
Publication Date: 2018.01.10 QUALCOMM INC
  • EP2625833B1 patent drawingFigure 1
  • EP2625833B1 patent drawingFigure 2
  • EP2625833B1 patent drawingFigure 3

AI summary

Communication in a dominant interference scenario may be supported by performing inter-cell interference coordination (ICIC). Resource coordination/partitioning may be performed to allocate resources to a serving Node B located near the vicinity of a strong interfering Node B. The interfering Node B may avoid transmitting on the allocated/protected resources, possibly except for a common reference signal (CRS). A UE can then communicate with the serving Node B on the protected resources in the presence of the interfering Node B and may observe no interference (possibly except for the CRS) from the interfering Node B. When CRS tones of an interferer may collide with control/data tones of a serving cell, CRS interference cancelation (CRS IC) or puncturing of interfered resource elements (REs) may be appropriate. Certain aspects of the present disclosure provide techniques, where the UE may dynamically switch between CRS IC and RE puncturing based on certain parameters.