Dynamic Subframe Allocation for Interference Mitigation

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Solution Overview

Problem

Heterogeneous wireless communication systems face challenges in managing interference and optimizing subframe allocation due to the introduction of low-power nodes, which leads to imbalanced uplink and downlink coverage and limited performance gains.

Innovation Solution

Implementing dynamic special subframe allocation and resource partitioning techniques to mitigate interference and enhance system capacity by configuring almost blank subframes and adjusting subframe allocations based on traffic load and device associations.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If low-power nodes are introduced to enhance network coverage, then system capacity is improved, but uplink and downlink coverage becomes imbalanced and interference increases

Engineering Contradiction:

Improvesystem capacityVSAvoidinterference

Core Design Contradiction:

ProductivityVSObject-affected harmful factors

Solution Approach 1:

The patent segments the transmission time into different types of subframes (normal subframes and almost blank subframes) to separate interference-prone transmissions from interference-sensitive receptions. This temporal segmentation allows low-power nodes to transmit data in normal subframes while macro cells perform channel estimation in almost blank subframes with reduced power, thereby resolving the contradiction between system capacity and interference.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent implements dynamic subframe allocation where the pattern of almost blank subframes and normal subframes can be configured and adjusted based on network conditions, traffic load, and cell-specific requirements. This dynamic approach allows the system to optimize the balance between capacity and interference mitigation in real-time.

Inventive Principle:

Principle #15Dynamics

2Productivity

If special subframe allocation is implemented to mitigate interference, then spectral efficiency is improved, but device complexity increases

Engineering Contradiction:

Improvespectral efficiencyVSAvoiddevice complexity

Core Design Contradiction:

ProductivityVSDevice complexity

Solution Approach 1:

The patent employs periodic patterns of almost blank subframes interspersed with normal subframes, creating a regular, predictable structure that simplifies device implementation. Devices can be configured with periodic patterns (e.g., every 40 or 80 radio frames) rather than handling arbitrary complex schedules, thereby achieving spectral efficiency gains without excessive device complexity.

Inventive Principle:

Principle #19Periodic action

3Measurement precision

If almost blank subframes are configured for channel estimation, then measurement accuracy is improved, but transmission power is reduced

Engineering Contradiction:

Improvemeasurement accuracyVSAvoidtransmission power

Core Design Contradiction:

Measurement precisionVSPower

Solution Approach 1:

The patent extracts the channel estimation function from regular data transmission by dedicating specific almost blank subframes solely to reference signal transmission and channel estimation. This separation allows macro cells to transmit at reduced power during these subframes, improving measurement accuracy by eliminating data transmission interference while maintaining sufficient signal strength for accurate channel state information acquisition.

Inventive Principle:

Principle #2Taking out (Extraction)

Data Source

PatentUS11018786B2Reduced transmission power time interval allocation

Publication Date: 2021.05.25 COMCAST CABLE COMM LLC

AI summary

Aspects relate to allocation of reduced transmission power time intervals. Nodes may provide respective coverage areas. The nodes may indicate to each other respective configurations of reduced transmission power time intervals.