Dynamic Resource Allocation for Interference Control in Heterogeneous Cellular Networks

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Solution Overview

Problem

Existing radio communication systems face interference and inefficient frequency utilization when large and small cell base stations share a frequency band, with existing methods either leading to high processing loads or ineffective frequency use due to interference and resource allocation challenges.

Innovation Solution

A radio communication method where the large cell base station dynamically allocates dedicated and shared resources based on information from mobile terminals and small cell base stations, broadcasting resource allocation information to reduce interference and enhance frequency utilization efficiency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If the large cell base station and small cell base station operate at the same frequency, then frequency utilization efficiency is improved, but interference between the base stations increases

Engineering Contradiction:

Improvefrequency utilization efficiencyVSAvoidinterference between base stations

Core Design Contradiction:

ProductivityVSObject-affected harmful factors

Solution Approach 1:

The frequency band is segmented into dedicated resources for the large cell base station and shared resources for both large and small cell base stations. This segmentation allows the system to maintain high frequency utilization through shared resources while protecting against interference using dedicated resources for the large cell base station.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Different quality levels of resource allocation are applied locally: the large cell base station receives guaranteed dedicated resources in areas where interference is critical, while shared resources are made available in areas where frequency utilization is prioritized. This local differentiation resolves the contradiction between interference avoidance and efficient frequency use.

Inventive Principle:

Principle #3Local quality

2Object-affected harmful factors

If the large cell base station and small cell base station operate at different frequencies, then interference between the base stations is reduced, but frequency utilization efficiency deteriorates due to white space areas

Engineering Contradiction:

Improveinterference between base stationsVSAvoidfrequency utilization efficiency

Core Design Contradiction:

Object-affected harmful factorsVSProductivity

Solution Approach 1:

The patent merges the resource allocation strategies of large cell and small cell base stations by introducing shared resources that both can utilize. This combination allows small cell base stations to operate in areas where large cell base stations do not provide coverage, eliminating white space problems while maintaining interference protection through dedicated resources.

Inventive Principle:

Principle #5Merging (Combining)

3Productivity

If resource allocation is controlled to share frequency bands between large and small cell base stations, then frequency utilization efficiency is improved, but the processing load and complexity increase

Engineering Contradiction:

Improvefrequency utilization efficiencyVSAvoidresource allocation control complexity

Core Design Contradiction:

ProductivityVSDevice complexity

Solution Approach 1:

The patent extracts the complexity of dynamic resource allocation from the small cell base station by having the large cell base station determine the allocation of shared resources. The small cell base station only needs to follow the allocation decisions made by the large cell base station, significantly reducing its processing burden while maintaining efficient frequency sharing.

Inventive Principle:

Principle #2Taking out (Extraction)

4Object-affected harmful factors

If dedicated resources are allocated to the large cell base station, then interference protection is improved, but frequency utilization efficiency deteriorates due to constant resource reservation

Engineering Contradiction:

Improveinterference protectionVSAvoidfrequency utilization efficiency

Core Design Contradiction:

Object-affected harmful factorsVSProductivity

Solution Approach 1:

The patent introduces dynamics into resource allocation by allowing the large cell base station to adaptively adjust the amount of shared resources based on current interference conditions and traffic demands. This dynamic approach ensures that dedicated resources provide necessary interference protection while shared resources maximize frequency utilization when conditions permit.

Inventive Principle:

Principle #15Dynamics

Data Source

PatentEP2475209B1Frequency sharing method and radio base station

Publication Date: 2016.07.20 NTT DOCOMO INC

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AI summary

When a frequency band is shared between a large cell system having a large cell base station and a small cell system having a small cell base station, the large cell base station dynamically controls dedicated resources for the large cell base station and shared resources for both the large cell base station and the small cell base station based on predetermined information, broadcasts allocation information of dedicated resources for the large cell base station and shared resources for both the large cell base station and the small cell base station, to the small cell base station belonging to the own cell, and the small cell base station belongs to at least one large cell base station and determines resource assignment in the own cell based on the resource allocation information broadcast from the large cell base station.