LTE Interference Coordination via AOA-Based Resource Grouping

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Solution Overview

Problem

Current interference coordination methods in LTE systems are ineffective in managing co-frequency interference due to random scheduling of users on the same frequency band, leading to varying channel quality and increased Block Error Rate (BLER), especially for cell-edge users.

Innovation Solution

A method that divides time-frequency resources into multiple resource subsets and groups users based on Angles of Arrival (AOA) to allocate mutually orthogonal resources, using priority sequences to reduce co-frequency interference among cells.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If random scheduling of users on the same frequency band is used, then device complexity is reduced, but co-frequency interference increases and channel quality varies

Engineering Contradiction:
Improvescheduling complexityVSAvoidco-frequency interference
Core Design Contradiction:
Device complexityVSObject-affected harmful factors

Solution Approach 1:

The frequency band is segmented into multiple resource subsets, and users are grouped into different user groups based on their Angles of Arrival. Each user group is allocated specific resource subsets, preventing random scheduling while reducing interference through structured segmentation of both frequency resources and user groups.

Inventive Principle:
Principle #1Segmentation

2Object-affected harmful factors

If resource subsets are allocated to reduce interference, then co-frequency interference is reduced, but device complexity increases due to resource division and user grouping

Engineering Contradiction:
Improveco-frequency interferenceVSAvoidresource allocation complexity
Core Design Contradiction:
Object-affected harmful factorsVSDevice complexity

Solution Approach 1:

Users are pre-grouped into different user groups based on their Angles of Arrival before resource allocation. This preliminary grouping simplifies the subsequent resource subset allocation process, as resources can be systematically assigned to user groups rather than individually configuring resources for each user, thereby reducing overall allocation complexity.

Inventive Principle:
Principle #10Preliminary action

3Reliability

If users with same AOA are allocated orthogonal resources, then channel quality is improved, but productivity decreases due to reduced frequency resource reuse

Engineering Contradiction:
Improvechannel qualityVSAvoidspectral efficiency
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The patent introduces spatial dimension (Angle of Arrival) as an additional degree of freedom for resource allocation. By grouping users based on AOA and allocating resources in both frequency and spatial dimensions, the system achieves orthogonal resource allocation for users with same AOA while still allowing frequency resource reuse across different spatial groups, thereby maintaining spectral efficiency while improving channel quality.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

Data Source

PatentEP2373109B1Interference coordination method and access network device
Publication Date: 2018.04.18 CHINA ACAD OF TELECOMM TECH
  • EP2373109B1 patent drawingFigure 1~2
  • EP2373109B1 patent drawingFigure 3~4
  • EP2373109B1 patent drawingFigure 5

AI summary

The present invention discloses a method and access network device for interference coordination, said method comprises: getting time-frequency resource of cell, and dividing said time-frequency resource into multiple resource subsets; grouping users to be scheduled in the cell into multiple user groups according to AOA, the amount of said user groups is equal to the amount of said resource subsets, different user groups have different resource subset, selection priority orders; allocating time-frequency resource of the resource subsets to users, which are in neighboring cells and have the same direction, according to said resource subset selection priority orders of the user groups. The present invention could reduce inter-cell co-frequency interference and improve channel quality.