Radio Base Station Resource Scheduling with Pathloss Compensation

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Solution Overview

Problem

Current frequency selective scheduling algorithms in LTE networks require high computational complexity and often prioritize users in the cell center, leading to unfair resource allocation and increased inter-cell interference.

Innovation Solution

A method that estimates channel quality by considering pathloss between user equipment and the serving base station, as well as gain towards neighboring base stations, to compensate for pathloss and minimize interference, thereby optimizing resource allocation and fairness across the cell.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If frequency selective scheduling algorithms prioritize users with good channel quality, then cell throughput is maximized, but fairness among user equipments deteriorates

Engineering Contradiction:
Improvecell throughputVSAvoidfairness among UEs
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The patent modifies the channel quality indicator by adding pathloss compensation to the original CQI measurement. This parameter change transforms the scheduling metric from pure channel quality to a composite metric that includes both channel quality and pathloss, enabling the scheduler to achieve both throughput and fairness objectives simultaneously

Inventive Principle:
Principle #35Parameter changes

2Productivity

If channel dependent scheduling prioritizes mobile terminals with good channel conditions, then cell throughput is maximized, but mobile terminals with bad channel conditions are starved

Engineering Contradiction:
Improvecell throughputVSAvoidservice quality for cell-edge users
Core Design Contradiction:
ProductivityVSEase of operation

Solution Approach 1:

The scheduling metric is changed by incorporating pathloss compensation. The modified metric combines instantaneous channel quality with pathloss information, allowing cell-edge users with poor channel conditions but high pathloss (indicating they are at the edge of coverage) to be prioritized, thus improving their service quality while maintaining overall throughput

Inventive Principle:
Principle #35Parameter changes

3Reliability

If proportional fair scheduling is used to improve fairness, then overall fairness is controlled, but computational complexity increases

Engineering Contradiction:
Improveoverall fairnessVSAvoidscheduling algorithm complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

Instead of implementing the full proportional fair algorithm with its complex calculations, the patent applies a simplified approach by adding pathloss compensation to the CQI. This partial implementation achieves fairness improvement without the full computational burden of traditional PF scheduling

Inventive Principle:
Principle #16Partial or excessive action

4Reliability

If pathloss compensation is applied to improve fairness, then resource allocation fairness is enhanced, but inter-cell interference increases

Engineering Contradiction:
Improveresource allocation fairnessVSAvoidinter-cell interference
Core Design Contradiction:
ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The patent applies different scheduling priorities to different spatial locations within the cell. By using pathloss compensation, the scheduler identifies and prioritizes cell-edge users locally, while cell-center users continue to be scheduled based on their channel conditions. This local differentiation improves fairness without causing excessive inter-cell interference since only edge users receive enhanced priority

Inventive Principle:
Principle #3Local quality

Data Source

PatentEP2684414B1A radio base station and a method therein for scheduling radio resources
Publication Date: 2017.05.10 TELEFONAKTIEBOLAGET LM ERICSSON (PUBL)
  • EP2684414B1 patent drawingFigure 1
  • EP2684414B1 patent drawingFigure 2
  • EP2684414B1 patent drawingFigure 3

AI summary

A radio base station and a method therein are provided for scheduling a radio resource to a user equipment. The radio base station estimates a first channel quality and determines a pathloss between the user equipment and the serving radio base station and a gain based on the pathloss. The radio base station also obtains a gain of the user equipment towards of neighbouring radio base stations, and determines a fraction of the determined pathloss, based on the gain and the obtained gains. The radio base station further determines a second channel quality of the channel based on the estimated first channel quality, the determined fraction and the determined pathloss to be compensated for; and schedules a radio resource for the user equipment based on the determined second channel quality.