Inter-Cell Interference Control via Dynamic Uplink Power Adjustment

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Solution Overview

Problem

In cellular communication systems where neighboring cells operate on the same frequency band, inter-cell interference occurs, affecting uplink communications due to limited transmission power capabilities of terminal devices, and existing interference cancellation methods are insufficient in some cases.

Innovation Solution

The solution involves detecting inter-cell interference and determining the capability of interference cancellation, with access nodes controlling uplink transmit power of terminal devices on a sub-frame level by adjusting power settings to either decrease or increase transmit power based on interference cancellation capabilities, and communicating these adjustments between access nodes to optimize signal strength and reduce interference.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If interference cancellation is used to reduce inter-cell interference, then interference strength decreases, but desired signal strength may also be reduced due to power control adjustments

Engineering Contradiction:
Improveinterference strengthVSAvoiddesired signal strength
Core Design Contradiction:
Object-affected harmful factorsVSStrength

Solution Approach 1:

The patent dynamically changes the uplink transmit power parameter based on interference cancellation capability. When interference cancellation is capable, the system decreases uplink transmit power to reduce interference; when interference cancellation is not capable, the system increases uplink transmit power to maintain desired signal strength. This parameter adjustment resolves the contradiction by adapting power levels to the actual interference cancellation capability of the receiver.

Inventive Principle:
Principle #35Parameter changes

2Strength

If uplink transmit power is increased to maintain signal strength, then desired signal strength is improved, but inter-cell interference increases

Engineering Contradiction:
Improvedesired signal strengthVSAvoidinter-cell interference
Core Design Contradiction:
StrengthVSObject-generated harmful factors

Solution Approach 1:

The system dynamically adjusts the uplink transmit power parameter based on the receiver's interference cancellation capability. When the receiver can effectively cancel interference, the transmit power is decreased to reduce inter-cell interference. When interference cancellation capability is insufficient, transmit power is increased to maintain signal strength. This conditional parameter adjustment resolves the contradiction between signal strength and interference generation.

Inventive Principle:
Principle #35Parameter changes

3Object-affected harmful factors

If interference cancellation capability is enhanced, then interference control improves, but device complexity increases

Engineering Contradiction:
Improveinterference controlVSAvoidinterference cancellation capability
Core Design Contradiction:
Object-affected harmful factorsVSDevice complexity

Solution Approach 1:

The patent implements a feedback mechanism where the receiver determines its interference cancellation capability and communicates this information back to the transmitter. The transmitter then adjusts uplink transmit power based on this feedback. This feedback loop enables effective interference control without requiring complex interference cancellation processing at the transmitter side, thereby resolving the contradiction between interference control performance and device complexity.

Inventive Principle:
Principle #23Feedback

Data Source

PatentEP3437385B1Interference control in cellular communication system
Publication Date: 2022.07.27 NOKIA SOLUTIONS & NETWORKS OY
  • EP3437385B1 patent drawingFigure 1~2
  • EP3437385B1 patent drawingFigure 3~4
  • EP3437385B1 patent drawingFigure 5~6

AI summary

This document discloses s solution for inter-cell interference control in a cellular communication system. A method comprises: detecting, by an access node managing an interfered cell in a cellular communication system, inter-cell interference from an interfering cell; determining whether or not interference cancellation performed for a signal received through the access node is capable of cancelling said inter-cell interference; and controlling, on a basis of a result of said determining, uplink transmit power of a terminal device on time-frequency resources allocated to the terminal device.