Pre-emptive Inter-cell Interference Suppression via Unscheduled PRB Traffic Dilution

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Solution Overview

Problem

Existing techniques for mitigating inter-cell interference (ICI) in cellular wireless communication networks rely on reactive procedures, where interference must be detected and quantized before mitigation strategies can be implemented, leading to inefficiencies and performance degradation.

Innovation Solution

The method involves detecting unscheduled physical resource blocks (PRBs) and diluting downlink traffic across these blocks, while reducing the transmission power of scheduled PRBs, thereby pre-emptively suppressing inter-cell interference without relying on measured interference levels.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If reactive interference mitigation techniques are used, then interference can be addressed after detection, but system performance degrades due to the delay and inefficiency of detecting and quantizing interference before mitigation

Engineering Contradiction:

Improveinterference mitigation effectivenessVSAvoidtime delay in interference mitigation

Core Design Contradiction:

ReliabilityVSLoss of time

Solution Approach 1:

The patent applies preliminary action by proactively identifying unscheduled PRBs and pre-diluting downlink traffic across them before interference occurs. The access node detects unscheduled PRBs and redistributes traffic in advance, eliminating the need to wait for interference detection and quantization. This preemptive approach resolves the contradiction by performing mitigation actions before the harmful effect (interference) manifests, thus improving reliability without time delay.

Inventive Principle:

Principle #10Preliminary action

2Object-generated harmful factors

If transmission power is reduced on scheduled PRBs, then inter-cell interference is suppressed, but downlink traffic capacity may be compromised

Engineering Contradiction:

Improveinter-cell interferenceVSAvoiddownlink traffic capacity

Core Design Contradiction:

Object-generated harmful factorsVSProductivity

Solution Approach 1:

The patent applies segmentation by dividing downlink traffic into two segments: traffic diluted across unscheduled PRBs and traffic on scheduled PRBs. By segmenting the traffic distribution, the system can reduce power on scheduled PRBs to suppress interference while maintaining overall capacity through the unscheduled PRB segment. This resolves the contradiction by creating separate functional zones where interference suppression and capacity maintenance occur independently.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent applies parameter changes by dynamically adjusting the distribution of downlink traffic across different PRBs based on their scheduled/unscheduled status. The access node modifies traffic allocation parameters to route more traffic through unscheduled PRBs, which allows for power reduction on scheduled PRBs without significantly impacting overall downlink capacity. This parameter adjustment resolves the contradiction by changing the operational state of the system to balance interference suppression and capacity maintenance.

Inventive Principle:

Principle #35Parameter changes

Data Source

PatentUS12267785B2Pre-emptive suppression of inter-cell interference in cellular wireless communication networks

Publication Date: 2025.04.01 TELEFONAKTIEBOLAGET LM ERICSSON (PUBL)

AI summary

Embodiments of a method in an access node of a wireless communication network pre-emptively reduces intercell interference, ICI, in neighboring cells. The access node is configured to transmit downlink traffic to a plurality of user equipments, UEs, in a coverage area of the access node. At least one unscheduled physical resource block, PRB, is detected. Downlink traffic across is diluted across the at least one unscheduled PRB. Finally, transmission power of scheduled PRBs is reduced.