LTE In-Device Coexistence via Predictive CCA Scheduling

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Solution Overview

Problem

Existing LTE devices face challenges in efficiently operating on both licensed and unlicensed carrier spectrums due to interference and regulatory requirements, particularly when coexisting with Wi-Fi systems.

Innovation Solution

The implementation of a method that coordinates wireless transmissions on one carrier with clear channel assessments on another carrier, involving techniques such as muting transmissions during CCA periods, adjusting CCA thresholds based on in-device interference, and relying on indications from base stations to determine channel availability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If LTE devices perform clear channel assessment (CCA) on unlicensed carriers to check for Wi-Fi transmissions, then coexistence with Wi-Fi systems is improved, but transmission efficiency on licensed carriers deteriorates due to interference from simultaneous transmissions

Engineering Contradiction:
Improvecoexistence with Wi-Fi systemsVSAvoidtransmission efficiency on licensed carriers
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The device performs CCA on the unlicensed carrier before initiating transmission on the licensed carrier. By checking the unlicensed channel status in advance and predicting potential interference, the device can proactively adjust its licensed carrier transmission strategy, preventing interference before it occurs and maintaining both Wi-Fi coexistence and transmission efficiency

Inventive Principle:
Principle #10Preliminary action

2Object-affected harmful factors

If LTE devices mute transmissions on licensed carriers during CCA periods on unlicensed carriers, then interference with CCA is reduced, but transmission continuity on licensed carriers deteriorates

Engineering Contradiction:
Improveinterference with CCAVSAvoidtransmission continuity on licensed carriers
Core Design Contradiction:
Object-affected harmful factorsVSDuration of action of moving object

Solution Approach 1:

The device performs CCA on the unlicensed carrier in advance before licensed carrier transmission. By predicting the CCA outcome and potential interference timing, the device can schedule licensed carrier transmissions to avoid overlapping with CCA periods, eliminating the need for muting and maintaining transmission continuity

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The device dynamically adjusts its transmission strategy based on real-time CCA results and predicted interference conditions. Instead of static muting during fixed CCA periods, the device flexibly schedules licensed carrier transmissions according to actual channel conditions, maintaining both interference avoidance and transmission continuity

Inventive Principle:
Principle #15Dynamics

3Productivity

If LTE devices perform both CCA on unlicensed carriers and transmissions on licensed carriers simultaneously, then spectrum utilization is improved, but in-device interference increases causing transmission failures

Engineering Contradiction:
Improvespectrum utilizationVSAvoidin-device interference
Core Design Contradiction:
ProductivityVSObject-generated harmful factors

Solution Approach 1:

The device performs CCA on the unlicensed carrier and predicts potential interference before initiating licensed carrier transmission. By having the capability to predict interference in advance, the device can make informed decisions about simultaneous operations, maintaining high spectrum utilization while avoiding in-device interference through predictive scheduling

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The device uses feedback from CCA results and interference predictions to dynamically adjust its transmission strategy. By continuously monitoring channel conditions and predicting interference, the device can optimize simultaneous operations on both carriers, maintaining high spectrum utilization while preventing in-device interference through adaptive control

Inventive Principle:
Principle #23Feedback

Data Source

PatentEP3843314B1In-device coexistence with other technologies in LTE license assisted access operation
Publication Date: 2025.04.30 MOTOROLA MOBILITY LLC
  • EP3843314B1 patent drawingFigure 1~2
  • EP3843314B1 patent drawingFigure 3
  • EP3843314B1 patent drawingFigure 4A~4B

AI summary

Methods and structures are disclosed which facilitate co-existence of Long Term Evolution (LTE) type communication signal reception and transmission using one carrier, such as a licensed carrier, and another carrier, such as an unlicensed carrier, in the presence of other transmissions using the other carrier.