LTE DTX Pattern for Wi-Fi Coexistence

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Solution Overview

Problem

The coexistence of LTE and Wi-Fi systems on shared unlicensed frequency bands leads to interference due to overlapping operations, necessitating a method to optimize transmission patterns to enhance spectral efficiency and fairness between the two Radio Access Technologies (RATs).

Innovation Solution

Implementing a Discontinuous Transmission (DTX) communication pattern that cycles between active and inactive periods of transmission, with parameters set based on the LTE System Frame Number (SFN) numerology, allowing alignment with transition boundaries and optimizing transmission power and duty cycles to minimize interference and maximize coexistence.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If LTE and Wi-Fi systems operate simultaneously on shared unlicensed frequency bands, then spectral efficiency and capacity of the LTE system are improved, but interference between the two Radio Access Technologies increases

Engineering Contradiction:
Improvespectral efficiencyVSAvoidinterference
Core Design Contradiction:
ProductivityVSObject-generated harmful factors

Solution Approach 1:

The patent applies periodic action by implementing Discontinuous Transmission (DTX) patterns where LTE transmissions are periodically switched on and off in predetermined time intervals. This allows Wi-Fi systems to access the shared medium during inactive periods while LTE maintains regular transmissions during active periods, thereby reducing interference while preserving spectral efficiency through structured time-division multiplexing.

Inventive Principle:
Principle #19Periodic action

Solution Approach 2:

The patent segments the shared communication medium into distinct time intervals by dividing transmission opportunities into active periods for LTE and inactive periods for Wi-Fi. This temporal segmentation is achieved through DTX patterns that create structured gaps in LTE transmissions, allowing different radio access technologies to operate in different time slots without causing harmful interference to each other.

Inventive Principle:
Principle #1Segmentation

2Object-generated harmful factors

If Discontinuous Transmission (DTX) communication pattern is implemented with cycling between active and inactive periods, then interference between LTE and Wi-Fi is reduced, but transmission time and productivity are affected

Engineering Contradiction:
ImproveinterferenceVSAvoidtransmission time
Core Design Contradiction:
Object-generated harmful factorsVSLoss of time

Solution Approach 1:

The patent applies dynamics by making the DTX pattern configurable and adaptable to different traffic conditions and service requirements. Transmission parameters such as cycle duration, active period length, and duty cycle can be dynamically adjusted based on channel conditions, traffic load, and quality of service requirements, allowing the system to optimize between interference reduction and transmission efficiency in real-time.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent implements parameter changes by allowing flexible configuration of DTX pattern parameters including cycle time, active/inactive period durations, and duty cycle percentages. These parameters can be modified based on network conditions, traffic priorities, and coexistence requirements with other radio access technologies, enabling optimization of both interference management and spectral efficiency through parameter tuning.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP3210428B1Coexistence on a shared communication medium
Publication Date: 2020.10.14 QUALCOMM INC
  • EP3210428B1 patent drawingFigure 1
  • EP3210428B1 patent drawingFigure 2
  • EP3210428B1 patent drawingFigure 3

AI summary

Techniques for co-existence on a shared communication medium are disclosed. To foster co-existence, operation of a first Radio Access Technology (RAT) may be cycled between active periods and inactive periods of transmission, on a communication medium shared with a second RAT, in accordance with a Discontinuous Transmission (DTX) communication pattern. One or more cycling parameters of the DTX communication pattern may be set based on a frame structure associated with the first RAT. Transmission may proceed over the communication medium in accordance with the first RAT and the one or more cycling parameters of the DTX communication pattern.