LBT Occasion Provisioning for Uplink Reliability

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Solution Overview

Problem

Wireless communication networks face interference and performance degradation due to transmission uncertainty in unlicensed spectra, particularly in 5G URLLC-U, which requires stringent reliability and low latency, and existing methods struggle to robustly handle interference and resource allocation effectively.

Innovation Solution

Implementing a method that includes provisioning Listen Before Talk (LBT) occasions for user equipment (UEs) before uplink transmissions, allowing them to acknowledge downlink transmissions and adjust their transmissions based on detection results, thereby reducing interference and enhancing reliability without requiring precise detection of base station transmissions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If Listen Before Talk (LBT) procedures are implemented before uplink transmissions, then interference is reduced and reliability is improved, but transmission latency increases and resource overhead increases

Engineering Contradiction:
Improveuplink transmission reliabilityVSAvoidtransmission latency
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The patent applies preliminary action by implementing LBT procedures before uplink transmissions to detect potential interference in advance. The UE performs LBT in designated LBT occasions prior to transmitting uplink acknowledgments or data, allowing the system to proactively identify and avoid interference conditions rather than reacting after interference occurs, thus improving reliability while managing latency through structured timing.

Inventive Principle:
Principle #10Preliminary action

2Reliability

If Listen Before Talk (LBT) procedures are implemented before uplink transmissions, then interference is reduced and reliability is improved, but resource overhead increases

Engineering Contradiction:
Improveuplink transmission reliabilityVSAvoidresource overhead
Core Design Contradiction:
ReliabilityVSQuantity of substance

Solution Approach 1:

The patent applies partial action by implementing LBT procedures selectively rather than continuously. LBT is performed only in specific LBT occasions that are provisioned for the UE, and only before certain uplink transmissions. This partial implementation reduces resource overhead compared to continuous LBT while still providing sufficient interference detection to improve uplink transmission reliability in critical scenarios.

Inventive Principle:
Principle #16Partial or excessive action

3Reliability

If transmission detection is made more robust to handle uncertainty in unlicensed spectrum, then reliability is improved, but resource overhead increases and complexity increases

Engineering Contradiction:
Improvetransmission detection robustnessVSAvoiddetection procedure complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent applies segmentation by dividing the detection process into distinct LBT occasions that are provisioned separately for different UEs and different uplink transmission types. Rather than implementing a single complex detection mechanism, the system segments detection into multiple simpler, scheduled LBT occasions, reducing overall system complexity while maintaining robustness through distributed detection opportunities.

Inventive Principle:
Principle #1Segmentation

4Reliability

If Listen Before Talk (LBT) occasions are provisioned for all UEs before uplink transmissions, then uplink transmission robustness is improved, but resource overhead increases

Engineering Contradiction:
Improveuplink transmission robustnessVSAvoidresource overhead
Core Design Contradiction:
ReliabilityVSQuantity of substance

Solution Approach 1:

The patent applies universality by creating LBT occasions that serve multiple functions: they provide interference detection for uplink acknowledgments, detect potential conflicts with downlink transmissions, and enable robust transmission scheduling. These multi-functional LBT occasions reduce the need for separate detection mechanisms for different transmission types, thereby improving uplink robustness while managing resource overhead through consolidated detection procedures.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Data Source

PatentEP3804447B1UE/gnb transmission detection and impact on reliability
Publication Date: 2023.12.13 QUALCOMM INC
  • EP3804447B1 patent drawingFigure 1
  • EP3804447B1 patent drawingFigure 2
  • EP3804447B1 patent drawingFigure 3

AI summary

A method of wireless communication includes receiving, by a user equipment (UE) from a base station, downlink transmissions, and performing, by the UE, a listen before talk (LBT) procedure in an LBT occasion provisioned, by the base station, for the UE immediately prior to an uplink transmission that includes an acknowledgement of a downlink transmission. The method also includes transmitting, by the UE to the base station, the uplink transmission based on results of the LBT procedure. In another aspect, a method of wireless communication includes provisioning, by a base station for all served UEs, an LBT occasion immediately prior to an uplink transmission by the UEs. The uplink transmission includes an acknowledgement of a downlink transmission. The method additionally includes transmitting, by the base station to the UEs, downlink transmissions, and receiving, by the base station, the uplink transmission.