Grant-Free Uplink Detection Signals for Terminal Identification

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Solution Overview

Problem

In future radio communication systems like NR, the lack of UL grants in grant-free transmission leads to challenges in identifying the user terminal transmitting UL data, resulting in potential declines in communication throughput and spectral efficiency.

Innovation Solution

The implementation of a detection signal transmitted using specific radio resources, allowing the radio base station to recognize UL grant-free transmission and identify the user terminal, through the use of signal sequences, time and frequency resources, and indicators.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Speed

If UL grant-free transmission is employed to reduce latency, then communication speed is improved, but the ability to identify the user terminal transmitting UL data deteriorates

Engineering Contradiction:
Improvecommunication speedVSAvoiduser terminal identification information
Core Design Contradiction:
SpeedVSLoss of information

Solution Approach 1:

A detection signal is introduced as an intermediary element that carries user terminal identification information. This detection signal is transmitted together with UL data in grant-free uplink transmission, enabling the base station to identify the transmitting user terminal without requiring traditional UL grants. The detection signal acts as a mediator that bridges the gap between rapid grant-free transmission and necessary terminal identification.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Speed

If UL grant-free transmission is used to reduce latency, then communication speed is improved, but communication throughput deteriorates

Engineering Contradiction:
Improvecommunication speedVSAvoidcommunication throughput
Core Design Contradiction:
SpeedVSProductivity

Solution Approach 1:

The detection signal serves as an intermediary that enables the base station to efficiently process grant-free uplink transmissions by providing terminal identification. This allows the system to maintain high communication speed while improving throughput through better resource management and reduced errors in identifying transmitting terminals.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Speed

If UL grant-free transmission is used to reduce latency, then communication speed is improved, but spectral efficiency deteriorates

Engineering Contradiction:
Improvecommunication speedVSAvoidspectral efficiency
Core Design Contradiction:
SpeedVSLoss of energy

Solution Approach 1:

The detection signal acts as an intermediary that enables efficient spectral utilization in grant-free transmission. By providing terminal identification information, it allows the base station to properly manage and allocate spectral resources, reducing waste and improving overall spectral efficiency while maintaining the low-latency benefits of grant-free transmission.

Inventive Principle:
Principle #24Intermediary (Mediator)

Data Source

PatentEP3641464B1Terminal, radio communication method and base station
Publication Date: 2025.08.06 NTT DOCOMO INC
  • EP3641464B1 patent drawingFigure 1A~1B
  • EP3641464B1 patent drawingFigure 2
  • EP3641464B1 patent drawingFigure 3

AI summary

According to one aspect of the present invention, a user terminal has a transmission section that transmits UL data without a UL transmission indication from a radio base station, and a control section that determines a radio resource for a detection signal for detecting the UL data. When transmitting the UL data, the transmission section transmits the detection signal by using the determined radio resource. According to one aspect of the present invention, even when UL data is transmitted without UL transmission indications from a radio base station, the decline in communication throughput and the like can be reduced.