Adaptive URLLC Uplink Frequency Switching for Reliable Retransmission

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Solution Overview

Problem

Existing wireless communication systems face challenges in meeting the stringent latency and reliability requirements for Ultra-Reliable Low-Latency Communications (URLLC), particularly in overcoming fading and errors in open loop power controls during uplink transmissions.

Innovation Solution

Adapting uplink transmissions for URLLC by employing multiple transmissions with adaptive retransmissions, progressive terminations, or a hybrid approach, using a UE to transmit in a reserved frequency region and adjust to a second frequency region based on network grants for improved reliability and latency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If open loop power control is used for uplink transmissions, then the system complexity is reduced, but reliability deteriorates due to fading and errors

Engineering Contradiction:
Improvepower control complexityVSAvoidtransmission reliability
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The patent implements closed-loop power control where the network entity provides feedback to the UE about transmission quality. The UE adjusts its transmit power based on this feedback to overcome fading and errors, thereby improving reliability while maintaining manageable system complexity through automated feedback-based adjustment.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The patent introduces dynamic power adjustment mechanisms where transmit power is not fixed but adapts in real-time based on channel conditions and network feedback. This dynamic approach allows the system to respond to fading and errors, improving transmission reliability without requiring overly complex predetermined control schemes.

Inventive Principle:
Principle #15Dynamics

2Reliability

If multiple transmissions with adaptive retransmissions are employed, then reliability is improved, but latency increases

Engineering Contradiction:
Improvedelivery reliabilityVSAvoidtransmission latency
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The patent employs pre-scheduled retransmission opportunities and prepares transmission resources in advance. By having predetermined retransmission slots and pre-configured adaptive mechanisms ready, the system can quickly respond to transmission failures without excessive waiting time, thus improving reliability while minimizing latency.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent implements early termination of retransmission sequences when successful delivery is achieved. If a transmission succeeds on the first attempt or early retransmission, the system skips unnecessary subsequent retransmissions, thereby reducing overall latency while maintaining high reliability through the availability of backup retransmission opportunities.

Inventive Principle:
Principle #21Skipping (Rushing through)

3Object-affected harmful factors

If frequency region adaptation is implemented, then interference is reduced, but system complexity increases

Engineering Contradiction:
ImproveinterferenceVSAvoidfrequency adaptation complexity
Core Design Contradiction:
Object-affected harmful factorsVSDevice complexity

Solution Approach 1:

The patent uses network-based feedback mechanisms where the network entity monitors interference conditions and provides guidance to UEs about suitable frequency regions. This feedback-driven approach allows dynamic frequency adaptation to reduce interference while keeping UE complexity manageable through centralized network control and automated UE response.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The network entity acts as an intermediary that coordinates frequency region assignments between multiple UEs and transmissions. By centralizing frequency adaptation control in the network, the system can optimize interference management across the cell while reducing the computational burden on individual UEs, thus lowering overall system complexity.

Inventive Principle:
Principle #24Intermediary (Mediator)

Data Source

PatentEP3491869B1Techniques for adaptive transmissions during urllc
Publication Date: 2025.12.03 QUALCOMM INC
  • EP3491869B1 patent drawingFigure 1
  • EP3491869B1 patent drawingFigure 2
  • EP3491869B1 patent drawingFigure 3

AI summary

A method and apparatus for adapting uplink transmissions during wireless communications are described. The method and apparatus include transmitting, by a user equipment (UE) operating in a Ultra-Reliable Low-Latency Communications (URLLC) mode, a first transmission to a network entity in a first frequency region, the first frequency region corresponding to a reserved frequency division multiplexing (FDM) region of an uplink channel. The method and apparatus include receiving an downlink grant from the network entity in response to transmitting the first transmission, the downlink grant indicating at least a second frequency region for uplink transmissions different from the first frequency region. The method and apparatus include adapting the first frequency region to the second frequency region for transmitting one or both of a retransmission or a subsequent transmission based on the downlink grant.