Sidelink DCI Scheduling for Low-Latency URLLC Data Transmission

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Solution Overview

Problem

The existing LTE D2D and V2X sidelink communication systems suffer from high latency and unreliable scheduling information transmission, which fails to meet the stringent requirements of Ultra-Reliable and Low-Latency Communication (URLLC) services, particularly due to the two-step process of sidelink scheduling information transmission and poor channel conditions.

Innovation Solution

A method and system where a network device transmits separate DCIs to both terminals involved in sidelink communication, allowing them to receive scheduling information directly, thereby reducing latency and improving reliability by ensuring simultaneous scheduling information delivery.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If sidelink scheduling information is transmitted in two steps (base station to sending UE, then sending UE to receiving UE), then the system maintains backward compatibility with legacy LTE design, but the transmission latency increases significantly

Engineering Contradiction:
Improvebackward compatibilityVSAvoidtransmission latency
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The patent segments the scheduling information transmission by sending separate DCIs to the first terminal (for transmission) and second terminal (for reception) simultaneously through the base station, rather than transmitting as a single unified process. This segmentation allows parallel delivery of scheduling information to both endpoints, reducing overall latency while maintaining compatibility with existing LTE DCI mechanisms.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The base station performs preliminary action by pre-configuring and simultaneously transmitting both the first DCI to the sending terminal and the second DCI to the receiving terminal before the actual sidelink data transmission occurs. This advance preparation of scheduling information for both parties eliminates waiting time and enables immediate data transmission, directly addressing the latency issue.

Inventive Principle:
Principle #10Preliminary action

2Ease of manufacture

If sidelink scheduling information is forwarded through the sending UE via PSCCH, then the system uses existing sidelink control channels, but the reliability deteriorates when channel conditions between UEs are poor

Engineering Contradiction:
Improveuse of existing channelsVSAvoidscheduling information transmission reliability
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The base station acts as an intermediary by directly transmitting the second DCI containing scheduling information to the receiving terminal, bypassing the unreliable UE-to-UE PSCCH channel. This mediator approach ensures that critical scheduling information reaches both terminals through the more reliable base station interface, particularly when direct UE channel conditions are poor, while still utilizing standard DCI formats.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Loss of time

If separate DCIs are transmitted to both terminals simultaneously, then transmission latency is reduced and reliability is improved, but the network device complexity increases

Engineering Contradiction:
Improvetransmission latencyVSAvoidnetwork device complexity
Core Design Contradiction:
Loss of timeVSDevice complexity

Solution Approach 1:

The base station merges the scheduling function for both terminals into a unified process, simultaneously generating and transmitting the first DCI to the sending terminal and the second DCI to the receiving terminal as part of a single scheduling operation. This combining of scheduling tasks reduces overall system complexity compared to managing separate scheduling processes, while achieving parallel delivery of scheduling information to minimize latency.

Inventive Principle:
Principle #5Merging (Combining)

Data Source

PatentEP3841808B1Data transmission method, device and system
Publication Date: 2025.11.05 GUANGDONG OPPO MOBILE TELECOMMUNICATIONS CORP LTD
  • EP3841808B1 patent drawingFigure 1~2
  • EP3841808B1 patent drawingFigure 3~5
  • EP3841808B1 patent drawingFigure 6~9

AI summary

Embodiments of the present disclosure provide a data transmission method, device and system. The method comprises: a network device transmits a first DCI and a second DCI to a first terminal and a second terminal, respectively. The first terminal transmits sidelink data on a time-frequency resource determined by the first sidelink scheduling information in the first DCI. And the second terminal receives the sidelink data on the time-frequency resource determined by the second sidelink scheduling information in the second DCI.