Sidelink Grant-Free Resource Allocation for Low-Latency V2X

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Solution Overview

Problem

Conventional V2X transmission schemes in LTE and NR face limitations such as scheduling-related latency, reliance on dynamic signaling, and resource collision in sidelink communications, particularly in Mode 2 grant-free transmissions where UEs autonomously select resources without knowing the transmitter's configuration.

Innovation Solution

The proposed methods involve configuring sidelink grant-free resources using RRC signaling or system information for in-coverage UEs, and preconfiguring resources for out-of-coverage UEs, allowing UEs to determine resources without dynamic signaling by relying on semi-static configurations and blind detection, with mechanisms for resource selection and pattern indication using DMRS or SCI.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If base station schedules sidelink resources using downlink control information, then resource allocation is centralized and controllable, but scheduling latency increases and transmission reliability decreases

Engineering Contradiction:

Improvetransmission reliabilityVSAvoidscheduling latency

Core Design Contradiction:

ReliabilityVSLoss of time

Solution Approach 1:

The base station pre-configures multiple sidelink transmission patterns including time-frequency resources, periodicity, and duration before actual transmission occurs. The transmitting UE selects and autonomously uses these pre-configured patterns without requiring real-time scheduling, thereby eliminating scheduling latency while maintaining centralized resource management.

Inventive Principle:

Principle #10Preliminary action

2Loss of time

If UE autonomously selects sidelink resources, then scheduling latency is reduced, but resource collision increases

Engineering Contradiction:

Improvescheduling latencyVSAvoidresource collision

Core Design Contradiction:

Loss of timeVSReliability

Solution Approach 1:

The sidelink resource pool is segmented into multiple distinct transmission patterns with different time-frequency configurations. Each pattern is assigned to specific UEs or UE groups, dividing the resource space to reduce collision probability while allowing autonomous selection within assigned patterns.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The transmitting UE performs sensing by monitoring sidelink control information from other UEs to identify occupied resources. Based on this feedback, the UE autonomously selects transmission patterns that avoid detected collisions, improving resource allocation reliability while maintaining low latency.

Inventive Principle:

Principle #23Feedback

3Adaptability or versatility

If multiple sidelink transmission patterns are configured, then resource allocation flexibility increases, but sensing complexity and device complexity increase

Engineering Contradiction:

Improveresource allocation flexibilityVSAvoidsensing complexity

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

Different transmission patterns are assigned to different UEs or UE groups based on their specific communication requirements. Each UE only needs to sense and select from its assigned patterns rather than all possible patterns, reducing sensing complexity while maintaining overall system flexibility.

Inventive Principle:

Principle #3Local quality

Data Source

PatentEP3912417B1Method and apparatus for sidelink transmission and resource allocation

Publication Date: 2025.07.02 HUAWEI TECH CO LTD

Figure 1A~1B
Figure 1C~1D
Figure 1E~1F

AI summary

Systems and methods of sidelink configuration, and sidelink transmission are provided. A base station transmits, and correspondingly a user equipment (UE) receives, a UE-specific radio resource control (RRC) signal for indicating a resource pool configuration and a sidelink configured grant (SL CG) configuration. The UE transmits a SL CG transmission using the transmission resource indicated by the SL CG configuration, without the UE receiving, in a downlink control information (DCI), a grant of transmission resources.