Sidelink Wake-Up Signaling on PSFCH for Low-Power DRX

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Solution Overview

Problem

Existing wireless communication technologies, particularly in sidelink communications, lack efficient mechanisms for power-saving signals like wake-up and go-to-sleep signals, leading to unnecessary energy consumption and potential interference issues when integrating new physical signals or channels.

Innovation Solution

Implement wake-up and go-to-sleep signals within the existing sidelink feedback channel framework, using dedicated resources that can overlap or be orthogonal to PSFCH resources, without requiring new physical signals or extra dedicated resources, allowing smooth coexistence with existing sidelink technologies.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Use of energy by moving object

If new physical signals or channels are introduced for wake-up and go-to-sleep functionality, then power-saving capability is improved, but system complexity and interference potential increase

Engineering Contradiction:

Improvepower consumptionVSAvoidsystem complexity

Core Design Contradiction:

Use of energy by moving objectVSDevice complexity

Solution Approach 1:

The patent combines wake-up and go-to-sleep signal functionality with the existing Physical Sidelink Feedback Channel (PSFCH) framework. The WUS and GTS are transmitted using the same physical channel structure as HARQ feedback, sharing resources in time-frequency-space-code domains. This merging approach enables power-saving functionality without introducing new physical signals, thereby reducing system complexity while maintaining energy efficiency.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The PSFCH resources are designed to serve multiple functions: traditional HARQ feedback transmission and the new wake-up/go-to-sleep signaling. By making the feedback channel universal, the system can handle both control feedback and power-saving signals through the same infrastructure, eliminating the need for dedicated resources and reducing overall system complexity.

Inventive Principle:

Principle #6Universality (Multi-functionality)

2Use of energy by moving object

If dedicated resources are allocated for wake-up and go-to-sleep signals, then power-saving functionality is improved, but resource overhead and system complexity increase

Engineering Contradiction:

Improvepower consumptionVSAvoidresource overhead

Core Design Contradiction:

Use of energy by moving objectVSQuantity of substance

Solution Approach 1:

The patent merges WUS/GTS signaling with HARQ feedback transmission by utilizing the same PSFCH resources. Instead of allocating separate dedicated resources for power-saving signals, the invention combines both functionalities into a single resource pool, thereby reducing resource overhead while enabling effective wake-up and go-to-sleep operations.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The PSFCH resources are designed to be universal, serving both HARQ feedback and power-saving signaling purposes. This multi-functionality allows the system to reduce resource overhead by eliminating redundant dedicated resources, as the same time-frequency-space-code resources can carry either feedback or wake-up/go-to-sleep signals depending on the transmission context.

Inventive Principle:

Principle #6Universality (Multi-functionality)

3Quantity of substance

If wake-up and go-to-sleep signals are integrated into existing feedback channel, then resource efficiency is improved, but compatibility and coexistence with existing sidelink technologies become challenging

Engineering Contradiction:

Improveresource efficiencyVSAvoidcompatibility

Core Design Contradiction:

Quantity of substanceVSAdaptability or versatility

Solution Approach 1:

The patent segments the PSFCH resources into different domains (time, frequency, space, code) and allows flexible allocation within these segments. This segmentation enables the system to allocate resources for WUS/GTS without disrupting existing HARQ feedback operations, as different segments can be used for different purposes. The segmented approach maintains compatibility with existing sidelink technologies while enabling new power-saving functionality.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The resource allocation for WUS/GTS within the PSFCH framework is designed to be dynamic rather than static. The system can adaptively allocate resources based on traffic conditions, device capabilities, and network requirements. This dynamic approach ensures compatibility with existing sidelink technologies while allowing efficient resource utilization for power-saving signals, as resources can be adjusted to coexist harmoniously with traditional feedback mechanisms.

Inventive Principle:

Principle #15Dynamics

Data Source

PatentUS12581414B2Wake-up signal and go-to-sleep signal for sidelink communications

Publication Date: 2026.03.17 TELEFONAKTIEBOLAGET LM ERICSSON (PUBL)

AI summary

A method, system and apparatus are disclosed for wake-up signal and go-to-sleep signal for sidelink communications. In one embodiment, a wireless device is configured to monitor a power saving signal for the SL DRX on at least one resource within a set of dedicated resources at a physical sidelink feedback channel, PSFCH, occasion. In one embodiment, a wireless device is configured to transmit, to a further WD, a power saving signal for the SL DRX on at least one resource within a set of dedicated resources at a physical sidelink feedback channel, PSFCH, occasion.