Wake-Up Signal Reference Sequence Indication for UE Synchronization

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Solution Overview

Problem

Current wireless communication systems face challenges in efficiently waking up user equipment (UE) from sleep mode while maintaining low power consumption and reducing latency, especially in scenarios where periodic wake-ups are unnecessary.

Innovation Solution

The method involves transmitting a wake-up signal (WUS) from a network node to a UE, along with parameters for a reference sequence, which the UE uses to perform synchronization after waking up, allowing for efficient frequency and timing loop refinement and reducing power consumption and latency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the UE performs periodic wake-ups to check for downlink data, then the UE can respond to network communications, but the power consumption increases and latency is introduced

Engineering Contradiction:

ImproveUE wake-up reliabilityVSAvoidUE power consumption

Core Design Contradiction:

ReliabilityVSUse of energy by moving object

Solution Approach 1:

The network node transmits the wake-up signal and reference sequence parameters in advance before the UE needs to wake up. The UE receives and stores these parameters during sleep mode, so when wake-up is triggered, the UE already has the necessary reference sequence information ready, eliminating the need for periodic full wake-ups and reducing power consumption while maintaining reliable communication initiation.

Inventive Principle:

Principle #10Preliminary action

2Reliability

If the UE wakes up frequently to check for communications, then the UE can maintain connectivity, but the latency increases due to repeated wake-up cycles

Engineering Contradiction:

ImproveUE connectivityVSAvoidWake-up latency

Core Design Contradiction:

ReliabilityVSLoss of time

Solution Approach 1:

The network node acts as an intermediary by transmitting both the wake-up signal and the reference sequence parameters through a single downlink signal. This intermediary approach allows the UE to wake up only when necessary (when actual communication is needed) rather than periodically, reducing latency while maintaining connectivity through the coordinated wake-up mechanism initiated by the network node.

Inventive Principle:

Principle #24Intermediary (Mediator)

3Use of energy by moving object

If the UE uses a low-power wake-up signal without reference sequence parameters, then the power consumption is reduced, but the UE cannot perform proper synchronization after wake-up

Engineering Contradiction:

ImproveWake-up power consumptionVSAvoidSynchronization precision

Core Design Contradiction:

Use of energy by moving objectVSMeasurement precision

Solution Approach 1:

The network node merges the wake-up signal function with the reference sequence parameter transmission in a single downlink signal. This combination allows the UE to receive both the wake-up trigger and the synchronization parameters simultaneously, enabling proper frequency and timing loop refinement after wake-up while maintaining low power consumption during the sleep state.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The reference sequence parameters are transmitted and stored in advance during the wake-up signal reception phase. This preliminary action ensures that when the UE performs synchronization after wake-up, the necessary reference sequence information is already available, enabling precise frequency and timing adjustment without requiring additional high-power signals.

Inventive Principle:

Principle #10Preliminary action

4Device complexity

If the network node transmits wake-up signals without reference sequence parameters, then the signal transmission is simplified, but the UE cannot refine frequency and timing loops after wake-up

Engineering Contradiction:

ImproveWake-up signal complexityVSAvoidFrequency and timing precision

Core Design Contradiction:

Device complexityVSMeasurement precision

Solution Approach 1:

The network node combines the wake-up signal with reference sequence parameters in a single integrated transmission. This merged signal structure maintains relative simplicity in the wake-up mechanism while providing the UE with the necessary information for frequency and timing loop refinement, achieving both simplicity and precision without requiring separate complex transmission phases.

Inventive Principle:

Principle #5Merging (Combining)

Data Source

PatentUS20240098637A1Reference sequence indication for a user equipment wake-up

Publication Date: 2024.03.21 QUALCOMM INC

AI summary

Various aspects of the present disclosure generally relate to wireless communication. In some aspects, an apparatus may receive a wake-up signal (WUS) indicating that the user equipment (UE) is to perform a wake-up from a sleep mode. The apparatus may determine a set of parameters for a reference sequence to be used in association with performing a synchronization after the wake-up. The apparatus may receive the reference sequence based at least in part on the set of parameters. Numerous other aspects are described.