Wake-Up Receiver Synchronization Channel for IoT Power Reduction

Solution Overview

Problem

Current wireless communication systems face challenges in efficiently awakening receivers from low power sleep states, particularly in machine-type communication and IoT applications, where minimizing resource usage is crucial, and existing synchronization methods are inefficient due to high power consumption and long synchronization times.

Innovation Solution

The implementation of a synchronization channel that uses a wake-up signal, such as a one-bit ON-OFF signal, to alert a wake-up receiver, allowing it to awaken only when necessary, and the use of modified synchronization signals that are more dense in time and less frequent, reducing the need for continuous monitoring of legacy synchronization channels.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If legacy synchronization channels are used for awakening receivers, then receivers can be awakened from sleep states, but power consumption is high and synchronization time is long

Engineering Contradiction:

Improvereceiver awakening capabilityVSAvoidpower consumption

Core Design Contradiction:

ReliabilityVSUse of energy by moving object

Solution Approach 1:

The patent segments the synchronization function into two distinct parts: a wake-up signal (WUS) for low-power receiver activation and traditional synchronization signals (PSS/SSS) for full synchronization. The WUS is a simplified, low-complexity signal that only needs to wake up the receiver, while the full synchronization is performed later using the standard signals. This segmentation allows the receiver to remain in low-power mode longer and only activate full synchronization processing when actually needed, thereby reducing overall power consumption.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The wake-up signal performs a preliminary action by activating the receiver from sleep state before the full synchronization process begins. This preliminary activation allows the receiver to be ready to process subsequent synchronization signals without requiring continuous monitoring of legacy synchronization channels, thus reducing the time and power required for complete synchronization while ensuring reliable receiver awakening.

Inventive Principle:

Principle #10Preliminary action

2Reliability

If legacy synchronization channels are used for awakening receivers, then receivers can be awakened from sleep states, but synchronization time is long

Engineering Contradiction:

Improvereceiver awakening capabilityVSAvoidsynchronization time

Core Design Contradiction:

ReliabilityVSLoss of time

Solution Approach 1:

The patent segments the synchronization function into two distinct parts: a wake-up signal (WUS) for low-power receiver activation and traditional synchronization signals (PSS/SSS) for full synchronization. The WUS is a simplified, low-complexity signal that only needs to wake up the receiver, while the full synchronization is performed later using the standard signals. This segmentation allows the receiver to remain in low-power mode longer and only activate full synchronization processing when actually needed, thereby reducing overall power consumption.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The wake-up signal performs a preliminary action by activating the receiver from sleep state before the full synchronization process begins. This preliminary activation allows the receiver to be ready to process subsequent synchronization signals without requiring continuous monitoring of legacy synchronization channels, thus reducing the time and power required for complete synchronization while ensuring reliable receiver awakening.

Inventive Principle:

Principle #10Preliminary action

3Measurement precision

If continuous monitoring of legacy synchronization channels is performed, then synchronization accuracy is maintained, but resource usage increases

Engineering Contradiction:

Improvesynchronization accuracyVSAvoidresource usage

Core Design Contradiction:

Measurement precisionVSUse of energy by moving object

Solution Approach 1:

The patent implements periodic action by having the receiver monitor for wake-up signals at specific intervals rather than continuously monitoring legacy synchronization channels. The receiver wakes up periodically to check for WUS, and only performs full synchronization processing when a WUS is detected. This periodic monitoring approach maintains synchronization accuracy when needed while significantly reducing resource usage during periods when no communication is required.

Inventive Principle:

Principle #19Periodic action

Solution Approach 2:

The patent extracts the essential awakening function from the complex legacy synchronization channel and creates a separate, simplified wake-up signal mechanism. This extracted WUS mechanism handles the basic receiver activation task independently, allowing the receiver to avoid continuous monitoring of the full legacy synchronization channels, thereby reducing resource usage while maintaining the ability to achieve synchronization when needed.

Inventive Principle:

Principle #2Taking out (Extraction)

Data Source

PatentEP3626003B1Synchronization channel for a wake-up receiver (WUR) in a communication device

Publication Date: 2024.01.17 QUALCOMM INC

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AI summary

A method for communication includes receiving in a user equipment (UE) a configuration for a modified synchronization channel, and the UE periodically awakening and synchronizing to a communication channel using the modified synchronization channel.