Selective Channel Removal in Multi-Channel Wake-Up Receivers

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Solution Overview

Problem

Existing wireless sensor network wake-up radios face challenges in detecting wake-up signals in the presence of interference, leading to increased latency and power consumption due to the need for frequent channel monitoring and retransmissions.

Innovation Solution

A method and device for detecting wake-up signals by splitting the signal across multiple frequency channels and time slots, determining signal quality, and removing channels with low signal-to-interference-plus-noise ratio, thereby reducing processing complexity and power consumption.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If a single narrow-band channel is used for wake-up signal transmission, then the system complexity is minimized and power consumption is reduced, but the probability of detection decreases and wake-up latency increases when interferers are present

Engineering Contradiction:
Improvesystem complexityVSAvoidprobability of detection
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The wake-up signal is segmented across multiple frequency channels instead of using a single channel. The transmitter divides the wake-up signal into multiple frequency components, and the receiver processes these distributed channels to detect the signal. This segmentation provides frequency diversity, allowing the system to overcome narrow-band interference while maintaining reasonable complexity through selective channel processing.

Inventive Principle:
Principle #1Segmentation

2Power

If the wake-up signal is transmitted on a single frequency channel, then the transmission is simple and power consumption is low, but long wake-up latencies occur when interferers are present due to multiple retransmissions

Engineering Contradiction:
Improvetransmit powerVSAvoidwake-up latency
Core Design Contradiction:
PowerVSLoss of time

Solution Approach 1:

The system transitions from single-channel transmission to multi-channel transmission by adding the frequency dimension. The wake-up signal is distributed across multiple frequency channels, creating a time-frequency grid structure. This dimensional expansion allows the receiver to exploit frequency diversity and detect signals more reliably without increasing transmit power, thereby reducing wake-up latency caused by retransmissions.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

3Reliability

If multiple frequency channels are processed in parallel at the receiver, then the probability of detection is improved in interference scenarios, but the receiver processing complexity and power consumption increase

Engineering Contradiction:
Improveprobability of detectionVSAvoidreceiver processing complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The receiver extracts and processes only the relevant frequency channels that contain wake-up signal components, rather than processing all possible channels. By identifying and isolating the specific channels where wake-up signals are transmitted, the system reduces the effective processing burden while maintaining detection reliability. This selective extraction approach balances between comprehensive multi-channel processing and computational efficiency.

Inventive Principle:
Principle #2Taking out (Extraction)

4Speed

If channel monitoring is performed frequently to meet latency requirements, then the wake-up detection speed is improved, but the power consumption of idle listening increases dramatically

Engineering Contradiction:
Improvewake-up detection speedVSAvoidpower consumption
Core Design Contradiction:
SpeedVSUse of energy by moving object

Solution Approach 1:

The wake-up radio employs periodic channel monitoring instead of continuous monitoring. The simplified wake-up radio wakes up at predetermined intervals to check for wake-up signals on multiple frequency channels, then returns to sleep mode. This periodic operation maintains acceptable wake-up detection speed by checking channels frequently enough to meet latency requirements while dramatically reducing average power consumption compared to continuous monitoring.

Inventive Principle:
Principle #19Periodic action

Data Source

PatentEP2628340B1System and method for selective channel removal in multi-channel receivers
Publication Date: 2014.08.13 STICHTING IMEC NEDERLAND
  • EP2628340B1 patent drawingFigure 1~2
  • EP2628340B1 patent drawingFigure 3~4
  • EP2628340B1 patent drawingFigure 5~6

AI summary

The present invention is related to a method for detecting a transmitted wake-up signal in a wireless communication system comprising a plurality of communication nodes. The method comprises the steps of: receiving at a communication node of said plurality a transmitted wake-up signal, said wake-up signal being split over a plurality of frequency channels and a plurality of time slots, determining per frequency channel an indication of the signal quality on that frequency channel, deciding per frequency channel on removing the signal portion corresponding to that frequency channel, based on the indication of the signal quality, thereby obtaining a reduced received wake-up signal, correlating the reduced received wake-up signal with a version of a local copy of the transmitted wake-up signal, detecting the transmitted wake-up signal from the result of the correlation step.