Optical Wireless Transceiver Motion-Based Power Control

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Solution Overview

Problem

Optical wireless communication systems, such as LiFi, often waste battery resources as access points and stations continuously transmit and receive signals even when there are no other devices in range, leading to inefficient power usage.

Innovation Solution

A transceiver apparatus with a motion sensor that switches between power configurations based on detected motion, transitioning from a low power state to an intermediate and then higher power state only when an optical wireless communication signal is received, optimizing power usage by activating components only when necessary.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the transceiver continuously transmits and receives signals, then communication availability is maintained, but power consumption increases

Engineering Contradiction:
Improvecommunication availabilityVSAvoidpower consumption
Core Design Contradiction:
ReliabilityVSUse of energy by moving object

Solution Approach 1:

The transceiver dynamically adjusts its power configuration based on real-time motion detection and signal presence. The system transitions between lower power configuration (when no motion or signal detected) and higher power configuration (when motion or signal detected), making the power consumption adaptive rather than static. This resolves the contradiction by maintaining communication availability only when necessary while reducing power consumption during idle periods.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system implements feedback loops where the motion sensor continuously monitors for motion and provides output to the controller, and the photodetector continuously monitors for optical signals and provides output to the controller. Based on this feedback, the controller adjusts the power configuration accordingly. This feedback mechanism ensures communication availability is maintained when needed while enabling power savings during idle periods, resolving the contradiction between reliability and power consumption.

Inventive Principle:
Principle #23Feedback

2Use of energy by moving object

If the transceiver uses lower power configuration, then power consumption is reduced, but detection of communication signals may be delayed

Engineering Contradiction:
Improvepower consumptionVSAvoidsignal detection delay
Core Design Contradiction:
Use of energy by moving objectVSLoss of time

Solution Approach 1:

The motion sensor operates in advance to detect motion before optical communication signals are transmitted. When motion is detected, the system proactively transitions to intermediate or higher power configuration, ensuring that the photodetector and receiver circuitry are already active and ready to detect incoming signals. This preliminary action based on motion detection prevents signal detection delays while still allowing the system to operate in lower power mode during truly idle periods.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The system uses periodic motion sensing to determine when to activate higher power modes. Instead of continuously operating at high power, the motion sensor periodically monitors for motion, and upon detection, triggers a transition to appropriate power configuration. This periodic monitoring approach balances power consumption with timely signal detection capability.

Inventive Principle:
Principle #19Periodic action

3Use of energy by moving object

If the transceiver transitions through intermediate power configuration, then power optimization is achieved, but system complexity increases

Engineering Contradiction:
Improvepower optimizationVSAvoidpower configuration management
Core Design Contradiction:
Use of energy by moving objectVSDevice complexity

Solution Approach 1:

The power management system is segmented into distinct, well-defined power configurations (lower power configuration and higher power configuration) with clear transition criteria. The controller implements a state machine approach where each configuration has specific characteristics and transition conditions are explicitly defined based on motion sensor output and photodetector output. This segmentation reduces the complexity of managing power states by creating discrete, manageable configurations rather than continuous power adjustment, while still achieving power optimization.

Inventive Principle:
Principle #1Segmentation

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

This approach significantly reduces power consumption by ensuring that devices only operate at higher power levels when an optical wireless communication signal is present, thereby extending battery life and improving efficiency in wireless communication systems.

Implementation Method 1

a motion sensor configured to sense motion of at least one object in a region about the transceiver apparatus and to produce motion sensor output based on said sensed motion

Methodology Applied
Scientific EffectMotion sensing:

Implementation Method 2

at least one photodetector configured to receive light of a second wavelength or second range of wavelengths and to produce a detection signal in response to the received light

Methodology Applied
Scientific EffectPhotoelectric effect: Photoelectric Effect

Implementation Method 3

Data may be transmitted using light by modulating at least one property of the light, for example the intensity of the light

Methodology Applied
Scientific EffectLight emission and modulation: Light Emitting Diode

Data Source

PatentEP3895343B1Optical wireless communication transceiver and method for controlling the power mode of such a transceiver
Publication Date: 2024.05.01 PURELIFI
  • EP3895343B1 patent drawingFigure 1
  • EP3895343B1 patent drawingFigure 2
  • EP3895343B1 patent drawingFigure 3

AI summary

An optical wireless communication (OWC) transceiver apparatus comprises: at least one light transmitter configured to transmit light of a first wavelength or first range of wavelengths; driver circuitry configured to receive a data signal and to process the data signal to produce a driving signal to drive the at least one light transmitter such that the at least one light transmitter produces a modulated optical signal representative of said data signal; at least one photodetector configured to receive light of a second wavelength or second range of wavelengths and to produce a detection signal in response to the received light; receiver circuitry configured to receive and process the detection signal to produce a receiver signal; demodulation circuitry configured to perform a decoding and/or demodulation process in accordance with an OWC protocol thereby to extract data from the receiver signal; wherein the transceiver apparatus further comprises: a motion sensor configured to sense motion of at least one object in a region about the transceiver apparatus and to produce motion sensor output based on said sensed motion, and a controller configured to move the transceiver apparatus from a lower power configuration to an intermediate power configuration in response to the motion sensor sensing motion, wherein in the intermediate power configuration the controller is configured to monitor output from at least the at least one photodetector and/or the receiver circuitry and move the transceiver apparatus from the intermediate power configuration to a higher power configuration in response to the monitored output being indicative that the at least one photodetector has received light representative of an optical wireless communication signal.