VLC Positioning Power Optimization via Sensor Duty Cycling
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Solution Overview
Problem
Conventional visible light communication (VLC) positioning systems face significant power consumption due to continuous operation of image sensors for decoding VLC messages, which is inefficient and leads to high energy expenditure.
Innovation Solution
A mobile device with image sensors configured to switch to a reduced duty cycle state based on motion relative to light fixtures, using positioning assistance data to decode light fixture identifications and predict their presence, thereby reducing unnecessary image sensor activation and power consumption.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If image sensors operate continuously to decode VLC messages, then positioning accuracy is maintained, but power consumption increases significantly
Solution Approach 1:
The system performs preliminary actions by decoding light fixture identifications and determining device motion in advance, allowing the controller to predict when light fixtures will be visible and schedule image sensor activation accordingly, avoiding continuous operation while maintaining positioning accuracy
Solution Approach 2:
The image sensors operate periodically rather than continuously, activated only during predicted periods when light fixtures are visible in the field of view. The controller schedules these periodic activations based on motion analysis and light fixture identification, significantly reducing power consumption while maintaining positioning functionality
2Productivity
If image sensors are enabled all the time, then VLC messages can be decoded continuously, but energy expenditure increases
Solution Approach 1:
The controller performs preliminary decoding of light fixture identifications and motion determination before activating image sensors, allowing the system to predict when VLC decoding is needed and activate sensors only during those periods, maintaining productivity while reducing energy expenditure
Solution Approach 2:
Instead of continuous operation, the system uses periodic image sensor activation scheduled based on predicted light fixture visibility. The controller manages periodic decoding cycles that align with actual VLC signal presence, maintaining necessary productivity with significantly reduced energy expenditure
Data Source
AI summary
Embodiments of apparatuses and methods of power optimization in VLC positioning are disclosed. In one embodiment, a mobile device may include image sensors configured to receive visible light communication signals, a memory configured to store the visible light communication signals, and a transceiver configured to receive positioning assistance data of a venue, and a controller configured to: decode one or more light fixtures within a field of view of the mobile device to obtain corresponding light fixture identifications, determine a motion of the mobile device with respect to the one or more light fixtures based on the light fixture identifications and the positioning assistance data of the venue, and switch the image sensors of the mobile device to a reduced duty cycle state based on the motion of the mobile device with respect to the one or more light fixtures within the field of view of the mobile device.