Visible Light Communication Using Red Luminance Modulation
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Solution Overview
Problem
Conventional methods for home electric appliance communication are limited to devices with three color light sources, restricting communication capabilities for appliances without such sources.
Innovation Solution
A transmitting method using a light emitter that changes luminance to transmit visible light signals, including data, preamble, and payload, by modulating the red color luminance, allowing communication with various apparatuses, including those without three color light sources.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If conventional methods using three color light sources are used, then communication can be established between illuminators, but communication is limited to devices with three color light sources only
Solution Approach 1:
The patent applies universality by enabling visible light communication using a single red color light source instead of requiring three color light sources. This makes the communication system universally applicable to various devices including home electric appliances with simple light emitters, eliminating the need for complex three-color configurations while maintaining communication capability across different device types
2Productivity
If visible light signal packet length is reduced, then data transmission speed increases, but signal reliability may deteriorate
Solution Approach 1:
The patent applies parameter changes by optimizing the luminance modulation pattern with specific timing parameters. The signal includes a preamble portion with alternating high and low luminance periods, followed by a data portion where luminance changes encode data. By carefully controlling the duration and pattern of luminance changes, the system achieves faster transmission while maintaining reliable signal recognition and decoding
Solution Approach 2:
The patent applies preliminary action by including a preamble portion before the actual data transmission. The preamble establishes synchronization and allows the receiving device to prepare for data reception, ensuring reliable communication even with shortened packet lengths. This preliminary signaling structure enables faster overall transmission by reducing setup time while maintaining signal reliability
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
Enables efficient communication between diverse home electric appliances, including those without three color light sources, by shortening visible light signal packets and maintaining constant average luminance, thus facilitating faster data transmission.
Implementation Method 1
transmitting method for transmitting a visible light signal by changing luminance of a light emitter... transmitting the visible light signal by changing luminance of a red color represented by a light source included in the light emitter
Data Source
AI summary
A transmitting method for enabling transmission of a visible light signal in short time includes: determining a pattern of change in luminance of the light emitter by modulating a signal; and transmitting the visible light signal by changing luminance of a red color represented by a light source according to the determined pattern. The visible light signal includes data, a preamble, and a payload. In the data, a first luminance value and a second luminance value appear along a time axis. In the payload, the first luminance value and the second luminance value appear alternately along the time axis, each of a time length in which the first luminance value is maintained and a time length in which the second luminance value is maintained is greater than a first predetermined value and is determined in accordance with the signal and a predetermined method.