Li-Pos: A Light Positioning Framework Leveraging OFDM for Visible Light Communication

Area of Science:

• Solid-state lighting design
• Visible Light Communication (VLC)
• Internet of Things (IoT) applications

Background:

• Accurate positioning of light sources and receivers is crucial for solid-state lighting.
• Visible Light Communication (VLC) systems are integral to intelligent buildings and IoT.
• Power and delay spread are key metrics in light-based communication systems.

Purpose of the Study:

• To determine power and delay spread from light sources to receiver planes in VLC systems.
• To optimize LED placement for improved signal reception and energy efficiency.
• To assess the Area Under the Curve (AUC) using analog orthogonal frequency-division multiplexing (OFDM).

Main Methods:

• Utilized Quadrature Amplitude Modulation (QAM) for VLC and Pulse-Width Modulation (PWM) for dimming.
• Analyzed receiver plane power using Mean Square Error (MSE) and Full-Width at Half-Maximum (FWHM) parameters.
• Implemented a framework for LED placement based on varying distances and FWHM.

Main Results:

• A 30% increase in AUC was observed when reducing the number of source LEDs from four to three.
• Received power was confirmed through analysis of LED power distribution across the receiver plane.
• The system demonstrated improved energy consumption with a simple linear lateration estimator.

Conclusions:

• Adjusting the number of LEDs is an effective strategy for enhancing energy efficiency in VLC systems.
• The proposed framework for LED placement optimizes power delivery and signal quality.
• The system shows promise for practical implementation in intelligent environments and IoT networks.