An Open-Source QAM MODEM for Visible Light Communication in FPGA for Real-Time Applications
Year: 2026
Type: article
Abstract: Visible Light Communication (VLC) is a transformative paradigm poised to revolutionize the automotive and numerous other sectors. As the demand for high data rates and low latency applications grows, the limited bandwidth of standard white LED-based lamps-typically restricted to a few MHz-presents a significant bottleneck. While high-order modulation schemes like Quadrature Amplitude Modulation (QAM) offer superior spectral efficiency, their computational complexity often hinders real-time implementation. Consequently, the existing literature lacks experimental validation of low-latency real-time VLC links. This work addresses this challenge by proposing a modified algorithm that is implemented in a resource-efficient QAM modulator/demodulator (MODEM) for an FPGA. The algorithm includes the synchronization loop. The proposed MODEM is available as open-source code and provides a scalable foundation for researchers to explore low-latency real-time VLC links. Experimental results demonstrate successful 2, 4, and 6 Mb/s links using 4-, 16-, and 64-QAM constellations, respectively, over a white-phosphor-power LED. We measured a latency of less than 1.3 μs.
Source: Sensors
DOI: 10.3390/s26030992
Author: Stefano Ricci
Institution: University of Florence
Language: English
Subfield: Electrical and Electronic Engineering
Field: Engineering
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $3,137
OpenAlex ID: W7127353027