Experimental Demonstration of 4-level PAM for Sub-pixel Optical Camera Communications

As Internet of Things (IoT) technologies proliferate, a scarcity of radio frequency (RF) spectrum resources becomes apparent. One promising solution lies in Visible Light Communication (VLC), which offers a novel approach to wireless data transmission. Optical Camera Communications (OCC), a sub-field of VLC, demonstrates potential for outdoor wireless sensor networks applications, particularly through sub-pixel OCC, a technique allowing the re-use of existing camera equipment for communication. This study presents an experimental demonstration of a sub-pixel OCC link using 4-Pulse Amplitude Modulation (4-PAM), an approach striking a balance between spectral efficiency and receiver complexity. The paper outlines the system architecture, experimental setup, and comprehensive results, focusing on the potential of a sub-pixel OCC system with 4-PAM for a wide range of applications, from indoor localization to smart environments and IoT connectivity. The results demonstrate the system’s ability to accurately distinguish between different signal levels under varying light conditions, contributing to the exploration of OCC links and providing a viable blueprint for their application in various technological domains. This experimental work bridges the theoretical and practical aspects, thereby fostering the continuous development and expansion of VLC technology.