Sunlight to signals: solar panel as an optical wireless communication receiver for sustainable communication systems

Abstract

The increasing adoption of intelligent transportation systems, smart cities, and energy-efficient wireless networks has further fueled the need for communication technologies that are not only high-speed and reliable but also sustainable and economical. Optical wireless communication (OWC) has been identified as a promising addition to existing radio frequency technologies because of its vast unregulated bandwidth, security features, and resistance to electromagnetic interference. However, the use of traditional optical receivers like photodiodes and avalanche photodiodes is accompanied by the need for separate power sources and is also prone to performance degradation due to high ambient light intensities, smaller receiver area, and the need for a complex optical design at the receiver to collect more energy, therefore increasing the system cost. In recent years, solar panels have gained attention as promising alternatives to conventional optical receivers because they can harvest energy and receive data at the same time. Although photovoltaic devices are primarily designed for power generation, their large sensing area, tolerance to strong ambient light, and widespread availability make them appealing for use in sustainable optical wireless communication systems. However, the inherent electrical properties of commercial silicon solar panels—such as high junction capacitance, which results in limited bandwidth—create major obstacles for achieving high data rates. In addition, much of the existing research has been limited to custom-built photovoltaic devices, controlled laboratory environments, or short-range indoor setups. As a result, the potential of commercially available solar panels for practical, real-world communication applications remains an unexplored research area. This thesis explores the feasibility, design, and optimization of solar panels as optical receivers, with a main emphasis on the use of commercial silicon solar panels and light emitting diode (LED) transmitters for reliable communication. This thesis systematically examines the communication performance of solar panel receivers, derives the bandwidth and sensitivity limits, and introduces new analog front-end designs to improve optical receiver communication performance. The first part of this thesis presents an in-depth experimental study of silicon solar pan els used as communication receivers under various optical and electrical conditions. The performance of solar panel receivers in terms of frequency response, time-domain response, received optical power sensitivity, and communication distance is examined. The effects of transmission distance, optical irradiance, modulation frequency, and ambient light on system performance are comprehensively explored. These experiments show that, although solar panels have very limited bandwidth, their performance can be greatly improved by proper analog signal processing. To overcome these challenges, this thesis develops and experimentally validates new analog front-end receiver designs specifically optimized for commercial solar panels. The proposed architectures employ carefully engineered impedance matching, filtering, and amplification techniques to extend the usable communication bandwidth beyond the photovoltaic device’s inherent electrical limitations. In contrast to earlier approaches based on reverse-biased operation or custom-fabricated receivers, the proposed solutions remain fully compatible with energy harvesting and are built entirely from off-the-shelf components, making them more practical for real-world deployment. Experimental evaluations show significant gains in both bandwidth and achievable data rates, enabling dependable optical communication with standard indoor LED sources under realistic operating conditions. The thesis also investigates simultaneous light information and power transfer (SLIPT) using solar panel–based receivers, with particular attention to the trade-off between harvested energy and communication quality. By examining multiple operating points and receiver configurations, this work offers valuable insight into joint optimization strategies that balance power collection with data throughput. These findings support the development of self-powered or energy-assisted optical wireless systems aimed at low-power and sustainable communication applications. In addition to the indoor environment, this thesis also encompasses the uncharted area of optical wireless communication in vehicular systems with solar-panel receivers. The vehicular system poses distinct challenges, including mobility issues, misalignment, limited orientation, and dead zones. The experimental work of this thesis explores these challenges and validates the use of solar panel receivers in vehicular communication systems, including vehicle-to vehicle and vehicle-to-infrastructure communication. The discussion emphasizes the significant shortcomings of current receiver designs and the need for orientation-resilient, robust receivers in dynamic environments. Overall, this thesis makes the following key contributions: (i) a comprehensive experimen tal characterization of commercial silicon solar panels as optical communication receivers, (ii) the design and validation of novel analog front-end circuits that significantly enhance communication bandwidth using off-the-shelf components, (iii) an in-depth investigation of SLIPT trade-offs in solar panel–based receivers, and (iv) an early exploration of vehicular optical wireless communication using solar panels, identifying open challenges and future research directions. By bridging the gap between laboratory demonstrations and real-world deployment, this work establishes solar panels as viable, sustainable, and low-cost optical receivers, paving the way for their integration into future intelligent transportation systems and energy-efficient wireless networks.