At the Wits OC Lab, our research is centred on manipulating light and information to overcome the challenges of communication through complex media. We pursue this through three interconnected themes:
- Experimental Systems: Designing and building next-generation optical wireless systems, including long-range free-space optical (FSO) links and high-speed visible light communication (VLC or LiFi).
- Theoretical Foundations: Developing novel coding, information-theoretic, and signal processing frameworks tailored to the unique physics of optical channels.
- Computational Intelligence: Integrating machine learning and artificial intelligence as powerful tools for modelling, predicting, and controlling light propagation, and as a novel computational paradigm in itself.
This work is driven by a dedicated team of postgraduate researchers. If you are an intellectually adventurous and self-motivated student keen to tackle fundamental problems in optics and communications and make a real impact, we invite you to learn more about joining our team.
Facilities
As part of the School of Electrical and Information Engineering, the lab leverages world-class infrastructure. We have a dedicated free-space optics laboratory equipped with programmable hardware, including Spatial Light Modulators (SLMs), Universal Software Radio Peripherals (USRPs), and Field-Programmable Gate Arrays (FPGAs). This facility supports a permanent, 300-metre urban free-space link and has an established line-of-sight for future kilometre-scale experiments.
Current Research Thrusts
Our projects are not isolated pursuits but rather focused applications of our core research themes. A central challenge we address is mitigating the effects of atmospheric turbulence, which distorts optical wavefronts and introduces crosstalk between communication channels.
All-Optical AI
Atmospheric turbulence can be modelled as a complex transmission matrix that scrambles optical signals. We are exploring a paradigm shift: instead of viewing this as a problem to be corrected, we treat the medium itself as a physical computer. The matrix-vector multiplications inherent in light's passage through a scattering medium perform computation. Our research investigates how to harness this "accidental" computation to build all-optical AI systems, turning a communication channel's primary challenge into a computational resource. [Idea]
Long-Range Free-Space Optical Communication
This research thrust poses fundamental questions: What are the ultimate limits of data rate and distance for atmospheric laser communications? We investigate advanced spatial structuring of light, such as mode-division multiplexing, to increase channel capacity and modal diversity for enhanced robustness. A key component of this work involves designing bespoke error-correction codes and digital signal processing (DSP) schemes. We use machine learning techniques to model and predict the channel's slow-varying, quasi-random behaviour, enabling proactive and adaptive link optimisation.
Low-Cost Optical Wireless for the Digital Divide
In this project, we are developing a low-cost, 3D-printed wireless optical communication system using off-the-shelf components wherever feasible. The goal is to create an accessible technology to help bridge the digital divide in underserved communities. This hardware also serves as an agile platform for field-testing the novel communication and coding schemes developed in our other research thrusts.
Hybrid Communication Systems
We are investigating the integration of optical wireless with other physical layers, including radio frequency (RF) and powerline communications (PLC). This work explores novel coding and modulation techniques to create robust, hybrid systems that can dynamically select the optimal transmission medium.
Publications
Please feel free to visit our individual ResearchGate or Google Scholar pages (accessible via the "Team" page) for up to date research publications.
For your convenience we also have an embedded view of selected publications below:
