ERI: SDR Beyond Radio: Enabling Experimental Research in Multi-Node Optical Wireless Networks via Software Defined Radio Tools and Techniques

University Of Massachusetts Boston, Dorchester MA

Investigators

Abstract

The wireless communications ecosystem continues to be the most influential enabling technology in modern society. We have near-ubiquitous Internet access because of our wireless infrastructure. Wireless connectivity also allows for more than access to information. The wireless Internet of Things has enabled remote control over a breadth of devices – from a coffee pot to a drone or a Tesla. Even in the absence of a human user, wireless networks connect devices in machine-to-machine communications, and they allow our ever-growing artificial intelligence infrastructure to consume massive amounts of data from remote sensors. As data demand continues to increase, the research community is looking towards novel technologies to support the future of wireless. This includes a renewed interest in optical wireless communication (OWC) as a candidate technology for ultra-dense wireless networks. There has been extensive progress in highspeed OWC links; but there are open challenges when considering deployment of multi-user and multi-cell OWC systems in dense environments. Much of the existing work in this area is based in theory or simulation with minimal experimental validation. This tendency is due to the limited availability of toolkits that are openly accessible and possess real-time signal processing capabilities for OWC waveforms. Considering the advancements in RF communications over the past two decades, the RF community has clearly benefited from the concept of software defined radio (SDR) and related tools for RF signal processing. Namely, SDR has created a more equitable opportunity for research in wireless communications by reducing the barrier to entry and making it more feasible for researchers to physically instantiate novel ideas. This project will bring the benefits of SDR to OWC through development of an open-source OWC toolkit that integrates with widely used SDR software and equipment. The toolkit will allow researchers to implement and analyze novel techniques for multi-cell/multi-user OWC networks. The toolkit’s workflow scales from low-level simulation to real-time experimental analysis, including opportunities to explore a variety of research problems that would enable practical deployment of indoor OWC networks. The developed software tools and hardware deployment playbooks will focus on test systems related to multiple access, intercell interference, and handover in dense OWC networks. This project also enables evaluation of optical wireless systems that require distributed transmitters – including dynamic range adaptation, spatial modulation, and indoor positioning. Lastly, device usage characterization is considered in order to provide a deeper understanding of device motion/orientation in dense networks. The resulting characterization will ultimately improve the accuracy of simulations that aim to evaluate highly directional communication systems in the presence of mobile devices. The project offers merit in fundamental OWC research and in the introduction of tools to enable future contributions from the OWC community. The experimental analysis of OWC systems will provide a baseline comparison with theoretical work to either validate theoretical/simulated models or recognize the unique characteristics that may have been overlooked in modeling such systems. Characterization of mobile device usage will also offer value to the research community by improving models for dynamic devices at the scale of indoor wireless networks. In summary, this project will provide baseline experimental analysis for a variety of multi-cell/multi-user OWC systems along with an open-source platform that allows other OWC researchers to bring novel system design ideas to fruition in experimental systems. In this way, the introduction of SDR-based OWC tools will make experimental research in OWC systems more accessible to OWC researchers who have previously focused on theoretical modeling or simulation, and to those who are looking to develop a research program in OWC. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.