Optical OFDMA for Multi-Cell/Multi-User Indoor Optical Wireless Networks

The research community continues to explore indoor optical wireless communications (OWC) as a potential candidate for increased network capacity in future networks. Much progress has been made in the area of high-speed point-to-point OWC links; however, there are still significant open challenges related to the allocation of resources in dynamic multi-cell and multi-user environments. In this work, we develop and demonstrate a multi-user DC-biased Optical OFDMA (DCO-OFDMA) implementation to dynamically allocate subcarriers across multiple OWC links. Our DCO-OFDMA codebase is integrated in the gr-owc library as an extension of the broadly used GNURadio software toolkit, along with a set of example flowgraphs for applying DCO-OFDMA in practice. Our implementation has been evaluated for various environments in simulation using the gr-owc optical wireless channel module, and experimentally using USRP hardware for SDRs with custom front-end OWC transmitter/receiver hardware. As a result, we provide an experimental analysis framework for DCO-OFDMA concepts that exist in the literature. More relevantly, we offer a testbed model with an easy-to-use and relatively low-cost design that allows for similar multi-cell/multi-user systems to be experimentally evaluated.