Speaker
Description
Optical wireless communication (OWC) technologies have gained significant interest over the past two decades; however, early research focused on point-to-point links and novel modulation techniques. More recently, the field has moved towards higher layer design and analysis of multi-cell / multi-user systems, leading to novel schemes for resource allocation across devices and overlapping OWC access points; but much of this work has been based in theory and simulation. Significant effort is required to develop proof-of-concept implementations of such systems, and this limits the opportunity for experimental evaluation of novel techniques for resource allocation and/or handover. To address this, we apply software-defined radio (SDR) tools and concepts that have benefitted the RF research community. Namely, SDR has created a more equitable opportunity for research in the wireless communications field by reducing the barrier to entry and making it more feasible for researchers to physically instantiate novel ideas. We bring this accessibility to OWC systems research by developing a baseline resource allocation implementation for multi-user / multi-cell systems. By developing this implementation within widely used SDR signal processing toolkits, we can offer the module as an open-source tool for other researchers to use as a “golden reference” that can be compared with novel resource allocation techniques and/or iterative improvements to the baseline technique.
The openly available software development toolkit of GNURadio provides an ideal platform for SDR implementation. In particular, GNURadio’s Out-Of-Tree (OOT) modules allow for the addition of custom signal processing blocks. Using this feature, we have developed gr-owc, an open source OOT module for OWC. In October 2021, we published our initial version of gr-owc, with signal processing blocks for OWC channel simulation and common OWC modulation/demodulation techniques. In this work, we will describe our recent contributions to gr-owc, including further development of our DC-biased Optical OFDM (DCO-OFDM) modules and implementation of resource allocation modules for merging multiple data streams via DCO-OFDMA. We will also introduce our methods for using gr-owc to instantiate a physical OWC testbed using X310 USRPs and a combination of custom and COTS front-end OWC hardware.
As a testbed, the key benefit of SDR is that the system is built off modular design principles such that front end transmitter/receiver hardware can be interchanged, and the waveforms generated in software can be parameterized to align with the characteristics of hardware currently in use. As such, we will also introduce our custom-built multi-color OWC transmitter where each color channel can be directly driven by a single real-valued signal from the USRPs with LFTX daughter cards. This enables experimental analysis of wavelength division multiplexing (WDM) and/or wavelength division multiple access (WDMA) systems. In summary, we will present our recent work that extends the initial functionality of gr-owc to include various resource allocation capabilities for testing multi-cell and multi-user OWC systems.
| Talk Length | 15 Minutes |
|---|---|
| Acknowledge | Acknowledge In-Person |
