In Partial Fulfillment of the Requirements for the Degree of Doctor of Philosophy
will defend his dissertation proposal
Building Reliable and Robust Wireless System
Connecting devices to the Internet in a reliable and robust way has been the bottleneck in big data era. Devices with connectivity are competing with each other to share the limited spectrum resources, causing spectrum crunch and interferences, which signicantly hampers the IoT vision. In this thesis, we demonstrate how serious the problem is, and then we propose two solutions to solve this problem. Our goal is to connect IoT devices to the Internet with reliability, robustness and adaptiveness using edge computing algorithms and methodologies in a practical manner. One solution is to embrace the interference that is due to spectrum sharing. We have achieved one way communication from WiFi devices to Zigbee devices. We design a novel modulation technique that runs on the WiFi devices (e.g., smartphone) and demodulation technique that runs on 802.15.4 devices (e.g., a wireless controller in a smarthome) to enable WiFi devices to directly communicate with 802.15.4 devices without any gateway. We have demonstrated the feasibility to send messages with a data rate of 16 bps in uncontrolled environment with o-the-shelf devices. In this way, we created a free side channel from the interference between dierent technologies. We will make the communication bidirectional in the following work.
Another solution is to avoid interference by exploring new spectrum resources that can provide connectivity as well, which is visible light communication. It is extremely challenging to get embedded VLC system to work robustly in bright and dynamic ambient light environment. To improve the robustness, we propose the adaptive noise cancellation technique. The proposed technique allows the receiver to correctly receive the light transmitted by the transmitter without any interference from the ambient light. We provide a detailed description of the modulation and demodulation schemes as well as ambient light cancellation mechanism, and their evaluations. We achieved a data rate of 3kbps in both controlled and uncontrolled environment. We will make the communication faster in the following work.
Date: Friday, April 28, 2017
Time: 10:00 AM
Place: PGH 550
Advisors: Prof. Omprakash Gnawali
Faculty, students, and the general public are invited.