Abstract: The past decades have witnessed revolutionary advancements in the area of wireless communications. This process saw an evolution from the first generation of wireless standards to the 5G and beyond, mainly for achieving improved data rates. Over the past decade, it has become increasingly important for researchers to find energy-efficient solutions to meet the ever-growing demands of users. In response, the radio frequency (RF) signals-based energy harvesting (EH) technique emerged as a plausible solution to provide a stable source of replenishing the power and alleviating the burden of replacing the batteries. Moreover, the emergence of Internet-of-Things (IoT) lately has led to the explosion of a plethora of low-power-consuming smart devices. Not to mention, the pandemic outburst of COVID-19 recently has aided the dependency on smart devices in our day-to-day lives to avoid physical human contact. To accommodate such a huge number of devices while efficiently utilizing the spectrum led to the resurgence of backscatter communication a technique widely adopted in radio frequency identification (RFID).
Motivated by the above, this thesis mainly focuses on and forms a part of the area designed for the applications of green IoT. Our main idea is to focus on the interaction of two different types of devices---a backscatter tag and an EH device. These two wireless devices operate at low power values and also decrease the dependency on conventional batteries in addition to performing the requisite tasks. Therefore, these two technologies have gained significant attention from the perspective of IoT. Our research work focuses on the hybrid user scenario that lies at the intersection of the research areas of the RF-EH and the backscatter communication. We explore various communication scenarios that revolve around the point that either the devices communicate amongst themselves with/without a relay or cooperatively send the information to an access point in the presence of a carrier emitter. Based on this and the device's specific properties, we formulate resource allocation problems tailored to these communication scenarios and devise computationally efficient solution approaches to those problems.
Publications:
Journals:
S. Gujral and S. Sarma, "Power Minimization in Multi-antenna Transmitter Aided Bidirectional Tag-to-Device Communications for IoT", in IEEE Transactions on Vehicular Technology, 2022, doi: 10.1109/TVT.2022.3201402.Â
S. Gujral and S. Sarma, "Wireless powered backscatter-aided cooperative communication scheme for IoT", in Wireless Networks 28.4 (2022): 1771-1784.Â
S. Gujral and S. Sarma, "Relay Aided Bidirectional Tag-to-Device Communications for Green IoT" [Under review].
S. Gujral and S. Sarma, "Backscattering Empowered Wireless Powered Cooperative Communications for Green IoT" [Under revision].
Conferences:
S. Gujral and S. Sarma, "Backscatter-NOMA Empowered Wireless Powered Cooperative Communications for Green IoT", National Conference on Communications (NCC-2024), IIT Madras, March 2024
S. Gujral, "Relay-Aided Bidirectional Communications Between Devices in a Hybrid User Scenario for IoT", National Conference on Communications (NCC), IIT Guwahati, July 2021.
S. Gujral, S. Sarma, and S. Banerjee, "Transmit Power Minimization in Bidirectional Tag-to-Device Communications for IoT", International Conference on COMmunication Systems & NETworkS (COMSNETS), January 2021.
S. Gujral and S. Sarma, "Cooperative Communication in Hybrid User Scenario incorporating Backscattering and Energy Harvesting", IEEE International Conference on Advanced Networks and Telecommunications Systems (ANTS), December 2019.