For next-generation wireless communication systems, reconfigurable intelligent surfaces (RIS) and non-orthogonal multiple access (NOMA) are key technology enhancements. However, RIS experiences hardware impairments leading to imperfect phase compensation. Similarly in NOMA, imperfect successive interference cancellation (SIC) can significantly degrade the performance of the communication system. As part of this talk, we will first derive suitable bounds for a RIS-assisted NOMA communication system under imperfect phase and SIC. Then, we use these bounds to perform user pairing and power allocation for enhancing spectral efficiency. We introduce user pairing algorithms designed for hybrid OMA-NOMA systems, which defaults to OMA to reduce complexity if the achievable sum rate (ASR) gain falls below a specified threshold. Numerical results are presented showcasing the efficacy of the proposed algorithms as compared with the state-of-the-art.
Abhinav Kumar received the Dual degree in Electrical Engineering and Information and Communication Technology, and the PhD degree in Electrical Engineering from the Indian Institute of Technology Delhi, India, in 2009 and 2013, respectively. From December 2013 to November 2014, he was a postdoctoral fellow at the University of Waterloo, Canada. Since November 2014, he has been with Indian Institute of Technology Hyderabad, India, where currently he is a professor. His research interests are in the different aspects of wireless communications and networking including 5G and Beyond communications, Internet of Things (IoT), Machine Learning (ML), Security and Privacy. He is a senior member of the IEEE, an editor for IEEE Transaction on Communications, and a Young Faculty Research Fellowship (YFRF) awaredee under Visvesvaraya PhD Scheme of Ministry of Electronics & Information Technology, MeitY, Govt. of India. He is currently the convenor of the faculty selection committee for the department of electrical engineering at IIT Hyderabad.