Sample menu:
Publications
- “Performance Analysis of Active Intelligent Reflecting Surface-Assisted System: BER and Sum-Rate Evaluation”, S. Sharma, K. Deka, C. Adjih, and A. Kumar, IEEE International Conference on Advanced Networks and Telecommunications Systems, ANTS 2023, 17-20 Dec. 2023, MNIT Jaipur, Rajasthan, India.
Synopsis: An active intelligent reflecting surface (IRS) has been introduced as a solution to address the double fading effect in passive IRS (PIRS)-assisted wireless systems, which is caused by a weak reflection link. The active IRS (AIRS) enhances the received signal strength by amplifying the reflected signal and applying a phase shift at the IRS panel. This paper presents the design and analysis of an AIRS-assisted wireless system, with a focus on examining the bit error rate (BER) and sum-rate performance of the system. Effect of imperfect channel state information, modulation order, the distance between IRS and the receiver, and the total reflected power at the IRS panel is studied. The simulation results demonstrate a significant performance improvement of AIRS compared to PIRS, with an improvement of around 15-20 dB. Unlike PIRS, which does not enhance system performance in the presence of a direct link, AIRS proves to be effective. Moreover, it is observed that a PIRS with an ultralarge number of reflecting elements may achieve performance comparable to AIRS when its total reflected power is lower.
- “Impact of Nonlinear Power Amplifier on BER Performance of OTFS Modulation”, S. Sharma, A. Singh, K. Deka and C. Adjih IEEE International Conference on Advanced Networks and Telecommunications Systems, ANTS 2023, 17-20 Dec. 2023, MNIT Jaipur, Rajasthan, India.
Synopsis: Recently, two-dimensional orthogonal time frequency space (OTFS) modulation technique has been introduced in wireless communications to combat the effects of multipath fading and Doppler spread. In this paper, we analyze the impact of nonlinear power amplifier (NPA) and phase noise on the OTFS system over the EVA channel model. The study focuses on the bit error rate (BER) performance concerning the input-back-off (IBO) and the nonlinearity parameter values of the NPA. The results demonstrate that both NPA and phase noise significantly degrade the OTFS system performance, especially for higher modulation schemes and low values of IBO. Furthermore, we numerically analyze the impact of system parameter variations on BER performance.
Related Work
- S. Sharma, K. Deka, "Sparse code and hybrid multiple access techniques", book chapter in "5G and Beyond Wireless Systems", 2021 - Springer
- A. Kumar, P. Hegde, R. Vaze, A. Alloum, C. Adjih, Breaking the Unit Throughput Barrier in Distributed System, NCC 2023, Guwahati, Feb. 2023.
