Ajay K. Sharma
Work place: National Institute of Technology, Delhi, India
E-mail: sharmaajayk@rediffmail.com
Website:
Research Interests: Engineering
Biography
Ajay K. Sharma received his B.E (ECE) degree from Punjab University, Chandigarh in the year 1986, MS in Electronics and Control from Birla Institute of Technology (BITS), Pilani in the year 1994 and Ph.D. in Electronics Communication and Computer Engineering in the year 1999.
After serving various organizations from 1986 to 1995, he joined National Institute of Technology (Erstwhile Regional Engineering College) Jalandhar as Assistant Professor in the Department of Electronics and Communication Engineering in the year 1996. From 2001, he worked as Professor in the ECE department and thereafter he has worked as Professor in Computer Science & Engineering from 2007 to 2013 in the same institute. He joined as Director, NIT Delhi in 2013 and presently working in NIT Delhi. His major areas of interest are broadband optical wireless communication systems and networks, dispersion compensation, fiber nonlinearities, optical soliton transmission, WDM systems and networks, Radio-over-Fiber (RoF) and wireless sensor networks and computer communication. He has published 272 research papers in the International/National Journals/Conferences and 12 books. He has supervised 18 Ph.D. and 48 M.Tech theses. He has completed two R&D projects funded by Government of India and one project is ongoing. He is the technical reviewer of reputed international journals like-Optical Engineering, Optics letters, Optics Communication, Digital Signal Processing. He has been appointed as the member of technical Committee on Telecom under International Association of Science and Technology Development (IASTD) Canada for the term 2004-2007.
Author Articles
Implementation of SRRC Filter in Mobile WiMax with DWT Based OFDM System
By Harpreet Kaur Manoj Kumar Ajay K. Sharma Harjit P. Singh
DOI: https://doi.org/10.5815/ijcnis.2016.04.08, Pub. Date: 8 Apr. 2016
Pulse shaping filter when applied to the symbols generated for transmission in a bandwidth limited systems allow for bandwidth containment that reduces the Inter-Symbol Interference (ISI) arising from multipath signal reflections which further minimizes the probability of errors at the receiver. Wavelets encompass the advantages of transforming and mapping data onto orthogonal subcarriers with optimal flexibility as well as less complexity which leads to increase the bandwidth efficiency of an Orthogonal Frequency Division Multiplexing (OFDM) system. In this paper Square Root Raised Cosine (SRRC) a pulse shaping technique when applied to Discrete Wavelet Transform (DWT) based OFDM system in mobile WiMax is simulated and its performance analysis in terms of Bit Error rate (BER) as a function of Signal to Noise Ratio (SNR) is investigated for various modulation schemes under AWGN channel. The results obtained show that SRRC filter offers to significantly improve BER for the given SNR and enhance the performance of physical layer in Mobile WiMax. The performance measurements and analysis is done in the simulation developed in MATLAB.
[...] Read more.Impact of Physical Layer Jamming on Wireless Sensor Networks with Shadowing and Multicasting
By Nischay Bahl Ajay K. Sharma Harsh K. Verma
DOI: https://doi.org/10.5815/ijcnis.2012.07.06, Pub. Date: 8 Jul. 2012
This paper analyzes the impact of a physical layer jamming on the performance of wireless sensor networks by performing exhaustive comparative simulations using multicasting and by employing varying intensity of shadowing (constant and log normal). Comprehensive result analysis reveals that jamming drastically degrades the legitimate traffic throughput in a network, and, the constant shadowing approach is a better fit for a static network, both, under static as well as mobile jammer environments, as compared to the log normal one. An improvement in sink-node packet delivery ratio by 15.02 % and 16.58 % was observed with static and mobile jammer environments respectively, under multicasting and constant shadowing mean of 8.0. Further, average sink-node packet delivery ratio with constant shadowing shows an improvement of 4.15% and 5.94%, using static and mobile jammer environment respectively, in comparison to the values obtained under log normal shadowing based network.
[...] Read more.Other Articles
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