Dr. Rahul Kaushik
@jiit.ac.in
Associate Professor, Electronics and Communication Engineering
Jaypee Institute of Information Technology, Noida
Dr. Rahul Kaushik received his B. Tech. (Electronics and Telecommunication Engineering) and M.Tech. (Electronics Engineering) degrees from University of Allahabad, India in 2001 and 2003 respectively. He has completed his Ph. D. in the area of Optical Wireless Communication from Jaypee Institute of Information Technology, Noida, India in 2017. He combines 18 years of teaching and research experience in the field of Electronics and Communication Engineering. He has joined Jaypee Institute of Information Technology (JIIT), Noida, India in July, 2007. Presently, he is designated as Associate Professor. Prior to this, he served G.L Bajaj Institute of Technology and Management, Greater Noida as Assistant Professor and Head of ECE department.
RESEARCH, TEACHING, or OTHER INTERESTS
Electrical and Electronic Engineering, Computer Networks and Communications
Scopus Publications
Scopus Publications
Ankur Sood and Rahul Kaushik
Springer Science and Business Media LLC
Palash Rai and Rahul Kaushik
Walter de Gruyter GmbH
Abstract A technique for the estimation of an optical signal-to-noise ratio (OSNR) using machine learning algorithms has been proposed. The algorithms are trained with parameters derived from eye-diagram via simulation in 10 Gb/s On-Off Keying (OOK) nonreturn-to-zero (NRZ) data signal. The performance of different machine learning (ML) techniques namely, multiple linear regression, random forest, and K-nearest neighbor (K-NN) for OSNR estimation in terms of mean square error and R-squared value has been compared. The proposed methods may be useful for intelligent signal analysis in a test instrument and to monitor optical performance.
Ankur Sood and Rahul Kaushik
Springer Science and Business Media LLC
Pooja Goel and Rahul Kaushik
Springer Science and Business Media LLC
Palash Rai and Rahul Kaushik
Walter de Gruyter GmbH
Abstract In this paper, a technique for optical performance monitoring (OPM) using deep learning-based artificial neural network (ANN) is implemented. ANN is trained with parameters derived from eye-diagram for the identification of optical signal to noise ratio (OSNR), chromatic dispersion (CD) and polarisation mode dispersion (PMD) simultaneously and independently in a 10 Gb/s system with non-return-to-zero (NRZ) on-off keying (OOK) data signal. ANN-based OPM confirms that the proposed approach can provide reliable estimated results. The mean squared errors for OSNR, CD and differential group delay (DGD) are found to be 4.6071 dB, 0.0417 ps/nm/km and 0.0016 ps/km, respectively. The proposed technique may be utilized in analyzing the signals of future heterogeneous optical communication networks intelligently.
Rashi Jain, Sakshi Dhiman, and Rahul Kaushik
Walter de Gruyter GmbH
Abstract In this paper, the performance of a mixed dual hop asymmetric radio frequency andfree space optical (RF-FSO) communication link is investigated. A closed form analytical expression for evaluating outage probability of mixed RF-FSO link is obtained. The source to relay link is RF link modelled using Nakagami-m fading. The relay to destination link is an FSO link subjected to atmospheric turbulence, modelled using K-distribution. Decode-and-Forward (DF) relaying protocol is used. Further, the effect of pointing error on the performance of the link is analysed using obtained closed form expression. It has been observed that increase in the pointing error leads to reduction in outage performance of the link.
Pooja Goel and Rahul Kaushik
Walter de Gruyter GmbH
Abstract The generation of 80 GHz millimeter wave (mm-wave) signal and its transmission over single mode fiber (SMF) is presented. The mm-wave signal is generated with dual parallel dual drive Mach Zehnder modulators using frequency quadrupling of 20 GHz radio frequency signal. Transmission of generated mm-wave signal over SMF has been investigated. The impact of varying modulation depth on optical side band suppression ratio and radio frequency spurious suppression ratio for different extinction ratios (ER) is studied. Further, the impact of dispersion, on received power is also analyzed. Error analysis between analytical and simulation results is carried out. It has been observed, that increasing ER leads to reduction in both peak error and mean error and the received power is reduced under the combined effect of second and third order dispersion at very high modulation depth.
Ankur Sood and Rahul Kaushik
Springer Science and Business Media LLC
Ankur Sood and Rahul Kaushik
IEEE
The proposed communication model using OFDM based radio over free space optical (RoFSO) system with WDM multiplexing is implemented. Two different 20Gbps - 60GHz data streams are transmitted at optical carriers of 193.1 THz and 193.3 THz frequency through single channel FSO link. The FSO link performance is analyzed for various dust conditions. The effect of channel attenuation due to size of suspended dust concentration in terms of particulate matter i.e. PM10 and PM2.5 is analyzed. The effect of various atmospheric turbulence conditions under light dust conditions is also considered in the analysis. Eye diagram pattern is observed under different dust conditions and corresponding bit error rate and Q-factor is measured. At detector output, SNR is measured by using spectrum analyzer. Also, electric constellation is observed for PM 10 and PM 2.5 under various dust conditions using constellation visualizer. The channel attenuation due to the combined effect of various dust pollutants and atmospheric turbulence conditions on FSO link is also analyzed.
Ankur Sood and Rahul Kaushik
Walter de Gruyter GmbH
Abstract An orthogonal frequency division multiplexed-radio over free space optics (OFDM-RoFSO) communication system with dual multiplexing is proposed. Eight input data streams are transmitted simultaneously by using wavelength division multiplexing (WDM) at level 1 and polarization division multiplexing (PDM) at level 2. Input data streams 1–4 and 5–8 are assigned with same set of carrier frequencies i.e. 193.1 THz, 193.3 THz, 193.5 THz and 193.7 THz and separate polarization levels (X and Y polarized) before transmitting through RoFSO link. A total data rate of 160 Gbps (4 × 2 × 20 Gbps) is achieved in this design. With proposed system, channel performance is evaluated under the influence of atmospheric attenuation and turbulence conditions while measuring system BER, Q-factor, SNR and received power etc. The effect of channel crosstalk is analysed for WDM-PDM dual multiplexed design while considering single input single output (SISO) and multiple input multiple output (MIMO) FSO configurations. The overall analysis predicts that a higher transmission rate and improved capacity levels can easily be achieved with dual multiplexed system.
Ankur Sood and Rahul Kaushik
VSB - Technical University of Ostrava
Ankur Sood and Rahul Kaushik
IEEE
The proposed system is implemented for dual multiplexed OFDM-RoFSO system under the effect of different turbulence conditions. Four distinct 20Gbps60 GHz data inputs are initially multiplexed at WDM level with assigned 193.1THz and 193. 3THz carrier frequencies and then at PDM level with horizontal and vertical polarizations. So, a total 80Gbps transmission rate is achieved in this design. The link performance is analysed for BER, received power, channel crosstalk etc. by considering both SISO and $2\\times 2$ MIMO based FSO configurations under weak, moderate and strong turbulence conditions. Results predict that minimum crosstalk levels are observed with $2\\times 2$ MIMO based FSO configuration under clear air attenuation. Eye diagram pattern is analysed to measure BER performance while data transmission through MIMO channel is carried out. A higher transmission rate with improved channel capacity and enhanced system performance is verified.
Pooja Goel and Rahul Kaushik
Walter de Gruyter GmbH
Abstract Radio-over-fiber (RoF) is a technology in which radio frequency (RF) signals are distributed from central station to remote antenna units using fiber. Wavelength division multiplexing (WDM) is a technique in which different data streams are allowed to be sent parallely over a single fiber at different frequencies for increasing bandwidth. Hence, RoF combined with WDM technology is a prominent solution for many applications. In this article, we have designed an 8-channel 40 Gbps WDM-RoF system for future generation networks. The performance of the system has been evaluated using a simulator and then compared with a 4-channel existing system. A dispersion compensating fiber with a dispersion value at −85 ps/nm/km is used for combating nonlinearity. The simulated 8-channel WDM-RoF system has been analyzed by varying bit rate, input power, number of loops (transmission span), and channel spacing using performance parameters such as Q-factor and BER. It has been observed that the performance of the network improved as the channel spacing increased from 50 to 200 GHz. Moreover, the system performance is reliable up to 200 km.
Ankur Sood and Rahul Kaushik
IEEE
Radio-over-free-space-optics (RoFSO) technology is used for transmission of millimeter wave signal using optical network without requiring any optical fiber installation. In this work, the transmission of 20 Gbits/s-60 GHz information is carried out through an OFDM system with 512 subcarriers that are multiplexed in a single channel. By using mode combining technique, Laguerre Gaussian (LG) 01 mode and Hermite Gaussian (HG) 00 modes are combined to generate a hybrid mode for signal transmission in FSO environment. A Dual port Dual drive Mach-Zehnder Modulator (DD-MZM) is configured to generate ODSB and OSSB modulated signals at its output. ODSB and OSSB based systems are compared in terms of received power and signal to noise ratio (SNR) at detector output. A similar analysis is done to measure received power and SNR by using 2, 3 and 4 bit QAM encoder. A 60 GHz RF signal is transmitted through an FSO link using hybrid optical mode to investigate performance in mitigating fading effect due to atmospheric turbulence under clear weather condition.
Pooja Goel and Rahul Kaushik
VSB - Technical University of Ostrava
The analysis of Optical Single Sideband (OSSB) generation with and without second-order sidebands for Radio over Fiber (RoF) is presented. The performance of systems based on hybrid coupler with distinct phase angle and Dual-Parallel Dual-Drive Mach-Zehnder Modulator (DP-DDMZM) is compared using simulation. Impact of parameters like SingleMode Fiber (SMF) length, Radiofrequency (RF) amplitude, and laser linewidth on Signal-to-Noise Ratio (SNR) has been investigated. It has been observed that eliminating one of the second-order sidebands with 120◦ hybrid coupler improves peak SNR in comparison to 90◦ hybrid coupler with both second-order sidebands and DP-DDMZM-based system without second-order sidebands irrespective of Continuous Wave (CW) laser linewidth.
Ankur Sood and Rahul Kaushik
IEEE
Free Space Optical (FSO) communication link under clear weather conditions is affected by irradiance fluctuations caused due to random atmospheric temperature variations. In this work, bit error rate (BER) performance of free space optical (FSO) communication link is analysed. A 60 GHz millimeter wave is generated using frequency quadrupling technique and transmitted via free space optical (FSO) communication link. Different atmospheric turbulence conditions such as weak, moderate and strong are observed for FSO channel and corresponding simulation results have been obtained. Channel models such as Gamma-gamma model for strong atmospheric turbulence conditions and Log normal model for weak to moderate turbulence are considered to evaluate system bit error rate (BER). Further, BER performance is analysed for certain parameters such as transmitter antenna aperture diameter, receiving antenna aperture diameter, beam divergence and optical wavelength used.
Shivam Wadhwa*, , Palash Rai, Rahul Kaushik, , and
Blue Eyes Intelligence Engineering and Sciences Engineering and Sciences Publication - BEIESP
The aim of indoor localization is to locate the objects inside a location wirelessly. This paper reports the models that predict the location along with floor and coordinates from the WAPs (Web Access Points) signal strengths of a user who connects to the internet at a specific location which had three locations. Starting with the cleaning of data, then assigning attributes into proper data types, making subset of dataset for each location, examining each column, and normalizing WAPs rows in order to build models. Different algorithms have been used to predict the location, floor, and coordinates of a logged in user. The models that have been used in this paper are k-Nearest Neighbor (k-NN) for location prediction, random forest for floor prediction and regression with k-NN for coordinate prediction.
Usha Sharma, Sushila Maheshkar, A. N. Mishra, and Rahul Kaushik
Springer Science and Business Media LLC
Kanika Ratra, Mansi Singh, Amit Kumar Goyal, and Rahul Kaushik
IEEE
In this paper, a multilayer structure is proposed to design a broadband reflector that has the capability to reflect a wide range of spectrum from ultra-violet to infra-red region for TE polarised light. The design analysis is carried out using transfer matrix method (TMM). The structure is designed using alternate layers of appropriate high and low refractive indices. The proposed structure demonstrates more than 97% reflectivity for the wavelength range of 0.3μm-2.5μm (solar spectrum). Thus, it has the potential to be used in various applications such as passive radiative cooler, and as a heliostat in concentrated solar power etc.
Vishal Narain Saxena and Rahul Kaushik
IEEE
The wall parameters namely, dielectric constant, attenuation constant and loss tangent have been calculated using insertion transfer function method. These parameters have been calculated with through-the-wall imaging (TWI) for three different types of walls. Experimental data has been collected by using A, B and C scanning. The experimental set up is created by connecting a vector network analyzer (VNA) to a computer in order to operate it as Step Frequency Continuous Wave (SFCW) radar. The data processing has been done using Mathworks® MAT LAB (R2013a) and National Instruments-Virtual Instrument Software Architecture (NI-VISA). All the calculations have been carried out in operating frequency range of 2 to 3 GHz.
Rahul Kaushik, Vineet Khandelwal, and R. C. Jain
Walter de Gruyter GmbH
Abstract Obtaining analytically closed-form expression for bit error rate (BER) of an optical wireless communication (OWC) system under weak atmospheric turbulence is extremely difficult and intractable. In this paper, a simple closed-form approximate expression for average BER of OWC system under weak turbulence condition is obtained using point estimate method. The proposed expression is used to compute the BER for on-off keying (OOK) and sub carrier intensity modulated (SIM) binary phase shift keying (BPSK) modulation schemes. Results obtained using proposed expression are compared with those obtained using Gauss-Hermite quadrature approximation and Monte-Carlo simulations.
Rahul Kaushik, Vineet Khandelwal, and R.C. Jain
Walter de Gruyter GmbH
Abstract In this paper, average channel capacity of optical wireless communication system is evaluated under the combined effect of geometrical loss, attenuation due to weather conditions and weak atmospheric turbulence using a simple closed form expression. Fading induced due to atmospheric turbulence is modeled by log-normal distribution. Considering the fact that the sum of log-normal random variables can be well approximated by another log-normal random variable, the proposed expression has been utilized to compute the channel capacity for spatial diversity reception employing maximum ratio combining and equal gain combining over uncorrelated turbulence-induced fading conditions. It is shown that spatial diversity is an effective technique to mitigate the impairments caused by various atmospheric conditions such as haze, rain and fog. The quantitative improvement in channel capacity achieved by using diversity techniques is investigated and compared. Accuracy of the results is validated with exact results computed using Monte Carlo simulation.
Rahul Kaushik, Vineet Khandelwal, and R. C. Jain
Walter de Gruyter GmbH
Abstract Weak atmospheric turbulence condition in an optical wireless communication (OWC) is captured by log-normal distribution. The analytical evaluation of average bit error rate (BER) of an OWC system under weak turbulence is intractable as it involves the statistical averaging of Gaussian Q-function over log-normal distribution. In this paper, a simple closed form approximation for BER of OWC system under weak turbulence is given. Computation of BER for various modulation schemes is carried out using proposed expression. The results obtained using proposed expression compare favorably with those obtained using Gauss-Hermite quadrature approximation and Monte Carlo Simulations.
George Jandieri, Zhuzhuna Diasamidze, and Rahul Kaushik
IEEE
Statistical characteristics of scattered electromagnetic waves in the ionospheric collision magnetized plasma are investigated taking into account both diffraction effects and polarization coefficients of the ordinary and extraordinary waves. Scintillation level is analyzed for the anisotropic Gaussian correlation function of electron density fluctuations containing anisotropy factor and angle of inclination of elongated plasma irregularities with respect to the line of forces of geomagnetic field. Second order statistical moments are calculated for new Alfven-type internal MHD wave in the ionospheric F region. Energy exchange between turbulent plasma flow and internal wave is investigated in the geometrical optics approximation. The influence of geometrical parameters of plasma irregularities of the second order statistical moments is analyzed. Numerical calculation are carried out using experimental data.
Vineet Khandelwal, Rahul Kaushik, and R. C. Jain
Springer Science and Business Media LLC