Dr. Garima Mathur | Malaviya National Institute of Technology, Jaipur (original) (raw)

Papers by Dr. Garima Mathur

Various sensors are already in a broad use today as part of different devices or as standalone de... more Various sensors are already in a broad use today as part of different devices or as standalone devices connected to a network usually to monitor industrial processes, equipments or installations. The advancements in technology, wireless communications have enhanced development of small, low power and low cost devices. Such devices when organized into a network, present a powerful platform that can be used in many interesting applications. Bluetooth is a low cost, short-range, wireless technology with small footprint, low power consumption and reasonable throughput. Bluetooth wireless technology has become global technology specification for "always on" wireless communication not just as a point-to-point but was a network technology as well. The kernel of this paper, deals about an implementation of bluetooth based sensor networks.

Workplace deviance means the intention or desire of the employees to cause harm to the organizati... more Workplace deviance means the intention or desire of the employees to cause harm to the organizations. In current era, organizations are facing the deviant behavior of employees because of that employees are not working properly, absenteeism is increasing and employees are having low level of belongingness towards their organization and the consequences of these issues are observed in the organizations in the form of lower productivity & high turnover rate. The current research was an attempt to find out the relationship between depression abusive supervision and organizational deviance. Confirmatory factor analysis was applied to confirm factors appeared through exploratory factor analysis. Structural equation modeling was applied to test the relationship between independent variables and dependent variable and also to develop a model. The results of the study indicated the significant impact of abusive supervision and depression on organizational deviance.

British Journal of Mathematics & Computer Science, 2014

In sphere decoding techniques, it was seen that the generalized sphere decoder algorithms have be... more In sphere decoding techniques, it was seen that the generalized sphere decoder algorithms have been applied to decode the MIMO systems. The transmitted vector is determined by decoding a sequence of determined sub problems.In this paper, the proposed sphere decoder has promised considerable performance as compared to the generalized sphere decoder. The proposed sphere decoding algorithm follows an adaptive radius selection approach for reducing the computational complexity as compared to the generalized sphere decoding algorithm and with the ideal ML decoder which applies on the QPSK signaling. Also it has proven that the proposed sphere decoder has given the performance near optimal like the ML decoder. The performance comparison is done under the Flat Rayleigh fading environment. We substantiate our new proposed reduced complexity near optimal sphere decoding algorithm with simulations.

IRE, 2018

- Now a days, technology reached enough that we are sitting in front of our personal computer tha... more - Now a days, technology reached enough that we
are sitting in front of our personal computer that can sense
and control human emotion known as “BLUE EYE
TECHNOLOGY”. In this technology the gadgets are used
which can sense the emotion level of human body like
facial and speech recognition etc. The technology which
are used in Blue Eye Technology can understand our
emotion at the mouse, it verifies our identity, feel our
presents and start interacting with us. In this paper a
discussion of new techniques known as Emotion Sensory
world of Blue Eye Technology which identify human
emotion (sad, happy, surprised) using image processing
technique.

Face recognition (FR) is a challenging issue due to variations in pose, illumination, and express... more Face recognition (FR) is a challenging issue due to variations in pose, illumination, and expression. The search results for most of the existing FR methods are satisfactory but still included irrelevant images for the target image. We have introduced a new technique uses an image-based approach towards artificial presents a new technique for human face recognition. This intelligence by removing redundant data from face images through image compression using Sobel Edge Detection (SED) and comparing this with the two-dimensional discrete cosine transform (2D-DCT) method for the better speed and efficiency. SED which is a popular edge detection method is considered in this work. There exists a function, edge.m which is in the image toolbox. In the edge function, the Sobel method uses the derivative approximation to find edges. Therefore, it returns edges at those points where the gradient of the considered image is maximum. The developed algorithm for the face recognition system formulates an image-based approach, using the Two-Dimensional Discrete Cosine Transform (2D-DCT) or SED for image compression and the Self-Organizing Map (SOM) Neural Network for recognition purposed, simulated in MATLAB.

This paper presents simulation of Viterbi decoder and Fano decoder for decoding the convolutional... more This paper presents simulation of Viterbi decoder and Fano decoder for decoding the convolutional codes in AWGN channel.
Graphs are plotted between Viterbi algorithm and Fano algorithm for decoding the convolutional codes of fixed code rate and fixed constraint
length. Results show that performance of Viterbi decoder is better than Fano decoder for the same code rate, constraint length and decoding
delay. Convolutional codes are widely used to encode digital data before transmission through noisy or error-prone communication channels
to reduce occurrence of errors. This paper presents CC(2,1,3) encoder which belongs to the convolutional encoder's class. It also presents
two different decoding techniques based on the Viterbi algorithm: the hard decision and the soft decision encoding techniques. Some simulated results obtained by using these two decoding techniques are presented as well.

Rate, Diversity & spectrum require a fundamental tradeoff in wireless communication. Emergence of... more Rate, Diversity & spectrum require a fundamental tradeoff in wireless
communication. Emergence of multiple antenna system h as opened another
very resourceful dimension space for information transmission in the air. This
system provides high gain in capacity without increasing the use of spectrum
reliability power consumption & less sensitivity to fading. In MIMO channels
the available detection scheme like Zero Forcing (ZF), Maximum likely
Hoods (ML), Minimum Mean- Square Erro r (MMSE) & Maximum Ratio
Combining (MRC) provide high optimal performance but complexity is high.
V-BLAST architecture reduces this complexity by splitting the information bit
stream into several sub stream & transmit them in parallel, using a set of
transmitter antennas. V-BLAST detection algorithm includes the interference
cancellation, interference nulling and optimal ordering procedure. In this paper
a new symbol detection algorithm is used for MIMO systems with features of
V-BLAST. This gives better error performance than linear receivers at the
expense of increased but tolerable level of complexity.
Index terms: Multiple Input Multiple Output (MIMO), Zero Forcing

Digital communications of sensing symbol vectors has found abundant diverse uses. These symbols a... more Digital communications of sensing symbol vectors has found abundant diverse uses. These symbols are determinate alphabet conducted over a multiple-input multiple-output (MIMO) channel having Gaussian noise. Proficient algorithms are reflected in exposure eg. Latches and have recognized well. The sphere decoder algorithm has optimal performance with reduced complexity. At high SNR the algorithm has a polynomial average complexity and is worst case complexity. The proficiency of the algorithm is the exponential rate cradle of growth. Complexity is affirmative for the numerous SNR and is small in the high SNR. To attain the sphere decoding solution, Schnorr-Euchner is applied through Maximum likelihood method, Depth-first Stack-based Sequential decoding. Thus this paper is focus on the receiver part of the transceiver system and provides a good look of optimal algorithm by vector symbol transmitted through MIMO channel.

The recent demand for mobile communication systems with high data rates has increased in the rece... more The recent demand for mobile communication systems with high data rates has increased in the recent years. New methods are essential in order to satisfy this huge
communication demand, exploiting the limited resources like as
the power and bandwidth as efficient as possible. Multiple Input and multiple Output (MIMO) systems with multiple antennas at the transmitter side and multiple antenna
as at the receiver side provides a better solution for the demand of high data rates by exploiting the spatial domain under the constraints of limited bandwidth and transmit power. Sphere decoding approach is one of the effective approach in MIMO system to identify the problem in multi user detection and ML detection problem. There are different approaches to improve the Sphere Decoding approach so that more accurate and optimized results will be obtained. One of such approach is suggested in this paper. In this work, instead of processing on complete state space, a K-best sphere decoder approach is suggested in this work. The
presented paper is about to define an improve approach for the selection of K best neighbors.

All optical NAND gates based on cross-phase modulation. It accomplish error-free performance at 1... more All optical NAND gates based on cross-phase modulation. It accomplish error-free performance at 10 Gb/s and the receiver sensitivity for a bit-error rate of 10-9 is below -15.0 dBm. The designing parameters are more accurate and sensible if we are utilizing the non-linear characteristics of fiber like Cross gain modulation (XGM).

Artificial Bee Colony (ABC) optimization algorithm is a swarm intelligence based nature inspired ... more Artificial Bee Colony (ABC) optimization algorithm is a swarm intelligence based nature inspired algorithm which has been proved a competitive algorithm with some popular natureinspired algorithms. However, it is found that the ABC algorithm prefers exploration at the cost of the exploitation. Therefore, in this paper a self adaptive fitness based position update strategy is presented. The proposed strategy is self-adaptive in nature and therefore no manual parameter setting is required. Further, the proposed strategy is used to solve a complex real world engineering optimization problems, namely, parameter estimation for frequency-modulated sound waves (FMSW).

This paper presents performance analysis of cooperative multiple-input multiple-output (MIMO) rel... more This paper presents performance analysis of cooperative multiple-input multiple-output (MIMO) relaying system with a single relay. The MIMO scheme is based on Alamouti space time block coding (STBC) over Rayleigh flat fading channels. The source node, equipped with two transmit antennas, simply broadcasts each STB code to the relay and the destination nodes. Then, the relay node, equipped with multiple antennas, amplifies-and-forwards (AF) the received STB codes. Finally, the destination node uses maximum ratio combining (MRC) and exploits the diversity gain obtained through the direct and the indirect links simultaneously. The moment generating functions (MGF) of the signal-to-noise ratio (SNR) for the direct and the indirect link are given in a closed form. These statistical results are then applied to derive a lower bound of the symbol error probability (SEP) for a particular signal of M-ary-quadrature-amplitude modulation (M-QAM) and to obtain the outage probability. Subsequently, simulation results of the SEP and the outage probabilities are presented to illustrate the performance improvement given by the MIMO cooperative diversity systems based on STBC schemes. key words: MIMO relay channel, space-time block coding, MRC scheme, moment generating function (MGF), outage probability.

This paper deals with 3 different techniques for feature extraction of image. Face detection is a... more This paper deals with 3 different techniques for feature extraction of image. Face detection is a necessary first-step in face recognition systems, with the purpose of localizing and extracting the face region from the background. The Self-Organizing Map (SOM) Neural Network has been used for training of database and simulation of FR system. The developed algorithm for the face recognition system formulates an image-based approach, using discrete wavelet transform (DWT), discrete cosine transform (DCT) and Sobel edge detection, simulated in MATLAB. Simulation results are very promising.

In the paper, vectors are regarded as column vectors. These are written in lowercase bold charact... more In the paper, vectors are regarded as column vectors. These are written in lowercase bold characters. For matrices, uppercase bold characters are used. and E {.}denote the Euclidean norm, transpose, complex conjugate transpose and expected value, respectively.

In the IEEE 802.16 (Wi-MAX) standard the Golden code is incorporated as a full-rate full-diversit... more In the IEEE 802.16 (Wi-MAX) standard the Golden code is incorporated as a full-rate full-diversity spacetime code. The worst case will dominate average decoding complexity on any channel with a significant line of sight component in this paper, we present Golden code that can be employed by mobile terminals with either one or two receive antennas, that is resilient to near singularity of the channel matrix, and that gives maximum likelihood (ML) performance. We have modified the golden ratio for low symbol error rate. The golden code is best for 2×2 system.

MIMO-OFDM (Multiple Input Multiple Output Orthogonal Frequency Division Multiplexing) system has ... more MIMO-OFDM (Multiple Input Multiple Output Orthogonal Frequency Division Multiplexing) system has been recognized as one of the most popular and competitive technique in a wireless environment nowadays. The performance is calculated in terms of Bit Error Rate (BER) versus the Signal to Noise Ratio (SNR). In this paper we discuss the BER performance of the MIMO-OFDM system with two different equalizers (ZF and MMSE) for various modulation techniques i.e. BPSK, QPSK, 16-QAM and 64-QAM using multipath fading channels i.e. AWGN (Additive White Gaussian Noise), Rayleigh and Rician channel. The multicarrier modulation is employed, which gives advantages like inter symbol interference (ISI) reduction, high data rate, higher reliability, and better performance in multipath fading. The simulation results show that, with MMSE and ZF equalizers, the BER performances is better in MMSE equalizer. Further we analyzed in different fading channels for various modulation techniques in both the equalizers.

This paper evaluates the performance of Alamouti Space Time Code (A-STC) with Space Time Trellis ... more This paper evaluates the performance of Alamouti Space Time Code (A-STC) with Space Time Trellis Code (STTC). In the proposed scheme, we fix the number of transmit antenna and vary the number of receive antenna with 4-PSK modulation for Rayleigh fading channel. When we compare the performance of Alamouti Space Time Code with Space Time Trellis Code for less than or equal to 4 receive antennas, Alamouti Space Time Code performs better but with increase in number of receive antennas the performance of both the codes approaches closer to each other although Alamouti Space Time Code is still superior to Space Time Trellis Code. For Rician Fading channel we selected 2:1 Alamouti Code. The result shows that Space Time Trellis Code gives enhanced result and provides advantage of coding gain when compared with Alamouti Space Time Code.

Soft iterative decoding techniques have shown to a great extent result in terms of Bit Error Rate... more Soft iterative decoding techniques have shown to a great extent result in terms of Bit Error Rate performance in wireless communication. By using MIMO system we attain high multiplexing gain. However, this is only possible if an expedient detection technique is used. ML detection technique allows soft decisions for each received bit along with good error performance. In this paper we propose new technique for decoding Multiple Input -Multiple Output (MIMO) system, which combine Sphere Decoding (SD) with Zero Forcing (ZF) ,MMSE and V-BLAST techniques to make accessible near optimal low complexity and high performance modified sphere decoding algorithm. Simulation results on a QPSK Modulation with 4 transmit and 4 receive antennas show that the propose sphere decoder can achieve the near-optimal performance.

The Golden code has recently been proposed as a 2x 2 space time block code that achieves the opti... more The Golden code has recently been proposed as a 2x 2 space time block code that achieves the optimal diversity-multiplexing gain tradeoff for a multiple antenna system. Double Space Time Transmit Diversity (DSTTD) is an open loop MIMO system with 4 transmits antennas. DSTTD achieves the best performance in rich scattering channels, spatial correlation degrade the performance. Spatial modulation (SM) is a low complexity modulation scheme which is recently proposed for multiple antenna wireless systems. SM is unable to achieve transmit diversity but it provides multiplexing gain by averting inter channel interference with respect to single antenna system. The aim of this paper is to present the design of multiple-antenna wireless systems that exploit the SM concept and can achieve transmit-diversity gain. A new modulation concept STBC-SM is discussed which outperformed Golden and DSTTD codes at higher SNR levels.

British Journal of Mathematics & Computer Science, 2014

IRE, 2018

The Transcendence of Artificial

— Time synchronized nodes in WSN play an important role in many services such as event monitoring... more — Time synchronized nodes in WSN play an important role in many services such as event monitoring, data collection. Because of unsynchronized clock of sensor motes, energy use of network increases considerably. Recently, a scheme for time synchronization using pairwise synchronization was proposed. The scheme used overheard nodes to synchronize nodes in the network thereby relaxing the burden of the network. But as the size of the network increases, nodes cannot perform overhearing from the parent node because of the constraint of limited range of motes. This paper proposes the good at producing time synchronized network using optimally powered overheard nodes in multilayered scenario. These nodes offer greater range to nodes, hence reducing the limitations such as high message delays, low throughput. The control to get an effect of the offered design has been made certain through many simulations. Results make clear that time taken to synchronize the network using optimally powered overheard nodes outdoes the existing designs in terms of performance parameters of the network such as throughput, network lifetime, end to end delay.