Papers by Vivekanand Mishra
The demand for high speed data transmission is increasing so as to fulfil the demand of high spee... more The demand for high speed data transmission is increasing so as to fulfil the demand of high speed the Duo-binary modulation Format is used. Hence this paper deals with the duo binary modulation technique in the optical single channel system at different fibres lengths and data bit rate. While increasing the length and data rate of the transmitter the bit error rate changes simultaneously. The demand for the high bit rate data transmission is increasing and thus easily accomplished.
Lecture notes in networks and systems, Nov 8, 2017
Fiber-optic mediation offers high speed for data mediation and also offered huge bandwidth for us... more Fiber-optic mediation offers high speed for data mediation and also offered huge bandwidth for use. Due to its adaptable merits and insignificant mediation losses, it becomes one of the most vital used communication techniques. Although Fiber-optic mediation has a plenty of merits, ‘Dispersion’ is the chief restrictive feature. Dispersion is the core issue responsible for impediment progress of optical mediation systems in terms of bit rate and long-haul mediation. Dispersion originate distortion and expansion in the pulses, thus recital of the fiber-optic communication. This inquiry paper gratified that inspection with 20 Gbps mediation network arrangement has been prepared with binary non-return to zero and duo binary modulation designs in symmetric dispersion compensation schemes. The coordination is imitated and evaluated by means of pre-, post-, and symmetric dispersion compensation outlines. All organizations are linked in expressions of bit error rate (BER), Q-factor, eye opening, and jitter. The outcome is investigated using optical software tool, i.e., OPTSIM.
A novel approach of analytically and numerically calculating the relationship of directivity with... more A novel approach of analytically and numerically calculating the relationship of directivity with the spacing height of copper grid layer over the patch, termed as radome structure by the present team of authors is presented. Numerous designs and models of radome structure are conceptually solved and evaluated using finite element method (FEM) based High Frequency Structure Simulator (HFSS) software tool. Single copper grid layer over the patch antenna for achieving high directivity is described. Newton's divided difference method is applied on the radome structure for evaluating the performance parameters of the antenna. A global formula is developed to indicate the relationship of the directivity with the spacing height of the patch antenna by varying the distance of copper grid layer and observing its effect on the directivity of the patch using electromagnetic wave solver HFSS.
Tunneling voltage of a nano-scale flash memory cell needs to be lowered considerably. This can be... more Tunneling voltage of a nano-scale flash memory cell needs to be lowered considerably. This can be done only by employing very thin tunnel dielectrics. Quantum dot floating gate devices have shown a potential to do so in sub-65 nm regime. In this work, conventional and quantum dots' FGMOS gate stacks for 65 nm and 45 nm technology nodes are simulated in Synopsys TCAD. The experiments are simulated for metal control gate structures with ultra-thin oxides with 3.3 nm and 2.5 nm thicknesses. Quantum dots arrangement is optimized to give similar results as that of a conventional structure. The devices exhibit significant memory windows with tunneling voltages as small as 12 V and 6 V, respectively, with quantum dot devices further requiring lesser tunneling times.
Optik, 2003
In this paper, we present a simple analysis, utilising the ABCD transformation matrix method, to ... more In this paper, we present a simple analysis, utilising the ABCD transformation matrix method, to analyze and determine the coupling efficiency between a laser diode and a conically lensed fiber. The calculated and measured results, i.e. the coupling efficiencies, were compared for microlenses etched at 20, 30 and 40 minutes. We found that the calculated results were in good agreement with the measured values.
Silicon, Apr 8, 2015
ABSTRACT
ABSTRACT The conventional microstrip patch antenna (MSA) have low gain and low directivity. This ... more ABSTRACT The conventional microstrip patch antenna (MSA) have low gain and low directivity. This paper presents coaxial feed rectangular microstrip patch antenna along with left-handed metamaterial (LHM) cover. The Proposed metamaterial cover increases the gain and directivity of the antenna in comparison to conventional microstrip patch antenna alone. The antenna has been designed for 8-10 GHz, hence it can be used for X-band application. S-Parameters (S11 and S22) are used for verifying the double-negative properties of the proposed metamaterial cover. The proposed antenna is simulated by using Ansoft HFSS.
International Journal of Electronics, Sep 17, 2014
ABSTRACT With the advent of technology, video has become a prominent entity that is shared over n... more ABSTRACT With the advent of technology, video has become a prominent entity that is shared over networks. With easy availability of various editing tools, data integrity and ownership issues have caused great concern worldwide. Video watermarking is an evolving field that may be used to address such issues. Till date, most of the algorithms have been developed for uncompressed domain watermarking and implemented on software platforms. They provide flexibility and simplicity, but at the same time, they are not suited for real-time applications. They work offline where videos are captured and then watermark is embedded in the video. In the present work, a hardware-based implementation of video watermarking is proposed that overcomes the limitation of software watermarking methods and can be readily adapted to the H.264 standard. This paper focuses on an invisible and robust video watermarking scheme, which can be easily implemented as an integral part of the standard H.264 encoder. The proposed watermarking algorithm involves Integer DCT-based watermark embedding method, wherein Integer DCT is calculated with a fully parallel approach resulting in better speed. The proposed video watermarking is designed with pipelining and parallel architecture for real-time implementation. Here, scene change detection technique is used to improve the performance. Different planes of the watermark are embedded in different frames of a particular scene in order to achieve robustness against various temporal attacks.
Microwave and Optical Technology Letters, Jul 31, 2003
trum. Furthermore, the lesser of the two relative permittivities determines the lowest frequency ... more trum. Furthermore, the lesser of the two relative permittivities determines the lowest frequency at which a mode of order n can propagate, because  n 1,2 2 ϭ 2 0 0 r 1,2 Ϫ k y n 2 Ͼ 0 for guided wave propagation. Allowed and forbidden bands are identified in Figure 5 for the three lowest-order TE z and TM z modes for waveguides with different heights. The quantity ͉L TE n z ͉ Ͼ 1 in the black zones, but Ͻ1 in the white zones; similarly for ͉L TM n z ͉. Obviously, the first allowed band appears when the frequency is greater than the modal cutoff frequency. For higher frequencies, band gaps appear that would be absent if r 2 were equal to r 1. A very thick waveguide would be overmoded, and the lowestorder modes would have certain characteristics not very different from that of the TM 0 z mode, because the TE 0 z mode is impossible in a parallel-plate waveguide. Therefore, we expected that the displayed filtration response for the lowest-order modes would not critically depend on the modal order and type. Indeed, this turned out to be the case, which is evident from the profiles of the allowed and forbidden bands depicted in Figure 6 for very high values of h. Incidentally, the TM 0 z mode is insensitive to h, and its characteristics are the same as those predicted by Srivastava et al. [9] for PBG structures of infinite transverse extent.
This paper gives architecture, design and deployment of a cost effective solution for Wi-Fi servi... more This paper gives architecture, design and deployment of a cost effective solution for Wi-Fi service inside running metro trains. This includes low cost Point-to-point (P2P) devices working in unlicensed "Industry, Scientific & Medicines" (ISM) frequency band A specially designed directional antenna and configuration modification for wireless security was done to achieve the desired result This is a first ever successful implementation in India with one of the major metro service providers. The results obtained are comparable to high cost and complex technology options. It was observed to show an improvement of signal strength by -20dB and handover timeout by 2 sec.
Radiation Measurements, May 1, 2012
ABSTRACT Silicon Drift Detector (SDD) based X-ray spectrometer has been developed for obtaining t... more ABSTRACT Silicon Drift Detector (SDD) based X-ray spectrometer has been developed for obtaining the elemental composition of unknown samples by detecting fluorescent X-rays in the energy region 1–25 keV by a non-destructive process. The use of new technology X-ray detector provides good energy resolution for detecting the elements separated with ∼150 eV apart. Here we present the design of a complete X-ray spectrometer intended for use in the future space-born experiment. The low energy threshold of <1 keV and the energy resolution of ∼150 eV at 5.9 keV, as measured from the system is comparable to the standard spectrometers available off-the-shelf. We evaluated the system performance for different signal peaking time, as well as for different input count rates and show that the performance remains stable for incident count rate up to 20,000 counts per second. We have also carried out a ‘proof of concept’ experiment of measuring fluorescent X-ray spectrum from various standard XRF samples from the USGS catalog irradiated by the laboratory X-ray source 241Am with 1 mCi activity. It is shown that intensities of various characteristic X-ray lines are well correlated with the respective elemental concentrations. A specific effort has been made while designing the developed X-ray spectrometer to use electronic components which are available in space grade so that the same electronic design can be used in the upcoming planetary missions with appropriate mechanical packaging.
Optik, 2014
We report here for the first time to our knowledge the characterization of mechanically induced l... more We report here for the first time to our knowledge the characterization of mechanically induced long period fiber gratings in novel MSM fiber structure. Reversible grating of same period and length was induced in single mode fiber, multimode fiber and novel multimode-singlemode-multimode (MSM) fiber structure. The spectral response of reversible LPFG in SMF is verified experimentally as well as from simulation results and then compared with the experimental spectral response of reversible LPFG in multimode fiber and MSM fiber structure. Reversible LPFG in novel MSM fiber structure is the most optimized and suitable grating for sensing application. For this grating we have obtained single resonant wavelength over a wide wavelength range and maximum transmission loss peak of around 20 dB.
For the high capacity data transmission, the optical network is emerging towards the Non-Return-Z... more For the high capacity data transmission, the optical network is emerging towards the Non-Return-Zero (NRZ) and Return-Zero (RZ) modulation formats as both the techniques are cost effective. In this paper RZ and NRZ schemes are considered to analyze the fiber optic communication system at 10 Gbps with different types of lasers at different fiber length. The performance is estimated on the basis of Eye opening, jitter and Q-value on the OPTSIM virtual instrument.
Opto-Electronics Review, 2015
This paper presents the implementation of a thinned fibre Bragg grating as a fuel adulteration se... more This paper presents the implementation of a thinned fibre Bragg grating as a fuel adulteration sensor for volatile organic compounds. The proposed sensor can detect upto 10% adulteration of benzene, toluene and xylene: hydrocarbons precisely, whereas traditional methods can detect only upto 20% adulteration. The results obtained from the experiments are verified using Finite Difference Time Domain method. It is found that experimental results have very less deviation from simulation results. The proposed sensor provides us with the new possibility that may have commercial application, as well.
Microwave and Optical Technology Letters, Nov 20, 1999
For the nonlinearized test, the IP is about 15 dB above the 3 compression point, and for the line... more For the nonlinearized test, the IP is about 15 dB above the 3 compression point, and for the linearized test, the IP is 30 3 dB above the amplifier's compression point, thus providing an improvement of 15 dB.
International journal of computer applications, Aug 30, 2012
Optical Burst Switching (OBS) is considered to be a promising paradigm for bearing IP traffic in ... more Optical Burst Switching (OBS) is considered to be a promising paradigm for bearing IP traffic in Wavelength Division Multiplexing (WDM) optical networks. Scheduling of data burst in data channels in an optimal way is one of a key problem in Optical Burst Switched networks. The main concerns in this paper is to schedule the incoming bursts in proper data channel such that more burst can be scheduled so burst loss will be less. There are different algorithms exists to schedule data burst on data channels. Non-preemptive Delay-First Minimum Overlap Channel with Void Filling and Nonpreemptive Segment-First Minimum Overlap Channel with Void Filling are best among other existing segmentation based void filling algorithms. Though it gives less burst loss but not existing the channel utilization efficiently. In this paper we introduce a new approach, which will give less burst loss and also utilize existing channels in efficient way. Also analyze the performance of this proposed scheduling scheme and compare it with the existing void filling algorithms. It is shown by simulations that the proposed scheme gives some better performances compared to the existing schemes.
Optik, May 1, 2014
ABSTRACT In this paper, the implementation of 100 Gbps optical communication system exploiting po... more ABSTRACT In this paper, the implementation of 100 Gbps optical communication system exploiting polarization diversity at transmitter and receiver is developed and investigated with pre-, post- and symmetrical dispersion compensation schemes by using dispersion shifted and dispersion compensated fibers through simulations to optimize high data rate optical transmission. Motivation to the current analysis is to compare all 3 compensation schemes and it's found that the pre compensation technique is superior to post and symmetrical compensation techniques in 100 Gbps PDM–OFDM communication system. On examination of symmetrical and post dispersion compensation schemes, it's found that the later is superior to the previous in this case. A 100 Gbps coherent optical OFDM workplace has been discovered in which two 50 Gbps data streams are combined into one wavelength by polarization beam combiner. By comparing one can get a promising system to the symmetrical high capacity access network with high spectral efficiency, cost effective, good flexibility.
H.264 is the advance video coding standard for the compression and distribution of a video conten... more H.264 is the advance video coding standard for the compression and distribution of a video content. It has larger complexity in order to satisfy the demand of high quality video at low bit rate. Moreover, it requires the effective implementation of all its internal blocks. In the paper, we focuses on the implementation of two important blocks for H.264 encoder. We propose low complexity design of quantization and Context Adaptive Variable Length Coding (CAVLC). The quantization process is responsible for scaling down the value of transform coefficients. CAVLC is useful for a bit stream generation and it is adopted from the concept of modified Variable Length Coding (VLC) technique. The efficient architectures are designed for quantization and CAVLC blocks to have parallel and pipeline data processing. They are implemented on Virtex 4 XC4VLX40 FPGA family using VHDL. The synthesized results are obtained with Xilinx ISE 14.2 and resource, device utilization and timing analysis are reported. The results are compared with related work that shows the better real time performance of both blocks.
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Papers by Vivekanand Mishra