Browsing by Author "Sharma, V."

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A robust transmission with enhancement of 5G PHY using FBMC and AMC for machine-to-machine communication node
(KeAi Communications Co., 2023) Sharma, V.; Arya, R.K.; Kumar, S.
Advancement of 5G new radios has enabled more robust communication for the Machine-to-Machine (M2M) communication node, using filter bank multicarrier (FBMC). This paper focuses on robust transmission over random fluctuations of the channel and also enhances the battery life for the massive machine type communication (mMTC) node. Filter bank multicarrier and Adaptive Modulation Coding (AMC) have been utilized together to enhance the performance of the 5G (NR) PHY layer. A frame-to-frame implementation is used to diminish the impact of fading using AMC, while efficient utilization of spectrum is achieved using FBMC. The selection of the AMC profile is obtained through the analysis of uplink packets using the Distance Statistics (DS). The FBMC is incorporated with 5G PHY in place of OFDM to achieve the optimum utilization of spectrum and also obtain a significant reduction in peak to average power ratio (PAPR) for robust transmission, which saves 10% of the battery requirement. On the basis of channel state information, distance statistics were employed to optimize the AMC. The optimum selection of AMC with FBMC will reduce the bit error rate (BER) against multipath fading and ensure the better utilization of available spectrum to attain the optimum utilization of the power amplifier. © 2023 The Authors
Adaptive DFT-s-OFDM employed novel multi layered scheme for reduction of PAPR for mMTC node in 5G (NR)
(Elsevier B.V., 2023) Sharma, V.; Arya, R.K.; Kumar, S.
In 5G New Radio, The DFT-s-OFDM is a promising multiplexing technique for enhancing the average power of subcarriers to reduce the overall peak-to-average power ratio (PAPR). The peak of subcarrier is too high then the impact of DFT-s-OFDM is quite inferior. An Adaptive DFT-s-OFDM employed multilayered novel mechanism has been proposed in this research article to reduce the PAPR. The extent of sub-band is varied in accordance with predefined threshold value to enhance average power, meanwhile clipping is applied to shape the peak value of subcarrier. The clipping technique reduced the subcarrier's peak power. The proposed approach has the greater impact in order to enhance the efficiency of non-linear Power Amplifier (PA). The PAPR is suppressed by the multilayered strategy in two ways. The first is the numerator element, which is the reduction of peak power by clipping operation, and the second is the denominator element, which is the improvement of average power through K-point DFT sub-band. The superior time–frequency localization of DFT-s-OFDM across uplink transmissions reduces the requirement for difficult node-to-node synchronization, which is potentially used by the mMTC nodes. The proposed adaptive DFT-s-OFDM modulation scheme performs better than conventional OFDM modulation, which is approximately 24% more effective at 6 dB. © 2023 Elsevier B.V.
Comparative Study of Power Optimization Technique for M2M Communication Node Under 5G (NR)
(Springer Science and Business Media Deutschland GmbH, 2023) Sharma, V.; Arya, R.K.; Kumar, S.; Pandey, K.
The direct Fourier transform-spread OFDM (DFT-s-OFDM) and cyclic prefix orthogonal frequency division multiplexing (CP-OFDM) are used for the end-to-end data transmission to support the 5G services and backward compatibility. Improving battery life has always been an important concern in 5G machine-to-machine (M2M) communication nodes. Efficient utilization of power amplifiers (PA) and inferior peak-to-average power ratio (PAPR) is helpful to achieve enhanced battery life. Filter bank multi-carrier (FBMC) multiplexing is an alternative to CP-OFDM that offers low PAPR with the benefits of CP removal. Another way to get low PAPR is single carrier OFDM (SC-FDMA). The transmission requirements between these services are different, which presents a challenge for waveform adaptability to PAPR issues. The DFT-s-OFDM technique is one of the choices to overcome the PAPR that is used in uplink scenarios. Apart from PAPR reduction, DFT-s-OFDM provides optimal use of nonlinear power amplifiers. In addition to PAPR analysis, spectral efficiency is also compared in the simulation results. Using parameters that adjust the cost of spectral efficiency, DFT-s-OFDM provides the extent of improvement in PAPR performance and bit error rate over traditional CP-OFDM, SC-FDMA, and FBMC against the noisy channel. Â© 2023, The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd.
Context Sensitive Tamil Language Spellchecker Using RoBERTa
(Springer Science and Business Media Deutschland GmbH, 2023) Rajalakshmi, R.; Sharma, V.; Anand Kumar, M.
A spellchecker is a tool that helps to identify spelling errors in a piece of text and lists out the possible suggestions for that word. There are many spell-checkers available for languages such as English but a limited number of spell-checking tools are found for low-resource languages like Tamil. In this paper, we present an approach to develop a Tamil spell checker using the RoBERTa (xlm-roberta-base) model. We have also proposed an algorithm to generate the test dataset by introducing errors in a piece of text. The spellchecker finds out the mistake in a given text using a corpus of unique Tamil words collected from different sources such as Wikipedia and Tamil conversations, and lists out the suggestions that could be the potential contextual replacement of the misspelled word using the proposed model. On introducing a few errors in a piece of text collected from a Wikipedia article and testing it on our model, an accuracy of 91.14% was achieved for error detection. Contextually correct words were then suggested for these erroneous words detected. Our spellchecker performed better than some of the existing Tamil spellcheckers in terms of both higher accuracy and lower false positives. Â© 2023, The Author(s), under exclusive license to Springer Nature Switzerland AG.
Efficient Channel Prediction Technique Using AMC and Deep Learning Algorithm for 5G (NR) mMTC Devices
(Institute of Electrical and Electronics Engineers Inc., 2022) Sharma, V.; Arya, R.K.; Kumar, S.
Efficient utilisation of adaptive modulation and coding ensures the quality transmission of information bits through the significant reduction in bit error rate (BER). Channel prediction using parametric estimation is not efficient for massive machine-type communication (mMTC) devices under the 5G New Radio (NR). In this paper, we have proposed a channel prediction scheme based on a deep learning (DL) algorithm possessed by parametric analysis. In deep learning, the pipeline methodology is used along with the image processing technique to predict the channel condition for optimal selection of the adaptive modulation and coding (AMC) profile. The deep learning-based pipelining approach utilises image restoration (IR) and image super-resolution (SR). The super-resolution method is used to de-noise the low-pixel 2-D image that is obtained from the parametric value of the beacon to predict the channel condition. The estimation results are compared with the conventional minimum mean square error (MMSE) and an approximation to the linear MMSE (ALMMSE) method, which is obtained through channel state information (CSI). The comparison results show that the parametric-enabled deep learning approach is superior, especially in poorer channel conditions. The performance of BER through parametric estimation along with the DL approach is 66% more efficient as compared to the conventional MMSE method for BPSK mapping. © 2013 IEEE.
Evaluation of implant properties, safety profile and clinical efficacy of patient-specific acrylic prosthesis in cranioplasty using 3D binderjet printed cranium model: A pilot study
(Churchill Livingstone, 2021) Basu, B.; Bhaskar, N.; Barui, S.; Sharma, V.; Das, S.; Govindarajan, N.; Hegde, P.; Perikal, P.J.; Antharasanahalli Shivakumar, M.; Khanapure, K.; Jagannatha, A.
There exists a significant demand to develop patient-specific prosthesis in reconstruction of cranial vaults after decompressive craniectomy. we report here, the outcomes of an unicentric pilot study on acrylic cranial prosthesis fabricated using a 3D printed cranium model with its clinically relevant mechanical properties. Methods: The semi-crystalline polymethyl methacrylate (PMMA) implants, shaped to the cranial defects of 3D printed cranium model, were implanted in 10 patients (mean age, 40.8 ± 14.8 years). A binderjet 3D printer was used to create patient-specific mould and PMMA was casted to fabricate prosthesis which was analyzed for microstructure and properties. Patients were followed up for allergy, infection and cosmesis for a period of 6 months. Results: As-cast PMMA flap exhibited hardness of 15.8 ± 0.24Hv, tensile strength of 30.7 ± 3.9 MPa and elastic modulus of 1.5 ± 0.1 GPa. 3D microstructure of the semi-crystalline acrylic implant revealed 2.5–15 µm spherical isolated pores. The mean area of the calvarial defect in craniectomy patients was 94.7 ± 17.4 cm2. We achieved a cranial index of symmetry (CIS -%) of 94.5 ± 3.9, while the average post-operative Glasgow outcome scale (GOS) score recorded was 4.2 ± 0.9. Conclusions: 3D printing based patient-specific design and fabrication of acrylic cranioplasty implant is safe and achieves acceptable cosmetic and clinical outcomes in patients with decompressive craniectomy. Our study ensured clinically acceptable structural and mechanical properties of implanted PMMA, suggesting that a low cost 3D printer based PMMA flap is an affordable option for cranioplasty in resource constrained settings. © 2021 Elsevier Ltd
Power Amplifier Optimization for M2M Node using DPD and Hybrid DFT-s-OFDM with CFR
(Dr D. Pylarinos, 2023) Sharma, V.; Arya, R.K.; Kumar, S.
Power Amplifiers (PAs) play a vital role in mobile communication. However, their inherent nonlinearity can lead to issues such as unwanted radiation, interference with neighboring channels, and distortion within the desired frequency range. To address these problems, PAs are typically operated at a lower power level than their saturation point, sacrificing power efficiency to improve Error Vector Magnitude (EVM) performance. Consequently, more than 70-80% of the DC power is wasted as heat. This inefficiency necessitates the exploration of techniques to enhance PA efficiency while maintaining acceptable linearity and performance. Digital Pre-Distortion (DPD) is a useful technique to linearize PAs. DPD allows affordable nonlinear PAs to function with minimal distortion in their nonlinear operating regions. This results in amplified signals with increased power output and improved power efficiency. Using nonlinear functions, the output signal of the PA can be linearized, mitigate distortions, and be effectively optimized. When using various operating channels and varying time, temperature, and PA nonlinearity, the DPD must adjust. In order to increase the power efficiency of 5G systems, DPD-enabled systems are inculcating with adaptive DFT-s-OFDM employed 5G physical layer along with the Crest Factor Reduction (CFR) algorithm. © 2023, Dr D. Pylarinos. All rights reserved.
Robust transmission using channel encoding towards 5G New Radio: A telemetry approach
(Elsevier Ltd, 2021) Sharma, V.; Arya, R.K.; Kumar, S.
This paper presents a robust channel encoding scheme under adaptive modulation and coding for a massive machine type communication device in 5G new radio. For the very first time, mode-selection and distance statistics algorithms have been simultaneously evaluated, in which together it provides the closest approximation of efficient adaptive modulation and coding with robust transmission. The prediction of optimum adaptive modulation and coding is based on the analysis of uplink packet using distance statistics, and downlink packet using mode-selection mechanism. The performance of 5G new radio by incorporating OFDM subcarrier has been evaluated using analytical as well as simulation approach. Mode-selection algorithm has been considered to predict the environmental condition under a fading channel while the distance statistics provide feedback of the previously transmitted channel condition. The result of both the approaches provide a better bit error rate for adaptive modulation & coding profile under 1/4, 1/18, 1/16 and 1/32 cyclic prefix. © 2021
Time series with sentiment analysis for stock price prediction
(2019) Sharma, V.; Khemnar, R.; Kumari, R.; Mohan, B.R.
Stock price prediction has been a major area of research for many years. Accurate predictions can help investors take correct decisions about the selling/purchase of stocks. This paper aims to predict and gauge stock costs and patterns, utilizing the power of machine learning, content examination and fundamental analysis, to give traders a hands-on tool for keen speculations particularly for the volatile Indian Stock Market. We propose a technique to analyze and predict the stock price with the help of sentiment analysis and decomposable time series model along with multivariate-linear regression. � 2019 IEEE.
Time series with sentiment analysis for stock price prediction
(Institute of Electrical and Electronics Engineers Inc., 2019) Sharma, V.; Khemnar, R.; Kumari, R.; Mohan, B.R.
Stock price prediction has been a major area of research for many years. Accurate predictions can help investors take correct decisions about the selling/purchase of stocks. This paper aims to predict and gauge stock costs and patterns, utilizing the power of machine learning, content examination and fundamental analysis, to give traders a hands-on tool for keen speculations particularly for the volatile Indian Stock Market. We propose a technique to analyze and predict the stock price with the help of sentiment analysis and decomposable time series model along with multivariate-linear regression. Â© 2019 IEEE.
Towards evaluating resilience of SIP server under low rate DoS attack
(2011) Kumar, A.; Santhi Thilagam, P.; Pais, A.R.; Sharma, V.; Sadalkar, K.M.
Low rate Denial-of Service, DoS, attack recently emerged as the greatest threat to enterprise VoIP systems. Such attacks are difficult to detect and capable of discovering vulnerabilities in protocols with low rate traffic and it noticeably affects the performance of Session Initiation Protocol, SIP, communication. In this paper, we deeply analysis the resilience of SIP server against certain low rate DoS attacks. For this purpose we define performance metrics of SIP server under attack and non-attack scenarios. The performance degradation under attacks gives a measure of resilience of the SIP server. In order to generate normal SIP traffic and the attacks, we defined our own XML scenarios and implemented them using a popular open source tool known as SIPp. The system under evaluation was an open source SIP server. � 2011 Springer-Verlag.
Towards evaluating resilience of SIP server under low rate DoS attack
(2011) Kumar, A.; Santhi Thilagam, P.S.; Pais, A.R.; Sharma, V.; Sadalkar, K.
Low rate Denial-of Service, DoS, attack recently emerged as the greatest threat to enterprise VoIP systems. Such attacks are difficult to detect and capable of discovering vulnerabilities in protocols with low rate traffic and it noticeably affects the performance of Session Initiation Protocol, SIP, communication. In this paper, we deeply analysis the resilience of SIP server against certain low rate DoS attacks. For this purpose we define performance metrics of SIP server under attack and non-attack scenarios. The performance degradation under attacks gives a measure of resilience of the SIP server. In order to generate normal SIP traffic and the attacks, we defined our own XML scenarios and implemented them using a popular open source tool known as SIPp. The system under evaluation was an open source SIP server. Â© 2011 Springer-Verlag.