Faculty Publications
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Publications by NITK Faculty
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Item Reliable transmission and storage of medical images with patient information using error control codes(2004) Nayak, J.; Subbanna Bhat, P.; Kumar, M.S.; Acharya, A.U.A new method for compact storage and transmission of medical Images with concealed patient Information in noisy environment if evinced. Digital Watermarking is the technique adapted here for interleaving patient Information with medical images. The patient information, which comprises of text data and signal graph, is encrypted to prevent unauthorized access of data. The latest encryption algorithm (Rijndael) is used for encrypting the text information. Signal graphs (ECG, EEG EMG etc.) are compressed using DPCM technique. To enhance the robustness of the embedded information, the patient Information Is coded by Error Correcting Codes (ECC) Reed Solomon (RS) codes. The noisy scenario Is simulated by adding salt and pepper (S&P) noise to the embedded Image. For different Signal to Noise Ratio (SNR) of the image, Bit Error Rate (BER) and Number of Character Altered (NOCA) for text data and percentage distortion (PDIST) for the signal graph is evaluated. It Is elicited that coded systems can perform better than the uncoded systems. © 2004 IEEE.Item Energy efficient wireless sensor networks using asymmetric distributed source coding(2013) Rao, A.; Kulkarni, M.Wireless Sensor Networks (WSNs) are networks of sensor nodes deployed over a geographical area to perform a specific task. WSNs pose many design challenges. Energy conservation is one such design issue. In literature a wide range of solutions addressing this issue have been proposed. Generally WSNs are densely deployed. Thus the nodes with the close proximity are more likely to have the same data. Transmission of such non-aggregated data may lead to an inefficient energy management. Hence the data fusion has to be performed at the nodes so as to combine the redundant information into a single data unit. Distributed Source Coding is an efficient approach in achieving this task. In this paper an attempt has been made in modeling such a system. Various energy efficient codes were considered for the analysis. System performance in terms of energy efficiency has been made. Copyright © 2013 SPIE.Item 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. © 2023, The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd.Item Comparative Study of Millimeter-Wave-Over-Fiber Transmission Link with Different Photodiodes(Institute of Electrical and Electronics Engineers Inc., 2024) Singh, A.; Mishra, S.K.; Dinesh Achalaram, C.; Singh, M.In optical fiber communication, there is an expo- nential growth in data traffic demand. Hence, there is a need for advanced and efficient signal generation methods that offer a wider frequency range, higher tunability, and lower distortion. These optical fiber networks have long-distance capabilities and high data rates essential for intercontinental connections. This paper investigates the performance comparison of PIN photodetector and avalanche photodetector (APD) in optical fiber communication in terms of quality (Q) factor and eye patterns. The simulation model, utilizing microwave photonics (MWP) technology, implemented in OptiSystem software incorporates a Mach-Zehnder modulator (MZM) for optical signal modulation and a Bessel filter for spectral shaping. Photodetectors are susceptible to noise, which may occur due to thermal noise, shot noise, or dark current, and generate signals with increased bit error rate (BER) and degraded signal quality. To overcome these problems, photodetectors with suitable materials and designs are utilized to improve responsivity and reduce noise levels. A maximum Q factor of 7.6019 and minimum bit error rate of 1.4075 × 10-14 at 10 Gbps over a 25 km single-mode optical fiber network is obtained in the mm-wave wavelength range. Theoretical analysis of the suggested system is also discussed. © 2024 IEEE.Item A 2.71-pA/√Hz ultra-low noise, 70-dB dynamic range CMOS transimpedance amplifier with incorporated microstrip line techniques over extended bandwidth(John Wiley and Sons Ltd, 2023) Gorre, P.; Vignesh, R.; Kumar, S.; Song, H.; Roy, G.M.Recent advancements in the area of telemedicine have focused on remote patient monitoring services as a new frontier in medical applications. The present work reports a 65-nm complementary metal–oxide–semiconductor (CMOS)-based transimpedance amplifier (TIA) in an optical radar system for non-contact patient monitoring. A T-shaped microstrip line (MSL) integrated with variable gain common source TIA using MSL peaking technique and off-chip post-amplification integration is a newly proposed architecture to achieve a ultra-low noise, high dynamic range (DR) and high figure of merit over broadband than a traditional TIAs. First, the integrated T-shaped MSL develops an additional resonant frequency that resonates with a photodiode capacitance improving the bandwidth performance at higher Q values. Second, the shunt MSL peaking technique that introduces an additional conjugate pole-pair that cancels the effect of input capacitance helps to further improve the bandwidth of the TIA. Finally, an active feedback concept achieves a wide linear dynamic range enabling high TIA detectability. The proposed TIA realizes an impedance bandwidth of 770 MHz ranging from 7.12 to 7.89 GHz with a transimpedance gain of 105.1 dBΩ and ultra-low input-referred noise (IRN) density of 2.71 pA/√Hz. A high linear DR of 70 dB is achieved by employing a variable gain control scheme with a low group delay variation of 0.81 ns. The proposed work demonstrates a 1-Gb/s data rate while a bit-error rate less than 10−12 is achieved. The TIA consumes a power of 0.82 mW under the supply voltage of 1.2 V. © 2022 John Wiley & Sons Ltd.Item 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.