Conference Papers
Permanent URI for this collectionhttps://idr.nitk.ac.in/handle/123456789/28506
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Item BER performance improvement for secure wireless communication systems based on CSK-STBC techniques(2012) Abdulameer, L.F.; Jokhakar Jignesh, D.J.; Sripati, U.; Kulkarni, M.There has been a growing interest in the use of chaotic techniques for enabling secure communication in recent years. This need has been motivated by the emergence of a number of wireless services which require the channel to provide very low bit error rates (BER) along with information security. This paper investigates the feasibility of using chaotic communications over Multiple-Input Multiple-Output (MIMO) channels by combining chaos modulation with a suitable Space Time Block Code (STBC). It is well known that the use of Chaotic Modulation techniques can enhance communication security. However, the performance of systems using Chaos modulation has been observed to be inferior in BER performance as compared to conventional communication schemes. In order to overcome this limitation, we have proposed the use of a combination of Chaotic modulation and Alamouti Space Time Block Code. We have studied the performance of Chaos Shift Keying (CSK) with 2×1 Alamouti scheme for different chaotic maps over Additive White Gaussian Noise (AWGN) and Rayleigh fading channels. Our simulations indicate that the use of the Alamouti schemes can allow service providers to enhance security without degrading the BER performance while communicating over these channels. © 2012 IEEE.Item BER performance enhancement for secure wireless communication systems based on chaotic-MIMO techniques(2013) Abdulameer, L.F.; Jignesh, J.D.; Sripati, U.; Kulkarni, M.The growing interest in the use of chaotic techniques for enabling secure communication in recent years has been motivated by the emergence of a number of wireless services which require the service provider to provide low bit error rates (BER) along with information security. This paper investigates the feasibility of using chaotic communications over Multiple-Input-Multiple-Output (MIMO) channels. While the use of Chaotic maps can enhance security, it is seen that the overall BER performance gets degraded when compared to conventional communication schemes. In order to overcome this limitation, we have proposed the use of a combination of Chaotic modulation and Alamouti Space Time Block Code. The performance of Chaos Shift Keying (CSK) with 2×1 and 2×2 Alamouti schemes for different chaotic maps over wireless channels has been studied. It has been shown that the use of these schemes can provide security enhancement without the penalty of degradation of BER performance. Copyright © 2013 SPIE.Item Hybrid LDPC-STBC communications system based on chaos(Association for Computing Machinery, 2019) Abdulameer, L.F.; Jignesh, J.D.; Sripati, U.; Kulkarni, M.This paper attempts to show a communication strategy of implementing a hybrid of Low-Density Parity Check (LDPC) and Multiple Input Multiple Output (MIMO) based on chaotic technique. Many chaotic techniques which consider a significant part in the information security schemes was proposed, but one of the greatest defy in chaotic communications is the limitation of the system performance due to realistic channel conditions. We have investigated the theory and carried out detailed analysis pertaining to encoding/decoding of chaotic modulation schemes, the use of suitable LDPC coded MIMO schemes for providing secure and reliable communication. The aim of the hybrid scheme is that a correctly designed coded Space Time Block Code (STBC) is used to mitigate the declination of the signal caused by multipath scattering. The Bit-Error Rate (BER) performance of this hybrid scheme with two transmit antennas and two receive antennas under Rayleigh fading model is evaluated. The results indicate that that implementing LDPC (regular and irregular) coded STBC system decrease BER as compared with systems without implementing LDPC code for chaotic communication systems. Mathematical analysis for the hybrid system has been derived and achieved using Matlab. © 2019 Association for Computing Machinery.Item An Experimental Evaluation of MIMO-SAR Imaging with FMCW Radar(Institute of Electrical and Electronics Engineers Inc., 2022) Sriharsha Nag, T.S.; Vandana, G.S.; Pardhasaradhi, B.; Srihari, P.Synthetic aperture radar (SAR) imaging is a widely used technique to generate two-dimensional and three-dimensional imaging based on the principle of moving sensors. This paper presents an experimental investigation of SAR imaging using an IWR6843ISK frequency modulated continuous waveform(FMCW) radar sensor on a moving platform and providing the stationary targets. In this experiment, the moving platform is used to recreate images with a higher spatial resolution based on a two-dimensional fast Fourier transform (2D-FFT) algorithm. Three different configurations are explored, namely: SAR, single input multiple output SAR (SIMO-SAR), and multiple input and multiple outputs SAR for imaging multiple targets within the vicinity. The real-time data is collected by moving the radar from 1-21m and observing two different stationary targets. The received data is processed using the 2D-FFT algorithm and obtaining the imaging for various configurations. The experimental results reveal that target detection is accomplished for all three configurations and comparable with ground truth. The MIMO-SAR outperforms and is a suitable candidate for automotive SAR imaging. © 2022 IEEE.Item SAR Imaging with Automotive Radar: Range Migration Algorithm, Experiment, and Future Directions in Automotive Vehicle(Institute of Electrical and Electronics Engineers Inc., 2022) Sriharsha Nag, T.S.; Vandana, G.S.; Pardhasaradhi, B.; Srihari, P.Synthetic Aperture Radar (SAR) imaging with air-borne radar has many applications in remote sensing, surface mapping, and civil infrastructure monitoring. In contrast, the Millimeter wave (mmWave) radars are confined to the automotive industry to fetch information like range, azimuth, and elevation. In this paper, we proposed configuring the mm-wave radar in SAR mode to utilize the availability of multiple transmitters and receivers. The frequency modulated continuous wave (FMCW) radar is ported onto a moving platform, and a range migration algorithm (RMA) is performed to perform SAR imaging. The real-time experiment was conducted using IWR6843ISK radar and explored different configurations like SAR, single-input multiple-outputs SAR (SIMO-SAR), and multiple-input multiple-outputs SAR (MIMO-SAR). In addition to that, the platform movement is also considered by varying the speed from slow to high. The acquired I-Q data is processed using a range migration algorithm (RMA) by following the processing steps like a two-dimensional fast fourier transform (2D-FFT), Stolt interpolation, azimuth compression, and inverse FFT (IFFT). The experimental results reveal that the target detection is accomplished for all the cases. The best results can be obtained for MIMO configuration with a high-speed moving platform. These results can be highly applicable for the automotive industry to perform SAR imaging on SRR radars which are being deployed on the side of the vehicle to monitor the guard rails, crossing vehicles, and VRU. © 2022 IEEE.Item Performance of Orthogonal and Non-Orthogonal Space Time Block Code Through the Underwater Wireless Optical Channels(IEEE Computer Society, 2023) Naik, R.P.; Mans, R.; Shripathi Acharya, U.; Savidhan Shetty, C.S.Multiple input multiple output (MIMO) schemes have been integrated with the space-time (ST) codes to enhance the reliability of information transfer across the wireless channel. Due to their rich algebraic structure, space time block codes (STBCs) such as orthogonal STBCs (OSTBC), quasi-orthogonal STBC (QOSTBC), and non-orthogonal STBCs (NOSTBC), offer efficient implementation of a reliable communication system. The underwater wireless optical communication (UWOC) channel is perturbed by the weak turbulence and fading (referred as scintillation), and shares many properties with a wireless channel. In this paper, we have designed OSTBC/QOSTBC and NOSTBC schemes for UWOC system, which can significantly improve the integrity of information transfer across the underwater optical wireless channels. These codes have been suitably conditioned to operate with an UWOC system employing intensity modulation. Monte-Carlo bit error rate simulations of the proposed schemes are plotted and presented with respect to the available transmit power in dB. © 2023 IEEE.