Conference Papers
Permanent URI for this collectionhttps://idr.nitk.ac.in/handle/123456789/28506
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Item Non-orthogonal full rank space-time block codes over Eisenstein-Jacobi integers for MIMO systems(Institute of Electrical and Electronics Engineers Inc., 2017) Raghavendra, R.; G.D., G.S.; Shripathi Acharya, U.In this work we present a full rank Space Time Block Codes with Non-orthogonal designs designated as NSTBCs constructed from cyclic codes over GF(qm). Rank-Preserving Eisenstein-Jacobi map is employed to map the codewords over finite field to codewords over complex field. A generalized procedure for designing NSTBCs for MIMO system containing Nt Transmit antennas and Nr receive antennas is obtained. The computational complexity of the MIMO system employing the presented NSTBC with ML detection has been derived and an upper bound on the average probability of error is presented. It is shown that under quasi-static Rayleigh flat fading channel conditions at an ABER of 10-4 the proposed NSTBC MIMO system provides a gain of approximately 3 dB in compared with C (4,2,4) code. © 2017 IEEE.Item Performance of SM-NSTBC for Correlated HAP Fading Channels with Imperfect-CSI(Springer, 2020) Godkhindi Shrutkirthi, S.; G.D., G.D.; Shripathi Acharya, U.This paper analyzes the performance of Spatially Modulated Non-orthogonal Space Time Block Code (SM-NSTBC) scheme for a correlated high altitude platform (HAP) MIMO system in the presence of imperfect channel state information (Imp-CSI). The proposed SM-NSTBC employs cyclic codewords derived over Galois Field, which satisfies full rank property. The performance of SM-NSTBC is compared with traditional STBCs such as SM-OSTBC and STBC-SM schemes. It is observed through simulations that SM-NSTBC outperforms SM-OSTBC and STBC-SM schemes by a minimum of 2 dB in HAP correlated environments. Monte-Carlo simulations have been performed to validate the claims. © 2020, Springer Nature Singapore Pte Ltd.Item Experimental Evaluation of Reliable Underwater Optical Communication in the Presence of Turbulence and Blockage(Springer Science and Business Media Deutschland GmbH, 2020) Prasad Naik, R.; Shripathi Acharya, U.; Suyan, N.K.In this paper, we have evaluated the performance of underwater wireless optical communication (UWOC) link in the presence of turbulence, air bubbles and blockage of 2.5-m-length channel. To mitigate the effects of turbulence and air bubbles, we have employed channel coding and receiver diversity combining techniques. Blocking causes the burst errors, and to mitigate the effect of blocking, we have employed interleaved channel-coded receiver diversity combining technique. Bit error rate (BER) performance of UWOC system evolved, and improvement in BER is achieved by employing channel codes, receiver diversity combining and interleaved channel codes. © 2020, Springer Nature Singapore Pte Ltd.Item Sustainable Off-Grid Electricity Generation System for Low Power Lighting in Remote Locations(Institute of Electrical and Electronics Engineers Inc., 2020) Shenoy, B.B.; Mitra, J.; Shripathi Acharya, U.; Laxminidhi, T.This paper proposes an environmental friendly and sustainable approach to generate electricity for small lighting applications in rural and remote locations. In the proposed system, human muscle energy, abundantly available in rural and remote locations, has been converted into electrical energy to be stored in an alternative energy storage device, e.g. a supercapacitor. The usual bicycle with a minor modification is plugged to a charging platform. The charging platform has a power processing circuit and a Permanent Magnet Direct Current generator. The system has the ability to power up a 1 W white LED lamp for a duration of approximately 60 minutes, when the bicycle is pedaled for 4 minutes. The proposed system is not only eco-friendly, but also effectively caters to the challenges posed by seasonal variations and locational disadvantages and is targeted specifically for locations which are not having access to the power grid. © 2020 IEEE.Item FPGA Accelerated Track to Track Association and Fusion for ADAS Distributed Sensors(Institute of Electrical and Electronics Engineers Inc., 2023) Gopala Swamy, B.; Reddy, G.H.; Srihari, P.; Shripathi Acharya, U.; Pardhasaradhi, B.The integration and amalgamation of sensor data in the automotive domain play a pivotal role in informing real-time decision-making for advanced driver assistance and safety (ADAS) systems. In a distributed architecture, the track-to-track association (T2TA) modules are responsible for associating the correct track pairs and subsequently fusion modules fuses the information. The T2TA and fusion modules operate within the CPU framework, often leading to elevated latency across the system. This paper introduces digital signal processing (DSP) architectures for the T2TA and fusion modules, designed to meet stringent constraints in terms of both area and latency. These modules encompass critical operations such as matrix inversion, vector-to-matrix multiplications, and matrix-to-matrix multiplications. The challenge of vector-to-matrix multiplications is effectively addressed through the utilization of the constant co-efficient multiplication technique. Additionally, matrix-to-matrix multiplication is performed by employing a vector-to-vector multiplication architecture with Block RAMs (BRAMs). Further-more, matrix inversion is realized through the LU decomposition method. Moreover, this paper presents an innovative approach to expedite the T2TA and fusion modules by harnessing folded DSP architecture within a system-on-chip (SOC) framework. The results of simulations substantiate that the proposed architectures exhibit a remarkable suitability for applications necessitating low area, low power consumption, and high throughput capabilities. © 2023 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.