Optimizing intelligent reflecting surface assisted visible light communication networks under blockage and practical constraints using TLBO for IoT applications Vipul Dixit, Ajit Kumar, Nishant Sharan, Shikha Pandey, Atul Kumar, Ram Sewak Singh Scientific Reports, 2025 Wireless communication systems can enhance their capabilities by exploring new opportunities and addressing emerging challenges through the integration of the Internet of Things (IoT) in 6G networks. Visible Light Communication (VLC) stands out as a promising wireless access technology for IoT devices. This paper presents a novel Teaching-Learning-Based Optimization (TLBO) optimized Intelligent Reflecting Surface (IRS)-assisted VLC system aimed at maximizing Signal-to-Noise Ratio (SNR) and enhancing illuminance uniformity. The proposed system ensures improved communication for IoT devices, particularly in indoor environments. To enhance real-world applicability, the study evaluates system performance under realistic conditions, considering the impact of human and furniture blockages. A detailed investigation is conducted on the achievable SNR performance of the TLBO-optimized IRS-VLC system, demonstrating its ability to maintain robust and reliable communication in obstructed areas. Furthermore, the impact of the proposed system on illuminance uniformity is thoroughly analyzed, showing significant improvements in lighting efficiency and visibility. The effectiveness of the approach is validated using the Coefficient of Variation (CoV), confirming that the system achieves an optimal CoV range of 0-0.2 across the room, ensuring uniform illumination for IoT applications. The SNR and received power improve with increasing IRS elements, with optimal device positioning (e.g., edge-mid) outperforming suboptimal configurations (e.g., corner-opposite) due to geometric reflection efficiency and aperture gain, leading to a widening performance gap at larger IRS scales-highlighting the critical role of strategic IoT device placement in fixed sensor deployments. The findings highlight the potential of TLBO-optimized IRS-VLC systems in overcoming physical obstructions and improving both communication and lighting conditions in smart indoor environments. Additionally, detailed convergence analysis demonstrates that TLBO performs better than Genetic Algorithm (GA) and Particle Swarm Optimization (PSO) in terms of convergence speed, higher fitness value and lower sensitivity to initial conditions, making it most suitable for real-time IRS-VLC based IoT applications.
Minimizing positioning error through strategic LED arrangement: circular layout superiority in ANN-based VLP Ajit Kumar, Nishant Sharan, Vipul Dixit, S. K. Ghorai, R. Karibasappa, K. P. Ravikumar, Amresh Kumar Applied Optics, 2025 This research introduces a fingerprint-based artificial neural network approach for visible light positioning systems. The study evaluates four different light emitting diode (LED) configurations—square, rectangular, triangular, and circular—within a 5m×5m×3m indoor environment to determine which arrangement delivers the highest positioning accuracy. The analysis employs a receiver moving in a circular path within the receiver plane for the estimation of positioning accuracy across the entire trajectory. Comprehensive simulation results, including the cumulative distribution function, frequency distribution of positioning errors, and error magnitudes at different receiver locations, demonstrate that the mean positioning errors (in centimeters) are 15.2893, 12.4548, 52.5016, and 9.8749 for square, rectangular, triangular, and circular configurations, respectively. The findings indicate that the circular arrangement yields superior performance with minimal positioning error. This configuration creates consistent signal strength gradients across all directions, eliminating potential “dead zones” and maximizing line-of-sight connections between LEDs and the receiver regardless of position. The superior performance of the circular configuration underscores the significant impact of geometric arrangement on positioning accuracy, even when utilizing identical numbers of LEDs and signal processing techniques.
Feed forward ANN approach for PAPR abatement in an ADO-OFDM VLC system Nishant Sharan, Ajit Kumar, Vipul Dixit Journal of Optical Communications, 2025 Orthogonal frequency division multiplexing (OFDM), is one of the most commonly used multi-carrier modulation strategy in visible light communication (VLC) systems. The integration of OFDM enhances the immunity against ISI and supports high-speed data to a significant number of users. However, the summation of identical phase symbols during the IFFT process shoots the peak power leading to a high peak-to-average power ratio (PAPR) issue in an OFDM-based optical system (O-OFDM). High PAPR has been a considerable matter of concern over the past decade as it negatively impacts the bit error rate (BER) of the system. The work intends to implement the feed-forward artificial neural network (ANN) in an asymmetrically clipped direct current biased optical OFDM (ADO-OFDM) system in order to mitigate the PAPR while preserving the BER performance of the system. The application of a feed-forward network optimizes parameters in real time to minimize PAPR levels and maintain optimal signal quality in an ADO-OFDM system. The feed-forward ADO-OFDM shows a PAPR of 10 dB for a reference CCDF of 10−3 achieving a reduction of 2 dB compared to the typical ADO-OFDM system.
Investigation of Metasurface Absorber Using CdTe,Graphene and InSb for Terahertz Applications Nishant Sharan, Mohit Kumar Singh, Gundlapalli Mamatha, Naggalla Chandrika, Gujjapaneni Masthan Babu 2024 Control Instrumentation System Conference Guiding Tomorrow Emerging Trends in Control Instrumentation and Systems Engineering Ciscon 2024, 2024 This work analyzes the possibilities of graphene, indium antimonide (InSb), and cadmium telluride (CdTe) metasurface absorbers for terahertz (THz) applications. A possible method of regulating THz radiation, which is essential for many applications such as spectroscopy, imaging, and communication systems, is provided by metasurface absorbers. Because of their unique features, CdTe, InSb, and graphene are suitable options for metasurface absorbers in the THz range. High absorption coefficients and tunability are provided by CdTe, large THz absorption is shown by InSb, and ultra-wideband absorption and active modulation are offered by graphene. The results reveal important insights into the performance of the proposed metasurface absorbers in the range of 2-4 THz. The proposed metasurface’s optimum dimensions exhibits dual band effectiveness with absorptance exceeding 91%. The first band ranging between 2.59-2.70 THz displays absorptance 0.91 while the second band ranging between 2.83-2.96 THz shows the absorptance about 0.99 with an average tuning rate of 0.6 THz T−1.
Experimental Demonstration of Hybrid PLC-VLC System Ajit Kumar, Nishant Sharan, Swapan Ghorai Proceedings of IEEE Inc4 2023 2023 IEEE International Conference on Contemporary Computing and Communications, 2023 Visible light communication (VLC) is becoming more popular as spectrum scarcity becomes a serious issue for wireless communication. Availability to the base network, on the other hand, will probably alter the system for communication, incurring significant costs. Power line communication (PLC) technology appears to be an excellent fit for VLC, providing electricity and connecting VLC to the backbone system. In the present paper a hybrid PLC- VLC has been experimentally demonstrated with very less budget as well as low complexity. For PLC and VLC channel, Frequency Shift Keying (FSK) and On-Off Keying (OOK) modulation technique has been implemented. In the VLC system, 4× 1 MISO system has been employed. A pulse signal has been generated from the MATLAB Simulink and this signal has been transmitted through PLCMISO-VLC channel. All the waveforms of the signal have been traced on Digital Oscilloscope (DSO) successfully.
A Hybrid Combination of OMA and NOMA for Integrated VLC-RF System Ajit Kumar, Nishant Sharan, Saswata Bose 2023 International Conference on Network Multimedia and Information Technology Nmitcon 2023, 2023 The current paper proposes a hybrid OMA-Co-operative-NOMA (HOCN) scheme that unifies visible light communication and radio frequency (RF) systems by utilising the perfectly synchronised Wireless Information and Power Transfer (SWIPT) technique. The NOMA employs successive interference cancellation, a computationally demanding task that shortens battery life. As a result, in a cooperative system, an energy harvesting scheme SWIPT is also implemented to ensure that near users have enough power to relay data to far users. The achievable rate of users is the metric used to quantify the performance in this work. The proposed HOCN system's performance has been compared to that of the SC-NOMA and TDMA systems using a range of user pairings, including near-far, near-near, and far-far (N-F, N-N, F-F). Furthermore, the impact of various field of view (FOV - 400 & 600) combinations of near and distant user with varying LED semi-angles has been investigated. Using different LED transmit powers, the impact of power harvesting efficiency on the far user rate as well as the sum rate has been examined. The results show that proposed HOCN system is better option as it requires less transmitted power as well as smaller optical attocell.
VLC OFDM System: Overview, applications and challenges Advances in Engineering Research Volume 50, 2022
Minimizing positioning error through strategic LED arrangement: circular layout superiority<? TeX\break?> in ANN-based VLP A Kumar, N Sharan, V Dixit, SK Ghorai, R Karibasappa, KP Ravikumar, ... Applied Optics 64 (26), 7755-7767 , 2025 2025.0
Optimizing intelligent reflecting surface assisted visible light communication networks under blockage and practical constraints using TLBO for IoT applications V Dixit, A Kumar, N Sharan, S Pandey, A Kumar, RS Singh Scientific Reports 15 (1), 27400 , 2025 2025.0 Citations: 3
Feed forward ANN approach for PAPR abatement in an ADO-OFDM VLC system N Sharan, A Kumar, V Dixit Journal of Optical Communications , 2025 2025.0 Citations: 2
Performance Investigation of Metasurface Absorber Using CdTe and InAS for Terahertz Applications ST Kumar, YV Lakshmi, PT Sree, N Sharan, MK Singh International Conference on Intelligent Computing and Communication, 15-24 , 2024 2024.0
Investigation of Metasurface Absorber Using CdTe, Graphene and InSb for Terahertz Applications N Sharan, MK Singh, G Mamatha, N Chandrika, GM Babu 2024 Control Instrumentation System Conference (CISCON), 1-5 , 2024 2024.0
A Hybrid Combination of OMA and NOMA for Integrated VLC-RF System A Kumar, N Sharan, S Bose 2023 International Conference on Network, Multimedia and Information … , 2023 2023.0 Citations: 1
Alleviating LED nonlinearity in a HACO system using a blend of precoder and a μ-law compander N Sharan, SK Ghorai, A Kumar Wireless Personal Communications 131 (2), 1149-1165 , 2023 2023.0 Citations: 4
Experimental demonstration of hybrid plc-vlc system A Kumar, N Sharan, S Ghorai 2023 IEEE International Conference on Contemporary Computing and … , 2023 2023.0 Citations: 5
Performance analysis of downlink multipath multi-user NOMA-VLC system A Kumar, N Sharan, SK Ghorai Optical and Quantum Electronics 54 (10), 660 , 2022 2022.0 Citations: 15
LED non-linearity mitigation in a NOMA-OFDM VLC system using a union of precoder and companding N Sharan, SK Ghorai, A Kumar Optical and Quantum Electronics 54 (10), 648 , 2022 2022.0 Citations: 8
PAPR reduction using a Precoder and Compander combination in a NOMA-OFDM VLC system N Sharan, SK Ghorai, A Kumar 2022 2nd international conference on artificial intelligence and signal … , 2022 2022.0 Citations: 15
Papr reduction using blend of precoder and μ-law compander in HACO system N Sharan, SK Ghorai, A Kumar 2021 IEEE 2nd International Conference on Applied Electromagnetics, Signal … , 2021 2021.0 Citations: 3
Hybrid scheme of precoder with μ ‐law compander for PAPR reduction and nonlinearity improvement in ADO‐OFDM system N Sharan, SK Ghorai International Journal of Communication Systems 34 (16), e4961 , 2021 2021.0 Citations: 16
PAPR reduction and non-linearity alleviation using hybrid of precoding and companding in a visible light communication (VLC) system N Sharan, SK Ghorai Optical and quantum electronics 52 (6), 304 , 2020 2020.0 Citations: 28
Peak-to-average power ratio (PAPR) reduction using combination of precoding and companding techniques for VLC OFDM systems N Sharan, SK Ghorai, A Kumar 2019 TEQIP III Sponsored International conference on microwave integrated … , 2019 2019.0 Citations: 12
PAPR reduction using precoding and companding techniques for OFDM systems D Agarwal, N Sharan, MP Raja, A Agarwal 2015 International Conference on Advances in Computer Engineering and … , 2015 2015.0 Citations: 25
2023 IEEE International Conference on Contemporary Computing and Communications InC4 2023 A Kumar, N Sharan, S Ghorai, S Pathak, S Prabhu, L Priyadarsini, Y Siraj, ...
MOST CITED SCHOLAR PUBLICATIONS
PAPR reduction and non-linearity alleviation using hybrid of precoding and companding in a visible light communication (VLC) system N Sharan, SK Ghorai Optical and quantum electronics 52 (6), 304 , 2020 2020.0 Citations: 28
PAPR reduction using precoding and companding techniques for OFDM systems D Agarwal, N Sharan, MP Raja, A Agarwal 2015 International Conference on Advances in Computer Engineering and … , 2015 2015.0 Citations: 25
Hybrid scheme of precoder with μ ‐law compander for PAPR reduction and nonlinearity improvement in ADO‐OFDM system N Sharan, SK Ghorai International Journal of Communication Systems 34 (16), e4961 , 2021 2021.0 Citations: 16
Performance analysis of downlink multipath multi-user NOMA-VLC system A Kumar, N Sharan, SK Ghorai Optical and Quantum Electronics 54 (10), 660 , 2022 2022.0 Citations: 15
PAPR reduction using a Precoder and Compander combination in a NOMA-OFDM VLC system N Sharan, SK Ghorai, A Kumar 2022 2nd international conference on artificial intelligence and signal … , 2022 2022.0 Citations: 15
Peak-to-average power ratio (PAPR) reduction using combination of precoding and companding techniques for VLC OFDM systems N Sharan, SK Ghorai, A Kumar 2019 TEQIP III Sponsored International conference on microwave integrated … , 2019 2019.0 Citations: 12
LED non-linearity mitigation in a NOMA-OFDM VLC system using a union of precoder and companding N Sharan, SK Ghorai, A Kumar Optical and Quantum Electronics 54 (10), 648 , 2022 2022.0 Citations: 8
Experimental demonstration of hybrid plc-vlc system A Kumar, N Sharan, S Ghorai 2023 IEEE International Conference on Contemporary Computing and … , 2023 2023.0 Citations: 5
Alleviating LED nonlinearity in a HACO system using a blend of precoder and a μ-law compander N Sharan, SK Ghorai, A Kumar Wireless Personal Communications 131 (2), 1149-1165 , 2023 2023.0 Citations: 4
Optimizing intelligent reflecting surface assisted visible light communication networks under blockage and practical constraints using TLBO for IoT applications V Dixit, A Kumar, N Sharan, S Pandey, A Kumar, RS Singh Scientific Reports 15 (1), 27400 , 2025 2025.0 Citations: 3
Papr reduction using blend of precoder and μ-law compander in HACO system N Sharan, SK Ghorai, A Kumar 2021 IEEE 2nd International Conference on Applied Electromagnetics, Signal … , 2021 2021.0 Citations: 3
Feed forward ANN approach for PAPR abatement in an ADO-OFDM VLC system N Sharan, A Kumar, V Dixit Journal of Optical Communications , 2025 2025.0 Citations: 2
A Hybrid Combination of OMA and NOMA for Integrated VLC-RF System A Kumar, N Sharan, S Bose 2023 International Conference on Network, Multimedia and Information … , 2023 2023.0 Citations: 1
Minimizing positioning error through strategic LED arrangement: circular layout superiority<? TeX\break?> in ANN-based VLP A Kumar, N Sharan, V Dixit, SK Ghorai, R Karibasappa, KP Ravikumar, ... Applied Optics 64 (26), 7755-7767 , 2025 2025.0
Performance Investigation of Metasurface Absorber Using CdTe and InAS for Terahertz Applications ST Kumar, YV Lakshmi, PT Sree, N Sharan, MK Singh International Conference on Intelligent Computing and Communication, 15-24 , 2024 2024.0
Investigation of Metasurface Absorber Using CdTe, Graphene and InSb for Terahertz Applications N Sharan, MK Singh, G Mamatha, N Chandrika, GM Babu 2024 Control Instrumentation System Conference (CISCON), 1-5 , 2024 2024.0
2023 IEEE International Conference on Contemporary Computing and Communications InC4 2023 A Kumar, N Sharan, S Ghorai, S Pathak, S Prabhu, L Priyadarsini, Y Siraj, ...
