Conference Papers
Permanent URI for this collectionhttps://idr.nitk.ac.in/handle/123456789/28506
Browse
5 results
Search Results
Item Performance of QPSK modulation for FSO geo-synchronous satellite communication link under atmospheric turbulence(2013) Jokhakar Jignesh, D.; Sripati, U.; Kulkarni, M.In recent years, free space optical (FSO) communication has gained a considerable interest amongst the researchers due to certain benefits it has to offer over RF links such as availability of large unlicensed bandwidth, high data rates, negligible electromagnetic interference, ease of installation etc. However the conventionally used FSO systems use On-Off Keying (OOK) as the modulation technique. Such a link requires high levels of transmit power. In this paper, we have suggested the use of QPSK modulation technique which allows us to reap the benefits of coherent detection. Our calculations show that QPSK is more inert to the changes in atmospheric conditions like temperature, air pressure, humidity, aerosol concentration etc. © 2013 IEEE.Item Outage Probability Analysis of Variable and Fixed Gain Relay-Assisted Dual-Hop RF-FSO Links Using Space–time Block Code Users(Springer Science and Business Media Deutschland GmbH, 2023) Naik, R.P.; Bhargava Kumar, L.B.; Krishnan, K.; Chung, W.-Y.In this paper, we have implemented an analytical study on a relay-assisted dual-hop system using fixed and variable gains for the radio-frequency (RF) and free-space optical communication (FSO). RF and FSO links are realized using the Rayleigh and Malaga distribution functions. Simulation results shows that pointing errors become severe, system performance deteriorates, and conjointly that the RF users exploiting space–time block coding (STBC) will enhance the performance of the end-to-end system. Outage probability of the end-to-end communication link operated with the STBC using the variable and fixed gain system implemented and plotted with respect to average SNR. From the obtained results, fixed gain relay-based communication link performs better efficient than the variable gain relay system. © 2023, The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd.Item Outage Probability Analysis of Dual Hop FSO Convergent with RF-UWOC Hybrid Link for SAGSIN in 6G-IoT Systems(Institute of Electrical and Electronics Engineers Inc., 2024) Rajeshwari, V.; Ishana Chellam, S.; Yukta Sri, C.K.; Kavitha, K.; Suveetha Dhanaselvam, P.; Karthikeyan, B.; Krishnan, P.This paper analyses the effectiveness of a novel hybrid communication system designed for a space-air-ground-sea integrated network (SAGSIN) within 6G Internet of Things (6G-IoT) environments. The system employs a dual-hop mechanism, featuring a free-space optical (FSO) link with a Malaga distribution for communication between ground and ships, along with a hybrid Radio Frequency - Underwater Wireless Optical Communication (RF-UWOC) link characterized by Nakagami-m and exponential generalized Gamma distributions for ship-to-underwater Autonomous Vehicle (AUV) communication. In this configuration, the ship serves as a Decode-and-Forward relay, where the RF link bolsters system reliability, and the UWOC link ensures secure communication. To optimize overall performance, the system implements a selection combining technique to identify the best signal from both RF and UWOC links. The paper evaluates the end-to-end cumulative distribution function (CDF) of the channel through the Meijer-G hypergeometric function. It also examines the outage probability of the proposed system across various weather conditions in the FSO channel, the effects of the Nakagami fading parameter m, and variations in salinity in the UWOC link. © 2024 IEEE.Item Energy Harvesting Optimization in FSO Communication with SLIPT Using Advanced Splitting Methods(Institute of Electrical and Electronics Engineers Inc., 2025) Angayarkanni, V.; Sheeba, A.; Dharshini V, M.; Suvetha, P.; Kavitha, K.; Suveetha Dhanaselvam, P.; Karthikeyan, B.; Krishnan, P.This paper presents an analysis of Simultaneous Lightwave Information and Power Transfer (SLIPT) in FreeSpace Optical (FSO) communication systems, incorporating key techniques such as AC-DC Separation (ADS), Power Splitting (PS), Time Switching (TS), and a hybrid Time Switching-Power Splitting (TS-PS) scheme. Closed-form expressions for the average harvested energy are derived, considering FSO turbulence channels modeled using the Málaga distribution. Furthermore, the analysis evaluates the impact of various turbulence conditions, including clear air, heavy rain, drizzle, and light fog, as well as the influence of receiver aperture size and other system and channel parameters. The primary focus of the result is to assess the energy harvesting performance under these diverse operating conditions. © 2025 IEEE.Item Performance Analysis of Triple Hop RF-RIS Convergent with FSO and UWOC System(Institute of Electrical and Electronics Engineers Inc., 2025) Sheeba, A.; Dharshini V, M.; Suvetha, P.; Kavitha, K.; Suveetha Dhanaselvam, P.; Karthikeyan, B.; Angayarkanni, V.; Krishnan, P.This paper proposes a hybrid communication system for integration within the space-air-ground-sea network (SAGSIN) architecture, tailored for 6G Internet of Things (6GIoT) applications. The system employs a triple-hop link combining Reconfigurable Intelligent Surface (RF-RIS), Free Space Optics (FSO), and Underwater Wireless Optical Communication (UWOC), facilitating communication between a base station, a lighthouse, a ship, and Underwater Aerial Vehicles (UWAVs). The architecture, using differential phaseshift keying, is ideal for Underwater Optical Wireless Sensor Networks (UOWSNs) and Internet of Underwater Things (IoUT). Performance analysis models RF-RIS with Nakagamim distribution, the FSO link with the Malaga distribution, and the UWOC link using the Exponential Generalized Gamma (EGG) distribution. The system's end-to-end cumulative distribution function (CDF) is evaluated via the Meijer-G function, while outage probability is examined under varying conditions, including atmospheric turbulence, fading parameters, and salinity levels. This system shows promise for coastal environments with changing weather conditions like rain, haze, and fog. © 2025 IEEE.
