scholarly journals Recovery Capabilities of Rateless Codes on Simulated Turbulent Terrestrial Free Space Optics Channel Model

2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
A. Andò ◽  
S. Mangione ◽  
L. Curcio ◽  
S. Stivala ◽  
G. Garbo ◽  
...  
Keyword(s):  
Free Space ◽  
Channel Model ◽  
Optical Power ◽  
Optical Signal ◽  
Free Space Optics ◽  
Optical Turbulence ◽  
High Data ◽  
Space Optics ◽  
Error Mitigation ◽  
Channel Codes

Free Space Optics (FSO) links are affected by several impairments: optical turbulence, scattering, absorption, and pointing. In particular, atmospheric optical turbulence generates optical power fluctuations at the receiver that can degrade communications with fading events, especially in high data rate links. Innovative solutions require an improvement of FSO link performances, together with testing models and appropriate channel codes. In this paper, we describe a high-resolution time-correlated channel model able to predict random temporal fluctuations of optical signal irradiance caused by optical turbulence. Concerning the same channel, we also report simulation results on the error mitigation performance of Luby Transform, Raptor, and RaptorQ codes.

scholarly journals The Role and Challenges of Free-space Optical Systems

2014 ◽  
Vol 35 (4) ◽  
Author(s):  
Sushank Chaudhary ◽  
Angela Amphawan
Keyword(s):  
Free Space ◽  
Satellite Communications ◽  
Radio Networks ◽  
Optical Systems ◽  
Free Space Optics ◽  
Free Space Optical ◽  
Optical Carrier ◽  
High Data ◽  
Space Optics ◽  
Data Rates

AbstractComplementing wireless radio networks with free-space optics (FSO) achieves high data rates by modulating radio subcarriers over an optical carrier without expensive optical fiber cabling, enabling a pervasive platform for reaching underserved areas. In this paper, we review the main features of FSO for terrestrial and inter-satellite communications. Simulations of 1 Gbps data transmission through FSO links in both terrestrial and inter-satellite communications have been investigated to highlight potential atmospheric challenges in FSO.

scholarly journals Review on Free Space Optics

2013 ◽  
Vol 8 (1) ◽  
pp. 734-742 ◽  
Author(s):  
Er. Rajeev Thakur ◽  
Er. Sukhbir Singh ◽  
Er. Abhishek Sharma
Keyword(s):  
Free Space ◽  
High Speed ◽  
Free Space Optics ◽  
High Data ◽  
Space Optics ◽  
Free Spectrum ◽  
Data Rates ◽  
High Bandwidth ◽  
Bottle Neck ◽  
High Data Rates

Present era demands high bandwidth with high data rates especially for internet. For high data rates requires high speed transmission medium like optical fiber. To overcome the bottle neck of last mile communication free space optics has emerged as a better option for radio engineers. Using Infrared beams provides license free spectrum, high bandwidth with maximum data rates. In this paper different aspects for utilizing an FSO link are reviewed showing there advantages and disadvantages. 

scholarly journals Prediction of Received Optical Power for Switching Hybrid FSO/RF System

Electronics ◽  
2020 ◽  
Vol 9 (8) ◽  
pp. 1261
Author(s):  
Renát Haluška ◽  
Peter Šuľaj ◽  
Ľuboš Ovseník ◽  
Stanislav Marchevský ◽  
Ján Papaj ◽  
...  
Keyword(s):  
Optical Communication ◽  
Free Space ◽  
Communication Systems ◽  
Prediction Models ◽  
Optical Power ◽  
Free Space Optics ◽  
Communication Line ◽  
Atmospheric Transmission ◽  
Space Optics ◽  
Weather Information

This study deals with the problem of fiber-free optical communication systems—known as free space optics—using received signal strength identifier (RSSI) prediction analysis for hard switching of optical fiber-free link to base radio-frequency (RF) link and back. Adverse influences affecting the atmospheric transmission channel significantly impair optical communications, therefore attention was paid to the practical design, as well as to the implementation of the monitoring device that is used to record and process weather information along a transmission path. The article contains an analysis and methodology of the solution of the high availability of the optical link. Attention was paid to the technique of hard free space optics (FSO)/RF-switching with regard to the amount of received optical power detected and its relation to the quantities influencing the optical communication line. For this purpose, selected methods of machine learning were used, which serve to predict the received optical power. The process of analysis of prediction of received optical power is realized by regression models. The study presents the design of the optimal data input matrix model, which forms the basis for the training of the prediction models for estimating the received optical power.

scholarly journals Performance Investigation of a High Data Rate Mode Division Multiplexed-Free Space Optics Link Under Harsh Weather Conditions

2021 ◽  
Vol 9 ◽  
Author(s):  
Mehtab Singh ◽  
Sahil Nazir Pottoo ◽  
Suvidhi ◽  
Sanjeev Dewra ◽  
Rishabh ◽  
...  
Keyword(s):  
Information Transmission ◽  
Free Space ◽  
Weather Conditions ◽  
Data Rate ◽  
High Data Rate ◽  
Sensor Data ◽  
Free Space Optics ◽  
High Data ◽  
Space Optics ◽  
Dust Weather

The requirement of high data rate information transmission is rising exponentially for supporting different services including social networking, web streaming, and biomedical sensor data transmission. Such services required high channel bandwidth with secure information transmission and immunity to electromagnetic interference. Radio over free space optics (RoFSO) is witnessed as a promising technological solution to provide high data rate transmission over free space channel. We report on the design of a 2×10 Gb/s-10 GHz RoFSO transmission system using the mode division multiplexing technique and evaluate its transmission performance over varying levels of dust weather conditions. The comparison of non-return to zero (NRZ) and return to zero (RZ) binary digital optical modulation techniques is carried out in the proposed system. It is found that the proposed system using NRZ modulation serves 14.5 km transmission range; however, in the case of RZ modulation, it was restricted to 10 km for a target bit error rate (BER) of 10−6, thus resulting in a noticeable link enhancement of 4.5 km. Also, we demonstrate NRZ-based MDM-RoFSO link performance and availability in dust weather conditions using the BER, maximum reachable link range, and eye diagram as key performance parameters. We obtain a reliable transmission of 20 Gb/s-20 GHz data through HG00 and HG01 channels over a link range of 2500–108 m depending on the external dust weather condition. Furthermore, since this investigation shows the feasibility of RoFSO for small size cells, which is an essential feature of 5G mobile network, the proposed system can thus be implemented as a backhaul/fronthaul link for high-band (above 6 GHz) 5G services and for providing secure transmission of biomedical sensor data.

Millimetre Waves Over Free Space Optics System for 5G Application

2018 ◽  
Vol 0 (0) ◽  
Author(s):  
Shakthi Murugan K H ◽  
M Sumathi
Keyword(s):  
Free Space ◽  
Communication Systems ◽  
Free Space Optics ◽  
60 Ghz ◽  
5G Networks ◽  
High Data ◽  
Space Optics ◽  
Data Rates ◽  
Increasing Demand ◽  
Mm Waves

AbstractWith advancement in communication systems and ever increasing demand of bandwidth, research has been oriented towards 5G networks. For achieving high data rates, mm waves are employed using radio over fiber (RoF) technique. This work focus on employing mm waves in free space optics. Two independent channels are employed with each having 5 Gbps data rate and 60 GHz of radio signal. Output signal received is observed by analyzing using BER and eye diagrams.

Free space optics communication channel with amplitude/frequency shift keying modulation technique based raised cosine line coding

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Mahmoud M.A. Eid ◽  
Vishal Sorathiya ◽  
Sunil Lavadiya ◽  
Ismail A. Abd El-Aziz ◽  
Ahmed Nabih Zaki Rashed
Keyword(s):  
Frequency Shift ◽  
Free Space ◽  
Optical Signal ◽  
Channel Length ◽  
Free Space Optics ◽  
Noise Power ◽  
Frequency Shift Keying ◽  
Space Optics ◽  
Shift Keying ◽  
Modulation Schemes

Abstract The objective of the study is to simulate frequency shift keying (FSK)/amplitude shift keying (ASK) modulation schemes with raised cosine line coding based free space optics channel in clear weather conditions. The max. Q and optical signal/noise ratio (OSNR) with FSO channel length variations are simulated for the previous and proposed models at DRs of 10 Gbps, and also the max. Q factor with data rate (DR) variations is demonstrated for the previous and proposed models at 10 km FSO channel length. Max. Q, min. BER, signal power (SP), noise power, and total optical power (TOP) based FSK and ASK modulation schemes are illustrated through APD receiver with FSO channel length of 10 km.

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