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 Modulation Techniques of Free Space Optics using Various Link Ranges

2019 ◽  
Vol 9 (2) ◽  
pp. 2952-2955
Keyword(s):  
Free Space ◽  
Free Space Optics ◽  
Free Space Optical ◽  
Optical Links ◽  
Space Optics ◽  
Data Rates ◽  
Modulation Techniques ◽  
Efficient Communication ◽  
Link Budget ◽  
Attenuation Values

Free space optics is the present trend, which enables the communication to achieve the expected data rates for the increasing user demands. The utility of FSO in free space medium enables higher data rates than the conventional microwave links for efficient communication. Several researchers have performed the analysis of free space optics by use of different modulation techniques and optimization of the link budget in free space optical links. In this work, CW laser transmitting source ranging to 10dB of output level, link ranges of 500, 1000 and 1500 mts with attenuation values of 0.2, 0.7 and 0.9 dB/Km respectively are considered. The analysis of free space optics is carried out by using various modulation techniques such as ASK, PSK, FSK, MZ, EA, Dual Drive MZ and it is observed that Dual Drive MZ modulation performs well when compared with the other modulation techniques.

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.

scholarly journals An Overview of Free Space Optics with Quantum Cascade Lasers

2014 ◽  
Vol 60 (3) ◽  
pp. 259-264 ◽  
Author(s):  
Janusz Mikołajczyk
Keyword(s):  
Free Space ◽  
Open Space ◽  
Quantum Cascade Lasers ◽  
Optical Systems ◽  
Optical Data ◽  
Free Space Optics ◽  
Free Space Optical ◽  
Quantum Cascade ◽  
Space Optics ◽  
Cascade Lasers

Abstract The article presents an overview of the work on quantum cascade lasers application in free space optical systems (Free Space Optics - FSO). There are discussed the main issues of the open-space laser communications and their practical construction. Comparative analyses of each FSO technology were performed. Brief description of quantum cascade (QC) lasers and some developments related to the use of these lasers in optical data link are also presented. In summary, the constructed models of FSO links with QC lasers are characterized.

Review on Wavelength Division Multiplexing Free Space Optics

2018 ◽  
Vol 0 (0) ◽  
Author(s):  
S. Magidi ◽  
A. Jabeena
Keyword(s):  
Wavelength Division Multiplexing ◽  
Free Space ◽  
Access Network ◽  
Research Direction ◽  
Hybrid Network ◽  
Free Space Optics ◽  
Wavelength Division ◽  
Space Optics ◽  
Current State ◽  
Data Rates

AbstractWavelength division multiplexing-based free space optics (WDM FSO) has emerged as a potential communication network candidate for last-mile access among other applications. FSO has received much attention in the last few years as a complement as well as an alternative to radio frequency-based communication due to spectrum crisis among other reasons. On the other hand, WDM has been considered as one of the next-generation optical access network candidates for bandwidth efficiency and increased data rates. A hybrid network of these two technologies thus has emerged as another research direction. In this article, we present the background, progress and the current state of WDM FSO.

Mitigation of Atmospheric Turbulences Using Mode Division Multiplexing based on Decision Feedback Equalizer for Free Space Optics

2020 ◽  
Vol 41 (2) ◽  
pp. 185-193 ◽  
Author(s):  
Abdullah Almogahed ◽  
Angela Amphawan ◽  
Yousef Fazea
Keyword(s):  
Free Space ◽  
Minimum Mean Square Error ◽  
Decision Feedback ◽  
Free Space Optics ◽  
Decision Feedback Equalizer ◽  
Free Space Optical ◽  
Space Optics ◽  
Link Distance ◽  
Mode Division Multiplexing ◽  
Simulation Results

AbstractIn mode division multiplexing (MDM) free space optical (FSO) communication system, the atmospheric turbulences such as fog, rain, and haze cause adverse effects on system performance. This paper investigates the mitigation of atmospheric turbulences of FSO using MDM and decision feedback equalizer (DFE) with minimum mean square error (MMSE) algorithm. The implementation of the MMSE algorithm is used to optimize both the feedforward and the feedback filter coefficients of DFE. The proposed system comprises three parallel 2.5Gbit/s channels using Hermite–Gaussian modes. A data rate of 7.5Gbit/s over 40 m, 800 m, 1400 m, and 2km under medium fog, rain, haze, and clear weather, respectively, has been achieved. In addition, it is noticed that the link distance is reduced while increasing the attenuation. The simulation results revealed that a DFE improves the performance MDM FSO system while maintaining high throughput and desired low bit error rate.

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