scholarly journals Spatial Jitter Influence on the Average BLER Performance of SIMO FSO Links over Atmospheric Turbulence Channels

Electronics ◽  
2021 ◽  
Vol 10 (16) ◽  
pp. 2033
Author(s):  
Nikolaos A. Androutsos ◽  
Hector E. Nistazakis ◽  
Efstratios V. Chatzikontis ◽  
Argyris N. Stassinakis ◽  
George S. Tombras
Keyword(s):  
Atmospheric Turbulence ◽  
Communication Systems ◽  
Optical Beam ◽  
Space Optics ◽  
Significant Research ◽  
Analytical Formulas ◽  
Radio Systems ◽  
Point To Point ◽  
Average Block ◽  
Combined Impact

In the recent years, Free Space Optics (FSO) technology has attracted significant research and commercial interest mostly because of its many advantages in comparison with other radio systems used for point-to-point connections. However, the reliable operation of these systems significantly depends on the conditions of the atmosphere in the area in which the optical beam propagates. The most important of these conditions are atmospheric turbulence and the misalignment between the optical beam and the receiver, which is also known as the pointing errors effect. In this work, in order to obviate the performance mitigation caused by these phenomena, we examined the most widely accepted and one of the most effective techniques, i.e., the implementation of receivers’ diversity. Various metrics have been investigated to evaluate the performance of such systems, but most of them do not take into account that the ultra-fast modern optical communication systems use blocks of bits for the transmission and codes for the detection and/or correction of erroneous bits. Thus, by taking these aspects into account, in this work, we investigated the combined impact of spatial jitter and atmospheric turbulence on the total average block error rate of an optical wireless system with receivers’ diversity. Novel closed-form analytical formulas were derived.

scholarly journals Moment-Based Analysis of Reg. Triangular QAM in Turbulent Atmospheric Channels with Pointing Errors incorporates Zero and Non-zero Boresight

2020 ◽  
Author(s):  
Muhammad Nabeel Shahid ◽  
Furqan Haider Qureshi ◽  
Shahzad Amin Sheikh ◽  
Qasim Umar Khan ◽  
Muhammad Zeeshan
Keyword(s):  
Atmospheric Turbulence ◽  
Error Rate ◽  
Amplitude Modulation ◽  
Communication Systems ◽  
Symbol Error Rate ◽  
Quadrature Amplitude Modulation ◽  
Optical Beam ◽  
Beam Radius ◽  
Pointing Errors ◽  
Average Symbol Error Rate

Abstract In recent years, free-space optical (FSO) technology has gained fame in communication systems due to its high data rates and license-free feature. Triangular quadrature amplitude modulation (TQAM) is an efficient modulation scheme that uses even bits per symbol, and it has a low average symbol error rate (ASER) than square quadrature amplitude modulation (SQAM). In this paper, we theoretically investigate the performance of subcarrier triangular quadrature amplitude modulation (SC-TQAM) corrupted by atmospheric turbulence in the presence of pointing errors (P.E) in FSO communications. We have considered boresight displacement, P.E effect, and atmospheric turbulence. To represent the atmospheric turbulence we consider Log-normal, Rayleigh and Rician distributions which exhibit weak, moderate and strong weather effects. The P.E is employed using Rayleigh and Rician distribution that incorporates zero and non-zero boresight displacement respectively. The moment generating functions of these models have been derived. P.E is modeled using an optical beam radius and receiver aperture radius. The combination of these parameters will help enhance the average symbol error rate (ASER). Furthermore, we have derived an analytical expression that is used to develop numerical results. The ASER performance is observed against average received irradiance, optical beam radius, P.E standard deviation and receiver aperture radius. In the end, the ASER performance is evaluated against SNR and Monte Carlo simulations are performed which validates the theoretical results.

scholarly journals Influence of Aircraft Power Electronics Processing on Backup VHF Radio Systems

Electronics ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 777
Author(s):  
Jan Leuchter ◽  
Radim Bloudicek ◽  
Jan Boril ◽  
Josef Bajer ◽  
Erik Blasch
Keyword(s):  
Power Electronics ◽  
Electromagnetic Interference ◽  
Communication Systems ◽  
Electromagnetic Compatibility ◽  
Intermediate Frequency ◽  
Radio Communication ◽  
Very High Frequency ◽  
Switching Power ◽  
Radio Systems ◽  
The Impact

The paper describes the influence of power electronics, energy processing, and emergency radio systems (ERS) immunity testing on onboard aircraft equipment and ground stations providing air traffic services. The implementation of next-generation power electronics introduces potential hazards for the safety and reliability of aircraft systems, especially the interferences from power electronics with high-power processing. The paper focuses on clearly identifying, experimentally verifying, and quantifiably measuring the effects of power electronics processing using switching modes versus the electromagnetic compatibility (EMC) of emergency radio systems with electromagnetic interference (EMI). EMI can be very critical when switching power radios utilize backup receivers, which are used as aircraft backup systems or airport last-resort systems. The switching power electronics process produces interfering electromagnetic energy to create problems with onboard aircraft radios or instrument landing system (ILS) avionics services. Analyses demonstrate significant threats and risks resulting from interferences between radio and power electronics in airborne systems. Results demonstrate the impact of interferences on intermediate-frequency processing, namely, for very high frequency (VHF) radios. The paper also describes the methodology of testing radio immunity against both weak and strong signals in accordance with recent aviation standards and guidance for military radio communication systems in the VHF band.

scholarly journals A Survey of Free Space Optics (FSO) Communication Systems, Links, and Networks

IEEE Access ◽  
2020 ◽  
pp. 1-1
Author(s):  
Samir A. Al-Gailani ◽  
Mohd Fadzli Mohd Salleh ◽  
Ali A. Salem ◽  
Redhwan Q. Shaddad ◽  
Usman Ullah Sheikh ◽  
...  
Keyword(s):  
Free Space ◽  
Communication Systems ◽  
Free Space Optics ◽  
Space Optics

Performance Analysis of FSO Links in Turbulent Atmosphere

2020 ◽  
pp. 100-156
Author(s):  
Banibrata Bag ◽  
Akinchan Das ◽  
Aniruddha Chandra ◽  
Rastislav Róka
Keyword(s):  
Atmospheric Turbulence ◽  
Communication Systems ◽  
Weather Conditions ◽  
Free Space Optical ◽  
Wireless Optical Communication ◽  
Adverse Weather Conditions ◽  
Adverse Weather ◽  
Optical Communication Systems ◽  
Active Research ◽  
Atmospheric Channel

The free-space optical communications technology is emerging as an attractive substitute to RF communications. It can satisfy the current demands for higher bandwidth to the customer. Atmospheric turbulence is a major obstacle in wireless optical communication systems. To fully utilize the terabit capacity of FSO system, it has to overcome various challenges offered by the heterogeneous nature of the atmospheric channel. Currently, FSO communication through atmospheric turbulence under adverse weather conditions is an active research topic. A lot of studies and experiments have been carried out on the effect of attenuation due to atmospheric turbulence; but still, much more research is necessary for fulfilling the current demands and commercial needs for implementing this technology successfully. This chapter discussed the various limitations of FSO system which are faced during data transmission through the atmospheric channel and various ways to improve the performance regarding BER, outage probability, and channel capacity.

Mechanisms for Parallel Data Transport

2012 ◽  
pp. 172-198
Author(s):  
Jewel Okyere-Benya ◽  
Georgios Exarchakos ◽  
Vlado Menkovski ◽  
Antonio Liotta ◽  
Paolo Giaccone
Keyword(s):  
Communication Systems ◽  
Parallel Transport ◽  
Building Blocks ◽  
Basic Structure ◽  
Transport Mechanisms ◽  
Data Transport ◽  
High Performing ◽  
Parallel Data ◽  
Parallel Downloading ◽  
Point To Point

Evolving paradigms of parallel transport mechanisms are necessary to satisfy the ever increasing need of high performing communication systems. Parallel transport mechanisms can be described as a technique to send several data simultaneously using several parallel channels. The authors’ survey captures the entire building blocks in designing next generation parallel transport mechanisms by firstly analyzing the basic structure of a transport mechanism using a point to point scenario. They then proceed to segment parallel transport into four categories and describe some of the most sophisticated technologies such as Multipath under Point to Point, Multicast under Point to Multipoint, Parallel downloading under Multipoint to Point, and Peer to Peer streaming under Multipoint to Multipoint. The Survey enables the authors to stipulate that high performing parallel transport mechanisms can be achieved by integrating the most efficient technologies under these categories, while using the most efficient underlying Point to Point transport protocols.

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