Performance Investigation of FSO–OFDM Communication Systems under the Heavy Rain Weather

2017 ◽  
Vol 39 (1) ◽  
Author(s):  
Florence Rashidi ◽  
Jing He ◽  
Lin Chen
Keyword(s):  
Communication System ◽  
Communication Systems ◽  
Orthogonal Frequency Division Multiplexing ◽  
Attenuation Factor ◽  
Heavy Rain ◽  
Rain Attenuation ◽  
Optical Signal ◽  
Atmospheric Conditions ◽  
Free Space Optical ◽  
Rainfall Condition

AbstractThe challenge in the free-space optical (FSO) communication is the propagation of optical signal through different atmospheric conditions such as rain, snow and fog. In this paper, an orthogonal frequency-division multiplexing technique (OFDM) is proposed in the FSO communication system. Meanwhile, considering the rain attenuation models based on Marshal & Palmer and Carbonneau models, the performance of FSO communication system based on the OFDM is evaluated under the heavy-rain condition in Changsha, China. The simulation results show that, under a heavy-rainfall condition of 106.18 mm/h, with an attenuation factor of 7 dB/km based on the Marshal & Palmer model, the bit rate of 2.5 and 4.0 Gbps data can be transmitted over the FSO channels of 1.6 and 1.3 km, respectively, and the bit error rate of less than 1E − 4 can be achieved. In addition, the effect on rain attenuation over the FSO communication system based on the Marshal & Palmer model is less than that of the Carbonneau model.

scholarly journals Fog and Rain Attenuation Characterization and Performance of Terrestrial Free Space Optical Communication in Akure, Nigeria

2019 ◽  
Vol 4 (3) ◽  
pp. 125-134
Author(s):  
Joseph Sunday Ojo ◽  
Owolawi P. A. ◽  
Ajewole M. O. ◽  
Adetunji R. M.
Keyword(s):  
Free Space ◽  
Communication Systems ◽  
Outer Space ◽  
Rain Attenuation ◽  
Integration Time ◽  
Atmospheric Conditions ◽  
Free Space Optical ◽  
High Data ◽  
Space Optical Communication ◽  
And Performance

 Reliable broadband communication requires secure high data rate and bandwidth links. With the observed increase in broadband users, known communication systems such as RF and microwave links cannot promise such requirements due to link interference and low bandwidth. A current communication system that promises such requirements and more is Free Space Optical (FSO) communication. This system basically involves the transmission of signal-modulated optical radiation from a transmitter to a receiver through the atmosphere or outer space. However, location-variant atmospheric channel degrades the performance of an FSO system under severe atmospheric conditions, thus necessitating local atmospheric attenuation studies. This paper presents the characterization of both fog- and rain-induced attenuation and the performance of an FSO system in a terrestrial terrain at Akure, Nigeria. One-year archived visibility data and in-situ measured 1-minute integration time rain rate data obtained from Nigerian Meteorological Agency (NIMET) and the Department of Physics, Federal University of Technology, Akure were used to compute the fog- and rain-induced specific attenuations using Kruse model and Carboneur model respectively. The performance of the FSO system is analyzed through link margin by using the parameters of a commercial optical transceiver, Terescope 5000.

scholarly journals Serial DF Relayed FSO Links over Mixture Gamma Turbulence Channels and Nonzero Boresight Spatial Jitter

Computation ◽  
2019 ◽  
Vol 7 (3) ◽  
pp. 34 ◽  
Author(s):  
Androutsos ◽  
Nistazakis ◽  
Khalid ◽  
Muhammad ◽  
Tombras
Keyword(s):  
Communication Systems ◽  
Optical Signal ◽  
Propagation Path ◽  
Atmospheric Conditions ◽  
Free Space Optical ◽  
Decode And Forward ◽  
Pointing Error ◽  
Composite Channels ◽  
Turbulence Effects ◽  
Significant Phenomenon

Over the past few years, terrestrial free space optical (FSO) communication systems have demonstrated increasing research and commercial interest. However, due the signal’s propagation path, the operation of FSO links depends strongly on atmospheric conditions and related phenomena. One such significant phenomenon is the scintillation caused by atmospheric turbulence effects; in order to address the significant performance degradation that this causes, several statistical models have been proposed. Here, turbulence-induced fading of the received optical signal is investigated through the recently presented mixture Gamma distribution, which accurately describes the irradiance fluctuations at the receiver’s input of the FSO link. Additionally, at the same time, it significantly reduces the mathematical complexity of the expressions used for the description of composite channels with turbulence along with nonzero boresight pointing error-induced fading. In order to counterbalance the performance mitigation due to these effects, serial decode-and-forward relays are employed, and the performance of the system is estimated through derived mathematical expressions.

Design of 16 × 40 Gbps hybrid PDM-WDM FSO communication system and its performance comparison with the traditional model under diverse weather conditions of Bangladesh

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
A. K. M. Sharoar Jahan Choyon ◽  
Ruhin Chowdhury
Keyword(s):  
Wavelength Division Multiplexing ◽  
Communication System ◽  
Channel Model ◽  
Optical Power ◽  
Weather Conditions ◽  
Optical Signal ◽  
Performance Comparison ◽  
Traditional Model ◽  
Atmospheric Conditions ◽  
Free Space Optical

Abstract A comprehensive design is proposed for free-space optical (FSO) communication system by hybridizing polarization division multiplexing (PDM) with wavelength division multiplexing (WDM) and its performance is investigated under diverse turbulent weather conditions of Bangladesh. Here we consider gamma–gamma (G–G) distribution for the turbulent FSO channel model. Moreover, a PDM-WDM technique not only maximizes the link capacity of FSO system but also enhances the spectral efficiency (SE) of the system. Besides, the performance of this hybrid PDM-WDM FSO system is compared with the traditional model and the proposed hybrid system exhibits excellent performance under diverse atmospheric conditions of Bangladesh. Performance analysis of the proposed model as well as the comparison with the traditional model is described in terms of optical power spectrum (OPS), optical signal to noise ratio (OSNR), bit error rate (BER), Q factor, constellation diagrams, and eye diagrams.

scholarly journals Design and performance analysis of spectral-efficient hybrid CPDM-CO-OFDM FSO communication system under diverse weather conditions

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Ruhin Chowdhury ◽  
A. K. M. Sharoar Jahan Choyon
Keyword(s):  
Performance Analysis ◽  
Communication System ◽  
Orthogonal Frequency Division Multiplexing ◽  
Channel Model ◽  
Signal To Noise Ratio ◽  
Optical Power ◽  
Weather Conditions ◽  
Multipath Fading ◽  
Optical Signal ◽  
Free Space Optical

Abstract A comprehensive design is proposed for the free-space optical (FSO) communication system by hybridizing circular polarization division multiplexing (CPDM) with coherent optical orthogonal frequency division multiplexing (CO-OFDM) and its performance is investigated realistically under diverse turbulent weather conditions of Bangladesh. Here, we consider Gamma–Gamma distribution for the turbulent FSO channel model. Moreover, the proposed scheme presents an excellent performance since the CPDM technique not only maximizes the link capacity of the FSO system but also enhances the spectral efficiency of the system. Besides, multipath fading, which is appeared during the FSO transmission, is significantly mitigated by OFDM modulation. The outcomes from the simulation confirm the advantages of the proposed hybrid scheme and also it can serve as a reference for the FSO application even in turbulent weather conditions. Performance analysis of the proposed model is described in terms of the optical power spectrum, optical signal-to-noise ratio, bit error rate, Q factor, constellation diagrams, and eye diagrams.

FSO-Based Analysis of LTE-A MAC Protocols to Achieve Improved QoS

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Prabhjot Kaur ◽  
Hardeep Singh Saini
Keyword(s):  
Data Transmission ◽  
Orthogonal Frequency Division Multiplexing ◽  
Optical Signal ◽  
Transmission Efficiency ◽  
Mac Protocols ◽  
Wireless Access Networks ◽  
Free Space Optical ◽  
Medium Access ◽  
Carrier Sense ◽  
Efficient Data

AbstractFiber wireless (Fi-Wi) communication network is the amalgamation of optical and wireless access networks, which provides better bandwidth for achieving efficient data transmission. Medium access control (MAC) protocols are used in the wireless network for controlling the data flow from the transmitter to the receiver end. The delay produced by these protocols tells about the system efficiency. This paper shows a Fi-Wi system in the long-term evaluation-advanced (LTE-A) environment, which incorporates the dependency of delay generated by the specific MAC protocols during the transmission process. This paper aimed to scrutinize the effects of Carrier Sense Multiplexing Access with Collision Detection (CSMA/CD), Carrier Sense Multiplexing Access with Collision Avoidance (CSMA/CA) and Slotted ALOHA on the performance of the Fi-Wi system. Free space optical (FSO) channel is incorporated to forward the data to user end. In such system, the optical signal is multiplexed using the Orthogonal Frequency Division Multiplexing (OFDM) technique and finally the data are fetched at the receiver end and different criterions such eye-height, Q-factor and bit error rate are evaluated. Simulation results are performed using MATLAB software. The comparative analysis is also performed in terms of data transmission efficiency, delay and throughput of MAC protocols. This shows the effective results of the proposed system according to the delay produced by MAC protocols.

Bidirectional Hybrid Optical Communication System Based on Wavelength Division Multiplexing for Outdoor Applications

2021 ◽  
Author(s):  
Sinan M. Abdulsatar ◽  
Mohammed A. Saleh ◽  
Abadulla Abass ◽  
M. H. Ali ◽  
Mohammed Ali Yaseen
Keyword(s):  
Wavelength Division Multiplexing ◽  
Optical Communication ◽  
Data Transmission ◽  
Communication System ◽  
Optical Switch ◽  
Heavy Rain ◽  
Free Space Optical ◽  
Wavelength Division ◽  
Backup System ◽  
All Optical

Abstract The simulation and investigation of a 32×10 Gb/s WDM all–optical bidirectional hybrid communication system for outdoor applications is presented in this article via multidisciplinary softwares. In order to track the system condition, a strain sensor based on fiber Bragg grating (FBG) is integrated in–line with the fiber optic link (FO–link). Then, a free space optical link (FSO–link) with 4–channel is simulated to act backup or rescue to the FO–link in the event of disaster or bombing. The FO–link is working well until the strain reach to 180 µε, after that the FO–link has degraded. Therefore, an optical switch is incorporated in between these systems (FO–link & FSO–link) to turn–on the FSO–link which act as a backup system to FO–link and maintains the continuity of the data transmission. According to the hybrid link results, there is an efficient enhancement in the Q–factor as compared with the FO–link even when there is heavy rain.

scholarly journals Fog and rain attenuation characterization and performance of terrestrial free space optical communication in Akure, Nigeria

2020 ◽  
Vol 4 (3) ◽  
pp. 125-134
Author(s):  
Ajewole M. O ◽  
Owolawi P. A ◽  
Ojo J. S ◽  
Adetunji R. M.
Keyword(s):  
Free Space ◽  
Communication Systems ◽  
Outer Space ◽  
Rain Attenuation ◽  
Integration Time ◽  
Free Space Optical ◽  
High Data ◽  
Space Optical Communication ◽  
And Performance ◽  
One Year

Reliable broadband communication requires secure high data rate and bandwidth links. With the observedincrease in broadband users, known communication systems such as RF and microwave links cannot promise suchrequirements due to link interference and low bandwidth. A current communication system that promises suchrequirements and more is Free Space Optical (FSO) communication. This system basically involves the transmissionof signal-modulated optical radiation from a transmitter to a receiver through the atmosphere or outer space. However,location-variant atmospheric channel degrades the performance of an FSO system under severe atmosphericconditions, thus necessitating local atmospheric attenuation studies.This paper presents the characterization of both fog- and rain-induced attenuation and the performance ofan FSO system in a terrestrial terrain at Akure, Nigeria. One-year archived visibility data and in-situ measured 1-minute integration time rain rate data obtained from Nigerian Meteorological Agency (NIMET) and the Departmentof Physics, Federal University of Technology, Akure were used to compute the fog- and rain-induced specificattenuations using Kruse model and Carboneur model respectively. The performance of the FSO system is analyzedthrough link margin by using the parameters of a commercial optical transceiver, Terescope 5000.

scholarly journals Optimization of system’s parameters for wavelength conversion of E-band signals

2022 ◽  
Vol 12 (2) ◽  
pp. 1659
Author(s):  
Yazan Alkhlefat ◽  
Sevia Mahdaliza Idrus Sutan Nameh ◽  
Farabi M. Iqbal
Keyword(s):  
Communication Systems ◽  
Orthogonal Frequency Division Multiplexing ◽  
High Speed ◽  
Wavelength Conversion ◽  
Signal To Noise Ratio ◽  
Optical Amplifier ◽  
Optical Signal ◽  
Error Vector Magnitude ◽  
Wavelength Converter ◽  
High Data

Current and future wireless communication systems are designed to achieve the user’s demands such as high data rate and high speed with low latency and simultaneously to save bandwidth and spectrum. In 5G and 6G networks, a high speed of transmitting and switching is required for internet of things (IoT) applications with higher capacity. To achieve these requirements a semiconductor optical amplifier (SOA) is considered as a wavelength converter to transmit a signal with an orthogonal frequency division multiplexing with subcarrier power modulation (OFDM-SPM). It exploits the subcarrier’s power in conventional OFDM block in order to send additional bits beside the normally transmitted bits. In this paper, we optimized the SOA’s parameters to have efficient wavelength conversion process. These parameters are included the injection current (IC) of SOA, power of pump and probe signals. A 7 Gbps OFDM-SPM signal with a millimeter waves (MMW) carrier of 80 GHz is considered for signal switching. The simulation results investigated and analyzed the performance of the designed system in terms of error vector magnitude (EVM), bit error rate (BER) and optical signal-to-noise ratio (OSNR). The optimum value of IC is 0.6 A while probe power is 9.45 and 8.9 dBm for pump power. The simulation is executed by virtual photonic integrated (VPI) software.

scholarly journals Investigations of Free Space Optical Communications Under Real-World Atmospheric Conditions

2020 ◽  
Vol 116 (1) ◽  
pp. 475-490 ◽  
Author(s):  
Tobias Siegel ◽  
Shun-Ping Chen
Keyword(s):  
Optical Communications ◽  
Free Space ◽  
Communication Systems ◽  
New Technologies ◽  
Weather Conditions ◽  
Optical Systems ◽  
Limiting Factors ◽  
Atmospheric Conditions ◽  
Free Space Optical ◽  
Atmospheric Channel

AbstractDue to the increasing demand for higher bandwidth in modern communication systems, conventional networks are continuously expanded with new technologies to improve coverage. Free space optical communications (FSOC) shows some significant advantages concerning system setup time in comparison with the classical fiber optical systems on one hand, substantial spectral bandwidth and performances in comparison with the wireless systems under certain conditions on the other hand. This makes this technology not only a reasonable extension for metropolitan area networks but also provides the capability to set up a network after an outage in case of natural disaster quickly. But transmitting data by using FSOC involves some limiting factors that have to be considered prior to each installation. Since the atmospheric channel is not static, the influence of changing weather conditions or industrial smog have a significant impact on the available bitrate. A simulation platform is developed and presented in this paper for investigation of FSOC considering these circumstances. Regarding the atmospheric channel, turbulence, distance-dependent beam divergence, and applied modulation schemes, a general overview of the capabilities is presented and discussed. The insight of this paper should help to make a decision under which preconditions either the FSOC provides a meaningful application possibility, or the limiting factors become too crucial and other technologies must be considered.

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