Investigation on Pointing Error in Multi-Beam Free Space Optical Communication System

2018 ◽  
Vol 0 (0) ◽  
Author(s):  
Jayson K. Jayabarathan ◽  
S. Robinson

AbstractFree space optical (FSO) communication has fascinated a lot of attention for a variety of applications in telecommunication area. It is dream of every researcher and telecommunication society to make it a real alternative solution for the last mile problem, to replace fiber optics. FSO is much favored because of its low maintenance cost and deployment time. Pointing error is one of the main challenges in FSO communication system which affects its performance especially at high data links that leads to significant performance degradation. In this paper, the impact of pointing error for multi-beam Hybrid Wavelength Division Multiplexing (HWDM) FSO system is investigated. Then the effect of link distance and Bit Error Rate (BER) are estimated by accounting the pointing error and atmospheric attenuation. The effect of change of link distance is examined while changing the number of beams between the transmitter and receiver as well. In this attempt, the HWDM system is considered by combining eight Dense Wavelength Division Multiplexing (DWDM) channels and four Coarse Wavelength Division Multiplexing (CWDM) channels. In addition, the influences of BER and receiver sensitivity are analyzed for the proposed system by incorporating Erbium Doped Fiber Amplifier (EDFA) at the receiver end. The data rate 2.5 Gbps is considered for both CWDM and DWDM channels for investigation.

2016 ◽  
Vol 2016 ◽  
pp. 1-8 ◽  
Author(s):  
Sooraj Parkash ◽  
Anurag Sharma ◽  
Harsukhpreet Singh ◽  
Harjit Pal Singh

We successfully demonstrate 40 GB/s 8 channels’ Dense Wavelength Division Multiplexing (DWDM) over free space optical (FSO) communication system. Each channel is transmitting 5 GB/s data rate in downstream separated by 0.8 nm (100 GHz) channel spacing with 1.8 GHz filter bandwidth. DWDM over FSO communication system is very effective in providing high data rate transmission with very low bit error rate (BER). The maximum reach of designed system is 4000 m without any compensation scheme. The simulation work reports minimum BER for Return-to-Zero (RZ) modulation format at different channels 1, 4, and 8 are found to be 2.32e-17, 1.70e-16, and 9.51e-15 at 4000 m distance, respectively. Sharp increase in BER occurs if data rate and distance increase up to 10 GB/s and 5000 m.


2021 ◽  
Author(s):  
Ebrahim E. Elsayed

Abstract In this paper, the implementation of a dense wavelength division multiplexing (DWDM) 32 × 40 Gbps (1.28 Tera bit/s) for the free-space optical (FSO) communication system is investigated. Analysis is performed for return-to-zero (RZ) and non-return-to-zero (NRZ) line codes for 1 km free space optic length. Motivation to the current analysis is to compare RZ and NRZ lines codes in the DWDM-FSO communication system and it is found that the NRZ line code is better than RZ code. A 1.28 Tb/ps wavelength division multiplexed communication system for free space optic channel workplace has been discovered in which 32 channel each of 40 Gbps data streams are combined using wavelength division multiplexed. The study includes the attenuation caused by atmospheric effect and beam divergence. Bit-error rate (BER), quality factor (Q), and eye diagram are indicator of performance evaluation. By comparing one can get a promising system to the high capacity access network with more bandwidth, cost effective and good flexibility.


2021 ◽  
Author(s):  
Ebrahim E. Elsayed

Abstract In this paper, the implementation of a dense wavelength division multiplexing (DWDM) 32 × 40 Gbps (1.28 Tera bit/s) for the free-space optical (FSO) communication system is investigated. Analysis is performed for return-to-zero (RZ) and non-return-to-zero (NRZ) line codes for 1 km free space optic length. Motivation to the current analysis is to compare RZ and NRZ lines codes in the DWDM-FSO communication system and it is found that the NRZ line code is better than RZ code. A 1.28 Tb/ps wavelength division multiplexed communication system for free space optic channel workplace has been discovered in which 32 channel each of 40 Gbps data streams are combined using wavelength division multiplexed. The study includes the attenuation caused by atmospheric effect and beam divergence. Bit-error rate (BER), quality factor (Q), and eye diagram are indicator of performance evaluation. By comparing one can get a promising system to the high capacity access network with more bandwidth, cost effective and good flexibility.


2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Bentahar Attaouia ◽  
Kandouci Malika ◽  
Ghouali Samir

AbstractThis work is focused to carry out the investigation of wavelength division multiplexing (WDM) approach on free space optical (FSO) transmission systems using Erbium Ytterbium Doped Waveguide Amplifier (EYDWA) integrated as post-or pre-amplifier for extending the reach to 30 Km for the cost-effective implementation of FSO system considering weather conditions. Furthermore, the performance of proposed FSO-wavelength division multiplexing (WDM) system is also evaluated on the effect of varying the FSO range and results are reported in terms of Q factor, BER, and eye diagrams. It has been found that, under clear rain the post-amplification was performed and was able to reach transmission distance over 27 Km, whereas, the FSO distance has been limited at 19.5 Km by using pre-amplification.


2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Kavitha Thandapani ◽  
Maheswaran Gopalswamy ◽  
Sravani Jagarlamudi ◽  
Naveen Babu Sriram

Abstract Free Space Optical (FSO) communication has evolved as a feasible technique for wireless implementations which offers higher bandwidth capacities over various wavelengths and refers to the transmission of modulated visible beams through atmosphere in order to communicate. Wavelength Division Multiplexing (WDM) is a technology that multiplexes numerous carrier signals onto single fiber using nonidentical wavelengths and enables the efficiency of bandwidth and expanded data rate. Multiple Input Multiple Output (MIMO) is implemented to improve the quality and performance of free space optical communication in various atmospheric conditions. In this paper, a WDM-based FSO communication system is being implemented that benefits from MIMO which receives multiple copies of the signal at receiver that are independent and analyzed for various streams of data in MIMO i.e. 2 × 2, 4 × 4, 8 × 8. Various factors like BER, Quality Factor are analyzed for the WDM-based FSO communication with MIMO using the OptiSystem for various data streams of MIMO under different atmospheric conditions.


2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Rupinder Kaur ◽  
Charanjit Singh ◽  
Rajbir Kaur

Abstract Hybrid wavelength-division-multiplexing (WDM) and free space optical (FSO) access networks are getting great attention due to numerous advantages. In this work, hybrid WDM-FSO system is demonstrated for 55 km at capacity of 5 × 10 Gbit/s using compressed spectrum return to zero (CSRZ) WDM-FSO in downstream and nonreturn to zero (NRZ) in upstream for demonstrating transmitter diversity which inturn decrease the interchannel interference. For the suppression of Rayleigh backscattering (RB) interferometric beat noise, bidirectional cyclic multiplexer is employed. Cyclic multiplexer provide λ 1 to λ 5 wavelengths for optical line terminal (OLT) to ONU transmission and λ 2 to λ 6 for ONU to OLT transmission. Insertion losses of each component are considered and in the end, power budget is also calculated. Results revealed that FSO length of 780–1050 m are obtained using various WDM-FSO downstream signals and their power budget, redundant budget, maximum distance, and insertion losses also calculated.


2021 ◽  
Author(s):  
Sinan M. Abdulsatar ◽  
Mohammed A. Saleh ◽  
Abadulla Abass ◽  
M. H. Ali ◽  
Mohammed Ali Yaseen

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.


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