scholarly journals Manchester Signaling Scheme for Ground to Satellite DWDM Communication

2020 ◽  
Vol 8 (5) ◽  
pp. 4290-4293

For the modulation of various data streams, Wavelength division multiplexing is utilized. Further, Dense Wavelength Division multiplexing is the type of WDM which is capable of spacing the wavelengths more closely due to its greater capacity. This technology is widely used in fiber optics as it utilizes the bandwidth in an appropriate manner. Various researchers have been carried out to make it worth using. Recently, in research, the author had used DWDM in clear weather conditions and turbulence generated in a channel. In this work, the author had utilized the RZ modulation technique which has some drawbacks. Due to this, the performance of the entire model is affected. Thus in this paper, a novel approach is presented to overcome the problems of the existing system. In the novel system, RZ encoding is replaced by Manchester encoding. Manchester encoding has several advantages over RZ encoding. Further, the simulation of the model is performed under the optisystem. Here, the Q-factor of both (proposed and with RZ encoding) models are determined in terms of a single channel, 4 channels, and 16 channels. The results showed the effectiveness of the proposed system as it increases the quality of the signal transmitted from one source to another.

2012 ◽  
Vol 571 ◽  
pp. 457-461 ◽  
Author(s):  
Xiao Lei Chen ◽  
Qing Chun Zhao ◽  
Hong Xi Yin ◽  
Xin Yu Dou

In this paper, we numerically investigate the wavelength division multiplexing (WDM) transmission between chaotic optical secure channel and nonchaotic fiber-optic channel. When the channel spacing is 0.8 nm, a 2.5-Gbits/s message masked by the chaotic optical secure channel and a 10-Gbits/s message carried by the nonchaotic fiber-optic channel can be achieved simultaneously. The results show that the Q-factor of the recovered message can be increased significantly when the launched power is reduced appropriately. The deterioration on the quality of communications caused by fiber dispersion can be compensated obviously when the symmetrical dispersion compensation scheme is adopted. In addition, the message is masked by chaos shift keying in the chaotic optical secure channel. The multiplexing distance between the chaotic optical secure channel and the nonchaotic fiber-optic channel is up to 150 km.


2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Anurupa Lubana ◽  
Sanmukh Kaur ◽  
Yugnanda Malhotra

AbstractIn this work, we study and analyze the performance of Raman + Erbium-Ytterbium codoped fiber hybrid optical amplifier (HOA) for an ultradense wavelength division multiplexing (UD-WDM) system having 100 channels. The system has been investigated considering initial values of channel spacing and data rate of 0.1 nm (12.5 GHz) and 100 GB/s, respectively. Initially, the two important WDM system parameters—wavelength and channel spacing—have been selected and then optimization of the proposed HOA has been performed in terms of EYDFA length, pump power and Er+ concentration to achieve higher values of average gain, Q-factor and lower gain variation ratio. The optimized configuration of the HOA results in the achievement of higher value of average gain, Q-factor and gain variation ratio of 47 dB, 14 and 0.14, respectively, which confirms its viability for UD-WDM system applications.


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.


2019 ◽  
Vol 0 (0) ◽  
Author(s):  
I. S. Amiri ◽  
Fatma Mohammed Aref Mahmoud Houssien ◽  
Ahmed Nabih Zaki Rashed ◽  
Abd El-Naser A. Mohammed

AbstractThe 16-channels dense wavelength division multiplexing (DWDM) systems have been optimized by utilizing hybrid configurations of conventional optical fiber amplifiers (EDFA, RAMAN and SOA) and optical photodetectors (PIN, APD(Si) and APD(InGaAs)). The DWDM systems were implemented for 5 Gb/s channel speed using one of these configurations with 100 GHz channel spacing and 25 km amplifying section. The hybrid configurations are the combinations of (PIN + EDFA), (PIN + RAMAN), (PIN + SOA), (APD(Si) + EDFA), (APD(Si) + RAMAN), (APD(Si) + SOA), (APD(InGaAs) + EDFA), (APD(InGaAs) + RAMAN) and (APD(InGaAs) + SOA). Based on BER, Q-factor and eye diagrams, the performance was compared for these configurations under influences of various thermal noise levels of photodetectors over different fiber lengths ranging from 25 km up to 150 km. The results revealed that both APD structures give optimum performance at input power Pin = 5 dBm due to high internal avalanche gain. EDFA outperforms RAMAN and SOA amplifiers. SOA amplifier shows degraded performance because of nonlinearity effects induced. RAMAN amplifier seems to be the best alternative for long reach DWDM systems because it minimizes the effects of fiber nonlinearities. The configuration (APD(Si) + EDFA) is the most efficient and recommended to be used for transmission distance beyond 100 km due to its larger Q-factor.


Author(s):  
Yousef S. Kavian ◽  
Bin Wang

Resilient optical transport networks have received much attention as the backbone for future Internet protocol (IP) networks with enhanced quality of services (QoS) by avoiding loss of data and revenue and providing acceptable services in the presence of failures and attacks. This chapter presents the principles of designing survivable Dense-Wavelength-Division-Multiplexing (DWDM) optical transport networks including failure scenarios, survivability hierarchy, routing and wavelength assignment (RWA), demand matrix models, and implementation approaches. Furthermore, the chapter addresses some current and future research challenges including dealing with multiple simultaneous failures, QoS-based RWA, robustness and future demand uncertainty accommodation, and quality of service issues in the deployment of resilient optical backbones for next generation transport networks.


Author(s):  
Judy C.R. Tseng ◽  
Wen-Ling Tsai ◽  
Gwo-Jen Hwang ◽  
Po-Han Wu

In developing traditional learning materials, quality is the key issue to be considered. However, for high technical e-training courses, not only the quality of the learning materials but also the efficiency of developing the courses needs to be taken into consideration. It is a challenging issue for experienced engineers to develop up-to-date e-training courses for inexperienced engineers before further new technologies are proposed. To cope with these problems, a concept relationship-oriented approach is proposed in this paper. A system for developing e-training courses has been implemented based on the novel approach. Experimental results showed that the novel approach can significantly shorten the time needed for developing e-training courses, such that engineers can receive up-to-date technologies in time.


2018 ◽  
Vol 0 (0) ◽  
Author(s):  
◽  
Chakresh Kumar

AbstractIn this paper we have study the performance of different optical amplifiers (Erbium doped amplifier (EDFA), RAMAN amplifier, and semiconductor optical amplifier (SOA)) for 80 channels wavelength division multiplexing (WDM) system with the data rate at 10 Gbps data rate for the transmission distance of 280 km After getting the results of these amplifiers the performance of these has to be compared The Q-factor values achieved better in EDFA as compared to SOA and RAMAN. While the BER getting good in SOA as compared with other amplifiers but in EDFA after 200 km it goes saturated, the Power achieved at the power estimator is getting better in EDFA optical amplifier while in other amplifier it achieved negative. At the end it is also study the Power with frequency in THz and the Eye Diagram of such amplifiers results.


2020 ◽  
Vol 9 (6) ◽  
pp. 2427-2435
Author(s):  
Ary Syahriar ◽  
Rahmat Alamtaha ◽  
Zulkifli Alamtaha ◽  
Putri Wulandari

To increase bandwidth and number of channels per fiber for more than one wavelength in the same fiber the dense wavelength division multiplexing (DWDM) technology has been utilized. One of the devices that are important in DWDM is an optical interleaver. This paper discussed the effects of temperatures in the DWDM interleaver by using the Mach-Zehnder interferometer (MZI) structures which is arranged in two-stage cascaded MZI and the three-stage cascaded MZI geometries. The main consequences of increase temperature inside the fiber optics are the change of effective refractive index in the material of silica fiber due to the thermo-optics effects. In our analysis we have used the transfer matrix method to investigate the wavelength dependence of output power to the temperatures changes that varies from 30oC to 430ºC. In the calculation we have used the C-Band range wavelength which is around 1530 to 1565 nm. It has been shown that the change of temperatures may shift the wavelength inside the MZI output power in linear manners. These effects may be used to tune wavelength transmission inside the MZI structures to suit the ITU-T defined grid. 


2019 ◽  
Vol 24 (5) ◽  
pp. 115
Author(s):  
Humam Husseinˡ ◽  
Dogu Cagdas Atilla1 ◽  
Essa Essa2 ◽  
Cagatay Aydin1

In recent years, there has been a growing and continuous demand for great (data rates) beyond existing wired and wireless networks. Radio-over-Fiber technology is considered as an efficient and practical solution for providing broadband wireless. In this paper, many techniques are used to implement a system that has the capability to provide a great bit rate, broadband bandwidth, and minimum cost. So Radio-over-Fiber technology was used to modulate the light with radio-signal and transmission the signals through an optical fiber cable. Wavelength-Division-Multiplexing technique was used to send many signals through the same link, and Subcarrier Multiplexing-Amplitude Shift keying as a modulation format. 2Gpbs separate on two channels was transmitted on Single-Mode Fiber. The average results obtained from our experience was as follows: maximum Q factor average = 4.9712925, minimum BER average = 3.63*10-7, total power average (dBm) = -51.1502, the OSNR average (dB) = 52.085 for channel_1. The results of channel_2 were: maximum Q factor average = 5.5901325, minimum BER average = 1.26*10-8, total power average (dBm) = -46.60135, the average of optical signal-to-noise ratio (dB) = 54.65. All the average result that has from our simulation was very good and acceptable. The simulation and performance test of our experience was done using Optisystem 7.0.   http://dx.doi.org/10.25130/tjps.24.2019.100


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