scholarly journals Multilevel Manchester (2 bits/symbol) coding with optical equaliser for increasing the transmission distance of high-speed fibre optic links

2020 ◽  
Vol 14 (4) ◽  
pp. 182-188
Author(s):  
Festus Idowu Oluwajobi ◽  
Dong-Nhat Nguyen ◽  
Nafizah Khan ◽  
Amin Malekmohammadi
2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Rabiu Imam Sabitu ◽  
Nafizah Goriman Khan ◽  
Amin Malekmohammadi

AbstractThis report examines the performance of a high-speed MDM transmission system supporting four nondegenerate spatial modes at 10 Gb/s. The analysis adopts the NRZ modulation format to evaluate the system performance in terms of a minimum power required (PN) and the nonlinear threshold power (PTH) at a BER of 10−9. The receiver sensitivity, optical signal-to-noise ratio, and the maximum transmission distance were investigated using the direct detection by employing a multimode erbium-doped amplifier (MM-EDFA). It was found that by properly optimizing the MM-EDFA, the system performance can significantly be improved.


2018 ◽  
Vol 2018 ◽  
pp. 1-7
Author(s):  
Xinyue Guo ◽  
Shuangshuang Li ◽  
Yang Guo

With the rapid development of light-emitting diode, visible light communication (VLC) has become a candidate technology for the next generation of high-speed indoor wireless communication. In this paper, we investigate the performance of the 32-quadrature amplitude modulation (32-QAM) constellation shaping schemes for the first time, where two special circular constellations, named Circular (4, 11, 17) and Circular (1, 5, 11, 15), and a triangular constellation are proposed based on the Shannon’s criterion. Theoretical analysis indicates that the triangular constellation scheme has the largest minimum Euclidian distance while the Circular (4, 11, 17) scheme achieves the lowest peak-to-average power ratio (PAPR). Experimental results show that the bit error rate performance is finally decided by the value of PAPR in the VLC system due to the serious nonlinearity of the LED, where the Circular (4, 11, 17) scheme always performs best under the 7% preforward error correction threshold of 3.8 × 10−3 with 62.5Mb/s transmission data rate and 1-meter transmission distance.


Author(s):  
James Akhwaba

Abstract Communication technology has drastically evolved in the last 10 years across the globe. With increased demand for data and voice traffic, fibre-optic network is preferred to transmit high-speed broadband. Nonetheless, fibre-optic infrastructure involves huge construction challenges and continues to fail because of ineffective leadership, stakeholder management and government policies. The main purpose of this study was to investigate how government policy intervenes on the joint influence of leadership skills and stakeholder management on execution of fibre-optic infrastructure in Nairobi County, Kenya. This study adopted the pragmatism paradigm approach, with a cross-sectional survey design. Census was used to select 187 respondents from a target population of 187 functional staff in fibre-optic infrastructure departments. A questionnaire was used to collect quantitative data while an interview guide was used to collect qualitative data. Statistical analysis techniques were used to analyse the data. It was demonstrated that government policy has a significant intervening influence on the joint influence of leadership skills and stakeholder management on execution of fibre-optic infrastructure. Therefore, governments should come up with policies to guide and regulate execution of fibre-optic infrastructure, review building code to allow for fibre-optic services in new buildings, develop right of way conduits and establish a centrally coordinated authority to facilitate time-bound issuance of permits and related services. It was suggested that similar studies should be carried out in other countries and target vendors and contractors engaged in supply of equipment and construction of fibre-optic infrastructure.


1985 ◽  
Author(s):  
K. L. Monham ◽  
P. G. McTiernan ◽  
B. T. Debney ◽  
J. Hankey
Keyword(s):  

Author(s):  
Stephen John Curran

Data communication with aircraft presents unique technical challenges and these challenges are more pronounced when the aircraft are travelling over oceanic or other remote areas. When in populated areas, systems are available that can support high speed data services, one Gigabit per second (Gbps) and beyond via, terrestrial ground stations. However no such systems exist to provide airborne communications with high bandwidths among aircraft and between aircraft and the ground in more remote regions. Passengers will expect data service on the aircraft similar to what they typically experience on the ground. Multimedia activities, such as video streaming, are very bandwidth intensive and the provision of these services presents a serious technical challenge. On the ground, fibre optic cables are the method of choice for the provision of high speed data service, and in contrast, an airborne high speed data communications solution will need to be a wireless one.


2019 ◽  
Vol 0 (0) ◽  
Author(s):  
Meet Kumari ◽  
Reecha Sharma ◽  
Anu Sheetal

AbstractNowadays, bandwidth demand is enormously increasing, that causes the existing passive optical network (PON) to become the future optical access network. In this paper, next generation passive optical network 2 (NG-PON2) based, optical time division multiplexing passive optical network (OTDM-PON), wavelength division multiplexing passive optical network (WDM-PON) and time & wavelength division multiplexing passive optical network (TWDM-PON) systems with 20 Gbps (8 × 2.5 Gbps) downstream and 20 Gbps (8 × 2.5 Gbps) upstream capacity for eight optical network units has been proposed. The performance has been compared by varying the input power (−6 to 27 dBm) and transmission distance (10–130 km) in terms of Q-factor and optical received power in the presence of fiber noise and non-linearities. It has been observed that TWDM-PON outperforms OTDM-PON and WDM-PON for high input power and data rate (20/20 Gbps). Also, TWDM-PON shows its superiority for long-reach transmission up to 130 km, which is a cost-effective solution for future NG-PON2 applications.


2017 ◽  
Vol 68 (1) ◽  
pp. 111
Author(s):  
Arun Kumar ◽  
L. Anjaneyulu

<p class="p1">Testing of underwater system for defence application is carried out from submersible platform at specified depth. The underwater platform houses the article under test, equipment and instruments required to conduct the test and to control the platform. During development phase of defence systems, large numbers of sensors are mounted on the test article and data is collected to validate the design. Data acquisition system, video camera and high speed video cameras are positioned on the platform to record physical parameters and observe visually the performance of the article under evaluation. Since the data and video signals are parallely recorded on ship, the bandwidth demand for real-time data communication from underwater platform to control station is very high. The existing technology presently used for underwater communication has limitation of bandwidth and not suitable for defence application. This paper describes in detail the design and development of a re-deployable data communication link by laying a specially designed negatively buoyant fibre optic cable in high-sea from ship to underwater platform to provide higher bandwidth required for defence application. The link has been successfully used for sea state less than one during evaluation of underwater defence system. The availability of bandwidth from underwater platform to control system can be increased significantly by laying fibre optic cable in high sea. It also provides unlimited bandwidth for the above requirement.<span class="Apple-converted-space"> </span></p>


1983 ◽  
Vol 19 (6) ◽  
pp. 202 ◽  
Author(s):  
A.X. Widmer ◽  
P.A. Franaszek
Keyword(s):  

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