scholarly journals Adaptive Equalization for Dispersion Mitigation in Multi-Channel Optical Communication Networks

Electronics ◽  
2019 ◽  
Vol 8 (11) ◽  
pp. 1364 ◽  
Author(s):  
Farman Ali ◽  
Shabbir Ahmad ◽  
Fazal Muhammad ◽  
Ziaul Haq Abbas ◽  
Usman Habib ◽  
...  

Optical communication networks (OCNs) provide promising and cost-effective support for the ultra-fast broadband solutions, thus enabling them to address the ever growing demands of telecommunication industry such as high capacity and end users’ data rate. OCNs are used in both wired and wireless access networks as they offer many advantages over conventional copper wire transmission such as low power consumption, low cost, ultra-high bandwidth, and high transmission rates. Channel effects caused by light propagation through the fiber limits the performance, hence the data rate of the overall transmission. To achieve the maximum performance gain in terms of transmission rate through the OCN, an optical downlink system is investigated in this paper using feed forward equalizer (FFE) along with decision feedback equalizer (DFE). The simulation results show that the proposed technique plays a key role in dispersion mitigation in multi-channel optical transmission to uphold multi-Gb/s transmission. Moreover, bit error rate (BER) and quality factor (Q-factor) below 10 − 5 and above 5, respectively, are achieved with electrical domain equalizers for the OCN in the presence of multiple distortion effects showing the effectiveness of the proposed adaptive equalization techniques.

Author(s):  
В.Л. Мартынов ◽  
В.И. Дорошенко ◽  
Н.М. Божук ◽  
Ю.Г. Ксенофонтов

Решению вопросов, связанных с телекоммуникационным оборудованием, функционирующем в водной среде, в настоящее время уделяется особое внимание. На смену традиционным подводным системам обмена информацией в гидроакустических полях приходят открытые системы её оптической передачи и приёма, базирующиеся на лазерных технологиях. Это вызвано необходимостью трансляции с высокой разрешающей способностью видеоданных, среди которых, например, может быть либо визуальное отображение подводных систем в динамике, либо результаты мониторинга объектов подводной инфраструктуры в реальном масштабе времени, либо что-то другое с учётом требований Заказчика. Канал передачи такого большого объёма информации при условии ее считывания с задаваемым качеством должен иметь пропускную способность более 1 Мбит/с. Такую высокую скорость передачи невозможно реализовать в подводных гидроакустических системах, граница технических возможностей которых на превышает 10...50 кбит/с. В аналогичной ситуации при заданных параметрах канала связи частоты несущих оптического диапазона имеют порядок 1014 Гц, что обеспечивает динамический диапазон полосы пропускания в районе 1012…1013 Гц. С учётом условия квазимонохроматичности применение гидроакустических средств для передачи видеоданных становится проблематичным, так как техническая реализация такой задачи потребует слишком большого времени. С учётом сказанного, преимуществом подводных беспроводных оптических систем связи является их высокая широкополосность, которая обеспечит высокую скорость передачи данных. В статье обосновывается целесообразность использования открытых оптических системы связи для создания высокоскоростных подводных инфотелекоммуникаций, среди которых наиболее предпочтительными являются лазерные системы. Special attention is currently paid to the solution of issues related to telecommunication equipment operating in the aquatic environment. The traditional underwater systems for the exchange of information in hydroacoustic fields are being replaced by open systems for its optical transmission and reception, based on laser technologies.This is due to the need to broadcast high-resolution video data, among which, for example, there can be either a visual display of underwater systems in dynamics, or the results of monitoring objects of underwater infrastructure in real time, or something else, taking into account the requirements of the Customer. The transmission channel of such a large amount of information, provided it is read with a specified quality, must have a bandwidth of more than 1 Mbit / s. Such a high transmission rate cannot be realized in underwater sonar systems, the technical capabilities limit of which does not exceed 10 ... 50 kbit/s. In a similar situation, given the parameters of the communication channel, the carrier frequencies of the optical range are 1014 Hz, which provides a dynamic bandwidth range about 1012…1013Hz. Taking into account the condition of quasimonochromaticity, the use of hydroacoustic means for transmitting video data becomes problematic, since the technical implementation of such a task will take too long. In view of the above, the advantage of underwater wireless optical communication systems is their high broadband, which will provide a high data transfer rate. The article substantiates the expediency of using open optical communication systems for creating high-speed underwater information telecommunications, among which the most preferable are laser systems.


Author(s):  
Qutaiba I. Ali ◽  
Firas S. Alsharbaty

Abstract: Power grid is one of the most important manifestations of the modern civilization and the engine of it where it is described as a digestive system of the civil life. It is a structure has three main functions: generation, transmission lines, distribution. This concept was appropriate for a century. However, the beginning of the twenty-first century brought dramatic changes on different domains: media, human growth, economic, environmental, political, and technical etc. Smart grid is a sophisticated structure including cyber and physical bodies hence it reinforces the sustainability, the energy management, the capability of integration with microgrids, and exploiting the renewable energy resources. The quantum leap of smart grid is related to the advanced communication networks that deal with the cyber part. Moreover, the communication networks of smart grid offer attractive capabilities such as monitoring, control, and protection at the level of real time. The wireless communication techniques in integration frame are promised solution to compensate the requirements of smart grid designing such as wireless local area networks, worldwide interoperability for microwave access, long term evolution, and narrowband- internet of things. These technologies could provide high capacity, flexibility, low-cost maintenance for smart grid. However, the multi-interfaces in smart grid may exploit by persons or agencies to implement different types of cyber-attacks may lead to dangerous damage. This research paper reviews the up-to-date researches in the field of smart grid to handle the new trends and topics in one frame in order to offer integration vision in this vital section. It concentrates on the section of communication networks the mainstay of smart grid. This paper discusses the challenging and requirements of adopting the wireless communication technologies and delves deeply into literature review to devise and suggest solutions to compensate the impairments efficiently. Moreover, it explores the cyber security that representing the real defiant to implement the concept of smart grid safely.


Author(s):  
Shaohua Lu ◽  
Weidong Hu ◽  
Xiaojun Hu

Due to their low cost and improved safety compared to lithium-ion batteries, sodium-ion batteries have attracted worldwide attention in recent decades.


2019 ◽  
Vol 28 (1) ◽  
pp. 224-231
Author(s):  
Randa S. Hammad ◽  
El_Sayed M. El_Rabaie ◽  
Fathi. E. Abd-El-Samie ◽  
Ibrahim M. El-Dokany

2021 ◽  
Vol 10 (1) ◽  
pp. 210-220
Author(s):  
Fangfang Wang ◽  
Ruoyu Hong ◽  
Xuesong Lu ◽  
Huiyong Liu ◽  
Yuan Zhu ◽  
...  

Abstract The high-nickel cathode material of LiNi0.8Co0.15Al0.05O2 (LNCA) has a prospective application for lithium-ion batteries due to the high capacity and low cost. However, the side reaction between the electrolyte and the electrode seriously affects the cycling stability of lithium-ion batteries. In this work, Ni2+ preoxidation and the optimization of calcination temperature were carried out to reduce the cation mixing of LNCA, and solid-phase Al-doping improved the uniformity of element distribution and the orderliness of the layered structure. In addition, the surface of LNCA was homogeneously modified with ZnO coating by a facile wet-chemical route. Compared to the pristine LNCA, the optimized ZnO-coated LNCA showed excellent electrochemical performance with the first discharge-specific capacity of 187.5 mA h g−1, and the capacity retention of 91.3% at 0.2C after 100 cycles. The experiment demonstrated that the improved electrochemical performance of ZnO-coated LNCA is assigned to the surface coating of ZnO which protects LNCA from being corroded by the electrolyte during cycling.


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