Wyniki wyszukiwania - Biblioteka Nauki

1

Peripheral challenge by Small and Medium Sized Ports (SMPs) in Multi-Port Gateway Regions: the case study of northeast of China

100%

Feng L. , Notteboom T.

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tom S 1

55--66

EN

This paper focuses on the role of small and medium-sized ports (SMPs) in enhancing the competitiveness and logistics performance of multi-port gateway regions and associated inland logistics systems. The concepts developed will be applied to the ports in the northeast of China, a multi-port gateway region around the Bohai Sea Economic Rim (BER). Port competition is analyzed by multi-variable methodology and generalized common characteristics of SMPs compared to gateway ports, and the similarities of SMPs and SMEs are also compared. Later in this paper, we analyze the role of a SMP in such region in different variables: (a) cargo volume and market share; (b) international connectivity; (c) relative cluster position; (d) port city and hinterland connection; and (e) logistics and distribution function. The five-dimension analysis combined with in-depth cases study of typical Yingkou port describes a profile of SMPs in the BER and provides future study possibility for more SMPs cases worldwide.

2

Performance of massive MIMO systems under the effect of fading channel

89%

Alzamil A. A.

Przegląd Elektrotechniczny

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2021

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tom R. 97, nr 1

53--55

EN

This paper evaluates the performance of an uplink OFDM-based communication system considering multipath propagation environment where a Massive MIMO approach is exploited. In this context, Zero Forcing detector is used and assessed. Numerical analysis of the mathematical model was conducted on MATLAB. The results presented in this paper include Bit Error rate (BER) and the channel capacity of QPSK/OFDM transmission through a fading channel. Performance results verify the positive effect of Massive MIMO even when reduced complexity detection technique is used.

PL

Analizowano właściwości systemu komunikacyjnego bazującego na OFDM. Uwzględniono wielostrumieniowy rozsył z eksploatacja dużego MIMO. Opracowano model matematyczny I przeprowadzono symulację określającą BER I pojemność kanału dla przesyłu QPSK/OFDM.

3

Analysis of inter-satellite free-space optical link performance considering different system parameters

88%

Kaur S.

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tom Vol. 27, No. 1

10--13

EN

The welcome and adaptation of optical wireless technology by the modern era has brought forward the concept of an inter-satellite free-space optical communication system. In the present work, I study the combined effect of selection of different operating wavelengths and detector types along with the pointing errors at the transmitter and receiver side on the performance of an inter-satellite free-space optical link. The link performance has been optimized by measuring and analyzing the bit error rate and quality-factor of received signal under different scenarios. Performance of the inter-satellite link has also been investigated considering different modulation formats and data rates for LEO and MEO distances.

4

Hexagonal Photonic Crystal Fiber Behaviour as a Chromatic Dispersion Compensator of a 40 Gbps Link

88%

Betancur-Pérez A. F. , Botero-Cadavid J. F. , Reyes-Vera E. , Gómez-Cardona N.

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2017

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tom Vol. 63, No. 1

93--98

EN

In this paper, the capabilities of chromatic dispersion compensation of a photonic crystal fiber with a hexagonal distribution of circular air holes was investigated. The vector finite element method with scattering boundary condition was used to analyze a set of configurations of the fiber in which the distance between air holes’ centers was modified. With this method it was possible to obtain the values of chromatic dispersion and confinement factor in the C fiber band. The best suited configurations were tested in a 160 km optical link with a bit rate of 40 Gbps. The performance was evaluated by measuring the bit error rate for a set of 20 channels with channel spacing of 100 GHz. T e simulation results showed that is possible to reach values of hromatic dispersion as low as −850 ps/nm⋅km, confinement losses close to 10⁻³ dB/km and good BER results in the order of 10⁻¹⁷ for a wavelength of 1550 nm.

5

Comparison of Different Wavelength Propagations over Few-Mode Fiber based on Space Division Multiplexing in Conjunction with Electrical Equalization

88%

Al-Dawoodi A. , Fareed A. , Masuda T. , Ghazi A. , Fakhrudeen A. M. , Aljunid S. A. , Idrus S. Z. S. , Amphawan A.

International Journal of Electronics and Telecommunications

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2019

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tom Vol. 65, No. 1

5--10

EN

Nonlinearities in optical fibers deteriorate system performances and become a major performance-limiting issue. This article aims to investigate the compensation of nonlinear distortions in optical communication systems based on different wavelength propagations over few-mode fiber (FMF). The study adopted Space Division Multiplexing (SDM) based on decision feedback equalizer (DFE). Various transmission wavelength of the FMF system is applied to mitigate the attenuation effect on the system. In this paper, different wavelengths (780, 850 and 1550 nm) are used in SDM. Extensive simulation is performed to assess the attenuation and Bit Error Rate (BER) in each case. The results show that the wavelength of 1550 nm produces higher power and less attenuation in the transmission. Furthermore, this wavelength produces the best distance with less BER compared to 780 nm and 850 nm wavelengths. Moreover, the validations show improvement in BER and eye diagram.

6

Algorithm Based New Tone Reservation Method for Mitigating PAPR in OFDM Systems

88%

Saha S. , Chakrabarty S. , Bhattacharjee S. , Sil S.

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tom Vol. 63, No. 3

293--298

EN

There are abundant methods to mitigate PAPR in OFDM signals among which algorithm based tone reservation is of great popularity owing to its low complexity as well as decent BER. Here we have put forward a new distinct algorithm based Tone Reservation technique which is not only less complex and calculates its own threshold as well as PRT signal (unlike other algorithms requiring predetermined threshold and PRT) but also aptly modifies the data by bit by bit comparison with a modified copy of itself (algorithm modified) thus scaling the peaks as and providing a decent BER and good PAPR reduction.

7

Comparison of Different Wavelength Propagations over Few-Mode Fiber based on Space Division Multiplexing in Conjunction with Electrical Equalization

75%

Al-Dawoodi A. , Fareed A. , Masuda T. , Ghazi A. , Fakhrudeen A. M. , Aljunid S. A. , Idrus S. Z. S. , Amphawan A.

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8

Analiza skuteczności zakłóceń emisji FH

71%

Jendruszczak D. , Bugaj J.

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2019

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tom Vol. 60, nr 6

40--45

PL

W artykule została przedstawiona analiza skuteczności zakłócania emisji ze skaczącą częstotliwością (emisji FH – ang. Frequency Hopping). Praca została podzielona na dwie zasadnicze części: symulację procesu zakłócania przy wykorzystaniu programu MATLAB/Simulink oraz praktyczną analizę zakłócania pracy radiostacji rodziny PR4G pracującej w trybie FH. Do analizy skuteczności zakłóceń, miarą jakości transmisji, wykorzystany został współczynnik BER (ang. Bit Error Rate) bitowa stopa błędów.

EN

This paper presents the analysis of the effectiveness of FH (Frequency Hopping) emission jamming. The survey was divided into two main parts: simulation of jamming using the MATLAB/Simulink program and practical jamming of the PR4G family radio working in the FH mode. To analyze the effectiveness of jamming, the measure of transmission quality, in both cases was used the Bit Error Rate (BER).

9

Gigabitowy moduł optoelektroniczny do systemu LLRF TESLA

71%

Poźniak K. T. , Romaniuk R. S. , Jałmużna W. , Ołowski K. , Perkuszewski K. , Zieliński J. , Kierzkowski K.

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tom Vol. 46, nr 7

55-60

PL

Zaprezentowano koncepcję oraz realizację gigabitowego optycznego dystrybutora danych synchronicznych do systemu kontrolnego LLRF eksperymentu TESLA. Projekt oparto na programowalnym układzie FPGA Cyclone oraz komercyjnych układach serdes i konwerterach optycznych. Moduł jest osadzony na płycie bazowej systemu LLRF, ktora zapewnia komunikację z systemem sterowania komputerowego, konfigurację matrycy FPGA, integrację z innymi modułami funkcjonalnymi oraz właściwe zasilanie. Opisano implementację sprzętową i oprogramowanie dla testów BER łącza optycznego oraz zamieszczono wyniki badań. Krótko scharakteryzowano obecnie dostępne w technologii FPGA protokoły szybkiej transmisji szeregowej.

EN

The paper presents the idea and realization of a gigabit synchronous data distributor designed to work in the LLRF control system of TESLA technology based X-ray FEL. The design bases on a relatively simple and cheap FPGA chip Cyclone. Commercially available SERDES (serializer/deserializer) and optical transceiver chips were applied. The optoelectronic module is embedded on the main LLRF BMB (backbone motherboard). The MB provides communication with the outside computer control system, programmable chip configuration, integration with other functional modules and power supply. The hardware implementation is here described and the used software for BER (bit-error-rate) testing of the multigigabit optical link. The measurement results are presented. The appendix contains a comparison between the available protocols of serial data transmission for FPGA technology.

10

Fuzzy Model of 16PSK and 16QAM Modulation

63%

Butkiewicz B. S.

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tom Vol. 57, No. 4

437-442

EN

In the paper, a concept of Additive Fuzzy Noise (AFN) channel is introduced. The theoretical equations are derived for Bit Error Rate (BER) and Symbol Error Rate (SER) with some digital modulation scheme in the AFN channel. Following modulations are considered: Phase Shift Keying (16PSK), Quadrature Amplitude Modulation (16QAM). The fuzzy approach to these modulations is presented. The BER and SER values are calculated using possibility theory. The results obtained by fuzzy noise model are compared with conventional approach, where probability models of the noise are used.