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Wyszukujesz frazę "free space optics" wg kryterium: Temat


Wyświetlanie 1-12 z 12
Tytuł:
Relay-assisted WDM-FSO System: A Better Solution for Communication under Rain and Haze Weather Conditions
Autorzy:
Dayal, N.
Singh, P.
Kaur, P.
Powiązania:
https://bibliotekanauki.pl/articles/958123.pdf
Data publikacji:
2017
Wydawca:
Instytut Łączności - Państwowy Instytut Badawczy
Tematy:
Free Space Optics
Wavelength Division Multiplexing
Opis:
Among various conventional wireless communication systems, Free Space Optics (FSO) may be distinguished as well, which provides a good level security, high data rates, an enormous bandwidth and negligible susceptibility to electromagnetic interference. The main problem arises with unfavorable weather conditions, which affect the system’s parameters and require an aversion to other paths. The weather conditions discussed are rain and haze. Elimination of their adverse effects is essential for establishing a better communication system. The routing path is a major issue, as its decreased parameters lead to the diversion of the transmitted signal or to its total loss. In this article, increased system path length and proficiency levels are demonstrated by using relays, which are assisted by Wavelength Division Multiplexing (WDM).
Źródło:
Journal of Telecommunications and Information Technology; 2017, 4; 54-59
1509-4553
1899-8852
Pojawia się w:
Journal of Telecommunications and Information Technology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
An Overview of Free Space Optics with Quantum Cascade Lasers
Autorzy:
Mikołajczyk, J.
Powiązania:
https://bibliotekanauki.pl/articles/226628.pdf
Data publikacji:
2014
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
quantum cascade laser
free space optics
laser communications
Opis:
The article presents an overview of the work on quantum cascade lasers application in free space optical systems (Free Space Optics - FSO). There are discussed the main issues of the open-space laser communications and their practical construction. Comparative analyses of each FSO technology were performed. Brief description of quantum cascade (QC) lasers and some developments related to the use of these lasers in optical data link are also presented. In summary, the constructed models of FSO links with QC lasers are characterized.
Źródło:
International Journal of Electronics and Telecommunications; 2014, 60, 3; 259-264
2300-1933
Pojawia się w:
International Journal of Electronics and Telecommunications
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Performance Analysis of WDM-FSO Link under Turbulence Channel
Autorzy:
Mazin, Ali A. Ali
Powiązania:
https://bibliotekanauki.pl/articles/1192036.pdf
Data publikacji:
2016
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Tematy:
free space optics
BER
Atmospheric Turbulence
NRZ format
RZ technique
Opis:
In this paper, the performance analysis of FSO communication link in various atmospheric turbulence has been analysis for different bit rate using NRZ and RZ technique. The effect of turbulence on the link performance has been investigated by varying bit rate, turbulence strength and modulation format. FSO performance carried out for BER, Q. factor, received power under maximum link. Simulation results show that RZ format is best for strong turbulence. Where NRZ technique is used for low and medium turbulence.
Źródło:
World Scientific News; 2016, 50; 160-173
2392-2192
Pojawia się w:
World Scientific News
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Compact QCL driver for free-space transmitter
Autorzy:
Mikołajczyk, J.
Garlińska, M.
Wesołowski, M.
Wojtas, J.
Bielecki, Z.
Powiązania:
https://bibliotekanauki.pl/articles/201659.pdf
Data publikacji:
2012
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
free space optics
laser communication
quantum cascade lasers
laser driver
Opis:
The paper presents investigations of a free space optical transmitter operating with quantum cascade lasers. The main goal of the research was to determine influence of lasers driver parameters on an optical data link performance. Using some commercial driving devices, the laser pulse limitations of power, repetition rate and time duration have been observed. In the paper, the preliminary results of the designed laser driver are described. The driver was developed at the Institute of Optoelectronics, MUT in cooperation with scientists from the Faculty Electrical Engineering, WUT. It is characterized by high current efficiency, high pulse repetition rate, and compact construction. Additionally, the driver also includes a controller of Peltier modules
Źródło:
Bulletin of the Polish Academy of Sciences. Technical Sciences; 2012, 60, 4; 763-768
0239-7528
Pojawia się w:
Bulletin of the Polish Academy of Sciences. Technical Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Optical Wireless Communications Operated at Long-Wave Infrared Radiation
Autorzy:
Mikolajczyk, Janusz
Szabra, Dariusz
Prokopiuk, Artur
Achtenberg, Krzysztof
Wojtas, Jacek
Bielecki, Zbigniew
Powiązania:
https://bibliotekanauki.pl/articles/226104.pdf
Data publikacji:
2020
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
optical wireless communication
free space optics
quantum cascade lasers
optoelectronics
telecommunications
Opis:
This paper presents some construction analysis and test results of a Free Space Optics system operating at the wavelength of 9.35 μm. In the system, a quantum cascade laser and a photoreceiver with mercury cadmium telluride photodetectors were used. The main parameters of these elements were discussed taking into account a data link operation. It also provides to determine a data range for various weather conditions related to scattering and scintillation. The results of numerical analyses defined the properties of currently available FSO technologies working in the near infrared or in the short infrared range of spectrum versus the performances of the developed system. The operation of this system was verified in three different test environments. The obtained results may also contain important issues related to the practical application of any FSO system.
Źródło:
International Journal of Electronics and Telecommunications; 2020, 66, 2; 383-387
2300-1933
Pojawia się w:
International Journal of Electronics and Telecommunications
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Analysis of Free-Space Optics Development
Autorzy:
Mikołajczyk, J.
Bielecki, Z.
Bugajski, M.
Piotrowski, J.
Wojtas, J.
Gawron, W.
Szabra, D.
Prokopiuk, A.
Powiązania:
https://bibliotekanauki.pl/articles/221245.pdf
Data publikacji:
2017
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
optical communications
open path laser communications
line of sight communications
free space optics
Opis:
The article presents state of work in technology of free-space optical communications (Free Space Optics - FSO). Both commercially available optical data links and their further development are described. The main elements and operation limiting factors of FSO systems have been identified. Additionally, analyses of FSO/RF hybrid systems application are included. The main aspects of LasBITer project related to such hybrid technology for security and defence applications are presented.
Źródło:
Metrology and Measurement Systems; 2017, 24, 4; 653-674
0860-8229
Pojawia się w:
Metrology and Measurement Systems
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Comparative BER Analysis of Free Space Optical System Using Wavelength Diversity over Exponentiated Weibull Channel
Autorzy:
Shah, Dhaval
Joshi, Hardik
Kothari, Dilipkumar
Powiązania:
https://bibliotekanauki.pl/articles/2055211.pdf
Data publikacji:
2021
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
bit error rate
exponentiated weibull distribution
free space optics
FSO
wavelingth diversity
optimal combining
Opis:
Atmospheric turbulence is considered as major threat to Free Space Optical (FSO) communication as it causes irradiance and phase fluctuations of the transmitted signal which degrade the performance of FSO system. Wavelength diversity is one of the techniques to mitigate these effects. In this paper, the wavelength diversity technique is applied to FSO system to improve the performance under different turbulence conditions which are modeled using Exponentiated Weibull (EW) channel. In this technique, the data was communicated through 1.55 µm, 1.31 µm, and 0.85 µm carrier wavelengths. Optimal Combining (OC) scheme has been considered to receive the signals at receiver. Mathematical equation for average BER is derived for wavelength diversity based FSO system. Results are obtained for the different link length under different turbulence conditions. The obtained average BER results for different turbulence conditions characterized by EW channel is compared with the published result of average BER for different turbulence which is presented by classical channel model. A comparative BER analysis shows that maximum advantage of wavelength diversity technique is obtained when different turbulence conditions are modeled by EW channel.
Źródło:
International Journal of Electronics and Telecommunications; 2021, 67, 4; 665--672
2300-1933
Pojawia się w:
International Journal of Electronics and Telecommunications
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
FSO system performance analysis based on novel Gamma–Chi-square irradiance PDF model
Autorzy:
Todorović, Jelena
Spalević, Petar
Panić, Stefan
Milosavljević, Bojana
Gligorijević, Milan
Powiązania:
https://bibliotekanauki.pl/articles/2033970.pdf
Data publikacji:
2021
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
free space optics
FSO
Gamma-Chi-square distribution
atmospheric turbulence
pointing error
on-off keying
OOK
Opis:
In order to provide a novel analytically traceable free space optics (FSO) channel model for describing turbulence based irradiance fluctuations, following basic scintillation theory principles, we have derived closed-form expression for probability density function (PDF) of a new statistical Gamma–Chi-square model. Further, capitalizing on provided model, error performances of FSO system over on-off keying (OOK) transmission scheme both in the presence of atmospheric turbulence and misalignment fading (pointing error) is investigated. For both cases, the average bit error rate (ABER) at the receiving side of the system is determined in an analytically closed form. The results are graphically presented in order to analyze the impact of different levels of turbulence, as well as other relevant parameters, on the quality of the received signal in the OOK modulated FSO system.
Źródło:
Optica Applicata; 2021, 51, 3; 335-348
0078-5466
1899-7015
Pojawia się w:
Optica Applicata
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Peak detection unit for Free-Space-Optics receiver
Autorzy:
Achtenberg, Krzysztof
Mikołajczyk, Janusz
Szabra, Dariusz
Prokopiuk, Artur
Bielecki, Zbigniew
Powiązania:
https://bibliotekanauki.pl/articles/221334.pdf
Data publikacji:
2019
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
peak detection
infrared receiver module for optical communications
open path laser communications
free space optics
quantum cascade laser
Opis:
The paper presents verification of a peak detection method cooperating with infrared radiation detector module applications. The work has been divided into parts including SPICE simulations and presentation of results obtained with the constructed prototype. The design of the peak detector dedicated to applications with very short pulses requires a different approach than that for standard solutions. It is mainly caused due to the ratio of pulse width and time period. In the described application this ratio is less than 10%. The paper shows testing of an analogue circuit which is capable to be inserted in these applications.
Źródło:
Metrology and Measurement Systems; 2019, 26, 2; 377-385
0860-8229
Pojawia się w:
Metrology and Measurement Systems
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Impact of Finite-Sized Aperture on the Performance of Differential Multihop DF-FSO Network
Autorzy:
Agarwal, Deepti
Yadav, Poonam
Powiązania:
https://bibliotekanauki.pl/articles/2200711.pdf
Data publikacji:
2022
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
differencial modulation
K-distribution
Free space optics (FSO)
Average bit error rate (BER)
Decode and forward relaying
pointing error
Opis:
This paper investigates the differential binary modulation for decode-and-forward (DF) based relay-assisted free space optical (FSO) network under the effect of strong atmospheric turbulence together with misalignment error (ME). The atmospheric fading links experience K-distributed turbulence. First we derive novel closed form expression for average bit error rate (BER) and outage probability (OP) in terms of Meijer’s G function. Further, the OP of differential DF-FSO system with multiple relays is derived. We also analyze the asymptotic performance for the sake of getting the order of diversity and the coding gain. The power allotment term is utilized to examine the effect of different power allotment techniques on BER and OP. The simulation results have been used to validate the derived analytical results.
Źródło:
International Journal of Electronics and Telecommunications; 2022, 68, 4; 807--813
2300-1933
Pojawia się w:
International Journal of Electronics and Telecommunications
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Review of peak signal detection methods in nanosecond pulses monitoring
Autorzy:
Achtenberg, Krzysztof
Mikołajczyk, Janusz
Szabra, Dariusz
Prokopiuk, Artur
Bielecki, Zbigniew
Powiązania:
https://bibliotekanauki.pl/articles/221035.pdf
Data publikacji:
2020
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
peak detection
pulse amplitude
free space optics
constant fraction discriminator
leading edge discriminator
sample and hold
ADC
fast acquisition
Opis:
The paper is a review of analog and digital electronics dedicated to monitor nanosecond pulses. Choosing the optimal peak detector construction depends on many factors for example precision, complexity, or costs. The work shows some virtues and limitations of selected peak detection methods, for example standard peak detector with rectifier, sample and hold circuit with triggering units and ADC fast acquisition. However, the main attention is paid to problems of results from effective triggering signal for sample and hold operation. The obtained results allow for designing a peak detector construction as an alternative for costly and very complex fast acquisition systems based on ADC and FPGA technologies.
Źródło:
Metrology and Measurement Systems; 2020, 27, 2; 203-218
0860-8229
Pojawia się w:
Metrology and Measurement Systems
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Performance analysis of MPPM FSO transmission over Gamma–Chi-square strong atmospheric turbulence
Autorzy:
Todorovic, Jelena
Spalevic, Petar
Panic, Stefan
Abdullah, Majid Hamid
Pantelic, Ivan
Powiązania:
https://bibliotekanauki.pl/articles/2202766.pdf
Data publikacji:
2023
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
FSO
free space optics
ABER
average bit error rate
MPPM
multi-pulse pulse-position
novel Gamma-Chi-square distribution
channel model
strong atmospheric turbulence
Opis:
In this paper, performance analysis of free space optical (FSO) system operating in conditions of strong atmospheric turbulence over Gamma–Chi-square turbulence model, has been carried out. We have observed reception over multi-pulse pulse-position (MPPM) modulation format for the case of strong atmospheric turbulence conditions modeled with Gamma–Chi-square turbulence model and have compared it with turbulence modeling distributions such are: Gamma–Gamma distribution, K-distribution, negative exponential distribution, log–normal distribution. First, we have provided closed-form analytical expressions for average bit error rate (ABER) at the reception for each observed case and then based on them, we have obtained numerical and Monte Carlo simulation results in order to observe turbulence level impact on system performance.
Źródło:
Optica Applicata; 2023, 53, 1; 111--126
0078-5466
1899-7015
Pojawia się w:
Optica Applicata
Dostawca treści:
Biblioteka Nauki
Artykuł
    Wyświetlanie 1-12 z 12

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