Informacja

Drogi użytkowniku, aplikacja do prawidłowego działania wymaga obsługi JavaScript. Proszę włącz obsługę JavaScript w Twojej przeglądarce.

Wyszukujesz frazę "time hopping" wg kryterium: Temat


Wyświetlanie 1-4 z 4
Tytuł:
DS-UWB and TH-UWB Energy Consumption Comparison
Autorzy:
Elabboubi, A.
Elbahhar, F.
Heddebaut, M.
Elhillali, Y.
Powiązania:
https://bibliotekanauki.pl/articles/958085.pdf
Data publikacji:
2016
Wydawca:
Instytut Łączności - Państwowy Instytut Badawczy
Tematy:
energy consumption
multi-user techniques
Nakagami fading channel
TH time hopping
UWB
Opis:
The energy consumption of the wireless communication systems is starting to be unaffordable. One way to improve the power consumption is the optimization of the communication techniques used by the communication networks and devices. In order to develop an energy efficient UWB multi-user communication system, the choice of modulation and multi access technique is important. This paper compares two Ultra-wideband multi-user techniques, i.e. the DS-UWB and the TH-UWB in the case of the Nakagami-m fading channel. For the DS-UWB technique, the orthogonal (T-OVSF, ZCD) and non-orthogonal (Kasami) codes are used. For TH-UWB, authors consider different modulations (PPM, PSM, PAM). This comparison allows choosing the best solution in terms of energy consumption, data rate and communication range. Two different studies are realized to find the most efficient technique to use. In the first study, the same number of users for the different type of codes (data rate values) is chosen and the total energy consumption for several distances and path-loss coefficient is computed. In the second one, the multiusers effects (same data rate) for various values of distances and path-loss are evaluated.
Źródło:
Journal of Telecommunications and Information Technology; 2016, 1; 101-109
1509-4553
1899-8852
Pojawia się w:
Journal of Telecommunications and Information Technology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Improved CSE with DLS-MMSE Criteria in TH-UWB System
Autorzy:
Djebbari, Ali
Elahmar, Sid Ahmed
Powiązania:
https://bibliotekanauki.pl/articles/2058501.pdf
Data publikacji:
2022
Wydawca:
Instytut Łączności - Państwowy Instytut Badawczy
Tematy:
channel shortening equalizer
inter-symbol interferences
rake receiver
time hopping
ultra-wide band
ZF-MMSE
Opis:
This article presents a study on the use of deter ministic least squares criteria combined with the minimum mean square error method for the purpose of computing filter coefficients of the channel shortening equalizer. This method is well known to alleviate inter-symbol interference in time hopping UWB systems. The validity of this method is applied to shorten the impulse response of the effective UWB channels and, therefore, reduce the complexity of the rake receiver. Results show a very promising advantage compared to partial rake (P-Rake), selective-rake (S-Rake) and optimal maximum shortening signal-to-noise ratio methods.
Źródło:
Journal of Telecommunications and Information Technology; 2022, 1; 93--98
1509-4553
1899-8852
Pojawia się w:
Journal of Telecommunications and Information Technology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Reduction of BER using RSC code for Optical Code Division Multiple Access Networks
Autorzy:
Panda, Satyasen
Powiązania:
https://bibliotekanauki.pl/articles/1178316.pdf
Data publikacji:
2017
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Tematy:
Cross Correlation (CC)
Multiple Access Interface (MAI)
Optical Code Division Multiple Access (OCDMA)
Random Sparse Code (RSC)
Wavelength hopping time spreading (WHTS)
Opis:
In this study, a two dimensional (2-D) wavelength hopping and time spreading (WHTS) optical code division multiple access (OCDMA) code is designed using Sparse ruler technique. The proposed 64 bit 2-D code is constructed by an algorithm based on random spacing of sparse codes referred in this work as Random Sparse Code (RSC). The performance of the proposed 2-D RSC is evaluated in terms of bit error rate (BER), received signal power and time domain analysis of received signals. The system performance of the OCDMA system utilizing 2-D RSC code improved significantly due to less BER, low cross correlation property and simple encoder/decoder design. The output BER is much lower at a data rate of 1.25 gbps and 2.5 gbps for a distance of 100 km with ITU-T standard single mode fiber with attenuation level of 0.2dB/km.
Źródło:
World Scientific News; 2017, 81, 2; 106-120
2392-2192
Pojawia się w:
World Scientific News
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Effect of doping on time-of-flight transient currents in twin crystalline layers: a Monte-Carlo study
Autorzy:
Rybicki, J.
Powiązania:
https://bibliotekanauki.pl/articles/1941715.pdf
Data publikacji:
2000
Wydawca:
Politechnika Gdańska
Tematy:
hopping transport
time-of-flight experiment
Monte Carlo methods
Opis:
In the paper we present the results of the Monte Carlo simulations of time-of-flight transient currents in hopping systems containing various, concentrations of transport-active centres placed in an inert matrix, and doped with various concentrations of additional transport-active centres, characterised by a different ionisation potential than the host transport centres. Such hopping centre distribution can be found in molecularly doped organic crystals. The carriers are allowed to jump between localised states of two kinds: the host transport sites of concentration c/sub 0/, and the additional doping sites of concentration c/sub d/. We deal only with the dependence of the carrier mobility on doping level, and on the difference of ionisation potentials between the host and dopant centres, at fixed external field and temperature. The results of simulations performed for various dopings, and various hopping sites distributions in energy, are discussed. The carrier jump statistics is discussed in detail.
Źródło:
TASK Quarterly. Scientific Bulletin of Academic Computer Centre in Gdansk; 2000, 4, 1; 33-48
1428-6394
Pojawia się w:
TASK Quarterly. Scientific Bulletin of Academic Computer Centre in Gdansk
Dostawca treści:
Biblioteka Nauki
Artykuł
    Wyświetlanie 1-4 z 4

    Ta witryna wykorzystuje pliki cookies do przechowywania informacji na Twoim komputerze. Pliki cookies stosujemy w celu świadczenia usług na najwyższym poziomie, w tym w sposób dostosowany do indywidualnych potrzeb. Korzystanie z witryny bez zmiany ustawień dotyczących cookies oznacza, że będą one zamieszczane w Twoim komputerze. W każdym momencie możesz dokonać zmiany ustawień dotyczących cookies