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Tytuł:
Adaptive procedure for automatic modulation recognition
Autorzy:
Liedtke, F.
Powiązania:
https://bibliotekanauki.pl/articles/308334.pdf
Data publikacji:
2004
Wydawca:
Instytut Łączności - Państwowy Instytut Badawczy
Tematy:
modulation recognition
modulation classification
signal analysis
radio monitoring
Opis:
An adaptive procedure for automatic modulation recognition is described. With it the automatic modulation classification and recognition of radio communication signals with a priori unknown parameters is possible effectively. The results of modulation recognition are important in the context of radio monitoring or electronic support measurements. The special features of the procedure are the possibility to adapt it dynamically to nearly all modulation types, and the capability to recognize continuous phase modulation (CPM) signals like Gaussian minimum-shift keying (GMSK) too. A time synchronization to the symbol rate is not necessary.
Źródło:
Journal of Telecommunications and Information Technology; 2004, 4; 91-97
1509-4553
1899-8852
Pojawia się w:
Journal of Telecommunications and Information Technology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Binaural masking of amplitude modulation
Autorzy:
Kordus, M.
Sęk, A.
Kociński, J.
Powiązania:
https://bibliotekanauki.pl/articles/177557.pdf
Data publikacji:
2005
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
masking
masking in the modulation domain
modulation filterbank
Opis:
A new concept concerned with the transformation of acoustic stimuli in the auditory system postulates the existence of a form of spectral analysis applied to the amplitude changes of the stimuli. It is assumed that this analysis takes place in the so-called modulation filters, i.e. bandpass linear filters tuned to different rates of the amplitude changes. The most striking argument supporting this idea is an effect of masking in the amplitude modulation domain whose nature can be easily explained basing on this concept. As the modulation filters are situated on the higher levels of the auditory system, it is also assumed that this form of masking is entirely a central process. However, most of the studies concerned with masking in the modulation domain used monaural listening only. Therefore, the main purpose of the presented here experiments was to investigate whether this type of masking is entirely a central process. Using a Three-Alternative Forced-Choice (3AFC) procedure the binaural and monaural masked thresholds of amplitude modulation were determined. A sinusoidal carrier at a frequency of 4 kHz was amplitude modulated by a specially designed band of noise characterized by a very low value of the crest factor, which was used as a masking signals. Different bandwidths of the modulating masking signals were used as well as different center frequencies to investigate whether the masking patterns in the modulation domain depend on the masker bandwidth and its center frequency. The modulating target (masked) signal was a pure tone at a frequency range from 2 to 256 Hz. Both modulating signals were applied to the same sinusoidal carrier signal. The most effective masking was noticed when the rate of the sinusoidal modulation was close to the center frequency of the masking signal or when it was in its spectral range and decreased outside of this range. The character of this dependence confirms the existence of some form of a frequency selectivity in the modulation rate domain similarly to the audible frequency domain. The thresholds for monaural and binaural listening were very close to each other. This implies that masking in the modulation domain is a central process.
Źródło:
Archives of Acoustics; 2005, 30, 1; 5-17
0137-5075
Pojawia się w:
Archives of Acoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Modulation index optimization for wavelength modulation spectroscopy
Autorzy:
Mohammadi, M. J.
Khorsandi, A.
Ghavami, S. S.
Powiązania:
https://bibliotekanauki.pl/articles/949416.pdf
Data publikacji:
2016
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
wavelength modulation spectroscopy
NIR laser spectroscopy
molecular spectroscopy
Opis:
In this work, the second-harmonic component of wavelength modulation spectroscopy is simulated for R(22) CO2 absorption line to investigate the effect of gas temperature and pressure on the modulation index. We found that the optimum value of modulation index, that is 2.2, is not affected by temperature but gas pressure will change the optimized modulation index. Specifically, when the gas pressure decreased to lower pressures of less than 100 mbar, the modulation index is also decreased and tended exponentially to about two. Accordingly, the optimum value of modulation index is recalculated for a range of CO2 gas pressures to establish a nearly zero pressure deviation in the spectroscopy of very low pressure samples.
Źródło:
Optica Applicata; 2016, 46, 4; 639-650
0078-5466
1899-7015
Pojawia się w:
Optica Applicata
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Resource allocation in MIMO systems specific to radio communication
Autorzy:
Ghaderi, Bahar
Parhizgar, Naser
Powiązania:
https://bibliotekanauki.pl/articles/140794.pdf
Data publikacji:
2019
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
spatial modulation
multi quadrature amplitude modulation
modulation
Huffman coding
MIMO systems
Opis:
The performance of the multi-input multi-output (MIMO) systems can be improved by spatial modulation. By using spatial modulation, the transmitter can select the best transmit antenna based on the channel variations using channel state information (CSI). Also, the modulation helps the transmitter to select the best modulation level such that the system has the best performance in all situations. Hence, in this paper, two issues are considered including spatial modulation and information modulation selection. For the spatial modulation, an optimal solution for obtaining the probability of selecting antenna is calculated and then Huffman coding is used such that the transmitter can select the best transmit antenna to maximize the channel capacity. For the information modulation, a multi quadrature amplitude modulation (MQAM) strategy is used. In this modulation, the modulation size is changed based on the channel state variations; therefore, the best modulation index is used for transmitting data in all channel situations. In simulation results, the optimal method is compared with Huffman mapping. In addition, the effect of modulation on channel capacity and a bit error rate (BER) is shown.
Źródło:
Archives of Electrical Engineering; 2019, 68, 1; 91-100
1427-4221
2300-2506
Pojawia się w:
Archives of Electrical Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Experimental research of the AMWG algorithm for assessing amplitude modulation in wind turbine noise
Autorzy:
Czapla, Marcjanna
Wszołek, Tadeusz
Powiązania:
https://bibliotekanauki.pl/articles/24202008.pdf
Data publikacji:
2022
Wydawca:
Politechnika Poznańska. Instytut Mechaniki Stosowanej
Tematy:
wind turbine noise
amplitude modulation
modulation depth
modulation frequency
hałas turbin wiatrowych
modulacja amplitudy
głębokość modulacji
częstotliwość modulacji
Opis:
The operation of a wind turbine (WT) is characterized by fluctuations in sound pressure amplitude associated with the passage of the propeller blade through the tower. Amplitude Modulation (AM) is one of the factors that contributes to the increased annoyance of wind turbine noise. The phenomenon of AM is currently the subject of research in many research centers around the world in the context of a parametric assessment of its impact on annoyance. Despite the development of many methods to measure the AM of a WT noise, there is no commonly accepted method. This paper discusses the most crucial factors that stimulate the phenomenon of AM and the implementation in the MATLAB environment of the algorithm to find the frequency and depth of AM proposed by the Amplitude Modulation Working Group (AMWG). The results of verification of the developed algorithm as well as the measurement results of the frequency and depth of modulation for two measurement samples of a 2 MW wind turbine are presented.
Źródło:
Vibrations in Physical Systems; 2022, 33, 3; art. no. 2022317
0860-6897
Pojawia się w:
Vibrations in Physical Systems
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Mодуляция как переводческая трансформация
Modulation as a translation transformation
Autorzy:
Гочев (Gochev), Гочо (Gocho)
Powiązania:
https://bibliotekanauki.pl/articles/967812.pdf
Data publikacji:
2012
Wydawca:
Uniwersytet Łódzki. Wydawnictwo Uniwersytetu Łódzkiego
Tematy:
translation
modulation
translation transformation
Opis:
Modulation is a process which involves changing the informative parameters of the source language word. The concrete manifestation of this transformation is the act of replacing the source language words with equivalents unrelated to the systematic regularities of lexis and as such they might a) have relevance to these regularities, i.e. the equivalent exhibits a semantic or associative link with the source language word, or b) not have relevance to these regularities, i.e. the equivalent does not exhibit a semantic or associative link with the source language word, but its use is justified by extralinguistic factors (e.g. logical reasoning or a concrete situation).
Źródło:
Acta Universitatis Lodziensis. Folia Linguistica Rossica; 2012, 08; 43-49
1731-8025
2353-9623
Pojawia się w:
Acta Universitatis Lodziensis. Folia Linguistica Rossica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
An Energy Efficient QAM Modulation with Multidimensional Signal Constellation
Autorzy:
Markiewicz, T. G.
Powiązania:
https://bibliotekanauki.pl/articles/227049.pdf
Data publikacji:
2016
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
communication system
QAM modulation
lattice
multidimensional constellations
Opis:
Packing constellations points in higher dimensions, the concept of multidimensional modulation exploits the idea drawn from geometry for searching dense sphere packings in a given dimension, utilising it to minimise the average energy of the underlying constellations. The following work analyses the impact of spherical shaping of the constellations bound instead of the traditional, hyper-cubical bound. Balanced constellation schemes are obtained with the N-dimensional simplex merging algorithm. The performance of constellations of dimensions 2, 4 and 6 is compared to the performance of QAM modulations of equivalent throughputs in the sense of bits transmitted per complex (twodimensional) symbols. The considered constellations give an approximately 0.7 dB to 1 dB gain in terms of BER over a standard QAM modulation.
Źródło:
International Journal of Electronics and Telecommunications; 2016, 62, 2; 159-165
2300-1933
Pojawia się w:
International Journal of Electronics and Telecommunications
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Decreasing of error probability in telecommunication access networks by using amplitude modulation of many components
Autorzy:
Klymash, M.
Gorbatyy, I.
Powiązania:
https://bibliotekanauki.pl/articles/411412.pdf
Data publikacji:
2014
Wydawca:
Polska Akademia Nauk. Oddział w Lublinie PAN
Tematy:
telecommunication access network
data transmission
bit error rate
quadrature amplitude modulation
amplitude modulation of many components
Opis:
The paper addresses the research of data transmission technologies in telecommunication access networks. These networks are characterized by limited bandwidth and are suitable for high speed data transmission. Particular attention is paid on the data transmission technologies in telecommunication access networks based on symmetrical telecommunication lines. Paper proposes the method of adaptive data transmission in telecommunication access networks using amplitude modulation of many components. The results of mathematical modeling are presented, which allows estimating the bit error rate decrease in telecommunication access networks using this method.
Źródło:
ECONTECHMOD : An International Quarterly Journal on Economics of Technology and Modelling Processes; 2014, 3, 1; 55-60
2084-5715
Pojawia się w:
ECONTECHMOD : An International Quarterly Journal on Economics of Technology and Modelling Processes
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Fuzzy Model of 16PSK and 16QAM Modulation
Autorzy:
Butkiewicz, B. S.
Powiązania:
https://bibliotekanauki.pl/articles/227079.pdf
Data publikacji:
2011
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
fuzzy modulation
BER
possibility
probability
PSK
QAM
noise
signal
Opis:
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.
Źródło:
International Journal of Electronics and Telecommunications; 2011, 57, 4; 437-442
2300-1933
Pojawia się w:
International Journal of Electronics and Telecommunications
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Chaotic-based Orthogonal Frequency Division Multiplexing with Index Modulation
Autorzy:
Hussien, Sura H.
Abdullah, Hamsa A.
Powiązania:
https://bibliotekanauki.pl/articles/2174449.pdf
Data publikacji:
2022
Wydawca:
Instytut Łączności - Państwowy Instytut Badawczy
Tematy:
AWGN
chaos communications
DCSK
index modulation
Opis:
Orthogonal frequency division multiplexing with index modulation (OFDM-IM), stands out among conventional communication technologies, as it uses the indices of the available transmit entities. Thanks to such an approach, it offers a novel method for the transmission of extra data bits. Recent years have seen a great interest in chaos-based communications. The spectrum-spreading signals used in chaotic signal modulation technologies are orthogonal to the existing mixed signals. This paper presents how well a non-coherent differential chaos shift keying communication system performs across an AWGN. Different types of detection methods are simulated, bit error rate and power spectral density are calculated and then compared with standard OFDM with index modulation. The results of simulations concerning the performance of a DCSK system, adding to the security of the proposed solution and offering a comparable bit error rate performance, are presented in the paper as well.
Źródło:
Journal of Telecommunications and Information Technology; 2022, 4; 33--38
1509-4553
1899-8852
Pojawia się w:
Journal of Telecommunications and Information Technology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Modified Topology and Modulation Technique for Z-Source Neutral-Point Clamped Inverter
Autorzy:
Akbari, Ehsan
Zishan, Farhad
Powiązania:
https://bibliotekanauki.pl/articles/2175930.pdf
Data publikacji:
2022
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
modulation
optimization
multilevel inverter
MZS-NPC
Opis:
The impedance network makes it possible to increase and decrease the voltage, which is not available in normal inverters (voltage and current sources).This paper presents a modified topology and modulation technique for a three-phase Modified Z-Source Neutral-Point Clamped (MZS-NPC) inverter. A modulation scheme for the proposed topology is designed based on maximum gain control method to achieve the maximum voltage gain by simple implementation and balancing the neutral point voltage of the dc link. In order to supply the desired voltage to the critical load in an islanded micro-grid, a closed-loop ac voltage controller is realized in fuel cell or photovoltaic applications based on the proposed inverter. The ability to reinforce and validity of topology operations and modulation techniques has been demonstrated by simulation. It should be noted that the simulations are implemented in MATLAB / Simulink software.
Źródło:
Power Electronics and Drives; 2022, 7, 42; 210--226
2451-0262
2543-4292
Pojawia się w:
Power Electronics and Drives
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Laser frequency counting and frequency modulation width measurement from a FFT signal
Autorzy:
Křen, P.
Powiązania:
https://bibliotekanauki.pl/articles/221880.pdf
Data publikacji:
2012
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
laser
modulation width
frequency measurement
optical frequency synthesizer
Opis:
A new method of optical frequency beat counting based on fast Fourier transform (FFT) analysis is described. Signals with a worse signal-to-noise ratio can be counted correctly comparing to the conventional counting method of detecting each period separately. The systematic error of FFT counting below 10 Hz is demonstrated and can be decreased. Additionally the modulation width of a frequency-stabilized laser with high frequency modulation index can be simultaneously measured during a carrier frequency measurement against an optical frequency synthesizer or other laser.
Źródło:
Metrology and Measurement Systems; 2012, 19, 3; 565-572
0860-8229
Pojawia się w:
Metrology and Measurement Systems
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Symulacyjna aproksymacja charakterystyki przetwarzania flickermetru dla modulacji amplitudy i częstotliwości
Simulation approximation of flickermeter conversion characteristic for amplitude and frequency modulation
Autorzy:
Majchrzak, J.
Wiczyński, G.
Powiązania:
https://bibliotekanauki.pl/articles/156720.pdf
Data publikacji:
2007
Wydawca:
Stowarzyszenie Inżynierów i Techników Mechaników Polskich
Tematy:
flikermetr
wskaźnik Pst
modulacja AM
modulacja FM
flickermeter
Pst indicator
FM modulation
AM modulation
Opis:
Flickermetr jest potoczną nazwą układu pomiarowego przeznaczonego do oceny odczuwania migotania światła wywołanego wahaniami napięcia. Normatywna charakterystyka przetwarzania flickermetru jest określona mało licznym zestawem par wartości głębokości modulacji i częstotliwości harmonicznego lub prostokątnego sygnału modulującego dla modulacji amplitudy napięcia wejściowego. Wielkością wyjściową jest wskaźnik krótkookresowego migotania światła Pst. W celu dokładniejszego odtworzenia charakterystyki przeprowadzono badania symulacyjne dla modulacji amplitudy i częstotliwości napięcia wejściowego. Zamodelowano elementy toru normatywnego flickermetru, tj. filtry o stałych parametrach zapisane w postaci operatorowej wraz z multiplikatorami, narzędzie do wyznaczania wartości Pst, źródło sygnału testowego oraz narzędzia do prezentacji i archiwizacji wyników badań. W artykule przedstawiono wyniki badań symulacyjnych zrealizowanych przy pomocy standardowych przebiegów testowych dla modulacji amplitudy AM oraz częstotliwości FM. Zamieszczono specyficzne fragmenty wyznaczonych charakterystyk oraz przykład wpływu ograniczenia pasma napięcia wejściowego na wynik pomiaru flickermetrem dla modulacji FM. Wyniki symulacji porównano z nielicznymi punktami normatywnymi. Sformułowano uwagi przydatne w diagnostyce flickermetru.
Flickermeter is a measurement system for estimation of the disturbances coming from flickering of light caused by the fluctuations of voltage. The disturbances are described on the basis of values of short-term coefficient Pst and long-term coefficient Plt of light flickers. The flickermeter system considered in the paper consists of two main components: a signal channel simulating perception processes in the chain: light source-eye-brain and a statistics module. Signal chains action is a map for bounded number of standard points of characteristic conversion. The simulation works with realization interpolation and extrapolation standard points was advisable. Presented results come from tests for AM and FM modulation.Before using the results, the verification was necessary. The conclusions formulated are useful in flickermeter's diagnostic.
Źródło:
Pomiary Automatyka Kontrola; 2007, R. 53, nr 9 bis, 9 bis; 629-632
0032-4140
Pojawia się w:
Pomiary Automatyka Kontrola
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Digital vector modulator with diagnostic circuit for particle accelerator
Autorzy:
Tarnowski, S.
Piotrowski, A.
Powiązania:
https://bibliotekanauki.pl/articles/397924.pdf
Data publikacji:
2010
Wydawca:
Politechnika Łódzka. Wydział Mikroelektroniki i Informatyki
Tematy:
modulacja wektorowa
modulacja cyfrowa
diagnostyka
vector modulation
digital modulation
diagnostics
Opis:
Modern particle accelerators[8] have very strict requirements for controlling signal. To generate signal controlling field in cavities there is a possibility to use digital vector modulator and analog upconverter[6]. Hardware circuit consists of FPGA device, digital to analog converter and low pass filter. For experiments there is also a need to design and develop measurement circuit. Same circuit could be used in final application as diagnostics module. This enables an option for constant long term measurement and fault detection. This paper presents construction of such module.
Źródło:
International Journal of Microelectronics and Computer Science; 2010, 1, 1; 85-88
2080-8755
2353-9607
Pojawia się w:
International Journal of Microelectronics and Computer Science
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The effect of space vector modulation algorithm on characteristics of three-phase voltage inverter for drives of optical telescopes
Autorzy:
Tomasov, V.
Usoltsev, A.
Zolov, P.
Gribanov, P.
Powiązania:
https://bibliotekanauki.pl/articles/200303.pdf
Data publikacji:
2017
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
multilevel inverter
space vector modulation
modulation algorithm
current ripple
precision AC drive
inwerter
modulacja
napęd AC
Opis:
The effect of space vector modulation algorithm on magnitude of current vector ripples was considered on the mathematical model of a three-level three-phase voltage inverter with symmetric active inductive load. Limitations on the use of such inverters as a power supply for precision drive of optical telescopes were specified.
Źródło:
Bulletin of the Polish Academy of Sciences. Technical Sciences; 2017, 65, 5; 629-637
0239-7528
Pojawia się w:
Bulletin of the Polish Academy of Sciences. Technical Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A comparison of different modulation techniques performances in an underground multiuser communications scenario
Autorzy:
Badescu, A.-M.
Powiązania:
https://bibliotekanauki.pl/articles/106166.pdf
Data publikacji:
2012
Wydawca:
Uniwersytet Marii Curie-Skłodowskiej. Wydawnictwo Uniwersytetu Marii Curie-Skłodowskiej
Tematy:
modulation techniques
commercial communication systems
CDMA
16-QAM
QPSK
Opis:
The potential use of typical commercial communication systems with ultra high frequencies for the underground emergency/military situations will be investigated, as commercial systems have already a fully developed market that makes them cheap and reliable. The possible usage of broadband techniques like CDMA in the direct sequence will be studied because most commercial communication systems have already been designed to support multiple users, as the underground propagation has many possible applications. The performances of both modulation techniques are evaluated from the point of view of the quality of the signals, power spectral density and the effect that the propagation medium has on the transmitted signals such that the best modulation technique is determined. The 16QAM and QPSK modulations (two of the most popular modulation techniques in the terrestrial wireless system) are compared in a scenario where a number of underground sources share the same physical channel (and antenna) - the receiver is placed at the ground level so the generated signals must propagate through the dielectric layer in order to reach it. The transmitted power, electric and magnetic fields as well as occupied bandwidth are also calculated.
Źródło:
Annales Universitatis Mariae Curie-Skłodowska. Sectio AI, Informatica; 2012, 12, 2; 73-85
1732-1360
2083-3628
Pojawia się w:
Annales Universitatis Mariae Curie-Skłodowska. Sectio AI, Informatica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
M-ary phase modulation for digital watermarking
Autorzy:
Xin, Y.
Pawlak, M.
Powiązania:
https://bibliotekanauki.pl/articles/908050.pdf
Data publikacji:
2008
Wydawca:
Uniwersytet Zielonogórski. Oficyna Wydawnicza
Tematy:
cyfrowy znak wodny
odporność
pojemność danych
multibit watermarking
M-ary phase modulation
watermark robustness
data capacity
Opis:
In spread spectrum based watermarking schemes, it is a challenging task to embed multiple bits of information into the host signal. M-ary modulation has been proposed as an effective approach to multibit watermarking. It has been proved that an M-ary modulation based watermarking system outperforms significantly a binary modulation based watermarking system. However, in the existing M-ary modulation based algorithms, the value of M is restricted to be less than 256, because as M increases, the computation workload for data extraction advances exponentially. In this paper, we propose an efficient M-ary modulation scheme, i.e., M-ary phase modulation, which reduces the computation in data extraction to a very low level. With this scheme, it is practical to implement an M-ary modulation based algorithm with a high value of M, e.g., M = 220. This is significant for a watermarking system, because it can either greatly increase the data capacity of a watermark given the necessary watermark robustness, or considerably improve the watermark robustness given the amount of information of the watermark. The superiority of the proposed scheme is verified by simulation results.
Źródło:
International Journal of Applied Mathematics and Computer Science; 2008, 18, 1; 93-104
1641-876X
2083-8492
Pojawia się w:
International Journal of Applied Mathematics and Computer Science
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Performance analysis of variable speed multiphase induction motor with pole phase modulation
Autorzy:
Liu, H.
Wang, J.
Zhang, Z.
Powiązania:
https://bibliotekanauki.pl/articles/140991.pdf
Data publikacji:
2016
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
induction motor (IM)
pole phase modulation (PPM)
efficiency
FEM
Opis:
The pole phase modulation (PPM) technique is an effective method to extend speed range and torque capabilities for an integrated starter and hybrid electric vehicles applications. In this paper, the five pole-phase combination types of a multiphase induction motor (IM) with 36 stator slots and 36 stator conductors are presented and compared quantitatively by using the time-stepping finite element method (TS-FEM). The 36 stator conductors of the proposed multiphase IM are fed by a 36 leg inverter and the current phase angle and amplitude of each stator conductor can be controlled independently. This paper focuses on the winding connection, the PPM technique and the performance comparative analysis of each pole-phase combination types of the proposed multiphase IM. The flux distribution, air-gap flux density, output torque, core losses and efficiency of five pole-phase combination types have been investigated.
Źródło:
Archives of Electrical Engineering; 2016, 65, 3; 425-436
1427-4221
2300-2506
Pojawia się w:
Archives of Electrical Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Optical self-phase modulation using a new photonic crystal coupled-cavity waveguide
Autorzy:
Bahadori-Haghighi, S
Ghayour, R
Powiązania:
https://bibliotekanauki.pl/articles/173977.pdf
Data publikacji:
2014
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
photonic crystal
slow light
coupled-cavity waveguide
self-phase modulation
Opis:
In this paper, self-phase modulation of an optical pulse using a new photonic crystal coupled-cavity waveguide is simulated and analyzed. The structure of the new coupled-cavity waveguide is introduced and its advantage over the previous type of coupled-cavity waveguide is discussed. In order to obtain a high group index over a large bandwidth and benefit from the slow light phenomenon, the group index and group velocity dispersion parameter curves of the guided mode are calculated. Finally, the transient simulation of the structure is performed using a finite-difference time-domain method. The calculated required length of the coupled-cavity waveguide for a maximum phase shift of π is about 31 μm. Spectral broadening of the optical pulse as a result of self-phase modulation is also presented and discussed.
Źródło:
Optica Applicata; 2014, 44, 1; 29-38
0078-5466
1899-7015
Pojawia się w:
Optica Applicata
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Modeling of the inverse base width modulation effect in HBT transistor with graded SiGe base
Autorzy:
Zaręba, A.
Łukasiak, L.
Jakubowski, A.
Powiązania:
https://bibliotekanauki.pl/articles/308625.pdf
Data publikacji:
2007
Wydawca:
Instytut Łączności - Państwowy Instytut Badawczy
Tematy:
heterojunction bipolar transistor
SiGe
base width modulation
Opis:
A model of the position of the edge of emitter-base junction in the base and collector current pre-exponential ideality factor in HBT transistor with a SiGe base is presented. The model is valid for transistors with nonuniform profiles of doping and Ge content. The importance of taking into account the dependence of the effective density of states in SiGe on local Ge content and that of electron diffusion coefficient in SiGe on drift field for modeling accuracy is studied.
Źródło:
Journal of Telecommunications and Information Technology; 2007, 3; 88-92
1509-4553
1899-8852
Pojawia się w:
Journal of Telecommunications and Information Technology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Comparison of Wavelet Decomposition Coefficients Transmission Systems Using Splines and Classical Types of Modulation
Autorzy:
Kutin, A. I.
Powiązania:
https://bibliotekanauki.pl/articles/309261.pdf
Data publikacji:
2015
Wydawca:
Instytut Łączności - Państwowy Instytut Badawczy
Tematy:
multi-speed channels
spline-modulation
spline Savitzky-Golay filter
wavelet decomposition
Opis:
Wavelets are becoming increasingly used as a tool for the analysis of non-stationary data. To transmit the coefficients resulting from the signal decomposition traditionally their combination into a single data packet is used, without including unequal energy contribution of each factor and impact of the decomposition level. This paper analyzes (at different transmission speeds) the signals properties produced by classical modulation methods and spline modulation for wavelet coefficients transmission proposed by the author. For all signal types the additive Gaussian noise is used as a noise disturbance.
Źródło:
Journal of Telecommunications and Information Technology; 2015, 3; 25-31
1509-4553
1899-8852
Pojawia się w:
Journal of Telecommunications and Information Technology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
An improved space vector modulation strategy for common-mode voltage reduction in matrix rectifier
Autorzy:
Liu, X.
Zhang, Q.
Hou, D.
Powiązania:
https://bibliotekanauki.pl/articles/950664.pdf
Data publikacji:
2014
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
matrix converter
space vector modulation
common-mode voltage
Opis:
The matrix rectifier modulated by the classical space vector modulation (SVM) strategy generates common-mode voltage (CMV). The high magnitude and high du/dt of the CMV causes serious problems such as motor damage, electromagnetic noise and many others. In this paper, an improved SVM strategy is proposed by replacing the zero vectors with suitable couple of active ones that substantially eliminate the CMV. Theoretical analysis proves that the proposed strategy can reduce the amplitude of the CMV to half of the original value. In addition, the quality of the input and output waveforms is not affected by extra active vectors. Simulation and experimental results demonstrate the feasibility and effectiveness of the proposed strategy are shown.
Źródło:
Archives of Electrical Engineering; 2014, 63, 1; 93-106
1427-4221
2300-2506
Pojawia się w:
Archives of Electrical Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Pilot Based MMSE Channel Estimation for Spatial Modulated OFDM Systems
Autorzy:
Soman, Anetha Mary
Nakkeeran, R.
Shinu, Mathew John
Powiązania:
https://bibliotekanauki.pl/articles/2055222.pdf
Data publikacji:
2021
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
MIMO
multicarrier modulation
spatial modulation
channel estimation
channel model
interpolation
Opis:
Due to the multifold growth in demands of multimedia services and mobile data, the request for increased channel capacity in mobile and wireless communication has been quickly increasing. Developing a wireless system with more spectral efficiency under varying channel condition is a key challenge to provide more bit rates with limited spectrum. Multiple Input Multiple Output(MIMO) system with Orthogonal Frequency Division Multiplexing (OFDM) gives higher gain by using the direct and the reflected signals, thus facilitating the transmission at high data rate. An integration of Spatial Modulation (SM) with OFDM (SM OFDM) is a newly evolved transmission technique and has been suggested as a replacement for MIMO -OFDM transmission. In practical scenarios, channel estimation is significant for detecting transmitted data coherently. This paper proposes pilot based, Minimum Mean Square Error (MMSE) channel estimation for the SM OFDM communication system. We have focused on analyzing Symbol Error Rate (SER) and Mean Square error (MSE) under Rayleigh channel employing International Telecommunication Union (ITU) specified Vehicular model of Pilot based MMSE channel estimator using windowed Discrete Fourier Transform (DFT) and MMSE weighting function. Simulation output shows that proposed estimator’s SER performance lies close to that of the MMSE optimal estimator in minimizing aliasing error and suppressing channel noise by using frequency domain data windowing and time domain weighting function. Usage of the Hanning window eliminates error floor and has a compact side lobe level compared to Hamming window and Rectangular window. Hanning window has a larger MSE at low Signal to Noise Ratio (SNR) values and decreases with high SNR values. It is concluded that data windowing technique can minimize the side lobe level and accordingly minimize channel estimation error when interpolation is done. MMSE weighting suppresses channel noise and improves estimation performance. Since Inverse Discrete Fourier Transform(IDFT)/DFT transforms can be implemented with fast algorithms Inverse Fast Fourier Transform( IFFT)/Fast Fourier Transform(FFT) computational complexity can be remarkably reduced.
Źródło:
International Journal of Electronics and Telecommunications; 2021, 67, 4; 685--691
2300-1933
Pojawia się w:
International Journal of Electronics and Telecommunications
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
An Improved M-ary Modulation Scheme Based on Chaotic Dynamics
Autorzy:
Abdullah, Hikmat N.
Sahar, Asaad H.
Saeed, Thamir R.
Powiązania:
https://bibliotekanauki.pl/articles/958105.pdf
Data publikacji:
2019
Wydawca:
Instytut Łączności - Państwowy Instytut Badawczy
Tematy:
chaos
M-ary modulation
non-coherent detection
zigzag map
Opis:
This paper proposes an improved chaos-based M-ary modulation system. It reproduces deterministic chaotic dynamics to create M-ary non-coherent modulation. The proposed modulation system transmits data using autonomous chaotic sequences. It separates the chaotic dynamics through the use of interleavers and realigns them through the use deinterleavers. The simulation results show that the improved scheme overperforms its traditional counterpart. The degree of improvement grows as the M-ary order is increased, with a penalty of increased system complexity.
Źródło:
Journal of Telecommunications and Information Technology; 2019, 4; 13-19
1509-4553
1899-8852
Pojawia się w:
Journal of Telecommunications and Information Technology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Impacts of modulation for direct payments in Hungary
Wpływ modulacji na bezposrednie płace na Węgrzech
Autorzy:
Vasary, M.
Molnar, J.
Zsolt, B.
Powiązania:
https://bibliotekanauki.pl/articles/868774.pdf
Data publikacji:
2013
Wydawca:
The Polish Association of Agricultural and Agribusiness Economists
Tematy:
modulation
direct payment
payment
subsidy redeployment
calculation
Hungary
Opis:
The redeployment of subsidies through modulation was a new element in the system of Hungarian agricultural support in the premium year of 2012. In harmony with EU principles, it has become possible (within Hungarian implementation) to create a system which enables the radical moderation of actual volumes of subsidy redeployment resulting from modulation. The basis of model calculations was created by the finalized data of ARDA about payments in the premium year of 2011. Following the running of calculations, it can be confirmed that the implementation of the Hungarian method has resulted in reduced payments only in the case of 2% of all farmers eligible for direct subsidies, and about 10% of those who are actually involved in payment reduction.
Nową częścią węgierskiego systemu wsparcia rolnictwa w roku składkowym 2012 było przegrupowanie dotacji poprzez modulację. Na Węgrzech możliwe stało się stworzenie systemu, który zgodnie z zasadami UE umożliwiał radykalne obniżenie aktualnej wysokości przegrupowania dotacji będącej wynikiem modulacji. Podstawą do obliczenia modelu były dane ARDA na temat wpłat za rok składkowy 2011. Można potwierdzić, że wprowadzenie węgierskiej metody skutkowało zmniejszeniem składek tylko w przypadku 2% wszystkich rolników, którym przysługują bezpośrednie dotacje i ok. 10% w przypadku tych, którzy rzeczywiście przyczyniają się do zmniejszenia składek.
Źródło:
Roczniki Naukowe Stowarzyszenia Ekonomistów Rolnictwa i Agrobiznesu; 2013, 15, 4
1508-3535
2450-7296
Pojawia się w:
Roczniki Naukowe Stowarzyszenia Ekonomistów Rolnictwa i Agrobiznesu
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
An Overview of Carrier-based Modulation Methods for Z-Source Inverter
Autorzy:
Roomi, Muhammad M.
Powiązania:
https://bibliotekanauki.pl/articles/1193846.pdf
Data publikacji:
2019
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
AC/DC
power conversion
impedance source inverter
modulation methods
shoot through
phase opposition disposition
reference disposition
Opis:
Single-stage energy converters, in particular, the Z-Source Inverter (ZSI) or impedance source inverter, has gained significant attention in the recent years. ZSI ensures flexible energy conversions (dc–dc, dc–ac, ac–ac and ac–dc) because of its unique ability to boost the output voltage in typical renewable energy systems. The impedance network integrated between the energy source and the load contributes to the unique functionality of the ZSI. As substantial research has been conducted on the ZSI, this article provides a review on the operation of ZSI. The article initially examines the various topologies commonly adopted for the application of the ZSI. Subsequently, details of the various modulation methods that are commonly used to obtain the voltage boosting using ZSI are documented. Additionally, the phenomenon of neutral point formation, which is an important impediment to the adoption of multilevel ZSIs and the limitation of the modulation methods, is explained.
Źródło:
Power Electronics and Drives; 2019, 4, 39; 15-31
2451-0262
2543-4292
Pojawia się w:
Power Electronics and Drives
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Single side band modulation and bandpass subsampling
Autorzy:
Poćwiardowski, P.
Kobylarz, P.
Powiązania:
https://bibliotekanauki.pl/articles/332618.pdf
Data publikacji:
2001
Wydawca:
Polskie Towarzystwo Akustyczne
Opis:
Paper describes the efficient method of gaining information from beamformer based on band subsampling technique. In active sonar systems, where centre (carrier) frequency is known (neglecting the Doppler shift), it is feasible to use the subsampling techniques, widely used elsewhere. The subsampling techniques can be used for narrow band signals. One of the advantages of this method lays in the use of noiseless heterodyne in mixer circuit, which provides errorless signal shifting to zero frequency. The use of subsampling provides good opportunity for decreasing the amount of digital processing, hardware components and followed by capital expenditure consumed during fabrication of sonars systems. lt also allows increasing the spatial resolution of sonar by increasing the number of preformed beams in the sonar array.
Źródło:
Hydroacoustics; 2001, 4; 201-204
1642-1817
Pojawia się w:
Hydroacoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Application of the FPAA to Sample Input Signal for Laboratory Exercise: Pulse Amplitude Modulation
Autorzy:
Grzechca, Damian
Chruszczyk, Lukas
Powiązania:
https://bibliotekanauki.pl/articles/227335.pdf
Data publikacji:
2020
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
field programmable analog array (FPAA)
signal processing
pulse amplitude modulation (PAM)
student laboratory
Opis:
This paper presents exemplary exercise on the fundamentals of signal processing course which is offered for second year bachelor level students. Application of Field Programmable Analog Array (FPAA) for pulse amplitude modulation (PAM) exercise is described with signal processing laboratory. There are presented two methods for implementing PAM modulation and demodulation technique in FPAA module. Example configuration files are available form Authors’ web site.
Źródło:
International Journal of Electronics and Telecommunications; 2020, 66, 1; 25-28
2300-1933
Pojawia się w:
International Journal of Electronics and Telecommunications
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Analog-based duobinary-4-PAM for electrical bandwidth limited optical fiber links
Autorzy:
Suhr, L.F.
Madsen, P.
Monroy, I. T.
Olmos, J. J. V.
Powiązania:
https://bibliotekanauki.pl/articles/173933.pdf
Data publikacji:
2016
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
optical communications
advanced modulation formats
multilevel modulation
Opis:
This paper presents a demonstration of a seven level duobinary-4-PAM signal operating at 10.16 Gbit/s. The polybinary generation is achieved by a simple electrical Bessel filter of 5th order, with a frequency cut-off of 1.8 GHz. We assess the impact of the filter placement, either at the transmitter or the receiver, and find the impact is minimal in terms of bit error rate performance in transmissions of up to 40 km of single mode fiber.
Źródło:
Optica Applicata; 2016, 46, 1; 71-78
0078-5466
1899-7015
Pojawia się w:
Optica Applicata
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Study of all-optical logic XOR gate based on linear optical amplifier cross-gain modulation
Autorzy:
Li, X
Jin, J
Li, H
Zhang, Q
Powiązania:
https://bibliotekanauki.pl/articles/174514.pdf
Data publikacji:
2015
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
linear optical amplifier
cross-gain modulation
XOR gate
Opis:
All-optical logic is the key to future high speed and large capacity optical transmission, the realization of optical packet switching and optical computing, and it has a very profound influence on the development of future optical communication. A linear optical amplifier as a new type of semiconductor optical amplifier, which has a good gain characteristic, has better signal performance than a traditional semiconductor optical amplifier in the wavelength conversion. This article presents a numerical simulation model of all-optical logic XOR gate and its logic operation based on cross-gain modulation of linear optical amplifier, and has also completed some of the basic logic operations, including AND, OR, NOT operations.
Źródło:
Optica Applicata; 2015, 45, 4; 447-457
0078-5466
1899-7015
Pojawia się w:
Optica Applicata
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Model flickermetru dla modulacji częstotliwości napięcia wejściowego
A model of the flickermeter for frequency modulation of input voltage
Autorzy:
Wiczyński, G.
Powiązania:
https://bibliotekanauki.pl/articles/153232.pdf
Data publikacji:
2007
Wydawca:
Stowarzyszenie Inżynierów i Techników Mechaników Polskich
Tematy:
flickermetr
model
wskaźnik Pst
modulacja FM
flickermeter
Ps
indicator
frequency modulation
Opis:
Flickermetr jest potoczną nazwą układu do pomiaru uciążliwości odczuwania migotania światła wywołanego wahaniami napięcia. Przetwarzanie toru sygnałowego tego układu jest na tyle złożone, że analityczne wyznaczenie wartości wyjściowych nie jest proste. Założonym celem prac opisanych w artykule jest budowa prostego modelu dla modulacji częstotliwości FM sygnału wejściowego. Obecnie brak specyfikacji normatywnej flickermetru do modulacji FM. W artykule zaproponowano model flickermetru dla modulacji FM sygnałami wolnozmiennymi i w zakresie od 1Hz do 100 Hz. Dokonano ocenę prawidłowości aproksymacji charakterystyk dla modulacji FM przebiegami harmonicznym i prostokątnym, bazując na wynikach symulacji numerycznych. Prezentowany model ułatwia zrozumienie działania badanego toru sygnałowego flickermetru i weryfikację prawidłowości działania rzeczywistych układów pomiarowych w rozpatrywanym zakresie częstotliwości sygnału modulującego FM.
The aim of studies presented in the paper is a structure of the simple model for FM frequency modulation of the input signal. There is a lack of the flickermeter standard specification in this subject. Based on results of numerical simulations, evaluation of approximation correctness of characteristics for FM modulation with harmonic as well as rectangular waveforms has been made. The equations for FM modulation using slowly varying signals and signals in the frequency range from 1 Hz to 100 Hz are proposed. The presented model facilitates understanding the operation of the tested flickermeter signal chain and verification of the operation correctness of real measuring systems in the considered frequency range.
Źródło:
Pomiary Automatyka Kontrola; 2007, R. 53, nr 9 bis, 9 bis; 633-636
0032-4140
Pojawia się w:
Pomiary Automatyka Kontrola
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Using of Golden Code Orthogonal Super-Symbol in Media-Based Modulation for Single-Input Multiple-Output Schemes
Autorzy:
Bamisaye, Ayodeji James
Quazi, Tahmid
Powiązania:
https://bibliotekanauki.pl/articles/2142306.pdf
Data publikacji:
2022
Wydawca:
Instytut Łączności - Państwowy Instytut Badawczy
Tematy:
golden code
media-based modulation
radio RF mirrors
SIMO
Opis:
The media-based modulation (MBM) scheme is capable of providing high throughput, increasing spectrum efficiency, and enhancing bit error rate (BER) performance of communication systems. In this paper, an MBM employing radio frequency (RF) mirrors and golden code is investigated in a single-input multiple-output (GC-SIMO) application. The aim is to reduce complexity of the system, maximize linear relationships between RF mirrors and improve spectral efficiency of MBM to in order to obtain a high data rate with the use of less hardware. Orthogonal pairs of the super-symbol in the GC scheme’s encoder are employed, transmitted via different RF mirrors at different time slots in order to achieve the full data rate and high diversity. In the results having BER of 10−5 , the GC-SIMO, MBM exhibits better performance than GD-SIMO, with the gain of approximately 7 dB and 6.5 dB SNR for 4 b/s/Hz and 6 b/s/Hz, respectively. The derived theoretical average error probability of the proposed scheme is validated with the use of the Monte Carlo simulation.
Źródło:
Journal of Telecommunications and Information Technology; 2022, 2; 43--48
1509-4553
1899-8852
Pojawia się w:
Journal of Telecommunications and Information Technology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Przetwornik z modulacją kwadraturową do pomiaru parametrów wiatru
Transducer with quadrature modulation for measurements of wind parameters
Autorzy:
Rylski, A.
Powiązania:
https://bibliotekanauki.pl/articles/157100.pdf
Data publikacji:
2008
Wydawca:
Stowarzyszenie Inżynierów i Techników Mechaników Polskich
Tematy:
sensory
tensometry
modulacja kwadraturowa
mostki niezrównoważone
sensors
strain gauge
quadrature modulation
unbalanced bridge
Opis:
W artykule opisano kształt belki przetwornika tensometrycznego charakteryzującego się stałym współczynnikiem ugięcia w funkcji zmian prędkości wiatru oraz zaproponowano mostkową modulację kwadraturową do jednoczesnego pomiaru dwóch parametrów wiatru: prędkości i kierunku. Ta konstrukcja nie posiada elementów ruchomych i jest niewrażliwa na zmiany temperatury i wilgotności powietrza.
The paper presents the shape of a strain gauge transducer beam which is characterized by a constant deflection coefficient at wind speed changes. The bridge quadrature modulation is proposed for simultaneous measurements of the wind intensity and direction. The presented construction has no movable elements and is insensitive to changes in air temperature and humidity.
Źródło:
Pomiary Automatyka Kontrola; 2008, R. 54, nr 12, 12; 857-859
0032-4140
Pojawia się w:
Pomiary Automatyka Kontrola
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Type of modulation identification using Wavelet Transform and Neural Network
Autorzy:
Walenczykowska, M.
Kawalec, A.
Powiązania:
https://bibliotekanauki.pl/articles/201661.pdf
Data publikacji:
2016
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
modulation identification
artificial neural networks
continuous wavelet transform (CWT)
identyfikacja modulacji
sztuczne sieci neuronowe (SSN)
transformacja falkowa (CWT)
Opis:
Automatic recognition of the signal modulation type turned out to be useful in many areas, including electronic warfare or surveillance. The wavelet transform is an effective way to extract signal features for identification purposes. In this paper there are M-ary ASK, M-ary PSK, M-ary FSK, M-ary QAM, OOK and MSK signals analysed. The mean value, variance and central moments up to five of continuous wavelet transform (CWT) are used as signal features. The principal component analysis (PCA) is applied to reduce a number of features. A multi-layer neural network trained with backpropagation learning algorithm is considered as a classifier. There are two research variants: interclass and intraclass recognition with a wide range of signal-to-noise ratio (SNR).
Źródło:
Bulletin of the Polish Academy of Sciences. Technical Sciences; 2016, 64, 1; 257-261
0239-7528
Pojawia się w:
Bulletin of the Polish Academy of Sciences. Technical Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Evolutionary optimization of Sigma-Delta modulated analog stimulus
Autorzy:
Golonek, T.
Powiązania:
https://bibliotekanauki.pl/articles/397702.pdf
Data publikacji:
2015
Wydawca:
Politechnika Łódzka. Wydział Mikroelektroniki i Informatyki
Tematy:
analog electronic circuits testing
evolutionary optimization
sigma-delta modulation
pulse density modulation
analogowy układ elektroniczny
optymalizacja ewolucyjna
modulacja sigma-delta
modulacja gęstości impulsów
Opis:
This paper proposes the evolutionary technique of the stimulus signal optimization for the analog electronic circuit testing purpose. The obtained signal is coded with Sigma-Delta modulation usage that allows to generate it easily by simple microcontrollers without the necessity of expensive D/A peripherals applying. The signal with the controlled impulses density may be obtained on the external output terminal of the typical timer and finally, it defines the analog signal that can be reconstructed after low pass filtering.
Źródło:
International Journal of Microelectronics and Computer Science; 2015, 6, 4; 130-135
2080-8755
2353-9607
Pojawia się w:
International Journal of Microelectronics and Computer Science
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Modulation effect of vibration frequency of an unsprung heavy machine under the variable road adhesion conditions
Autorzy:
Chwastek, S.
Powiązania:
https://bibliotekanauki.pl/articles/244951.pdf
Data publikacji:
2013
Wydawca:
Instytut Techniczny Wojsk Lotniczych
Tematy:
mobile heavy machines
unsprung vehicles
galloping effect
adhesion factor
slipping action
frequency modulation of vibration
Opis:
Mobile heavy machines as unsprung vehicles exhibit low dissipation ability, hence the ride even at low speeds may give rise to intensive vibration. Particularly dangerous situations occur when the road wheels break away from the road surface due to the ’galloping’ effect, being the result of excited vertical and angular vibration of the machine frame in the vertical plane of symmetry. That implies a major restriction on the ride velocity, which negatively impacts on the machine performance. Vibrations thus produced are mostly in the low-frequency range and hence energy dissipation in tyres will reduce the vibration intensity in a minor degree only. The motion of tired wheels will always involve some slipping. While investigating the feasibility of increasing the efficiency of the vibration reduction systems, one ought to take into account the variable adhesion of road wheels due to different dynamic loading acting on the vehicle axles during the ride. Observations of unsprung machines during the ride suggest the occurrence of self-excited vibration. Mobile machines constitute dynamic systems, which can be governed by nonlinear, sometimes non-stationary differential equations of motion. Their stability also depends on intensity of external vibrations. This study investigates the motion of unsprung mobile machines, taking into account the dynamic processes in the driving system under the conditions of the variable adhesion of road wheels. The model of interaction between a tired wheel and the terrain takes into account the relationship between the road wheel adhesion factor and the slipping action. Mathcad supported by Matlab-Simulink and in the frequency domain – simulations in the time domain. The purpose of the simulation procedure was to find the causes of the vibration modulation frequency and determine the conditions triggering the occurrence of self-excited vibrations. Simulations are supported by the analysis of motion stability.
Źródło:
Journal of KONES; 2013, 20, 4; 55-62
1231-4005
2354-0133
Pojawia się w:
Journal of KONES
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Analytical Models for Distribution of the Envelope and Phase of Linearly Modulated Signals in AWGN Channel
Autorzy:
Moazzeni, T
Jiang, Y.
Selvaraj, H.
Chen, T.
Powiązania:
https://bibliotekanauki.pl/articles/226459.pdf
Data publikacji:
2014
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
digital modulation
linear modulation
probability density function
phase
AWGN
Opis:
In this paper, analytical expressions for the distribution of the envelope and phase of linearly modulated signals such as BPSK, M-PSK, and M-QAM in AWGN are presented. We perform numerical simulations for different orders of signal constellations. The results show that the proposed theoretical models are in excellent agreement with the estimated distributions from various numerical experiments.
Źródło:
International Journal of Electronics and Telecommunications; 2014, 60, 1; 79-82
2300-1933
Pojawia się w:
International Journal of Electronics and Telecommunications
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Seed priming improves salt stress tolerance during germination by modulation of antioxidative capacity
Autorzy:
Kubala, S.
Wojtyla, L.
Garnczarska, M.
Powiązania:
https://bibliotekanauki.pl/articles/79921.pdf
Data publikacji:
2013
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
conference
seed priming
salt stress
reactive oxygen species
stress tolerance
germination
modulation
antioxidant capacity
Źródło:
BioTechnologia. Journal of Biotechnology Computational Biology and Bionanotechnology; 2013, 94, 2
0860-7796
Pojawia się w:
BioTechnologia. Journal of Biotechnology Computational Biology and Bionanotechnology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Influence of Modulation Detection Threshold on Speech Intelligibility
Autorzy:
Leo, K.
Powiązania:
https://bibliotekanauki.pl/articles/1504420.pdf
Data publikacji:
2011-06
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
43.55.Hy
Opis:
Speech intelligibility in classrooms and lecture halls was investigated. Acoustical measurements in the rooms have been performed, with special concern about 125 ms of early decay phenomenon. Weighting function of early reflections relative energy derived from modulation threshold and speech modulation spectrum of signal is proposed.
Źródło:
Acta Physica Polonica A; 2011, 119, 6A; 1023-1026
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Optical gradient force of cosh-Gaussian with sine-azimuthal and half-space phase modulation
Autorzy:
Fu, R.
Gao, X.
Shen, H.
Xin, Q
Lu, X.
Guo, L.
Powiązania:
https://bibliotekanauki.pl/articles/173789.pdf
Data publikacji:
2013
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
optical gradient force
cosh-Gaussian beams
wavefront modulation
Opis:
The optical gradient force distributions in focal plane of cosh-Gaussian beams with sine-azimuthal variation wavefront and half space phase modulation were investigated. Results show that optical gradient force distributions can be affected considerably by the phase retardation of half-space phase modulation, of a phase parameter that indicates the phase change frequency on an increasing azimuthal angle, and beam parameters in cosh terms of the incident beams. Many gradient force patterns occur, including cross-shape, multiple optical trap arrays, multiple-trap wheel, and many kinds of gradient force lines and curves. Symmetry of the whole gradient force pattern can also be altered remarkably. Above results may find wide applications in optical trapping systems.
Źródło:
Optica Applicata; 2013, 43, 4; 719-730
0078-5466
1899-7015
Pojawia się w:
Optica Applicata
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Modernization of DVB-S2 Standard Using Signal-Code Constructions Based on Amplitude Modulation of Many Components
Autorzy:
Horbatyi, Ivan
Yashchyshyn, Yevhen
Powiązania:
https://bibliotekanauki.pl/articles/227156.pdf
Data publikacji:
2020
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
DVB-S2 standard
frequency efficiency
energy efficiency
amplitude modulation of many components
Opis:
It is proposed to modernize the DVB-S2 standard by using AMMC (amplitude modulation of many components) signals instead of 8PSK (8-phase shift keying) and APSK (amplitude-phase shift keying) signals, and to modernize the DVB-S2 standard equipment by using the AMMC modulator and AMMC demodulator. Usage of AMMC makes it possible to reduce the symbol error rate in communication channel up to 52 times. The satellite digital video broadcast systems that apply signal-code constructions based on AMMC are characterized by a higher energy efficiency from 1 to 2.6 dB compared with signal-code constructions based on 8PSK and APSK.
Źródło:
International Journal of Electronics and Telecommunications; 2020, 66, 2; 315-320
2300-1933
Pojawia się w:
International Journal of Electronics and Telecommunications
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Performance of coherent modulation scheme used in acoustic underwater communication system
Autorzy:
Schmidt, Jan H.
Schmidt, Aleksander M.
Kochańska, Iwona
Powiązania:
https://bibliotekanauki.pl/articles/127757.pdf
Data publikacji:
2019
Wydawca:
Politechnika Poznańska. Instytut Mechaniki Stosowanej
Tematy:
underwater acoustic communications
shallow underwater channel
coherent modulation
akustyczna komunikacja podwodna
płytki kanał podwodny
modulacja koherentna
Opis:
The development of an acoustic underwater communication system for shallow waters is still a big scientific and construction challenge. Currently, non-coherent modulations in combination with strong channel coding are used to achieve reliable communication with low rate in such a channel. To obtain transmission with a higher transmission rate, it is required to use coherent modulation. This paper presents the assumptions of such a transmission system and the results of data transmission carried out by this system in the channel with the Rician fading, which reflects the short range shallow water channel. A digital version of the carrier phase modulation known as Phase-Shift Keying was selected for simulation.
Źródło:
Vibrations in Physical Systems; 2019, 30, 1; 1-8
0860-6897
Pojawia się w:
Vibrations in Physical Systems
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The diagnosis of onboard generators (alternators)
Autorzy:
Gębura, A.
Radoń, T.
Powiązania:
https://bibliotekanauki.pl/articles/258804.pdf
Data publikacji:
2009
Wydawca:
Politechnika Gdańska. Wydział Inżynierii Mechanicznej i Okrętownictwa
Tematy:
technical diagnostics
frequency modulation
Opis:
In the paper selected problems related to diagnostics of onboard generators and alternators fitted with control systems are discussed. Problems refer to commutator generators and synchronous single- and threephase alternators. Special attention is paid to commutation effects. Results of incorrectness and possibility to detect them are discussed. There are also discussed effects associated with changes in a character of pulsation, which occur during shortings or insulation clearances in rotor or stator wiring. Possibility of diagnosis of generator’s or alternator’s parts by means of analysis of pulsation component parameters is indicated. In the case of alternators a number of diagnostic methods based on observation of changes in shape of voltage or frequency modulation, is discussed. This allows to detect many mechanical or electrical faults of generators, alternators or their control systems.
Źródło:
Polish Maritime Research; 2009, 3; 36-40
1233-2585
Pojawia się w:
Polish Maritime Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Amplitude and Frequency Modulation in Speaker Recognition Systems
Autorzy:
Ciota, Z.
Powiązania:
https://bibliotekanauki.pl/articles/397977.pdf
Data publikacji:
2012
Wydawca:
Politechnika Łódzka. Wydział Mikroelektroniki i Informatyki
Tematy:
modulacja AM-FM
filtr Gabora
transformata Hilberta
biometryka głosu
spektrogram
przetwarzanie mowy
AM-FM modulation
Gabor filters
Hilbert transform
speaker recognition system
spectrogram analysis
speech processing
Opis:
The paper presents a review of the nowadays methods of voice vector extraction, applied in such speech processing, like person identification and emotion recognition. A special attention was held on mixed time-frequency analysis based on temporary frequency approach. The methods of calculation of time - frequency voice characterization were also described. The most important building blocks of identification and recognition of speakers have been presented. The characterization of feature vectors suitable for identification and verification in microcomputer systems was described. Components and appropriate method of speech identification based on the long-term spectra vectors were discussed.
Źródło:
International Journal of Microelectronics and Computer Science; 2012, 3, 2; 41-44
2080-8755
2353-9607
Pojawia się w:
International Journal of Microelectronics and Computer Science
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
OFDM modulation and adaptive equalization for underwater communications
Autorzy:
Kochańska, I.
Lasota, H.
Salamon, R.
Powiązania:
https://bibliotekanauki.pl/articles/332731.pdf
Data publikacji:
2005
Wydawca:
Polskie Towarzystwo Akustyczne
Opis:
Transmission performances of a shallow underwater channel are limited due to multiple reflections of sound waves off the bottom and water surface, and to the non-stationarity caused mainly by water surface movement. In traditional narrowband telecommunication modems complex Decision Feedback Equalizers are used for minimizing the influence of intersymbol interferences caused by multipath propagation of sound waves. The article proposes adapting OFDM modulation and adaptive equalization based on Kalman filtration techniques for use in underwater communications system. The OFDM modulation is used in wideband ADSL telecommunication modems. The Kalman filtration algorithm is used for time-varying processes identification. The techniques were tested in simulation environment with promising results.
Źródło:
Hydroacoustics; 2005, 8; 77-82
1642-1817
Pojawia się w:
Hydroacoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Research on a scheme of generating ultra-wideband doublet signal based on the cross-gain modulation in a semiconductor optical amplifier
Autorzy:
Zhang, K.
Shao, J.
Powiązania:
https://bibliotekanauki.pl/articles/173646.pdf
Data publikacji:
2018
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
ultra-wideband
UWB
semiconductor optical amplifier
SOA
cross-gain modulation
XGM
Opis:
We propose a novel scheme for generating ultra-wideband doublet signal based on the cross-gain modulation effect in a semiconductor optical amplifier. This scheme requires only a semiconductor optical amplifier and an optical source. By using OptiSystem software, we simulate and analyze the effect of the input signal light power and wavelength, the pulse width and injection current on the generated doublet pulse. In addition, the optimal range of parameters are also given in the simulation process.
Źródło:
Optica Applicata; 2018, 48, 1; 127-135
0078-5466
1899-7015
Pojawia się w:
Optica Applicata
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Epigenetic modulation of the activity of transgen and endogenous gene based on the example of chalcone synthase in flax
Autorzy:
Zuk, M.
Dzialo, M.
Szopa, J.
Powiązania:
https://bibliotekanauki.pl/articles/951257.pdf
Data publikacji:
2015
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
epigenetic modulation
mutagenesis
genetic modification
chalcone synthase
flax
transgenic plant
phenylpropanoid
Źródło:
BioTechnologia. Journal of Biotechnology Computational Biology and Bionanotechnology; 2015, 96, 1
0860-7796
Pojawia się w:
BioTechnologia. Journal of Biotechnology Computational Biology and Bionanotechnology
Dostawca treści:
Biblioteka Nauki
Artykuł
Wyświetlanie 1-50 z 355

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