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Wyszukujesz frazę "Modulation" wg kryterium: Temat


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:
Recognition of narrowband radio signals using autoregressive models and pattern comparison approach
Autorzy:
Łopatka, J.
Powiązania:
https://bibliotekanauki.pl/articles/308156.pdf
Data publikacji:
2002
Wydawca:
Instytut Łączności - Państwowy Instytut Badawczy
Tematy:
signal models
modulation recognition
Opis:
This paper presents an improved spectral recognition method for digitally modulated radio signals. It is based on a signal autoregressive (AR) model. Model poles are used as signal features for neural network based on recognition process. To reduce an influence of the signal noise and distortions introduced by the digital receiver, a nonlinear Z plane transformation is proposed.
Źródło:
Journal of Telecommunications and Information Technology; 2002, 1; 56-59
1509-4553
1899-8852
Pojawia się w:
Journal of Telecommunications and Information Technology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Fuzzy logic classifier for radio signals recognition
Autorzy:
Łopatka, J.
Pędzisz, M.
Powiązania:
https://bibliotekanauki.pl/articles/308362.pdf
Data publikacji:
2001
Wydawca:
Instytut Łączności - Państwowy Instytut Badawczy
Tematy:
modulation recognition
fuzzy logic
Opis:
This paper presents a new digital modulation recognition algorithm for classifying baseband signals in the presence of additive white Gaussian noise. Elaborated classification technique uses various statistical moments of the signal amplitude, phase and frequency applied to the fuzzy classifier. Classification results are given and it is found that the technique performs well at low SNR. The benefits of this technique are that it is simple to implement, has generalization property and requires no apriori knowledge of the SNR, carrier phase or baud rate of the signal for classification.
Źródło:
Journal of Telecommunications and Information Technology; 2001, 2; 31-34
1509-4553
1899-8852
Pojawia się w:
Journal of Telecommunications and Information Technology
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:
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:
The simple analysis method of nonlinear frequency distortions in FMCW radar
Autorzy:
Kulpa, K. S.
Wojtkiewicz, A.
Nałęcz, M.
Misiurewicz, J.
Powiązania:
https://bibliotekanauki.pl/articles/309080.pdf
Data publikacji:
2001
Wydawca:
Instytut Łączności - Państwowy Instytut Badawczy
Tematy:
radar
nonlinear frequency distortions
linear frequency modulation
Opis:
The paper presents a simple method for estimating nonlinear frequency distortions of linear frequency modulated (LFM) signals used in FMCW radars. This method, derived from the polynomial model of the nonlinear FM signal phase, is based on finding the maximum of two-dimensional chirp-like transform of the IF video signal. The IF signal is obtained by mixing transmitted FM signal with its delayed copy. Using suggested transform we show that the presented method is able to detect and classify signal distortions.
Źródło:
Journal of Telecommunications and Information Technology; 2001, 4; 26-29
1509-4553
1899-8852
Pojawia się w:
Journal of Telecommunications and Information Technology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Evaluation of potential dangers of Mobile Telecommunication frequencies and modulations
Autorzy:
Bamisaye, A. J.
Powiązania:
https://bibliotekanauki.pl/articles/307594.pdf
Data publikacji:
2013
Wydawca:
Instytut Łączności - Państwowy Instytut Badawczy
Tematy:
electromagnetic fields
frequency
health
mobile communication
modulation
Opis:
Mobile Telecommunication is one of the fastest growing technologies in the world. The effects of its high frequencies and complex modulations to the exposed population are considered in this paper. Experimental studies examining a variety of effects on all levels of the organism, ranging from effects on single cells to effects which manifest themselves as reactions of the entire body, there have been a number of epidemiological studies in order to establish the possible causal correlations between higher exposures to HF EMFs. Recommendations on the reduction of the effects of EMFs of Mobile Telecommunication on humans was presented.
Źródło:
Journal of Telecommunications and Information Technology; 2013, 2; 30-34
1509-4553
1899-8852
Pojawia się w:
Journal of Telecommunications and Information Technology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Performance Enhancement of Chaotic Error Correction Coding Using Consecutive Sequences
Autorzy:
Sahar, Asaad H.
Abdullah, Hikmat N.
Saed, Thamir R.
Powiązania:
https://bibliotekanauki.pl/articles/24200739.pdf
Data publikacji:
2023
Wydawca:
Instytut Łączności - Państwowy Instytut Badawczy
Tematy:
chaos communication
DCSK modulation
error correction
suboptimal receiver
Opis:
The use of chaotic dynamics for error correction is the subject of extensive research, as the approach allows to avoid the use of redundant data. This work proposes a new technique for non-coherent chaos communications for modifying error-correction depending on chaotic dynamics. In the proposed system, there are two consecutive sequences created from a comparable chaotic map, with the second series being created as the latest value of the initial one. Generation of a sequential chaotic sequence with a comparable chaotic dynamic delivers additional information to the receiver, allowing it to appropriately recover information and, hence, facilitate the receiver’s bit-error performance. For error correction and for detecting the symbol that is transmitted, a suboptimal technique based on the nearest distance between chaotic map trajectories over the n-dimensional sequence received is utilized. Simulation results show that the proposed error correction approach improves Eb/N0 as the dimension of the trajectory map increases, indicating that the method improves overall error correction performance. With the dimension of 4, a gain of 0.8 dB in Eb/N0 is achieved compared with an approach without any error-correcting schemes, at the bit-error probability of 10−3.
Źródło:
Journal of Telecommunications and Information Technology; 2023, 2; 10--16
1509-4553
1899-8852
Pojawia się w:
Journal of Telecommunications and Information Technology
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:
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:
A Soft-Output STBC Decoder for Aeronautical Telemetry
Autorzy:
Louёt, Yves
Othman, Rami
Skrzypczak, Alexandre
Powiązania:
https://bibliotekanauki.pl/articles/309130.pdf
Data publikacji:
2020
Wydawca:
Instytut Łączności - Państwowy Instytut Badawczy
Tematy:
continuous-phase modulation
CPM
pulse amplitude modulation
PAM
shaped offset quadrature phase shift keying
SOQPSK
space-time block coding
STBC
ternary symbol
Opis:
Alamouti encoding is a well-known space time block encoding technique used to improve the received signal quality in Rayleigh fading channels. In aeronautical telemetry, this encoding technique is applied to shaped offset quadrature phase shift keying tier generation (SOQPSK-TG) modulation in order to handle the two-antenna issue. It is provided for in telemetry-related IRIG standards. In this paper, we propose a unique decoding architecture for Alamouti-encoded SOQPSK-TG signals, taking advantage of pulse amplitude modulation decomposition with soft and hard outputs. We exploit this result to obtain a Viterbi algorithm (VA) for hard decoding and a soft output Viterbi algorithm (SOVA) for soft and hard decoding, with a twofold benefit: operation using one trellis structure, unlike decoders that are based on the 8-waveforms cross-correlated trellis-coded quadrature modulation (XTCQM) approximation, and very attractive bit error rate performance, as well as a complexity trade-off.
Źródło:
Journal of Telecommunications and Information Technology; 2020, 1; 13-20
1509-4553
1899-8852
Pojawia się w:
Journal of Telecommunications and Information Technology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Performance Analysis of SPSK with Dual Polarized Transmit Antennas over Rayleigh Fading Channel
Autorzy:
Subramani, M.
Neduncheran, A. V.
Ponnusamy, V.
Powiązania:
https://bibliotekanauki.pl/articles/307739.pdf
Data publikacji:
2018
Wydawca:
Instytut Łączności - Państwowy Instytut Badawczy
Tematy:
ABER
dual polarized antenna
Rayleigh fading
spatial modulation
SPSK
SSK
Opis:
In this paper, the Space Polarization Shift Keying (SPSK) system, which is an extended version of Space Shift Keying (SSK) and includes both space and polarization dimensions with dual polarized antennas, is studied. The capacity and error probability analysis of SPSK for different polarization configurations are dealt with over the Rayleigh fading channel with a rich scattering environment. The analysis conducted shows that the SPSK with a dual polarized antenna (DP) offers better results than SPSK with a single orthogonal polarized antenna SPSK(SP), under non-LOS conditions. SPSK(DP) outperforms SSK by 4.2 dB over the correlated Rayleigh fading channel at 3 bits/s/Hz.
Źródło:
Journal of Telecommunications and Information Technology; 2018, 1; 58-61
1509-4553
1899-8852
Pojawia się w:
Journal of Telecommunications and Information Technology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Utilization of the SOA Deep Saturation and Power Averaging Effect to Counteract Intra-Channel Crosstalk in DWDM System
Autorzy:
Dyc, F. M.
Mazurek, P.
Turkiewicz, J. P.
Powiązania:
https://bibliotekanauki.pl/articles/308974.pdf
Data publikacji:
2014
Wydawca:
Instytut Łączności - Państwowy Instytut Badawczy
Tematy:
cross-gain modulation
Dense Wavelength Division Multiplexing
Semiconductor Optical Amplifier
Opis:
The Semiconductor Optical Amplifier (SOA) is a key component of cost-effective short/medium range transmission systems. However it can introduce signal distortions. In this paper the authors investigate the possibility to reduce the signal distortions in SOA operating with the multiple wavelength channels. Using numerical simulations the negative influence of the nonlinear effects, namely cross-gain modulation (XGM) and the patterning effect can be reduced in deep SOA saturation regime. The self-healing effect is pronounced for the 4 or more wavelength channels and the transmitted symbol length longer than double of the SOA recovery time.
Źródło:
Journal of Telecommunications and Information Technology; 2014, 2; 22-28
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:
Vertical cavity surface emitting lasers in radio over fiber applications
Autorzy:
Marozsák, T.
Udvary, E.
Powiązania:
https://bibliotekanauki.pl/articles/309233.pdf
Data publikacji:
2003
Wydawca:
Instytut Łączności - Państwowy Instytut Badawczy
Tematy:
modulacja analogowa
zniekształcenia
VCSEL
analog modulation
nonlinear distortion
radio over fiber
Opis:
Theoretical and experimental study of using direct modulated vertical cavity surface emitting lasers in radio over fiber applications is presented. The nonlinear distortion and signal to noise ratio are investigated and evaluated in case of short-range multi-carrier transmission. Nonlinear characterization and comparison of the different kind of semiconductor lasers are also presented.
Źródło:
Journal of Telecommunications and Information Technology; 2003, 1; 36-40
1509-4553
1899-8852
Pojawia się w:
Journal of Telecommunications and Information Technology
Dostawca treści:
Biblioteka Nauki
Artykuł

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