scholarly journals Algorithm of phase-frequency distortion adaptive compensation for broadband signals during propagation through transionospheric channels.

2021 ◽  
Author(s):  
V.V. Batanov ◽  
◽  
L.E. Nazarov ◽  
◽  
Keyword(s):  
Information Systems ◽  
General Concept ◽  
Linear Filter ◽  
Adaptive Compensation ◽  
Digital Signals ◽  
Distortion Compensation ◽  
Wideband Signals ◽  
Acceptable Quality ◽  
Shift Keying ◽  
Computational Procedures

The models of distortions of digital broadband signals during their propagation through transionospheric channels which are equivalent to a linear filter with an impulse response determined by a number of parameters, in particular, the central frequency of the signals, are presented. Distortions of the phase-frequency characteristics of digital broadband signals due to the dispersion properties of the ionosphere causes time scattering and the appearance of interference noise which reduces the reliability of information systems and with certain characteristics of the radiochannel destroys their operation. This determines the relevance of developing computational procedures for processing digital signals that reduce the effectiveness of this type of interference, a characteristic property of which is the linear dependence of their power on the power of information signals. The description of the algorithm for adaptive compensation of these distortions based on the use of information signals and the formation of an inverse filter is given, which corresponds to the general concept of "blind" processing. The possibility of the considered distortion compensation for digital wideband signals with phase shift keying and achievement of probabilistic characteristics of erroneous reception providing an acceptable quality of a radiochannels for information systems has been shown by means of computer simulations.

scholarly journals Algorithms of distortion compensation for broadband signals propagated through satellite ionospheric channels.

2021 ◽  
Vol 2021 (6) ◽  
Author(s):  
V.V. Batanov ◽  
◽  
L.E. Nazarov ◽  
◽  
Keyword(s):  
Computer Simulations ◽  
Frequency Band ◽  
Digital Signal ◽  
Computational Procedure ◽  
Linear Filter ◽  
Linear Filtering ◽  
Digital Signals ◽  
Distortion Compensation ◽  
Complex Envelope ◽  
Wideband Signals

Methods for describing of digital signal complex envelope distortions due to influence of satellite ionosphere radiolines based on linear filtering methods are presented. Distortions of the phase-frequency characteristics of the digital signal envelopes due to the dispersion properties of the ionosphere cause time scattering and the occurrence of intersymbol interference, which reduce the reliability of communication. This determines the relevance of the development of the computational procedure for processing digital signals that reduce the effectiveness of this type of interferences. The descriptions of the algorithms for compensation of these distortions based on the use of the broadband pilot-signals and the formation of an inverse linear filter are given. A useful property of the considered pilot-signals is the coincidence of their structure (frequency band, envelope type, manipulation law) with the structure of information digital signals. By means of computer simulations of this algorithms, the possibility of almost complete compensation of the considered distortions of wideband signals is shown.

scholarly journals A Concept for Club Information Systems (CIS) - An Example for Applied Sports Informatics

2020 ◽  
Vol 19 (1) ◽  
pp. 102-122
Author(s):  
Thomas Blobel ◽  
Martin Lames
Keyword(s):  
Information Systems ◽  
Business Intelligence ◽  
Best Practice ◽  
Interdisciplinary Approach ◽  
General Concept ◽  
Sports Clubs ◽  
Sports Science ◽  
It Systems ◽  
Starting Point ◽  
Practice Models

AbstractIn professional sports clubs, the growing number of individual IT-systems increases the need for central information systems. Various solutions from different suppliers lead to a fragmented situation in sports. Therefore, a standardized and independent general concept for a club information systems (CIS) is necessary. Due to the different areas involved, an interdisciplinary approach is required, which can be provided by sports informatics. The purpose of this paper is the development of a general and sports informatics driven concept for a CIS, using methods and models of existing areas, especially business intelligence (BI). Software engineering provides general methods and models. Business intelligence addresses similar problems in industry. Therefore, existing best practice models are examined and adapted for sport. From sports science, especially training systems and information systems in sports are considered. Practical relevance is illustrated by an example of Liverpool FC. Based on these areas, the requirements for a CIS are derived, and an architectural concept with its different components is designed and explained. To better understand the practical challenges, a participatory observation was conducted during years of working in sports clubs. This paper provides a new sports informatics approach to the general design and architecture of a CIS using best practice models from BI. It illustrates the complexity of this interdisciplinary topic and the relevance of a sports informatics approach. This paper is meant as a conceptional starting point and shows the need for further work in this field.

Encryption of Analog and Digital signals through Synchronized Chaotic Systems

2011 ◽  
pp. 415-438
Author(s):  
Kehui Sun
Keyword(s):  
Secure Communication ◽  
Communication Systems ◽  
Chaotic Sequence ◽  
Digital Signals ◽  
Encryption Schemes ◽  
Shift Keying ◽  
Chaos Shift Keying ◽  
Sequence Generator ◽  
Chaotic Secure Communication ◽  
Spreading Spectrum

Chaos is characterized by aperiodic, wideband, random-like, and ergodicity. Chaotic secure communication has become one of the hot topics in nonlinear dynamics since the early 1990s exploiting the technique of chaos synchronization. As distinguished by the type of information being carried, chaos-based communication systems can be categorized into analogy and digital, including four popular techniques such as Chaos Masking, Chaos Shift Keying, Chaos Modulation, and Chaos Spreading Spectrum. In this chapter, the principles of these schemes and their modifications are analyzed by theoretical analysis as well as dynamic simulation. In addition, chaos-based cryptography is a new approach to encrypt information. After analyzing the performances of chaotic sequence and designing an effective chaotic sequence generator, the authors briefly presented the principle of two classes of chaotic encryption schemes, chaotic sequence encryption and chaotic data stream encryption.

scholarly journals Estimation of signal reception probability characteristics using models of fading transionosphere channels

2020 ◽  
Vol 2020 (11) ◽  
Author(s):  
L.E. Nazarov ◽  
◽  
V.M. Smirnov ◽  
Keyword(s):  
Phase Shift ◽  
Distribution Density ◽  
Empirical Distribution ◽  
Phase Shift Keying ◽  
Digital Signals ◽  
Rician Distribution ◽  
Spatial Fluctuations ◽  
Shift Keying ◽  
Temporal And Spatial ◽  
Signal Fading

Statistical models of narrow-band transionosphere channels, which determine the occurrence of signal fading due to random temporal and spatial fluctuations of the electron density of ionospheric irregularities, are considered. Fading models are based on the use of empirical relationships with respect to the distribution density of the amplitude of the signals at the output of the transionosphere channel as a random process. The parameters of empirical distribution densities (lognormal distribution, m-Nakagami distribution, Rician distribution) are related to the scintillation coefficient of signal fading. Using the considered models of signal fading, a technique is presented for estimating the probability of erroneous reception of digital signals with phase shift keying during reception. Using this technique, estimates of energy losses with respect to propagation in free space were made, reaching 0.001 for a scintillation coefficient value of 0.5 to 3 dB for signals with 2- and 4-phase shift keying.

WIDEBAND SIGNAL DISPERSION DISTORTION COMPENSATORS PERFORMANCE AND COMPUTATIONAL COMPLEXITY ESTIMATION

2020 ◽  
Author(s):  
Е.О. ЛОБОВА
Keyword(s):  
Computational Complexity ◽  
Computational Efficiency ◽  
Filter Bank ◽  
Digital Filters ◽  
Radio Link ◽  
Distortion Compensation ◽  
Wideband Signal ◽  
Wideband Signals ◽  
Complexity Estimation

Предлагается методика оценки вычислительной эффективности и значений ключевых параметров устройства компенсации дисперсионных искажений широкополосных сигналов в декаметровом диапазоне на основе банка фильтров. Рассматриваются результаты сравнения качества и вычислительной сложности алгоритмов компенсации дисперсионных искажений на основе банка цифровых фильтров и классического фильтра-компенсатора. The article proposes a methodology for evaluating the computational efficiency and the main parameters of a device for compensating dispersion distortions of wideband signals in the HF radio link based on a filter bank. The article also discusses the results of comparing the performance and computational complexity of dispersion distortion compensation algorithms based on a bank of digital filters and a classical compensator filter.

Analysis of DWDM System Using DPSK Modulation Technique with Raman–EDFA Hybrid Optical Amplifier

2017 ◽  
Vol 38 (4) ◽  
Author(s):  
Manveer Singh Gill ◽  
Sanjeev Dewra
Keyword(s):  
Fiber Amplifier ◽  
Optical Amplifier ◽  
Input Power ◽  
Erbium Doped Fiber Amplifier ◽  
Differential Phase Shift ◽  
Transmission Distance ◽  
Acceptable Quality ◽  
Signal Input ◽  
Shift Keying ◽  
Hybrid Optical Amplifier

AbstractThis paper evaluates the performance of differential phase shift keying (DPSK) optical system based on Raman–erbium-doped fiber amplifier (EDFA) hybrid optical amplifier (HOA) is obtained at 64×20 Gbps with 0.1 THz channel spacing. A DPSK signal with bit rate of 20 Gbps is transmitted up to 210 km at 0 dBm signal input power and up to 166 km at –10 dBm signal input power with acceptable quality factor and bit error rate (BER). It is also found that the transmission distance up to 264 km has been covered at 10 dBm signal input power using Raman–EDFA HOA.

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