scholarly journals Generalizing the sampling theorem for a frequency-time domain to sample signals under the conditions of a priori uncertainty

2021 ◽  
Vol 3 (9(111)) ◽  
pp. 6-15
Author(s):  
Mykola Kaliuzhnyi
Keyword(s):  
Time Domain ◽  
A Priori ◽  
Double Series ◽  
Sampling Theorem ◽  
Reference Points ◽  
Orthogonal Functions ◽  
Radio Monitoring ◽  
Shannon Sampling Theorem ◽  
Radio Signals ◽  
A Priori Uncertainty

The radio monitoring of radiation and interference with electronic means is characterized by the issue related to the structural-parametric a priori uncertainty about the type and parameters of the ensemble of signals by radio-emitting sources. Given this, it is a relevant task to devise a technique for the mathematical notation of signals in order to implement their processing, overcoming their a priori uncertainty in terms of form and parameters. A given problem has been solved by the method of generalization and proof for the finite signals of the Whittaker-Kotelnikov-Shannon sampling theorem (WKS) in the frequency-time domain. The result of proving it is a new discrete frequency-temporal description of an arbitrary finite signal in the form of expansion into a double series on the orthogonal functions such as sinx/x, or rectangular Woodward strobe functions, with an explicit form of the phase-frequency-temporal modulation function. The properties of the sampling theorem in the frequency-time domain have been substantiated. These properties establish that the basis of the frequency-time representation is orthogonal, the accuracy of approximation by the basic functions sinx/x and rectangular Woodward strobe functions are the same, and correspond to the accuracy of the UCS theorem approximation, while the number of reference points of an arbitrary, limited in the width of the spectrum and duration, signal, now taken by frequency and time, is determined by the signal base. The devised description of signals in the frequency-time domain has been experimentally investigated using the detection-recovery of continuous, simple pulse, and linear-frequency-modulated (LFM) radio signals. The constructive nature of the resulting description has been confirmed, which is important and useful when devising methods, procedures, and algorithms for processing signals under the conditions of structural-parametric a priori uncertainty.

Study on Fault Diagnosis of Gear Transmission which is Based on ADAMS

2012 ◽  
Vol 215-216 ◽  
pp. 812-816
Author(s):  
Shi Ming Wang ◽  
Xian Zhu Ai ◽  
Chao Lv ◽  
Li Na Ma
Keyword(s):  
Time Domain ◽  
Mechanical Energy ◽  
Electric Energy ◽  
Image Data ◽  
Real Data ◽  
Sampling Theorem ◽  
Drive Gear ◽  
Ocean Wave Energy ◽  
Shannon Sampling Theorem ◽  
Simulation Parameters

Introduced a transmission system of a new oscillation buoy ocean wave energy generation device, the system can transform the mechanical energy into electric energy. A pair of gear model was built by SOLIDWORKS, the parameter is just the same as the real data, then imported the model into ADAMS. Under the same simulation parameters, two experiments were done, one engaged without failure, the other engaged with one broken tooth of drive wheels. Calculated TIME and STEPS by Shannon sampling theorem, simulated the marker point’s acceleration of the drive gear, then obtain image data of time domain and frequency domain, after analyzed, found this method has a significant meaning to practice.

Method for measuring distortions of a speech signal during its transmission over a communication channel to a biometric identification system

2020 ◽  
pp. 65-72
Author(s):  
V. V. Savchenko ◽  
A. V. Savchenko
Keyword(s):  
Speech Signal ◽  
Communication Channel ◽  
Speaker Identification ◽  
A Priori ◽  
Small Samples ◽  
Practical Implementation ◽  
Identification System ◽  
New Information ◽  
Discrimination Criterion ◽  
A Priori Uncertainty

This paper is devoted to the presence of distortions in a speech signal transmitted over a communication channel to a biometric system during voice-based remote identification. We propose to preliminary correct the frequency spectrum of the received signal based on the pre-distortion principle. Taking into account a priori uncertainty, a new information indicator of speech signal distortions and a method for measuring it in conditions of small samples of observations are proposed. An example of fast practical implementation of the method based on a parametric spectral analysis algorithm is considered. Experimental results of our approach are provided for three different versions of communication channel. It is shown that the usage of the proposed method makes it possible to transform the initially distorted speech signal into compliance on the registered voice template by using acceptable information discrimination criterion. It is demonstrated that our approach may be used in existing biometric systems and technologies of speaker identification.

Detection of Changes in the Random Signal Properties by Spectral Methods Under the Conditions of A Priori Uncertainty

1999 ◽  
Vol 53 (9-10) ◽  
pp. 1-10
Author(s):  
V. A. Omel'chenko ◽  
V. V. Balabanov ◽  
B. M. Bezruk ◽  
Yu. N. Goloborod'ko
Keyword(s):  
Spectral Methods ◽  
A Priori ◽  
Random Signal ◽  
A Priori Uncertainty

TAKING INTO CONSIDERATION OF THE MULTIPLE MODE OF THE FUNCTIONING AND CHARACTERISTICS OF THE CONTROL IN RELIABILITY MODELS OF REPLACEMENT TIME SYSTEMS

2019 ◽  
Author(s):  
Iryna Kononova
Keyword(s):  
A Priori ◽  
Telecommunication System ◽  
Structural Element ◽  
Reliability Models ◽  
Quick Recovery ◽  
Reliability Indicators ◽  
A Priori Uncertainty ◽  
Control Of Parameters ◽  
Time Systems ◽  
Time Reserve

The article evaluates the reliability indicators of telecommunication system equipment, which can be represented by multi-mode objects of continuous and episodic use with a time reserve operating under conditions of a priori uncertainty. Particular attention is paid to consideration of the process of functioning of the system with a replenished time reserve. The telecommunication system includes an object represented by one structural element and used in different modes of operation. In each mode, the object can be used continuously or episodically (the object performs tasks that occur at random times), herewith only a certain part of its equipment is operating. The restoration of the facility's operation in each mode is based on the "quick" recovery scheme ("quick" recovery means that the repair time is much less than the average working time of the element between failures). Also, some cases of the transition of an object from one mode to another are considered, and the control system operates according to the method of sequential control of parameters. In this case, the system, after waiting mode, begins to analyze the first parameter of the monitored complex, then the second and so on. After analyzing the parameters, the system enters the waiting mode. These calculated ratios allow for a comprehensive assessment of the reliability of telecommunication equipment, taking into account the totality of the main factors that significantly affect the reliability of the equipment in real conditions of operation, make it possible to solve important practical problems which arise from the improvement of existing equipment and development of existing equipment.

Spatial filtering of signals with spectrum overlapping

2019 ◽  
pp. 27-33
Author(s):  
M. E. Shevchenko ◽  
A. V. Gorovoy ◽  
S. N. Solovyov
Keyword(s):  
Antenna Arrays ◽  
A Priori ◽  
Spatial Filtering ◽  
Spatial Filter ◽  
Radio Sources ◽  
Probability Of Error ◽  
Shift Keying ◽  
A Priori Uncertainty

The paper considers the spatial filtering methods of signals with spectrum overlapping under conditions of a priori uncertainty of the directions of arrival from radio sources. The estimates of the directions of signals arrival obtained by ESPRIT or MUSIC are used in order to build a spatial filter. It is shown that when using ESPRIT, unlike MUSIC, an additional calculations of filter coefficients based on estimates of the directions of signals arrival are not required, and the quadrature components of the signals are formed simultaneously with estimates of the direction of their arrival. The probability of error performances of minimum shift keying signals which were divided by spatial filtering on the basis of ESPRIT and MUSIC using seven-element circular and angular antenna arrays are given.

scholarly journals Nyquist-Shannon sampling theorem applied to refinements of the atomic pair distribution function

2011 ◽  
Vol 84 (13) ◽  
Author(s):  
Christopher L. Farrow ◽  
Margaret Shaw ◽  
Hyunjeong Kim ◽  
Pavol Juhás ◽  
Simon J. L. Billinge
Keyword(s):  
Distribution Function ◽  
Pair Distribution Function ◽  
Sampling Theorem ◽  
Atomic Pair Distribution Function ◽  
Atomic Pair ◽  
Shannon Sampling Theorem

ASSESSMENT OF THE ELECTROMAGNETIC ENVIRONMENT AND RADIO MONITORING OF SIGNAL PROPAGATION AND RECEPTION CONDITIONS

2020 ◽  
Author(s):  
С.В. КИЗИМА ◽  
Е.Г. РУДЕНКОВА
Keyword(s):  
Frequency Spectrum ◽  
Electromagnetic Compatibility ◽  
Measurement Data ◽  
Signal Propagation ◽  
Radio Sources ◽  
Electromagnetic Environment ◽  
Radio Monitoring ◽  
Radio Frequency Spectrum ◽  
Radio Signals ◽  
Problematic Situations

Рассматривается технология комплексного радиомониторинга излучений в заданной географической точке. Полученные результаты сопоставляются с разрешенными уровнями излучений. Технология направлена на решение задач оценки условий распространения и приема радиосигналов, планирования использования радиочастотного спектра (РЧС), выявления помех и других проблемных ситуаций, связанных с обеспечением электромагнитной совместимости ( ЭМС) действующих и перспективных радиосредств. The article describes the technology of complex radio monitoring of emissions from multiple radio sources. The measurement data are compared with the permitted emission levels. The application of the technology helps to assess the conditions for the propagation and reception of radio signals, planning the use of the radio frequency spectrum, identifying interference and other problematic situations related to electromagnetic compatibility of existing and promising radio facilities.

Sign in / Sign up

Export Citation Format

Share Document