REFINED MODEL FOR CALCULATION OF LIMITING SECRET EFFICIENCY OF WI-FI COMMUNICATION CHANNEL

2012 ◽  
Vol 71 (16) ◽  
pp. 1465-1473
Author(s):  
Vladimir M. Shokalo ◽  
A. A. Strelnitskiy ◽  
M.K. Abdul-Hussein ◽  
E.V. Yagudina
Author(s):  
D. Van Dyck

An (electron) microscope can be considered as a communication channel that transfers structural information between an object and an observer. In electron microscopy this information is carried by electrons. According to the theory of Shannon the maximal information rate (or capacity) of a communication channel is given by C = B log2 (1 + S/N) bits/sec., where B is the band width, and S and N the average signal power, respectively noise power at the output. We will now apply to study the information transfer in an electron microscope. For simplicity we will assume the object and the image to be onedimensional (the results can straightforwardly be generalized). An imaging device can be characterized by its transfer function, which describes the magnitude with which a spatial frequency g is transferred through the device, n is the noise. Usually, the resolution of the instrument ᑭ is defined from the cut-off 1/ᑭ beyond which no spadal information is transferred.


2020 ◽  
pp. 65-72
Author(s):  
V. V. Savchenko ◽  
A. V. Savchenko

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.


2019 ◽  
Vol 41 ◽  
pp. 53-62
Author(s):  
I. A. Batyrev ◽  
◽  
S. M. Dobrovolskiy ◽  
A. M. Semenov ◽  
Yu. F. Strugov ◽  
...  

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