scholarly journals Formation of Minimax Ensembles of Aperiodic Gold Codes

2020 ◽  
Vol 23 (2) ◽  
pp. 26-37
Author(s):  
V. Yu. Zubarev ◽  
B. V. Ponomarenko ◽  
E. G. Shanin ◽  
A. G. Vostretsov
Keyword(s):  
Discrete Choice ◽  
Communication Systems ◽  
Periodic Signal ◽  
Directed Search ◽  
Code Length ◽  
Mutual Correlation ◽  
Gold Code ◽  
Digital Communication Systems ◽  
Aperiodic Signal ◽  
Unconditional Preference

Introduction. Signals constructed on the basis of ensembles of code sequences are widely used in digital communication systems. During development of such systems, the most attention is paid to analysis, synthesis and implementation of periodic signal ensembles. Theoretic methods for synthesis of periodic signal ensembles are developed and are in use. Considerably fewer results are received regarding construction of aperiodic signal ensembles with given properties. Theoretical methods for synthesis of such ensembles are practically nonexistent.Aim. To construct aperiodic Gold code ensembles with the best ratios of code length to ensemble volume among the most known binary codes.Materials and methods. Methods of directed search and discrete choice of the best ensemble based on unconditional preference criteria are used.Results. Full and truncated aperiodic Gold code ensembles with given length and ensemble volume were constructed. Parameters and shape of auto- and mutual correlation functions were shown for a number of constructed ensembles. Comparison of the paper results with known results for periodic Gold code ensembles has been conducted regarding growth of minimax correlation function values depending on code length and ensemble volume.Conclusion. The developed algorithms, unlike the known ones, make it possible to form both complete ensembles and ensembles taking into account the limitation of their volume. In addition, the algorithms can be extended to the tasks of forming ensembles from other families, for example, assembled from code sequences belonging to different families.

Picture Quality Judgments in a Digital Television System

1974 ◽  
Vol 16 (2) ◽  
pp. 139-145 ◽  
Author(s):  
Stanley M. Soliday ◽  
James A. Gardner
Keyword(s):  
Response Surface ◽  
Communication Systems ◽  
Digital Communication ◽  
Sampling Frequency ◽  
Digital Television ◽  
Code Length ◽  
Picture Quality ◽  
Television System ◽  
Digital Communication Systems

Digital communication systems distort their signals as a consequence of the digitization process. The distortions are related to the code length and sampling frequency of the system. The present study assessed viewers' responses to these variables by using simulated digital television. To do this, 24 subjects rated the quality of pictures distorted by several combinations of the variables. A response surface generated from the ratings showed that the ratings were affected by both variables, but most profoundly by code length. Interpretation of the surface's contours from the perspective of system costs revealed that costs should be considered solely from the standpoint of code length.

Security Analysis of Wireless Authentication Protocols

2019 ◽  
Vol 9 (2) ◽  
pp. 247-252 ◽  
Author(s):  
Ashish Joshi ◽  
Amar Kumar Mohapatra
Keyword(s):  
Execution Time ◽  
Communication Systems ◽  
Security Analysis ◽  
Cryptographic Protocols ◽  
Command Line ◽  
Time Analysis ◽  
Authentication Protocols ◽  
Replay Attack ◽  
Peer Communication ◽  
Digital Communication Systems

Background & Objective: Cryptographic protocols had been evident method for ensuring con dentiality, Integrity and authentication in various digital communication systems. However the validation and analysis of such cryptographic protocols was limited to usage of formal mathematical models until few years back. Methods: In this paper, various popular cryptographic protocols have been studied. Some of these protocols (PAP, CHAP, and EAP) achieve security goals in peer to peer communication while others (RADIUS, DIAMETER and Kerberos) can work in multiparty environment. These protocols were validated and analysed over two popular security validation and analysis tools AVISPA and Scyther. The protocols were written according to their documentation using the HLPSL and SPDL for analysis over AVISPA and Scyther respectively. The results of these tools were analysed to nd the possible attack an each protocol. Afterwards The execution time analysis of the protocols were done by repeating the experiment for multiple iterations over the command line versions of these tools.As the literature review suggested, this research also validates that using password based protocols (PAP) is faster in terms of execution time as compared to other methods, Usage of nonces tackles the replay attack and DIAMETER is secure than RADIUS. Results and Conclusion: The results also showed us that DIAMETER is faster than RADIUS. Though Kerberos protocol was found to safe, the results tell us that it is compromisable under particular circumstances.

scholarly journals Effect of Correlated Non-Gaussian Quadratures on the Performance of Binary Modulations

2011 ◽  
Vol 2011 ◽  
pp. 1-6
Author(s):  
Valentine A. Aalo ◽  
George P. Efthymoglou
Keyword(s):  
Communication Systems ◽  
Gaussian Quadrature ◽  
Wireless Communication Systems ◽  
High Signal ◽  
Random Waves ◽  
The Central Limit Theorem ◽  
Gaussian Quadratures ◽  
Non Gaussian ◽  
Digital Communication Systems ◽  
Composite Signal

The received signal in many wireless communication systems comprises of the sum of waves with random amplitudes and random phases. In general, the composite signal consists of correlated nonidentical Gaussian quadrature components due to the central limit theorem (CLT). However, in the presence of a small number of random waves, the CLT may not always hold and the quadrature components may not be Gaussian distributed. In this paper, we assume that the fading environment is such that the quadrature components follow a correlated bivariate Student-t joint distribution. Then, we derive the envelope distribution of the received signal and obtain new expressions for the exact and high signal-to-noise (SNR) approximate average BER for binary modulations. It also turns out that the derived envelope pdf approaches the Rayleigh and Hoyt distributions as limiting cases. Using the derived envelope pdf, we investigate the effect of correlated nonidentical quadratures on the error rate performance of digital communication systems.

Effects of Deep Learning Technologies on Employment in the Field of Digital Communication Systems

2021 ◽  
Vol 12 (4) ◽  
pp. 35-42
Author(s):  
Thomas Alan Woolman ◽  
Philip Lee
Keyword(s):  
Artificial Intelligence ◽  
Deep Learning ◽  
Communication Systems ◽  
Digital Communication ◽  
The United States ◽  
Learning Technologies ◽  
Technological Unemployment ◽  
Current State ◽  
Challenges And Opportunities ◽  
Digital Communication Systems

There are significant challenges and opportunities facing the economies of the United States in the coming decades of the 21st century that are being driven by elements of technological unemployment. Deep learning systems, an advanced form of machine learning that is often referred to as artificial intelligence, is presently reshaping many aspects of traditional digital communication technology employment, primarily network system administration and network security system design and maintenance. This paper provides an overview of the current state-of-the-art developments associated with deep learning and artificial intelligence and the ongoing revolutions that this technology is having not only on the field of digital communication systems but also related technology fields. This paper will also explore issues and concerns related to past technological unemployment challenges, as well as opportunities that may be present as a result of these ongoing technological upheavals.

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