Operation of a Discrete Communication System

2021 ◽  
pp. 172-214
Author(s):  
Stevan Berber
Keyword(s):  
Communication System ◽  
Communication Systems ◽  
Likelihood Function ◽  
System Structure ◽  
Mathematical Expressions ◽  
System P ◽  
Special Cases ◽  
Shift Keying ◽  
Correlation Receiver ◽  
Discrete Counterpart

In this chapter, based on definitions of signal synthesizers and analysers, a general and generic scheme of a discrete communication system is developed in order to deduce practical systems as its special cases. The synthesizer is transferred into a discrete transmitter, and the analyser is used as a correlation receiver followed by an optimum detector. The system structure is presented in terms of mathematical operators and supported by exact mathematical expressions based on the theory of discrete-time stochastic processes. The likelihood function is derived, and the maximum likelihood rule is applied to specify the decision process and construct the optimum detector. A multilevel system and a quadrature phase-shift keying system are deduced as special cases, and the bit error probability expression is derived. For the sake of continuity and completeness in presenting communication systems theory, a generic digital communication system is developed and related to its discrete counterpart.

Digital Bandpass Modulation Methods

2021 ◽  
pp. 215-304
Author(s):  
Stevan Berber
Keyword(s):  
Communication Systems ◽  
Orthonormal Basis ◽  
System Structure ◽  
Special Cases ◽  
Frequency Domains ◽  
Shift Keying ◽  
Modulation Methods ◽  
Power And Energy ◽  
Digital Communication Systems ◽  
Generic System

This chapter presents mathematical models of baseband and bandpass digital communication systems based on binary and quaternary phase-shift keying, frequency-shift keying, and quadrature amplitude modulation. The systems are deduced as special cases from the general generic system structure and the related theory of orthonormal basis functions. The systems are uniquely presented using mathematical operators and detailed derivatives for signals in time and frequency domains at the system’s vital points, that is, the transmitter, the receiver, and the noise generator, using the concepts of both stochastic (continuous and discrete) and deterministic (continuous and discrete) signal processing. The vital characteristics of the system and its blocks are expressed in terms of amplitude spectral density, autocorrelation functions, power and energy spectral densities, and bit error probability.

scholarly journals A Novel Detection Scheme for EBPSK System

2012 ◽  
Vol 2012 ◽  
pp. 1-14 ◽  
Author(s):  
Xianqing Chen ◽  
Lenan Wu
Keyword(s):  
Communication System ◽  
Communication Systems ◽  
Low Complexity ◽  
Detection Technique ◽  
Joint Detection ◽  
Phase Shift Keying ◽  
Detection Scheme ◽  
New Approach ◽  
Shift Keying ◽  
Binary Phase Shift Keying

We introduce the extended binary phase shift keying (EBPSK) communication system which is different from traditional communication systems by using a special impacting filter (SIF) for demodulation. The joint detection technique is applied at the demodulator side in order to improve the performance of the system under intersymbol interference (ISI). The main advantage of the joint detection technique, when compared to conventional threshold approaches, lies in its ability to use the amplitude and the correlation between neighboring bits, thus significantly improving performance, with low complexity. Moreover, we concentrate not only on increasing the bit rate of the system, but also on designing a bandwidth efficient communication system. Simulation results show that this new approach significantly outperforms the conventional method of using threshold decision by from 3.5 to 5 dB. The new system also occupies a narrower bandwidth. So joint detection is an effective method for EBPSK demodulation under ISI.

Unified Hybrid Free Space Optical/Radio Frequency Communication System Based on Microwave Photonics

2013 ◽  
Vol 765-767 ◽  
pp. 2706-2709
Author(s):  
Ke Deng ◽  
Bing Zhong Wang ◽  
Zhou Shi Yao
Keyword(s):  
Radio Frequency ◽  
Communication System ◽  
Free Space ◽  
Communication Systems ◽  
Microwave Photonics ◽  
System Structure ◽  
Free Space Optical ◽  
Communication Mode ◽  
Communication Subsystems ◽  
Communication System Design

Hybrid free space optical/radio frequency communication systems improve reliability of links. However, independent communication subsystems increase the system complexity, weight, size, and power consumption. Based on microwave photonics, a unified hybrid free space optical/radio frequency communication system design is proposed. The communication subsystems share antenna, modulator, and demodulator to simplify system structure. Operating principle is expounded by theoretical reference, and 3dB theoretical loss is found in millimeter-wave communication mode.

PERFORMANCE OF FREQUENCY-MODULATED DIFFERENTIAL-CHAOS-SHIFT-KEYING COMMUNICATION SYSTEM OVER MULTIPATH FADING CHANNELS WITH DELAY SPREAD

2005 ◽  
Vol 15 (12) ◽  
pp. 4027-4033 ◽  
Author(s):  
YONGXIANG XIA ◽  
CHI K. TSE ◽  
FRANCIS C. M. LAU ◽  
GÉZA KOLUMBÁN
Keyword(s):  
Fading Channels ◽  
Communication System ◽  
Communication Systems ◽  
Multipath Fading ◽  
Equivalent Model ◽  
Delay Spread ◽  
Error Performance ◽  
Multipath Fading Channels ◽  
Shift Keying ◽  
Chaos Shift Keying

Multipath performance is an important consideration for chaos-based communication systems. In this letter, the performance of the FM-DCSK communication system over multipath fading channels is evaluated by computer simulations. Both Rayleigh fading and Ricean fading are considered, and the low-pass equivalent model of the FM-DCSK system is used in the simulation. Based on this model, we analyze the bit error performance of the system and the effects of system parameters on the bit-error performance.

scholarly journals The emergence of systematicity: how environmental and communicative factors shape a novel communication system

2018 ◽  
Author(s):  
Jonas Nölle ◽  
Marlene Staib ◽  
Riccardo Fusaroli ◽  
Kristian Tylén
Keyword(s):  
Working Memory ◽  
Social Factors ◽  
Communication System ◽  
Communication Systems ◽  
Language Use ◽  
Structural Features ◽  
Closed Set ◽  
Linguistic Structure ◽  
System P ◽  
The Moment

Where does linguistic structure come from? We suggest that systematicity in language evolves adaptively in response to environmental and contextual affordances associated with the practice of communication itself. In two experiments, we used a silent gesture referential game paradigm to investigate environmental and social factors promoting the propagation of systematicity in a novel communication system. We found that structure in the emerging communication systems evolve contingent on structural properties of the environment. More specifically, interlocutors spontaneously relied on structural features of the referent stimuli they communicated about to motivate systematic aspects of the evolving communication system even when idiosyncratic iconic strategies were equally afforded. Furthermore, we found systematicity to be promoted by the nature of the referent environment. When the referent environment was open and unstable, analytic systematic strategies were more likely to emerge compared to stimulus environments with a closed set of referents. Lastly, we found that displacement of communication promoted systematicity. That is, when interlocutors had to communicate about items not immediately present in the moment of communication, they were more likely to evolve systematic solutions, supposedly due to working memory advantages. Together, our findings provide experimental evidence for the idea that linguistic structure evolves adaptively from contextually situated language use.

Communication Systems for Factory Automation: A Design Approach Based on MMS and WSs Technologies

2010 ◽  
Vol 102-104 ◽  
pp. 936-940
Author(s):  
Bing Hai Zhou ◽  
Ke Lin Xu
Keyword(s):  
Control Systems ◽  
Communication System ◽  
Communication Systems ◽  
Manufacturing Systems ◽  
System Structure ◽  
Design Approach ◽  
Direct Result ◽  
Automated Manufacturing Systems ◽  
Development Environment ◽  
Factory Automation

Factory automation (FA) is a direct result of the underlying communication systems. To integrate the FA information and make FA control systems with flexibility and interoperability in automated manufacturing systems, the manufacturing message specification (MMS), Web services’ (WSs) technologies and typical FA systems are analyzed. A new design approach of the communication system structure is presented for FA systems in this paper. A prototype of FA control systems is used for evaluating performance of the communication system structure in C++ Visual Studio.NET and Java Borland Builder 9.0 development environment. The experimental results show that the proposed design approach is valid and promising.

The Design of Wireless Broadband Communication System Based on OFDMA

2012 ◽  
Vol 241-244 ◽  
pp. 2275-2278
Author(s):  
Zuo Xue Liu ◽  
Jian Mei Dai ◽  
Bo Liu
Keyword(s):  
Communication System ◽  
Communication Systems ◽  
System Structure ◽  
Antenna Gain ◽  
Broadband Communication ◽  
Allocation Model ◽  
Receiving Antenna ◽  
Wireless Broadband ◽  
Transmitting Antenna ◽  
Wired Communication

A Wireless Broadband Communication System has been made up based on OFDMA and AMC technologies. The system structure and working pattern is introduced, the OFDMA allocation model, the MIMO and AMC scheme are present, and the parameter such as transmitting power, receiver sensitivity, transmitting antenna gain and receiving antenna gain are designed. The system enables high quality wireless broadband communication. As a supplement with wired communication systems, the system could fulfill the requirement of recovery local communication rapidly when some accidents take place.

Discrete Bandpass Modulation Methods

2021 ◽  
pp. 305-385
Author(s):  
Stevan Berber
Keyword(s):  
Phase Shift ◽  
Discrete Time ◽  
Time Domain ◽  
Communication Systems ◽  
Intermediate Frequency ◽  
System Structure ◽  
Phase Shift Keying ◽  
Shift Keying ◽  
Modulation Methods ◽  
Power And Energy

This chapter presents mathematical models of discrete baseband and bandpass communication systems based on binary phase-shift keying, quaternary phase-shift keying, frequency-shift keying, and quadrature amplitude modulation. The operation of intermediate-frequency systems where all processing is performed in the discrete-time domain are presented. The systems are deduced as special cases from a generic system structure that is based on the application of orthonormal basis functions. The block schematics of systems are uniquely presented using mathematical operators. Detailed derivatives are presented for signals in the discrete-time domain at the vital points of the system’s structure, using the concepts of both discrete stochastic and discrete deterministic signal processing. The vital characteristics of the discrete system and its blocks are expressed in terms of amplitude spectral density, autocorrelation functions, power and energy spectral densities, and bit error probability.

Fault Tree Analysis for a Modern Communication System

2017 ◽  
Vol 7 (1) ◽  
Author(s):  
Kamal Hamid ◽  
Nadim Chahine
Keyword(s):  
Communication System ◽  
Communication Systems ◽  
Fault Tree ◽  
Fault Tree Analysis ◽  
Theory And Practice ◽  
Tree Analysis ◽  
Satisfactory Performance ◽  
System Components ◽  
Link Budget ◽  
Simulation Results

Wireless communications became one of the most widespread means for transferring information. Speed and reliability in transferring the piece of information are considered one of the most important requirements in communication systems in general. Moreover, Quality and reliability in any system are considered the most important criterion of the efficiency of this system in doing the task it is designed to do and its ability for satisfactory performance for a certain period of time, Therefore, we need fault tree analysis in these systems in order to determine how to detect an error or defect when happening in communication system and what are the possibilities that make this error happens. This research deals with studying TETRA system components, studying the physical layer in theory and practice, as well as studying fault tree analysis in this system, and later benefit from this study in proposing improvements to the structure of the system, which led to improve gain in Link Budget. A simulation and test have been done using MATLAB, where simulation results have shown that the built fault tree is able to detect the system’s work by 82.4%.

scholarly journals Peptide signaling without feedback in signal production operates as a true quorum sensing communication system in Bacillus subtilis

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Iztok Dogsa ◽  
Mihael Spacapan ◽  
Anna Dragoš ◽  
Tjaša Danevčič ◽  
Žiga Pandur ◽  
...  
Keyword(s):  
Gene Expression ◽  
Bacillus Subtilis ◽  
Quorum Sensing ◽  
Cell Density ◽  
Communication System ◽  
Communication Systems ◽  
Feedback Loop ◽  
Signal Molecules ◽  
Specific Cell ◽  
Sharp Transition

AbstractBacterial quorum sensing (QS) is based on signal molecules (SM), which increase in concentration with cell density. At critical SM concentration, a variety of adaptive genes sharply change their expression from basic level to maximum level. In general, this sharp transition, a hallmark of true QS, requires an SM dependent positive feedback loop, where SM enhances its own production. Some communication systems, like the peptide SM-based ComQXPA communication system of Bacillus subtilis, do not have this feedback loop and we do not understand how and if the sharp transition in gene expression is achieved. Based on experiments and mathematical modeling, we observed that the SM peptide ComX encodes the information about cell density, specific cell growth rate, and even oxygen concentration, which ensure power-law increase in SM production. This enables together with the cooperative response to SM (ComX) a sharp transition in gene expression level and this without the SM dependent feedback loop. Due to its ultra-sensitive nature, the ComQXPA can operate at SM concentrations that are 100–1000 times lower than typically found in other QS systems, thereby substantially reducing the total metabolic cost of otherwise expensive ComX peptide.

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