Improvement of GSM system performance due to frequency hopping and/or discontinuous transmission

2002 ◽  
Author(s):  
M.C. Ronchini ◽  
E. Galani
Keyword(s):  
System Performance ◽  
Frequency Hopping

Performance of orthogonal stochastic code signals in the presence of delayed interference

2021 ◽  
Author(s):  
M.N. Chesnokov ◽  
A.A. Litvinov ◽  
A.A. Soloviev ◽  
D.B. Volgushev
Keyword(s):  
Code Generation ◽  
Spread Spectrum ◽  
System Performance ◽  
Gaussian Approximation ◽  
Multipath Propagation ◽  
Frequency Hopping ◽  
Accurate Estimation ◽  
Code Length ◽  
Probability Of Error ◽  
Correlation Receiver

This article provides analytical expressions for performance evaluation of hybrid FH-DSSS system in delayed interference and fluctuation noise presence. Delayed interference is quite common in environment with multiple obstacles, occurring as consequence of signal reflection and multipath propagation (fig. 1). Introduction describes known methods of mitigating this interference many of whom include either use of direct sequence spreading or some variation on hybrid sequence spreading including pseudo random frequency hopping and periodical signal ensemble change. To improve on those methods considered dynamic program method for orthogonal stochastic spread spectrum code generation based on Viterby algorithm [6]. Section 1 of the paper describes FH-DSSS signal, it’s delayed interference, equation corresponding to their sum on the receiver input and noncoherent correlator response to it. By using Gaussian approximation, expressions derived for equivalent signal/noise level estimation and corresponding average probability of error at the output of the correlation receiver. By including actual signal statistic, like code length and cross-correlation value, final expressions (8)–(15) allow for accurate estimation of correlation receiver response to signal sequences with specific spread spectrum codes, as well as calculation for probability of error for M-ary spread spectrum communication system in delayed interference presence. Accuracy of the Gaussian approximation is examined in section 2 of the paper based on comparisons between analytical results and simulation modeling. Numerical results obtained, which showcase dependence of system performance on various signal characteristics, such as correlation properties, spreading code length, signal ensemble size and frequency hop delay time. Plotted graph on fig. 2 shows advantage from using M-ary orthogonal signals over binary in delayed interference presence for code sequences with length N = 32, 64, 128. Graph on fig. 3 shows gains from frequency hopping when interference delay equals to approximately half of signal information symbol. In the end performance gains from using hybrid FH-DSSS system under electronic suppression by delayed interference is also evaluated. As shown on fig. 4,a system performance significaly depend on value of delay between received signal and it’s delayed copy.

The relationship of a retinal-gain index to system performance.

1960 ◽  
Author(s):  
S. Seidenstein ◽  
R. Chernikoff ◽  
F. V. Taylor
Keyword(s):  
System Performance ◽  
Relationship Of ◽  
The Relationship

The use of event-related potentials in the enhancement of system performance

1976 ◽  
Author(s):  
Christopher Wickens ◽  
Jack Isreal ◽  
Gregory McCarthy ◽  
Daniel Gopher ◽  
Emanuel Donchin
Keyword(s):  
System Performance ◽  
Event Related Potentials ◽  
Related Potentials

Study of 1024-QAM system performance in the presence of filtering imperfections

1989 ◽  
Vol 136 (2) ◽  
pp. 175-179 ◽  
Author(s):  
P. Mathiopoulos ◽  
H. Ohnishi ◽  
K. Feher
Keyword(s):  
System Performance

Effects of Observer Variation on Performance in Probabilistic Diagnosis of Jaundice

1981 ◽  
Vol 20 (03) ◽  
pp. 163-168 ◽  
Author(s):  
G. Llndberg
Keyword(s):  
Physical Examination ◽  
System Performance ◽  
Transition Matrix ◽  
Bayes Theorem ◽  
Observer Variation ◽  
Kappa Statistics ◽  
Diagnostic Categories ◽  
Number Of Patients ◽  
Probability Transition Matrix ◽  
Probabilistic Diagnosis

A system for probabilistic diagnosis of jaundice has been used for studying the effects of taking into account the unreliability of diagnostic data caused by observer variation. Fourteen features from history and physical examination were studied. Bayes’ theorem was used for calculating the probabilities of a patient’s belonging to each of four diagnostic categories.The construction sample consisted of 61 patients. An equal number of patients were tested in the evaluation sample. Observer variation on the fourteen features had been assessed in two previous studies. The use of kappa-statistics for measuring observer variation allowed the construction of a probability transition matrix for each feature. Diagnostic probabilities could then be calculated with and without the inclusion of weights for observer variation. Tests of system performance revealed that discriminatory power remained unchanged. However, the predictions rendered by the variation-weighted system were diffident. It is concluded that taking observer variation into account may weaken the sharpness of probabilistic diagnosis but it may also help to explain the value of probabilistic diagnosis in future applications.

KINERJA iLEARNING RAHARJA ASK AND NEWS (IRAN) DALAM MENDUKUNG KEGIATAN TRIDHARMA IDUHELP!

CCIT Journal ◽  
2014 ◽  
Vol 8 (1) ◽  
pp. 18-33
Author(s):  
Untung Rahardja ◽  
Meta Amalya Dewi ◽  
Fitri Lisnawati
Keyword(s):  
Information Technology ◽  
System Performance ◽  
Communication Media ◽  
Related Method ◽  
Literature Reviews ◽  
The World ◽  
Information And Communication ◽  
System Requirements ◽  
Three Stages ◽  
Care System

Advances in information technology and communications which we achieve now actually been recognized and felt in the world of education in general. Currently College Prog implement a Tridharma terms Tridharma iDuHelp!. Tridharma is one of the basic responsibilities that students must be developed simultaneously and together. In this Tridharma still there are problems in the system iDuHelp! service. So IRAN (iLearning Prog Ask and News) in collaboration with iDuHelp! in providing answers and information needed by the student. In its application in Tridharma iDuHelp! IRAN There is a related method in it, such as iLearning methods that are currently being developed. With iLearning method can facilitate conduct research in detail, accurately, and clearly by using mindmapping. Besides the method of analysis is also done with three stages  namely the identification of the problem, identifying needs, and identifying system requirements. In this study using 4 literature reviews that can be used as references in preparing this paper. In this article explained about the problems that arise and solving problems in accurately using the flow Flowchart. In the implementation of the prototype shown iDuHelp! As well as the performance of Iran. So the end result of the study is a system performance to information and communication media of Iran can maximize iDuHelp! care system  It is widely integrated in a university.

Improving Production System Performance Using Overall Equipment Effectiveness

2020 ◽  
Vol 6 (1) ◽  
Author(s):  
Lance Clarence ◽  
Wan Muhammad Noor Sarbani Mat Daud
Keyword(s):  
Production System ◽  
System Performance ◽  
Intelligent System ◽  
Global Market ◽  
Equipment Failure ◽  
Intuitive Knowledge ◽  
Analysis Tools ◽  
New Process ◽  
Knowledge Delivery

In the competition among organization on the global market, no organization will tolerate losses. Overall Equipment Effectiveness (OEE) overall is a new process in which the efficiency of a system is calculated and complicated manufacturing issues are truly simplified to simple and intuitive knowledge delivery. It thinks about the exceptionally important measures of productivity. An endeavour has been done to measure and analyse existing Overall Equipment Effectiveness (OEE) at company Kirino in hope to reduce unplanned downtime losses on equipment failure and tooling damage to maximize the productivity. The methods used to analyse these various causes were analysis tools and Intelligence Systems. After knowing the causes of various activities that leads to high rates of defects, then recommendations for improvements that could be used by company Kirino were ready to be made using intelligent system as a medium of solution

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