scholarly journals EVALUATION OF THE INFLUENCE OF THE VALUE OF THE DYNAMIC RANGE OF THE RADIO RECEIVER ON THE NOISE IMMUNITY OF RECEIVING SIGNALS WITH QUADRATURE AMPLITUDE MODULATION

T-Comm ◽  
2021 ◽  
Vol 15 (6) ◽  
pp. 65-69
Author(s):  
Vitaly G. Dovbnya ◽  
◽  
Dmitry S. Koptev ◽  
Ivan G. Babanin ◽  
Alexander A. Knyazev ◽  
...  
Keyword(s):  
Transmission Lines ◽  
Information Exchange ◽  
Noise Immunity ◽  
Digital Communication ◽  
Dynamic Range ◽  
Signal To Noise Ratio ◽  
Frequency Converter ◽  
Technical Requirements ◽  
Communication Lines

The improvement of digital communication lines of radio information transmission systems in the direction of increasing the complexity of the signal-code structures used, increasing the speed of information exchange, the use of modern channel compaction technologies, on the one hand, and the high complexity of the surrounding electromagnetic environment, on the other hand, objectively determines the need to improve the radio receiving systems of digital communication lines in the direction of increasing their noise immunity. In this regard, in order to justify the technical requirements for noise immunity to radio receiving systems of the designed transmission lines, it is advisable to take into account the basic indicators of the quality of functioning of the radio receiving device, in order to obtain analytical expressions and graphical dependencies for evaluating the noise immunity of receiving signals with more complex combined types of modulation (QAM-64 and higher), used and planned for use. Of the large number of indicators that characterize the dynamic range, the most informative and sufficiently characterize the quality of the linear path are: the dynamic range for reducing the transmission coefficient (compression) by 1 dB and the dynamic range for third-order intermodulation distortion. The effect of interference received on the side channels (which include combination and mirror), as well as on neighboring channels, limits the lower limit of the dynamic range of the receiving device and, as a result, reduces the resulting signal-to-noise ratio at the output. The degree of suppression of the combination channels is determined, first of all, by the frequency plan and the linearity of the amplitude characteristic of the mixer of the first frequency converter, the mirror channel – the quality of filtering the mirror frequencies in the input preselector, the neighboring channel – the selectivity of the filters of the main selection. In this article, an analytical model and the resulting graphical dependencies are developed to assess the degree of influence of compression distortions on the noise immunity of receiving multi-position quadrature-amplitude modulated signals, and the requirements for the value of the dynamic range of radio receiving systems are theoretically justified.

scholarly journals MATHEMATICAL MODEL OF THE RECEIVING PATH OF DIGITAL COMMUNICATION LINES

T-Comm ◽  
2021 ◽  
Vol 15 (5) ◽  
pp. 52-57
Author(s):  
Vitaly G. Dovbnya ◽  
◽  
Dmitry S. Koptev ◽  
Keyword(s):  
Mathematical Model ◽  
Noise Immunity ◽  
Digital Communication ◽  
Automatic Gain Control ◽  
Clock Synchronization ◽  
Gain Control ◽  
Communication Line ◽  
Digital Signals ◽  
Dynamic Errors ◽  
Communication Lines

Modern trends in the development of digital communication lines of fixed information transmission services, as well as the characteristics of continuous channels today determine the noise immunity of radio receiving systems. The main directions of its increase in terms of the radio receiving device as a whole and the demodulator device in particular are as follows: reducing the frequency and nonlinear distortions of the signal in the linear path, increasing the stability and purity of the spectral line of oscillations of local oscillators, increasing the selectivity for the mirror and combination channels of reception, compensation for intersymbol and cross – polarization interference, improving the functioning of the automatic gain control device (reducing static and dynamic errors), improving the quality of the functioning of the carrier wave recovery device and the clock synchronization device. Taking into account all of the above factors in order to increase the overall noise immunity of a digital communication line is a very difficult and urgent task, the solution of which must begin with the development of a mathematical model of a continuous digital communication line channel. This article discusses the radio receiving path of a digital communication line in an urban environment. The obtained analytical expressions are aimed at interpreting the processes of converting digital signals in the structural elements of radio receiving systems. The originality of the mathematical model developed in the article lies in the fact that it additionally, in comparison with similar models, takes into account the following number of factors: frequency instability and phase fluctuations of oscillations of the local oscillator synthesizer, dynamic and static errors in the operation of automatic gain control devices, carrier vibration recovery devices and devices clock synchronization of radio receiving systems of digital signals.

scholarly journals METHOD OF IMPROVED TDICCD DESIGN BASED ON SENSOR CLOCKING

2020 ◽  
Vol V-3-2020 ◽  
pp. 689-693
Author(s):  
M. Wan ◽  
Y. Guo ◽  
S. Li ◽  
T. Liu
Keyword(s):  
Dynamic Range ◽  
Signal To Noise Ratio ◽  
Sequence Diagram ◽  
Signal Quality ◽  
Signal To Noise ◽  
Application Range ◽  
Final Output ◽  
Noise Ratio ◽  
Derivation Process

Abstract. The final output signal quality of TDICCD is related to the key parameters such as working mode, output mode, signal-to-noise ratio, dynamic range and so on. We can improve these parameters of TDICCD by reasonably designing the sensor clocking. Therefore, this text discussed four methods of improved TDICCD sensor clocking to solve some problem in TDICCD application based on using the principle of TDICCD. The technique of TDICCD Taps merging can reduce the number of TDICCD Taps, which helps to reduce the size of the TDICCD rear-end circuit significantly; The technique of TDICCD continuous transfer clocking can improve the charge transfer efficiency, which helps to promote the final signal-to-noise ratio; The technique of pixel binning clocking can enlarge the dynamic range of image; The technique of TDICCD area-array working mode can extend the field of TDICCD working; The principle, derivation process, clocking sequence diagram and application range of these clocking design schemes are given in this paper. At the same time, it also explains its actual effect and the matters to be noted.

scholarly journals Machine Learning Classification for Assessing the Degree of Stenosis and Blood Flow Volume at Arteriovenous Fistulas of Hemodialysis Patients Using a New Photoplethysmography Sensor Device

Sensors ◽  
2019 ◽  
Vol 19 (15) ◽  
pp. 3422 ◽  
Author(s):  
Chiang ◽  
Chao ◽  
Tu ◽  
Kao ◽  
Yang ◽  
...  
Keyword(s):  
Machine Learning ◽  
Blood Flow ◽  
Dynamic Range ◽  
Signal To Noise Ratio ◽  
Support Vector ◽  
Flow Volume ◽  
Machine Learning Classification ◽  
Blood Flow Volume ◽  
Sensor Device

The classifier of support vector machine (SVM) learning for assessing the quality of arteriovenous fistulae (AVFs) in hemodialysis (HD) patients using a new photoplethysmography (PPG) sensor device is presented in this work. In clinical practice, there are two important indices for assessing the quality of AVF: the blood flow volume (BFV) and the degree of stenosis (DOS). In hospitals, the BFV and DOS of AVFs are nowadays assessed using an ultrasound Doppler machine, which is bulky, expensive, hard to use, and time consuming. In this study, a newly-developed PPG sensor device was utilized to provide patients and doctors with an inexpensive and small-sized solution for ubiquitous AVF assessment. The readout in this sensor was custom-designed to increase the signal-to-noise ratio (SNR) and reduce the environment interference via maximizing successfully the full dynamic range of measured PPG entering an analog–digital converter (ADC) and effective filtering techniques. With quality PPG measurements obtained, machine learning classifiers including SVM were adopted to assess AVF quality, where the input features are determined based on optical Beer–Lambert’s law and hemodynamic model, to ensure all the necessary features are considered. Finally, the clinical experiment results showed that the proposed PPG sensor device successfully achieved an accuracy of 87.84% based on SVM analysis in assessing DOS at AVF, while an accuracy of 88.61% was achieved for assessing BFV at AVF.

scholarly journals The Communication Satellites’s Target Effectiveness Evaluating Methodology

2020 ◽  
Vol 6 (3) ◽  
pp. 6-16
Author(s):  
E Abazina ◽  
A. Kovalsky ◽  
A. Pitrin
Keyword(s):  
Decision Making ◽  
Russian Federation ◽  
Information Exchange ◽  
Noise Immunity ◽  
The State ◽  
Limited Time ◽  
Stated Choice ◽  
The Russian Federation ◽  
Choice Method

There is an approach of the communication satellites comparison presents in the paper. It can be applied in situations when it is necessary to make the promptly and reasonably decision on the communication satellites choice in conditions of limited time for decision-making. The stated choice method differs from the known ones by taking into account the overall characteristics of the satellite, which significantly affect the quality of its intended tasks. The estimated characteristics in the work are the availability, bandwidth, noise immunity, reliability and controlability of the satellite. The paper also presents the approbation results of the propsed method to determine the most effective communication satellite in a geostationary orbital grouping belonging to the Russian Federation, involved in the organization of information exchange of mobile subscribers on the territory of the state.

An Over 120dB Dynamic Range Linear Response Single Exposure CMOS Image Sensor with Two-stage Lateral Overflow Integration Trench Capacitors

2020 ◽  
Vol 2020 (7) ◽  
pp. 143-1-143-6 ◽  
Author(s):  
Yasuyuki Fujihara ◽  
Maasa Murata ◽  
Shota Nakayama ◽  
Rihito Kuroda ◽  
Shigetoshi Sugawa
Keyword(s):  
Linear Response ◽  
Dynamic Range ◽  
Signal To Noise Ratio ◽  
Cmos Image Sensor ◽  
Image Sensor ◽  
Signal To Noise ◽  
Single Exposure ◽  
Two Stage ◽  
Noise Ratio ◽  
Maximum Signal

This paper presents a prototype linear response single exposure CMOS image sensor with two-stage lateral overflow integration trench capacitors (LOFITreCs) exhibiting over 120dB dynamic range with 11.4Me- full well capacity (FWC) and maximum signal-to-noise ratio (SNR) of 70dB. The measured SNR at all switching points were over 35dB thanks to the proposed two-stage LOFITreCs.

An Analysis of On-Bord High-Voltage Converters of Single-Phase Alternating Current with Increased Miroelectric Power Factor

2020 ◽  
Vol 10 (10) ◽  
pp. 44-51
Author(s):  
Yury Yu. SKOROKHOD ◽  
◽  
Sehgey I. VOL’SKIY ◽  
Keyword(s):  
High Voltage ◽  
Single Phase ◽  
Input Current ◽  
Voltage Converter ◽  
Input Unit ◽  
Power Circuit ◽  
Electrical Systems ◽  
Static Converters ◽  
Technical Requirements

The power circuit arrangements of on-board high-voltage static converters fed from a 3000 V AC single-phase network that in the general case produce multi-channel AC and DC output voltages are considered. The basic technical requirements posed to such converters are formulated. The general structural diagram of high-voltage converters with improved electric power consumption quality is given. Possible power circuit arrangements for the high-voltage converter input unit based on single-phase input current correction devices are considered. A classification and criteria for comparative evaluation of the possible power circuit arrangements of these devices are proposed. The information presented in the article will be of interest for specialists engaged in designing on-board electrical systems involving high-voltage converters that must comply with strict requirements for the quality of consumed single-phase input current.

Pre-Processing of Hyperspectral Images Using Nonlinear Filters

2013 ◽  
Vol 11 (1) ◽  
pp. 8-13
Author(s):  
V. Behar ◽  
V. Bogdanova
Keyword(s):  
Signal To Noise Ratio ◽  
Correlation Coefficients ◽  
Hyperspectral Images ◽  
Spectral Correlation ◽  
Edge Preserving ◽  
Improvement Factor ◽  
Filter Output ◽  
Average Improvement ◽  
Processing Procedure

Abstract In this paper the use of a set of nonlinear edge-preserving filters is proposed as a pre-processing stage with the purpose to improve the quality of hyperspectral images before object detection. The capability of each nonlinear filter to improve images, corrupted by spatially and spectrally correlated Gaussian noise, is evaluated in terms of the average Improvement factor in the Peak Signal to Noise Ratio (IPSNR), estimated at the filter output. The simulation results demonstrate that this pre-processing procedure is efficient only in case the spatial and spectral correlation coefficients of noise do not exceed the value of 0.6

Image Quality Enhancing by Efficient Histogram Equalization

2014 ◽  
Vol 2 (2) ◽  
pp. 47-58
Author(s):  
Ismail Sh. Baqer
Keyword(s):  
Image Quality ◽  
Contrast Enhancement ◽  
Mean Squared Error ◽  
Signal To Noise Ratio ◽  
Histogram Equalization ◽  
Gray Level ◽  
Signal To Noise ◽  
Squared Error ◽  
Noise Ratio

A two Level Image Quality enhancement is proposed in this paper. In the first level, Dualistic Sub-Image Histogram Equalization DSIHE method decomposes the original image into two sub-images based on median of original images. The second level deals with spikes shaped noise that may appear in the image after processing. We presents three methods of image enhancement GHE, LHE and proposed DSIHE that improve the visual quality of images. A comparative calculations is being carried out on above mentioned techniques to examine objective and subjective image quality parameters e.g. Peak Signal-to-Noise Ratio PSNR values, entropy H and mean squared error MSE to measure the quality of gray scale enhanced images. For handling gray-level images, convenient Histogram Equalization methods e.g. GHE and LHE tend to change the mean brightness of an image to middle level of the gray-level range limiting their appropriateness for contrast enhancement in consumer electronics such as TV monitors. The DSIHE methods seem to overcome this disadvantage as they tend to preserve both, the brightness and contrast enhancement. Experimental results show that the proposed technique gives better results in terms of Discrete Entropy, Signal to Noise ratio and Mean Squared Error values than the Global and Local histogram-based equalization methods

On-board converter of signals of inductive sensors of speed IS-1165M1 with increased noise immunity

2017 ◽  
Vol 13 (3) ◽  
pp. 30-38
Author(s):  
Y. B. Gorbatkin ◽  
V. A. Chernyshev ◽  
S. S. Sevostyanov ◽  
A. V. Gladkov
Keyword(s):  
Noise Immunity ◽  
Dynamic Range ◽  
Rocket Engines ◽  
Flight Tests ◽  
Speed Sensor ◽  
Inductive Sensors ◽  
Turbo Pump

The article is devoted to the development of a secondary converter for measuring the speed of turbo-pump aggregates of rocket engines. The principle of the induction speed sensor is considered in the article. A method is proposed for generating output pulses from signals of induction speed sensors, which consists in the preliminary integration of the signals of the speed sensor. This method allows to increase the reliability and accuracy of the formation of signals of induction speed sensors, as well as to increase the noise immunity of the secondary converter and significantly increase the dynamic range of measuring the speed. The data of flight tests of the developed secondary converter are given.

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