scholarly journals Stability of radio loops covering navigation systems and communication systems

2021 ◽  
Vol 2061 (1) ◽  
pp. 012073
Author(s):  
AL Boran-Keshishyan ◽  
AA Alekseev ◽  
VV Popov
Keyword(s):  
Communication Systems ◽  
Satellite Communication ◽  
Antenna System ◽  
Guidance System ◽  
Navigation Systems ◽  
Radio Communication ◽  
External Loop ◽  
Transmission Of Information ◽  
External Causes

Abstract The development of the concept of E-navigation in modern shipping makes it necessary to create very reliable lines for the transmission of information packets and the interchange of data via radio networks to a huge number of consumers, practically all over the world. With such a scale, radio communication must be extremely reliable and stable, which is provided by the planetary system of satellite communication channels. The study proposes a method of signal loops of satellite communication systems for diagnosing the quality of the radio path, which will allow quickly localizing the external causes of the deterioration of the linear stability of communication in the absence of deep diagnostics during the daily operation of radio transmitting equipment. The organization of an external loop will make it possible to make a more accurate spatial adjustment of the antenna system to the zone of stable traffic with an increase in the steepness of the guidance system characteristics according to its own signal returned from the loop from the satellite. The external loop allows for more precise tuning of the antenna system of the stations, relative to the “steepness” of your own signal and to localize the external causes of signal deterioration by applying the method of signal loops.

CLEAR SKY DIURNAL BEHAVIOR OF TROPOSPHERIC SCINTILLATION AT KU-BAND SATELLITE COMMUNICATION IN EQUATORIAL MALAYSIA

2015 ◽  
Vol 77 (10) ◽  
Author(s):  
Ibtihal F. El-Shami ◽  
Hong Yin Lam ◽  
Jafri Din ◽  
Siat Ling Jong
Keyword(s):  
Communication Systems ◽  
Satellite Communication ◽  
Prediction Models ◽  
Elevation Angle ◽  
Signal Amplitude ◽  
Radio Communication ◽  
Significant Discrepancy ◽  
Comparison Results ◽  
Diurnal Behavior ◽  
Tropospheric Scintillation

Tropospheric scintillation is referred to rapid fluctuation of received signal amplitude. It can cause propagation impairments that affect satellite communication systems operating at above 10 GHz of frequency. In this work, we have exploited 1 year of measured broadcasting signal data collected in Johor, Malaysia to investigate the effects of scintillation intensity on a SatCom system operating at 11.075 GHz with its links pointed towards the MEASAT-1 satellite (an elevation angle of 75.61°). We have investigated the behavior of this scintillation amplitude through the classification and analysis of a time-series satellite broadcasting signal and have then compared the statistical results with existing scintillation prediction models. The comparison results indicate that there is a significant discrepancy between measured data and those models and that the performance of these prediction models does not appear to be satisfactory, with the exception of the ITU-R and the Ortgies Refractivity model. In addition, we have investigated the diurnal behavior of the scintillation intensity at four different periods of the day and proposed a modified Marzano model to accommodate local meteorological input parameters. The models performances are assessed against the available measurement dataset. The proposed models provide system operators and radio communication engineers with critical information on the fluctuations of tropospheric scintillation variance on the satellite signal during a typical day taken into the account of local meteorological peculiarities.

scholarly journals DEVELOPMENT OF A MATHEMATICAL MODEL OF THE FUNCTIONING OF MULTI-ANTENNA RADIO COMMUNICATIONS WITH SPECTRALLY EFFECTIVE SIGNALS UNDER THE INFLUENCE OF DESTABILIZING FACTORS

ScienceRise ◽  
2020 ◽  
Vol 4 ◽  
pp. 40-45
Author(s):  
Viktor Ostapchuk ◽  
Oleg Sova ◽  
Andrii Shyshatskyi ◽  
Olexander Harashchuk
Keyword(s):  
Mathematical Model ◽  
Communication Systems ◽  
Noise Immunity ◽  
High Mobility ◽  
Negative Influence ◽  
Antenna System ◽  
Radio Communication ◽  
Radio Communications ◽  
Destabilizing Factors ◽  
Antenna Systems

The necessity of developing a mathematical model for the functioning of multi-antenna radio communication facilities with spectrally effective signals under the influence of destabilizing factors has been substantiated. The results of the study of the influence of destabilizing factors on the multi-antenna systems with spectrally effective signals are presented. New analytical dependences have been obtained, which make it possible to calculate the effect of destabilizing factors on the efficiency of multi-antenna system with spectrally effective signals. Object of research: development of a mathematical model of the functioning of multi-antenna radio communication facilities with spectrally effective signals under the influence of destabilizing factors. Investigated problem: taking into account additional destabilizing factors on the multi-antenna of a radio communication facility with spectrally effective signals. Main scientific results: when transmitting information in multi-antenna radio communication systems with spectrally effective signals, the following are taken into account: Type of parameters of deliberate interference, type and parameters of deliberate fading, type and parameters of security code structures, phase jitter, slope of the constellation matrix, Intersymbol interference, high mobility of objects (transmitter and receiver), the number of receiving and transmitting antennas, the number of subcarriers in the antenna channel. It has been established that taking into account all the parameters in the system makes it possible to assess the state of the channel, to develop measures to reduce the negative influence of destabilizing factors on the noise immunity of multi-antenna systems. A review of the practical use of research results: radio communication facilities with programmable architecture. Innovative technologies product: technology for substantiating the architecture of transceivers, software for programmable radio equipment, which can increase the noise immunity of radio communications, taking into account additional destabilizing factors and software for radio monitoring equipment. Overview of an innovative technological product: programmable radios, software for radio communications.

scholarly journals METHOD FOR IMPROVING THE OPERATIONAL AND TECHNICAL CHARACTERISTICS OF cavity RESONATORS

2021 ◽  
pp. 168-172
Author(s):  
В.В. Тимофеев
Keyword(s):  
Communication Systems ◽  
Frequency Separation ◽  
Radio Communication ◽  
Frequency Signal ◽  
Cavity Resonators ◽  
Current Trends ◽  
Technical Issues ◽  
Technical Solutions ◽  
Metrological Evaluation

В работе выполнен анализ известных технических решений в области частотного разноса принимаемого и передаваемого сигналов радиочастотных ретрансляторов сигналов и проблемных вопросов технического характера, связанных с их реализацией, предложено собственное решение улучшения амплитудно-частотных характеристик систем фильтров с использованием объёмных резонаторов, выполненное с учётом современных тенденций реализации подобных систем. Целью работы является повышение технических характеристик объёмных резонаторов. В работе предлагается вариант повышения эксплуатационно-технических характеристик объёмных резонаторов. Предлагаемое решение апробировано на практике, выполнена метрологическая оценка его результатов. Результатом исследования является разработка метода повышения эксплуатационно-технических характеристик объёмных резонаторов, ориентированная на улучшение качества их работы. Предлагаемое решение может быть применено при производстве ремонта и регламентном обслуживании объёмных резонаторов, в ходе их эксплуатации в системах радиосвязи различного назначения, реализованных с их использованием. The paper analyzes the known technical solutions in the field of frequency separation of the received and transmitted signals of radio frequency signal repeaters and technical issues related to their implementation, and offers its own solution to improve the amplitude-frequency characteristics of filter systems using cavity resonators, made taking into account current trends in the implementation of such systems. The aim of this work is to improve the technical characteristics of cavity resonators. In this paper, we propose a variant of improving the operational and technical characteristics of cavity resonators. The proposed solution was tested in practice, metrological evaluation of its results was performed. The result of the research is the development of a method for improving the operational and technical characteristics of cavity resonators, focused on improving the quality of their work. The proposed solution can be applied in the production of repairs and routine maintenance of cavity resonators, during their operation in radio communication systems for various purposes, implemented with their use.

scholarly journals Analysis of Fade Dynamic at Ku-Band in Malaysia

2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
Siat Ling Jong ◽  
Michele D’Amico ◽  
Jafri Din ◽  
Hong Yin Lam
Keyword(s):  
Communication Systems ◽  
Satellite Communication ◽  
Heavy Rain ◽  
Rain Attenuation ◽  
Time Interval ◽  
Radio Communication ◽  
System Operator ◽  
Typical Day ◽  
One Year ◽  
Ku Band

This work investigates fade dynamics of satellite communication systems in equatorial heavy rain region based on a one year of Ku-band propagation measurement campaign carried out in Universiti Teknologi Malaysia (UTM), Johor, Malaysia. First order statistics of rain attenuation are deduced and the results are found to be in good agreement with those obtained from other beacon measurements gathered within the same area (Kuala Lumpur). Moreover, the fade duration and slope statistics of the satellite signal variations are also carefully derived and subsequently compared with the ITU-R recommendation model. Such information is useful for the system operator and radio communication engineer for the design of appropriate fade mitigation techniques as well as the quality of service that could be offered to the user (according to the time interval for a typical day). Further evaluation on the performances of several ITU-R models in the heavy rain region are needed based on the measurement database available of this climatic region.

scholarly journals The analysis of truncated ARQ and HARQ schemes using transition diagrams

2020 ◽  
Vol 12 (2) ◽  
pp. 35-51
Author(s):  
Herald N. Kundaeli
Keyword(s):  
Real Time ◽  
Communication Systems ◽  
Digital Communication ◽  
New Method ◽  
Quality Of Information ◽  
Transmission Of Information ◽  
Digital Communication Systems ◽  
Efficient Transmission

In digital communication systems, ARQ and HARQ schemes are employed in order to ensure efficient transmission of information and utilisation of the channel by retransmitting information that has not being received correctly at the receiver. In some applications, however, such as real-time services, the quality of information is degraded if too many retransmission trials are employed for each unit of erroneously received information. The  retransmissions are therefore limited leading to truncated ARQ and HARQ schemes. In this study we develop a new method for deriving the  expressions for the throughput efficiencies of truncated ARQ and HARQ schemes and investigate how the efficiencies vary with the number of allowed retransmissions. Keywords: ARQ, HARQ, Throughput Efficiency, Truncated ARQ.

scholarly journals Improving the quality of spatial separation of signals in radio communication systems

2019 ◽  
Vol 104 ◽  
pp. 02005 ◽  
Author(s):  
Aleksandr I. Okorochkov ◽  
Bogdan B. Malyutin ◽  
Mohamed Amine Laouar ◽  
Nadezhda A. Dmitrienko
Keyword(s):  
Antenna Array ◽  
Antenna Arrays ◽  
Communication Systems ◽  
Spatial Separation ◽  
Radio Communication ◽  
Research Results

The article presents the research results of dependence of the signal-to-interference ratio in the focus area of the reflecting antenna array on its length, as well as the influence of the center displacement of the antenna array of different sizes on the signal-to-interference ratio. The research results show that short-focus reflecting antenna arrays have better characteristics than long-focus ones. By displacing the center of the antenna array, the signal-to-interference ratio can be increased by almost 20 dB.

scholarly journals Evaluation of Concurrent Variation in Rain Specific Attenuation and Tropospheric Amplitude Scintillation Over Akure, Southwest Nigeria

2021 ◽  
Author(s):  
Ayodeji Gabriel Ashidi ◽  
Joseph Sunday Ojo ◽  
Oluwaseyi Julius Ajayi ◽  
Toluwalope Mary Akinmoladun
Keyword(s):  
Communication Systems ◽  
Satellite Communication ◽  
Signal Amplitude ◽  
Rain Attenuation ◽  
Coefficient Of Determination ◽  
Integration Time ◽  
Radio Communication ◽  
Amplitude Scintillation ◽  
Specific Attenuation ◽  
Rain Specific Attenuation

AbstractRain constitutes a major limitation to the performance and use of terrestrial and satellite communication systems with operational frequencies greater than 10 GHz. The situation gets further complicated by fast fluctuations in the received signal amplitude due to in homogeneities in atmospheric weather conditions; a phenomenon known as amplitude scintillation. The concurrent evaluation of the two phenomena guarantees a better fade margin determination for the planning of radio communication over any location. This work employs 3 years of in-situ measurement of temperature, humidity, rainfall rate and rainfall amount for the estimation of tropospheric amplitude scintillation and rain specific attenuation over Akure (7.17° N, 5.18° E, 358 m) South West Nigeria. Davis vantage pro weather station at 1-min integration time was used for the measurement and the ITU models for rain specific attenuation (ITU-R P.838-3) and amplitude scintillation (ITU–R 618-13) were employed for the estimation. Time series and statistical analyses of the phenomena show that rain attenuation is the more prominent cause of signal degradation at Ku-band frequencies. Nevertheless, the need to make an extra fade margin allowance of about 0.25 dB due to amplitude scintillation fade subsists to forestall any loss of synchronization on the link. Also, a 3-parameter power-law expression developed for estimating amplitude scintillation fade from rain attenuation performed excellently well, as indicated by average root mean square error (RMSE) and coefficient of determination (R2) values of 0.002151 and 0.8747, respectively.

scholarly journals DEVELOPMENT OF THEORETICAL PROVISIONS OF TRANSMISSION OF DISCRETE MESSAGES OF MILITARY RADIOCOMMUNICATION SYSTEMS

2020 ◽  
Vol 2 (60) ◽  
pp. 180-183
Author(s):  
A. Shyshatskyi ◽  
O. Cherniak ◽  
A. Lyashenko ◽  
S. Paniuk ◽  
A. Doroshets ◽  
...  
Keyword(s):  
Communication Systems ◽  
Communication Theory ◽  
Link Quality ◽  
Practical Significance ◽  
Radio Communication ◽  
Radio Communications ◽  
Finite Duration ◽  
Radio Systems ◽  
Signal Fading

Modern military radio systems operate in the complex conditions of the electronic environment, due to the limited frequency range, the influence of deliberate interference and signal fading. One of the ways to improve the effectiveness of military radio communication systems is to develop indicators (methods, techniques) for evaluating the effectiveness of military radio communication systems. The analysis found that known approaches to evaluating the performance of military radio communications systems are based on the use of bit error probability in a channel, which is a rather rough indicator of channel estimation. This necessitates the development of theoretical provisions for the transmission of discrete messages to military radio systems. In order to improve the known theoretical provisions for the transmission of discrete messages of military radio communication systems, the authors of the article developed indicators for assessing the quality of functioning of military radio communication systems that operate in complex conditions of electronic conditions. In the course of the study, the authors of the research substantiated two indicators of link quality in the fading channel: the probability of correctly receiving a message of finite duration and the likelihood of a link of finite duration without breaks. The first metric is the overall metric (communication) quality of the communication, and the second metric is the quality of the channel in the session of the final duration. During the research, the authors used the basic principles of communication theory, theories of insecurity, the theory of transmission of discrete messages, etc. The proposed results can be used to evaluate the status of radio channels when they are exposed to a variety of origins and signal fading. The practical significance of these results is that they can be used to upgrade existing radios or to develop new ones by developing appropriate software

scholarly journals Method for automatic modulation classification of spectral-effective radio signals based on the classification of radio signals patterns in the parameter space of phase diagram by the criterion of the minimum Euclidean distance

2020 ◽  
Vol 2020 (11) ◽  
Author(s):  
E.P. Kadukov ◽  
◽  
I.K. Utimisheva ◽  
Keyword(s):  
Parameter Space ◽  
Communication Systems ◽  
Satellite Communication ◽  
Additive White Gaussian Noise ◽  
Continuous Phase Modulation ◽  
Modulation Classification ◽  
Radio Communication ◽  
Automatic Modulation Classification ◽  
Radio Signals

A method for automatic modulation classification (AMC) of spectral-effective radio signals generated based on various kinds of roll-off filters is presented. The developed method is intended for automatic radio monitoring (RM) of radio emission parameters without demodulation using digital oscilloscopes in order to control compliance with the discipline and radio communication regulations by users of satellite communication systems (SCS). It is proposed to AMC based on the results of the parameters analysis of the phase diagrams (PD) of radio signals. The proposed approach to AMC is based on the idea of displaying radio signals characterized by many different modulation parameters in the form of pattern in the parameter space of PD of continuous phase modulation radio signals (CPM). Developed an alphabet of classes and was proposed a dictionary of features for a variety of alternatives for CPM AMC. To assess the nature of changes in the parameters of the PD of radio signals, reference descriptions of specific classes of the a priori dictionary are obtained, taking into account changes in the variable parameters that form a set of recognition alternatives. The influence of the size of the analyzed fragment and the signal-to-noise ratio (SNR) under the influence of additive white Gaussian noise (AWGN), characteristic of satellite channels, on the quality for CPM AMC, has been estimated. The article substantiates the content of the main stages of the classification of CPM in the parameter space of PD. As a result of statistical experiments, estimates of the probabilities of correct for CPM AMC were obtained.

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