scholarly journals ALGORITHM FOR DETERMINING THE BOUNDARIES OF THE ZONE OF INTERFERENCE OPERATION OF THE RADIO CHANNEL OF THE UHF / VHF RANGE COMMUNICATION IN THE CONDITIONS OF OPERATION OF THE RADIOSHENOPRIAD SOURCE SYSTEM AT DIFFERENT HEIGHTS

Author(s):  
O. Iohov ◽  
◽  
V. Maliuk ◽  
Ye. Kaplun ◽  
◽  
...  

A method for determining the limits of the maximum size of the stable radio reception area in the UHF / VHF range for mobile radio communication under the conditions of the radio interference system is proposed. The radio is intended to use a directional antenna or screen. Increasing the size of the stable radio reception area is provided by the optimal orientation at each point of the antenna device in azimuth and angle using the model of the radio channel, which allows to calculate the signal / interference ratio taking into account the spatial location of radio interference sources and digital 3D antenna pattern. receiver. The problem of determining the boundaries of the zone of stable radio exchange of mobile radio means using directional antennas in the conditions of real interference is formulated in the form of the problem of finding a single isoline in a scalar field. To determine the coordinates of the points of the map belonging to the isoline, a modification of the wave algorithm is proposed, which is low complexity and unambiguous results. Examples of practical use of the proposed numerical method allow us to conclude that the results are inconsistent with the data obtained in the known works by the analytical method for a particular case. At the same time, the numerical approach used significantly expands the possibilities of calculations by taking into account the location of multiple sources of radio interference at different altitudes, as well as the optimal orientation of the digital 3D - pattern of the antenna device of the signal receiver. The effectiveness of the proposed method is confirmed by increasing the area of the noise-tolerant radio exchange zone by 2.8 times in relation to the option of using a mobile radio with a dipole antenna. For the case of optimal orientation of the directional antenna of the receiver by the azimuth angle, additional optimization by the angle of the place gives a gain of 1.5 times.

2015 ◽  
Vol 713-715 ◽  
pp. 1405-1408
Author(s):  
Yi Huai Yang ◽  
Li Fang Wang ◽  
Ming Xiu Shen

Mobile radio channel models are essential for the development, evaluation and test of current mobile radio communication systems and also crucial for the realization of the future systems. Nakagami-m distribution is important for channel modeling in mobile communication. It can repeat system tests in the development, design, or test laboratory. In this study, we make a simulation study of the Nakagami-m distribution. We focus on study the PDF of Nakagami-m distribution under different values ofand, we also simulate the SER Vs.SNR over Nakagami-m fading channel for QPSK


Author(s):  
Е.А. Ищенко ◽  
Ю.Г. Пастернак ◽  
В.А. Пендюрин ◽  
С.М. Фёдоров

Для обеспечения радиосвязи применяются различные конструкции антенн, которые могут обладать всенаправленными или узконаправленными диаграммами направленности, при этом наибольшей защитой канала связи от помех и от перехвата обладают направленные антенны. Но их недостатком является то, что для обеспечения связи во всех направлениях требуется или установка группы антенн, или использование поворотных платформ, которые ухудшают показатели надежности системы, а также усложняют ее. Поэтому, как правило, для обеспечения связи применяют всенаправленные антенны, которые имеют диаграмму направленности в виде тороида. Недостаткaми таких антенн являются малый коэффициент направленного действия, а также прием большого числа шумов, что усложняет последующую обработку сигналов. Предлагается конструкция дипольной антенны, помещенной в активный метаматериал, с возможностью формирования луча путем коммутации слоев конструкции, что формирует динамически перестраиваемые рефлекторы. Получаемые в процессе функционирования системы диаграммы направленности обладают высокими значениями КНД, а также высокой помехозащищённостью и защитой от перехвата ввиду направленных свойств. Была получена конструкция антенны, помещенная в кубическую структуру активного метаматериала, с возможностью коммутации проводников с использованием pin-диодов или МЭМС-коммутаторов, что позволяет обеспечить быстрое переключение режимов работы устройства, формирование направленного луча и обеспечение помехозащищенной и защищенной от перехвата связи To ensure radio communication, various antenna designs are used, which can have omnidirectional or narrowly directional radiation patterns, while directional antennas have the greatest protection of the communication channel from interference and interception. However, their disadvantage is that to ensure communication in all directions, either the installation of a group of antennas or the use of turntables are required, which degrade the reliability of the system, as well as complicate it. Therefore, as a rule, to provide communication, omnidirectional antennas are used, which have a radiation pattern in the form of a toroid. The disadvantage of such antennas is, as a rule, a small directional coefficient, as well as the reception of a large number of noises, which complicates the subsequent signal processing. In this work, we propose a design of a dipole antenna placed in an active metamaterial with the possibility of forming a beam by switching the layers of the structure, which forms dynamically tunable reflectors. Directional patterns obtained in the course of system operation have high directivity values, as well as high noise immunity and protection against interception due to directional properties. As a result of the study, we obtained an antenna design, placed in a cubic structure of an active metamaterial with the possibility of switching conductors using pin diodes or MEMS switches, which allows for fast switching of device operating modes, formation of a directed beam and providing noise-immune and interception-proof communication


Author(s):  
Rinkle Chhabra ◽  
Anuradha Saini

Mobile Ad Hoc Networks (MANET) are autonomous, infrastructure less and self-configuring networks. MANETs has gained lots of popularity due to on the fly deployment i.e. small network setup time and ability to provide communication in obstreperous terrains. Major challenges in MANETs include routing, energy efficiency, network topology control, security etc. Primary focus in this article is to provide method and algorithm to ensure significant energy savings using re-configurable directional antennas. Significant energy gains can be clinched using directional antenna. Key challenges while using directional antenna are to find destination location, antenna focusing, signal power and distance calculations. Re-configurable directional antenna can ensure significant energy gains if used intelligently. This article provides a brief insight into improved energy savings using re-configurable directional antennas and an associated algorithm


Sensors ◽  
2021 ◽  
Vol 21 (12) ◽  
pp. 4112
Author(s):  
Fidel Alejandro Rodríguez-Corbo ◽  
Leyre Azpilicueta ◽  
Mikel Celaya-Echarri ◽  
Peio Lopez-Iturri ◽  
Ana V. Alejos ◽  
...  

The characterization of different vegetation/vehicle densities and their corresponding effects on large-scale channel parameters such as path loss can provide important information during the deployment of wireless communications systems under outdoor conditions. In this work, a deterministic analysis based on ray-launching (RL) simulation and empirical measurements for vehicle-to-infrastructure (V2I) communications for outdoor parking environments and smart parking solutions is presented. The study was carried out at a frequency of 28 GHz using directional antennas, with the transmitter raised above ground level under realistic use case conditions. Different radio channel impairments were weighed in, considering the progressive effect of first, the density of an incremental obstructed barrier of trees, and the effect of different parked vehicle densities within the parking lot. On the basis of these scenarios, large-scale parameters and temporal dispersion characteristics were obtained, and the effect of vegetation/vehicle density changes was assessed. The characterization of propagation impairments that different vegetation/vehicle densities can impose onto the wireless radio channel in the millimeter frequency range was performed. Finally, the results obtained in this research can aid communication deployment in outdoor parking conditions.


Author(s):  
О.А. ШОРИН ◽  
Р.Ю. КАСПАРИ

Рассмотрены характеристики и аудитория сетей профессиональной радиосвязи и критических коммуникаций. Проведен анализ используемых в России технологий профессиональной радиосвязи и перспектив развития данного сегмента телекоммуникационного рынка, произведена оценка его объемов в пятилетней перспективе. Показано, что внедряемая технология широкополосной профессиональной связи МАКВИЛ не только решает назревшие проблемы, связанные с модернизацией морально и физически устаревших систем ведомственной и корпоративной транкинговой связи, но и открывает новые возможности роста рынка услуг передачи критически важной информации. The characteristics and audience of professional mobile radio and critical communication networks are reviewed. The analysis of professional mobile radio technologies used in Russia and the prospects for the development of this segment of the telecommunications market is carried out, as well as its volume is estimated in the five-year perspective. It is shown that McWiLL broadband professional radio communication technology not only solves the urgent problems associated with the modernization of morally and physically obsolete systems of departmental and corporate trunking communications, but also opens up new opportunities for the growth of the market for critical information transmission services.


2013 ◽  
Vol 660 ◽  
pp. 184-189 ◽  
Author(s):  
Yan Zhai ◽  
Xing Wei ◽  
Lei Liu ◽  
Liao Yuan Wu

In order to tackle the data transmission bottlenecks of the gateway node in clustering Ad hoc Networks, the paper proposes a communication method. Firstly, DMAC (Distributed and Mobility-Adaptive Clustering) algorithm and Omni-directional antenna is well introduced and discussed. Then the ICMMDA (The Inter-cluster Communication Method based on Directional Antennas) policy building virtual channels between two hops away cluster-head and using directional antenna is brought about. Lastly, the simulation shows that the method can reduce the end-to-end delay between two clusters and improve the network throughput.


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