scholarly journals Introduction to random division multiple access (RDMA) applicable for mobile satellite communications

2019 ◽  
Vol 8 (4) ◽  
pp. 577
Author(s):  
Dimov Stojce Ilcev
Keyword(s):  
Communication Systems ◽  
Multiple Access ◽  
Satellite Communication ◽  
Satellite Communications ◽  
Mobile Satellite ◽  
Orthogonal Channels ◽  
Random Division

This paper describes in particular Random Division Multiple Access (RDMA) applicable in Mobile Satellite Communications (MSC). In satellite communication systems, as a rule, especially in Mobile Satellite Communications (MSC) many users are active at the same time. The problem of simultaneous communications between many single or multipoint mobile satellite users, however, can be solved by using Multiple Access (MA) technique. Since the resources of the systems such as the transmitting power and the bandwidth are limited, it is advisable to use the channels with complete charge and to create a different MA to the channel. This generates a problem of summation and separation of signals in the transmission and reception parts, respectively. Deciding this problem consists in the development of orthogonal channels of transmission in order to divide signals from various users unambiguously on the reception part.   

scholarly journals Dynamic Radio Links Selection for Mobile Satellite Communication Systems

2019 ◽  
Vol 5 (4) ◽  
pp. 28-36 ◽  
Author(s):  
S. Dvornikov ◽  
S. Yakushenko ◽  
D. Lyanguzov
Keyword(s):  
Communication Systems ◽  
Satellite Communication ◽  
Satellite Communications ◽  
Radio Lines ◽  
Practical Application ◽  
Dynamic Identification ◽  
Communications Systems ◽  
Selection For ◽  
Mobile Satellite ◽  
Mobile Satellite Communication

In this paper presents suggestions for the noise immunity improval of mobile satellite communications lines in difficult physical and geographical conditions through the use of automatic dynamic identification algorithms for the suitability of radio lines and the dynamic antenna orientation devices of mobile satellite communications systems. Based on the results obtained, recommendations for practical application are formulated.

INNOVATIVE METHOD OF SATELLITE COMMUNICATION

2019 ◽  
Author(s):  
Teodor Narytnik ◽  
Vladimir Saiko
Keyword(s):  
Communication Systems ◽  
High Speed ◽  
Satellite Communication ◽  
Radio Channel ◽  
Satellite Communications ◽  
Service Area ◽  
Satellite Systems ◽  
Orbit Satellite ◽  
Geometric Size ◽  
Distributed Satellite

The technical aspects of the main promising projects in the segments of medium and low-orbit satellite communication systems are considered, as well as the project of the domestic low-orbit information and telecommunications system using the terahertz range, which is based on the use of satellite platforms of the micro- and nanosatellite class and the distribution of functional blocks of complex satellite payloads more high-end on multiple functionally related satellites. The proposed system of low-orbit satellite communications represents the groupings of low-orbit spacecraft (LEO-system) with the architecture of a "distributed satellite", which include the groupings of the root (leading) satellites and satellite repeaters (slaves). Root satellites are interconnected in a ring network by high-speed links between the satellites. The geometric size of the “distributed satellite” is the area around the root satellite with a radius of about 1 km. The combination of beams, which are formed by the repeater satellites, make up the service area of the LEO system. The requirements for the integrated service area of the LEO system (geographical service area) determine the requirements for the number of distributed satellites in the system as a whole. In the proposed system to reduce mutual interference between the grouping of the root (leading) satellites and repeater satellites (slaves) and, accordingly, minimizing distortions of the information signal when implementing inter-satellite communication, this line (radio channel) was created in an unlicensed frequency (e.g., in the terahertz 140 GHz) range. In addition, it additionally allows you to minimize the size of the antennas of such a broadband channel and simplify the operation of these satellite systems.

MATHEMATICAL MODEL OF THE RADIATING APERTURE OF HEADLIGHTS CONSISTING OF SEGMENT-PARABOLIC ANTENNAS

2021 ◽  
pp. 69-78
Author(s):  
Ю.Г. Пастернак ◽  
В.А. Пендюрин ◽  
К.С. Сафонов
Keyword(s):  
Mathematical Model ◽  
Antenna Arrays ◽  
Communication Systems ◽  
High Speed ◽  
Satellite Communication ◽  
The Arctic ◽  
Northern Latitudes ◽  
Electronic Model ◽  
Mobile Satellite ◽  
High Orbit

Решение задачи связи в Арктике, а также в тундре, в тайге, в лесу, в море, на полях возможно только с использованием мобильных систем спутниковой связи. ФГУП «Космическая связь» (г. Москва) располагает группировкой спутников, которая постоянно расширяется. Для надежной связи в Арктике и в северных широтах, помимо геостационарных спутников, запущены спутники, движущиеся по высокоорбитальным траекториям. Для переключения со спутника на спутник, входящий в зону видимости абонента, необходимо использовать антенные решетки. Проблема заключается в том, что в настоящее время отсутствуют мобильные терминалы высокоскоростной спутниковой связи, а стоимость зарубежных аналогов препятствует широкому их использованию (достигает 50 тысяч долларов). Обычно радиолокационная связь (РЛС) с фазированной антенной решеткой используется для наблюдения за тысячами угловых точек, для отслеживания сотни целей. Такие требования могут быть выполнены только путем сканирования луча в пространстве в течение микросекунды. Ясно, что необходимо электронное управление лучом, поскольку механически вращать антенну не представляется возможным. Лишь некоторая часть вышеуказанных проблем будет затрагиваться в этой статье, ниже будут представлены электронная модель антенной решетки и её математическая модель The solution of the communication problem in the Arctic, as well as in the tundra, in the taiga, in the forest, in the sea, in the fields is possible only with the use of mobile satellite communication systems. FSUE "Space Communications" (Moscow) has a constantly expanding group of satellites. For reliable communication in the Arctic and Northern latitudes, in addition to geostationary satellites, satellites moving along high-orbit trajectories were launched. To switch from one satellite to the other included in the subscriber's visibility area, it is necessary to use antenna arrays. The problem is that currently there are no mobile terminals for high-speed satellite communication, and the cost of foreign analogues prevents their widespread use (up to 50 thousand dollars). Typically, a phased array radar is used to track thousands of corner points to track hundreds of targets. Such requirements can only be met by scanning the beam in space for a microsecond. It is clear, that electronic beam control is necessary since it is not possible to mechanically rotate the antenna. Only some of the above problems will be touched upon in this article. An electronic model of the antenna array and its mathematical model is presented

ON-BOARD DIGITAL SWITCHING OPTIONS FOR CIVIL COMMUNICATION SATELLITES

2020 ◽  
Author(s):  
О.В. МЕНТУС ◽  
А.А. АКОПОВ
Keyword(s):  
Communication Systems ◽  
Satellite Communication ◽  
Satellite Communications ◽  
Provision Of Services ◽  
Digital Switching ◽  
Switching Options

Рассматриваются варианты построения полезных нагрузок с цифровой коммутацией для спутниковой связи на примере перспективного космического аппарата «Экспресс-АМУ4». Показано, что использование цифровой коммутации в отечественных спутниках связи позволяет обеспечить гибкость оказания услуг и более успешно конкурировать с зарубежными спутниковыми системами связи. This article considers variants of digital switching payloads for satellite communications on the example of a promising spacecraft Express-AMU4. It is shown that the use of digital switching in domestic communication satellites allows providing flexibility in the provision of services and more successfully competing with foreign satellite communication systems.

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