scholarly journals Estimation of the synchronization error for spaced-apart ground points of satellite communication

2021 ◽  
Vol 5 (2) ◽  
pp. 102-109
Author(s):  
R. B. Kovalev ◽  
V. V. Kornienko ◽  
V. N. Ratushnak
Keyword(s):  
Satellite Communication ◽  
Time Synchronization ◽  
Reference Signal ◽  
Signal Propagation ◽  
Satellite Communications ◽  
Propagation Time ◽  
Engineering System ◽  
Mutual Synchronization ◽  
Ongoing Research ◽  
Mutual Correlation

A significant number of patents and publications in the open press show the intensity of the ongoing research to create new methods of synchronization and specialized ground-based equipment for frequency-time synchronization. The article considers the implementation of an autonomous synchronization system between ground-based satellite communication points, which is used in conditions of unfavorable reception or absence of signals from global navigation satellite systems. The paper presents studies on the assessment of the error of time synchronization of geographically separated ground points of satellite communications. The basics of constructing the receiving equipment of a radio engineering system are considered and the mutual correlation of the reference signal of the receiving equipment and the received input synchronization signal is calculated. The results of field tests of mutual synchronization equipment are presented, where the potential synchronization accuracy of equipment at ground objects with previously unknown coordinates was determined, while the synchronization equipment provided measurement of the signal propagation time from one ground object to another with the formation of universal time scales on points. The method of mutual synchronization of linked points is carried out by the duplex method at a frequency of 1065 MHz (request) and 625 MHz (response) by phase-code-manipulated signals with a base equal to 1023 and a duration of 0,1 ms.

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.

DEVELOPMENT OF A SPACE TECHNOLOGY CAPACITY BUILDING INITIATIVE AT THE FEDERAL UNIVERSITY OF TECHNOLOGY, AKURE, NIGERIA

2021 ◽  
Vol 15 (1) ◽  
pp. 38-52
Author(s):  
Folasade Dahunsi ◽  
Oluwasina Aderinwale ◽  
Abayomi Adesida ◽  
Abiola Alayande ◽  
J. Ojo ◽  
...  
Keyword(s):  
Capacity Building ◽  
Satellite Communication ◽  
Spatial Information ◽  
Low Cost ◽  
Data Communication ◽  
Positive Development ◽  
Space Technology ◽  
Ongoing Research ◽  
Ground Station ◽  
Means Of Transmission

Satellite communication is a wireless means of transmission of intelligible signals/information. When properly utilized it will bring about a great and positive development on the economic growth of any nation. The Federal Government of Nigeria made a giant step in the communication sector by launching five satellites into space: NigeriaSat-1, NigComSat- 1, NigeriaSat-2r, NigeriaSat-X and NigComSat-1R. With adequate spatial information, informed decisions can be made by stakeholders and adequate steps taken to ensure the growth of the nation. Demand for training capacity building in space technology is increasing. Unfortunately, space technology is a relatively expensive field with ongoing research for affordable training approaches. This paper presents methods of building capacity by developing Demo Satellites that receive telemetry data with radiofrequency and internet of things communication protocol. Web Dashboard was developed for remote monitoring of ground station and for exploring mobility in data communication, Localization was achieved to also track the Demo Satellites and the ground station in real-time. It is shown that the implementation of a low-cost capacity building programme is not only possible but a goal that should be aimed at. Multiple segments in the design of the schematics produced can be reused. It presents a pioneer satellite constellation prototype that displays the capabilities of a satellite in solving some of the country’s challenges and creating awareness on space research and its trends.

scholarly journals Optimal approach for building scheduling algorithm in satellite communication

2018 ◽  
Vol 7 (2.28) ◽  
pp. 181
Author(s):  
Ali M. Al-Saegh
Keyword(s):  
Quality Of Service ◽  
Communication Networks ◽  
Satellite Communication ◽  
Scheduling Algorithm ◽  
Satellite Communications ◽  
Satellite Networks ◽  
Communication Links ◽  
Optimal Approach ◽  
Proper Solutions

Building scheduling algorithms in satellite communication links became a necessity according to the typical problems that satellite networks suffers from, such as congestions, jamming, mobility, atmospheric impairment, and achieving the quality of service (QoS) requirements. However, building efficient algorithms needs several considerations that should be taken into account. Such as satellite and earth station node(s), link parameters and specifications, along with the service requirements and limitations. This paper presents efficient approach for accumulating the effective considerations that the designer should employ as a framework for building proper and efficient scheduling algorithm. The proposed approach provides proper solutions to the satellite communications impairments and satisfies the quality of service requirements in satellite communication networks.  

scholarly journals Analysis of Time Diversity Gain for Satellite Communication Link based on Ku-Band Rain Attenuation Data Measured in Malaysia

2018 ◽  
Vol 8 (4) ◽  
pp. 2608
Author(s):  
Islam Md. Rafiqul ◽  
Ali Kadhim Lwas ◽  
Mohamed Hadi Habaebi ◽  
Md Moktarul Alam ◽  
Jalel Chebil ◽  
...  
Keyword(s):  
Satellite Communication ◽  
Satellite Communications ◽  
Earth Satellite ◽  
Rain Attenuation ◽  
Diversity Gain ◽  
Communication Link ◽  
Time Diversity ◽  
Communication Links ◽  
System Time ◽  
Diversity Technique

<p><span>This paper reports a study on mitigation of propagation impairments on Earth–space communication links. The study uses time diversity as a technique for mitigating rain propagation impairment in order to rectify rain fade. Rain attenuation time series along earth-to-satellite link were measured for two years period at 12.255 GHz in Malaysia. The time diversity technique was applied on measured rain fade to investigate the level of possible improvement in system. Time diversity gain from measured one-minute rain attenuation for two years period was estimated and significant improvement was observed with different delays of time. These findings will be utilized as a useful tool for link designers to apply time diversity as a rain fade mitigation technique in Earth-satellite communications systems.</span></p>

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.

scholarly journals Ultra Wide Band Antenna with Defected Ground Plane and Microstrip Line Fed for Wi-Fi/Wi-Max/DCS/5G/Satellite Communications

2020 ◽  
Author(s):  
Ashish Singh ◽  
Krishnananda Shet ◽  
Durga Prasad
Keyword(s):  
Radiation Pattern ◽  
Satellite Communication ◽  
Ground Plane ◽  
Wide Band ◽  
Satellite Communications ◽  
Ultra Wide Band ◽  
Wireless Applications ◽  
Directional Radiation ◽  
Ring Antenna ◽  
Theoretical Results

In this chapter, ultra wide band angular ring antenna has been proposed for wireless applications. It has been observed that antenna resonate from 2.9 to 13.1 GHz which has 10.2 GHz bandwidth. Further, it is observed that antenna has nearly omni-directional radiation pattern for E and H-plane at 3.5, 5.8, and 8.5 GHz. The theoretical analysis of the proposed has been done using circuit theory analysis. It was also found using simulation that antenna has good input and output response of 0.2 ns. Proposed antenna measured, simulated, and theoretical results matches for antenna characteristics, i.e., reflection coefficient and radiation pattern. Bandwidth of antenna lies between 2.9 and 13.1 GHz, so this antenna is suitable for Wi-Fi, Wi-Max, digital communication system (DCS), satellite communication, and 5G applications.

scholarly journals Wideband power amplifier based on Wilkinson power divider for s-band satellite communications

2019 ◽  
Vol 8 (4) ◽  
pp. 1531-1536
Author(s):  
Mussa Mabrok ◽  
Zahriladha Zakaria ◽  
Tole Sutikno ◽  
Ammar Alhegazi
Keyword(s):  
Power Amplifier ◽  
Return Loss ◽  
Satellite Communication ◽  
Satellite Communications ◽  
Wireless Networking ◽  
Power Divider ◽  
Design System ◽  
Class A ◽  
Wilkinson Power Divider ◽  
Radar Satellite

This paper presents design and simulation of wideband power amplifier based on multi-section Wilkinson power divider. Class-A topology and ATF-511P8 transistor have been used. Advanced Design System (ADS) software used to simulate the designed power amplifier. The simulation results show an input return loss (S11)-10dB, gain (S21)10 dB over the entire bandwidth, and an output power around 28dBm at the Centre frequency of 3GHz. The designed amplifier is stable over the entire bandwidth (K1). Inter-modulation distortion is -65.187dBc which is less than -50dBc. The designed amplifier can be used for the microwave applications which include weather radar, satellite communication, wireless networking, mobile, and TV.

scholarly journals Satellite Communications. SDPSK Modulator for Radiation Tolerant Satellite Modem / SDPSK Modulators Radiācijas Noturīgam Satelīta Modēmam

2013 ◽  
Vol 50 (1) ◽  
pp. 76-83
Author(s):  
A. Skorodumovs
Keyword(s):  
Pulse Shaping ◽  
Satellite Communication ◽  
Satellite Communications ◽  
Data Rate ◽  
Modulation Scheme ◽  
Differential Phase Shift ◽  
Shaping Filter ◽  
Change Communication ◽  
Power Radiation ◽  
Radiation Tolerant

After a satellite has been launched, it is impossible to reprogram the hardware modulator. Therefore, a nanoRTU FPGA-based controller (AAC Microtec) in a modified modulation scheme may be programmed as a modem backend for softwaredefined radio (SDR) in the satellite communication system in order to adjust the balance of data rate vs. link reliability, enable coding or encryption system, change communication protocols, etc. For this purpose, a low-power radiation-tolerant reprogrammable satellite modem back-end has been realized for the satellite-to-Earth communication. This paper describes realization of a low data rate modulator based on a robust and reliable symmetric differential phase shift keying (SDPSK) modulation scheme combined with a raised cosine pulse shaping filter in nanoRTU, and presents results of its testing

scholarly journals Model of forming a spatial-temporary radio frequency portrait of subscriber terminals in satellite communication systems monitoring

2020 ◽  
Vol 100 (4) ◽  
pp. 78-86
Author(s):  
M. Baldychev ◽  
◽  
A. Bosyy ◽  
O. Galtseva ◽  
Keyword(s):  
Radio Frequency ◽  
Software Defined Radio ◽  
Communication Systems ◽  
Satellite Communication ◽  
A Priori ◽  
Complex Structure ◽  
Satellite Communications ◽  
Physical Parameters ◽  
Time Frequency ◽  
Spatio Temporal

Currently, the development of satellite communications systems (SCS) is associated with the development of signals of complex structure. The popularization and distribution of software-defined radio systems (Software-defined radio, SDR) are noted, which leads to a decrease of quality of functioning of the SCS. Promising areas of countering the unauthorized use of the time-frequency resource of the KA repeater are methods aimed at determining the location of subscriber terminals (ST) and analyzing the service and semantic parts of the transmitted message. Accounting for changes of physical parameters requires the use of a large amount of heterogeneous a priori data; it is not achievable task in practice. According to the theory of mathematical statistics, the approximation is used at solving problems of sample analysis. The result of the approximation is a spatio-temporal radio-frequency portrait (STRFP) of an ST participating in the formation of a group signal. Thus, the aim of the research is to develop a model of changing the physical parameters of a radio signal and to study the possibility of approximating physical parameters in order to form a spatio-temporal radiofrequency portrait of an ST SCS.

THE MAIN DIRECTIONS OF THE CONCEPT OF COMMUNICATIONS IN A LOW-ORBIT RELAY SATELLITES COMMUNICATION SYSTEM

2021 ◽  
Author(s):  
И.Н. ПАНТЕЛЕЙМОНОВ ◽  
А.А. МОНАСТЫРЕНКО ◽  
А.В. БЕЛОЗЕРЦЕВ ◽  
В.В. БОЦВА ◽  
Л.В. ЩЕРБАТЫХ ◽  
...  
Keyword(s):  
Communication System ◽  
Information Exchange ◽  
Satellite Communication ◽  
Satellite Communications ◽  
Broadband Access ◽  
Transmission Networks ◽  
Mobile Satellite ◽  
Access To Data ◽  
Subscriber Terminal ◽  
Mobile Satellite Communication

Рассмотрены проблемы организации связи в системе персональной подвижной спутниковой связи (СППСС) на низкоорбитальных спутниках-ретрансляторах для обеспечения широкополосного доступа к сетям передачи данных с применением небольшого персонального абонентского терминала (АТ). Дан краткий анализ существующих СППСС, определены требования к системе связи,представлены основные направления организации информационного обмена,предложенорешение создания АТ. The paper is devoted to the problems of communication organization in the low-orbit personal mobile satellite communication system for providing broadband access to data transmission networks using a small personal subscriber terminal. A brief analysis of the existing systems of personal mobile satellite communications is given, the requirements for the communication system are defined, the main directions of information exchange organization are considered, and a solution for creating a subscriber terminal is proposed.

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