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Single-carrier frequency-domain equalization (SC-FDE) occupies a concise transmitting structure and a low peak-to-average power ratio (PAPR). These advantages are conducive to the miniaturization of the satellite systems and increase the robustness to the non-linear distortion of amplifiers. Nowadays, satellite communication systems set out to work at Ka or higher frequency bands to support the high...
Satellite to ground links are extremely vulnerable to any type of terrestrial interference due to the relatively weak satellite signal at the ground stations. This can cause connection failures or degradation in performance at the ground station, which could in some cases be significant or even catastrophic. The great flexibility of software defined radio (SDR) systems facilitates the implementation...
The usage of Fade Mitigation Techniques (FMT) is mandatory for satellite communications operating over 10GHz once the atmospheric propagation effects get severe with the increase of the frequency-band. Site Diversity (SD) and Orbital Diversity (OD) are two effective techniques to mitigate rain attenuation. Considering an operation at Q-band (40GHz) both these schemes are preliminary investigated:...
Satellites give exceptional points of interest, for example, remote scope with fast sending, separation lack of care, transmission capacity on interest, safety to physical debacles, and offering broadband connections. TCP has been produced for wired systems that have a lower delay and a low piece mistake rate. It is the most usually utilized transport layer convention as a part of the Internet and...
In this short paper, we propose a hybrid TCP PEP combined XOR coding with TCP Hybla on split PEP in satellite communication. To evaluate performance of the proposed protocol we set up a test bed of satellite communication network. As a result of performance evaluation of the proposed Hybrid TCP on split PEP, the file transmission speed improved more than 40% in high error rate environment. Therefore,...
As one possible continuation of development of Masat-1, the first Hungarian satellite, in 2015, a group of student, from Faculty of Electrical Engineering and Informatics and Mechanical Engineering, decided to realize a PocketQube-class satellite, called Smog-1. Smog-1 is a 5 cm cubesat as PocketQube with less than 180 g mass. The aim of Smog-1 is to measure the radio frequency (RF) smog caused by...
Since several years, satellite communications are playing a remarkable role in telecommunications infrastructures, thus the increasing interest in transporting internet traffic over satellite links. Many technologies such as the deployment of multicast and real-time audio/video streaming application are likely to increase the percentage in the context of TCP traffic in internet. The Transport Control...
For the application needs of CAPS (Chinese Area Positioning System) in a particular field, we design and implement the CAPS satellite data push communications system. The system mainly includes data transmission equipment in the satellite central station (document broadcast software, data packers, jammers, modulators, high power amplifier and antenna), Slightly Inclined Geo-Synchronous Orbit satellite,...
This paper analyzes a mobile satellite communication system with respect to the BER performance between a geostationary satellite and a moving node. Specifically, we study a scenario where the channel causes ionospheric scintillation-based multipath fading within the UHF frequency band. The scenario considers medium and high ionospheric scintillation indexes for Rural Area (RA) and Hilly Terrain (HT)...
This paper proposes an adaptive modulation scheme using rain fading predictions obtained via Kaiman filtering in order to mitigate the effects of rain on cognitive radio-based geostationary (GEO) satellites operating in the Ka-band. In the proposed scheme, the need for adaptation is identified prior to the rain attenuation event, allowing for enough time for the transmitter and receiver to reconfigure,...
As an important simulation platform for wireless communication, OPNET Modeler implements the wireless channel by 14 wireless channel pipeline stages for terrestrial mobile communication system, but does not support the proper realization of Long Term Evolution (LTE) based satellite communication system. In this paper, we analyze the differences between these two communication systems from the aspect...
This paper presents the design and simulation of a typical Ka band satellite beacon receiver for propagation experimentation. Using satellite beacon signal as a reference signal in satellite wave propagation study is one of the most important methos. Satellite beacons are frequently available for pointing large antennas, but such signals can be used for measuring the effect of natural phenomena such...
This paper describes the determination of ionospheric and tropospheric effects on satellite communications between Inmetro ground station and GPS constellation satellites This is made with the use of a geodesic receiver to collect data and with post processing softwares for PPP implementations. The satellite communication link is used for time and frequency maintenance of Local Time Scale UTC (INXE)...
This paper presents the system dimensioning of a Q-band downlink satellite beacon providing coverage over the Indian region. The paper addresses the tradeoff analysis associated in the design process to meet the conflicting requirements of optimization of payload mass/power, beacon availability and user terminal size. The design is optimized to facilitate the collection of propagation data over diverse...
In this article, we present the performance of an automated train transit system using radars and a Geo stationary satellite. The Radars placed along the railway tracks update the accurate speed and position of the train to the central base station which controls the trains over a wide geographic region. The central base station directs the train by communicating via a Geo stationary satellite. The...
Satellite systems may integrate Standardized Digital Professional Mobile Radio systems into an existing infrastructure over long distances without the need of dedicated transport networks, even in disaster relief situations. Simulation-based decision support can predict possible interferences like shadowing or multipath effects, but especially in time-critical emergency scenarios, a trade-off between...
A communication satellite consists of subsystems which are functioning together to form a whole system. All subsystems consist of thousands of components and there is no possibility of repair once the satellite launched into orbit. Therefore, the necessity of high reliability becomes a rule rather than an exception. TUSAT (Turkish National Communication Satellite) is planned to have both C and Ku...
In the last years EHF (Extremely High Frequency / 30-300 GHz) band is acquiring more and more interest in different fields, such as telecommunications, radar applications and Earth observation, due to advantageous characteristics. Actually, the higher operating frequency with respect to traditional ranges (Ka and lower) allows the achievement of some advantages: no crowding in frequency and hence...
In this paper we investigate the effectiveness of iterative (turbo) synchronization at improving the link reliability of digital video broadcasting return channel via satellite (DVB-RCS) for different modulation schemes in the presence of strong phase noise. We also propose a multi-user scheme that enables two remote terminals, each using QPSK, to simultaneously use the same frequency band. All additional...
Researches on multicast has explored security challenges faced by group communications. Multicast transport protocols and multicast security protocols need to work closely to provide reliable and secure multicast services. However, there has been comparatively little work carried out to specify how exactly the two technologies can work together efficiently. In this paper, authors present an example...
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