Space Ground Segment: receiving, transmitting, controlling and data processing
Roghayeh Doost; Saber Shahidzadeh; Roghieh Karimzadeh Baee; Pedram Hajipour
Volume 16, Issue 3 , September 2023, , Pages 1-14
Abstract
Aeronautical-ESIM (A-ESIM) provides a satellite broadband service for aircraft occupants. Due to the frequency sharing of Aeronautical-ESIM (A-ESIM) satellite broadband service with previous ones, there is a possibility of its frequency interference on them. According to the resolution WRC 2019, the ...
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Aeronautical-ESIM (A-ESIM) provides a satellite broadband service for aircraft occupants. Due to the frequency sharing of Aeronautical-ESIM (A-ESIM) satellite broadband service with previous ones, there is a possibility of its frequency interference on them. According to the resolution WRC 2019, the A-ESIM frequency interference on co-frequency ground stations must be prevented by observing the Power Flux Density (PFD) mask . However, the approval of the PFD condition fulfillment method has been postponed to the World Radio Communication Conference 2023. In this regard, some countries have simulated and determined the minimum allowable height of A-ESIM from the ground, so that the PFD reached the ground does not exceed the specified mask. In many cases, only limited positions of unauthorized heights will cause the PFD to override the mask. Therefore, in this paper, with a new solution, the authorized and unauthorized positions of A-ESIM are determined at any height less than the minimum allowable height, relative to a fixed ground station. In addition, the unauthorized positions of the A-ESIM in both take-off and landing positions are simulated and determined depending on the slope of the A-ESIM
Space New Technologies
Pedram Hajipour; Roghieh Karimzadeh Baee; Houman Zarrabi; Roghayeh Doost; Leila Mohammadi
Volume 16, Issue 2 , June 2023, , Pages 27-42
Abstract
According to the technical specifications of the future generations of telecommunication (the fifth generation and later), which should provide new services with very high data rates in the minimum time and a wide coverage, as well as the exponential increase in traffic, the use of combined space-air ...
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According to the technical specifications of the future generations of telecommunication (the fifth generation and later), which should provide new services with very high data rates in the minimum time and a wide coverage, as well as the exponential increase in traffic, the use of combined space-air networks Land is essential. It should be noted that the management of this type of combined networks has major challenges in providing such services. Meanwhile, the intelligent management of resources in satellite-based hybrid networks will lead to increased capacity and improved service quality. For this purpose, in this article, a comprehensive review of the use of artificial intelligence in the field of satellite communications will be discussed. In the field of intelligent increase of capacity, various factors such as how to configure the network, how to allocate resources such as spectrum, energy and power will be investigated with consideration of intelligent interference management. Finally, in the field of service quality improvement, factors such as how to model and intelligently predict traffic, as well as how to deal with harmful environmental conditions, will be presented.
investigating space radiation
Roghieh Karimzadeh Baee; Hamideh Daneshvar; Amir Hossin Ahmadi; Parvin Sojoodi
Volume 16, Issue 1 , March 2023, , Pages 59-74
Abstract
With the advent of GaN technology, achieving microwave power with high efficiency by solid-state devices has become more available. Therefore, the use of SSPA amplifiers with GaN technology in satellites, especially LEO satellites, has been considered. space radiation can affect the performance and reliability ...
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With the advent of GaN technology, achieving microwave power with high efficiency by solid-state devices has become more available. Therefore, the use of SSPA amplifiers with GaN technology in satellites, especially LEO satellites, has been considered. space radiation can affect the performance and reliability of components in space systems, which needs to be investigated. One of the most important technologies that can be affected by radiation effects is GaN transistors. In this paper, the effect of TID on GaN transistors in the SSPA amplifier board is investigated. Since commercial components have been used in the engineering sample of the SSPA amplifier and the calculations obtained from the RDM estimates under the worst conditions show that it is necessary to conduct a test for these components, the radiation resistance test was performed for this amplifier. The results of the test conducted in this article show that the SSPA GaN board has radiation tolerance up to a dose of approximately 16 krad. Therefore, mismatched GaN transistors are resistant up to this amount of dose. This is while the sequencer board actually has less tolerance than 5.5 krad
