scholarly journals Spectrum prediction and interference detection for satellite communications [International Communications Satellite Systems Conference]

2019 ◽  
Author(s):  
L. Pellaco ◽  
N. Singh ◽  
J. Jalden
Keyword(s):  
Satellite Communications ◽  
Interference Detection ◽  
Spectrum Prediction ◽  
Satellite Systems

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.

scholarly journals FAIR AND STANDARD ACCESS TO SPATIAL DATA AS THE MEANS FOR ACHIEVING SUSTAINABLE DEVELOPMENT GOALS

2019 ◽  
Vol XLII-4/W20 ◽  
pp. 33-39
Author(s):  
I. Ivánová ◽  
N. Brown ◽  
R. Fraser ◽  
N. Tengku ◽  
E. Rubinov
Keyword(s):  
Spatial Data ◽  
Best Practice ◽  
Satellite Communications ◽  
Scientific Data ◽  
Geospatial Data ◽  
Global Navigation Satellite Systems ◽  
Precise Positioning ◽  
Satellite Systems ◽  
Fair Principles ◽  
Time Accuracy

Abstract. FAIR, which stands for Findable, Accessible, Interoperable and Reusable, are the main principles adopted for sharing scientific data across communities. Implementing FAIR principles in publishing increases the value of digital resources, and the reuse of these by humans as well as machines. Introducing FAIR practices to the geospatial domain is especially relevant for the foundation geospatial data, such as precise positioning data. Within the next five years, Global Navigation Satellite Systems (GNSS), with corrections from internet or satellite communications, will permit national coverage of positioning services with real-time accuracy of several centimetres or better. However, implementing FAIR principles is not yet common practice in the geospatial domain. There are dozens of standards available for defining and sharing geospatial data. These include the ISO 19100 series of standards, OGC specifications and several community profiles and best practice. However, in most cases these standards fall short in ensuring the FAIR distribution of geospatial resources. As our preliminary findings show, current geodetic metadata and data are not yet fully FAIR and data discovery and access is still very challenging. In this paper we discuss the concept of FAIR and its meaning for geodetic data, explore the needs of precise positioning users and their requirement for metadata and present preliminary results on the FAIRness of current geodetic standards.

scholarly journals First Evidences of Ionospheric Plasma Depletions Observations Using GNSS-R Data from CYGNSS

2020 ◽  
Vol 12 (22) ◽  
pp. 3782
Author(s):  
Carlos Molina ◽  
Adriano Camps
Keyword(s):  
Electromagnetic Waves ◽  
Satellite Communications ◽  
Study Data ◽  
Global Navigation Satellite Systems ◽  
Ionospheric Scintillation ◽  
Electron Content ◽  
Signal Delay ◽  
Total Electron ◽  
Satellite Systems ◽  
Plasma Depletions

At some frequencies, Earth’s ionosphere may significantly impact satellite communications, Global Navigation Satellite Systems (GNSS) positioning, and Earth Observation measurements. Due to the temporal and spatial variations in the Total Electron Content (TEC) and the ionosphere dynamics (i.e., fluctuations in the electron content density), electromagnetic waves suffer from signal delay, polarization change (i.e., Faraday rotation), direction of arrival, and fluctuations in signal intensity and phase (i.e., scintillation). Although there are previous studies proposing GNSS Reflectometry (GNSS-R) to study the ionospheric scintillation using, for example TechDemoSat-1, the amount of data is limited. In this study, data from NASA CYGNSS constellation have been used to explore a new source of data for ionospheric activity, and in particular, for travelling equatorial plasma depletions (EPBs). Using data from GNSS ground stations, previous studies detected and characterized their presence at equatorial latitudes. This work presents, for the first time to authors’ knowledge, the evidence of ionospheric bubbles detection in ocean regions using GNSS-R data, where there are no ground stations available. The results of the study show that bubbles can be detected and, in addition to measure their dimensions and duration, the increased intensity scintillation (S4) occurring in the bubbles can be estimated. The bubbles detected here reached S4 values of around 0.3–0.4 lasting for some seconds to few minutes. Furthermore, a comparison with data from ESA Swarm mission is presented, showing certain correlation in regions where there is S4 peaks detected by CYGNSS and fluctuations in the plasma density as measured by Swarm.

Propagation Delay Difference Estimation for Initial Random Access in LTE Compatible Mobile Satellite Communications System

2013 ◽  
Vol 846-847 ◽  
pp. 647-650
Author(s):  
Cheng Mei Li ◽  
Jian Jun Wu ◽  
Xiao Ning Zhang ◽  
Xi Luan ◽  
Hai Ge Xing
Keyword(s):  
Estimation Method ◽  
Random Access ◽  
Satellite Communications ◽  
Propagation Delay ◽  
Satellite System ◽  
Satellite Systems ◽  
Access Channel ◽  
Geo Satellite ◽  
Mobile Satellite ◽  
Delay Difference

In this paper, a two-step propagation delay difference estimation method is proposed for LTE compatible multi-beam satellite systems to ensure the initial random access (RA). For GEO satellite system, there exists a large propagation delay difference, we cannot directly apply the LTE delay estimation method. To deal with this issue, we first divide a satellite beam into some layered small sub-areas according to the different delay difference values. Then, two types of Physical Random Access Channel (PRACH) preamble burst format are given. The detailed PRACH parameters are provided. Finally, simulations are performed and the results verify the availability of our proposed design.

scholarly journals Interference-Aware Radio Resource Management for Cognitive High-Throughput Satellite Systems

Sensors ◽  
2019 ◽  
Vol 20 (1) ◽  
pp. 197 ◽  
Author(s):  
Rui Zhang ◽  
Yuhan Ruan ◽  
Yongzhao Li ◽  
Can Liu
Keyword(s):  
Resource Management ◽  
High Throughput ◽  
Radio Resource Management ◽  
Satellite Communications ◽  
Substantial Improvement ◽  
System Throughput ◽  
Future Research ◽  
Radio Resource ◽  
Satellite Systems ◽  
Full Frequency Reuse

By providing interactive broadband services to geographical areas underserved by terrestrial infrastructure, multi-beam satellite systems play a central role in future wireless communications. Targeting the terabit throughput requirements in satellite communications, we introduce a cognitive radio-based high-throughput satellite (HTS) system architecture where full frequency reuse is employed among beams. Moreover, by analyzing the characteristics of the considered architecture, we discuss the design challenges of radio resource management in cognitive HTS systems exposed to both intra-system and inter-system co-channel interference. Furthermore, to combat interference with low overhead, we propose a generic interference-aware resource management framework based on joint spatial division and multiplexing (JSDM). Under this framework, user grouping along with two-stage precoding is studied to achieve substantial improvement in the overall system throughput. Finally, some future research directions and challenges are also given.

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