Orthogonal Coded Modulation in Alerting Channel for GEO Mobile Satellite System

2010 ◽  
Author(s):  
Qian Gao ◽  
Guang-xia Li ◽  
Jing Lv
Keyword(s):  
Satellite System ◽  
Coded Modulation ◽  
Mobile Satellite

Access Control Algorithm with Limited Power Constraint for Mobile Satellite Communications

2014 ◽  
Vol 548-549 ◽  
pp. 1286-1289
Author(s):  
Ya Zhe Gao ◽  
Xiao Han Xia ◽  
Zi Ming Su ◽  
Xi Luan ◽  
Jian Jun Wu
Keyword(s):  
Admission Control ◽  
Control Algorithm ◽  
Load Capacity ◽  
Satellite Communications ◽  
Satellite System ◽  
Power Constraint ◽  
Priority Service ◽  
Limited Power ◽  
Mobile Satellite ◽  
Service Priority

The problem of admission control caused by the limitation of resource in hotspot beams in satellite system is considered in this paper. Based on the idea of borrowing resources from surrounding beams, we give a scheme that the beam reserve resources is borrowed proportionally. After that, the original admission control algorithm based on service priority is modified in order to protect access rate of the low priority service. Simulation results prove that the proved scheme can increases the available beam load capacity effectively and provide a guarantee for the access of those services with low priority.

scholarly journals A Method for Determination and Compensation of a Cant Influence in a Track Centerline Identification Using GNSS Methods and Inertial Measurement

2019 ◽  
Vol 9 (20) ◽  
pp. 4347 ◽  
Author(s):  
Wladyslaw Koc ◽  
Cezary Specht ◽  
Jacek Szmaglinski ◽  
Piotr Chrostowski
Keyword(s):  
Local Coordinate System ◽  
Target Position ◽  
Satellite System ◽  
Railway Track ◽  
Inertial Measurement ◽  
Track Geometry ◽  
Method Of Calculation ◽  
Mobile Satellite ◽  
Global Navigation Satellite ◽  
Geometric Layout

At present, the problem of rail routes reconstruction in a global reference system is increasingly important. This issue is called Absolute Track Geometry, and its essence is the determination of the axis of railway tracks in the form of Cartesian coordinates of a global or local coordinate system. To obtain such a representation of the track centerline, the measurement methods are developed in many countries mostly by the using global navigation satellite system (GNSS) techniques. The accuracy of this type of measurement in favorable conditions reaches one centimeter. However, some specific conditions cause the additional supporting measurements with a use of such instruments as tachymetry, odometers, or accelerometers to be needed. One of the common issues of track axis reconstruction is transforming the measured GNSS antenna coordinates to the target position, i.e., to the place between rails on the level of rail heads. The authors in their previous works described the developed methodology, while this article presents a method of determining the correction of horizontal coordinates for measurements in arc sections of the railway track. The presence of a cant causes the antenna’s center to move away from the track axis, and for this reason, the results must be corrected. This article presents a method of calculation of mentioned corrections for positions obtained from mobile satellite surveying with additional inertial measurement. The algorithm presented in the article and its implementation have been illustrated on an example of a complex geometric layout, where cant transitions exist without transition curves in horizontal plane. Such a layout is not preferable due to the additional accelerations and their changes. However, it allows the verification of the presented methods.

S-band terminals for INSAT mobile satellite system

1998 ◽  
Author(s):  
R. Gupta ◽  
A. Dissanayake ◽  
E. Kohls ◽  
R. Allnutt ◽  
G. Corbin ◽  
...  
Keyword(s):  
Satellite System ◽  
Mobile Satellite

scholarly journals Application of Least Squares with Conditional Equations Method for Railway Track Inventory Using GNSS Observations

Sensors ◽  
2020 ◽  
Vol 20 (17) ◽  
pp. 4948
Author(s):  
Krzysztof Czaplewski ◽  
Zbigniew Wisniewski ◽  
Cezary Specht ◽  
Andrzej Wilk ◽  
Wladyslaw Koc ◽  
...  
Keyword(s):  
Measurement Data ◽  
Satellite System ◽  
Theoretical Description ◽  
Railway Track ◽  
Land Surveying ◽  
Gnss Receivers ◽  
Mobile Satellite ◽  
Global Navigation Satellite ◽  
Gnss Observations ◽  
Observation Results

Satellite geodetic networks are commonly used in surveying tasks, but they can also be used in mobile surveys. Mobile satellite surveys can be used for trackage inventory, diagnostics and design. The combination of modern technological solutions with the adaptation of research methods known in other fields of science offers an opportunity to acquire highly accurate solutions for railway track inventory. This article presents the effects of work carried out using a mobile surveying platform on which Global Navigation Satellite System (GNSS) receivers were mounted. The satellite observations (surveys) obtained were aligned using one of the methods known from classical land surveying. The records obtained during the surveying campaign on a 246th km railway track section were subjected to alignment. This article provides a description of the surveying campaign necessary to obtain measurement data and a theoretical description of the method employed to align observation results as well as their visualisation.

Channel Quality Approximation Based on Shadow Fading Model in GEO Mobile Satellite System

2013 ◽  
Vol 791-793 ◽  
pp. 1941-1944
Author(s):  
Ya Dan Zheng ◽  
Ming Ke Dong ◽  
Jian Jun Wu
Keyword(s):  
Large Scale ◽  
Adaptive Modulation ◽  
Original Data ◽  
Satellite System ◽  
Adaptive Modulation And Coding ◽  
Small Scale ◽  
Shadow Fading ◽  
Channel Quality ◽  
The Difference ◽  
Mobile Satellite

CQI(Channel Quality Indicator) is an essential indicator for AMC(Adaptive Modulation and Coding) technique in LTE. Due to the long delay of GEO satellite channel, CQI prediction is necessary to ensure effective AMC. This paper proposes the approximation from real CQI data containing small scale fading to that containing only large scale fading to do prediction. The concrete correlation features and the difference between the approximation and the original data are all analyzed. Simulation is done for confirmation. It shows that the approximate large scale CQI data is feasible and rational for prediction and ensuring AMC efficiency.

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