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In this paper, we propose a polarization filtering-based transmission scheme to enhance the physical layer security in the dual-polarized satellite communication. To prevent eavesdropping, this paper first divides the information sequence into two parts and modulates them independently. Subsequently, a pair of dual polarization states (PSs) is selected to carry the two modulated signals based on the...
A satellite-based Automatic Identification System (S-AIS) receiver has a high probability of message collisions, both in time and in frequency, for a zone densely populated by AIS-enabled ships. Banks of time-and-frequency selective detectors (that use message fields from un-collided messages from the same ship-track together with interference cancellation) decode collided messages. Algorithms are...
This paper presents a novel technique to improve data demodulation performance of global navigation satellite system (GNSS) signals with data and pilot signal components (e.g. suitable for Galileo E1B/C open service (OS) signals [1]). This technique is called Pilot-aided data demodulation because it uses the coherence between residual phase errors on the data and the pilot components of the GNSS signal...
The Terrestrial AIS networks have been in operation over the last two decades and helped with the smooth sailing of numerous ships. During this time, the need for information of ships, over a larger footprint seemed necessary, and hence Satellite based AIS systems have been developed. The Satellite-Automatic Identification System (S-AIS) is a critical maritime monitoring system that ensures safety...
The vessel monitoring system at the sea which mainly uses Automatic Identification System (AIS) technology will be more effective if it is combined with the satellite technology. This id due to the satellite can cover reach thousands of kilometers when orbiting in the space. Unfortunately, the process of receiving AIS signals from the transmitter has the problem of very low received power that reaches...
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,...
The application of global satellite navigation system to the user satellite at high elliptical orbit can overcome the disadvantage that the equipment of the ground control system is complex and high cost. But with the increasing of the altitude of user satellite, the number of usable satellites reduces, even less than four. In order to achieve navigating and positioning using the global satellite...
A satellite moving in relation to a GPS receiver generates a shift in the carrier frequency and the C/A code signal reception. This deviation is know as the Doppler effect and it varies in time depending on the relative acceleration of the GPS satellite/receiver and it can hinder or even preclude data reception. This paper presents an approach to mitigate this problem, based on the insertion of adaptive...
This paper addresses the problem of error correction of AIS messages by using the a priori knowledge of some information in the messages. Indeed, the AIS recommendation sets a unique value or a range of values for certain fields in the messages. Moreover, the physics can limit the range of fields, such as the speed of the vessel or its position (given the position of the receiver). The repetition...
This article provides an overview of the Digital Video Broadcasting - Satellite (DVB-S) specifications and the context of its extension to mobility. Different ways for receiving digital television on mobile devices are summarized. Then, the overall demonstrator from the antenna to the baseband signal processing is presented. Some attention is paid to the analog channel selection and QPSK frequency...
Dual component systems share energy to optimize tracking and data-down-load, but usually omit acquisition considerations. This paper proposes a new concept that makes all the energy available for pilot, all available for tracking and download, but vastly enhances acquisition sensitivity and TTFF.
This article presents a methodology related to the computation of civil aviation acquisition, tracking and data demodulation thresholds adapted to the case of Galileo E1 OS/SoL signal. These thresholds are compared against worst case link budgets representing operational scenarios. It is shown that these thresholds provide a positive margin although these theoretical results would probably require...
This paper describes an innovative receiver architecture for the satellite-based Automatic Identification System (AIS). The receiver performance has been fully validated in the presence of the typical satellite channel characteristics. In particular, it is shown that the devised receiver provides an excellent performance against the noise, as well as a large resilience against message collisions,...
This paper summarises the results of several sessions of measurements executed in the context of the research project named “J-ORTIGIA”. The scope of the project was to validate all kinds of hybrid reception supported by the DVB-SH able to counteract fading in satellite and terrestrial environments. The results of the measurements have also contributed to the 2nd issue of the DVB-SH Implementation...
The first stage of the signal processing chain in a Global Positioning System (GPS) receiver is the acquisition, which provides for a desired satellite coarse code phase and Doppler frequency estimates to subsequent stages. Thus, acquisition is a two-dimensional search, implemented as demodulation and non-coherent correlation. For a certain Doppler estimate, software-defined GPS receivers typically...
In order to meet both the dynamic qualities and the acquisition accuracy of multi-mode receiver, this paper gives a variable sampling FFT+PMF Fast Acquisition method on the basis of analyzing the every system signals' characteristics and related technologies. Combine with DSP+FPGA, it forms a hardware platform, gives part of the capture program and DSP capture process.
In this work we investigate the potential for sensing beach soil moisture with the L band GPS bistatic radar concept. Characterisation of sediment surface (properties like humidity) is indeed important to better understand morphodynamic activity of intertidal part of beaches. In our approach we compare the direct GPS Signal to Noise Ratio with the reflected one in order to measure the soil moisture...
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