A5004321310- Optical Wireless Communication Technologies
- Satellite Communication Systems
- Adaptive optics and wavefront sensing
- Optical Network Technologies
- Radio Wave Propagation Studies
- Advanced Photonic Communication Systems
- Advanced Optical Network Technologies
- Atmospheric and Environmental Gas Dynamics
- Atmospheric chemistry and aerosols
- Optical measurement and interference techniques
- Atmospheric aerosols and clouds
- Orbital Angular Momentum in Optics
- Underwater Vehicles and Communication Systems
- Error Correcting Code Techniques
- Advanced optical system design
- Optical Systems and Laser Technology
- Advanced Measurement and Detection Methods
- Planetary Science and Exploration
- Methane Hydrates and Related Phenomena
- Geophysics and Gravity Measurements
- Advanced Measurement and Metrology Techniques
- Infrared Target Detection Methodologies
- Stellar, planetary, and galactic studies
- Astronomical Observations and Instrumentation
- Advanced Wireless Communication Technologies
Airbus (Germany)
2020
Airbus (Netherlands)
2020
Deutsches Zentrum für Luft- und Raumfahrt e. V. (DLR)
2014-2019
Institute for Mobile and Satellite Communication Technology
2018
Universitat Politècnica de Catalunya
2010-2013
Nowadays, the search for a distribution capable of modeling probability density function (PDF) irradiance data under all conditions atmospheric turbulence in presence aperture averaging still continues.Here, family PDFs alternative to widely accepted Log-Normal and Gamma-Gamma distributions is proposed model PDF received optical power free-space communications, namely, Weibull exponentiated (EW) distribution.Particularly, it shown how EW offers an excellent fit simulation experimental...
Abstract. The annual and seasonal variability of aerosol optical properties observed by means a Raman lidar over Northeastern Spain has been assessed. representativeness first checked against sun-photometer measurements in terms thickness. Then the cycle planetary boundary layer thickness its fraction compared to columnar thickness, ratio, backscatter-related Ångström exponent height are analyzed discussed. Winter summer mean profiles extinction, backscatter ratio retrieved with algorithm...
Broadband internet access has become a vertex for the future development of society and industry in digital era. Geostationary orbit (GEO) satellite can provide global broadband coverage, becoming complementary solution to optical fiber network. Low-earth-orbit (LEO) constellations have been proposed last years they may reality soon, but still based on radiofrequency ground-to-satellite links. Optical technologies offer multiple THz available spectrum, which be used feeder link. The DLR's...
In this paper, a digital transmission scheme protected by packet-level forward error correction (FEC) coding technique is proposed for optical feeder links in satellite communication system. The architectures of the gateway and are defined, including building blocks interface between radio frequency (RF) front-end front-end, as well signal processor. system designed to cater Terabit/s high-throughput (HTS) applications. addition, turbulent atmospheric channel modeled different elevation...
In this study, the performance of decode‐and‐forward relay‐assisted free‐space‐optical (FSO) communication systems under atmospheric turbulence‐induced fading and misalignment errors is investigated. To mitigate adverse effects turbulence, aperture‐averaging receivers are considered both at relay destination sides. The modelled via exponentiated‐Weibull distribution, which has recently been proposed to characterise an FSO link in presence finite‐sized receiver aperture. expression for moment...
Recently a new proposal to model the fading channel in free-space optical links, namely, exponentiated Weibull (EW) distribution, has been made. It suggested that EW distribution can probability density function (PDF) of irradiance under weak-to-strong conditions presence aperture averaging. Here, we carry out an analysis fade and bit error-rate (BER) performance using simulation results experimental data. The BER assumes intensity modulation/direct detection with on-off keying, expressions...
Optical feeders for geostationary High Throughput Satellites (HTS) systems based on 1.55μm wavelength technology are expected to enable transmit up several terabits over one active link. A desirable option of transmission architecture is an optical feeder link transparent with respect the user air interface. This can be implemented using either a digital or analog modulation carrier. The increases bandwidth transmitted, however it benefits from error correcting codes, interleaving and...
To overcome data rate limitations of RF communication links with satellites, TNO and DLR envision optical free-space feeder for next generation high throughput satellites. This paper provides a feasibility assessment such the technology needed. The main results link budget turbulence modeling terabit/s are presented. Based on these parameters, requirements status link-subsystems discussed, roadmap is presented, aimed at achieving terabit per second links.
The exponentiated Weibull (EW) distribution has been recently proposed for the modelling of free-space optical (FSO) links in presence finite sized receiver aperture. In this paper, performance FSO communication systems over EW is studied. Specifically, probability density function (PDF) and cumulative (CDF) instantaneous signal-to-noise ratio (SNR), turbulence fading, are derived statistics SNR utilized to analyse an system a generalized environment with induced misalignment errors path...
The recently proposed exponentiated Weibull (EW) fading channel model is assessed with partially coherent beams (PCBs) using the Gaussian Schell-model (GSM) theory. use of a PCB in free-space optical links has been suggested as an atmospheric turbulence mitigation technique, called transmitter aperture averaging. A wave optics code based on GSM theory used to generate propagating turbulence, and probability distribution function (PDF) obtained from simulated irradiance data. This study PDF...
Summary In this paper, a packet‐level forward error correction coding technique and pre‐distortion adaptive optics technology are applied to digital transmission scheme for optical feeder links in geostationary Earth orbit satellite communication system. The architectures of the gateway defined, including building blocks interface between radio frequency front‐end front‐end, as well signal processor. system is designed cater Terabit/s high‐throughput applications. performance evaluated...
The German Aerospace Center (DLR) and the European Southern Observatory (ESO) performed a measurement campaign together in April July 2016 at Teide-Observatory (Tenerife), with support of Space Agency (ESA), to investigate use laser guide stars (LGS) ground space optical communications. Atmospheric turbulence causes strong signal fluctuations uplink, due scintillation beam wander. In communications, downlink channel as reference for pointing pre-distortion adaptive optics is limited by size...
For the next generation of very high throughput communication satellites, free-space optical (FSO) between ground stations and geostationary telecommunication satellites is likely to replace conventional RF links. To mitigate atmospheric turbulence, TNO DLR propose Adaptive Optics (AO) apply uplink pre-correction. In order demonstrate feasibility AO pre-correction an FSO link has been tested over a 10 km range. This paper shows that most advantageous for low point ahead angles (PAAs), as...
In response to a comment by H. T. Yura and S. Rose on our recent work about the exponentiated Weibull distribution [Opt. Express 20, 13055–13064 (2012)], we present here defense of proposed model from their criticism.
In terrestrial free-space laser communication, aside from pointing issues, the major problem that have to be dealt with is turbulent atmosphere produces irradiance fluctuations in received signal, greatly reducing link performance. Aperture averaging standard method used mitigate these consisting increasing area of detector, or effectively it by using a collecting lens diameter as large possible. Prediction aperture factor for Gaussian beam currently available theory compared data collected...
Summary Nowadays, large geostationary orbit (GEO) satellites can offer capacities up to 260 Gbps. In the midterm, in order cope with forecasted traffic demand, multibeam high throughput satellite systems are already being deployed. Optical GEO feeder link technology may provide transmission data rates of several terabits per second by making use wavelength division multiplexing schemes. This work identifies physical layer techniques that enable DVB‐S2X RF modulated signals over optical...
For the next generation of very high throughput communication satellites, TNO and DLR envision optical free-space between ground stations geostationary telecommunication satellites to replace traditional RF links. To mitigate atmospheric turbulence, an Adaptive Optics (AO) system will be used apply uplink pre-correction. OFELIA, terminal breadboard was developed demonstrate pre-correction principle over realistic link. Currently, integration tests have been performed verify AO performance....
The goal of near real-time delivery data from spacecraft in polar low Earth orbits to the customers can be achieved by utilization Arctic and Antarctic hubs a Ground Station Network.Additionally, commanding satellites these provide novel opportunities for operations.The challenge high-rate repatriation such remote sites met means laser communications ground geostationary satellites.We present system architecture operations concept setup employing European Data Relay System (EDRS) uplinks an...
TNO and DLR envision optical free-space communication between ground stations geostationary telecommunication satellites to replace the traditional RF links for next generation of Very High Throughput Satellites. To mitigate atmospheric turbulence, an Adaptive Optics (AO) system will be used. are developing breadboards validate Terabit/s using AO system. In this paper breadboard activities first results sub-systems presented. Performance these subsystems evaluated viability terabit/s feeder links.