New Publications are available for Satellite communication systems
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New Publications are available now online for this publication.
Please follow the links to view the publication.Keynote: Global navigation satellite systems and the ionosphere
http://dl-live.theiet.org/content/conferences/10.1049/cp.2012.0378
The ionosphere is an important source of positioning error for Global Navigation Satellite Systems GNSS. The factors affecting the GNSS signals are introduced and the implications for modern GNSS applications are discussed. The paper also describes the current use of Global Navigation Satellite Systems for ionospheric corrections and shows specific examples of the use of GNSS for ionospheric measurement. (4 pages)Two-time, two-frequency coherency of the stochastic field in characterization of the transionospheric UHF channel of propagation
http://dl-live.theiet.org/content/conferences/10.1049/cp.2012.0389
The analytical solution to the spaced position and frequency coherence functions of the GNSS type fields propagating through the ionosphere is given. The explicitly constructed coherence functions are obtained for the quadratic structure function of the electron density fluctuations of the ionosphere and the inhomogeneous background ionosphere, where the dependence of the plasma frequency along the line of sight is presented by two half-parabolic layers modelling the topside and bottom side ionosphere with different scales. The solution to the problem is expressed through the appropriate solutions of the equation for the function of the parabolic cylinder. (4 pages)Mid-latitude upper ionosphere plasma FDTD formulation for inter-satellite link analysis
http://dl-live.theiet.org/content/conferences/10.1049/cp.2012.0392
This article presents the derivation of governing equations for the propagating wave under the influence of magneto-ionic plasma (i.e. Earth's Ionosphere), ready to be used in Finite Difference Time Domain algorithm. The governing equations and constituent relations are derived from the magneto ionic theory given by Appleton-Hartree, discussed by Ratcliffe and Budden. The frequency domain relations, are then converted to time domain suitable for inclusion in the time stepping algorithm used in FDTD method developed by Taflove. Although the intention is to achieve a Full Wave analysis, for waveform attenuation, group velocity, and wavefront direction, but due to limited scope of this paper, only the derivations are detailed. Plane wave formulation is discussed, leaving the spherical wave formulation for later publication. (9 pages)Assessment of the reliability of loss of mains protection incorporating satellite communications
http://dl-live.theiet.org/content/conferences/10.1049/cp.2012.0029
This paper builds upon the earlier research which proposed the use of satellite communication media to achieve improved performance of the Loss-Of-Mains (LOM) protection by eliminating nuisance tripping and ensuring reliable islanding detection. The focus of this paper is the practical development of the laboratory based trial of the satellite based LOM protection and the experimental assessment of the performance of such protection scheme. (6 pages)Design and preliminary testing of a corrugated dual band feedhorn for digital satellite television
http://dl-live.theiet.org/content/conferences/10.1049/ic.2011.0206
We are designing a triple band feedhorn structure that is intended to become a future replacement of existing LNB feedhorns on satellite dish assemblies. Here we show work on the first stage of the design; the band 2 and 3 structure which must have a return loss performance of - 20dB or better. We also present results of a model to generate circularly polarised waves for testing in the laboratory.Design of GPS IF signal acquisition and tracking circuits based on FPGA
http://dl-live.theiet.org/content/conferences/10.1049/cp.2011.0956
This paper presents a FPGA design of a novel GPS IF signal acquisition and tracking circuits, which acquires and tracks the GPS LI frequency and C/A code without FFT and Costas loop. The suggested acquisition circuit consists of 40 branches and each of which acquires 0.5 KHz bandwidth of GPS IF signal. The tracking circuit re-acquires the GPS IF signal based on the SV number and Doppler frequency offered by the acquisition circuit and then tracks the acquired signal by means of a simple dynamic local carrier jumping method proposed in this paper instead of the traditional Costas Loop based method. A unique data demodulation technique that is suitable for the carrier jumping method is also introduced to correctly recover the modulation data. Simulation results and FPGA test show that the proposed design works well for GPS IF signal acquisition and tracking and is promising for low cost and low power FPGA applications for GPS signal processing.The four-way real-time audio and video transmission system design and implementation by satellite-based communication channel
http://dl-live.theiet.org/content/conferences/10.1049/cp.2011.1025
In order to achieve four-way real-time audio and video transmission in low bandwidth satellite communication channel between the center station and the remote PDA (Personal Digital Assistant) terminals, we propose a real-time audio and video transmission design and implementation to really ensure the full use of the satellite-based communication channel and the transmission quality of audio and video, at the same time, reduces the transmission delay. By simulation experiments, some satisfactory results in transmitting have been achieved.Research of on-board optical/electric switching of broadband multimedia satellite
http://dl-live.theiet.org/content/conferences/10.1049/cp.2011.0950
On-board switching has been the development trend of satellite communication. There is electronic bottleneck in the development of on-board ATM switch, so the optical switch is the inevitable direction of future broadband multimedia satellite. The paper brings forward a scheme about on-board mixed optical/electronic switching of GEO, analyses the switching mode of the scheme, discusses the key techniques.A high reliable satellite communication for emergency communications
http://dl-live.theiet.org/content/conferences/10.1049/cp.2011.0781
In this paper, a novel high reliable satellite communication architecture is presented for emergency communication, which is based on the telecommand, telemetry and control (TT&C) system. The TT&C system is capable to provide high reliable communication among the different TT&C ground stations. In the meantime, there are lots of ground stations located in different areas in China. And many of these areas belong to earthquake-prone zone. It makes sense by using such resources in the emergency especially when other communication manners no longer work. Moreover, in this new architecture, no specific satellite systemic level revision is necessary such that the current satellite in orbit can be utilized. The revisions are only focused on the telecommand, telemetry and control ground station. As a result, it is easily to be implemented comparing with other emergency communication scheme.Analyzing raim performance for an MEO/GEO hybrid GNSS constellation
http://dl-live.theiet.org/content/conferences/10.1049/cp.2011.0930
MEO/GEO hybrid constellation is employed in some GNSS systems such as BeiDou. With the increased number of satellite vehicles in view and strengthened geometry, positioning performance (accuracy, integrity and availability) is to be significantly improved. In this research, a number of performance analyses have been conducted regarding the key parameters, including minimum detectable bias (MDB), external reliability and protecting levels in integrity. Both MEO/GEO hybrid constellation and MEO only constellation are evaluated for comparison. Conclusion can be drawn from the test results that, the introduction of GEO satellites in addition to the traditional constellation has great benefits of improved performances, not only the positioning accuracy and availability, but also the integrity. With the help of geostationary satellites in the hybrid constellation, RAIM performance has been significantly improved. MDB values for all the satellites are decrease, e.g., from 7.8m down to 4.9m.Satellite-to-Ground Radiowave Propagation
http://dl-live.theiet.org/content/books/ew/pbew054e
<p xmlns="http://pub2web.metastore.ingenta.com/ns/">This book is a follow-up to the award-winning first edition and is written as a comprehensive guide for those who need to obtain a working knowledge of radiowave propagation on satellite-to-ground links at frequencies above 1 GHz and as a reference book for experts in the field. To accomplish this, expanded sections of explanatory text, copiously illustrated, enable an undergraduate or non-specialist to grasp the fundamentals involved. An extensive reference list permits the expert to go to the source material should the level of enquiry go beyond the level of this book. The book is broken down into chapters that deal with the major propagation phenomena classes. After a broad introductory chapter, there are extensively updated chapters on ionospheric effects, clear air effects, attenuation effects and depolarisation effects. New chapters on mobile communications effects and optical communications effects are followed by a chapter on restoration of performance during impairments.</p>International cooperation - the challenges and opportunities
http://dl-live.theiet.org/content/conferences/10.1049/ic.2010.0066
Presents a collection of slides that discuss the following: International Cooperation; UK MOD; equal value exchange; repayment; procurement; operation and maintenance; International Telecommunications Union; paper satellites and game changing programme. (13 pages)Future Ministry of Defence beyond line of sight requirements 2
http://dl-live.theiet.org/content/conferences/10.1049/ic.2010.0060
Presents a collection of slides covering the following topics: Milsatcom; UK defence policy; and military satellite communication. (7 pages)Future Ministry of Defence beyond line of sight requirements
http://dl-live.theiet.org/content/conferences/10.1049/ic.2010.0059
Presents a collection of slides covering the following topics: satellite communication system; skynet 5 communication; and MOD BLOS capability strategy. (21 pages)Delivering Ka-band Milsatcom services - opportunities & challenges
http://dl-live.theiet.org/content/conferences/10.1049/ic.2010.0063
Presents a collection of slides covering the following topics: Ka-band freqeuncy spectrum; ITU frequency allocations; USG systems; European satellites; UK Ka-band Milsatcom background; Avanti Ka-band satellites; HYLAS-1 Ka-band satellites; and HYLAS-2 Ka-band satellites. (11 pages)Skynet 5 and beyond - meeting the military requirement
http://dl-live.theiet.org/content/conferences/10.1049/ic.2010.0061
Presents a collection of slides covering the following topics: skynet 5 communication; military requirement; and military satellite communication system. (31 pages)High altitude platforms and Milsatcom for future capacity requirements
http://dl-live.theiet.org/content/conferences/10.1049/ic.2010.0062
Present a collection o slides covering the following topics: high altitude platform; UK Milsatcom; HAP platform; tactical ad hoc network; and cognitive routing. (26 pages)Spectrum issues debating Milsatcom vs commercial bands
http://dl-live.theiet.org/content/conferences/10.1049/ic.2010.0065
Presents a collection of slides covering the following topics: Milsatcom demand drivers; military satcom sector definition; hard military satellites; commercial satellites; mobile bands; FSS bands; spectrum efficiency; and military bands. (17 pages)EDA and satellite communication
http://dl-live.theiet.org/content/conferences/10.1049/ic.2010.0067
Presents a collection of slides covering the following topics: EDA satcom; satellite communication; and UK MilSatcom. (16 pages)Future Beyond Line of Sight (BLOS) Programme
http://dl-live.theiet.org/content/conferences/10.1049/ic.2010.0057
Presents a collection of slides covering the following topics: future core networks; defence core network services; future BLOS capability; Anglo-French future military satcom joint concept; MILSAT traffic analysis; and C4 architecture overarching technical strategy. (21 pages)Coaxial waveguides for satellite communications
http://dl-live.theiet.org/content/conferences/10.1049/ic.2010.0176
The design of a nested, coaxial multiband circular waveguide structure, with a matching dielectric stub insert for satellite communications is presented. Waveguide sizes are calculated for the frequency bands under study. Two waveguides are placed inside one another and preliminary results are presented showing different frequency bands travelling in separate waveguides.Ground based technologies to deliver Satcom on the move
http://dl-live.theiet.org/content/conferences/10.1049/ic.2010.0064
Presents a collection of slides covering the following topics: changing threats; strategic defence review green paper; COTM policy; Thales technology development strategy; and low profile active antenna system development. (17 pages)MilSatcom delivery across Afghanistan: a personal experience of growth
http://dl-live.theiet.org/content/conferences/10.1049/ic.2010.0058
Presents a collection of slides covering the following topics: Op FINGAL; Op HERRICK; CIS capability; operational CIS constants; and operational CIS providers. (25 pages)One scheme of cooperative diversity with two satellites based on the Alamouti code
http://dl-live.theiet.org/content/conferences/10.1049/cp.2010.0640
Aiming at the low Earth orbiting (LEO) satellite mobile communication, the cooperative diversity technology is applied to the forward downlink in this paper, and one scheme for cooperative diversity with two satellites based on the Alamouti code is presented. To reduce the non-negligible path delay from the different satellite to the same terminal, the synchronous CDMA is used and satellites are distinguished by the spreading codes which are orthogonal each other in this scheme. Simulation results show the satellite cooperative diversity system can obtain better performance than the traditional uncoded BPSK system with the same fading channel and system parameters. Though the satellite cooperative diversity system has worse performance than the traditional satellite diversity system, it has the advantage in communication range and low complex mobile terminal. Particularly, this new scheme can be used as an effective means to improve the performance in the area where the gateway can not be built.Safety arguments for next generation, location aware computing
http://dl-live.theiet.org/content/conferences/10.1049/cp.2010.0813
Concerns over accuracy, availability, integrity, and continuity have limited the integration of Global Positioning System (GPS) and Global Navigation Satellite System (GLONASS) for safety-critical applications. More recent augmentation systems, such as the European Geostationary Navigation Overlay Service (EGNOS) and the North American Wide Area Augmentation System (WAAS) have begun to address these concerns. Augmentation architectures build on the existing GPS/GLONASS infrastructures to support location-based services in Safety of Life (SoL) applications. Much of the technical development has been directed by air traffic management requirements, in anticipation of the more extensive support to be offered by GPS III and Galileo. WAAS has already been approved to provide vertical guidance for aviation applications. During the next twelve months, the full certification of EGNOS for SoL applications is expected. This paper discusses similarities and differences between the safety assessment techniques used in Europe and North America. (6 pages)Scintillation of a tracked gaussian beam for ground-to-satellite laser communication
http://dl-live.theiet.org/content/conferences/10.1049/cp.2010.0638
Recent researches have revealed that, for a tracked uplink Gaussian beam, the scintillation index predicted by the weak fluctuation theory is significantly different from that of the numerical wave optics simulation method when the size of the transmitter aperture is large. In this paper, turbulence-induced scintillation index and the probability distribution of fluctuating irradiance for a tracked uplink Gaussian beam are studied using numerical wave optics simulation method. The simulated data show that in the discrepancy region between the weak fluctuation theory and the numerical simulation method, the simulated fluctuating irradiance is not governed by the generally accepted lognormal distribution even when the weak fluctuation condition is still satisfied.Sensor integration for mobile mapping and feature analysis
http://dl-live.theiet.org/content/conferences/10.1049/cp.2010.0399
The ITS (Intelligent Transportation Systems) group at the Institute of Technology Blanchardstown (ITB) has been working on issues in the automated analysis of road signage and delineation since 2002. This research is concerned with the detection and analysis of road signage and raised pavement markers from image data. This involved the design and construction of a prototype portable mobile mapping system that linked GPS to machine vision data. A new mobile mapping system has now been developed that is distinguished from its predecessors by its ability to give survey-grade geo-referenced positions for substandard delineation [7]. The new system also logs and presents in real-time the data supplied by all the different sensor systems together under a common graphical user interface. (5 pages)Accounting for sensor drift in miniature, wireless inertial measurement and positioning systems: an extended Kalman Filtering approach
http://dl-live.theiet.org/content/conferences/10.1049/cp.2010.0522
This work describes the design and development of a location aware, wireless inertial measurement system incorporating Kalman Filtering based real-time correction for sensor drift. The Tyndall prototyping mote is employed as a wireless sensor networking platform and its suitability as a flexible architecture for a wide range of applications is highlighted. The system comprises of an Inertial Measurement Unit (IMU) with 3 axis gyroscopes, accelerometers and magnotometers and a newly developed 25 mm Global Positioning Satellite (GPS) transceiver interface layer. A methodology for fusioning GPS and IMU data is presented highlighting how an extended Kalman filter can be employed to re-calibrate the IMU in realtime, correcting for sensor drift. A Labview based visualisation tool is described enabling real-time analysis of GPS, IMU, Kalman Filter and correction data. Finally some initial experimental results are presented highlighting the effectiveness of the system.Safety and disaster preparedness for strategic global infrastructure: communication satellite systems
http://dl-live.theiet.org/content/conferences/10.1049/cp.2010.0810
The paper seeks to examine the importance of safety and disaster preparedness for strategic global infrastructure communication satellite systems using a design approach based on space qualified components with: system level fault protection, integrated redundant on-board data handling systems, identified and potential satellite single point of failures, in-orbit satellite spares for risk mitigation, ground station design considerations including provisioning of cold and hot redundancy units and subsystem equipment to preclude ground station failures. (4 pages)An advanced LEO satellite network model based on MPLS-TP
http://dl-live.theiet.org/content/conferences/10.1049/cp.2010.0792
LEO (Low Earth Orbit) satellite networks are capable of providing broadband access to end users in any part of the world. With the characteristics of high-speed movement and rapid dynamic topology of LEO satellites, networking has always been one of the key issues in LEO satellite network. MPLSTP (Multi-Protocol Label Switching-Transport Profile) is an excellent packet transport network (PTN) technology in terrestrial networks, which can support multi-service and have perfect function of QoS (Quality of Service), OAM (Operation & Administration & Maintenance) and survivability. In this paper, the characteristics of LEO satellite network and functional architecture of MPLS-TP are introduced. Then an advanced LEO satellite network model based on MPLS-TP (ALSN-M) is proposed, which can guarantee a connection-oriented seamless data transmission. Furthermore topology and routing algorithms of proposed LEO satellite network model is analyzed. In the end, the paper describes how to setup and remove a LSP (Label Switched Path) and how to maintain an exiting LSP when a handover happens.A novel scheme for wide-area time synchronization
http://dl-live.theiet.org/content/conferences/10.1049/cp.2010.0262
Modern electric power protection, monitoring, and control systems rely on the availability of high-accuracy time. Precise time enables technologies like synchrophasors, IEC 61850 Process Bus, and highly accurate, wide-area power system event reporting. Today, high-accuracy time is generally provided by Global Positioning System (GPS) clocks. However, if GPS is the only source of accurate time, it becomes the single point of failure in systems that rely on precise time. GPS may become unreliable due to solar activity, intentional or unintentional jamming, or the U.S. Department of Defense (DoD) modifying GPS accuracy or turning off the satellite system. (5 pages)Co-dependence of wireless, copper and fibre in the roll out of Digital Britain
http://dl-live.theiet.org/content/conferences/10.1049/ic.2009.0202
Presents a collection of slides covering the following topics: UK market; wire-line; sub-loop unbundling; fibre to the home; satellite communication; broadband wireless association; WIMAX; cable broadband; passive optical network; free space optical FSO; spectrum allocations; broadband speed. (17 pages)Walking navigation system for the blind person
http://dl-live.theiet.org/content/conferences/10.1049/ic.2009.0040
Blind persons suffer much inconvenience in walking because it is not comfortable and not easy to get information about surrounding environment. In this paper, we propose a silent walking navigation system to guide blind person without noise to nearby people. According to the distance, we can divide the proposed system into two parts. The long range and surrounding information can be found by the PDA (personal digital assistant) containing navigation map, GPS (global positioning system) and a wireless Bluetooth earphone. And the short range information can be gathered by the white stick, ultrasonic sensor and vibrator. For the long range and the surrounding information, GPS receiver sends the position information to the PDA that contains the digital map and produces the navigation data. Next, the TTS (text to speech) program can convert the text information to the audible speech information. This information about area information and routes is finally transmitted to the earphone of the blind person through Bluetooth communication. For the short range information, ultrasonic sensor on white stick detects obstacles and delivers this information to vibrator to alarm the danger about obstructions. Walking tests are made in town and campus. Experimental results show the blind person can walk safer and more correctly. (4 pages)Performance analysis of explicit congestion notification (ECN) function on satellite MPLS
http://dl-live.theiet.org/content/conferences/10.1049/cp.2009.1152
In this paper, explicit congestion notification (ECN) is developed and deployed on satellite MPLS to improve network performance in transmitting IP packet data. Network simulations conducted within 3 scenarios: MPLS scenario, satellite MPLS scenario, and satellite MPLS with addition of ECN function scenario. The simulation results demonstrate a performance enhancement in term of throughput and utilization improvement. In addition, delay reduction on satellite MPLS with addition of ECN function scenario can be achieved that are compared to satellite MPLS scenario. (8 pages)A practical joint source channel coding scheme for digital satellite broadcasting service based on scalable video coding
http://dl-live.theiet.org/content/conferences/10.1049/cp.2009.1219
In this paper, we propose a joint source-channel coding scheme that can provide and sustain high quality video service in spite of deteriorated transmission channel conditions of the DVB-S2 satellite broadcasting service. Especially by combining the layered characteristics of the SVC (scalable video coding) and the robust channel coding capability of LDPC (low density parity check) employed for DVB-S2, a new concept of layered joint source-channel coding for digital satellite broadcasting service is developed. Rain attenuation in high frequency band like Ka-band is a major factor for lowering the link capacity in satellite broadcasting service. Therefore, it is necessary to devise a new technology to dynamically manage the rain attenuation by adopting a joint source-channel coding that can apply variable code rates for both source and channel codings. For this purpose, we develop a layered joint source-channel coding scheme combining SVC and LDPC, and prove the performance of the proposed scheme by extensive simulations where SVC coded video is transmitted over various error-prone channels with AWGN (additive white Gaussian noise) patterns. (5 pages)Extending satellite longevity and life-cycle effectiveness through dynamically reconfigurable communications systems
http://dl-live.theiet.org/content/conferences/10.1049/cp.2009.1173
The ability to support multiple mission objectives increases the longevity, mission life, flexibility, and cost effectiveness of satellite communications systems. One key technology area that helps achieve these goals is reconfigurable, software-based radio systems. While the application of this technology to ground based systems has evolved and proven valuable over the past several decades, the application of software-based configuration of digital signal processing technology in the communications satellite domain has been very limited. This is due to a number of reasons, including; survivability in the space environment, limited power, reconfiguration requirements, and the complexity of managing software deployment and configuration. This paper presents current work on a new family of space- qualified communications systems based on a hardware architecture that supports complete or partial reconfiguration of the communications processing elements. The approach utilises recent advances in radio management software, signal processing hardware, and adaptable systems. The processing elements support multiple communications links and modulation techniques concurrently. (6 pages)Best design of deep-space communication with a 2-hop downlink at 32 GHz
http://dl-live.theiet.org/content/conferences/10.1049/cp.2009.1232
We apply an optimum design to deep-space communication at Ka band and above, made with a 2-hop downlink trough a data relay satellite orbiting the Earth, with transparent transponder. The optimum requires that each hop be designed for providing half of the total noise-to-signal power ratio (twice the total signal-to-noise power ratio) tolerated for a given probability of symbol error. We have applied the optimum design equations to design a deep-space downlink at 32 GHz, at a distance of 2 astronomical units (about planet Mars) at Spino d'Adda, Gera Lario and Fucino, in Italy. (5 pages)Overview of the U.S. 17/24-GHz broadcast satellite service
http://dl-live.theiet.org/content/conferences/10.1049/cp.2009.1230
This paper is an introduction to the U.S. 17/24-GHz broadcast satellite service (BSS) regulations and implications for satellite manufacturers. The 17/24-GHz BSS band is commonly called the Reverse BSS band. An overview of U.S. 17/24-GHz satellite regulations is provided. A summary of the satellite (space segment) technical requirements imposed by the FCC on the Reverse BSS band is offered. An overview of the satellite architectures proposed by the current FCC filings for DIRECTV, EchoStar, Intelsat, Pegasus and Spectrum-5 is presented and the implications of these architectures on satellite system design are discussed. An evaluation of available current technology to support Reverse BSS needs is provided and assessments of the areas of key technical challenges are summarized. (10 pages)Future military satellite communications using V and W bands
http://dl-live.theiet.org/content/conferences/10.1049/cp.2009.1160
The United States Military projected increase satellite communications (SATCOM) data throughput will place additional stress on current frequency allocations. Future high technology systems requirements challenge current data rate and bandwidth solution. V and W band communications hold promise of substantially increasing available RF bandwidth for military and provide connectivity at up to Gigabits per second data rate. (3 pages)Sixteen-hour droplet constellations for northern hemisphere coverage
http://dl-live.theiet.org/content/conferences/10.1049/cp.2009.1186
This paper extends the author's previous research on constellations covering the three major populated regions of the Northern Hemisphere using 16-hour period satellites with a single two-day repeating ground track (RGT). This array has apogees separated by 120 degrees appropriately spaced to give optimum satellite coverage to the three Northern Hemisphere (NH) continents- North America, Europe and Asia. By using more satellites the duration and size of the droplets constituting the active arcs can be markedly reduced. This reduction in droplet size facilitates the use of a single fixed ground user antenna, aimed at the center of the droplet. Examples presented in this paper include 8- 12- and 16-satellite arrays. Obviously, the costs of fixed ground antennas are much less than the costs for fully pointing antennas, so the effect on total system cost can be very significant. Since active arcs occur only in the NH, and at higher latitudes, no interferences with GEO satellites using the same frequencies can occur. (9 pages)Test of an experimental Satcom network in EHF band
http://dl-live.theiet.org/content/conferences/10.1049/cp.2009.1161
In 2008, the French MoD has started an experimental Satcom network which aims at using EHF resources (44/21 GHz) in an efficient manner. It will lead to an operational use of this frequency band in order to cope with the lack of SHF frequency resources. Contrary to the SHF concept of use where links are planned with constant data rates and static margins, the EHF band requires the use of fading mitigation techniques to adapt to transmission conditions. The EHF experiment consists of two networks: 1) the first one is based on DVB-S2/DVB-RCS (Digital Video Broadcasting Satellite 2) / (Digital Video Broadcasting-Return Channel Satellite) standards, 2) the second one uses a frequency hopping Electronic Protected Modem (EPM). The aim of the experiment is to: 1) assess solutions based on COTS (Components On the Shelf) (DVB-S2/DVB-RCS) and EPM 2) test and define EHF terminals, 3) define and to test services offer in EHF The transmission tests with the simulator and the satellite show that the dynamic rate adaptation function is well matched for the 2 types of modems and that the new concept of dynamic resources allocation for the DVB network can be an efficient solution for the use of the EHF resources. For the network tests, several aspects were studied: 1) Services offer of such networks (data rate, availability, type of applications), 2) Behavior of routing and transport protocols with the dynamic rate adaptation, 3) Share of data rate between applications (QoS management), 4) Use of a multicast and unicast IPSec solution (called SatlPSec), 5)Use of multicast flows for DVB-S2, 6) Test of applications (multicast FTP, video- conference, military applications, data base replications...). (9 pages)Analysis and compare of weak GPS signal acquisition algorithms
http://dl-live.theiet.org/content/conferences/10.1049/cp.2009.1998
This paper first gives the theoretical derivation of weak GPS signal acquisition algorithms, then discusses the performance of these algorithms from executive time and detection possibility two parts. The results turn that coherent correlation non-coherent accumulation has the advantage of efficiency in time process, while the bit-edge guess algorithm gains better in detection possibility. As for the coherent correlation with differential accumulation it has larger output SNR (Signal to Noise Ratio) then the coherent correlation with non-coherent accumulation in the same condition. Further work will be done to realize real time acquisition in a software platform receiver based on the useful analysis above.Technological piggybacks: a way to prepare the future of communication satellites
http://dl-live.theiet.org/content/conferences/10.1049/cp.2009.1190
The communication satellite business is facing the competition of terrestrial networks where techniques and technologies keep progressing at a sustained rhythm. New technologies are the true opportunities for the communication satellites to improve and enhance their competitiveness, to adapt to the evolving needs of satellite operators and to create new applications. Compared with other areas of Research and Development, R&D in space communication is mainly characterized by costly and lengthy developments for a small number of satellites delivered per year (few units). This sets a real problem regarding the return on R&D investment. Technological satellites are the best way to explore, to evaluate and qualify new technologies, but they demand a tremendous financial effort for satellite manufacturers, operators and space agencies. Technological piggyback is a scaled-down alternative to technological satellite: a small advanced payload or piece of equipment is embarked on a satellite as a test bed. There are three types of technological piggybacks: new product or service, experimentation and measurement in orbit, validation and heritage acquisition. There are several types of flight opportunities for technological passengers: micro or nano-satellites dedicated to research, institutional technological satellites and also commercial satellites. Thales Alenia Space, as a satellite manufacturer, is willing to propose technological passengers for embankment on GEO communication satellites. (5 pages)Development of dual beam tracking lens antenna for satellite communications to trains
http://dl-live.theiet.org/content/conferences/10.1049/cp.2009.1183
A hemispherical lens-reflector uses of a ground plane to recovers the full aperture of a spherical lens. This is advantageous for applications requiring a low-profile antenna such as on trains. We have developed a 61 cm diameter lens with a mechanical beam steering system using two independently steered primary feeds for Ku and Ka bands. The intended application is satellite communications to enable media and internet services for passengers. We report the design rationale along with measured radiation patterns at 10-12 GHz, 20 GHz and 30 GHz. (7 pages)Preamble insertion in future satellite-terrestrial OFDM mobile broadcasting standards
http://dl-live.theiet.org/content/conferences/10.1049/cp.2009.1171
This paper investigates the possibility of inserting in future satellite-terrestrial OFDM standards a preamble in order to improve frame detection and frequency estimation performance. The preamble, based on a complementary set of sequences, is exploited by a novel joint frame detection/frequency estimation scheme. Numerical results show that this strategy can outperform the classical guard interval based schemes, especially in very challenging scenarios, such as hybrid satellite-terrestrial mobile channels. (6 pages)Satellite replacements for geostationary satellite systems with millimeter example
http://dl-live.theiet.org/content/conferences/10.1049/cp.2009.1185
The late W. T. Brandon observed that selected Molniya orbits could allow simple low cost ground antennas. We choose select Molniya eccentricity to allow three kinds of Brandon antennas. These high gain ground antennas would allow Molniya systems to be directly competitive with geostationary systems in the Northern Temperate Zone. They would relieve congestion in the GEO band, and allow much higher frequencies. We show an 85 GHz example. (10 pages)Mobile TV delivery enhancement using hierarchical modulation
http://dl-live.theiet.org/content/conferences/10.1049/cp.2009.1229
The aim of this paper is to highlight the benefits of the use of hierarchical modulation technique for mobile TV delivery over land mobile satellite channel. This modulation technique allows merging two separate (respectively High Priority and Low Priority) streams into one single symbol sequence. Receivers in satellite Line Of Sight can receive both streams, while disadvantaged receivers can demodulate only the High Priority stream. The paper gives an explanation of hierarchical modulation theory within DVB-SH waveform. A study of the required operating points for both streams is presented and we assess the good matching between theory and our simulation results. The dimensioning of Mobile TV systems using hierarchical modulation is addressed so as to demonstrate the quality of service increase over the satellite coverage. (5 pages)Real-time estimation of excess atmospheric attenuation using an artificial neural network with a two-frequency input
http://dl-live.theiet.org/content/conferences/10.1049/cp.2009.1194
A simple artificial neural network is considered for real-time estimation of excess atmospheric attenuation on a satellite communication link with known attenuation at two frequencies. All atmospheric contributors to attenuation are considered except for gases. The network has a two-layer feed-forward structure with 32 neurons in the hidden layer. Its performance is evaluated by computer simulation using 447 hours of measured attenuation data at 20, 40, and 50 GHz. Estimated attenuation tracks well the measured attenuation at 50 GHz. Estimation error standard deviation is 0.36 dB. RMS error is a function of attenuation: it increases slowly with attenuation, but the ratio of error to attenuation decreases with increasing attenuation. This approach accurately estimates excess attenuation without requiring assumptions, but required training data. (4 pages)Cost-driven optimisation of a vertical handover scheme in DVB-RCS+M networks with terrestrial gap-fillers
http://dl-live.theiet.org/content/conferences/10.1049/cp.2009.1167
Recently, an increasing drive towards wireless networks integration is observed. In the future, terminals are expected to host multi-mode radio interfaces that permit switching to different access technologies according to a host of factors such as topology, mobility and network congestion. This paper investigates the effects of joint satellite-terrestrial resource management on connection-level performance for high-speed trains in mobile DVB-RCS (Digital Video Broadcasting - Return Channel Satellite) systems complemented by terrestrial gap-fillers. In our study, generic terrestrial cellular networks are used to provide temporary backup capacity (vertical handover, roaming) when satellite resources are not available for handover. We developed an analytical model to derive usual network performance statistics such as new connection blocking probability, handover failure probability, and overall resource utilisation. These values are combined with an estimation of the terrestrial resources roaming expense to derive a cumulative cost function which is used to analyse the effectiveness of our probabilistic admission control policy. For each configuration, optimal design parameters are provided that minimise the cost function under a wide range of network conditions. (6 pages)Appropriate random phase feeding technique forsatellite-communication-on-the-move
http://dl-live.theiet.org/content/conferences/10.1049/cp.2009.0407
Resolving the side lobe level deterioration of the antenna is a key technology on the satellite-communication-on-the-move (SOTM). Aiming at improving the performance of the multi-panel phased array antenna for SOTM we analyzed its characteristics and the phase quantization error. The appropriate random phase feeding technique based on the genetic algorithm (GA) is proposed. It applied the GA to optimize phase weightings of sub-arrays. And the phase quantization errors are transformed nonperiodic errors. In simulation results compared with rounding method it provides steady and optimal random phase distribution to the multi-panel phased array antennae and it effectively decreases the side lobe level of the antenna pattern. (4 pages)