ITC/USA 2008 Conference Proceedings / The Forty-Fourth Annual International Telemetering Conference and Technical Exhibition / October 27-30, 2008 / Town and Country Resort & Convention Center, San Diego, California / In this paper, we propose the exploitation of array beamforming technology in high-speed aeronautical communication applications, e.g., the integrated Network Enhanced Telemetry (iNET) system. By flexible steering of beams and nulls, an array can enhance desired signals whereas the undesired signals such as interference and jammers are suppressed. The proposed adaptive beamforming technology is DSP-based and network-aware, and is designed for the use at aerial vehicle platforms to increase transmission power efficiency, improve receiving signal sensitivity, mitigate interference/multipath effects, and extend the communication range.

In this thesis, a study of the capacity of a suggested three - dimensional Air-to-Ground cellular system is being made. The Outside Cell Interference Factor (OCIF) is being calculated through simulations for reverse and forward link using seven loops, from the interfering cells around the desired cell for different values of the maximum height of the cell and its radius. Capacity per cell as well as delay and throughput for packet data transmission was calculated for the first time through closed form equations, with the use of the load factor, the activity factor and sectoring gain using the Automatic Repeat Request (ARQ) algorithm for the correction of errors. Moreover, in this thesis, the algorithm which has been created is being analyzed and used for the simulations. Moreover, for the first time, a case study has been made involving the study of capacity of the Air – to - Ground system for the airports of Greece, in three basic scenarios in which the number of the users, the delay and the throughput per cell is being calculated. In the first scenario, we are restricting to the three major airports of the country, while in the second it expands to six airports covering from the radio-coverage side almost all Greece. In the first two scenarios the same cell radius of 175 km is being used, while in the third the radius is reduced to 100 km and the airports are increased to nineteen. In all three scenarios we assume that all the users use the same service. The voice services are also studied of 12.2 kbps and data with transmission rate 64, 128 and 384 kbps. From scenarios 1 and 2 (cell radius 175 km), it was found that we can service at the same time up to 179 voice subscribers per cell at bit rate 12.2 kbps which reduces to 33 users for video call of 64 kbps and in 18 for video call of 128 kbps. In scenario 3 (cell radius 100km),it was found that we can serve at the same time until 126 voice subscribers per cell at bit rate 12.2 kbps which reduces to 23 users for video call of the 64 kbps and in 13 for video call of 128 kbps. In scenario 3 although the capacity per cell is lower than in scenarios 1 and 2, it provides greater total capacity (for all Greece) in relation to these scenarios.

Yes / Modern aeronautical telecommunication networks (ATN) make use of different simultaneous datalinks to deliver robust, secure and efficient ATN services. This paper proposes a Multiple Attribute Decision Making based optimal datalink selection algorithm which considers different attributes including safety, QoS, costs and user/operator preferences. An intelligent TRigger-based aUtomatic Subjective weighTing (i-TRUST) method is also proposed for computing subjective weights necessary to provide user flexibility. Simulation results demonstrate that the proposed algorithm significantly improves the performance of the ATN system. / Innovate U.K. Project SINCBAC-Secure Integrated Network Communications for Broadband and ATM Connectivity: Application number 18650-134196.

No / Random packet errors and erasures are common in satellite communications. These types of packet losses could become significant in mobile satellite scenarios like satellite-based aeronautical communications where mobility at very high speeds is a routine. The current adaptive coding and modulation (ACM) schemes used in new satellite systems like the DVBRCS2 might offer some solutions to the problems posed by random packet errors but very little or no solution to the problems of packet erasures where packets are completely lost in transmission. The use of the current ACM schemes to combat packet losses in a high random packet errors and erasures environment like the satellite-based aeronautical communications will result in very low throughput. Network coding (NC) has proved to significantly improve throughput and thus saves bandwidth resources in such an environment. This paper focuses on establishing how in random linear network coding (RLNC) the satellite bandwidth utilization is affected by changing values of the generation size, rate of packet loss and number of receivers in a satellite-based aeronautical reliable IP multicast communication. From the simulation results, it shows that the bandwidth utilization generally increases with increasing generation size, rate of packet loss and number of receivers.

Nowadays, several studies are launched for the design of reliable and safe communications systems that introduce Unmanned Aerial Vehicle (UAV), this paves the way for UAV communication systems to play an important role in a lot of applications for non-segregated military and civil airspaces. Until today, rules for integrating commercial UAVs in airspace still need to be defined, the design of secure, highly reliable and cost effective communications systems still a challenging task. This thesis is part of this communication context. Motivated by the rapid growth of UAV quantities and by the new generations of UAVs controlled by satellite, the thesis aims to study the various possible UAV links which connect UAV/aircraft to other communication system components (satellite, terrestrial networks, etc.). Three main links are considered: the Forward link, the Return link and the Mission link. Due to spectrum scarcity and higher concentration in aircraft density, spectral efficiency becomes a crucial parameter for largescale deployment of UAVs. In order to set up a spectrally efficient UAV communication system, a good understanding of transmission channel for each link is indispensable, as well as a judicious choice of the waveform. This thesis begins to study propagation channels for each link: a mutipath channels through radio Line-of-Sight (LOS) links, in a context of using Meduim Altitude Long drones Endurance (MALE) UAVs. The objective of this thesis is to maximize the solutions and the algorithms used for signal reception such as channel estimation and channel equalization. These algorithms will be used to estimate and to equalize the existing muti-path propagation channels. Furthermore, the proposed methods depend on the choosen waveform. Because of the presence of satellite link, in this thesis, we consider two low-papr linear waveforms: classical Single-Carrier (SC) waveform and Extented Weighted Single-Carrier Orthogonal Frequency-Division Multiplexing (EW-SC-OFDM) waveform. channel estimation and channel equalization are performed in the time-domain (SC) or in the frequency-domain (EW-SC-OFDM). UAV architecture envisages the implantation of two antennas placed at wings. These two antennas can be used to increase diversity gain (channel matrix gain). In order to reduce channel equalization complexity, the EWSC- OFDM waveform is proposed and studied in a muti-antennas context, also for the purpose of enhancing UAV endurance and also increasing spectral efficiency, a new modulation technique is considered: Spatial Modulation (SM). In SM, transmit antennas are activated in an alternating manner. The use of EW-SC-OFDM waveform combined to SM technique allows us to propose new modified structures which exploit exces bandwidth to improve antenna bit protection and thus enhancing system performances.

Yes / This paper presents the architectural design, software implementation, the validation and flight trial results of an aeronautical communications system developed within the Seamless Aeronautical Networking through integration of Data links Radios and Antennas (SANDRA) project funded by the European 7th Framework Aeronautics and Transport Programme. Based on Software Defined Radio (SDR) techniques, an Integrated Modular Radio (IMR) platform was developed to accommodate several radio technologies. This can drastically reduce the size, weight and cost in avionics with respect to current radio systems implemented as standalone equipment. In addition, the modular approach ensures the possibility to dynamically reconfigure each radio element to operate on a specific type of radio link. A radio resource management (RRM) framework is developed in the IMR consisting of a communication manager for the resource allocation and management of the different radio links and a radio adaptation manager to ensure protocol convergence through IP. The IMR has been validated though flight trials held at Oberpfaffenhofen, Germany in June 2013. The results presented in the paper validate the flexibility and scalability of the IMR platform and demonstrate seamless service coverage across different airspace domains through interworking between the IMR and other components of the SANDRA network. / European Commission

De nos jours, l'utilisation des drones ne cesse d'augmenter et de nombreuses études sont réalisées afin de mettre en place des systèmes de communication dronique destinés à des applications non seulement militaires mais aussi civiles. Pour le moment, les règles d'intégration des drones commerciaux dans l’espace aérien doivent encore être définies et le principal enjeu occupation est d'assurer une communication fiable et sécurisée. Cette thèse s’inscrit dans ce contexte de communication. Motivée par la croissance rapide du nombre des drones et par les nouvelles générations des drones commandés par satellite, la thèse vise à étudier les différents liens possibles qui relient le drone aux autres composants du système de communication. Trois principaux liens sont à mettre en place : le lien de contrôle, le lien de retour et le lien de mission. En raison de la rareté des ressources fréquentielles déjà allouées pour les futurs systèmes droniques, l'efficacité spectrale devient un paramètre crucial pour leur déploiement à grande échelle. Afin de mettre en place un système de communication par drones spectralement efficace, une bonne compréhension des canaux de transmission pour chacune des trois liaisons est indispensable, ainsi qu’un choix judicieux de la forme d’onde. Cette thèse commence par étudier les canaux de propagation pour chaque liaison : canaux de type muti-trajets avec ligne de vue directe, dans un contexte d’utilisation de drones à moyenne altitude et longue endurance (drones MALE). L’objectif de cette thèse est de proposer de nouveaux algorithmes de réception permettant d’estimer et égaliser ces canaux de propagation muti-trajets. Les méthodes proposées dépendent du choix de la forme d’onde. Du fait de la présence d’un lien satellite, les formes d’onde considérées sont de type mono-porteuse (avec un faible facteur de crête) : SC et EW-SCOFDM. L’égalisation est réalisée dans le domaine temporel (SC) ou fréquentiel (EW-SC-OFDM). L'architecture UAV prévoit l'implantation de deux antennes placées aux ailes. Ces deux antennes peuvent être utilisées pour augmenter le gain de diversité (gain de matrice de canal). Afin de réduire la complexité de l'égalisation des canaux, la forme d'onde EW-SC-OFDM est proposée et étudiée dans un contexte muti-antennes, dans le but d'améliorer l'endurance de l'UAV et d'accroître l'efficacité spectrale, une nouvelle technique de modulation est considérée: Modulation spatiale ( SM). Dans SM, les antennes de transmission sont activées en alternance. L'utilisation de la forme d'onde EW-SC-OFDM combinée à la technique SM nous permet de proposer de nouvelles structures modifiées qui exploitent l’étalement spectrale pour mieux protéger des bits de sélection des antennes émettrices et ainsi améliorer les performances du système. / Nowadays, several studies are launched for the design of reliable and safe communications systems that introduce Unmanned Aerial Vehicle (UAV), this paves the way for UAV communication systems to play an important role in a lot of applications for non-segregated military and civil airspaces. Until today, rules for integrating commercial UAVs in airspace still need to be defined, the design of secure, highly reliable and cost effective communications systems still a challenging task. This thesis is part of this communication context. Motivated by the rapid growth of UAV quantities and by the new generations of UAVs controlled by satellite, the thesis aims to study the various possible UAV links which connect UAV/aircraft to other communication system components (satellite, terrestrial networks, etc.). Three main links are considered: the Forward link, the Return link and the Mission link. Due to spectrum scarcity and higher concentration in aircraft density, spectral efficiency becomes a crucial parameter for largescale deployment of UAVs. In order to set up a spectrally efficient UAV communication system, a good understanding of transmission channel for each link is indispensable, as well as a judicious choice of the waveform. This thesis begins to study propagation channels for each link: a mutipath channels through radio Line-of-Sight (LOS) links, in a context of using Meduim Altitude Long drones Endurance (MALE) UAVs. The objective of this thesis is to maximize the solutions and the algorithms used for signal reception such as channel estimation and channel equalization. These algorithms will be used to estimate and to equalize the existing muti-path propagation channels. Furthermore, the proposed methods depend on the choosen waveform. Because of the presence of satellite link, in this thesis, we consider two low-papr linear waveforms: classical Single-Carrier (SC) waveform and Extented Weighted Single-Carrier Orthogonal Frequency-Division Multiplexing (EW-SC-OFDM) waveform. channel estimation and channel equalization are performed in the time-domain (SC) or in the frequency-domain (EW-SC-OFDM). UAV architecture envisages the implantation of two antennas placed at wings. These two antennas can be used to increase diversity gain (channel matrix gain). In order to reduce channel equalization complexity, the EWSC- OFDM waveform is proposed and studied in a muti-antennas context, also for the purpose of enhancing UAV endurance and also increasing spectral efficiency, a new modulation technique is considered: Spatial Modulation (SM). In SM, transmit antennas are activated in an alternating manner. The use of EW-SC-OFDM waveform combined to SM technique allows us to propose new modified structures which exploit exces bandwidth to improve antenna bit protection and thus enhancing system performances.