ITC/USA 2014 Conference Proceedings / The Fiftieth Annual International Telemetering Conference and Technical Exhibition / October 20-23, 2014 / Town and Country Resort & Convention Center, San Diego, CA / Airbus is authorized to use S-band for Telemetry transmission until 2015. In October 2011, the decision was taken to move to C-band in 2013, to cope with Airbus development aircraft planning. The objective was a real challenge for 2 main reasons: C-band channel was not characterized in Airbus transmission environment and it was necessary to validate the propagation performance for Flight Tests uses. The selected solution is based on Coded Orthogonal Frequency Division Multiplexing (COFDM) modulation. There was no existing solution so it has led the Airbus Test Centre to drive the development of its own C Band solution. C-band telemetry at Airbus has been tested and evaluated in flight from April 2012. The first goal was to check the coverage and the impact of the bad weather condition. Besides, it was necessary to characterize the channel to choose the optimised parameters for the waveform in the Toulouse Blagnac environment. This selection of parameters allows the high quality and increased data rate required for Airbus Telemetry to be reached. The test results consolidated the choice of a COFDM modulation, when given the high sensitivity to multipath of usual Frequency Modulation in the airport environment full of buildings and aircrafts. Moreover, it has been possible to reach a similar quality to the S-band telemetry systems, thanks to a fine tuning of the waveform parameters, and tracking system. Deployment of the system by modifying 8 reception antennas and 12 development aircrafts was done over a span of 4 weeks in January 2014. No impact on Airbus A350 certification campaign occurred due to close collaboration with Flight Test Operations. The new Telemetry system enables an increase of telemetry capabilities in the future, especially the data throughput, simplified remote control and monitoring. This experience is an opportunity to set up a new standard.

International Telemetering Conference Proceedings / October 20-23, 2003 / Riviera Hotel and Convention Center, Las Vegas, Nevada / Tactical unmanned aerial vehicles (UAV’s) can deliver real-time battlefield video directly to the soldier providing unprecedented situational awareness. The video communications system must be compact, lightweight, secure, and easy to deploy without a complicated ground station. Pacific Microwave Research, Inc. is developing a system capable of providing reliable and secure video communications to handheld terminals throughout the theater. PMR’s Coded Orthogonal Frequency Division Multiplex (COFDM) video transmission system is designed for tactical video transmission in battlefield or Military Operations in Urban Terrain (MOUT) environments. Using digital modulation coding, the system provides a very robust link in the mobile environment.

International Telemetering Conference Proceedings / October 25-28, 1999 / Riviera Hotel and Convention Center, Las Vegas, Nevada / This paper presents a mathematical model for Coded Orthogonal Frequency Division Multiplexing (COFDM) in frequency selective multipath encountered in aeronautical telemetry. The use of the fast Fourier transform (FFT) for modulation and demodulation is reviewed. Error control coding with interleaving in frequency is able to provide reliable data communications during frequency selective multipath fade events. Simulations demonstrate QPSK mapped COFDM performs well in a multipath fading environment with parameters typically encountered in aeronautical telemetry.

Le sujet de cette thèse est la conception et la réalisation d'un modem radio COFDM et pouvant être utilisé dans le cadre des applications de la société ADVANTEN.<br />Le premier chapitre est consacré à l'étude des canaux de propagation et aux caractéristiques de la modulation OFDM.<br />Dans le second chapitre, des techniques de synchronisation du récepteur et d'estimation de canal sont présentées. La sélection et le dimensionnement d'une solution adaptée au besoin spécifique sont effectués dans ce chapitre.<br />Dans la suite de l'étude, des algorithmes de codage de canal sont comparés. Nous montrons comment ils permettent une amélioration notable de la qualité de la liaison radio. Des résultats de simulation convaincants sont présentés.<br />Le problème du rapport puissance instantanée à puissance moyenne des signaux OFDM est exposé. Une solution innovante pour réduire ce rapport est proposée.<br />Enfin, les résultats de la phase de réalisation du modem sont donnés dans le chapitre cinq.

ITC/USA 2013 Conference Proceedings / The Forty-Ninth Annual International Telemetering Conference and Technical Exhibition / October 21-24, 2013 / Bally's Hotel & Convention Center, Las Vegas, NV / Systems using single carrier modulations for flight test transmissions perfectly fit noisy and time selective channels. However, the densification of the airport environment now makes the aero channel also frequency selective due to multiple reflections on surrounding buildings, especially while taxiing and taking off. Obviously, this has a direct consequence on hardware resources and user data rates. In such a context, COFDM represents an appealing solution thanks to its inherent robustness to multipath fading channels. But a direct application of an off-the-shelf COFDM standard is not straightforward as these standards are designed for specific channels whose characteristics are quite different from the aero one. That is why we made an experiment at Toulouse-Blagnac airport to jointly sound the channel and qualify a COFDM waveform. This paper then describes the construction of the waveform and the results of the channel sounding. From this, different standard paradigms are compared.

This Master thesis is focused on detailed description of the DVB-T2 system. This work deals with the description of the particular parts of models and with typical RF transmission channels for fixed and mobile reception. In order to simulate the impact of the fading transmission channels on the transmitted signal there was developed an appropriate application in MATLAB. The graphic user interface of this application allows set the transmission parameters of DVB-T2 and the parameters of the transmission channels. Results of simulations with various settings are evaluated and compared with the results, obtained from the DVB-T measurements.

The first topic of this thesis presents a bus driver design which is based on a charge recycle technique. The proposed design is mainly composed of a differential low swing circuit and a charge recycling circuit. The differential low swing signaling has been adopted to achieve low power and robust data transmission. The charge recycle is utilized to reduce power dissipation on long lines for the differential low swing signaling. The second topic is the coded orthogonal frequency division multiplex demodulation (COFDM) demodulator compliant with the European digital video broadcasting over terrestrial (DVB-T). It can recover the frequency offset of COFDM signal and dynamically select the FFT stages to synchronize the start of a symbol. The proposed design mainly contains four blocks : a time synchronization block, a frequency synchronization block, a 2K/8K FFT processor, and a channel estimation block.

<p>DAB (Digital Audio Broadcasting) is the radio digital system developed as an european standard by the ETSI, EN 300 400, based on the Eureka-147 group works, to improve the performance of the analogue radio systems (AM and FM). The system is based on the OFDM technology which allows DAB to exploit the spectrum frequencies in a better way with a higher quality of sound for mobile receivers specially. The main part of the OFDM system is based on the FFT algorithms to spread the data flow over different orthogonal carriers. The simulation has been developed in Simulink^TMand Matlab^TMand the layout designed follows faithfully the standard for the transmission system. The simulation can be reloaded by the user with the information presented in this thesis. Thus, this work can be continued to complete the DAB whole system simulation. The results obtained running this simulation show the main DAB system characteristics.</p>

DAB (Digital Audio Broadcasting) is the radio digital system developed as an european standard by the ETSI, EN 300 400, based on the Eureka-147 group works, to improve the performance of the analogue radio systems (AM and FM). The system is based on the OFDM technology which allows DAB to exploit the spectrum frequencies in a better way with a higher quality of sound for mobile receivers specially. The main part of the OFDM system is based on the FFT algorithms to spread the data flow over different orthogonal carriers. The simulation has been developed in Simulink&lt;sup&gt;TM&lt;/sup&gt;and Matlab&lt;sup&gt;TM&lt;/sup&gt;and the layout designed follows faithfully the standard for the transmission system. The simulation can be reloaded by the user with the information presented in this thesis. Thus, this work can be continued to complete the DAB whole system simulation. The results obtained running this simulation show the main DAB system characteristics.

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