Broadcasting systems have to deal with channel diversity in order to offer the best rate to the users. Hierarchical modulation is a practical solution to provide several rates in function of the channel quality. Unfortunately the performance evaluation of such modulations requires time consuming simulations. We propose in this paper a novel approach based on the channel capacity to avoid these simulations. The method allows to study the performance in terms of spectrum efficiency of hierarchical and also classical modulations combined with error correcting codes. Our method will be applied to the DVB-SH standard which considers hierarchical modulation as an optional feature.

The Stokes decomposition theorem deals with the electrical field E-->=X,Y of a light beam. The theorem asserts that a beam can be viewed as the sum of two differently polarized parts. This result was recently discussed for light in the frame of the unified theory of coherence. We study the general case of an electromagnetic wave which can be in radio, radar, communications, or light. We assume stationary components with any power spectrum and finite or infinite bandwidth. We show that an accurate definition of polarization and unpolarization is a key parameter which rules the set of solutions of the problem. When dealing with a ``strong definition'' of unpolarization, the problem is treated in the frame of stationary processes and linear invariant filters. When dealing with a ``weak definition'', solutions are given by elementary properties of bidimensional random variables.

In networks with very large delay like satellite IPbased networks, standard TCP is unable to correctly grab the available resources. To overcome this problem, Performance Enhancing Proxies (PEPs), which break the end-to-end connection and simulate a receiver close enough to the sender, can be placed before the links with large delay. Although splitting PEPs does not modify the transport protocol at the end nodes, they prevent the use of security protocols such as IPsec. In this paper, we propose solutions to replace the use of PEPs named SatERN. This proposal, based on Explicit Rate Notification (ERN) protocols over IP, does not split connections and is compliant with IP-in- IP tunneling solutions. Finally, we show that the SatERN solution achieves high satellite link utilization and fairness of the satellite traffic.

This paper introduces a new error correction strategy using cyclic redundancy checks (CRC) for a trellis coded system in the presence of bit stuffing. The proposed receiver is designed to simultaneously demodulate, decode and correct the received message in the presence of bit stuffing. It is based on a Viterbi algorithm exploiting the conditional transitions of an appropriate extended trellis. The receiver is evaluated with automatic identification system (AIS) messages constructed with a 16 bit CRC and a Gaussian Minimum Shift Keying (GMSK) modulation. The stuffed bits are inserted after any sequence of five consecutive bits 1 as requested by the AIS recommendation. Simulation results illustrate the algorithm performance in terms of packet error rate. A gain of more than 2,5 dB is obtained when compared to the conventional GMSK receiver.

Digital Spectral Analysis provides a single source that offers complete coverage of the spectral analysis domain. This self-contained work includes details on advanced topics that are usually presented in scattered sources throughout the literature. The theoretical principles necessary for the understanding of spectral analysis are discussed in the first four chapters: fundamentals, digital signal processing, estimation in spectral analysis, and time-series models. An entire chapter is devoted to the non-parametric methods most widely used in industry. High resolution methods are detailed in a further four chapters: spectral analysis by stationary time series modeling, minimum variance, and subspace-based estimators. Finally, advanced concepts are the core of the last four chapters: spectral analysis of non-stationary random signals, space time adaptive processing: irregularly sampled data processing, particle filtering and tracking of varying sinusoids. Suitable for students, engineers working in industry, and academics at any level, this book provides a rare complete overview of the spectral analysis domain.

The delineation of P and T waves is important for the interpretation of ECG signals. We propose a Bayesian detection-estimation algorithm for simultaneous detection, delineation, and estimation of P and T waves. A block Gibbs sampler exploits the strong local dependencies in ECG signals by imposing block constraints on the P and T wave locations. The proposed algorithm is evaluated on the annotated QT database and compared with two classical algorithms.

Le NPR (noise power ratio) et l’EVM (error vector magnitude) sont deux méthodes de mesure des distorsions ou des dégradations, linéaires ou non, des modulateurs numériques et des chaînes de transmission de signaux modulés. Chaque méthode mesure un bruit qui peut être ajouté au bruit thermique du système dans le bilan de liaison. On montre dans quelles conditions ces deux mesures donnent la même valeur et comment on peut remplacer l’une par l’autre afin de simplifier les simulations ainsi que les bancs de mesure, en particulier pour des mesures en large bande.

Since no similar studies has been proposed, this work intends to present the first conclusions about the possibilities of satellite communications in the distribution of MANET routing signaling. The improvements on MANET routing protocols will be evaluated to figure out if it is interesting or not to introduce this new role for satellites. For that purpose we shall delimit the applicative context. Mobile ad hoc networks are suitable for a wide range of applications. However, the presence of satellite terminals are not always guaranteed. One of the objectives of this work is to identify the applicative contexts where the hybrid terrestrial-satellite signaling distribution is suitable. Another point is the routing protocol itself. A lot of MANET routing protocols are available from the literature. Therefore we need to analyze the different routing solutions so to identify the most adaptable to a hybrid terrestrialsatellite signaling distribution. Finally, we intend to describe the steps and the crucial points of MANET routing protocol evaluation. Several tasks are involved: network modeling, scenario and performance metrics, output analysis techniques, etc. Therefore we highlight the complexity of MANET routing evaluation and present guidelines to achieve valid and representative results

Broadcasting systems have to deal with channel variability in order to offer the best rate to the users. Hierarchical modulation is a practical solution to provide different rates to the receivers in function of the channel quality. Unfortunately, the performance evaluation of such modulations requires time consuming simulations. We propose in this paper a novel approach based on the channel capacity to avoid these simulations. The method allows to study the performance of hierarchical and also classical modulations combined with error correcting codes. We will also compare hierarchical modulation with time sharing strategy in terms of achievable rates and indisponibility. Our work will be applied to the DVB-SH and DVB-S2 standards, which both consider hierarchical modulation as an optional feature.