ITC/USA 2005 Conference Proceedings / The Forty-First Annual International Telemetering Conference and Technical Exhibition / October 24-27, 2005 / Riviera Hotel & Convention Center, Las Vegas, Nevada / Hardware implementing forward error correction (FEC) is currently available for utilization by the airborne telemetry system designer. This paper will discuss the potential benefits along with drawbacks when using this technology. Laboratory testing is supplemented with real-world flight testing. Performance results comparing FEC and non-FEC systems are presented for both IRIG-106 Pulse Code Modulation/Frequency Modulation, PCM/FM, (or Continuous Phase Frequency Shift Keying, CPFSK, with filtering, or ARTM Tier 0) and Shaped Offset Quadrature Phase Shift Keying, Telemetry Group version (SOQPSK-TG or ARTM Tier I) waveforms.

International Telemetering Conference Proceedings / October 26-29, 1998 / Town & Country Resort Hotel and Convention Center, San Diego, California / There are well-known advantages in using pseudo-random sequences for testing of data communication links. The sequences, also called pseudo-noise (PN) sequences, approximate random data very well, especially for sequences thousands of bits long. They are easy to generate and are widely used for bit error rate testing because it is easy to synchronize a slave pattern generator to a received PN stream for bit-by-bit comparison. There are other aspects of PN sequences, however, that are not as widely known or applied. This paper points out how some of the less familiar characteristics of PN sequences can be put to practical use in the design of a Digital Test Set and other specialbuilt test equipment used for checkout of the EOS AM-1 Space Data Receiver. The paper also shows how knowledge of these PN sequence characteristics can simplify troubleshooting the digital sections in the Space Data Receiver. Finally, the paper addresses the sufficiency of PN data testing in characterizing the performance of a receiver/data recovery system.

In the thesis the design of process tolerant, use-aware radio-frequency front-ends were explored. First, the design of fuzzy logic and equation based controllers, which can adapt to multi-dimensional channel conditions, are proposed. Secondly, the thesis proves that adaptive systems can have multiple modes of operation depending upon the throughput requirements of the system. Two such modes were demonstrated: one optimizing the energy-per-bit (energy priority mode) and another achieving the lowest power consumption at the highest throughput (data priority mode). Finally, to achieve process tolerant channel adaptive operation a self-learning methodology is proposed which learns the optimal re-configuration setting for the system on-the-fly. Implications of the research are discussed and future avenues of further research are proposed.

International Telemetering Conference Proceedings / October 23-26, 2000 / Town & Country Hotel and Conference Center, San Diego, California / Bit error rate (BER) and bandwidth efficiency of several variations of enhanced Feher patented quadrature phase shift keying (FQPSK) [1] are described. An enhanced FQPSK increases the channel packing density of that of the IRIG 106-00 standardized FQPSK-B by approximately 50% in adjacent channel interference (ACI) environment. As the bandwidth efficiency of FQPSK-B DOUBLES (2×) that of pulse code modulation/Frequency modulation (PCM/FM) [5], the enhanced FQPSK, with a simpler transceiver than FQPSK-B, has a channel packing density of TRIPLE (3×) that of PCM/FM. One of the other enhanced FQPSK prototypes has an end to end system loss of only 0.4 dB at BER=1x10^(-3) and 0.5 dB at BER=1x10^(-4) from ideal linearly amplified QPSK theory. The enhanced FQPSK has a simple architecture, thus is inexpensive and has small size, for ultra high bit rate implementation. With low redundancy forward error correction (FEC) coding which expands the spectrum by approximately 10%, further improvement of about 3-4.5dB E N b o is attained with NLA FQPSK-B and enhanced FQPSK at BER=1x10^(-5) .

One would like to evaluate and compare complex digital communication systems based upon their overall bit error rate. Unfortunately, analytical expressions for bit error rate for even simple communication systems are notoriously difficult to evaluate accurately. Therefore, communication engineers often resort to simulation techniques to evaluate these error probabilities. In this thesis importance sampling techniques (variations of standard Monte Carlo methods) are studied in relation to both linear and non-linear detectors. Quick simulation, an importance sampling method based upon the asymptotics of the error estimator, is studied in detail. The simulated error probabilities are compared to values obtained by numerically inverting Laplace Transform expressions for these quantities.

Dans le cadre de la nouvelle société de l'information multimédia et communicante, cette thèse propose des contributions méthodologiques et techniques relatives à la représentation, l'animation et la transmission des objets virtuels.<br /><br />Les méthodes existantes sont analysées de façon comparée et les performances des standards multimédias actuels évaluées en termes de réalisme d'animation et de débit de transmission. Pour surmonter les limitations mises en évidence, un nouveau cadre de modélisation et d'animation de personnages virtuels est proposé. Le modèle SMS (Skeleton, Muscle and Skin), fondé sur le concept de contrôleur de déformation d'un maillage, est introduit et sa formulation mathématique développée. Le graphe de scène 3D et le flux de compression associés à SMS sont décrits. L'approche SMS est évaluée dans le cadre d'un nouveau service de transmission télévisuelle d'un signeur virtuel destinés aux déficients auditifs. Le modèle SMS a été promu dans le standard MPEG-4 version 5.

Studies indicate the educational needs of highly gifted students are best met through accelerated learning. It is difficult to recognize very young children that are suited for an accelerated curriculum because younger students frequently lack school records or portfolios used to identify gifted students. This study examined the accuracy of cognitive ability and achievement tests in predicting academic achievement by the end of second grade, correlating test results and final grade averages collected from sixteen children ages five to six who entered a public school program for high-ability learners in kindergarten. A multiple regression analysis indicated the Wechsler Preschool and Primary Scale of Intelligence produced the highest mean IQ score and a strong correlation with reading achievement. The Wechsler Individual Achievement Test contributed in small part to the prediction of academic achievement. The Naglieri Nonverbal Ability Test and the Kaufman Brief Intelligence Test-Second Edition had negative correlations with final grade averages, indicating they are not predictors of academic achievement for these students.

Most existing telephone networks transmit narrowband coded speech which has been bandlimited to 4 kHz. Compared with normal speech, this speech has a muffled quality and reduced intelligibility, which is particularly noticeable in sounds such as /s/, /f/ and /sh/. Speech which has been bandlimited to 8 kHz is often coded for this reason, but this requires an increase in the bit rate. Wideband enhancement is a scheme that adds a synthesized highband signal to narrowband speech to produce a higher quality wideband speech signal. The synthesized highband signal is based entirely on information contained in the narrowband speech, and is thus achieved at zero increase in the bit rate from a coding perspective. Wideband enhancement can function as a post-processor to any narrowband telephone receiver, or alternatively it can be combined with any narrowband speech coder to produce a very low bit rate wideband speech coder. Applications include higher quality mobile, teleconferencing, and internet telephony. This thesis examines in detail each component of the wideband enhancement scheme: highband excitation synthesis, highband envelope estimation, and narrowband-highband envelope continuity. Objective and subjective test measures are formulated to assess existing and new methods for all components, and the likely limitations to the performance of wideband enhancement are also investigated. A new method for highband excitation synthesis is proposed that uses a combination of sinusoidal transform coding-based excitation and random excitation. Several new techniques for highband spectral envelope estimation are also developed. The performance of these techniques is shown to be approaching the limit likely to be achieved. Subjective tests demonstrate that wideband speech synthesized using these techniques has higher quality than the input narrowband speech. Finally, a new paradigm for very low bit rate wideband speech coding is presented in which the quality of the wideband enhancement scheme is improved further by allocating a very small bitstream for highband envelope and gain coding. Thus, this thesis demonstrates that wideband speech can be communicated at or near the bit rate of a narrowband speech coder.

Nous abordons dans cette thèse le problème du calcul de la topologie de courbes algébriques planes. Nous présentons un algorithme qui, grâce à l'application d'outils algébriques comme les bases de Gröbner et les représentations rationnelles univariées, ne nécessite pas de traitement particulier de cas dégénérés. Nous avons implanté cet algorithme et démontré son efficacité par un ensemble de comparaisons avec les logiciels similaires. Nous présentons également une analyse de complexité sensible a la sortie de cet algorithme. Nous discutons ensuite des outils nécessaires pour l'implantation d'algorithmes de géométrie non-linéaire dans CGAL, la bibliothèque de référence de la communauté de géométrie algorithmique. Nous présentons un noyau univarié pour CGAL, un ensemble de fonctions nécessaires pour le traitement d'objets courbes définis par des polynômes univariés. Nous avons validé notre approche en la comparant avec les implantations similaires.

<p>Bit-serial multiplication with a fixed coefficient is commonly used in integrated circuits, such as digital filters and FFTs. These multiplications can be implemented using basic components such as adders, subtractors and D flip-flops. Multiplication with the same coefficient can be implemented in many ways, using different structures. Other studies in this area have focused on how to minimize the number of adders/subtractors, and often assumed that the cost for D flip-flops is neglectable. That simplification has been proved to be far too great, and further not at all necessary. In digital devices low power consumption is always desirable. How to attain this in bit-serial multipliers is a complex problem. </p><p>The aim of this thesis was to find a strategy on how to implement bit-serial multipliers with as low cost as possible. An important step was achieved by deriving formulas that can be used to calculate the carry switch probability in the adders/subtractors. It has also been established that it is possible to design a power model that can be applied to all possible structures of bit- serial multipliers.</p>