Égalisation itérative pour les transmissions multicodes de la liaison descendante de l'UMTS-FDD

- Cet article propose un récepteur itératif de faible complexité pour les transmissions multicodes de la liaison descendante de l'UMTS-FDD. Ce dispositif repose sur un égaliseur de canal itératif minimisant l'erreur quadratique moyenne (EQM) non biaisée en sortie du récepteur à chaque itération en fonction de la fiabilité de l'information a priori disponible. Les simulations numériques montrent que le récepteur proposé présente un compromis performances/complexité entre l'égaliseur linéaire et le récepteur de type turbo égaliseur présenté dans [1]

Liability in Software Engineering: Overview of the LISE Approach and Illustration on a Case Study

© ACM – 2010. This is the authors' pre-version of the work. It is posted here by permission of ACM for your personal use. Not for redistribution. The definitive version was published in the Proceedings of the 32nd ACM/IEEE international Conference on Software Engineering (ICSE'10) - Volume 1 – 978-1-60558-719-6/10/05 – (May 2-8 – 2010) http://doi.acm.org/10.1145/1806799.1806823LISE is a multidisciplinary project involving lawyers and computer scientists with the aim to put forward a set of methods and tools to (1) define software liability in a precise and unambiguous way and (2) establish such liability in case of incident. This report provides an overview of the overall approach taken in the project based on a case study. The case study illustrates a situation where, in order to reduce legal uncertainties, the parties to a contract wish to include in the agreement specific clauses to define as precisely as possible the share of liabilities between them for the main types of failures of the system

Proteome Serological Determination of Tumor-Associated Antigens in Melanoma

Proteome serology may complement expression library-based approaches as strategy utilizing the patients' immune responses for the identification pathogenesis factors and potential targets for therapy and markers for diagnosis. Melanoma is a relatively immunogenic tumor and antigens recognized by melanoma-specific T cells have been extensively studied. The specificities of antibody responses to this malignancy have been analyzed to some extent by molecular genetic but not proteomics approaches. We screened sera of 94 melanoma patients for anti-melanoma reactivity and detected seropositivity in two-thirds of the patients with 2–6 antigens per case detected by 1D and an average of 2.3 per case by 2D Western blot analysis. For identification, antigen spots in Western blots were aligned with proteins in 2-DE and analyzed by mass spectrometry. 18 antigens were identified, 17 of which for the first time for melanoma. One of these antigens, galectin-3, has been related to various oncogenic processes including metastasis formation and invasiveness. Similarly, enolase has been found deregulated in different cancers. With at least 2 of 18 identified proteins implicated in oncogenic processes, the work confirms the potential of proteome-based antigen discovery to identify pathologically relevant proteins

A Chip-Interleaving Pattern Retaining Orthogonality in DS-CDMA Systems: Application to the Multicode Downlink

Abstract — Interleaving the chip-level sequence resulting from spreading before transmission in direct spread code division multiple access (DS-CDMA) systems have been reported to allow significant improvements over conventional (non chipinterleaved) DS-CDMA. This transmission scheme has been shown to be of particular interest when used in conjunction with iterative receivers, allowing performance close to the multiple access (MAI) and intersymbol (ISI) interference-free case to be reached. This paper addresses the application of chip-interleaving to existing or near-future DS-CDMA systems. An interleaving pattern is introduced that allows the orthogonality property to be retained between interleaved and non-interleaved signals. In addition, a low-complexity receiver based on iterative channel equalization is designed for the multicode downlink of chipinterleaved DS-CDMA systems. Numerical simulations show that used in conjunction with the proposed interleaving scheme, the proposed receiver allows the interference-free performance of the non-interleaved case to be attained. I

Iterative channel equalization for the multicode

International audienceThis paper proposes an iterative receiver derived from recent advances in narrowband turbo equalization for the multicode transmission scheme of the downlink of DS-CDMA systems with long scrambling sequences. The proposed scheme is based on a chip-rate linear equalizer exchanging soft information on the composite multiuser signal with the channel decoder in an iterative process. When all spreading codes are known from the receiver, the equalizer may evolve from a linear minimum mean square error (MMSE) equalizer to an inter-chip interference (ICI) canceller, according to the reliability of the estimation of the chip-rate multiuser signal previously performed. When only partial knowledge about the codes is available, the equalizer becomes a hybrid structure between the linear MMSE equalizer and the ICI canceller. Numerical simulations demonstrate the efficiency of the proposed scheme compared to linear equalizers and multistage interference cancellers. In particular, it is shown that this receiver can still achive high performance in the présence of unknown codes, which makes it particularly attractive for future downlink high speed packet transmission systems