Orange S.A.

About: Orange S.A. is a company organization based out in Paris, France. It is known for research contribution in the topics: Terminal (electronics) & Signal. The organization has 6735 authors who have published 9190 publications receiving 156440 citations. The organization is also known as: Orange SA & France Télécom.

Widely tunable 1.55-/spl mu/m lasers for wavelength-division-multiplexed optical fiber communications

Abstract: Widely tunable lasers are essential components for high-capacity wavelength-division-multiplexed (WDM) transmission and photonic switching systems. For these optical fiber communication systems, they offer several advantages to increase the capacity, the functionality, and the flexibility of WDM networks. Nevertheless, these widely tunable transmitters must satisfy several stringent requirements depending on the specific application for which they are intended. Using criteria defined to compare the performances of several widely tunable laser structures reported in the literature, we pointed out a structure which presents a good tradeoff between high performances and technological processing simplicity. We designed and realized this component, the sampled-grating distributed Bragg reflector laser. Its tuning mechanism and main characteristics are first discussed. A short review is then made to compare these results to those measured on different widely tunable structures, and to propose improvements needed for practical implementation of these lasers for WDM optical fiber communications.

GeMSS: A Great Multivariate Short Signature

Abstract: The purpose of this document is to present GeMSS : a Great Multivariate Signature Scheme. As suggested by its name, GeMSS is a multivariate-based [14, 22, 4, 2, 20, 19] signature scheme producing small signatures. It has a fast verification process, and a medium/large public-key. GeMSS is in direct lineage from QUARTZ [18] and borrows some design rationale of the Gui multivariate signature scheme [5]. The former schemes are built from the Hidden Field Equations crypotsystem (HFE) [17, published in 1996] by using the so-called minus and vinegar modifiers, i.e. HFEv[12]. It is fair to say that HFE, and its variants, are the most studied schemes in multivariate cryptography. QUARTZ produces signatures of 128 bits for a security level of 80 bits and was submitted to the Nessie Ecrypt competition [15] for public-key signatures. In contrast to many multivariate schemes, no practical attack has been reported against QUARTZ. This is remarkable knowing the intense activity in the cryptanalysis of multivariate schemes, e.g. [16, 13, 7, 8, 11, 10, 6, 9, 4, 2, 3, 1, 19, 21]. The best known attack remains [8] that serves as a reference to set the parameters for GeMSS.

Spatial Data Multiplexing Over OFDM/OQAM Modulations

Abstract: Multi-carrier modulations (MCM) and especially orthogonal schemes such as orthogonal frequency division multiplexing (OFDM) are currently used in many radio transmission standards. Among these modulations, OFDM/OQAM (also referred as OFDM/Offset QAM) is an interesting alternative to classical OFDM modulation, as it does not require the use of guard interval. This characteristic makes its spectral efficiency optimal. In this paper we investigate the combination of OFDM/OQAM and multiple-input multiple-output (MIMO) over radio channels associated to non iterative and iterative receivers. We focus on spatial data multiplexing (SDM) which is a well known MIMO technique designed to improve the capacity.

Visible-light communication system enabling 73 Mb/s data streaming

Abstract: The hOME Gigabit Access (OMEGA) home-area-network project aims at bridging the gap between home and access network and providing Gb/s connectivity to users. The project considers a combination of various technologies such as radio-frequency and wireless optical links operating at infrared and visible wavelengths. When combined with power-line communications (PLC), this enables a home backbone that meets the project's “without new wires” vision. A technology-independent MAC layer will control this network and provide services as well as connectivity to any number of devices the user wishes to connect to in any room of a house/apartment. In order to make this vision come true, substantial progress had to be achieved in the fields of optical wireless physical layer development and data-link-layer protocol design. This paper reports an experimental demonstration of an indoor visible-light wireless link including a MAC layer protocol adapted to optical wireless communications systems. The system operates at 84 Mb/s broadcast and was successfully used to transmit three highdefinition video streams.