Alcatel-Lucent

About: Alcatel-Lucent is a based out in Stuttgart, Germany. It is known for research contribution in the topics: Signal & Network packet. The organization has 37003 authors who have published 53332 publications receiving 1430547 citations. The organization is also known as: Alcatel-Lucent S.A. & Alcatel.

Optical regeneration at 40 Gb/s and beyond

Abstract: As optical amplifiers have opened new perspectives for optical communication systems with ultrahigh capacities and long-haul transmission distances (more than 1 Tb/s over 10 000 km), fundamental limits are being felt. In order to overcome these propagation impairments, another technology revolution is soon required. Promising developments concern in-line all-optical regeneration, which makes it possible to transmit optical data over virtually unlimited distances. In this paper, we recall the basic principles of optical regeneration in optical communication systems and review the current technology alternatives foreseen for future 40-Gb/s transmission system implementation, as investigated in Alcatel Research and Innovation. The alternative offered by optoelectronic regeneration is also discussed, so as to identify and highlight the advantages of the all-optical approach.

Exact Quantization of the Even-Denominator Fractional Quantum Hall State at ν = 5 / 2 Landau Level Filling Factor

Abstract: We report ultralow temperature experiments on the obscure fractional quantum Hall effect at Landau level filling factor $\ensuremath{ u}\phantom{\rule{0ex}{0ex}}=\phantom{\rule{0ex}{0ex}}5/2$ in a very high-mobility specimen of $\ensuremath{\mu}\phantom{\rule{0ex}{0ex}}=\phantom{\rule{0ex}{0ex}}1.7\ifmmode\times\else\texttimes\fi{}{10}^{7}{\mathrm{cm}}^{2}/\mathrm{V}\mathrm{s}$. We achieve an electron temperature as low as $\ensuremath{\sim}4\mathrm{mK}$, where we observe vanishing ${R}_{\mathrm{xx}}$ and, for the first time, a quantized Hall resistance, ${R}_{\mathrm{xy}}\phantom{\rule{0ex}{0ex}}=\phantom{\rule{0ex}{0ex}}h/(5/2){e}^{2}$ to within 2 ppm. ${R}_{\mathrm{xy}}$ at the neighboring odd-denominator states $\ensuremath{ u}\phantom{\rule{0ex}{0ex}}=\phantom{\rule{0ex}{0ex}}7/3$ and $8/3$ is also quantized. The temperature dependences of the ${R}_{\mathrm{xx}}$ minima at these fractional fillings yield activation energy gaps ${\ensuremath{\Delta}}_{5/2}\phantom{\rule{0ex}{0ex}}=\phantom{\rule{0ex}{0ex}}0.11$, ${\ensuremath{\Delta}}_{7/3}\phantom{\rule{0ex}{0ex}}=\phantom{\rule{0ex}{0ex}}0.10$, and ${\ensuremath{\Delta}}_{8/3}\phantom{\rule{0ex}{0ex}}=\phantom{\rule{0ex}{0ex}}0.055\mathrm{K}$.

Discriminative utterance verification for connected digits recognition

Abstract: Utterance verification represents an important technology in the design of user-friendly speech recognition systems It involves the recognition of keyword strings and the rejection of nonkeyword strings This paper describes a hidden Markov model-based (HMM-based) utterance verification system using the framework of statistical hypothesis testing The two major issues on how to design keyword and string scoring criteria are addressed For keyword verification, different alternative hypotheses are proposed based on the scores of antikeyword models and a general acoustic filler model For string verification, different measures are proposed with the objective of detecting nonvocabulary word strings and possibly erroneous strings (so-called putative errors) This paper also motivates the need for discriminative hypothesis testing in verification One such approach based on minimum classification error training is investigated in detail When the proposed verification technique was integrated into a state-of-the-art connected digit recognition system, the string error rate for valid digit strings was found to decrease by 57% when setting the rejection rate to 5% Furthermore, the system was able to correctly reject over 999% of nonvocabulary word strings

An efficient block-matching algorithm for motion-compensated coding

Abstract: We present an efficient search technique which minimizes the computations necessary for estimating the motion in video-sequences by the block matching method We also discuss the theoretical basis for conducting such a reduced search by our technique We then present two algorithms which employ the proposed technique for estimating the motion typical of video-conferencing environment Next, the results of computer simulations on a real video-sequence are included which demonstrate the effectiveness of the proposed technique Finally, the results of a study of statistical properties of block motion-compensated frame difference signals are also summarized, to assist in future choice of a coding strategy for such signals