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.

Vibrational energy transfer of CO/Cu(100): Nonadiabatic vibration/electron coupling

Abstract: Vibrational energy relaxation of the internal C–O stretching mode of carbon monoxide in the c(2×2) overlayer on the Cu(100) surface at 120 K is measured by picosecond pump–probe spectroscopy. A resonant 1.5 ps infrared pulse at ν=2085 cm−1 pumps the C–O stretching mode. The energy relaxation is monitored by sum frequency generation from a delayed pair of 1.5 ps infrared and visible pulses. A single component decay, with a decay time of 2.0 ±0.5 ps, is reported. Uncertainties in the actual excited state lifetime are discussed, and the actual lifetime is estimated to be 2.0 ±1.0 ps. This lifetime is close to the lower limit of 1.2 ps set by the observed vibrational linewidth of 4.5 cm−1. The energy relaxation process is interpreted to occur by nonadiabatic energy transfer to the electrons (electron‐hole pair excitations) of the copper substrate, and the measurement supports previous assertions that the nonadiabatic energy transfer rate for this system is very rapid. The nonadiabatic energy transfer lifetime of this mode has previously been estimated by density‐functional calculations [T. T. Rantala and A. Rosen, Phys. Rev. B 34, 837 (1986)], and has recently been calculated by extrapolation of ab initio Hartree–Fock electronic structure calculations for CO on copper clusters [M. Head‐Gordon and J. Tully, preceding paper, J. Chem. Phys. 96, 3939 (1992)]. The calculated lifetimes in both cases are in the 1–3 ps range, in good agreement with the experimentally measured value.

IASI instrument: technical overview and measured performances

Abstract: The Infrared Atmospheric Sounding Interferometer (IASI) is a key payload element of the METOP series of European meteorological polar-orbit satellites. IASI will provide very accurate data about the atmosphere, land and oceans for application to weather predictions and climate studies. The IASI measurement technique is based on passive IR remote sensing using an accurately calibrated Fourier Transform Spectrometer operating in the 3.7 - 15.5 μm spectral range and an associated infrared imager operating in the 10.3-12.5 μm spectral range. The optical configuration of the sounder is based on a Michelson interferometer. Interferograms are processed by the on-board digital processing subsystem which performs the inverse Fourier Transform and the radiometric calibration. The integrated infrared imager allows the co registration of the IASI sounder with AVHRR imager on-board METOP. The first model (proto-flight) of IASI has successfully completed a verification program conducted at ALCATEL SPACE premises in Cannes. This paper provides a brief overview of the IASI mission, instrument architecture and key performances results. A companion paper1 by Alcatel provides more information on instrument design and development.

An ESPRIT-Based Approach for 2-D Localization of Incoherently Distributed Sources in Massive MIMO Systems

Abstract: In this paper, an approach of estimating signal parameters via rotational invariance technique (ESPRIT) is proposed for two-dimensional (2-D) localization of incoherently distributed (ID) sources in large-scale/massive multiple-input multiple-output (MIMO) systems. The traditional ESPRIT-based methods are valid only for one-dimensional (1-D) localization of the ID sources. By contrast, in the proposed approach the signal subspace is constructed for estimating the nominal azimuth and elevation direction-of-arrivals and the angular spreads. The proposed estimator enjoys closed-form expressions and hence it bypasses the searching over the entire feasible field. Therefore, it imposes significantly lower computational complexity than the conventional 2-D estimation approaches. Our analysis shows that the estimation performance of the proposed approach improves when the large-scale/massive MIMO systems are employed. The approximate Cramer-Rao bound of the proposed estimator for the 2-D localization is also derived. Numerical results demonstrate that albeit the proposed estimation method is comparable with the traditional 2-D estimators in terms of performance, it benefits from a remarkably lower computational complexity.

Program category selection with filtered data and displayed cascaded cards

Abstract: An apparatus and method for presenting a viewer with an overall representation of the present number of entertainment programs available for selection given one week of program schedule data for 300 or more channels and one or more filtering criteria to limit the number of items represented in the overall representation. Sequentially applied filters will filter the group of program schedule data items that has at least 100,000 half hour time slots offered by 300 channels each week into a smaller subgroup where individual consideration of each item of the subgroup can be made in a reasonable time. A set top box drives the display of overall representations or results of filtering criteria on a commercial TV set. Once a reasonable sized subgroup is obtained, other displays provide specific information of the program offerings of the subgroup. Selection of the filtering criteria and selection from within a subgroup is interactively made by a viewer through the use of a controller that looks and operates very much like a TV remote control. This makes the interaction familiar, easy and predictable.

Information-guided channel-hopping for high data rate wireless communication

Abstract: In this letter, we introduce information-guided channel-hopping, a new scheme for high data rate communication over Rayleigh fading channel using multiple transmit antennas. This scheme is proposed based on the fact that the independence character of multi-channel can be used as an additional information transmitting channel, and the maximum likelihood decoding can be achieved in a simple way by decoupling of the signals conveyed by different methods. The analysis results prove that the capacity behavior of this scheme is better than that of the space-time block coding for more than two transmit antennas.