25,559 research outputs found
Blind Demixing for Low-Latency Communication
In the next generation wireless networks, lowlatency communication is
critical to support emerging diversified applications, e.g., Tactile Internet
and Virtual Reality. In this paper, a novel blind demixing approach is
developed to reduce the channel signaling overhead, thereby supporting
low-latency communication. Specifically, we develop a low-rank approach to
recover the original information only based on a single observed vector without
any channel estimation. Unfortunately, this problem turns out to be a highly
intractable non-convex optimization problem due to the multiple non-convex
rankone constraints. To address the unique challenges, the quotient manifold
geometry of product of complex asymmetric rankone matrices is exploited by
equivalently reformulating original complex asymmetric matrices to the
Hermitian positive semidefinite matrices. We further generalize the geometric
concepts of the complex product manifolds via element-wise extension of the
geometric concepts of the individual manifolds. A scalable Riemannian
trust-region algorithm is then developed to solve the blind demixing problem
efficiently with fast convergence rates and low iteration cost. Numerical
results will demonstrate the algorithmic advantages and admirable performance
of the proposed algorithm compared with the state-of-art methods.Comment: 14 pages, accepted by IEEE Transaction on Wireless Communicatio
Quantum ESPRESSO: a modular and open-source software project for quantum simulations of materials
Quantum ESPRESSO is an integrated suite of computer codes for
electronic-structure calculations and materials modeling, based on
density-functional theory, plane waves, and pseudopotentials (norm-conserving,
ultrasoft, and projector-augmented wave). Quantum ESPRESSO stands for "opEn
Source Package for Research in Electronic Structure, Simulation, and
Optimization". It is freely available to researchers around the world under the
terms of the GNU General Public License. Quantum ESPRESSO builds upon
newly-restructured electronic-structure codes that have been developed and
tested by some of the original authors of novel electronic-structure algorithms
and applied in the last twenty years by some of the leading materials modeling
groups worldwide. Innovation and efficiency are still its main focus, with
special attention paid to massively-parallel architectures, and a great effort
being devoted to user friendliness. Quantum ESPRESSO is evolving towards a
distribution of independent and inter-operable codes in the spirit of an
open-source project, where researchers active in the field of
electronic-structure calculations are encouraged to participate in the project
by contributing their own codes or by implementing their own ideas into
existing codes.Comment: 36 pages, 5 figures, resubmitted to J.Phys.: Condens. Matte
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