2,168 research outputs found
Non-Volatile Magnonic Logic Circuits Engineering
We propose a concept of magnetic logic circuits engineering, which takes an
advantage of magnetization as a computational state variable and exploits spin
waves for information transmission. The circuits consist of magneto-electric
cells connected via spin wave buses. We present the result of numerical
modeling showing the magneto-electric cell switching as a function of the
amplitude as well as the phase of the spin wave. The phase-dependent switching
makes it possible to engineer logic gates by exploiting spin wave buses as
passive logic elements providing a certain phase-shift to the propagating spin
waves. We present a library of logic gates consisting of magneto-electric cells
and spin wave buses providing 0 or p phase shifts. The utilization of phases in
addition to amplitudes is a powerful tool which let us construct logic circuits
with a fewer number of elements than required for CMOS technology. As an
example, we present the design of the magnonic Full Adder Circuit comprising
only 5 magneto-electric cells. The proposed concept may provide a route to more
functional wave-based logic circuitry with capabilities far beyond the limits
of the traditional transistor-based approach
Density Evolution and Functional Threshold for the Noisy Min-Sum Decoder
This paper investigates the behavior of the Min-Sum decoder running on noisy
devices. The aim is to evaluate the robustness of the decoder in the presence
of computation noise, e.g. due to faulty logic in the processing units, which
represents a new source of errors that may occur during the decoding process.
To this end, we first introduce probabilistic models for the arithmetic and
logic units of the the finite-precision Min-Sum decoder, and then carry out the
density evolution analysis of the noisy Min-Sum decoder. We show that in some
particular cases, the noise introduced by the device can help the Min-Sum
decoder to escape from fixed points attractors, and may actually result in an
increased correction capacity with respect to the noiseless decoder. We also
reveal the existence of a specific threshold phenomenon, referred to as
functional threshold. The behavior of the noisy decoder is demonstrated in the
asymptotic limit of the code-length -- by using "noisy" density evolution
equations -- and it is also verified in the finite-length case by Monte-Carlo
simulation.Comment: 46 pages (draft version); extended version of the paper with same
title, submitted to IEEE Transactions on Communication
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