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Abstract-In this paper, simple autonomous chaotic circuits
coupled by resistors are investigated. By carrying out computer
calculations and circuit experiments, irregular self-switching phenomenon
of three spatial patterns characterized by the phase
states of quasi-synchronization of chaos can be observed from
only four simple chaotic circuits. This is the same phenomenon
as chaotic wandering of spatial patterns observed very often from
systems with a large number of degrees of freedom. Namely, one
of spatial-temporal chaos observed from systems of large size can
be also generated in the proposed system consisting of only four
chaotic circuits. A six subcircuits case and a coupled chaotic circuits
networks are also studied, and such systems are confirmed
to produce more complicated spatio-temporal phenomena.
標(biāo)簽：
investigated
Abstract-In
autonomous
resistors
上傳時(shí)間：
2014-06-09
上傳用戶：h886166
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We introduce a sub-cell WENO reconstruction method to evaluate spatial derivatives in the high-order ADER scheme. The basic idea in our reconstruction is to use only r stencils to reconstruct the point-wise values of solutions and spatial derivatives for the 2r-1 th order
ADER scheme in one dimension, while in two dimensions, the dimension-by-dimension sub-cell reconstruction approach for spatial derivatives is employed. Compared with the original ADER scheme of Toro and Titarev (2002) [2] that uses the direct derivatives of reconstructed polynomials for solutions to evaluate spatial derivatives, our method not only reduces greatly the computational costs of the ADER scheme on a given mesh,
but also avoids possible numerical oscillations near discontinuities, as demonstrated by a number of one- and two-dimensional numerical tests. All these tests show that the 5th-order ADER scheme based on our sub-cell reconstruction method achieves the desired accuracy, and is essentially non-oscillatory and computationally cheaper for problems with discontinuities.
標(biāo)簽：
高精度格式
上傳時(shí)間：
2016-01-13
上傳用戶：ccsdcczd
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This report presents a tutorial of fundamental array processing and beamforming theory relevant to microphone array speech processing. A microphone array consists of multiple microphones placed at different spatial locations. Built upon a knowledge of sound propagation principles, the multiple inputs can be manipulated to enhance or attenuate signals emanating from particular directions. In this way, microphone arrays provide a means of enhancing a desired signal in the presence of corrupting noise sources. Moreover, this enhancement is based purely on knowledge of the source location, and so microphone array techniques are applicable to a wide variety of noise types. Microphone arrays have great potential in practical applications of speech processing, due to their ability to provide both noise robustness and hands-free signal acquisition.
標(biāo)簽：
Microphone array
Tutorial
Array Signal Processing
上傳時(shí)間：
2016-06-12
上傳用戶：halias
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Employing multiple transmit and receive antennas, namely using multi-input multi-output
(MIMO) systems, has proven to be a major breakthrough in providing reliable wireless
communication links. Since their invention in the mid-1990s, transmit diversity, achieved
through space-time coding, and spatial multiplexing schemes have been the focus of much
research in the area of wireless communications.
標(biāo)簽：
Communication
Systems
Coding
MIMO
for
上傳時(shí)間：
2020-05-26
上傳用戶：shancjb
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To meet the future demand for huge traffic volume of wireless data service, the research on the fifth generation
(5G) mobile communication systems has been undertaken in recent years. It is expected that the spectral and energy
efficiencies in 5G mobile communication systems should be ten-fold higher than the ones in the fourth generation
(4G) mobile communication systems. Therefore, it is important to further exploit the potential of spatial multiplexing
of multiple antennas. In the last twenty years, multiple-input multiple-output (MIMO) antenna techniques have been
considered as the key techniques to increase the capacity of wireless communication systems. When a large-scale
antenna array (which is also called massive MIMO) is equipped in a base-station, or a large number of distributed
antennas (which is also called large-scale distributed MIMO) are deployed, the spectral and energy efficiencies can
be further improved by using spatial domain multiple access. This paper provides an overview of massive MIMO
and large-scale distributed MIMO systems, including spectral efficiency analysis, channel state information (CSI)
acquisition, wireless transmission technology, and resource allocation.
標(biāo)簽：
Large-scale
Antenna
Systems
上傳時(shí)間：
2020-05-27
上傳用戶：shancjb
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Many wireless communications channels consist of multiple signal paths from the
transmitter to receiver. This multiplicity of paths leads to a phenomenon known
as multipath fading. The multiple paths are caused by the presence of objects in the
physical environment that, through the mechanisms of propagation, alter the path of
radiated energy. These objects are referred to as scatterers. In the past, researchers
often looked at ways to mitigate multipath scattering, such as in diversity systems.
Multiple-input, multiple-output (MIMO) systems, on the other hand, use multipath
diversity to their advantage; a MIMO system has the ability to translate increased
spatial diversity into increased channel capacity.
標(biāo)簽：
Multiple-Output
Multiple-Input
Channel
Models
上傳時(shí)間：
2020-05-31
上傳用戶：shancjb
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In this thesis several asp ects of space-time pro cessing and equalization for wire-
less communications are treated. We discuss several di?erent metho ds of improv-
ing estimates of space-time channels, such as temp oral parametrization, spatial
parametrization, reduced rank channel estimation, b o otstrap channel estimation,
and joint estimation of an FIR channel and an AR noise mo del. In wireless commu-
nication the signal is often sub ject to intersymb ol interference as well as interfer-
ence from other users.
標(biāo)簽：
Communications
Space-Time
Processing
Wireless
for
上傳時(shí)間：
2020-06-01
上傳用戶：shancjb
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Part I provides a compact survey on classical stochastic geometry models. The basic models defined
in this part will be used and extended throughout the whole monograph, and in particular to SINR based
models. Note however that these classical stochastic models can be used in a variety of contexts which
go far beyond the modeling of wireless networks. Chapter 1 reviews the definition and basic properties of
Poisson point processes in Euclidean space. We review key operations on Poisson point processes (thinning,
superposition, displacement) as well as key formulas like Campbell’s formula. Chapter 2 is focused on
properties of the spatial shot-noise process: its continuity properties, its Laplace transform, its moments
etc. Both additive and max shot-noise processes are studied. Chapter 3 bears on coverage processes,
and in particular on the Boolean model. Its basic coverage characteristics are reviewed. We also give a
brief account of its percolation properties. Chapter 4 studies random tessellations; the main focus is on
Poisson–Voronoi tessellations and cells. We also discuss various random objects associated with bivariate
point processes such as the set of points of the first point process that fall in a Voronoi cell w.r.t. the second
point process.
標(biāo)簽：
Stochastic
Geometry
Networks
Wireless
Volume
and
上傳時(shí)間：
2020-06-01
上傳用戶：shancjb
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The explosion in demand for wireless services experienced over the past 20 years
has put significant pressure on system designers to increase the capacity of the
systems being deployed. While the spectral resource is very scarce and practically
exhausted, the biggest possibilities are predicted to be in the areas of spectral reuse
by unlicensed users or in exploiting the spatial dimension of the wireless channels.
The former approach is now under intense development and is known as the cogni-
tive radio approach (Haykin 2005).
標(biāo)簽：
Multi-Antenna
Wireless
Channels
Modeling
上傳時(shí)間：
2020-06-01
上傳用戶：shancjb
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In this research, we have designed, developed implemented a wireless sensor
networks based smart home for safe, sound and secured living environment for
any inhabitant especially elderly living alone. We have explored a methodology
for the development of efficient electronic real time data processing system to
recognize the behaviour of an elderly person. The ability to determine the
wellness of an elderly person living alone in their own home using a robust,
flexible and data driven artificially intelligent system has been investigated. A
framework integrating temporal and spatial contextual information for
determining the wellness of an elderly person has been modelled. A novel
behaviour detection process based on the observed sensor data in performing
essential daily activities has been designed and developed.
標(biāo)簽：
Smart
Homes
上傳時(shí)間：
2020-06-06
上傳用戶：shancjb
