Joint space-time trellis decoding and channel estimation in correlated fading channels

This letter addresses the issue of joint space-time trellis decoding and channel estimation in time-varying fading channels that are spatially and temporally correlated. A recursive space-time receiver which incorporates per-survivor processing (PSP) and Kalman filtering into the Viterbi algorithm is proposed. This approach generalizes existing work to the correlated fading channel case. The channel time-evolution is modeled by a multichannel autoregressive process, and a bank of Kalman filters is used to track the channel variations. Computer simulation results show that a performance close to the maximum likelihood receiver with perfect channel state information (CSI) can be obtained. The effects of the spatial correlation on the performance of a receiver that assumes independent fading channels are examined.

Placing space/time through photography’s old and new technologies

The discovery that an impressively strong 3-dimensional effect in a 2-dimensional photographic representation of natural outdoor scenes occurs when a single camera is directed around one point in the scene, thus drawing into relief the subject of attention and blurring the surrounding space, has important implications for understanding basic processes in 3-dimensional vision. For the development of new ways for generating 3D effects in motion and static representations of scenes we might well learn from photography’s old technologies, as well as digital technologies of the static print, which have yet to release the full impact of their potential in the representation of motion and space.

Building movements : installations : space-time twister; the rub

The two collaborative installations are part of the Building Movements event and aim to generate a shared ‘body of actions’. We are proposing to emphasise attention to constructed environments (buildings, clothes, landscapes…) as active participants in ecologies of lived experience, with particular interest in how we can more explicitly approach our environments as spatial research devices, i.e. how constructed environments can offer key questions and provocations in any research enquiry.

Enchanting David Bowie space/time/body/memory

This exciting collection is organized according to the key themes of space, time, body, and memory - themes that literally and metaphorically address the key questions and intensities of his output.

Affine and curvature collineations in space-time

Graham Hall

Confinement of spinless particles by Coulomb potentials in two-dimensional space-time

The problem of confinement of spinless particles in 1 + 1 dimensions is approached with a linear potential by considering a mixing of Lorentz vector and scalar couplings. Analytical bound-states solutions are obtained when the scalar coupling is of sufficient intensity compared to the vector coupling. (c) 2005 Elsevier B.V. All rights reserved.

Confinement of fermions by mixed vector-scalar linear potentials in two-dimensional space-time

The problem of confinement of fermions in 1 + 1 dimensions is approached with a linear potential in the Dirac equation by considering a mixing of Lorentz vector and scalar couplings. Analytical bound-states solutions are obtained when the scalar coupling is of sufficient intensity compared to the vector coupling. (C) 2002 Elsevier B.V. B.V. All rights reserved.

Arithmetic fuchsian groups and space time block codes

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Feeding selectivity of ichthyofauna in a tropical stream: space-time variations in trophic plasticity

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

A model for Hopfions on the space-time S(3)xR

We construct static and time dependent exact soliton solutions for a theory of scalar fields taking values on a wide class of two dimensional target spaces, and defined on the four dimensional space-time S-3 X R. The construction is based on an ansatz built out of special coordinates on S3. The requirement for finite energy introduce boundary conditions that determine an infinite discrete spectrum of frequencies for the oscillating solutions. For the case where the target space is the sphere S-2, we obtain static soliton solutions with nontrivial Hopf topological charges. In addition, such Hopfions can oscillate in time, preserving their topological Hopf charge, with any of the frequencies belonging to that infinite discrete spectrum. (C) 2005 American Institute of Physics.

Compton scattering in noncommutative space-time at the Next Linear Collider

We study Compton scattering in the noncommutative (NC) counterpart of QED. Interactions in NC QED have momentum dependent phase factors and the gauge fields have Yang-Mills type couplings; this modifies the cross sections and they are different from the commuting standard model. Collider signals of noncommutative space-time are studied at the Next Linear Collider (NLC) operating in the e gamma mode. Results for different polarized cases are presented and it is shown that the Compton process can probe the noncommutative scale in the range of 1-2.5 TeV for typical proposed NLC energies.