Results 231 to 240 of about 381,897 (285)

Time-variant channel estimation using discrete prolate spheroidal sequences

IEEE Transactions on Signal Processing, 2005
We propose and analyze a low-complexity channel estimator for a multiuser multicarrier code division multiple access (MC-CDMA) downlink in a time-variant frequency-selective channel. MC-CDMA is based on orthogonal frequency division multiplexing (OFDM).
T. Zemen, C.F. Mecklenbrauker
openaire   +3 more sources

Measurement of Time-Variant Linear Channels

IEEE Transactions on Information Theory, 2006
The goal of channel measurement or operator identification is to obtain complete knowledge of a channel operator by observing the image of a finite number of input signals. In this paper, it is shown that the spreading support of the operator (that is, the support of the symplectic Fourier transform of the Kohn-Nirenberg symbol of the operator) has ...
Pfander, Götz E., Walnut, David
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Modeling the time-variant MIMO channel

2nd European Conference on Antennas and Propagation (EuCAP 2007), 2007
This paper studies two different modeling strategies for capturing the time-variant behavior of multiple-input multiple-output wireless channels. The first method generates a multi-variate random description of the channel matrix based on the measured space-time covariance. The second method describes the physical variation of the multipath propagation
M.A. Jensen, J.W. Wallace
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Time variant models for satellite channel

[1992 Proceedings] Vehicular Technology Society 42nd VTS Conference - Frontiers of Technology, 2003
Different methods used to design mathematical models for a satellite channel are considered. These channel models, based on homogeneous Markov chains, are used as a basis for evaluation of OSI layer two protocols. The parameter design of the models is based on measured block error probabilities, obtained by German PTT on the Olympus 20/30-GHz channel ...
M.A. Jolfaei, D. Kreuer, O. Maly, U. Quernheim, W. Kremer   +4 more
openaire   +1 more source

Channel Phase Estimate in Time Variant SIMO Systems

2006 IEEE International Conference on Acoustics Speed and Signal Processing Proceedings, 2006
This paper introduces a novel ML based approach to channel identification for time variant SIMO (Single Input Multiple Output) systems fed by a stochastic process. We focus on the particular case where the unknowns are represented by the channels phases, that find applications in RADAR interferometry.
MONTI-GUARNIERI, ANDREA VIRGILIO, TEBALDINI, STEFANO   +1 more
openaire   +2 more sources

Identification of time-variant directional mobile radio channels

IMTC/99. Proceedings of the 16th IEEE Instrumentation and Measurement Technology Conference (Cat. No.99CH36309), 2003
For the identification of the time-variant, directional structure of the mobile radio channel impulse response, a broadband vector channel sounder is described. The measurement procedure relies on periodic multifrequency excitation signals, correlation processing and joint delay-azimuth superresolution based on the ESPRIT algorithm.
R. S. Thomä, D. Hampicke, A. Richter, G. Sommerkorn, A. Schneider, U. Trautwein   +5 more
openaire   +1 more source

Simulation methods for time-variant wideband channels

GLOBECOM 97. IEEE Global Telecommunications Conference. Conference Record, 2002
For an in-depth investigation of modern modulation techniques suited for wideband mobile communications, it is necessary to simulate randomly time-variant multipath channels. A time-variant multipath channel distorts a transmission link by frequency and time dispersion. In comparison to the simulation of time dispersion caused by multipath propagation,
Wetzker, Gunnar, Jondral, Friedrich
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Optimal pilot pattern for time variant channels

2013 IEEE International Conference on Communications (ICC), 2013
In order to estimate a transmission channel, a typical wireless communications system multiplexes a fixed pattern of symbols known at the receiver within the data-symbols. In Long Term Evolution (LTE), these reference symbols can consume up to 14.2% of the total transmission bandwidth. In this work, we investigate an optimal pilot-symbol pattern design
Michal Simko, Qi Wang, Markus Rupp
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Two time variant models for satellite channels

[Conference Record] SUPERCOMM/ICC '92 Discovering a New World of Communications, 2003
The authors consider different methods to design mathematical models for a satellite channel. These channel models, being based on homogeneous Markov chains, are used as a basis for evaluations of the open systems interconnection (OSI) layer 2 protocols.
M.A. Jolfaei, D. Kreuer, O. Maly, U. Querheim   +3 more
openaire   +1 more source

A channel estimation-based adaptive equaliser for time-variant communications channels

Conference Record of The Twenty-Ninth Asilomar Conference on Signals, Systems and Computers, 2002
For the purpose of tackling the problem of equalisation in a time variant environment, a novel approach is developed which uses two finite impulse response filters; one is a channel estimator and the other is an equalisation filter. The gradient algorithm with degree 1 least-square fading memory prediction is adopted for the channel estimator.
T. Shimamura, S. Semnani, C.F.N. Cowan
openaire   +1 more source