Results 201 to 210 of about 42,582 (256)

Transmit Diversity Schemes for WCDMA

Wireless Personal Communications, 2003
Previous work on transmitter antenna diversity has shown that the use of multiple transmitter antennas at the base station results in improved performance due to increase of diversity (path diversity). This happens with no bandwidth cost, even when the signal quality along several paths is poor, but the receiver estimates the channel with accuracy ...
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Geolocation using transmit and receive diversity

IEEE Global Telecommunications Conference, 2004. GLOBECOM '04., 2005
Geolocation using received signal strength (RSS) has large errors due to multipath fading, since fading results in high variations in RSS. We show how and when spatial diversity combined with channel knowledge at the receiver can be used to combat fading effects to increase accuracy in location estimation.
Pulkit Grover, Rajiv Agarwal, Ajit Kumar Chaturvedi   +2 more
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Transmit diversity in 3G CDMA systems

IEEE Communications Magazine, 2002
Transmit diversity (TD) is one of the key contributing technologies to defining the ITU endorsed 3G systems W-CDMA and cdma2000. Spatial diversity is introduced into the signal by transmitting through multiple antennas. The antennas are spaced far enough apart that the signals emanating from them can be assumed to undergo independent fading.
R. Thomas Derryberry, Steven D. Gray, Dumitru Mihai Ionescu, Giridhar D. Mandyam, Balaji Raghothaman   +4 more
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Transmit diversity as a combination of spatial and delay diversity

2000 IEEE Sixth International Symposium on Spread Spectrum Techniques and Applications. ISSTA 2000. Proceedings (Cat. No.00TH8536), 2002
We present performance results of some of the algebraic space-time (ST) block codes based on the combination of Hadamard spreading sequences with rotated constellations. Given a vector x in a rotated constellation in dimension n that has full spatial diversity, we spread each component x/sub j/ of x by a different Hadamard sequence of length n and send
M.O. Damen, K. Abed-Meraim, null Teng Joon Lim   +2 more
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Integration of transmit power control, transmit diversity and receive beamforming

ICC 2001. IEEE International Conference on Communications. Conference Record (Cat. No.01CH37240), 2002
In this paper an algorithm for joint power control, transmit diversity and receive beamforming is proposed where transmit diversity and receive beamforming weight vectors and downlink power allocations are calculated jointly such that signal to interference ratio at each mobile is above threshold.
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Transmit diversity for arrays with correlated Rayleigh fading

Conference Record of the Thirty-Fourth Asilomar Conference on Signals, Systems and Computers (Cat. No.00CH37154), 2002
Transmit diversity is usually presented for the case of independently faded channels. In this paper the structure of a linear transmitter that can be optimized for a Rayleigh-fading environment in which the fading may be correlated is derived. The transmitter achieves the best mix of array gain-obtained by beamforming, and diversity gain-obtained by ...
Cornelius van Rensburg, Benjamin Friedlander   +1 more
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Differential Multiple-Length Transmit Diversity

IEEE Communications Letters, 2004
We propose a new bandwidth-efficient differential transmit diversity scheme as an extension of differential space-time block codes from orthogonal designs. The information is coded in both the difference of successive unit-length vectors and the length difference of successive transmit vectors.
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An algorithm for generalized transmit diversity

GLOBECOM'01. IEEE Global Telecommunications Conference (Cat. No.01CH37270), 2002
In this paper an algorithm for generalized transmit diversity is proposed. Depending on the signal-to-interference-plus-noise ratio maximization criterion full diversity (all available transmit antennas) or partial diversity (only subset of all available transmit antennas) is used and phase adjustment is applied between selected antennas.
D.M. Novakovic, M.J. Juntti, M.L. Dukic
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On transmit diversity for TD-SCDMA

The 57th IEEE Semiannual Vehicular Technology Conference, 2003. VTC 2003-Spring., 2004
In TD-SCDMA (UMTS TDD 1.28 Mcps mode) advanced techniques such as closed loop transmit diversity (CLTD) are foreseen. Deployment of CLTD influences the choice of receiver architecture and depends on propagation conditions, mobile speed, feedback delay, antenna weight computation and quantization.
I. Held, A. Kerroum
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Transmit Diversity Based Interference Cancellation

VTC Spring 2008 - IEEE Vehicular Technology Conference, 2008
In this paper, we describe a transmit diversity technique for canceling partially-known interference. For a single interferer in a flat fading channel, the desired user transmitter transmits conjugated and time-reversed interferer symbols in two successive symbol periods (or subcarriers) along with one desired user symbol.
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