The Experts below are selected from a list of 300 Experts worldwide ranked by ideXlab platform
A. Paulraj - One of the best experts on this subject based on the ideXlab platform.
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base station Transmitting Antenna arrays for multipath environments
Signal Processing, 1996Co-Authors: D. Gerlach, A. PaulrajAbstract:Abstract Adaptive Transmitting Antenna arrays can increase the capacity of mobile radio networks by reusing a channel among several users. To reuse bandwidth, a Transmitting Antenna array can exploit feedback information from the mobile receivers in order to track changes in the multipath environment. When the mobile is moving rapidly, the required feedback rates can become significant. We present a new method for transmission beamforming, which, by exploiting the subspace structure present in the spatial channel, requires much lower feedback data rates than previous methods. We consider Antenna arrays at the base only, and the mobile has a single omnidirectional Antenna.
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Spectrum reuse using Transmitting Antenna arrays with feedback
Proceedings of ICASSP '94. IEEE International Conference on Acoustics Speech and Signal Processing, 1994Co-Authors: D. Gerlach, A. PaulrajAbstract:Currently, a central base station communicates simultaneously with several mobile users by allocating a separate time or frequency channel for each mobile to prevent undesired crosstalk. However, each time or frequency channel may be reused among several mobiles by means of an Antenna array at the base station which points a separate beam at each user. The downlink beamformer would normally operate in an "open loop" mode, in which the base steers a mainlobe in the direction of each mobile. Such a system may operate effectively in a free space environment with no multipath. In the presence of scattering, open loop methods will not perform adequately. A new "closed loop" technique is presented in which each mobile user feeds back to the base estimates of the received signal amplitudes. Using feedback, the base station can achieve precision beamforming resulting in lower crosstalk and improved signal separation even in the presence of strong scattering environments.
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Adaptive Transmitting Antenna methods for multipath environments
1994 IEEE GLOBECOM. Communications: The Global Bridge, 1994Co-Authors: D. Gerlach, A. PaulrajAbstract:Adaptive Transmitting Antenna arrays hold great promise for increasing the capacity of mobile radio networks by reusing a channel among several users. To reuse bandwidth, a Transmitting Antenna array requires feedback information from the mobile receivers in order to track changes in the multipath environment. When the mobile is moving rapidly, the required feedback rates can become significant. We present a new method for transmission beamforming, which, by exploiting the subspace structure present in the spatial channel, requires much lower feedback data rates than previous methods.
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Adaptive Transmitting Antenna arrays with feedback
IEEE Signal Processing Letters, 1994Co-Authors: D. Gerlach, A. PaulrajAbstract:We address the problem of Transmitting multiple cochannel signals from an Antenna array to several receivers so that each receiver gets its intended signal with minimum crosstalk from the remaining signals. In addition to the usual "information" mode, we propose a "probing" mode during which probing signals received at the mobiles are fed back to the transmitter. These probing signals are used to identify an unknown propagation environment, enabling the transmitter to form the necessary transmission beampatterns.
D. Gerlach - One of the best experts on this subject based on the ideXlab platform.
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base station Transmitting Antenna arrays for multipath environments
Signal Processing, 1996Co-Authors: D. Gerlach, A. PaulrajAbstract:Abstract Adaptive Transmitting Antenna arrays can increase the capacity of mobile radio networks by reusing a channel among several users. To reuse bandwidth, a Transmitting Antenna array can exploit feedback information from the mobile receivers in order to track changes in the multipath environment. When the mobile is moving rapidly, the required feedback rates can become significant. We present a new method for transmission beamforming, which, by exploiting the subspace structure present in the spatial channel, requires much lower feedback data rates than previous methods. We consider Antenna arrays at the base only, and the mobile has a single omnidirectional Antenna.
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Spectrum reuse using Transmitting Antenna arrays with feedback
Proceedings of ICASSP '94. IEEE International Conference on Acoustics Speech and Signal Processing, 1994Co-Authors: D. Gerlach, A. PaulrajAbstract:Currently, a central base station communicates simultaneously with several mobile users by allocating a separate time or frequency channel for each mobile to prevent undesired crosstalk. However, each time or frequency channel may be reused among several mobiles by means of an Antenna array at the base station which points a separate beam at each user. The downlink beamformer would normally operate in an "open loop" mode, in which the base steers a mainlobe in the direction of each mobile. Such a system may operate effectively in a free space environment with no multipath. In the presence of scattering, open loop methods will not perform adequately. A new "closed loop" technique is presented in which each mobile user feeds back to the base estimates of the received signal amplitudes. Using feedback, the base station can achieve precision beamforming resulting in lower crosstalk and improved signal separation even in the presence of strong scattering environments.
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Adaptive Transmitting Antenna methods for multipath environments
1994 IEEE GLOBECOM. Communications: The Global Bridge, 1994Co-Authors: D. Gerlach, A. PaulrajAbstract:Adaptive Transmitting Antenna arrays hold great promise for increasing the capacity of mobile radio networks by reusing a channel among several users. To reuse bandwidth, a Transmitting Antenna array requires feedback information from the mobile receivers in order to track changes in the multipath environment. When the mobile is moving rapidly, the required feedback rates can become significant. We present a new method for transmission beamforming, which, by exploiting the subspace structure present in the spatial channel, requires much lower feedback data rates than previous methods.
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Adaptive Transmitting Antenna arrays with feedback
IEEE Signal Processing Letters, 1994Co-Authors: D. Gerlach, A. PaulrajAbstract:We address the problem of Transmitting multiple cochannel signals from an Antenna array to several receivers so that each receiver gets its intended signal with minimum crosstalk from the remaining signals. In addition to the usual "information" mode, we propose a "probing" mode during which probing signals received at the mobiles are fed back to the transmitter. These probing signals are used to identify an unknown propagation environment, enabling the transmitter to form the necessary transmission beampatterns.
Chien-ching Chiu - One of the best experts on this subject based on the ideXlab platform.
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An optimization of UWB Antenna location
2009 IEEE Symposium on Computers and Communications, 2009Co-Authors: Yen-fu Chen, Chien-ching ChiuAbstract:A novel optimization procedure for the location of Transmitting Antenna in ultra-wideband (UWB) wireless communication systems is presented. The impulse responses of different transceiver locations are computed by ray-tracing techniques and inverse fast Fourier transform (IFFT). By using the impulse responses of these multi-path channels, the bit error rate (BER) performance for binary pulse amplitude modulation (BPAM) impulse radio UWB communication system are calculated. Based on the BER performance, outage probability of arbitrary region of receivers for any given location of the transmitter can be computed. The optimization of location of Transmitting Antenna in this paper is using nonuniform steady-state genetic algorithm (NU-SSGA) to minimize the outage probability. The optimization algorithm includes not only good searching accuracy but also calculating efficiency.
Shi-wei Dong - One of the best experts on this subject based on the ideXlab platform.
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Wideband Monopolar Transmitting Antenna for Wireless Power Transfer and Communication Application
2018 IEEE Wireless Power Transfer Conference (WPTC), 2018Co-Authors: Xiaojun Li, Shi-wei DongAbstract:A proximity-fed circular patch Antenna with linear polarization and monopole-like radiation pattern is presented. The Antenna achieves a bandwidth (|S11|
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Analysis on Local Deformation of Microwave Power Transmitting Antenna Array
2018 International Applied Computational Electromagnetics Society Symposium - China (ACES), 2018Co-Authors: Shi-wei Dong, Yazhou Dong, Ying Wang, Xiaojun LiAbstract:To understand the influence of the local deformation on the performance of a microwave power transmission system, the analysis model for the local deformation of the Transmitting Antenna array is proposed. Based on the analysis model, the local deformation of the Transmitting Antenna array is investigated for the MW-level SSPS with the construction requirement consequently being specified.
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Spatial structure of electromagnetic field in the power Transmitting Antenna fresnel region
Proceedings of 2014 3rd Asia-Pacific Conference on Antennas and Propagation, 2014Co-Authors: Shi-wei Dong, Yazhou Dong, Ying Wang, Lisheng Yang, Zhengjun Li, Wenli FuAbstract:Microwave power transmission is the key of space solar power station. Microwave power Transmitting array is introduced firstly. Using Wilcox expansion spatial structure of electromagnetic field is discussed, especially in the Fresnel region. Power distribution is depicted subsequently.
Thomas J. Minardo - One of the best experts on this subject based on the ideXlab platform.
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Performance of a meandered line as an electrically small Transmitting Antenna
IEEE Transactions on Antennas and Propagation, 1998Co-Authors: Thomas J. Warnagiris, Thomas J. MinardoAbstract:For Antennas to radiate at maximum efficiency, their dimensions must be on the same order as the radiated wavelength. At frequencies below 30 MHz, Antennas with efficient radiation are often too large for mobile and portable applications. Smaller Antennas can be made to radiate efficiently by use of matching networks. For installation convenience and ease of adjustment, these networks are usually placed between the transmitter and the Antenna input; but it has been found that for best radiation efficiency, matching network elements should be placed at points on the Antenna structure. Unfortunately, such matching networks must be tuned for each Transmitting frequency and, when mounted on the Antenna, they cannot easily be tuned. A meander element Antenna was found to present some electrical and mechanical properties allowing convenient placement of tuning elements when configured as an electrically small Transmitting Antenna. Some simplified design guidelines were derived from experimental data
