The Experts below are selected from a list of 6678 Experts worldwide ranked by ideXlab platform

Robert W Heath - One of the best experts on this subject based on the ideXlab platform.

  • falp fast beam alignment in mmwave systems with low resolution phase shifters
    IEEE Transactions on Communications, 2019
    Co-Authors: Nitin Jonathan Myers, Amine Mezghani, Robert W Heath
    Abstract:

    Millimeter wave (mmWave) systems can enable high data rates if the link between the transmitting and receiving radios is configured properly. Fast configuration of mmWave links, however, is challenging due to the use of large Antenna arrays and hardware constraints. For example, a large amount of training overhead is incurred by exhaustive search-based beam alignment in typical mmWave phased arrays. In this paper, we present a framework called FALP for Fast beam Alignment with Low-resolution Phase shifters. FALP uses an efficient set of Antenna Weight vectors to acquire channel measurements, and allows faster beam alignment when compared to exhaustive scan. The Antenna Weight vectors in FALP can be realized in ultra-low power phase shifters whose resolution can be as low as one-bit. From a compressed sensing (CS) perspective, the CS matrix designed in FALP satisfies the restricted isometry property and allows CS algorithms to exploit the fast Fourier transform. The proposed framework also establishes a new connection between channel acquisition in phased arrays and magnetic resonance imaging.

  • falp fast beam alignment in mmwave systems with low resolution phase shifters
    arXiv: Signal Processing, 2019
    Co-Authors: Nitin Jonathan Myers, Amine Mezghani, Robert W Heath
    Abstract:

    Millimeter wave (mmWave) systems can enable high data rates if the link between the transmitting and receiving radios is configured properly. Fast configuration of mmWave links, however, is challenging due to the use of large Antenna arrays and hardware constraints in these systems. The large amount of training overhead incurred by exhaustive search-based beam alignment in typical mmWave systems is one common example. We present a framework for Fast beam Alignment with Low-resolution Phase shifters which we refer to as FALP. FALP designs an efficient set of Antenna Weight vectors to acquire channel measurements, and allows faster beam alignment when compared to exhaustive scan. The Antenna Weight vectors in FALP can be realized in ultra-low power phase shifters whose resolution can be as low as one-bit. From a compressed sensing (CS) perspective, the CS matrix designed in FALP satisfies the restricted isometry property and allows CS algorithms to exploit the fast Fourier transform. The proposed framework also establishes a new connection between channel acquisition in phased arrays and magnetic resonance imaging.

J R Zeidler - One of the best experts on this subject based on the ideXlab platform.

  • a simple gradient sign algorithm for transmit Antenna Weight adaptation with feedback
    IEEE Transactions on Signal Processing, 2003
    Co-Authors: B C Banister, J R Zeidler
    Abstract:

    In this paper, a simple algorithm for adaptation of the complex baseband Weights of a transmit Antenna array using feedback from the receiver is proposed and analyzed. The system utilizes stochastic gradient adaptation to maximize the power delivered to the receiver for a constrained transmission power, which provides both fading diversity and beam steering gain. Dual perturbed transmission Weight vectors are time multiplexed onto the pilot signal, and the receiver generates feedback selecting the perturbed Weight vector which delivers greater power. This feedback is used to provide Weight adaptation at the transmitter, and this adaptation is shown to be an update by a coarse estimate of the gradient of the delivered power. The performance of the algorithm is analyzed in terms of convergence and tracking of an AR1 fading channel, with simulations confirming the analysis. Bit error rate (BER) simulations in a dynamic fading channel show that the algorithm outperforms previously proposed vector selection feedback, and in slower fading, the algorithm substantially outperforms diversity space time coding.

  • implementation of transmit Antenna Weight adaptation through stochastic gradient feedback
    Asilomar Conference on Signals Systems and Computers, 2001
    Co-Authors: B C Banister, J R Zeidler
    Abstract:

    Feedback assisted transmission Antenna Weight adaptation has been proposed for Third Generation cellular systems to provide increased capacity on the forward link. This approach provides enhancement concurrently from fading mitigation and beam steering. One such algorithm maximizes the usable power to the mobile by perturbation extracted gradient adaptation of the transmit Weight vector. With perfect channel estimation and other idealized assumptions this method has been shown to be capable of providing Weights approaching that of the optimal multi-element transmitter. In this paper a method for common perturbation transmission is introduced and compared to dedicated perturbation transmission in a CDMA system. In addition, a subspace Weighting approach is introduced to enhance the algorithm performance in correlated fading. Simulations of the algorithm operating in a cdma2000 system incorporate feedback bit errors, latency and channel estimation errors with a dedicated pilot.

  • tracking performance of a stochastic gradient algorithm for transmit Antenna Weight adaptation with feedback
    International Conference on Acoustics Speech and Signal Processing, 2001
    Co-Authors: B C Banister, J R Zeidler
    Abstract:

    The tracking performance of a transmit Antenna Weight adaptation algorithm applied in a fading channel is considered. The system uses a stochastic gradient algorithm incorporating gradient sign feedback from a receiving unit to adjust the transmit Weights. The feedback is simply a bit indicating which of two normalized perturbed transmission Weights delivers greater power to the receiver. A reasonable performance measure is defined and an analytic estimate of the performance in an AR1 vector fading channel is derived and compared to simulations.

  • a stochastic gradient algorithm for transmit Antenna Weight adaptation with feedback
    International Workshop on Signal Processing Advances in Wireless Communications, 2001
    Co-Authors: B C Banister, J R Zeidler
    Abstract:

    It is generally accepted that the downlink of next generation cellular systems will require greater capacity than the uplink, due to the asymmetry of data traffic patterns. The use of transmit adaptive Antenna arrays at the base station is a promising area for downlink capacity improvement. This paper describes a gradient algorithm utilizing mobile to base feedback in order to achieve some of those possible gains. A simple algorithm for adaptation of the complex baseband Weights of a transmit Antenna array utilizing feedback from the receiving unit is presented. A dedicated pilot signal is transmitted from the transmitting unit with a pair of perturbed test Weights; a feedback bit is transmitted from the receiving unit indicating which Weight vector provided the larger power; the transmitting unit adjusts a base Weight to this selection and continues the process. This approach is shown to be a coarse stochastic gradient algorithm. The settling time and steady state characteristics of the algorithm are investigated analytically and verified by simulation, and the algorithm is shown to converge to those Weights which maximize the power delivered to the receiver.

Nitin Jonathan Myers - One of the best experts on this subject based on the ideXlab platform.

  • falp fast beam alignment in mmwave systems with low resolution phase shifters
    IEEE Transactions on Communications, 2019
    Co-Authors: Nitin Jonathan Myers, Amine Mezghani, Robert W Heath
    Abstract:

    Millimeter wave (mmWave) systems can enable high data rates if the link between the transmitting and receiving radios is configured properly. Fast configuration of mmWave links, however, is challenging due to the use of large Antenna arrays and hardware constraints. For example, a large amount of training overhead is incurred by exhaustive search-based beam alignment in typical mmWave phased arrays. In this paper, we present a framework called FALP for Fast beam Alignment with Low-resolution Phase shifters. FALP uses an efficient set of Antenna Weight vectors to acquire channel measurements, and allows faster beam alignment when compared to exhaustive scan. The Antenna Weight vectors in FALP can be realized in ultra-low power phase shifters whose resolution can be as low as one-bit. From a compressed sensing (CS) perspective, the CS matrix designed in FALP satisfies the restricted isometry property and allows CS algorithms to exploit the fast Fourier transform. The proposed framework also establishes a new connection between channel acquisition in phased arrays and magnetic resonance imaging.

  • falp fast beam alignment in mmwave systems with low resolution phase shifters
    arXiv: Signal Processing, 2019
    Co-Authors: Nitin Jonathan Myers, Amine Mezghani, Robert W Heath
    Abstract:

    Millimeter wave (mmWave) systems can enable high data rates if the link between the transmitting and receiving radios is configured properly. Fast configuration of mmWave links, however, is challenging due to the use of large Antenna arrays and hardware constraints in these systems. The large amount of training overhead incurred by exhaustive search-based beam alignment in typical mmWave systems is one common example. We present a framework for Fast beam Alignment with Low-resolution Phase shifters which we refer to as FALP. FALP designs an efficient set of Antenna Weight vectors to acquire channel measurements, and allows faster beam alignment when compared to exhaustive scan. The Antenna Weight vectors in FALP can be realized in ultra-low power phase shifters whose resolution can be as low as one-bit. From a compressed sensing (CS) perspective, the CS matrix designed in FALP satisfies the restricted isometry property and allows CS algorithms to exploit the fast Fourier transform. The proposed framework also establishes a new connection between channel acquisition in phased arrays and magnetic resonance imaging.

B C Banister - One of the best experts on this subject based on the ideXlab platform.

  • a simple gradient sign algorithm for transmit Antenna Weight adaptation with feedback
    IEEE Transactions on Signal Processing, 2003
    Co-Authors: B C Banister, J R Zeidler
    Abstract:

    In this paper, a simple algorithm for adaptation of the complex baseband Weights of a transmit Antenna array using feedback from the receiver is proposed and analyzed. The system utilizes stochastic gradient adaptation to maximize the power delivered to the receiver for a constrained transmission power, which provides both fading diversity and beam steering gain. Dual perturbed transmission Weight vectors are time multiplexed onto the pilot signal, and the receiver generates feedback selecting the perturbed Weight vector which delivers greater power. This feedback is used to provide Weight adaptation at the transmitter, and this adaptation is shown to be an update by a coarse estimate of the gradient of the delivered power. The performance of the algorithm is analyzed in terms of convergence and tracking of an AR1 fading channel, with simulations confirming the analysis. Bit error rate (BER) simulations in a dynamic fading channel show that the algorithm outperforms previously proposed vector selection feedback, and in slower fading, the algorithm substantially outperforms diversity space time coding.

  • implementation of transmit Antenna Weight adaptation through stochastic gradient feedback
    Asilomar Conference on Signals Systems and Computers, 2001
    Co-Authors: B C Banister, J R Zeidler
    Abstract:

    Feedback assisted transmission Antenna Weight adaptation has been proposed for Third Generation cellular systems to provide increased capacity on the forward link. This approach provides enhancement concurrently from fading mitigation and beam steering. One such algorithm maximizes the usable power to the mobile by perturbation extracted gradient adaptation of the transmit Weight vector. With perfect channel estimation and other idealized assumptions this method has been shown to be capable of providing Weights approaching that of the optimal multi-element transmitter. In this paper a method for common perturbation transmission is introduced and compared to dedicated perturbation transmission in a CDMA system. In addition, a subspace Weighting approach is introduced to enhance the algorithm performance in correlated fading. Simulations of the algorithm operating in a cdma2000 system incorporate feedback bit errors, latency and channel estimation errors with a dedicated pilot.

  • tracking performance of a stochastic gradient algorithm for transmit Antenna Weight adaptation with feedback
    International Conference on Acoustics Speech and Signal Processing, 2001
    Co-Authors: B C Banister, J R Zeidler
    Abstract:

    The tracking performance of a transmit Antenna Weight adaptation algorithm applied in a fading channel is considered. The system uses a stochastic gradient algorithm incorporating gradient sign feedback from a receiving unit to adjust the transmit Weights. The feedback is simply a bit indicating which of two normalized perturbed transmission Weights delivers greater power to the receiver. A reasonable performance measure is defined and an analytic estimate of the performance in an AR1 vector fading channel is derived and compared to simulations.

  • a stochastic gradient algorithm for transmit Antenna Weight adaptation with feedback
    International Workshop on Signal Processing Advances in Wireless Communications, 2001
    Co-Authors: B C Banister, J R Zeidler
    Abstract:

    It is generally accepted that the downlink of next generation cellular systems will require greater capacity than the uplink, due to the asymmetry of data traffic patterns. The use of transmit adaptive Antenna arrays at the base station is a promising area for downlink capacity improvement. This paper describes a gradient algorithm utilizing mobile to base feedback in order to achieve some of those possible gains. A simple algorithm for adaptation of the complex baseband Weights of a transmit Antenna array utilizing feedback from the receiving unit is presented. A dedicated pilot signal is transmitted from the transmitting unit with a pair of perturbed test Weights; a feedback bit is transmitted from the receiving unit indicating which Weight vector provided the larger power; the transmitting unit adjusts a base Weight to this selection and continues the process. This approach is shown to be a coarse stochastic gradient algorithm. The settling time and steady state characteristics of the algorithm are investigated analytically and verified by simulation, and the algorithm is shown to converge to those Weights which maximize the power delivered to the receiver.

Amine Mezghani - One of the best experts on this subject based on the ideXlab platform.

  • falp fast beam alignment in mmwave systems with low resolution phase shifters
    IEEE Transactions on Communications, 2019
    Co-Authors: Nitin Jonathan Myers, Amine Mezghani, Robert W Heath
    Abstract:

    Millimeter wave (mmWave) systems can enable high data rates if the link between the transmitting and receiving radios is configured properly. Fast configuration of mmWave links, however, is challenging due to the use of large Antenna arrays and hardware constraints. For example, a large amount of training overhead is incurred by exhaustive search-based beam alignment in typical mmWave phased arrays. In this paper, we present a framework called FALP for Fast beam Alignment with Low-resolution Phase shifters. FALP uses an efficient set of Antenna Weight vectors to acquire channel measurements, and allows faster beam alignment when compared to exhaustive scan. The Antenna Weight vectors in FALP can be realized in ultra-low power phase shifters whose resolution can be as low as one-bit. From a compressed sensing (CS) perspective, the CS matrix designed in FALP satisfies the restricted isometry property and allows CS algorithms to exploit the fast Fourier transform. The proposed framework also establishes a new connection between channel acquisition in phased arrays and magnetic resonance imaging.

  • falp fast beam alignment in mmwave systems with low resolution phase shifters
    arXiv: Signal Processing, 2019
    Co-Authors: Nitin Jonathan Myers, Amine Mezghani, Robert W Heath
    Abstract:

    Millimeter wave (mmWave) systems can enable high data rates if the link between the transmitting and receiving radios is configured properly. Fast configuration of mmWave links, however, is challenging due to the use of large Antenna arrays and hardware constraints in these systems. The large amount of training overhead incurred by exhaustive search-based beam alignment in typical mmWave systems is one common example. We present a framework for Fast beam Alignment with Low-resolution Phase shifters which we refer to as FALP. FALP designs an efficient set of Antenna Weight vectors to acquire channel measurements, and allows faster beam alignment when compared to exhaustive scan. The Antenna Weight vectors in FALP can be realized in ultra-low power phase shifters whose resolution can be as low as one-bit. From a compressed sensing (CS) perspective, the CS matrix designed in FALP satisfies the restricted isometry property and allows CS algorithms to exploit the fast Fourier transform. The proposed framework also establishes a new connection between channel acquisition in phased arrays and magnetic resonance imaging.