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    A fast converging integrated implementation of zero-knowledge beamforming algorithm for phased-array receivers

    , Article Analog Integrated Circuits and Signal Processing ; 2019 ; 09251030 (ISSN) Ahmadikia, A ; Atarodi, M ; Sharif University of Technology
    Springer New York LLC  2019
    Abstract
    This paper presents a new implementation of adaptive beamforming algorithm that can be fully implemented on chip. It does not require the knowledge of the incoming signal direction or phase shifter characteristics. Besides, it eliminates the need for the ADC to convert the analog output signal to digital values for the microprocessor and the DAC to apply the calculated values to the control voltages of the analog phase shifters. Thus, it exhibits better convergence speed. In addition, the need for the complex and power-hungry processor is eliminated. Therefore, this implementation consumes less power. Analytical equations and constraints on system design parameters are derived, and the... 

    A fast converging integrated implementation of zero-knowledge beamforming algorithm for phased-array receivers

    , Article Analog Integrated Circuits and Signal Processing ; 2019 ; 09251030 (ISSN) Ahmadikia, A ; Atarodi, S. M ; Sharif University of Technology
    Springer New York LLC  2019
    Abstract
    This paper presents a new implementation of adaptive beamforming algorithm that can be fully implemented on chip. It does not require the knowledge of the incoming signal direction or phase shifter characteristics. Besides, it eliminates the need for the ADC to convert the analog output signal to digital values for the microprocessor and the DAC to apply the calculated values to the control voltages of the analog phase shifters. Thus, it exhibits better convergence speed. In addition, the need for the complex and power-hungry processor is eliminated. Therefore, this implementation consumes less power. Analytical equations and constraints on system design parameters are derived, and the... 

    Designi an Adaptive Beamforming Algorithm, Robust Against Direction-of-Arrival Mismatch

    , M.Sc. Thesis Sharif University of Technology Rahmani, Mostafa (Author) ; Bastani, Mohammad Hasan (Supervisor)
    Abstract
    Adaptive beamforming performance is very sensitive to any mismatch between actual and presumed steering vectors of desired signal. In addition to this sensitivity, presence of desired signal in training snapshots dramatically reduces the convergence rate, as compared to the case that signal-free training snapshots are available.
    The present work is aimed at proposing a new adaptive beamformer that is robust against direction-of-arrival (DOA) mismatch and has high convergence rate. This method is based on desired signal elimination from training snapshots and sub-array beamforming technique. To this end, a Blocking matrix that converts primary data to desired signal free data is... 

    Robust and rapid converging adaptive beamforming via a subspace method for the signal-plusinterferences covariance matrix estimation

    , Article IET Signal Processing ; Vol. 8, Issue. 5 , July , 2014 , pp. 507-520 ; ISSN: 17519675 Rahmani, M ; Bastani, M. H ; Sharif University of Technology
    Abstract
    The presence of the desired signal (DS) in the training snapshots makes the adaptive beamformer sensitive to any steering vector mismatch and dramatically reduces the convergence rate. Even the performance of the most of the existing robust adaptive beamformers is degraded when the signal-to-noise ratio (SNR) is increased. In this study, a high converging rate robust adaptive beamformer is proposed. This method is a promoted eigenspace-based beamformer. In this paper, a new signal-plus-interferences (SPI) covariance matrix estimator is proposed. The subspace of the ideal SPI covariance matrices is exploited and the estimated covariance matrix is projected into this subspace. This projection... 

    A new adaptive beamforming algorithm for WCDMA systems (uplink)

    , Article 2007 IEEE International Conference on Telecommunications and Malaysia International Conference on Communications, ICT-MICC 2007, Penang, 14 May 2007 through 17 May 2007 ; February , 2007 , Pages 145-149 ; 1424410940 (ISBN); 9781424410941 (ISBN) Ghamari Adian, M ; Sharif University of Technology
    2007
    Abstract
    In the realization of adaptive beamforming algorithms, the least-mean-squares (LMS) algorithm had been the most popular scheme used for Smart Antenna systems. This Paper proposes an alternate scheme in the form of the Normalized LMS (NLMS) algorithm with active tap detection for WCDMA systems. By taking advantage of spatial filtering, the proposed scheme promises to reduce the bandwidth required for transmitting data by improving convergence rate. The performance of the Frequency Domain NLMS algorithm in the presence of multipath effects and multiple users is analyzed using simulations. This analysis is compared to that of LMS algorithm and suggests improvement in the convergence rate and...