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2017 9th IEEE International Conference on Communication Software and Networks (ICCSN 2017)

作者： Chunsheng Liu Jin Cai Zhongrui Huang Xiaoping Wang Shiwa Chen Electronic Engineering Institute

ISBN: (纸本)9781509038237;9781509038220

This paper proposes a new method for the pattern synthesis of sparse concentric circular array. This method can avoid the premature and improve the poor capability of local optimization of the traditional genetic algorithm. Alternatively implementing the two kinds of genetic breeding operations can effectively alleviate the dependence of the algorithm's convergence on the choice of the initial group. This paper takes the nine-ringed concentric circular array as simulation object. The results show that the number of array elements can be decreased from 278 to 140 with the simultaneous reduction in peak sidelobe level to-21.27 d B, and the distortion of mainlobe is avoided.

关键词： concentric circular array niche genetic algorithm sidelobe level

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circular and concentric circular Antenna array Synthesis Using Cat Swarm Optimization

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IETE TECHNICAL REVIEW 2015年第3期32卷 204-217页

作者： Ram, Gopi Mandal, Durbadal Kar, Rajib Ghoshal, Sakti Prasad Natl Inst Technol Durgapur Dept Elect & Commun Engn Durgapur India Natl Inst Technol Durgapur Dept Elect Engn Durgapur India

This paper proposes an algorithm called cat swarm optimization (CSO) for the optimal design of non-uniform single-ring circular antenna array (CAA) and non-uniform three-ring concentric circular antenna array (CCAA). The algorithm is used to determine an optimum set of current excitation weights and antenna inter-element separations for CAA of 8, 10 and 12 elements and optimal current excitation weights for CCAA, respectively, which provide radiation pattern with maximum reduction of side lobe level (SLL). Two 3-ring CCAAs, one having the set of 4-, 6-, 8-, elements and the other having 8-, 10-, 12- elements, with and without centre element are considered. Simulation results show a considerable improvement of SLL and some restricted improvement of 3-dB beamwidth with respect to the corresponding uniform cases of both the types of antenna array and the corresponding results of some recent literature reported in this paper.

关键词： concentric circular array circular array CSO SLL 3-dB beamwidth

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Dot-shaped transmit beamforming with nonuniform time-modulated concentric circular frequency diverse array

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MICROWAVE AND OPTICAL TECHNOLOGY LETTERS 2024年第1期66卷 e33890-e33890页

作者： Yesilyurt, Ugur Arican, Galip Orkun Aksoy, Ertugrul Erzurum Tech Univ Elect & Elect Engn Dept Erzurum Turkiye Aselsan Inc Ankara Turkiye Gazi Univ Elect Elect Engn Dept Ankara Turkiye Erzurum Tech Univ Elect & Elect Engn Dept TR-25100 Erzurum Turkiye

In this study, a true three-dimensional dot-shaped beamforming, in which the transmitted energy in a spatial region (azimuth, elevation, and range) is focused is performed with the nonuniform time-modulated concentric circular frequency diverse array (NUTM-CCFDA). The CCFDA structure with a radially outward increasing frequency offset between the rings has structural symmetry that provides the advantage of full scanning in the azimuth plane without any significant change in beam shape. Moreover, the NUTM, where the antenna elements are simply excited with a different modulation frequency in each ring, uses the in-phase/quadrature channel modulator to realize a single sideband. The proposed NUTM-CCFDA structure exhibits efficient beam scanning with the switch time-on instant without using variable phase shifters to steer the dot-shaped beam. Thus, NUTM-CCFDA not only realizes a true dot-shaped beam with better angle resolution on the first harmonic components but also has a simpler configuration than the conventional frequency diverse arrays with sophisticated variable frequency/phase shifters.

关键词： concentric circular array dot-shaped beam frequency diverse array nonuniform time modulation

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DESIGN OF FREQUENCY-INVARIANT BEAMFORMERS WITH SPARSE concentric circular arrayS

DESIGN OF FREQUENCY-INVARIANT BEAMFORMERS WITH SPARSE CONCEN...

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IEEE Workshop on Applications of Signal Processing to Audio and Acoustics (WASPAA)

作者： Buchris, Yaakov Cohen, Israel Amar, Alon Technion Israel Inst Technol Andrew & Erna Viterbi Fac Elect & Comp Engn IL-3200003 Haifa Israel

ISBN: (纸本)9798350323726

Frequency-invariant (FI) beamformers are used in audio and acoustic applications to enhance broadband signals with possibly varying angles of arrival. One of the main challenges is designing such beamformers using a small number of sensors while still performing well under adverse conditions. This paper introduces a new design approach for FI beamformers with sparse concentric circular arrays. We propose an iterative greedy design that optimizes both the number of required sensors and rings while preserving the pre-defined directivity pattern's properties for different frequencies and azimuthal steering directions. Experimental results demonstrate the benefits of the proposed sparse sensor design and FI beamformer in terms of array gain and rotationally invariant beampattern, under limited computational and hardware constraints.

关键词： concentric circular array frequency-invariant beamformer rotation invariance sparse array

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Optimal Design of Single and Multi-ring Planar array Antenna Using Simplex-PSO

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IETE JOURNAL OF RESEARCH 2017年第6期63卷 881-892页

作者： Bera, Rajesh Mandal, Durbadal Kar, Rajib Ghoshal, Sakti Prasad NIT Durgapur Dept ECE Durgapur India NIT Durgapur Dept EE Durgapur India

In this paper, optimal design of single-ring and multi-ring circular array, hexagonal array, and elliptical array of isotropic antenna has been carried out using Simplex Particle Swarm Optimization (Simplex-PSO). The synthesis of the array geometry is first formulated as an optimization problem with the goal of side lobe level reduction and is then solved using Simplex-PSO algorithm for optimum current excitations. To overcome the premature convergence characteristic of PSO, Simplex-PSO is considered while preserving the fast converging property of PSO. Two design examples are presented which illustrate the effectiveness of Simplex-PSO algorithm, and the optimization goal for each example is easily achieved. The design results obtained using Simplex-PSO are superior to those obtained using popular algorithms like PSO and its variant craziness-based PSO (CRPSO) and PSO with aging leader and challengers (ALC-PSO) in a statistically significant way.

关键词： concentric circular array concentric elliptical array concentric hexagonal array Directivity Evolutionary optimization Side lobe level Simplex-PSO

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Constant-Beamwidth Beamforming With Nonuniform concentric Ring arrays

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IEEE-ACM TRANSACTIONS ON AUDIO SPEECH AND LANGUAGE PROCESSING 2022年 30卷 1952-1962页

作者： Kleiman, Avital Cohen, Israel Berdugo, Baruch Technion Israel Inst Technol Andrew & Erna Viterbi Fac Elect & Comp Engn IL-3200003 Haifa Israel

Solutions for frequency-invariant beamforming with concentric circular arrays are used in many applications, including microphone arrays and audio communication. However, existing methods focus on the azimuth-beamwidth and consider uniformly spaced circular arrays. This paper presents an approach to designing a constant elevation-beamwidth beamformer for nonuniform concentric ring arrays. The suggested beamformer aims to maximize the array directivity factor while maintaining fixed beamwidth over a wide range of frequencies. The introduced methodology simultaneously selects the ring placements and designs the beamformer weights that achieve optimal performance. We present the problem constraints and cost function, resulting in a sparse beamformer design. In addition, a uniformly spaced beamformer is incorporated into the optimization cost function to attain improved performance. Time-domain implementation of the ideal beamformer is also presented in this work. Furthermore, in the proposed array configuration, all sensors on each ring share the same weight value. Thus, the computational complexity and the physical hardware required in a physical setup are significantly reduced. Experimental results demonstrate the advantages of the nonuniform beamformer compared to a uniform beamformer in terms of directivity index, white noise gain, and sidelobe attenuation.

关键词： Geometry array signal processing Parallel processing White noise Cost function Microphone arrays Computational complexity array processing concentric circular array constant-beamwidth beamforming microphone array frequency-invariant beamforming directivity-factor white-noise-gain sparse design

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Controlling Elevation and Azimuth Beamwidths With concentric circular Microphone arrays

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IEEE-ACM TRANSACTIONS ON AUDIO SPEECH AND LANGUAGE PROCESSING 2021年 29卷 1491-1502页

作者： Sharma, Rajib Cohen, Israel Berdugo, Baruch Technion Israel Inst Technol Andrew & Erna Viterby Fac Elect Engn IL-3200003 Haifa Israel

Solutions for frequency-invariant or constant-beamwidth beamforming with concentric circular arrays (CCAs) generally control only the azimuth-beampattern. This work introduces a beamforming methodology, which instead of designing a fixed beamwidth across the spectrum, maximizes the directivity-factor under the constraint that the beamwidth is greater than or equal to a pre-defined target-beamwidth, in both the elevation and the azimuth. The principal idea lies in dynamically weighting the microphones of the CCA based on two factors - (i) their corresponding ring number or radius, and (ii) their alignment with the signal-path. The parameters controlling the weights are determined using a modified gradient-descent algorithm. Experimental results show the flexibility and advantage of the proposed methodology over state-of-the-art methods.

关键词： array signal processing Azimuth Heuristic algorithms Process control Parallel processing Microphone arrays Speech processing concentric circular array constant-beamwidth beamforming microphone array frequency-invariant beamforming directivity-factor white-noise-gain

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GREEDY DESIGN OF circular concentric arrayS FOR BROADBAND MVDR 18

GREEDY DESIGN OF CIRCULAR CONCENTRIC ARRAYS FOR BROADBAND MV...

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18th International Workshop on Acoustic Signal Enhancement (IWAENC)

作者： Buchris, Yaakov Cohen, Israel Amar, Alon Technion Israel Inst Technol Andrew & Erna Viterbi Fac Elect & Comp Engn IL-3200003 Haifa Israel

ISBN: (纸本)9798350361865;9798350361858

Adaptive beamforming is applied in audio and acoustic applications to enhance a broadband signal of interest while suppressing interferences in challenging acoustic time-varying environments. A significant challenge in designing such beamformers is to minimize the number of sensors while maintaining a required level of performance. Herein, we focus on designing sparse broadband adaptive beamformers for concentric circular arrays, often used in video conferencing and various home vocal applications. We propose an iterative greedy design that selects a small number of sensors distributed over the rings of the array while imposing several constraints regarding the desired attributes of the beamformer. One of the constraints is a joint sparsity constraint on the sensor subset selection. This constraint ensures shared use of all the selected sensors for the bandwidth of interest, contributing to resource consumption reduction. Experimental results demonstrate the benefits of the proposed sparse sensor design in terms of desired signal frequency-invariant recovery and interference suppression level under limited computational and hardware constraints.

关键词： concentric circular array joint-sparse array adaptive beamforming MVDR

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Massive-MIMO Hybrid Precoder Design Using Few-Bit DACs for 2D Antenna array Structures

Massive-MIMO Hybrid Precoder Design Using Few-Bit DACs for 2...

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IEEE International Conference on Communications (ICC)

作者： Mahmood, Mobeen Koc, Asil Tho Le-Ngoc McGill Univ Dept Elect & Comp Engn Montreal PQ Canada

ISBN: (纸本)9781728171227

This paper investigates the performance of different antenna array structures for hybrid massive-MIMO precoding schemes using few-bit DACs. Particularly, the proposed hybrid scheme includes two precoding stages: the RF-beamforming stage is designed via the slowly time-varying channel second-order correlation matrix, while the baseband multi-user (MU) precoding stage is constructed via the regularized zero-forcing (RZF) technique to mitigating the MU-interference. For the same system cost and complexity, we examine the achieved sum-rate and energy efficiency of various 2D antenna array structures, namely, uniform linear array (ULA), uniform rectangular array (URA), uniform circular array (UCA), and concentric circular array (CCA), in serving multiple users at different angular locations. The Monte Carlo simulation results indicate the higher achievable rate and energy efficiency of CCA by using low-resolution DACs as compared to various 2D array structures. We also show that only (3-5)-bit DACs are sufficient to provide comparable spectral and energy efficiencies.

关键词： Hybrid precoding massive MIMO few-bit DACs uniform linear array uniform circular array uniform rectangular array concentric circular array

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2D Antenna array Structures for Hybrid Massive MIMO Precoding

2D Antenna Array Structures for Hybrid Massive MIMO Precodin...

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IEEE Global Communications Conference (GLOBECOM) on Advanced Technology for 5G Plus

作者： Mahmood, Mobeen Koc, Asil Le-Ngoc, Tho McGill Univ Dept Elect & Comp Engn Montreal PQ Canada

ISBN: (纸本)9781728182988

This paper investigates the performance behaviours of various antenna array structures for hybrid massive-MIMO precoding schemes. In particular, the proposed hybrid scheme includes two cascaded stages: the RF-beamforming stage is designed via the eigen-decomposition of the massive-MIMO channel second-order correlation matrix while the baseband multi-user (MU) precoding stage is constructed via the regularized zero-forcing (RZF) technique to mitigating the MU-interference in the reduced-dimension effective MU-channel. A transfer block is introduced between the RF-beamforming and baseband precoding stages to significantly reduce the number of required RE chains. For the same number of antenna elements with half-wavelength spacing, we examine the achieved sum-rate performance of different 2D antenna array structures, namely, uniform linear array (ULA), uniform rectangular array (URA), uniform circular array (UCA), and concentric circular array (CCA), in serving multiple users in various angle-of-departure (AoD) settings. Simulation results indicate that, among the array structures, URA and CCA can offer both smaller array sizes and higher achieved sum-rate. Furthermore, for various user angular locations, the sum-rate of URA can vary about 2 bits/s/Hz while CCA can give an invariant sum-rate performance.

关键词： Hybrid precoding uniform linear array uniform circular array uniform rectangular array concentric circular array massive MIMO

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