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Open Access

Focusing Ability Enhancement in Broadside Direction of Array: From UCA to UCCA

Department of Electronic Engineering, Tsinghua University, and also with Beijing National Research Center for Information Science and Technology (BNRist), Beijing 100084, China
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Abstract

To meet the ever-increasing demand for the data rates of wireless communications, extremely large-scale antenna array (ELAA) has emerged as one of the candidate technologies for future 6G communications. The significantly increased number of antennas in ELAA gives rise to near-field communications, necessitating tailored beamforming techniques within the near-field regions to accommodate the spherical-wave propagation characteristics. Among various array geometries of ELAA, uniform circular array (UCA) has gained much attention for its distinct capability of maintaining uniform beam pattern across different azimuth angles. However, existing analysis of near-field UCA beamforming indicates that the near-field region severely declines in the broadside of UCA, where the system fails to benefit from near-field communications. To tackle this problem, the near-field beamforming technique of uniform concentric circular arrays (UCCAs) is investigated in this paper, which has the potential to enlarge the near-field region in the broadside direction. First, the analysis of beamforming gain in the 3D space with UCA and UCCA is provided. Then, the distinct beamforming characteristics that set UCCA apart from UCA are delineated, revealing the superiority of UCCA in extending the near-field region in broadside at the cost of slightly reduced near-field region in the coplane. Simulation results are provided to verify the effectiveness of the theoretical analysis of beamforming gain with UCCA and the enhanced focusing ability of UCCA in the broadside direction.

References

[1]

H. Lu and Y. Zeng, Communicating with extremely large-scale array/surface: Unified modeling and performance analysis, IEEE Trans. Wirel. Commun., vol. 21, no. 6, pp. 4039–4053, 2022.

[2]

M. Cui, Z. Wu, Y. Lu, X. Wei, and L. Dai, Near-field MIMO communications for 6G: Fundamentals, challenges, potentials, and future directions, IEEE Commun. Mag., vol. 61, no. 1, pp. 40–46, 2023.

[3]
E. Bjornson, O. T. Demir, and L. Sanguinetti, A primer on near-field beamforming for arrays and reconfigurable intelligent surfaces, in Proc. 2021 55th Asilomar Conf. Signals, Systems, and Computers, Pacific Grove, CA, USA, 2021, pp. 105−112.
[4]
M. Cui and L. Dai, Near-field wideband beamforming for extremely large antenna arrays, arXiv preprint arXiv: 2109.10054, 2021.
[5]

H. Zhang, N. Shlezinger, F. Guidi, D. Dardari, and Y. C. Eldar, 6G wireless communications: From far-field beam steering to near-field beam focusing, IEEE Commun. Mag., vol. 61, no. 4, pp. 72–77, 2023.

[6]

H. Zhang, N. Shlezinger, F. Guidi, D. Dardari, M. F. Imani, and Y. C. Eldar, Beam focusing for near-field multiuser MIMO communications, IEEE Trans. Wirel. Commun., vol. 21, no. 9, pp. 7476–7490, 2023.

[7]

Z. Wu and L. Dai, Multiple access for near-field communications: SDMA or LDMA? IEEE J. Select. Areas Commun., vol. 41, no. 6, pp. 1918–1935, 2023.

[8]

V. Kallnichev, Analysis of beam-steering and directive characteristics of adaptive antenna arrays for mobile communications, IEEE Antennas Propag. Mag., vol. 43, no. 3, pp. 145–152, 2001.

[9]
Z. Wu, M. Cui, and L. Dai, Enabling more users to benefit from near-field communications: From linear to circular array, arXiv preprint arXiv: 2212.14654, 2022.
[10]

Y. Xie, B. Ning, L. Li, and Z. Chen, Near-field beam training in THz communications: The merits of uniform circular array, IEEE Wirel. Commun. Lett., vol. 12, no. 4, pp. 575–579, 2023.

[11]

S. C. Chan and H. H. Chen, Uniform concentric circular arrays with frequency-invariant characteristics—Theory, design, adaptive beamforming and DOA estimation, IEEE Trans. Signal Process., vol. 55, no. 1, pp. 165–177, 2007.

[12]
M. Mahmood, A. Koc, and T. Le-Ngoc, 2D antenna array structures for hybrid massive MIMO precoding, in Proc. GLOBECOM 2020-2020 IEEE Global Communications Conference, Taipei, China, 2020.
[13]

G. Huang, J. Chen, and J. Benesty, Insights into frequency-invariant beamforming with concentric circular microphone arrays, IEEE/ACM Trans. Audio Speech Lang. Process., vol. 26, no. 12, pp. 2305–2318, 2018.

[14]

O. El Ayach, S. Rajagopal, S. Abu-Surra, Z. Pi, and R. W. Heath, Spatially sparse precoding in millimeter wave MIMO systems, IEEE Trans. Wirel. Commun., vol. 13, no. 3, pp. 1499–1513, 2014.

[15]

K. T. Selvan and R. Janaswamy, Fraunhofer and Fresnel Distances: Unified derivation for aperture antennas, IEEE Antennas Propag. Mag., vol. 59, no. 4, pp. 12–15, 2017.

[16]

M. Cui and L. Dai, Channel estimation for extremely large-scale MIMO: Far-field or near-field? IEEE Trans. Commun., vol. 70, no. 4, pp. 2663–2677, 2022.

[17]

F. Zhang, W. Fan, and G. F. Pedersen, Frequency-invariant uniform circular array for wideband mm-wave channel characterization, IEEE Antennas Wirel. Propag. Lett., vol. 16, pp. 641–644, 2017.

[18]

D. Dardari, N. Decarli, A. Guerra, and F. Guidi, LOS/NLOS near-field localization with a large reconfigurable intelligent surface, IEEE Trans. Wirel. Commun., vol. 21, no. 6, pp. 4282–4294, 2022.

[19]
A. Kosasih and E. Bjornson, Finite beam depth analysis for large arrays, arXiv preprint arXiv: 2306.12367, 2023.
Tsinghua Science and Technology
Pages 1593-1603
Cite this article:
Wu Z, Dai L. Focusing Ability Enhancement in Broadside Direction of Array: From UCA to UCCA. Tsinghua Science and Technology, 2024, 29(5): 1593-1603. https://doi.org/10.26599/TST.2023.9010127

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Received: 27 August 2023
Revised: 14 October 2023
Accepted: 23 October 2023
Published: 02 May 2024
© The Author(s) 2024.

The articles published in this open access journal are distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/).

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