MIMO performance enhancement of MIMO arrays using PCS-based near-field optimization technique

Wang, Yipeng, Chen, Xiaoming, Pei, Huiling, Sha, Wei EI, Huang, Yi ORCID: 0000-0001-7774-1024 and Kishk, Ahmed A (2023) MIMO performance enhancement of MIMO arrays using PCS-based near-field optimization technique. SCIENCE CHINA-INFORMATION SCIENCES, 66 (6). 162302-.

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Abstract

Extensive efforts have been made in designing large multiple-input multiple-output (MIMO) arrays. Nevertheless, improvements in conventional antenna characteristics cannot ensure significant MIMO performance improvement in realistic multipath environments. Array decorrelation techniques have been proposed, achieving correlation reductions by either tilting the antenna beams or shifting the phase centers away from each other. Hence, these methods are mainly limited to MIMO terminals with small arrays. To avoid such problems, this work proposes a decorrelation optimization technique based on phase correcting surface (PCS) that can be applied to large MIMO arrays, enhancing their MIMO performances in a realistic (non-isotropic) multipath environment. First, by using a near-field channel model and an optimization algorithm, a near-field phase distribution improving the MIMO capacity is obtained. Then the PCS (consisting of square elements) is used to cover the array’s aperture, achieving the desired near-field phase distribution. Two examples demonstrate the effectiveness of this PCS-based near-field optimization technique. One is a 1 × 4 dual-polarized patch array (working at 2.4 GHz) covered by a 2 × 4 PCS with 0.6λ center-to-center distance. The other is a 2 × 8 dual-polarized dipole array, for which a 4 × 8 PCS with 0.4λ center-to-center distance is designed. Their MIMO capacities can be effectively enhanced by 8% and 10% in single-cell and multi-cell scenarios, respectively. The PCS has insignificant effects on mutual coupling, matching, and the average radiation efficiency of the patch array, and increases the antenna gain by about 2.5 dB while keeping broadside radiations to ensure good cellular coverage, which benefits the MIMO performance of the array. The proposed technique offers a new perspective for improving large MIMO arrays in realistic multipath in a statistical sense.

Item Type:	Article
Uncontrolled Keywords:	antenna correlation, array antenna, multiple-input multiple-output (MIMO) capacity
Divisions:	Faculty of Science and Engineering > School of Electrical Engineering, Electronics and Computer Science
Depositing User:	Symplectic Admin
Date Deposited:	01 Aug 2023 10:52
Last Modified:	16 Mar 2024 02:45
DOI:	10.1007/s11432-022-3595-y
Related URLs:	Author Publisher
URI:	https://livrepository.liverpool.ac.uk/id/eprint/3172016