Degree of Freedom Analysis for Holographic MIMO Based on a Mutual-Coupling-Compliant Channel Model

doi:10.12142/ZTECOM.202401005

ZTE Communications ›› 2024, Vol. 22 ›› Issue (1): 34-40.DOI: 10.12142/ZTECOM.202401005

• Special Topic • Previous Articles Next Articles

Degree of Freedom Analysis for Holographic MIMO Based on a Mutual-Coupling-Compliant Channel Model

SUN Yunqi¹^,²(), JIAN Mengnan¹^,², YANG Jun¹^,², ZHAO Yajun¹^,², CHEN Yijian¹^,²

^1.State Key Laboratory of Mobile Network and Mobile Multimedia Technology, Shenzhen 518055, China
^2.ZTE Corporation, Shenzhen 518057, China

Received:2023-12-14 Online:2024-03-28 Published:2024-03-28
About author:SUN Yunqi (sun.yunqi@zte.com.cn) received his BE and PhD degrees from Tsinghua University, China in 2017 and 2022, respectively. He is currently an engineer with ZTE Corporation. His research interests include massive MIMO, holographic MIMO, antenna theory, and radio sensing.
JIAN Mengnan received her BS degree in information engineering from Beijing Institute of Technology, China in 2016 and MS degree from Tsinghua University, China in 2019. She is currently an engineer with ZTE Corporation. Her research interests include massive MIMO, reconfigurable intelligent surfaces, and holographic MIMO.
YANG Jun received his BS degree in geophysics from the China University of Geosciences (Wuhan) in 2011 and joint-training PhD degree in geophysics from the University of Science and Technology of China and the University of North Carolina at Charlotte, USA in 2016. He is currently an algorithm engineer with ZTE Corporation. His research interests include reconfigurable intelligent surfaces, MIMO channel modeling, and computational electromagnetics.
ZHAO Yajun received his BE, MS, and PhD degrees. Since 2010, he has assumed the role of Chief Engineer at the Wireless and Computing Product R&D Institute, ZTE Corporation. Prior to this, he contributed to wireless technology research at the Wireless Research Department, Huawei. Currently, his primary focus centers on 5G standardization technology and the advancement of future mobile communication technology, particularly 6G. His research pursuits encompass a broad spectrum, including reconfigurable intelligent surfaces (RIS), spectrum sharing, flexible duplex, CoMP, and interference mitigation. He has played an instrumental role in founding the RIS Tech Alliance (RISTA) and currently holds the position of Deputy Secretary General within the organization. Additionally, he is a founding member of the RIS task group under the purview of the China IMT-2030 (6G) Promotion Group, where he serves as the deputy leader.
CHEN Yijian graduated from Central South University, China. He is currently working at ZTE Corporation. His research interests include reconfigurable intelligent metasurfaces, extremely large-scale MIMO technology, and electromagnetic information theory.
Supported by:
National Key Research and Development Program of China(2020YFB1807600)

Abstract

Abstract:

Degree of freedom (DOF) is a key indicator for spatial multiplexing layers of a wireless channel. Traditionally, the channel of a multiple-input multiple-output (MIMO) half-wavelength dipole array has a DOF that equals the antenna number. However, recent studies suggest that the DOF could be less than the antenna number when strong mutual coupling is considered. We utilize a mutual-coupling-compliant channel model to investigate the DOF of the holographic MIMO (HMIMO) channel and give a upper bound of the DOF with strong mutual coupling. Our numerical simulations demonstrate that a dense array can support more DOF per unit aperture as compared with a half-wavelength MIMO system.

Key words: channel model, degree of freedom, holographic MIMO, mutual coupling

SUN Yunqi, JIAN Mengnan, YANG Jun, ZHAO Yajun, CHEN Yijian. Degree of Freedom Analysis for Holographic MIMO Based on a Mutual-Coupling-Compliant Channel Model[J]. ZTE Communications, 2024, 22(1): 34-40.

Figures/Tables 8

Table 1 ULA and UPA configurations for mutual coupling simulation

Configuration Index	Configuration Type	Distance/ $λ$	Spacing/ $λ$	Antenna Number	Aperture Area
1	ULA_FF	200	0.5	16	$7.5 λ$
2	ULA_NF	10	0.5	16	$7.5 λ$
3	ULA_FF_MC	200	0.25	16	$3.75 λ$
4	ULA_NF_MC	10	0.25	16	$3.75 λ$
5	ULA_FF_DEN	200	0.25	31	$7.5 λ$
6	ULA_NF_DEN	10	0.25	31	$7.5 λ$
7	ULA_FF_UDEN	200	0.1	76	$7.5 λ$
8	ULA_NF_UDEN	200	0.1	76	$7.5 λ$
9	UPA_FF	200	0.5	16	$1.5 λ × 1.5 λ$
10	UPA_NF	10	0.5	16	$1.5 λ × 1.5 λ$
11	UPA_FF_MC	200	0.25	16	$0.75 λ × 0.75 λ$
12	UPA_NF_MC	10	0.25	16	$1.5 λ × 1.5 λ$
13	UPA_FF_DEN	200	0.25	49	$1.5 λ × 1.5 λ$
14	UPA_NF_DEN	10	0.25	49	$1.5 λ × 1.5 λ$
15	UPA_FF_UDEN	200	0.1	256	$1.5 λ × 1.5 λ$
16	UPA_NF_UDEN	200	0.1	256	$1.5 λ × 1.5 λ$

Table 1 ULA and UPA configurations for mutual coupling simulation

Configuration Index	Configuration Type	Distance/ $λ$	Spacing/ $λ$	Antenna Number	Aperture Area
1	ULA_FF	200	0.5	16	$7.5 λ$
2	ULA_NF	10	0.5	16	$7.5 λ$
3	ULA_FF_MC	200	0.25	16	$3.75 λ$
4	ULA_NF_MC	10	0.25	16	$3.75 λ$
5	ULA_FF_DEN	200	0.25	31	$7.5 λ$
6	ULA_NF_DEN	10	0.25	31	$7.5 λ$
7	ULA_FF_UDEN	200	0.1	76	$7.5 λ$
8	ULA_NF_UDEN	200	0.1	76	$7.5 λ$
9	UPA_FF	200	0.5	16	$1.5 λ × 1.5 λ$
10	UPA_NF	10	0.5	16	$1.5 λ × 1.5 λ$
11	UPA_FF_MC	200	0.25	16	$0.75 λ × 0.75 λ$
12	UPA_NF_MC	10	0.25	16	$1.5 λ × 1.5 λ$
13	UPA_FF_DEN	200	0.25	49	$1.5 λ × 1.5 λ$
14	UPA_NF_DEN	10	0.25	49	$1.5 λ × 1.5 λ$
15	UPA_FF_UDEN	200	0.1	256	$1.5 λ × 1.5 λ$
16	UPA_NF_UDEN	200	0.1	256	$1.5 λ × 1.5 λ$

References 20

1	PIZZO A, MARZETTA T L, SANGUINETTI L. Spatially-stationary model for holographic MIMO small-scale fading [J]. IEEE journal on selected areas in communications, 2020, 38(9): 1964–1979. DOI: 10.1109/JSAC.2020.3000877
2	HUANG C W, HU S, ALEXANDROPOULOS G C, et al. Holographic MIMO surfaces for 6G wireless networks: opportunities, challenges, and trends [J]. IEEE wireless communications, 2020, 27(5): 118–125. DOI: 10.1109/MWC.001.1900534
3	AN J C, YUEN C, HUANG C W, et al. A tutorial on holographic MIMO communications: part I: channel modeling and channel estimation [J]. IEEE communications letters, 2023, 27(7): 1664–1668. DOI: 10.1109/LCOMM.2023.3278683
4	AN J C, YUEN C, HUANG C W, et al. A tutorial on holographic MIMO communications: part II: performance analysis and holographic beamforming [J]. IEEE communications letters, 2023, 27(7): 1669–1673. DOI: 10.1109/LCOMM.2023.3278682
5	AN J C, YUEN C, HUANG C W, et al. A tutorial on holographic MIMO communications: part III: open opportunities and challenges [J]. IEEE communications letters, 2023, 27(7): 1674–1678. DOI: 10.1109/LCOMM.2023.3278676
6	PIZZO A, MARZETTA T, SANGUINETTI L. Holographic MIMO communications under spatially-stationary scattering [C]//Proc. 54th Asilomar Conference on Signals, Systems, and Computers. IEEE, 2020: 702–706. DOI: 10.1109/IEEECONF51394.2020.9443506
7	ZHANG H B, ZHANG H L, DI B Y, et al. Holographic integrated sensing and communication [J]. IEEE journal on selected areas in communications, 2022, 40(7): 2114–2130. DOI: 10.1109/JSAC.2022.3155548
8	DENG R Q, ZHANG Y T, ZHANG H B, et al. Reconfigurable holographic surfaces for ultra-massive MIMO in 6G: practical design, optimization and implementation [J]. IEEE journal on selected areas in communications, 2023, 41(8): 2367–2379. DOI: 10.1109/JSAC.2023.3288248
9	ZHU J A, LIU K Z, WAN Z, et al. Sensing RISs: enabling dimension-independent CSI acquisition for beamforming [J]. IEEE transactions on information theory, 2023, 69(6): 3795–3813. DOI: 10.1109/TIT.2023.3243836
10	GOLDSMITH A. Wireless communications [M]. New York: Cambridge University Press, 2005
11	JAFAR S ALI, FAKHEREDDIN M J. Degrees of freedom for the MIMO interference channel [J]. IEEE transactions on information theory, 2007, 53(7): 2637–2642. DOI: 10.1109/TIT.2007.899557
12	TSE D, VISWANATH P. Fundamentals of wireless communication [M]. Cambridge: Cambridge University Press, 2005
13	PIZZO A, DE JESUS TORRES A, SANGUINETTI L, et al. Nyquist sampling and degrees of freedom of electromagnetic fields [J]. IEEE transactions on signal processing, 2022, 70: 3935–3947. DOI: 10.1109/TSP.2022.3183445
14	PIZZO A, MARZETTA T L, SANGUINETTI L. Degrees of freedom of holographic MIMO channels [C]//Proc. IEEE 21st International Workshop on Signal Processing Advances in Wireless Communications (SPAWC). IEEE, 2020: 1–5. DOI: 10.1109/SPAWC48557.2020.9154219
15	WEI L, HUANG C W, ALEXANDROPOULOS G C, et al. Tri-polarized holographic MIMO surfaces for near-field communications: channel modeling and precoding design [J]. IEEE transactions on wireless communications, 2023, 22(12): 8828–8842. DOI: 10.1109/TWC.2023.3266298
16	SHEN Y S, HE Z, SHA W, et al. Electromagnetic effective-degree-of-freedom prediction with parabolic equation method [J]. IEEE transactions on antennas and propagation, 2023, 71(4): 3752–3757. DOI: 10.1109/TAP.2022.3233487
17	YUAN S, CHEN X M, HUANG C W, et al. Effects of mutual coupling on degree of freedom and antenna efficiency in holographic MIMO communications [J]. IEEE open journal of antennas and propagation, 2023, 4: 237–244. DOI: 10.1109/OJAP.2023.3245667
18	AKROUT M, SHYIANOV V, BELLILI F, et al. Super-wideband massive MIMO [J]. IEEE journal on selected areas in communications, 2023, 41(8): 2414–2430. DOI: 10.1109/JSAC.2023.3288269
19	ORFANIDIS S J. Electromagnetic waves and antennas [M]. Rutgers: Rutgers University, 2002
20	CHU L J. Physical limitations of omni-directional antennas [J]. Journal of applied physics, 1948, 19(12): 1163–1175. DOI: 10.1063/1.1715038

[1]	ZHU Zhihao, ZHANG Yueping. Differential Quasi-Yagi Antenna and Array [J]. ZTE Communications, 2023, 21(3): 37-44.
[2]	Stefano Buzzi, Carmen D’Andrea. Massive MIMO 5G Cellular Networks: mm-Wave vs. μ-Wave Frequencies [J]. ZTE Communications, 2017, 15(S1): 41-49.
[3]	ZHANG Jianhua, WANG Chao, WU Zhongyuan, ZHANG Weite. A Survey of Massive MIMO Channel Measurements and Models [J]. ZTE Communications, 2017, 15(1): 14-22.
[4]	YIN Xuefeng, ZHANG Nan, Stephen Wang, CHENG Xiang. Measurement-Based Spatial-Consistent Channel Modeling Involving Clusters of Scatterers [J]. ZTE Communications, 2017, 15(1): 28-34.
[5]	ZHANG Ping, CHEN Jianqiao, TANG Tian. An Overview of Non-Stationary Property for Massive MIMO Channel Modeling [J]. ZTE Communications, 2017, 15(1): 3-7.
[6]	Seyyed Hamed Fouladi, Raúl Chávez-Santiago, Pål Ander Floor, Ilangko Balasingham, and Tor A. Ramstad. Sensing, Signal Processing, and Communication for WBANs [J]. ZTE Communications, 2014, 12(3): 3-12.

Degree of Freedom Analysis for Holographic MIMO Based on a Mutual-Coupling-Compliant Channel Model

RichHTML

PDF

Knowledge

Abstract

Cite this article

share this article

Figures/Tables 8

References 20

Related Articles 6

Recommended Articles

Metrics