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Shi J, Li M, Tang L, Li X, Jia X, Guo C, Bai H, Ma H, Wang X, Niu P, Weng J, Yao J. All-Dielectric Integrated Meta-Antenna Operating in 6G Terahertz Communication Window. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2024; 20:e2308958. [PMID: 38189638 DOI: 10.1002/smll.202308958] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/06/2023] [Revised: 12/27/2023] [Indexed: 01/09/2024]
Abstract
Efficient transceivers and antennas at terahertz frequencies are leading the development of 6G terahertz communication systems. The antenna design for high-resolution terahertz spatial sensing and communication remains challenging, while emergent metallic metasurface antennas can address this issue but often suffer from low efficiency and complex manufacturing. Here, an all-dielectric integrated meta-antenna operating in 6G terahertz communication window for high-efficiency beam focusing in the sub-wavelength scale is reported. With the antenna surface functionalized by metagrating arrays with asymmetric scattering patterns, the design and optimization methods are demonstrated with a physical size constraint. The highest manipulation and diffraction efficiencies achieve 84.1% and 48.1%. The commercially accessible fabrication method with low cost and easy to implement has been demonstrated for the meta-antenna by photocuring 3D printing. A filamentous focal spot is measured as 0.86λ with a long depth of focus of 25.3λ. Its application for integrated imaging and communication has been demonstrated. The proposed technical roadmap provides a general pathway for creating high-efficiency integrated meta-antennas with great potential in high-resolution 6G terahertz spatial sensing and communication applications.
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Affiliation(s)
- Jia Shi
- Tianjin Key Laboratory of Optoelectronic Detection Technology and System, School of Electronic and Information Engineering, Tiangong University, Tianjin, 300387, China
- Key Laboratory of Opto-Electronics Information Technology (Ministry of Education), School of Precision Instruments and Opto-Electronic Engineering, Tianjin University, Tianjin, 300072, China
- National Mobile Communications Research Laboratory, Southeast University, Nanjing, 210096, China
| | - Meiling Li
- Tianjin Key Laboratory of Optoelectronic Detection Technology and System, School of Electronic and Information Engineering, Tiangong University, Tianjin, 300387, China
| | - Longhuang Tang
- Institute of Fluid Physics, China Academy of Engineering Physics, Mianyang, 621900, China
| | - Xianguo Li
- Tianjin Key Laboratory of Optoelectronic Detection Technology and System, School of Electronic and Information Engineering, Tiangong University, Tianjin, 300387, China
| | - Xing Jia
- Institute of Fluid Physics, China Academy of Engineering Physics, Mianyang, 621900, China
| | - Cuijuan Guo
- Tianjin Key Laboratory of Optoelectronic Detection Technology and System, School of Electronic and Information Engineering, Tiangong University, Tianjin, 300387, China
| | - Hua Bai
- Tianjin Key Laboratory of Optoelectronic Detection Technology and System, School of Electronic and Information Engineering, Tiangong University, Tianjin, 300387, China
| | - Heli Ma
- Institute of Fluid Physics, China Academy of Engineering Physics, Mianyang, 621900, China
| | - Xiang Wang
- Institute of Fluid Physics, China Academy of Engineering Physics, Mianyang, 621900, China
| | - Pingjuan Niu
- Tianjin Key Laboratory of Optoelectronic Detection Technology and System, School of Electronic and Information Engineering, Tiangong University, Tianjin, 300387, China
| | - Jidong Weng
- Institute of Fluid Physics, China Academy of Engineering Physics, Mianyang, 621900, China
| | - Jianquan Yao
- Key Laboratory of Opto-Electronics Information Technology (Ministry of Education), School of Precision Instruments and Opto-Electronic Engineering, Tianjin University, Tianjin, 300072, China
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Govind B, Tapen T, Apsel A. Ultra-compact quasi-true time delay for boosting wireless channel capacity. Nature 2024; 627:88-94. [PMID: 38448694 DOI: 10.1038/s41586-024-07075-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2023] [Accepted: 01/16/2024] [Indexed: 03/08/2024]
Abstract
Massive-data connectivity has driven the need for efficient, directed communications through beamforming arrays1-10. Delay elements are critical in any beamforming signal chain. However, these elements impose fundamental limits on size, channel capacity, power efficiency and effective isotropic radiated power11. Although passive phase shifters do not consume DC power, they suffer from narrow bandwidth, poor phase resolution and low power-handling capacity. They introduce a beam squint, in which different frequency components experience different time delays, blurring signals so that they cannot be resolved. This severely limits the data rate of the wireless link, that is, its channel capacity. Although true time delay (TTD) elements12 solve this problem and service a broad bandwidth, they comprise wavelength-scale transmission lines, making them prohibitively area-inefficient for modern semiconductor processes. Here we address this long-standing problem by introducing a quasi-true time delay (Q-TTD) that miniaturizes TTD elements and breaks fundamental channel-capacity limits of these wireless links. We demonstrate this mechanism for a microwave device implemented in a complementary metal-oxide-semiconductor (CMOS) technology. Key to shrinking the footprint is a reflective-type phase-shifting structure with 3D variable TTD reflectors within a sub-wavelength footprint. This achieves ultra-broadband phase tuning by using them to vary the length of the waveguide's path to ground. They produce a delay-to-area ratio that yields a substantially higher on-chip channel capacity compared with existing state-of-the-art methods. This component, when integrated in arrays, enables high-resolution imaging and low-squint beamforming for wideband communication, on-chip radar and other applications.
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Affiliation(s)
- Bala Govind
- Department of Electrical and Computer Engineering, Cornell University, Ithaca, NY, USA.
| | - Thomas Tapen
- Department of Electrical and Computer Engineering, Cornell University, Ithaca, NY, USA
| | - Alyssa Apsel
- Department of Electrical and Computer Engineering, Cornell University, Ithaca, NY, USA
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Taleb F, Alfaro-Gomez M, Al-Dabbagh MD, Ornik J, Viana J, Jäckel A, Mach C, Helminiak J, Kleine-Ostman T, Kürner T, Koch M, Mittleman DM, Castro-Camus E. Propagation of THz radiation in air over a broad range of atmospheric temperature and humidity conditions. Sci Rep 2023; 13:20782. [PMID: 38012178 PMCID: PMC10682482 DOI: 10.1038/s41598-023-47586-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2023] [Accepted: 11/14/2023] [Indexed: 11/29/2023] Open
Abstract
As the need for higher data rates for communication increases, the terahertz (THz) band has drawn considerable attention. This spectral region promises a much wider bandwidth and the transmission of large amounts of data at high speeds. However, there are still challenges that need to be addressed before the THz telecommunications technology hits the consumer market. One of the recurring concerns is that THz radiation is greatly absorbed by atmospheric water-vapor. Although many studies have presented the attenuation of THz signals under different atmospheric conditions, these results analyze specific temperature or humidity values, leaving the need for a more comprehensive analysis over a wider range of climate conditions. In this work, we present the first study of the attenuation of THz radiation over a broad range of temperatures and humidity values. It is worth noticing that all of our measurements have been undertaken at atmospheric pressure unlike many previous studies where the pressure was not kept constant for various temperatures. Furthermore, we extend our analysis beyond the impact of absolute humidity on the bit error rate in THz communications. We also discuss the refractivity of the atmosphere, examining its variations across different temperatures and humidity levels. THz propagation is studied using two different measurement systems, a long-path THz time-domain spectrometer as well as a quasi-optic setup with vector network analyze. We also compare the results with the ITU-R P.676-13 propagation model. We conclude that the attenuation at the absorption peaks increases linearly with water content and has no dependence on the temperature, while the refractive index, away from absorption lines, namely at 300 GHz shows a sub-linear increase with humidity.
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Affiliation(s)
- Fatima Taleb
- Department of Physics and Material Sciences Center, Philipps-Universität Marburg, Renthof 5, 35032, Marburg, Germany
| | - Mariana Alfaro-Gomez
- Universidad Autonoma de Aguascalientes, Av. Universidad 940, Cd. Universitaria, 20100, Aguascalientes, Mexico
| | | | - Jan Ornik
- Department of Physics and Material Sciences Center, Philipps-Universität Marburg, Renthof 5, 35032, Marburg, Germany
| | - Juan Viana
- Department of Physics and Material Sciences Center, Philipps-Universität Marburg, Renthof 5, 35032, Marburg, Germany
| | - Alexander Jäckel
- Department of Physics and Material Sciences Center, Philipps-Universität Marburg, Renthof 5, 35032, Marburg, Germany
| | - Cornelius Mach
- Department of Physics and Material Sciences Center, Philipps-Universität Marburg, Renthof 5, 35032, Marburg, Germany
| | - Jan Helminiak
- Department of Physics and Material Sciences Center, Philipps-Universität Marburg, Renthof 5, 35032, Marburg, Germany
| | | | - Thomas Kürner
- Institut für Nachrichtentechnik, Technische Universität Braunschweig, 38106, Braunschweig, Germany
| | - Martin Koch
- Department of Physics and Material Sciences Center, Philipps-Universität Marburg, Renthof 5, 35032, Marburg, Germany
| | - Daniel M Mittleman
- School of Engineering, Brown University, 184 Hope Street, Providence, RI, 02912, USA
| | - Enrique Castro-Camus
- Department of Physics and Material Sciences Center, Philipps-Universität Marburg, Renthof 5, 35032, Marburg, Germany.
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Broucke R, Singh N, Van Osta M, Van Kerrebrouck J, Demeester P, Lemey S, Torfs G. A compact SiGe D-band power amplifier for scalable photonic-enabled phased antenna arrays. Sci Rep 2023; 13:20560. [PMID: 37996612 PMCID: PMC10667256 DOI: 10.1038/s41598-023-47908-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2023] [Accepted: 11/20/2023] [Indexed: 11/25/2023] Open
Abstract
To address the rising demand for high-speed wireless data links, communication systems operating at frequencies beyond [Formula: see text] are being targeted. A key enabling technology in the development of these wireless systems is the phased antenna array. Yet, the design and implementation of such steerable antenna arrays at frequencies over [Formula: see text] comes with a multitude of challenges. In particular, the cointegration of active electronics at each antenna element poses a major hurdle due to the inherent space constraints in the array. This article proposes a novel scalable concept for opto-electronic phased antenna arrays operating at 140 GHz. It details the system architecture of a transmitter that enables the implementation of large scale, wideband, 2D steerable phased antenna arrays and presents the design and measurement of a compact SiGe power amplifier (PA) chip to be used as one of its key building blocks. The amplifier achieves a gain of 20 dB at 135 GHz, features a [Formula: see text] of 14.6 dBm and can support data rates up to 45 Gbps in a limited footprint of only 540μm × 550μm. This makes it one of the fastest, most powerful D-band power amplifiers in literature with a footprint compatible with [Formula: see text]-spaced phased array integration.
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Affiliation(s)
- Reinier Broucke
- Department of Information Technology, IDLab, Ghent University - imec, 9052, Ghent, Belgium.
| | - Nishant Singh
- Department of Information Technology, IDLab, Ghent University - imec, 9052, Ghent, Belgium
| | - Michiel Van Osta
- Department of Information Technology, IDLab, Ghent University - imec, 9052, Ghent, Belgium
| | - Joris Van Kerrebrouck
- Department of Information Technology, IDLab, Ghent University - imec, 9052, Ghent, Belgium
| | - Piet Demeester
- Department of Information Technology, IDLab, Ghent University - imec, 9052, Ghent, Belgium
| | - Sam Lemey
- Department of Information Technology, IDLab, Ghent University - imec, 9052, Ghent, Belgium
| | - Guy Torfs
- Department of Information Technology, IDLab, Ghent University - imec, 9052, Ghent, Belgium
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Song Z, Ma X, Jiang W, Zhang L, Jiang M, Hu F, Zeng L. Polarization insensitive flexible ultra-broadband terahertz metamaterial absorber. APPLIED OPTICS 2023; 62:8905-8910. [PMID: 38038036 DOI: 10.1364/ao.505226] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/06/2023] [Accepted: 11/01/2023] [Indexed: 12/02/2023]
Abstract
We propose a polarization insensitive, flexible ultra-broadband terahertz (THz) metamaterial absorber. It consists of a chromium composite resonator on the top, a polyimide (PI) dielectric layer in the middle, and a chromium substrate. The simulation results show that the absorption achieves more than 90% ultra-wideband absorption in the range of 1.92-4.34 THz. The broadband absorption is produced by the combination of electric dipole resonance and magnetic resonance, as well as impedance matching with free space. Due to the rotational symmetry of the unit structure, the absorber is insensitive to polarization of the THz wave and has a larger range of incident angles. The total thickness of the absorber is only 13.4 µm, showing highly flexible and excellent high-temperature resistance characteristics. Therefore, it has potential applications in THz wave stealth and electromagnetic shielding.
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Jia R, Kumar S, Tan TC, Kumar A, Tan YJ, Gupta M, Szriftgiser P, Alphones A, Ducournau G, Singh R. Valley-conserved topological integrated antenna for 100-Gbps THz 6G wireless. SCIENCE ADVANCES 2023; 9:eadi8500. [PMID: 37910611 DOI: 10.1126/sciadv.adi8500] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/22/2023] [Accepted: 09/29/2023] [Indexed: 11/03/2023]
Abstract
The topological phase revolutionized wave transport, enabling integrated photonic interconnects with sharp light bending on a chip. However, the persistent challenge of momentum mismatch during intermedium topological mode transitions due to material impedance inconsistency remains. We present a 100-Gbps topological wireless communication link using integrated photonic devices that conserve valley momentum. The valley-conserved silicon topological waveguide antenna achieves a 12.2-dBi gain, constant group delay across a 30-GHz bandwidth and enables active beam steering within a 36° angular range. The complementary metal oxide semiconductor-compatible valley-conserved devices represent a major milestone in hybrid electronic-photonic-based topological wireless communications, enabling terabit-per-second backhaul communication, high throughput, and intermedium transport of information carriers, vital for the future of communication from the sixth to X generation.
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Affiliation(s)
- Ridong Jia
- Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University, 21 Nanyang Link, Singapore 637371, Singapore
- Centre for Disruptive Photonic Technologies, The Photonics Institute, Nanyang Technological University, 21 Nanyang Link, Singapore 637371, Singapore
| | - Sonu Kumar
- School of Electrical and Electronic Engineering, Nanyang Technological University, 50 Nanyang Ave, Singapore 639798, Singapore
| | - Thomas Caiwei Tan
- Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University, 21 Nanyang Link, Singapore 637371, Singapore
- Centre for Disruptive Photonic Technologies, The Photonics Institute, Nanyang Technological University, 21 Nanyang Link, Singapore 637371, Singapore
| | - Abhishek Kumar
- Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University, 21 Nanyang Link, Singapore 637371, Singapore
- Centre for Disruptive Photonic Technologies, The Photonics Institute, Nanyang Technological University, 21 Nanyang Link, Singapore 637371, Singapore
| | - Yi Ji Tan
- Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University, 21 Nanyang Link, Singapore 637371, Singapore
- Centre for Disruptive Photonic Technologies, The Photonics Institute, Nanyang Technological University, 21 Nanyang Link, Singapore 637371, Singapore
| | - Manoj Gupta
- Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University, 21 Nanyang Link, Singapore 637371, Singapore
- Centre for Disruptive Photonic Technologies, The Photonics Institute, Nanyang Technological University, 21 Nanyang Link, Singapore 637371, Singapore
| | - Pascal Szriftgiser
- Laboratoire de Physique des Lasers, Atomes et Molécules, PhLAM, UMR 8523, Université de Lille, CNRS, 59655 Villeneuve d'Ascq, France
| | - Arokiaswami Alphones
- School of Electrical and Electronic Engineering, Nanyang Technological University, 50 Nanyang Ave, Singapore 639798, Singapore
| | - Guillaume Ducournau
- Institut d'Electronique de Microélectronique et de Nanotechnologie, Université de Lille 1, Lille, France
| | - Ranjan Singh
- Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University, 21 Nanyang Link, Singapore 637371, Singapore
- Centre for Disruptive Photonic Technologies, The Photonics Institute, Nanyang Technological University, 21 Nanyang Link, Singapore 637371, Singapore
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7
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Liu Y, Wang Y, Fu X, Shi L, Yang F, Luo J, Zhou QY, Fu Y, Chen Q, Dai JY, Zhang L, Cheng Q, Cui TJ. Toward Sub-Terahertz: Space-Time Coding Metasurface Transmitter for Wideband Wireless Communications. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2023; 10:e2304278. [PMID: 37552812 PMCID: PMC10582441 DOI: 10.1002/advs.202304278] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/04/2023] [Revised: 07/20/2023] [Indexed: 08/10/2023]
Abstract
A space-time coding metasurface (STCM) operating in the sub-terahertz band to construct new-architecture wireless communication systems is proposed. Specifically, a programmable STCM is designed with varactor-diode-tuned metasurface elements, enabling precise regulation of harmonic amplitudes and phases by adjusting the time delay and duty cycle of square-wave modulation signal loaded on the varactor diodes. Independent electromagnetic (EM) regulations in the space and time domains are achieved by STCM to realize flexible beam manipulations and information modulations. Based on these features, a sub-terahertz wireless communication link is constructed by employing STCM as a transmitter. Experimental results demonstrate that the STCM supports multiple modulation schemes including frequency-shift keying, phase-shift keying, and quadrature amplitude modulations in a wide frequency band. It is also shown that the STCM is capable of realizing wide-angle beam scanning in the range of ±45o , which offers an opportunity for user tracking during the communication. Thus, the STCM transmitter with high device density and low power consumption can provide low-complexity, low-cost, low-power, and low-heat solutions for building the next-generation wireless communication systems in the sub-terahertz frequency and even terahertz band.
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Affiliation(s)
- Yujie Liu
- State Key Laboratory of Millimeter WavesSoutheast UniversityNanjing210096China
| | - Yu Wang
- State Key Laboratory of Millimeter WavesSoutheast UniversityNanjing210096China
| | - Xiaojian Fu
- State Key Laboratory of Millimeter WavesSoutheast UniversityNanjing210096China
- Institute of Electromagnetic SpaceSoutheast UniversityNanjing210096China
| | - Lei Shi
- State Key Laboratory of Millimeter WavesSoutheast UniversityNanjing210096China
| | - Fei Yang
- State Key Laboratory of Millimeter WavesSoutheast UniversityNanjing210096China
| | - Jiang Luo
- School of Electronics and InformationHangzhou Dianzi UniversityHangzhou310018China
| | - Qun Yan Zhou
- State Key Laboratory of Millimeter WavesSoutheast UniversityNanjing210096China
| | - Yuan Fu
- State Key Laboratory of Millimeter WavesSoutheast UniversityNanjing210096China
| | - Qi Chen
- State Key Laboratory of Millimeter WavesSoutheast UniversityNanjing210096China
| | - Jun Yan Dai
- State Key Laboratory of Millimeter WavesSoutheast UniversityNanjing210096China
- Institute of Electromagnetic SpaceSoutheast UniversityNanjing210096China
| | - Lei Zhang
- State Key Laboratory of Millimeter WavesSoutheast UniversityNanjing210096China
- Institute of Electromagnetic SpaceSoutheast UniversityNanjing210096China
| | - Qiang Cheng
- State Key Laboratory of Millimeter WavesSoutheast UniversityNanjing210096China
- Institute of Electromagnetic SpaceSoutheast UniversityNanjing210096China
| | - Tie Jun Cui
- State Key Laboratory of Millimeter WavesSoutheast UniversityNanjing210096China
- Institute of Electromagnetic SpaceSoutheast UniversityNanjing210096China
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Chen C, Zhang H, Hou J, Zhang Y, Zhang H, Dai J, Pang S, Wang C. Deep Learning in the Ubiquitous Human-Computer Interactive 6G Era: Applications, Principles and Prospects. Biomimetics (Basel) 2023; 8:343. [PMID: 37622948 PMCID: PMC10452467 DOI: 10.3390/biomimetics8040343] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2023] [Revised: 07/15/2023] [Accepted: 07/21/2023] [Indexed: 08/26/2023] Open
Abstract
With the rapid development of enabling technologies like VR and AR, we human beings are on the threshold of the ubiquitous human-centric intelligence era. 6G is believed to be an indispensable cornerstone for efficient interaction between humans and computers in this promising vision. 6G is supposed to boost many human-centric applications due to its unprecedented performance improvements compared to 5G and before. However, challenges are still to be addressed, including but not limited to the following six aspects: Terahertz and millimeter-wave communication, low latency and high reliability, energy efficiency, security, efficient edge computing and heterogeneity of services. It is a daunting job to fit traditional analytical methods into these problems due to the complex architecture and highly dynamic features of ubiquitous interactive 6G systems. Fortunately, deep learning can circumvent the interpretability issue and train tremendous neural network parameters, which build mapping relationships from neural network input (status and specific requirements of a 6G application) to neural network output (settings to satisfy the requirements). Deep learning methods can be an efficient alternative to traditional analytical methods or even conquer unresolvable predicaments of analytical methods. We review representative deep learning solutions to the aforementioned six aspects separately and focus on the principles of fitting a deep learning method into specific 6G issues. Based on this review, our main contributions are highlighted as follows. (i) We investigate the representative works in a systematic view and find out some important issues like the vital role of deep reinforcement learning in the 6G context. (ii) We point out solutions to the lack of training data in 6G communication context. (iii) We reveal the relationship between traditional analytical methods and deep learning, in terms of 6G applications. (iv) We identify some frequently used efficient techniques in deep-learning-based 6G solutions. Finally, we point out open problems and future directions.
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Affiliation(s)
- Chunlei Chen
- School of Computer Engineering, Weifang University, Weifang 261061, China; (C.C.); (J.H.); (Y.Z.); (H.Z.); (J.D.); (S.P.)
| | - Huixiang Zhang
- School of Cyberspace Security, Northwestern Polytechnical University, Xi’an 710072, China;
| | - Jinkui Hou
- School of Computer Engineering, Weifang University, Weifang 261061, China; (C.C.); (J.H.); (Y.Z.); (H.Z.); (J.D.); (S.P.)
| | - Yonghui Zhang
- School of Computer Engineering, Weifang University, Weifang 261061, China; (C.C.); (J.H.); (Y.Z.); (H.Z.); (J.D.); (S.P.)
| | - Huihui Zhang
- School of Computer Engineering, Weifang University, Weifang 261061, China; (C.C.); (J.H.); (Y.Z.); (H.Z.); (J.D.); (S.P.)
| | - Jiangyan Dai
- School of Computer Engineering, Weifang University, Weifang 261061, China; (C.C.); (J.H.); (Y.Z.); (H.Z.); (J.D.); (S.P.)
| | - Shunpeng Pang
- School of Computer Engineering, Weifang University, Weifang 261061, China; (C.C.); (J.H.); (Y.Z.); (H.Z.); (J.D.); (S.P.)
| | - Chengduan Wang
- School of Computer Engineering, Weifang University, Weifang 261061, China; (C.C.); (J.H.); (Y.Z.); (H.Z.); (J.D.); (S.P.)
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