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Experimental Demonstration of High-Speed 4 x 4 Imaging Multi-CAP MIMO Visible Light Communications

JOURNAL OF LIGHTWAVE TECHNOLOGY 2018年第10期36卷 1944-1951页

作者： Werfli, Khald Chvojka, Petr Ghassemlooy, Zabih Hassan, Navid Bani Zvanovec, Stanislav Burton, Andrew Haigh, Paul Anthony Bhatnagar, Manav R. Northumbria Univ Opt Commun Res Grp Newcastle Upon Tyne NE1 8ST Tyne & Wear England Czech Tech Univ Dept Electromagnet Field Prague 16627 Czech Republic Chinese Acad Sci QIEM Beijing 100864 Peoples R China UCL Dept Elect & Elect Engn London WC1E 6BT England Indian Inst Technol Delhi New Delhi 110016 India

In general, visible light communication (VLC) systems, which utilise white light-emitting diodes (LEDs), only offer a bandwidth limited to the lower MHz region. Therefore, providing VLC-based high data rate communications systems using VLC becomes a challenging task. To address this challenge, we propose a solution based on multiplexing in both the frequency and space domains. We experimentally demonstrate a 4 x 4 imaging multiple-input multiple-output (MIMO) VLC system (i.e., space multiplexing) utilising multiband carrierless amplitude and phase (m-CAP) modulation (i.e., frequency multiplexing). Independently, both MIMO and m-CAP have separately shown the remarkable ability to improve the transmission speeds in VLC systems, and hence, here we combine them to further improve the net data rate. We investigate the link performance by varying the number of sub-carriers m, link distance L, and signal bandwidth B-sig. From all the values tested, we show that a data rate of similar to 249 Mb/s can be maximally achieved for m = 20, B-sig = 20 MHz, and L = 1m, at a bit error rate of 3.2 x 10(-3) using LEDs with similar to 4 MHz bandwidth.

关键词： Modulation bandwidth multi-band carrier-less amplitude and phase modulation multiple-input multiple-output visible light communications

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Low-Complexity MIMO Detection Based on DRSD With ISMMSE-PIC

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IEEE ACCESS 2024年 12卷 70235-70244页

作者： Shin, Sang-Sik Jae Kim, Ho Kim, Hyoung-Nam Pusan Natl Univ Dept Elect Engn Busan 46241 South Korea

This paper introduces a low-complexity multiple-input multiple-output (MIMO) detection method based on dimension-reduction-soft-demodulation (DRSD) with iterative soft minimum-mean-squared-error parallel interference cancellation (ISMMSE-PIC). The conventional ISMMSE-PIC detection method exhibits several drawbacks, such as inordinate dependence on decoder performance and modulation-order sensitivity. Therefore, a DRSD-based strategy is presented to search over a part of the set of transmitted symbols for calculating log-likelihood ratio (LLR) values, such as maximum likelihood detection, to improve detection performance. The scheme for the rest of the symbols directly utilizes ISMMSE-PIC detection for computing the corresponding LLR values. The computational complexity of the proposed scheme is similar to that of ISMMSE-PIC, whereas its bit error rate performance is comparatively higher. The complexity analysis and simulation results validate the proposed algorithm.

关键词： Symbols MIMO communication Vectors Detectors Transmitting antennas Receiving antennas Computational complexity Detection algorithms multiple-input multiple-output iterative soft minimum-mean-squared-error parallel interference cancellation dimension reduction soft demodulation geometric symmetry

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A compact SWB MIMO antenna with 45° clock-wise square patch inclusions for polarization diversity applications

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INTERNATIONAL JOURNAL OF MICROWAVE AND WIRELESS TECHNOLOGIES 2023年第3期15卷 513-525页

作者： Agarwal, Shobit Sharma, Ashwani Zuazola, Ignacio J. Garcia Kumar, Manoj Indian Inst Technol Ropar Dept Elect Engn Rupnagar Punjab India London Metropolitan Univ Sch Comp & Digital Media 166-220 Holloway Rd London N7 8DB England

In this paper, a compact super wideband annular ring antenna using 45 degrees clock-wise square patch inclusions for super high frequency and polarization diversity applications is proposed. The inclusions consist of a combination of squares and circles into one another in the inner area of a main annular ring radiator. The antenna uses a partial ground plane having a stair-type defected ground structure, is designed on an FR-4 substrate, and has a total size of 25 x 26 x 1.6 mm(3) (0.17 lambda x 0.18 lambda). The design was fabricated and experimental results fairly agreed with simulations and resulted in an antenna with an operating frequency from 2.07 to 30 GHz;that is, a large fractional bandwidth of 174.2% with a bandwidth (BW) ratio of 14.5:1 and a high BW dimension ratio, BW per unit electrical length of 5693, and a measured peak gain of 8 dBi with an average gain of 5 dBi for the overall operating frequency. For the polarization diversity, a 4 x 4 multiple input-multiple output configuration is additionally presented, offering an effective isolation of >= 22.5 dB between ports and corroborated by measurements.

关键词： Annular ring antenna bandwidth dimension ratio defected ground structure multiple-input multiple-output polarization diversity

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3 x 3 MIMO Fiber-Wireless System in W-Band With WDM/PDM RoF Transmission Capability

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JOURNAL OF LIGHTWAVE TECHNOLOGY 2021年第24期39卷 7794-7803页

作者： Dat, Pham Tien Rottenberg, Francois Kanno, Atsushi Yamamoto, Naokatsu Kawanishi, Tetsuya Natl Inst Informat & Commun Technol Network Res Inst Tokyo 1840015 Japan Catholic Univ Louvain ICTEAM Inst B-1348 Louvain La Neuve Belgium Waseda Univ Sch Fundamental Sci & Engn Tokyo 1698050 Japan

We propose and demonstrate a 3 x 3 full multiple-input multiple-output (MIMO) fiber-wireless system in the W-band with wavelength-division multiplexing (WDM) and polarization-division multiplexing (PDM) radio-over-fiber (RoF) transmission capability. The system is realized using two highly stable RoF links based on the optical self-heterodyne method and PDM transmission in one of the RoF links. We experimentally demonstrate and confirm satisfactory performances for a 3 x 3 MIMO offset quadrature amplitude modulation-based filter-bank multicarrier signal. Total capacities of approximately 110 and 132 Gb/s, corresponding to spectral efficiencies of approximately 8.5 and 10.2 bits/s/Hz, respectively, are achieved for the system using antennas placed in the same and alternately different polarizations, respectively. The system is applicable to WDM and combined WDM/PDM RoF transmissions. It provides a scalable solution for facilitating large-scale MIMO signal transportation and can be a promising solution for future mobile transport and radio access networks in high-frequency bands.

关键词： MIMO communication Optical fiber polarization Optical fiber networks Wavelength division multiplexing Interference Wireless communication Digital signal processing Fifth-generation and beyond millimeter-wave mobile fronthaul multiple-input multiple-output radio-over-fiber seamless fiber-wireless system

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Improved Gauss-Seidel detector for large-scale MIMO systems

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IET COMMUNICATIONS 2022年第4期16卷 291-302页

作者： Khoso, Imran A. Zhang, Xiaofei Shaikh, Abdul Hayee Sahito, Fahad Dayo, Zaheer Ahmed Nanjing Univ Aeronaut & Astronaut Coll Elect & Informat Engn Nanjing 211106 Peoples R China Beijing Univ Posts & Telecommun Coll Elect & Commun Engn Beijing Peoples R China

Large-scale multiple-input multiple-output (LS-MIMO) is one of the promising technologies beyond the 5G cellular system in which large antenna arrays at the base station (BS) improve the system capacity and energy-efficiency. However, the large number of antennas at the BS makes it challenging to design low-complexity high-performance data detectors. Thus, a number of iterative detection methods, such as Gauss-Seidel and conjugate gradient, are introduced to achieve complexity-performance tradeoff. However, their performance deteriorates for the systems with small BS-to-user antenna ratio or for the channels that exhibit correlation. This paper proposes a new efficient iterative detection algorithm based on the improved Gauss-Seidel iteration to address this problem. The proposed method performs one conjugate gradient iteration that enables better performance with less number of iterations. A new hybrid iteration is introduced and a low-complexity initial estimation is utilised to enhance detection accuracy while reducing the complexity further. In addition, a novel preconditioning technique is proposed to maintain the benefits of the proposed detector in correlated MIMO channels. It is mathematically demonstrate that the proposed detector achieves low approximated error. Theoretical analysis and numerical results show that the proposed algorithm provides a faster convergence rate compared to conventional methods.

关键词： conjugate gradient iteration detection accuracy iterative detection methods correlated MIMO channels hybrid iteration system capacity exhibit correlation signal detection complexity-performance tradeoff MIMO communication improved Gauss-Seidel iteration 5G cellular system BS-to-user antenna ratio base station efficient iterative detection algorithm performance deteriorates LS-MIMO large-scale MIMO systems low approximated error energy-efficiency multiple-input multiple-output cellular radio iterations 5G mobile communication improved Gauss-Seidel detector gradient methods low-complexity initial estimation low-complexity high-performance data detectors antenna arrays

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Tree physiology optimization on SISO and MIMO PID control tuning

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NEURAL COMPUTING & APPLICATIONS 2019年第11期31卷 7571-7581页

作者： Halim, A. Hanif Ismail, I. Univ Teknol PETRONAS Elect & Elect Engn Dept Tronoh 31750 Perak Malaysia

The tuning of proportional-integral-derivative (PID) controller is essential for any control application in order to ensure the best performance by step change or disturbance. This paper presents the tuning of PID controller for single-input single-output (SISO) and multiple-input multiple-output (MIMO) control systems using tree physiology optimization (TPO). TPO is a metaheuristic algorithm inspired from a plant growth system derived based on the idea of plant architecture and Thornley model (TM). The basic principle of TM simplifies the plant growth into shoots and roots part. The plant shoots grow towards sunlight with the help of nutrients supplied by the root system in order to undergo photosynthesis process, a process of converting light photon into carbon. The carbon gain from the shoots extension will be supplied to the root system in order for the root to grow and search for water plus nutrients. As a result, the nutrients are supplied upwards towards shoot system for further extension. This concept runs iteratively in order to ensure optimum plant growth. The iterative search of shoot towards better light supported by the root counterparts leads to an optimization idea of TPO algorithm. TPO also has a unique exploration strategy due to its multiple branches and shoots that can be defined by user. This concept may improve the search mechanism with a better trade-off between diversification and intensification search. A simulation of SISO control system and an industrial application of MIMO control are applied to demonstrate the effectiveness of the proposed algorithm and compared with other optimization methods such as particle swarm optimization, Ziegler-Nichols, Tyreus-Luyben and Chien-Hrones-Reswick methods. The results clearly exhibit the capability of TPO algorithm towards finding the optimum PID parameters for SISO and MIMO process with faster settling time and better performance with respect to other methods.

关键词： Single-input single-output multiple-input multiple-output Tree physiology optimization Particle swarm optimization Ziegler-Nichols Tyreus-Luyben Chien-Hrones-Reswick

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Degrees of Freedom of Multi-Cell MIMO Interference Broadcast Channels With Distributed Base Stations

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KSII TRANSACTIONS ON INTERNET AND INFORMATION SYSTEMS 2019年第2期13卷 635-656页

作者： Huang, Hongbing Liu, Junyi Zhang, Yi Cai, Qing Zhang, Bowei Jiang, Fengwen State Grid Zhejiang Elect Power Co Ltd Informat & Telecommun Branch Hangzhou 310026 Zhejiang Peoples R China Chongqing Univ Coll Commun Engn Chongqing 400044 Peoples R China

In this paper, we investigate the degrees of freedom (DoF) of a multi-cell multi-user multiple-input multiple-output (MIMO) interference broadcast channel (IBC) with non-cooperation distributed base stations (BS), where each BS serves users of its corresponding cell. When all BSs simultaneously transmit their own signals over the same frequency band in the MIMO IBC, the edge users in each cell will suffer the inter-cell interference (ICI) and inter-user interference (IUI) signals. In order to eliminate the ICI and IUI signals, a distributed space time interference alignment (DSTIA) approach is proposed where each BS has only limited access to distributed moderately-delay channel state information at the transmitter (CSIT). It is shown that the DSTIA scheme can obtain the appreciate DoF gains. In addition, the DoF upper bound is asymptotically achievable as the number of antenna at each BS increases. It is shown that the DSTIA method can get DoF gains over other interference alignment schemes with delayed CSIT in literature. Moreover, the DSTIA method can attain higher DoFs than the IA schemes with global CSIT for certain antenna configurations.

关键词： Degrees of freedom interference broadcast channel channel state information multiple-input multiple-output interference alignment

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Adaptive Quadrature Spatial Modulation

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IETE TECHNICAL REVIEW 2020年第6期37卷 579-590页

作者： Oladoyinbo, S. Pillay, N. Xu, H. Univ KwaZulu Natal Sch Engn ZA-4041 Durban South Africa

In this paper, we investigate an enhanced form of spatial modulation, in the form of quadrature spatial modulation (QSM). The existing analytical error performance of QSM does not agree well with Monte Carlo simulation results in the low signal-to-noise ratio (SNR) region. Hence, the first contribution of the paper is to formulate a new analytical bound on error performance, which improves on the validation of simulation results at low SNRs. Secondly, a link adaptation technique for QSM is investigated in order to further improve its error performance. The proposed scheme is based on a selection technique between candidate transmission modes chosen to satisfy a target spectral efficiency, which employs optimal transmit antenna selection and modulation order selection, such as to minimize the average bit error probability (BEP). Euclidean distance-based antenna selection is employed to select the enumeration of transmit antennas for each transmission candidate, while the instantaneous BEP (IBEP) is employed to select the transmission candidate mode. Significant SNR gain over QSM is demonstrated. In order to reduce the computational complexity (CC) overhead of optimal transmit antenna selection, the third contribution is to investigate suboptimal low-complexity transmit antenna selection for the proposed scheme. Monte Carlo simulation results demonstrate a trade-off between the error performance and CC.

关键词： Adaptive quadrature spatial modulation Euclidean distance-based antenna selection Instantaneous bit error probability Low-complexity transmit antenna selection multiple-input multiple-output Quadrature spatial modulation

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Secure Transmission for Interference Networks: User Selection and Transceiver Design

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IEEE SYSTEMS JOURNAL 2019年第3期13卷 2839-2850页

作者： Zhao, Nan Cao, Qiuyi Gui, Guan Cao, Yang Zhang, Shun Chen, Yunfei Sari, Hikmet Dalian Univ Technol Sch Informat & Commun Engn Dalian 116023 Peoples R China Xidian Univ State Key Lab Integrated Serv Networks Xian 710071 Shaanxi Peoples R China Nanjing Univ Posts & Telecommun Nanjing 210028 Jiangsu Peoples R China Univ Warwick Sch Engn Coventry CV4 7AL W Midlands England Sequans Commun F-92700 Colombes France

Interference is usually regarded as a detrimental factor that degrades the performance of a wireless network. However, when it is used properly, the security of transmission can be effectively improved. In this paper, user selection and transceiver design are proposed to guarantee the secure transmission in a multiple-input multiple-output interference network with an eavesdropper. First, user selection is performed to select the most suitable user to transmit confidential information according to the topology and path loss in each time slot among all users. Then, based on user selection, the transceivers of the users are jointly designed to maximize the secrecy rate of the selected user while guaranteeing a minimum transmission rate for other users. Due to the nonconvexity of the optimization problem, it is transformed into a convex second-order cone programming with the help of successive approximations. An alternate iteration algorithm is proposed to obtain the optimal solution. The fairness of the user selection is considered, and a modified scheme is proposed to share the opportunity of secure transmission among users. Finally, simulation results are presented to show the effectiveness and efficiency of the proposed schemes.

关键词： Interference networks multiple-input multiple-output physical layer security secrecy rate transceiver design user selection

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A Robustness and Low-Complexity Selection Criterion for Switching between multiplexing and Diversity in MIMO Transmission

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WIRELESS PERSONAL COMMUNICATIONS 2011年第2期60卷 171-190页

作者： Pan, Chien-Hung Natl Chiao Tung Univ Dept Commun Engn 1001 Ta Hsueh Rd Hsinchu 300 Taiwan

In this paper, we propose a new QR-based selection criterion with reduced complexity for the development of switching between spatial multiplexing (SM) and spatial diversity (SD) transmission. Then, we investigate an effect of the QR-decomposition processes by exploiting orthogonal structure of channel matrix. Additionally, to solve the problem of the error transmission mode in transmitter, we claim that the proposed QR-based detection at receiver can be used to form the successive interference cancellation (SIC) detection and orthogonal space-time block code (O-STBC) decoding for the SM transmission and the SD transmission, respectively. Simulation results show that the proposed scheme is capable of achieving optimum performance, but at a low-complexity level.

关键词： multiple-input multiple-output Switching Minimum Euclidean distance QR-decomposition

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