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A stability-guaranteed smooth-scheduled MIMO robust emergency autopilot for a lateral surface jammed UAV

PROCEEDINGS OF THE INSTITUTION OF MECHANICAL ENGINEERS PART G-JOURNAL OF AEROSPACE ENGINEERING 2018年第12期232卷 2286-2299页

作者： Sahin, Ismail Hakki Kasnakoglu, Cosku TOBB Univ Econ & Technol Ankara Turkey Turkish Aerosp Ind Ankara Turkey

This paper investigates a methodology for autopilot design for an unmanned air vehicle where one of the lateral control surfaces, i.e. the aileron or rudder, becomes jammed and unusable. The autopilot handles the automatic recovery, autonomous guidance and landing of the disabled unmanned aerial vehicle. An accurate nonlinear aircraft model is used to build local flight control laws using loop-shaping to decouple longitudinal and lateral channels. The design is carried out in a way to allow smooth scheduling over the local controllers without losing stability and performance, culminating in a robust emergency autopilot over the full flight envelope. The autopilot is tested on an example distress scenario involving aileron surface jam. It is confirmed through simulations that the autopilot design is capable of resuming safe flight and autonomous navigation under the fault scenario and is able to safely land the unmanned aerial vehicle to a target runway.

关键词： Flight control guidance navigation unmanned air vehicle smooth scheduling multiple-input multiple-output robust loop-shaping surface jam

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Twisting-Rate-Controlled 125 μm Cladding Randomly Coupled Single-Mode 12-Core Fiber

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JOURNAL OF LIGHTWAVE TECHNOLOGY 2018年第2期36卷 325-330页

作者： Sakamoto, Taiji Aozasa, Shinichi Mori, Takayoshi Wada, Masaki Yamamoto, Takashi Nozoe, Saki Sagae, Yuto Tsujikawa, Kyozo Nakajima, Kazuhide NTT Access Networks Serv Syst Labs Tsukuba Ibaraki 3050805 Japan

A multicore fiber design with more than 10 coupled cores is investigated numerically and experimentally. It is revealed that a randomly coupled 12-core structure with a square lattice core arrangement can be realized within a 125 mu m cladding by employing fiber twisting of more than a few pi rad/m. A 125 mu m-clad twisting-rate-controlled 12-core fiber is then fabricated and a relative core density of 12 compared with conventional single-mode fiber is achieved while maintaining a low spatial mode dispersion characteristic of 8.4 ps/root km at 1550 nm. Finally, we experimentally evaluated the performance of 12 spatial channels by conducting a 24 x 24 MIMO transmission experiment.

关键词： Modal dispersion multicore fiber multiple-input multiple-output

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Preliminary results of a new MIMO plasma shape controller for EAST

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FUSION ENGINEERING AND DESIGN 2018年 128卷 38-46页

作者： Guo, Y. Xiao, B. J. Wang, Y. H. Liu, L. Huang, Y. Yuan, Q. P. Pironti, A. Albanese, R. Ambrosino, R. Yang, F. Qiu, Q. L. Calabro, G. Crisanti, F. Chinese Acad Sci Inst Plasma Phys Hefei 230031 Anhui Peoples R China Univ Sci & Technol China Sch Nucl Sci & Technol Hefei 230026 Anhui Peoples R China Univ Sci & Technol China Dept Modern Phys Hefei 230026 Anhui Peoples R China Univ Cassino Univ Napoli Federico 2 CREATE Via Claudio 19 I-80125 Naples Italy Univ Napoli Parthenope Via Claudio 19 I-80125 Naples Italy Anhui Med Univ Dept Comp Sci Hefei Anhui Peoples R China ENEA EUROfus Via E Fermi 45 I-00044 Rome Italy

The efficient and safe operation of large fusion devices relies on plasma configuration inside the vacuum chamber. Due to EAST PF coils distribution, it is difficult to physical decouple plasma control parameters and poloidal field (PF) coils current. In this paper, we present a MIMO decoupling controller aimed to overcome the intrinsic limitations of simpler SISO controller, this new controller has been validated by means of the Tokamak Simulation Code (TSC) and implemented on the EAST tokamak. Preliminary results show the potential of this approach for the EAST plasma shape control systems.

关键词： multiple-input multiple-output Plasma shape control EAST TSC

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A fuzzy C-regression model algorithm using a new PSO algorithm

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INTERNATIONAL JOURNAL OF ADAPTIVE CONTROL AND SIGNAL PROCESSING 2018年第1期32卷 115-133页

作者： Taieb, Adel Soltani, Moez Chaari, Abdelkader Natl Higher Engn Sch Tunis ENSIT Lab Engn Ind Syst & Renewable Energy 5 Ave Taha Hussein TunisBP 56 Tunis 1008 Tunisia

In this paper, a new methodology is introduced for the identification of the parameters of the multiple-input-multiple-output local linear Takagi-Sugeno fuzzy models using the weighted recursive least squares (WRLS). The WRLS is sensitive to initialization, which leads to no convergence. In order to overcome this problem, adaptive chaos particle swarm optimization is proposed to optimize the initial states of WRLS. This new algorithm is improved versions of the original particle swarm optimization algorithm. Finally, comparative experiments are designed to verify the validity of the proposed clustering algorithm and the Takagi-Sugeno fuzzy model identification method, and the results show that the new method is effective in describing a complicated nonlinear system with significantly high accuracies compared with approaches in the literature.

关键词： chaos adaptive particle swarm optimization fuzzy C-regression model clustering algorithm identification multiple-input multiple-output Takagi-Sugeno fuzzy models

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On the DoF Region for the Asymmetric MIMO Two-Way X Relay Channel

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IEEE TRANSACTIONS ON COMMUNICATIONS 2018年第1期66卷 119-132页

作者： Liu, Kangqi Yuan, Xiaojun Tao, Meixia Shanghai Jiao Tong Univ Dept Elect Engn Shanghai 200240 Peoples R China Univ Elect Sci & Technol China Natl Key Lab Sci & Technol Commun Chengdu 611731 Sichuan Peoples R China

In this paper, we study the degrees of freedom (DoF) region for the multiple-input multiple-output two-way X relay channel with asymmetric antenna setting. In this channel model, there are two groups of source nodes, each group contains two source nodes, every source node in one group exchanges independent messages with every source node in another group via a common relay node, and each node has a different number of antennas. First, we derive an outer bound of the DoF region by using the cut-set theorem and the genie-message approach. Then, we obtain an inner bound of the DoF region by proposing a new transmission scheme that collectively utilizes antenna deactivation, pairwise signal alignment, cyclic signal alignment, and generalized signal alignment techniques. In the case of symmetric data exchange, our inner bound coincides with the outer bound, and thus, our proposed transmission strategy is optimal. We also obtain the optimal sum DoF for the special case, where the source nodes within a same group are equipped with the same number of antennas. This paper provides new insights for the study of more complicated relay networks.

关键词： multiple-input multiple-output two-way relay channel interference alignment signal alignment degrees of freedom

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

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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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Design of Reconfigurable SDR Platform for Antenna Selection Aided MIMO Communication System

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IEEE ACCESS 2019年 7卷 169267-169280页

作者： Zhang, Peichang Xu, Jiajun Zhong, Shida Feng, Haogang Huang, Lei Yuan, Tao Zhang, Jiankang Shenzhen Univ Coll Elect & Informat Engn Shenzhen 518060 Peoples R China Univ Southampton Sch Elect & Comp Sci Southampton SO17 1BJ Hants England

In recent years, antenna selection (AS) has become one of the most popular research topics for massive multiple-input multiple-output (MIMO) system due to its capability of reducing the number of radio frequency chains utilized for MIMO communications, while remaining the MIMO advantages, such as increased bandwidth efficiency and reliability. In this paper, an efficient norm-based AS (NBAS) algorithm is investigated and implemented in the software defined radio (SDR) MIMO communication platform, which consists of field-programmable gate arrays (FPGAs). Owing to the high freedom and fast reconfigurable FPGA hardware, the SDR MIMO communication platform is capable of developing prototype of NBAS-aided MIMO system. More specifically, the implemented NBAS aided SDR MIMO system is capable of achieving uplink communication from users to the base station via time division duplex (TDD). A time-varying fading channel generation model is designed for SDR MIMO platform to enrich our experimental results. Additionally, a novel multiplexer (MUX) circuit module is designed and implemented to enhance the hardware performance of the FPGA in term of delay and resource usage. The results show that by implementing the low-complexity NBAS, the channel capacity performance of the SDR MIMO system can be significantly improved by around 15%. It is also showed that our proposed optimized MUX circuit intellectual property may reduce the critical path delay by about 2.16 ns, and save at lease 3% hardware resources in SDR FPGA.

关键词： multiple-input multiple-output antenna selection software defined radio FPGA

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SWORD: Towards a Soft and Open Radio Design for Rapid Development, Profiling, Validation and Testing

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IEEE ACCESS 2019年 7卷 186017-186040页

作者： Georgis, Georgios Filo, Marcin Thanos, Alexios Husmann, Christopher Ducoing, J. C. De Luna Tafazolli, Rahim Nikitopoulos, Konstantinos Univ Surrey Inst Commun Syst 5G Innovat Ctr Wireless Syst Lab Guildford GU2 7XH Surrey England

The vision, as we move to future wireless communication systems, embraces diverse qualities targeting significant enhancements from the spectrum, to user experience. Newly-defined air-interface features, such as large number of base station antennas and computationally complex physical layer approaches come with a non-trivial development effort, especially when scalability and flexibility need to be factored in. In addition, testing those features without commercial, off-the-shelf equipment has a high deployment, operational and maintenance cost. On one hand, industry-hardened solutions are inaccessible to the research community due to restrictive legal and financial licensing. On the other hand, research-grade real-time solutions are either lacking versatility, modularity and a complete protocol stack, or, for those that are full-stack and modular, only the most elementary transmission modes are on offer (e.g., very low number of base station antennas). Aiming to address these shortcomings towards an ideal research platform, this paper presents SWORD, a SoftWare Open Radio Design that is flexible, open for research, low-cost, scalable and software-driven, able to support advanced large and massive multiple-input multiple-output (MIMO) approaches. Starting with just a single-input single-output air-interface and commercial off-the-shelf equipment, we create a software-intensive baseband platform that, together with an acceleration/profiling framework, can serve as a research-grade base station for exploring advancements towards future wireless systems and beyond.

关键词： Acceleration multiple-input multiple-output SIMD software-defined radios beamforming

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MIMO channel estimation and evaluation for airborne traffic surveillance in cellular networks

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JOURNAL OF APPLIED REMOTE SENSING 2018年第1期12卷

作者： Vahidi, Vahid Saberinia, Ebrahim Univ Nevada Dept Elect & Comp Engn Las Vegas NV 89154 USA

A channel estimation (CE) procedure based on compressed sensing is proposed to estimate the multiple-input multiple-output sparse channel for traffic data transmission from drones to ground stations. The proposed procedure consists of an offline phase and a real-time phase. In the offline phase, a pilot arrangement method, which considers the interblock and block mutual coherence simultaneously, is proposed. The real-time phase contains three steps. At the first step, it obtains the priori estimate of the channel by block orthogonal matching pursuit;afterward, it utilizes that estimated channel to calculate the linear minimum mean square error of the received pilots. Finally, the block compressive sampling matching pursuit utilizes the enhanced received pilots to estimate the channel more accurately. The performance of the CE procedure is evaluated by simulating the transmission of traffic data through the communication channel and evaluating its fidelity for car detection after demodulation. Simulation results indicate that the proposed CE technique enhances the performance of the car detection in a traffic image considerably. (C) 2018 Society of Photo- Optical Instrumentation Engineers (SPIE).

关键词： channel estimation compressed sensing orthogonal frequency-division multiplexing multiple-input multiple-output group sparsity linear minimum mean square error

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Compact MIMO antenna for application to smart glasses using T-shaped ground plane

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MICROWAVE AND OPTICAL TECHNOLOGY LETTERS 2018年第8期60卷 2010-2013页

作者： Ryu, Jongin Kim, Hyeongdong Hanyang Univ Dept Elect & Comp Engn Microwave Engn Lab Seoul South Korea

A compact multiple-input multiple-output (MIMO) antenna design for application to smart glasses is proposed in this letter. The proposed MIMO antenna system is comprised of two symmetrical meander antennas operating in the 2.4-GHz wireless local area network band and a T-shaped ground for high isolation. The operation mechanism of the proposed MIMO antennas can be explained using the analysis of a three-port network. Accordingly, the T-shaped ground plane operates as a decoupling structure such that the isolation between antennas can be controlled by tuning the T-shaped ground plane. The reflection coefficient characteristic was measured to be less than -7.5 dB, whereas the isolation obtained was higher than 15 dB. The diversity performance was evaluated using the measured three-dimensional radiation patterns, and the envelope correlation coefficients in the target band were less than 0.1.

关键词： decoupling structure high isolation multiple-input multiple-output

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