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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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Machine Intelligence at the Edge With Learning Centric Power Allocation

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IEEE TRANSACTIONS ON WIRELESS COMMUNICATIONS 2020年第11期19卷 7293-7308页

作者： Wang, Shuai Wu, Yik-Chung Xia, Minghua Wang, Rui Poor, H. Vincent Southern Univ Sci & Technol Dept Elect & Elect Engn Shenzhen 518055 Peoples R China Southern Univ Sci & Technol Dept Comp Sci & Engn Shenzhen 518055 Peoples R China Univ Hong Kong Dept Elect & Elect Engn Hong Kong Peoples R China Sun Yat Sen Univ Sch Elect & Informat Technol Guangzhou 510006 Peoples R China Southern Marine Sci & Engn Guangdong Lab Zhuhai 519082 Peoples R China Princeton Univ Dept Elect Engn Princeton NJ 08544 USA

While machine-type communication (MTC) devices generate considerable amounts of data, they often cannot process the data due to limited energy and computational power. To empower MTC with intelligence, edge machine learning has been proposed. However, power allocation in this paradigm requires maximizing the learning performance instead of the communication throughput, for which the celebrated water-filling and max-min fairness algorithms become inefficient. To this end, this paper proposes learning centric power allocation (LCPA), which provides a new perspective on radio resource allocation in learning driven scenarios. By employing 1) an empirical classification error model that is supported by learning theory and 2) an uncertainty sampling method that accounts for different distributions at users, LCPA is formulated as a nonconvex nonsmooth optimization problem, and is solved using a majorization minimization (MM) framework. To get deeper insights into LCPA, asymptotic analysis shows that the transmit powers are inversely proportional to the channel gains, and scale exponentially with the learning parameters. This is in contrast to traditional power allocations where quality of wireless channels is the only consideration. Last but not least, a large-scale optimization algorithm termed mirror-prox LCPA is further proposed to enable LCPA in large-scale settings. Extensive numerical results demonstrate that the proposed LCPA algorithms outperform traditional power allocation algorithms, and the large-scale optimization algorithm reduces the computation time by orders of magnitude compared with MM-based LCPA but still achieves competing learning performance.

关键词： Machine learning Resource management Data models Wireless communication Computational modeling Image edge detection Training Empirical classification error model edge machine learning learning centric communication multiple-input multiple-output resource allocation

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A Limited Feedback Joint Precoding for Amplify-and-Forward Relaying

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IEEE TRANSACTIONS ON SIGNAL PROCESSING 2010年第3期58卷 1347-1357页

作者： Huang, Yongming Yang, Luxi Bengtsson, Mats Ottersten, Bjorn Southeast Univ Sch Informat Sci & Engn Nanjing 210096 Peoples R China Royal Inst Technol ACCESS Linnaeus Ctr KTH Signal Proc Lab SE-10044 Stockholm Sweden Univ Luxembourg Luxembourg Luxembourg

This paper deals with the practical precoding design for a dual hop downlink with multiple-input multiple-output (MIMO) amplify-and-forward relaying. First, assuming that full channel state information (CSI) of the two hop channels is available, a suboptimal dual hop joint precoding scheme, i.e., precoding at both the base station and relay station, is investigated. Based on its structure, a scheme of limited feedback joint precoding using joint codebooks is then proposed, which uses a distributed codeword selection to concurrently choose two joint precoders such that the feedback delay is considerably decreased. Finally, the joint codebook design for the limited feedback joint precoding system is analyzed, and results reveal that independent codebook designs at the base station and relay station using the conventional Grassmannian subspace packing method is able to guarantee that the overall performance of the dual hop joint precoding scheme improves with the size of each of the two codebooks. Simulation results show that the proposed dual hop joint precoding system using distributed codeword selection scheme exhibits a rate or BER performance close to the one using the optimal centralized codeword selection scheme, while having lower computational complexity and shorter feedback delay.

关键词： Amplify-and-forward relaying dual hop Grassmannian codebook joint precoding limited feedback multiple-input multiple-output

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Generalized OSTBC-based subcarrier intensity-modulated MIMO optical wireless communication system

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INTERNATIONAL JOURNAL OF COMMUNICATION SYSTEMS 2017年第6期30卷 1-9页

作者： Sharma, Nikhil Bansal, Ankur Garg, Parul Netaji Subhas Inst Technol Div Elect & Commun Engn New Delhi India

In this paper, we analyze an optical wireless communication (OWC) system having a source and a destination node, equipped with multiple transmit and receive apertures, respectively. We utilize generalized orthogonal space-time block codes (OSTBCs) of any arbitrary order and subcarrier intensity modulation scheme for data transmission over gamma-gamma (GG) fading optical links using M-ary phase-shift keying (PSK) constellation. A symbol-wise decoding is utilized, and the closed-form expression of the approximate average symbol error rate (SER) of multi-aperture-based OWC system is obtained for the generalized OSTBC and an arbitrary M-PSK constellation. Using the derived SER expression, we analytically evaluate the diversity order and the coding gain of the OWC system with GG atmospheric turbulence. It has been shown by the numerical results that the maximum possible diversity is achieved by using the symbol-wise maximum likelihood decoding in the destination. Copyright (C) 2016 John Wiley & Sons, Ltd.

关键词： orthogonal space-time block codes optical wireless communication subcarrier intensity modulation multiple-input multiple-output

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Applying Machine Learning Approach to Identifying Channels in MIMO Networks for Communications in 5G-Enabled Sustainable Smart Cities

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MOBILE NETWORKS & APPLICATIONS 2023年 1-13页

作者： Stalin, Shalini Gupta, Manish Makanyadevi, K. Agrawal, Amit Jain, Anupriya Pandit, Shraddha V. Rizwan, Ali Indian Inst Informat Technol IIIT Bhopal Dept Informat Technol Bhopal 462003 Madhya Pradesh India Moradabad Inst Technol Dept Comp Sci & Engn Moradabad India Kumarasamy Coll Engn Dept Comp Sci & Engn Karur 639113 Tamil Nadu India Sreedattha Grp Educ Inst Dept Comp Sci & Engn & Director T&P Hyderabad Telangana India Manav Rachna Int Inst Res & Studies Faridabad India PES Modern Coll Engn Dept Artificial Intelligence & Data Sci Shivajinagar Pune Maharashtra India King Abdulaziz Univ Fac Engn Dept Ind Engn Jeddah 21589 Saudi Arabia

During the process of sending a signal across a transmission channel that has a broad bandwidth, the multiple-input multiple-output, or MIMO, system will frequently require a larger quantity of energy and power than it would under normal circumstances. This is because the transmission channel will have a greater capacity to carry more data. When there are so many different sets of signals that have been found, it is necessary to be able to differentiate between them using one of the many different methods that have been developed. One of the methods that is now one of the most extensively employed in the process of discovery is called maximum likelihood detection. This method is also frequently referred to as machine learning (ML) detection. This is as a result of the very high throughput that ML detection has. On the other hand, the exponential growth in ideal throughput is far smaller than the complexity of the framework and the amount of energy that it consumes. In order to better simplify communication between the transmitter and the receiver, the major goal of this endeavor is to locate the shortest viable routing route for the physical data transmission layer and use that information to design the routing path. Because of this, both the quantity of energy that is used and the level of complexity that the system has will both drop. Improved Iterative Based Dijkstra Algorithm (IIBDA) to Gauge the Most Limited Course of the Channel with a Restricted Maximum Likelihood-Detection (RMLD) Design was a method that was presented to solve the problem. This was done in order to address the concerns that had been raised and resolved in the prior discussion. This was done in an effort to discover answers to problems such as these. The Execution Examination illustrates how the Complexity and Control Utilization in the Proposed Strategy may be Decreased by showing how these factors might be Addressed. An FPGA Virtex-6 was used for putting the suggested plan into action in or

关键词： Improved Iterative Based Dijkstra Algorithm (IIBDA) Restricted Maximum Likelihood-Detection (RMLD) Quadrature Phase Shift Keying (QPSK) multiple-input multiple-output FPGA (Field Programmable Gate Array)

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Analysis on the performance of normalised gain difference power allocation for MIMO-NOMA-based VLC

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INTERNATIONAL JOURNAL OF NANOTECHNOLOGY 2022年第2-5期19卷 113-125页

作者： Elewah, Ibrahim A. Jasman, Faezah Ng, Sha Shiong Univ Sains Malaysia USM Inst Nano Optoelect Res & Technol INOR George Town 11800 Malaysia Amer Coll Middle East Dept Engn & Technol Egila Kuwait

In this study, we build a 4 x 4 multiple-input multiple-output (MIMO) non-orthogonal multiple access (NOMA) based visible light communication (VLC) system. The main goal of this study is to optimise the power consumption on the indoor VLC system by using normalised gain difference power allocation (NGDPA) to ensure the same achievable sum rate even for users on the system borders. The proposed system is simulated to serve 2, 3, and up to 4 users. The obtained results were compared with 4 x 4 MIMO using NOMA without applying NGDPA. It was found that the proposed system shows an almost constant achievable sum rate for all users regardless of their current position within the system coverage area. The results show that users on the system edge can share up to 97.32% of the maximum achievable sum rate. The relation between normalised offset and sum rate gain for 2, 3, and 4 users' scenarios is also discussed. The findings revealed that the system using NOMA with NGDPA scheme can utilise more sum rate gain with increasing the number of users. Through this study, it can be deduced that the 4 x 4 MIMO-NOMA-VLC system with NGDPA scheme has been performance.

关键词： energy-efficient light source VLC visible light communication MIMO multiple-input multiple-output NOMA non-orthogonal multiple access NGDPA normalised gain difference power allocation

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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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Performance and Design of Coherent and Differential Space-Time Coded FSO Systems

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JOURNAL OF LIGHTWAVE TECHNOLOGY 2012年第11期30卷 1569-1577页

作者： Bayaki, Ehsan Schober, Robert Univ British Columbia Dept Elect & Comp Engn Vancouver BC V6T 1Z4 Canada

Free-space optical (FSO) communication enables high rate data transmission over the atmospheric channel. However, turbulence-induced fading poses severe challenges for operating these systems. Employing spatial diversity has been proposed as an effective measure to improve system performance. In this paper, we first develop a comprehensive model for multiple-input multiple-output (MIMO) coherent and differential FSO systems with heterodyne detection taking into account all relevant signal and noise terms. For the sake of comparison, a similar model is also developed for direct detection. An asymptotic performance analysis is presented for MIMO FSO systems employing coherent and differential space-time codes (STCs) over Gamma-Gamma fading channels. We consider the practically important case of two transmit and an arbitrary number of receive apertures and provide a simple STC design criterion for coherent and differential FSO systems. Our results reveal that, in contrast to FSO systems with intensity modulation and direct detection (IM/DD), for coherent and differential FSO systems, orthogonal space-time block codes previously introduced in the RF literature, are preferable over repetition STCs, which do not yield full diversity. We quantify the asymptotic performance gain of coherent space-time coded FSO systems compared to IM/DD systems and show that this gain is mainly caused by the superiority of heterodyne detection compared to direct detection rather than the different STC and modulation designs.

关键词： Atmospheric turbulence coherent detection free-space optical communication multiple-input multiple-output space-time code design

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Adaptive MIMO-FSO space diversity MRC reception characteristics over Malaga turbulence channel with pointing errors

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TELECOMMUNICATION SYSTEMS 2024年第1期86卷 117-126页

作者： Chen, Dan Ai, Feier Wang, Chenhao Zhao, Peiyan Lu, Mengmeng Xian Univ Technol Sch Automat & Informat Engn Xian 710048 Shaanxi Peoples R China Shaanxi Vocat & Tech Coll Xian 710018 Shaanxi Peoples R China

Atmospheric turbulence channels experience quasi-static fading, which makes it relatively straightforward to utilize feedback information for link adaptive transmission. Applying adaptive modulation to MIMO systems can effectively mitigate the degradation of Free-Space Optical (FSO) signals under adverse turbulence conditions. In this paper, the joint influence of pointing error and Malaga distribution turbulence fading on the probability density function (PDF) of the received light intensity of a MIMO channel employing maximal ratio combining (MRC) is considered. The PDF of MRC combined channel is derived based on the moment generation function. Then, using the cumulative density function (CDF)-based method, we analyze the asymptotic spectral efficiency (SE) and average bit error rate (BER) performance of the adaptive MPSK-MIMO system under different turbulence intensities, beam waist radius, jitter standard deviation, and the number of transmit/receive apertures. In addition, we also compare the average BER performance of adaptive and non-adaptive MIMO systems with MRC receivers. Monte Carlo simulation further verifies our analysis. The derived results help quantify the diversity order of the systems we are considering.

关键词： Adaptive modulation multiple-input multiple-output Malaga turbulence model Pointing error Maximal ratio combining (MRC)

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Coding Gain Distance Exact Estimation for Space-Time Trellis Coded Modulation

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CIRCUITS SYSTEMS AND SIGNAL PROCESSING 2013年第2期32卷 919-929页

作者： Vladeanu, Calin Univ Politehn Bucuresti Bucharest 061071 Romania

Space-time (ST) trellis coded modulation (TCM) represents a high spectral efficiency technique for multiple antennas transmissions over fading channels. In literature, it was shown that ST-TCM technique offers full diversity when the rank criterion is met. However, "brute force" methods were used in almost all previous work to search for full diversity ST-TCM codes. In the present paper, we aim to derive an exact expression for the minimum coding gain distance (CGD) in the case of full diversity ST-TCM codes with minimum memory size, for two transmit antennas. Therefore, we transpose the ST-TCM design rules into operations over the set of modulo-M integer numbers (Z (M) ), between the current trellis state and encoder's input information symbol value, in order to derive the transmitted M-levels phase shift keying modulated (M-PSK) output values. In this context, a new design method is introduced to control the code's minimum CGD value of full diversity ST-TCM schemes.

关键词： multiple-input multiple-output Space-time trellis coded modulation Transmit diversity Coding gain distance

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