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Full envelope flight control system design using qualitative feedback theory

JOURNAL OF GUIDANCE CONTROL AND DYNAMICS 1996年第1期19卷 23-29页

作者： Reynolds, OR Pachter, M Houpis, CH U.S. Air Force Institute of Technology Wright-Patterson Air Force Base Ohio 45433-7655

A controlled plant's characteristics can vary widely throughout its operational envelope. This is a major problem in nominal plant-based control system design, Hence, gain scheduling is often used for full envelope design. In this paper, it is proposed to address the plant's variability using robust control design concepts, minimizing the need for gain scheduling, In particular, the frequency-domain-based quantitative feedback theory multiple input multiple output robust controls design method is employed for the synthesis of a full envelope flight control system for an F-16 aircraft derivative, Qualitative feedback theory addresses structured uncertainty that is caused by full envelope operation. Thus, qualitative feedback theory robust control is particularly suited for full envelope controller design, Compensators and prefilters for the aircraft's pitch and lateral/directional channels are designed to meet level 1 flying qualities specifications, and these designs are validated using simulations.

关键词： Quantitative Feedback Theory Flight Control Design Elevator Trim Handling Qualities Sideslip Angle Pilot Flight Envelope Aircraft Dynamics multiple input multiple output Elevator Deflection

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PSO-optimized Pareto and Nash equilibrium gaming-based power allocation technique for multistatic radar network

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ETRI JOURNAL 2021年第1期43卷 17-30页

作者： Harikala, Thoka Satya Narayana, Ravinutala SV Univ Dept Elect & Commun Tirupati Andhra Pradesh India

At present, multiple input multiple output radars offer accurate target detection and better target parameter estimation with higher resolution in high-speed wireless communication systems. This study focuses primarily on power allocation to improve the performance of radars owing to the sparsity of targets in the spatial velocity domain. First, the radars are clustered using the kernel fuzzy C-means algorithm. Next, cooperative and noncooperative clusters are extracted based on the distance measured using the kernel fuzzy C-means algorithm. The power is allocated to cooperative clusters using the Pareto optimality particle swarm optimization algorithm. In addition, the Nash equilibrium particle swarm optimization algorithm is used for allocating power in the noncooperative clusters. The process of allocating power to cooperative and noncooperative clusters reduces the overall transmission power of the radars. In the experimental section, the proposed method obtained the power consumption of 0.014 to 0.0119 atK = 2,M = 3 andK = 2,M = 3, which is better compared to the existing methodologies-generalized Nash game and cooperative and noncooperative game theory.

关键词： Kernel fuzzy C-means multiple input multiple output Nash equilibrium particle swarm optimization power allocation

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Optical Spatial Modulation

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JOURNAL OF OPTICAL COMMUNICATIONS AND NETWORKING 2011年第3期3卷 234-244页

作者： Mesleh, Raed Elgala, Hany Haas, Harald Univ Tabuk Dept Elect Engn Tabuk 71491 Saudi Arabia Jacobs Univ Sch Elect Engn & Comp Sci Bremen Germany Jacobs Univ Dept Elect Engn & Sci D-28759 Bremen Germany Univ Edinburgh Inst Digital Commun Edinburgh EH9 3JL Midlothian Scotland

In this paper, a power and bandwidth efficient pulsed modulation technique for optical wireless (OW) communication is proposed. The scheme is called optical spatial modulation (OSM). In OSM, multiple transmit units exist where only one transmitter is active at any given time instance. The spatially separated transmit units are considered as spatial constellation points. Each unique sequence of incoming data bits is mapped to one of the spatial constellation points, i.e., activating one of the transmit units. This is the fundamental concept of the spatial modulation (SM) technique. In OW communication systems, the active transmitter radiates a certain intensity level at a particular time instance. At the receiver side, the optimal SM detector is used to estimate the active transmitter index. An overall increase in the data rate by the base 2 logarithm of the number of transmit units is achieved. The optical MIMO (multiple-input multiple-output) channel and the channel impulse response are obtained via Monte Carlo simulations by applying ray tracing techniques. It will be shown in this paper that the optical MIMO channel is highly correlated if transmitter and receiver locations are not optimized, which results in a significant power penalty. The power efficiency can be improved by increasing the number of receive units to enhance receive diversity and/or by using soft and hard channel coding techniques. Conversely, it is shown that aligning transmit and receive units creates nearly uncorrelated channel paths and results in substantial enhancements in system performance even as compared to the diversity or coding gain. The resultant aligned scheme is shown to be very efficient in terms of power and bandwidth as compared to on-off keying, pulse position modulation, and pulse amplitude modulation. In this paper also, the upper bound bit error ratios of coded and uncoded OSM are analyzed. The analytical results are validated via Monte Carlo simulations and the results de

关键词： Direct detection Diversity Hard coding Intensity modulation multiple input multiple output Optical wireless communication On-off keying Pulse amplitude modulation Pulse position modulation Spatial modulation Soft coding

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Design and Analysis of Four-Port MIMO System Optimization Methodology with Machine Learning Approaches of Validated Antenna Parameters

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WIRELESS PERSONAL COMMUNICATIONS 2024年第1期136卷 213-232页

作者： Babu, K. Vasu Sree, Gorre Naga Jyothi BVRIT HYDERABAD Coll Engn Women Dept Elect & Commun Engn Bachupally Telangana India Vasireddy Venkatadri Inst Technol Dept Elect & Commun Engn Nambur Andhra Pradesh India

A four-element MIMO array antenna for the generation of 5G cellphones to operate at lower sub-6 GHz systems and which is optimized using the current design approach. For acceptable performance related to the optimum design parameters EM simulations are performed instead of traditional optimizations method due to time-consuming process for antenna design. Depending on the nonlinear relationship and complexity for design characteristics an effective method of deep learning (DL) is to determining optimum physical parameters. For designing of the MIMO antenna array this technique proposes resource efficient and time using DL approach. To reduce design space and generation of an effective dataset the technique applied is feature reduction method. To predict the S-parameters developing a novel dual-channel deep neural network. The designed antenna is optimized and achieved the - 10 dB impedance bandwidth of 40% (2.8-4.2 GHz), ECC is 0.018, TARC value is - 22 dB, isolation is - 35 dB, mean effective gain ratio is approaches to unity and CCL is 0.32 bps/Hz.

关键词： Deep learning (DL) Envelope correlation coefficient multiple input multiple output 5G cellphones Total active reflection coefficient

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Sequential loop closure in design of a robust rotorcraft flight control system

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JOURNAL OF GUIDANCE CONTROL AND DYNAMICS 1997年第6期20卷 1235-1240页

作者： Gorder, PJ Hess, RA UNIV CALIF DAVIS DEPT MECH & AEROSP ENGNDAVISCA 95616

Rotorcraft flight control systems present many significant design challenges. First, large variations in the response characteristics of rotorcraft result from the wide range of airspeeds of typical operation (hover to over 100 kn). Second, the assumption of vehicle rigidity often employed in the design of fixed-wing flight control systems is rarely justified in rotorcraft where rotor degrees of freedom can have a significant impact on the system performance and stability. A methodology is proposed for the design of robust rotorcraft flight control systems utilizing quantitative feedback theory (QFT). QFT is a technique that accounts for variability in the dynamic response of the controlled element in the design of robust control systems. It was developed to address a multiple-input/single-output (MISO) design problem, but the extension of this technique to address multiple-input/multiple-output (MIMO) systems was employed to address the Eight control system (FCS) design of a UH-60 Black Hawk Helicopter. This was accomplished by constructing a set of MISO systems mathematically equivalent to the MIMO system. QFT was applied to each member of the set independently, Inherent conservatism in this design technique leads to limitations in its utility. A second approach utilizing the sequential closure of control loops proved an improved method for designing of robust MIMO FCSs. An analysis of the two FCS design methodologies is presented.

关键词： Rotorcrafts multiple input multiple output Flight Control System Closed Loop Transfer Function Dynamic Response UH 60 Black Hawk Helicopter Airspeed Yaw Frequency Domain Pilot

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L-shaped reconfigurable band decoupling assisted dual band four port MIMO antenna for 5G and IoT application

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AEU-INTERNATIONAL JOURNAL OF ELECTRONICS AND COMMUNICATIONS 2024年 179卷

作者： Mamta Nath, Vandana GGSIP Univ Dept ECE USICT Delhi 110078 India

Reconfigurable MIMO antennas adapt dynamically to changing communication needs and environmental conditions by changing their emission patterns, polarization, and frequency characteristics. By adjusting the antenna configuration, reconfigurable MIMO systems can prevent interference and improve spectral efficiency, resulting in increased data rates and optimal utilization of available frequency ranges. Furthermore, the antenna parameters are optimized to obtain better results and help to enhance the overall efficiency of the model. In this study, an L-shaped reconfigurable band decoupling assisted dual band four port MIMO antenna is designed. The antenna reconfigurability has been obtained from a band stop filter with a pin diode in the proposed design, with four PIN diodes in each individual antenna for improved isolation. The mutual coupling between the antenna elements has been reduced by inserting a DGS to the antenna elements. The presented reconfigurable four-port Lshaped MIMO antenna is applied over 5G and IoT applications. The overall dimensions of the antenna is 40 x 40 x 0.508 mm3, which resonates over a dual frequency range between 2.344 GHz for 5G applications and 1.433 GHz for IoT applications. Rogers RT Duroid 5880 substrate with a thickness of 0.508 mm, a dielectric constant of 2.2, a relative permeability of 1, and loss tangents of 0.009 in the proposed design and coplanar waveguide feed line are employed, and an I-shaped stub is used to increase isolation. Defected ground structure (DGS) is used in this work to minimize the antenna mutual coupling issue.

关键词： multiple input multiple output Rogers RT Duroid 5880 Coplanar waveguide Band stop filter Pin diodes Defected ground structure

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A polarization-division multiplexing SSB-OFDM system with beat interference cancellation receivers

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OPTICS COMMUNICATIONS 2018年 416卷 137-144页

作者： Yang, Peiling Ma, Jianxin Zhang, Junyi Beijing Univ Posts & Telecommun Sch Elect Engn State Key Lab Informat Photon & Opt Commun Beijing 100876 Peoples R China Beijing Univ Posts & Telecommun Sch Elect Engn Beijing Key Lab Space Ground Interconnect & Conve Beijing 100876 Peoples R China

In this paper, we have proposed a polarization-division multiplexing (PDM) single-sideband optical orthogonal frequency division multiplexing (SSB-OOFDM) scheme with signal-signal beat interference cancellation receivers with balanced detection (ICRBD). This system can double channel capacity and improve spectrum efficiency (SE) with the reduced guard band (GB) due to the PDM. multiple input multiple output (MIMO) technique is used to solve polarization mode dispersion (PMD) associated with channel estimation and equalization. By simulation, we demonstrate the efficacy of the proposed technique for a 2x40 Gbit/s 16-QAM SSB-PDM-OOFDM system according to the error vector magnitude (EVM) and the constellation diagrams.

关键词： Polarization division multiplexing multiple input multiple output Orthogonal polarization modulation SSB-OOFDM signal Guard band

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High-Speed Integrated Visible Light Communication System: Device Constraints and Design Considerations

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IEEE JOURNAL ON SELECTED AREAS IN COMMUNICATIONS 2015年第9期33卷 1750-1757页

作者： Rajbhandari, Sujan Chun, Hyunchae Faulkner, Grahame Cameron, Katherine Jalajakumari, Aravind V. N. Henderson, Robert Tsonev, Dobroslav Ijaz, Muhammad Chen, Zhe Haas, Harald Xie, Enyuan McKendry, Jonathan J. D. Herrnsdorf, Johannes Gu, Erdan Dawson, Martin D. O'Brien, Dominic Univ Oxford Dept Engn Sci Oxford OX1 3PJ England Univ Edinburgh CMOS Sensors & Syst Grp Edinburgh EH9 3JL Midlothian Scotland Univ Edinburgh Inst Digital Commun Li FI R&D Ctr Edinburgh EH9 3JL Midlothian Scotland Univ Strathclyde Inst Photon Glasgow G1 1XQ Lanark Scotland

Visible light communications (VLC) has the potential to play a major part in future smart home and next generation communication networks. There is significant ongoing work to increase the achievable data rates using VLC, to standardize it and integrate it within existing network infrastructures. The future of VLC systems depends on the ability to fabricate low cost transceiver components and to realize the promise of high data rates. This paper reports the design and fabrication of integrated transmitter and receiver components. The transmitter uses a two dimensional individually addressable array of micro light emitting diodes (mu LEDs) and the receiver uses an integrated photodiode array fabricated in a CMOS technology. A preliminary result of a MIMO system implementation operating at a data rate of 1 Gbps is demonstrated. This paper also highlights the challenges in achieving highly parallel data communication along with the possible bottlenecks in integrated approaches.

关键词： Visible light communications optical communication system design multiple input multiple output optical wireless communications link budget analysis integrated optical system design

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Rectangular DR-based dual-band CP-MIMO antenna with inverted Z-shaped slot

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INTERNATIONAL JOURNAL OF ELECTRONICS 2020年第10期107卷 1559-1573页

作者： Kumar, Vipan Sri Sai Coll Engn & Technol Elect & Commun Engn Dept Pathankot India

In this paper, a dual-band circular polarised (CP), multiple input multiple output (MIMO) antenna with bi-directional polarisation is presented. Designed antenna is operating at two frequency bands i.e. 5.4 GHz-6.2 GHz and 7.0 GHz-7.4 GHz. A rectangular dielectric resonator (DR) is excited by two ports for designing an MIMO antenna system. To generate the Circular polarisation, ground plane is modified by etching an inverted Z-shaped slot. The fundamental mode , and higher order mode , are generated in the antenna structure due to the specified geometry which excites the circular polarisation. 3-dB axial ratio (AR) bandwidth of 300 MHz (5.7 GHz-6.0 GHz) and 200 MHz (7.0 GHz-7.2 GHz) is obtained for the lower and upper bands, respectively. Maximum isolation is 19 dB, and 15 dB for the targeted bands have been achieved. S-parameters, gain and radiation pattern are measured to authenticate the simulated results. Envelope correlation, diversity gain, mean effective gain and channel capacity loss are calculated from the measured parameters;their values lie within the optimum range. Results show that antenna is suitable for WLAN 5.5/5.8 GHz and X-band downlink communication at 7.0 GHz.

关键词： Circular polarisation multiple input multiple output bi-directional polarisation z-shaped slot

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Comparing optical transport technologies for x-hauling 5G small cells in the sub-6 GHz

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JOURNAL OF OPTICAL COMMUNICATIONS AND NETWORKING 2022年第4期14卷 204-210页

作者： Rafel, Albert Maes, Jochen Martlesham Heath BT Labs BT Appl Res Ipswich Suffolk England Nokia Bell Labs Fixed Networks Grp Antwerp Belgium

Mobile network operators are facing the rollout of 5G New Radio small cells in the next few years. High cell density will require intensive support of optical transport, and there are multiple options depending on cell configuration and capacity. Comparing these optical technologies in terms of capacity and cost is important to maximize return on the likely limited deployment budget. We developed a model that can be used by operators in the strategy and decision-making phase and present example results on outdoor 5G small cells using the sub-6-GHz spectrum bands. (C) 2022 Optica Publishing Group

关键词： Dense wavelength division multiplexing multiple input multiple output Optical networks Optical systems Passive optical networks Time division multiplexing

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