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Impact Load Compensation Inverter Based on Nonlinear Adaptive multiple input multiple output Control Strategy

APPLIED SCIENCES-BASEL 2025年第6期15卷

作者： Wang, Shuai Zhao, Ke Duan, Jiandong Sun, Li Harbin Inst Technol Sch Elect Engn & Automat Harbin 150001 Peoples R China

A nonlinear adaptive multiple-input multiple-output (NAMIMO) controller is designed to control a super capacitor compensation inverter. The proposed controller effectively suppresses the effects of impact loads from natural gas generation systems. In this paper, the transient current model of the compensation system is transformed into the power model using transient power theory, and then a direct power control algorithm with a vector control strategy is designed based on the whole power model. The proposed strategy can not only effectively suppress the impact of impact loads on the system but also maintain the stability of the microgrid to a certain extent. Meanwhile, the PLL control structure is replaced by an adaptive algorithm, which not only solves the system instability problem but also improves the dynamic response of the compensation system. In addition, the functional advantages, the frequency is bounded and stable throughout the whole process, and this differential frequency modulation allows the compensation system to exit the compensation smoothly. Finally, the simulation and experimental results on a 600 kW natural gas generator demonstrate that the proposed compensation strategy and control algorithm can effectively suppress the impact load effects.

关键词： multiple-input multiple-output super capacitor impact load natural gas generator inverter

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multiple-input multiple-output over-the-horizon radar: experimental results

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IET RADAR SONAR AND NAVIGATION 2009年第4期3卷 290-303页

作者： Frazer, G. J. Abramovich, Y. I. Johnson, B. A. DSTO ISR Div Edinburgh SA Australia LM Australia Pty Ltd Edinburgh SA Australia

Results from an experiment that applied one class of multiple-input multiple-output (MIMO) waveform techniques to over-the-horizon radar (OTHR) are reported. The experiment objective was to demonstrate that adaptive transmitter beamforming could be used in an appropriately design radar to reject spatially discrete Doppler-spread clutter. In the particular MIMO radar architecture that the authors call non-causal transmit beamforming, conventional or adaptive transmitter beamforming occurs following waveform transmission, propagation, scatter from targets and clutter sources, return propagation and finally signal reception. In the case reported herein spatially discrete clutter was successfully rejected to the noise floor of the radar return with rejection in excess of 35 dB achieved using common adaptive algorithms and straightforward training data selection. As part of the rejection algorithm the transmitted waveform direction-of-departure (DOD) from the transmitter array to the target was estimated and used as the preserved steer direction in the adaptive beamformer. The DOD estimates agree well with the geometrically determined true values. The demonstration of non-causal transmit beamforming suggests that it will be possible to create multiple simultaneous adaptive range-dependent transmitter beams with an appropriately designed OTHR. This has several applications including for the mitigation of Doppler-spread clutter.

关键词： radar signal processing array signal processing MIMO communication adaptive transmitter beamforming Radar equipment, systems and applications direction-of-departure spatially discrete Doppler-spread clutter multiple-input multiple-output waveform techniques Signal processing and detection over-the-horizon radar parameter estimation Doppler radar

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multiple-input multiple-output synthetic aperture radar antenna arrangement for wide-swath remote sensing

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JOURNAL OF APPLIED REMOTE SENSING 2015年第1期9卷

作者： Shao, Huaizong Wang, Wen-Qin Univ Elect Sci & Technol China Sch Commun & Informat Engn High Tech Sect Chengdu 611731 Peoples R China

Simultaneous high-resolution and wide-swath (HRWS) remote sensing imaging is of great importance in future microwave remote sensing, but it is limited by the minimum antenna area constraint. multiple-input multiple-output (MIMO) synthetic aperture radar (SAR) offers new opportunities due to its increased degrees of freedom and system flexibility. We investigate four elevation MIMO SAR antenna arrangements, namely narrow-beam transmission narrow-beam reception, narrow-beam transmission wide-beam reception, wide-beam transmission narrow-beam reception, and wide-beam transmission wide-beam reception (WTWR) in HRWS remote sensing. Their signal models, system gains and range ambiguity-to-signal ratio performances are comparatively investigated. Three waveforms that have a large time-bandwidth product and constant modulus are designed for the MIMO SAR system and the impacts of their mutual interferences due to imperfect waveform orthogonality are also simulated. Simulation results show that MIMO SAR is superior to conventional single-antenna SAR and existing multichannel SAR techniques in wide-swath remote sensing. (C) 2015 Society of Photo-Optical Instrumentation Engineers (SPIE)

关键词： multiple-input multiple-output wide-swath high-resolution wide-swath high-resolution synthetic aperture radar (SAR) multichannel SAR waveform diversity

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multiple-input multiple-output visible light communication system based on disorder dispersion components

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OPTICAL ENGINEERING 2017年第10期56卷

作者： Yang, Tao Zhang, Qi Hao, Yue Zhou, Xin-hui Yi, Ming-dong Wei, Wei Huang, Wei Li, Xing-ao Nanjing Univ Posts & Telecommun Key Lab Organ Elect & Informat Displays Synerget Innovat Ctr Organ Elect & Informat Displ Nanjing Jiangsu Peoples R China

A multiple-input multiple-output visible light communication (VLC) system based on disorder dispersion components is presented. Instead of monochromatic sources and large size photodetectors used in the traditional VLC systems, broadband sources with different spectra act as the transmitters and a compact imaging chip sensor accompanied by a disorder dispersion component and a calculating component serve as the receivers in the proposed system. This system has the merits of small size, more channels, simple structure, easy integration, and low cost. Simultaneously, the broadband sources are suitable to act as illumination sources for their white color. A regularized procedure is designed to solve a matrix equation for decoding the signals at the receivers. A proof-of-concept experiment using on-off keying modulation has been done to prove the feasibility of the design. The experimental results show that the signals decoded by the receivers fit well with those generated from the transmitters, but the bit error ratio is increased with the number of the signal channels. The experimental results can be further improved using a high-speed charge-coupled device, decreasing noises, and increasing the distance between the transmitters and the receivers. (C) 2017 Society of Photo-Optical Instrumentation Engineers (SPIE)

关键词： multiple-input multiple-output visible light communication regularization algorithm

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Hybrid space-frequency domain pre-equalization for DC-biased optical orthogonal frequency division multiplexing based imaging multiple-input multiple-output visible light communication systems

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OPTICAL ENGINEERING 2017年第3期56卷

作者： Chen, Chen Zhong, Wen-De Nanyang Technol Univ Sch Elect & Elect Engn Singapore Singapore

We propose a hybrid space-frequency domain pre-equalization technique for indoor multiple-input multiple-output visible light communication (MIMO-VLC) systems using DC-biased optical orthogonal frequency division multiplexing with an imaging receiver. The proposed hybrid space-frequency domain pre-equalization is jointly performed in both space and frequency domains for the purpose of achieving comparable signal-to-noise ratio performances of different channels in an imaging MIMO-VLC system. It is shown by the simulation results that a four-channel imaging MIMO-VLC system with a raw data rate of 1.2 Gb/s using hybrid space-frequency domain pre-equalization achieves significantly improved bit error rate performance than the system using only frequency domain pre-equalization, resulting in up to 52.6% improvement in communication coverage area at a target BER of 10(-3). (C) 2017 Society of Photo-Optical Instrumentation Engineers (SPIE)

关键词： visible light communication multiple-input multiple-output orthogonal frequency division multiplexing pre-equalization communication coverage

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Distributed Interference Alignment Algorithm for multiple-input multiple-output Networks with Uncoordinated Interference

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COGNITIVE COMPUTATION 2013年第2期5卷 215-224页

作者： Zhong, Liang Zhu, Guangxi Kong, Zhengmin Liu, Jian Huazhong Univ Sci & Technol Wuhan Natl Lab Optoelect Natl Engn Lab Next Generat Internet Access Syst Dept Elect & Informat Engn Wuhan 430074 Peoples R China Wuhan Univ Dept Automat Wuhan 430072 Peoples R China

This paper introduces a novel two-step interference alignment beamforming algorithm for a multiple-antenna interference channel with uncoordinated interference. The proposed algorithm performs subspace division of the signal space by using the total least squares method to use all available degrees of freedom in the system. The algorithm also uses the minimum mean square error as a criterion to maximize the sum rate of the system. Simulation results indicate that the sum rate of the proposed algorithm outperforms the sum rates of previous works in the context of a network with uncoordinated interference. The performance levels of these algorithms are also compared for different uncoordinated interference strengths. Almost the same trend is obtained for the sum rate performance.

关键词： multiple-input multiple-output Interference alignment Total least squares Minimum mean square error

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Perfect orthogonal waveform scheme used for high-resolution multiple-input multiple-output synthetic aperture radar system

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JOURNAL OF APPLIED REMOTE SENSING 2016年第3期10卷

作者： Li, Shufeng Jin, Libiao Commun Univ China Sch Informat & Engn Dingfuzhuang East St 1 Beijing 100024 Peoples R China

We investigate multiple-input multiple-output (MIMO) synthetic aperture radar (SAR) scheme with an ultra-low side-lobe ratio performance for using complete complementary sequences (CCS) waveform. It is shown that the CCS can be applied in a MIMO SAR system to obtain high resolution in range direction. In addition, the azimuth channel scheme with the multiple subsequences of CCS is also considered. First, we introduce the concept of CCS and establish the transmitter model based on CCS in MIMO SAR system. Then, we propose the corresponding imaging algorithm for employing the CCS to accurately focus the raw data of the MIMO SAR system and derive the range cell migration correction. Considering the signal complexity, we make use of the CCS pairs to analyze the MIMO SAR imaging algorithm. Finally, simulation results demonstrate the validity and feasibility of the proposed MIMO SAR scheme and the potential advantage of CCS. (C) 2016 Society of Photo-Optical Instrumentation Engineers (SPIE)

关键词： multiple-input multiple-output imaging algorithm complete complementary sequence

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Channel estimation of pulse-shaped multiple-input multiple-output orthogonal frequency division multiplexing systems

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IET COMMUNICATIONS 2010年第17期4卷 2104-2114页

作者： Wan, F. Zhu, W. -P. Swamy, M. N. S. Univ So Calif Ming Hsieh Dept Elect Engn Los Angeles CA 90089 USA Concordia Univ Dept Elect & Comp Engn Ctr Signal Proc & Commun Montreal PQ H3G 1M8 Canada

Most of the existing multiple-input multiple-output orthogonal frequency division multiplexing (MIMO-OFDM) channel estimation methods do not take into account the effect of the pulse-shaping filter in the transmitter nor of the matched filter in the receiver, thus leading to an estimation solution for the composite channel including the pulse-shaping and matched filters, instead of the pure wireless channel. This solution is not sufficiently accurate because of the extra length of the composite channel induced by the two filters especially in the scenario with a small pure channel length. In this study, the authors present a novel methodology for the estimation of the pure multipath channels of pulse-shaped MIMO-OFDM systems. By utilising the knowledge of pulse-shaping and matched filters, the authors develop two channel estimation approaches, namely, a semi-blind approach for the sampling duration-based channels, in which the multipath occurs at the sampling instant and a training-based least-square technique for the upsampling duration-based channels where the multipath may occur in a fraction of sampling duration. A number of computer simulation-based experiments are conducted, and these simulation results confirm the efficacy of the proposed approaches.

关键词： MIMO-OFDM pulse-shaping Interpolation and function approximation (numerical analysis) Modulation and coding methods Radio links and equipment least squares approximations matched filter upsampling duration-based channels semi-blind approach Communication channel equalisation and identification OFDM modulation matched filters channel estimation estimation solution multiple-input multiple-output pulse-shaped MIMO orthogonal frequency division multiplexing systems least-square technique MIMO communication

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Theoretical and simulation analysis of a novel multiple-input multiple-output scheme over multimode fiber links with dual restricted launch techniques

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OPTICAL ENGINEERING 2012年第6期51卷

作者： Wang, Yuanquan Chi, Nan Li, Rongling Fang, Wuliang Zhang, Junwen Tao, Li Shao, Yufeng Chinese Acad Sci Shanghai Inst Microsyst & Informat Technol Key Lab Wireless Sensor Network & Commun Shanghai Peoples R China Fudan Univ Ctr Comp Dept Commun Sci & Engn State Key Lab ASIC & SystInformat Sch Shanghai 200433 Peoples R China

Different launching methods over multimode fiber (MMF) are reviewed and compared under various aspects such as coupling coefficient, mode power distribution, and bit error rate performance. Among these, center launch and ring launch are elaborated and chosen as the inputs of multiple-input multiple-output (MIMO) scheme for center launch exciting limited lower-order modes while ring launch exciting limited higher ones. Furthermore, we discuss the theoretical background and give a new wide-band MMF MIMO mathematical model. This paper also proposes a novel MMF MIMO system combining the dual restricted launches together with multi-segments receiving. The simulated results indicate that an aggregate data rate of 20 Gb/s over 800-m graded index-multimode fiber can be achieved by using this newly established MIMO scheme. (c) 2012 Society of Photo-Optical Instrumentation Engineers (SPIE). [DOI: 10.1117/***.51.6.065002]

关键词： optical communication multimode fiber multiple-input multiple-output restricted launch multi-segments receiving

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Novel Movement-Based Methods for the Calibration of Colocated multiple-input multiple-output Radars

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IEEE ACCESS 2023年 11卷 116090-116108页

作者： Guerzoni, Giorgio Faghand, Elahe Vitetta, Giorgio Matteo Vincenzi, Loris Mehrshahi, Esfandiar Univ Modena & Reggio Emilia Dept Engn Enzo Ferrari I-41124 Modena Italy Shahid Beheshti Univ Fac Elect Engn Dept Telecommun Tehran *** Iran

It is well-known that the availability of transmit and receive arrays in colocated multiple-input multiple-output radar systems can be exploited to detect multiple targets, and estimate their range and angular coordinates. Unluckily, the accuracy achieved in the estimation of target parameters can be severely affected by hardware nonidealities. The impact of these nonidealities can be mitigated through the adoption of specific methods explicitly developed to estimate and compensate for them, i.e., briefly, of calibration methods. As far as we know, until now, most of the calibration techniques proposed in the technical literature for colocated multiple-input multiple-output radars are based on the idea of placing one or more reference targets in front of the considered radar device at perfectly known and fixed locations, and quantifying the difference between the expected radar image and the measured one. In this manuscript, two novel calibration methods are proposed. Both exploit the measurements captured by a colocated multiple-input multiple-output radar device at multiple positions;for this reason, the acquisition of such measurements involves the movement of the radar. The first one does not require any knowledge about the nature, number, position or radar cross section of the reference targets, provided that all these are in far-field;the second one, instead, needs a single reference target in near-field conditions, with the only constraints for it to be pointwise and isolated from stray targets in the range domain. This drastically simplifies the experimental setup to be employed for radar calibration. The proposed methods are tested on a commercial radar device and compared with a traditional method for radar calibration.

关键词： Calibration multiple-input multiple-output radar synthetic aperture radar

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