检索结果-内蒙古大学图书馆

INTERACTION MEASURES AND DECENTRALIZED CONTROL OF CHEMICAL-PLANTS

COMPUTERS & CHEMICAL ENGINEERING 1993年第Sup1期17卷 S335-S341页

作者： ZEGHAL, S PALAZOGLU, AN ECOLE CENT PARIS LAB GIC F-92295 CHATENAY MALABRY FRANCE CTR RECH CHEM DIGUE BP 76 F-78600 MAISONS LAFFITTE FRANCE UNIV CALIF DAVIS DEPT CHEM ENGN DAVIS CA 95616 USA

Control system synthesis consists of two major subtasks: selection of measurements and manipulated variables, and deciding on the structure interconnecting the measured and manipulated variables along with the control law governing the interconnections. For multiple-input-mutiple-output systems, a decentralized control structure is generally preferred to a fully centralized structure. A major step in this controller design process is therefore the pairing problem: which manipulated variables to connect to which measurements? The answer to this question has undoubtedly to account for loop interactions that arise within the system. Work has been carried out using Relative Gain Array (RGA) and Block Relative Gain (BRG) interaction measures to develop automated pairing procedures and implement them as a portable software. A methodology involving the use of this software in conjuction with dynamic simulation and Internal Model Control design techniques for controllers was used on a particular case study to generate a satisfactory control structure.

关键词： DYNAMIC SIMULATION PROCESS CONTROL INTERACTIONS PAIRING RELATIVE GAIN ARRAY BLOCK RELATIVE GAIN INTERNAL MODEL CONTROL multiple-input multiple-output SPEEDUP

来源：评论

学校读者我要写书评

暂无评论

Closed-Form Power Normalization Methods for a Satellite MIMO System

引用

SENSORS 2022年第7期22卷 2586页

作者： Segneri, Andrea Baldominos, Alejandro Goussetis, George Mengali, Alberto Fonseca, Nelson J. G. Heriot Watt Univ Inst Sensors Signals & Syst Edinburgh EH14 4AS Midlothian Scotland European Space Agcy Telecom Syst & Tech Sect NL-2201 AZ Noordwijk Netherlands European Space Agcy Antenna & Submillimetre Waves Sect NL-2201 AZ Noordwijk Netherlands

The paper proposes a new set of normalization techniques for precoding/beamforming matrices applicable to broadband multiuser multiple-input multiple-output (MIMO) satellite systems. The proposed techniques adapt known normalization methods to account for the signal attenuation experienced by users due to the degradation of antenna gain and free space losses towards the edge of the coverage. We use, as an example, an array-fed reflector (AFR) antenna onboard a satellite in geosynchronous orbit (GEO), which provides a favorable trade-off between high-directivity, reconfigurability, and the requirement for digital processing, but suffers from high scan losses away from broadside due to optical aberrations when considered for global coverage applications. Three different precoding/beamforming techniques are employed, namely zero forcing (ZF), minimum mean squared error (MMSE), and matched filtering (MF). Low-complexity power normalization techniques digitally applied after the beamformer are introduced that, in the absence of any atmospheric effects, lead to iso-flux-like characteristics whilst satisfying the power constraint per feed. In comparison with other methods reported in the literature, mainly based on iterative algorithms, the proposed techniques consist in closed-form expressions to provide uniform signal-to-noise ratio (SNR) and signal-to-noise plus interference ratio (SNIR) across the users without significant impact on the payload sum rate. Numerical results are presented to comparatively demonstrate the achieved performance in terms of total capacity and distribution of SNR and SNIR at various noise and interference scenarios.

关键词： multiple-input multiple-output satellite communications array-fed reflectors linear precoding power normalization techniques

来源：评论

学校读者我要写书评

暂无评论

Biquadratic optimization based joint transmit and receive beamforming with sequential rank relaxation

引用

SIGNAL PROCESSING 2021年 179卷 107819-107819页

作者： Zhou, Junwei Li, Hongbin Cui, Wei Beijing Inst Technol Sch Informat & Elect Beijing 100081 Peoples R China Stevens Inst Technol Dept Elect & Comp Engn Hoboken NJ 07030 USA

We consider the joint design of transmit and receive beamforming in multiple-input-multiple-output (MIMO) systems by utilizing prior knowledge of the target and interferences. The design problem is to maximize the receiver output signal-to-interference-plus-noise-ratio (SINR) with the transmit power constraint for each element. A conventional SINR maximization is based on the transmit and receive iteration (T-R iteration), which often converges slowly. In contrast, we formulate the problem as a biquadratic optimization by lumping together the transmit and receive beamformers, which allows us to update them at the same time, thus bypassing T-R iteration and initialization. Our approach converges significantly faster and often to a better beamforming solution, especially when strong interferences are present. Simulation results show that the proposed approach reduces the computational complexity by tens to hundreds of times than the T-R iteration method, depending on the interference level, while the latter may exhibit a considerable SINR loss when prematurely terminated or poorly initialized. (C) 2020 Elsevier B.V. All rights reserved.

关键词： multiple-input multiple-output Joint transmit and receive beamforming Semidefinite relaxation

来源：评论

学校读者我要写书评

暂无评论

Compact self decoupled MIMO antenna pairs covering 3.4-3.6 GHz band for 5G handheld device applications

引用

AEU-INTERNATIONAL JOURNAL OF ELECTRONICS AND COMMUNICATIONS 2021年 141卷

作者： Moses, Abi T. Zerith Moses, Nesasudha Karunya Inst Technol & Sci Dept Elect & Commun Engn Coimbatore Tamil Nadu India

A self-decoupled 4-port multiple-input multiple-output (MIMO) antenna pair working in the midband of the 5G spectrum (3.5 GHz) for handheld device application is presented in this paper. The antenna includes two vertically placed blocks printed exactly at the middle of the two lengthy frames of the handheld device. The selfdecoupled antenna pair structure consists of two monopole antenna separated by a distance of 7 mm, a T-shaped parasitic structure, and a stub at the backside connecting the ground plane. The monopole antennas are excited by a simple coaxial feeding structure. The T-shaped element not only serves as a radiator but plays a vital role in providing port isolation between the two ports to obtain a self-isolated antenna pair. The self-decoupled antenna pair operates from 3.4 to 3.6 GHz with isolation higher than 16.5 dB in the entire utilization band. The parametric analysis of the optimal parameters and the evolution design of the antenna pair is studied for a better interpretation of the working principle of the MIMO system. The total efficiency and peak gain of all the antennas are more than 78% and 5 dB respectively in the whole utilization bandwidth. The worst-case envelope correlation coefficient (ECC) value among the elements of the antenna pair is less than 0.03, which is less than the ideal value of 0.5. Other MIMO diversity parameters such as Channel Capacity Loss (CCL), Mean Effective Gain (MEG), Total Active Reflection Coefficient (TARC), and Diversity Gain (DG) of the designed antenna are calculated and analyzed with the measured results. A model of the designed handheld device is fabricated and analyzed. The measured results indicate the suitability of the design for a capable candidate in 5G handheld device applications.

关键词： Sub-6 GHz Self-isolated multiple-input multiple-output Mobile terminal antenna Envelope Correlation Coefficient (ECC) Channel Capacity Loss (CCL)

来源：评论

学校读者我要写书评

暂无评论

A compact coplanar waveguide-fed band-notched four-port flexible ultra-wide band-multi-input-multi-output slot antenna for wireless body area network and Internet of Things applications

引用

INTERNATIONAL JOURNAL OF RF AND MICROWAVE COMPUTER-AIDED ENGINEERING 2022年第9期32卷 e23289-e23289页

作者： Du, Chengzhu Yang, Zhipeng Zhong, Shunshi Shanghai Univ Elect Power Coll Elect & Informat Engn Shanghai 200090 Peoples R China Shanghai Univ Sch Commun & Informat Engn Shanghai Peoples R China

In this letter a novel notched multi-input-multi-output (MIMO) flexible slot antenna with a C-slot is proposed and designed for wireless body area network (WBAN) and Internet of Things (IoT) applications. The proposed antenna is comprised of four similar elements with the feed line of coplanar waveguide (CPW). Antenna is printed on flexible liquid crystal polymer (LCP) substrate with compact dimensions. The proposed UWB-MIMO slot antenna can operate in range of 2.85-10.85 GHz with notched band from 4.9-6.425 GHz. The achieved notched band can filter the interference of WLAN (5.15-5.825 GHz), by adding an inverted orthogonal branch, great isolation is achieved, which is better than 24 dB over working bands. What's more, the parameters of diversity performance like gain, envelope correlation coefficient (ECC) and diversity gain (DG) are also analyzed. The actual measurement of bending test and the effect of human body indicates that the presented antenna is suitable for WBAN and IoT applications.

关键词： band-notched coplanar waveguide flexible antenna liquid crystal polymer multiple-input multiple-output WBAN Internet of Things

来源：评论

学校读者我要写书评

暂无评论

Optical Camera Communications for IoT-Rolling-Shutter Based MIMO Scheme with Grouped LED Array Transmitter

引用

SENSORS 2020年第12期20卷 3361.-3361.页

作者： Teli, Shivani Rajendra Matus, Vicente Zvanovec, Stanislav Perez-Jimenez, Rafael Vitek, Stanislav Ghassemlooy, Zabih Czech Tech Univ Fac Elect Engn Prague 16627 Czech Republic Univ Las Palmas Gran Canaria Inst Technol Dev & Innovat Commun Las Palmas Gran Canaria 35001 Spain Northumbria Univ Opt Commun Res Grp Newcastle Upon Tyne NE1 7RU Tyne & Wear England

In optical camera communications (OCC), the provision of both flicker-free illumination and high data rates are challenging issues, which can be addressed by utilizing the rolling-shutter (RS) property of the image sensors as the receiver (Rx). In this paper, we propose an RS-based multiple-input multiple-output OCC scheme for the Internet of things (IoT) application. A simplified design of multi-channel transmitter (Tx) using a 7.2 x 7.2 cm(2) small 8 x 8 distributed light emitting diode (LED) array, based on grouping of LEDs, is proposed for flicker-free transmission. We carry out an experimental investigation of the indoor OCC system by employing a Raspberry Pi camera as the Rx, with RS capturing mode. Despite the small area of the display, flicker-free communication links within the range of 20-100 cm are established with data throughput of 960 to 120 bps sufficient for IoT. A method to extend link spans up to 1.8 m and the data throughput to 13.44 kbps using different configurations of multi-channel Tx is provided. The peak signal-to-noise ratio of similar to 14 and 16 dB and the rate of successfully received bits of 99.4 and 81% are measured for the shutter speeds of 200 and 800 mu s for a link span of 1 m, respectively.

关键词： optical camera communications rolling-shutter camera Internet of things multiple-input multiple-output light-emitting diodes

来源：评论

学校读者我要写书评

暂无评论

Golden codeword-based generalized spatial modulation

引用

INTERNATIONAL JOURNAL OF COMMUNICATION SYSTEMS 2022年第10期35卷 e5144-e5144页

作者： Sibanda, Nathael Xu, Hongjun Pillay, Narushan Univ KwaZulu Natal Sch Elect Elect & Comp Engn Coll Agr Engn & Sci Elect Engn Durban South Africa

Conventional-generalized spatial modulation (C-GSM) is an NTxNR multiple-input multiple-output (MIMO) spatial modulation (SM) scheme that transmits the same complex amplitude/phase modulation symbol from multiple active transmit antennas. By using two active transmit antennas during a transmission interval, C-GSM is capable of achieving high spectral efficiencies. However, as the size of the signal constellation/domain increases, the minimum Euclidean distances (ED) between the symbols decrease. Hence, this leads to a degradation of the average bit error rate (ABER) performance of the scheme. Hence, motivated to improve the error performance of C-GSM schemes, first, this study proposes a new scheme called Golden codeword-based generalized spatial modulation (GCW-GSM), which combines C-GSM and the Golden code to take advantage of the benefits of both while avoiding their drawbacks. The proposed scheme uses conventional quadrature amplitude modulation (C-QAM), and it is investigated over Rayleigh frequency-flat fading channels with additive white Gaussian noise. Second, a closed-form expression of the theoretical average bit error probability of the proposed GCW-GSM scheme is formulated. Compared to simulation results, it proves to be increasingly tight at high signal-to-noise ratio values. Finally, the proposed scheme performance over the Rayleigh-frequency-flat fading channel is compared to that over the Rician channel. An improvement in the error performance of 6dB with spectral efficiency of 10bits/s/Hz is seen in 4x4 C-16QAM GCW-GSM over 4x4 C-256QAM conventional-spatial modulation and 4x4 C-256QAM C-GSM schemes at a bit error rate (BER) of 1x10(-5). The 4x4 C-16QAM GCW-GSM scheme exhibits an improvement in the error performance of 2.9dB with spectral efficiency of 10bits/s/Hz over the 4x4 C-64QAM conventional quadrature spatial modulation scheme at a BER of 1x10(-5). Finally, the 4x4 16-QAM GCW-GSM under Rayleigh fading has a performance gain of 3 dB over 4x4 16

关键词： generalized spatial modulation Golden code multiple-input multiple-output space-time block codes spectral efficiency

来源：评论

学校读者我要写书评

暂无评论

Multi-Target Localization of MIMO Radar with Widely Separated Antennas on Moving Platforms Based on Expectation Maximization Algorithm

引用

REMOTE SENSING 2022年第7期14卷 1670-1670页

作者： Lu, Jiaxin Liu, Feifeng Sun, Jingyi Miao, Yingjie Liu, Quanhua Beijing Inst Technol Sch Informat & Elect Beijing 100081 Peoples R China Minist Educ Key Lab Elect & Informat Technol Satellite Nav Beijing Inst Technol Beijing 100081 Peoples R China Xiaomi Commun Co Ltd Beijing 100085 Peoples R China

This paper focuses on multi-target parameter estimation of multiple-input multiple-output (MIMO) radar with widely separated antennas on moving platforms. Aiming at the superimposed signals caused by multi-targets, the well-known expectation maximization (EM) is used in this paper. Target's radar cross-section (RCS) spatial variations, different path losses and spatially-non-white noise appear because of the widely separated antennas. These variables are collectively referred to as signal-to-noise ratio (SNR) fluctuations. To estimate the echo delay/Doppler shift and SNR, the Q function of EM algorithm is extended. In addition, to reduce the computational complexity of EM algorithm, the gradient descent is used in M-step of EM algorithm. The modified EM algorithm is called generalized adaptive EM (GAEM) algorithm. Then, a weighted iterative least squares (WILS) algorithm is used to jointly estimate the target positions and velocities based on the results of GAEM algorithm. This paper also derives the Cramer-Rao bound (CRB) in such a non-ideal environment. Finally, extensive numerical simulations are carried out to validate the effectiveness of the proposed algorithm.

关键词： expectation maximization parameter estimation superimposed signals SNR fluctuations multiple-input multiple-output

来源：评论

学校读者我要写书评

暂无评论

Hybrid Full Frequency Precoding for Integrated Remote Wireless Sensor and Multibeam Satellite Networks

引用

KSII TRANSACTIONS ON INTERNET AND INFORMATION SYSTEMS 2016年第6期10卷 2546-2566页

作者： Li, Hongjun Dong, Feihong Gong, Xiangwu Deng, Changliang Jia, Luliang Wang, Jingchao PLA Univ Sci & Technol Coll Commun Engn Nanjing 210007 Peoples R China Inst China Elect Syst Engn Co Beijing 100141 Peoples R China PLAAF 95899 Unit Beijing 100085 Peoples R China

This paper investigates an efficient transmission scheme for the remote wireless sensors to receive information which is rarely discussed in the integrated remote wireless sensor and multibeam satellite networks (IWSMSNs). The networks can be employed to exchange sensing information for emergency scenario, ocean scenario, and so on, which are isolated from available terrestrial networks. As the efficient transmission link is important to the IWSMSNs, we propose a hybrid full frequency (HFF) precoding by taking advantage of frequency reuse and multiple-input multiple-output (MIMO) precoding. Considering energy efficiency and sinks fairness are crucial to transmission link, thus the HFF precoding problems are formulated as transmit power minimization (TPM) and max-min fair (MMF) received signal to interference plus noise ratio (SINR) problems, which can be transformed to indefinite quadratic optimization programs. Then this paper presents a semi-definite programming (SDP) algorithm to solve the problems for the IWSMSNs. The promising potential of HFF for the real IWSMSNs is demonstrated through simulations.

关键词： hybrid full frequency precoding multiple-input multiple-output integrated remote wireless sensor and multibeam satellite networks semi-definite programming

来源：评论

学校读者我要写书评

暂无评论

OFDM-based 2D generalized optical quadrature spatial modulation for MIMO-OWC systems

引用

OPTICAL ENGINEERING 2022年第12期61卷 126103-126103页

作者： Qiu, Yu Xu, Xuhui Shen, Ming Meng, Yuwei Yu, Rongdong Zhu, Binbin Wang, Zhan Zhejiang Zheneng Lanxi Elect Power Generat Co Ltd Jinhua Peoples R China Zhejiang Energy Digital Technol Co Ltd Hangzhou Peoples R China Shenzhen Hua Chuang Chip Lighting Co Ltd Shenzhen Peoples R China

An innovative scheme, named orthogonal frequency division multiplexing (OFDM)-based two-dimensional (2D) generalized optical quadrature spatial modulation (GOQSM), is proposed for bandlimited multiple-input multiple-output optical wireless communication (MIMO-OWC) systems. In this scheme, by way of combining two consecutive time slots into one time block, 2D GOQSM mapping can be executed in spatial domain and time domain. Therefore, more spatial bits can be transmitted, resulting in the increase of system spectral efficiency. Furthermore, discrete Fourier transform (DFT) spreading is further introduced in OFDM-based 2D GOQSM systems, so as to substantially reduce the peak-to-average power ratio (PAPR) of the transmitted signals. To evaluate and compare the performance of OFDM-based 2D GOQSM systems with other traditional systems, numerical simulations are conducted under various spectral efficiencies. The obtained simulation results prove that the proposed OFDM-based 2D GOQSM scheme with DFT spreading can achieve better bit error rate performance and lower PAPR than other benchmark schemes. (c) 2022 Society of Photo-Optical Instrumentation Engineers (SPIE)

关键词： optical wireless communication multiple-input multiple-output quadrature spatial modulation

来源：评论

学校读者我要写书评

暂无评论

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案：

请选择收藏分类：

通借通还

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：