检索结果-南通市图书馆

off-grid DOA estimation via a deep learning framework

Science China(Information Sciences) 2023年第12期66卷 222-237页

作者： Yan HUANG Yanjun ZHANG Jun TAO Cai WEN Guisheng LIAO Wei HONG State Key Lab of Millimeter Waves Southeast University Key Laboratory of Underwater Acoustic Signal Processing of Ministry of Education Southeast University School of Information Science and Technology Northwest University National Key Lab of Radar Signal Processing Xidian University

Direction-of-arrival(DOA) estimation problem is one of the most important tasks for array signal processing. Conventional methods are limited by either the computational complexity or the resolution. In this paper, a novel deep learning(DL) framework for super-resolution DOA estimation is developed, where the grid mismatch problem is fully considered into the DL DOA estimation and the offset between the real DOA and the discrete sampling grid is thereby trained as a part of the network output. Specifically, we first model the DOA estimation problem as a multi-classification task and obtain the on-grid estimation result with a resolution of 1° as the first output. Then we designed another regression module to estimate the offset between target angles and the corresponding grids. By combining both on-grid and offset estimation results, the accurate off-grid estimation is achieved. In addition, the method of fusing low-level features and high-level features by skip connection is adopted between the on-grid estimation module and the offset estimation module. The high-level features in the first part of the network are combined with the original input to improve the training speed and the estimation accuracy. Herein, our training dataset contains a large number of off-grid signal data, which is close to the practical application. Also, the utilization of the off-grid part information improves DOA estimation performance compared to existing DL-based methods,achieving more accurate DOA estimations. Numerous simulation results have demonstrated the superiority of the proposed method in DOA estimation precision, and a good performance advantage maintains even when using a limited number of snapshots. Further, we test the proposed method on the real millimeter-wave radar system, and it outperforms the other state-of-the-art methods, especially for two adjacent targets in the same range and Doppler bin.

关键词： direction-of-arrival (DOA) estimation deep learning (DL) off-grid array signal processing

来源：

同方期刊数据库评论

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

off-grid Sparse Bayesian Inference with Biased Total grids for Dense Time Delay Estimation

引用

Journal of Shanghai Jiaotong university(Science) 2023年第6期28卷 763-771页

作者：魏爽李文瑶苏颖刘睿 College of Information Mechanical and Electrical EngineeringShanghai Engineering Research Center of Intelligent Education and BigdataShanghai Normal UniversityShanghai 200234China

For dense time delay estimation(TDE),when multiple time delays are located within a grid interval,it is dificult for the existing sparse Bayesian learning/inference(SBL/SBI)methods to obtain high estimation accuracy to meet the application requirements.To solve this problem,this paper proposes a method named off-grid sparse Bayesian inference-biased total grid(OGSBI-BTG),where a mesh evolution process is conducted to move the total grids iteratively based on the position of the off-grid between two grids.The proposed method updates the off-grid dictionary matrix by further reconstructing an optimum mesh and offsetting the off-grid vector.Experimental results demonstrate that the proposed approach performs better than other state-of-the-art SBI methods and multiple signal classification even when the grid interval is larger than the gap of true time delays.In this paper,the time domain model and frequency domain model of TDE are studied.

关键词： off-grid sparse Bayesian inference(SBI) time delay estimation(TDE) biased total grids(BTG)

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Use of hydrogen storage in an off-grid system for implementing a renewable-energy system

引用

Clean Energy 2021年第4期5卷 704-712页

作者： Yasuhiro Noro Satoshi Uchiyama Department of Electrical and Electronic Engineering Kogakuin UniversityTokyoJapan

This paper presents the purpose,advantages,system constitution,operation method and estimation results of using hydrogen storage in a small-scale electric power(off-grid)system when renewable energy sources are introduced.It is assumed that all electricity is supplied from renewable energy sources without using a diesel generator that requires fossil fuels.In other words,for a small-scale electric power system on a remote island,a power-supply system comprising a photovoltaic power-generation system,storage battery,hydrogen-production system,storage tank and a fuel cell is considered.The condition under which the total construction cost is minimized by considering the equipment capacity,operation method of the battery and fuel cell as parameters is investigated.The results demonstrate that the construction cost can be reduced by applying the method of surplus magnification and hydrogen storage.The initial cost is~70%when hydrogen storage is added as compared with the case in which a storage battery alone is used.Such a cost-effective system can contribute to Japan’s self-reliance with regard to the energy sector in the future.

关键词： hydrogen storage storage battery fuel cell photovoltaic generation off-grid remote island

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Optimal Configuration of an off-grid Hybrid Wind-Hydrogen Energy System: Comparison of Two Systems

引用

Energy Engineering 2021年第6期118卷 1641-1658页

作者： Zekun Wang Yan Jia Yingjian Yang Chang Cai Yinpeng Chen School of Energy and Power Engineering Inner Mongolia University of TechnologyHohhot010051China Key Laboratory of Wind Energy and Solar Energy Technology(Inner Mongolia University of Technology) Ministry of EducationHohhot010051China Inner Mongolia Autonomous Region Wind Power Technology and Testing Engineering Technology Research Center Inner Mongolia University of TechnologyHohhot010051China Institute of Engineering Thermophysics Chinese Academy of SciencesBeijing100190China Key Laboratory of Wind Energy Utilization Chinese Academy of SciencesBeijing100190China

Due to the uncertainty of renewable energy power generation and the non-linearity of load demand,it becomes complicated to determine the capacity of each device in hybrid renewable energy power generation systems.This work aims to optimize the capacity of two types of the off-grid hybrid wind-hydrogen energy system.We considered the maximum profit of the system and the minimum loss of power supply probability as optimization goals.Firstly,we established steady-state models of the wind turbine,alkaline electrolyzer,lead-acid battery,and proton exchange membrane fuel cell in matrix laboratory software to optimize the capacity.Secondly,we analyzed the operating mode of the system and determined two system structures(system contains batteries whether or not).Finally,according to the wind speed and load in the sample area,we compared the economics of the two systems and selected the optimal configuration for the area.In the same calculation example data,the non-dominated sorting genetic algorithm-II(NSGA-II)is used to optimize the capacity of each device in the two systems.The results showed that the profit of the without battery-equipped system is 32.38%higher than another system.But the power supply reliability is the opposite.To avoid the contingency of the calculation results,we used the traditional genetic algorithm(GA)and ant colony optimization(ACO)to calculate the same example.The results showed that NSGA-II is significantly better than GA and ACO in terms of iteration steps and calculation results.The required architecture for the System-I composes of 3 numbers of 10 kW wind turbines,61 sets of 12 V·240 Ah leadacid batteries,8 kW electrolytic cell,and 6 kW PEMFC.The net profit and LPSP are ¥44,315 and 0.01254 respectively.The required architecture for the System-II composes of 2 numbers of 10 kW wind turbines,24 kW electrolytic cells,and 18 kW *** profit and LPSP are ¥58,663 and 0.03244,respectively.This paper provided two schemes for the optimal configuration of the hybrid wind-hydrogen energy system in isla

关键词： Optimization wind energy hybrid energy system off-grid fuel cell

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

off-grid correction for improving scatterer localization performance in compressive sampling SAR tomography

引用

Science China(Information Sciences) 2021年第2期64卷 266-267页

作者： Xiaoxiang ZHU Anxi YU Zhen DONG Manqing WU Qi LIU College of Electronic Science and Technology National University of Defense Technology China Electronic Technology Group Corporation (CETC) China Xi'an Satellite Control Center (XSCC)

Dear editor,SAR tomography（TomoSAR） [1] as an adavnced technique forms an elevation aperture along the elevation direction.Therefore, it has the ability of resolving layovers, which are common in urban environments. For the moment, TomoSAR is broadly applied to map the urban areas with existence of large quantities of layovers. Let y = [y1,..., y M ];be the measurement vector with M elements,

关键词： synthetic aperture radar tomography (SAR tomography) scatterer detection compressive sensing (CS) off-grid non-linear least squares (NLS)

来源：

同方期刊数据库评论

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

off-grid Compressed Channel Estimation with Parallel Interference Cancellation for Millimeter Wave Massive MIMO

引用

China Communications 2024年第3期21卷 51-65页

作者： Liu Jinru Tian Yongqing Liu Danpu Zhang Zhilong Beijing Laboratory of Advanced Information Network Beijing Key Laboratory of Network System Architecture and ConvergenceBeijing University of Posts and TelecommunicationsBeijing100876China

Millimeter wave(mmWave)massive multiple-input multiple-output(MIMO)plays an important role in the fifth-generation(5G)mobile communications and beyond wireless communication systems owing to its potential of high capacity.However,channel estimation has become very challenging due to the use of massive MIMO antenna array.Fortunately,the mmWave channel has strong sparsity in the spatial angle domain,and the compressed sensing technology can be used to convert the original channel matrix into the sparse matrix of discrete angle grid.Thus the high-dimensional channel matrix estimation is transformed into a sparse recovery problem with greatly reduced computational complexity.However,the path angle in the actual scene appears randomly and is unlikely to be completely located on the quantization angle grid,thus leading to the problem of power leakage.Moreover,multiple paths with the random distribution of angles will bring about serious interpath interference and further deteriorate the performance of channel estimation.To address these off-grid issues,we propose a parallel interference cancellation assisted multi-grid matching pursuit(PIC-MGMP)algorithm in this paper.The proposed algorithm consists of three stages,including coarse estimation,refined estimation,and inter-path cyclic iterative inter-ference cancellation.More specifically,the angular resolution can be improved by locally refining the grid to reduce power leakage,while the inter-path interference is eliminated by parallel interference cancellation(PIC),and the two together improve the estimation accuracy.Simulation results show that compared with the traditional orthogonal matching pursuit(OMP)algorithm,the normalized mean square error(NMSE)of the proposed algorithm decreases by over 14dB in the case of 2 paths.

关键词： channel estimation compressed sensing inter-path interference millimeter wave massive MIMO off-grid parallel interference cancellation

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

基于off-grid的CS-ISAR成像研究

基于Off-Grid的CS-ISAR成像研究

引用

作者：王彬电子科技大学

学位级别：硕士

逆合成孔径雷达（ISAR）具有很高的成像分辨率,使其在军用及民用领域得到了广泛的应用。但ISAR成像往往面临着采样率高、数据存储量大以及实时处理比较困难等问题,对这些问题的探索已成为ISAR领域的热门研究课题。本文以ISAR目标的稀疏... 详细信息

逆合成孔径雷达（ISAR）具有很高的成像分辨率,使其在军用及民用领域得到了广泛的应用。但ISAR成像往往面临着采样率高、数据存储量大以及实时处理比较困难等问题,对这些问题的探索已成为ISAR领域的热门研究课题。本文以ISAR目标的稀疏特性为背景,对压缩感知ISAR成像中off-grid问题以及参数估计问题进行了深入的研究,针对发射的稀疏探频信号提出了相应改进的压缩感知ISAR成像算法。本文主要工作概述如下:1、针对传统ISAR信号没有完全利用压缩感知稀疏特性进行成像的问题,建立了发射稀疏探频信号的ISAR成像模型,给出了稀疏探频信号的ISAR成像流程,并通过仿真验证了模型的可行性。2、针对传统稀疏重构算法难以解决off-grid模型的问题,分别提出了结合带外排除技术和局部优化技术的BOMP算法和BLOOMP算法。从理论上详细推导并证明了这两种算法,同时分析了这两种算法的计算复杂度以及它们在噪声情况下的重构性能。仿真实验表明:相同仿真条件下,与BOMP算法相比,BLOOMP算法在重构成功率及重建误差方面具有更优越的性能。3、针对实际成像条件下目标参数未知的问题,提出联合参数估计与ISAR成像重建方法。（1）当目标点落在基矩阵的网格点上且基矩阵取决于未知的目标旋转率,提出基于稀疏贝叶斯学习（Sparse Bayesian Learning,SBL）的稀疏探频ISAR成像方法。通过联合利用SBL技术和梯度搜索算法,能够同时获取目标旋转率和高分辨率的ISAR图像。仿真和实测数据实验验证了所提方法的有效性。（2）当目标点不落在基矩阵的网格点上,提出了基于off-grid模型的联合参数估计与ISAR成像方法。根据改进的数学模型,联合参数扰动算法和梯度搜索算法,能够在off-grid模型下同时实现对目标旋转率的估计和高分辨率ISAR成像重建。仿真实验验证了所提方法的正确性和有效性。

关键词：逆合成孔径雷达成像压缩感知稀疏探频 off-grid 参数估计

来源：

同方学位论文库评论

在线全文

同方学位论文库

学校读者我要写书评

暂无评论

基于变分稀疏贝叶斯的off-grid DOA估计

引用

海南大学学报（自然科学版） 2019年第3期37卷 193-202页

作者：冯晓敏沈重张鲲海南大学信息与通信工程学院海南海口570228 海南大学南海海洋资源利用国家重点实验室海南海口570228 海南热带海洋学院MTA教育中心海南三亚572022

针对传统稀疏贝叶斯学习方法在解决低信噪比条件下信号到达角DOA估计中,到达角不完全落在阵元端离散化网格点上的情况,提出了一种基于变分稀疏贝叶斯学习期望最大化的离格DOA处理方法.该方法首先对均匀线阵的实际接收信号off-grid情况... 详细信息

针对传统稀疏贝叶斯学习方法在解决低信噪比条件下信号到达角DOA估计中,到达角不完全落在阵元端离散化网格点上的情况,提出了一种基于变分稀疏贝叶斯学习期望最大化的离格DOA处理方法.该方法首先对均匀线阵的实际接收信号off-grid情况建立参数化稀疏模型,利用变分稀疏贝叶斯学习方法,通过最小化KL散度寻求一个与后验概率近似的概率分布,其次期望最大化方法分别在期望阶段和最大化阶段进行参数推断,进一步在离格误差模型下以较高的精度和分辨率实现信号到达角的估计,最后仿真结果表明,该方法不仅在传统SBL方法的基础上提高了运算效率,而且具有更高的空域分辨率和角度估计精度,该方法具有优越的角度估计性能.

关键词： DOA估计 off-grid 稀疏贝叶斯学习变分推断期望最大化

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Innovative Approaches to Energy Provision in off-grid Rural Communities—A Case of Botswana

引用

Journal of Sustainable Bioenergy Systems 2018年第3期8卷 82-91页

作者： Clever Ketlogetswe Jerekias Gandure University of Botswana Mechanical Engineering Department Gaborone Botswana

Although renewable energy technologies applications to rural communities to improve energy access have been embraced in numerous parts of the world, sustainability of these systems is increasingly becoming critical as far as realization of long term benefits is concerned. The current manuscript proposes approaches deemed to provide appropriate match between technology and users in a select of Botswana’s rural communities. The methodology includes a participatory and inclusive approach in which the local community is engaged in the generation of their own energy. Available information indicates that available feedstock in selected communities is sufficient to generate and provide sustainable energy supply for the community.

关键词： Energy Provision Innovation off-grid Rural Communities Sustainability

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

PV-Hybrid off-grid and Mini-grid Systems for Rural Electrification in Sub-Saharan Africa

引用

Smart grid and Renewable Energy 2018年第10期9卷 171-185页

作者： Jordy Charly Isidore Rabetanetiarimanana Mamy Harimisa Radanielina Hery Tiana Rakotondramiarana Institute for the Management of Energy (IME) University of Antananarivo Antananarivo Madagascar

Rural electrification remains a great challenge for Sub-Saharan Africa (SSA) as access to electricity is a prerequisite to accelerate its development. The present paper reviews the measures adopted to promote access to electricity in rural and remote areas of SSA. The main barriers to rural electrification in these developing countries are presented before showing technologies used for the aforementioned purpose. Then, adopted methods for enhancing the use of renewable energy in SSA are shown. Moreover, the policy adopted by decision makers and project planners are also highlighted. In addition, the optimal solutions proposed by researchers are given such as the cost-effective off-grid system type that might be a viable alternative to diesel power generation.

关键词： Rural Electrification Renewable Energy Developing Countries Sub-Saharan Africa PV Microgrid off-grid

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

欢迎您,

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

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

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

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

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：