检索结果-内蒙古大学图书馆

Blind synchronization in asynchronous UWB networks based on the transmit-reference scheme

EURASIP JOURNAL ON WIRELESS COMMUNICATIONS AND NETWORKING 2006年第0期2006卷 1-14页

作者： Djapic, Relja Leus, Geert van der Veen, Alle-Jan Trindade, Antonio TNO ICT NL-2612 CT Delft Netherlands Delft Univ Technol Dept Elect Engn Delft Inst Microelect & Submicron Technol NL-2628 CD Delft Netherlands

Ultra-wideband (UWB) wireless communication systems are based on the transmission of extremely narrow pulses, with a duration inferior to a nanosecond. The application of transmit reference (TR) to UWB systems allows to side-step channel estimation at the receiver, with a tradeoff the effective transmission bandwidth, which is reduced by the usage of a reference pulse. Similar to CDMA systems, different users can share the same available bandwidth by means of different spreading codes. This allows the receiver to separate users, and to recover the timing information of the transmitted data packets. The nature of UWB transmissions-short, burst-like packets-requires a fast synchronization algorithm, that can accommodate several asynchronous users. Exploiting the fact that a shift in time corresponds to a phase rotation in the frequency domain, a blind and computationally efficient synchronization algorithm that takes advantage of the shift invariance structure in the frequency domain is proposed in this paper. Integer and fractional delay estimations are considered, along with a subsequent symbol estimation step. This results in a collision-avoiding multiuser algorithm, readily applicable to a fast acquisition procedure in a UWB ad hoc network. Copyright (C) 2006 Relja Djapic et al.

关键词： .transmitted data synchronization algorithm Transmit-Reference Blind synchronization Asynchronous UWB

来源：评论

学校读者我要写书评

暂无评论

A hybrid systems approach to global synchronization and coordination of multi-agent sampled-data systems

引用

IFAC-PapersOnLine 2015年第27期48卷 123-128页

作者： Teel, Andrew R. Poveda, Jorge I. Elect. and Comp. Eng. Dept. Univ. of California Santa BarbaraCA93106-9560 United States

A global synchronization algorithm for a network of resetting clocks is presented. Each clock signals its neighbors when it resets to zero after reaching the end of its period. Based on where a neighbor is located at the time of the signal, the neighboring clock adjusts its value instantaneously to synchronize with the signaling clock. Subsequently, the sychronization algorithm is used in the context of networked, multi-agent sampled-data systems. Here, agents update their internal state, based on the values of the internal states of their neighbors, when their clock variable resets to zero. The synchronization algorithm, together with additional sampling of the internal states of neighbors, is used to synchronize and coordinate the agents of the networked sampled-data system. These actions enable achieving the stability property that would result if the agents performed their state updates simultaneously. The models associated with these algorithms are presented in terms of hybrid dynamical systems. Well-posed models are developed that exhibit robustness properties, including robustness to small communication delays and to small mismatch in the natural frequency of each clock, and for which extensive analysis tools are available, including an invariance principle and a reduction principle. © 2015, IFAC (International Federation of Automatic Control) Hosting by Elsevier Ltd. All rights reserved.

关键词： Multi agent systems Clocks Hybrid systems Sampled data control systems Software agents Stability synchronization Communication delays Global synchronization Hybrid dynamical systems Invariance principle Robustness properties Sampled data systems Stability properties synchronization algorithm

来源：评论

学校读者我要写书评

暂无评论

Research on synchronization Technology for OFDM Underwater Acoustic Communication System

Research on Synchronization Technology for OFDM Underwater A...

引用

International Conference on Intelligent Transportation, Big Data & Smart City (ICITBS)

作者： Zhang De Fan Maojun Zha Wenzhong Xiong Minglei Chen Longdong China Elect Technol Grp Corp Inst 3 Beijing 100015 Peoples R China Nanjing Univ Sci & Technol Nanjing 210094 Jiangsu Peoples R China China Elect Technol Grp Corp Informat Sci Acad Beijing 100086 Peoples R China Boya Gongdao Beijing Robot Technol Co Ltd Beijing Peoples R China

ISBN: (纸本)9781728113074

The underwater acoustic channel is a kind of dual-selective fading channel, which has the characteristics of time-varying, space-variation and frequency-variation. It has serious multipath effect and Doppler effect. The characteristics of severe multipath interference, large background noise, large delay spread, and narrow usable bandwidth are the main obstacles to get the performance of high-speed, reliable acoustic communications. Orthogonal Frequency Division Multiplexing (OFDM) technology is a modulation technique with high spectrum utilization and has the advantage of strong anti-multipath capability, and has become a common technique to solve these problems. But another problem is that the OFDM device is very sensitive to synchronization errors. synchronization errors will have a serious impact on OFDM communication systems and become one of the key technologies of OFDM. Therefore, it is of great practical significance to study OFDM synchronization techniques in underwater acoustic channels. This paper mainly studies the application of OFDM synchronization algorithm in underwater wireless communication under underwater acoustic channels.

关键词： synchronization algorithm OFDM underwater acoustic communication

来源：评论

学校读者我要写书评

暂无评论

An OFDM-PON symbol synchronization technology based on absolute value error of training sequence

An OFDM-PON symbol synchronization technology based on absol...

引用

3rd International Conference on Consumer Electronics, Communications and Networks (CECNet)

作者： Chen, Jian Zhang, Fang Yu, Lihui Hu, Tong Li, Yingchun Song, Yingxiong Shanghai Univ Key Lab Specialty Fiber Opt & Opt Access Networks Shanghai 200041 Peoples R China

ISBN: (纸本)9781479928606

a simple, low cost and robust OFDM-PON symbol synchronization technology is proposed and experimentally demonstrated. The main idea of this algorithm is to make use of the periodicity of the OFDM symbol to achieve symbol and frame synchronization at the receiver. This technology is applicable for the OFDM-PON system as some simple subtraction is required but without any multiplication. Using the proposed synchronization algorithm, a real-time OFDM-PON signal transmission at 2.5Gb/s over 25km standard single-mode fiber is achieved and the optical power of-12.5dBm corresponds to the system bit error rate of only 0.11634%. And most importantly, it provides the real time symbol synchronization for the point-to-point and point-tomultipoint OFDM-PON network.

关键词： OFDM-PON synchronization algorithm training sequence

来源：评论

学校读者我要写书评

暂无评论

A Distributed Analysis and Design Method for the synchronization of Linear Heterogeneous SISO Systems by Static State Control 23

A Distributed Analysis and Design Method for the Synchroniza...

引用

23rd Mediterranean Conference on Control and Automation (MED)

作者： Khodaverdian, Saman Adamy, Jurgen Tech Univ Darmstadt Inst Automat Control & Mechatron Control Methods & Robot Lab Landgraf Georg Str 4 D-64283 Darmstadt Germany

ISBN: (纸本)9781479999361

We present a design scheme for the synchronization of linear heterogeneous SISO systems by static feedback controllers. Extending some recent results, a distributed method is provided for synchronizing non-identical agents by a simple synchronization controller for homogeneous agents. In [4], it was shown that for a special condition heterogeneous agents can be synchronized by static controllers. In this paper, we present a constructive approach to analyze the satisfiability of this condition in a distributed manner and to design an appropriate controller.

关键词： Networked systems heterogeneous agents synchronization algorithm static

来源：评论

学校读者我要写书评

暂无评论

Fast and Low-Complexity Frame-Level synchronization for Direct-Sequence Transmitted Reference Receivers

Fast and Low-Complexity Frame-Level Synchronization for Dire...

引用

International Conference on Advances in Computer Science and Engineering

作者： Niemiao Zhao, Zhangzhong Haerbin Inst Technol Haerbin Peoples R China

ISBN: (纸本)9780878492510

in this paper,we proposed and analyzed a frame-level synchronization (FLS) algorithm for the UWB direct-sequnce transmitted-reference (DS-TR) receiver. In DS-TR systems, Symbol-level synchronization is not enough for data modulation, the position of low duty cycle signal in each frame is still unknown. The algorithm which we proposed has a moderate accuracy but a very low complexity and fast synchronization speed compared with conventional approaches requiring subnanosecond-level accuracy. Detailed analysis of the algorithm is carried out based on our in-depth analysis.

关键词： Ultra-wideband (UWB) DS-TR synchronization algorithm

来源：评论

学校读者我要写书评

暂无评论

Model Predictive Control of a Voltage-Source Inverter With Seamless Transition Between Islanded and Grid-Connected Operations

引用

IEEE TRANSACTIONS ON INDUSTRIAL ELECTRONICS 2017年第10期64卷 7906-7918页

作者： Li, Xiao Zhang, Haiyu Shadmand, Mohammad B. Balog, Robert S. Texas A&M Univ Dept Elect & Comp Engn College Stn TX 77840 USA

Inverter-based distributed generation (DG) system is becoming an attractive solution for high penetration of renewable energy sources to the main grid. DG system should be able to supply power to the local loads whenever necessary even in case of utility power outage. Thus, the inverters in DG systems are expected to operate in both grid-connected and islanded mode, where they are acting as a current source for the ac grid and a voltagesource for the load, respectively. Transition between modes of operation is nontrivial and can cause deviations in voltage and current, because of mismatch in frequency, phase, and amplitude between the inverter output voltage and the grid voltage. Thus, it is necessary to have seamless transition between grid-connected and islanded mode. This paper presents a new control strategy with seamless transfer characteristics for a grid-connected voltage-source inverter using model predictive control (MPC) framework. The main objectives of the proposed predictive controller are: 1) decoupled power control in grid-connected mode, which enables the proposed power electronics interface to provide ancillary services such as reactive power compensation;2) load voltage control in islanded mode;and 3) seamless transition between modes of operation through proposed synchronization and phase adjustment algorithm. The proposed controller features simplicity to implement since only one cost function should be minimized for all modes of operation, and hence no ambiguity in the control algorithm that could cause mode transition problems. An autotuning strategy for weight factors inMPC cost function is proposed to simplify the weight factor tuning strategy. The stability analysis of the proposed controller is provided. Simulation and experimental results validate the expected performance and effectiveness of the proposed control strategy.

关键词： Grid-connected mode islanded mode model predictive control (MPC) seamless transfer stability synchronization algorithm weight factor tuning

来源：评论

学校读者我要写书评

暂无评论

Synchronizing Computer Simulations with Measurement Data for a Case of Atrial Flutter

引用

ANNALS OF BIOMEDICAL ENGINEERING 2009年第7期37卷 1287-1293页

作者： Lines, Glenn T. MacLachlan, Mary C. Linge, Svein Tveito, Aslak Simula Res Lab Ctr Biomed Computing N-1325 Lysaker Norway Telemark Univ Coll N-3901 Porsgrunn Norway Univ Oslo Inst Informat N-0316 Oslo Norway

Atrial flutter is a common supraventricular tachycardia that can be treated using radiofrequency catheter ablation, a procedure that is guided by electroanatomical mapping systems. In this paper, we propose an algorithm for incorporating mapping data into computer simulations of atrial electrical activity with the purpose of creating a more accurate map of electrical activation. The algorithm takes as input the extracellular potential values recorded at a number of sites throughout the atria and estimates the activation time for the entire atrial domain. We test the algorithm using synthetic mapping data and an anatomically detailed atrial geometry with an activation pattern typical of atrial flutter. The results show that the algorithm performs well with synthetic mapping data with information from relatively few mapping sites and in the presence of modeling and measurement error.

关键词： Bidomain and monodomain models synchronization algorithm Computer simulations Synthetic eletroanatomical mapping data Atrial flutter

来源：评论

学校读者我要写书评

暂无评论

Comparison of synchronization algorithms for OFDM-based Vehicular Ad Hoc Network

Comparison of Synchronization Algorithms for OFDM-based Vehi...

引用

International Conference on Consumer Electronics, Communications and Networks

作者： Cong Liu Yong Bai College of Information Science & Technology Hainan University

ISBN: (纸本)9781457714146

OFDM (Orthogonal Frequency Division Multiplexing) has been applied in Vehicular Ad Hoc Networks (VANET) due to its ability to counteract the frequency-selective fading and its high spectral efficiency. For instance, OFDM-based IEEE802.11 802.11p has been standardized for VANET. In OFDM-based VANET, synchronization of the carrier frequency at the receiver must be performed accurately to avoid performance degradation. This paper compares the effectiveness of three synchronization algorithms to estimate the carrier frequency offset (CFO) of OFDM signals in VANET. The simulation is conducted using the parameters of IEEE 802.11p and performed under several channel models including Additive White Gaussian Noise (AWGN) channel, Rayleigh channel, and COST 207 channel models.

关键词： OFDM IEEE802.11p synchronization algorithm

来源：评论

学校读者我要写书评

暂无评论

Design of output LCL filter and control of single-phase inverter for grid-connected system

引用

ELECTRICAL ENGINEERING 2017年第4期99卷 1217-1232页

作者： Sedo, Jozef Kascak, Slavomir Univ Zilina Dept Mechatron & Elect Univ 1 Zilina 01026 Slovakia

In this paper, an implementation of the control and the synchronization algorithms for a voltage source inverter (VSI) used in a grid-connected structure is carried out. The main purpose is to show the combined operation of the control and synchronization algorithm for achieving the proper behavior of the grid inverter for the single-phase utility grid system. In order to obtain a proper functionality of the system during perturbation, a proportional integral controller structure along with second-order generalized integrator phase-locked loop is designed and used as synchronization algorithm. Another aim is to control power factor at grid, to feed power into the grid and to decrease phase current distortion of VSI. Secondly, the design of the output LCL filter is proposed in this paper. The results of simulations of the inverter system connected to grid (220 V, 50 Hz) using MATLAB/Simulink are also shown. Simulation results confirm that the grid input power factor is nearly one and the distortion of phase current of the proposed system is reduced, causing the total harmonic distortion for various power conditions falls within 5%. The last chapter shows the experimental verifications of the proposed control algorithm.

关键词： Smart grid inverter synchronization algorithm Output LCL filter Notch filter

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：