检索结果-南通市图书馆

Golay Pair Aided timing synchronization Algorithm for Distributed MIMO-OFDM System

在线全文

学校读者我要写书评

暂无评论

China Communications 2018年第9期15卷 178-188页

作者： Weizhi Zhong Xiaoyi Lu Lei Xu Xin Liu College of Astronautics Nanjing University of Aeronautics and Astronautics China Dalian University of Technology School of information and communications

In order to solve the problem of inaccurate synchronization for distributed multiple-input multiple-output(MIMO) orthogonal frequency division multiplexing(OFDM) system in both multipath and low signal to noise ratio(SNR) channels, a golay pair aided timing synchronization(GPATS) method is proposed in this paper. A new synchronous training sequence based on the golay pair with guard interval is designed in GPATS method. By utilizing the unique properties of the new training sequence, the different timing point and the inter-transmitter delays(ITD) are obtained at the receiver. Simulation results show that, compared with the traditional synchronization approaches, the proposed algorithm can provide high accuracy in detecting different time offsets caused by the distributed transmitters of the MIMO-OFDM system, especially over multipath and low SNR channels.

关键词： distributed MIMO-OFDM system timing synchronization golay pair multipath low SNR

Practical timing synchronization for Network Dynamics in Large Machine-to-Machine Networks

在线全文

学校读者我要写书评

暂无评论

China Communications 2016年第10期13卷 160-168页

作者： Lei Gu Shih-Chun Lin Fudan University and China Telecom Research Center Bank of Communication Ltd. the School of Electrical and Computer Engineering Georgia Institute of Technology

Efficient multi-machine cooperation and network dynamics still remain open that jeopardize great applications in largescale machine-to-machine(M2M) networks. Among all possible machine cooperation controls, to synchronize tremendous machines in a timing-efficient brings one of the greatest challenge and serves as the foundation for any other network control policies. In this paper, we propose a linear-time synchronization protocol in large M2M networks. Specifically, a closed-form of synchronization rate is provided by developing the statistical bounds of the second smallest eigenvalue of the graph Laplacian matrix. These bounds enable the efficient control of network dynamics, facilitating the timing synchronization in networks. Through a practical study in Metropolis, simulation results confirm our theoretical analysis and provide effective selection of wireless technologies, including Zigbee, Wi-Fi, and cellular systems, with respect to the deployed density of machines. Therefore, this paper successfully demonstrates a practical timing synchronization, to make a breakthrough of network dynamic control in real-world machine systems, such as Internet of Things.

关键词： timing synchronization network dynamics graph Laplacian matrix distributed protocol internet of things(IoTs) machine-to-machine(M2M) communications

timing synchronization Method for Asymmetrically Clipped DC Biased Optical OFDM System

在线全文

学校读者我要写书评

暂无评论

Optics and Photonics Journal 2016年第8期6卷 14-18页

作者： Yong Wang College of Information & Communication Engineering Harbin Engineering University Harbin China

In a typical intensity-modulated direct-detection optical system, the information is carried on the intensity of the optical signal, and therefore can only be positive. Existing synchronization methods for RF-based OFDM system cannot be used directly in asymmetrically clipped DC biased optical of DM (ADO-OFDM) system. In order to solve the above problem, according to the characteristics of ADO-OFDM signal, the modified training symbol is presented. The simulation results show that the modified synchronization method gives good performance.

关键词： Optical Wireless Communication ADO-OFDM timing synchronization

timing synchronization and Ranging in Networked UAV-Aided OFDM Systems

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

Journal of Communications and Information Networks 2018年第4期3卷 45-54页

作者： Chaoxing Yan Jingjing Wang Lingang Fu Chunxiao Jiang Ming Chen Yong Ren Beijing Research Institute of Telemetry Beijing 100076China Department of Electrical Engineering Tsinghua UniversityBeijing 100084China Tsinghua Space Center Tsinghua UniversityBeijing 100084China Key Laboratory of EDA Research Institute of Tsinghua University in ShenzhenShenzhen 518057China

The space-air-ground network architecture integrates satellite systems,aerial networks,and terrestrial networks,where the unmanned aerial vehicle(UAV)communication in the air segment has attracted particular interest and demonstrated tremendous potential in both military and civilian *** frequency division multiplexing(OFDM)can be an effective solution to provide high rate and reliable transmission in UAV communication systems because of its high spectral efficiency and robustness against frequency selective *** herein focus our attention on two critical issues in our proposed UAV aided OFDM system,i.e.,timing synchronization and ***,extensive simulations are conducted for ***,we design a real-world field test for verifying the effectiveness of our proposed multi-UAV OFDM communication system.

关键词： space-air-ground network UAV-aided communication systems timing synchronization OFDMranging

Fast synchronization scheme for SMCC+system with lower SNR

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

Journal of Systems Engineering and Electronics 2005年第1期16卷 47-51页

作者： LuoRenze WangRuyan ChengXiantao ZhuWeile DepartmentofElectronicEngineering UniversityofElectronicScienceandTechnologyofChinaChengdu610054P.R.China DivisionofCommunicationandInformationEngineering ChongqingUniversityofPostsandTelecommunicationChongqing400065P.R.China

synchronization with lower SNR hadn't been considered by the conventional publications. Based on the Synchronized multi-carrier CDMA plus (SMCC+) system, which is one of the candidate schemes of digital terrestrial TV broadcasting (DTTB) standard in China, a scheme under lower SNR with one short training sequence and one Barker code group, which were constructed in time domain. Computer simulation results show that the timing estimator here is designed to avoid the ambiguity which occured in Tufvesson's timing synchronization method. The 99.9% correct timing synchronization probability and lower false probability are got in AWGN and Rayleigh fading channels with SNR under -20 dB, and the optimum properties of frequency synchronization are obtained at the same time. It is shown that the proposed scheme is much better than the conventional synchronization methods.

关键词： SMCC+ system timing synchronization frequency synchronization lower SNR.

Joint optimization of time and frequency synchronization based on polynomial sequences for OFDM systems

在线全文

学校读者我要写书评

暂无评论

The Journal of China Universities of Posts and Telecommunications 2009年第3期16卷 19-23页

作者： ZHANG Yan-yan ZHANG Jian-hua HUANG Jiang-chun ZHANG Ping Key Laboratory of Universal Wireless Communication Beijing University of Posts and Telecommunications Ministry of Education Beijing 100876 China Wireless Technology Innovation Institute Beijing University of Posts and Telecommunications Beijing 100876 China

In orthogonal frequency division multiplexing （OFDM） systems, time and frequency synchronization are two critical elements for guaranteeing the orthogonality of OFDM subcarriers. Conventionally, with the employment of pseudo-noise （PN） sequences in preamble design, the preamble information is not fully utilized in both symbol timing offset acquisition and carrier frequency offset estimation. In this article, a new synchronization algorithm is proposed for jointly optimizing the time and frequency synchronization. This algorithm uses polynomial sequences as synchronization preamble instead of PN sequences. Theoretical analysis and simulation results indicate that the proposed algorithm is much more accurate and reliable than other existing methods.

关键词： frequency synchronization joint optimization OFDM polynomial sequences timing synchronization

Fractionally Spaced Equalization Algorithms in 60GHz Communication System

在线全文

学校读者我要写书评

暂无评论

China Communications 2014年第6期11卷 23-31页

作者： YUE Guangrong DONG Aixian HONG Hao GUO Jianmei WANG Lei National Key Laboratory of Science and Technology on Communications University of Electronic Science and Technology of China The Navy Academy of Armament

Several fractionally spaced equalizers(FSE) which could be used in 60 GHz systems are presented in this paper. For 60 GHz systems, low-power equalization algorithms are favorable. We focus on FSE in both time domain(TD) and frequency domain(FD) in order to meet different complexity requirements of 60 GHz systems. Compared with symbol spaced equalizer(SSE), FSE can relax the requirement of sampling synchronization hardware significantly. Extensive simulation results show that our equalization algorithms not only eliminate ISI efficiently, but are also robust to timing synchronization errors.

关键词： fractionally spaced equalizers 60GHz timing synchronization lowcomplexity

Line-of-Sight MIMO for High Capacity Millimeter Wave Backhaul in FDD Systems

在线全文

学校读者我要写书评

暂无评论

Journal of Communications and Information Networks 2020年第2期5卷 177-193页

作者： Ye Xue Xuanyu Zheng Vincent K.N.Lau Hong Kong University of Science and Technology Hong Kong 999077China

Wireless backhaul is considered to be the key part of the future wireless network with dense small cell traffic and high capacity *** this paper,we focus on the design of a high spectral efficiency line-of-sight(LoS)multiple-input multiple-output(MIMO)system for millimeter wave backhaul using dual-polarized frequency division duplex(FDD).High spectral efficiency is very challenging to achieve for the system due to various physical impairments such as phase noise(PHN),timing offset(TO)as well as the poor condition number of the LoS *** this paper,we propose a holistic solution containing TO compensation,PHN estimation,precoder/decorrelator optimization of the LoS MIMO for wireless backhaul,and the interleaving of each *** show that the proposed solution has a robust performance with end-to-end spectral efficiency of 60 bit/s/Hz for 88 MIMO.

关键词： line-of-sight MIMO wireless backhaul FDD timing synchronization phase noise

Implementation of synchronization Technology in Orthogonal Frequency Division Multiplex System Based on Field Programming Gate Array

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

Semiconductor Photonics and Technology 2008年第1期14卷 32-36页

作者： YI Qing-ming XIE Sheng-li College of Electronics ＆ Information South China University of Technology Guangzhou 510641 CHN Department of Electronics Engineering Jinan University Guangzhou 510632 CHN

In this paper,analyzed is the symbol synchronization algorithm in orthogonal frequency division multiplex(OFDM)system,and accomplished are the hardware circuit design of coarse and elaborate synchronization *** on the analysis of coarse and elaborate synchronization algorithms,multiplexed are,the module accumulator,division and output judgement,which can evidently save the hardware resource *** analysis of circuit sequence and wave form simulation of the design scheme shows that the proposed method efficiently reduce system resources and power consumption.

关键词： orthogonal frequency division multiplex timing synchronization field programmable gate array