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China Communications 2021年第3期18卷 29-38页

作者： Zhendong Mao Mugen Peng Xiqing Liu State Key Laboratory of Networking and Switching Technology Beijing University of Posts and TelecommunicationsBeijing 100876China

Reconfigurable intelligent surface(RIS)can manipulate the wireless propagation environment by smartly adjusting the amplitude/phase in a programmable panel,enjoying the improved *** accurate acquisition of the instantaneous channel state information(CSI)in the cascaded RIS chain makes an indispensable contribution to the performance ***,it is quite challenging to estimate the CSI in a time-variant scenario due to the limited signal processing capability of the passive elements embedded in a RIS *** this work,a channel estimation scheme for the RIS-assisted wireless communication system is proposed,which is demonstrated to perform well in a time-variant *** cascaded RIS channel is modeled as a state-space model based upon the mobility *** addition,to fully exploit the time correlation of channel,Kalman filter is employed by taking the prior information of channels into ***,the optimal reflection coefficients are derived according to the minimum mean square error(MMSE)*** results show that the proposed methods exhibit superior performance if compared with a conventional channel estimation scheme.

关键词： reconfigurable intelligent surface(RIS) channel estimation time-variant channel kalman filter

channel estimation based on distributed compressed sensing in amplify-and-forward relay networks

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The Journal of China Universities of Posts and Telecommunications 2010年第5期17卷 44-49页

作者： WANG Dong-hao NIU Kai HE Zhi-qiang TIAN Bao-yu School of Information and Telecommunication Engineering Beijing University of Posts and Telecommunications Beijing 100876 China

In orthogonal frequency-division multiplexing （OFDM） amplify-and-forward （AF） relay networks,in order to exploit diversity gains over frequency-selective fading channels,the receiver needs to acquire the knowledge of channel state information （CSI）.In this article,based on the recent methodology of distributed compressed sensing （DCS）,a novel channel estimation scheme is *** joint sparsity model 2 （JSM-2） in DCS theory and simultaneous orthogonal matching pursuit （SOMP） are both introduced to improve the estimation performance and increase the spectral *** results show that compared with current compressed sensing （CS） methods,the estimation error of our scheme is reduced dramatically in high SNR region while the pilot number is still kept small.

关键词： channel estimation DCS relay networks SOMP

channel estimation in TDD mode

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The Journal of China Universities of Posts and Telecommunications 2006年第3期13卷 34-37页

作者： ZHANG Yi GU Jian YANG Da-cheng School of Telecommunication Engineering Beijing University of Posts and Telecommunications Beijing 100876 China

An efficient solution is proposed in this article for the channel estimation in time division duplex （TDD） mode wireless communication systems. In the proposed solution, the characteristics of fading channels in TDD mode systems are fully exploited to estimate the path delay of the fading channel. The corresponding amplitude is estimated using the minimum mean square error （MMSE） criterion. As a result, it is shown that the proposed novel solution is more accurate and efficient than the traditional solution, and the improvement is beneficial to the performance of Joint Detection.

关键词： channel estimation MMSE TDD

channel estimation in space and frequency domain for MIMO-OFDM systems

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The Journal of China Universities of Posts and Telecommunications 2009年第3期16卷 40-44页

作者： PAN Pei-sheng,ZHENG Bao-yu College of Communication and Information,Nanjing University of Posts and Telecommunications,Nanjing 210003,China College of Communication and Information Nanjing University of Posts and Telecommunications Nanjing 210003 China

Multiple-input multiple-output （MIMO） systems can be combined with orthogonal frequency division multiplexing （OFDM） systems to improve the capacity and quality of wireless communications. In this article, a channel estimation technique in both space and frequency domain for MIMO-OFDM systems is proposed. It is shown that the proposed scheme with space-frequency pilot tones achieve optimal minimum mean square error （MMSE） channel estimation. Simulation results indicate that the proposed method achieves good performance.

关键词： channel estimation MIMO OFDM space frequency pilot tones

channel estimation in integrated radar and communication systems with power amplifier distortion

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Journal of Systems Engineering and Electronics 2024年第5期35卷 1098-1108页

作者： LIU Yan YI Jianxin WAN Xianrong RAO Yunhua HAO Caiyong School of Electronic Information Wuhan UniversityWuhan 430072China Shenzhen Research Institute of Wuhan University Shenzhen 518057China State Radio Monitoring Center of China Shenzhen 518120China

To reduce the negative impact of the power amplifier(PA)nonlinear distortion caused by the orthogonal frequency division multiplexing(OFDM)waveform with high peak-to-average power ratio(PAPR)in integrated radar and communication(RadCom)systems is studied,the channel estimation in passive sensing *** channel estimation methods are proposed based on different pilot patterns,considering nonlinear distortion and channel *** proposed methods achieve sparse channel results by manipulating the least squares(LS)frequency-domain channel estimation results to preserve the most significant *** decision-aided method is used to optimize the sparse channel results to reduce the effect of nonlinear *** results show that the channel estimation performance of the proposed methods is better than that of the conventional methods under different pilot *** addition,the bit error rate performance in communication and passive radar detection performance show that the proposed methods have good comprehensive performance.

关键词： channel estimation integrated radar and communication(RadCom) passive sensing nonlinear distortion power amplifier(PA) pilot pattern

channel estimation and Compensation for Underwater Acoustic Pipeline Communication

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Journal of Beijing Institute of Technology 2017年第2期26卷 252-258页

作者： Weijiang Wang Nan Su Jianyan Liu School of Information and Electronics Beijing Institute of Technology Beijing 100081 China

An estimation and compensation algorithm for underwater acoustic pipeline channel is investigated.A joint time-frequency adaptive signal-to-noise ratio（SNR）estimation based on the maximum likelihood method is introduced firstly,and the Cramer-Rao lower bound（CRLB）is proposed so as to evaluate the performance of the SNR estimation *** frequency-selective fading channel part,estimation and compensation are made to improve the robustness of the system on the basis of the LMS ***,real-time update iteration algorithm in the frequency domain is investigated to realize synchronous receiving and *** verification,simulations and actual data tests were made,and the results show that the algorithm possesses great robustness,efficiency and accuracy inrealization of SNR estimation,signal detection and frequency impulse compensation for the channel.

关键词： acoustic pipeline communication signal-to-noise ratio (SNR) estimation channel estimation compensation

channel estimation and Throughput Evaluation for 5G Wireless Communication Systems in Various Scenarios on High Speed Railways

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China Communications 2018年第4期15卷 86-97页

作者： yanrong zhao xiyu wang gongpu wang ruisi he yulong zou zhuyan zhao school of computer and information technology beijing jiaotong universityBeijing 100044China the state key laboratory of rail traffic control and safety beijing jiaotong universityBeijing 100044China the key laboratory of broadband wireless communication and sensor network technology of ministry of education nanjing university of posts and telecommunicationsNanjing 210003China nokia bell labs beijing Beijing 100044China

The fifth generation （5G） wireless communication is currently a hot research topic and wireless communication systems on high speed railways （HSR） are important applications of 5G technologies. Existing stud- ies about 5G wireless systems on high speed railways （HSR） often utilize ideal channel parameters and are usually based on simple scenarios. In this paper, we evaluate the down- link throughput of 5G HSR communication systems on three typical scenarios including urban, cutting and viaduct with three different channel estimators. The channel parameters of each scenario are generated with tapped delay line （TDL） models through ray-tracing sim- ulations, which can be considered as a good match to practical situations. The channel estimators including least square （LS）, linear minimum mean square error （LMMSE）, and our proposed historical information based ba- sis expansion model （HiBEM）. We analyze the performance of the HiBEM estimator in terms of mean square error （MSE） and evaluate the system throughputs with different channel estimates over each scenario. Simulation results are then provided to corroborate our proposed studies. It is shown that our HiBEM estimator outperforms other estimators and that the sys-tem throughput can reach the highest point in the viaduct scenario.

关键词： 5G channel estimation HSR tapped delay line throughput pertbrmanceanalysis wireless communication.

channel estimation and channel tracking for correlated block-fading channels in massive MIMO systems

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Digital Communications and Networks 2018年第2期4卷 138-147页

作者： Suresh Dahiya Arun Kumar Singh Department of Electrical Engineering Indian Institute of Technology Jodhpur Rajasthan 342011 India

This paper presents a channel estimation and tracking method for correlated block-fading channels in massive MIMO wireless cellular systems. In order to conserve resources, the proposed algorithm requires the uplink pilot signal only once, at the start of communication. By utilizing the temporal correlation between consecutive Resource Blocks （RBs） and the error correction capability of turbo codes, the channel matrix in subsequent RBs is estimated at the Base Station （BS） itself using the uplink data of current the RB and the estimated channel matrix of previous the RB. Compared to existing blind estimation methods, the proposed method places fewer limitations on the system settings such as the number of BS antennas, the number of users, and the number of coherent channel usage compared to existing blind estimation methods. Simulation results show that the proposed algorithm provides better performance for a moderate RB size, a high-order of QAM scheme, and a smaller ratio of the number of BS antennas and mobile terminals （N/K）. For a reasonably small N/K （order of 10）, the proposed scheme achieves a lower symbol error probability than the conventional pilot-based estimation approach.

关键词： Massive MIMO channel estimation Resource block Turbo coding Mobile terminal

channel estimation for MIMO-OFDM systems in wireless mobile channels

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High Technology Letters 2008年第4期14卷 354-358页

作者：陆震 Ge Jianhua Department of Electrical Engineering Shanghai Jiaotong University Shanghai 200240 P.R. China State Key Laboratory of Integrated Services Networks Xidian University Xi＇an 710071 P.R. China

New training sequences and frame structure are proposed to estimate time-varying channel for multi-pie-input multiple-output and orthogonal frequency division multiplexing (MIMO-OFDM) *** sequences are modulatable orthogonal polyphase sequences,which have both good autocorrela-tions and *** channel impulse response (CIR) can be obtained by measuring the cor-relation between the received training sequence and the locally generated training *** trainingsequences are used as guard interval instead of cyclic prefix,which not only improve the transmission ef-ficiency but also enable the channel estimator to track time-varying *** simulation results showthat the proposed method has about 2dB SNR gain over conventional methods in fast time-varying chan-nel.

关键词： MIMO OFDM channel estimation modulatabale orthogonal polyphase sequence

channel estimation for MIMO-OFDM systems in mobile wireless channels

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Journal of Harbin Institute of Technology(New Series) 2008年第6期15卷 841-845页

作者：吴赟罗汉文宋文涛 College of Information Science & Technology Donghua University Dept.of Electronic Engineering Shanghai Jiaotong University

A channel estimation method is proposed for nmltiple-input multiple-output orthogonal frequency division muhiplexing （MIMO-OFDM） systems in time-varying fading channels. In this method, a decision-directed space-alternating generalized expectation-maximization （SAGE） algorithm is introduced to the tracking of time-varying fading. In order to improve the estimation performance of the SAGE algorithm, a low rank approximation method is presented by using the signal subspace of the channel frequency autocorrelation matrix. The study reveals that this method can be incorporated into the SAGE algorithm. Furthermore, a modified fast sub- space tracking algorithm is given to adaptively estimate the signal subspace by utilizing training OFDM blocks sent at regular interval. Simulation results demonstrate the considerable benefits of the proposed channel estimation method.

关键词： MIMO-OFDM channel estimation SAGE subspace tracking