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Shannon information capacity of time reversal wideband multiple-input multiple-output system based on correlated statistical channels

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Chinese Physics B 2016年第5期25卷 5-10页

作者：杨瑜王秉中丁帅 Institute of Applied Physics University of Electronic Science and Technology of China

Utilizing channel reciprocity, time reversal（TR） technique increases the signal-to-noise ratio（SNR） at the receiver with very low transmitter complexity in complex multipath environment. Present research works about TR multiple-input multiple-output（MIMO） communication all focus on the system implementation and network building. The aim of this work is to analyze the influence of antenna coupling on the capacity of wideband TR MIMO system, which is a realistic question in designing a practical communication system. It turns out that antenna coupling stabilizes the capacity in a small variation range with statistical wideband channel response. Meanwhile, antenna coupling only causes a slight detriment to the channel capacity in a wideband TR MIMO system. Comparatively, uncorrelated stochastic channels without coupling exhibit a wider range of random capacity distribution which greatly depends on the statistical channel. The conclusions drawn from information difference entropy theory provide a guideline for designing better high-performance wideband TR MIMO communication systems.

关键词： information entropy time reversal wideband multiple-input multiple-output(MIMO) system antenna mutual coupling

Parameter estimation of LFM signals based on time reversal

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Journal of Systems Engineering and Electronics 2023年第3期34卷 674-681页

作者： MA Xinjie QI Wei CHE Kaijun WU Gang School of Electronic Science and Engineering Xiamen UniversityXiamen 361005China Beijing Institute of Tracking and Telecommunications Technology Beijing 100094China Jiuquan Satellite Launch Center Jiuquan 736200China

In this paper,parameter estimation of linear frequency modulation(LFM)signals containing additive white Gaussian noise is *** the center frequency estimation of an LFM signal is affected by the error propagation effect,resulting in a higher signal to noise ratio(SNR)threshold,a parameter estimation method for LFM signals based on time reversal is *** proposed method avoids SNR loss in the process of estimating the frequency,thus reducing the SNR *** simulation results show that the threshold is reduced by 5 dB compared with the discrete polynomial transform(DPT)method,and the root-mean-square error(RMSE)of the proposed estimator is close to the Cramer-Rao lower bound(CRLB).

关键词： linear frequency modulation(LFM)signal time reversal Cramer-Rao lower bound(CRLB) parameter estimation

The time reversal effect of the impulse response of crust

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Acta Seismologica Sinica(English Edition) 2001年第4期14卷 394-403页

作者：郑文衡王乘陈湘鹏 1. Engineering Computation and Simulation Institute Huazhong University of Science & Technology 430074 Wuhan China

In this paper, the time reversal processes of impulse response of crust are simulated by means of a dynamical finite element method (DFEM). The results indicate that a small undulating load during a long period may cause a focused brevity impact in a chaos-response system. The physical principle for this phenomenon is that the wave interferes or multiples superposition. Based on this knowledge, a new view toward the mechanism for preparing and triggering an earthquake is proposed. Finally, an interpretation of crust response to the sea tides is given.

关键词： time reversal impulse response earthquake dynamics simulation

Extracting the Subsonic Anti-Symmetric Lamb Wave from a Submerged Thin Spherical Shell Backscattering Through Iterative time reversal

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Journal of Ocean University of China 2014年第4期13卷 589-596页

作者： YU Xiaotao PENG Linhui YU Gaokun School of Information Science and Engineering Ocean University of China State Key Laboratory of Acoustics Chinese Academy of Sciences

The extraction of the weakly excited anti-symmetric Lamb wave from a submerged thin spherical shell backscattering is very difficult if the carrier frequency of the incident short tone burst is not at its frequency of greatest enhancement. Based on a single channel iterative time reversal technique, a method for isolating the subsonic anti-symmetric Lamb wave is proposed in this paper. The approach does not depend on the form function of a thin shell and any other priori knowledge, and it is also robust in the presence of some stochastic noise. Both theoretical and numerical results show that the subsonic anti-symmetric Lamb wave can be identified, even when the carrier frequency of the incident short tone burst is away from the frequency of greatest enhancement. The phenomenon may also be observed even in the case that the subsonic anti-symmetric Lamb wave is submerged in the noise, other than the case with the Signal to Noise Ratio being less than 10 d B, when the amplitude of the noise is comparable with the specular wave. In this paper, each iteration process contains a traditional transmission and time reversal transmission steps. The two steps can automatically compensate the time delay of the subsonic anti-symmetric Lamb wave relative to the specular wave and within-mode dispersion in the forward wave propagation.

关键词： backscattering Lamb wave time reversal frequency of greatest enhancement SNR

Solution for Hardware-in-the-Loop Radar Netting Simulation Problem by Utilizing time reversal Method

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Journal of Beijing Institute of Technology 2003年第S1期12卷 86-90页

作者：刘峰曾涛龙腾刘伟 Department of Electronic Engineering School of Information Science and TechnologyBeijing Institute of TechnologyBeijing 100081China

A new method of radar netting simulation with hardware-in-the-loop (HWIL) is introduced based on the idea of time reversal. It is the high authenticity, low cost and great simplification in design that the method does provide. Along with several paragraphs about the vital features, the model of probability is explained in an analytical way to find out the feasibility of this method.

关键词： HWIL simulation time reversal radar-countermeasure simulation

NEAR-FIELD SOURCE LOCALIZATION METHOD AND APPLICATION USING THE time reversal MIRROR TECHNIQUE

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Journal of Electronics(China) 2011年第4期28卷 531-538页

作者： Fu Yongqing Jiang Yulei Liu Zhanya Department of Information and Communication Engineering Harbin Engineering University Harbin 150001 China

In order to develop the acoustic keyboard for Personal Computer(PC),it is necessary to seek high-precision near-field source localization algorithm for identifying the keyboard *** of all,the focusing property of time reversal Mirror(TRM) is introduced,and then a mathe-matical model of microphone array receiving typing sound is established according to the realization of acoustic keyboard from which the TRM localization algorithm is carried *** results through computer simulation show that the localization Root Mean Square Error(RMSE) performance of the algorithm can reach 10-3,which demonstrates that the algorithm possesses a high accuracy for the actual near-field acoustic source localization,with potential of developing the computer acoustic ***,for the purpose of testing its effect on actual near-field source localization,we organize three experiments for acoustic keyboard characters *** experiment results show that the positioning error of TRM algorithm is less than 1 cm within a provided acoustic keyboard *** will provide theoretical guidance for the further research of computer acoustic keyboard.

关键词： time reversal Near-field source Location Acoustic keyboard

The Analysis Method of time reversal for Defect Diagnosis of Concealed Structure

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Journal of Southeast University(English Edition) 1999年第1期15卷 113-116页

作者：韩晓林汪凤泉朱宽军东南大学工程力学系

In this paper, a new method of time reversal for defect diagnosis of concealed structure has been proposed based on the detecting technique of structure acoustic wave and the theory of time reversal. The time reversal recurrence formula for detecting the acoustic wave speed constitution of concealed structures with bilevel asynchronous test has been established. The wave speed constitution can be reconstructed in 2 D graticule form by means of this method. The result of model test shows the method is valid.

关键词： defect diagnosis time reversal concealed structure

A novel power-combination method using a time-reversal pulse-compression technique

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Chinese Physics B 2023年第8期32卷 283-288页

作者：陆希成田锦张荣威汪海波邱扬 College of Mechanical and Electrical Engineering Xidian UniversityXi'an 710071China School of Information and Communications Engineering Xi'an Jiaotong UniversityXi'an 710049China Northwest Institute of Nuclear Technology Xi'an 710024China

The electromagnetic time-reversal(TR)technique has the characteristics of spatiotemporal focusing in a time-reversal cavity(TRC),which can be used for pulse compression,thus forming an electromagnetic pulse with high peak power.A time-reversed pulse-compression method in a single channel has high pulse compression ***,single channel pulse compression can only generate limited *** paper proposes a novel TR power-combination method in a multichannel TRC to obtain higher peak power based on TR pulse-compression ***,the TR power-combination model is given,and the crosstalk properties of the associated channel and the influence of the reversal performance are ***,the power-combination performances for the TR pulse compression,such as combined signal to noise ratio(SNR)and combined compression gain,are analyzed by numerical simulation and experimental *** results show that the proposed method has obvious advantages over pulse-compression methods using a single channel cavity,and is more convenient for power combination.

关键词： time reversal time-reversal cavity power combination pulse compression

Iterative time reversal Technique for Inspection of Composite Structures

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Iterative Time Reversal Technique for Inspection of Composit...