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He G.,Chongqing University | He G.,Chongqing University of Science and Technology | Tang Y.,Chongqing University | Tang Y.,Chongqing University of Science and Technology | And 3 more authors.
Chinese Journal of Mechanical Engineering (English Edition) | Year: 2011

For the purpose of improving the precision of the inertial guidance system, it is necessary to enhance the accuracy of the accelerometer. Combining the micro-fabrication processes with resonant sensor technology, a high-resolution inertial-grade novel micro resonant accelerometer is studied. Based on the detecting theory of the resonant sensors, the accelerometer is designed, fabricated, and tested. The accelerometer consists of one proofmass, two micro leverages and two double-ended-tuning-fork (DETF) resonators. The sensing principle of this accelerometer is based on that the natural frequency of the DETF resonator shifts with its axial load which is caused by inertial force. The push-pull configuration of the DETF is for temperature compensation. The two-stage micro leverage mechanisms are employed to amplify the force and increase the sensitivity of the accelerometer. The micro leverage and the resonator are modeled for static analysis and nonlinear modal analysis via theory method and finite element method (FEM), respectively. The geometrical parameters of them are optimized. The amplification factor of the leverage is 102, and the sensitivity of the resonator on theory is about 62 Hz/g. The samples of the accelerometer are fabricated with deep reactive ion etching (DRIE) technology which can get a high-aspect ratio structure for contributing a greater sensing-capacitance. The measuring results of the samples by scanning electron microscopy (SEM) show that the process is feasible, because of the complete structure, the sound combs and micro leverages, and the acceptable errors. The frequency of the resonator and the sensitivity of the accelerometer are tested via printed circuit board (PCB), respectively. The result of the test shows that the frequency of the push-resonator is about 54 530 Hz and the sensitivity of the accelerometer is about 55 Hz/g. The amplification factor of the leverage is calculated more accurately because the coupling of the two stages leverage is considered during derivation of the analysis formula. In addition, the novel differential structure of the accelerometer can greatly improve the sensitivity of the accelerometers. Copyright © 2011 Chinese Journal of Mechanical Engineering. Source


Su C.,Institute of Electronic Engineering | Fang H.,Beijing Institute of Technology
2nd International Conference on Information Science and Engineering, ICISE2010 - Proceedings | Year: 2010

In order to select the tap number of feedforward filter of a fractionally spaced decision feedback equalizer (FS-DFE), the relationship between the order and the equalization performance was studied. Under the known channel characteristics, in variant signal noise ratio and order of feedforward filter, the optimal tap coefficients of FS-DFE was calculated with given algorithm, then the bit error rate performance was simulated using Monte Carlo method and compared with that of symbol spaced decision feedback equalizer (SS-DFE). Finally a method of how to select the order of FS-DFE feedforward filter based on simulation result was proposed and it could be taken as a reference of FS-DFE engineering design. © 2010 IEEE. Source


Zhang M.,Institute of Electronic Engineering | Zhang M.,Key Laboratory of Electronic Control Technology | Lu Q.-T.,Institute of Electronic Engineering | Lu Q.-T.,Key Laboratory of Electronic Control Technology | Zhu Y.-X.,Tsinghua University
Yingyong Kexue Xuebao/Journal of Applied Sciences | Year: 2015

A blind recognition method of self-synchronous scrambler based on the linear block code with unbiased information source is proposed. Different run characteristics of the linear block code and random sequence are analyzed, leading to the conclusion that the run feature of correctly extracted scrambler sequence differs from that of the wrong one. A polynomial of the scrambler is determined with maximum value search in all possible Euclidean distances between the run ratios of extracted and random sequences. Experiments and simulation results show correctness of the theoretical analysis. Blind recognition of self-synchronous scrambler after the linear block code with unbiased information source can be realized, useful in engineering application. ©, 2015, Press of Shanghai Scientific and Technical Publishers. All right reserved. Source


Yuan L.,Shandong Institute of Business and Technology | Huilian C.,Institute of Electronic Engineering | Hui F.,Shandong Institute of Business and Technology | Da Y.,Shandong Institute of Business and Technology | And 2 more authors.
International Conference on Signal Processing Proceedings, ICSP | Year: 2010

Three-dimensional single-input-multiple-output synthetic aperture radar (SIMO-SAR) imaging method is proposed in this paper based on Capon adaptive beam-forming technology, and we have designed the downward-looking geometry architecture and signal echo model of the imaging system. Imaging algorithm is derived from the model and simulated. The advantages of three-dimensional imaging with SIMO-SAR are shown by the simulation results that it can get the height information of the targets besides the azimuth and range information, thus the targets can be located accurately and viewed in a stereogram. Furthermore, the algorithm can give better three-dimensional resolution. © 2010 IEEE. Source


Su C.,Institute of Electronic Engineering | Fang H.,Beijing Institute of Technology
2nd International Conference on Information Engineering and Computer Science - Proceedings, ICIECS 2010 | Year: 2010

To select the order (tap number) of feedforward filter of a fractionally spaced decision feedback equalizer (FS-DFE), the relationship between the order and the equalization performance was studied. Under the known channel characteristics, in variant signal noise ratio and order of feedforward filter, the optimal tap coefficients of FS-DFE was calculated with given algorithm, then the bit error rate performance was simulated using Monte Carlo method and compared with that of symbol spaced decision feedback equalizer (SS-DFE). Finally a method of how to select the order of FS-DFE feedforward filter based on simulation result was proposed and this method could be taken as a reference of FS-DFE engineering design. ©2010 IEEE. Source

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