A new variable step-size algorithm for a second-order lattice form structure adaptive infinite impulse response （IIR） notch filter to detection and estimation frequency of sinusoids in Gaussian noises is proposed. U...A new variable step-size algorithm for a second-order lattice form structure adaptive infinite impulse response （IIR） notch filter to detection and estimation frequency of sinusoids in Gaussian noises is proposed. Utilizing least square kurtosis of output signals as a cost function, the new gradient-based algorithm to update frequency of the adaptive IIR notch filter and the new variable step-size algorithm are given. The computer simulation results show that the proposed algorithm has better ability in suppressing colored Gaussian noises and better accuracy in estimating parameters at low SNR than previous algorithms.展开更多
In this paper,a new design method for digital infinite impulse response(IIR)filters with nearly linear-phase response is presented using fractional derivative constraints(FDCs).In the proposed method,design problem of...In this paper,a new design method for digital infinite impulse response(IIR)filters with nearly linear-phase response is presented using fractional derivative constraints(FDCs).In the proposed method,design problem of an IIR frlter is constructed as the minimization of phase error between the desired and designed phase response of an allpass filter(APF)such that the designed lowpass filter(LPF)or highpass frlter(HPF)yields less passband(ep),and stopband errors(es)with optimal stopband attenuation(As).In order to have accurate passband(pb)response,FDCs are imposed on appropriate reference frequency,where the optimality of these FDCs are ensured by using a new greedy based sorting mechanism.The simulated results reflect the efficiency of the proposed method in term of improved passband response along with better transition width.However,small reduction in^is observed within the allowable limit,when compared to noin-fractional design approach,but the designed filter remains immune to wordlength(WL)effect.展开更多
To design approximately linear-phase complex coefficient finite impulse response （FIR） digital filters with arbitrary magnitude and group delay responses, a novel neural network approach is studied. The approach is ...To design approximately linear-phase complex coefficient finite impulse response （FIR） digital filters with arbitrary magnitude and group delay responses, a novel neural network approach is studied. The approach is based on a batch back-propagation neural network algorithm by directly minimizing the real magnitude error and phase error from the linear-phase to obtain the filter＇s coefficients. The approach can deal with both the real and complex coefficient FIR digital filters design problems. The main advantage of the proposed design method is the significant reduction in the group delay error. The effectiveness of the proposed method is illustrated with two optimal design examples.展开更多
A prototype IIR bandpass filter is derived from an analog bandpass filter using bilinear transformation. The formulas relating the IIR bandpass filter's coefficients with its centre frequency and bandwidth are obt...A prototype IIR bandpass filter is derived from an analog bandpass filter using bilinear transformation. The formulas relating the IIR bandpass filter's coefficients with its centre frequency and bandwidth are obtained. Using N sections of such filters, a cascade IIR bandpass filter is constructed. Based on given specifications and the formulas, the parameter N and the bandwidth of prototype filter can be obtained, and the required cascade IIR bandpass filter is obtained. The filter has a small set of coefficients with a simple structure, therefore is easy to design. The described approach is especially suitable for hardware implementation.展开更多
In this paper, the analysis method of stochastic response of piled offshore platform excited by stationary filtered white noise is presented. With this method, the strong ground motion is considered as three direction...In this paper, the analysis method of stochastic response of piled offshore platform excited by stationary filtered white noise is presented. With this method, the strong ground motion is considered as three direction stationary filtered white noise process, the theoretic solutions of three special integration equations are derived with the residue theorem, and the expression of response nodal displacements and member forces of offshore platform excited by the stationary filtered white noise is put forward. The stochastic response of a piled offshore platform excited by the stationary filtered white noise, which is located 114.3 m in water depth, is computed. The results are compared with those obtained with the response spectrum analysis method and the stationary white noise model analysis method, and the corresponding conclusion is drawn.展开更多
This paper develops a new hyperstable adaptive algorithm which can be used inthe multichannel ⅡR conflguration and/or the high-order ⅡR or zero-pole configuration for jointprocess estimation.
All digital implementation of receiver is a main topic on digital communication recently. The design of interpolation filter is one of the important problems for all digital implementation of receiver. In this paper, ...All digital implementation of receiver is a main topic on digital communication recently. The design of interpolation filter is one of the important problems for all digital implementation of receiver. In this paper, for full response linear modulation signal, a interpolation criterion is proposed. An interpolation formula is presented on bandwidth-limited transmission signal. For example, using the raised cosine roll off function as the system pulse response, the feasibility and effectiveness on the interpolation formula are certified by theoretical and numerical analysis. The computer simulation result on 16-QAM signal is given.展开更多
The filter proposed in this paper is expected to reduce noise whose frequency is lower than higher order harmonics of real signals.It is based on the distributive characteristics of noise,and uses analog circuits to s...The filter proposed in this paper is expected to reduce noise whose frequency is lower than higher order harmonics of real signals.It is based on the distributive characteristics of noise,and uses analog circuits to select the high peak and low peak of the input signal and applies their average in order to reduce random noise.So it has no cutoff frequency and higher order harmonics of real signals are remained.As a result,it gives an instant response to changes in input signals and retains the integrity of real signals.Furthermore,it has only a small phase delay.The simulation results of slew rate,phase delay and spectral analysis under MULTISIM indicate that the quick response noise filter achieves a high slew rate of 472 V/ms and the phase shift is nearly zero.By having it used in a color tester design,it is also demonstrated that the proposed filter effectively reduces noise and remains signal integrity.With the filter 's help,the relative standard deviation of the spectrograph decreases from 1% to 0.22%,indicating better stability.展开更多
Due to low parameter sensitivity for balanced realiza- tions, balanced structure becomes a good candidate for an statespace adaptive infinite impluse response （IIR） filter. Here, using coefficients of the transfer f...Due to low parameter sensitivity for balanced realiza- tions, balanced structure becomes a good candidate for an statespace adaptive infinite impluse response （IIR） filter. Here, using coefficients of the transfer function as the adaptive filtering parameters, a balanced adaptive IIR filtering algorithm is proposed for output-error minimization. The algorithm in the internally balanced realization guarantees that the adaptive IIR filter always minimizes the ratio of maximum-to-minimum eigenvalue of the Grammian matrices at the each iteration. Simulation results are provided to corroborate the proposed algorithm.展开更多
This paper presents the design of Optimal Infinite-Impulse Response (IIR) digital filters using Genetic Algorithm (GA). IIR filter is essentially a digital filter with Recursive responses. Since the error surface of d...This paper presents the design of Optimal Infinite-Impulse Response (IIR) digital filters using Genetic Algorithm (GA). IIR filter is essentially a digital filter with Recursive responses. Since the error surface of digital IIR filters is generally nonlinear and multimodal, global optimization techniques are required in order to avoid local minima. This paper presents heuristic way for the designing IIR filters. GA is a powerful global optimization algorithm introduced in combinatorial optimization problems. The paper finds the optimum Coefficients of IIR digital filter through GA. Design of Lowpass and High pass IIR digital filter is proposed to provide estimate of transition band. It is found that the calculated values are more optimal than fda tool available for the design of filter in MATLAB. The simulation result of the employed examples shows an improvement on transition band and mean-square-error (MSE). The position of pole-zero is also presented to describe stability and results are compared with Simulated Annealing (SA) method.展开更多
Using Time-Varying AR (TVAR) model and adaptive notch filter is a new method for the non-stationary jammer suppression in Direct Sequence Spread Spectrum (DSSS). The performance of TVAR model for Instantaneous Frequen...Using Time-Varying AR (TVAR) model and adaptive notch filter is a new method for the non-stationary jammer suppression in Direct Sequence Spread Spectrum (DSSS). The performance of TVAR model for Instantaneous Frequency (IF) estimation will be affected by some factors such as basis functions. Focusing on this problem, the optimal basis function of TVAR model for the IF estimation of the LFM signal is obtained in this paper. Besides the depth and width of notching, the phase properties of notch filter affect the Signal-to-Interference plus-Noise Ratio (SINR) of correlation output to the narrowband jammer suppression in DSSS, in response to the problem the closed solution of correlation output SINR improvement has been derived when a single frequency jammer passes through direct IIR notch filter, and its performance has been compared with those of five coefficient FIR filters. Later, a novel method for LFM jammer suppression based on Fourier basis TVAR model and direct IIR notch filter is proposed. The simulation results show the effectiveness of the proposed method.展开更多
Four optimal approaches of high-order finite-impulse response(FIR) digital filters were developed for designing four types filters using neural network algorithms. The solutions were presented as parallel algorithms t...Four optimal approaches of high-order finite-impulse response(FIR) digital filters were developed for designing four types filters using neural network algorithms. The solutions were presented as parallel algorithms to approximate the desired frequency response specification. Therefore, these methods avoid matrix inversion, and make a fast calculation of the filter’s coefficients possible. The convergence theorems of these proposed algorithms were presented and proved to illustrate them stable, and the implementation of these methods was described together with some design guidelines. The simulation results show that the ripples of the designed FIR filters are significantly little in the pass-band and stop-band, and the proposed algorithms are of fast convergence.展开更多
We develop a rapid and convenient experimental method of absolutely calibrating the transmission of an x-ray flatresponse filter. The calibration experiment is performed on a small laser-target facility, and a set of ...We develop a rapid and convenient experimental method of absolutely calibrating the transmission of an x-ray flatresponse filter. The calibration experiment is performed on a small laser-target facility, and a set of high resolution holographic flat-field grating spectrometers is used as a discrimination system of the laser-produced x-ray source. Given that the holographic flat-field grating has a relatively large width, the grating is divided into two regions for use in that direction,where one region has the filter added and the other region does not. The filter transmission is determined by dividing the x-ray signal counts detected when the filter is in the line of sight by those detected when the filter is out of the line of sight.We find that the calibration results of this experiment agree with the calibration results using a synchrotron radiation source,as well as simulation results. Our method is not only highly reliable but also rapid and convenient.展开更多
文摘A new variable step-size algorithm for a second-order lattice form structure adaptive infinite impulse response （IIR） notch filter to detection and estimation frequency of sinusoids in Gaussian noises is proposed. Utilizing least square kurtosis of output signals as a cost function, the new gradient-based algorithm to update frequency of the adaptive IIR notch filter and the new variable step-size algorithm are given. The computer simulation results show that the proposed algorithm has better ability in suppressing colored Gaussian noises and better accuracy in estimating parameters at low SNR than previous algorithms.
文摘In this paper,a new design method for digital infinite impulse response(IIR)filters with nearly linear-phase response is presented using fractional derivative constraints(FDCs).In the proposed method,design problem of an IIR frlter is constructed as the minimization of phase error between the desired and designed phase response of an allpass filter(APF)such that the designed lowpass filter(LPF)or highpass frlter(HPF)yields less passband(ep),and stopband errors(es)with optimal stopband attenuation(As).In order to have accurate passband(pb)response,FDCs are imposed on appropriate reference frequency,where the optimality of these FDCs are ensured by using a new greedy based sorting mechanism.The simulated results reflect the efficiency of the proposed method in term of improved passband response along with better transition width.However,small reduction in^is observed within the allowable limit,when compared to noin-fractional design approach,but the designed filter remains immune to wordlength(WL)effect.
基金supported by the National Natural Science Foundation of China(6087602250677014)+2 种基金the High-Tech Research and Development Program of China(2006AA04A104)the Hunan Provincial Natural Science Foundation of China (06JJ202407JJ5076).
文摘To design approximately linear-phase complex coefficient finite impulse response （FIR） digital filters with arbitrary magnitude and group delay responses, a novel neural network approach is studied. The approach is based on a batch back-propagation neural network algorithm by directly minimizing the real magnitude error and phase error from the linear-phase to obtain the filter＇s coefficients. The approach can deal with both the real and complex coefficient FIR digital filters design problems. The main advantage of the proposed design method is the significant reduction in the group delay error. The effectiveness of the proposed method is illustrated with two optimal design examples.
文摘A prototype IIR bandpass filter is derived from an analog bandpass filter using bilinear transformation. The formulas relating the IIR bandpass filter's coefficients with its centre frequency and bandwidth are obtained. Using N sections of such filters, a cascade IIR bandpass filter is constructed. Based on given specifications and the formulas, the parameter N and the bandwidth of prototype filter can be obtained, and the required cascade IIR bandpass filter is obtained. The filter has a small set of coefficients with a simple structure, therefore is easy to design. The described approach is especially suitable for hardware implementation.
文摘In this paper, the analysis method of stochastic response of piled offshore platform excited by stationary filtered white noise is presented. With this method, the strong ground motion is considered as three direction stationary filtered white noise process, the theoretic solutions of three special integration equations are derived with the residue theorem, and the expression of response nodal displacements and member forces of offshore platform excited by the stationary filtered white noise is put forward. The stochastic response of a piled offshore platform excited by the stationary filtered white noise, which is located 114.3 m in water depth, is computed. The results are compared with those obtained with the response spectrum analysis method and the stationary white noise model analysis method, and the corresponding conclusion is drawn.
文摘This paper develops a new hyperstable adaptive algorithm which can be used inthe multichannel ⅡR conflguration and/or the high-order ⅡR or zero-pole configuration for jointprocess estimation.
文摘All digital implementation of receiver is a main topic on digital communication recently. The design of interpolation filter is one of the important problems for all digital implementation of receiver. In this paper, for full response linear modulation signal, a interpolation criterion is proposed. An interpolation formula is presented on bandwidth-limited transmission signal. For example, using the raised cosine roll off function as the system pulse response, the feasibility and effectiveness on the interpolation formula are certified by theoretical and numerical analysis. The computer simulation result on 16-QAM signal is given.
基金Sponsored by the National High Technology Research and Development Program(Grant No.863-2-5-1-13B)
文摘The filter proposed in this paper is expected to reduce noise whose frequency is lower than higher order harmonics of real signals.It is based on the distributive characteristics of noise,and uses analog circuits to select the high peak and low peak of the input signal and applies their average in order to reduce random noise.So it has no cutoff frequency and higher order harmonics of real signals are remained.As a result,it gives an instant response to changes in input signals and retains the integrity of real signals.Furthermore,it has only a small phase delay.The simulation results of slew rate,phase delay and spectral analysis under MULTISIM indicate that the quick response noise filter achieves a high slew rate of 472 V/ms and the phase shift is nearly zero.By having it used in a color tester design,it is also demonstrated that the proposed filter effectively reduces noise and remains signal integrity.With the filter 's help,the relative standard deviation of the spectrograph decreases from 1% to 0.22%,indicating better stability.
基金supported by the National Natural Science Foundation of China(61201321)the Basic Research Foundation of Northwestern Polytechnical University(JC20100217)
文摘Due to low parameter sensitivity for balanced realiza- tions, balanced structure becomes a good candidate for an statespace adaptive infinite impluse response （IIR） filter. Here, using coefficients of the transfer function as the adaptive filtering parameters, a balanced adaptive IIR filtering algorithm is proposed for output-error minimization. The algorithm in the internally balanced realization guarantees that the adaptive IIR filter always minimizes the ratio of maximum-to-minimum eigenvalue of the Grammian matrices at the each iteration. Simulation results are provided to corroborate the proposed algorithm.
文摘This paper presents the design of Optimal Infinite-Impulse Response (IIR) digital filters using Genetic Algorithm (GA). IIR filter is essentially a digital filter with Recursive responses. Since the error surface of digital IIR filters is generally nonlinear and multimodal, global optimization techniques are required in order to avoid local minima. This paper presents heuristic way for the designing IIR filters. GA is a powerful global optimization algorithm introduced in combinatorial optimization problems. The paper finds the optimum Coefficients of IIR digital filter through GA. Design of Lowpass and High pass IIR digital filter is proposed to provide estimate of transition band. It is found that the calculated values are more optimal than fda tool available for the design of filter in MATLAB. The simulation result of the employed examples shows an improvement on transition band and mean-square-error (MSE). The position of pole-zero is also presented to describe stability and results are compared with Simulated Annealing (SA) method.
基金Supported by the Natural Science Foundation of Hebei Province (F2010000442)
文摘Using Time-Varying AR (TVAR) model and adaptive notch filter is a new method for the non-stationary jammer suppression in Direct Sequence Spread Spectrum (DSSS). The performance of TVAR model for Instantaneous Frequency (IF) estimation will be affected by some factors such as basis functions. Focusing on this problem, the optimal basis function of TVAR model for the IF estimation of the LFM signal is obtained in this paper. Besides the depth and width of notching, the phase properties of notch filter affect the Signal-to-Interference plus-Noise Ratio (SINR) of correlation output to the narrowband jammer suppression in DSSS, in response to the problem the closed solution of correlation output SINR improvement has been derived when a single frequency jammer passes through direct IIR notch filter, and its performance has been compared with those of five coefficient FIR filters. Later, a novel method for LFM jammer suppression based on Fourier basis TVAR model and direct IIR notch filter is proposed. The simulation results show the effectiveness of the proposed method.
基金Project (50677014) supported by the National Natural Science Foundation of China project (20060532002) supported by the Doctoral Special Fund of Ministry of Education, China+1 种基金project (NCET-04-0767) supported by the Program for New Century Excellent Talents in Universityprojects(06JJ2024, 03GKY3115, 04FJ2003, and 05GK2005) supported by the Foundation of Hunan Provincial Science and Technology
文摘Four optimal approaches of high-order finite-impulse response(FIR) digital filters were developed for designing four types filters using neural network algorithms. The solutions were presented as parallel algorithms to approximate the desired frequency response specification. Therefore, these methods avoid matrix inversion, and make a fast calculation of the filter’s coefficients possible. The convergence theorems of these proposed algorithms were presented and proved to illustrate them stable, and the implementation of these methods was described together with some design guidelines. The simulation results show that the ripples of the designed FIR filters are significantly little in the pass-band and stop-band, and the proposed algorithms are of fast convergence.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.11405158 and 11775203)the Presidential Foundation of China Academy of Engineering Physics(Grant No.YZJJLX 2016007)
文摘We develop a rapid and convenient experimental method of absolutely calibrating the transmission of an x-ray flatresponse filter. The calibration experiment is performed on a small laser-target facility, and a set of high resolution holographic flat-field grating spectrometers is used as a discrimination system of the laser-produced x-ray source. Given that the holographic flat-field grating has a relatively large width, the grating is divided into two regions for use in that direction,where one region has the filter added and the other region does not. The filter transmission is determined by dividing the x-ray signal counts detected when the filter is in the line of sight by those detected when the filter is out of the line of sight.We find that the calibration results of this experiment agree with the calibration results using a synchrotron radiation source,as well as simulation results. Our method is not only highly reliable but also rapid and convenient.
