An optimal design approach of high order FIR digital filter is developed based on the algorithm of neural networks with cosine basis function . The main idea is to minimize the sum of the square errors between the amp...An optimal design approach of high order FIR digital filter is developed based on the algorithm of neural networks with cosine basis function . The main idea is to minimize the sum of the square errors between the amplitude response of the desired FIR filter and that of the designed by training the weights of neural networks, then obtains the impulse response of FIR digital filter . The convergence theorem of the neural networks algorithm is presented and proved, and the optimal design method is introduced by designing four kinds of FIR digital filters , i.e., low-pass, high-pass, bandpass , and band-stop FIR digital filter. The results of the amplitude responses show that attenuation in stop-bands is more than 60 dB with no ripple and pulse existing in pass-bands, and cutoff frequency of passband and stop-band is easily controlled precisely .The presented optimal design approach of high order FIR digital filter is significantly effective.展开更多
A new approach for the design of two-dimensional （2-D） linear phase FIR digital filters based on a new neural networks algorithm （NNA） is provided. A compact expression for the transfer function of a 2-D linear ph...A new approach for the design of two-dimensional （2-D） linear phase FIR digital filters based on a new neural networks algorithm （NNA） is provided. A compact expression for the transfer function of a 2-D linear phase FIR filter is derived based on its frequency response characteristic, and the NNA, based on minimizing the square-error in the frequency-domain, is established according to the compact expression. To illustrate the stability of the NNA, the convergence theorem is presented and proved. Design examples are also given, and the results show that the ripple is considerably small in passband and stopband, and the NNA-based method is of powerful stability and requires quite little amount of computations.展开更多
This paper presents a new joint optimization method for the design of sharp linear-phase finite-impulse response （FIR） digital filters which are synthesized by using basic and multistage frequency-response-masking ...This paper presents a new joint optimization method for the design of sharp linear-phase finite-impulse response （FIR） digital filters which are synthesized by using basic and multistage frequency-response-masking （FRM） techniques. The method is based on a batch back-propagation neural network algorithm with a variable learning rate mode. We propose the following two-step optimization technique in order to reduce the complexity. At the first step, an initial FRM filter is designed by alternately optimizing the subfilters. At the second step, this solution is then used as a start-up solution to further optimization. The further optimization problem is highly nonlinear with respect to the coefficients of all the subfilters. Therefore, it is decomposed into several linear neural network optimization problems. Some examples from the literature are given, and the results show that the proposed algorithm can design better FRM filters than several existing methods.展开更多
In this paper a novel method to generate high-precision and continuously adjustable digital time-delay by utilizing the linear phase of a FIR filter is presented. The generated time-delay can be continuously changed b...In this paper a novel method to generate high-precision and continuously adjustable digital time-delay by utilizing the linear phase of a FIR filter is presented. The generated time-delay can be continuously changed by adjusting the filter weights. The time-delay is pre cise and valid for wide-band, while the computational load is low. The proposed approach can find applications in wide-band digital beamforming, adaptive delay estimation, temporal analy sis of reflected waveform, etc.. In the paper, the basic principle, design steps and simulation re sults are given. Also shown are some typical practical applications.展开更多
A digital measuring method for power system harmonic impedances is presented.Based on the idea of injecting current to the power system and measuring harmonic impedances directly,a digital receiving set is designed to...A digital measuring method for power system harmonic impedances is presented.Based on the idea of injecting current to the power system and measuring harmonic impedances directly,a digital receiving set is designed to receive harmonic signals from the power system.To obtain the harmonic impedances,the signals are handled by digital filters.Simulation results show that this measuring set fits the requirement of industrial measurement.展开更多
基金This project was supported by the National Natural Science Foundation of China (50277010)Doctoral Special Fund of Ministry of Education (20020532016) and Fund of Outstanding Young Scientist of Hunan University.
文摘An optimal design approach of high order FIR digital filter is developed based on the algorithm of neural networks with cosine basis function . The main idea is to minimize the sum of the square errors between the amplitude response of the desired FIR filter and that of the designed by training the weights of neural networks, then obtains the impulse response of FIR digital filter . The convergence theorem of the neural networks algorithm is presented and proved, and the optimal design method is introduced by designing four kinds of FIR digital filters , i.e., low-pass, high-pass, bandpass , and band-stop FIR digital filter. The results of the amplitude responses show that attenuation in stop-bands is more than 60 dB with no ripple and pulse existing in pass-bands, and cutoff frequency of passband and stop-band is easily controlled precisely .The presented optimal design approach of high order FIR digital filter is significantly effective.
文摘A new approach for the design of two-dimensional （2-D） linear phase FIR digital filters based on a new neural networks algorithm （NNA） is provided. A compact expression for the transfer function of a 2-D linear phase FIR filter is derived based on its frequency response characteristic, and the NNA, based on minimizing the square-error in the frequency-domain, is established according to the compact expression. To illustrate the stability of the NNA, the convergence theorem is presented and proved. Design examples are also given, and the results show that the ripple is considerably small in passband and stopband, and the NNA-based method is of powerful stability and requires quite little amount of computations.
基金the National Natural Science Foundation of China under Grant Nos.50677014 and 60876022the Doctoral Special Fund of Ministry of Education of China under Grant No.20060532002+1 种基金the National High-Tech Research and Development 863 Program of China under Grant No.2006AA04A104the Foundation of Hunan Provincial Natural Science Foundation of China under Grant No.07JJ5076
文摘This paper presents a new joint optimization method for the design of sharp linear-phase finite-impulse response （FIR） digital filters which are synthesized by using basic and multistage frequency-response-masking （FRM） techniques. The method is based on a batch back-propagation neural network algorithm with a variable learning rate mode. We propose the following two-step optimization technique in order to reduce the complexity. At the first step, an initial FRM filter is designed by alternately optimizing the subfilters. At the second step, this solution is then used as a start-up solution to further optimization. The further optimization problem is highly nonlinear with respect to the coefficients of all the subfilters. Therefore, it is decomposed into several linear neural network optimization problems. Some examples from the literature are given, and the results show that the proposed algorithm can design better FRM filters than several existing methods.
文摘In this paper a novel method to generate high-precision and continuously adjustable digital time-delay by utilizing the linear phase of a FIR filter is presented. The generated time-delay can be continuously changed by adjusting the filter weights. The time-delay is pre cise and valid for wide-band, while the computational load is low. The proposed approach can find applications in wide-band digital beamforming, adaptive delay estimation, temporal analy sis of reflected waveform, etc.. In the paper, the basic principle, design steps and simulation re sults are given. Also shown are some typical practical applications.
文摘A digital measuring method for power system harmonic impedances is presented.Based on the idea of injecting current to the power system and measuring harmonic impedances directly,a digital receiving set is designed to receive harmonic signals from the power system.To obtain the harmonic impedances,the signals are handled by digital filters.Simulation results show that this measuring set fits the requirement of industrial measurement.
