共查询到20条相似文献,搜索用时 31 毫秒
1.
A method is proposed for the exact decomposition of a general multi-dimensional (m-d) rational transfer function in terms of order one, each one of which is a function of only one of the m variables. This method is used for the realization of general, linear m-d filters, with great modularity, and high parallelism. By using known nonsingular matrices, the coefficients of the decomposed filter can be expressed in terms of the coefficients of the given transfer function and the elements of these matrices. An algorithm for the determination of these coefficients is given and a class of matrices is proposed which leads to simple realizations. 相似文献
2.
二维零相位FIR数字滤波器设计的闭式最小二乘解 总被引:1,自引:0,他引:1
本文二维零相位FIR数字滤波器的解析最小二乘设计技术。通过建立频域误差差函数的矩阵形式,并运用与设计问题有关的矩阵的一些性质,得到了滤波器系数的闭式解,使得由给定的频响指标可直接计算滤波器系数,而不必对矩阵进行数值示逆,也不需要基于迭代运算的优化过程。文中给出了滤波器实例,其结果证实了该设计方法的简便性与有效性。 相似文献
3.
A separable-denominator 2-D digital filter (SD-2DDF) can be decomposed into the cascade form of a pair of 1-D digital filters (1DDFs) with different delay elements. Based on this reduced-dimensional decomposition, in this paper, we propose a new technique for designing SD-2DDFs in the spatial domain. The technique determines the coefficient matrices of 1DDFs by nonlinear optimization techniques first, and then a SD-2DDF can be easily synthesized. In addition, since the existent 1-D linear system realization techniques can be used to choose a good starting point for the optimization, extremely accurate design results can be easily achieved. 相似文献
4.
It is well known that IIR digital filters require quite fewer computations,comparedwith FIR filters,in order to meet stringent magnitude specifications when the phase distortioncan be tolerated.An approximately linear phase,however,can be also obtained with the IIRfilter by making use of a technique without increasing the complexity.Based on a certain numberof attenuation zeros in the pass band,a new approach is developed for the design of polyphasewave digital filters with exact magnitude responses and Chebyshev approximation of the desiredphase responses.The minimum number of attenuation zeros is estimated,and some examples areincluded. 相似文献
5.
6.
格型滤波器在数值计算性能和结构的模块化等方面都优于直接型,但实现起来较复杂。本文提出一种实现PIR数字滤波器的简化格型结构,它所需的硬件设备量只有常规格型实现时的一半,与直接型实现时相当。文中给出了从直接型到简化格型的综合算法。并对线性相位FIR数字滤波器的格型综合算法作了简化。用实例演示了本文的主要结论。 相似文献
7.
Aiming at the deviation of pole and zero in filters which caused by the finite word length (FWL) effects,the sensitivity of pole and zero for FIR digital filters to coefficient errors was studied based on the state-space model.Unlike the IIR filter,the system matrix in state-space model of the FIR filter was defective.A set of generalized eigenvectors of defective matrix was introduced to analyze the pole sensitivity and derive the measure expression,and optimal realizations with respect to pole-zero sensitivity for FIR filters were proposed by finding optimal transformation matrices according to the similarity transformation theory.Theoretical analysis and simulation experiments show that the poles of a FIR filter are more sensitive to coefficient errors,and the proposed optimal realizations can reduce the sensitivity. 相似文献
8.
This paper presents architecture design techniques for implementing both single-rate and multirate high-speed finite impulse response (FIR) digital filters, with emphasis on the multirate multistage interpolated FIR (IFIR) digital filters. Well-known techniques to achieve high-speed and low-power applications for the single-rate digital FIR architecture are summarized, followed by the introduction of variable filter order selection, optimal filter decomposition, memory-saving and mirror symmetric filter pairs techniques which offer further gains in both performance and complexity reduction for the multirate multistage digital FIR architecture. A filter design example with TSMC 0.25?µm standard cell for 64-QAM baseband demodulator shows that the area is reduced by 39% for low-complexity application. Moreover, for high-speed application, the chip can operate at 714?MHz. Finally, a designed decimator which is used in the CDMA cellular shows that the area is reduced by 70% as compared with conventional approach. 相似文献
9.
A new method is proposed for designing complex all-pass IIR filters, the all-pass IIR filters with complex coefficients, in this paper. By minimizing the integration of certain square phase error over interested frequencies, an eigenvector of an appropriate real, symmetric and positive-definite matrix is computed to get the filter coefficients. The stability is achieved by specifying properly the desired phase specifications. If an appropriate iterative process is used, equiripple complex all-pass filter design can be obtained. The method is simple and the performance is comparable to the existing methods. Several examples are presented to demonstrate the effectiveness of the approach. 相似文献
10.
Alejandro G. Yepes Francisco D. Freijedo Jesús Doval‐Gandoy Óscar López Sánchez Pablo Fernández‐Comesaña Jano Malvar Álvarez 《ETRI Journal》2010,32(1):33-43
The increasing demand for non‐sinusoidal currents affects the quality of distribution networks. Harmonic detection is a crucial step in the cancellation of those components by active power filters. In this paper, the discrete cosine transform (DCT) is compared with different implementations based on Fourier transforms, demonstrating their equivalences and the advantages provided by the former. We demonstrate that the phase error in the presence of grid frequency deviations and the transient length are reduced by half in comparison to the discrete Fourier transform. A novel algorithm is developed to provide frequency adaptation to the DCT, taking advantage of its good features. The window width is adjusted in real time according to the actual value of the grid fundamental frequency by means of a phase‐locked loop. A technique based on dithering is employed to overcome the limitation caused by the truncation of the window number of samples, so the frequency resolution is enhanced. The theoretical approach is verified by simulated and experimental results. 相似文献
11.
12.
This paper proposes 2-D variable IIR digital filter structures with a small amount of calculations for coefficient update. The proposed realization method uses the 2-D parallel allpass structure derived from the separable denominator 2-D filter as the prototype structure for 2-D variable digital filters. In order to reduce the amount of calculations, all the redundant first-order complex allpass sections are combined by modularization of the variable structure. Furthermore, we can realize a very compact variable structure with a minimal number of first-order complex allpass sections by combining complex allpass sections with their complex conjugate allpass sections. Comparison of the calculation loads of the variable structures is presented to demonstrate that the amount of calculations for coefficient update of the proposed variable structure is far less than that of the original and the modular variable structure. 相似文献
13.
在CDMA2000系统中,信道是经过QPSK四相扩频正交调制传输的,数字中频与模拟中频相比能产生严格的幅相平衡正交信号,处理时能保证有严格的线性相位,为此介绍了CDMA2000系统数字中频调制解调实现的方案,对其中抗混叠滤波器,数字频率合成器的设计方法进行了详细的讨论,最后给出了用基于高密度逻辑门电路可编程集成片编辑器(FPGA Compiler)实现的结果。 相似文献
14.
FIR低通和带通滤波器的关系分析与仿真 总被引:2,自引:1,他引:1
为了避开直接设计带通滤波器的繁琐设计步骤要求,利用低通滤波器与带通滤波器的关系,间接设计带通滤波器是创新之处,即通过设计简单的低通滤波器从而达到设计带通滤波器的要求。介绍了窗函数法FIR数字低通、带通滤波器的设计,给出了低通滤波器与带通滤波器的频率响应函数,并分析了它们之间的关系,得出了相关结论,结合实例,利用Matlab证实了该结论的正确性,为带通滤波器的设计提供了一种新方法。 相似文献
15.
16.
应用现代时间序列分析方法,基于ARMA新息模型、白噪声估值器和观测预报器,对带白色观测噪声的多通道ARMA信号,在线性最小方差最优信息融合准则下,提出了统一的和通用的按矩阵加权、按标量加权和按对角阵加权的多传感器信息融合Wiener滤波器,可统一处理滤波、平滑和预报问题.提出了计算局部估计误差方差和协方差的公式,它们被用于计算最优加权.同单传感器情形相比,可提高滤波精度.一个目标跟踪仿真例子说明了其有效性,且说明了三种加权融合滤波器的精度无显著差异,因而利用按标量加权融合滤波器以轻微的精度损失提供一种快速融合估计算法,便于实时应用. 相似文献
17.
提出一种基于QR分解的小波域图像水印算法,是将水印信息矩阵做QR分解并嵌入到做离散小波变换后的载体图像的两个特殊的区域.首先将原始图像进行归一化处理后做离散小波变换,并计算出嵌入区域的嵌入强度;再将水印按照密钥进行置乱;然后再对置乱后的信息做正交分解,得到两个正交矩阵;分别将这两个正交矩阵使用加性规则自适应地嵌入到小波变换域的低频和对角方向上;最后小波逆变换得到含水印的图像.实验结果证明,本算法具有较好的鲁棒性、安全性和不可见性,特别是抗几何攻击效果尤其明显. 相似文献
18.
一种设计对数FIR数字滤波器的方法 总被引:1,自引:0,他引:1
本文提出了一种设计具有等波纹对数幅度响应的线性相位FIR数字滤波器的方法,该设计方法以多次交换算法为基础。在给定通带与阻带误差比、通带误差和阻带误差三种情况下讨论该设计方法。介绍几个低通对数FIR滤波器的设计例子,来说明该设计方法的效率。 相似文献
19.
在数字滤波器的设计中,为了能够有效地进行抽取滤波,往往采用多级抽取的方法。文中引入一种半带FIR(有限冲激响应)滤波器来实现多级抽取。半带滤波器是一种特殊的低通FIR数字滤波器,它的通带和阻带关于二分之一Nyquist频率对称,因而有近一半的滤波器系数为0,所以用它来实现数字滤波可以大幅度地减少运算量,有利于滤波器的实时实现。半带FIR滤波器主要应用于多速率系统中,可以提高系统的效率。剖析了半带FIR滤波器的原理、性质及实现的方法,给出了基于MATLAB和QuartusⅡ联合的半带FIR滤波器的设计仿真过程,并对结果进行了分析。 相似文献