共查询到20条相似文献,搜索用时 0 毫秒
1.
Efficient hard-wired digital fast-Fourier-transform processor 总被引:1,自引:0,他引:1
A hard-wired dedicated fast-Fourier transform processor is described, which has high speed, low power consumption, small size and low cost. The technique is applicable to any size of transform, and could readily be adapted to employ improved components or a more efficient control algorithm. 相似文献
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《Electronics letters》1969,5(15):330-331
A technique is described by which the computing time required for the fast-Fourier-transform algorithm can be reduced at the expense of frequency resolution, with no reduction in accuracy. 相似文献
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Yonghong Zeng Xiaomei Li 《Signal Processing, IEEE Transactions on》1999,47(7):2050-2053
The multidimensional (MD) polynomial transform is used to convert the MD W transform (MDDWT) into a series of one-dimensional (1-D) W transforms (DWTs). Thus, a new polynomial transform algorithm for the MDDWT is obtained. The algorithm needs no operations on complex data. The number of multiplications for computing an r-dimensional DWT is only 1 times that of the commonly used row-column method. The number of additions is also reduced considerably 相似文献
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Many algorithms have been proposed for multidimensional frequency estimation from a single snapshot or multiple snapshots of data mixture. Most of these algorithms fail when one or more identical frequencies are found in certain dimensions. In this paper, a multidimensional frequency estimation technique from a single datum snapshot is proposed. It applies LU decomposition (Gaussian Elimination) on an eigenvector-based algorithm for multidimensional frequency estimation. This proposed technique is simulated using a MATLAB code. The average root mean square error (RMSE) is investigated as a performance measure of the proposed technique. A comparison between original eigenvector-based (traditional) and the proposed techniques is introduced. The simulation results show that the RMSE of the proposed technique is less than the original one, and it has a more efficient solution for an identical frequency case but at the expense of complexity. 相似文献
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In this paper, we present an index permutation-based fast algorithm for the multidimensional discrete Hartley transform (MD-DHT). By reordering the MD-DHT input sequence, we first convert the MD-DHT into a multiple sum that contains a number of one-dimensional discrete W transforms (1D-DWTs). We then use a combination of the 1D-DWTs and the multidimensional polynomial transform to compute the multiple sum. It is shown that the number of multiplications and additions required for the proposed algorithm are approximately 1/m and 2m+1/3m times that of the commonly used row-column DHT method, respectively. The developed algorithm is also simple in structure and easy to realize in programming. 相似文献
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The BIFORE transform is generalised to r dimensions. The corresponding power spectrum consists of ?i = 1r(1+ki) spectral points (Nt = 2ki), which are invariant under cyclic shifts of the r-dimensional input data. A physical interpretation of the BIFORE power spectrum is presented. 相似文献
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The bilinear transformation is extended to transform multi-variable polynomials, using discrete convolution and the Kronecker product. This approach is very simple, easy for computer implementation, and useful in complex curve fitting and stability studies of discrete systems and the design of digital filters etc. 相似文献
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Multidimensional spectral estimation 总被引:1,自引:0,他引:1
《Proceedings of the IEEE. Institute of Electrical and Electronics Engineers》1982,70(9):1029-1039
Methods of multidimensional power spectral estimation are reviewed. Seven types of estimators are discussed: Fourier, separable, data extension, MLM, MEM, AR, and Pisarenko estimators. Particular emphasis is given to MEM where current research is quite active. Theoretical developments are reviewed and computational algorithms are discussed. 相似文献
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Havlicek Joseph P. Harding David S. Bovik Alan C. 《Multidimensional Systems and Signal Processing》1998,9(4):391-398
In this brief paper, we extend the notion of multicomponent signal into multiple dimensions. A definition for multidimensional instantaneous bandwidth is presented and used to develop criteria for determining the multicomponent nature of a signal. We demonstrate application of the criteria by testing the validity of a multicomponent interpretation for a complicated nonstationary texture image. 相似文献
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本文首先通过引进一种序列的重排技术将m(m2) 维离散Fourier变换 (m-D DFT)转化为一系列的一维广义离散Fourier变换(GDFT)的多重和.然后引入一维离散W变换(DWT)以及多维多项式变换(MD-PT)计算该多重和以减少冗余的算术运算,从而得到了高效的多维DFT算法,该算法与常用的行-列DFT算法相比,乘法仅约为行-列法的1/2m,而加法仅约为行-列法的(2m+1)/4m.对于2维DFT的计算,本文方法同单纯的多项式变换方法相比,乘法与加法分别减少50%与40%左右.另外,本文算法计算结构简单,易于编程实现,通过数值实验验证了本文算法的高效性. 相似文献
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Multidimensional spherical coordinates quantization 总被引:1,自引:0,他引:1
《IEEE transactions on information theory / Professional Technical Group on Information Theory》1983,29(4):570-576
Several investigators have considered polar coordinates quantization of a circularly symmetric source; in particular, the independent bivariate Gaussian source. Their schemes quantize the polar coordinates independently in an attempt to reduce the mean-square error below that of an analogous rectangular coordinates quantizer yet retain an implementation simpler than that of the optimal bivariate quantizer. The design of a spherical coordinates quantizer ink dimensions withk>2(k=2 matches published results) is considered. Examples are presented along with comparisons to the rectangular (one-dimensional) and optimal schemes. 相似文献
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Pattichis M.S. Bovik A.C. Havlicek J.W. Sidiropoulos N.D. 《IEEE transactions on image processing》2001,10(3):448-464
The present a novel class of multidimensional orthogonal FM transforms. The analysis suggests a novel signal-adaptive FM transform possessing interesting energy compaction properties. We show that the proposed signal-adaptive FM transform produces point spectra for multidimensional signals with uniformly distributed samples. This suggests that the proposed transform is suitable for energy compaction and subsequent coding of broadband signals and images that locally exhibit significant level diversity. We illustrate these concepts with simulation experiments. 相似文献
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《IEEE transactions on information theory / Professional Technical Group on Information Theory》2009,55(3):961-976
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New methods that yield covert fluorescent images are of significant interest for applications in anti‐counterfeit technology. Printing methods that offer access to spatially controlled fluorescence intensity are needed in order to accurately reproduce unique and complex images. Herein, the use of photoreactive inks containing 9,9′‐bis(anthracene)sulfoxide (AnSO) to create complex images with spatially controlled fluorescence intensity is presented. Under UV irradiation, the SO‐bridge between anthracene units in AnSO is extruded to yield the highly luminescent molecule 9,9′‐bianthryl (BA) in quantitative yields. The irreversible formation of BA is leveraged to create multidimensional fluorescent security features that can be patterned using light and easily interpreted using the CCD camera of a mobile phone. 相似文献
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In this paper, we review our recent work using the nonequilibrium Green's function method to model nanotransistors. After presenting a motivation for the need of quantum mechanical modeling, an account of the equations and implementation is given for both 1-D and 2-D modeling. Examples are given to highlight the use of the developed models. Finally, possible future directions in quantum mechanical modeling of transport in nanotransistors are highlighted along with computational challenges. 相似文献
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Lev-Ari H. Parker S.R. Kailath T. 《IEEE transactions on information theory / Professional Technical Group on Information Theory》1989,35(3):497-508
A universal characterization of maximum-entropy covariances for multidimensional signals is presented. It is shown that the maximum-entropy extension of an arbitrary partial covariance of a nonstationary multidimensional signal always has a banded inverse, i.e the inverse is sparse and has the same support as the given partial covariance. A dual formulation of the problem that makes it possible to approximate maximum-entropy extensions with models selected from suitably constrained model sets is introduced. It is proved that the best approximation in terms of multidimensional recursible autoregressive models can be determined by solving a set of linear equations. A simple graph-theoretic criterion is introduced to characterize those partial covariances whose maximum-entropy extension coincides with its autoregressive approximation, as in the conventional (one-dimensional stationary) maximum-entropy problem 相似文献