In this paper, the theory and design of a class of perfectreconstruction (PR) biorthogonal nonuniform cosine-modulated filter banks (CMFB) is proposed. It is based on a recombination or merging structure previously proposed by the authors [ 13. By relaxing the original CMFB and the recombination transmultiplexer (TMUX) to be biorthogonal. nonuniform CMFBs with lower system delay can be obtained...

Recently it has been shown that principal component filter banks (PCFB) are optimum orthonormal filter banks for subband coding for the uniform case in which all decimation ratios are the same. In this paper we present the analogous results for the nonuniform case. In contrast to the uniform case where there is only one PCFB, there are more than one PCFB’s in the nonuniform case. For a fixed se...

The FFT is used widely in signal processing for efficient computation of the Fourier transform (FT) of finitelength signals over a set of uniformly-spaced frequency locations. However, in many applications, one requires nonuniform sampling in the frequency domain, i.e., a nonuniform FT . Several papers have described fast approximations for the nonuniform FT based on interpolating an oversample...

This paper deals with the problem of the Direction Of Arrival (DOA) estimation with nonuniform linear arrays. The proposed method is a combination of the Expectation Maximization (EM) and the ESPRIT methods. The EM algorithm interpolates the nonuniform array to an equivalent uniform array, and then, the application of ESPRIT is possible, in order to estimate the DOA. One of this method noveltie...

In this article, small scale effects on free vibration analysis of non-uniform nanobeams is discussed. Small scale effects are modelled after Eringen’s nonlocal elasticity theory while the non-uniformity is presented by exponentially varying width among the beams length with constant thickness. Analytical solution is achieved for free vibration with different boundary conditions. It is shown th...

A nonuniform SF6 gas flow initial condition has been actualized in the context of shock tube experiment for the Richtmyer-Meshkov instability study. Two kinds of amplitude have been used to design the membrane supports which initially materialize the gaseous interface. The visualizations of air/SF6 sinusoidal interfaces and shock wave propagations in the nonuniform field were obtained by Schlie...

A wavelet approach to the analysis of nonuniform high-speed interconnects with frequency dependent parameters is presented in this paper. The nonuniform interconnects are modeled by the use of nonuniform multiconductor transmission line equations in the frequency domain. Two different methods are proposed here (differential and integral formulation): in both of them the space variable is expand...

Wave, antenna impedance, plasma density, and temperature anisotropy measurements are carried out for a helicon plasma source in nonuniform and uniform static magnetic fields. Strong axial density gradients associated with the nonuniform magnetic fields are observed to affect wave fields, absorption, and source efficiency. The wave field and antenna input impedance measurements are compared with...