Quadrature mirror filter

About: Quadrature mirror filter is a research topic. Over the lifetime, 955 publications have been published within this topic receiving 28900 citations.

Design and Implementation of Efficient Analysis and Synthesis QMF Bank for Multicarrier Cognitive Radio Communication.

Abstract: The present section deals with a new type of technique for designing an efficient two channel Quadrature Mirror Filter Bank with constant phase in frequency. For achieving the Perfect Reconstruction Condition in Filter bank, an attempt has been made to design the low pass prototype filter with its impulse response and frequency response in three regions namely pass band, stop band and transition band region. With the error in terms of Reconstruction and the attenuation in the stop band as seen in the prototype filter response, one can evaluate the performance of the introduced filter with the help of filter coefficients generated in the design examples that affects the quality of filter bank design under the constraints of Near Perfect Reconstruction Conditions.

Quadrature mirror filter

Abstract: The temporal quadrature mirror filter filtering video signals by using a hardmard transform comprises: a first means hardmard transforming the band limitted video signal; a first permuter decimating the output of the first means for encoding; a second permuter interpolating the encoded signal for the inverse hardmard transform; a second means reconstructing the original video signal.

Signal-adapted binary tree-structured paraunitary filter bank design

Abstract: Signal adapted filter bank design that uses energy compaction as the adaptation criterion has been applied in the past to quadrature mirror filter (QMF) banks, as well as to M-channel FIR paraunitary filter banks. This analysis was extended to tree-structured filter banks having signal adapted, FIR QMF banks at each level. It showed that fewer parameter allocations to represent filter coefficients are required for tree structured filter banks with similar energy compaction performance, compared to an equivalent structure filter bank with M channels.

On optimization of broadband beamformer for hearing aid applications

Abstract: This paper considers various wideband signal model optimization techniques and associated performance results using steerable fixed beam microphone array processing for hearing aid applications in free-space and reverberant conditions. We first review and compare various conventional broadband and narrowband array optimization techniques. Then new results on maximum energy criterion broadband array optimization formulated for subband processing are presented. The uniformly spaced subband and the nonuniformly spaced subband using quadrature mirror filter approaches are treated. Then algorithms for implementing the hearing aid's search mode based on direction-of-arrival (DOA) estimation techniques for acoustic signals using subspace methods are discussed. Finally, various simulation results under the maximum energy criterion and DOA estimation for free-space and reverberant conditions are presented to demonstrate the feasibility of the proposed techniques.

Design of Biorthogonal Wavelets Based on Parameterized Filter for the Analysis of X-ray Images

Abstract: The X-ray bone images are extensively used by the medical practitioners to detect the minute fractures as they are painless and economical compared to other image modalities. This paper proposes a parameterized design of biorthogonal wavelet based on the algebraical construction method. In order to assign the characters of biorthogonal wavelet, there are two kinds of parameters which are introduced in construction process. One is scale factor and another one is sign factor. In edge detection, the necessary condition of wavelet design is put forward and two wavelet filers are built. The simulation results show that the parameterized design of biorthogonal wavelet is simple and feasible. The biorthogonal wavelet zbo6.6 performs well in detecting the edges with better quality. The various performance metrics like Ratio of Edge pixels to size of image (REPS), peak signal to noise ratio (PSNR) and computation time are compared for various biorthogonal wavelets.