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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.


Papers
More filters
Journal ArticleDOI
TL;DR: An analytical criterion evaluating the performances of any perfect reconstruction linear transform in the frame of scene adaptive coding is derived, thereafter, used in order to optimize linear multiresolution transforms.
Abstract: Scene adaptive coders are constituted by the cascade of a linear transform, scalar quantization, entropy coding and a buffer controlled by a feedback loop for bit rate regulation. The main contribution of this paper is to derive an analytical criterion evaluating the performances of any perfect reconstruction linear transform in the frame of scene adaptive coding. This criterion is, thereafter, used in order to optimize linear multiresolution transforms. The optimization adapts the filters parameters to the codec features and to the statistics of the 2-D sources; so, the authors call these transforms adapted multiresolution transforms (AMTs). The transforms under study are implemented by a cascade of separable perfect-reconstruction (PR) FIR two-band filter banks that can change at each resolution level. Two types of filter banks are envisaged: the PR orthogonal quadrature mirror filter (QMF) bank, which allows to implement the orthogonal AMT and the PR linear-phase filter (LPF) bank, which implements the biorthogonal AMT. They perform the optimization of the filters in their factorized lattice form, taking the finite length of the multipliers into account. Their criterion also allows them to show the performances achieved by these two linear multiresolution transforms compared to other linear (multiresolution) transforms. >

14 citations

Journal ArticleDOI
TL;DR: The characterization and design of dual-tree filter banks for forming Hilbert transform pairs of wavelet bases are studied and an analytical solution to the sampled-data design problem is obtained for a special case.
Abstract: Characterization and design of dual-tree filter banks for forming Hilbert transform pairs of wavelet bases are studied. The characterization extends the existing results for quadrature mirror filter banks to general prefect reconstruction filter banks that satisfy only a mild technical assumption regarding the ratio of determinants of the two filter banks. We establish equivalent relationships of Hilbert transform pairs on scaling filters, wavelet filters, or scaling functions. The design of scaling filters of a dual filter bank is formulated as a sampled-data Hinfin optimization problem. The wavelet filters are then determined using the relationship on the determinants of the filter banks. We convert the sampled-data problem into an equivalent discrete-time Hinfin control problem, which can be solved by standard Hinfin control theory. An analytical solution to the sampled-data design problem is obtained for a special case. The sampled-data design approach usually gives infinite impulse response filter. In the case where the primal filter bank is of finite impulse response (FIR), we may truncate the impulse responses to get FIR approximations. They also lead to approximate Hilbert transform pairs. Design examples are presented

14 citations

Journal ArticleDOI
01 Dec 2003
TL;DR: In this paper, a wavelet detection scheme based on the MMSE criterion and then made adaptive using the LMS algorithm is theoretically analyzed and software simulated, and the proposed wavelet detector is near-far resistant and shows better BER performance compared with a decorrelator, but with higher computation costs.
Abstract: A novel digital transmission system based on wavelet signalling has been proposed and analysed. The basic system consists of a bank of filters derived using the quadrature constrained least square (QCLS) algorithm and satisfying the perfect reconstructed quadrature mirror filter (PR-QMF) theory. A multicarrier CDMA system is constructed using this technique, where a user's data is spread in the frequency domain and constraints are imposed to ensure channel orthogonality. The system exploits the localisation properties of the wavelets in time and frequency to develop data channels that have compact PSD characteristics and are resilient in an environment exposed to fading. Practical implementation of the wavelet transmission system using a bank of polyphase filters is considered. Simulation results are presented which show the wavelet system can better combat ISI and multiple access interference than an FFT-based multicarrier modulation system when both systems operate in identical fading environments. A wavelet detection scheme based on the MMSE criterion and then made adaptive using the LMS algorithm is theoretically analysed and software simulated. The proposed wavelet detector is near–far resistant and shows better BER performance compared with a decorrelator, but with higher computation costs.

14 citations

Journal ArticleDOI
TL;DR: In this paper, Chebyshev polynomial based fractional order differentiator has been used for filtering operation on an image and pre-processing has been performed by using this filter.
Abstract: . Discrimination between texture edges and geometrical edges is very difficult in low contrast images. Satellite images are low contrast images. It is important to extract the edges that are not clearly visible in case of Satellite images. The present work encompasses a new edge detection algorithm using newly constructed differentiator. Chebyshev polynomial based fractional order differentiator has been used for filtering operation on an image. High pass and Low pass filters are designed with the concept of Quadrature Mirror Filter (QMF). Pre-processing has been performed by using this filter. Sobel edge detection method has been applied on this pre-processed image. The algorithm has been tested with two different satellite images.

14 citations

Journal ArticleDOI
TL;DR: The orthonormal wavelet bases are generated from Haar and Daubechies Quadrature Mirror Filter bank and the BER performance of this system as compared to Fourier based V-BLAST system shows significant improvement.
Abstract: Wavelet based OFDM V-BLAST system design and its simulation results are briefly discussed in this article. The orthonormal wavelet bases are generated from Haar and Daubechies Quadrature Mirror Filter (QMF) bank. The BER performance of this system as compared to Fourier based OFDM V-BLAST system shows significant improvement.

14 citations

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Performance
Metrics
No. of papers in the topic in previous years
YearPapers
20231
20227
20214
20203
20197
201812