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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
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Book ChapterDOI
01 Jan 2023
TL;DR: In this article , a population-based meta-heuristics differential search optimization algorithm was used to obtain the optimal filter coefficients for the filter bank's low-pass prototype filter, which was obtained by optimizing the objective function, which is a weighted sum of mean square pass-band error, mean square stopband error and ripple measure.
Abstract: To design a perfect reconstruction, quadrature mirror filter is an area of concern because of its usefulness in several digital signal processing applications. Their performance is measured in terms of ripple measure (amplitude distortion), stop-band error, and pass-band error for perfect reconstruction. In this manuscript, perfect reconstruction is obtained by optimizing the objective function, which is a weighted sum of mean-square pass-band error, mean-square stop-band error, and ripple measure. Using a population-based meta-heuristics differential search optimization algorithm, the objective function is optimized to obtain the optimal filter coefficients for the filter bank’s low pass prototype filter. The suggested algorithm results have compared to previously report evolutionary optimization algorithms. The performance attributes have been significantly improved over previously published filter bank design methodologies.
Journal ArticleDOI
Abstract: For pulse radars, coherent moving target indication processes and discrete Fourier transform-based Doppler filter banks are used to separate moving targets from stationary objects and clutter. These processes utilize the Doppler frequency shift of the moving target. Because the moving target indication processes and Doppler filter bank processes are performed with the pulse repetition period as a unit, several pulses are required to obtain output from the filter bank. If the search radar considered here uses an electronically scanned antenna, the fact that several pulses are required for one steered beam means that search capability is limited (e.g., the searchable region is narrowed). A method is proposed here that uses the quadrature mirror filter with a range cell as the process unit for the Doppler filter process for high-speed target Doppler separation to reduce the number of pulses required for each beam. The quadrature mirror filter is a filter that performs the orthogonal wavelet transform. This original signal can be separated without wasting information in the time-frequency domain. Long transmitted pulses are used in computer simulations to show that the number of pulses needed in the Doppler filter bank can be reduced using this method.
01 Jan 2006
TL;DR: This paper presents abinational architecture based onrete Fourier Transform filter bank and Quadrature Mirror filter bank trees for realizing areconfigurable lowcomplexity high-speed channelizer.
Abstract: Theflexibility ofasoftware-defined radio (SDR)depends onitscapability tooperate inmulti-standard wireless communication environments. Themostcomputationally intensive part ofthedigital front endofanSDRreceiver is thechannelizer, whichextracts multiple narrowband signalsfromawideband input signal. Thecompatibility of thechannnelizer withdifferent communications standard isguaranteed byitsreconfigurabilit y. Low powerand high-speed arethetwoother desirable characteristics ofa channelizer. Thispaper presents acombinational architecturebased onDiscrete Fourier Transform filter bankand Quadrature Mirror filter banktrees forrealizing areconfigurable lowcomplexity high-speed channelizer. Our hybrid channelizer hasanadditional complexity of38% overthequadrature mirror filter bank, butthedelay ofthe former isreduced by94%whencompared tothelatter. Thustheproposed channelizer architecture offers abetter trade-off between thecomplexity anddelay.
Patent
21 Apr 2005
TL;DR: In this paper, a warped processing module modifies a spectral content of a digital audio signal with a set of gains for a plurality of non-linearly-scaled frequency bands determined by a warping factor lambda of a warped delay line.
Abstract: This invention describes a method for adjusting loudness and spectral content of digital audio signals in a real-time using warped spectral filtering. A warped processing module modifies a spectral content of a digital audio signal with a set of gains for a plurality of non-linearly-scaled frequency bands determined by a warping factor lambda of a warped delay line. Warped delay line signals, generated by the warped delay line, are processed by a warped filter block containing multiple warped finite impulse response filters, e.g., Mth band filters, using individual warped spectral filtering in said plurality of the non-linearly-scaled frequency bands, which is followed by a conventional processing by a dynamic range control/equalization block. The present invention describes another innovation, that is embedding the warped processing module in a two-channel quadrature mirror filter (QMF) bank for improving processing efficiency at high sample rates.
Proceedings ArticleDOI
24 Sep 1990
TL;DR: Experimental results show that the median filter demonstrated the best noise-removing and edge-preserving capabilities, speed of operation, and ease of implementation for both small- and large-size Chinese characters.
Abstract: A facsimile (fax) signal processing system designed for filtering documents with printed Chinese characters is described. Filtering algorithms are applied to remove noise corrupting the image scanned by the fax machine and to preserve the edges. A total of six filtering algorithms have been chosen for investigation, namely, weighted average filter, separable median filter, median with checking filter, Lee's filter, gradient inverse filter and rotating variance filter. Documents containing Chinese characters are scanned and then stored in the RAM of a personal computer. Random noise is then added, and filtering performed. Experimental results show that all of the six algorithms are capable of removing some of the noise. However, the median filter demonstrated the best noise-removing and edge-preserving capabilities, speed of operation, and ease of implementation for both small- and large-size Chinese characters. >
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Performance
Metrics
No. of papers in the topic in previous years
YearPapers
20231
20227
20214
20203
20197
201812