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Showing papers on "Quadrature mirror filter published in 2008"


Book
10 Nov 2008
TL;DR: This work focuses on the development of discrete wavelet transforms for convolution and filtering in the time domain and frequency domain, and on the design of filter banks for these transformations.
Abstract: Preface. Acknowledgments. 1. Vector Spaces, Signals, and Images. 1.1 Overview. 1.2 Some common image processing problems. 1.3 Signals and images. 1.4 Vector space models for signals and images. 1.5 Basic wave forms the analog case. 1.6 Sampling and aliasing. 1.7 Basic wave forms the discrete case. 1.8 Inner product spaces and orthogonality. 1.9 Signal and image digitization. 1.10 Infinitedimensional inner product spaces. 1.11 Matlab project. Exercises. 2. The Discrete Fourier Transform. 2.1 Overview. 2.2 The time domain and frequency domain. 2.3 A motivational example. 2.4 The onedimensional DFT. 2.5 Properties of the DFT. 2.6 The fast Fourier transform. 2.7 The twodimensional DFT. 2.8 Matlab project. Exercises. 3. The discrete cosine transform. 3.1 Motivation for the DCT: compression. 3.2 Initial examples thresholding. 3.3 The discrete cosine transform. 3.4 Properties of the DCT. 3.5 The twodimensional DCT. 3.6 Block transforms. 3.7 JPEG compression. 3.8 Matlab project. Exercises. 4. Convolution and filtering. 4.1 Overview. 4.2 Onedimensional convolution. 4.3 Convolution theorem and filtering. 4.4 2D convolution filtering images. 4.5 Infinite and biinfinite signal models. 4.6 Matlab project. Exercises. 5. Windowing and Localization. 5.1 Overview: Nonlocality of the DFT. 5.2 Localization via windowing. 5.3 Matlab project. Exercises. 6. Filter banks. 6.1 Overview. 6.2 The Haar filter bank. 6.3 The general onstage twochannel filter bank. 6.4 Multistage filter banks. 6.5 Filter banks for finite length signals. 6.6 The 2D discrete wavelet transform and JPEG 2000. 6.7 Filter design. 6.8 Matlab project. 6.9 Alternate Matlab project. Exercises. 7. Wavelets. 7.1 Overview. 7.2 The Haar Basis. 7.3 Haar wavelets versus the Haar filter bank. 7.4 Orthogonal wavelets. 7.5 Biorthogonal wavelets. 7.6 Matlab Project. Exercises. References. Solutions. Index.

98 citations


Book
Siwei Lyu1, Hany Farid1
07 Feb 2008
TL;DR: A set of natural image statistics are described that are built upon two multi-scale image decompositions, the quadrature mirror filter pyramid decomposition and the local angular harmonic decomposition that capture certain statistical regularities of natural images.
Abstract: We describe a set of natural image statistics that are built upon two multi-scale image decompositions, the quadrature mirror filter pyramid decomposition and the local angular harmonic decomposition. These image statistics consist of first- and higher-order statistics that capture certain statistical regularities of natural images. We propose to apply these image statistics, together with classification techniques, to three problems in digital image forensics: (1) differentiating photographic images from computer-generated photorealistic images, (2) generic steganalysis; (3) rebroadcast image detection. We also apply these image statistics to the traditional art authentication for forgery detection and identification of artists in an art work. For each application we show the effectiveness of these image statistics and analyze their sensitivity and robustness.

33 citations


Journal ArticleDOI
TL;DR: This paper presents two peak constrained least-squares quadrature mirror filter (QMF) banks design methods that converge efficiently in all the simulations, and achieve QMF banks with better performances and lower computational complexities than that obtained by other algorithms in literature.

21 citations


Journal ArticleDOI
TL;DR: An algorithm for the efficient gathering of candidate discrete coefficients is developed, based on the trellis-based searching approach, which substantially alleviates the overheads of optimization program, especially when the wordlengths and the number of nonzero digits are large.
Abstract: In this brief, efficient multiplierless design of lattice quadrature mirror filter bank is presented. Previous work by the authors has shown that splitting each lattice stage into cascade of subrotations results in larger stopband attenuation of filter than the conventional direct quantization. This brief extends the work further by exploiting the subrotations which yield more flexible sum of signed powers-of-two quantization. This enables us to find more possible discrete representations, and hence to reduce the quantization error. Also, an algorithm for the efficient gathering of candidate discrete coefficients is developed, based on the trellis-based searching approach. It substantially alleviates the overheads of optimization program, especially when the wordlengths and the number of nonzero digits are large. Several design examples are provided to show that the proposed structure with the candidate gathering algorithm provides improved frequency response.

21 citations


Journal Article
TL;DR: The Third Generation CURRENT CONVEYOR BASED CURRENT-MODE First Order ALL-PASS FILTER and QUADRATURE OSCILLATOR as mentioned in this paper, the first generation of the current confederacy.
Abstract: THIRD GENERATION CURRENT CONVEYOR BASED CURRENT-MODE FIRST ORDER ALL-PASS FILTER AND QUADRATURE OSCILLATOR

20 citations


Journal Article
TL;DR: A new algorithm is presented for the design of near perfect reconstruction quadrature mirror filter bank using the perfect reconstruction condition or magnitude response condition of prototype filter at frequency to adjust the filters coefficients using optimization algorithm.
Abstract: In this paper, various algorithms for designing quadrature mirror filter are reviewed and a new algorithm is presented for the design of near perfect reconstruction quadrature mirror filter bank. In the proposed algorithm, objective function is formulated using the perfect reconstruction condition or magnitude response condition of prototype filter at frequency (ω = 0.5π) in ideal condition. The cutoff frequency is iteratively changed to adjust the filters coefficients using optimization algorithm. The performances of the proposed algorithm are evaluated in term of computation time, reconstruction error and number of iterations. The design examples illustrate that the proposed algorithm is superior in term of peak reconstruction error, computation time, and number of iterations. The proposed algorithm is simple, easy to implement, and linear in nature. Keywords—Aliasing cancellations filter bank, Filter banks, quadrature mirror filter (QMF), subband coding.

19 citations


Journal ArticleDOI
TL;DR: It is shown that the 9/7 wavelet filter bank can be obtained using gain-optimized9/7 filter bank, and is judged inferior both in terms of objective error measurements and informal visual inspections.
Abstract: Maximum regular wavelet filter banks have received much attention in the literature, and it is a general conception that they enjoy some type of optimality for image coding purposes. To investigate this claim, this article focuses on one particular biorthogonal wavelet filter bank, namely, the 2-channel 9/7. As a comparison, we generate all possible 9/7 filter banks with perfect reconstruction and linear phase while having a different number of zeros at z = -1 for both analysis and synthesis lowpass filters. The best performance is obtained when the filter bank has 2/2 zeros at z = -1 for the analysis and synthesis lowpass filters, respectively. The competing wavelet 9/7 filter bank, which has 4/4 zeros at z = -1, is thus judged inferior both in terms of objective error measurements and informal visual inspections. It is further shown that the 9/7 wavelet filter bank can be obtained using gain-optimized 9/7 filter bank.

11 citations


Patent
20 Aug 2008
TL;DR: In this article, a method and an apparatus for decoding and encoding a multi-channel audio signal are provided to reduce operation quantity required to convert the multichannel audio signal into a time index/frequency index signal.
Abstract: A method and an apparatus for decoding and encoding a multi-channel audio signal are provided to reduce operation quantity required to convert the multi-channel audio signal into a time index/frequency index signal in order to extract or apply spatial information from or to the multi-channel audio signal. A signal on a frequency index of a down-mix signal is divided according to a band. The down-mix signal is converted into a QMF(Quadrature Mirror Filter) domain through at least two analysis filters bank having different filter coefficients according to the divided frequency band(40). The converted sub-band signals are up-mixed to a multi-channel signal by using spatial information(50). After that, the up-mixed multi-channel signal is converted into a time domain(60).

9 citations


Journal ArticleDOI
TL;DR: Modifications and extensions are presented of the designs and architectures of wavelet packet based synthesis and analysis pairs of filter bank trees (Sablatash and Lodge in Digital Signal Process 13: 58–92, 2003) that can be used as transmultiplexers that exhibit a number of advantages over the previous designs and address three shortcomings.
Abstract: A review is presented first of the evolution of transmultiplexers since about 1966, in the context of a long progression of theoretical advances and developments leading to recent proposals to fundamentally improve OFDM type systems using principles of perfect reconstruction filter (PRF) banks. The equivalence of transmultiplexers to OFDM type multi-user systems is discussed. The desirable goals for performance and implementation of transmultiplexers or multiband, multiuser communication systems that are addressed and met in this paper using filter bank trees are set down. Then modifications and extensions are presented of the designs and architectures of wavelet packet based synthesis and analysis pairs of filter bank trees (Sablatash and Lodge in Digital Signal Process 13: 58–92, 2003) that can be used as transmultiplexers. These exhibit a number of advantages over the previous designs and address three shortcomings of the designs used to illustrate basic principles in Sablatash and Lodge (Digital Signal Process 13:58–92, 2003). The first of these is the asymmetry of the magnitude frequency responses of the multiplexer channels, which is addressed using a symmetric design for a lowpass and highpass quadrature mirror filter (QMF) pair described herein. The second is the problem of minimizing the total delay of the signal in passing through the analysis and synthesis filter banks. This is addressed using an architecture involving DFT polyphase synthesis filter banks to replace the wideband VSB filters at the roots of the two identical synthesis filter bank trees, but results in the multiplexer having fewer levels. In this way a tradeoff is effected of lower delay and complexity with fewer levels of bandwidth on demand. At the receiver matching DFT polyphase analysis filters and the other matching analysis filters are implemented. The third shortcoming is the difficulty in designing a synchronization scheme if the filters in the synthesis and analysis filter banks have non-linear phase. This is addressed by designing linear phase filters that do not affect the ISI to any significant degree for communication purposes, although exact perfect reconstruction is lost, but greatly ease and improve the design of the synchronization scheme. Relationships of this paper and its advantages over recent research studies and IEEE 802.22 standards proposals using PR filter banks for multi-user systems to greatly improve on OFDM systems are discussed.

9 citations


Proceedings ArticleDOI
12 May 2008
TL;DR: A novel design for a two-channel IIR quadrature-mirror filter (QMF) bank with near-perfect reconstruction (NPR) is presented, and the proposed QMF banks have a lower algorithmic complexity than comparable designs.
Abstract: A novel design for a two-channel IIR quadrature-mirror filter (QMF) bank with near-perfect reconstruction (NPR) is presented. The analysis filter-bank is given by an efficient polyphase network (PPN) implementation based on allpass filters. The arising phase distortions are almost compensated by stable allpass filters, designed via analytical closed-form expressions. In a first design, the remaining aliasing, amplitude and phase distortions become arbitrarily small in dependence of the tolerable system delay and algorithmic complexity, respectively. In a second design, aliasing and amplitude distortions are completely canceled and phase distortions are minimized at the expense of an additional signal delay. The proposed QMF banks have a lower algorithmic complexity than comparable designs.

8 citations


Proceedings ArticleDOI
01 Oct 2008
TL;DR: In this paper, the design, performance and simulation of wavelet based OFDM V-BLAST MIMO system has been discussed, which is based upon orthonormal wavelets bases generated from Haar quadrature mirror filter.
Abstract: In this article, design, performance and simulation of wavelet based OFDM V-BLAST MIMO system has been discussed. Wavelet based OFDM technique is based upon orthonormal wavelets bases generated from Haar quadrature mirror filter (QMF) bank. The BER performance of this system has been observed with three different V-BLAST detection algorithms. The three V-BLAST detection algorithms implemented in this article are: zero forcing (ZF), minimum mean squared error (MMSE) and QR-decomposition based V-BLAST detection algorithms.

Journal ArticleDOI
TL;DR: Three specific rational-coefficient BWFBs with attractive features are obtained by adjusting the parameters and are systematically verified to exhibit performance competitive to several state-of-the-art BW FBs for image compression, and yet require lower computational costs.
Abstract: We had presented a simple technique, which is based on the theory of Diophantine equation, for parametrization of popular biorthogonal wavelet filter banks (BWFBs) having the linear phase and arbitrary multiplicity of vanishing moments (VMs), and constructed a type of parametric BWFBs with one free parameter [15]. Here we generalize this technique to the case of two parameters, and construct a type of parametric BWFBs with two free parameters. The closed-form parameter expressions of the BWFBs are derived, with which any two-parameter family of BWFBs having preassigned VMs can be constructed, and six families, i.e., 9/11, 10/10, 13/11, 10/14, 17/11, and 10/18 families, are considered here. Two parameters provide two degrees of freedom to optimize the resulting BWFBs with respect to other criteria. In particular, in each family, three specific rational-coefficient BWFBs with attractive features are obtained by adjusting the parameters: the first is not only very close to a quadrature mirror filter (QMF) bank, but has optimum coding gain; the second possesses characteristics that are close to the irrational BWFB with maximum VMs by Cohen et al.; and the last which has binary coefficients can realize a multiplication-free discrete wavelet transform. In addition, two BWFBs are systematically verified to exhibit performance competitive to several state-of-the-art BWFBs for image compression, and yet require lower computational costs.

Journal ArticleDOI
TL;DR: In this article, a self-lifting scheme was proposed to construct biorthogonal wavelet transform (WT) in z-domain and in time domain and showed that lifting-based WT is superior to convolution-based one.
Abstract: The authors presents a new lifting scheme, the self-lifting scheme, and prove that self-lifted wavelets based on orthogonal or biorthogonal wavelets remain biorthogonal. In contrast to self-lifting, the existing lifting scheme can be called cross-lifting. Compared with cross-lifting, the self-lifting scheme provides new approaches for constructing biorthogonal wavelets, as well as factorising wavelet filter bank (WFB). For constructing wavelets, the self-lifting-based method updates one part of a wavelet filter by the other part of the same filter and obtains two updated filters in one pass, whereas the cross-lifting based method updates one filter by another filter and obtains one updated filter in one pass. To factorise WFB, self-lifting takes one part of a filter as the factor to decompose the other part of the same filter and obtains two factorised filters in one pass, whereas cross-lifting based one takes one part of a filter as the factor to decompose the corresponding part of the other filter and obtains one factorised filter in one pass. Several examples show how to use self-lifting scheme to produce new wavelets with desirable properties, how to factorise complex WFBs into simple lifting filter banks, how to implement self-lifting-based discrete wavelet transform (WT) in z-domain and in time domain and why lifting-based WT is superior to convolution-based one.

Proceedings ArticleDOI
01 Oct 2008
TL;DR: The proposed technique protects the data quality by applying Linear Predictive Coding-10 and achieves the low bit rate by applying Quadrature Mirror Filter in an attempt to improve the dataquality at low bit rates as well as fast transmission of data.
Abstract: High data quality at low bit rate is an essential goal that people want to achieve. It is necessary to transfer data at low bit rate so that the bandwidth of the medium can be utilized efficiently. In most of the speech coding techniques the goal of low bit rate transfer is achieved but the data quality is affected badly. The proposed technique is an attempt to improve the data quality at low bit rate as well as fast transmission of data. The proposed technique protects the data quality by applying Linear Predictive Coding-10 and achieves the low bit rate by applying Quadrature Mirror Filter. A comprehensive analysis is on the basis of given parameters as size, compression time, Signal to Noise Ratio, power, energy, power in air, energy in air, mean, standard deviation and intensity.

01 Jan 2008
TL;DR: In this article, the authors proposed the perfect reconstruction condition of two channel multirate filter banks in the fractional Fourier domain (FRFD), based on the theorem for FRFD analysis of signal sampling rate conversion and fractional convolution theory.
Abstract: Sub-band coders have been applied widely in the image processing and speech signal processing.Two-channel multirate digital filter banks are the basic components of the tree-structured sub-band coders.This paper proposes the perfect reconstruction condition of two channel multirate filter banks in the fractional Fourier domain(FRFD),based on the theorem for FRFD analysis of signal sampling rate conversion and fractional convolution theory.Then,this paper illustrates that it is possible to design two-channel FIR Quadrature Mirror Filter Banks(QMFB)and Conjugate Quadrature Mirror Filter Banks(CQMFB)through the prototype filters of FIR QMFB and CQMFB in Fourier domain.The proposed theorems in this study advance the generalization of filter banks in FRFD,which are the bases of the applications of FRFT in the practices,such as image processing,speech signal processing,etc.Finally,the effectiveness of the proposed methods is verified by the simulations.

Journal ArticleDOI
TL;DR: The proposed unified framework has the advantages of on-the-fly computation, memory requirement independent of the input signal length, adaptability to varied cascading patterns of filter banks (FBs), and most of all, producing exactly the same subband coefficients as those obtained by the conventional global transform that buffers the whole signal.

Patent
Jung Chi Ho, Sung Ho Young1
06 Aug 2008
TL;DR: In this paper, a method and an apparatus for reproducing audio having an auto volume controlling function are provided to adjust volumes depending on each frequency band in consideration of user input volume and equal loudness curves.
Abstract: A method and an apparatus for reproducing audio having an auto volume controlling function are provided to differently adjust volumes depending on each frequency band in consideration of user input volume and equal loudness curves. An apparatus for reproducing audio having an auto volume controlling function includes a band splitter(110), an audio monitoring unit(120), and a volume controller(130). The band splitter splits a reproduced audio signal according to each frequency band by using a band pass filter or a quadrature mirror filter. The audio monitoring unit calculates energy of the audio signals split on the basis of a user input volume value and audio reproducing information. The volume controller splits the audio signal according to the frequency bands by using the band pass filter and the quadrature mirror filter and differently adjusts amplitudes of the split audio signals according to the frequency bands depending on volume control values generated from the audio monitoring unit.

01 Jan 2008
TL;DR: This thesis solves the lack of a closed-form run-time solution to the nontrivial problem of rotating wavelets, which is fundamental to solving the environment lighting problem, and derives closed- form expressions for linear phase-shifting in the Haar domain for one-dimensional signals, which can be generalized to N- dimensional signals due to separability.
Abstract: In this thesis, we establish the underlying research background necessary for tackling the problem of phase-shifting in the wavelet transform domain. Solving this problem is the key to reducing the redundancy and huge storage requirement in Image-Based Rendering (IBR) applications, which utilize wavelets. Image-based methods for rendering of dynamic glossy objects do not truly scale to all possible frequencies and high sampling rates without trading storage, glossiness, or computational time, while varying both lighting and viewpoint. This is due to the fact that current approaches are limited to precomputed radiance transfer (PRT), which is prohibitively expensive in terms of memory requirements when both lighting and viewpoint variation are required together with high sampling rates for high frequency lighting of glossy material. At the root of the above problem is the lack of a closed-form run-time solution to the nontrivial problem of rotating wavelets, which we solve in this thesis. We specifically target Haar wavelets, which provide the most efficient solution to solving the tripleproduct integral, which in turn is fundamental to solving the environment lighting problem. The problem is divided into three main steps, each of which provides several key theoretical contributions. First, we derive closed-form expressions for linear phase-shifting in the Haar domain for one-dimensional signals, which can be generalized to N-dimensional signals due to separability.

Journal Article
TL;DR: The alias-free condition for the conventional two-channel quadrature mirror filter bank is analyzed using complex arithmetic and a new class of complex quadratures mirror filter banks is proposed.
Abstract: This work consists of three parts. First, the alias-free condition for the conventional two-channel quadrature mirror filter bank is analyzed using complex arithmetic. Second, the approach developed in the first part is applied to the complex quadrature mirror filter bank. Accordingly, the structure is simplified and the theory is easier to follow. Finally, a new class of complex quadrature mirror filter banks is proposed. Interesting properties of this new structure are also discussed. Keywords—Aliasing cancellation, complex signal processing, polyphase realization, quadrature mirror filter banks.

Proceedings Article
01 Oct 2008
TL;DR: In this paper, the application of spectral factorization by using Grobner basis approach to the problem of 2D finite support QMF filter bank design is proposed along with illustrative example.
Abstract: In this paper, the application of spectral factorization by using Grobner basis approach to the problem of 2-D finite support QMF filter bank design is proposed along with illustrative example. Earlier, it has been shown that the Grobner basis can be applied to solve the problem of 2-D factorization and its effectiveness in dealing with polynomial equation system are demonstrated. Despite the fact that there exist many good techniques for designing one dimensional QMF synthesis and analysis filter banks, the two-dimensional counterpart has a major bottleneck due to the generalization of 2-D spectral factorization. The proposed algorithm is the direct generalization of the 1-D QMF filter bank design by spectral factorization. Furthermore, the filter coefficients can be computed in symbolic forms and thus provide a good opportunity for further optimization if additional criteria are given.

Proceedings ArticleDOI
12 May 2008
TL;DR: This paper derives the Haar filter bank for 1-D space signals, based on the recently introduced framework for space signal processing, and shows that it has a similar yet different form compared to the time case.
Abstract: We derive the Haar filter bank for 1-D space signals, based on our recently introduced framework for 1-D space signal processing, termed this way since it is built on a symmetric space shift operation in contrast to the directed time shift operation. The framework includes the proper notions of signal and filter spaces, "z-transform," convolution, and Fourier transform, each of which is different from their time equivalents. In this paper, we extend this framework by deriving the proper notions of a Haar filter bank for space signal processing, and show that it has a similar yet different form compared to the time case. Our derivation also sheds light on the nature of filter banks and makes a case for viewing them as projections on subspaces rather than as based on filters.

Proceedings ArticleDOI
01 Dec 2008
TL;DR: An IEEE 754 single precision floating-point runtime re-configurable architecture to reduce the power consumption of the filter bank in the audio decoder and achieves low powered decoding process without significantly compromising on the accuracy and speed.
Abstract: There is an ever demanding need to develop low power audio devices using MP3 technology. From the profiled results of MP3 algorithm on ARM processors it has been observed that, the synthesis filter bank in the audio decoder consumes maximum power. Hence to reduce the power consumption of the filter bank, we developed an IEEE 754 single precision floating-point runtime re-configurable architecture. The proposed architecture consumes less power at run time as the last 12 bits of the mantissa part of the synthesis filter coefficients are zero most of the time and hence the corresponding multipliers will be switched off. Since the active multipliers during inverse polyphase quadrature mirror filter banks (IPQMF) are less, we are able to achieve low powered decoding process without significantly compromising on the accuracy and speed. We synthesized and simulated the architecture using 0.35 mum process technology under Synopsys environment. A uniform worst case power reduction of 23.7% has been achieved in the frequency range from 1MHz to 20 MHz when all the multipliers are in active state.

Patent
Masahiro Kudo1
31 Jan 2008
TL;DR: In this article, a signal processing apparatus consisting of a first filter on an in-phase signal channel, a second filter on a quadrature signal channel and a plurality of filter stages having each of more than one signal paths crossing each other which connects the first filter and the second filter is described.
Abstract: A signal processing apparatus, comprising: a first filter on an in-phase signal channel; a second filter on a quadrature signal channel; a plurality of filter stages having each of more than one signal paths crossing each other which connects the first filter and the second filter; and at least more than one of the filter stages of more than one of a plurality of the filter stages comprises a switching circuit disconnecting more than one of the signal paths and a correction unit correcting direct current offsets of the first filter and the second filter by using the switching circuit.

Journal ArticleDOI
TL;DR: The result provides a simple way to implement redundant perfect reconstruction filter banks, which constitute tight frames of l2(Zn) when iterated, which is nearly shift-invariant as well as limited-redundancy.
Abstract: It is shown under a divisibility condition the sampling matrix for a filter bank can be replaced without loss of perfect reconstruction. This is the generalization of the common knowledge that removing up/downsampling will not alter perfect reconstruction. The result provides a simple way to implement redundant perfect reconstruction filter banks, which constitute tight frames of l2(Zn) when iterated. As an example, a quincunx-sampled frame is presented, which is nearly shift-invariant as well as limited-redundancy.

01 Jan 2008
TL;DR: In this article, the relationship between QMFB and QMHT was established for systems with perfect reconstruction for a given quadrature mirror filter bank and the filter specifications and the design procedure for the QM HT were investigated.
Abstract: Applying a /2 π frequency shift to the original quadrature mirror filter bank (QMFB), ( ) ( ) 0 0 z H z H z P - = . The related QMHT is obtained by substituting -jz z → into ( ) z P. This work establishes the relationship between QMFB and QMHT for systems with perfect reconstruction. For a given QMFB, filter specifications and the design procedure for the QMHT are investigated.

Patent
Colin L. Perry1
31 Mar 2008
TL;DR: In this paper, the gain and/or phase adjustment of an analog quadrature filter can be fine-tuned by switching one or more resistors coupled to the filter.
Abstract: Methods and apparatus to fine gain and/or phase adjustment of analog quadrature filters are described. In one embodiment, gain and/or phase of an analog quadrature filter may be digitally controlled by switching one or more resistors coupled to the quadrature filter. Other embodiments are also described.

Journal ArticleDOI
TL;DR: It is shown, that maximal probability of signal detection is obtained in case of non-zero delay time of received signal, which depends on filter bandwidth.
Abstract: In this paper we consider wideband signal against noise receiving by quadrature correlation receiver with input band-pass filter. We obtain analytical expressions of detection characteristics. We analyzed dependences of correct receiving on delay time, signal-to-noise ratio and input filter bandwidth. It is shown, that maximal probability of signal detection is obtained in case of non-zero delay time of received signal, which depends on filter bandwidth.

01 Jan 2008
TL;DR: An efficient method for the optimal design of filter banks and wavelets based on the lifting structure is presented and simulation results show that the filter banks designed by the proposed method can offer the coding performance improvement compared to Daubechies filters in JPEG-2000.
Abstract: The lifting scheme is an efficient tool to construct second-generation wavelets. It has been used to realize Daubechies wavelet transform in image compression standard JPEG-2000. Daubechies wavelets can provide better image coding performance than discrete cosine transform (DCT) which is used in JPEG because the wavelets can present signal more efficiently than DCT. However, for high compression rate, the details of the decompressed images in JPEG-2000 are degraded. The reason is that Daubechies filters are maximally flat while their frequency selectivity is very poor. In this paper, we present an efficient method for the optimal design of filter banks and wavelets based on the lifting structure. The design problem is expressed as an optimization problem where the frequency selectivity of filters is optimized for a given regularity order. The simulation results show that the filter banks designed by our proposed method can offer the coding performance improvement compared to Daubechies filters in JPEG-2000.