The Experts below are selected from a list of 255 Experts worldwide ranked by ideXlab platform
Tongwen Chen - One of the best experts on this subject based on the ideXlab platform.
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Multirate minimum variance control design and control performance assessment a data driven subspace approach
IEEE Transactions on Control Systems and Technology, 2007Co-Authors: Xiaorui Wang, Biao Huang, Tongwen ChenAbstract:This paper discusses minimum variance control (MVC) design and control performance assessment based on the MVC-benchmark for Multirate Systems. In particular, a dual-rate System with a fast control updating rate and a slow output sampling rate is considered, which is not uncommon in practice. A lifted model is used to analyze the Multirate System in a state-space framework and the lifting technique is applied to derive a subspace equation for Multirate Systems. From the subspace equation, the Multirate MVC law and the algorithm are developed to estimate the Multirate MVC-benchmark variance or performance index. The Multirate optimal controller is calculated from a set of input/output (I/O) open-loop experimental data and, thus, this approach is data-driven since it does not involve an explicit model. In parallel, the presented MVC-benchmark estimation algorithm requires a set of open-loop experimental data and close-loop routine operating data. No explicit models, namely, transfer function matrices, Markov parameters, or interactor matrices, are needed. This is in contrast to traditional control performance assessment algorithms. The proposed methods are illustrated through a simulation example
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On spectral theory of cyclostationary signals in Multirate Systems
IEEE Transactions on Signal Processing, 2005Co-Authors: Jiandong Wang, Tongwen Chen, Biao HuangAbstract:This paper studies two problems in the spectral theory of discrete-time cyclostationary signals: the cyclospectrum representation and the cyclospectrum transformation by linear Multirate Systems. Four types of cyclospectra are presented, and their interrelationships are explored. In the literature, the problem of cyclospectrum transformation by linear Systems was investigated only for some specific configurations and was usually developed with inordinate complexities due to lack of a Systematic approach. A general Multirate System that encompasses most common Systems-linear time-invariant Systems and linear periodically time-varying Systems-is proposed as the unifying framework; more importantly, it also includes many configurations that have not been investigated before, e.g., fractional sample-rate changers with cyclostationary inputs. The blocking technique provides a Systematic solution as it associates a Multirate System with an equivalent linear time-invariant System and cyclostationary signals with stationary signals; thus, the original problem is elegantly converted into a relatively simple one, which is solved in the form of matrix multiplication.
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Optimal filtering for Multirate Systems
IEEE Transactions on Circuits and Systems II: Express Briefs, 2005Co-Authors: Jie Sheng, Tongwen Chen, Sirish L. ShahAbstract:For a Multirate System where the output sampling is slower than the input updating, this brief aims at designing filters for fast state estimation in the H/sub 2/ and H/sub /spl infin// settings. Because of the Multirate nature, linear matrix inequality solutions to the design problems involve a nonconvex constraint, which is numerically tackled by the product reduction algorithm. Finally, a design example is given and the effectiveness of the approach is illustrated.
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Representations of linear periodically time-varying and Multirate Systems
IEEE Transactions on Signal Processing, 2002Co-Authors: A.s. Mehr, Tongwen ChenAbstract:The linear switched time-varying (LSTV), polyphase (blocked), and alias-component representations of linear periodically time-varying (LPTV) Systems are studied. In particular, alias-components are related to the time-shifted versions of the System. It is shown that in general, a filterbank is equivalent to the cascade connection of two LPTV Systems. By generalizing some of the results of the LSTV representation of LPTV Systems, it is shown that for relatively coprime integers p and m, a p-channel filterbank that has LPTV filters with period m is equivalent to an mp-channel filterbank with LTI filters. The representation of Multirate Systems that have LPTV kernels is discussed next. Due to the presence of the upsampler and downsampler, there are some degrees of freedom in the choice of the kernel. This redundancy is dealt with by choosing from various subclasses so that there is a one-to-one relationship between a Multirate System and its kernel. Then, we find the LPTV kernel that has the least period.
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System identification issues in Multirate Systems
Engineering Solutions for the Next Millennium. 1999 IEEE Canadian Conference on Electrical and Computer Engineering (Cat. No.99TH8411), 1Co-Authors: Sirish L. Shah, Tongwen ChenAbstract:Discusses System identification of Multirate Systems. In particular, the practically useful case of Systems with fast manipulative variable sampling and slow output sampling is considered. The lifting method is used to analyze the Multirate System in a state-space framework. A subspace identification algorithm, is first used to identify the lifted Multirate System. The single-rate model at the faster sampling rate is then extracted from this estimated System, three possible extracting algorithms are also presented. The paper also discusses methods to generate an excitation sequence for identifying Multirate Systems. Simulation and experiment results are included in the paper.
T Nishitani - One of the best experts on this subject based on the ideXlab platform.
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asynchronous Multirate System design for programmable dsps
International Conference on Acoustics Speech and Signal Processing, 1992Co-Authors: I Kuroda, T NishitaniAbstract:A software design System for asynchronous Multirate/multitask processing is developed for a programmable digital signal processor, the NEC77240. A new scheduling method which combines static and dynamic scheduling is proposed. This avoids runtime overheads due to interrupts in asynchronous Multirate System design for digital signal processors (DSPs). The processing delay is avoided by introducing deadline scheduling in the static scheduling. In this System, a block diagram description language is extended to describe a asynchronous multitask processing. By using this scheduling method, asynchronous Multirate processing such as arbitrary sampling ratio rate conversion, asynchronous interface and multimedia applications can be efficiently realized by programmable DSPs. >
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ICASSP - Asynchronous Multirate System design for programmable DSPs
[Proceedings] ICASSP-92: 1992 IEEE International Conference on Acoustics Speech and Signal Processing, 1992Co-Authors: I Kuroda, T NishitaniAbstract:A software design System for asynchronous Multirate/multitask processing is developed for a programmable digital signal processor, the NEC77240. A new scheduling method which combines static and dynamic scheduling is proposed. This avoids runtime overheads due to interrupts in asynchronous Multirate System design for digital signal processors (DSPs). The processing delay is avoided by introducing deadline scheduling in the static scheduling. In this System, a block diagram description language is extended to describe a asynchronous multitask processing. By using this scheduling method, asynchronous Multirate processing such as arbitrary sampling ratio rate conversion, asynchronous interface and multimedia applications can be efficiently realized by programmable DSPs. >
Biao Huang - One of the best experts on this subject based on the ideXlab platform.
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Multirate minimum variance control design and control performance assessment a data driven subspace approach
IEEE Transactions on Control Systems and Technology, 2007Co-Authors: Xiaorui Wang, Biao Huang, Tongwen ChenAbstract:This paper discusses minimum variance control (MVC) design and control performance assessment based on the MVC-benchmark for Multirate Systems. In particular, a dual-rate System with a fast control updating rate and a slow output sampling rate is considered, which is not uncommon in practice. A lifted model is used to analyze the Multirate System in a state-space framework and the lifting technique is applied to derive a subspace equation for Multirate Systems. From the subspace equation, the Multirate MVC law and the algorithm are developed to estimate the Multirate MVC-benchmark variance or performance index. The Multirate optimal controller is calculated from a set of input/output (I/O) open-loop experimental data and, thus, this approach is data-driven since it does not involve an explicit model. In parallel, the presented MVC-benchmark estimation algorithm requires a set of open-loop experimental data and close-loop routine operating data. No explicit models, namely, transfer function matrices, Markov parameters, or interactor matrices, are needed. This is in contrast to traditional control performance assessment algorithms. The proposed methods are illustrated through a simulation example
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On spectral theory of cyclostationary signals in Multirate Systems
IEEE Transactions on Signal Processing, 2005Co-Authors: Jiandong Wang, Tongwen Chen, Biao HuangAbstract:This paper studies two problems in the spectral theory of discrete-time cyclostationary signals: the cyclospectrum representation and the cyclospectrum transformation by linear Multirate Systems. Four types of cyclospectra are presented, and their interrelationships are explored. In the literature, the problem of cyclospectrum transformation by linear Systems was investigated only for some specific configurations and was usually developed with inordinate complexities due to lack of a Systematic approach. A general Multirate System that encompasses most common Systems-linear time-invariant Systems and linear periodically time-varying Systems-is proposed as the unifying framework; more importantly, it also includes many configurations that have not been investigated before, e.g., fractional sample-rate changers with cyclostationary inputs. The blocking technique provides a Systematic solution as it associates a Multirate System with an equivalent linear time-invariant System and cyclostationary signals with stationary signals; thus, the original problem is elegantly converted into a relatively simple one, which is solved in the form of matrix multiplication.
P P Vaidyanathan - One of the best experts on this subject based on the ideXlab platform.
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ACSCC - Role of bandwidth in the quality of inversion of linear Multirate Systems with noise
2012 Conference Record of the Forty Sixth Asilomar Conference on Signals Systems and Computers (ASILOMAR), 2012Co-Authors: P P Vaidyanathan, Piya PalAbstract:A Multirate System called the fractional sampling rate alteration System makes frequent appearance in many signal processing applications including fractionally spaced equalizers (FSE) and in Multirate feedback control. In some applications it is necessary to invert this System, as in the example of a zero-forcing FSE. There is usually noise at the input of the inverse, and the noise amplification properties depend crucially on the bandwidth of the original System, as shown in this paper. Even though this effect is qualitatively known in FSE applications, the purpose of this paper is to provide the quantitative theoretical foundations for this effect. It will be shown that if the System has excess bandwidth, then the noise gain can be readily controlled, whereas unbounded noise amplification can result if there is no excess bandwidth.
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discrete probability density estimation using Multirate dsp models
International Conference on Acoustics Speech and Signal Processing, 2003Co-Authors: P P Vaidyanathan, Byungjun YoonAbstract:We propose a model based approach for estimation of probability mass functions for discrete random variables. The model is based on tools from Multirate signal processing. Similar in principle to the kernel based methods, the approach takes advantage of well-known results from Multirate signal processing theory. Similarities to and differences from wavelet based approaches are also indicated where appropriate. In the final form, the probability estimates are obtained by filtering the square root of the histogram through a Multirate System whose components are biorthogonal partners of each other.
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Effects of Multirate Systems on the Statistical Properties of Random Signals
IEEE Transactions on Signal Processing, 1993Co-Authors: V. Sathe, P P VaidyanathanAbstract:In Multirate digital signal processing, we often encounter time-varying linear Systems such as decimators, interpolators, and modulators. In many applications, these building blocks are interconnected with linear filters to form more complicated Systems. It is often necessary to understand the way in which the statistical behavior of a signal changes as it passes through such Systems. While some issues in this context have an obvious answer, the analysis becomes more involved with complicated interconnections. For example, consider this question: if we pass a cyclostationary signal with period K through a fractional sampling rate-changing device (implemented with an interpolator, a nonideal low-pass filter and a decimator), what can we say about the statistical properties of the output? How does the behavior change if the filter is replaced by an ideal low-pass filter? In this paper, we answer questions of this nature. As an application, we consider a new adaptive filtering structure, which is well suited for the identification of band-limited channels. This structure exploits the band-limited nature of the channel, and embeds the adaptive filter into a Multirate System. The advantages are that the adaptive filter has a smaller length, and the adaptation as well as the filtering are performed at a lower rate. Using the theory developed in this paper, we show that a matrix adaptive filter (dimension determined by the decimator and interpolator) gives better performance in terms of lower error energy at convergence than a traditional adaptive filter. Even though matrix adaptive filters are, in general, computationally more expensive, they offer a performance bound that can be used as a yardstick to judge more practical "scalar Multirate adaptation" schemes.
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ICASSP - Commutativity of D-dimensional decimation and expansion matrices, and application to rational decimation Systems
[Proceedings] ICASSP-92: 1992 IEEE International Conference on Acoustics Speech and Signal Processing, 1992Co-Authors: T. Chen, P P VaidyanathanAbstract:Multidimensional (MD) Multirate Systems, which find applications in the coding and compression of image and video data, have attracted much attention. The basic building blocks in a MD Multirate System are the decimation matrix M, the expansion matrix L, and MD digital filters. With D denoting the number of dimensions, M and L are D*D nonsingular integer matrices. When these matrices are diagonal, most of the one-dimensional Multirate results can be extended automatically. However, for the nondiagonal case, these extensions are nontrivial. One example of this nature is the commutativity of MD decimation and expansion matrices. Using the concepts of coprimeness and least common right/left multiples of integer matrices, a set of necessary and sufficient conditions is derived for a decimation matrix and an expansion matrix to commute. This commutativity is also used to derive an efficient polyphase implementation of an MD decimation System with rational decimation matrix. >
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Least common right/left multiples of integer matrices and applications to multidimensional Multirate Systems
[Proceedings] 1992 IEEE International Symposium on Circuits and Systems, 1Co-Authors: T. Chen, P P VaidyanathanAbstract:The basic building blocks in a multidimensional (MD) Multirate System are the decimation matrix and the expansion matrix. These matrices are D*D nonsingular integer matrices, where D is the number of dimensions. The authors show that properties of integer matrices, such as greatest common right/left divisors and right/left coprimeness play important roles in MD Multirate Systems. They also introduce the concept of least common right/left multiple of integer matrices and derive many useful properties of them. They illustrate the importance of these by applying them to several issues in MD Multirate signal processing, including interchangeability of decimators and expanders, delay-chain Systems, and periodicity matrices. >
I Kuroda - One of the best experts on this subject based on the ideXlab platform.
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asynchronous Multirate System design for programmable dsps
International Conference on Acoustics Speech and Signal Processing, 1992Co-Authors: I Kuroda, T NishitaniAbstract:A software design System for asynchronous Multirate/multitask processing is developed for a programmable digital signal processor, the NEC77240. A new scheduling method which combines static and dynamic scheduling is proposed. This avoids runtime overheads due to interrupts in asynchronous Multirate System design for digital signal processors (DSPs). The processing delay is avoided by introducing deadline scheduling in the static scheduling. In this System, a block diagram description language is extended to describe a asynchronous multitask processing. By using this scheduling method, asynchronous Multirate processing such as arbitrary sampling ratio rate conversion, asynchronous interface and multimedia applications can be efficiently realized by programmable DSPs. >
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ICASSP - Asynchronous Multirate System design for programmable DSPs
[Proceedings] ICASSP-92: 1992 IEEE International Conference on Acoustics Speech and Signal Processing, 1992Co-Authors: I Kuroda, T NishitaniAbstract:A software design System for asynchronous Multirate/multitask processing is developed for a programmable digital signal processor, the NEC77240. A new scheduling method which combines static and dynamic scheduling is proposed. This avoids runtime overheads due to interrupts in asynchronous Multirate System design for digital signal processors (DSPs). The processing delay is avoided by introducing deadline scheduling in the static scheduling. In this System, a block diagram description language is extended to describe a asynchronous multitask processing. By using this scheduling method, asynchronous Multirate processing such as arbitrary sampling ratio rate conversion, asynchronous interface and multimedia applications can be efficiently realized by programmable DSPs. >
