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Computationally efficient systolic architecture for computing the discrete Fourier transform

IEEE TRANSACTIONS ON signal processing 2005年第12期53卷 4640-4651页

作者： Nash, JG Centar Los Angeles CA 90077 USA

A new high-performance systolic architecture for calculating the discrete Fourier transform (DFT) is described which is based on two levels of transform factorization. One level uses an index remapping that converts the direct transform into structured sets of arithmetically simple four-point transforms. Another level adds a row/column decomposition of the DFT. The architecture supports transform lengths that are not powers of two or based on products of coprime numbers. Compared to previous systolic implementations, the architecture is computationally more efficient and uses less hardware. It provides low latency as well as high throughput, and can do both one- and two-dimensional DFTs. An automated computer-aided design tool was used to find latency and throughput optimal designs that matched the target field programmable gate array structure and functionality.

关键词： computation fast algorithms parallel processing architectures systolic and wavefront architectures transforms

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Local signal to noise ratio

Local signal to noise ratio

引用

Conference on advanced signal processing algorithms, architectures, and implementations XVI

作者： Galleani, Lorenzo Cohen, Leon Nelson, Douglas CUNY 695 Pk Ave New York NY 10021 USA US Dept Def Ft George G Meade MD 20755 USA Politecn Torino Dipartimento Elettron I-10129 Turin Italy

ISBN: (纸本)0819463922

We argue that the standard definition of signal to noise ratio may be misleading when the signal or noise are nonstationary. We introduce a new measure that we call local signal to noise ratio (LSNR) which is well suited to take into account nonstationary situations. The advantage of our measure is that it is a local property unlike the standard SNR which is a single number representing the total duration of the signal. We simulated a number of cases to show that our measure is more indicative of the noise and signal level for nonstationary situations.

关键词： signal to Noise Ratio time-frequency white noise

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Wigner equations of motion for classical systems

Wigner equations of motion for classical systems

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Conference on advanced signal processing algorithms, architectures, and implementations X

作者： Galeani, L Cohen, L CUNY New York NY 10021 USA

ISBN: (纸本)0819437611

We present a general procedure for obtaining equations of motion for the Wigner distribution of functions that are governed by ordinary and partial differential equations. For the case of fields we show that in general one must consider Wigner distributions of the four variables, position, momentum, time and frequency. We also show that in general one cannot write an equation of motion for position and momentum however it can be done in some cases, the Schrodinger equation being one such case. Our method leads to an equation of motion for the Schrodinger equation with time dependent potentials in contrast to the result obtained by Wigner and Moyal which was for time independent potentials.

关键词： Ordinary differential equations Partial differential equations Fourier transforms Oscillators Differential equations Acoustics Electromagnetism signal processing Switches

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Information theoretic signal detection on the time-frequency plane

Information theoretic signal detection on the time-frequency...

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Conference on advanced signal processing algorithms architectures and implementations Xiii

作者： Aviyente, S Michigan State Univ E Lansing MI 48824 USA

ISBN: (纸本)0819450782

A comprehensive theory for time-frequency based signal detection has been developed during the past decade. The time-frequency detectors proposed in literature are linear structures operating on the time-frequency representation of the signals and are equivalent to quadratic receivers that are defined in the,time domain. In this paper, an information theoretic approach for signal detection on the time-frequency plane is introduced. In recent years, Renyi entropy has been proposed as an effective measure for quantifying signal complexity on the time-frequency plane and some important properties of this measure have been proven. In this paper, a new approach that uses the entropy functional as the test statistic for signal detection is developed. The minimum error detection algorithm is derived and the performance of this new signal detection method is demonstrated through examples.

关键词： signal detection Time-frequency analysis Detection and tracking algorithms Interference (communication) Sensors Radar Algorithm development Backscatter signal to noise ratio Receivers

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Denoising using time-frequency and image processing methods

Denoising using time-frequency and image processing methods

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Conference on advanced signal processing algorithms, architectures, and implementations IX

作者： Nelson, D Cristóbal, G Kober, V Cakrak, F Loughlin, P Cohen, L US Dept Def Ft Meade MD 20755 USA

ISBN: (纸本)0819432938

We present a number of methods that use image and signed processing techniques for removal of noise from a signal. The basic idea is to first construct a time-frequency density of the noisy signal. The time-frequency density, which is a function of two variables, can then be treated as an "image", thereby enabling use of image processing methods to remove noise and enhance the image. Having obtained an enhanced time-frequency density, one then reconstructs the signal. Various time frequency-densities are used and also a number of image processing methods are investigated. Examples of human speech and whale sounds are given. In addition, new methods are presented for estimation of signal parameters from the time-frequency density.

关键词： Electronic filtering Interference (communication) Fourier transforms Time-frequency analysis Frequency modulation Fermium Transform theory signal processing Optical filters Filtering (signal processing)

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Arrays of randomly spaced sensors 6

Arrays of randomly spaced sensors

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Conference on advanced signal processing algorithms, architectures, and implementations VI

作者： Lorenzelli, F Yao, K UNIV CALIF LOS ANGELES DEPT ELECT ENGNLOS ANGELESCA 90095

ISBN: (纸本)0819422347

This paper considers a class of blind beamforming problems in which the amount of prior information is very limited. The array sensors are placed in unknown locations within a geographical region, and have unknown frequency/spatial response. The sensors communicate synchronously with a main processor unit. The array is illuminated by a source, which may be narrow- or broadband, in near or far field. Additional disturbances may be present, in the form of interferers, possibly correlated or coherent with the main signal, and additive noise. The goal is required to steer beam toward the desired signal. Four schemes are presented, each based on the type of prior available information.

关键词： blind beamforming broadband array processing random array

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PIPELINED ADAPTIVE DFE architectures 4

PIPELINED ADAPTIVE DFE ARCHITECTURES

引用

4TH CONF ON advanced signal processing algorithms, architectures, AND implementations

作者： SHANBHAG, NR PARHI, KK Univ. of Minnesota/Twin Cities (United States)

ISBN: (纸本)0819412767

Fine-grain pipelined adaptive decision-feedback equalizer (ADFE) architectures are developed using the relaxed look-ahead technique. This technique, which is an approximation to the conventional look-ahead computation, maintains functionality of the algorithm rather than the input-output behavior. Thus, it results in substantial hardware savings as compared to either parallel processing or look-ahead techniques. The delay relaxation, delay transfer relaxation, and sum relaxation are introduced for purposes of pipelining. Both the conventional and the predictor form of ADFE have been pipelined. The performance of the pipelined algorithms for the equalization of a magnetic recording channel is studied. It is demonstrated via simulations that, for a byte error rate of 10^-7 or less, speed-ups of up to 8 can be easily achieved with the conventional ADFE. The predictor form of ADFE allows much higher speed-ups (up to 32) for less than 1 dB of SNR degradation.

关键词： signal to noise ratio Magnetism Algorithm development Error analysis Optical filters Digital filtering Finite impulse response filters Nonlinear filtering Parallel processing Transform theory

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Window design for signal-dependent spectrogram using optimal kernel techniques 6

Window design for signal-dependent spectrogram using optimal...

引用

Conference on advanced signal processing algorithms, architectures, and implementations VI

作者： Carson, CC Baraniuk, RG UNIV CALIF BERKELEY DEPT ELECT ENGN & COMP SCIBERKELEYCA 94720

ISBN: (纸本)0819422347

Time-frequency distributions (TFDs) have proven useful in a wide variety of nonstationary signal processing applications. While sophisticated optimal bilinear TFDs have been developed to extract the maximum possible time- frequency information from signals, certain applications dictate simpler linear, running-FFT processing techniques. In this paper, we propose a signal-dependent short-time Fourier transform/spectrogram that enjoys many of the advantages of optimal bilinear TFDs yet retains the simplicity and efficiency of running-FFT processing. In addition, we extend the optimal kernel design problem to linear spaces of signals.

关键词： time-frequency analysis spectrogram Wigner distribution optimal kernel design

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Evolutionary spectrum estimation by deconvolving bilinear time-frequency distributions

Evolutionary spectrum estimation by deconvolving bilinear ti...

引用

SPIE Conference on advanced signal processing algorithms, architectures, and implementations Viii

作者： Emresoy, MK El-Jaroudi, A Univ Pittsburgh Real Time Signal Proc Lab Pittsburgh PA 15261 USA

ISBN: (纸本)0819429163

A deconvolution technique to estimate the Evolutionary Spectrum (ES) of nonstationary signals by deconvolving the blurring effects of the kernel function fi om bilinear time frequency distributions (TFD) is presented. The resulting ES has desirable properties such as positivity, higher resolution, higher concentration in time-frequency. The proposed algorithm is computationally more efficient compared to the recently proposed entropy based deconvolution method. Unlike the entropy method the new algorithm can be adapted to deconvolve TFDs other than the spectrogram.

关键词： evolutionary spectrum bilinear time-frequency distributions deconvolution

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Quartic functions for time-frequency analysis with applications to signal adaptive kernel design

Quartic functions for time-frequency analysis with applicati...

引用

Conference on advanced signal processing - algorithms, architectures, and implementations VII

作者： ONeill, JC Ecole Normale Superieure de Lyon (United States)

ISBN: (纸本)0819425842

In time-frequency analysis, we extend functions of one variable to functions of two variables. The functions of two variables provide information about the signal that is not easily discernible from the functions of one variable. In this paper, we investigate a method for creating quartic functions of three variables and also a quartic function of all four variables. These quartic functions provide a meaningful representation of the signal that goes beyond the well known quadratic functions. The quartic functions are applied to the design of signal-adaptive kernels for Cohen's class and shown to provide improvements over previous methods.

关键词： time-frequency analysis kernel design quartic functions

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