We review, recent work on defining the time-frequency moments of a signal. Expressions are given for moments dropt(m)drop(omega), and of all orders n, m, in terms of the amplitude and phase of the signal and spectrum....
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ISBN:
(纸本)0819441880
We review, recent work on defining the time-frequency moments of a signal. Expressions are given for moments dropt(m)drop(omega), and of all orders n, m, in terms of the amplitude and phase of the signal and spectrum. Knowing the time-frequency moments is of interest for a variety of reasons. including their potential utility as features for classification of nonstationary signals, and also because from the moments one call construct the time-varying spectral density, or approximate it using a few moments.
We present a method for writing the differential equation for the smoothed Wigner distribution that corresponds to the solution of an ordinary linear differential equation. The method can be applied on an, linear ordi...
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ISBN:
(纸本)0819441880
We present a method for writing the differential equation for the smoothed Wigner distribution that corresponds to the solution of an ordinary linear differential equation. The method can be applied on an, linear ordinary differential equation with constant or time-varying coefficients.
Electron-optical image converters (EOIC) have been known to be useful in recording and investigating highspeed processes, nuclear physics experiments, automatic environmental control, medicine etc. In this paper the c...
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ISBN:
(纸本)0819441880
Electron-optical image converters (EOIC) have been known to be useful in recording and investigating highspeed processes, nuclear physics experiments, automatic environmental control, medicine etc. In this paper the cathode ray tubes with the cathodoluminescent screen having a sufficiently high level of the radiation temporal coherence (particularly on the basis of rare-earth phosphors) are proposed to be utilised as devices for the dynamic data input into the holographic correlator for realisation of TV signal recognition in real time. This approach allows combining both the radiation source and the spatial light modulator functions in one compact device.
The proceedings contains 56 papers from the conference on SPIE: advancedsignalprocessingalgorithms, architectures, and implementations xI. The topics discussed include: modulation frequency and efficient audio codi...
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The proceedings contains 56 papers from the conference on SPIE: advancedsignalprocessingalgorithms, architectures, and implementations xI. The topics discussed include: modulation frequency and efficient audio coding;application of wavelet- and wavelet-packet-transform to human skin data;Wigner distribution and pulse propagation;time-frequency analysis using sidelobe apodization;spectral phase algorithm for detecting and estimating pitch;and minimum entropy approach to denoising time-frequency distributions.
This paper shows the design and the evaluation of on-line arithmetic modules for the most common operators used in DSP applications, using FPGAs as the target technology. The designs are highly optimized for the targe...
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ISBN:
(纸本)0819441880
This paper shows the design and the evaluation of on-line arithmetic modules for the most common operators used in DSP applications, using FPGAs as the target technology. The designs are highly optimized for the target technology and the common range of precision in DSP. The results are based on experimental data collected using CAD tools. All designs are synthesized for the same type of devices (xilinxxC4000) for comparison, avoiding rough estimates of the system performance, and generating a more reliable and detailed comparison of on-line signalprocessing solutions with other 'state of the art' approaches, such as distributed arithmetic. We show that on-line designs have a hard stand for basic DSP applications that use only addition and multiplication. However, we also show that on-line designs are able to overtake other approaches as the applications become more sophisticated, e.g. when data dependencies exist, or when non constant multiplicands restrict the use of other approaches.
Coherent adaptation algorithms are proposed for a beamformer in the WCDMA reverse link. The coherent adaptation algorithm improves the convergence speed by constraining the desired signal component of the filtered out...
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ISBN:
(纸本)0819441880
Coherent adaptation algorithms are proposed for a beamformer in the WCDMA reverse link. The coherent adaptation algorithm improves the convergence speed by constraining the desired signal component of the filtered output to be always coherent in phase with the reference signal at each iteration. With the coherent constraint, the performance of coherent methods is significantly improved. We present the simulation results that show the various desirable characteristics of coherent methods such as a fast convergence speed. insensitiveness to fading parameters over conventional methods.
We present an efficient array processor for downdating the ULVD. The array processor exploits the block structure of the decomposition to determine the effective rank at every step of modification and maintains the ra...
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ISBN:
(纸本)0819441880
We present an efficient array processor for downdating the ULVD. The array processor exploits the block structure of the decomposition to determine the effective rank at every step of modification and maintains the rank-revealing nature of the decomposition throughout the steps by tracking exact quantities of Frobenius norms of all three blocks of the lower triangular factor in the decomposition. Thus. a deflation step that is necessary to compute its numerical rank can be often avoided. This feature of the algorithm is particularly attractive to its array processor implementation because the deflation steps usually require some condition estimation. and most of good condition estimators are not well pipelined.
We describe a fast and efficient algorithm for automatic detection and estimation of the fundamental frequency F0 of a harmonic time-domain signal. The method is based on differentiation of the short time Fourier tran...
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ISBN:
(纸本)0819441880
We describe a fast and efficient algorithm for automatic detection and estimation of the fundamental frequency F0 of a harmonic time-domain signal. The method is based on differentiation of the short time Fourier transform (STFT) phase, which is implemented as a cross-spectral product. In estimating and isolating the fundamental frequency, several enhancement processes are developed and applied to the TF surface to improve the signal quality. We describe the algorithm in detail and demonstrate the processing gain achieved at each step. In addition, we apply the algorithm to human speech to recover the pitch fundamental F0 and report the evaluation of the algorithm's performance on the Western Michigan vowel corpus [3].
Mainly digital images are under sampled. It is the same for SPOT digital image satellite. The very meaning is that the instrument is too much powerful for this sampling. The worth side effect is that artifacts (aliasi...
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ISBN:
(纸本)0819441880
Mainly digital images are under sampled. It is the same for SPOT digital image satellite. The very meaning is that the instrument is too much powerful for this sampling. The worth side effect is that artifacts (aliasing) are introduced in the image, the good side is that images can be improved if the sampling density is increased. In this paper we use images from the two HRVIR instruments onboard SPOT1-4 satellite to multiply by a factor two the density and the resolution of the image.
We address two classical problems relating to harmonic signals. The first of these is the blind recovery of the carrier of a single sideband-AM communication signal, and the second is the isolation and blind estimatio...
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ISBN:
(纸本)0819441880
We address two classical problems relating to harmonic signals. The first of these is the blind recovery of the carrier of a single sideband-AM communication signal, and the second is the isolation and blind estimation of the fundamental of a time-varying harmonic signal. The methods are based on cross-spectra estimated from the short time Fourier transform, a generalization of the Chinese remainder theorem and joint Fourier and autocorrelation representations of the signal spectrum. These tools are developed, and their utility is demonstrated in the solutions of the the two problems. By an additional application of a frequency-lag autocorrelation function, it is demonstrated that the harmonic fundamental can be recovered, even if it is not present in the original spectrum.
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