The concern here is of retrieving damped harmonics and polynomial phase signals in the presence of additive noise. The damping function is not limited to the exponential model, and in certain cases, the additive noise...
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ISBN:
(纸本)0819416207
The concern here is of retrieving damped harmonics and polynomial phase signals in the presence of additive noise. The damping function is not limited to the exponential model, and in certain cases, the additive noise does not have to be white. Three classes of algorithms are presented, namely DFT based, Kumaresan-Tufts type extensions, and subspace variants including the MUSIC algorithm. Preference should be based on the available data length and frequency separations. In addition, retrieval of self coupled damped harmonics, which may be present when nonlinearities exist in physical systems, is investigated. Simulation examples illustrate main points of the paper.
Speech is metered if the stresses occur at a nearly regular rate. Metered speech is common in poetry, and it can occur naturally in speech, if the speaker is spelling a word or reciting words or numbers from a list. I...
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ISBN:
(纸本)0819445584
Speech is metered if the stresses occur at a nearly regular rate. Metered speech is common in poetry, and it can occur naturally in speech, if the speaker is spelling a word or reciting words or numbers from a list. In radio communications, the CQ request, call sign and other codes are frequently metered. In tactical communications and air traffic control, location, heading and identification codes may be metered. Moreover metering may be expected to survive even in HF communications, which are corrupted by noise, interference and mistuning. For this environment, speech recognition and conventional machine-based methods are not effective. We describe Time-Frequency methods which have been adapted successfully to the problem of mitigation of HF signal conditions and detection of metered speech. These methods are based on modeled time and frequency correlation properties of nearly harmonic functions. We derive these properties and demonstrate a performance gain over conventional correlation and spectral methods. Finally, in addressing the problem of HF single sideband (SSB) communications, the problems of carrier mistuning, interfering signals, such as manual Morse, and fast automatic gain control (AGC) must be addressed. We demonstrate simple methods which may be used to blindly mitigate mistuning and narrowband interference, and effectively invert the fast automatic gain function.
Amin et. al. recently developed a time-frequency MUSIC algorithm with narrow band models for the estimation of direction of arrival (DOA) when the source signals are chirps. In this research, we consider wideband mode...
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Amin et. al. recently developed a time-frequency MUSIC algorithm with narrow band models for the estimation of direction of arrival (DOA) when the source signals are chirps. In this research, we consider wideband models. The joint time-frequency analysis is first used to estimate the chirp rates of the source signals and then the DOA is estimated by the MUSIC algorithm with an iterative approach.
In this paper we consider using 'digit serial' processing to build high performance parallel structures, in particular, parallel signal processors. Digit serial arithmetic processors have digit serial data tra...
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ISBN:
(纸本)0819406945
In this paper we consider using 'digit serial' processing to build high performance parallel structures, in particular, parallel signal processors. Digit serial arithmetic processors have digit serial data transmission combined with digit serial computation. Three digit serial arithmetic processors are presented and compared with their digit parallel counterparts. We show that by using a digit serial approach we can achieve a higher throughput than with a digit parallel processor, even though the two processors are structurally similar and have components of similar complexity.
The Rapid Prototyping of Application Specific signal Processors (RASSP) program has as its goal the dramatic improvement of the process by which signal processors are specified, designed, documented, manufactured, and...
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ISBN:
(纸本)0819416207
The Rapid Prototyping of Application Specific signal Processors (RASSP) program has as its goal the dramatic improvement of the process by which signal processors are specified, designed, documented, manufactured, and supported. A key part of the RASSP process is the method of architecture selection. An architecture overview is presented, together with a discussion of architecture classification, architecture evaluation factors, and signalprocessing flow. Two important architecture support aspects are briefly discussed: open systems architecture and integrated diagnostics. Recommendations for preferred approaches and rules of thumb for architecture selection are given. Finally, the RASSP architecture selection process is outlined, including a discussion of a standard hardware/software module interface.
The need to construct architectures in VLSI has focused attention on unnormalized floating point arithmetic. Certain unnormalized arithmetics allow one to 'pipe on digits,' thus producing significant speed up ...
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ISBN:
(纸本)0819406945
The need to construct architectures in VLSI has focused attention on unnormalized floating point arithmetic. Certain unnormalized arithmetics allow one to 'pipe on digits,' thus producing significant speed up in computation and making the input problems of special purpose devices such as systolic arrays easier to solve. We consider the error analysis implications of using unnormalized arithmetic in numerical algorithms. We also give specifications for its implementation. Our discussion centers on the example of Gaussian elimination. We show that the use of unnormalized arithmetic requires change in the analysis of this algorithm. We will show that only for certain classes of matrices that include diagonally dominant matrices (either row or column), Gaussian elimination is as stable in unnormalized arithmetic as in normalized arithmetic. However, if the diagonal elements of the upper triangular matrix are post normalized, then Gaussian elimination is as stable in unnormalized arithmetic as in normalized arithmetic for all matrices.
We present an algorithm-based fault tolerant scheme for QR decomposition, that extends the well-known Gentleman-Kung-McWhirter triangular systolic array architecture. Assuming that the array is subject to transient fa...
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ISBN:
(纸本)0819416207
We present an algorithm-based fault tolerant scheme for QR decomposition, that extends the well-known Gentleman-Kung-McWhirter triangular systolic array architecture. Assuming that the array is subject to transient faults, widely separated in time and each affecting a single processor, we give an algorithm that corrects the full triangular array with computational overhead equivalent, on average, to the interpolation of a single extra vector into the data stream.
An efficient algorithm is presented for computing the continuous wavelet transform and the wideband ambiguity function on a sample grid with uniform time spacing but arbitrary sampling in scale. The method is based on...
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ISBN:
(纸本)0819406945
An efficient algorithm is presented for computing the continuous wavelet transform and the wideband ambiguity function on a sample grid with uniform time spacing but arbitrary sampling in scale. The method is based on the chirp z-transform and requires the same order of computation as constant-bandwidth analysis techniques, such as the short-time Fourier transform and the narrowband ambiguity function. An alternative spline approximation method which is more efficient when the number of scale samples is large is also described.
A general approach for obtaining joint representations in signal analysis is presented. The method is applied to scale representations. We define a new scale operator and show that it leads to joint representations of...
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ISBN:
(纸本)0819406945
A general approach for obtaining joint representations in signal analysis is presented. The method is applied to scale representations. We define a new scale operator and show that it leads to joint representations of the Altes and Marinovic type and we also define joint representations with inverse frequency and show that it leads to Bertrand-Bertrand type distributions. We derive the uncertainty principle for scale and obtain the minimum time-scale uncertainty signal.
A massively parallel signal and image processing architecture is considered. The architecture is comprised of 2D arrays of cells that simulate the response of retina neurons. The results of simulations are compared to...
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ISBN:
(纸本)0819416207
A massively parallel signal and image processing architecture is considered. The architecture is comprised of 2D arrays of cells that simulate the response of retina neurons. The results of simulations are compared to previously published experimental results and the system is applied to detection of spatio-temporal features in sequences of images representative of pulse- doppler radar images. By arranging the output layer so that the cells respond to various key input features an array of feature extraction cells can be obtained. The system is characterized by developing an image space to feature space mapping.
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