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Title:
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An Adaptive Optimal-Kernel Time-Frequency Representation |
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Author:
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Jones, Douglas L.; Baraniuk, Richard G.
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Type:
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Journal Paper |
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Keywords:
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Temporary |
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Citation:
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D. L. Jones and R. G. Baraniuk, "An Adaptive Optimal-Kernel Time-Frequency Representation," IEEE Transactions on Signal Processing, vol. 43, no. 10, pp. 2361-2371, 1995. |
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Abstract:
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Time-frequency representations with fixed windows or kernels figure prominently in many applications, but perform well only for limited classes of signals. Representations with signal- dependent kernels can overcome this limitation. However, while they often perform well, most existing schemes are block-oriented techniques unsuitable for on-line implementation or for tracking signal components with characteristics that change with time. The time-frequency representation developed here, based on a signal-dependent radially Gaussian kernel that adapts over time, overcomes these limitations. The method employs a short-time ambiguity function both for kernel optimization and as an intermediate step in computing constant-time slices of the representation. Careful algorithm design provides reasonably efficient computation and allows on-line implementation. Certain enhancements, such as cone-kernel constraints and approximate retention of marginals, are easily incorporated with little additional computation. While somewhat more expensive than fixed-kernel representations, this new technique often provides much better performance. Several examples illustrate its behavior on synthetic and real-world signals. |
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Date Published:
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1995-10-01 |
