BIOMEDICAL IMAGING GROUP (BIG)
Laboratoire d'imagerie biomédicale (LIB)

Continuous-Time AR Model Identification: Does Sampling Rate Really Matter?

S. Maggio, H. Kirshner, M. Unser

Proceedings of the Eighteenth European Signal Processing Conference (EUSIPCO'10), Ålborg, Kingdom of Denmark, August 23-27, 2010, pp. 1469-1473.

We address the problem of identifying continuous-time auto regressive (CAR) models from sampled data. The exponential nature of CAR autocorrelation functions is taken into account by means of exponential B-splines modelling, allowing one to associate the available digital data with a CAR model. A maximum likelihood (ML) estimator is then derived for identifying the optimal parameters; it relies on an exact discretization of the sampled version of the continuous-time model. We provide both time- and frequency-domain interpretations of the proposed estimator, while introducing a weighting function that describes the CAR power spectrum by means of discrete Fourier transform values. We present experimental results demonstrating that the proposed exponential-based ML estimator outperforms currently available polynomial-based methods, while achieving Cramér-Rao lower bound values even for relatively low sampling rates. 

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AUTHOR="Maggio, S. and Kirshner, H. and Unser, M.",
TITLE="Continuous-Time {AR} Model Identification: {D}oes Sampling Rate
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