### Resumé

Originalsprog | Engelsk |
---|---|

Tidsskrift | I E E E Transactions on Signal Processing |

Vol/bind | 65 |

Udgave nummer | 9 |

Sider (fra-til) | 2247 - 2261 |

ISSN | 1053-587X |

DOI | |

Status | Udgivet - 1 maj 2017 |

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*I E E E Transactions on Signal Processing*,

*65*(9), 2247 - 2261. https://doi.org/10.1109/TSP.2017.2655489

}

*I E E E Transactions on Signal Processing*, bind 65, nr. 9, s. 2247 - 2261. https://doi.org/10.1109/TSP.2017.2655489

**Variational Bayesian Inference of Line Spectra.** / Badiu, Mihai Alin; Hansen, Thomas Lundgaard; Fleury, Bernard Henri.

Publikation: Bidrag til tidsskrift › Tidsskriftartikel › Forskning › peer review

TY - JOUR

T1 - Variational Bayesian Inference of Line Spectra

AU - Badiu, Mihai Alin

AU - Hansen, Thomas Lundgaard

AU - Fleury, Bernard Henri

PY - 2017/5/1

Y1 - 2017/5/1

N2 - In this paper, we address the fundamental problem of line spectral estimation in a Bayesian framework. We target model order and parameter estimation via variational inference in a probabilistic model in which the frequencies are continuous-valued, i.e., not restricted to a grid; and the coefficients are governed by a Bernoulli-Gaussian prior model turning model order selection into binary sequence detection. Unlike earlier works which retain only point estimates of the frequencies, we undertake a more complete Bayesian treatment by estimating the posterior probability density functions (pdfs) of the frequencies and computing expectations over them. Thus, we additionally capture and operate with the uncertainty of the frequency estimates. Aiming to maximize the model evidence, variational optimization provides analytic approximations of the posterior pdfs and also gives estimates of the additional parameters. We propose an accurate representation of the pdfs of the frequencies by mixtures of von Mises pdfs, which yields closed-form expectations. We define the algorithm VALSE in which the estimates of the pdfs and parameters are iteratively updated. VALSE is a gridless, convergent method, does not require parameter tuning, can easily include prior knowledge about the frequencies and provides approximate posterior pdfs based on which the uncertainty in line spectral estimation can be quantified. Simulation results show that accounting for the uncertainty of frequency estimates, rather than computing just point estimates, significantly improves the performance. The performance of VALSE is superior to that of state-of-the-art methods and closely approaches the Cramér-Rao bound computed for the true model order.

AB - In this paper, we address the fundamental problem of line spectral estimation in a Bayesian framework. We target model order and parameter estimation via variational inference in a probabilistic model in which the frequencies are continuous-valued, i.e., not restricted to a grid; and the coefficients are governed by a Bernoulli-Gaussian prior model turning model order selection into binary sequence detection. Unlike earlier works which retain only point estimates of the frequencies, we undertake a more complete Bayesian treatment by estimating the posterior probability density functions (pdfs) of the frequencies and computing expectations over them. Thus, we additionally capture and operate with the uncertainty of the frequency estimates. Aiming to maximize the model evidence, variational optimization provides analytic approximations of the posterior pdfs and also gives estimates of the additional parameters. We propose an accurate representation of the pdfs of the frequencies by mixtures of von Mises pdfs, which yields closed-form expectations. We define the algorithm VALSE in which the estimates of the pdfs and parameters are iteratively updated. VALSE is a gridless, convergent method, does not require parameter tuning, can easily include prior knowledge about the frequencies and provides approximate posterior pdfs based on which the uncertainty in line spectral estimation can be quantified. Simulation results show that accounting for the uncertainty of frequency estimates, rather than computing just point estimates, significantly improves the performance. The performance of VALSE is superior to that of state-of-the-art methods and closely approaches the Cramér-Rao bound computed for the true model order.

KW - Line spectral estimation

KW - complex sinusoids

KW - model order selection

KW - Bayesian inference

KW - von Mises distribution

KW - super-resolution

KW - Bernoulli-Gaussian model

KW - sparse estimation

UR - http://ieeexplore.ieee.org/document/7827161/

U2 - 10.1109/TSP.2017.2655489

DO - 10.1109/TSP.2017.2655489

M3 - Journal article

VL - 65

SP - 2247

EP - 2261

JO - I E E E Transactions on Signal Processing

JF - I E E E Transactions on Signal Processing

SN - 1053-587X

IS - 9

ER -