## Virtues and Vices of Quartic Time-Frequency Distributions (2000)

Venue: | in IEEE Trans. on Signal Processing |

Citations: | 2 - 1 self |

### BibTeX

@INPROCEEDINGS{O'neill00virtuesand,

author = {Jeffrey C. O'neill and Patrick Flandrin},

title = {Virtues and Vices of Quartic Time-Frequency Distributions},

booktitle = {in IEEE Trans. on Signal Processing},

year = {2000},

pages = {http://mdsp.bu.edu/j}

}

### OpenURL

### Abstract

We present results concerning three different types of quartic (fourth order) time-frequency distributions. First, we present new results on the recently introduced local ambiguity function, and show that it provides more reliable estimates of instantaneous chirp rate than the Wigner distribution. Second, we introduce the class of quartic, shiftcovariant, time-frequency distributions, and investigate distributions that localize quadratic chirps. Finally, we present a shift covariant distribution of time and chirp-rate. I. Introduction T HE notion of a time-frequency distribution (TFD) [1], [2], [3] is inherently a concept that is not well defined [4]. A frequency is something that is measured over a period of time (e.g. how many times does the heart beat in a minute), and we would like to specify this frequency description at an instant of time (e.g. how fast is the heart beating right now). Nevertheless, TFD's have proven to be useful in many applications [5]. TFD's have been defin...