TY - GEN
T1 - Generalized time-shift covariant quadratic time-frequency representations with arbitrary group delays
AU - Papandreou-Suppappola, Antonia
N1 - Funding Information:
1 Introduction Quadratic time-frequency representations (QTFRs) are classified based on properties that they satisfy as different QTFRs are best suited for analyzing different types of nonstationary signals [l]. Cohen’s class QTFRs [2, 11 are used in speech as they preserve the signal’s constant time and frequency shifts. The hyperbolic class QTFRs [3] preserve the signal’s scale changes and hyperbolic time-shifts and are thus useful for analyzing Doppler-invariant signals. Other classes include the scale and time-shift covariant affine class [4, 51, and the scale and power dispersive time-shift covariant power classes [6]. In this paper, we propose new generalized QTFR classes that preserve time-shifts corresponding to arbitrary group delays and unify both existing and new classes. We also propose the new exponential class with QTFRs that preserve frequency-shifts and time-shifts with exponential group delay. 2 Generalized Time-Shift Covariant QTFR Classes The generalized time-shift covariance property is useful for analyzing signals propagating through systems with dispersion characteristics corresponding to group delays C T ( ~ )[7, 81. For a QTFR Tx(t,f ) the generalized time-shift covariance is defined as T&E)X(t,f) = Tx(t-Cm9.f) (1) work was supported in part by ONR grant N00014-92-
PY - 1995
Y1 - 1995
N2 - We propose new classes of quadratic time-frequency representations (QTFRs) that satisfy the generalized time-shift covariance property important for analyzing signals propagating through systems with group delay dependent characteristics. We obtain these classes from Cohen's (1966) class and the affine class of constant time-shift covariant QTFRs using a generalized warping that depends on the desirable group delay time-shift covariance. We develop formulations for the new classes, desirable properties with kernel constraints, new QTFR members, and intersection subclasses. We also propose the new exponential class of frequency-shift covariant and exponential time-shift covariant QTFRs.
AB - We propose new classes of quadratic time-frequency representations (QTFRs) that satisfy the generalized time-shift covariance property important for analyzing signals propagating through systems with group delay dependent characteristics. We obtain these classes from Cohen's (1966) class and the affine class of constant time-shift covariant QTFRs using a generalized warping that depends on the desirable group delay time-shift covariance. We develop formulations for the new classes, desirable properties with kernel constraints, new QTFR members, and intersection subclasses. We also propose the new exponential class of frequency-shift covariant and exponential time-shift covariant QTFRs.
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U2 - 10.1109/ACSSC.1995.540609
DO - 10.1109/ACSSC.1995.540609
M3 - Conference contribution
AN - SCOPUS:68949099911
T3 - Conference Record - Asilomar Conference on Signals, Systems and Computers
SP - 553
EP - 557
BT - Conference Record of the 29th Asilomar Conference on Signals, Systems and Computers, ACSSC 1995
A2 - Singh, Avtar
PB - IEEE Computer Society
T2 - 29th Asilomar Conference on Signals, Systems and Computers, ACSSC 1995
Y2 - 30 October 1995 through 1 November 1995
ER -