Sampling time-frequency localized functions and constructing localized time-frequency frames
نویسندگان
چکیده
منابع مشابه
Time-frequency localized functions and operators in Gabor analysis
Analyzing a signal in regard to its time-varying frequency content is a classical method in science. Recently this method has grown into a rich mathematical theory within applied harmonic analysis, with applications ranging from radio and mobile communications to medical image processing and geophysics. This thesis addresses the following three fundamental, but not yet fully understood question...
متن کاملLocalized subclasses of quadratic time-frequency representations
We discuss the existence of classes of quadratic time-frequency representations (QTFRs), e.g. Cohen, power, and generalized time-shift covariant, that satisfy a time-frequency (TF) concentration property. This important property yields perfect QTFR concentration along group delay curves. It also (1) simpli es the QTFR formulation and property kernel constraints as the kernel reduces from 2-D to...
متن کاملAn optimally concentrated Gabor transform for localized time-frequency components
Gabor analysis is one of the most common instances of time-frequency signal analysis. Choosing a suitable window for the Gabor transform of a signal is often a challenge for practical applications, in particular in audio signal processing. Many time-frequency (TF) patterns of different shapes may be present in a signal and they can not all be sparsely represented in the same spectrogram. We pro...
متن کاملTime-frequency Localized Cdma for Downlink Multi-carrier Systems
An OFDM-CDMA system that utilizes the channel-correlation in both time and frequency to reduce multiple access interference is proposed. Orthogonal Walsh-Hadamard codes are used for spreading and in order for the codewords to stay orthogonal at the receiver, the channel response must be flat in both time and frequency. A frequency selective fading channel will, however, distort the codewords an...
متن کاملTime - Frequency Analysis of Frames *
The theory of frames is fundamental to timefrequency (TF or time-scale signal expansions like Gabor ysis of frames via two “TF frame representations” called the Weyl symbol and Wigner distribution of a frame. The T F analysis shows how a frame’s properties depend on the signal’s T F location and on certain frame parameters. 1 I N T R O D U C T I O N Linear time-frequency (TF) or time-scale sign...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
ژورنال
عنوان ژورنال: European Journal of Applied Mathematics
سال: 2016
ISSN: 0956-7925,1469-4425
DOI: 10.1017/s095679251600053x