Title :
Time-stretched short time Fourier transform
Author :
Nuruzzaman, Abul ; Boyraz, Ozdal ; Jalali, Bahram
Author_Institution :
Dept. of Electr. Eng., California Univ., Los Angeles, CA, USA
Abstract :
We propose and demonstrate time-stretched short-time Fourier transform (TS-STFT) to overcome the limitation of analog to digital converter (ADC) in time-frequency analysis of nonstationary signals. Experimentally, time-frequency analysis of highly chirped RF signals with chirp rate as high as 350 GHz/ns is demonstrated. An effective real-time sampling rate of 320 GSa/s is achieved. In our TS-STFT system, first ultra short window is applied on highly chirped signals. Then the window is stretched in time by photonic time stretch technique to allow its capture by the ADC to perform STFT in digital domain. This method enhances the analog bandwidth and effective sampling rate of the sampling ADC and enable us realize the instantaneous behavior of highly chirped ultra fast signal.
Keywords :
Fourier transforms; analogue-digital conversion; signal sampling; time-frequency analysis; RF signals; analog bandwidth; analog to digital converter; chirp rate; chirped signals; digital domain; nonstationary signals; optical sampling; photonic time stretch; real-time sampling; sampling ADC; sampling rate; time-frequency analysis; time-stretched short-time Fourier transform; ultra fast signal; Analog-digital conversion; Chirp; Fiber nonlinear optics; Fourier transforms; Nonlinear optics; Optical fiber dispersion; Optical signal processing; Sampling methods; Signal sampling; Time frequency analysis;
Conference_Titel :
Instrumentation and Measurement Technology Conference, 2004. IMTC 04. Proceedings of the 21st IEEE
Print_ISBN :
0-7803-8248-X
DOI :
10.1109/IMTC.2004.1350988
