نتایج جستجو برای: chirp signal
تعداد نتایج: 420128 فیلتر نتایج به سال:
In this paper, the issue of single channel speech enhancement of non-stationary voiced speech is addressed. The non-stationarity of speech is well known, but state of the art speech enhancement methods assume stationarity within frames of 20–30 ms. We derive optimal distortionless filters that take the non-stationarity nature of voiced speech into account via linear constraints. This is facilit...
The paper investigates performance of spread spectrum signals performance in a bandlimited channel. Available spectrum spreading techniques are discussed. The performance is evaluated as the time of flight (ToF) accuracy estimation using the direct correlation technique. Numerical simulations have been carried out. Ultrasonic transducer was approximated as a bandlimited channel for simulation. ...
In this paper, the effect of optical pulse shape on the performance of direct sequence optical code division multiple access in presence of fiber group velocity dispersion (GVD) and pulse linear chirp is analyzed. In our analysis, chirp-Gaussian shape and chirp-Hyperbolic-Secant shape optical orthogonal codes are employed as address sequence. Avalanche photodiode (APD) is used in an optical cor...
The frequency chirp properties of both SOA-Mach-Zehnder interferometer and nonlinear polarization rotation wavelength converters are studied and their feasibility for supporting combined frequency shift keying/ intensity modulation (FSK/IM) labeling scheme are experimentally assessed. Introduction Labelled optical burst switching (LOBS) is considered a promising technique for efficient IP over ...
This paper discusses the design and development of a FPGA-based chirp generator for high resolution Unmanned Aerial Vehicle (UAV) Synthetic Aperture Radar. The desired bandwidth of the chirp signal is 100MHz (combination of I and Q channels) with a chirp rate of 5MHz/μs. Two algorithms based on the Memory-based architecture and the Direct Digital Synthesizer (DDS) architecture are presented. Th...
This article investigates the possibility and convenience of a filtering operation in the joint time/chirp-rate (TCR) domain, and proposes a novel linear TCR filter for decomposing multicomponent signals into their quadratic and/ or cubic phase chirp components with monotonic instantaneous chirp-rate (ICR) laws only. The TCR domain mask of the filter is selected on a display of a TCR representa...
Time–frequency representations of a signal can provide a useful means for obtaining parameter estimates for signals consisting of various chirps. We demonstrate the utility of including edge information extracted from these time–frequency representations when using a Hough transformation to perform this task. In particular, we show that using the edge information: (1) reduces the variance of th...
The chirp of an ultrashort laser pulse can be extracted with high accuracy from a modified spectrum auto-interferometric correlation waveform by using a new time domain algorithm that allows signal averaging. We display results revealing high sensitivity to chirp even with signal-to-noise levels approaching unity. Correction algorithms have been developed to accommodate signal distortion arisin...
Biorthogonal Fourier transform for multichirp-rate signal detection over dispersive wireless channel
Biorthogonal Fourier transform (BFT), consistent with the matched signal transform (MST), has been introduced to demodulate the M-ray chirp-rate signal which possesses good orthogonality in the BFT domain. Here, we analyze the characteristics of BFT detection in a further step, including the resolution capability of the multichirp-rate signal, the property of pulse compression, the closed-form ...
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