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The research on blind source separation is a focus in the community of signal processing and has been developed in recent years. In this contribution, we propose to independent component analysis (ICA) when the measured signals are contaminated by additive noise, a method is proposed of combining wavelet threshold de-noising and independent component analysis to separate noisy mixed speech signals...
Generalized Gaussian distribution is a class of symmetry distribution with the Gaussian and Laplacian distribution as the special cases, with delta distribution and uniformity distribution as limit. It is widely applied a great many fields. In this paper, we first deduce the Generalized Gaussian parameter ratio function, and then present a fast parameter estimation of generalized Gaussian distribution;...
In passive radar based on illuminators of opportunity, one of the key problems is the suppression of the direct path interference (DPI) from the illuminator. This paper analyzes the DPI and the effect of which on passive radar in practical application, and demonstrates the importance of the suppression of DPI prior to analog to digital converter (ADC). Based on which, a new, efficient, automatic cancellation...
Wideband radar systems are vulnerable to external wideband interferences, in order to realize the high resolution target image under the wideband interferences condition, this paper presents an adaptive sidelobe cancellations (SLC) algorithm which use stretch processing. Conventional analog time delay units (TDUs) were superseded by frequency-dependent digital phase weight in the proposed method,...
The method of direction-of-arrival (DOA) estimation for signals based on phase-difference was brought forward. First, apply FFT to the outputs of every array element, then, measure the signals' frequencies and phases of the peak points. Calculate one by one the phase differences of the peak points corresponding to all the array elements, thus to get the phase delays. Then the DOA can be estimated...
In this paper, an iterative high-resolution DOA algorithm is proposed for DOA estimation for CDMA systems. The algorithm iteratively removes detected signals from the received data and searches the residue spatial spectrum for further signals. It does not require any computationally expensive eigen decomposition or spatial smoothing in coherent multipath scenarios. Results are presented illustrating...
In this paper, a short-time multifractals models has been proposed, which is an extension of multifractals models. In the section 2, the mind of short-time multifractal spectrum has been introduced. In section 3, the short time multifractal spectrum based on probability measure and wavelet have been proposed. In section 3 is the calculation method of short time multifractal spectrum, and we analyzed...
Fast affine projection (FAP) algorithm is widely used recently for its NLMS like computational complexity and RLS like convergence rate. The regularization parameter in the FAP algorithm is used to guarantee a well behaved inverse of the covariance matrix, and it plays an important role in the performance of the FAP algorithm. However, the fixed value of the regularization parameter in the conventional...
A modulation classification scheme for MPSK signals is proposed. Frequency and timing synchronization is achieved before fourth-order-cumulant based modulation classification algorithm is carried out. The recognition range include BPSK, QPSK, 8PSK and pi/4 DQPSK
Hyperspectral remote sensing data, the spectral resolution of which is less than 10 nm, include a mass of diagnosing spectrum information and can be used to non-destructively detect disease stresses of vegetation. A field experiment had been done to collect the canopy spectral reflectance of winter wheat. Canopy reflectance spectra were surveyed, and the disease index (DI) were gained by the field...
Fractal functions usually have variable singularity strengths characterized by time-varying local Holder exponents. To determine these strengths is thus attractive and challenging. We present a novel algorithm for estimating these singularity strengths in terms of local wavelet spectrum based on maximal overlap discrete wavelet transform. The validity and stability are verified by Monte-Carlo experiments...
Firstly the wavelet coefficients are estimated by NeighShrink scheme and then 0-1 binary character coefficients are obtained. Based on the above binary coefficients, the intra and inter relativity exponents are defined respectively for each wavelet coefficients. Finally decision coefficients are determined according to the magnitudes of the intra and inter relativity exponents. This algorithm overcomes...
This paper discusses the problem of frequency estimation of one-dimensional harmonics in multiplicative and additive noises. To alleviate the resolution limitation of the traditional Fourier-based algorithms, we introduce a novel wavelet based approach to harmonic retrieval. A wavelet mother function with tunable parameter is constructed by modulating a window function, which makes it easier to get...
Visible (VIS) and near infrared reflectance spectroscopy (NIRS) was used to identify and authenticate different monosodium glutamate species. Samples from Xihu, Linhua, Taitaile and Foshou monosodium glutamate were homogenised and scanned in the visible (VIS) and near infrared (NIR) region (325-1075 nm) in reflectance. Partial least squares (PLS) models were developed to identify different monosodium...
Fractal geometry is a new method to apply in analyzing fault signals. After researching the characteristic of rolling bearings, a new quantificational definition about fault signals of rolling bearings is proposed. Based on fractal theory and the conception of box dimension it can describe both non-stationary and non-linear signals of vibration signals generated by rolling bearings. Experiment results...
This paper addresses the design problem of linear-phase finite-impulse response (FIR) notch filters based on a neural networks optimization technique. The main idea is to minimize the weighted square-error function in the frequency-domain. The convergence theorem of the neural networks algorithm is proved to illustrate the proposed algorithm stable, and the implementation of the approach is also described...
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