An explicit connection between fitting exponential models and pole-zero to observed data is made. The problem formulated as a constrained nonlinear minimization problem. This then solved using simplified iterative algorithm. algorithm applied simulated data, the performance of compared previous results.

This article gives a brief tutorial on transform-domain communication system (TDCS), OFDM, and MC-CDMA. The primary goal of this is to give detailed description the TDCS transmitter receiver systems highlight fundamental differences relative OFDM idea in synthesize smart adaptive waveform avoid interference at instead more traditional mitigating receiver. Unlike MC-CDMA, has very little exposure current literature.

The growth of wireless applications and spectral limitations are serious concerns for both the military civilian communities. Cognitive radio (CR) technologies expand spectrum efficiency using elements space, time frequency diversity that up to now have not been exploited. An adaptive waveform (AW) generation technique is presented which adapts changing electromagnetic environment synthesizes features in domain. Spectral coexistence with other also addressed can be accomplished static...

A 2004 paper had offered a theoretical proof that ideally the roots of minimum variance distortionless response (MVDR) beamformer array polynomial lie on unit circle (UC). However, existing MVDR methods fail to exploit this fundamental property adequately. This proposes new adaptive beamforming design via UC optimization for uniform linear arrays (ULA). The proposed method starts with sample matrix inversion (SMI) and optimizes criterion each root separately by splitting <inline-formula...

Several studies have revealed that spectrum congestion is primarily due to the inefficient use of versus unavailability. Cognitive radio (CR) and ultra wide band (UWB) technologies been proposed as candidates address this problem. Currently, a CR determines unused frequency bands transmits overlay waveforms in these bands, while UWB underlay span entire coexisting with primary users. This suggests most occupied by users underused. work proposes general soft decision cognitive (SDCR)...

Test of orthogonality projected subspaces (TOPS) estimates directions arrival wideband sources by exploiting between signal and noise in spectral domain. TOPS performs well at mid signal-to-noise ratio (SNR) range, but fares poorly high SNR noise-free cases. The pseudospectrum often exhibits spurious peaks all levels. This paper attempts to explain the cause poor performance, proposes suitable modifications extend effectiveness from low case. proposed modified-TOPS (mTOPS) achieves reduction...

The bearing estimation problem is formulated as a matrix-approximation problem. columns of matrix X are formed by the snapshot vectors from an N-element array. then approximated in least-square sense. rank well partial structure space spanned prespecified. After computed, bearings sources and, consequently, spatial correlation source signals estimated. performance proposed technique compared with two existing methods using simulation. comparison made terms bias, mean-squared error, failure...

An eigenvalue filtering method is proposed that applies a transformation to an autocorrelation matrix, which has the effect of truncating undesired eigenvalues so corresponding matrix function closely approximates pseudoinverse. It shown using computer simulation compared forward-backward method, enhances threshold in SNR by about 6-8 dB. Further improvement obtained simple subset selection and second iteration.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML"...

We consider the bearing estimation problem as a matrix approximation problem. The columns of X are embedded with snapshot vectors from an N element array. is approximated by <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">M</inf> in least square sense. rank, well structure space spanned , prespecified. After computed, bearings sources, spatial correlation source signals can be estimated. Our technique then compared other methods such MUSIC and...

A high resolution one-step algorithm for estimating the angles of arrivals multiple wideband sources is proposed. For a dense and equally spaced array structure, bilinear transformation utilized in frequency domain coherent signal subspace processing. When compared with existing approaches, proposed noniterative does not need knowledge initial estimates arrival angles. The performance presented using simulated data.

An optimal method (OM) for estimation of the parameters rational transfer functions from prescribed impulse response data is presented. The multidimensional nonlinear fitting error minimization problem has been theoretically decoupled into two subproblems reduced computational complexities. proposed approach applicable identifying models with arbitrary numbers poles and zeros. denominator subproblem possesses weighted-quadratic structure which utilized to formulate an efficient iterative...

A new algorithm is presented for automatic target recognition (ATR) where the templates are obtained via singular value decomposition (SVD) of high range resolution (HRR) profiles. SVD analysis a large class HRR data reveals that range-space eigenvectors corresponding to largest accounts more than 90% energy. Hence, it proposed be used as classification. The effectiveness normalization and Gaussianization profile improved classification performance also studied. With extensive simulation...

Automatic target recognition (ATR) using high range resolution (HRR) radar signatures is developed classical Bayesian multiple hypothesis theory. An eigen-template-based matched filtering (ETMF) algorithm presented where the templates are formed dominant range-space eigenvector of detected HRR training profiles and classification performed normalized (MF). The proposed approach extended to multi-look sequential ATR new observation recursively combined probabilistically with previous steps...

We propose an algorithm for estimation of the optimal "system" parameters time sequences (TSs) computed by finite-difference time-domain (FDTD) method, with goal accurate representation time-signature using low-order models. The FDTD method requires computation very long to accurately characterize slowly decaying transient behavior resonant structures. Therefore, it becomes critical investigate methods reducing computational such objects. Several researchers have argued that FDTD-TS can be...

This paper presents ATR results with High Range Resolution (HRR) profiles used for classification. It is shown that effective HRR-ATR performance can be achieved if the templates are formed via Singular Value Decomposition (SVD) of detected HRR profiles. demonstrated theoretically in mean-squared sense, eigen-vectors represent optimal feature set. SVD analysis a large class XPATCH and MSTAR HRR-data clearly indicates significant proportion (> 90%) target energy accounted by range correlation...

In this paper, we derive a novel variation of the adaptive matched filter (AMF) which enforces unit circle roots property by exploiting polynomial conjugate-symmetry. Motivated theoretical necessity for minimum-variance distortionless response (MVDR) beamformer and based on proportionality AMF MVDR solutions, apply our approach to problem radar moving target detection from stationary platform. The proposed unit-circle constrained (UCRC-AMF) shows improved performance with limited secondary...

The goal of this paper is to demonstrate the benefits a tracking and identification algorithm that uses belief data association filter for target recognition. By associating track ID information, accumulates evidence classifying High-Range Resolution (HRR) radar signatures from moving target. A history can be utilized reduce search space targets given pose range. technique follows work Mitchell Westerkamp by processing HRR amplitude location feature sets. new aspect multiple same type....

An improved structured matrix approximation approach for simultaneous estimation of frequencies and wavenumbers from 2-D array data is proposed. A quasi-linear relationship the error with polynomial coefficients both spatial temporal domains derived. This leads to an iterative optimization criterion simultaneously in domains. By performing simulations it shown that method capable resolving signals closely spaced frequency wavenumber at low SNR. Next, extendibility least-squares fitting...

This paper develops a new algorithm for estimating the parameters of multiple chirp signals in noise. The proposed method uses Compressive Sensing (CS) formulation Discrete Chirp Fourier Transform (DCFT) basis to achieve superior estimator performance. Unlike or time-frequency based approaches, DCFT incorporates underlying signal model formulating transform [1] -[4]. In this work CS exploits parametric fast recovery highly accurate parameter estimation results polynomial time using...

Change Detection (CD) is the process of identifying temporal or spectral changes in signals images. and analysis change provide valuable information transformations a scene. Hyperspectral sensors spatial spectrally rich that can be exploited for Detection. This paper develops analyzes various CD algorithms detection using single-pass multi-pass For validation performance comparisons, obtained are compared conventional similarity correlation coefficient as well traditional algorithms, such...

This paper evaluates and expands upon the existing end-to-end process used for vibrometry target classification identification. A fundamental challenge in vehicle using signature data is determination of robust signal features. The methodology this involves comparing performance features taken from automatic speech recognition, seismology, structural analysis work. These provide a means to reduce dimensionality possibility improved separability. performances different groups are compared...

This paper presents a new general proof that the roots of polynomial corresponding to minimum variance filter computed using true Toeplitz covariance matrix must fall on unit circle (UC). Unlike previous applicable Minimum Variance Distortionless Response (MVDR) case only, does not rely Wiener-Khinchin theorem map problem into frequency domain. Furthermore, is class sensor array signal processing problems beyond MVDR. Next, closed-form solutions UC constrained (UCRC) MVDR beamformer and...

A new 1-D hybrid automatic target recognition (ATR) algorithm is developed for high range resolution (HRR) profiles. The proposed combines eigen-template based matched filtering (ETMF) and hidden Markov modeling (HMM) techniques to achieve superior HRR-ATR performance. In the algorithm, each HRR test profile first scored by ETMF which then followed independent HMM scoring. scoring step produces a limited number of "most likely" models that are aspect dependent. These reduced used improved in...

Algorithms are presented for least-squares approximation of Toeplitz and Hankel matrices from noise corrupted or ill-composed matrices, which may not have correct structural rank properties. Utilizing Caratheodery theorem on complex number representation to model the it is shown that these possess specific row column structures. The inherent structures exploited develop a computational algorithm estimation closest, in Frobenius norm sense, given noisy rank-excessive matrices. Simulation...