The paper deals with the parameter identification of Hammerstein systems having piecewise-linear nonlinearities with asymmetric dead-zones. A new form of nonlinearity representation provides a special form of Hammerstein model. Parameter estimation is carried out iteratively with measured input and output data records and estimated internal variables. To demonstrate the feasibility of the ident...

a r t i c l e i n f o a b s t r a c t Keywords: Quadrature amplitude modulation Peak-to-average power ratio Nonlinear high power amplifier Hammerstein channel B-spline neural network Equalization High bandwidth-efficiency quadrature amplitude modulation (QAM) signaling widely adopted in high-rate communication systems suffers from a drawback of high peak-to-average power ratio, which may cause ...

in this study a numerical method is developed to solve the hammerstein integral equations. to this end the kernel has been approximated using the leastsquares approximation schemes based on legender-bernstein basis. the legender polynomials are orthogonal and these properties improve the accuracy of the approximations. also the nonlinear unknown function has been approximated by using the berns...

The class of nonlinear dynamic systems which can be represented by the block-oriented models, ie, by interconnection of linear dynamic and nonlinear static subsystems, has been studied by many authors. In the simplest case the models consist of a combination of two blocks giving the so-called Hammerstein (nonlinear-linear) and Wiener (linear-nonlinear) models and there are many methods for nonl...

Making use of the Volterra approach, black box modeling is applied to a large scale analog circuitry for an ADSL (asymmetric digital subscriber line) central office application. Reducing the number of free parameters through special assumptions on the Volterra kernels, one ends up with the Hammerstein model. Taking the first few taps of the Volterra kernels and approximating the last taps throu...

Sub- and ultraharmonic (SUH) ultrasound contrast imaging is an alternative modality to the second harmonic imaging, since, in specific conditions it could produce high quality echographic images. This modality enables the contrast enhancement of echographic images by using SUH present in the contrast agent response but absent from the nonperfused tissue. For a better access to the components ge...

A novel recursive algorithm for identification of Hammerstein structures is developed. The linear and nonlinear parameters are separated and estimated recursively in a parallel manner, but each updating algorithm employs the estimation produced by the other at the previous time instant. Hence, it is termed the Alternately Recursive Least Square (ARLS) algorithm.When compared with Recursive Leas...

Rationalized Haar functions are developed to approximate the solution of the nonlinear Volterra–Fredholm–Hammerstein integral equations. The properties of rationalized Haar functions are first presented. These properties together with the Newton–Cotes nodes and Newton–Cotes integration method are then utilized to reduce the solution of Volterra–Fredholm–Hammerstein integral equations to the sol...

Abstract: In this paper, a Sinc-collocation method based on the double exponential transformation for solving Fredholm and Volterra Hammerstein integral equations is presented. Some properties of the Sinc-collocation method required for our subsequent development are given and utilized to reduce the computation of solution of the Hammerstein integral equations to some algebraic equations. Numer...

The paper presents a procedure for identification continuous-time Hammerstein systems. To improve the representation of the nonlinear functions, the set of basis functions is iteratively refined. It is possible to identify the dominant nonlinearities, applying a singular value decomposition to the input matrix. In our approach, the linear dynamic subsystem is described by a transfer function of...