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Electrical and Computer Engineering

Theses/Dissertations

1994

Adaptive filters

Articles 1 - 2 of 2

Full-Text Articles in Engineering

Narrow-Band Interference Rejection In Spread Spectrum Using An Eigen Analysis Based Approach, Aparna Vadhri May 1994

Narrow-Band Interference Rejection In Spread Spectrum Using An Eigen Analysis Based Approach, Aparna Vadhri

Theses

A new adaptive technique is suggested for rejecting narrow-band interferences in spread spectrum communications. When data is coded using a pseudo-noise code, the received signal consists of a wide-band signal with almost white spectral properties, thermal noise, and correlated narrow-band interferences. A new approach is proposed which exploits the statistical properties of the received signal via eigenanalysis of the received data. While the energy of the wide-band signal is distributed over all the eigenvalues of the signal autocorrelation matrix, the energy of the interference is concentrated in a few large eigenvalues. Hence, the eigenvectors corresponding to the large eigenvalues are …


Adaptive Notch Filter, Yuchen Huang Jan 1994

Adaptive Notch Filter, Yuchen Huang

Dissertations and Theses

The thesis presents a new adaptive notch filter (ANF) algorithm that is more accurate and efficient and has a faster convergent rate than previous ANF algorithms. In 1985, Nehorai designed an infinite impulse response (UR) ANF algorithm that has many advantages over previous ANF algorithms. It requires a minimal number of parameters with constrained poles and zeros. It has higher stability and sharper notches than any ANF algorithm until now. Because of the special filter structure and the recursive prediction error (RPE) method, however, the algorithm is very sensitive to the initial estimate of the filter coefficient and its covariance. …