A modified μ-weighted normalised frequency-domain LMS algorithm

Author

Punjabi, Harish S. ; Townsend, J. Keith ; Duel-Hallen, Alexandra

Author_Institution

Dept. of Electr. & Comput. Eng., North Carolina State Univ., Raleigh, NC, USA

fYear

1994

fDate

28 Nov- 2 Dec 1994

Firstpage

232

Abstract

The transversal adaptive filter using the least mean square (LMS) algorithm of Widrow and Ropf (1976) has been widely used mainly due to its relative ease of implementation. The major drawback of this time-domain LMS (TDLMS) algorithm is that as the eigenvalue spread of the input autocorrelation matrix increases, the convergence speed of the algorithm decreases. This led to the transform domain adaptive filters where the input signals are orthogonalized. Normalized frequency domain LMS algorithms (NFDLMS) are known to be faster than the time domain implementations. However, in some implementations with low signal to return noise ratio, NFDLMS algorithms can have stability problems. The stability problem can be solved by weighting the normalization gain μ. We perform computer simulations for the telephone echo channel and show that the modified μ-weighted NFDLMS algorithm is 8 times faster than the time-domain LMS (TDLMS) algorithm and more stable than the NFDLMS algorithm over a wide range of signal to noise ratios

Keywords

adaptive filters; adaptive signal processing; echo suppression; filtering theory; frequency-domain analysis; least mean squares methods; numerical stability; telecommunication channels; telephony; computer simulations; convergence speed; eigenvalue spread; input autocorrelation matrix; least mean square algorithm; low signal to return noise ratio; modified μ-weighted LMS algorithm; normalization gain weighting; normalized frequency domain LMS algorithms; signal to noise ratios; stability problems; telephone echo channel; time-domain LMS algorithm; transform domain adaptive filters; transversal adaptive filter; Adaptive filters; Autocorrelation; Computer simulation; Convergence; Eigenvalues and eigenfunctions; Frequency domain analysis; Least squares approximation; Signal to noise ratio; Stability; Time domain analysis;

fLanguage

English

Publisher

ieee

Conference_Titel

Global Telecommunications Conference, 1994. GLOBECOM '94. Communications: The Global Bridge., IEEE

Conference_Location

San Francisco, CA

Print_ISBN

0-7803-1820-X

Type

conf

DOI

10.1109/GLOCOM.1994.513413

Filename

513413