Title :
Feasibility of LMS adaptation of an all-pass equalizer
Author :
Wiedmann, Ralf ; Kenney, John G. ; Kolodziej, Wojtek
Author_Institution :
Inst. fur Nachrichtenubertragung, Stuttgart Univ., Germany
Abstract :
In a magnetic recording channel with a two-sided transition response, a low-order all-pass filter can be used to equalize the channel for decision feedback equalization so that its overall transfer function is minimum-phase. A form of the least-mean square (LMS) algorithm is proposed for adapting the poles of an arbitrary-order all-pass filter. An estimate of the gradient of the mean-squared error with respect to the locations of the poles only requires the knowledge of the filter output, and not its internal states. This gradient is characterized numerically, and is shown to yield optimal filter design
Keywords :
FIR filters; adaptive equalisers; adaptive filters; all-pass filters; filtering theory; least mean squares methods; magnetic recording; poles and zeros; transfer functions; FIR filter; LMS adaptation; all-pass equalizer; decision feedback equalization; filter output; least-mean square; low-order all-pass filter; magnetic recording channel; mean-squared error gradient; minimum phase transfer function; optimal filter design; poles location; two-sided transition response; Decision feedback equalizers; Detectors; Filters; Finite impulse response filter; Least squares approximation; Magnetic recording; Magnetic separation; Sampling methods; State estimation; Transfer functions; Transversal filters;
Conference_Titel :
Global Telecommunications Conference, 1997. GLOBECOM '97., IEEE
Conference_Location :
Phoenix, AZ
Print_ISBN :
0-7803-4198-8
DOI :
10.1109/GLOCOM.1997.644338
