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Feed-Forward Adaptive Equalization

IP.com Disclosure Number: IPCOM000060489D
Original Publication Date: 1986-Apr-01
Included in the Prior Art Database: 2005-Mar-08

Publishing Venue

IBM

Related People

Authors:
Schneider, RC Zimmerman, VW [+details]

Abstract

A method of adaptive equalization is described that compensates for variations in the high frequency components of a tape or disk read signal. Unlike many known methods of adaptive equalization, the adjustment is made without the need for detected data or a known training sequence. As shown in Fig. 1, the read signal passes through an amplifier, fixed equalizer and automatic gain control (AGC) circuit. This is conventional and well known. The signals at point A (the output of AGCl) are of the same uniform amplitude. However, their shape may be different, indicating too much or too little compensation. Fig. 2 shows two read signals, with the one at the right having too little compensation.