Linear Methods for Highdensity Magnetic Recording of Data

Noise in magnetic recording is contributed by the media, electronics, and mechanical imperfections in servoing. These affect signal-to-noise as a function of track width and linear density in different ways. Coding and modulation schemes for highdensity recording must address these noise sources accurately. We propose here to linearize the channel via ac biasing and then use techniques from information and communication theory to increase track densities without sacrificing too much in linear densities. © 1989 IEEE