Compensation of nonlinearities in high-density magnetic recording channels

• Published in: IEEE transactions on magnetics Vol. 30; no. 6; pp. 5079 - 5086
• Main Authors: Biglieri, E., Chiaberto, E., Maccone, G.P., Viterbo, E.
• Format: Journal Article
• Language: English
• Published: New York, NY IEEE 01.11.1994; Institute of Electrical and Electronics Engineers
• Subjects: Applied sciences; Decision feedback equalizers; Detectors; Electronics; Error probability; Exact sciences and technology; Intersymbol interference; Magnetic heads; Magnetic noise; Magnetic recording; Nonlinear distortion; Recording and replay of audio and video signals; Saturation magnetization; Storage and reproduction of information; Viterbi algorithm; Viterbi code; Volterra series; Recording density; Recording head; Theoretical study; Nonlinearity; Recording material; Magnetic saturation; Magnetic recording
• ISSN: 0018-9464; 1941-0069
• DOI: 10.1109/20.334299

Volterra-series models of magnetic-saturation recording channels are used to derive readback structures that compensate for channel nonlinearities. These structures are based on a canceler of linear and nonlinear channel distortions, and can achieve significant improvement in terms of mean-square error and error probability. Proper operation of the canceler requires reliable preliminary decisions to be taken on the information symbols. These decisions are obtained by passing the received signal through a linear equalizer, then processing the equalized signal through a symbol-by-symbol detector or a Viterbi detector. By using the data obtained in [4] for magneto-resistive heads, it was found that symbol-by-symbol preliminary detection performs adequately. A Volterra model was also obtained experimentally for the recording channel generated by magneto-inductive heads that exhibit higher-order nonlinear effects. In order to recover data from this highly distorted channel the preliminary detection scheme needs a 4-state Viterbi detector.< >