Coding and characterization for digital recording
The objective of this dissertation is to apply communication theory to digital magnetic recording channels in order to achieve more reliable and higher density storage systems. In chapters 2 and 3, the combined ECC/RLL codes which not only satisfy channel constraints but also have good error correcting capabilities are studied. Sequential decoding (Stack algorithm) matched to the combined codes are investigated. The performance of the combined codes are compared, via computer simulations. The linear superposition model for the magnetic recording channel becomes inaccurate at high data rates or densities. In chapter 4, the nonlinear behavior of the recording channel is studied. An estimation technique for modelling the magnetic recording channel including nonlinearities is presented. The influence of the physical parameters of the channel on the matched filter bound and the loss due to intersymbol interference are studied in chapter 5. Chapter 6 deals with partial response signalling for digital recording channels. Using a Lorentzian channel model, coding and detection for the partial response system in digital recording channels are studied.