The thesis studies digital signal detection and coding for magnetic recording channels. A maximum-likelihood detection scheme for a magnetic recording channel model is synthesized. A recursive algorithm is developed for computing the channel noise statistics, which are used for the metric computations performed in a search. Maximum-likelihood detection is approximated as closely as desired by increasing the tree search depth. The algorithm achieves an improvement of up to 5 dB in signal-to-noise ratio over other available algorithms. The implementation of the algorithm is feasible. Results of performance simulation are shown. A method of performance analysis for the algorithm is developed. A simple analytic formula for error probability is obtained, which is applied to coding and reduced-state sequence estimation (RSSE) as well as to performance estimation. Results are supported by various simulations. This is the first known analytic method for evaluating error performance of jitter corrupted channels. Another result is an algorithm for Reduced-State Sequence Estimation (RSSE). For a given number of states that are allowed to use in a trellis search, the algorithm guarantees a minimal performance degradation, which is a property not possessed by any of the other known RSSE algorithms. By selecting alive states, instead of using the metric of each single state, we evaluate a combined metric of each suitable subset of the states. When the reduced number of states is two, the only additional computation needed for each metric calculation is a read-only memory access. Results are supported by simulation.
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Details
Title
Detection and coding for high density digital magnetic recording
Creators
Miaolin Chen
Contributors
E. A. Trachtenberg (Advisor)
Awarding Institution
Drexel University
Degree Awarded
Doctor of Philosophy (Ph.D.)
Publisher
Drexel University; Philadelphia, Pennsylvania
Number of pages
x, 145 pages
Resource Type
Dissertation
Language
English
Academic Unit
College of Engineering (1970-2026); Mechanical Engineering (and Mechanics) [Historical]; Drexel University