A novel timing acquisition technique for perpendicular magnetic recording channels

Timing recovery is essential to signal detection in magnetic recording. The paper presents the development of timing acquisition techniques for partial response (PR) equalized perpendicular magnetic recording channels. Because preamble sequences are used to help in the acquisition process, the optimality of different preamble sequences is investigated for different user densities. Variable threshold detectors (VTDs), designed to tackle hang up and false lock problems, are presented. A new timing error detector (TED), which is very. simple to implement, is developed by exploiting the features of the preamble sequence and PR target. Using analytical and simulation studies, the new TED is shown to be optimal for the chosen target and preamble.