Timing recovery for the magnetic recording channel using the wave difference method

Timing recovery using the wave difference method is proposed for use in a magnetic recording read channel. The scheme uses an oversampling ratio of two and is suitable for mixed-signal or digital implementations. A simple class of prefilter that significantly improves the signal-to-interference ratio of the generated timing-error estimate is described. This prefilter also allows a simple implementation based on an absolute value, rather than squaring or fourth-order nonlinearity. Simulation results for this scheme are presented for a range of recording densities and channel noise levels.