Global Timing Control With Applications to Tape Storage Channels

A new approach is introduced for symbol synchronization in multi-channel data storage systems called Global Timing Control (GTC). Applying results from optimum filtering theory to the state-space model of the timing process in multichannel data storage systems, a multi-input multi-output PLL solution is derived. Efficient implementations are developed through simplifications of the optimal solution obtained. The performance of the GTC technique is analyzed using actual readback waveforms captured in commercial tape drive systems. The results demonstrate the impressive robustness of GTC and its excellent resilience against loss-of-lock phenomena.