Sedat Oelcer

Compensation of PLL Loop Delay in Read Channels for Tape Storage Systems

This paper studies loop-delay compensation as a means to improve the robustness of timing recovery loops in tape storage systems. The delay compensation scheme is derived under fairly general assumptions and is found to match a known Kalman-filtering-based solution if a random-walk model of frequency-offset evolution is assumed. Extensions of the scheme to achieve delay compensation in multichannel tape-drive systems that employ global timing control are presented. The practical effectiveness of delay compensation is demonstrated using actual readback waveforms captured on commercial tape drives.

Cyclic Equalization and Channel Identification for Magnetic Tape Recording Systems Using the Data Set Separator (DSS)

Cyclic equalization and channel identification for read channels in linear tape open (LTO) tape drive systems are addressed using the readback waveform of the data set separator (DSS). The approach is extended to channel identification to extract the dibit response of the magnetic recording channel from the DSS readback waveform.