Timing Recovery Strategies in Magnetic Recording Systems

At some point in a digital communications receiver, the received analog signal must be sampled. Good performance requires that these samples be taken at the right times. The process of synchronizing the sampler with the received analog waveform is known as timing recovery. Conventional timing recovery techniques perform well only when operating at high signal-to-noise ratio (SNR). Nonetheless, iterative error-control codes allow reliable communication at very low SNR, where conventional techniques fail. This paper provides a detailed review on the timing recovery strategies based on per-survivor processing (PSP) that are capable of working at low SNR. We also investigate their performance in magnetic recording systems because magnetic recording is a primary method of storage for a variety of applications, including desktop, mobile, and server systems. Results indicate that the timing recovery strategies based on PSP perform better than the conventional ones and are thus worth being employed in magnetic recording systems.

[1]  Tong Zhang,et al.  New Phase-Locked Loop Design: Understanding the Impact of a Phase-Tracking Channel Detector , 2010, IEEE Transactions on Magnetics.

[2]  Umberto Mengali,et al.  Approximate ML decoding of coded PSK with no explicit carrier phase reference , 1994, IEEE Trans. Commun..

[3]  A. Glavieux,et al.  Near Shannon limit error-correcting coding and decoding: Turbo-codes. 1 , 1993, Proceedings of ICC '93 - IEEE International Conference on Communications.

[4]  Heinrich Meyr,et al.  Digital communication receivers - synchronization, channel estimation, and signal processing , 1997, Wiley series in telecommunications and signal processing.

[5]  Joachim Hagenauer,et al.  A Viterbi algorithm with soft-decision outputs and its applications , 1989, IEEE Global Telecommunications Conference, 1989, and Exhibition. 'Communications Technology for the 1990s and Beyond.

[6]  K. Mueller,et al.  Timing Recovery in Digital Synchronous Data Receivers , 1976, IEEE Trans. Commun..

[7]  H. Shafiee.  Timing recovery for sampling detectors in digital magnetic recording , 1996, Proceedings of ICC/SUPERCOMM '96 - International Conference on Communications.

[8]  S. McLaughlin,et al.  Joint timing recovery and turbo equalization for coded partial response channels , 2002 .

[9]  Costas N. Georghiades,et al.  The expectation-maximization algorithm for symbol unsynchronized sequence detection , 1991, IEEE Trans. Commun..

[10]  G. David Forney,et al.  Maximum-likelihood sequence estimation of digital sequences in the presence of intersymbol interference , 1972, IEEE Trans. Inf. Theory.

[11]  Umberto Mengali,et al.  Synchronization Techniques for Digital Receivers , 1997, Applications of Communications Theory.

[12]  Roy D. Cideciyan,et al.  A PRML System for Digital Magnetic Recording , 1992, IEEE J. Sel. Areas Commun..

[13]  John R. Barry,et al.  Per-survivor iterative timing recovery for coded partial response channels , 2004, IEEE Global Telecommunications Conference, 2004. GLOBECOM '04..

[14]  H. Thapar,et al.  A class of partial response systems for increasing storage density in magnetic recording , 1987 .

[15]  Jan W. M. Bergmans,et al.  Digital baseband transmission and recording , 1996 .

[16]  John R. Barry,et al.  Per-survivor timing recovery for uncoded partial response channels , 2004, 2004 IEEE International Conference on Communications (IEEE Cat. No.04CH37577).

[17]  Jaekyun Moon,et al.  Equalization for maximum likelihood detectors , 1995 .

[18]  Andrew C. Singer,et al.  Turbo equalization: principles and new results , 2002, IEEE Trans. Commun..

[19]  John Cocke,et al.  Optimal decoding of linear codes for minimizing symbol error rate (Corresp.) , 1974, IEEE Trans. Inf. Theory.

[20]  G. J. Parker,et al.  Three-dimensional modeling of perpendicular reading with a soft underlayer , 2002 .

[21]  John R. Barry,et al.  Per-survivor iterative timing recovery for coded partial response channels , 2004, GLOBECOM.

[22]  Riccardo Raheli,et al.  Per-Survivor Processing: a general approach to MLSE in uncertain environments , 1995, IEEE Trans. Commun..

[23]  Robert G. Gallager,et al.  Low-density parity-check codes , 1962, IRE Trans. Inf. Theory.

[24]  Dan Raphaeli,et al.  Combined turbo equalization and turbo decoding , 1997, GLOBECOM 97. IEEE Global Telecommunications Conference. Conference Record.

[25]  John R. Barry,et al.  A new timing recovery architecture for fast convergence , 2003, Proceedings of the 2003 International Symposium on Circuits and Systems, 2003. ISCAS '03..

[26]  Jaekyun Moon,et al.  Timing Recovery in Conjunction With Maximum Likelihood Sequence Detection in the Presence of Intersymbol Interference , 2008, IEEE Transactions on Circuits and Systems I: Regular Papers.

[27]  Piya Kovintavewat,et al.  Timing Recovery Based on Per-Survivor Processing , 2004 .

[28]  Stephen B. Wicker,et al.  Turbo Coding , 1998 .

[29]  Li Du,et al.  An EPR4 read/write channel with digital timing recovery , 1998 .

[30]  J.R. Barry,et al.  Iterative timing recovery , 2004, IEEE Signal Processing Magazine.