Guzik Technical Enterprises Presents:

This text contains a comprehensive review of modern magnetic recording systems and measurements with numerous original contributions and the available results on measurement and characterization of Non-Linear Transition Shift, Partial Erasure, testing of PRML Error Margin, performance of PRML channels and more.

It is a must-read source for channel, head, and media engineers, test engineers, R&D staff, consultants, and the students, whose interests lie in the field of magnetic recording. With more than 270 pages and over 100 illustrations, the book is a considerable extension of the previous text "PRML: A Practical Approach", published by Guzik Technical Enterprises
in 1995.

Price: U.S. $75

Order this book at Guzik Technical Enterprises

Refer to Guzik Part number 99-900000-01.

Content

I. Introduction to Magnetic Recording

1.1 Write and Read Processes: An Overview

1.2 Isolated Transition and Inter-Symbol Interference (ISI): Linear Superposition

1.3 Noise in Magnetic Recording

1.4 Magnetic Recording: Linear and Track Densities

References

2. Channel Coding and Error Correction

2.1 Magnetic Recording Channel

2.2 NRZ and NRZI Data

2.3 Channel Codes: Requirements of the Magnetic Recording Channel

2.4 Run-Length Limited (RLL) Codes

2.5 User Data Rate, Channel Data Rate and Flux Frequency

2.4 Principles of Error Correction

2.4.1 Error Detection: Parity Checking

2.4.2 Hamming Distance. Error Detection and Correction Theorems

2.4.3 Cyclic Codes

2.4.4 Mathematics of ECC References

3. Peak Detection and Window Margin

3.1 Peak Detection System

3.2 Signal to Noise Ratio and Error Rate of the Threshold Detector

3.3 Error Rate of the Zero-Crossing Detector

3.4 Window Margin (Bit-Shift Distribution) References

4. Off-Track Performance

4.1 Structure of Magnetic Track. Signal, Noise, Interference, Track profile and Error Rate.

4.2 747 Test

5. Hard Transition Shift and Overwrite

5.1 Demagnetization Field

5.2 Hard/Easy Transition Shift for DC-Erased Media

5.3 Asymmetry and Overwrite Tests. Nature of the overwrite signal

5.4 Overwrite Signal for Different Overwrite Ratios. Proximity Effect

5.4 Spectrum of the Overwrite Signal References

6. Non-Linear Transition Shift (NLTS) and Partial Erasure: Dibit Transition

6.1 Non-Linear Transition Shift for Dibit Transition

6.2 Precompensation of NLTS

6.3 Interactions of NLTS with Hard Transition Shift : Hard/Easy and Easy/Hard dibits

6.4 Partial Erasure

6.5 Spectral Measurement of Partial Erasure References

7. Measurement of Non-Linear Transition Shift

7.1 Method of Harmonic Elimination (5-th harmonic)

7.1.1 Theory of Harmonic Elimination Method

7.1.2 Algorithm summary: First Method of Harmonic Elimination

7.1.3 Summary of algorithm: Second Method of Harmonic Elimination

7.1.4 Measurement of Hard Transition shift using spectral elimination

7.1.5 Influence of Partial Erasure on Harmonic Elimination Method

7.1.6 Separating Partial Erasure and NLTS for Harmonic Elimination Method

7.1.7 Influence of Partial Erasure on Precompensation measurement for Harmonic Elimination Method. Estimation of NLTS and Partial Erasure from Precompensation Measurements

7.1.8 Influence of Additive noise on Harmonic Elimination Method

7.2 Methods based on Pseudo-Random Sequences

7.2.1. Pseudo Random Sequences

7.2.2 Theory of the dipulse extraction method

7.2.3. Method of Dipulse Extraction: Statement of the algorithm

7.2.4 NLTS Measurements: Method of Time Domain Correlation Analysis using Pseudo -Random Sequences

7.2.5 Influence of Partial Erasure on Dipulse Extraction method

7.2.6 Influence of Partial Erasure on Time Correlation Extraction method

7.2.7 Performance of Pseudo-Random methods: Influence of PW50

7.3 NLTS Measurements: Method of Pulse Matching

7.4 NLTS Measurements: Method of Timing Interval Measurements.

References

8. NLTS and Partial Erasure for a Series of Transitions

8.1 Interaction of Adjacent Transitions

8.2 NLTS for a dibit versus NLTS for a random pattern

8.3 Interactions between NLTS and Hard Transition Shift: Series of Transitions

8.4 Harmonic Elimination Patterns for Measuring Individual Transition's NLTS

8.5 Precompensation for Series of Transitions

8.6 Partial Erasure for a Series of Transitions

8.7 Transition Modulation and Head/Media Parameters

9. Introduction to PRML

9.1 PRML Detection System

9.2 PRML Bandwidth and Frequency Response

9.3 Partial Response Polynomials. EPR4 and E2PR4 Systems

9.4 Channel and User Densities of PR4, EPR4 and E2PR4 References

10. Principles of Equalization

10.1 Equalization using Transversal Filter

10.2 Reshaping Problem

10.3 Adaptive Adjustment of Equalizer

10.4 Practical Recommendations References

11. Principles of PRML Clock and Gain Recovery

11.1 Phase Locked Loop

11.2 Phase Error Calculation for PRML

11.3 Gain Recovery References

12. Maximum Likelihood Detection

12.1 State Diagram and Trellis: Peak Detection, PR4, EPR4 and E2PR4

12.2 Trellis in NRZI Representation

12.3 Maximum Likelihood Detection

12.4 Interleave for PR4 trellis. PR4 Viterbi Detector Using Sliding Threshold

12.5 Error Events in Maximum Likelihood Detection

12.5.1 Properties of Gaussian Noise

12.5.2 Minimum Distance Error Events

12.5.3 Error Rate of PRML systems with Gaussian noise

12.5.4 Error Rates of PR4, EPR4 and E2PR4 systems with Gaussian noise. Gain of Viterbi Detector Over Threshold detector. References

13. PRML Error Margin Analysis

13.1 Principle of Error Margin Analysis. Natural System Stressing

13.2 Stressing Maximum Likelihood Detector by Noise Amplification

13.3 Sequenced Amplitude Margin (SAM) algorithm

13.3.1 Algorithm of SAM

13.3.2 Sequenced Amplitude Margin without Equations

13.3.3 Equivalence of Amplitude Margin to Channel Noise Amplification

13.3.4 Choosing the 0% Margin in SAM Plot

13.4 Method of Error Filters

13.5 Method of Partial Histograms

13.6 Performance of Error Margin Algorithms: Experimental session References

14. Performance of PRML Channels

14.1 Influence of Shape Distortions on PRML Error Rate: Theory

14.2 Influence of NLTS and Partial Erasure on PRML Channel

14.3 Influence of Equalization on the PRML Error Rate

14.4 PR4, EPR4 and E2PR4 - Myths, Facts, and Expectations.

References

Appendix 1: Fourier Transform, Convolution and Correlation

Appendix 2: Overwrite, Hard Transition Shift, Non-Linear Transition Shift and Partial Erasure: Practical Approach

Appendix 3: Signal Detection in Magnetic Recording.

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About the Author

Alexander Taratorin received his PhD in Physics in 1986. Dr. Taratorin became the principal scientist at Guzik Technical Enterprises in 1993. While there, he was involved in the development of magnetic test equipment, PRML detection and magnetic measurement algorithms. In 1996 he joined the IBM Research Division at the Almaden Research Center (currently the San Jose Research Center, Hitachi Global Storage Technologies).

His proficiencies include different aspects of magnetic recording physics: PRML channel detection, characterization of non-linear distortions, head and media noise measurements, high data rate recording and perpendicular recording systems.

Dr. Taratorin has several U.S. Patents in the field of magnetic recording. He published papers in IEEE Transactions on Magnetics, the Journal of Applied Physics, and has made numerous presentations at international conferences. Dr. Taratorin taught several courses on Magnetic Recording at Stanford University and Santa Clara University.

Dr. Taratorin wrote several books on magnetic recording. His books PRML: A Practical Approach (1995) and Characterization of Magnetic Recording Systems (1996), published by Guzik Technical Enterprises, became a popular source of reference worldwide. He has also co-authored a well-known textbook entitled Magnetic Information Storage Technology (together with S.X.Wang), published by Academic Press in 1999.