Dynamic magnetic information storage or retrieval – Modulating or demodulating
Patent
1991-07-02
1993-10-19
Mis, David
Dynamic magnetic information storage or retrieval
Modulating or demodulating
360 32, 360 39, G11B 509, G11B 2006
Patent
active
052551270
ABSTRACT:
In transmission or recording of a digital signal by means of digital amplitude and phase modulation, particularly recording into and reproducing the same from the a magnetic recording medium, a digital amplitude/phase modulated signal to be demodulated is commonly affected by the non-linear amplitude characteristics and the effects of unwanted jitter and envelope variation. As the result, the error rate of decoded data will be increased. For compensation, the Viterbi decoding technique is employed with the use of a weighted distance value calculated by multiplying an Euclidean distance between the signal point of a reproduction signal and the datum point of each code by a positive weighting factor which is determined smaller when the code datum point is located further from the origin point of a coordinate system. Accordingly, the weighted distance of each reproduction signal point from its corresponding datum point can approximately be uniform thus ensuring less error decoding in general.
REFERENCES:
patent: 4077021 (1978-02-01), Csajika et al.
patent: 4403263 (1983-09-01), Kageyama et al.
"Digital Video Recording: New Results in Channel Coding and Error Protection", Jurgen K. R. Heitmann, SMPTE Journal, Feb. 1984, pp. 140-144.
"An Analytical Approach to the Standardization of Digital Videotape Recorders", Jurgen K. R. Heitmann, SMPTE Journal, pp. 229-232, Mar. 1982.
"An Experimental Digital VTR Capable of 12-Hour Recording", C. Yamamitsu et al., IEEE Transactions On Consumer Electronics, vol. CE-33, No. 3, Aug. 1977, pp. 240-248.
"An Experimental Digital Video Recording System", L. M. H. E. Driessen et al., IEEE Transactions On Consumer Electronics, vol. CE-32, No. 3, Aug. 1986, pp. 362-371.
"Digital Television Recording with Low Tape Consumption", John L. E. Baldwin, SMPTE Journal, Jul. 1979, vol. 88, pp. 490-492.
"Signal System Design for a Digital Video Recording System", Luigi Gallo, SMPTE Journal, vol. 86, Oct. 1977, pp. 749-756.
"Recording of Quadrature Amplitude-Modulated Signal On Magnetic Recording Channel", Masaaki Kobayashi et al., The Transactions of the IEICE, vol. E73, No. 5, May 1990, pp. 665-669.
"A Study of Multi-Level Signal Recording for Digital VCR", Masaaki Kobayashi et al., ITEJ Technical Report, vol. 13, No. 60, pp. 1-6, Nov. 1989.
Kobayashi Masa-aki
Nakatsu Etsuto
Ohta Haruo
Shimazaki Hiroaki
Matsushita Electric - Industrial Co., Ltd.
Mis David
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