Boots – shoes – and leggings
Patent
1996-01-30
1997-07-22
Mai, Tan V.
Boots, shoes, and leggings
G06G 702
Patent
active
056509545
ABSTRACT:
Apparatus for performing time and frequency-domain filtering in a sampled communication channel for the transmission of binary information. A received signal is provided to a double-domain, analog transversal equalizer comprising a plurality of serially connected, active, analog filter sections with associated tap locations, each filter section having a programmable frequency response and adaptively controlled one-bit delay. The filter sections provide sequential, cumulative frequency domain filtering as the received signal propagates through the equalizer. The transfer function of each filter section has a linear phase polynomial denominator and a real (at s=j.omega.) polynomial numerator, facilitating independent control of the delay and frequency response of each filter section. A plurality of analog multipliers multiply signals present at the tap locations by analog tap weight signals to generate a plurality of product signals, and an analog summer adds the product signals to generate an output filtered signal before sampling occurs. An LMS error-based adaptive tap weight control circuit iteratively generates optimal analog tap weight signals, a delay control circuit provides the necessary timing signals at the bit-rate to control the time delay of each analog filter section and a location of zeros circuit controls the location of zeros in the transfer function, and hence the frequency response, of each filter section. The double-domain transversal equalizer provides aperiodic and controlled frequency response at low frequencies and does not require a noise suppressing prefilter.
REFERENCES:
patent: 4146840 (1979-03-01), McRae et al.
patent: 4346412 (1982-08-01), Conley
patent: 5060088 (1991-10-01), Dolivo et al.
patent: 5153875 (1992-10-01), Takatori
patent: 5189637 (1993-02-01), Eriksson
patent: 5258933 (1993-11-01), Johnson et al.
patent: 5325130 (1994-06-01), Miller et al.
patent: 5392171 (1995-02-01), Kovner et al.
patent: 5422760 (1995-06-01), Abbott
patent: 5430768 (1995-07-01), Minuhin et al.
patent: 5459757 (1995-10-01), Minuhin et al.
patent: 5563819 (1996-10-01), Nelson
R.D. Gitlin et al., "Data Communications Principles", Plenum Press, New York, 1992, pp. 488-508.
A. Gersho, "Adaptive Equalization of Highly Dispersive Channels for Data Transmission", The Bell System Technical Journal, Jan. 1969, pp. 55-70.
D.S. Humpherys, "Equiripple Network Approximations Using Iteration Techniques", Proceedings of National Electronics Conference, vol. 20, 1964, pp. 753-758.
R.L. Geiger et al., "Active Filter Design Using Operational Transconductance Amplifiers: A Tutorial", IEEE Circuit and Devices, vol. 1, No. 2, Mar. 1995, pp. 20-32.
F.J. MacWilliams et al., "Pseudo-Random Sequences and Arrays", IEEC Proceedings, vol. 64, No. 12, Dec. 1976, pp. 1715-1729.
K. Han et al., "Comparison of Different Detection Techniques for Digital Magnetic Recording Channels", IEEE Transactions on Magnetics, vol. 31, No. 2, Mar. 1995, pp. 1128-1133.
R.D. Cideciyan et al., "A PRML System for Digital Magnetic Recording", IEEE Journal on Selected Areas of Communications, vol. 10, No. 1, Jan. 1992, pp. 38-56.
E. Healey, "Choosing the right PRML read channel", Data Storage, Nov./Dec. 1995, pp. 27-34.
J.D. Coker et al., "Implementation of PRML in a Rigid Disk Drive", IEEE Transactions on Magnetics, vol. 27, No. 6, Nov. 1991, pp. 4538-4543.
P. Kabal et al., "Partial-Response Signaling", IEEE Transactions on Communications, vol. com-23, No. 9, Sep. 1975, pp. 921-934.
G. Kerwin et al., "Performance Evaluation of the Disk Drive Industry's Second Generation PRML Data Channel", IBM Technical Paper, FD-1 (No Date).
K.C. Bracken et al., "Adaptive Continuous-Time Equalization and FDTS/DF Sequence Detection", I.E.E.E. Transactions on Magnetics, vol. 31, No. 6, Nov. 1995, pp. 3048-3050.
H. K. Thapar et al., "A Claim of Partial Response Systems for Increasing Storage Density in Magnetic Recording", IEEE Transactions on Magnetics, vol. Mag-23, No. 5, Sep. 1987, pp. 3666-3668.
Heller III Edward P.
Mai Tan V.
McCarthy Bill D.
McCarthy Randall K.
Seagate Technology Inc.
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