Pulse or digital communications – Equalizers – Automatic
Reexamination Certificate
2005-11-01
2005-11-01
Chin, Stephen (Department: 2634)
Pulse or digital communications
Equalizers
Automatic
C375S233000, C375S231000, C360S065000
Reexamination Certificate
active
06961373
ABSTRACT:
A method and apparatus is disclosed to overcome the effects of intersymbol interference during data transmission. Overcoming the effects of intersymbol interference makes possible higher data transmission rates for a given error rate. In one embodiment a receiver-transmitter pair is configured with a precode filter at the transmit side and a feed forward filter and a feedback filter at the receive side. Filter coefficients are calculated to reduce the undesirable effects of the channel, such as intersymbol interference. In one embodiment a training process occurs with the feedforward filter and a feedback filter, such that the first N coefficients of the feedback filter are set to zero. Thereafter, the coefficients of the feedforward filter are subject to spectral factorization and separated into minimum phase roots and maximum phase roots. The minimum phase roots comprise the precode filter coefficients and the maximum phase roots are established as feedforward filter coefficients.
REFERENCES:
patent: 4359778 (1982-11-01), Lee
patent: 4583235 (1986-04-01), Dömer et al.
patent: 4956838 (1990-09-01), Gilloire et al.
patent: 5222084 (1993-06-01), Takahashi
patent: 5305307 (1994-04-01), Chu
patent: 5633863 (1997-05-01), Gysel et al.
patent: 5646958 (1997-07-01), Tsujimoto
patent: 5856970 (1999-01-01), Gee et al.
patent: 5896452 (1999-04-01), Yip et al.
patent: 6088827 (2000-07-01), Rao
patent: 6147979 (2000-11-01), Michel et al.
patent: 6160790 (2000-12-01), Bremer
patent: 6167082 (2000-12-01), Ling et al.
patent: 6201831 (2001-03-01), Agazzi et al.
patent: 6226332 (2001-05-01), Agazzi et al.
patent: 6249544 (2001-06-01), Azazzi et al.
patent: 6252904 (2001-06-01), Agazzi et al.
patent: 6253345 (2001-06-01), Agazzi et al.
patent: 6259729 (2001-07-01), Seki
patent: 6272173 (2001-08-01), Hatamian
patent: 6351531 (2002-02-01), Tahernezhaadi et al.
patent: 6356555 (2002-03-01), Rakib et al.
patent: 6480532 (2002-11-01), Vareljian
patent: 6493448 (2002-12-01), Mann et al.
patent: 6584160 (2003-06-01), Amrany et al.
patent: 6618480 (2003-09-01), Polley et al.
patent: 6665402 (2003-12-01), Yue et al.
patent: 6751255 (2004-06-01), Reuven et al.
patent: 2001/0036160 (2001-11-01), Curran et al.
patent: 2002/0067824 (2002-06-01), Wang
patent: 2002/0106016 (2002-08-01), Egelmeers et al.
patent: 2002/0176492 (2002-11-01), Zangi et al.
patent: 2002/0191552 (2002-12-01), Watkinson
patent: 2003/0067888 (2003-04-01), Bina et al.
patent: 2004/0125487 (2004-07-01), Sternad et al.
Wu, S.,Boyd, S., Vandenberghe, L.;FIR Filter Design via Spectral Factorization and Convex Optimization; Chapter 1 of Applied Computational Control, Signal and Communications; Biswas Datta editor; 1997; www.stanford.edu/˜boyd/reports/magdes.pdf; pp. 1-33.
Defination of Minimum Phase; www-ccrma.stanford.edu/˜jos/filters/Definition_Minimum_Phase.html.
FIR filter optimization as pre-emphasis of high-speed backplane data transmission; Li, M.; Wang, S., Tao, T., Kawasniewski, T.; Electronics Letters; Jul. 8, 2004; vol. 40, No. 14.
Oscar Agazzi, et al., “10Gb/s PMD Using PAM-5 Trellis Coded Modulation”, Broadcom,IEEE802.3, Albuquerque, New Mexico, Mar. 6-10, 2000, 38 pages.
Jamie E. Kardontchik, “4D Encoding in Level-One's Proposal for 1000BAS-T”, Advanced Micro Devices, Aug. 21, 1997—Rev. B, pp. 1-24.
Erich F. Haratsch, et al., “A 1-Gb/s Joint Equalizer and Trellis Decoder for 1000BASE-T Gigabit Ethernet”,IEEE Journal of Solid-State Circuits, vol. 36, No. 3, Mar. 2001, pp. 374-384.
Mehdi Hatamian, et al., “Design Considerations for Gigabit Thernet 1000Base-T Twisted Pair Transceivers”, IEEE 1998 Custom Integrated Circuits Conference, pp. 335-342.
Gottfried Ungerboeck, “Trellis-Coded Modulation with Redundant Signal Sets”,IEEE Communications Magazine, Feb. 1987, vol. 25, No. 2, pp. 5-21.
“Gigabit Ethernet Over Category 5”, Copyright 2000-2001 Agilent Technologies, 12 pages.
M.P. Sellers, et al., “Stabilized Precoder for Indoor Radio Communications”,IEEE Communications Letters, vol. 4, No. 10, Oct. 2000. pp. 315-317.
“Wirescope 350—Understanding ELFEXT”, © 2000 Agilent Technologies, 2 pages.
David Crawford, “Adaptive Filters”, © David Crawford 1996, pp. 1-5.
David A. Johns, et al., “Integrated Circuits for Data Transmission Over Twisted-Pair Channels”,IEEE Journal of Solid-State Circuits, vol. 32, No. 3, Mar. 1997, pp. 398-406.
Prof. David Johns, University of Toronto, “Equalization”, © D.A. Johns 1997, 29 pages.
David Smalley, “Equalization Concepts: A Tutorial”, Atlanta Regional Technology Center, Texas Instruments, pp. 1-29, Oct. 1994.
Shao-Po Wu, et al., “FIR Filter Design via Spectral Factorization and Convex Optimization”, to appear as Chapter 1 ofApplied Computational Control, Signal and Communications, Biswa Datta Editor, Birkhauser, 1977, pp. 1-33.
Richard D. Wesel, et al., “Achievable Rates for Tomlinson-Harashima Precoding”,IEEE Transactions on Information Theory, vol. 44, No. 2, Mar. 1998, pp. 824-831.
Wolfgang H. Gerstacker, et al., “Blind Equalization Techniques for xDSL Using Channel Coding and Precoding”, submitted to AEÜ Int. J. Electr. Commun., pp. 1-4, May 1999.
Chip Fleming, “A Tutorial on Convolutional Coding with Viterbi Decoding”, © 1999-2002, Spectrum Applications, pp. 1-6.
“ELFEXT—Introduction”, Fluke Networks™, ©2000, pp. 1-2.
“Iowegian's dspGuru FIR FAQ Part 2: Properties”, © 1999-2000 Iowegian International Corp., pp. 1-4.
“28.5 Protocol Implementation Conformance Statement (PICS) Proforma for Clause 28, Physical Layer Link Signaling for 10 Mb/s, 100 Mb/s and 1000 Mb/s Auto-Negotiation on Twisted Pair”,IEEE Std. 802.3, 1998 Edition, pp. 6-14 and 18-44.
M. Tomlinson, “New automatic equalizer employing modulo arithmetic,”Electronic Letters, vol. 7, pp. 138-139, 1971.
H. Harashima and H. Miyakawa, “Matched-transmission technique for channels with intersymbol interference,”IEEE Transactions on Communications, vol. COM-20, No. 4, pp. 774-780, Aug. 1972.
P. Kabal and S. Pasupathy, “Partial-response signaling,”IEEE Transactions on Communications, vol. COM-23, No. 9, pp. 921-934, Sep. 1975.
R. F. H. Fischer, W. H. Gerstacker, and J. B. Huber, “Dynamics limited precoding, shaping, and blind equalization for fast digital transmission over twisted pair lines,”IEEE Journal on Selected Areas in Communications, vol. 13, No. 9, pp. 1622-1633, Dec. 1995.
R. F. H. Fischer and J. B. Huber, “Comparison of precoding schemes for digital subscriber lines,”IEEE Transactions on Communications, vol. 45, No. 3, pp. 334-343, Mar. 1997.
Chin Stephen
Pathak Sudhanshu C.
SolarFlare Communications, Inc.
Weid & Miller, Ltd.
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