Pulse or digital communications – Synchronizers – Phase displacement – slip or jitter correction
Reexamination Certificate
2007-01-30
2007-01-30
Kim, Kevin (Department: 2611)
Pulse or digital communications
Synchronizers
Phase displacement, slip or jitter correction
C375S260000, C375S229000, C375S226000, C455S017000, C455S023000, C455S702000
Reexamination Certificate
active
10042780
ABSTRACT:
Various methods and apparatus for frequency-domain estimation of carrier frequency offsets are provided in which the carrier frequency offset estimate is robust against non-white (frequency-dependent) noise. A carrier-specific weighting factor is associated with each carrier of a multi-carrier signal. Using the carrier-specific weighting factors, a carrier frequency offset estimate is computed from received signals and estimated channel transfer functions associated with each of the carriers. Because greater weights are given to carriers whose frequencies include lower noise and/or carriers transmitting a known sequence of symbols, the estimate of the carrier frequency offset is improved. The carrier frequency offset estimate may then be applied in a feedback loop to phase-compensate a subsequently received signal.
REFERENCES:
patent: 5228062 (1993-07-01), Bingham
patent: 5282222 (1994-01-01), Fattouche et al.
patent: 5450456 (1995-09-01), Mueller
patent: 5487069 (1996-01-01), O'Sullivan et al.
patent: 6442211 (2002-08-01), Hampel et al.
patent: 6628738 (2003-09-01), Peeters et al.
patent: 6704374 (2004-03-01), Belotserkovsky et al.
patent: 6862262 (2005-03-01), Imamura
patent: 2003/0086504 (2003-05-01), Magee et al.
patent: 2003/0112902 (2003-06-01), Ghosh et al.
patent: 1172956 (2002-01-01), None
“dspGuru: Invinite Impulse Response Filter FAQ”, Loweigan International, 1999-2004, pags 1-2.
Beek et al., “ML Estimation of Time and Frequency Offset in OFDM Systems,”IEEE Trans. on Signal Processing, vol. 45, No. 7, pp. 1800-1805, (Jul. 1997).
Boelcskei, “Blind estimation of symbol Timing and Carrier Frequency Offset in Pulse Shaping OFDM Systems,”Proc. of IEEE Int. Conf. on Acoustics, Speech and Signal Processing, pp. 2749-2752, Phoenix, AZ, (Mar. 1999).
Chang et al., “A New Estimation Scheme For Frequency and Timing Offsets in OFDM Systems,”Proc. of the IEEE Vehicular Technology Conference, pp. 1832-1835, Boston, MA, (Sep. 2000).
Classen et al., “Frequency Synchronization Algorithms for OFDM Systems suitable for Communication over Frequency-Selective Fading Channels,”Proc. of The IEEE Vehicular Technology Conference, pp. 1655-1659, Stockholm, Sweden, (Jun. 1994).
Gunther et al., “A New Approach for Symbol Frame Synchronization and Carrier Frequency Estimation in OFDM Communications,”Proc. of The IEEE Int. Conf. on Acoustics, Speech and Signal Processing, pp. 2725-2728, Phoenix, AZ, (Mar. 1999).
Hwang et al., “Frequency and Timing Period Offset Estimation Technique for OFDM Systems,”Electronics Letters, vol. 34, No. 6, pp. 520-521, (Mar. 19, 1998).
Jin et al., “The Estimation of Time Delay and Doppler Stretch of Wideband Signals,”IEEE Trans. on Signal Processing, vol. 43, No. 4, pp. 904-916, (Apr. 1995).
Kang et al., “Decision-directed maximum likelihood estimation of OFDM frame synchronization offset,”Electronics Letters, vol. 30, No. 25, pp. 2153-2154, (Dec. 8, 1994).
Lambrette et al., “OFDM Burst Frequency Synchronization by Single Carrier Training Data,”IEEE Communications Letters, vol. 1, No. 2, pp. 46-48, (Mar. 1997).
Lim et al., “An Efficient Carrier Frequency Offset Estimation Scheme for an OFDM System,”Proc. of the IEEE Vehicular Technology Conference, pp. 2453-2457, Boston, MA, (Sep. 2000).
Luise et al., “Carrier Frequency Acquisition and Tracking for OFDM Systems,”IEEE Trans. on Communications, vol. 44 No. 11, pp. 1590-1598, (Nov. 1996).
Moose et al., “A Technique for Orthogonal Frequency Division Multiplexing Frequency Offset Correction,”IEEE Trans. on Communications, vol. 42 No. 10, pp. 2908-2914, (Oct. 1994).
Pollet et al., “Synchronization with DMT Modulation,”IEEE Communications Magazine, pp. 80-86, (Apr. 1999).
Rinne et al., “An Equalization Method for Orthogonal Frequency Division Multiplexing Systems in Channels with Multipath Propagation, Frequency Offset and Phase Noise,”IEEE, pp. 1442-1446, (1996).
Schmidl et al., “Blind synchronisaation for OFDM,”Electronics Letters, vol. 33, No. 2, pp. 113-114, (Jan. 16, 1997).
Simoens et al., “A New Method for Joint Cancellation of Clock and Carrier Frequency Offsets in OFDM receivers over Frequency Selective Channels,”2000 IEEE 51stVehicular Technology Conference Proceedings, pp. 390-394, Tokyo, Japan, (May 2000).
Tureli et al., “Blind Carrier Synchronization and Channel Identification for OFDM Communications,”Proc. of IEEE Int. Conf. on Acoustics, Speech and Signal Processing, pp. 3509-3512, Seattle, WA, (May 1998).
Visser et al., “A Novel Method for Blind Frequency Offset Correction in an OFDM System,”Proc. of the IEEE PIMRC, pp. 816-820, Boston, MA, (Sep. 1998).
Wei et al., “Synchronization Requirement for Multi-user OFDM on Satellite Mobile and Two-path Rayleigh Fading Channels,”IEEE Trans. on Communications, vol. 43, No. 2, pp. 887-895, (Feb. 1995).
Kim Kevin
Withrow & Terranova , PLLC
Wong Linda
LandOfFree
Method and apparatus for frequency-domain tracking of... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Method and apparatus for frequency-domain tracking of..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Method and apparatus for frequency-domain tracking of... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3779727