Pulse or digital communications – Receivers – Interference or noise reduction
Reexamination Certificate
2006-05-30
2006-05-30
Tran, Khanh (Department: 2631)
Pulse or digital communications
Receivers
Interference or noise reduction
C375S232000
Reexamination Certificate
active
07054396
ABSTRACT:
The equalizer of the present invention operates on input multipath signal samples, preferably at chip or sub-chip resolution, to remove or substantially cancel the effects of one or more secondary signals from the main path signal. Using predetermined path information for one or more of the secondary path signals, including magnitude, phase, and time offset relative to the main path signal, the equalizer compensates input multipath signal samples by subtracting estimated secondary signal values from the input samples. For each input sample, the equalizer forms a sliced sample, where the sliced sample represents a nominal phase value defined by the modulation scheme used in the original chip or symbol transmission that is closest in value to the actual phase of the input sample. These sliced samples are held in a running buffer and used, in combination with the predetermined path information and scaling logic, to form the estimated secondary signal values for compensating the input samples.
REFERENCES:
patent: 5077753 (1991-12-01), Grau, Jr. et al.
patent: 5361276 (1994-11-01), Subramanian
patent: 5414734 (1995-05-01), Marchetto et al.
patent: 5673286 (1997-09-01), Lomp
patent: 5689528 (1997-11-01), Tsujimoto
patent: 5692008 (1997-11-01), Van Nee
patent: 5706314 (1998-01-01), Davis et al.
patent: 5809060 (1998-09-01), Cafarella et al.
patent: 5995538 (1999-11-01), Lomp
patent: 6009089 (1999-12-01), Huang et al.
patent: 6069917 (2000-05-01), Werner et al.
patent: 6075812 (2000-06-01), Cafarella et al.
patent: 6333947 (2001-12-01), van Heeswyk et al.
patent: 6541950 (2003-04-01), Townsend et al.
patent: 6563858 (2003-05-01), Fakatselis et al.
patent: 6647007 (2003-11-01), Zoernack
patent: 6700929 (2004-03-01), Shan et al.
patent: 6728324 (2004-04-01), Shan et al.
patent: 0932263 (1999-07-01), None
patent: 0 981 206 (2000-02-01), None
patent: WO 98/26544 (1998-06-01), None
Lingwood, Stephen et al., “ASIC Implementaion of a Direct-Sequence Spread-Spectrum RAKE-Receiver,” IEEE 44thVehicular Technology Congerence, Jun. 8-10, 1994, XP010123293.
Väisänen, Kari and Renfors, Markku, “Efficient Digital Filters for Pulse-Shaping and Jitter-Free Frequency Error Detection and Timing Recovery,” Signal Processing, vol. 81, No. 4, Apr., 2001 pp. 829-844, XP004234879.
International Search Report for PCT/US2004/014055 mailed Nov. 4, 2004.
3COM Corporation, “IEEE 802.11b Wireless LANs,” http://www.3com.com/technology/tech—net/white—papers/503072a.html.
Andren, Carl and Webster, Mark, “CCK Modulation Delivers 11Mbps for High Rate IEEE 802.11 Extension,” Wireless Symposium/Portable by Design Conference Proceedings, Mar. 14, 2000 XP002147321.
Fuente, M. P., Guo, Y. J., and Barton, S.K., “A New Scheme for Direct Sequence Spread Spectrum Radio LANs,” IEEE 4th International Symposium, Mainz Germany, Sep. 22-25, 1996, XP010208831.
Hou, Wen-Shang, and Chen, Bor-Sen, “Adaptive Detection in Asynchronous Code-Division Multiple-Acess System in Multipath Fading Channels,” IEEE Transactions on Communications, vol. 48, No. 5, May 2000, pp. 863-874.
Kim, Su II and Lee Hwang Soo, “Performance Improvement of RAKE Receiver for a Multicode DS-CDMA System with Multistage Interference Cacellation Detectors,” Proceedings of IEEE Tencon '99, Sep. 15-17, 1999, vol. 1, pp. 573-576.
Prasad, Ramjee and Ojanpera, Tero, “An Overview of CDMA Evolution Toward Wideband CDMA,” IEEE Communications Surveys, 1998, http://www.comsoc.org/pubs/surveys/4q98issue/prasad.html.
RF Micro Devices, Inc.
Tran Khanh
Withrow & Terranova , PLLC
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