Reduced lattice demodulation method and apparatus

Details Reduced lattice demodulation method and apparatus Reduced lattice demodulation method and apparatus

2007-06-08

2010-12-07

Liu, Shuwang (Department: 2611)

Pulse or digital communications

Spread spectrum

Direct sequence

C375S348000

Reexamination Certificate

active

07848390

ABSTRACT:
RAKE-based receivers utilize lattice reduction for improving symbol estimation accuracy. Channel response estimates and received signal streams are transformed from a constellation lattice basis to an integer lattice basis to increase the orthogonality of symbol estimation decision regions. In one embodiment, received signal streams are processed by generating despread signal samples from received signal streams transmitted using different spreading codes. Channel response associated with the different received signal streams is estimated and transformed from a first lattice basis to a second lattice basis having greater orthogonality between decision regions than the first lattice basis. The despread signal samples are aligned to the second lattice and combining weights generated based on the transformed channel response estimate. Symbol estimation decision statistics are generated based on the combining weights and the aligned despread signal samples. Soft bit values are generated for decoding based on the symbol estimation decision statistics.

REFERENCES:
patent: 6724843 (2004-04-01), Clarkson et al.
patent: 2006/0029124 (2006-02-01), Grant et al.
patent: 2006/0176971 (2006-08-01), Nissani (Nissensohn)
patent: 2007/0047629 (2007-03-01), Fulghum
patent: 2008/0019262 (2008-01-01), Lillie et al.
patent: 2429884 (2007-03-01), None
Yao, Huan, “Efficient Signal, Code and Receiver Designs for MIMO Communication Systems”, Jun. 2003, MIT, accessed Jul. 31, 2010.
Agrell, E. et al. “Closest Point Search in Lattices.” IEEE Transactions on Information Theory, vol. 48, No. 8, Aug. 2002, pp. 2201-2214.
Berenguer, I. et al. “Lattice-Reduction-Aided Receivers for MIMO-OFDM in Spatial Multiplexing Systems.” 15th IEEE International Symoposium on Personal, Indoor and Mobile Radio Communications, 2004 (PIMRC 2004), vol. 2, Sep. 5-8, 2004, pp. 1517-1521.
Berenguer, Inaki et al. “MIMO Antenna Selection with Lattice-Reductin-Aided Linear Receivers.” IEEE Transactions on Vehicular Technology, vol. 53, No. 5, Sep. 2004, pp. 1289-1302.
Grant, Stephen J. et al. “Generalized RAKE Receivers for MIMO Systems.” Proc. 58th IEEE Vehicular Technology Conference, Orlando, FL, Oct. 2003, pp. 424-428.
Grant, Stephen J. et al. “Reduced Complexity Joint Detection Generalized RAKE Receiver for WCDMA MIMO Systems.” Proc. 62nd IEEE Vehicular Technology Conf., Stockholm, Sweden, May 2005.
Lenstra, A. K. et al. “Factoring Polynomials with Rational Coefficients.” Mathematische Annalen 261 (1982), pp. 515-534.
Co-pending U.S. Appl. No. 11/438,921, filed May 23, 2006.

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