Pulse or digital communications – Spread spectrum – Direct sequence
Reexamination Certificate
2005-03-29
2005-03-29
Ha, Dac V. (Department: 2634)
Pulse or digital communications
Spread spectrum
Direct sequence
C375S148000, C375S349000, C370S335000, C370S342000, C370S479000, C455S303000
Reexamination Certificate
active
06873646
ABSTRACT:
A single-user detection method operates to reduce the effects of interference in multi-user detection systems. Based upon a number of received user codes, a receiver defines a frame of symbols containing at least one window. A symbol amplitude of a single-user in a multi-user system is approximated over the window of the frame and a perturbative correction value is calculated based upon a correlation or decorrelation matrix, which is determined by the delay spread of the signals. An estimation of the symbol amplitude of the single-user signal is calculated over one or a number of windows of the frame. The single-user signal is detected when the symbol amplitudes of the entire signal within the frame has been calculated.
REFERENCES:
patent: 5467368 (1995-11-01), Takeuchi et al.
patent: 5790606 (1998-08-01), Dent
patent: 5917829 (1999-06-01), Hertz et al.
patent: 6240099 (2001-05-01), Lim et al.
patent: 6301293 (2001-10-01), Huang et al.
A. J. Viterbi, “Very Low Rate Convolutional Codes for Maximum Theoretical Performance of Spread-Spectrum Multiple-Access Channels,” IEEE Journal on Selected Areas in Communications, vol. 8, No. 4, pp. 641-649, May 1990.
S. Moshavi, “Multi-User Detection for DS-CDMA Communications,” IEEE Communications Magazine, vol. 34, No. 10, pp. 124-136, Oct. 1996.
C. C. Lu, “Perturbation methods for canceling multi-user interference,” The Sixth IEEE Symposium on Computers and Communications, Hammamet, Tunisia, pp. 204-209, Jul., 2001.
C. C. Lu, “Perturbation Methods for canceling interference in CDMA systems,” The Eighth IEEE International Conference on Electronics, Circuits and Systems, Malta, pp. 1143-1146, Sep. 2001.
C. C. Lu, “Perturbation principle of multi-user detection,” The 3rdIEEE International Conference on Mobile and Wireless Communications Networds, Recife, Brazil, Aug. 2001.
S. Verdu, “Minimum probability of error for asynchronous Gaussian multiple-access channels,” IEEE Trans. Information Theory, vol. IT-32, No. 1, pp. 85-96, Jan. 1986.
R. Lupas and S. Verdu, “Linear multiuser detectors for synchronous code-division multiple-access channels”, IEEE Trans. Information Theory, vol. 35, No. 1, pp123-136, Jan. 1989.
M. Honig, U. Madhow and S. Verdu, “Blind adaptive multiuser detection”, IEEE Trans. Information Theory, vol. 41, No. 4, pp. 944-960, Jul. 1995.
S. Moshavi, “Multi-user detection for DS-CDMA communications”, IEEE Communications Magazine, pp. 124-136, Oct. 1996.
C. C. Lu, “Frequency acquisition in a synchronous CDMA cordless phone using fast Walsh transform,” IEEE PIMRC '95, Toronto, Canada, pp. 990-994, Sep. 1995.
C. C. Lu, “Computer simulation of a synchronized CDMA cellular phone system,” IS-COM '93, 1993 International Symposium on Communications, vol. 1 p. 12-67, (Published by National Chiao Tung Univ., Hsinchu, Taiwan, Dec. 1993).
D. Divsalar, M. K. Simon and D. Raphaeli, “Improved parallel interference cancellation for CDMA,” IEEE trans. Commun., vol. 46, No. 2, pp. 258-268, Feb. 1998.
Ha Dac V.
Industrial Technology Research Institute
Shaw Pittman LLP
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