Pulse or digital communications – Equalizers – Automatic
Reexamination Certificate
2006-09-26
2006-09-26
Ha, Dac V. (Department: 2634)
Pulse or digital communications
Equalizers
Automatic
C375S350000, C708S323000
Reexamination Certificate
active
07113540
ABSTRACT:
Multi-Input-Multi-Output (MIMO) Optimal Decision Feedback Equalizer (DFE) coefficients are determined from a channel estimate h by casting the MIMO DFE coefficient problem as a standard recursive least squares (RLS) problem and solving the RLS problem. In one embodiment, a fast recursive method, e.g., fast transversal filter (FTF) technique, then used to compute the Kalman gain of the RLS problem, which is then directly used to compute MIMO Feed Forward Equalizer (FFE) coefficients gopt. The complexity of a conventional FTF algorithm is reduced to one third of its original complexity by choosing the length of a MIMO Feed Back Equalizer (FBE) coefficients bopt(of the DFE) to force the FTF algorithm to use a lower triangular matrix. The MIMO FBE coefficients bopare computed by convolving the MIMO FFE coefficients goptwith the channel impulse response h. In performing this operation, a convolution matrix that characterizes the channel impulse response h extended to a bigger circulant matrix. With the extended circulant matrix structure, the convolution of the MIMO FFE coefficients goptwith the channel impulse response h may be performed easily performed in the frequency domain.
REFERENCES:
patent: 5448590 (1995-09-01), Kostic
patent: 6188722 (2001-02-01), Velez et al.
patent: 1 248 425 (2002-10-01), None
Kailath, Sayed: “Displacement structure: theory and applications” Siam Review, vol. 37, No. 3, Sep. 1995, pp. 297-386, XP002189613 New York, US.
Sailer: “Decision feedback equalization for powerline and HIPERLAN” Dissertation Submitted to the Swiss Federal Institute of Technology, Zurich, for the Degree of Doctor of Technical Sciences, Apr. 11, 2001, pp. 1-126, XP002189615, Zurich CD.
Chun, Kailath: “Generalized displacement structure for block-Toeplitz, Toeplitz-block, and Toeplit-derived matrices” NATO ASI Series, vol. F70, 1991, pp. 215-236, XP000852863 Berlin, DE ISSN: 0258-1248.
Cioffi, Kailath: “Fast, recursive-least-squares transversal filters and adaptive filtering” IEEE Transactions on Acoustics, Speech and Signal Processing, vol. 32, No. 2, April 1984, pp. 304-337, XP008015403, New York, US.
Ljung et al.: “Fast calculation of gain matrices for recursive estimation schemes” International Journal of Control, vol. 27, No. 1, Jan. 1978, pp. 1-19, XP008002548, Basingstoke, GB, ISSN: 0020-7179.
Al-Dhahir Cioffi: “MMSE decision feedback equalizers: finite-length results” IEEE Transactions on Information Theory, vol. 41, No. 4, Jul. 1995, pp. 961-975, XP002190789, New York, US.
Naofal Al-Dhahir and John M. Cioffi, Fast Computation of Channel-Estimate Based Equalizers in Packet Data Transmission, IEEE Transactions on Signal Processing, vol. 43, No. 11, pp. 2462-2473, Nov. 1995.
Naofal Al-Dhahir and Ali H. Sayed, A Computationally-Efficient FIR MMSE-DFE for Multi-User Communications, Signals, Systems, and Computers. Conference Record of the Thirty-Third Asilomar Conference on, vol. 1, 1999, pp. 207-209.
Naofal Al-Dhahir and Ali H. Sayed, Cordic-Based MMSE-DFE Coefficient Computation, Digital Signal Processing Journal, vol. 9, No. 3, pp. 178-194, Jul. 1999.
Naofal Al-Dhahir and Ali H. Sayed, The Finite-Length Multi-Input Multi-Output MMSE-DFE, IEEE Transactions on Signal Processing, vol. 48, No. 10, pp. 2921-2936, Oct. 2000.
Naofal Al-Dhahir and Ali H. Sayed, A Computationally-Efficient FIR MMSE-DFE for Multi-User Communications, Signals, Systems, and Computers. Conference Record of the Thirty-Fourth Asilomar Conference on, vol. 2, 2000 pp. 1867-1871.
Merched Ricardo
Yousef Nabil R.
Garlick Bruce
Garlick & Harrison & Markison
Ha Dac V.
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