United States Patent 7,769,118
Haghighat August 3, 2010
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Method and apparatus for equalizing received signals based on independent component analysis
Abstract
The present invention is related to a method and apparatus for blindly equalizing received signals in the time domain based on independent component analysis (ICA). Received signals are demodulated and over-sampled by a rate at least twice the symbol rate to populate a mixing matrix. The received signal samples are cast into the form of a signal separation problem as represented by the multiplication of the mixing matrix with the transmitted symbols such that the unknowns can be solved by ICA. Applying ICA to the received signal samples provides a de-mixing matrix which can be multiplied by the received signal samples to estimate the transmitted symbol sequence. The proposed ICA-based equalization method simultaneously corrects other transmission imperfections, such as DC-offset, carrier phase offset and in-phase and quadrature imbalance, all in the time domain. As an alternative to over-sampling, multiple copies of the received signals are received via a plurality of antennas.
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Inventors: Haghighat; Afshin (Ile-Bizard, CA)
Assignee: InterDigital Technolgy Corporation (Wilmington, DE)
Appl. No.: 11/618,012
Filed: December 29, 2006
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Related U.S. Patent Documents
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Application Number Filing Date Patent Number Issue Date
60772479 Feb., 2006
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Current U.S. Class: 375/350 ; 375/332
Current International Class: H04B 1/10 (20060101); H04L 27/22 (20060101)
Field of Search: 375/260,262,265,267,324,329,332,340,341,346,347,350 329/304
