Resumes
Resumes
Yuwen Su Phones & Addresses
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El Cerrito, CA
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San Francisco, CA
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Albany, CA
Publications
Us Patents
Method And Apparatus For Wireline Characterization
View pageUS Patent:
6718019, Apr 6, 2004
Filed:
Sep 18, 2001
Appl. No.:
09/955616
Inventors:
Sam Heidari - Menlo Park CA
Behrooz Rezvani - San Ramon CA
Hojat Khelghati - San Jose CA
Yuwen Su - Cupertino CA
Qasem Aldrubi - Fremont CA
Behrooz Rezvani - San Ramon CA
Hojat Khelghati - San Jose CA
Yuwen Su - Cupertino CA
Qasem Aldrubi - Fremont CA
Assignee:
Ikanos Communications, Inc. - Fremont CA
International Classification:
H04M 1100
US Classification:
379 9305, 379 2202, 379 101, 379400
Abstract:
The current invention provides a method and apparatus for wireline characterization is disclosed. The method may be implemented with any modulation protocol but is particularly suited for multi-carrier modulation protocols such as discrete multi-tone (DMT). The apparatus may be incorporated into physical or logical modems. In an embodiment of the invention an apparatus for wireline characterization in a modem with a transmit path and a receive path each configured to couple with a remote modem via a wireline in which available communication bandwidth is split into a number of independent sub-channels is disclosed. The apparatus comprises: a tone selector, a cumulative loss estimator and a shift register. The tone selector selects a subset of the number of sub-channels within the bandwidth of a received wireline communication for which subset the sum of the square roots of the corresponding sub-channel indices may be expressed as an integer power ânâ of 2. The cumulative loss estimator cumulates the insertion losses across the selected subset of the sub-channels and outputs a binary value corresponding thereto.
Method And Apparatus For Insertion Loss Estimation In Wireline Communications
View pageUS Patent:
6516049, Feb 4, 2003
Filed:
Jun 6, 2001
Appl. No.:
09/876195
Inventors:
Sam Heidari - Menlo Park CA
Behrooz Rezvani - San Ramon CA
Hojat Khelghati - San Jose CA
Yuwen Su - Cupertino CA
Qasem Aldrubi - Fremont CA
Behrooz Rezvani - San Ramon CA
Hojat Khelghati - San Jose CA
Yuwen Su - Cupertino CA
Qasem Aldrubi - Fremont CA
Assignee:
Ikanos Communications, Inc. - Fremont CA
International Classification:
H04M 124
US Classification:
379 101, 379 103, 379 22, 379 2701, 379 28, 379 30, 370248, 324520
Abstract:
The current invention provides a method and apparatus for determining insertion loss in wireline communication systems. The method may be implemented with any modulation protocol but is particularly suited for multi-carrier modulation protocols such as discrete multi-tone (DMT). The method for calculation of the insertion loss uses a received signal and a discrete subset of frequency ranges, e. g. DMT tones, within that signal. For each of the subset of frequency ranges the average received power on each of the selected set of tones is determined. Next the average power on each received subset of tones is converted to log using a simple log estimation circuit that avoids the complexity associated with log tables and other prior art methods of computing logarithms. Then the sum of the log of the average power received in each of the selected subset of tone bins is determined. Next, the known transmitted power for the selected subset of tones is expressed as log , is summed and is then subtracted from the sum of the log of the average power received.