07035326 is referenced by 12 patents and cites 1 patents.

The present invention provides a method and apparatus for demodulating data received over a communication medium carrying a transmission having multiple pilot tones with pilot data modulated thereon and message tones with message data modulated thereon and with the pilot tones and message tones frequency division multiplexed with respect to one another. In an embodiment of the invention the communication protocol utilized for modulation and demodulation is discrete multi tone (DMT). The invention allows message processing and equalizer training to proceed in parallel before equalizer training tables have been completed thus reducing the time associated with modem initialization. The apparatus in one embodiment of the invention includes on the receive path of a DMT or other multi-tone modem, a fast Fourier transform engine (FFT), a message processor, and a decoder. The FFT converts the received data from a time domain to a frequency domain. The received data in the frequency domain includes successive sets of pilot tones together with message tones. The message processor selects pairs of message and pilot tones proximate to one another in the frequency domain in each set of pilot tones and message tones. The message tone in each pair is then equalized with the pilot tone in the pair to substantially remove frequency dependent phase shifts imparted by the communication medium to the message tone. The equalized message tone is then decoded in the decoder to the corresponding specific set of message data which it represents.

Title
Method and apparatus for initializing modem communications
Application Number
10/71536
Publication Number
7035326 (B1)
Application Date
February 8, 2002
Publication Date
April 25, 2006
Inventor
Fernando Ramirez Mireles
Walnut Creek
CA, US
Avadhani Sridhar
Santa Clara
CA, US
John Gevargiz
Manhattan Beach
CA, US
Hojat Khelghati
San Jose
CA, US
Saman Behtash
Bergamo
IT
Mazen M Shihabi
Irvine
CA, US
Sam Heidari
Menlo Park
CA, US
Agent
Charles C Cary
IP Creators
Assignee
Ikanos Communication
CA, US
IPC
H04B 1/38
H03H 7/40
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