Title:
DIGITAL SUBSCRIBER'S LINE TRANSMISSION SYSTEM
Document Type and Number:
Japanese Patent JP3480313
Kind Code:
B2
Abstract:
PROBLEM TO BE SOLVED: To take the measure of TCM Cross-talk only by changing a part of softwear by informing a subscriber's side ADSL of a specific phase of an ISDN ping-pong by an ADSL on a station side and detecting an NEXT and FEXT section respectively by each ADSL on the station side/subscriber's side.
SOLUTION: At the time of an initial training, an NEXT section and an FEXT section synchronized with a TCM 400 Hz are information of. The information of this 400 Hz is performed from the station side to the subscriber's side, TCM Cross-talk selects a carrier of fewer frequency, two signal points are modulated by shifting a phase by 90 degrees out of signal points of a four value QAM and transmits them. By using the signals different by the 90 degrees, it is possible to discriminate between the NEXT section and the FEXT section by modulated two kinds of signal points having a 90 degrees phase difference even if there is an error in the phase of the modulated signal point.
Inventors:
Kiyoshi Miyoshi
Yutaka Awata
Hiroyasu Murata
Nobukazu Koizumi
Kei Sasaki
Yutaka Awata
Hiroyasu Murata
Nobukazu Koizumi
Kei Sasaki
Application Number:
JP14491398A
Publication Date:
December 15, 2003
Filing Date:
May 26, 1998
Export Citation:
Assignee:
富士通株式会社
International Classes:
H04L5/16; H04B3/32; H04J11/00; H04L5/14; H04L7/00; H04L12/50; H04L27/26; H04M3/00; H04M11/06; (IPC1-7): H04M11/06; H04L5/14; H04M3/00
Domestic Patent References:
| JP10303872A | ||||
| JP200032096A | ||||
| JP200031936A | ||||
| JP200078105A |
Attorney, Agent or Firm:
Junichi Yokoyama