JPS5669940A - Echo canceling device for data modem - Google Patents

Echo canceling device for data modem

Info

Publication number
JPS5669940A
JPS5669940A JP14666679A JP14666679A JPS5669940A JP S5669940 A JPS5669940 A JP S5669940A JP 14666679 A JP14666679 A JP 14666679A JP 14666679 A JP14666679 A JP 14666679A JP S5669940 A JPS5669940 A JP S5669940A
Authority
JP
Japan
Prior art keywords
signal
circuit
data
transmitted
data modem
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
JP14666679A
Other languages
Japanese (ja)
Inventor
Mitsuharu Yano
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
NEC Corp
Original Assignee
NEC Corp
Nippon Electric Co Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by NEC Corp, Nippon Electric Co Ltd filed Critical NEC Corp
Priority to JP14666679A priority Critical patent/JPS5669940A/en
Publication of JPS5669940A publication Critical patent/JPS5669940A/en
Pending legal-status Critical Current

Links

Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04B—TRANSMISSION
    • H04B3/00—Line transmission systems
    • H04B3/02—Details
    • H04B3/20—Reducing echo effects or singing; Opening or closing transmitting path; Conditioning for transmission in one direction or the other
    • H04B3/23—Reducing echo effects or singing; Opening or closing transmitting path; Conditioning for transmission in one direction or the other using a replica of transmitted signal in the time domain, e.g. echo cancellers

Landscapes

  • Engineering & Computer Science (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Signal Processing (AREA)
  • Cable Transmission Systems, Equalization Of Radio And Reduction Of Echo (AREA)

Abstract

PURPOSE:To improve the error rate of data bits as to data MODEM for two-wire full-duplex communication by attenuating a transmitted signal on detecting transmitted data being insignificant and by generating a psuedoecho signal by the attenuation output. CONSTITUTION:The same signal as transmitted data to be supplied from terminal 1 to data MODEM enters pattern detecting circuit 2, which detect the predetermined pattern showing that insignificant data is being transmitted. When identity is detected, a signal is supplied to attenuating circuit 4, where the signal transmitted from terminal 3 and data MODEM is attenuated by prescribed extent and then outputted to the two-wire circuit from terminal 6 via hybrid circuit 5. Psuedo-echo signal generating circuit 8 generates a psuedo-echo signal from the output of attenuating circuit 4 and supplies it to subtracter 7, which generates and supplies the difference signal from the received signal from the circuit to the input terminal of data MODEM. Thus, the SN ratio of data MODEM can be improved.
JP14666679A 1979-11-13 1979-11-13 Echo canceling device for data modem Pending JPS5669940A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP14666679A JPS5669940A (en) 1979-11-13 1979-11-13 Echo canceling device for data modem

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP14666679A JPS5669940A (en) 1979-11-13 1979-11-13 Echo canceling device for data modem

Publications (1)

Publication Number Publication Date
JPS5669940A true JPS5669940A (en) 1981-06-11

Family

ID=15412865

Family Applications (1)

Application Number Title Priority Date Filing Date
JP14666679A Pending JPS5669940A (en) 1979-11-13 1979-11-13 Echo canceling device for data modem

Country Status (1)

Country Link
JP (1) JPS5669940A (en)

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