JPS54124616A - Time division multiplex echo stopping unit - Google Patents

Time division multiplex echo stopping unit

Info

Publication number
JPS54124616A
JPS54124616A JP3267878A JP3267878A JPS54124616A JP S54124616 A JPS54124616 A JP S54124616A JP 3267878 A JP3267878 A JP 3267878A JP 3267878 A JP3267878 A JP 3267878A JP S54124616 A JPS54124616 A JP S54124616A
Authority
JP
Japan
Prior art keywords
signals
comparator
pam
switch
transmitted
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
JP3267878A
Other languages
Japanese (ja)
Inventor
Yutaka Okumura
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 JP3267878A priority Critical patent/JPS54124616A/en
Publication of JPS54124616A publication Critical patent/JPS54124616A/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

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 make a PCM coder needless by subjecting signals of plural signal pathes to PAM multiplexing and comparing levels of transmission signals and receiving signals with each other and comparing these levels with reference values as PAM signals. CONSTITUTION:Transmission PAM signals from a channel board have the polarity discriminated by comparators 1-1 to 1-3. If the polarity is negative, the output of comparator 1-1 is selected by switch 1-4 and is transmitted to comparator 4; and if the polarity is positive, the output of comparator 1-2 is selected by switch 1-4 and is transmitted to comparator 4. Receiving-side PAM signals are rectified similarly to the transmission side. The output from rectifier circuit 2 is compared with signals, which are read from analogue shift register 3-4, by comparator 3-2, and the larger one of them is selected by switch 3-1 and becomes the new value of 3-4 and is transmitted to comparator 4. 3-5 in the figure indicates the amplifier to compensate the transfer loss of 3-4; and when the amplification factor of this amplifier is selected properly, proper erroneous interruption prevention can be performed for echo signals which are delayed by near-end delay.
JP3267878A 1978-03-20 1978-03-20 Time division multiplex echo stopping unit Pending JPS54124616A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP3267878A JPS54124616A (en) 1978-03-20 1978-03-20 Time division multiplex echo stopping unit

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP3267878A JPS54124616A (en) 1978-03-20 1978-03-20 Time division multiplex echo stopping unit

Publications (1)

Publication Number Publication Date
JPS54124616A true JPS54124616A (en) 1979-09-27

Family

ID=12365524

Family Applications (1)

Application Number Title Priority Date Filing Date
JP3267878A Pending JPS54124616A (en) 1978-03-20 1978-03-20 Time division multiplex echo stopping unit

Country Status (1)

Country Link
JP (1) JPS54124616A (en)

Similar Documents

Publication Publication Date Title
ES8206935A1 (en) Signal wave control circuit
ES8606756A1 (en) Method to test the function of an adaptive echo canceller.
JPS5781732A (en) Method and device for detecting echo in voice channel signal
JPS54124616A (en) Time division multiplex echo stopping unit
SE8004570L (en) tonreciever
JPS57210748A (en) Data transmission system
JPS55163934A (en) Digital signal transmitter
JPS55149553A (en) Specific pulse inserting and removing circuit in data transmission system
JPS5763964A (en) Aural switch circuit
JPS6473933A (en) Data multiplex deciding circuit
ATE167601T1 (en) HYBRID ANALOG DIGITAL SIGNAL PROCESSING
JPS6412728A (en) Echo canceller
JPS5612148A (en) Order-wire signal transmission system
JPS53144610A (en) Digital signal transmission line system
JPS6410732A (en) Signal conversion transmission circuit
JPS56169462A (en) Demodulation circuit for frequency shift modulation signal
JPS56156020A (en) Arithmetic processor
JPS558122A (en) Synchronizer
JPS57109445A (en) Telemeter device for pcm communication system
JPS54918A (en) Facsimile transmission system
JPS5413718A (en) Digital repeating transfer system for tone signal
JPS53133470A (en) Convergence value detecting system
JPS5599862A (en) Multiplex transmission of analog and digital signal
JPS56123155A (en) Digital polarity control circuit
JPS53112016A (en) Signal transmitter