JPS54124616A - Time division multiplex echo stopping unit - Google Patents
Time division multiplex echo stopping unitInfo
- 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
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.
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) |
-
1978
- 1978-03-20 JP JP3267878A patent/JPS54124616A/en active Pending
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