JPS6439141A - Input level control system - Google Patents
Input level control systemInfo
- Publication number
- JPS6439141A JPS6439141A JP19484387A JP19484387A JPS6439141A JP S6439141 A JPS6439141 A JP S6439141A JP 19484387 A JP19484387 A JP 19484387A JP 19484387 A JP19484387 A JP 19484387A JP S6439141 A JPS6439141 A JP S6439141A
- Authority
- JP
- Japan
- Prior art keywords
- gain
- training signal
- modem
- input level
- coding
- 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
Landscapes
- Transmission Systems Not Characterized By The Medium Used For Transmission (AREA)
Abstract
PURPOSE:To control a voice band compression coding device at an optimum input level by varying the gain in response to detection of a MODEN training signal. CONSTITUTION:The gain of an amplifier 4 serving as a gain varying means of a voice band compression coding device is shown by 20logR2/R1 or 20logR3/R1 and varied by the resistances R2 and R3. A selector 5 performs the switch and connection between the R2 and R3 to vary the gain of the amplifier 4 when a training signal detecting circuit 1 detects a MODEM training signal. Thus a voice coding part 8 and a MODEM coding part 9 are switched by selectors 7 and 10 when the MODEM training signal is detected. The signal subjected to the A/D conversion 6 is supplied to the part 9 and the coding output is transmitted via the selector 10.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP19484387A JPS6439141A (en) | 1987-08-04 | 1987-08-04 | Input level control system |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP19484387A JPS6439141A (en) | 1987-08-04 | 1987-08-04 | Input level control system |
Publications (1)
Publication Number | Publication Date |
---|---|
JPS6439141A true JPS6439141A (en) | 1989-02-09 |
Family
ID=16331197
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
JP19484387A Pending JPS6439141A (en) | 1987-08-04 | 1987-08-04 | Input level control system |
Country Status (1)
Country | Link |
---|---|
JP (1) | JPS6439141A (en) |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPH03203466A (en) * | 1989-12-29 | 1991-09-05 | Sharp Corp | Modulator and demodulator |
-
1987
- 1987-08-04 JP JP19484387A patent/JPS6439141A/en active Pending
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPH03203466A (en) * | 1989-12-29 | 1991-09-05 | Sharp Corp | Modulator and demodulator |
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