JPS57143970A - Self-testing system for multifrequency signal receiver - Google Patents
Self-testing system for multifrequency signal receiverInfo
- Publication number
- JPS57143970A JPS57143970A JP56029714A JP2971481A JPS57143970A JP S57143970 A JPS57143970 A JP S57143970A JP 56029714 A JP56029714 A JP 56029714A JP 2971481 A JP2971481 A JP 2971481A JP S57143970 A JPS57143970 A JP S57143970A
- Authority
- JP
- Japan
- Prior art keywords
- circuit
- output
- fault
- circuits
- discrete fourier
- 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.)
- Granted
Links
Classifications
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04Q—SELECTING
- H04Q1/00—Details of selecting apparatus or arrangements
- H04Q1/18—Electrical details
- H04Q1/30—Signalling arrangements; Manipulation of signalling currents
- H04Q1/44—Signalling arrangements; Manipulation of signalling currents using alternate current
- H04Q1/444—Signalling arrangements; Manipulation of signalling currents using alternate current with voice-band signalling frequencies
- H04Q1/45—Signalling arrangements; Manipulation of signalling currents using alternate current with voice-band signalling frequencies using multi-frequency signalling
- H04Q1/457—Signalling arrangements; Manipulation of signalling currents using alternate current with voice-band signalling frequencies using multi-frequency signalling with conversion of multifrequency signals into digital signals
- H04Q1/4575—Signalling arrangements; Manipulation of signalling currents using alternate current with voice-band signalling frequencies using multi-frequency signalling with conversion of multifrequency signals into digital signals which are transmitted in digital form
Landscapes
- Engineering & Computer Science (AREA)
- Computer Networks & Wireless Communication (AREA)
- Digital Transmission Methods That Use Modulated Carrier Waves (AREA)
- Monitoring And Testing Of Exchanges (AREA)
Abstract
PURPOSE:To test both circuits, finding a real number part, and finding an imaginary number part, in a discrete Fourier transformation circuit, by finding the absolute value of a discrete Fourier transformation output and comparing the value with a threshold value. CONSTITUTION:An input singal from an input terminal 1 is inputted to a circuit 2 which finds the real number part of discrete Fourier transformation DFT, and a circuit 3 which finds the imaginary number part of the DFT. While the circuits 2 and 3 are in normal operation, the output of a circuit 6 which finds the absolute value of a discrete Fourier transformation output is fixed with out reference to its phase. If however, the circuit 2 has a fault to cease its output 4, the output of the circuit 6 becomes equal to that of the circuit 3, and when the circuit 3 has a fault, the output of the circuit 6 becomes equal to the output 4 of the circuit 2. For the purpose, a relation between the threshold value 8 and phase of a comparing circuit 9 is selected adequately; when both the circuits operate normally, the output 7 of the circuit 6 increases above the threshold value 8 and when either one of the circuits 2 and 3 has a fault, the output 7 of the circuit 6 becomes less than the threshold value 8, so that the fault is detected.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP56029714A JPS57143970A (en) | 1981-03-02 | 1981-03-02 | Self-testing system for multifrequency signal receiver |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP56029714A JPS57143970A (en) | 1981-03-02 | 1981-03-02 | Self-testing system for multifrequency signal receiver |
Publications (2)
Publication Number | Publication Date |
---|---|
JPS57143970A true JPS57143970A (en) | 1982-09-06 |
JPH0343819B2 JPH0343819B2 (en) | 1991-07-03 |
Family
ID=12283770
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
JP56029714A Granted JPS57143970A (en) | 1981-03-02 | 1981-03-02 | Self-testing system for multifrequency signal receiver |
Country Status (1)
Country | Link |
---|---|
JP (1) | JPS57143970A (en) |
Citations (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS52106614A (en) * | 1976-03-04 | 1977-09-07 | Fujitsu Ltd | Signal detection |
-
1981
- 1981-03-02 JP JP56029714A patent/JPS57143970A/en active Granted
Patent Citations (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS52106614A (en) * | 1976-03-04 | 1977-09-07 | Fujitsu Ltd | Signal detection |
Also Published As
Publication number | Publication date |
---|---|
JPH0343819B2 (en) | 1991-07-03 |
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