EP0262860A2
Expired / Lapsed
EP
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Digital signal analysis by transformation to vector domain
Assignee: AT&T Inc
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Filing: 1987-09-23
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Granted: —
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Expires: 2007-09-23
Abstract
Abstract A method (10) for digital measurement of analog parameters includes the steps of generating a test signal (12) in the circuit under test, transforming (14) that signal into an analytic signal in the vector domain, and then demodulating the analytic signal into its natural components, envelope, and phase in a process common to the evaluation of all circuit parameters. The frequency, phase jitter, transient measurements, signal level, noise, and envelope delay distortion are then evaluated in separate routines by analysis of, or calculation with, the components of the analytic signal. These analog parameters are all measured in the digital domain by means of a digital signal processor.
Inventors
- 👤 Richard Clair Fuller
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-30 22:59
CPC Classifications
H; H04; H04B; H04B3/00; H04B3/02; H04B3/46; G; G01; G01R; G01R31/00
Claims Analysis
Total Claims: 22
Claim 1
Independent Claim
48 words
A method for evaluating, in the digital domain, the parameters of a circuit, CHARACTERIZED BY generating a test signal in the circuit; then transforming said test signal into an analytic signal in the vector domain; and then evaluating the envelope of said test signal from said analytic signal.
Claim 2
Independent Claim
48 words
A method for evaluating, in the digital domain, the parameters of a circuit, CHARACTERIZED BY generating a test signal in the circuit; then transforming said test signal into an analytic signal in the vector domain; and then evaluating the envelope of said test signal from said analytic signal.
Claim 3
Dependent Claim
40 words
The method of claim 1, further CHARACTERIZED BY after said envelope evaluating, evaluating at least one parameter for said circuit chosen from the group consisting of the level, the envelope delay, the distortion, and the phase of said test signal.
Claim 4
Dependent Claim
18 words
The method of claim 2, further CHARACTERIZED BY evaluating the level by calculating the mean of said envelope.
Claim 5
Dependent Claim
37 words
The method of claim 2, further CHARACTERIZED BY evaluating the envelope delay distortion in the envelope of the analytic signal by extraction of the phase of the envelope modulation for a sequence of test carrier signal frequencies.
Claim 6
Dependent Claim
22 words
The method of claim 2, further CHARACTERIZED BY remodulating the envelope delay distortion signal by appending said envelope to a generated carrier.
Claim 7
Dependent Claim
22 words
The method of claim 2, further CHARACTERIZED BY evaluating the phase of said test signal from the analytic signal and the envelope.
Claim 8
Dependent Claim
26 words
The method of claim 3, further CHARACTERIZED BY after said level evaluating, evaluating the noise of said test signal by finding the variance in said level.
Claim 9
Dependent Claim
32 words
The method of claim 7, further CHARACTERIZED BY after said phase evaluating, evaluating at least one parameter chosen from the group consisting of the phase jitter, the frequency, and the transient measurements.
Claim 10
Dependent Claim
38 words
The method of claim 8, further CHARACTERIZED BY evaluating the frequency of said test signal, on a per sample basis, by calculating the difference between the phase of the present sample and the phase of the previous sample.
Claim 11
Dependent Claim
53 words
The method of claim 9, further CHARACTERIZED BY after said frequency evaluating, evaluating the phase jitter on a per sample basis by calculating the difference between the phase of the test signal and a discrete function calculated from a frequency obtained by a long average of the frequency samples of said test signal.
Claim 12
Dependent Claim
44 words
The method of claim 8, further CHARACTERIZED BY evaluating the transients by: detecting dropouts by comparing the envelope samples to a threshold value; detecting gain hits by finding rapid changes in envelope samples; and, detecting phase hits by finding rapid changes in phase samples.
Claim 13
Dependent Claim
53 words
A measurement system for evaluating, in the digital domain, the parameters of a circuit CHARACTERIZED BY means for generating a test signal in the circuit; means for transforming said test signal into an analytic signal in the vector domain; and means for evaluating the envelope of said test signal from said analytic signal.
Claim 14
Dependent Claim
53 words
A measurement system for evaluating, in the digital domain, the parameters of a circuit CHARACTERIZED BY means for generating a test signal in the circuit; means for transforming said test signal into an analytic signal in the vector domain; and means for evaluating the envelope of said test signal from said analytic signal.
Claim 15
Dependent Claim
25 words
The measurement system of claim 12, further CHARACTERIZED BY means for evaluating the level of said test signal by calculating the mean of said envelope.
Claim 16
Dependent Claim
25 words
The measurement system of claim 13, further CHARACTERIZED BY means for evaluating the noise of said test signal by finding the variance of said level.
Claim 17
Dependent Claim
35 words
The measurement system of claim 12, further CHARACTERIZED BY means for evaluating the envelope delay distortion by extracting the phase of the envelope modulation from the analytic signal for a sequence of test signal frequencies.
Claim 18
Dependent Claim
32 words
The measurement system of claim 12, further CHARACTERIZED BY means for remodulating the signal by appending said envelope to a carrier of one of the test frequencies and retransmitting the resulting signal.
Claim 19
Dependent Claim
25 words
The measurement system of claim 12, further CHARACTERIZED BY means for evaluating the phase of said test signal from the analytic signal and the envelope.
Claim 20
Dependent Claim
41 words
The measurement system of claim 17, further CHARACTERIZED BY means for evaluating the frequency of said test signal on a per sample basis by calculating the difference between the phase of the present sample and the phase of the previous sample.
Claim 21
Dependent Claim
52 words
The measurement system of claim 18, further CHARACTERIZED BY means for evaluating the phase jitter on a per sample basis by calculating the difference between the phase of the test signal and a discrete function calculated from a frequency obtained from a long average of the frequency samples of the test signal.
Claim 22
Dependent Claim
47 words
The measurement system of claim 15, further CHARACTERIZED BY means for detecting dropouts by comparing the envelope samples to a threshold value; means for detecting gain hits by finding rapid changes in envelope samples; and means for detecting phase hits by finding rapid changes in phase samples.
References Cited (Backward Citations)
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