US4550222A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for interception-protected frequency band compressed transmission of speech signals
Assignee: Siemens AG
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Filing: 1982-07-23
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Granted: 1985-10-29
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Expires: 2002-07-23
Abstract
Abstract In order to achieve a good masking, together with minimum bandwidth requirement of sample values of spectral channels which are to be transmitted in the timing of consecutive analysis intervals in a time division multiplex sum signal, and of other predetermined speech parameters which likewise represent sample values, including at least one item of synchronizing information, at the transmitting end, the time-wise overlap of the sample values and of the synchronizing information are effected pseudo-randomly within consecutive frames of the sum signal and the analog sum signal obtained in this manner is transmitted across a shaping network to the receiving end, either directly in its base frequeny, or in a desired higher frequency position, or else indirectly by modulation onto a carrier.
Inventors
- 👤 Manfred Hanni
- 👤 Josef Brusch
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 22:54
CPC Classifications
H; H04; H04B; H04B1/00; H04B1/66; H04K; H04K1/00; H04K1/06
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
133 words
In a process for interception-resistant transmission of speech signals, in which speech signals are sampled, in a time overlapping manner, to obtain, in each of a plurality of analysis intervals, sample values of mean spectral power and predetermined speech parameters over a plurality of spectral channels, the sample values and at least one item of synchronizing information for each analysis interval are combined into a sum signal, the sum signals are transmitted in respective time-division multiplex frames, the sum signals are received and distributed, frame-by-frame, and the original speech signals are synthetically generated from the distributed sample values, the improvement therein comprising the steps of: transmitting the sample values and the synchronizing information pseudo-randomly internested within consecutive frames in the sum signal; and shaping the sum signal with a shaping network for transmission.
Claim 2
Dependent Claim
133 words
In a process for interception-resistant transmission of speech signals, in which speech signals are sampled, in a time overlapping manner, to obtain, in each of a plurality of analysis intervals, sample values of mean spectral power and predetermined speech parameters over a plurality of spectral channels, the sample values and at least one item of synchronizing information for each analysis interval are combined into a sum signal, the sum signals are transmitted in respective time-division multiplex frames, the sum signals are received and distributed, frame-by-frame, and the original speech signals are synthetically generated from the distributed sample values, the improvement therein comprising the steps of: transmitting the sample values and the synchronizing information pseudo-randomly internested within consecutive frames in the sum signal; and shaping the sum signal with a shaping network for transmission.
Claim 3
Dependent Claim
23 words
The improved process of claim 1, and further comprising the step of: transmitting the shaped sum signal in its own base frequency position.
Claim 4
Dependent Claim
23 words
The improved process of claim 1, and further comprising the step of: transmitting the shaped sum signal in a predetermined higher frequency position.
Claim 5
Dependent Claim
24 words
The improved process of claim 1, and further comprising the step of: transmitting the shaped sum signal by modulating the same onto a carrier.
Claim 6
Dependent Claim
31 words
The improved process of claim 1, and further comprising the step of: regulating the volume of the speech signal to a constant sum level as one of the predetermined speech parameters.
Claim 7
Dependent Claim
29 words
The improved process of claim 1, and further comprising the steps of: generating random noise; and sampling and inserting random noise into an analysis interval to represent blank values.
Claim 8
Dependent Claim
28 words
The improved process of claim 6, wherein the step of inserting random noise samples is further defined as: pseudo-randomly changing the number of random noise samples from frame-to-frame.
Claim 9
Dependent Claim
35 words
The improved process of claim 7, wherein the step of pseudo-randomly changing the number of random noise samples is further defined as: changing the number from frame-to-frame in the order of a maximum of 10%.
Claim 10
Dependent Claim
41 words
The improved process of claim 1, and further comprising the steps of: inverting each second sample value of the consecutive sample values within a frame prior to transmission; and canceling the inversion in the received signals prior to distribution for synthesis.
Claim 11
Dependent Claim
39 words
The improved process of claim 1, for two-wire duplex operation, comprising the steps of: splitting the available bandwidth into two halves for the transmission of one sum signal in one direction and another sum signal in the opposite direction.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1988-10-28 | 1989-04-29 | 1989-10-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-10-28 | 1993-04-29 | 1993-10-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-10-28 | 1997-04-29 | 1997-10-29 | $7700.00 | Window Closed / Lapsed |