US3668643A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Data transmission system
Assignee: Data Instruments Co
•
Filing: 1970-08-14
•
Granted: 1972-06-06
•
Expires: 1990-08-14
Abstract
Abstract A data transmission system which utilized a plurality of predetermined frequencies to transmit data is disclosed. The system is particularly useful for synchronous data transmission for example where a change from one predetermined frequency to another is utilized to code binary or trinary data. A plurality of gating signals, each separated by a finite time are generated and used to detect the presence of the predetermined frequencies. The coincidence of pulses representative of the period of the transmitted frequency and the gating signal associated with the transmitted frequency is detected and utilized to identify the transmitted frequency. The predetermined frequencies and gate durations are selected so as to allow the jitter associated with transmitted frequency to go undetected.
Inventors
- 👤 Lloyd M Germain
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 18:10
CPC Classifications
H; H04; H04L; H04L27/00; H04L27/26
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
131 words
In a system for sequentially transmitting a plurality of predetermined frequencies an apparatus for detecting the transmitted frequency comprising: means for generating an electrical signal representative of the period of the transmitted frequency; gate generation means for generating a plurality of gating signals each of said gates being separate from one another by a finite period of time and with no gating signals being generated during said finite period of time; and detecTion means for detecting the coincidence of at least one of said gating signals and said electrical signal representative of the period of the transmitted frequency coupled to said gate generation means and said means for generating electrical signals representative of the periods of the transmitted frequencies; whereby the detection of said coincidence is indicative of the transmitted frequency.
Claim 2
Dependent Claim
131 words
In a system for sequentially transmitting a plurality of predetermined frequencies an apparatus for detecting the transmitted frequency comprising: means for generating an electrical signal representative of the period of the transmitted frequency; gate generation means for generating a plurality of gating signals each of said gates being separate from one another by a finite period of time and with no gating signals being generated during said finite period of time; and detecTion means for detecting the coincidence of at least one of said gating signals and said electrical signal representative of the period of the transmitted frequency coupled to said gate generation means and said means for generating electrical signals representative of the periods of the transmitted frequencies; whereby the detection of said coincidence is indicative of the transmitted frequency.
Claim 3
Dependent Claim
23 words
The apparatus defined in claim 1 wherein at least one gating signal is generated for each predetermined frequency by said gate generation means.
Claim 4
Dependent Claim
35 words
The apparatus as defined in claim 2 wherein at least one of the gating signals generated for a lower predetermined frequency is longer in duration that a gating signal generated for a higher predetermined frequency.
Claim 5
Dependent Claim
33 words
The apparatus defined in claim 2 including a separate detection means for each predetermined frequency and wherein said gate generation means transmits at least one gating signal to each of said detection means.
Claim 6
Dependent Claim
45 words
The system defined in claim 1 wherein at least three predetermined frequencies are used and wherein the number of cycles between one frequency and the next higher frequency is greater than the number of cycles between said next higher frequency and the next higher frequency.
Claim 7
Dependent Claim
45 words
The system defined in claim 2 wherein at least three predetermined frequencies are used and wherein the number of cycles between one frequency and the next higher frequency is greater than the number of cycles between said next higher frequency and the next higher frequency.
Claim 8
Dependent Claim
34 words
The system defined in claim 4 wherein at least one of the gating signals generated for a lower predetermined frequency is longer in duration than a gating signal generated for a higher predetermined frequency.
Claim 9
Dependent Claim
12 words
The system defined in claim 7 wherein four predetermined frequencies are utilized.
Claim 10
Independent Claim
156 words
A system for transmitting data by coding a plurality of predetermined frequencies comprising: a transmitter for encoding said data into said predetermined frequencies; transmission means coupled to said transmitter; and a receiver coupled to said transmission means for detecting said predetermined frequencies comprising: means for generating an electrical signal representative of the period of the transmitted frequency; gate generation means for generating a plurality of gating signals each of said gating signals being separate from one another by a finite period of time and with no gating signals being generated during said finite period of time; and detection means for detecting the coincidence of at least one of said gating signals and said electrical signal representative of the period of the transmitted frequency coupled to said gate generation means and said means for generating electrical signals representative of the periods of the transmitted frequencies; whereby the detection of said coincidence is indicitive of the transmitted frequency.
Claim 11
Independent Claim
156 words
A system for transmitting data by coding a plurality of predetermined frequencies comprising: a transmitter for encoding said data into said predetermined frequencies; transmission means coupled to said transmitter; and a receiver coupled to said transmission means for detecting said predetermined frequencies comprising: means for generating an electrical signal representative of the period of the transmitted frequency; gate generation means for generating a plurality of gating signals each of said gating signals being separate from one another by a finite period of time and with no gating signals being generated during said finite period of time; and detection means for detecting the coincidence of at least one of said gating signals and said electrical signal representative of the period of the transmitted frequency coupled to said gate generation means and said means for generating electrical signals representative of the periods of the transmitted frequencies; whereby the detection of said coincidence is indicitive of the transmitted frequency.
Claim 12
Dependent Claim
26 words
The system defined in claim 9 wherein said transmitter includes a Wien-bridge oscillator for generating said predetermined frequencies, said oscillator having at least two resistor-capacitor networks.
Claim 13
Dependent Claim
30 words
The system defined in claim 10 wherein the time constants of said two resistor-capacitor networks remain substantially equal for at least two of the predetermined frequencies generated by said oscillator.
Claim 14
Dependent Claim
34 words
The system defined in claim 10 wherein at least one of the gating signals generated for a lower predetermined frequency is longer in duration than a gating signal generated for a higher predetermined frequency.
Claim 15
Dependent Claim
33 words
The system defined in claim 12 including a separate detection means for each predetermined frequency and wherein said gate generation means transmits at least one gating signal to each of said detection means.
Claim 16
Dependent Claim
45 words
The system defined in claim 9 wherein at least three predetermined frequencies are used and wherein the number of cycles between one frequency and the next higher frequency is greater than the number of cycles betwEen said next higher frequency and the next higher frequency,
Claim 17
Dependent Claim
45 words
The system defined in claim 14 wherein at least three predetermined frequencies are used and wherein the number of cycles between one frequency and the next higher frequency is greater than the number of cycles between said next higher frequency and the next higher frequency.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-06-06 | 1975-12-06 | 1976-06-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-06-06 | 1979-12-06 | 1980-06-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-06-06 | 1983-12-06 | 1984-06-06 | $7700.00 | Window Closed / Lapsed |