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US4975654A
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Data signal discrimination method and apparatus
Assignee: GN Hearing Care Corp
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Filing: 1989-03-10
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Granted: 1990-12-04
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Expires: 2009-03-10
Abstract
Abstract A method and apparatus for discriminating the data signal of a transmitter means. Binary encoded data is transmitted between a transmitter means and a receiver means in an amplitude modulated signal varying about a threshold level. A means and method are included for determining the number of threshold crossings of the carrier during each of a number of discrete successive time intervals. A further method and means characterizes those of said time intervals wherein the number of threshold crossings equals or exceeds a first predetermined number as a mark, and those of said time intervals wherein the number of threshold crossings does not exceed said predetermined number as a null. The number of successive marks not separated by a predetermined number of nulls is then counted by a further aspect of the method and means. A series of successive marks in excess of a second predetermined number is then characterized as a one, and a series of successive marks in a range below said second predetermined number is characterized as a zero. The signal transmitted by said transmitter means is discriminated from interference by spurious signals.
Inventors
- 👤 Anthony J. Becker
- 👤 Vincent Pluvinage
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 16:05
CPC Classifications
H; H04; H04L; H04L27/00; H04L27/02; H04L27/06
Claims Analysis
Total Claims: 44
Claim 1
Independent Claim
173 words
A method for discriminating the data signal of a transmitter means wherein binary encoded data is transmitted between said transmitter means and a receiver means in an amplitude modulated signal, said signal being an AC carrier varying about a first threshold level, comprising: determining the number of threshold crossings of the carrier during each of a number of discrete successive time intervals; characterizing those of said time intervals wherein the number of threshold crossings equals or exceeds a first predetermined number as a mark, and those of said time intervals wherein the number of threshold crossings does not exceed said first predetermined number as a null; counting the number of successive marks, wherein said successive marks are not separated by a predetermined number of nulls; characterizing a series of successive marks in excess of a second predetermined number as a one, and a series of successive marks in a range below said second predetermined number as a zero; whereby said signal transmitted by said transmitter means is discriminated from interference by spurious signals.
Claim 2
Independent Claim
173 words
A method for discriminating the data signal of a transmitter means wherein binary encoded data is transmitted between said transmitter means and a receiver means in an amplitude modulated signal, said signal being an AC carrier varying about a first threshold level, comprising: determining the number of threshold crossings of the carrier during each of a number of discrete successive time intervals; characterizing those of said time intervals wherein the number of threshold crossings equals or exceeds a first predetermined number as a mark, and those of said time intervals wherein the number of threshold crossings does not exceed said first predetermined number as a null; counting the number of successive marks, wherein said successive marks are not separated by a predetermined number of nulls; characterizing a series of successive marks in excess of a second predetermined number as a one, and a series of successive marks in a range below said second predetermined number as a zero; whereby said signal transmitted by said transmitter means is discriminated from interference by spurious signals.
Claim 3
Dependent Claim
66 words
The method of claim 1 further including the steps of: detecting the peak signal amplitude of said AC carrier signal; characterizing a second threshold level, wherein said second threshold level is characterized between said first threshold level and said peak signal amplitude; and enabling said discrimination method only on those cycles of the carrier wherein the peak amplitude of said cycle exceeds said second threshold level.
Claim 4
Dependent Claim
19 words
The method of claim 2 wherein said second threshold level is characterized at about one-half the peak signal amplitude.
Claim 5
Dependent Claim
13 words
The method of claim 1 wherein said discrete time interval is 640 μs.
Claim 6
Dependent Claim
13 words
The method of claim 1 wherein said predetermined number of nulls equals two.
Claim 7
Dependent Claim
19 words
The method of claim 1 wherein said binary encoded data is transmitted by means of a ceramic bimorph transducer.
Claim 8
Dependent Claim
33 words
The method of claim 6 wherein changes in temperature and operating conditions in the transducer are compensated for by using the natural resonance of said transducer to vary the amount of driving current.
Claim 9
Dependent Claim
45 words
The method of claim 6 wherein said transducer means is driven to generate said AC carrier signal by driving means, said driving means including a control means for enabling said driving means to oscillate in response to an alternating feedback input to said control means.
Claim 10
Dependent Claim
14 words
The method of claim 8 wherein said control means includes a digital logic gate.
Claim 11
Dependent Claim
13 words
The method of claim 1 wherein said carrier signal is an ultrasonic signal.
Claim 12
Dependent Claim
16 words
The method of claim 10 wherein the frequency of said carrier signal is about 25 khz.
Claim 13
Dependent Claim
32 words
The method of claim 1 wherein the modulation length of said carrier signal characterized as a "1" is about two times the modulation length of said carrier signal characterized as a "0".
Claim 14
Dependent Claim
35 words
The method of claim 1 wherein said number of successive marks is determined by counting the number of negative going threshold crossings of said carrier during each of a number of discrete successive time intervals.
Claim 15
Dependent Claim
37 words
The method of claim 13 wherein said negative going threshold crossings are determined by comparing a received signal to a slowly varying voltage waveform input, generating a square wave output therefrom, and counting said square wave output.
Claim 16
Dependent Claim
29 words
The method of claim 14 wherein a mark is characterized when the number of negative threshold crossings counted during said discrete successive time interval reaches a third predetermined value.
Claim 17
Dependent Claim
31 words
The method of claim 14 wherein a null is characterized when the number of negative threshold crossings counted during said discrete successive time interval does not reach a third predetermined value.
Claim 18
Dependent Claim
12 words
The method of claim 16 wherein said third predetermined value equals seven.
Claim 19
Dependent Claim
22 words
The method of claim 1 wherein a data input of one is characterized when said second predetermined number equals or exceeds five.
Claim 20
Dependent Claim
32 words
The method of claim 1 wherein a zero is characterized when the range below said second predetermined number is equal to or greater than two, but less than or equal to four.
Claim 21
Dependent Claim
13 words
The method of claim 1 wherein the number of successive nulls is counted.
Claim 22
Dependent Claim
17 words
The method of claim 20 wherein a count of two successive nulls is characterized as a space.
Claim 23
Dependent Claim
21 words
The method of claim 21 wherein data inputs are characterized only when said data are separated by at least one space.
Claim 24
Independent Claim
180 words
An apparatus for discriminating the data signal of a transmitter means wherein binary encoded data is transmitted between said transmitter means and a receiver means in an amplitude modulated signal, said signal being an AC carrier varying about a first threshold level, comprising: means for determining the number of threshold crossings of the carrier during each of a number of discrete successive time intervals; means for characterizing those of said time intervals wherein the number of threshold crossings equals or exceeds a first predetermined number as a mark, and those of said time intervals wherein the number of threshold crossings does not exceed said predetermined number as a null; means for counting the number of successive marks, wherein said successive marks are not separated by a predetermined number of nulls; means for characterizing a series of successive marks in excess of a second predetermined number as a one, and a series of successive marks in a range below said second predetermined number as a zero; whereby said signal transmitted by said transmitter means is discriminated from interference with spurious signals.
Claim 25
Independent Claim
180 words
An apparatus for discriminating the data signal of a transmitter means wherein binary encoded data is transmitted between said transmitter means and a receiver means in an amplitude modulated signal, said signal being an AC carrier varying about a first threshold level, comprising: means for determining the number of threshold crossings of the carrier during each of a number of discrete successive time intervals; means for characterizing those of said time intervals wherein the number of threshold crossings equals or exceeds a first predetermined number as a mark, and those of said time intervals wherein the number of threshold crossings does not exceed said predetermined number as a null; means for counting the number of successive marks, wherein said successive marks are not separated by a predetermined number of nulls; means for characterizing a series of successive marks in excess of a second predetermined number as a one, and a series of successive marks in a range below said second predetermined number as a zero; whereby said signal transmitted by said transmitter means is discriminated from interference with spurious signals.
Claim 26
Dependent Claim
69 words
The apparatus of claim 23, further including: means for detecting the peak signal amplitude of said AC carrier signal; means for characterizing a second threshold level, wherein said second threshold level is characterized between said first threshold level and said peak signal amplitude; and means for enabling said discrimination method only on those cycles of the carrier wherein the peak amplitude of said cycle exceeds said second threshold level.
Claim 27
Dependent Claim
14 words
The apparatus of claim 23 wherein said transmitter means includes a ceramic bimorph transducer.
Claim 28
Dependent Claim
38 words
The apparatus of claim 25 wherein said transmitter means includes means for compensating for changes in temperature and operating conditions in said transducer by using the natural resonance of said transducer to vary the amount of driving current.
Claim 29
Dependent Claim
47 words
The apparatus of claim 25 wherein said transmission means further includes: means for driving said transducer to generate said AC carrier signal, wherein said driving means includes control means for enabling said driving means to oscillate in response to an alternating feedback input to said control means.
Claim 30
Dependent Claim
14 words
The apparatus of claim 27 wherein said control means is a digital logic gate.
Claim 31
Dependent Claim
14 words
The apparatus of claim 23 wherein said discrete successive time interval is 640 μs.
Claim 32
Dependent Claim
13 words
The apparatus of claim 23 wherein said predetermined number of nulls is two.
Claim 33
Dependent Claim
13 words
The apparatus of claim 23 wherein said carrier signal is an ultrasonic signal.
Claim 34
Dependent Claim
15 words
The apparatus of claim 23 wherein the frequency of said carrier signal is 25 khz.
Claim 35
Dependent Claim
29 words
The apparatus of claim 23 wherein the modulation length of said carrier signal characterized as about two times the modulation length of said carrier signal characterized as a zero.
Claim 36
Dependent Claim
39 words
The apparatus of claim 23 wherein said means for determining said number of successive marks includes means for counting the number of negative going threshold crossings of the carrier during each of a number of discrete successive time intervals.
Claim 37
Dependent Claim
34 words
The apparatus of claim 34 including means for comparing a received signal to a slowly varying voltage waveform, means for generating a square wave output therefrom, and means for counting said square wave output.
Claim 38
Dependent Claim
34 words
The apparatus of claim 35 wherein said means for counting successive marks records a count when the value recorded in said threshold counter during said discrete successive time interval reaches a third predetermined number.
Claim 39
Dependent Claim
11 words
The apparatus of claim 36 including means for counting successive nulls.
Claim 40
Dependent Claim
35 words
The apparatus of claim 37 wherein said means for counting nulls records a count when the value recorded in said threshold counter during said discrete successive time interval does not reach a third predetermined value.
Claim 41
Dependent Claim
31 words
The apparatus of claim 23 including means for outputting a data signal of "1" when said mark counting means counts the number of successive marks as equal to or exceeding five.
Claim 42
Dependent Claim
43 words
The apparatus of claim 23 including means for outputting a data signal of zero when the mark counting means counts the number of successive marks in a range from that equal to or greater than two, but less than or equal to four.
Claim 43
Dependent Claim
24 words
The apparatus of claim 37 including means for characterizing a space when said means for counting successive nulls reaches said predetermined number of nulls.
Claim 44
Dependent Claim
17 words
The apparatus of claim 41 wherein said data input received is separated by one or more spaces.
References Cited (Backward Citations)
US4532930A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1993-12-03 | 1994-06-04 | 1994-12-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-12-03 | 1998-06-04 | 1998-12-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-12-03 | 2002-06-04 | 2002-12-04 | $7700.00 | Window Closed / Lapsed |