US4581749A
Expired / Lapsed
US
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Data frequency modulator with deviation control
Assignee: Motorola Solutions Inc
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Filing: 1984-07-02
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Granted: 1986-04-08
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Expires: 2004-07-02
Abstract
Abstract An automatic deviation control circuit for an angle modulated data transmitter is disclosed wherein the deviation level of modulated data is controlled by a modulation cancelling deviation error detection feedback loop. After the modulation is cancelled from a sample of modulated carrier by a predetermined value of deviation, residual modulation is detected, sampled following a predetermined number of like-level data bits, and applied to the modulation path gain to increase or decrease the deviation such that the residual modulation is minimized.
Inventors
- 👤 Scott N. Carney
- 👤 Steven H. Goode
- 👤 Donald L. Linder
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 09:04
CPC Classifications
H; H03; H03C; H03C3/00; H03C3/02; H03C3/09; H03C3/0908; H03C3/0983; H03C3/0941; H03C3/0966; H04; H04L; H04L27/00; H04L27/18; H04L27/20; H04L27/2003; H04L27/2007; H04L27/2017; H03C2200/00; H03C2200/0037; H03C2200/005
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
191 words
An automatic deviation control circuit for an angle modulated data transmitter employing a radio carrier comprising: means for angle modulating a precursor of the radio crrier to a deviation value having a proportionality to a data input level derived from at least one data bit; means for indicating a first difference between said carrier precursor deviation value and a predetermined positive deviation value when a data bit is at a first binary level, and for indicating a second difference between said carrier precursor deviation value and a predetermined negative deviation value when a data bit is at a second binary level; means for detecting a predtermined non-unity number of consecutive like-level data bits; means for sampling said first difference when said predetermined number of consecutive data bits of said first binary level is detected and for sampling said second difference when said predetermined number of consecutive data bits of said second binary level is detected; and means for varying said proportionality of said radio carrier precursor deviation value to said data input level in accordance with said first and second difference samples, thereby controlling the deviation of the angle modulated transmitter.
Claim 2
Dependent Claim
191 words
An automatic deviation control circuit for an angle modulated data transmitter employing a radio carrier comprising: means for angle modulating a precursor of the radio crrier to a deviation value having a proportionality to a data input level derived from at least one data bit; means for indicating a first difference between said carrier precursor deviation value and a predetermined positive deviation value when a data bit is at a first binary level, and for indicating a second difference between said carrier precursor deviation value and a predetermined negative deviation value when a data bit is at a second binary level; means for detecting a predtermined non-unity number of consecutive like-level data bits; means for sampling said first difference when said predetermined number of consecutive data bits of said first binary level is detected and for sampling said second difference when said predetermined number of consecutive data bits of said second binary level is detected; and means for varying said proportionality of said radio carrier precursor deviation value to said data input level in accordance with said first and second difference samples, thereby controlling the deviation of the angle modulated transmitter.
Claim 3
Dependent Claim
37 words
An automatic deviation control circuit in accordance with claim 1 wherein said means for varying said proportionality of said radio carrier precursor deviation further comprises means for comparing said first difference sample to said second difference sample.
Claim 4
Dependent Claim
37 words
An automatic deviation control circuit in accordance with claim 2 wherein said means for comparing said first difference sample to said second difference sample further comprises means for sampling and holding the output of said comparing means.
Claim 5
Dependent Claim
35 words
An automatic deviation control circuit in accordance with claim 1 wherein said means for varying said proportionality of said radio carrier precursor deviation value to said data input level further comprises a variable gain amplifier.
Claim 6
Dependent Claim
30 words
An automatic deviation control circuit in accordance with claim 1 wherein said means for indicating said first difference and said second difference is a variable reference divider phase locked loop.
Claim 7
Dependent Claim
261 words
An automatic deviation control circuit for an angle modulated data transmitter employing a radio carrier comprising: means for angle modulating a precursor of the radio carrier to a deviation value having a proportionality to a data input level derived from a sequence of data bits; means for generating a first signal corresponding to a predetermined positive deviation value when a data bit is at a first binary level and for generating a second signal corresponding to a predetermined negative deviation value when a data bit is at a second binary level; means for comparing and detecting the difference between said carrier precursor deviation value and said first generated signal, and for comparing and detecting the difference between said carrier precursor deviation value and said second generated signal; means for counting a predetermined number of consecutive like-level data bits; means for sampling and holding in a first location said detected difference between said carrier precursor deviation value and said first generated signal when said counting means counts a predetermined number of consecutive bits of said first binary level; means for sampling and holding in a second location said detected difference between said carrier precursor deviation value and said second generated signal when said counting means counts a predetermined number of consecutive bits of said second binary level; means for comparing said first and second location samples; and means for varying said proportionality of said carrier precursor deviation value to said data input level in accordance with said first and second location sample comparison thereby controlling the deviation of the angle modulated transmitter.
Claim 8
Dependent Claim
261 words
An automatic deviation control circuit for an angle modulated data transmitter employing a radio carrier comprising: means for angle modulating a precursor of the radio carrier to a deviation value having a proportionality to a data input level derived from a sequence of data bits; means for generating a first signal corresponding to a predetermined positive deviation value when a data bit is at a first binary level and for generating a second signal corresponding to a predetermined negative deviation value when a data bit is at a second binary level; means for comparing and detecting the difference between said carrier precursor deviation value and said first generated signal, and for comparing and detecting the difference between said carrier precursor deviation value and said second generated signal; means for counting a predetermined number of consecutive like-level data bits; means for sampling and holding in a first location said detected difference between said carrier precursor deviation value and said first generated signal when said counting means counts a predetermined number of consecutive bits of said first binary level; means for sampling and holding in a second location said detected difference between said carrier precursor deviation value and said second generated signal when said counting means counts a predetermined number of consecutive bits of said second binary level; means for comparing said first and second location samples; and means for varying said proportionality of said carrier precursor deviation value to said data input level in accordance with said first and second location sample comparison thereby controlling the deviation of the angle modulated transmitter.
Claim 9
Dependent Claim
26 words
An automatic deviation control circuit in accordance with claim 6 further comprising means for sampling and holding said comparison of said first and second location samples.
Claim 10
Dependent Claim
28 words
An automatic deviation control circuit in accordance with claim 6 wherein said means for varying said proportionality of said carrier precursor deviation value is a variable gain amplifier.
Claim 11
Independent Claim
174 words
A method of controlling the deviation of an angle modulated data transmitter employing a radio carrier comprising the steps of: angle modulating a precursor of the radio carrier to a deviation value having a proportionality to a data input level derived from at least one data bit; indicating a first difference between said carrier precursor deviation value and a predetermined positive deviation value when a data bit is at a first binary level, and indicating a second difference between said carrier precursor deviation value and a predetermined negative deviation value when a data bit is at a second binary level; detecting a predetermined non-unity number of consecutive like-level data bits; sampling said first difference when said predetermined number of consecutive data bits of said first binary level is detected and sampling said second difference when said predetermined number of consecutive data bits of said second binary level is detected; and varying said proportionality of said radio carrier precursor deviation value to said data input level in accordance with said first and second difference samples.
Claim 12
Independent Claim
174 words
A method of controlling the deviation of an angle modulated data transmitter employing a radio carrier comprising the steps of: angle modulating a precursor of the radio carrier to a deviation value having a proportionality to a data input level derived from at least one data bit; indicating a first difference between said carrier precursor deviation value and a predetermined positive deviation value when a data bit is at a first binary level, and indicating a second difference between said carrier precursor deviation value and a predetermined negative deviation value when a data bit is at a second binary level; detecting a predetermined non-unity number of consecutive like-level data bits; sampling said first difference when said predetermined number of consecutive data bits of said first binary level is detected and sampling said second difference when said predetermined number of consecutive data bits of said second binary level is detected; and varying said proportionality of said radio carrier precursor deviation value to said data input level in accordance with said first and second difference samples.
Claim 13
Dependent Claim
35 words
A method in accordance with claim 9 wherein said step of varying the proportionality of said radio carrier precursor deviation further comprises the step of comparing said first difference sample to said second difference sample.
Claim 14
Dependent Claim
31 words
A method in accordance with claim 10 wherein said step of comparing said first difference sample to said second difference sample further comprises the step of sampling and holding the comparison.
References Cited (Backward Citations)
US2977417A
Cited
US3327216A
Cited
US3729678A
Cited
US3866122A
Cited
US3787775A
Cited
US4066841A
Cited
US3938045A
Cited
US3993868A
Cited
US4063197A
Cited
US4229821A
Cited
US4486782A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1989-04-07 | 1989-10-07 | 1990-04-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-04-07 | 1993-10-07 | 1994-04-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-04-07 | 1997-10-07 | 1998-04-08 | $7700.00 | Window Closed / Lapsed |