US4759037A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Passband equalization of modulated quadrature-related carrier signals
Assignee: AT&T Inc
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Filing: 1986-04-28
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Granted: 1988-07-19
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Expires: 2006-04-28
Abstract
Abstract A technique is disclosed for equalizing an incoming signal including quadrature-related carrier signals by forming the product of the incoming signal at at least one prescribed time and only one real-valued coefficient associated with each time. In one embodiment of the present invention, the equalized incoming signal is demodulated into a first pair of component signals. At least one of these component signals is then used to generate each coefficient. In another embodiment of the present invention, each coefficient is generated in response to at least one of the component signals in the first pair along with a second pair of component signals which are formed by demodulating the incoming signal. This technique can be advantageously adapted to incorporate a number of coefficient updating algorithms and is suitable for use in a number of modulation formats.
Inventors
- 👤 Walter Debus, Jr.
- 👤 Peter D. Karabinis
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 21:12
CPC Classifications
H; H04; H04L; H04L27/00; H04L27/01
Claims Analysis
Total Claims: 27
Claim 1
Independent Claim
90 words
Apparatus for compensating for distortion in an incoming signal comprising quadrature-related carrier signals, said incoming signal having a value which varies with time, and said apparatus comprising means for equalizing said incoming signal by multiplying the value of said incoming signal existing at at least one prescribed time by only one real-valued coefficient associated with each prescribed time; means for demodulating the equalized incoming signal into a first pair of component signals; and means for generating each coefficient in response to at least one component signal in said first pair.
Claim 2
Dependent Claim
90 words
Apparatus for compensating for distortion in an incoming signal comprising quadrature-related carrier signals, said incoming signal having a value which varies with time, and said apparatus comprising means for equalizing said incoming signal by multiplying the value of said incoming signal existing at at least one prescribed time by only one real-valued coefficient associated with each prescribed time; means for demodulating the equalized incoming signal into a first pair of component signals; and means for generating each coefficient in response to at least one component signal in said first pair.
Claim 3
Dependent Claim
29 words
The apparatus of claim 1 wherein said component signals have respective amplitudes and said generating means comprises means for sampling the amplitude of each component signal at predetermined times.
Claim 4
Dependent Claim
26 words
The apparatus of claim 2 wherein said generating means further comprises decoding means for quantizing each sampled amplitude into one of a plurality of predetermined values.
Claim 5
Dependent Claim
29 words
The apparatus of claim 3 wherein said decoding means also forms error signals each being equal to the algebraic difference between each sampled amplitude and the associated quantized value.
Claim 6
Dependent Claim
38 words
The apparatus of claim 4 wherein said generating means comprises processing means for forming each coefficient in response to at least one of said error signals and said quantized sampled amplitudes of said first pair of component signals.
Claim 7
Dependent Claim
33 words
The apparatus of claim 5 wherein said quantized sampled amplitudes each have an algebraic sign and said processing means forms each coefficient in response to the algebraic signs of said quantized sampled amplitudes.
Claim 8
Dependent Claim
36 words
The apparatus of claim 6 wherein said error signals each have an algebraic sign and said processing means also forms each coefficient in response to the algebraic sign of at least one of said error signals.
Claim 9
Dependent Claim
23 words
The apparatus of claim 5 wherein said processing means forms each coefficient in response to the algebraic signs of said quantized sampled amplitudes.
Claim 10
Dependent Claim
21 words
The apparatus of claim 1 further comprising means for a demodulating said incoming signal into a second pair of component signals.
Claim 11
Dependent Claim
22 words
The apparatus of claim 9 wherein said generating means generates each coefficient also in response to said second pair of component signals.
Claim 12
Dependent Claim
41 words
The apparatus of claim 10 wherein said first and second pairs of component signals each have an amplitude and said generating means comprises means for sampling the amplitude of each component signal in said first and second pairs at predetermined times.
Claim 13
Dependent Claim
34 words
The apparatus of claim 11 wherein said generating means further comprises decoding means for quantizing the sampled amplitude of each component signal in said first pair into one of a plurality of predetermined values.
Claim 14
Dependent Claim
29 words
The apparatus of claim 12 wherein said decoding means also forms error signals each being equal to the algebraic difference between each sampled amplitude and the associated quantized value.
Claim 15
Dependent Claim
33 words
The apparatus of claim 13 wherein said generating means comprises processing means for forming each coefficient in response to at least one of said error signals and said second pair of component signals.
Claim 16
Dependent Claim
41 words
The apparatus of claim 14 wherein said error signals have associated algebraic signs and said processing means forms each coefficient in response to said second pair of component signals and the algebraic signs of at least one of said error signals.
Claim 17
Dependent Claim
57 words
The apparatus of claim 14 wherein said second pair of component signals and said error signals each have an algebraic sign and said generating means comprises processing means for forming each coefficient in response to the algebraic signs of said second pair of component signals and the algebraic signs of at least one of said error signals.
Claim 18
Dependent Claim
27 words
The apparatus of claim 10 wherein said quadrature-related carrier signals have a predetermined frequency and said generating means generates each coefficient as a function of said frequency.
Claim 19
Dependent Claim
36 words
The apparatus of claim 17 wherein said equalizing means comprise a delay line having at least one delay element and said generating means generates each coefficient as a function of the delay provided by said element.
Claim 20
Dependent Claim
27 words
The apparatus of claim 1 wherein said quadrature-related carrier signals have a predetermined frequency and said generating means generates each coefficient as a function of said frequency.
Claim 21
Dependent Claim
36 words
The apparatus of claim 19 wherein said equalizing means comprises a delay line having at least one delay element and said generating means generates each coefficient as a function of the delay provided by said element.
Claim 22
Independent Claim
73 words
A method of compensating for distortion in an incoming signal comprising quadrature-related carrier signals, said method comprising the steps of equalizing said incoming signal by multiplying said incoming signal at at least one prescribed time by only one real-valued coefficient associated with each prescribed time; demodulating the equalized incoming signal into a first pair of component signals; and generating each coefficient in response to at least one component signal in said first pair.
Claim 23
Independent Claim
73 words
A method of compensating for distortion in an incoming signal comprising quadrature-related carrier signals, said method comprising the steps of equalizing said incoming signal by multiplying said incoming signal at at least one prescribed time by only one real-valued coefficient associated with each prescribed time; demodulating the equalized incoming signal into a first pair of component signals; and generating each coefficient in response to at least one component signal in said first pair.
Claim 24
Dependent Claim
59 words
Apparatus for compensating for distortion in an incoming signal comprising quadrature-related carrier signals having a predetermined frequency, said apparatus comprising means for equalizing said incoming signal by multiplying said incoming signal at prescribed times by a coefficient associated with each prescribed time; and means for generating said coefficients in response to said equalized incoming signal and predetermined sinusoidal signals.
Claim 25
Dependent Claim
59 words
Apparatus for compensating for distortion in an incoming signal comprising quadrature-related carrier signals having a predetermined frequency, said apparatus comprising means for equalizing said incoming signal by multiplying said incoming signal at prescribed times by a coefficient associated with each prescribed time; and means for generating said coefficients in response to said equalized incoming signal and predetermined sinusoidal signals.
Claim 26
Dependent Claim
13 words
The apparatus of claim 22 wherein said sinusoidal signals vary with said frequency.
Claim 27
Dependent Claim
25 words
The apparatus of claim 22 wherein said equalizing means includes delay line elements and said sinusoidal signals vary with the delay provided with said elements.
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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) | 1991-07-19 | 1992-01-18 | 1992-07-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-07-19 | 1996-01-18 | 1996-07-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-07-19 | 2000-01-18 | 2000-07-19 | $7700.00 | Window Closed / Lapsed |