US3743975A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Adjustable equalizer control apparatus
Assignee: AT&T Inc
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Filing: 1972-02-22
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Granted: 1973-07-03
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Expires: 1992-02-22
Abstract
Abstract Apparatus for controlling an equalizer having a plurality of independently adjustable, serially connected equalizer sections. The apparatus controls the equalizer to minimize the square of transmission system misalignment integrated over all frequencies in the operating band of the system. The effect of each section of the equalizer at all frequencies in the operating band is considered in determining required adjustments for all sections.
Inventors
- 👤 Yu Kao Chih
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 16:11
CPC Classifications
H; H04; H04B; H04B3/00; H04B3/02; H04B3/04; H04B3/14; H04B3/141
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
141 words
Apparatus for controlling the frequency response levels of the several sections of an adjustable equalizer, said equalizer serving to equalize transmission line apparatus in a transmission system, comprising: means for applying a test sweep signal of a predetermined amplitude to said transmission line, said test sweep signal having monotonically varying frequency; detector means responsive to the output signal of said equalizer for comparing the amplitude of said test sweep signal as transmitted by said transmission system to a predetermined reference amplitude level to develop an output signal representative of the misalignment of said transmission system for all frequencies in said test sweep signal; and means responsive to the output signal of said detector for adjusting the frequency responses of said equalizer sections to levels which reduce the square of said misalignment signal integrated over all frequencies in said test sweep signal.
Claim 2
Dependent Claim
141 words
Apparatus for controlling the frequency response levels of the several sections of an adjustable equalizer, said equalizer serving to equalize transmission line apparatus in a transmission system, comprising: means for applying a test sweep signal of a predetermined amplitude to said transmission line, said test sweep signal having monotonically varying frequency; detector means responsive to the output signal of said equalizer for comparing the amplitude of said test sweep signal as transmitted by said transmission system to a predetermined reference amplitude level to develop an output signal representative of the misalignment of said transmission system for all frequencies in said test sweep signal; and means responsive to the output signal of said detector for adjusting the frequency responses of said equalizer sections to levels which reduce the square of said misalignment signal integrated over all frequencies in said test sweep signal.
Claim 3
Dependent Claim
159 words
Apparatus for controlling the several sections of an adjustable equalizer, each of said sections having a normalized frequency response function the amplitude of which is controlled by an equalizer control signal, said equalizer serving to equalize transmission line apparatus in a transmission system, comprising: means for applying a test sweep signal of a predetermined amplitude to said transmission line, said test sweep signal having monotonically varying frequency; detector means responsive to the output signal of said equalizer for comparing the amplitude of said test sweep signal as transmitted by said transmission system to a predetermined reference amplitude level to develop a signal proportional to the misalignment of said transmission system for all frequencies in said test sweep signal; and means responsive to said misalignment signal for developing equalizer control signals for adjusting the amplitude of each of said frequency responses to levels which reduce the square of said misalignment signal integrated over alL frequencies in said test sweep signal.
Claim 4
Dependent Claim
159 words
Apparatus for controlling the several sections of an adjustable equalizer, each of said sections having a normalized frequency response function the amplitude of which is controlled by an equalizer control signal, said equalizer serving to equalize transmission line apparatus in a transmission system, comprising: means for applying a test sweep signal of a predetermined amplitude to said transmission line, said test sweep signal having monotonically varying frequency; detector means responsive to the output signal of said equalizer for comparing the amplitude of said test sweep signal as transmitted by said transmission system to a predetermined reference amplitude level to develop a signal proportional to the misalignment of said transmission system for all frequencies in said test sweep signal; and means responsive to said misalignment signal for developing equalizer control signals for adjusting the amplitude of each of said frequency responses to levels which reduce the square of said misalignment signal integrated over alL frequencies in said test sweep signal.
Claim 5
Dependent Claim
91 words
The apparatus defined in claim 2 wherein said means responsive to said misalignment signal comprises: means for determining a vector of products of said misalignment signal and the normalized frequency response of each of said equalizer sections integrated over all frequencies in said test sweep signal; and means for multiplying said vector of products by the inverse of a matrix of all pairwise products of the normalized frequency responses of said equalizer sections integrated over all frequencies in said test sweep signal to produce a vector of said equalizer control signals.
Claim 6
Dependent Claim
70 words
The apparatus defined in claim 3 wherein said means for determining comprises: means for multiplying said misalignment signal by the normalized frequency response function for each of said equalizer sections at all frequencies in said test sweep signal to produce a plurality of weighted misalignment signals; and means for integrating each of said weighted misalignment signals over all frequencies in said test sweep signal to produce said vector of products.
Claim 7
Dependent Claim
123 words
The apparatus defined in claim 3 wherein said means for determining comprises: means for determining an initial integral-square misalignment representative of the square of said misalignment signal integrated over all frequencies in said test sweep signal; means for incrementing each of said equalizer control quantities in turn; means for determining a plurality of differential integral-square misalignments each representative of the difference between said initial integral-square misalignment and an integral-square misalignment representative of the square of said misalignment signal after the incrementing of an equalizer control quantity integrated over all frequencies in said sweep signal; and means for dividing each of said differential integral-square misalignments by a quantity proportional to the increment in the corresponding equalizer control quantity to produce said vector of products.
Claim 8
Independent Claim
128 words
The method of equalizing a transmission system including an adjustable equalizer having a plurality of adjustable equalizer sections, each having a frequency response level controlled by an equalizer control quantity, comprising the steps of: applying a test sweep signal to said transmission system, said test sweep signal having monotonically varying frequency; comparing the amplitude of said test sweep signal as transmitted by said transmission system to a predetermined reference level to develop a signal representative of the misalignment of said system at all frequencies in said test sweep signal; and processing said misalignment signal to produce equalizer control quantities for adjusting the frequency response levels of each of said equalizer sections to reduce the square of said misalignment signal integrated over all frequencies in said test sweep signal.
Claim 9
Independent Claim
128 words
The method of equalizing a transmission system including an adjustable equalizer having a plurality of adjustable equalizer sections, each having a frequency response level controlled by an equalizer control quantity, comprising the steps of: applying a test sweep signal to said transmission system, said test sweep signal having monotonically varying frequency; comparing the amplitude of said test sweep signal as transmitted by said transmission system to a predetermined reference level to develop a signal representative of the misalignment of said system at all frequencies in said test sweep signal; and processing said misalignment signal to produce equalizer control quantities for adjusting the frequency response levels of each of said equalizer sections to reduce the square of said misalignment signal integrated over all frequencies in said test sweep signal.
Claim 10
Independent Claim
212 words
The method of equalizing a transmission system including an adjustable equalizer having a plurality of independently adjustable equalizer sections, each having a frequency response level controlled by an equalizer control quantity and characterized by a predetermined normalized frequency response function, comprising the steps of: applying a test sweep signal to said transmission system, said test sweep signal having monotonically varying frequency; comparing the amplitude of said test sweep signal as transmitted by said transmission system to a predetermined reference level to develop a signal representative of the misalignment of said system at all frequencies in said test sweep signal; multiplying said misalignment signal at all frequencies in said test sweep signal by the normalized frequency response function of each of said equalizer sections at the corresponding frequency to produce a plurality of weighted misalignment signals; integrating each of said weighted misalignment signals over all frequencies in said test sweep signal to produce a vector of integrAted weighted misalignment quantities; and multiplying said vector of integrated weighted misalignment quantities by a predetermined matrix of said normalized frequency response functions integrated over all frequencies in said test sweep signal to produce a plurality of equalizer control quantities for reducing the square of said misalignment signal integrated over all frequencies in said test sweep signal.
Claim 11
Independent Claim
212 words
The method of equalizing a transmission system including an adjustable equalizer having a plurality of independently adjustable equalizer sections, each having a frequency response level controlled by an equalizer control quantity and characterized by a predetermined normalized frequency response function, comprising the steps of: applying a test sweep signal to said transmission system, said test sweep signal having monotonically varying frequency; comparing the amplitude of said test sweep signal as transmitted by said transmission system to a predetermined reference level to develop a signal representative of the misalignment of said system at all frequencies in said test sweep signal; multiplying said misalignment signal at all frequencies in said test sweep signal by the normalized frequency response function of each of said equalizer sections at the corresponding frequency to produce a plurality of weighted misalignment signals; integrating each of said weighted misalignment signals over all frequencies in said test sweep signal to produce a vector of integrAted weighted misalignment quantities; and multiplying said vector of integrated weighted misalignment quantities by a predetermined matrix of said normalized frequency response functions integrated over all frequencies in said test sweep signal to produce a plurality of equalizer control quantities for reducing the square of said misalignment signal integrated over all frequencies in said test sweep signal.
Claim 12
Independent Claim
227 words
The method of equalizing a transmission system including an adjustable equalizer having a plurality of adjustable equalizer sections, each having a frequency response level controlled by an equalizer control quantity and characterized by a predetermined normalized frequency response function, comprising the steps of: applying a test sweep signal to said transmission system, said test sweep signal having monotonically varying frequency; comparing the amplitude of said test sweep signal as transmitted by said transmission system to a predetermined reference level to develop a signal representative of the misalignment of said system at all frequencies in said test sweep signal; squaring said misalignment signal for all frequencies in said test sweep signal; integrating said squared misalignment signal overall frequencies in said test sweep signal to produce an initial integral-square misalignment quantity; incrementing each of said equalizer control quantities in turn; repeating the first through fourth of the above steps for each incremented control quantity to produce a vector of incremented integral-square misalignment quantities; subtracting said initial integral-square misalignment quantity from each of said incremented integral square misalignment quantities to produce a vector of differential integral-square misalignment quantities; and multiplying said vector of differential integral-square misalignment quantities by a predetermined matrix of said normalized frequency response functions integrated over all frequencies in said test sweep signal to produce equalizer control quantities for reducing the integral-square misalignment of said transmission system.
Claim 13
Independent Claim
227 words
The method of equalizing a transmission system including an adjustable equalizer having a plurality of adjustable equalizer sections, each having a frequency response level controlled by an equalizer control quantity and characterized by a predetermined normalized frequency response function, comprising the steps of: applying a test sweep signal to said transmission system, said test sweep signal having monotonically varying frequency; comparing the amplitude of said test sweep signal as transmitted by said transmission system to a predetermined reference level to develop a signal representative of the misalignment of said system at all frequencies in said test sweep signal; squaring said misalignment signal for all frequencies in said test sweep signal; integrating said squared misalignment signal overall frequencies in said test sweep signal to produce an initial integral-square misalignment quantity; incrementing each of said equalizer control quantities in turn; repeating the first through fourth of the above steps for each incremented control quantity to produce a vector of incremented integral-square misalignment quantities; subtracting said initial integral-square misalignment quantity from each of said incremented integral square misalignment quantities to produce a vector of differential integral-square misalignment quantities; and multiplying said vector of differential integral-square misalignment quantities by a predetermined matrix of said normalized frequency response functions integrated over all frequencies in said test sweep signal to produce equalizer control quantities for reducing the integral-square misalignment of said transmission system.
References Cited (Backward Citations)
US3573667A
Cited
US3633129A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-07-02 | 1977-01-01 | 1977-07-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-07-02 | 1981-01-01 | 1981-07-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-07-02 | 1985-01-01 | 1985-07-03 | $7700.00 | Window Closed / Lapsed |