US6693975B2
Expired / Lapsed
US
⏱️ 0.0 years remaining
Low-order HDSL2 transmit filter
Assignee: Conexant Inc
•
Filing: 2001-01-26
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Granted: 2004-02-17
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Expires: 2021-01-26
Abstract
Abstract The present invention comprises a method of obtaining coefficients for a transmit filter such that the power spectral density of the output for the different frequencies comes close to but does not exceed a maximum power spectral density of a communication(s) standard. By first doing a convex optimization procedure to obtain the autocorrelation coefficients for the filter and then using the autocorrelation coefficients to determine the filter coefficients, a low-order filter that closely approximates the desired output power spectral densities can be produced.
Inventors
- 👤 Bijit Halder
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 21:40
CPC Classifications
H; H03; H03H; H03H17/00; H03H17/02
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
63 words
A digital transmit filter for a communication system having a maximum prescribed output power spectral density, the digital transmit filter having filter coefficients selected such that the output power spectral density of the system is below the maximum output power spectral density of the communication system, the filter coefficients being selected from optimized autocorrelation coefficients for the filter in a convex optimization procedure.
Claim 2
Dependent Claim
63 words
A digital transmit filter for a communication system having a maximum prescribed output power spectral density, the digital transmit filter having filter coefficients selected such that the output power spectral density of the system is below the maximum output power spectral density of the communication system, the filter coefficients being selected from optimized autocorrelation coefficients for the filter in a convex optimization procedure.
Claim 3
Dependent Claim
21 words
The digital transmit filter of claim 1 wherein spectral factorization is used to determine the filter coefficients from the autocorrelation coefficients.
Claim 4
Dependent Claim
21 words
The digital transmit filter of claim 2 wherein spectral factors of the spectral factorization are found using a root finding method.
Claim 5
Dependent Claim
26 words
The digital transmit filter of claim 1 wherein the system includes an interpolating filter that affects affects the total output power spectral density of the system.
Claim 6
Dependent Claim
23 words
The digital transmit filter of claim 1 wherein a discrete approximization of an upper bound constraint is done in the convex optimization procedure.
Claim 7
Dependent Claim
22 words
The digital transmit filter of claim 1 wherein the digital transmit filter is implemented with different coefficients for upstream and downstream directions.
Claim 8
Dependent Claim
18 words
The digital transmit filter of claim 1 wherein the digital transmit filter has fewer than one hundred coefficients.
Claim 9
Dependent Claim
17 words
The digital transmit filter of claim 1 wherein the digital transmit filter has thirty-two or fewer coefficients.
Claim 10
Independent Claim
46 words
A method of determining filter coefficients for a digital transmit filter of a communication system having a maximum prescribed output power spectral density, comprising optimizing autocorrelation coefficients for the digital transmit filter in a convex optimization procedure; and determining the filter coefficients from the autocorrelation coefficients.
Claim 11
Independent Claim
46 words
A method of determining filter coefficients for a digital transmit filter of a communication system having a maximum prescribed output power spectral density, comprising optimizing autocorrelation coefficients for the digital transmit filter in a convex optimization procedure; and determining the filter coefficients from the autocorrelation coefficients.
Claim 12
Dependent Claim
18 words
The method of claim 9 wherein the filter coefficients are determined from the autocorrelation coefficients using spectral factorization.
Claim 13
Dependent Claim
16 words
The method of claim 10 wherein the spectral factorization is done using a root finding method.
Claim 14
Dependent Claim
25 words
The method of claim 9 wherein a discrete approximization of an upper bound constraint of the autocorrelation coefficients is done in the convex optimization procedure.
Claim 15
Dependent Claim
15 words
The method of claim 9 wherein the digital transmit filter is for a DSL system.
Claim 16
Dependent Claim
16 words
The method of claim 13 wherein the digital transmit filter is for a high-bit DSL system.
Claim 17
Dependent Claim
16 words
The method of claim 9 wherein the digital transmit filter has fewer than one hundred coefficients.
Claim 18
Dependent Claim
15 words
The method of claim 9 wherein the digital transmit filter has thirty-two or fewer coefficients.
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| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
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| 3.5 Years (Year 4) | 2007-02-16 | 2007-08-18 | 2008-02-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2011-02-16 | 2011-08-18 | 2012-02-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2015-02-16 | 2015-08-18 | 2016-02-17 | $7700.00 | Window Closed / Lapsed |