EP0448758A1
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EP
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Method for the determination of FIR filter coefficients in equalizers
Assignee: Alcatel Lucent Deutschland AG
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Filing: 1990-03-28
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Granted: —
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Expires: 2010-03-28
Abstract
Abstract The invention relates to a method of creating an FIR filter being adapted to the channel impulse response of a time-dispersive transmission channel comprising the steps of creating several FIR sub-filters in parallel, selecting the tap locations of each sub-filter, determining the sub-filter tap coefficients in such a manner that the output impulse responses of the sub-filters are partially or entirely orthogonal with respect to each other, and creating an FIR filter by weighted combination of the parallel sub-filters.
Inventors
- 👤 Paul A. M. Bune
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-08 08:24
CPC Classifications
H; H04; H04L; H04L25/00; H04L25/02; H04L25/03; H04L25/03006; H04L25/03012; H04L25/03019; H04L25/03038; H04L2025/03592; H04L2025/03598; H04L2025/03611; H04L2025/03656; H04L2025/03662
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
111 words
A method of creating, either by computation or by composition, a finite impulse response (FIR) filter for equalization, said FIR filter being adapted to the momentary channel impulse response of a time-dispersive transmission channel, comprising the steps of - creating several FIR sub-filters in parallel, - selecting the tap locations of each sub-filter, - determining the sub-filter tap coefficients in such a manner that the output impulse responses of the sub-filters (which are equal to the convolutions of the respective sub-filter impulse responses with the channel impulse response) are partially or entirely orthogonal with respect to each other, and - creating an FIR filter by weighted combination of the parallel sub-filters.
Claim 2
Dependent Claim
71 words
A method as claimed in claim 1, characterized in that the creation of the said sub-filters comprises the steps of - choosing the first sub-filter to have one tap (e.g., the identity FIR filter having one tap at the zero location with coefficient value 1), and - choosing each subsequent sub-filter to contain taps at the same locations as in the preceding sub-filter and one additional tap at a different location.
Claim 3
Dependent Claim
62 words
A method as claimed in claim 2, characterized in that the additional tap of each sub-filter but the first one is positioned in such a manner that the sub-filter is the optimal equalization filter, according to a given equalizer performance criterion, with respect to the output impulse response of the filter which is formed by the weighted combination of all preceding sub-filters.
Claim 4
Dependent Claim
61 words
A method as claimed in claim 2, characterized in that the additional tap of each sub-filter is positioned to the location of the element with the highest absolute value in the output impulse response of the filter which is formed by the weighted combination of all preceding sub-filters, said location not yet being covered by the taps in the preceding sub-filter.
Claim 5
Dependent Claim
63 words
A method as claimed in claim 2, characterized in that, when the channel impulse response is assumed or known to be symmetrical about zero and the equalizer is transversal, each subsequent sub-filter but the first one is chosen to contain taps at the same locations as in the preceding sub-filter and two additional taps at two different locations symmetrical about the zero location.
References Cited (Backward Citations)
No citation records indexed.
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