EP0543568A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
High resolution filtering using low resolution processors
Assignee: Conexant Inc
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Filing: 1992-11-12
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Granted: —
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Expires: 2012-11-12
Abstract
Abstract A high-speed digital filter with a large dynamic range is constructed by operating two low-resolution filters (545,548) in parallel, which is referred to as an "overlap" mode of operation. In this overlap mode of operation, both low-resolution adaptive filters operate on the input data (a n ) simultaneously, but the characteristics of both filters are controlled so that one filter (545) performs a coarse level of filtering, while the other filter (548) performs a finer level of filtering and also removes any errors introduced by the first filter. Some application examples include echo canceling, equalization, and deghosting filters.
Inventors
- 👤 Daniel Amrany
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-06 04:45
CPC Classifications
H; H03; H03H; H03H21/00; H03H21/0012
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
110 words
A filter structure (540) comprising a first adaptive filter (545) responsive to a first signal (a n ), a second adaptive filter (548) responsive to said first signal, means (546) responsive to an output signal of said first adaptive filter and to an output signal of said second adaptive filter for forming an output signal (rs'(t)) that corresponds to the combination of the output signal of said first adaptive filter and a preselected amount of the output signal of the second adaptive filter, which amount is greater than zero, and means (547) responsive to said output signal for controlling characteristics of said first adaptive filter and said second adaptive filter.
Claim 2
Dependent Claim
24 words
A structure as claimed in claim 1 wherein said means for controlling affects the characteristics of said first filter only during a training interval.
Claim 3
Dependent Claim
51 words
A structure as claimed in claim 2 wherein, during said training interval, characteristics of said second filter are unaffected, and at times other than said training interval the characteristics of said first filter remain unchanged while the characteristics of said second adaptive filter are modified in accordance with said output signal.
Claim 4
Dependent Claim
15 words
A structure as claimed in claim 1 wherein said output signal forms said first signal.
Claim 5
Dependent Claim
66 words
A structure as claimed in claim 1,2 or 3 wherein said means (165, FIG.5) for forming an output signal is also responsive to a second input signal (b̂ n ) so that the output signal is formed from the second input signal less said combination (b' n ) of the output signal of said first adaptive filter and said preselected amount of said second adaptive filter.
Claim 6
Dependent Claim
52 words
A structure as claimed in claim 5 wherein said means for controlling comprises a slicer (170) responsive to said output signal and means (165) for substracting from said output the output signal of said slicer thereby forming a signal for controlling characteristics of said first adaptive filter and said second adaptive filter.
Claim 7
Independent Claim
91 words
A method for filtering a first input signal (a n ), comprising the steps, of filtering the first input signal with a first filter (545) to provide a first output signal, filtering the first input signal with a second filter (548) to provide a second output signal, and combining the first output signal and the second output signal to provide a filtered output signal (rs'(t)), where the characteristics of the first filter are determined during a training interval and the characteristics of the second filter are determined after the training interval.
Claim 8
Dependent Claim
40 words
A method as claimed in claim 7 wherein the step of combining comprises the step of combining the filtered output signal (b' n ) with a second input signal (b̂ n ) to provide an output signal (eq n ).
Claim 9
Dependent Claim
36 words
A method as claimed in claim 8 wherein the step of combining the filtered output signal and the second input signal subtracts the filtered output signal from the second input signal to provide the output signal.
References Cited (Backward Citations)
No citation records indexed.
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