US5909426A
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US
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Orthogonal LMS algorithms for fast line echo canceler training
Assignee: Boeing North American Inc
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Filing: 1997-03-31
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Granted: 1999-06-01
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Expires: 2017-03-31
Abstract
Abstract An echo canceler for calculating an echo impulse response during a training sequence, wherein a sequence of data samples is selected such that a full rank data correlation matrix comprised of such data samples is diagonal at the Nth iteration. The echo canceler estimates the echo impulse response based on such data samples and an echo generated during the training sequence using a normalized least means square algorithm, wherein the length of the data sequence to sound the echo channel is N. This normalized LMS algorithm, wherein the data sequence is specifically selected, converges toward an echo impulse response much faster than standard LMS algorithms, while having a computational complexity comparable to that of the standard LMS algorithm.
Inventors
- 👤 Thomas C. Liau
- 👤 Wei K. Tsai
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 08:51
CPC Classifications
H; H04; H04B; H04B3/00; H04B3/02; H04B3/20; H04B3/23; H04B3/238
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
146 words
A method for estimating the echo impulse response, comprising: transmitting with a transmitter a data sequence of length N to sound an echo channel, wherein said echo z n returns as a result of such sounding; selecting data samples d n such that vector h n which is comprised of the data samples d n produces a data matrix which is diagonal to the Nth iteration; receiving with an echo canceler the data samples d n and the echo z n ; calculating with the echo canceler the echo impulse response x' n using a least means square algorithm and the data vector h n of data samples d n and the sounded echo z n , wherein the echo canceler estimates the echo impulse response x' n with the following equation: ##EQU9## wherein the echo impulse response x n is calculated out to N iterations.
Claim 2
Independent Claim
146 words
A method for estimating the echo impulse response, comprising: transmitting with a transmitter a data sequence of length N to sound an echo channel, wherein said echo z n returns as a result of such sounding; selecting data samples d n such that vector h n which is comprised of the data samples d n produces a data matrix which is diagonal to the Nth iteration; receiving with an echo canceler the data samples d n and the echo z n ; calculating with the echo canceler the echo impulse response x' n using a least means square algorithm and the data vector h n of data samples d n and the sounded echo z n , wherein the echo canceler estimates the echo impulse response x' n with the following equation: ##EQU9## wherein the echo impulse response x n is calculated out to N iterations.
Claim 3
Dependent Claim
7 words
The method of claim 1, wherein N=50.
Claim 4
Independent Claim
149 words
A method for estimating the echo impulse response, comprising: transmitting with a transmitter a data sequence of length N to sound an echo channel, wherein said echo z n returns as a result of such sounding; selecting data samples d n such that vector h n which is comprised of the data samples d n produces a data matrix which is diagonal to the Nth iteration; receiving with an echo canceler the data samples d n and the echo z n ; calculating with the echo canceler the echo impulse response x' n using a least means square algorithm and the data vector h n of data samples d n and the sounded echo z n , wherein the echo canceler estimates the echo impulse response x' n with the following equation: ##EQU10## wherein k=ceiling (n/N); and calculating the echo impulse response x' n in more than N Iterations.
Claim 5
Independent Claim
149 words
A method for estimating the echo impulse response, comprising: transmitting with a transmitter a data sequence of length N to sound an echo channel, wherein said echo z n returns as a result of such sounding; selecting data samples d n such that vector h n which is comprised of the data samples d n produces a data matrix which is diagonal to the Nth iteration; receiving with an echo canceler the data samples d n and the echo z n ; calculating with the echo canceler the echo impulse response x' n using a least means square algorithm and the data vector h n of data samples d n and the sounded echo z n , wherein the echo canceler estimates the echo impulse response x' n with the following equation: ##EQU10## wherein k=ceiling (n/N); and calculating the echo impulse response x' n in more than N Iterations.
Claim 6
Dependent Claim
19 words
The method of claim 3, wherein the echo impulse response is calculated out to a multiple of N iterations.
Claim 7
Dependent Claim
20 words
The method of claim 4, wherein the estimated echo z' n is calculated by the echo canceler as follows: ##EQU11##
Claim 8
Dependent Claim
17 words
The method of claim 3, wherein the echo impulse response is calculated for 6 times N iterations.
Claim 9
Independent Claim
162 words
A method for estimating the echo impulse response, comprising: transmitting with a transmitter a data sequence of length N to sound an echo channel, wherein said echo z n returns as a result of such sounding; selecting data samples d n such that vector h n which is comprised of the data samples d n produces a data matrix which is diagonal to the Nth iteration; receiving with an echo canceler the data samples d n and the echo z n ; calculating with the echo canceler the echo impulse response x' n using a least means square algorithm and the data vector h n of data samples d n and the sounded echo z n wherein the echo canceler estimates the echo impulse response x' n with the following equation: ##EQU12## for N iterations; and wherein the echo canceler estimates the echo impulse response x' n with the following equation: ##EQU13## wherein k=ceiling (n/N); and for iterations in excess of N.
Claim 10
Independent Claim
162 words
A method for estimating the echo impulse response, comprising: transmitting with a transmitter a data sequence of length N to sound an echo channel, wherein said echo z n returns as a result of such sounding; selecting data samples d n such that vector h n which is comprised of the data samples d n produces a data matrix which is diagonal to the Nth iteration; receiving with an echo canceler the data samples d n and the echo z n ; calculating with the echo canceler the echo impulse response x' n using a least means square algorithm and the data vector h n of data samples d n and the sounded echo z n wherein the echo canceler estimates the echo impulse response x' n with the following equation: ##EQU12## for N iterations; and wherein the echo canceler estimates the echo impulse response x' n with the following equation: ##EQU13## wherein k=ceiling (n/N); and for iterations in excess of N.
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