US6317419B1
Expired / Lapsed
US
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Method and apparatus for training an echo canceler in a PCM modem context
Assignee: MACOM Technology Solutions Holdings Inc
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Filing: 1998-06-10
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Granted: 2001-11-13
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Expires: 2018-06-10
Abstract
Abstract An improved echo canceler training technique may be employed by a digital server modem in a PCM modem context, such as a V.90 modem system. The disclosed echo canceler training technique establishes the digital impairments within the echo path by transmitting a training signal from a transmitter located at the digital server modem. The echo signal generated in response to the training signal is received by the digital server modem and appropriately analyzed to accurately model the echo path. The echo canceler resident at the server modem is than suitably trained to compensate for the modeled echo path. In the preferred embodiment, the echo canceler training signal is also used during in the context of downstream digital impairment learning by the analog client modem. In the context of the echo canceler training, the server modem does not rely upon any processing or analysis performed by the client modem; the server modem trains its echo canceler without receiving any information from the client modem.
Inventors
- 👤 Sverrir Olafsson
- 👤 Zhenyu Zhou
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 04:52
CPC Classifications
H; H04; H04B; H04B3/00; H04B3/02; H04B3/20; H04B3/23; H04L; H04L25/00; H04L25/38; H04L25/40; H04L25/49; H04L25/4917; H04L25/4927
Claims Analysis
Total Claims: 24
Claim 1
Independent Claim
129 words
An echo cancellation method for a modem system comprising a first modem having an echo canceler, a transmitter configured to transmit signals to a second modem over a downstream communication channel and a receiver configured to receive signals from said second modem over an upstream communication channel, where an echo channel conveys echo signals between said transmitter and said receiver, said method comprising the steps of: transmitting a training signal; receiving a training echo signal, said training echo signal being associated with said training signal; and determining, in response to said training echo signal, one or more digital impairments associated with said communication channel; generating one or more parameters based on said one or more digital impairments; and configuring said echo canceler according to said one or more parameters.
Claim 2
Dependent Claim
129 words
An echo cancellation method for a modem system comprising a first modem having an echo canceler, a transmitter configured to transmit signals to a second modem over a downstream communication channel and a receiver configured to receive signals from said second modem over an upstream communication channel, where an echo channel conveys echo signals between said transmitter and said receiver, said method comprising the steps of: transmitting a training signal; receiving a training echo signal, said training echo signal being associated with said training signal; and determining, in response to said training echo signal, one or more digital impairments associated with said communication channel; generating one or more parameters based on said one or more digital impairments; and configuring said echo canceler according to said one or more parameters.
Claim 3
Dependent Claim
32 words
The echo cancellation method of claim 1 , wherein said training signal being formatted to enable said second modem to establish characteristics of said downstream channel in response to said training signal.
Claim 4
Dependent Claim
25 words
The echo cancellation method of claim 1 , wherein said one or more digital impairments are caused by a robbed-bit signaling in said downstream channel.
Claim 5
Dependent Claim
25 words
The echo cancellation method of claim 1 , wherein said one or more digital impairments are caused by a digital pad in said downstream channel.
Claim 6
Dependent Claim
41 words
The echo cancellation method of claim 1 , wherein said one or more digital impairments are caused by a robbed-bit signaling prior to a digital pad, said digital pad and a robbed-bit signaling after said digital pad in said downstream channel.
Claim 7
Dependent Claim
24 words
The training method of claim 1 , wherein said one or more digital impairments are caused by a robbed-bit signaling in said upstream channel.
Claim 8
Dependent Claim
106 words
A training method for use by a first modem having an echo canceler, said first modem being in communication with a second modem over a communication channel, said method comprising: transmitting a digital impairment learning signal, wherein said digital impairment learning signal is capable of being used by said second modem to design a set of signal point constellations; receiving an echo signal, said echo signal being associated with said digital impairment learning signal; analyzing said echo signal to determine one or more digital impairments of said communication channel; and configuring said echo canceler according to said one or more digital impairments of said communication channel.
Claim 9
Dependent Claim
106 words
A training method for use by a first modem having an echo canceler, said first modem being in communication with a second modem over a communication channel, said method comprising: transmitting a digital impairment learning signal, wherein said digital impairment learning signal is capable of being used by said second modem to design a set of signal point constellations; receiving an echo signal, said echo signal being associated with said digital impairment learning signal; analyzing said echo signal to determine one or more digital impairments of said communication channel; and configuring said echo canceler according to said one or more digital impairments of said communication channel.
Claim 10
Dependent Claim
19 words
The training method of claim 7 , wherein said communication channel includes a downstream channel and an upstream channel.
Claim 11
Dependent Claim
24 words
The training method of claim 8 , wherein said one or more digital impairments are caused by a robbed-bit signaling in said downstream channel.
Claim 12
Dependent Claim
24 words
The training method of claim 8 , wherein said one or more digital impairments are caused by a digital pad in said downstream channel.
Claim 13
Dependent Claim
40 words
The training method of claim 8 , wherein said one or more digital impairments are caused by a robbed-bit signaling prior to a digital pad, said digital pad and a robbed-bit signaling after said digital pad in said downstream channel.
Claim 14
Dependent Claim
24 words
The training method of claim 8 , wherein said one or more digital impairments are caused by a robbed-bit signaling in said upstream channel.
Claim 15
Dependent Claim
132 words
A first modem device in communication with a second modem over a communication channel, said first modem device comprising: a transmitter capable of transmitting a digital impairment learning signal, wherein said digital impairment learning signal is capable of being used by said second modem to design a set of signal point constellations; a receiver; a learning element; and an echo canceler; wherein said transmitter transmits said digital impairment learning signal to said second modem device, and said receiver receives an echo signal, said echo signal being associated with said digital impairment learning signal, and wherein said learning element receives said echo signal from said receiver, determines one or more digital impairments of said communication channel and configures said echo canceler according to said one or more digital impairments of said communication channel.
Claim 16
Dependent Claim
132 words
A first modem device in communication with a second modem over a communication channel, said first modem device comprising: a transmitter capable of transmitting a digital impairment learning signal, wherein said digital impairment learning signal is capable of being used by said second modem to design a set of signal point constellations; a receiver; a learning element; and an echo canceler; wherein said transmitter transmits said digital impairment learning signal to said second modem device, and said receiver receives an echo signal, said echo signal being associated with said digital impairment learning signal, and wherein said learning element receives said echo signal from said receiver, determines one or more digital impairments of said communication channel and configures said echo canceler according to said one or more digital impairments of said communication channel.
Claim 17
Dependent Claim
47 words
The first modem device of claim 13 further comprising a digital impairment emulator, wherein said digital impairment emulator receives one or more parameters based on said one or more digital impairments from said learning element and said digital impairment emulator provides an input to said echo canceler.
Claim 18
Dependent Claim
26 words
The first modem device of claim 13 further comprising an inverter configured to process said echo signal to compensate for the presence of a robbed-bit signaling.
Claim 19
Dependent Claim
29 words
The first modem device of claim 13 further comprising a linear converter element, wherein said linear converter element converts each 8-bit PCM code into a corresponding 14-bit linear code.
Claim 20
Dependent Claim
101 words
A communication device for communication with a remote device over a communication channel having a downstream communication channel and an upstream communication channel, said communication device comprising: a transmitter capable of transmitting a training signal; a receiver capable of receiving a training echo signal, said training echo signal being associated with said training signal; and a learning element capable of determining, in response to said training echo signal, one or more digital impairments associated with said communication channel; an echo canceler; wherein said learning element configures said echo canceler according to said one or more digital impairments of said communication channel.
Claim 21
Dependent Claim
101 words
A communication device for communication with a remote device over a communication channel having a downstream communication channel and an upstream communication channel, said communication device comprising: a transmitter capable of transmitting a training signal; a receiver capable of receiving a training echo signal, said training echo signal being associated with said training signal; and a learning element capable of determining, in response to said training echo signal, one or more digital impairments associated with said communication channel; an echo canceler; wherein said learning element configures said echo canceler according to said one or more digital impairments of said communication channel.
Claim 22
Dependent Claim
46 words
The communication device of claim 17 further comprising a digital impairment emulator, wherein said digital impairment emulator receives one or more parameters based on said one or more digital impairments from said learning element and said digital impairment emulator provides an input to said echo canceler.
Claim 23
Dependent Claim
26 words
The first modem device of claim 17 further comprising an inverter configured to process said echo signal to compensate for the presence of a robbed-bit signaling.
Claim 24
Dependent Claim
29 words
The first modem device of claim 17 further comprising a linear converter element, wherein said linear converter element converts each 8-bit PCM code into a corresponding 14-bit linear code.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2004-11-12 | 2005-05-14 | 2005-11-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2008-11-12 | 2009-05-14 | 2009-11-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2012-11-12 | 2013-05-14 | 2013-11-13 | $7700.00 | Window Closed / Lapsed |