Forward compatible and expandable high speed communications system and method of operation
First Claim
1. A high speed communications system capable of supporting a downstream data transmission from an upstream transceiver using an analog signal consisting of M data carrying signals contained within a bandwidth F, said system comprising:
- a channel interface circuit for coupling to and receiving said analog signal; and
a front end receiving circuit for processing the analog signal and converting it to a digital signal;
a processing circuit for performing signal processing operations on N of said M data carrying signals (N<
M) from the digital signal using a first frequency portion f1 of the digital signal (f1<
F) and for extracting selected data from said N data carrying signals; and
wherein said selected data can be varied by varying resources available to said processing circuit, and said processing circuit does not process data carrying signals from the downstream data transmission outside of said first frequency portion f1.
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Accused Products
Abstract
A high speed communications system is provided which uses a selectable, desirable portion of the total available bandwidth of a transmission channel. In a preferred embodiment, the invention is an ADSL compatible modem which selects a sub-set of the available downstream DMT sub-channels based on an evaluation of such sub-channels by appropriate signal processing circuitry. An analog front end (AFE) contains sub-band filtering causes an upstream transceiver to use only this selected number of available sub-channels for downstream data transmission. This reduces hardware costs and complexity while still preserving compatibility with applicable ADSL standards and providing a high speed data link. The target data rate of the modem can be further enhanced to the point of achieving full protocol capability by increasing or upgrading the AFEs, and/or the signal processing circuitry in order to increase the number of processable transmitted downstream sub-channels.
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Citations
67 Claims
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1. A high speed communications system capable of supporting a downstream data transmission from an upstream transceiver using an analog signal consisting of M data carrying signals contained within a bandwidth F, said system comprising:
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a channel interface circuit for coupling to and receiving said analog signal; and
a front end receiving circuit for processing the analog signal and converting it to a digital signal;
a processing circuit for performing signal processing operations on N of said M data carrying signals (N<
M) from the digital signal using a first frequency portion f1 of the digital signal (f1<
F) and for extracting selected data from said N data carrying signals; and
wherein said selected data can be varied by varying resources available to said processing circuit, and said processing circuit does not process data carrying signals from the downstream data transmission outside of said first frequency portion f1. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13)
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14. A high speed communications system capable of supporting a downstream data transmission from an upstream transceiver using an analog signal consisting of M data carrying signals contained within a bandwidth F, said system comprising:
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a channel interface circuit for coupling to and receiving said analog signal; and
a front end receiving circuit for processing the analog signal and converting it to a digital signal;
a processing circuit for extracting N data carrying signals (N<
M) from the digital signal using a first frequency portion f1 of the digital signal (f1<
F); and
a front end transmitting circuit for transmitting control information to cause said upstream transceiver to transmit downstream data only using the N data carrying signals; and
wherein the control information transmitted to the upstream transceiver includes feedback information indicating that only N of the M data carrying signals are desirable for downstream data transmission, even during times when said channel is capable of supporting more than N data carrying signals and further wherein the control information transmitted to the upstream transceiver further includes feedback information indicating that;
(i) the system can support any data protocols used by said upstream transceiver; and
(ii) that they are connected through a channel with substantial signal attenuation characteristics for data signals other than the N data carrying signals.
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15. A scalable high speed communications system capable of supporting an upstream transceiver which can transmit M modulated sub-channels using an analog signal through a channel to said system, said system comprising:
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a channel interface circuit for coupling to and receiving said analog signal from the channel;
an analog front end circuit for processing the analog signal and converting it to a digital signal, the front end circuit including a sub-band filter and an analog to digital converter;
a processing circuit for extracting data from the digital signal, the digital signal including data from a first number N of said sub-channels, where N<
M/k where k is a scaling factor, and said processing circuit can accommodate any integer value for k>
=1, and;
wherein said N sub-channels can be varied based on resources available to said processing circuit, and said processing circuit extracts data only from said N sub-channels, regardless of whether additional ones of said M sub-channels can be used for transmitting data between the system and said upstream transceiver; and
further wherein the N sub-channels are selected so as to reduce the amount of processing required to extract the selected data from the digital signal, as compared to an amount of processing required to extract the selected data if it were carried by a different set of N sub-channels. - View Dependent Claims (16, 17, 18, 19, 20, 21, 22)
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23. A scalable high speed communications system capable of supporting an upstream transceiver which can transmit M modulated sub-channels using an analog signal through a channel to said system, said system comprising:
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a channel interface circuit for coupling to and receiving said analog signal from the channel;
an analog front end circuit for processing the analog signal and converting it to a digital signal, the front end circuit including a sub-band filter and an analog to digital converter;
a processing circuit for extracting data from the digital signal the digital signal including data from a first number N of said sub-channels, where N≦
M/k, where k is a scaling factor, and said processing circuit can accommodate any integer value for k>
=1, and;
wherein said N sub-channels can be varied based on resources available to said processing circuit, and said processing circuit extracts data only from said N sub-channels, regardless of whether additional ones of said M sub-channels can be used for transmitting data between the system and said upstream transceiver; and
further wherein the N sub-channels are selected so as to reduce the amount of processing required to extract the selected data from the digital signal, as compared to an amount of processing required to extract the selected data if it were carried by a different set of N sub-channels;
further wherein the N sub-channels can be selected by an initialization process to set up a data link to the upstream transceiver.
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24. A scalable high speed communications system capable of supporting an upstream transceiver which can transmit M modulated sub-channels using an analog signal through a channel to said system, said system comprising:
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a channel interface circuit for coupling to and receiving said analog signal from the channel;
an analog front end circuit for processing the analog signal and converting it to a digital signal, the front end circuit including a sub-band filter and an analog to digital converter;
a processing circuit for extracting data from the digital signal, the digital signal including data from a first number N of said sub-channels, where N≦
M/k, where k is a scaling factor, and said processing circuit can accommodate any integer value for k>
=1, and;
wherein said N sub-channels can be varied based on resources available to said processing circuit, and said processing circuit extracts data only from said N sub-channels, regardless of whether additional ones of said M sub-channels can be used for transmitting data between the system and said upstream transceiver; and
further wherein the N sub-channels are selectable by an initialization process to set up a data link with the remote transceiver, and are selected so as to reduce the amount of processing required to extract the selected data from the digital signal, as compared to an amount of processing required to extract the selected data if it were carried by a different set of N sub-channels;
further wherein the M sub-channels can be received from the upstream transmitter during said initialization process, and thereafter, only N sub-channels are received.
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25. A scalable high speed communications system capable of supporting an upstream transceiver which can transmit M modulated sub-channels using an analog signal through a channel to said system, said system comprising:
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a channel interface circuit for coupling to and receiving said analog signal from the channel;
an analog front end circuit for processing the analog signal and converting it to a digital signal, the front end circuit including a sub-band filter adapted to bandpass said analog signal under control of a user of such system, and an analog to digital converter;
a processing circuit for extracting data from the digital signal, the digital signal including data from a first number N of said sub-channels bandpassed by said sub-band filter under control of said user, where N<
M/k, and where k is a scaling factor and said processing circuit can accommodate any integer value for k>
=1 and;
wherein said N sub-channels can be varied based on resources available to said processing circuit, and said processing circuit extracts data only from said N sub-channels, regardless of whether additional ones of said M sub-channels can be used for transmitting data between the system and said upstream transceiver; and
further wherein said user of such system can increase a target data rate of the system by modularly augmenting the front end circuit to include additional bandwidth and analog to digital conversion capacity such that an additional second number of sub-channels P from the M sub-channels (N+P<
M) can be processed.
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26. A scalable high speed communications system capable of supporting an upstream transceiver which can transmit M modulated sub-channels using an analog signal through a channel to said system, said system comprising:
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a channel interface circuit for coupling to and receiving said analog signal from the channel, an analog front end circuit for processing the analog signal and converting it to a digital signal, the front end circuit including a sub-band filter adapted to bandpass said analog signal under control of a user of such system, and an analog to digital converter;
a processing circuit for extracting data from the digital signal, the digital signal including data from a first number N of said sub-channels bandpassed by said sub-band filter under control of said user, where N≦
M/k, and where k is a scaling factor, and said processing circuit can accommodate any integer value for k >
=1, and;
wherein said N sub-channels can be varied based on resources available to said processing circuit, and said processing circuit extracts data only from said N sub-channels regardless of whether additional ones of said M sub-channels can be used for transmitting data between the system and said upstream transceiver; and
further wherein said user of such system can increase a target data rate of the system by modularly augmenting the front end circuit to include additional bandwidth and analog to digital conversion capacity such that an additional second number of sub-channels P from the M sub-channels (N+P<
M) can be processed; and
a front end transmitting circuit for transmitting control information to cause said upstream transceiver to transmit downstream data only using the N sub-channels.
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27. A scalable high speed communications system capable of supporting an upstream transceiver which can transmit M modulated sub-channels using an analog signal through a channel to said system, said system comprising:
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a channel interface circuit for coupling to and receiving said analog signal from the channel;
an analog front end circuit for processing the analog signal and converting it to a digital signal, the front end circuit including a sub-band filter adapted to bandpass said analog signal under control of a user of such system, and an analog to digital converter;
a processing circuit for extracting data from the digital signal the digital signal including data from a first number N of said sub-channels bandpassed by said sub-band filter under control of said user, where N≦
M/k and where k is a scaling factor, and said processing circuit can accommodate any integer value for k>
=1, and,a front end transmitting circuit for transmitting control information to cause said upstream transceiver to transmit downstream data only using the N sub-channels; and
wherein said N sub-channels can be varied based on resources available to said processing circuit, and said processing circuit extracts data only from said N sub-channels, regardless of whether additional ones of said M sub-channels can be used for transmitting data between the system and said upstream transceiver; and
further wherein said user of such system can increase a target data rate of the system by modularly augmenting the front end circuit to include additional bandwidth and analog to digital conversion capacity such that an additional second number of sub-channels P from the M sub-channels (N+P<
M) can be processed; and
further wherein said control information transmitted to the upstream transceiver includes feedback information indicating that only N of the M sub-channels are usable for downstream data transmission, even during times when said channel is capable of supporting more than N sub-channels.
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28. A high speed communications system capable of supporting an upstream transceiver which can transmit M modulated sub-channels using an analog signal through a channel to said system, said system comprising
a channel interface circuit for coupling to and receiving said analog signal from the channel; -
an analog front end circuit for processing the analog signal and converting it to a digital signal, the front end circuit including a sub-band filter and an analog to digital converter;
a processing circuit for extracting data from the digital signal, the digital signal including data from a first number N of said subchannels, where N<
M;
a front end transmitting circuit for transmitting control information to cause said upstream transceiver to transmit downstream data only using the N sub-channels; and
wherein the control information transmitted to the upstream transceiver includes feedback information indicating that only N of the M sub-channels are usable for downstream data transmission, even during times when said channel is capable of supporting more than N sub-channels; and
further wherein the control information transmitted to the upstream transceiver further includes feedback information indicating that;
(i) the system can support any data protocols used by said upstream transceiver; and
(ii) that the system and upstream transceiver are connected through a channel with substantial signal attenuation characteristics for sub-channels other than the N sub-channels.
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29. A high speed communications system for processing an analog data signal from a channel capable of supporting a downstream data transmission using a bandwidth F from a remote transciever also capable of using a bandwidth F, said system comprising:
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a channel interface circuit for coupling to and receiving said analog data signal from the channel, and a front end receiving circuit for processing the analog data signal and converting it to a digital signal;
a processing circuit for extracting selected data from the digital signal, the digital signal including data from a first frequency bandwidth portion f1 of said bandwidth and for generating feedback information indicating to the remote transceiver that the bandwidth other than f1 is unsuitable for data transmission even when said channel can support said bandwidth F;
wherein the feedback information contains intentionally altered channel characteristic information.
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30. A high speed communications system for processing an analog data signal from a channel capable of supporting a downstream data transmission using a bandwidth F from a remote transciever also capable of using a bandwidth F, said system comprising:
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a channel interface circuit for coupling to and receiving said analog data signal from the channel; and
a front end receiving circuit for processing the analog data signal and converting it to a digital signal;
a processing circuit for extracting selected data from the digital signal, the digital signal including data from a first frequency bandwidth portion f1 of said bandwidth and for generating feedback information indicating to the remote transceiver that the bandwidth other than f1 is unsuitable for data transmission even when said channel can support said bandwidth F, said feedback information containing intentionally altered channel characteristic information;
wherein the feedback information, including the size and center of first frequency bandwidth portion f1, can be controlled by a user of such system.
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31. A high speed communications system for processing an analog data signal from a channel capable of supporting a downstream data transmission using a bandwidth F from a remote transciever also capable of using a bandwidth F, said system comprising:
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a channel interface circuit for coupling to and receiving said analog data signal from the channel; and
a front end receiving circuit for processing the analog data signal and converting it to a digital signal;
a processing circuit for extracting selected data from the digital signal, the digital signal including data from a first frequency bandwidth portion f1 of said bandwidth and for generating feedback information indicating to the remote transceiver that the bandwidth other than f1 is unsuitable for data transmission even when said channel can support said bandwidth F, said feedback information containing intentionally altered channel characteristic information;
wherein the feedback information, including the size and center of first frequency bandwidth portion f1, can be controlled by a user of such system; and
further wherein the ratio of f1 to F is approximately 0.5 or less, and this ratio can be increased through modular additions to the front end receiving circuit.
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32. A high speed communications system for transmitting digital information in a channel capable of supporting a transmission bandwidth F, said system comprising:
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an upstream data transceiver capable of modulating the digital information to generate an analog data signal data transmission using said transmission bandwidth F; and
a downstream data transceiver channel interface circuit for coupling to and receiving said analog data signal from the upstream data transciever through said channel, the downstream data transceiver including (i) a front end receiving circuit for processing the analog data signal and converting it to a digital signal; and
(ii) a processing circuit for demodulating the digital signal, the digital signal including data from a first frequency bandwidth portion f1 of said bandwidth and for generating feedback information indicating to the upstream transceiver that the bandwidth other than f1 is unsuitable for data transmission; and
(iii) a front end transmitting circuit for transmitting the feedback information using a second frequency bandwidth portion f2 to cause said upstream transceiver to transmit downstream data only using the first frequency portion fl;
wherein the feedback information contains intentionally altered channel characteristic information. - View Dependent Claims (33, 34)
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35. A method of operating a high speed communications system that is coupled to a remote transceiver through a channel capable of supporting an analog data transmission having a bandwidth F, said method comprising:
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(a) receiving said analog data signal from the remote transceiver through the channel;
and (b) generating a digital signal based on sampling a portion of the analog data transmission signal corresponding to a first frequency bandwidth portion fl; and
(c) processing the digital signal to extract data from the digital signal; and
(d) generating feedback information indicating to the remote transceiver that the bandwidth other than f1 should not be used for data transmission, even if an analog data signal with bandwidth>
f1 is supportable in the channel and by the remote transceiver; and
(e) determining an optimal size and location of first frequency bandpass portion f1 so as to minimize the amount of processing required to extract the data from the digital signal, as compared to some other size and location for said first frequency bandpass portion f1. - View Dependent Claims (36, 37)
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38. A method of operating a high speed communications system that is coupled to a remote transceiver through a channel capable of supporting an analog data transmission having a bandwidth F, said method comprising:
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(a) receiving said analog data signal from the remote transceiver through the channel;
and (b) generating a digital signal based on sampling a portion of the analog data transmission signal corresponding to a first frequency bandwidth portion f1; and
(c) processing the digital signal to extract data from the digital signal; and
generating feedback information indicating to the remote transceiver that the bandwidth other than f1 should not be used for data transmission, even if an analog data signal with bandwidth >
f1 is supportable in the channel and by the remote transceiver; and
wherein step (a) occurs during an initialization period, and said received analog transmission signal is generated by the remote transceiver to have a bandwidth >
f1; and
after said initialization period the remote transceiver only transmits an analog data signal within first frequency bandwidth portion f1.
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39. A method of operating a high speed communications system that is coupled to a remote transceiver through a channel capable of supporting an analog data transmission signal including M modulated sub-channels, said method comprising:
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(a) receiving said analog data transmission signal from the remote transceiver through the channel; and
(b) generating a digital signal based on sampling a portion of the analog data transmission signal corresponding to a first frequency bandwidth portion f1; and
(c) processing the digital signal to extract data from N of the sub-channels, where N<
M; and
(d) generating feedback information indicating to the remote transceiver that the sub-channels other than the N sub-channels should not be used for data transmission, even if said channel and/or the remote transceiver is capable of supporting more than N sub-channels; and
(e) determining an optimal set of N sub-channels so as to minimize the amount of processing required to extract the data from the digital signal. - View Dependent Claims (40)
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41. A method of operating a high speed communications system that is coupled to a remote transceiver through a channel capable of supporting an analog data transmission signal including M modulated sub-channels, said method comprising:
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(a) receiving said analog data transmission signal from the remote transceiver through the channel; and
(b) generating a digital signal based on sampling a portion of the analog data transmission signal corresponding to a first frequency bandwidth portion f1; and
(c) processing the digital signal to extract data from N of the sub-channels, where N<
M; and
(d) generating feedback information indicating to the remote transceiver that the sub-channels other than the N sub-channels should not be used for data transmission, even if said channel and/or the remote transceiver is capable of supporting more than N sub-channels; and
wherein;
step (a) occurs during an initialization period, and said received analog transmission signal can be generated by said remote transceiver to include data for M sub-channels; and
after step (d) the remote transceiver only transmits an analog data signal using the N sub-channels.
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42. A method of operating a high speed communications system that is coupled to a remote transceiver through a channel capable of supporting an analog data transmission signal including M modulated sub-channels, said method comprising:
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(a) receiving said analog data transmission signal from the remote transceiver through the channel, and (b) generating a digital signal based on sampling a portion of the analog data transmission signal corresponding to a first frequency bandwidth portion f1; and
(c) processing the digital signal to extract data from N of the sub-channels where N<
M; and
(d) generating feedback information indicating to the remote transceiver that the sub-channels other than the N sub-channels should not be used for data transmission even if said channel and/or the remote transceiver is capable of supporting more than N sub-channels; and
wherein the system transmits feedback information containing intentionally altered channel characteristic information.
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43. A method of operating a high speed communications system that is coupled through a channel to a remote transceiver operating at a maximum data rate Y using a bandwidth F, said method comprising:
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(a) receiving an analog initialization signal from the remote transceiver through the channel; and
(b) generating a digital signal based on sampling a portion of the analog data transmission signal corresponding to a first frequency bandwidth portion fl, where f1<
F; and
(c) processing the digital signal to extract data from the digital signal such that an effective receiving rate X (where X<
Y) is achieved by the system;
(d) generating feedback information pertaining to the channel transmission characteristics indicating to the remote transceiver that data rates higher than X should not be used;
(e) thereafter receiving an analog data signal transmitted by the remote transceiver to have a bandwidth fl;
(f) repeating steps (b) and (c);
(g) determining an optimal location and size of bandwidth portion f1 so as to minimize the amount of processing required to extract the data from the digital signal at the receiving rate X, as compared to an amount of processing required to extract the data from the digital signal at the receiving rate X from a different bandwidth portion f1. - View Dependent Claims (44)
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45. A high speed communications data receiver for communicating through a channel with a remote transmitter that is capable of transmitting a data signal with a particular frame rate T and data rate Y, the receiver comprising:
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a channel interface circuit for coupling to and receiving said data signal; and
an analog front end circuit for sampling the data signal and converting it to a digital signal; and
a processing circuit that;
(i) is configurable for processing the digital signal at a data rate<
=X and using said frame rate T, where X is determined for such processing circuit prior to initialization of a data transmission and X<
Y/2;
(ii) generates a transmission control signal for causing said remote transmitter to transmit at a data rate no greater than X during a data transmission;
(iii) is configurable to support said data transmission at least in part with assistance from resources from a host processing device;
wherein signal processing requirements for the processing circuit are reduced from that otherwise required to support data rate Y because processing resources sufficient to support a fractional rate of the available data rate Y are used to support said data rate X; and
further wherein X is determined by evaluating signal processing capabilities available to said processing circuit prior to said data transmission, including resources of said host processing device. - View Dependent Claims (46, 47, 48, 49)
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50. A high speed communications data receiver for communicating through a channel at a controllable data rate X with a remote transceiver capable of transmitting a data signal at a frame rate T, and a data rate Y, where X/Y<
- ½
, the receiver comprising;a channel interface circuit for coupling to and receiving an analog data signal from the remote transceiver; and
an analog front end circuit for data sampling the analog signal and converting it to a digital signal; and
a processing circuit for determining said rate X based on processing capabilities available for extracting data from the digital signal, and for generating a transmission control signal for causing said remote transceiver to transmit using said frame rate T, and a data rate substantially equal to said data rate X during a data transmission, and said processing circuit being implemented at least in part by signal processing software executed by a host processing device coupled to the data receiver. - View Dependent Claims (51, 52, 53, 54)
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55. A method for communicating through a channel with a remote transceiver that is capable of transmitting a data signal at a frame rate T, and a data rate Y, the method comprising the steps of:
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receiving said data signal at a local transceiver; and
sampling the data signal and converting it to a digital signal at said local transceiver; and
processing the digital signal at a data rate<
=X and using said frame rate T at said local transceiver, where X is determined for said local transceiver prior to initialization of a data transmission and X<
Y/2; and
generating a transmission control signal for causing said remote transceiver to transmit at a data rate no greater than X during a data transmission; and
transmitting data in the channel at a data rate that is intentionally reduced from that supportable by said remote transceiver and by the channel, so that said local transceiver can;
(1) support such data transmission with data signal sampling resources and digital signal processing resources that are reduced from that required to support data rate Y;
(2) adjust said data rate in response to changes in said data signal sampling resources and digital signal processing resources.- View Dependent Claims (56, 57)
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58. A method for communicating through a channel at a controllable data rate X with an upstream transmitter capable of transmitting a data signal at a frame rate T, and a data rate Y, where X/Y <
- ½
, the method comprising the steps of;receiving said data signal; and
sampling the data signal and converting it to a digital signal; and
determining said rate X based on processing capabilities available f or extracting data from the digital signal; and
generating a transmission control signal for causing said upstream transmitter to transmit at said frame rate T and a data rate substantially equal to said data rate X during a data transmission transmitting data in the channel at a data rate that is intentionally reduced from that supportable by the channel, such that said said data transmission can be supported with data signal sampling resources and digital signal processing resources that are reduced from that required to support data rate Y, and said data rate is adjustable in response to changes in said data signal sampling resources and digital signal processing resources. - View Dependent Claims (59, 60, 61, 62)
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63. A method for communicating through a channel between a local and a remote transceiver, which remote transceiver supports up to a first maximum number M modulated sub-channels, the method comprising the steps of:
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(a) determining a second maximum number N of modulated sub-channels supportable by signal processing resources at the local transceiver; and
(b) transmitting data transmission control signals for causing the remote transceiver to transmit using at most said N modulated sub-channels, where N<
=M;
(c) transmitting data between the local and remote transceiver during a data transmission using at most said N modulated sub-channels; and
(d) dynamically adjusting a number of, or a data loading for, said N modulated sub-channels in response to changes in said signal processing resources. - View Dependent Claims (64, 65, 66, 67)
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Specification