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US5377230A Expired / Lapsed US ⏱️ 0.0 years remaining

Extended bandwidth transmitter for crosstalk channels

Assignee: Conexant Inc
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Filing: 1992-05-01
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Granted: 1994-12-27
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Expires: 2012-05-01
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Abstract

Abstract In many data communications systems, crosstalk is a significant channel impairment. If all transmitters in such a system must utilize the same shaping function, and if the transmitters are furthermore nominally Nyquist bandlimited, then the crosstalk generally cannot be mitigated by equalization. However, by extending the bandwidth of the transmitted signal in accordance with the principles of the invention, the resultant crosstalk can be efficiently mitigated by equalization. This extended bandwidth signal is produced by adding significant additional energy outside the traditional Nyquist band.

Inventors

  • 👤 Glenn D. Golden

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-26 17:45
CPC Classifications
H; H04; H04B; H04B3/00; H04B3/02; H04B3/32

Claims Analysis

Total Claims: 18
Claim 1
Independent Claim 126 words
Apparatus for transmitting a sequence of data symbols occurring at a rate of 1/T symbols/second, over a communications channel, the apparatus comprising: means for accepting the sequence of data symbols; and transmitter means responsive to the accepted sequence of data symbols for placing energy from each symbol into a first spectral region and a second spectral region to provide an output signal to the communications channel; where the first spectral region bandwidth is at least 1/T Hz and the second spectral region is of bandwidth p/T Hz, the second spectral region being disjoint from the first spectral region, where 1<p<1, and where the first spectral region includes an interference spectral region and the second spectral region is located a Nyquist multiple from the interference spectral region.
Claim 2
Dependent Claim 126 words
Apparatus for transmitting a sequence of data symbols occurring at a rate of 1/T symbols/second, over a communications channel, the apparatus comprising: means for accepting the sequence of data symbols; and transmitter means responsive to the accepted sequence of data symbols for placing energy from each symbol into a first spectral region and a second spectral region to provide an output signal to the communications channel; where the first spectral region bandwidth is at least 1/T Hz and the second spectral region is of bandwidth p/T Hz, the second spectral region being disjoint from the first spectral region, where 1<p<1, and where the first spectral region includes an interference spectral region and the second spectral region is located a Nyquist multiple from the interference spectral region.
Claim 3
Dependent Claim 26 words
The apparatus of claim 1, where the interference spectral region is a crosstalk dominant region from an interfering cyclostationary signal having a rate of 1/T symbols/second.
Claim 4
Dependent Claim 157 words
Apparatus for transmitting a signal on a communications channel, the communications channel introducing an interfering cyclostationary signal having a rate of 1/T symbols/second, the apparatus comprising: means responsive to a sequence of data symbols for providing a first signal, said sequence of data symbols occurring at a rate of 1/T symbols/second, and said first signal having energy substantially in a first frequency range of bandwidth at least 1/T Hz; means responsive to the sequence of data symbols for providing a second signal, said second signal having energy substantially in a second frequency range of width p/T Hz, that is disjoint from the first frequency range, where 0<p<1; and means for combining the first signal and the second signal to provide a transmitted signal to the communications channel; where the first frequency range includes an interference region representative of the interfering cyclostationary signal and the second frequency range is located at a Nyquist multiple from the interference region.
Claim 5
Dependent Claim 157 words
Apparatus for transmitting a signal on a communications channel, the communications channel introducing an interfering cyclostationary signal having a rate of 1/T symbols/second, the apparatus comprising: means responsive to a sequence of data symbols for providing a first signal, said sequence of data symbols occurring at a rate of 1/T symbols/second, and said first signal having energy substantially in a first frequency range of bandwidth at least 1/T Hz; means responsive to the sequence of data symbols for providing a second signal, said second signal having energy substantially in a second frequency range of width p/T Hz, that is disjoint from the first frequency range, where 0<p<1; and means for combining the first signal and the second signal to provide a transmitted signal to the communications channel; where the first frequency range includes an interference region representative of the interfering cyclostationary signal and the second frequency range is located at a Nyquist multiple from the interference region.
Claim 6
Dependent Claim 17 words
The apparatus of claim 3 further comprising means for varying the bandwidth of the second frequency range.
Claim 7
Dependent Claim 17 words
The apparatus of claim 4 further comprising means for controlling the output power of the combined signal.
Claim 8
Dependent Claim 144 words
Apparatus for use in a communications system comprising: means for accepting from the communications channel a data signal and an interfering cyclostationary signal that is frequency synchronous to the data signal, the data signal representing a sequence of data symbols occurring at a rate of 1/T symbols/second; and means for equalizing the accepted data signal and the accepted interfering cyclostationary signal to provide the sequence of data symbols; where the data signal is a cyclostationary signal and comprises energy in a first frequency band and a second frequency band that is disjoint from the first, the second frequency band comprising a range of frequencies that are located at Nyquist multiples from a portion of the frequency band of said interfering cyclostationary signal, whereby equalization of the accepted data signal and the accepted interfering cyclostationary signal mitigates the interference caused by said interfering cyclostationary signal.
Claim 9
Dependent Claim 144 words
Apparatus for use in a communications system comprising: means for accepting from the communications channel a data signal and an interfering cyclostationary signal that is frequency synchronous to the data signal, the data signal representing a sequence of data symbols occurring at a rate of 1/T symbols/second; and means for equalizing the accepted data signal and the accepted interfering cyclostationary signal to provide the sequence of data symbols; where the data signal is a cyclostationary signal and comprises energy in a first frequency band and a second frequency band that is disjoint from the first, the second frequency band comprising a range of frequencies that are located at Nyquist multiples from a portion of the frequency band of said interfering cyclostationary signal, whereby equalization of the accepted data signal and the accepted interfering cyclostationary signal mitigates the interference caused by said interfering cyclostationary signal.
Claim 10
Dependent Claim 25 words
The apparatus of claim 6 wherein the portion of the frequency band of the interfering cyclostationary signal contains substantial energy of the interfering cyclostationary signal.
Claim 11
Independent Claim 140 words
A method for transmitting a sequence of data symbols occurring at a rate of 1/T symbols/second, over a communications channel, the method comprising the steps of: accepting the sequence of data symbols; placing energy from each accepted symbol into a first spectral region and a second spectral region, where the second spectral region is disjoint from the first spectral region; and providing an output signal representative of the accepted sequence of data symbols to the communications channel, the output signal comprising the energy placed into the first and second spectral regions; where the first spectral region bandwidth is at least 1/T Hz and the second spectral region is of bandwidth p/T Hz, where 0<p<1, and where the first spectral region includes an interference spectral region and the second spectral region is located a Nyquist multiple from the interference spectral region.
Claim 12
Independent Claim 140 words
A method for transmitting a sequence of data symbols occurring at a rate of 1/T symbols/second, over a communications channel, the method comprising the steps of: accepting the sequence of data symbols; placing energy from each accepted symbol into a first spectral region and a second spectral region, where the second spectral region is disjoint from the first spectral region; and providing an output signal representative of the accepted sequence of data symbols to the communications channel, the output signal comprising the energy placed into the first and second spectral regions; where the first spectral region bandwidth is at least 1/T Hz and the second spectral region is of bandwidth p/T Hz, where 0<p<1, and where the first spectral region includes an interference spectral region and the second spectral region is located a Nyquist multiple from the interference spectral region.
Claim 13
Dependent Claim 26 words
The method of claim 8, where the interference spectral region is a crosstalk dominant region from an interfering cyclostationary signal having a rate of 1/T symbols/second.
Claim 14
Independent Claim 162 words
A method for mitigating the interference from a cyclostationary signal occurring at a rate of 1/T symbols/second that is present on a communications channel, the method comprising the steps of: accepting a sequence of data symbols occurring at rate 1/T symbols/second; providing a first signal representative of the accepted sequence of data symbols, where the energy of the first signal is substantially within a first frequency band of bandwidth at least 1/T Hz; providing a second signal in response to the sequence of data symbols, where the energy of the accepted second signal is substantially in a second frequency band of bandwidth p/T Hz, where 0<p<1, the second frequency band being disjoint from the first frequency band; and combining the first signal and the second signal for transmission on the communications channel. where the first frequency range includes an interference region representative of the interfering cyclostationary signal and the second frequency range is located at a Nyquist multiple from the interference region.
Claim 15
Independent Claim 162 words
A method for mitigating the interference from a cyclostationary signal occurring at a rate of 1/T symbols/second that is present on a communications channel, the method comprising the steps of: accepting a sequence of data symbols occurring at rate 1/T symbols/second; providing a first signal representative of the accepted sequence of data symbols, where the energy of the first signal is substantially within a first frequency band of bandwidth at least 1/T Hz; providing a second signal in response to the sequence of data symbols, where the energy of the accepted second signal is substantially in a second frequency band of bandwidth p/T Hz, where 0<p<1, the second frequency band being disjoint from the first frequency band; and combining the first signal and the second signal for transmission on the communications channel. where the first frequency range includes an interference region representative of the interfering cyclostationary signal and the second frequency range is located at a Nyquist multiple from the interference region.
Claim 16
Dependent Claim 62 words
The method of claim 10 further comprising the steps of: receiving the transmitted first and second signals and the interfering cyclostationary signal; and equalizing the received transmitted first and second signals, and the received interfering cyclostationary signal to provide an output sequence representative of the sequence of data symbols, whereby the equalization substantially removes the interference caused by the interfering cyclostationary signal.
Claim 17
Independent Claim 144 words
A method for use in a communications system comprising the steps of: receiving from the communications channel a data signal and an interfering cyclostationary signal that is frequency synchronous to the data signal, the data signal representing a sequence of data symbols occurring at a rate of 1/T symbols/second; and equalizing the received data signal and the received interfering cyclostationary signal to provide the sequence of data symbols; where the data signal is a cyclostationary signal and comprises energy in a first frequency band and a second frequency band that is disjoint from the first, the second frequency band comprising a range of frequencies that are located at Nyquist multiples from a portion of the frequency bandwidth of said interfering cyclostationary signal, whereby equalization of the received data signal and the received interfering cyclostationary signal mitigates the interference caused by said interfering cyclostationary signal.
Claim 18
Independent Claim 144 words
A method for use in a communications system comprising the steps of: receiving from the communications channel a data signal and an interfering cyclostationary signal that is frequency synchronous to the data signal, the data signal representing a sequence of data symbols occurring at a rate of 1/T symbols/second; and equalizing the received data signal and the received interfering cyclostationary signal to provide the sequence of data symbols; where the data signal is a cyclostationary signal and comprises energy in a first frequency band and a second frequency band that is disjoint from the first, the second frequency band comprising a range of frequencies that are located at Nyquist multiples from a portion of the frequency bandwidth of said interfering cyclostationary signal, whereby equalization of the received data signal and the received interfering cyclostationary signal mitigates the interference caused by said interfering cyclostationary signal.

References Cited (Backward Citations)

US4079355A Cited
US4745622A Cited
US4881241A Cited
US5095495A Cited
US5163044A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1997-12-26 1998-06-27 1998-12-27 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 2001-12-26 2002-06-27 2002-12-27 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2005-12-26 2006-06-27 2006-12-27 $7700.00 Window Closed / Lapsed

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