US6061568A
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US
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Method and apparatus for mitigating intermodulation effects in multiple-signal transmission systems
Assignee: Unwired Planet LLC
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Filing: 1996-10-01
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Granted: 2000-05-09
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Expires: 2016-10-01
Abstract
Abstract Method and apparatus for mitigating intermodulation distortion effects in frequency division multiple access (FDMA) communications systems. In one embodiment, an effective transmit power level is determined for each communication signal to be transmitted, and signals are allocated to frequency channels such that a smooth tapering of transmit power levels across contiguous frequency channels is achieved. Such smooth power tapering across frequency channels minimizes the possibility that two high power signals will generate an intermodulation distortion product sufficient to disrupt transmission of an immediately adjacent low power signal. In another exemplary embodiment, communication signals are allocated such that high power signals are positioned near a frequency band center, while low power signals are positioned near frequency band edges. As a result, intermodulation distortion between frequency bands in a multiple-band communication system is also minimized.
Inventors
- 👤 Paul W. Dent
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 08:50
CPC Classifications
H; H04; H04L; H04L5/00; H04L5/02; H04L5/06; H04J; H04J1/00; H04J1/02; H04J1/12; H04W; H04W72/00; H04W72/50; H04W72/54; H04W72/541; H04W72/04; H04W72/044; H04W72/0453; Y; Y02; Y02D; Y02D30/00; Y02D30/70
Claims Analysis
Total Claims: 33
Claim 1
Independent Claim
79 words
A method for allocating frequency channels in a communications system, comprising the steps of: establishing transmit power levels for a plurality of information signals; and assigning frequency channels for transmitting the information signals, based upon the established transmit power levels, to selectively position intermodulation products of the information signals in frequency, wherein each information signal coinciding in frequency with a positioned intermodulation product is transmitted using a transmit power level sufficient to overcome interference from the coinciding intermodulation product.
Claim 2
Independent Claim
79 words
A method for allocating frequency channels in a communications system, comprising the steps of: establishing transmit power levels for a plurality of information signals; and assigning frequency channels for transmitting the information signals, based upon the established transmit power levels, to selectively position intermodulation products of the information signals in frequency, wherein each information signal coinciding in frequency with a positioned intermodulation product is transmitted using a transmit power level sufficient to overcome interference from the coinciding intermodulation product.
Claim 3
Dependent Claim
36 words
The method of claim 1, wherein a transmit power level established for an information signal is based on a distance between a transmitting station transmitting the information signal and a receiving station receiving the information signal.
Claim 4
Dependent Claim
26 words
The method of claim 1, wherein information signals are assigned to frequency channels to achieve a smooth tapering of transmit power levels across contiguous frequency channels.
Claim 5
Dependent Claim
37 words
The method of claim 1, wherein information signals are assigned to frequency channels such that intermodulation products resulting from signals having higher transmit power levels do not coincide in frequency with signals having lower transmit power levels.
Claim 6
Dependent Claim
45 words
The method of claim 1, wherein communication signals are assigned to frequency channels such that intermodulation products generated by signals assigned to channels within a frequency band do not substantially interfere with transmission of other signals also assigned to channels within the same frequency band.
Claim 7
Dependent Claim
42 words
The method of claim 1, wherein communication signals are assigned to frequency channels such that intermodulation products generated by signals assigned to channels within a frequency band do not substantially interfere with transmission of signals assigned to channels in other frequency bands.
Claim 8
Independent Claim
103 words
A method for allocating frequency channels in a communications system, comprising the steps of: establishing transmit power levels for a plurality of information signals; and assigning frequency channels for transmitting the information signals, based upon the established transmit power levels, to control and thereby mitigate intermodulation effects resulting from processing the information signals for transmission, wherein the information signals are assigned to frequency channels such that an intermodulation product resulting from transmission of two particular information signals coincides in frequency with a third information signal having a transmit power level which is similar to transmit power levels of the two particular information signals.
Claim 9
Independent Claim
103 words
A method for allocating frequency channels in a communications system, comprising the steps of: establishing transmit power levels for a plurality of information signals; and assigning frequency channels for transmitting the information signals, based upon the established transmit power levels, to control and thereby mitigate intermodulation effects resulting from processing the information signals for transmission, wherein the information signals are assigned to frequency channels such that an intermodulation product resulting from transmission of two particular information signals coincides in frequency with a third information signal having a transmit power level which is similar to transmit power levels of the two particular information signals.
Claim 10
Independent Claim
90 words
A method for allocating frequency channels in a communications system, comprising the steps of: establishing transmit power levels for a plurality of information signals; and assigning frequency channels for transmitting the information signals, based upon the established transmit power levels, to mitigate intermodulation effects which result from processing the information signals for transmission, wherein information signals are assigned to frequency channels such that signals having higher transmit power levels are positioned near a frequency band center and signals having lower transmit power levels are positioned near a frequency band edge.
Claim 11
Independent Claim
90 words
A method for allocating frequency channels in a communications system, comprising the steps of: establishing transmit power levels for a plurality of information signals; and assigning frequency channels for transmitting the information signals, based upon the established transmit power levels, to mitigate intermodulation effects which result from processing the information signals for transmission, wherein information signals are assigned to frequency channels such that signals having higher transmit power levels are positioned near a frequency band center and signals having lower transmit power levels are positioned near a frequency band edge.
Claim 12
Independent Claim
81 words
A method for allocating frequency channels in a communications system, comprising the steps of: determining signal transmit power levels to be used in transmitting information signals from at least one transmitting station to at least one receiving station; and using the signal transmit power levels in assigning the information signals to available frequency channels to thereby selectively position intermodulation products of the information signals in frequency such that the intermodulation products do not substantially interfere with transmission of the information signals.
Claim 13
Independent Claim
81 words
A method for allocating frequency channels in a communications system, comprising the steps of: determining signal transmit power levels to be used in transmitting information signals from at least one transmitting station to at least one receiving station; and using the signal transmit power levels in assigning the information signals to available frequency channels to thereby selectively position intermodulation products of the information signals in frequency such that the intermodulation products do not substantially interfere with transmission of the information signals.
Claim 14
Dependent Claim
67 words
The method of claim 9, wherein said step of using the signal transmit power levels in assigning the information signals to available frequency channels comprises the steps of: determining levels of intermodulation interference existing in available frequency channels; and assigning a particular information signal to an available frequency channel having a level of intermodulation interference which is insufficient to substantially disrupt transmission of the particular information signal.
Claim 15
Dependent Claim
48 words
The method of claim 10, wherein the particular information signal is assigned to an available frequency channel in which a ratio between the signal transmit power level of the information signal and a level of intermodulation interference in the available channel is greater than a minimum target value.
Claim 16
Dependent Claim
34 words
The method of claim 8, wherein an information signal is not assigned to a most suitable available frequency channel so that the most suitable available frequency channel may be reserved for another information signal.
Claim 17
Dependent Claim
33 words
The method of claim 9, wherein frequency channels are re-assigned as additional information signals are incorporated into the system so that each information signal is transmitted without being substantially disrupted by intermodulation interference.
Claim 18
Dependent Claim
24 words
The method of claim 13, wherein frequency channels are continually re-assigned to maintain a smooth tapering of transmit power levels across contiguous frequency channels.
Claim 19
Independent Claim
160 words
A method for allocating frequency channels in a communications system, comprising the steps of: determining signal transmit power levels to be used in transmitting information signals from at least one transmitting station to at least one receiving station; and using the signal transmit power levels to selectively assign the information signals to available frequency channels and to thereby selectively position intermodulation products of the information signals in frequency such that the intermodulation products do not substantially interfere with transmission of the information signals, wherein said step of using the signal transmit power levels to selectively assign the information signals to available frequency channels comprises the steps of: determining, for available frequency channels, adjacent transmit power levels used to transmit information signals in channels adjacent the available frequency channels; and assigning a particular information signal to an available frequency channel having adjacent transmit power levels which are most similar to the signal transmit power level determined for the particular information signal.
Claim 20
Independent Claim
160 words
A method for allocating frequency channels in a communications system, comprising the steps of: determining signal transmit power levels to be used in transmitting information signals from at least one transmitting station to at least one receiving station; and using the signal transmit power levels to selectively assign the information signals to available frequency channels and to thereby selectively position intermodulation products of the information signals in frequency such that the intermodulation products do not substantially interfere with transmission of the information signals, wherein said step of using the signal transmit power levels to selectively assign the information signals to available frequency channels comprises the steps of: determining, for available frequency channels, adjacent transmit power levels used to transmit information signals in channels adjacent the available frequency channels; and assigning a particular information signal to an available frequency channel having adjacent transmit power levels which are most similar to the signal transmit power level determined for the particular information signal.
Claim 21
Independent Claim
161 words
A method for allocating frequency channels in a communications system, comprising the steps of: determining a signal transmit power level to be used in transmitting an information signals from a transmitting station to a receiving station; and assigning the information signal, based on the signal transmit power level, to an available frequency channel in which transmission of the information signal will not be substantially disrupted by intermodulation interference resulting from transmission of other information signals in the system, wherein frequency channels are re-assigned as additional information signals are incorporated into the system so that each information signal is transmitted without being substantially disrupted by intermodulation interference, wherein frequency channels are continually re-assigned to maintain a smooth tapering of transmit power levels across contiguous frequency channels, and wherein frequency channels are continually re-assigned such that higher-power information signals are located near a center of a frequency band and such that lower-power information signals are located near an edge of a frequency band.
Claim 22
Independent Claim
161 words
A method for allocating frequency channels in a communications system, comprising the steps of: determining a signal transmit power level to be used in transmitting an information signals from a transmitting station to a receiving station; and assigning the information signal, based on the signal transmit power level, to an available frequency channel in which transmission of the information signal will not be substantially disrupted by intermodulation interference resulting from transmission of other information signals in the system, wherein frequency channels are re-assigned as additional information signals are incorporated into the system so that each information signal is transmitted without being substantially disrupted by intermodulation interference, wherein frequency channels are continually re-assigned to maintain a smooth tapering of transmit power levels across contiguous frequency channels, and wherein frequency channels are continually re-assigned such that higher-power information signals are located near a center of a frequency band and such that lower-power information signals are located near an edge of a frequency band.
Claim 23
Dependent Claim
84 words
A base station for transmitting a plurality of signals modulated on a plurality of carriers within a frequency band, comprising: a channel allocation processor establishing transmit power levels for the signals and allocating the signals to the carriers, in accordance with the transmit power levels, such that intermodulation products of the signals are selectively positioned in frequency, wherein each signal coinciding in frequency with a positioned intermodulation product is transmitted using a transmit power level sufficient to overcome interference from the coinciding intermodulation product.
Claim 24
Dependent Claim
84 words
A base station for transmitting a plurality of signals modulated on a plurality of carriers within a frequency band, comprising: a channel allocation processor establishing transmit power levels for the signals and allocating the signals to the carriers, in accordance with the transmit power levels, such that intermodulation products of the signals are selectively positioned in frequency, wherein each signal coinciding in frequency with a positioned intermodulation product is transmitted using a transmit power level sufficient to overcome interference from the coinciding intermodulation product.
Claim 25
Dependent Claim
111 words
A base station for transmitting a plurality of signals modulated on a plurality of carriers within a frequency band, comprising: a channel allocation processor establishing transmit power levels for the signals and allocating the signals to the carriers, in accordance with the transmit power levels, such that the signals are transmitted without being substantially disrupted by intermodulation interference produced in transmitting the signals, wherein the channel allocation processor allocates the signals to the carriers such that higher transmit power levels are allocated to carrier frequencies disposed more centrally within the frequency band and lower base station transmit power levels are allocated to carrier frequencies disposed toward edges of the frequency band.
Claim 26
Dependent Claim
111 words
A base station for transmitting a plurality of signals modulated on a plurality of carriers within a frequency band, comprising: a channel allocation processor establishing transmit power levels for the signals and allocating the signals to the carriers, in accordance with the transmit power levels, such that the signals are transmitted without being substantially disrupted by intermodulation interference produced in transmitting the signals, wherein the channel allocation processor allocates the signals to the carriers such that higher transmit power levels are allocated to carrier frequencies disposed more centrally within the frequency band and lower base station transmit power levels are allocated to carrier frequencies disposed toward edges of the frequency band.
Claim 27
Dependent Claim
85 words
A mobile switching center for use in a communications system, comprising: a channel allocation processor determining transmit power levels for a plurality of information signals and allocating the information signals to a plurality of frequency channels, in accordance with the determined transmit power levels, such that intermodulation products of the information signals are selectively positioned in frequency, wherein each information signal coinciding in frequency with a positioned intermodulation product is transmitted using a transmit power level sufficient to overcome interference from the coinciding intermodulation product.
Claim 28
Dependent Claim
85 words
A mobile switching center for use in a communications system, comprising: a channel allocation processor determining transmit power levels for a plurality of information signals and allocating the information signals to a plurality of frequency channels, in accordance with the determined transmit power levels, such that intermodulation products of the information signals are selectively positioned in frequency, wherein each information signal coinciding in frequency with a positioned intermodulation product is transmitted using a transmit power level sufficient to overcome interference from the coinciding intermodulation product.
Claim 29
Dependent Claim
100 words
A channel allocation processor for use in a communications system, comprising: means for establishing transmit power levels for a plurality of information signals transmitted on a plurality of frequency channels from a transmitting station to at least one receiving station; and means for allocating the information signals to the frequency channels, in accordance with the established transmit power levels, such that intermodulation products of the information signals are selectively positioned in frequency, wherein each information signal coinciding in frequency with a positioned intermodulation product is transmitted using a transmit power level sufficient to withstand interference from the coinciding intermodulation product.
Claim 30
Dependent Claim
100 words
A channel allocation processor for use in a communications system, comprising: means for establishing transmit power levels for a plurality of information signals transmitted on a plurality of frequency channels from a transmitting station to at least one receiving station; and means for allocating the information signals to the frequency channels, in accordance with the established transmit power levels, such that intermodulation products of the information signals are selectively positioned in frequency, wherein each information signal coinciding in frequency with a positioned intermodulation product is transmitted using a transmit power level sufficient to withstand interference from the coinciding intermodulation product.
Claim 31
Independent Claim
106 words
A method for allocating transmit frequencies in a contiguous band of transmit frequencies including at least one center transmit frequency comprising the steps of: ordering downlink transmit powers associated with signals to be transmitted to remote stations; allocating a first signal having a greatest downlink transmit power to said at least one center transmit frequency in said contiguous band; allocating a second signal having a second greatest downlink transmit power to a transmit frequency which is substantially adjacent to said at least one center frequency; and continuing to allocate remaining signals in decreasing order of downlink transmit power outwardly from said at least one center frequency.
Claim 32
Independent Claim
106 words
A method for allocating transmit frequencies in a contiguous band of transmit frequencies including at least one center transmit frequency comprising the steps of: ordering downlink transmit powers associated with signals to be transmitted to remote stations; allocating a first signal having a greatest downlink transmit power to said at least one center transmit frequency in said contiguous band; allocating a second signal having a second greatest downlink transmit power to a transmit frequency which is substantially adjacent to said at least one center frequency; and continuing to allocate remaining signals in decreasing order of downlink transmit power outwardly from said at least one center frequency.
Claim 33
Dependent Claim
41 words
The method of claim 1, wherein the information signals are assigned to frequency channels such that intermodulation products resulting from transmission of the information signals coincide in frequency with information signals having transmit power levels sufficient to overcome the intermodulation products.
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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) | 2003-05-09 | 2003-11-08 | 2004-05-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2007-05-09 | 2007-11-08 | 2008-05-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2011-05-09 | 2011-11-08 | 2012-05-09 | $7700.00 | Window Closed / Lapsed |