US5551070A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Cartesian multicarrier feedback
Assignee: Telefonaktiebolaget LM Ericsson AB
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Filing: 1993-01-28
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Granted: 1996-08-27
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Expires: 2013-01-28
Abstract
Abstract A system for transmission of combined, multi-carrier signals wherein combiner/filters, commonly called combiners, have been eliminated. A cartesian feedback loop linearizes the system and thereby suppresses carrier frequency intermodulation by feeding back a portion of the combined multi-carrier signal to each channel device.
Inventors
- 👤 Ulf Skarby
- 👤 Par Bergsten
- 👤 Bo Hedberg
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 22:52
CPC Classifications
H; H04; H04B; H04B1/00; H04B1/02; H04B1/04; H04B1/0483; H03; H03F; H03F1/00; H03F1/34; H03F3/00; H03F3/20; H03F3/24; H04L; H04L27/00; H04L27/26; H04L27/2601; H04L27/2626; H04L27/2627; H04L27/2637; H04B2001/0408; H04B2001/0433
Claims Analysis
Total Claims: 20
Claim 1
Independent Claim
93 words
A system for transmitting combined, multi-carrier signals comprising: channel modulation means for generating a modulated signal for each channel to be transmitted; summing means for summing said modulated signals to generate a composite signal; power amplifying means for amplifying said composite signal to generate a combined, multi-carrier signal including intermodulation products; feedback means including a cartesian feedback loop for feeding back a portion of said combined, multi-carrier signal to said channel modulation means wherein said intermodulation products of said combined, multi-carrier signal are suppressed; and antenna means for transmitting said combined, multi-carrier signal.
Claim 2
Independent Claim
93 words
A system for transmitting combined, multi-carrier signals comprising: channel modulation means for generating a modulated signal for each channel to be transmitted; summing means for summing said modulated signals to generate a composite signal; power amplifying means for amplifying said composite signal to generate a combined, multi-carrier signal including intermodulation products; feedback means including a cartesian feedback loop for feeding back a portion of said combined, multi-carrier signal to said channel modulation means wherein said intermodulation products of said combined, multi-carrier signal are suppressed; and antenna means for transmitting said combined, multi-carrier signal.
Claim 3
Dependent Claim
14 words
The system of claim 1, wherein said modulated signal is an intermediate frequency signal.
Claim 4
Dependent Claim
26 words
The system of claim 2, further comprising: upconverting means for upconverting said composite signal to a radio frequency prior to amplification by said power amplifying means.
Claim 5
Dependent Claim
35 words
The system of claim 3, further comprising: downconverting means for downconverting said portion of said combined, multi-carrier signal from said radio frequency to said intermediate frequency prior to being fedback to said channel modulation means.
Claim 6
Dependent Claim
38 words
The system of claim 1 wherein said channel modulation means further comprises: means for comparing components of said fedback portion of said combined, multi-carrier signal to I and Q baseband reference components to generate a loop error signal.
Claim 7
Dependent Claim
23 words
The system of claim 1 wherein said feedback means further comprises: a cartesian feedback loop having a loop gain which suppresses intermodulation frequencies.
Claim 8
Dependent Claim
28 words
The system of claim 1 wherein said feedback means acts as a bandpass filter having a loop gain characteristic centered proximate each carrier frequency in said multi-carrier signal.
Claim 9
Independent Claim
90 words
A method for transmitting combined, multi-carrier signals comprising the steps of: inputting reference baseband signals for each channel to be transmitted; generating a modulated signal based on each of said reference baseband signals; summing together each modulated signal to generate a composite signal; amplifying said composite signal to generate a combined, multi-carrier signal including intermodulation products; suppressing said intermodulation products in said combined, multi-carrier signal by feeding back a portion thereof using a cartesian feedback loop to a modulator associated with said each channel; and transmitting said combined, multi-carrier signal.
Claim 10
Independent Claim
90 words
A method for transmitting combined, multi-carrier signals comprising the steps of: inputting reference baseband signals for each channel to be transmitted; generating a modulated signal based on each of said reference baseband signals; summing together each modulated signal to generate a composite signal; amplifying said composite signal to generate a combined, multi-carrier signal including intermodulation products; suppressing said intermodulation products in said combined, multi-carrier signal by feeding back a portion thereof using a cartesian feedback loop to a modulator associated with said each channel; and transmitting said combined, multi-carrier signal.
Claim 11
Dependent Claim
18 words
The method of claim 8, wherein said step of generating further comprises: generating an intermediate frequency modulated signal.
Claim 12
Dependent Claim
24 words
The method of claim 9, further comprising the step of: upconverting said composite signal to a radio frequency prior to amplifying said composite signal.
Claim 13
Dependent Claim
26 words
The method of claim 10, further comprising the step of: comparing components of said fedback portion with said reference baseband signals prior to said generating step.
Claim 14
Dependent Claim
31 words
The method of claim 11 further comprising the step of: downconverting said portion of said combined, multi-carrier signal from said radio frequency to said intermediate frequency prior to said comparing step.
Claim 15
Dependent Claim
26 words
The method of claim 8 further comprising the step of: comparing components of said fedback portion with said reference baseband signals prior to said generating step.
Claim 16
Dependent Claim
32 words
The method of claim 8 wherein said step of suppressing further comprises the step of: providing a cartesian feedback loop having a loop gain which maximizes carrier frequencies and minimizes intermodulation frequencies.
Claim 17
Dependent Claim
46 words
The method of claim 8 wherein said step of suppressing intermodulation further comprises the step of: feeding back said portion of said combined, multi-carrier signal to effectively bandpass filter said combined multi-carrier signal with a loop gain centered on carrier frequencies of said combined, multi-carrier signal.
Claim 18
Independent Claim
121 words
A system for transmitting a combined, multicarrier signal comprising: a first and second modulator which generate a modulated signal for each of a first carrier frequency and a second carrier frequency to be transmitted, thereby generating a plurality of modulated signals; an adder which adds said modulated signals to generate a composite signal; a power amplifier which amplifies said composite signal to generate a combined, multi-carrier signal including intermodulation frequencies; a cartesian feedback loop which returns a portion of said combined, multi-carrier signal to said first and second modulators having a loop gain which maximizes a return of said first and second carrier frequencies and suppresses a return of said intermodulation frequencies; and an antenna for transmitting said combined, multi-carrier signal.
Claim 19
Independent Claim
121 words
A system for transmitting a combined, multicarrier signal comprising: a first and second modulator which generate a modulated signal for each of a first carrier frequency and a second carrier frequency to be transmitted, thereby generating a plurality of modulated signals; an adder which adds said modulated signals to generate a composite signal; a power amplifier which amplifies said composite signal to generate a combined, multi-carrier signal including intermodulation frequencies; a cartesian feedback loop which returns a portion of said combined, multi-carrier signal to said first and second modulators having a loop gain which maximizes a return of said first and second carrier frequencies and suppresses a return of said intermodulation frequencies; and an antenna for transmitting said combined, multi-carrier signal.
Claim 20
Dependent Claim
29 words
The system of claim 16 wherein: said feedback loop acts as a bandpass filter having said loop gain characteristic centered proximate each of said first and second carrier frequencies.
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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) | 1999-08-27 | 2000-02-26 | 2000-08-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2003-08-27 | 2004-02-26 | 2004-08-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2007-08-27 | 2008-02-26 | 2008-08-27 | $7700.00 | Window Closed / Lapsed |