Patent US5854811A successfully refreshed from Google Patents.
US5854811A
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Circuit and method for compensating for nonlinear distortion of input signal
Assignee: NEC Corp
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Filing: 1995-11-03
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Granted: 1998-12-29
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Expires: 2015-11-03
Abstract
Abstract A distortion compensating circuit comprises a frequency control section, a filtering section and an eliminating section. Major frequencies are detected from an input signal including major signals having the major frequencies by a major frequency detector performing spectrum analysis of the input signal. Receiving the major frequencies, the frequency control section calculates distortion frequencies from the major frequencies based on predetermined formulae representing the nonlinear distortion. The predetermined formulae are stored in advance. The frequency control section generates frequency control signals indicating the distortion frequencies. After the input signal is divided into a first signal and a second signal, the filtering section extracts frequency components having the distortion frequencies from the first signal in response to the frequency control signals. The frequency components are eliminated from the second signal by combining the phase-reversed frequency component with the second signal by the eliminating section.
Inventors
- 👤 Chiharu Sasaki
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 06:12
CPC Classifications
H; H04; H04B; H04B1/00; H04B1/06; H04B1/10; H04B1/12; H04B1/123
Claims Analysis
Total Claims: 31
Claim 1
Independent Claim
137 words
A circuit for compensating for non-linear distortion of an input signal, said input signal including a major signal having a predetermined frequency, said circuit comprising: a spectrum analyzer for analyzing said input signal and detecting said major signal and generating a detected major frequency signal representing said predetermined frequency; a distortion frequency calculator for calculating a distortion frequency signal based on said detected major frequency signal and a predetermined formula representing said nonlinear distortion; a branching circuit for branching said input signal into a first signal and a second signal; an extractor, responsive to said distortion frequency signal, for extracting a frequency component having said distortion frequency from said first signal received from said branching circuit; and an eliminator for eliminating a signal having said distortion frequency from said second signal based on said extracted frequency component.
Claim 2
Dependent Claim
137 words
A circuit for compensating for non-linear distortion of an input signal, said input signal including a major signal having a predetermined frequency, said circuit comprising: a spectrum analyzer for analyzing said input signal and detecting said major signal and generating a detected major frequency signal representing said predetermined frequency; a distortion frequency calculator for calculating a distortion frequency signal based on said detected major frequency signal and a predetermined formula representing said nonlinear distortion; a branching circuit for branching said input signal into a first signal and a second signal; an extractor, responsive to said distortion frequency signal, for extracting a frequency component having said distortion frequency from said first signal received from said branching circuit; and an eliminator for eliminating a signal having said distortion frequency from said second signal based on said extracted frequency component.
Claim 3
Dependent Claim
68 words
The circuit according to claim 1, wherein said distortion frequency calculator comprises: a storage for storing said predetermined formula; a calculator for calculating said distortion frequency using said predetermined formula and said predetermined frequency; and a controller for controlling said storage and said calculator so as to generate an extraction control signal, said extraction control signal causing said extractor to pass said frequency component of said distortion frequency.
Claim 4
Dependent Claim
25 words
The circuit according to claim 1, wherein said extractor comprises a band-pass filter having a variable passband frequency which is set at said distortion frequency.
Claim 5
Dependent Claim
24 words
The circuit according to claim 2, wherein said extractor comprises a band-pass filter having a variable passband frequency determined by said extraction control signal.
Claim 6
Dependent Claim
58 words
The circuit according to claim 1, wherein said extractor comprises: an adjuster for adjusting a phase and an amplitude of said frequency component for generating an adjusted frequency component; and wherein said eliminator comprises a combiner for combining said adjusted frequency component with said second signal so as to cancel out said frequency component from said second signal.
Claim 7
Dependent Claim
14 words
The circuit according to claim 1, wherein said predetermined formula represents an intermodulation distortion.
Claim 8
Dependent Claim
22 words
The circuit according to claim 6, wherein said predetermined formula represents one of a secondary intermodulation distortion and a tertiary intermodulation distortion.
Claim 9
Dependent Claim
14 words
The circuit according to claim 1, wherein said predetermined formula represents a harmonic distortion.
Claim 10
Dependent Claim
22 words
The circuit according to claim 8, wherein said predetermined formula represents one of a secondary harmonic distortion and a tertiary harmonic distortion.
Claim 11
Dependent Claim
20 words
The circuit according to claim 1, wherein said predetermined formula represents one of an intermodulation distortion and a harmonic distortion.
Claim 12
Dependent Claim
153 words
A circuit for compensating for intermodulation distortion of an input signal, said input signal including a plurality of major signals, each having a corresponding predetermined frequency, said circuit comprising: a spectrum analyzer for analyzing said input signal and detecting said plurality of major signals and generating a detected major frequencies signal representing each of said predetermined frequencies; a distortion frequency calculator for calculating a plurality of distortion frequency signals based on said detected major frequencies signal and a plurality of predetermined formulae representing secondary and tertiary intermodulation distortion; a branching circuit for branching said input signal into a first signal and a second signal; an extractor, responsive to said distortion frequency signals, for extracting frequency components from said first signal received from said branching circuit, said frequency components having said distortion frequencies; and an eliminator for eliminating a signal having said distortion frequency from said second signal based on said extracted frequency components.
Claim 13
Dependent Claim
153 words
A circuit for compensating for intermodulation distortion of an input signal, said input signal including a plurality of major signals, each having a corresponding predetermined frequency, said circuit comprising: a spectrum analyzer for analyzing said input signal and detecting said plurality of major signals and generating a detected major frequencies signal representing each of said predetermined frequencies; a distortion frequency calculator for calculating a plurality of distortion frequency signals based on said detected major frequencies signal and a plurality of predetermined formulae representing secondary and tertiary intermodulation distortion; a branching circuit for branching said input signal into a first signal and a second signal; an extractor, responsive to said distortion frequency signals, for extracting frequency components from said first signal received from said branching circuit, said frequency components having said distortion frequencies; and an eliminator for eliminating a signal having said distortion frequency from said second signal based on said extracted frequency components.
Claim 14
Dependent Claim
72 words
The circuit according to claim 11, wherein said distortion frequency calculator comprises: a storage for storing said predetermined formulae; a calculator for calculating said distortion frequencies using said predetermined formulae and said predetermined frequencies; and a controller for controlling said storage and said calculator so as to generate said second number of extraction control signals, said extraction control signals causing said extractor to pass said frequency components having said distortion frequencies, respectively.
Claim 15
Dependent Claim
27 words
The circuit according to claim 12, wherein said extractor comprises said second number of band-pass filters having variable passband frequencies determined by said extraction control signals, respectively.
Claim 16
Dependent Claim
149 words
A circuit for compensating for harmonic distortion of an input signal, said input signal including a plurality of major signals, each having a predetermined frequency, said circuit comprising: a spectrum analyzer for analyzing said input signal and detecting said plurality of major signals and generating a detected major frequencies signal representing said predetermined frequencies; a distortion frequency calculator for calculating a plurality of distortion frequency signals based on said detected major frequencies signal and at least one predetermined formula representing said harmonic distortion; a branching circuit for branching said input signal into a first signal and a second signal; an extractor, responsive to said distortion frequency signals, for extracting frequency components having from said first signal received from said branching circuit, said frequency components having said distortion frequencies; and an eliminator for eliminating a signal having said distortion frequency from said second signal based on said extracted frequency components.
Claim 17
Dependent Claim
149 words
A circuit for compensating for harmonic distortion of an input signal, said input signal including a plurality of major signals, each having a predetermined frequency, said circuit comprising: a spectrum analyzer for analyzing said input signal and detecting said plurality of major signals and generating a detected major frequencies signal representing said predetermined frequencies; a distortion frequency calculator for calculating a plurality of distortion frequency signals based on said detected major frequencies signal and at least one predetermined formula representing said harmonic distortion; a branching circuit for branching said input signal into a first signal and a second signal; an extractor, responsive to said distortion frequency signals, for extracting frequency components having from said first signal received from said branching circuit, said frequency components having said distortion frequencies; and an eliminator for eliminating a signal having said distortion frequency from said second signal based on said extracted frequency components.
Claim 18
Dependent Claim
75 words
The circuit according to claim 14, wherein said distortion frequency calculator comprises: a storage for storing said at least one predetermined formula; a calculator for calculating said distortion frequencies using said predetermined formula and said predetermined frequencies; and a controller for controlling said storage and said calculator so as to generate said second number of extraction control signals, said extraction control signals causing said extractor to pass said frequency components having said distortion frequencies, respectively.
Claim 19
Dependent Claim
29 words
The circuit according to claim 15, wherein said extractor comprises said second number of band-pass filters having variable passband frequencies determined by respective ones of said extraction control signals.
Claim 20
Dependent Claim
160 words
A transmission system comprising: a power amplifier for amplifying a power of an input signal to generate an amplified input signal, said input signal including a plurality of major signals, each having a respective predetermined frequency; a spectrum analyzer for analyzing said amplified input signal and detecting said plurality of major signals and generating a detected major frequencies signal representing said predetermined frequencies; a distortion frequency calculator for calculating a plurality of distortion frequency signals based on said detected major frequencies signal and a plurality of predetermined formulae representing said nonlinear distortion; a branching circuit for branching said amplified input signal into a first signal and a second signal; an extractor, responsive to said distortion frequency signals, for extracting frequency components having from said first signal received from said branching circuit, said frequency components having said distortion frequencies, respectively; and an eliminator for eliminating a signal having said distortion frequency from said second signal based on said extracted frequency components.
Claim 21
Dependent Claim
160 words
A transmission system comprising: a power amplifier for amplifying a power of an input signal to generate an amplified input signal, said input signal including a plurality of major signals, each having a respective predetermined frequency; a spectrum analyzer for analyzing said amplified input signal and detecting said plurality of major signals and generating a detected major frequencies signal representing said predetermined frequencies; a distortion frequency calculator for calculating a plurality of distortion frequency signals based on said detected major frequencies signal and a plurality of predetermined formulae representing said nonlinear distortion; a branching circuit for branching said amplified input signal into a first signal and a second signal; an extractor, responsive to said distortion frequency signals, for extracting frequency components having from said first signal received from said branching circuit, said frequency components having said distortion frequencies, respectively; and an eliminator for eliminating a signal having said distortion frequency from said second signal based on said extracted frequency components.
Claim 22
Independent Claim
122 words
A method for compensating for non-linear distortion of an input signal, said input signal including a major signal having a predetermined frequency, said method comprising steps of: spectrum analyzing said input signal to detect said major signal and generating a detected major frequency signal representing said predetermined frequency; calculating a distortion frequency relative to said predetermined frequency based on said detected major frequency signal and a predetermined formula representing said nonlinear distortion; branching said input signal into a first signal and a second signal; extracting a frequency component having said distortion frequency from said first signal in response to said detected major frequency signal; and eliminating a signal having said distortion frequency from said second signal based on said extracted frequency component.
Claim 23
Independent Claim
122 words
A method for compensating for non-linear distortion of an input signal, said input signal including a major signal having a predetermined frequency, said method comprising steps of: spectrum analyzing said input signal to detect said major signal and generating a detected major frequency signal representing said predetermined frequency; calculating a distortion frequency relative to said predetermined frequency based on said detected major frequency signal and a predetermined formula representing said nonlinear distortion; branching said input signal into a first signal and a second signal; extracting a frequency component having said distortion frequency from said first signal in response to said detected major frequency signal; and eliminating a signal having said distortion frequency from said second signal based on said extracted frequency component.
Claim 24
Dependent Claim
14 words
The method according to claim 18, wherein said predetermined formula represents an intermodulation distortion.
Claim 25
Dependent Claim
22 words
The method according to claim 19, wherein said predetermined formula represents one of a secondary intermodulation distortion and a tertiary intermodulation distortion.
Claim 26
Dependent Claim
14 words
The method according to claim 18, wherein said predetermined formula represents a harmonic distortion.
Claim 27
Dependent Claim
22 words
The method according to claim 21, wherein said predetermined formula represents one of a secondary harmonic distortion and a tertiary harmonic distortion.
Claim 28
Independent Claim
136 words
A method for compensating for intermodulation distortion of an input signal, said input signal including a plurality of major signals, each having a respective predetermined frequency, said method comprising steps of: spectrum analyzing said input signal to detect said plurality of major signals and generating a detected major frequencies signal representing each of said predetermined frequencies; calculating a plurality of distortion frequencies from said predetermined frequencies based on said detected major frequencies signal and a plurality of predetermined formulae representing secondary and tertiary intermodulation distortions; branching said input signal into a first signal and a second signal; extracting frequency components from said first signal in response to said calculated distortion frequencies, said frequency components having said distortion frequencies; and eliminating a signal having said distortion frequencies from said second signal based on said extracted frequency components.
Claim 29
Independent Claim
136 words
A method for compensating for intermodulation distortion of an input signal, said input signal including a plurality of major signals, each having a respective predetermined frequency, said method comprising steps of: spectrum analyzing said input signal to detect said plurality of major signals and generating a detected major frequencies signal representing each of said predetermined frequencies; calculating a plurality of distortion frequencies from said predetermined frequencies based on said detected major frequencies signal and a plurality of predetermined formulae representing secondary and tertiary intermodulation distortions; branching said input signal into a first signal and a second signal; extracting frequency components from said first signal in response to said calculated distortion frequencies, said frequency components having said distortion frequencies; and eliminating a signal having said distortion frequencies from said second signal based on said extracted frequency components.
Claim 30
Independent Claim
129 words
A method for compensating for harmonic distortion of an input signal, said input signal including a plurality of major signals, each having a respective predetermined frequency, said method comprising steps of: spectrum analyzing said input signal to detect said plurality of major signals and generating a detected major frequencies signal representing said predetermined frequencies; calculating a plurality of distortion frequencies based on said detected major frequencies signal and at least one predetermined formula representing said harmonic distortion; branching said input signal into a first signal and a second signal; extracting frequency components having from said first signal in response to said calculated distortion frequencies, said frequency components having said distortion frequencies; and eliminating a signal having said distortion frequency from said second signal based on said extracted frequency components.
Claim 31
Independent Claim
129 words
A method for compensating for harmonic distortion of an input signal, said input signal including a plurality of major signals, each having a respective predetermined frequency, said method comprising steps of: spectrum analyzing said input signal to detect said plurality of major signals and generating a detected major frequencies signal representing said predetermined frequencies; calculating a plurality of distortion frequencies based on said detected major frequencies signal and at least one predetermined formula representing said harmonic distortion; branching said input signal into a first signal and a second signal; extracting frequency components having from said first signal in response to said calculated distortion frequencies, said frequency components having said distortion frequencies; and eliminating a signal having said distortion frequency from said second signal based on said extracted frequency components.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2001-12-28 | 2002-06-29 | 2002-12-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2005-12-28 | 2006-06-29 | 2006-12-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2009-12-28 | 2010-06-29 | 2010-12-29 | $7700.00 | Window Closed / Lapsed |