WO1996019063A1 - Procede pour equilibrer les voies d'un amplificateur de type 'linc' - Google Patents
Procede pour equilibrer les voies d'un amplificateur de type 'linc' Download PDFInfo
- Publication number
- WO1996019063A1 WO1996019063A1 PCT/FR1995/001512 FR9501512W WO9619063A1 WO 1996019063 A1 WO1996019063 A1 WO 1996019063A1 FR 9501512 W FR9501512 W FR 9501512W WO 9619063 A1 WO9619063 A1 WO 9619063A1
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- WIPO (PCT)
- Prior art keywords
- channel
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- signal
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- Prior art date
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Classifications
-
- H—ELECTRICITY
- H03—ELECTRONIC CIRCUITRY
- H03F—AMPLIFIERS
- H03F1/00—Details of amplifiers with only discharge tubes, only semiconductor devices or only unspecified devices as amplifying elements
- H03F1/02—Modifications of amplifiers to raise the efficiency, e.g. gliding Class A stages, use of an auxiliary oscillation
- H03F1/0205—Modifications of amplifiers to raise the efficiency, e.g. gliding Class A stages, use of an auxiliary oscillation in transistor amplifiers
- H03F1/0294—Modifications of amplifiers to raise the efficiency, e.g. gliding Class A stages, use of an auxiliary oscillation in transistor amplifiers using vector summing of two or more constant amplitude phase-modulated signals
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
- H04L27/00—Modulated-carrier systems
- H04L27/32—Carrier systems characterised by combinations of two or more of the types covered by groups H04L27/02, H04L27/10, H04L27/18 or H04L27/26
- H04L27/34—Amplitude- and phase-modulated carrier systems, e.g. quadrature-amplitude modulated carrier systems
- H04L27/36—Modulator circuits; Transmitter circuits
- H04L27/366—Arrangements for compensating undesirable properties of the transmission path between the modulator and the demodulator
- H04L27/367—Arrangements for compensating undesirable properties of the transmission path between the modulator and the demodulator using predistortion
- H04L27/368—Arrangements for compensating undesirable properties of the transmission path between the modulator and the demodulator using predistortion adaptive predistortion
Definitions
- the invention relates to radio transmissions and more particularly relates to transmission devices.
- the invention is applicable in particular to telephone transmissions or the broadcasting of digital signals, in particular television signals, using MAQ (quadrature amplitude modulation) or OFDM (multiplex by orthogonal frequency division) modulation.
- MAQ quadrature amplitude modulation
- OFDM orthogonal frequency division
- the invention also applies to the processing of any analog signal that can be digitized.
- TOP traveling wave tube
- x and y are two components respectively in phase and in quadrature representative of the symbols to be emitted and w is the frequency of the carrier.
- phase ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇ ⁇
- the signals S1 and S2 with constant envelope can be amplified separately by non-linear amplifiers and then combined.
- the subject of the invention is a method for correcting the imbalance between the two amplification channels of an "LINC" type amplifier, that is to say with linear amplification produced with non-linear components, said amplifier comprising decomposition means for calculating from at least one input time signal two digital modulation signals each consisting of two components and associated respectively with said two amplifier channels, means for generating two components in phase and in quadrature of a carrier, modulation means providing for each channel a modulated signal representing in analog form the sum of two signals respectively resulting from the amplitude modulation of said two components of the carrier by respectively the two components of one of said modulation signals, amplification devices receiving after possible frequency transposition lesd its modulated signals, means for summing the output signals of said amplification devices, said method being characterized in that it consists in carrying out on at least one
- Adaptive filtering can be applied to the modulated digital signal that is present just before the digital-to-analog conversion. This solution has the advantage of simplicity but is only applicable if the frequency of the carrier is not too high for the available technology of filters and digital-analog converters.
- adaptive filtering will advantageously be applied to the two components of the modulation signal of at least one channel.
- the method is characterized in that said input signal consisting of two components respectively in phase and in quadrature, said reference values are those of said components in phase and in quadrature of the input signal and in that said corresponding measurement values are obtained by attenuation of the output signal of the summing and demodulation means by means of the two components of said carrier, said attenuation being dimensioned so as to divide the amplitude of the signal output of the summation means by an approximate value of the gains of the amplification devices.
- Adaptive filtering can be applied to each channel. Furthermore, if we want to avoid any risk instability, provision will also be made for the adaptations of the filterings applied on the two channels to be carried out alternately.
- the adaptive filtering is applied on a single channel and a second adaptive filtering of the two components of the modulation signal of the other channel is carried out, said second adaptive filtering being provided to minimize the error between the two components of the signal of modulation of said other channel and of the measurement values obtained by attenuation of the output signal of the amplification device of said other channel and demodulation by means of the two components of said carrier, said attenuation being dimensioned so as to divide the amplitude of the signal output of the amplification device of said other channel by an approximate value of the gain of the amplification device of said other channel.
- any problem of instability can be avoided if the adaptation of the filtering to be applied on one channel and the adaptation of the second filtering applied on the other channel are carried out alternately.
- FIG. 1 shows an overall diagram of a LINC amplifier to which the method according to the invention can be applied.
- - Figures 2 to 4 show several alternative embodiments implementing the method according to the invention.
- FIG. 1 represents by way of nonlimiting example the structure of a LINC amplifier in the case of an MAQ modulation.
- the input signal consists of two signals x, y obtained from corresponding symbols after appropriate shaping filtering (NYQUIST filters).
- the signals x, y, assumed in digital form, are processed by decomposition means 1, for example produced by means of a signal processor, to supply the four components II, Ql, 12, Q2 of the two modulation signals, according to the formulas mentioned above.
- decomposition means 1 for example produced by means of a signal processor
- these modulation signals are applied to modulation means MI, M2 which on the other hand receive the two components in phase MI and in quadrature MQ from a carrier.
- the phase II or 12 component is mixed with the MI phase component of the carrier, while the quadrature component Q1 or Q2 is mixed with the quadrature component MQ.
- the signals thus obtained are added to provide the digital signals SN1, SN2 which correspond, after digital-analog conversion Cl, C2, to the modulated signals SI, S2.
- the signals SI and S2 are amplified respectively by amplification devices A1, A2 whose outputs, respectively G1.S1 and G2.S2, are summed by a power coupler 3 for provide the output signal S.
- FIG. 2 represents a first possibility of implementing the method according to the invention.
- a programmable filter H is inserted between the modulation means M2 and the digital-analog converter C2 of the second channel.
- the filter H is for example a finite impulse response filter whose coefficients are supplied by a calculation system 4, produced for example by means of a signal processor.
- the system 4 receives the digital signals SN1, SN2 respectively from the modulation means Ml, M2 as well as a measurement signal S'1 + S'2 representative of the output signal S and obtained from the latter by attenuation A3, RF frequency transposition and analog-digital conversion.
- the system 4 is programmed to implement an algorithm for minimizing the error e between the measurement signal S'1 + S'2 and the sum of the signals SN1 and SN2.
- the algorithm will for example be an LMS least squares algorithm.
- the attenuator A3 should be dimensioned so as to divide the amplitude of the output signal S by the average of the gains Gl and G2 of the amplifiers Al and A2. As these gains are not always known exactly, we will have to settle for an approximate value. Experience shows, however, that an imprecision on the attenuation, for example of the order of 10%, does not significantly harm the correction of the imbalance. Although the diagram in Figure 2 shows that the attenuation only applies on the analog output signal, one could also realize the attenuation partly during the sampling of the analog signal by means of an asymmetric coupler and partly during the digital processing before comparison with the reference signal.
- Delay means R are inserted between the modulation means M1 and the digital-analog converter Cl of the first channel.
- the circuit R is dimensioned so as to introduce a delay DT equal to that caused by the filter H.
- the signal obtained by the sum of the signals SN1 and SN2 is delayed before being compared to the measurement signal S'1 + S'2.
- the delays to be applied DT 'and DT “correspond respectively to the delays introduced into the digital and analog parts included between the outputs of the modulators Ml and M2 and the output of the analog-digital converter C3.
- the delay DT ' can be determined exactly as a function of the different cycle times of the operations carried out and the number of stages of the filter H. If the delay DT "is not negligible, provision may advantageously be made for it to be adjustable and controlled automatically by the calculation system, for example by means of an algorithm based on a correlation calculation.
- a programmable filter H2 is inserted between the filtering means 2 and the modulation means M2 of the second channel.
- the filter H2 operates on the two components in phase 12 and in quadrature Q2 of the modulation signal of the second channel.
- the coefficients of the filter H2 are supplied by a calculation system 5 programmed to minimize the errors el, eQ between on the one hand the digital input signals x, y and on the other hand corresponding measurement signals x ', y' obtained from the output signal S.
- the signals x 1 and y 1 result from an attenuation A3 of the signal S followed by a frequency transposition RF, an analog-digital conversion C3 and a demodulation DM1, DM2 using the MI phase and MQ quadrature components of the carrier.
- the attenuation A3 should here be dimensioned to divide the amplitude of the output signal S by the gain Gl of the amplifier Al.
- delay means Ri are provided arranged between the filter 2 and the modulator Ml of the first channel so as to introduce a delay DT1 equal to that caused by the filter H2.
- the signals x and y each undergo the delays DT2 and DT3 before comparison with the homologous measurement signals x 'and y' so as to compensate for the delays due respectively to the digital and analog parts placed between the input signals x, y and the outputs x 'and y' of the demodulators DM1 and DM2.
- the calculation system 5 will for example be programmed to implement a LMS2 least squares algorithm for complex signals.
- the adaptive filtering H2 of the second channel is carried out in the same way as above.
- another programmable filter Hl is used placed between filter 2 and the modulator Ml, the coefficients of which are calculated so as to minimize the errors dl, dQ between on the one hand the components II and Ql of the signal modulation of the first channel and on the other hand of the corresponding measurement signals I 'and Q' obtained by attenuation A4, frequency transposition RF, analog-digital conversion and demodulation DM3, DM4 of the output signal G1.S1 of the amplifier A1 of the first channel.
- the second channel can use a least squares algorithm for complex signals and implemented by a signal processor 6.
- a signal processor 6 we will also provide means DT4, DT5 to delay the signals II and Ql before comparing them to their counterpart I 'and Q'.
- the calculation systems 5 and 6 can use a single signal processor executing in a multiplexed manner the algorithms LMS2 applied respectively to the two channels. For reasons of stability, it will be preferable to carry out the adaptations of the filtering of the two channels in an alternative manner.
- the filters H, Hl, H2 have been presented as separate programmable filters, such as those which are available on the market. However, these filters could be integrated into calculation systems 4, 5 insofar as their performance is compatible with the precision and speed of processing required by the application.
- the size of the programmable filters will take into account the desired quality of the correction. It can be noted that an oversizing of these filters does not necessarily require an increase in the power of the calculation systems, taking into account the fact that the updating of the coefficients is carried out infrequently.
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- Engineering & Computer Science (AREA)
- Power Engineering (AREA)
- Computer Networks & Wireless Communication (AREA)
- Signal Processing (AREA)
- Amplifiers (AREA)
- Digital Transmission Methods That Use Modulated Carrier Waves (AREA)
Abstract
Description
Claims
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
EP95940325A EP0797884A1 (fr) | 1994-12-15 | 1995-11-17 | Procede pour equilibrer les voies d'un amplificateur de type "linc" |
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
FR94/15361 | 1994-12-15 | ||
FR9415361A FR2728416B1 (fr) | 1994-12-15 | 1994-12-15 | Procede pour equilibrer les voies d'un amplificateur de type "linc" |
Publications (1)
Publication Number | Publication Date |
---|---|
WO1996019063A1 true WO1996019063A1 (fr) | 1996-06-20 |
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Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
PCT/FR1995/001512 WO1996019063A1 (fr) | 1994-12-15 | 1995-11-17 | Procede pour equilibrer les voies d'un amplificateur de type 'linc' |
Country Status (3)
Country | Link |
---|---|
EP (1) | EP0797884A1 (fr) |
FR (1) | FR2728416B1 (fr) |
WO (1) | WO1996019063A1 (fr) |
Cited By (14)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US6288606B1 (en) | 1998-11-10 | 2001-09-11 | Nokia Mobile Phones Ltd. | Linear power amplifier arrangement and method for its operation |
US7647030B2 (en) | 2004-10-22 | 2010-01-12 | Parkervision, Inc. | Multiple input single output (MISO) amplifier with circuit branch output tracking |
EP2222044A1 (fr) | 2009-02-19 | 2010-08-25 | Research In Motion Limited | Dispositif de communication mobile sans fil doté d'une amplification de puissance de phase séparée en phase (I) et en quadrature (Q) et de pré-distorsion d'amplificateur de puissance et de compensation d'équilibre IQ |
US8223885B2 (en) | 2009-02-19 | 2012-07-17 | Research In Motion Limited | Mobile wireless communications device with separate In-phase (I) and Quadrature (Q) phase power amplification and power amplifier pre-distortion and IQ balance compensation |
US8884694B2 (en) | 2007-06-28 | 2014-11-11 | Parkervision, Inc. | Systems and methods of RF power transmission, modulation, and amplification |
US8913691B2 (en) | 2006-08-24 | 2014-12-16 | Parkervision, Inc. | Controlling output power of multiple-input single-output (MISO) device |
US9094085B2 (en) | 2005-10-24 | 2015-07-28 | Parkervision, Inc. | Control of MISO node |
US9106316B2 (en) | 2005-10-24 | 2015-08-11 | Parkervision, Inc. | Systems and methods of RF power transmission, modulation, and amplification |
US9106500B2 (en) | 2006-04-24 | 2015-08-11 | Parkervision, Inc. | Systems and methods of RF power transmission, modulation, and amplification, including embodiments for error correction |
US9166528B2 (en) | 2004-10-22 | 2015-10-20 | Parkervision, Inc. | RF power transmission, modulation, and amplification embodiments |
US9419692B2 (en) | 2005-10-24 | 2016-08-16 | Parkervision, Inc. | Antenna control |
US9608677B2 (en) | 2005-10-24 | 2017-03-28 | Parker Vision, Inc | Systems and methods of RF power transmission, modulation, and amplification |
US9614484B2 (en) | 2005-10-24 | 2017-04-04 | Parkervision, Inc. | Systems and methods of RF power transmission, modulation, and amplification, including control functions to transition an output of a MISO device |
US10278131B2 (en) | 2013-09-17 | 2019-04-30 | Parkervision, Inc. | Method, apparatus and system for rendering an information bearing function of time |
Families Citing this family (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2005151543A (ja) * | 2003-10-20 | 2005-06-09 | Matsushita Electric Ind Co Ltd | 増幅回路 |
-
1994
- 1994-12-15 FR FR9415361A patent/FR2728416B1/fr not_active Expired - Fee Related
-
1995
- 1995-11-17 EP EP95940325A patent/EP0797884A1/fr not_active Ceased
- 1995-11-17 WO PCT/FR1995/001512 patent/WO1996019063A1/fr not_active Application Discontinuation
Non-Patent Citations (3)
Title |
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BATEMAN A: "THE COMBINED ANALOGUE LOCKED LOOP UNIVERSAL MODULATOR (CALLUM)", FROM PIONEERS TO THE 21ST. CENTURY, DENVER, MAY 10 - 13, 1992, vol. 1, 10 May 1992 (1992-05-10), INSTITUTE OF ELECTRICAL AND ELECTRONICS ENGINEERS, pages 759 - 763 * |
CASADEVALL & VALDOVINOS: "Performance analysis of QAM modulations applied to the LINC transmitter", IEEE TRANSACTIONS ON VEHICULAR TECHNOLOGY, vol. 42, no. 4, NEW YORK US, pages 399 - 406 * |
COX: "Linear amplification with nonlinear components", IEEE TRANSACTIONS ON COMMUNICATIONS, NEW YORK US, pages 1942 - 1945 * |
Cited By (26)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US6288606B1 (en) | 1998-11-10 | 2001-09-11 | Nokia Mobile Phones Ltd. | Linear power amplifier arrangement and method for its operation |
US7945224B2 (en) | 2004-10-22 | 2011-05-17 | Parkervision, Inc. | Systems and methods of RF power transmission, modulation, and amplification, including waveform distortion compensation embodiments |
US8913974B2 (en) | 2004-10-22 | 2014-12-16 | Parkervision, Inc. | RF power transmission, modulation, and amplification, including direct cartesian 2-branch embodiments |
US7647030B2 (en) | 2004-10-22 | 2010-01-12 | Parkervision, Inc. | Multiple input single output (MISO) amplifier with circuit branch output tracking |
US9143088B2 (en) | 2004-10-22 | 2015-09-22 | Parkervision, Inc. | Control modules |
US9197163B2 (en) | 2004-10-22 | 2015-11-24 | Parkvision, Inc. | Systems, and methods of RF power transmission, modulation, and amplification, including embodiments for output stage protection |
US9166528B2 (en) | 2004-10-22 | 2015-10-20 | Parkervision, Inc. | RF power transmission, modulation, and amplification embodiments |
US9768733B2 (en) | 2004-10-22 | 2017-09-19 | Parker Vision, Inc. | Multiple input single output device with vector signal and bias signal inputs |
US9197164B2 (en) | 2004-10-22 | 2015-11-24 | Parkervision, Inc. | RF power transmission, modulation, and amplification, including direct cartesian 2-branch embodiments |
US9419692B2 (en) | 2005-10-24 | 2016-08-16 | Parkervision, Inc. | Antenna control |
US9608677B2 (en) | 2005-10-24 | 2017-03-28 | Parker Vision, Inc | Systems and methods of RF power transmission, modulation, and amplification |
US9614484B2 (en) | 2005-10-24 | 2017-04-04 | Parkervision, Inc. | Systems and methods of RF power transmission, modulation, and amplification, including control functions to transition an output of a MISO device |
US9705540B2 (en) | 2005-10-24 | 2017-07-11 | Parker Vision, Inc. | Control of MISO node |
US9094085B2 (en) | 2005-10-24 | 2015-07-28 | Parkervision, Inc. | Control of MISO node |
US9106316B2 (en) | 2005-10-24 | 2015-08-11 | Parkervision, Inc. | Systems and methods of RF power transmission, modulation, and amplification |
US9106500B2 (en) | 2006-04-24 | 2015-08-11 | Parkervision, Inc. | Systems and methods of RF power transmission, modulation, and amplification, including embodiments for error correction |
US8913691B2 (en) | 2006-08-24 | 2014-12-16 | Parkervision, Inc. | Controlling output power of multiple-input single-output (MISO) device |
US8884694B2 (en) | 2007-06-28 | 2014-11-11 | Parkervision, Inc. | Systems and methods of RF power transmission, modulation, and amplification |
US8750417B2 (en) | 2009-02-19 | 2014-06-10 | Blackberry Limited | Mobile wireless communications device with separate in-phase (I) and quadrature (Q) phase power amplification and power amplifier pre-distortion and IQ balance compensation |
CN101895490B (zh) * | 2009-02-19 | 2013-12-04 | 黑莓有限公司 | 具有分离的同相和正交相位功率放大的移动无线通信设备和方法 |
US8526535B2 (en) | 2009-02-19 | 2013-09-03 | Blackberry Limited | Mobile wireless communications device with separate in-phase (I) and quadrature (Q) phase power amplification and power amplifier pre-distortion and IQ balance compensation |
EP2485448A1 (fr) * | 2009-02-19 | 2012-08-08 | Research In Motion Limited | Dispositif de communication mobile sans fil doté d'une amplification de puissance de phase séparée en phase (I) et en quadrature (Q) et de pré-distorsion d'amplificateur de puissance et de compensation d'équilibre IQ |
US8223885B2 (en) | 2009-02-19 | 2012-07-17 | Research In Motion Limited | Mobile wireless communications device with separate In-phase (I) and Quadrature (Q) phase power amplification and power amplifier pre-distortion and IQ balance compensation |
CN101895490A (zh) * | 2009-02-19 | 2010-11-24 | 捷讯研究有限公司 | 具有分离的同相和正交相位功率放大的移动无线通信设备 |
EP2222044A1 (fr) | 2009-02-19 | 2010-08-25 | Research In Motion Limited | Dispositif de communication mobile sans fil doté d'une amplification de puissance de phase séparée en phase (I) et en quadrature (Q) et de pré-distorsion d'amplificateur de puissance et de compensation d'équilibre IQ |
US10278131B2 (en) | 2013-09-17 | 2019-04-30 | Parkervision, Inc. | Method, apparatus and system for rendering an information bearing function of time |
Also Published As
Publication number | Publication date |
---|---|
FR2728416B1 (fr) | 1997-01-24 |
FR2728416A1 (fr) | 1996-06-21 |
EP0797884A1 (fr) | 1997-10-01 |
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