CN1254911C - Linearised radio transmitter - Google Patents
Linearised radio transmitter Download PDFInfo
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- CN1254911C CN1254911C CN 02816334 CN02816334A CN1254911C CN 1254911 C CN1254911 C CN 1254911C CN 02816334 CN02816334 CN 02816334 CN 02816334 A CN02816334 A CN 02816334A CN 1254911 C CN1254911 C CN 1254911C
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- digital
- signal processor
- digital signal
- transmitter
- converter
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- 238000005070 sampling Methods 0.000 claims description 18
- 238000012545 processing Methods 0.000 claims description 12
- 238000001514 detection method Methods 0.000 claims description 11
- GOLXNESZZPUPJE-UHFFFAOYSA-N spiromesifen Chemical compound CC1=CC(C)=CC(C)=C1C(C(O1)=O)=C(OC(=O)CC(C)(C)C)C11CCCC1 GOLXNESZZPUPJE-UHFFFAOYSA-N 0.000 claims description 8
- 238000005259 measurement Methods 0.000 claims description 5
- 230000005540 biological transmission Effects 0.000 claims description 4
- 238000012986 modification Methods 0.000 claims description 3
- 230000004048 modification Effects 0.000 claims description 3
- 230000004044 response Effects 0.000 claims description 3
- 235000019800 disodium phosphate Nutrition 0.000 description 15
- 238000010586 diagram Methods 0.000 description 4
- 230000006978 adaptation Effects 0.000 description 2
- 230000008859 change Effects 0.000 description 2
- 238000006243 chemical reaction Methods 0.000 description 1
- 238000012937 correction Methods 0.000 description 1
- 230000002950 deficient Effects 0.000 description 1
- 238000013461 design Methods 0.000 description 1
- 238000001914 filtration Methods 0.000 description 1
- 238000000034 method Methods 0.000 description 1
- 230000008569 process Effects 0.000 description 1
- 230000009467 reduction Effects 0.000 description 1
- 238000004088 simulation Methods 0.000 description 1
- 238000013519 translation Methods 0.000 description 1
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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
- H03F1/32—Modifications of amplifiers to reduce non-linear distortion
- H03F1/3241—Modifications of amplifiers to reduce non-linear distortion using predistortion circuits
- H03F1/3252—Modifications of amplifiers to reduce non-linear distortion using predistortion circuits using multiple parallel paths between input and output
-
- 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
- H03F1/32—Modifications of amplifiers to reduce non-linear distortion
-
- 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
- H03F1/32—Modifications of amplifiers to reduce non-linear distortion
- H03F1/3241—Modifications of amplifiers to reduce non-linear distortion using predistortion circuits
- H03F1/3247—Modifications of amplifiers to reduce non-linear distortion using predistortion circuits using feedback acting on predistortion circuits
-
- 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
- H03F1/32—Modifications of amplifiers to reduce non-linear distortion
- H03F1/3241—Modifications of amplifiers to reduce non-linear distortion using predistortion circuits
- H03F1/3294—Acting on the real and imaginary components of the input signal
-
- H—ELECTRICITY
- H03—ELECTRONIC CIRCUITRY
- H03F—AMPLIFIERS
- H03F2200/00—Indexing scheme relating to amplifiers
- H03F2200/207—A hybrid coupler being used as power measuring circuit at the output of an amplifier circuit
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- Physics & Mathematics (AREA)
- Nonlinear Science (AREA)
- Engineering & Computer Science (AREA)
- Power Engineering (AREA)
- Amplifiers (AREA)
- Transmitters (AREA)
Abstract
A linearised radio transmitter comprises a fixed digital signal processor (1), an output element (2), and a programmable digital signal processor (3). The fixed digital signal processor (1) includes a pre-distorter (5) which is controlled by the programmable digital signal processor (3) in dependence upon signals received by the programmable digital signal processor from the output element (2). The transmitter further comprises a digital amplitude control (15) and an analogue amplitude control (16) positioned between the pre-distorter (5) and the output element (2). Control means (14) are provided for simultaneously controlling the setting of the digital amplitude control (15) and the setting of the analogue amplitude control (16) such that their combined gain is constant.
Description
Technical field
The present invention relates to linearizing radio transmitter, relate in particular to and introduce the linearizing radio transmitter of self-adapted pre-distortion.This transmitter will be suitable for using in the third generation mobile base station.
Background technology
It is known that linearizing radio transmitter adopts the self-adapted pre-distortion technology.A kind of known exemplary transmitter shown in the circuit block diagram of Fig. 1 comprises dedicated digital signal processor (DSP, digitalsignal processor) 1, output sampling means 2 and Programmable DSPs 3.Special DSP 1 comprises coding and power control unit 4, digital predistorter 5, digital up converter 6 and IQ and DC error-corrector 7.Input data signal (D represents with label) is handled by parts 4, and parts 4 are carried out chnnel coding, power control and filter function for a plurality of channels.Digital predistorter 5 typically produces the distortion of signal amplitude and phase place, and is controlled by one group of coefficient that Programmable DSPs 3 is provided.Upconverter and error-corrector parts 6 and 7 provide frequency translation and the hardware error in the simulation process to proofread and correct, and are optional.The output of special DSP 1 is provided for D/A converter (DAC) 8, and the output of D/A converter 8 is provided for RF upconverter 9.The output of RF upconverter 9 is provided for output sampling means 2 via high power output amplifier 10.Feedback line 11 from output sampling means 2 leads to Programmable DSPs 3 via RF low-converter 12 and analog/digital converter 13.Programmable DSPs 3 is connected to the digital predistorter 5 and the error-corrector 7 of special DSP 1, thereby estimation error and self adaptation are provided.Programmable DSPs 3 also provides feedback line F, so that can compare to signal and the ideal signal from analog/digital converter 13.
The purpose of using predistortion is to reduce the power consumption requirement of transmitter.Most of power consumption is in amplifier 10, and main bias current and voltage decision by amplifier transistor.The general bias level of selecting is to guarantee that amplifier 10 can (peak envelope power PEP) be sent in the load with required peak envelope power.If bias level is lowered, then will make the distorted signals of max power level, cause the loss of system data transmission capacity.Can eliminate the distortion of output signal peak value by making the baseband digital signal predistortion, by this way, distortion does not appear in the follow-up non-linear signal that will make in RF processing and the amplifier 10.For the optimum of realizing output distortion reduces, must accurately mate the parameter of predistorter 5 and the parameter and the RF treatment characteristic of amplifier 10.In fact, system performance will change.RF low-converter 12 and analog/digital converter 13 are provided for measuring the means of output signal.3 pairs of measured output signals of Programmable DSPs and required optimum output signal compare, to estimate that required pre-distortion parameters is to obtain desirable counteracting.Then, the optimum distortion parameter that is calculated is fed back to predistorter 5.This distortion self adaptation ring tracking system is about the variation of time, temperature and output loading.
Identical with the transmitter of a lot of reality, the transmitter of Fig. 1 need be used to control the parts of power output, and this is finished by coding and power control unit 4.But, carry out distortion-free operation for system, D/A converter 8, RF upconverter 9, amplifier 10 and output sampling means 2 must adapt to the resultant signal dynamic range, and this resultant signal dynamic range is peak handling tolerance limit (the head room allowance) sum of required output signal-to-noise ratio (SNR), power control dynamic range and predistortion.When this system of design, universal experience is to guarantee nonlinear main source in amplifier 10, so D/A converter 8 is relative linear with RF upconverter 9.Like this, in order to realize the linear requirement in dynamic range and these two parts, just need a large amount of electrical source consumptions, this can reduce the gross efficiency gain of using predistortion to come linearized amplifier 10 to be produced.
Summary of the invention
The objective of the invention is to use the self-adapted pre-distortion linearisation to improve the interior power consumption of linearizing radio transmitter.
The invention provides a kind of linearizing radio transmitter, comprise first digital signal processor, second digital signal processor and output sampling means, described first digital signal processor comprises: digital predistorter, and described digital predistorter is controlled according to the signal that receives from described output sampling means by described second digital signal processor; And coding and power control unit, be used to revise the input signal that is input to described first digital signal processor.Described transmitter also comprises: D/A converter is positioned at output place of described first digital signal processor; Amplifier is between described D/A converter and described output sampling means; Digital amplitude control is between described digital predistorter and described D/A converter; The analog amplitude controller, between described D/A converter and described amplifier; And analog/digital converter, between described output sampling means and described second digital signal processor.Wherein, power detection and scope control assembly are provided, reception is from the output signal of described coding and power control unit, and present output signal to described digital amplitude control, described analog amplitude controller and described second digital signal processor, so that control the setting of described digital amplitude control and the setting of described analog amplitude controller simultaneously, make that their portfolio premium is constant.
Advantageously, this transmitter also comprises the RF upconverter between described analog/digital converter and analog gain controller, and the RF low-converter between described output sampling means and amplifier.
Advantageously, so be configured,, change the distortion factor that is applied to digital predistorter promptly according to the signal that receives from output sampling means by second digital signal processor.
In a preferred embodiment, power detection and scope control assembly are operated according to following algorithm:
If a) P1 is more than or equal to P2, the analog amplitude controller is adjusted into amplitude peak, and controls second digital signal processor, so that make the measurement of self-adaptive processing, the distortion factor of optimizing is applied to digital predistorter in response to output sampling means;
B) if P1 less than P2 but more than or equal to P3, is adjusted into amplitude peak with the analog amplitude controller, and controls second digital signal processor,, thereby new distortion factor is not applied to digital predistorter so that forbid self-adaptive processing; And
C) provide level if P1, adjusts the analog amplitude controller less than P3, and control second digital signal processor,, thereby new distortion factor is not applied to digital predistorter so that forbid self-adaptive processing less than amplitude peak;
Wherein, P1 is the power of being measured by power detection and scope control assembly, and P2 is first reference level, and P3 is second reference level and less than P2.
Advantageously, so carry out step c),, predistorter is forced to linear condition by revising distortion factor.
Preferably, P1 is each power setting sum that sends in coding and the power control unit.Replacedly, P1 is through the transmission coding of predetermined period of time measurement and the output peak power of power control unit.
Be easily, control assembly is operated according to the modification of described algorithm, wherein, P2 and P3 each by two parameter P2
High, P2
LowAnd P3
High, P3
LowReplace, and it is as follows to revise algorithm:
If a) P1 increases, then use P2
HighAnd P3
HighAnd
B) if P1 reduces, then use P2
LowAnd P3
LowP2
HighGreater than P2
Low, P3
HighGreater than P3
Low, and P2
LowGreater than P3
High
Description of drawings
Fig. 1 is the circuit block diagram that a kind of known exemplary transmitter is shown; And
Fig. 2 is the circuit block diagram that the linearizing radio transmitter of constructing according to the present invention is shown.
Embodiment
Utilize example to describe linearizing radio transmitter constructed according to the invention in detail now with reference to Fig. 2, Fig. 2 is the circuit block diagram of transmitter.
The transmitter of Fig. 2 is the modified form of the transmitter of Fig. 1, so identical label will be used for identical parts, and only is elaborated to revising part.Therefore, the transmitter of Fig. 2 comprises: power detection relevant with coding and power control unit 4 in special DSP 1 and scope control assembly 14, at the digital amplitude control assembly 15 of output place of digital predistorter 5 and the analogue amplitude control block (being generally analog attenuator) 16 between RF upconverter 9 and amplifier 10.
Power detection and scope control assembly 14 be control figure amplitude control assembly 15 and analogue amplitude control block 16 simultaneously and in tandem.This control is, by the amplitude setting that the amplitude setting of analogue amplitude control block 16 is mated digital amplitude control assembly 15, makes the portfolio premium of two parts constant, and no matter their independent setting.
Power detection and scope control assembly 14 are measured the gross output level of coding and power control unit 4, and, adjust digital amplitude control assembly 15, analogue amplitude control block 16 and Programmable DSPs 3 with respect to measured power according to the algorithm of following explanation.
In this algorithm, P1 is the power of being measured by power detection and scope control assembly 14, and P2 and P3 are reference levels, and wherein P2 is more than or equal to P3.Can perhaps according to the output peak power of the parts of measuring through one-period 4, determine the value of P1 by the individual channel power setting in the parts 4 is sued for peace.Usually, P2 is configured to following level: at this level place, and compare at the peak power output place, amplifier 10 can be worked relatively linearly.For the given maximum level of output distortion, along with degree of correction is low more, the parameter value of predistorter 5 is inessential more.Below level P2, self-adaptive processing is just die on and is under an embargo.Select level P3, thereby the characteristic of amplifier 10 is enough linear can completely forbid predistortion so that make, and perhaps the gain of introducing owing to the defective of analog attenuator 16 does not match and will can not cause because the result's that do not match of predistortion and amplifier characteristic unacceptable output distortion.Parameter P2 and P3 will depend on concrete enforcement, and for any fixed system of giving, all must determine by emulation or experience.
As P1 during more than or equal to P2, analogue amplitude control block 16 is adjusted into amplitude peak, and control Programmable DSPs 3, be applied to digital predistorter 5 so that make self-adaptive processing will optimize distortion factor in response to the measurement of output 2.
As P1 during less than P2 but more than or equal to P3, analogue amplitude control block 16 is adjusted into amplitude peak, and control Programmable DSPs 3, so that forbid self-adaptive processing, thereby new distortion factor is not applied to digital predistorter 5.
As P1 during less than P3, adjust analogue amplitude control block 16 so that the level less than amplitude peak to be provided, and control Programmable DSPs 3, so that forbid self-adaptive processing, thereby new distortion factor is not applied to digital predistorter 5.This less amplitude setting can be that fix or variable.When using variable amplitude to be provided with, also will adjust this setting, so that make the output power levels of RF upconverter 9 remain on nominal operating level according to P1.Select this nominal level,, optimize RF up-conversion linearity and SNR so that for the electrical source consumption of given level.Under the situation that the amplitude of using fixing horizontal reduces, select so that the output power levels of RF upconverter 9 is remained in the minimum deflection of nominal operating level.Option in this working range is perhaps by the described parts of whole bypass, perhaps by suitably revising described parameter, digital predistorter 5 to be forced to linear condition.In this case, can revise by simultaneously equivalent being carried out in the level control of all a plurality of channels, and in coding and power control unit 4, logically realize described digital gain control block 15.
In the revision of this algorithm, utilize two parameter P2
HighAnd P2
LowAnd P3
HighAnd P3
LowReplace each level P2 and P3.This algorithm is as follows: if P1 increases, then use P2
HighAnd P3
HighAnd if the P1 reduction, then use P2
LowAnd P3
LowTherefore, by with P2
HighBe set to greater than P2
LowAnd with P3
HighBe set to greater than P3
Low, realize lagging behind.In this case, P2
LowValue must be greater than P3
HighValue when amplitude control assembly 16 is not configured to amplitude peak is provided, forbid described self-adaptive processing so that guarantee.
The present invention has a plurality of advantages.At first, reduce the dynamic range requirement of DAC converter 8 and upconverter 9, so that reduce the electrical source consumption of transmitter.And, by reducing the dynamic range requirement of DAC converter 8, can adopt cheap apparatus with low resolution.Secondly, because output level is lowered, can be by the analog attenuator 16 RF upconverter LO leakage of decaying, leak the requirement that suppresses for filtering or for oscillator thereby also can reduce.
Claims (8)
1. a linearizing radio transmitter comprises first digital signal processor, second digital signal processor and output sampling means,
Described first digital signal processor comprises:
Digital predistorter, described digital predistorter is controlled according to the signal that receives from described output sampling means by described second digital signal processor; And
Coding and power control unit are used to revise the input signal that is input to described first digital signal processor,
Described transmitter also comprises:
D/A converter is positioned at output place of described first digital signal processor;
Amplifier is between described D/A converter and described output sampling means;
Digital amplitude control is between described digital predistorter and described D/A converter;
The analog amplitude controller, between described D/A converter and described amplifier; And
Analog/digital converter, between described output sampling means and described second digital signal processor,
Wherein, power detection and scope control assembly are provided, reception is from the output signal of described coding and power control unit, and present output signal to described digital amplitude control, described analog amplitude controller and described second digital signal processor, so that control the setting of described digital amplitude control and the setting of described analog amplitude controller simultaneously, make that their portfolio premium is constant.
2. transmitter as claimed in claim 1 also comprises RF upconverter between described D/A converter and described amplifier and the RF low-converter between described output sampling means and analog/digital converter.
3. transmitter as claimed in claim 1 or 2 wherein, is configured like this, so that according to the signal that is received from described output sampling means by described second digital signal processor, changes the distortion factor that is applied to described digital predistorter.
4. transmitter as claimed in claim 3, wherein, described power detection and scope control assembly are operated according to following algorithm:
If a) P1 is more than or equal to P2, described analog amplitude controller is adjusted into amplitude peak, and control described second digital signal processor,, the distortion factor of optimizing is applied to described digital predistorter so that make the measurement of self-adaptive processing in response to described output sampling means;
B) if P1 less than P2 but more than or equal to P3, described analog amplitude controller is adjusted into amplitude peak, and control described second digital signal processor,, thereby new distortion factor is not applied to described digital predistorter so that forbid described self-adaptive processing; And
C) if P1 less than P3, adjust described analog amplitude controller so that the level less than amplitude peak to be provided, and control described second digital signal processor,, thereby new distortion factor is not applied to described digital predistorter so that forbid described self-adaptive processing;
Wherein, P1 is the power of being measured by described power detection and scope control assembly, and P2 is first reference level, and P3 is second reference level and less than P2.
5. transmitter as claimed in claim 4 wherein, carries out described step c), by revising distortion factor, described predistorter is forced to linear condition.
6. transmitter as claimed in claim 4, wherein, P1 is each power setting sum in described transmission coding and the power control unit.
7. transmitter as claimed in claim 4, wherein, P1 is through the described transmission coding of predetermined period of time measurement and the output peak power of power control unit.
8. as any one the described transmitter in the claim 4 to 7, wherein, described power detection and scope control assembly are operated according to the modification of described algorithm, wherein, P2 and P3 each by two parameter P2
High, P2
LowAnd P3
High, P3
LowReplace, and described modification algorithm is as follows:
If a) P1 increases, then use P2
HighAnd P3
HighAnd
B) if P1 reduces, then use P2
LowAnd P3
Low
P2
HighGreater than P2
Low, P3
HighGreater than P3
Low, and P2
LowGreater than P3
High
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB0120307.4 | 2001-08-21 | ||
| GB0120307A GB2379109B (en) | 2001-08-21 | 2001-08-21 | Linearised radio transmitter |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN1545759A CN1545759A (en) | 2004-11-10 |
| CN1254911C true CN1254911C (en) | 2006-05-03 |
Family
ID=9920739
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN 02816334 Expired - Fee Related CN1254911C (en) | 2001-08-21 | 2002-08-21 | Linearised radio transmitter |
Country Status (4)
| Country | Link |
|---|---|
| EP (1) | EP1419573A1 (en) |
| CN (1) | CN1254911C (en) |
| GB (1) | GB2379109B (en) |
| WO (1) | WO2003019772A1 (en) |
Families Citing this family (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP1499015A1 (en) * | 2003-07-17 | 2005-01-19 | Siemens Aktiengesellschaft | Circuit and process for linearizing the characteristics of a GSM power amplifier |
| JP4641715B2 (en) | 2003-11-14 | 2011-03-02 | 富士通株式会社 | Distortion compensation apparatus and radio base station |
| US7590190B2 (en) * | 2004-11-10 | 2009-09-15 | Powerwave Technologies, Inc. | System and method for forward path gain control in a digital predistortion linearized transmitter |
| JP2006174079A (en) * | 2004-12-15 | 2006-06-29 | Sony Corp | Audio signal processing method and apparatus |
| FI20055355A0 (en) * | 2005-06-29 | 2005-06-29 | Nokia Corp | Method for data processing, pre-distortion arrangement, transmitter, network element and base station |
| CN101114854B (en) * | 2006-07-28 | 2011-05-18 | 北京信威通信技术股份有限公司 | Linearized control device and method for power amplifier of time division duplex system |
Family Cites Families (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO1992008297A1 (en) * | 1990-10-24 | 1992-05-14 | Motorola, Inc. | An apparatus and method for varying a signal in a transmitter of a transceiver |
| US5959499A (en) * | 1997-09-30 | 1999-09-28 | Motorola, Inc. | Predistortion system and method using analog feedback loop for look-up table training |
| GB9811382D0 (en) * | 1998-05-27 | 1998-07-22 | Nokia Mobile Phones Ltd | A transmitter |
-
2001
- 2001-08-21 GB GB0120307A patent/GB2379109B/en not_active Expired - Fee Related
-
2002
- 2002-08-21 CN CN 02816334 patent/CN1254911C/en not_active Expired - Fee Related
- 2002-08-21 EP EP02767602A patent/EP1419573A1/en not_active Withdrawn
- 2002-08-21 WO PCT/GB2002/003824 patent/WO2003019772A1/en not_active Application Discontinuation
Also Published As
| Publication number | Publication date |
|---|---|
| GB2379109B (en) | 2005-07-13 |
| GB0120307D0 (en) | 2001-10-17 |
| GB2379109A (en) | 2003-02-26 |
| CN1545759A (en) | 2004-11-10 |
| WO2003019772A1 (en) | 2003-03-06 |
| EP1419573A1 (en) | 2004-05-19 |
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