CN104378322A - Predistorter control method and device - Google Patents

Predistorter control method and device Download PDF

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Publication number
CN104378322A
CN104378322A CN201310353835.0A CN201310353835A CN104378322A CN 104378322 A CN104378322 A CN 104378322A CN 201310353835 A CN201310353835 A CN 201310353835A CN 104378322 A CN104378322 A CN 104378322A
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distortion coefficients
state parameter
output signal
linear device
predistorter
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CN104378322B (en
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周建民
陈培
久保徳郎
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Fujitsu Ltd
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Fujitsu Ltd
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Abstract

The invention provides a predistorter control method used for conducting predistortion on a data source signal input into a non-linear device through a predistorter. The method comprises the steps of determining an updating time frame, wherein the updating time frame is longer than the time for calculating a cost function and shorter than the convergence time of the updating algorithm of a unit for predistortion factor self-adaption updating operation; acquiring the state parameter of an output signal of the non-linear device; providing a predistortion factor obtained by the unit for predistortion factor self-adaption updating operation through calculation within the updating time frame to the predistorter if the variable of the state parameter within the updating time frame is smaller than or equal to a preset variable threshold value. The invention further provides a predistorter control device. By the adoption of the technical scheme, updating of the predistortion factor can be achieved within a short time without waiting for the convergence of the updating algorithm, the probability of factor updating is increased, and then the performance of a power amplifier is effectively improved.

Description

Predistorter control method and predistorter control device
Technical field
The present invention relates to power amplifier, in particular to a kind of predistorter control method and a kind of predistorter control device, control for the adaptive digital pre-distortion of power amplifier.
Background technology
Along with the development of the communication technology, the especially fast development of broadband communications technologies, the modulation system of various spectral efficient is used widely.And height power ratio (Peak-to-AveragePower Ratio, PAPR) problem wherein also makes to put forward higher requirement to the linearization technique of power amplifier (PA, Power Amplifier).
In the middle of the linearization technique of power amplifier, digital pre-distortion technology (DPD, DigitalPre-distortion) be that one is widely used and effective method, its general principle be signal through power amplifier amplify before, first by the predistorter contrary with the nonlinear characteristic of power amplifier, pre-distortion is carried out to transmission signal, to improve the nonlinear characteristic of whole transmitter system, makes whole system present linear characteristic as much as possible.
Power based on the outer distorted signal of detection zone produces pre-distortion coefficients, and reaching minimum method to make the power of distorted signal is one of traditional pre-distortion method.The method feedback loop simple (only needing single channel to feed back, without the need to quadrature demodulation and two-way ADC), without the need to the time synchronized of meticulous transmission and feedback signal, is a kind of solution of low cost.
Meanwhile, in Modern Communication System, be opposing near-far interference and decline, usually adopt and send signal power control technology (TPC, Transmission Power Control).When signal power is at Rapid Variable Design, amplifier shows different nonlinear characteristics, needs predistorter can the characteristic variations of follower amplifier fast; But owing to needing the power of accurate Calculation out-of-band distortion signal, often need the average of multiple sampling point to make convergence time longer with the moment random fluctuation of removing signal, the quick renewal to pre-distortion coefficients cannot be realized.
Summary of the invention
The present invention just based in the problems referred to above one of at least, propose a kind of new predistorter control technology, the renewal to pre-distortion coefficients can be completed at short notice, and without the need to waiting for the convergence of update algorithm, improve the possibility of coefficient update, thus effectively improve the performance of power amplifier.
In view of this, the present invention proposes a kind of predistorter control method, for carrying out pre-distortion by predistorter to the data source signal of unbalanced input device, wherein said predistorter control method comprises: time determining step, determine section update time, wherein, described update time section length be greater than and utilize the nonlinear distortion situation of the output signal of described non-linear device to calculate length computing time of corresponding cost function, be less than the convergence time length of the update algorithm of the unit carrying out the computing of pre-distortion coefficients adaptive updates; Characteristic determining step, obtains the state parameter variation characteristic of the output signal of described non-linear device; Upgrade determining step, when the state parameter of the output signal of described non-linear device is less than or equal to default variable quantity threshold value at the variable quantity in described update time section, Predicated execution is to the renewal of pre-distortion coefficients; Coefficient provides step, when the renewal of Predicated execution to pre-distortion coefficients, the unit pre-distortion coefficients that section calculates in described update time of carrying out the computing of pre-distortion coefficients adaptive updates is supplied to described predistorter.
In this technical scheme, due to when calculating pre-distortion coefficients, only needing real-time calculation cost function, thus only needing to make the length of section update time be greater than the computing time of this cost function, then without the need to waiting for the convergence of update algorithm, the renewal to pre-distortion coefficients can be realized.In other words, the time period (i.e. the time period of algorithmic statement) being now in fact equivalent to coefficient of first order to upgrade divides the time period in order to repeatedly coefficient update, thus coefficient update does not need to wait for that algorithmic statement just can realize each time, its in fact required condition is more easily met, even if perform power fast to power amplifier to control, but if the computing time of cost function can be greater than guaranteed output stable time period (when namely power variation is less than default variable quantity threshold value), the renewal to pre-distortion coefficients can be completed.
Particularly, non-linear device can be power amplifier, and the state parameter of the output signal of non-linear device can be the power of this output signal or the bias voltage of this non-linear device.
In technique scheme, preferably, described renewal determining step also comprises: when the state parameter of the output signal of described non-linear device is greater than described variable quantity threshold value at the variable quantity in described update time section, judge the renewal do not performed pre-distortion coefficients, or the pre-distortion coefficients obtaining pre-stored is supplied to described predistorter.
In this technical scheme, the reasons such as the execution due to TPC or the environmental factor based on external condition, may there is more violent numerical fluctuations in the state parameter of the output signal of non-linear device, now cannot perform the real-time update to pre-distortion coefficients.In the scenario above, a kind of mode is not for perform renewal; Another kind of mode is use the pre-distortion coefficients of pre-stored to upgrade, thus contributes to the performance under extreme conditions improving non-linear device.
In above-mentioned arbitrary technical scheme, preferably, described time determining step also comprises: when determining that the output signal of described non-linear device to carry out the state parameter change of known variant amount according to known period of change, determine described update time section and described known period of change between relativeness.
In this technical scheme, when the Changing Pattern of the output signal of non-linear device is known, then based on this Changing Pattern, concrete section update time can be determined.Such as the TPC under WCDMA network is controlled, its TPC cycle is 0.667ms, then can at first time with regard to the relativeness in config update time period and this TPC cycle, the start time of section update time is such as made to overlap with the start time in TPC cycle, or the finish time of section update time was overlapped with the finish time in TPC cycle, thus contribute to the management of the renewal process to pre-distortion coefficients.
In above-mentioned arbitrary technical scheme, preferably, described characteristic determining step comprises: the state parameter detecting the output signal of described non-linear device, to determine the state parameter variation characteristic of the output signal of described non-linear device; Or detection corresponds to the state parameter of the index signal of the output signal of described non-linear device, and using the state parameter variation characteristic of the state parameter variation characteristic of described index signal as the output signal of described non-linear device; Or carry out changing the adjustment control command controlled according to the state parameter for the output signal to described non-linear device, estimate the state parameter variation characteristic of the output signal of described non-linear device.
In this technical scheme, there is various ways in the acquisition for the state parameter of the output signal of described non-linear device, as several specific embodiment, can comprise: first kind of way, directly the state parameter of the output signal of non-linear device is measured, obtain its variable quantity in Preset Time (as the unit interval) (i.e. variation characteristic); The second way, measure the index signal of the output signal corresponding to non-linear device, such as before non-linear device, also comprise VGA(Variable gainattenuator, variable power attenuator), then can measure the signal that VGA exports to non-linear device, and using the variable quantity of the variable quantity of the state parameter of this signal as the state parameter of the output signal of non-linear device; The third mode, because TPC process is all undertaken controlling by concrete TPC signal (namely adjusting control command), thus can directly TPC signal be obtained and be analyzed, and wish the regulative mode of execution according to it, estimate the variable quantity of the state parameter of the output signal of non-linear device.
In above-mentioned arbitrary technical scheme, preferably, also comprise: parameters acquiring procedure, the output signal obtaining described non-linear device is at the state parameter of section correspondence described update time, described coefficient provides step also to comprise: for the current state parameter that section is acquired in current update time, there is the historic state parameter stored matched, then obtain further corresponding history pre-distortion coefficients and the historic state information relevant to described update algorithm of carrying out the unit of pre-distortion coefficients adaptive updates computing, to upgrade described history pre-distortion coefficients and described historic state information by the described unit carrying out the computing of pre-distortion coefficients adaptive updates, and the history pre-distortion coefficients after upgrading is supplied to described predistorter, if do not exist, then preset constant is supplied to described predistorter as pre-distortion coefficients, or the new pre-distortion coefficients that the described unit carrying out the computing of pre-distortion coefficients adaptive updates calculates is supplied to described predistorter, and by described new pre-distortion coefficients, the state information that described new pre-distortion coefficients is corresponding, and described current state parameter association store is corresponding historical data.
In this technical scheme, by pre-distortion coefficients, state information, state parameter are carried out association store, achieve and calculate new pre-distortion coefficients by historical data, the causality regulated before and after ensure that and continuity, and finally realize the performance improvement to non-linear device.
According to another aspect of the invention, also proposed a kind of predistorter control device, for carrying out pre-distortion by predistorter to the data source signal of unbalanced input device, wherein said predistorter control device comprises: time determination module, determine section update time, wherein, described update time section length be greater than and utilize the nonlinear distortion situation of the output signal of described non-linear device to calculate length computing time of corresponding cost function, be less than the convergence time length of the update algorithm of the unit carrying out the computing of pre-distortion coefficients adaptive updates; Characteristic determination module, obtains the state parameter variation characteristic of the output signal of described non-linear device; Upgrade judge module, when the state parameter of the output signal of described non-linear device is less than or equal to default variable quantity threshold value at the variable quantity in described update time section, Predicated execution is to the renewal of pre-distortion coefficients; Coefficient provides module, when the renewal of Predicated execution to pre-distortion coefficients, the unit pre-distortion coefficients that section calculates in described update time of carrying out the computing of pre-distortion coefficients adaptive updates is supplied to described predistorter.
In this technical scheme, due to when calculating pre-distortion coefficients, only needing real-time calculation cost function, thus only needing to make the length of section update time be greater than the computing time of this cost function, then without the need to waiting for the convergence of update algorithm, the renewal to pre-distortion coefficients can be realized.In other words, the time period (i.e. the time period of algorithmic statement) being now in fact equivalent to coefficient of first order to upgrade divides the time period in order to repeatedly coefficient update, thus coefficient update does not need to wait for that algorithmic statement just can realize each time, its in fact required condition is more easily met, even if perform power fast to power amplifier to control, but if the computing time of cost function can be greater than guaranteed output stable time period (when namely power variation is less than default variable quantity threshold value), the renewal to pre-distortion coefficients can be completed.
Particularly, non-linear device can be power amplifier, and the state parameter of the output signal of non-linear device can be the power of this output signal or the bias voltage of this non-linear device.
In technique scheme, preferably, described renewal judge module also for: when the state parameter of the output signal of described non-linear device is greater than described variable quantity threshold value at the variable quantity in described update time section, judge the renewal do not performed pre-distortion coefficients, or the pre-distortion coefficients obtaining pre-stored is supplied to described predistorter.
In this technical scheme, the reasons such as the execution due to TPC or the environmental factor based on external condition, may there is more violent numerical fluctuations in the state parameter of the output signal of non-linear device, now cannot perform the real-time update to pre-distortion coefficients.In the scenario above, a kind of mode is not for perform renewal; Another kind of mode is use the pre-distortion coefficients of pre-stored to upgrade, thus contributes to the performance under extreme conditions improving non-linear device.
In above-mentioned arbitrary technical scheme, preferably, described time determination module also for: when determine the output signal of described non-linear device according to known period of change carry out known variant amount state parameter change time, determine the relativeness between described non-renewable phase and described known period of change.
In this technical scheme, when the Changing Pattern of the output signal of non-linear device is known, then based on this Changing Pattern, concrete section update time can be determined.Such as the TPC under WCDMA network is controlled, its TPC cycle is 0.667ms, then can at first time with regard to the relativeness in config update time period and this TPC cycle, the start time of section update time is such as made to overlap with the start time in TPC cycle, or the finish time of section update time was overlapped with the finish time in TPC cycle, thus contribute to the management of the renewal process to pre-distortion coefficients.
In above-mentioned arbitrary technical scheme, preferably, described characteristic determination module also for the state parameter detecting the output signal of described non-linear device, determining the state parameter variation characteristic of the output signal of described non-linear device; Or detection corresponds to the state parameter of the index signal of the output signal of described non-linear device, and using the state parameter variation characteristic of the state parameter variation characteristic of described index signal as the output signal of described non-linear device; Or carry out changing the adjustment control command controlled according to the state parameter for the output signal to described non-linear device, estimate the state parameter variation characteristic of the output signal of described non-linear device.
In this technical scheme, there is various ways in the acquisition for the state parameter of the output signal of described non-linear device, as several specific embodiment, can comprise: first kind of way, directly the state parameter of the output signal of non-linear device is measured, obtain its variable quantity in Preset Time (as the unit interval) (i.e. variation characteristic); The second way, measure the index signal of the output signal corresponding to non-linear device, such as before non-linear device, also comprise VGA(Variable gainattenuator, variable power attenuator), then can measure the signal that VGA exports to non-linear device, and using the variable quantity of the variable quantity of the state parameter of this signal as the state parameter of the output signal of non-linear device; The third mode, because TPC process is all undertaken controlling by concrete TPC signal (namely adjusting control command), thus can directly TPC signal be obtained and be analyzed, and wish the regulative mode of execution according to it, estimate the variable quantity of the state parameter of the output signal of non-linear device.
In above-mentioned arbitrary technical scheme, preferably, also comprise: parameter acquisition module, the output signal obtaining described non-linear device is at the state parameter of section correspondence described update time, wherein, described coefficient provide module also for: for the current state parameter that section is acquired in current update time, if there is the historic state parameter stored matched, then obtain further corresponding history pre-distortion coefficients and the historic state information relevant to described update algorithm of carrying out the unit of pre-distortion coefficients adaptive updates computing, to upgrade described history pre-distortion coefficients and described historic state information by the described unit carrying out the computing of pre-distortion coefficients adaptive updates, and the history pre-distortion coefficients after upgrading is supplied to described predistorter, if do not exist, then preset constant is supplied to described predistorter as pre-distortion coefficients, or the new pre-distortion coefficients that the described unit carrying out the computing of pre-distortion coefficients adaptive updates calculates is supplied to described predistorter, and by described new pre-distortion coefficients, the state information that described new pre-distortion coefficients is corresponding, and described current state parameter association store is corresponding historical data.
In this technical scheme, by pre-distortion coefficients, state information, state parameter are carried out association store, achieve and calculate new pre-distortion coefficients by historical data, the causality regulated before and after ensure that and continuity, and finally realize the performance improvement to non-linear device.
By above technical scheme, the renewal to pre-distortion coefficients can be completed at short notice, and without the need to waiting for the convergence of update algorithm, improve the possibility of coefficient update, thus effectively improve the performance of power amplifier.
Accompanying drawing explanation
Fig. 1 shows the schematic block diagram of predistorter control method according to an embodiment of the invention;
Fig. 2 shows the schematic flow diagram of predistorter control device according to an embodiment of the invention;
Fig. 3 shows the structural representation carrying out the power amplification system of pre-distortion coefficients renewal based on output signal power according to an embodiment of the invention;
Fig. 4 shows the schematic diagram that pre-distortion coefficients according to an embodiment of the invention changes with the power adjustment of the output signal of power amplifier;
Fig. 5 is the middle schematic diagram according to power storage pre-distortion coefficients embodiment illustrated in fig. 3;
Fig. 6 is the middle schematic diagram according to state variable needed for power storage update algorithm embodiment illustrated in fig. 3;
Fig. 7 shows according to an embodiment of the invention to the schematic diagram that the numerical value of cost function adjusts;
Fig. 8 shows the structural representation carrying out the power amplification system of pre-distortion coefficients renewal based on output signal power according to another embodiment of the invention;
Fig. 9 shows the structural representation carrying out the power amplification system of pre-distortion coefficients renewal based on output signal power according to still another embodiment of the invention;
Figure 10 shows the structural representation that the bias voltage based on power amplifier according to an embodiment of the invention carries out the power amplification system of pre-distortion coefficients renewal;
Figure 11 is the middle schematic diagram storing pre-distortion coefficients according to bias voltage embodiment illustrated in fig. 10;
Figure 12 is the middle schematic diagram according to state variable needed for bias voltage storage update algorithm embodiment illustrated in fig. 10;
Figure 13 bias voltage based on power amplifier shown according to another embodiment of the invention carries out the structural representation of the power amplification system of pre-distortion coefficients renewal;
Figure 14 shows the structural representation that the bias voltage based on output signal power and power amplifier according to an embodiment of the invention carries out the power amplification system of pre-distortion coefficients renewal;
Figure 15 be embodiment illustrated in fig. 14 middle while carry out storing the schematic diagram of pre-distortion coefficients according to power and bias voltage;
Figure 16 for embodiment illustrated in fig. 14 middle while to carry out the schematic diagram of state variable needed for storage update algorithm according to power and bias voltage.
Embodiment
In order to more clearly understand above-mentioned purpose of the present invention, feature and advantage, below in conjunction with the drawings and specific embodiments, the present invention is further described in detail.It should be noted that, when not conflicting, the feature in the embodiment of the application and embodiment can combine mutually.
Set forth a lot of detail in the following description so that fully understand the present invention, but the present invention can also adopt other to be different from other modes described here and implement, and therefore, the present invention is not limited to the restriction of following public specific embodiment.
Fig. 1 shows the schematic block diagram of predistorter control method according to an embodiment of the invention.
As shown in Figure 1, predistorter control method according to an embodiment of the invention, for carrying out pre-distortion by predistorter to the data source signal of unbalanced input device, wherein said predistorter control method comprises: step 102, time determining step, determine section update time, wherein, described update time, the length of section was greater than length computing time utilizing the nonlinear distortion situation of the output signal of described non-linear device to calculate corresponding cost function, be less than the convergence time length of the update algorithm of the unit carrying out the computing of pre-distortion coefficients adaptive updates, step 104, characteristic determining step, obtains the state parameter variation characteristic of the output signal of described non-linear device, step 106, upgrades determining step, and when the state parameter of the output signal of described non-linear device is less than or equal to default variable quantity threshold value at the variable quantity in described update time section, Predicated execution is to the renewal of pre-distortion coefficients, step 108, coefficient provides step, when the renewal of Predicated execution to pre-distortion coefficients, the unit pre-distortion coefficients that section calculates in described update time of carrying out the computing of pre-distortion coefficients adaptive updates is supplied to described predistorter.
In this technical scheme, due to when calculating pre-distortion coefficients, only needing real-time calculation cost function, thus only needing to make the length of section update time be greater than the computing time of this cost function, then without the need to waiting for the convergence of update algorithm, the renewal to pre-distortion coefficients can be realized.In other words, the time period (i.e. the time period of algorithmic statement) being now in fact equivalent to coefficient of first order to upgrade divides the time period in order to repeatedly coefficient update, thus coefficient update does not need to wait for that algorithmic statement just can realize each time, its in fact required condition is more easily met, even if perform power fast to power amplifier to control, but if the computing time of cost function can be greater than guaranteed output stable time period (when namely power variation is less than default variable quantity threshold value), the renewal to pre-distortion coefficients can be completed.
Particularly, non-linear device can be power amplifier, and the state parameter of the output signal of non-linear device can be the power of this output signal or the bias voltage of this non-linear device.
In technique scheme, preferably, described renewal determining step also comprises: when the state parameter of the output signal of described non-linear device is greater than described variable quantity threshold value at the variable quantity in described update time section, judge the renewal do not performed pre-distortion coefficients, or the pre-distortion coefficients obtaining pre-stored is supplied to described predistorter.
In this technical scheme, the reasons such as the execution due to TPC or the environmental factor based on external condition, may there is more violent numerical fluctuations in the state parameter of the output signal of non-linear device, now cannot perform the real-time update to pre-distortion coefficients.In the scenario above, a kind of mode is not for perform renewal; Another kind of mode is use the pre-distortion coefficients of pre-stored to upgrade, thus contributes to the performance under extreme conditions improving non-linear device.
In above-mentioned arbitrary technical scheme, preferably, described time determining step also comprises: when determining that the output signal of described non-linear device to carry out the state parameter change of known variant amount according to known period of change, determine described update time section and described known period of change between relativeness.
In this technical scheme, when the Changing Pattern of the output signal of non-linear device is known, then based on this Changing Pattern, concrete section update time can be determined.Such as the TPC under WCDMA network is controlled, its TPC cycle is 0.667ms, then can at first time with regard to the relativeness in config update time period and this TPC cycle, the start time of section update time is such as made to overlap with the start time in TPC cycle, or the finish time of section update time was overlapped with the finish time in TPC cycle, thus contribute to the management of the renewal process to pre-distortion coefficients.
In above-mentioned arbitrary technical scheme, preferably, described characteristic determining step comprises: the state parameter detecting the output signal of described non-linear device, to determine the state parameter variation characteristic of the output signal of described non-linear device; Or detection corresponds to the state parameter of the index signal of the output signal of described non-linear device, and using the state parameter variation characteristic of the state parameter variation characteristic of described index signal as the output signal of described non-linear device; Or carry out changing the adjustment control command controlled according to the state parameter for the output signal to described non-linear device, estimate the state parameter variation characteristic of the output signal of described non-linear device.
In this technical scheme, there is various ways in the acquisition for the state parameter of the output signal of described non-linear device, as several specific embodiment, can comprise: first kind of way, directly the state parameter of the output signal of non-linear device is measured, obtain its variable quantity in Preset Time (as the unit interval) (i.e. variation characteristic); The second way, measure the index signal of the output signal corresponding to non-linear device, such as before non-linear device, also comprise VGA(Variable gainattenuator, variable power attenuator), then can measure the signal that VGA exports to non-linear device, and using the variable quantity of the variable quantity of the state parameter of this signal as the state parameter of the output signal of non-linear device; The third mode, because TPC process is all undertaken controlling by concrete TPC signal (namely adjusting control command), thus can directly TPC signal be obtained and be analyzed, and wish the regulative mode of execution according to it, estimate the variable quantity of the state parameter of the output signal of non-linear device.
In above-mentioned arbitrary technical scheme, preferably, also comprise: parameters acquiring procedure, the output signal obtaining described non-linear device is at the state parameter of section correspondence described update time, described coefficient provides step also to comprise: for the current state parameter that section is acquired in current update time, there is the historic state parameter stored matched, then obtain further corresponding history pre-distortion coefficients and the historic state information relevant to described update algorithm of carrying out the unit of pre-distortion coefficients adaptive updates computing, to upgrade described history pre-distortion coefficients and described historic state information by the described unit carrying out the computing of pre-distortion coefficients adaptive updates, and the history pre-distortion coefficients after upgrading is supplied to described predistorter, if do not exist, then preset constant is supplied to described predistorter as pre-distortion coefficients, or the new pre-distortion coefficients that the described unit carrying out the computing of pre-distortion coefficients adaptive updates calculates is supplied to described predistorter, and by described new pre-distortion coefficients, the state information that described new pre-distortion coefficients is corresponding, and described current state parameter association store is corresponding historical data.
In this technical scheme, by pre-distortion coefficients, state information, state parameter are carried out association store, achieve and calculate new pre-distortion coefficients by historical data, the causality regulated before and after ensure that and continuity, and finally realize the performance improvement to non-linear device.
Fig. 2 shows the schematic flow diagram of predistorter control device according to an embodiment of the invention.
As shown in Figure 2, predistorter control device 200 according to an embodiment of the invention, for carrying out pre-distortion by predistorter to the data source signal of unbalanced input device, wherein said predistorter control device 200 comprises: time determination module 202, determine section update time, wherein, described update time, the length of section was greater than length computing time utilizing the nonlinear distortion situation of the output signal of described non-linear device to calculate corresponding cost function, be less than the convergence time length of the update algorithm of the unit carrying out the computing of pre-distortion coefficients adaptive updates, characteristic determination module 204, obtains the state parameter variation characteristic of the output signal of described non-linear device, upgrade judge module 206, when the state parameter of the output signal of described non-linear device is less than or equal to default variable quantity threshold value at the variable quantity in described update time section, Predicated execution is to the renewal of pre-distortion coefficients, coefficient provides module 208, when the renewal of Predicated execution to pre-distortion coefficients, the unit pre-distortion coefficients that section calculates in described update time of carrying out the computing of pre-distortion coefficients adaptive updates is supplied to described predistorter.
In this technical scheme, due to when calculating pre-distortion coefficients, only needing real-time calculation cost function, thus only needing to make the length of section update time be greater than the computing time of this cost function, then without the need to waiting for the convergence of update algorithm, the renewal to pre-distortion coefficients can be realized.In other words, the time period (i.e. the time period of algorithmic statement) being now in fact equivalent to coefficient of first order to upgrade divides the time period in order to repeatedly coefficient update, thus coefficient update does not need to wait for that algorithmic statement just can realize each time, its in fact required condition is more easily met, even if perform power fast to power amplifier to control, but if the computing time of cost function can be greater than guaranteed output stable time period (when namely power variation is less than default variable quantity threshold value), the renewal to pre-distortion coefficients can be completed.
Particularly, non-linear device can be power amplifier, and the state parameter of the output signal of non-linear device can be the power of this output signal or the bias voltage of this non-linear device.
In technique scheme, preferably, described renewal judge module 206 also for: when the state parameter of the output signal of described non-linear device is greater than described variable quantity threshold value at the variable quantity in described update time section, judge the renewal do not performed pre-distortion coefficients, or the pre-distortion coefficients obtaining pre-stored is supplied to described predistorter.
In this technical scheme, the reasons such as the execution due to TPC or the environmental factor based on external condition, may there is more violent numerical fluctuations in the state parameter of the output signal of non-linear device, now cannot perform the real-time update to pre-distortion coefficients.In the scenario above, a kind of mode is not for perform renewal; Another kind of mode is use the pre-distortion coefficients of pre-stored to upgrade, thus contributes to the performance under extreme conditions improving non-linear device.
In above-mentioned arbitrary technical scheme, preferably, described time determination module 202 also for: when determine the output signal of described non-linear device according to known period of change carry out known variant amount state parameter change time, determine the relativeness between described non-renewable phase and described known period of change.
In this technical scheme, when the Changing Pattern of the output signal of non-linear device is known, then based on this Changing Pattern, concrete section update time can be determined.Such as the TPC under WCDMA network is controlled, its TPC cycle is 0.667ms, then can at first time with regard to the relativeness in config update time period and this TPC cycle, the start time of section update time is such as made to overlap with the start time in TPC cycle, or the finish time of section update time was overlapped with the finish time in TPC cycle, thus contribute to the management of the renewal process to pre-distortion coefficients.
In above-mentioned arbitrary technical scheme, preferably, described characteristic determination module 204 also for the state parameter detecting the output signal of described non-linear device, determining the state parameter variation characteristic of the output signal of described non-linear device; Or detection corresponds to the state parameter of the index signal of the output signal of described non-linear device, and using the state parameter variation characteristic of the state parameter variation characteristic of described index signal as the output signal of described non-linear device; Or carry out changing the adjustment control command controlled according to the state parameter for the output signal to described non-linear device, estimate the state parameter variation characteristic of the output signal of described non-linear device.
In this technical scheme, there is various ways in the acquisition for the state parameter of the output signal of described non-linear device, as several specific embodiment, can comprise: first kind of way, directly the state parameter of the output signal of non-linear device is measured, obtain its variable quantity in Preset Time (as the unit interval) (i.e. variation characteristic); The second way, measure the index signal of the output signal corresponding to non-linear device, such as before non-linear device, also comprise VGA(Variable gainattenuator, variable power attenuator), then can measure the signal that VGA exports to non-linear device, and using the variable quantity of the variable quantity of the state parameter of this signal as the state parameter of the output signal of non-linear device; The third mode, because TPC process is all undertaken controlling by concrete TPC signal (namely adjusting control command), thus can directly TPC signal be obtained and be analyzed, and wish the regulative mode of execution according to it, estimate the variable quantity of the state parameter of the output signal of non-linear device.
In above-mentioned arbitrary technical scheme, preferably, also comprise: parameter acquisition module 210, the output signal obtaining described non-linear device is at the state parameter of section correspondence described update time, wherein, described coefficient provide module also for: for the current state parameter that section is acquired in current update time, if there is the historic state parameter stored matched, then obtain further corresponding history pre-distortion coefficients and the historic state information relevant to described update algorithm of carrying out the unit of pre-distortion coefficients adaptive updates computing, to upgrade described history pre-distortion coefficients and described historic state information by the described unit carrying out the computing of pre-distortion coefficients adaptive updates, and the history pre-distortion coefficients after upgrading is supplied to described predistorter, if do not exist, then preset constant is supplied to described predistorter as pre-distortion coefficients, or the new pre-distortion coefficients that the described unit carrying out the computing of pre-distortion coefficients adaptive updates calculates is supplied to described predistorter, and by described new pre-distortion coefficients, the state information that described new pre-distortion coefficients is corresponding, and described current state parameter association store is corresponding historical data.
In this technical scheme, by pre-distortion coefficients, state information, state parameter are carried out association store, achieve and calculate new pre-distortion coefficients by historical data, the causality regulated before and after ensure that and continuity, and finally realize the performance improvement to non-linear device.
Fig. 3 shows the structural representation carrying out the power amplification system of pre-distortion coefficients renewal based on output signal power according to an embodiment of the invention.
As shown in Figure 3, from the data source signal of data source 302 after predistorter 304, obtain the signal after predistortion, this signal is converted to analog signal by digital-to-analogue (D/A) transducer 306.This analog signal is after upconverter 308 frequency up-converted is radiofrequency signal, input variable gain attenuator (VGA) 310, to carry out after gain-adjusted input power amplifier 312 again through VGA310, the signal after power amplifier 312 amplifies sends through antenna (not shown).
Meanwhile, a part of signal that power amplifier 312 exports feeds back to analog to digital converter 316 after low-converter 314 down-conversion, and the power amplifier obtaining feeding back after analog to digital converter 316 is sampled exports digital baseband signal.In out-of-band power computing unit 318, utilize Digital Signal Processing to analyze this baseband signal, the out-of-band power value of this digital baseband signal can be obtained.Then in predistorter coefficient update unit 320, out-of-band power value is optimized as cost function, utilizes update algorithm to calculate pre-distortion coefficients, to upgrade the coefficient of predistorter, thus realize self-adapted pre-distortion process.
Except said structure and treatment step, the application also added RSSI(Received SignalStrength Indication, received signal strength indicator) acquiring unit 322A, coefficient memory units 324 and renewal state variable memory cell 326, wherein:
RSSI acquiring unit 322A is used for directly measuring the output signal of power amplifier 312, with the situation of change of the power and power that obtain this output signal.
The pre-distortion coefficients that coefficient memory units 324 generates in history for storing predistorter system update unit 320, and the power of the output signal of the power amplifier 312 these pre-distortion coefficients and RSSI acquiring unit 322A obtained carries out association store.
As shown in Figure 4, according to one embodiment of present invention, obtain the curve chart of the changed power of the output signal of power amplifier 312.Wherein, assuming that be divided into 5 power grades, be respectively P1, P2, P3, P4 and P5, then correspond to the current corresponding power grade of output signal of power amplifier 312, need to generate corresponding pre-distortion coefficients, for predistorter, digital pre-distortion process is carried out to data source signal.
When for equal-wattage grade, the calculating of current pre-distortion coefficients needs to depend on other the one or more pre-distortion coefficients being in same power grade in history, such as in the diagram, p1 grade is corresponded to Deng all, and for calculating may need to depend on or with deng, for calculating may need to depend on or with deng (for the pre-distortion coefficients of other power grades shown in Fig. 4 and correspondence, with P1 and deng relation identical, repeat no more).Therefore, need the pre-distortion coefficients that will calculate in history, the pre-distortion coefficients used in the computational process of the pre-distortion coefficients especially below, may be needed, carry out association store with corresponding power grade.
Particularly, when performing the association store of power grade and pre-distortion coefficients, mode as shown in Figure 5 can be adopted: on the horizontal scale with power grade (P1, P2......Pi etc.) for independent variable, on the vertical scale with the pre-distortion coefficients calculated in history ( deng) be variable, form coordinate system or form.Wherein, corresponding to the pre-distortion coefficients of each power grade, the pre-distortion coefficients calculated assuming that current is then calculate exactly required history pre-distortion coefficients, and the numerical value of k is determined by the update algorithm specifically used, such as in one case, preferably, k=3.
Meanwhile, although have employed in Fig. 5 the pre-distortion coefficients corresponding when representing that power grade is Pi of form, but have more than is represent some pre-distortion coefficients, but all pre-distortion coefficients when to represent corresponding to power grade be Pi, namely the number of the pre-distortion coefficients that same power grade is corresponding can be one or more, such as in one case, preferably, each power grade corresponds to 5 pre-distortion coefficients, namely be specifically as follows or and all store corresponding to this power grade.
It should be noted that, although multiple pre-distortion coefficients can be represented, but in once " coefficient updating operation " of each foundation performed by a cost function, can only upgrade one of them pre-distortion coefficients, and in t namely represent current need perform upgrade pre-distortion coefficients which is specially, such as when representative or deng 5 pre-distortion coefficients time, may be current only to wherein such as upgrade.Certainly, if there is the time period of a longer power stability, make it possible to multiple cost functions that Continuous plus obtains corresponding to current power level, then can upgrade multiple pre-distortion coefficients of present level respectively, be equivalent to continuous several times and perform above-mentioned " coefficient updating operation ".
Upgrade state variable memory cell 326 for storing the state variable used when predistorter system update unit 320 generates pre-distortion coefficients in history, and the power of the output signal of the power amplifier 312 these state variables and RSSI acquiring unit 322A obtained carries out association store.
Particularly, when performing the association store of power grade and state variable, mode as shown in Figure 6 can be adopted: on the horizontal scale with power grade (P1, P2......Pi etc.) for independent variable, the state variable (S used time on the vertical scale to calculate pre-distortion coefficients in history 1.n-k, S 1.n-k+1... S i.ndeng) be variable, form coordinate system or form.Wherein, Fig. 5 with Fig. 6 is carried out associating when checking known: be actually by under each power grade, each pre-distortion coefficients of calculating and calculate this pre-distortion coefficients time the state variable that uses carry out association store, namely P1, s 1.n-kbe associated, P1, s 1.n-k+1be associated ... P2, s 2.n-kbe associated ... Pi, s i.nbe associated.
Further, although in Fig. 6 and foregoing description, with " S i.n" specifically represent calculating time the state variable that uses, but in fact, " S i.n" one or more concrete state variable may be comprised, especially when relating to the polynomial computation comprising multiple coefficient, or relate to the situation such as substep or interative computation of multiple step.Such as when comprising step in renewal computing, concrete example is as two steps, then this state variable can comprise: 1, indicate current state variable to belong to which calculation step; 2, the concrete state variable corresponding to the calculating process of pre-distortion coefficients; 3, the concrete state variable etc. corresponding to the calculating process of cost function.Certainly, for in multiple pre-distortion coefficients of comprising, when upgrading each pre-distortion coefficients, its corresponding state variable S used i.ncan be identical, thus can be multiplexing between this multiple pre-distortion coefficients; Certainly, state variable S i.nalso can not be multiplexing, then when calculating different pre-distortion coefficients, adopt different state variable (as or deng), to obtaining pre-distortion coefficients more accurately, thus realize better predistortion effect.
For the ease of understanding, below in conjunction with Fig. 7, a kind of concrete pre-distortion coefficients update algorithm being applicable to the application is described in detail.
Above-mentioned pre-distortion coefficients update algorithm comprises two steps:
(1) step 1, by the nonlinear distortion situation of the output signal of acquisition, calculates corresponding cost function, with the relation forming curves between this cost function and pre-distortion coefficients, and this this curve obtains a recessed interval.
The operating process of step 1 specifically with reference to shown in Fig. 7 (a), Fig. 7 (b) He Fig. 7 (c), can comprise:
1) supposition is starting point with x0, searches for the recessed interval of cost function f (x).
2) first can upgrade x1=x0+L(wherein along positive direction, L, for upgrading step-length, can be that fix or variable), and compare the numerical value of f (x1) and f (x0).
As shown in Figure 7 (a), as f (x1) > f (x0), the descending branch being now in recessed interval is then described, namely the not yet minimal point (end in recessed interval) in " arrival " recessed interval, then need to continue to upgrade forward, and make x2=x1+L, then compare the numerical value of f (x2) and f (x1).
As shown in Fig. 7 (b) He Fig. 7 (c), as f (x1) < f (x0), the ascent stage being now in recessed interval is then described, namely " in advance " minimal point in recessed interval, then need to upgrade backward, and make x2=x0-L, then compare the numerical value of f (x2) and f (x0).
3) above-mentioned steps is repeated, until finally find a minimum coefficient interval [α, β], and meet: f (α) > f (α+L) > f (β), or f (α) < f (α+L) < f (β), wherein β=α+2L.
(2) step 2, by the adjustment to pre-distortion coefficients, finally to make cost function close to the minimum value in this recessed interval as much as possible.
The operating process of step 2 specifically comprises:
1) by calculating and value of some point in the interval (such as interval [α, β]) comprising minimal point that obtains in step 1 of comparison function, the less interval comprising minimal point is obtained.
Suppose that f (x) is the unimodal function on interval [α, β], appoint and get x1, x2 ∈ [α, β], and meet x1 < x2.As f (x1) < f (x2), between new district [α ', β ']=[α, x2]; As f (x1) > f (x2), between new district [α ', β ']=[x1, β]; As f (x1)=f (x2), between new district [α ', β ']=[x1, x2].
2) because the minimal point of f (x) on [α, β] must be included in [α ', β '], thus by constantly updating x1, x2, interval is constantly shortened, then finally approaches minimal point, also just achieve the convergence of the update algorithm to pre-distortion coefficients.
Certainly, based on RSSI acquiring unit 322A directly to the mode that signal power is measured, except the power of the output signal of the detection power amplifier 312 shown in Fig. 3, also other modes can be adopted, than mode as shown in Figure 8.
Fig. 8 shows the structural representation carrying out the power amplification system of pre-distortion coefficients renewal based on output signal power according to another embodiment of the invention, wherein, RSSI acquiring unit 322A specifically obtains the power of VGA310 for the signal of input power amplifier 312.Gain due to power amplifier 312 is fixing or known, and the magnitude of power therefore obtained in the manner described above, can reflect the power condition of the output signal of power amplifier 312 equally.
In addition, due in the related, realize controlling the TPC of power amplification system often by sending concrete TPC instruction, thus RSSI acquiring unit 322A also can not directly measure the power of output signal, but based on the detection to TPC instruction, be concrete power adjustments numerical value by TPC command mappings, and it wishes the control object of execution and the effect after controlling based on this power adjustments numerical prediction, thus determine the situation after the contingent change of the power of the output signal of power amplifier 312 and/or change.
Certainly, no matter adopt the mode shown in Fig. 3, Fig. 8 or Fig. 9, its concrete coefficient update process and the storage mode etc. to pre-distortion coefficients, state variable etc., be in fact all identical, repeat no more herein.
Figure 10 shows the structural representation that the bias voltage based on power amplifier according to an embodiment of the invention carries out the power amplification system of pre-distortion coefficients renewal.
As shown in Figure 10, be different from the technical scheme shown in Fig. 3, Fig. 8 and Fig. 9, the numerical value of the bias voltage of power amplifier 312 is specifically have employed in the technical program, to replace the numerical value of the power in technique scheme, particularly, the numerical value of this bias voltage directly to be measured the bias voltage of power amplifier 312 by bias voltage acquiring unit 322B and is obtained.
Therefore, in the technical scheme shown in Figure 10, the pre-distortion coefficients that predistorter coefficient update unit 320 is calculated and the state variable used when calculating this pre-distortion coefficients, the numerical value of the bias voltage obtained with bias voltage acquiring unit 322B measurement is needed to carry out association store, for calculating and the renewal of the pre-distortion coefficients under different bias voltage.
As is illustrated by figs. 11 and 12, wherein, Figure 11 is the middle schematic diagram storing pre-distortion coefficients according to bias voltage embodiment illustrated in fig. 10 to concrete storage mode; Figure 12 is the middle schematic diagram according to state variable needed for bias voltage storage update algorithm embodiment illustrated in fig. 10.
First, the mode be similar to shown in Fig. 4 can be adopted, the numerical value of the bias voltage of power amplifier 312 is divided into multiple electric pressure, than V1, V2......Vj etc. as shown in figure 11.
Based on above-mentioned electric pressure, then when performing the association store of electric pressure and pre-distortion coefficients, mode as shown in figure 11 can be adopted: on the horizontal scale with electric pressure (V1, V2......Vj etc.) for independent variable, on the vertical scale with the pre-distortion coefficients calculated in history ( deng) be variable, form coordinate system or form.Wherein, corresponding to the pre-distortion coefficients of each power grade, the pre-distortion coefficients calculated assuming that current is then calculate exactly required history pre-distortion coefficients, and the numerical value of k is determined by the update algorithm specifically used, such as in one case, preferably, k=3.
Meanwhile, although have employed in Figure 11 the pre-distortion coefficients corresponding when representing that electric pressure is Vj of form, but have more than is represent some pre-distortion coefficients, but all pre-distortion coefficients when to represent corresponding to electric pressure be Vj, namely the number of the pre-distortion coefficients that same power grade is corresponding can be one or more, such as in one case, preferably, each electric pressure corresponds to 5 pre-distortion coefficients, namely be specifically as follows or and all store corresponding to this electric pressure.
It should be noted that, although multiple pre-distortion coefficients can be represented, but in once " coefficient updating operation " of each foundation performed by a cost function, can only upgrade one of them pre-distortion coefficients, and in t namely represent current need perform upgrade pre-distortion coefficients which is specially, such as when representative or deng 5 pre-distortion coefficients time, may be current only to wherein such as upgrade.Certainly, if there is the time period of a longer power stability, make it possible to multiple cost functions that Continuous plus obtains corresponding to current power level, then can upgrade multiple pre-distortion coefficients of present level respectively, be equivalent to continuous several times and perform above-mentioned " coefficient updating operation ".
Simultaneously, when performing the association store of electric pressure and state variable, mode as shown in figure 12 can be adopted: on the horizontal scale with electric pressure (V1, V2......Vj etc.) for independent variable, the state variable (S used time on the vertical scale to calculate pre-distortion coefficients in history 1.n-k, S 1.n-k+1... S j.ndeng) be variable, form coordinate system or form.Wherein, Figure 11 with Figure 12 is carried out associating when checking known: be actually by under each electric pressure, each pre-distortion coefficients of calculating and calculate this pre-distortion coefficients time the state variable that uses carry out association store, namely V1, s 1.n-kbe associated, V1, s 1.n-k+1be associated ... V2, s 2.n-kbe associated ... Vj, s j.nbe associated.
Further, although in Figure 12 and foregoing description, with " S j.n" specifically represent calculating time the state variable that uses, but in fact, " S j.n" one or more concrete state variable may be comprised, especially when relating to the polynomial computation comprising multiple coefficient, or relate to the situation such as substep or interative computation of multiple step.Such as when comprising step in renewal computing, concrete example is as two steps, then this state variable can comprise: 1, indicate current state variable to belong to which calculation step; 2, the concrete state variable corresponding to the calculating process of pre-distortion coefficients; 3, the concrete state variable etc. corresponding to the calculating process of cost function.Certainly, for in multiple pre-distortion coefficients of comprising, when upgrading each pre-distortion coefficients, its corresponding state variable S used i.ncan be identical, thus can be multiplexing between this multiple pre-distortion coefficients; Certainly, state variable S i.nalso can not be multiplexing, then when calculating different pre-distortion coefficients, adopt different state variable (as or deng), to obtaining pre-distortion coefficients more accurately, thus realize better predistortion effect.
Due in the related, relation between the bias voltage of the power of the output signal of power amplifier 312 and power amplifier 312 self can be (certain for what associate, also can not associate), thus bias voltage acquiring unit 322B also can not directly measure the bias voltage of power amplifier 312, but based on the detection to TPC instruction, be concrete power adjustments numerical value by TPC command mappings, and based on the incidence relation between power and bias voltage, thus determine the situation after the contingent change of the bias voltage of power amplifier 312 and/or change.
Certainly, no matter adopt the mode shown in Figure 10 or Figure 13, its concrete coefficient update process and the storage mode etc. to pre-distortion coefficients, state variable etc., be in fact all identical, repeat no more herein.
Figure 14 shows the structural representation that the bias voltage based on output signal power and power amplifier according to an embodiment of the invention carries out the power amplification system of pre-distortion coefficients renewal.
Based on Fig. 3 to Fig. 9, the application is specifically described and is obtained by the power parameter of the output signal to power amplifier 312, for the technical scheme of the concrete renewal computing of pre-distortion coefficients, and specifically describe how based on power grade, to the pre-distortion coefficients calculated and upgrade state variable and carry out association store.
Based on Figure 10 to Figure 13, the application specifically describes by obtaining the bias voltage of power amplifier 312, for the technical scheme of the concrete renewal computing of pre-distortion coefficients, and specifically describe how based on electric pressure, to the pre-distortion coefficients calculated and upgrade state variable and carry out association store.
Based on above-mentioned two kinds of different situations, upgrade computing to reach pre-distortion coefficients more accurately, can also while carry out pre-distortion coefficients renewal based on the power of the output signal of power amplifier 312 and the bias voltage of power amplifier 312.
Specifically as shown in figure 14, in this technical scheme, respectively by RSSI acquiring unit 322A and bias voltage acquiring unit 322B, the power of the output signal of power amplifier 312 and the bias voltage of power amplifier 312 can be obtained.
For the magnitude of power got and bias voltage numerical value, according to technique scheme, grade classification can be carried out to it, thus obtain concrete power grade and bias voltage level.Therefore, after executing the collection to power and bias voltage at every turn, the power grade simultaneously corresponding according to it and electric pressure, pre-distortion coefficients and the state variable of corresponding stored can be obtained respectively, for current state variable and pre-distortion coefficients computing from coefficient memory units 324, renewal state variable memory cell 326.
Owing to corresponding to power grade and electric pressure simultaneously, thus three-dimensional system of coordinate as shown in Figure 15 and Figure 16 or three-dimensional table can be set up, wherein, Figure 15 be embodiment illustrated in fig. 14 middle while carry out storing the schematic diagram of pre-distortion coefficients according to power and bias voltage; Figure 16 for embodiment illustrated in fig. 14 middle while to carry out the schematic diagram of state variable needed for storage update algorithm according to power and bias voltage.
Based on being similar to the power grade of P1, P2......Pi and being similar to the electric pressure of V1, V2......Vj, as shown in figure 15, when performing the association store of power grade, electric pressure and pre-distortion coefficients, can adopt: on the first coordinate with power grade (P1, P2......Pi etc.) for independent variable, on the second coordinate with electric pressure (V1, V2......Vj etc.) for independent variable, in three-dimensional with the pre-distortion coefficients that history calculates ( deng) be variable, form three-dimensional system of coordinate or three-dimensional table.Wherein, corresponding to the pre-distortion coefficients of each power grade and electric pressure, the pre-distortion coefficients calculated assuming that current is then calculate exactly required history pre-distortion coefficients, and the numerical value of k is determined by the update algorithm specifically used, such as in one case, preferably, k=3.
Certainly, although have employed in Figure 15 the pre-distortion coefficients corresponding when representing that power grade is Pi, electric pressure is Vj of form, but have more than is represent some pre-distortion coefficients, but represent corresponding to power grade be Pi, electric pressure be Vj time all pre-distortion coefficients, namely the number of same power grade and pre-distortion coefficients corresponding to electric pressure can be one or more, such as in one case, preferably, each power grade and electric pressure correspond to 5 pre-distortion coefficients, namely be specifically as follows or and all store corresponding to current power grade and electric pressure.
It should be noted that, although multiple pre-distortion coefficients can be represented, but in once " coefficient updating operation " of each foundation performed by a cost function, can only upgrade one of them pre-distortion coefficients, and in t namely represent current need perform upgrade pre-distortion coefficients which is specially, such as when representative or deng 5 pre-distortion coefficients time, may be current only to wherein such as upgrade.Certainly, if there is the time period of a longer power stability, make it possible to multiple cost functions that Continuous plus obtains corresponding to current power level, then can upgrade multiple pre-distortion coefficients of present level respectively, be equivalent to continuous several times and perform above-mentioned " coefficient updating operation ".
Simultaneously, when performing the association store of power grade, electric pressure and state variable, mode as shown in figure 16 can be adopted: on the first coordinate with power grade (P1, P2......Pi etc.) for independent variable, on the second coordinate with electric pressure (V1, V2......Vj etc.) for independent variable, the state variable (S used time in three-dimensional history to calculate pre-distortion coefficients 1.1.n-k, S 1.1.n- k+1... S i.j.ndeng) be variable, form coordinate system or form.Wherein, Figure 15 with Figure 16 is carried out associating when checking known: be actually by under each power grade and electric pressure, each pre-distortion coefficients of calculating and calculate this pre-distortion coefficients time the state variable that uses carry out association store, namely P1, V1, s 1.1.n-kbe associated, P1, V1, s 1.1.n-k+1be associated ... P1, V2, s 1.2.n-k+1be associated ... Pi, Vj, s i.j.nbe associated.
Further, although in Figure 16 and foregoing description, with " S i.j.n" specifically represent calculating time the state variable that uses, but in fact, " S i.j.n" one or more concrete state variable may be comprised, especially when relating to the polynomial computation comprising multiple coefficient, or relate to the situation such as substep or interative computation of multiple step.Such as when comprising step in renewal computing, concrete example is as two steps, then this state variable can comprise: 1, indicate current state variable to belong to which calculation step; 2, the concrete state variable corresponding to the calculating process of pre-distortion coefficients; 3, the concrete state variable etc. corresponding to the calculating process of cost function.Certainly, for in multiple pre-distortion coefficients of comprising, when upgrading each pre-distortion coefficients, its corresponding state variable S used i.ncan be identical, thus can be multiplexing between this multiple pre-distortion coefficients; Certainly, state variable S i.nalso can not be multiplexing, then when calculating different pre-distortion coefficients, adopt different state variable (as or deng), to obtaining pre-distortion coefficients more accurately, thus realize better predistortion effect.
More than be described with reference to the accompanying drawings technical scheme of the present invention, consider in correlation technique, in the time period must restrained in the update algorithm of pre-distortion coefficients, when the changed power of the output signal of power amplifier is all less, the renewal of pre-distortion coefficients can be realized, this in practical situations both, sometimes be difficult to or even may do not realize, such as WCDMA network needs every 0.667ms to change 3dB, then cannot reach above-mentioned condition, also the renewal of pre-distortion coefficients cannot be realized, therefore, the invention provides a kind of predistorter control method and a kind of predistorter control device, the renewal to pre-distortion coefficients can be completed at short notice, and without the need to waiting for the convergence of update algorithm, improve the possibility of coefficient update, thus effectively improve the performance of power amplifier.
The foregoing is only the preferred embodiments of the present invention, be not limited to the present invention, for a person skilled in the art, the present invention can have various modifications and variations.Within the spirit and principles in the present invention all, any amendment done, equivalent replacement, improvement etc., all should be included within protection scope of the present invention.

Claims (10)

1. a predistorter control method, for carrying out pre-distortion by predistorter to the data source signal of unbalanced input device, wherein said predistorter control method comprises:
Time determining step, determine section update time, wherein, described update time section length be greater than and utilize the nonlinear distortion situation of the output signal of described non-linear device to calculate length computing time of corresponding cost function, be less than the convergence time length of the update algorithm of the unit carrying out the computing of pre-distortion coefficients adaptive updates;
Characteristic determining step, obtains the state parameter variation characteristic of the output signal of described non-linear device;
Upgrade determining step, when the state parameter of the output signal of described non-linear device is less than or equal to default variable quantity threshold value at the variable quantity in described update time section, Predicated execution is to the renewal of pre-distortion coefficients;
Coefficient provides step, when the renewal of Predicated execution to pre-distortion coefficients, the unit pre-distortion coefficients that section calculates in described update time of carrying out the computing of pre-distortion coefficients adaptive updates is supplied to described predistorter.
2. predistorter control method according to claim 1, described renewal determining step also comprises:
When the state parameter of the output signal of described non-linear device is greater than described variable quantity threshold value at the variable quantity in described update time section, judge the renewal do not performed pre-distortion coefficients, or the pre-distortion coefficients obtaining pre-stored is supplied to described predistorter.
3. predistorter control method according to claim 1, described time determining step also comprises:
When determining that the output signal of described non-linear device to carry out the state parameter change of known variant amount according to known period of change, determine described update time section and described known period of change between relativeness.
4. predistorter control method according to any one of claim 1 to 3, described characteristic determining step comprises:
Detect the state parameter of the output signal of described non-linear device, to determine the state parameter variation characteristic of the output signal of described non-linear device;
Or detection corresponds to the state parameter of the index signal of the output signal of described non-linear device, and using the state parameter variation characteristic of the state parameter variation characteristic of described index signal as the output signal of described non-linear device;
Or carry out changing the adjustment control command controlled according to the state parameter for the output signal to described non-linear device, estimate the state parameter variation characteristic of the output signal of described non-linear device.
5. predistorter control method according to claim 4, also comprises:
Parameters acquiring procedure, the output signal obtaining described non-linear device is at the state parameter of section correspondence described update time;
Described coefficient provides step also to comprise: for the current state parameter that section is acquired in current update time,
If there is the historic state parameter stored matched, then obtain further corresponding history pre-distortion coefficients and the historic state information relevant to described update algorithm of carrying out the unit of pre-distortion coefficients adaptive updates computing, to upgrade described history pre-distortion coefficients and described historic state information by the described unit carrying out the computing of pre-distortion coefficients adaptive updates, and the history pre-distortion coefficients after upgrading is supplied to described predistorter
If do not exist, then preset constant is supplied to described predistorter as pre-distortion coefficients, or the new pre-distortion coefficients that the described unit carrying out the computing of pre-distortion coefficients adaptive updates calculates is supplied to described predistorter, and be corresponding historical data by state information corresponding to described new pre-distortion coefficients, described new pre-distortion coefficients and described current state parameter association store.
6. a predistorter control device, for carrying out pre-distortion by predistorter to the data source signal of unbalanced input device, wherein said predistorter control device comprises:
Time determination module, determine section update time, wherein, described update time section length be greater than and utilize the nonlinear distortion situation of the output signal of described non-linear device to calculate length computing time of corresponding cost function, be less than the convergence time length of the update algorithm of the unit carrying out the computing of pre-distortion coefficients adaptive updates;
Characteristic determination module, obtains the state parameter variation characteristic of the output signal of described non-linear device;
Upgrade judge module, when the state parameter of the output signal of described non-linear device is less than or equal to default variable quantity threshold value at the variable quantity in described update time section, Predicated execution is to the renewal of pre-distortion coefficients;
Coefficient provides module, when the renewal of Predicated execution to pre-distortion coefficients, the unit pre-distortion coefficients that section calculates in described update time of carrying out the computing of pre-distortion coefficients adaptive updates is supplied to described predistorter.
7. predistorter control device according to claim 6, described renewal judge module also for:
When the state parameter of the output signal of described non-linear device is greater than described variable quantity threshold value at the variable quantity in described update time section, judge the renewal do not performed pre-distortion coefficients, or the pre-distortion coefficients obtaining pre-stored is supplied to described predistorter.
8. predistorter control device according to claim 6, described time determination module also for: when determine the output signal of described non-linear device according to known period of change carry out known variant amount state parameter change time, determine the relativeness between described non-renewable phase and described known period of change.
9. the predistorter control device according to any one of claim 6 to 8, described characteristic determination module also for:
Detect the state parameter of the output signal of described non-linear device, to determine the state parameter variation characteristic of the output signal of described non-linear device;
Or detection corresponds to the state parameter of the index signal of the output signal of described non-linear device, and using the state parameter variation characteristic of the state parameter variation characteristic of described index signal as the output signal of described non-linear device;
Or carry out changing the adjustment control command controlled according to the state parameter for the output signal to described non-linear device, estimate the state parameter variation characteristic of the output signal of described non-linear device.
10. predistorter control device according to claim 9, also comprises:
Parameter acquisition module, the output signal obtaining described non-linear device is at the state parameter of section correspondence described update time;
Wherein, described coefficient provide module also for: for the current state parameter that section is acquired in current update time,
If there is the historic state parameter stored matched, then obtain further corresponding history pre-distortion coefficients and the historic state information relevant to described update algorithm of carrying out the unit of pre-distortion coefficients adaptive updates computing, to upgrade described history pre-distortion coefficients and described historic state information by the described unit carrying out the computing of pre-distortion coefficients adaptive updates, and the history pre-distortion coefficients after upgrading is supplied to described predistorter
If do not exist, then preset constant is supplied to described predistorter as pre-distortion coefficients, or the new pre-distortion coefficients that the described unit carrying out the computing of pre-distortion coefficients adaptive updates calculates is supplied to described predistorter, and be corresponding historical data by state information corresponding to described new pre-distortion coefficients, described new pre-distortion coefficients and described current state parameter association store.
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CN107835140A (en) * 2017-10-24 2018-03-23 东南大学 The digital pre-distortion system and its method of biobelt power amplifier are sent out altogether
CN108449096A (en) * 2018-03-26 2018-08-24 华南理工大学 A kind of pre-distortion method and system based on parallel-connection structure
CN111131104A (en) * 2019-12-12 2020-05-08 京信通信系统（中国）有限公司 Pre-distortion processing method, device, storage medium and equipment
CN112838996A (en) * 2020-12-31 2021-05-25 京信网络系统股份有限公司 Digital predistortion coefficient updating method, device, communication equipment and storage medium

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CN102480450A (en) * 2010-11-30 2012-05-30 富士通株式会社 Predistorter control device and method as well as power control state detection method

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CN102447441A (en) * 2010-09-30 2012-05-09 富士通株式会社 Power amplifying equipment and method for acquiring power regulation factor
CN102480450A (en) * 2010-11-30 2012-05-30 富士通株式会社 Predistorter control device and method as well as power control state detection method

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Publication number Priority date Publication date Assignee Title
CN107835140A (en) * 2017-10-24 2018-03-23 东南大学 The digital pre-distortion system and its method of biobelt power amplifier are sent out altogether
CN108449096A (en) * 2018-03-26 2018-08-24 华南理工大学 A kind of pre-distortion method and system based on parallel-connection structure
CN111131104A (en) * 2019-12-12 2020-05-08 京信通信系统（中国）有限公司 Pre-distortion processing method, device, storage medium and equipment
CN111131104B (en) * 2019-12-12 2022-12-06 京信网络系统股份有限公司 Pre-distortion processing method, device, storage medium and equipment
CN112838996A (en) * 2020-12-31 2021-05-25 京信网络系统股份有限公司 Digital predistortion coefficient updating method, device, communication equipment and storage medium
CN112838996B (en) * 2020-12-31 2022-03-25 京信网络系统股份有限公司 Digital predistortion coefficient updating method, device, communication equipment and storage medium

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