CN-113472300-B - Distortion compensation apparatus and method, computer-readable storage medium, and communication apparatus

CN113472300BCN 113472300 BCN113472300 BCN 113472300BCN-113472300-B

Abstract

The invention relates to a distortion compensation apparatus and method, a computer readable storage medium, and a communication apparatus. Provided is a distortion compensation apparatus that uses a distortion compensation model to perform distortion compensation on a signal to be amplified by an amplifier in which an internal state affecting distortion characteristics changes, wherein the distortion compensation model includes a plurality of calculation models having respective distortion compensation characteristics for the amplifier in different internal states, and a combiner that combines the plurality of calculation models at a combination ratio corresponding to the changed internal state.

Inventors

OHNISHI MASAHIKO
MOCHIDA EIJI

Assignees

住友电气工业株式会社
住友电气工业株式会社

Dates

Publication Date: 20260421
Application Date: 20210325
Priority Date: 20200330

Claims (16)

1. A distortion compensation apparatus that performs distortion compensation on a signal to be amplified by an amplifier using a distortion compensation model, an internal state of the amplifier that affects distortion characteristics being changed, wherein the distortion compensation model includes: a plurality of calculation models having respective distortion compensation characteristics for the amplifier in different internal states, and A combiner that combines the plurality of calculation models at a combination ratio corresponding to the changed internal state, wherein the combination ratio is dynamically changed, Wherein the combination ratio is based on parameters of the internal state, The distortion compensation characteristic of each of the plurality of calculation models has a characteristic for compensating for a first memory effect having a first response time in the amplifier, and A parameter calculation model for calculating the parameter of the internal state expresses a second memory effect in the amplifier having a second response time longer than the first response time.
2. The distortion compensation apparatus of claim 1, further comprising a generator that generates the parameter indicative of the internal state.
3. The distortion compensation apparatus of claim 2, wherein: Determining the combination ratio based on the parameter indicative of the internal state, and The parameter of the internal state is determined based on the level of the signal.
4. A distortion compensation apparatus according to claim 3, wherein the parameter of the internal state is determined further based on past values of the parameter of the internal state.
5. The distortion compensation apparatus according to any one of claims 1 to 4, wherein the combination ratio is calculated based on a level of the signal.
6. The distortion compensation apparatus according to any one of claims 1 to 4, wherein the combination ratio is calculated using a temperature-dependent parameter that changes depending on a temperature condition.
7. The distortion compensation apparatus of any of claims 1 to 4, wherein the plurality of calculation models are two calculation models.
8. The distortion compensation apparatus of any of claims 1 to 4, further comprising a selector, wherein: the plurality of computing models includes three or more computing models, and The selector is configured to select two or more calculation models to be combined by the combiner from among the three or more calculation models.
9. The distortion compensation device of claim 8, wherein the selector is configured to select the two or more calculation models based on a parameter indicative of the internal state.
10. The distortion compensation apparatus according to any one of claims 1 to 4, wherein The plurality of computing models includes: A first computational model having a first distortion compensation characteristic for the amplifier in a first internal state, A second calculation model having a second distortion compensation characteristic for the amplifier in a second internal state different from the first internal state, and The combination ratio has a value corresponding to a transitional internal state between the first internal state and the second internal state.
11. The distortion compensation apparatus according to any one of claims 1 to 4, wherein: The plurality of computing models includes: A first computational model having a first distortion compensation characteristic for the amplifier in a first internal state, A second calculation model having a second distortion compensation characteristic for the amplifier in a second internal state different from the first internal state, and A third calculation model having a third distortion compensation characteristic for the amplifier in a third internal state different from the first internal state and the second internal state, and The second internal state is an intermediate internal state between the first internal state and the third internal state.
12. The distortion compensation apparatus according to any one of claims 1 to 4, wherein: as the level of the input signal to the amplifier increases, the internal state is changed more greatly from an initial internal state, and as the level of the input signal decreases, the internal state is restored to the initial internal state over time, The plurality of computing models includes: a first computational model having a first distortion compensation characteristic for the amplifier in a first internal state; a second calculation model having a second distortion compensation characteristic for the amplifier in a second internal state different from the first internal state, The change from the initial internal state when in the second internal state is greater than the change from the initial internal state when in the first internal state, The first combination ratio is a combination ratio of the first computational model relative to a sum of the first computational model and the second computational model at a first time, A second combination ratio is a combination ratio of the first computational model relative to a sum of the first computational model and the second computational model at a second time subsequent to the first time, When the level of the input signal is zero at the first time, the second combination ratio is smaller than the first combination ratio, and The second combination ratio when the level of the input signal at the first time is a first level is greater than the second combination ratio when the level of the input signal at the first time is a second level that is less than the first level.
13. The distortion compensation apparatus of claim 12, wherein the second combination ratio is a sum of a first term that is less than the first combination ratio and a second term that increases as the level of the input signal increases at the first time.
14. A distortion compensation method for distortion compensating a signal to be amplified by an amplifier whose internal state affecting distortion characteristics is changed, comprising the steps of: A distortion compensation device combines a plurality of calculation models having respective distortion compensation characteristics for the amplifiers in different internal states at a combination ratio corresponding to the changed internal states, wherein the combination ratio is dynamically changed, Wherein the combination ratio is based on parameters of the internal state, The distortion compensation characteristic of each of the plurality of calculation models has a characteristic for compensating for a first memory effect having a first response time in the amplifier, and A parameter calculation model for calculating the parameter of the internal state expresses a second memory effect in the amplifier having a second response time longer than the first response time.
15. A non-transitory computer-readable storage medium storing a computer program for distortion compensation of a signal to be amplified by an amplifier whose internal state affecting distortion characteristics is changed, the computer program causing a computer to execute a process comprising: combining a plurality of calculation models having respective distortion compensation characteristics for the amplifiers in different internal states with a combination ratio corresponding to the changed internal states, wherein the combination ratio is dynamically changed, Wherein the combination ratio is based on parameters of the internal state, The distortion compensation characteristic of each of the plurality of calculation models has a characteristic for compensating for a first memory effect having a first response time in the amplifier, and A parameter calculation model for calculating the parameter of the internal state expresses a second memory effect in the amplifier having a second response time longer than the first response time.
16. A communication device, comprising: An amplifier amplifying a signal for communication, and A distortion compensation device that uses a distortion compensation model to perform distortion compensation on the signal, Wherein the amplifier is configured such that an internal state affecting the distortion characteristics is changed, Wherein the distortion compensation model comprises: A plurality of calculation models having respective distortion compensation characteristics for the amplifier in different internal states, an A combiner that combines the plurality of calculation models at a combination ratio corresponding to the changed internal state, wherein the combination ratio is dynamically changed, Wherein the combination ratio is based on parameters of the internal state, The distortion compensation characteristic of each of the plurality of calculation models has a characteristic for compensating for a first memory effect having a first response time in the amplifier, and A parameter calculation model for calculating the parameter of the internal state expresses a second memory effect in the amplifier having a second response time longer than the first response time.

Description

Distortion compensation apparatus and method, computer-readable storage medium, and communication apparatus Technical Field The present disclosure relates to a distortion compensation device, a distortion compensation method, a non-transitory computer-readable storage medium, and a communication device. Background The amplifier has a distortion characteristic. The distortion characteristics are also referred to as nonlinear characteristics. The distortion characteristic is represented by, for example, an AM-AM characteristic or an AM-PM characteristic. In the amplifier, an internal state affecting distortion characteristics may change. The internal state is a state such as generation of Idq drift, which is a phenomenon in which idle current Idq flowing through the amplifier changes. The generation of Idq drift changes the distortion characteristics of the amplifier. Idq drift is a phenomenon caused by the capture of carriers in impurity levels entering into semiconductors, and is caused in devices using compound semiconductors such as GaN, particularly in High Electron Mobility Transistors (HEMTs). The fluctuation of Idq drift changes the distortion characteristics of the amplifier. A method for compensating for distortion characteristics due to Idq drift is disclosed in japanese patent application laid-open nos. 2017-220744 and 2014-1770. Disclosure of Invention However, in distortion compensation of an amplifier for an internal state change affecting distortion characteristics, it is desirable to use distortion compensation characteristics corresponding to the changed internal state. Although patent documents 1 and 2 disclose a method for compensating for distortion characteristics due to Idq drift, a method for appropriately expressing distortion compensation characteristics corresponding to a changed internal state is not disclosed. Therefore, it is impossible to properly perform distortion compensation corresponding to the changed internal state. Accordingly, distortion compensation using distortion compensation characteristics corresponding to the changed internal state is desired. An aspect of the present disclosure is a distortion compensation apparatus. The distortion compensation apparatus of the present disclosure is a distortion compensation apparatus for distortion compensating a signal to be amplified by an amplifier in which an internal state affecting distortion characteristics is changed using a distortion compensation model, wherein the distortion compensation model includes a plurality of calculation models having respective distortion compensation characteristics for the amplifier in different internal states, and a combiner combining the plurality of calculation models in a combination ratio corresponding to the changed internal state. Another aspect of the present disclosure is a distortion compensation method. The distortion compensation method of the present disclosure is a distortion compensation method for distortion compensating a signal to be amplified by an amplifier in which an internal state affecting distortion characteristics is changed, the distortion compensation method including the step of a distortion compensation apparatus combining a plurality of calculation models having respective distortion compensation characteristics for the amplifier in different internal states at a combination ratio corresponding to the changed internal state. Another aspect of the present disclosure is a computer program. The computer program of the present disclosure is a computer program for distortion compensation of a signal to be amplified by an amplifier in which an internal state affecting distortion characteristics is changed, the computer program causing a computer to execute a process including combining a plurality of calculation models having respective distortion compensation characteristics for the amplifier in different internal states at a combination ratio corresponding to the changed internal state. Another aspect of the present disclosure is a communication device. The communication device of the present disclosure is a communication device including an amplifier that amplifies a signal for communication, and a distortion compensation device that uses a distortion compensation model to distortion compensate the signal, wherein the amplifier is configured such that an internal state affecting a distortion characteristic is changed, wherein the distortion compensation model includes a plurality of calculation models having respective distortion compensation characteristics for the amplifier in different internal states, and a combiner that combines the plurality of calculation models at a combination ratio corresponding to the changed internal state. Drawings Fig. 1 is a block diagram of a distortion compensation processing unit in a distortion compensation apparatus according to a first embodiment; fig. 2 is a configuration diagram of a communication device; fig. 3 is a hard