Distortion compensation device, distortion compensation method, and transmission device

Abstract

A distortion compensation device (2) is configured to comprise: an amplification target signal acquisition unit (21) that acquires an amplification target signal that is a signal to be subjected to power amplification by a power amplifier (4); and an operation state signal acquisition unit (22) that acquires an operation state signal indicating the operation state of the power amplifier (4). Furthermore, the distortion compensation device (2) is provided with a distortion compensation unit (25) that estimates, on the basis of the signal to be amplified acquired by the signal to be amplified acquisition unit (21) and the operation status signal acquired by the operation status signal acquisition unit (22), a signal in which distortion has been imparted to the signal to be amplified acquired by the signal to be amplified acquisition unit (21). The predistorted signal is output to the power amplifier (4) as a predistorted signal for compensating for distortion occurring in the signal to be amplified after power amplification by the power amplifier (4).

Description

Technical Field

[0001] The present disclosure relates to a distortion compensation device, a distortion compensation method and a transmitting device. Background Art

[0002] There is a transmitting device having a power amplifier that amplifies the power of a transmission signal. Due to the nonlinear characteristics of the power amplifier, distortion sometimes occurs in the amplified target signal after power amplification by the power amplifier. For example, in non-patent document 1, a distortion compensation device for compensating for distortion generated in the transmission signal after power amplification by the power amplifier is disclosed. The distortion compensation device has a distortion compensation unit that assigns the transmission signal as the power amplification target to a neural network (hereinafter referred to as a "learning model") and obtains a pre-distortion signal from the learning model for compensating for distortion generated in the transmission signal after power amplification by the power amplifier. The distortion compensation unit outputs the pre-distortion signal as a transmission signal to the power amplifier.

[0003] Prior art literature

[0004] Non-patent literature

[0005] Non-patent document 1: Slim Boumaiza, and Farouk Mkadem, "Wideband RF PowerAmplifier Predistortion using Real-Valued Time-Delay Neural Networks", European Microwave Conference (EuMC), 2009. Summary of the invention

[0006] Problems to be solved by the invention

[0007] The distortion generated in the transmission signal after power amplification by the power amplifier changes due to changes in the operating conditions of the power amplifier. Examples of the operating conditions of the power amplifier include the ambient temperature of the power amplifier, the carrier frequency of the transmission signal, or the bias voltage of the power amplifier.

[0008] In the distortion compensation device disclosed in non-patent document 1, the operating state of the power amplifier when the learning model is being learned is sometimes different from the operating state of the power amplifier when the distortion compensation unit obtains the predistortion signal from the learning model. Thus, when the operating state of the power amplifier is different, the distortion generated in the transmission signal after power amplification by the power amplifier is different. Therefore, there is a problem that even if the distortion compensation unit outputs the predistortion signal obtained from the learning model as a transmission signal to the power amplifier, it may not be able to compensate for the distortion generated in the transmission signal after power amplification by the power amplifier.

[0009] The present disclosure has been made to solve the above-mentioned problems, and an object of the present disclosure is to provide a distortion compensation device that can compensate for distortion generated in a signal that has been power-amplified by a power amplifier even if the operating condition of the power amplifier changes.

[0010] Means for solving problems

[0011] The distortion compensation device disclosed in the present invention includes: an amplification target signal acquisition unit that acquires an amplification target signal that is a signal to be power amplified by a power amplifier, and an operation status signal acquisition unit that acquires an operation status signal indicating the operation status of the power amplifier. In addition, the distortion compensation device includes a distortion compensation unit that estimates a signal that is distorted by the amplification target signal acquired by the amplification target signal acquisition unit based on the amplification target signal acquired by the amplification target signal acquisition unit and the operation status signal acquired by the operation status signal acquisition unit, and outputs the predistortion signal to the power amplifier as a predistortion signal for compensating for distortion generated in the amplification target signal after power amplification by the power amplifier.

[0012] Effects of the Invention

[0013] According to the present disclosure, even if the operating condition of the power amplifier changes, it is possible to compensate for distortion generated in a signal that has been power-amplified by the power amplifier. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 1 is a diagram showing the configuration of a transmission device including the distortion compensating device 2 according to the first embodiment.

[0015] Figure 2 1 is a hardware configuration diagram showing the hardware of the distortion compensating device 2 according to the first embodiment.

[0016] Figure 3 This is a hardware configuration diagram of a computer when the distortion compensation device 2 is implemented by software, firmware, or the like.

[0017] Figure 4 2 is a flowchart showing the processing procedure of the distortion compensation device 2, that is, the distortion compensation method.

[0018] Figure 5 1 is an explanatory diagram showing a configuration example of each of the distortion compensating unit 25 and the learning model 24 .

[0019] Figure 6 This is a diagram showing the configuration of a transmitting device including a distortion compensating device 2 according to the second embodiment.

[0020] Figure 7 1 is a hardware configuration diagram showing the hardware of the distortion compensating device 2 according to the second embodiment.

[0021] Figure 8 1 is a diagram showing the configuration of a transmitting device including the distortion compensating device 2 according to the third embodiment.

[0022] Fig. 9 1 is a hardware configuration diagram showing the hardware of the distortion compensating device 2 according to the third embodiment.

[0023] Fig.10 2 is an explanatory diagram showing the adjustment contents of the signal value by the signal value adjustment unit 27 .

[0024] Fig.11 1 is a diagram showing a configuration of an example of a transmission device including the distortion compensation device 2. DETAILED DESCRIPTION

[0025] Hereinafter, in order to explain the present disclosure in more detail, a mode for implementing the present disclosure will be described with reference to the drawings.

[0026] Implementation method 1.

[0027] Figure 1 1 is a diagram showing the configuration of a transmission device including the distortion compensating device 2 according to the first embodiment.

[0028] Figure 2 1 is a hardware configuration diagram showing the hardware of the distortion compensating device 2 according to the first embodiment.

[0029] Figure 1 The transmission device shown includes a signal generation unit 1 , a distortion compensation device 2 , a digital-to-analog converter (hereinafter referred to as “DAC”) 3 , a power amplifier 4 , and a transmission antenna 5 .

[0030] The signal generating unit 1 generates an amplification target signal which is a signal to be amplified by the power amplifier 4. The amplification target signal is, for example, a radio frequency (RF: Radio Frequency) transmission signal.

[0031] If a frequency converter for converting an intermediate frequency (IF) baseband signal into an RF transmission signal is provided at a preceding stage of the power amplifier 4, the amplification target signal may be an IF baseband signal.

[0032] The signal generating unit 1 outputs the amplification target signal to the distortion compensating device 2 .

[0033] The distortion compensating device 2 includes an amplification target signal acquiring unit 21 , an operation status signal acquiring unit 22 , a learning model storage unit 23 , and a distortion compensating unit 25 .

[0034] The distortion compensating device 2 obtains the amplification target signal from the signal generating unit 1 .

[0035] The distortion compensating device 2 imparts distortion to the signal to be amplified that can compensate for distortion generated in the signal to be amplified after power amplification by the power amplifier 4 .

[0036] The distortion compensating device 2 outputs the predistortion signal, which is the distortion-added signal to be amplified, to the power amplifier 4 via the DAC 3 .

[0037] The DAC 3 converts the predistortion signal output from the distortion compensation device 2 from a digital signal into an analog signal.

[0038] The DAC 3 outputs the analog predistortion signal to the power amplifier 4 .

[0039] The power amplifier 4 amplifies the power of the analog predistortion signal output from the distortion compensation device 2 .

[0040] The power amplifier 4 outputs the power-amplified predistortion signal as a transmission signal to the transmission antenna 5 .

[0041] The transmission antenna 5 radiates radio waves related to the transmission signal output from the power amplifier 4 into space.

[0042] The amplification target signal acquisition unit 21 obtains the signal by, for example, Figure 2 It is realized by the amplification object signal obtaining circuit 31 shown.

[0043] The amplification target signal acquisition unit 21 acquires the amplification target signal from the signal generation unit 1 .

[0044] The amplification target signal acquisition unit 21 outputs the amplification target signal to the distortion compensation unit 25 .

[0045] The operation status signal acquisition unit 22 uses, for example, Figure 2 It is realized by the operation status signal acquisition circuit 32 shown.

[0046] The operation status signal acquisition unit 22 acquires an operation status signal indicating the operation status of the power amplifier 4 .

[0047] The operation status signal acquisition unit 22 outputs the operation status signal to the distortion compensation unit 25. The operation status signal is a stable signal whose temporal variation of the signal value is smaller than that of the amplification target signal.

[0048] The operation status signal is, for example, temperature information indicating the ambient temperature of the power amplifier 4, frequency information indicating the carrier frequency of the amplification target signal obtained by the amplification target signal acquisition unit 21, bias voltage information indicating the bias voltage of the power amplifier 4, or backoff information indicating the backoff of the power amplifier 4.

[0049] If the ambient temperature of the power amplifier 4 changes, the distortion generated in the amplified target signal after power amplification by the power amplifier 4 changes. If the carrier frequency of the amplified target signal changes, the distortion generated in the amplified target signal after power amplification by the power amplifier 4 changes. If the bias voltage of the power amplifier 4 changes, the distortion generated in the amplified target signal after power amplification by the power amplifier 4 changes. If the back-off of the power amplifier 4 changes, the distortion generated in the amplified target signal after power amplification by the power amplifier 4 changes.

[0050] The learning model storage unit 23 uses, for example, Figure 2 The learning model storage circuit 33 shown is used to implement it.

[0051] The learning model storage unit 23 stores a learning model 24 .

[0052] Figure 1 The distortion compensation device 2 shown in the figure includes the learning model storage unit 23. However, this is only an example, and the learning model storage unit 23 may be provided outside the distortion compensation device 2.

[0053] The learning model 24 is implemented by, for example, a neural network.

[0054] During learning, the learning model 24 is given, as learning data, the amplification target signal acquired by the amplification target signal acquisition unit 21, the operation status signal acquired by the operation status signal acquisition unit 22, and a predistortion signal capable of compensating for distortion generated in the amplification target signal after power amplification by the power amplifier 4.

[0055] The learning model 24 is a learned model for which learning of the predistortion signal included in the learning data has been completed.

[0056] The distortion compensation unit 25 is configured to Figure 2 The distortion compensation circuit 35 shown is used to achieve this.

[0057] The distortion compensating unit 25 estimates a signal that is distorted with respect to the amplified object signal obtained by the amplified object signal obtaining unit 21, based on the amplified object signal obtained by the amplified object signal obtaining unit 21 and the operation status signal obtained by the operation status signal obtaining unit 22, as a predistortion signal for compensating for the distortion generated in the amplified object signal after power amplification by the power amplifier 4.

[0058] Specifically, the distortion compensating unit 25 gives the amplification target signal acquired by the amplification target signal acquiring unit 21 and the operation status signal acquired by the operation status signal acquiring unit 22 to the learning model 24 .

[0059] The distortion compensating unit 25 acquires, from the learning model 24 , a signal obtained by adding distortion to the amplification target signal acquired by the amplification target signal acquiring unit 21 , as a predistortion signal for compensating for distortion generated in the amplification target signal after power amplification by the power amplifier 4 .

[0060] The distortion compensating unit 25 outputs the predistortion signal to the power amplifier 4 via the DAC 3 .

[0061] exist Figure 1 In the distortion compensation device 2 shown, the distortion compensation unit 25 estimates a predistortion signal for compensating for distortion generated in the amplification target signal after power amplification by the power amplifier 4, using the learning model 24. However, this is only an example, and the distortion compensation unit 25 may estimate a predistortion signal for compensating for distortion generated in the amplification target signal after power amplification by the power amplifier 4, for example, using a rule base. In the rule base, there are described rules for determining a predistortion signal corresponding to the amplification target signal acquired by the amplification target signal acquisition unit 21 and the operation status signal acquired by the operation status signal acquisition unit 22.

[0062] exist Figure 1 In the embodiment, it is assumed that the amplification target signal acquisition unit 21, the operation status signal acquisition unit 22, the learning model storage unit 23 and the distortion compensation unit 25 as the structural elements of the distortion compensation device 2 are respectively implemented as follows: Figure 2 That is, it is assumed that the distortion compensation device 2 is implemented by the amplification target signal acquisition circuit 31, the operation status signal acquisition circuit 32, the learning model storage circuit 33 and the distortion compensation circuit 35.

[0063] The learning model storage circuit 33 is, for example, a non-volatile or volatile semiconductor memory such as RAM (Random Access Memory), ROM (Read Only Memory), flash memory, EPROM (Erasable Programmable Read Only Memory), EEPROM (Electrically Erasable Programmable Read Only Memory), a magnetic disk, a floppy disk, an optical disk, a compact disk, a mini disk, or a DVD (Digital Versatile Disc).

[0064] The amplification object signal acquisition circuit 31, the action status signal acquisition circuit 32 and the distortion compensation circuit 35 are, for example, a single circuit, a composite circuit, a programmed processor, a parallel programmed processor, an ASIC (Application Specific Integrated Circuit), an FPGA (Field Programmable Gate Array) or a combination thereof.

[0065] The components of the distortion compensation device 2 are not limited to those implemented by dedicated hardware, and the distortion compensation device 2 may be implemented by software, firmware, or a combination of software and firmware.

[0066] Software or firmware is stored as a program in a computer's memory. A computer refers to hardware that executes programs, such as a CPU (Central Processing Unit), a central processing unit, a processing unit, an arithmetic unit, a microprocessor, a microcomputer, a processor, or a DSP (Digital Signal Processor).

[0067] Figure 3 This is a hardware configuration diagram of a computer when the distortion compensation device 2 is implemented by software, firmware, or the like.

[0068] When the distortion compensation device 2 is implemented by software or firmware, the learning model storage unit 23 is configured on the computer's memory 41. A program for causing the computer to execute each process in the amplification target signal acquisition unit 21, the operation status signal acquisition unit 22, and the distortion compensation unit 25 is stored in the memory 41. Then, the processor 42 of the computer executes the program stored in the memory 41.

[0069] In addition, Figure 2 In FIG. 1 , an example is shown in which the components of the distortion compensation device 2 are respectively implemented by dedicated hardware. Figure 3 , an example is shown in which the distortion compensation device 2 is implemented by software or firmware, etc. However, this is only an example, and some components of the distortion compensation device 2 may be implemented by dedicated hardware, and the remaining components may be implemented by software or firmware, etc.

[0070] Next, Figure 1 The operation of the distortion compensating device 2 shown will be described.

[0071] The signal generating unit 1 generates a signal to be power-amplified, that is, an amplification target signal S. The amplification target signal S includes, for example, an I signal as an in-phase signal and a Q signal as a quadrature signal.

[0072] In the following, suppose that I IN (t) represents the I signal at time (t) generated by the signal generating unit 1, and Q IN (t) represents the Q signal at time (t).

[0073] The signal generating unit 1 outputs the amplification target signal S to the distortion compensating device 2 .

[0074] exist Figure 1 In the distortion compensation device 2 shown, the signal generation unit 1 generates the amplification target signal S including the I signal and the Q signal. However, the amplification target signal S may include any signal as long as it can be amplified by the power amplifier 4 and may not include the I signal and the Q signal.

[0075] Figure 4 2 is a flowchart showing the processing procedure of the distortion compensation device 2, that is, the distortion compensation method.

[0076] The amplification target signal acquisition unit 21 of the distortion compensation device 2 acquires the amplification target signal S( Figure 4 Step ST1).

[0077] The amplification target signal acquisition unit 21 outputs the amplification target signal S to the distortion compensation unit 25 .

[0078] The operation status signal acquisition unit 22 acquires the operation status signal OC indicating the operation status of the power amplifier 4. Figure 4 Step ST2).

[0079] The operation status signal acquisition unit 22 outputs the operation status signal OC to the distortion compensation unit 25 .

[0080] If the operating status signal OC is, for example, temperature information indicating the ambient temperature of the power amplifier 4 , the operating status signal acquisition unit 22 acquires the operating status signal OC from a temperature sensor that observes the ambient temperature of the power amplifier 4 .

[0081] If the operation status signal OC is, for example, frequency information indicating the carrier frequency of the amplification target signal, the operation status signal acquisition unit 22 acquires the operation status signal OC from the control device that controls the transmission device.

[0082] exist Figure 1 In the distortion compensation device 2 shown, the operation status signal acquisition unit 22 acquires one operation status signal OC and outputs the one operation status signal OC to the distortion compensation unit 25. However, this is only an example, and the operation status signal acquisition unit 22 may acquire two or more operation status signals OC and output the two or more operation status signals OC to the distortion compensation unit 25.

[0083] The distortion compensation unit 25 obtains the amplification target signal S from the amplification target signal acquisition unit 21, and obtains the operation status signal OC from the operation status signal acquisition unit 22. Figure 1 In the distortion compensation device 2 shown in FIG. 1 , the amplified object signal S includes I IN (t) and Q IN (t).

[0084] The distortion compensation unit 25 converts I IN (t), Q IN (t) and the operation status signal OC are respectively given to the learning model 24.

[0085] The distortion compensating unit 25 obtains a predistortion signal ( ) from the learning model 24 for compensating for distortion generated in the amplification target signal S′ after power amplification by the power amplifier 4. Figure 4 Step ST3).

[0086] The predistortion signal is a signal that adds distortion to the amplification target signal S in order to cancel the distortion generated in the amplification target signal S' after power amplification by the power amplifier 4. Generally, the distortion added to the amplification target signal S is a distortion having opposite characteristics to the distortion generated in the amplification target signal S' after power amplification by the power amplifier 4.

[0087] The predistortion signal output from the learning model 24 includes I OUT (t) and Q OUT (t).

[0088] The distortion compensation unit 25 includes I OUT (t) and Q OUT The predistortion signal (t) is output to the power amplifier 4 via the DAC 3 ( Figure 4 Step ST4).

[0089] Figure 5 1 is an explanatory diagram showing a configuration example of each of the distortion compensating unit 25 and the learning model 24 .

[0090] exist Figure 5 In the embodiment, the distortion compensation unit 25 includes M first delay devices 25a-m and M second delay devices 25b-m. m=1, ..., M, where M is an integer greater than 2. Figure 5 In FIG. 1 , the first delay device 25a - m and the second delay device 25b - m are respectively described as “D”. Here, the sampling interval of the distortion compensation unit 25 is assumed to be Δt.

[0091] I at time (t) IN (t) is given to any one of the input layers of the learning model 24. The first delay device 25a-1 makes I IN (t) is delayed by 1 sampling time Δt.

[0092] I, which is the output signal of the first delay device 25a-1 IN (t-Δt) is obtained by delaying the signal given one sampling time ago by Δt, and is given to any one of the multiple input layers. IN (t-Δt) is given to the first delay device 25 a - 2 .

[0093] The first delay device 25a-m (m=2, ..., M) makes the I of the output signal of the first delay device 25a-(m-1) IN (t-(m-1)·Δt) is delayed by one sampling time Δt.

[0094] I, which is the output signal of the first delay unit 25a-m IN (tm·Δt) is obtained by delaying a signal given one sampling time ago by Δt, and is given to any one of the multiple input layers. IN (tm·Δt) is given to the first delay device 25a-(m+1). However, if m=M, then I IN (tm·Δt) is not given to the first delay device 25a-(m+1).

[0095] Q at time (t) IN (t) is given to any one of the input layers of the learning model 24. The second delay device 25b-1 makes Q at time (t) IN (t) is delayed by 1 sampling time Δt.

[0096] The Q signal of the output signal of the second delay device 25b-1 is IN (t-Δt) is obtained by delaying the signal given one sampling time ago by Δt, and is given to any one of the multiple input layers. IN (t-Δt) is given to the second delay device 25b-2.

[0097] The second delay circuit 25b-m (m=2, ..., M) makes the Q of the output signal of the second delay circuit 25b-(m-1) IN (t-(m-1)·Δt) is delayed by one sampling time Δt.

[0098] The Q of the output signal of the second delay unit 25b-m is IN (tm·Δt) is obtained by delaying the signal given one sampling time ago by Δt, and is given to any one of the multiple input layers. IN (tm·Δt) is given to the second delay unit 25b-(m+1). However, if m=M, then QIN (tm·Δt) is not given to the second delay device 25b-(m+1).

[0099] In the multiple input layers of the learning model 24, except for the one assigned I IN (t), I IN (tm·Δt), Q IN (t), Q IN The input layer other than the input layer of (tm·Δt) is assigned an action status signal OC. For example, an action status signal OC indicating temperature information, an action status signal OC indicating frequency information, an action status signal OC indicating bias information, or an action status signal OC indicating fallback information is assigned to the input layer as the action status signal OC.

[0100] The signal given to the input layer of the learning model 24 is respectively transmitted to a plurality of intermediate layers in the learning model 24. The plurality of signals transmitted to the respective intermediate layers are weightedly added according to the weight coefficients determined by learning the predistortion signal included in the learning data.

[0101] The signals obtained by weighted addition in each intermediate layer are respectively transmitted to two output layers. The plurality of signals transmitted to each output layer are weighted added according to the weight coefficients determined by learning the predistortion signal included in the learning data.

[0102] The signal obtained by weighted addition in each output layer is the amplified target signal after distortion. The amplified target signal after distortion is a signal including I OUT (t) and Q OUT (t) is the predistorted signal.

[0103] right Figure 5 The input layer of the learning model 24 shown is not only endowed with the I IN (t), Q IN (t), also endowed with I IN (tm·Δt), Q IN (tm·Δt)(m=1, ..., M). Therefore, the predistortion signal is learned by taking into account the change of the time series signal including the current signal and the past signal. Therefore, the distortion compensation unit 25 can obtain the predistortion signal corresponding to the time change of the amplification target signal S from the learning model 24.

[0104] However, it is not limited to giving a time series signal to the input layer of the learning model 24, but it is also possible to give only I IN (t), Q IN (t).

[0105] The DAC 3 obtains the predistortion signal, which is the distortion-added signal to be amplified, from the distortion compensating device 2 .

[0106] The DAC 3 converts the predistortion signal from a digital signal to an analog signal.

[0107] The DAC 3 outputs the analog predistortion signal to the power amplifier 4 .

[0108] The power amplifier 4 obtains the analog predistortion signal from the distortion compensation device 2 .

[0109] The power amplifier 4 amplifies the power of the analog predistortion signal, and outputs the power-amplified predistortion signal to the transmission antenna 5 .

[0110] The predistortion signal is a signal to be amplified that is distorted in order to compensate for distortion generated in the signal after power amplification by the power amplifier 4. Therefore, the transmission signal, which is the signal after power amplification by the power amplifier 4, is a signal with little distortion.

[0111] The power amplifier 4 outputs the power-amplified transmission signal to the transmission antenna 5 .

[0112] The transmission antenna 5 radiates radio waves related to the transmission signal output from the power amplifier 4 into space.

[0113] In the above-mentioned first embodiment, the distortion compensation device 2 is configured to include: an amplification target signal acquisition unit 21 that acquires an amplification target signal that is a signal to be power-amplified by the power amplifier 4; and an operation status signal acquisition unit 22 that acquires an operation status signal indicating the operation status of the power amplifier 4. In addition, the distortion compensation device 2 includes a distortion compensation unit 25 that estimates a signal that is distorted by the amplification target signal acquired by the amplification target signal acquisition unit 21 based on the amplification target signal acquired by the amplification target signal acquisition unit 21 and the operation status signal acquired by the operation status signal acquisition unit 22, and outputs the predistortion signal to the power amplifier 4 as a predistortion signal for compensating for distortion generated in the amplification target signal after power amplification by the power amplifier 4. Therefore, even if the operation status of the power amplifier 4 changes, the distortion compensation device 2 can compensate for distortion generated in the signal after power amplification by the power amplifier 4.

[0114] Implementation method 2.

[0115] In the second embodiment, a distortion compensating device 2 is described. The distortion compensating device 2 includes a learning processing unit 26 that provides learning data to a learning model 24 to cause the learning model 24 to learn a predistortion signal included in the learning data.

[0116] Figure 6 2 is a diagram showing the structure of a transmission device including a distortion compensation device 2 according to Embodiment 2. Figure 6 In, with Figure 1 The same reference numerals denote the same or corresponding parts, and thus description thereof will be omitted.

[0117] Figure 7 2 is a hardware configuration diagram showing the hardware of the distortion compensation device 2 according to the second embodiment. Figure 7 In, with Figure 2 The same reference numerals denote the same or corresponding parts, and thus description thereof will be omitted.

[0118] Figure 6 The transmission device shown includes a signal generation unit 1 , a distortion compensation device 2 , a DAC 3 , a power amplifier 4 , a transmission antenna 5 , and an analog-to-digital converter (hereinafter referred to as “ADC”) 6 .

[0119] The ADC 6 converts the amplification target signal that has been power-amplified by the power amplifier 4 from an analog signal into a digital signal.

[0120] The ADC 6 outputs the digital amplification target signal to the distortion compensating device 2 .

[0121] Figure 6 The distortion compensating device 2 shown includes an amplification target signal acquiring unit 21 , an operation status signal acquiring unit 22 , a learning model storage unit 23 , a distortion compensating unit 25 , and a learning processing unit 26 .

[0122] The learning processing unit 26 performs, for example, Figure 7 The learning processing circuit 36 ​​shown is used to implement it.

[0123] The learning processing unit 26 acquires the learning data given to the learning model 24 .

[0124] The learning data acquired by the learning processing unit 26 includes the digital amplification target signal output from the ADC 6, the operation status signal acquired by the operation status signal acquisition unit 22, and the predistortion signal output from the distortion compensation unit 25. The digital amplification target signal output from the ADC 6 corresponds to the amplification target signal after power amplification by the power amplifier 4. The predistortion signal included in the learning data is a signal used as a supervisory signal.

[0125] The learning processing unit 26 gives the learning data to the learning model 24 to cause the learning model 24 to learn the predistortion signal included in the learning data.

[0126] exist Figure 6In the embodiment, it is assumed that the amplification target signal acquisition unit 21, the operation status signal acquisition unit 22, the learning model storage unit 23, the distortion compensation unit 25 and the learning processing unit 26, which are the components of the distortion compensation device 2, are respectively implemented as follows: Figure 7 That is, it is assumed that the distortion compensation device 2 is implemented by the amplification target signal acquisition circuit 31, the operation status signal acquisition circuit 32, the learning model storage circuit 33, the distortion compensation circuit 35 and the learning processing circuit 36.

[0127] The amplification object signal acquisition circuit 31, the action status signal acquisition circuit 32, the distortion compensation circuit 35 and the learning processing circuit 36 ​​are, for example, a single circuit, a composite circuit, a programmed processor, a parallel programmed processor, an ASIC, an FPGA or a combination thereof.

[0128] The components of the distortion compensation device 2 are not limited to those implemented by dedicated hardware, and the distortion compensation device 2 may be implemented by software, firmware, or a combination of software and firmware.

[0129] When the distortion compensation device 2 is implemented by software or firmware, the learning model storage unit 23 is configured in Figure 3 The memory 41 is shown. A program for causing the computer to execute each process in the amplification target signal acquisition unit 21, the operation status signal acquisition unit 22, the distortion compensation unit 25 and the learning processing unit 26 is stored in the memory 41. Figure 3 The illustrated processor 42 executes programs stored in the memory 41 .

[0130] In addition, Figure 7 In FIG. 1 , an example is shown in which the components of the distortion compensation device 2 are respectively implemented by dedicated hardware. Figure 3 , an example is shown in which the distortion compensation device 2 is implemented by software or firmware, etc. However, this is only an example, and some components of the distortion compensation device 2 may be implemented by dedicated hardware, and the remaining components may be implemented by software or firmware, etc.

[0131] Next, Figure 6 The operation of the distortion compensation device 2 shown in FIG. 2 is described below. Except for the learning processing unit 26, all other parts are the same as those in FIG. Figure 1 Since the distortion compensation device 2 shown is the same, the operation of the learning processing unit 26 will be mainly described here.

[0132] Most of the power of the amplification target signal that has been power-amplified by the power amplifier 4 is output to the transmission antenna 5 , and a portion of the power of the amplification target signal is output to the ADC 6 .

[0133] The ADC 6 converts the amplification target signal that has been power-amplified by the power amplifier 4 from an analog signal into a digital signal.

[0134] The ADC 6 outputs the digital amplification target signal to the distortion compensating device 2 .

[0135] The learning processing unit 26 acquires the learning data given to the learning model 24 .

[0136] That is, the learning processing unit 26 acquires the digital amplification target signal output from the ADC 6 , the operation status signal OC output from the operation status signal acquisition unit 22 , and the predistortion signal output from the distortion compensation unit 25 as learning data.

[0137] The learning processing unit 26 gives the learning data to the learning model 24 and causes the learning model 24 to learn the predistortion signal included in the learning data.

[0138] When the learned learning model 24 is given the amplification target signal S acquired by the amplification target signal acquisition unit 21 and the operation status signal OC acquired by the operation status signal acquisition unit 22 , it outputs predistortion signals corresponding to the amplification target signal S and the operation status signal OC, respectively.

[0139] The distortion compensation unit 25 obtains the amplification target signal S from the amplification target signal acquisition unit 21 and obtains the operation status signal OC from the operation status signal acquisition unit 22. The amplification target signal S includes I IN (t) and Q IN (t).

[0140] The distortion compensation unit 25 converts I IN (t), Q IN (t) and the operation status signal OC are respectively given to the learned learning model 24.

[0141] The distortion compensating unit 25 acquires, from the learning model 24 , a predistortion signal for compensating for distortion generated in the amplification target signal S′ after power amplification by the power amplifier 4 .

[0142] In the above-mentioned second embodiment, the distortion compensating device 2 is configured to include a learning processing unit 26, which acquires the amplification target signal after power amplification by the power amplifier 4, the operation status signal acquired by the operation status signal acquisition unit 22, and the predistortion signal output from the distortion compensating unit 25 as learning data, and gives the learning data to the learning model 24 to make the learning model 24 learn the predistortion signal. Therefore, the distortion compensating device 2 can compensate for the distortion generated in the signal after power amplification by the power amplifier 4 even if the operation status of the power amplifier 4 changes, and can also make the learning model 24 learn the predistortion signal.

[0143] Implementation method 3.

[0144] In the third embodiment, the distortion compensating device 2 including the signal value adjusting unit 27 for adjusting the signal value of the operation status signal OC will be described.

[0145] Figure 8 2 is a diagram showing the structure of a transmission device including the distortion compensation device 2 according to Embodiment 3. Figure 8 In, with Figure 1 and Figure 6 The same reference numerals denote the same or corresponding parts, and thus description thereof will be omitted.

[0146] Fig. 9 2 is a hardware configuration diagram showing the hardware of the distortion compensation device 2 according to the third embodiment. Fig. 9 In, with Figure 2 and Figure 7 The same reference numerals denote the same or corresponding parts, and thus description thereof will be omitted.

[0147] The signal value adjustment unit 27 performs, for example, Fig. 9 This is achieved by the signal value adjustment circuit 37 shown.

[0148] The signal value adjustment unit 27 adjusts the signal value of the operation status signal OC so that the signal change width of the operation status signal OC acquired by the operation status signal acquisition unit 22 matches the signal change width of the amplification target signal S acquired by the amplification target signal acquisition unit 21 .

[0149] The signal value adjustment unit 27 outputs the operation status signal OC′ after the signal value adjustment to the distortion compensation unit 25 .

[0150] exist Figure 8 In the distortion compensation device 2 shown in FIG. 1 , the signal value adjustment unit 27 is applied to Figure 1 However, this is only an example, and the signal value adjustment unit 27 may also be applied to Figure 6 The distortion compensation device 2 is shown.

[0151] exist Figure 8 In the embodiment, it is assumed that the amplification target signal acquisition unit 21, the operation status signal acquisition unit 22, the learning model storage unit 23, the signal value adjustment unit 27 and the distortion compensation unit 25, which are the structural elements of the distortion compensation device 2, are respectively implemented as follows: Fig. 9 That is, it is assumed that the distortion compensation device 2 is implemented by the amplification target signal acquisition circuit 31, the operation status signal acquisition circuit 32, the learning model storage circuit 33, the signal value adjustment circuit 37 and the distortion compensation circuit 35.

[0152] The amplification object signal acquisition circuit 31, the action status signal acquisition circuit 32, the signal value adjustment circuit 37 and the distortion compensation circuit 35 are, for example, a single circuit, a composite circuit, a programmed processor, a parallel programmed processor, an ASIC, an FPGA or a combination thereof.

[0153] The components of the distortion compensation device 2 are not limited to those implemented by dedicated hardware, and the distortion compensation device 2 may be implemented by software, firmware, or a combination of software and firmware.

[0154] When the distortion compensation device 2 is implemented by software or firmware, the learning model storage unit 23 is configured in Figure 3 The memory 41 is shown. A program for causing the computer to execute each process in the amplification target signal acquisition unit 21, the operation status signal acquisition unit 22, the signal value adjustment unit 27 and the distortion compensation unit 25 is stored in the memory 41. Figure 3 The illustrated processor 42 executes programs stored in the memory 41 .

[0155] In addition, Fig. 9 In FIG. 1 , an example is shown in which the components of the distortion compensation device 2 are respectively implemented by dedicated hardware. Figure 3 , an example is shown in which the distortion compensation device 2 is implemented by software or firmware, etc. However, this is only an example, and some components of the distortion compensation device 2 may be implemented by dedicated hardware, and the remaining components may be implemented by software or firmware, etc.

[0156] Next, Figure 8 The operation of the distortion compensation device 2 shown in FIG. 2 is described below. Except for the signal value adjustment unit 27, all other parts are the same as those in FIG. Figure 1 The distortion compensating device 2 shown is the same, and therefore, the operation of the signal value adjusting unit 27 will be mainly described here.

[0157] The signal value adjustment unit 27 acquires the amplification target signal S from the amplification target signal acquisition unit 21 , and acquires the operation status signal OC from the operation status signal acquisition unit 22 .

[0158] The signal value adjustment unit 27 adjusts the signal value of the operation status signal OC so that the signal change width of the operation status signal OC and the signal change width of the amplification target signal S coincide with each other.

[0159] For example, the operation status signal OC is frequency information indicating the carrier frequency of the amplified object signal S, and the signal variation amplitude of the carrier frequency is as follows: Fig.10When the frequency range is 1.0 [GHz] to 3.0 [GHz], if the upper limit value of the signal value of the amplification target signal S is "1" and the lower limit value of the signal value of the amplification target signal S is "-1", the signal value adjustment unit 27 adjusts the signal value of the operation status signal OC as follows.

[0160] Fig.10 1 is an explanatory diagram showing the adjustment contents of the signal value by the signal value adjustment unit 27 .

[0161] If the signal value of the operation status signal OC obtained from the operation status signal acquisition unit 22 is, for example, the upper limit value “3.0”, the signal value adjustment unit 27 adjusts the signal value of the operation status signal OC to “1” so that the signal value matches the upper limit value “1” of the signal value of the amplification target signal S.

[0162] If the signal value of the action status signal OC obtained from the action status signal acquisition unit 22 is, for example, the lower limit value "1.0", the signal value adjustment unit 27 adjusts the signal value of the action status signal OC to "-1" so that the signal value matches the lower limit value "-1" of the signal value of the amplification object signal S.

[0163] If the signal value of the operation status signal OC acquired from the operation status signal acquisition unit 22 is, for example, the median value “2.0”, the signal value adjustment unit 27 adjusts the signal value of the operation status signal OC to “0” so that the signal value matches the median value “0” of the signal value of the amplification target signal S.

[0164] The signal value adjustment unit 27 outputs the operation status signal OC′ after the signal value adjustment to the distortion compensation unit 25 .

[0165] Here, an example is shown in which the operation status signal OC is frequency information indicating the carrier frequency of the amplification target signal. However, this is only an example, and the operation status signal OC may also be temperature information indicating the ambient temperature of the power amplifier 4, bias voltage information indicating the bias voltage of the power amplifier 4, or back-off information indicating the back-off of the power amplifier 4. In this case, the signal value adjustment unit 27 also adjusts the signal value of the operation status signal OC in the same manner as the frequency information indicating the carrier frequency.

[0166] The distortion compensation unit 25 obtains the amplification target signal S from the amplification target signal acquisition unit 21, and obtains the operation status signal OC′ after the signal value is adjusted from the signal value adjustment unit 27. The amplification target signal includes I IN (t) and Q IN (t).

[0167] The distortion compensation unit 25 converts I IN (t), Q IN(t) and the operation status signal OC′ are respectively given to the learned learning model 24.

[0168] The learning model 24 is given the action status signal OC' after the signal value adjustment during learning, so that the upper limit of the weight relative to the amplified object signal S in the neural network is the same as the upper limit of the weight relative to the action status signal OC' in the neural network. Therefore, biased learning that emphasizes the amplified object signal S more than the action status signal OC is prevented. In addition, biased learning that emphasizes the action status signal OC more than the amplified object signal S is prevented. That is, the amplified object signal S and the action status signal OC' are learned with the same weight. As a result, the learning accuracy of the pre-distortion signal by the learning model 24 is improved.

[0169] Furthermore, even when the distortion compensating unit 25 obtains a predistortion signal from the learning model 24 , it is possible to obtain a predistortion signal with high distortion compensation accuracy.

[0170] In the above embodiment 3, Figure 8 The distortion compensation device 2 shown in the figure is configured to include a signal value adjustment unit 27, which adjusts the signal value of the action state signal so that the signal change amplitude of the action state signal obtained by the action state signal acquisition unit 22 is consistent with the signal change amplitude of the amplification target signal obtained by the amplification target signal acquisition unit 21, and outputs the action state signal after the signal value adjustment to the distortion compensation unit 25. Therefore, Figure 8 The distortion compensation device 2 shown in FIG. 1 is different from the distortion compensation device 2 shown in FIG. 1 in that it is able to compensate for the distortion generated in the signal after power amplification by the power amplifier 4 even if the operating condition of the power amplifier 4 changes. Figure 1 Compared with the distortion compensating device 2 shown in the figure, it is also possible to compensate for distortion with higher accuracy.

[0171] Figure 1 The transmitting device and Figure 8 The transmission device shown in the figure has a signal generation unit 1, a distortion compensation device 2, a DAC 3, a power amplifier 4 and a transmission antenna 5. In addition, Figure 6 The transmission device shown includes a signal generation unit 1 , a distortion compensation device 2 , a DAC 3 , a power amplifier 4 , a transmission antenna 5 , and an ADC 6 .

[0172] However, these are just examples. Fig.11 As shown, the transmitting device may also have a signal generating unit 1, a distortion compensation device 2, an orthogonal modulator 51, a DAC 3, a frequency converter 52, a power amplifier 4, a directional coupler 53, a transmitting antenna 5, a frequency converter 54, an automatic gain controller 55, an ADC 6 and an orthogonal demodulator 56.

[0173] Fig.111 is a diagram showing a configuration of an example of a transmission device including the distortion compensation device 2.

[0174] exist Fig.11 In the figure, for convenience of explanation, it is assumed that the signal generating unit 1 generates an IF baseband signal as a signal to be amplified.

[0175] The quadrature modulator 51 quadrature-modulates the predistortion signal output from the distortion compensation device 2 , that is, the distortion-added baseband signal, using a carrier signal.

[0176] The quadrature modulator 51 outputs the transmission signal, which is a baseband signal subjected to quadrature modulation, to the DAC 3 .

[0177] The frequency converter 52 converts the frequency of the analog transmission signal output from the DAC 3 into, for example, RF.

[0178] The frequency converter 52 outputs a transmission signal having an RF frequency to the power amplifier 4 .

[0179] The directional coupler 53 distributes the transmission signal, which has been power-amplified by the power amplifier 4, into two signals.

[0180] The directional coupler 53 outputs one of the two divided transmission signals to the transmission antenna 5 , and outputs the other transmission signal to the frequency converter 54 .

[0181] The frequency converter 54 converts the frequency of the transmission signal output from the directional coupler 53 into, for example, IF.

[0182] The frequency converter 54 outputs the transmission signal having the frequency IF to the automatic gain controller 55 .

[0183] The automatic gain controller 55 controls the gain of the transmission signal output from the frequency converter 54 .

[0184] The automatic gain controller 55 outputs the transmission signal after gain control to the ADC 6 .

[0185] The orthogonal demodulator 56 performs orthogonal demodulation on the digital transmission signal output from the ADC 6 using the carrier signal.

[0186] The orthogonal demodulator 56 outputs the baseband signal, which is the orthogonally demodulated transmission signal, to the distortion compensation device 2 .

[0187] In addition, the present disclosure enables free combination of the various embodiments, modification of arbitrary components of the various embodiments, or omission of arbitrary components of the various embodiments.

[0188] Industrial Applicability

[0189] The present disclosure is applicable to a distortion compensation device, a distortion compensation method, and a transmitting device.

[0190] Description of symbols

[0191] 1: signal generating unit; 2: distortion compensating device; 3: DAC; 4: power amplifier; 5: transmitting antenna; 6: ADC; 21: amplification object signal acquiring unit; 22: action status signal acquiring unit; 23: learning model storage unit; 24: learning model; 25: distortion compensating unit; 25a-1~25a-M: first delay device; 25b-1~25b-M: second delay device; 26: learning processing unit; 27: signal value adjusting unit; 31: amplification object signal acquiring circuit; 32: action status signal acquiring circuit; 33: learning model storage circuit; 35: distortion compensating circuit; 36: learning processing circuit; 37: signal value adjusting circuit; 41: memory; 42: processor; 51: quadrature modulator; 52: frequency converter; 53: directional coupler; 54: frequency converter; 55: automatic gain controller; 56: quadrature demodulator.

Claims

1. A distortion compensation device, wherein: The distortion compensation device has: an amplification target signal acquisition unit that acquires an amplification target signal that is a signal to be power-amplified by the power amplifier; an operation status signal acquisition unit that acquires an operation status signal indicating an operation status of the power amplifier; and a distortion compensating unit that estimates a signal that has been distorted for the amplified signal obtained by the amplified signal obtaining unit, based on the amplified signal obtained by the amplified signal obtaining unit and the action status signal obtained by the action status signal obtaining unit, and outputs the predistortion signal to the power amplifier as a predistortion signal for compensating for distortion generated in the amplified signal after power amplification by the power amplifier.

2. The distortion compensation device according to claim 1, characterized in that: The distortion compensating unit assigns the amplified object signal obtained by the amplified object signal acquiring unit and the action status signal obtained by the action status signal acquiring unit to a learning model, and acquires from the learning model a signal obtained by adding distortion to the amplified object signal obtained by the amplified object signal acquiring unit as a pre-distortion signal for compensating for the distortion generated in the amplified object signal after power amplification by the power amplifier.

3. The distortion compensation device according to claim 2, characterized in that: The distortion compensation device includes a learning processing unit, which obtains an amplified object signal after power amplification by the power amplifier, an operation status signal obtained by the operation status signal acquisition unit, and a pre-distortion signal output from the distortion compensation unit as learning data, and assigns the learning data to the learning model to cause the learning model to learn the pre-distortion signal.

4. The distortion compensation device according to claim 1, characterized in that: The distortion compensation device includes a signal value adjustment unit, which adjusts the signal value of the action status signal in such a manner that the signal change amplitude of the action status signal obtained by the action status signal acquisition unit is consistent with the signal change amplitude of the amplification object signal obtained by the amplification object signal acquisition unit, and outputs the action status signal after the signal value adjustment to the distortion compensation unit.

5. The distortion compensation device according to claim 1, characterized in that: The action status signal acquisition unit acquires temperature information indicating the ambient temperature of the power amplifier, frequency information indicating the carrier frequency of the amplification target signal acquired by the amplification target signal acquisition unit, bias voltage information indicating the bias voltage of the power amplifier, or backoff information indicating the backoff of the power amplifier as the action status signal.

6. A method for distortion compensation, wherein: The amplification target signal acquisition unit acquires an amplification target signal which is a signal to be power amplified by the power amplifier, an operation status signal acquisition unit to acquire an operation status signal indicating the operation status of the power amplifier; The distortion compensating unit estimates a signal that has been distorted for the amplified signal obtained by the amplified signal obtaining unit based on the amplified signal obtained by the amplified signal obtaining unit and the action status signal obtained by the action status signal obtaining unit, and outputs the predistortion signal to the power amplifier as a predistortion signal for compensating for distortion generated in the amplified signal after power amplification by the power amplifier.

7. A sending device, characterized in that: The sending device has: a power amplifier that amplifies the power of a signal to be amplified, that is, an amplification target signal; and a distortion compensating device for compensating for distortion generated in the amplification target signal after power amplification by the power amplifier, The distortion compensation device comprises: an amplification target signal acquisition unit that acquires a signal to be amplified by the power amplifier, that is, an amplification target signal; an operation status signal acquisition unit that acquires an operation status signal indicating an operation status of the power amplifier; and a distortion compensating unit that estimates a signal that has been distorted for the amplified signal obtained by the amplified signal obtaining unit, based on the amplified signal obtained by the amplified signal obtaining unit and the action status signal obtained by the action status signal obtaining unit, and outputs the predistortion signal to the power amplifier as a predistortion signal for compensating for distortion generated in the amplified signal after power amplification by the power amplifier.

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