JP6175852B2 - Power amplifier - Google Patents

Description

  The present invention relates to a power amplification device.

  In a digital wireless communication system, a linear amplification is required for a transmission power amplifier. In general, high linearity is required for a signal having a large peak power to average power ratio (PAPR). However, as the input power of the transmission power amplifier increases, the relationship between the input power and the output power changes from linear to non-linear, and the amplification factor gradually saturates. Therefore, in order to amplify a signal having a large PAPR, it is required to use a transmission amplifier having high linearity or increase power consumption in order to increase the back-off of the transmission power amplifier. Therefore, it is required to lower the PAPR by a process called peak suppression that suppresses peak power by clipping or the like.

  Also in the non-linear region, there is a DPD (Digital Pre Distortion) technique that suppresses non-linear distortion by giving a reverse characteristic of a transmission power amplifier to a transmission signal in advance by digital signal processing. In DPD, a reference signal (Ref signal) before input of the power amplifier is compared with a feedback signal (FB signal) obtained by feeding back a part of the signal amplified by the power amplifier, and distortion is calculated using a difference between these signals. Calculate and update the compensation factor. The distortion compensation coefficient is stored in the memory using the amplitude, power, or a function thereof of the reference signal as an address. By applying DPD processing to a transmission signal to be transmitted using a distortion compensation coefficient, distortion of the amplifier is compensated.

The peak suppression and DPD are combined to achieve high efficiency of the transmission power amplifier.
FIG. 1 is a diagram illustrating an example of a power amplifying apparatus that amplifies a transmission signal of one carrier. 1 includes a control unit, a first gain adjustment unit, a peak suppression unit, a second gain adjustment unit, a distortion compensation unit, and an amplifier. The distortion compensation unit includes a multiplier and a distortion compensation coefficient calculation unit. The control unit receives an instruction from the host device. The signal amplified by the amplifier is output from the antenna.

  FIG. 2 is a diagram illustrating an example of a power amplifying apparatus that multiplexes and amplifies transmission signals of a plurality of carriers. 2 includes a control unit, a first gain adjustment unit, a peak suppression unit, an adder, a second gain adjustment unit, a distortion compensation unit, and an amplifier. The distortion compensation unit includes a multiplier and a distortion compensation coefficient calculation unit. The control unit receives an instruction from the host device. The signal amplified by the amplifier is output from the antenna.

  There are a first gain adjustment unit and a second gain adjustment unit respectively before and after the peak suppression unit. The first gain adjustment unit adjusts the gain of the transmission signal for each carrier. The first gain adjustment unit is provided for each carrier. The second gain adjustment unit adjusts the gain of the signal synthesized after the peak suppression processing. When adjusting so as to reduce the gain of the transmission signal, the second gain adjustment unit does not adjust the gain.

  The peak suppression unit performs clipping so that a signal having an amplitude or power greater than or equal to a predetermined threshold value does not exceed the threshold value. The peak suppressor is provided for each carrier. The signals clipped (peak suppression processing) by the peak suppression unit are added by an adder.

The distortion compensator extracts a distortion compensation coefficient corresponding to the amplitude or power of the Ref signal from the LUT (Look Up Table) updated by the distortion compensation coefficient calculator, and multiplies the Ref signal to thereby compensate the distortion. Process. The distortion compensation coefficient calculation unit compares the Ref signal and the FB signal and updates the LUT intermittently. By sequentially updating the LUT, the distortion compensation coefficient converges to an optimum value (ideal value).

JP 2009-284044 A JP 2010-187153 A JP 2010-154017 A

  Conventionally, when adjusting to lower the gain, gain adjustment for each carrier is performed, and gain adjustment after carrier synthesis is not performed. In the peak suppression process, a fixed value that provides a PAPR that does not require a large backoff at the maximum output is set as the peak suppression threshold.

  Therefore, when the level is lowered from the maximum output (when the average power is lowered), peak suppression is not applied to the transmission signal, and the signal has a large PAPR. This signal is input to the distortion compensator and multiplied by the distortion compensation coefficient. However, since the frequency of occurrence of the signal with the maximum amplitude or maximum power is low, the distortion compensation coefficient has an ideal value that can sufficiently express the inverse characteristics of the transmission amplifier. It takes time to become. A distortion compensation coefficient that is not an ideal value does not maintain continuity with surrounding distortion compensation coefficients. As a result, there is a problem that the signal multiplied by the distortion compensation coefficient before the distortion compensation coefficient becomes an ideal value becomes spurious. Therefore, it is required to reduce the PAPR of the transmission signal.

  FIG. 3 is a diagram illustrating an example of the relationship between the PAPR of the signal after peak suppression and the cumulative probability distribution function (CCDF) when the average power is lowered. The horizontal axis of the graph in FIG. 3 is PAPR, and the vertical axis is CCDF. The unit of the horizontal axis of the graph of FIG. 3 is dB, and the unit of the vertical axis is%. In the graph of FIG. 3, a signal with a large PAPR appears with a low probability.

  An object of the technology disclosed herein is to provide a power amplifying device that suppresses generation of a signal having a low appearance frequency.

The disclosed technology employs the following means in order to solve the above-described problems.
That is, the first aspect is
A first gain adjustment unit that adjusts gains of transmission signals of a plurality of carriers based on a first gain adjustment value for each carrier;
A peak suppression unit that performs peak suppression of transmission signals of the plurality of carriers that have been gain-adjusted by the first gain adjustment unit based on a threshold adjustment value based on the first gain adjustment value for each carrier and a predetermined peak suppression threshold When,
An adder for combining the transmission signals of the plurality of carriers;
A second gain adjustment unit that adjusts the gain of the transmission signal synthesized by the addition unit based on a second gain adjustment value;
A distortion compensation unit that performs distortion compensation on the transmission signal gain-adjusted by the second gain adjustment unit;
An amplifying unit for amplifying the transmission signal subjected to distortion compensation by the distortion compensating unit;
It is set as the power amplification apparatus provided with.

An aspect of the disclosure may be realized by executing a program by an information processing device. That is, the disclosed configuration can be specified as a program for causing the information processing apparatus to execute the processing executed by each unit in the above-described aspect, or a computer-readable recording medium on which the program is recorded. Further, the disclosed configuration may be specified by a method in which the information processing apparatus executes the process executed by each of the above-described units.

  According to the disclosed technology, it is possible to provide a power amplifying apparatus that suppresses the occurrence of a signal having a low appearance frequency.

FIG. 1 is a diagram illustrating an example of a power amplifying apparatus that amplifies a transmission signal of one carrier. FIG. 2 is a diagram illustrating an example of a power amplifying apparatus that multiplexes and amplifies transmission signals of a plurality of carriers. FIG. 3 is a diagram showing an example of the relationship between the PAPR of the signal after peak suppression and the CCDF when the average power is lowered. FIG. 4 is a diagram illustrating a configuration example of the power amplification device according to the configuration example 1. FIG. 5 is a diagram illustrating an example of the gain adjustment value for each carrier transmitted from the host device to the power amplification device. FIG. 6 is a diagram illustrating an example of an operation flow of the control unit 102 of the power amplification device 100. FIG. 7 is a diagram illustrating a configuration example of the power amplification device according to the first modification. FIG. 8 is a diagram illustrating a configuration example of the power amplification device according to Configuration Example 2. FIG. 9 is a diagram illustrating an example of an operation flow of the control unit 202 of the power amplification device 200. FIG. 10 is a diagram illustrating an example of the relationship between the PAPR of the signal after peak suppression and the CCDF in the power amplifying apparatus 200. FIG. 11 is a diagram illustrating a configuration example of the power amplification device according to the second modification. FIG. 12 is a diagram illustrating a configuration example of the power amplification device according to Configuration Example 3. FIG. 13 is a diagram illustrating an example of an operation flow of the control unit 302 of the power amplification device 300. FIG. 14 is a diagram illustrating a configuration example of the power amplification device according to the third modification. FIG. 15 is a diagram illustrating an example of a hardware configuration of the power amplification device.

  Hereinafter, embodiments will be described with reference to the drawings. The configuration of the embodiment is an exemplification, and the disclosed configuration is not limited to the specific configuration of the disclosed embodiment. In implementing the disclosed configuration, a specific configuration according to the embodiment may be appropriately employed.

  Although an example of a power amplifying apparatus that synthesizes and amplifies signals of four carriers will be mainly described here, the number of carriers is not limited to four.

Embodiment
(Configuration example 1)
FIG. 4 is a diagram illustrating a configuration example of the power amplification device according to the configuration example 1. The power amplifying apparatus 100 of FIG. 4 may be included in a radio apparatus in a base station configured by a radio apparatus (RE: Radio Equipment) and a radio control apparatus (REC: Radio Equipment Control), for example.

4 includes a control unit 102, a first gain adjustment unit 110, a peak suppression unit 120, an adder 132, a second gain adjustment unit 134, a distortion compensation unit 140, and an amplifier 152. The first gain adjustment unit 110 includes a first gain adjustment unit 111, a first gain adjustment unit 112, a first gain adjustment unit 113, and a first gain adjustment unit 114. First gain adjustment section 111 adjusts the gain of the transmission signal of carrier # 1. First gain adjustment section 112 adjusts the gain of the transmission signal of carrier # 2. First gain adjustment section 113 adjusts the gain of the transmission signal of carrier # 3. First gain adjusting section 114 adjusts the gain of the transmission signal of carrier # 4. The peak suppression unit 120 includes a peak suppression unit 121, a peak suppression unit 122, a peak suppression unit 123, and a peak suppression unit 124. The peak suppression unit 121 performs peak suppression processing on the signal whose gain has been adjusted by the first gain adjustment unit 111. The peak suppression unit 122 performs peak suppression processing on the signal whose gain has been adjusted by the first gain adjustment unit 112. The peak suppression unit 123 performs peak suppression processing on the signal whose gain has been adjusted by the first gain adjustment unit 113. The peak suppression unit 124 performs peak suppression processing on the signal whose gain has been adjusted by the first gain adjustment unit 114. The control unit 102 of the power amplification device 100 receives an instruction from the host device 2000. The host device 2000 is, for example, a radio control device (REC). The transmission signal amplified by the amplifier 152 is output from the antenna 3000 toward the receiving device.

  The power amplifying apparatus 100 multiplexes, amplifies and outputs the transmission signals of carrier # 1 to carrier # 4. The power amplifying apparatus 100 receives the gain adjustment value for each carrier from the host apparatus 2000 and performs gain adjustment.

  The control unit 102 receives a gain adjustment value for each carrier from the higher-level device 2000. The control unit 102 calculates the first gain adjustment value in the first gain adjustment unit 110 and the second gain adjustment value in the second gain adjustment unit 134 based on the gain adjustment value for each carrier. The control unit 102 notifies the calculated first gain adjustment value and second gain adjustment value to the first gain adjustment unit 110 and the second gain adjustment unit 134, respectively. Further, the control unit 102 calculates a threshold adjustment value in the peak suppression unit 120 based on the gain adjustment value for each carrier. The control unit 102 notifies the peak suppression unit 120 of the calculated threshold adjustment value.

  The first gain adjustment unit 110 adjusts the gain of the transmission signal of each carrier for each carrier. The first gain adjustment unit 110 receives a first gain adjustment value for each carrier from the control unit 102. The first gain adjustment unit 110 performs gain adjustment for each carrier based on the received first gain adjustment value for each carrier.

  The peak suppressor 120 suppresses the peak of the signal level so as not to exceed a predetermined level for each carrier. The peak suppression unit 120 receives the threshold adjustment value from the control unit 102. The peak suppression unit 120 adds the threshold adjustment value received from the control unit 102 to the initial value of the peak suppression threshold to obtain a new peak suppression threshold. The peak suppression unit 120 suppresses the signal level peak so that it does not exceed the new peak suppression threshold. The peak suppression unit 120 outputs each signal subjected to the peak suppression processing to the adder 132.

  The adder 132 adds the outputs for each carrier of the peak suppression unit 120 and outputs the result to the second gain adjustment unit 134.

  The second gain adjustment unit 134 adjusts the gain of the signal. The second gain adjustment unit 134 receives the second gain adjustment value from the control unit 102. The second gain adjustment unit 134 adjusts the gain of the signal output from the adder 132 based on the received second gain adjustment value. The signal whose gain has been adjusted by the second gain adjustment unit 134 is output to the distortion compensation unit 140.

  The distortion compensation unit 140 includes a multiplier 142 and a distortion compensation coefficient calculation unit 144. The distortion compensation unit 140 performs DPD processing.

The multiplier 142 multiplies the distortion compensation coefficient output from the distortion compensation coefficient calculation unit 144 by the transmission signal output from the second gain adjustment unit 134. The signal multiplied by the multiplier 142 is output to the amplifier 152.

The distortion compensation coefficient calculation unit 144 is a Ref (Reference) that is an output of the second gain adjustment unit 134.
) Based on the signal, a distortion compensation coefficient is extracted from the LUT and output to the multiplier 142. The distortion compensation coefficient calculation unit 144 updates the LUT based on the Ref signal and an FB (Feedback) signal that is an output of the amplifier 152. In the LUT, the amplitude, power, or a function thereof of the reference signal is associated with the distortion compensation coefficient. The FB signal is converted into a digital signal by, for example, an ADC (Analog to Digital Converter) and input to the distortion compensation coefficient calculation unit 144.

The amplifier 152 amplifies the output of the multiplier 142 and outputs it to the antenna 3000 as an output signal. The amplifier 152 is, for example, a power amplifier. The signal input to the amplifier 152 is converted into an analog signal by, for example, a DAC (Digital to Analog Converter).

  The host device 2000 transmits a gain adjustment value for each carrier to the control unit 102 of the power amplification device 100. The host device 2000 is, for example, a REC.

  FIG. 5 is a diagram illustrating an example of the gain adjustment value for each carrier transmitted from the host device to the power amplification device. In the example of FIG. 5, -8 dB is required for carrier # 1, -8 dB for carrier # 2, -9 dB for carrier # 3, and -10 dB for carrier # 4.

The antenna 3000 transmits the output signal toward the receiving device.
FIG. 15 is a diagram illustrating an example of a hardware configuration of the power amplification device. FIG. 15 shows a host device 2000 in addition to the power amplifying device 100. As illustrated in FIG. 15, the power amplifying device 100 includes, for example, a connector 1010, an FPGA (Field Programmable Gate Array) 1020, a CPU (Central Processing Unit) 1030, a DAC 1040, and an upconverter as hardware components. (UP CONVERTER) 1050, power amplifier (PA) 1060, circulator 1070, down converter (DOWN CONVERTER) 1080, and ADC 1090. Various processes described in an operation example described later may be realized by an integrated circuit such as the FPGA 1020 and the CPU 1030.

  Various processes described in the operation examples described later can be realized by executing a prepared program on a computer. That is, a program corresponding to each process may be recorded in a memory (not shown), and each program may be read by the CPU 1030 to function as a process.

  The step of describing the program includes processes that are executed in parallel or individually even if they are not necessarily processed in time series, as well as processes that are executed in time series in the described order.

(Operation example 1)
An operation example of the control unit 102 of the power amplifying apparatus 100 will be described.

FIG. 6 is a diagram illustrating an example of an operation flow of the control unit 102 of the power amplification device 100.
The control unit 102 of the power amplifying apparatus 100 receives a gain adjustment value for each carrier from the host apparatus 2000. For example, the control unit 102 receives a gain adjustment value for each carrier as shown in FIG. 5 (S101).

The control unit 102 calculates a first gain adjustment value, a threshold adjustment value, and a second gain adjustment value for each carrier (S102). The control unit 102 calculates the first gain adjustment value of the carrier #n (n = 1, 2, 3, 4) as follows.

First gain adjustment value [dB] for carrier #n
= (| Minimum value of gain adjustment value |) [dB]
-(| Gain adjustment value of carrier #n |) [dB] (1)
Further, the control unit 102 calculates the threshold adjustment value as follows.

Threshold adjustment value = average value of the first gain adjustment value of each carrier (2)
Here, the average value of the first gain adjustment values of the carriers is the average value of the true values. Further, the control unit 102 calculates the second gain adjustment value as follows.

Second gain adjustment value [dB] = − (| minimum value of gain adjustment value |) [dB] (3)
For example, the carrier adjustment value of carrier #n instructed from host apparatus 2000 is the sum of the first carrier adjustment value of carrier #n and the second carrier adjustment value. That is, the power amplifying apparatus 100 performs carrier adjustment instructed by the host apparatus 2000 by the first carrier adjusting unit 110 and the second carrier adjusting unit 134.

  The control unit 102 transmits the first gain adjustment value for each carrier to the first gain adjustment unit 110. The control unit 102 transmits the threshold adjustment value to the peak suppression unit 120. The control unit 102 transmits the second gain adjustment value to the second gain adjustment unit 134 (S103).

  In first gain adjustment section 110, the gain of the transmission signal is adjusted for each carrier based on the first gain adjustment value. For example, the gain of the transmission signal of carrier # 1 is adjusted by the first gain adjustment unit 111 as shown in the following equation.

Output [dBm] of first gain adjustment unit 111
= (Carrier # 1 gain value) [dBm]
+ (First gain adjustment value of carrier # 1) [dB] (4)
The same applies to transmission signals of other carriers.

  In the peak suppression unit 120, the peak suppression threshold is adjusted based on the threshold adjustment value. The peak suppression threshold is adjusted as follows.

Adjusted peak suppression threshold [dBm]
= (Initial value of peak suppression threshold) [dBm] + (Threshold adjustment value) [dB] (5)
The second gain adjustment unit 134 adjusts the gain of the transmission signal that has been peak-suppressed and multiplexed based on the second gain adjustment value. The gain of the transmission signal that has been peak-suppressed and multiplexed is adjusted by the second gain adjustment unit 134 according to the following equation.

Output [dBm] of second gain adjustment unit 134
= (Gain value of multiplexed transmission signal) [dBm]
+ (2nd gain adjustment value) [dB] (6)
(Specific example 1)
Specific example 1 will be described. Here, it is assumed that four 40 dBm transmission signals are input to power amplification apparatus 100 from carrier # 1 to carrier # 4. A 40 dBm transmission signal is a transmission signal having an average power of 40 dBm. Further, it is assumed that the initial value of the peak suppression threshold in the peak suppression unit 120 is 53 dB. Further, it is assumed that a gain adjustment value for each channel as shown in FIG.

  Based on equation (1), the control unit 102 determines 0 dB as the first gain adjustment value for carrier # 1, 0 dB as the first gain adjustment value for carrier # 2, -1 dB as the first gain adjustment value for carrier # 3, -2 dB is calculated as the first gain adjustment value for carrier # 4. The first gain adjustment unit 111 outputs a signal of 40 dBm as a transmission signal after gain adjustment based on Expression (4). Similarly, the first gain adjustment unit 112 outputs a 40 dBm signal as a transmission signal after gain adjustment. The first gain adjustment unit 113 outputs a 39 dBm signal as a transmission signal after gain adjustment. The first gain adjustment unit 114 outputs a 38 dBm signal as a transmission signal after gain adjustment.

  The control unit 102 calculates a threshold adjustment value based on Expression (2). Since the true values of 0 dB, 0 dB, −1 dB, and −2 dB, which are the first gain adjustment values of the carriers, are 1, 1, 0.794, and 0.631, respectively, the true value of the threshold adjustment value is 0.856. Therefore, the threshold adjustment value is −0.67 dB. Here, since the initial value of the peak suppression threshold in the peak suppression unit 120 is 53 dB, the adjusted peak suppression threshold is 52.33 dB from Equation (5). The peak suppression unit 120 uses the adjusted peak suppression threshold to perform peak suppression processing so that the signal of each carrier does not exceed 52.33 dB. It is assumed that the signals of carrier # 1, carrier # 2, carrier # 3, and carrier # 4 after the peak suppression process are 39.7 dBm, 39.7 dBm, 38.8 dBm, and 37.9 dBm, respectively. Adder 132 synthesizes the signals of the carriers after the peak suppression processing. At this time, the magnitude of the combined signal is 45.11 dBm.

  The control unit 102 calculates −8 dB as the first gain adjustment value based on Expression (3). The second gain adjustment unit 134 adjusts the gain of the combined signal (the multiplexed signal) based on Expression (6). The average power of the signal after gain adjustment in the second gain adjustment unit 134 is 37.11 dBm. The signal whose gain has been adjusted by the second gain adjusting unit 134 is subjected to distortion compensation processing by the distortion compensating unit 140, amplified by the amplifier 152, and output.

(Modification 1)
In the configuration example 1, an example of a configuration in which transmission signals of a plurality of carriers are multiplexed and amplified is shown. However, in the modification example 1, an example of a configuration in which a transmission signal of one carrier is amplified is shown.

  FIG. 7 is a diagram illustrating a configuration example of the power amplification device according to the first modification. 7 includes a control unit 1102, a first gain adjustment unit 1110, a peak suppression unit 1120, a second gain adjustment unit 1134, a distortion compensation unit 1140, and an amplifier 1152. The control unit 1102 of the power amplification device 1100 receives an instruction from the host device 2000. The transmission signal amplified by the amplifier 1152 is output from the antenna 3000 toward the receiving device. Since the signal amplified by the power amplifying apparatus 1100 is a signal of one carrier, it differs from the power amplifying apparatus 100 in that an adder is not included.

  Since there is one carrier, the first gain adjustment value is 0 dB. That is, the first gain adjustment unit 1110 does not perform gain adjustment. Further, since the first gain adjustment value is 0 dB, the threshold adjustment value is 0 dB. That is, peak suppression section 1120 performs peak suppression based on the initial value of the peak suppression threshold.

(Configuration example 2)
The configuration example 2 has common points with the configuration example 1. Here, the description of the common points between Configuration Example 1 and Configuration Example 2 is omitted, and the differences between Configuration Example 1 and Configuration Example 2 will be described.

FIG. 8 is a diagram illustrating a configuration example of the power amplification device according to Configuration Example 2. The power amplifying apparatus 200 of FIG.
Includes a control unit 202, a power calculation unit 204, a first gain adjustment unit 210, a peak suppression unit 220, an adder 232, a second gain adjustment unit 234, a distortion compensation unit 240, and an amplifier 252. The first gain adjustment unit 210 includes a first gain adjustment unit 211, a first gain adjustment unit 212, a first gain adjustment unit 213, and a first gain adjustment unit 214. First gain adjustment section 211 adjusts the gain of the transmission signal of carrier # 1. First gain adjustment section 212 adjusts the gain of the transmission signal of carrier # 2. First gain adjustment section 213 adjusts the gain of the transmission signal of carrier # 3. First gain adjustment section 214 adjusts the gain of the transmission signal of carrier # 4. The peak suppressor 220 includes a peak suppressor 221, a peak suppressor 222, a peak suppressor 223, and a peak suppressor 224. The peak suppression unit 221 performs peak suppression processing on the signal whose gain has been adjusted by the first gain adjustment unit 211. The peak suppression unit 222 performs peak suppression processing on the signal whose gain has been adjusted by the first gain adjustment unit 212. The peak suppression unit 223 performs peak suppression processing on the signal whose gain has been adjusted by the first gain adjustment unit 213. The peak suppression unit 224 performs peak suppression processing on the signal whose gain has been adjusted by the first gain adjustment unit 214. The control unit 202 of the power amplification device 200 receives an instruction from the host device 2000. The transmission signal amplified by the amplifier 252 is output from the antenna 3000 toward the receiving device.

  The control unit 202 receives a gain adjustment value for each carrier from the higher-level device 2000. The control unit 202 calculates the first gain adjustment value in the first gain adjustment unit 210 and the second gain adjustment value in the second gain adjustment unit 234 based on the gain adjustment value for each carrier. The control unit 202 notifies the calculated first gain adjustment value and second gain adjustment value to the first gain adjustment unit 210 and the second gain adjustment unit 234, respectively. In addition, the control unit 202 acquires the average power of the signal of each carrier and the total of the average power from the power calculation unit 204. The total of the average power of each carrier may be calculated by the control unit 202. The control unit 202 calculates a threshold adjustment value in the peak suppression unit 220 based on the gain adjustment value for each carrier. The control unit 202 notifies the peak suppression unit 220 of the total value of the average power of each carrier and the threshold adjustment value.

  The power calculation unit 204 acquires the average power of the transmission signal of each carrier before being input to the first gain adjustment unit 210. The power calculator 204 calculates the sum of the average power of the transmission signals of each carrier. The power calculation unit 204 notifies the control unit 202 of the average power of each carrier and the total average power of transmission signals of each carrier. The power calculation unit 204 can be realized by a CPU, a DSP, an FPGA (Field-Programmable Gate Array), or the like.

  The peak suppression unit 220 suppresses the peak of the signal level so as not to exceed a predetermined level for each carrier. The peak suppression unit 220 receives the total of the average power of each carrier and the threshold adjustment value from the control unit 202. The peak suppression unit 220 adds the PAPR set value, the sum of the average power of each carrier received from the control unit 202, and the threshold adjustment value to obtain a new peak suppression threshold. The peak suppression unit 220 performs peak suppression on PAPR signals that exceed the PAPR set value. The PAPR set value is set in advance. The peak suppressor 220 suppresses the signal level peak so that it does not exceed the new peak suppression threshold. Peak suppression section 220 outputs each signal subjected to peak suppression processing to adder 232.

(Operation example 2)
An operation example of the control unit 202 of the power amplifying apparatus 200 will be described.

FIG. 9 is a diagram illustrating an example of an operation flow of the control unit 202 of the power amplification device 200.
The control unit 202 of the power amplification device 200 receives the gain adjustment value for each carrier from the higher-level device 2000. For example, the control unit 202 receives a gain adjustment value for each carrier as shown in FIG. 5 (S201).

  The control unit 202 receives the average power of the transmission signal of each carrier and the total of the average power of the transmission signal of each carrier from the power calculation unit 204 (S202). Here, the transmission signal of each carrier is the transmission signal of each carrier before being input to the first gain adjustment unit 210.

  The control unit 202 calculates a first gain adjustment value, a threshold adjustment value, and a second gain adjustment value for each carrier (S203). The calculation method of the first gain adjustment value, the threshold adjustment value, and the second gain adjustment value for each carrier is the same as that in the first operation example.

  The control unit 202 transmits the first gain adjustment value for each carrier to the first gain adjustment unit 210. The control unit 202 transmits the sum of the average power of the transmission signals of the carriers and the threshold adjustment value to the peak suppression unit 220. The control unit 202 transmits the second gain adjustment value to the second gain adjustment unit 234 (S204).

  In first gain adjustment section 210, the gain of the transmission signal is adjusted for each carrier based on the first gain adjustment value. The operation of the gain adjustment unit 210 is the same as that of the gain adjustment unit 110.

  In peak suppression section 220, the peak suppression threshold is adjusted based on the PAPR set value, the total average power of transmission signals of each carrier received from control section 202, and the threshold adjustment value. The peak suppression threshold is adjusted as follows.

Adjusted peak suppression threshold [dB]
= (Total of average power of transmission signals of each carrier) [dBm]
+ (PAPR set value) [dB] + (Threshold adjustment value) [dB] (7)
Second gain adjustment section 234 adjusts the gain of the transmission signal that is peak-suppressed and multiplexed based on the second gain adjustment value. The operation of the second gain adjustment unit 234 is the same as the operation of the second gain adjustment unit 134.

(Specific example 2)
Specific example 2 will be described. Here, it is assumed that four 40 dBm transmission signals are input to power amplifier 200 from carrier # 1 to carrier # 4. A 40 dBm transmission signal is a transmission signal having an average power of 40 dBm. Further, it is assumed that the PAPR set value in the peak suppression unit 220 is 7 dB. Further, it is assumed that a gain adjustment value for each channel as shown in FIG.

  Based on equation (1), the control unit 202 sets 0 dB as the first gain adjustment value for carrier # 1, 0 dB as the first gain adjustment value for carrier # 2, -1 dB as the first gain adjustment value for carrier # 3, -2 dB is calculated as the first gain adjustment value for carrier # 4. The first gain adjustment unit 211 outputs a signal of 40 dBm as a transmission signal after gain adjustment based on Expression (4). Similarly, the first gain adjustment unit 212 outputs a 40 dBm signal as a transmission signal after gain adjustment. The first gain adjustment unit 213 outputs a 39 dBm signal as a transmission signal after gain adjustment. The first gain adjustment unit 214 outputs a 38 dBm signal as a transmission signal after gain adjustment.

The control unit 202 calculates a threshold adjustment value based on Expression (2). Since the true values of 0 dB, 0 dB, −1 dB, and −2 dB, which are the first gain adjustment values of the carriers, are 1, 1, 0.794, and 0.631, respectively, the true value of the threshold adjustment value is 0.856. Therefore, the threshold adjustment value is −0.67 dB. The control unit 202 receives, from the power calculation unit 204, the total average power of the transmission signals of each carrier before being input to the first gain adjustment unit 110. Here, since the average power of the transmission signals of each carrier is 40 dBm, the total average power of the transmission signals of each carrier is 46 dBm. Here, since the PAPR set value in the peak suppression unit 220 is 7 dB, the peak suppression threshold after adjustment is 52.33 dB from Equation (7). The peak suppression unit 220 performs peak suppression processing using the adjusted peak suppression threshold so that the signal of each carrier does not exceed 52.33 dB. It is assumed that the signals of carrier # 1, carrier # 2, carrier # 3, and carrier # 4 after the peak suppression process are 39.7 dBm, 39.7 dBm, 38.8 dBm, and 37.9 dBm, respectively. Adder 232 combines the signals of the carriers after the peak suppression processing. At this time, the magnitude of the combined signal is 45.11 dBm.

  The control unit 202 calculates -8 dB as the first gain adjustment value based on Expression (3). The second gain adjustment unit 234 adjusts the gain of the combined signal (multiplexed signal) based on Expression (6). The average power of the signal after gain adjustment in the second gain adjustment unit 234 is 37.11 dBm. The signal whose gain has been adjusted by the second gain adjusting unit 234 is subjected to distortion compensation processing by the distortion compensating unit 240, amplified by the amplifier 252, and output.

  FIG. 10 is a diagram illustrating an example of a relationship between a PAPR of a signal after peak suppression and a cumulative probability distribution function (CCDF) in the power amplifying apparatus 200. The horizontal axis of the graph of FIG. 10 is PAPR, and the vertical axis is CCDF. The unit of the horizontal axis of the graph of FIG. 10 is dB, and the unit of the vertical axis is%. The curve shown by the dotted line in the graph of FIG. 10 is the same as that shown in the graph of FIG. 3, and a signal with a large PAPR appears with a low probability. A curve indicated by a solid line in the graph of FIG. 10 indicates the relationship between the PAPR of the signal after peak suppression in the power amplification device 200 and the CCDF. Here, the PAPR set value is set to 6.5 dB. In the power amplifying apparatus 200, a signal with a PAPR of 6.5 dB or more is not included due to peak suppression. In addition, the frequency of appearance of signals near the maximum PAPR (around 6.5 dB) is not low.

(Modification 2)
In the configuration example 2, the example of the configuration in which the transmission signals of a plurality of carriers are multiplexed and amplified is shown. However, in the modification example 2, the transmission signal of one carrier is amplified.

  FIG. 11 is a diagram illustrating a configuration example of the power amplification device according to the second modification. 11 includes a control unit 1202, a power calculation unit 204, a first gain adjustment unit 1210, a peak suppression unit 1220, a second gain adjustment unit 1234, a distortion compensation unit 1240, and an amplifier 1252. The control unit 1202 of the power amplification device 1200 receives an instruction from the host device 2000. The transmission signal amplified by the amplifier 1252 is output from the antenna 3000 to the receiving device. Since the signal amplified by the power amplifying apparatus 1200 is a signal of one carrier, it differs from the power amplifying apparatus 200 in that an adder is not included.

  Since there is one carrier, the first gain adjustment value is 0 dB. That is, the first gain adjustment unit 1210 does not perform gain adjustment.

(Configuration example 3)
The configuration example 3 has common points with the configuration example 1 or the configuration example 2. Here, description of the common points between Configuration Example 1 or Configuration Example 2 and Configuration Example 3 is omitted, and differences between Configuration Example 1, Configuration Example 2 and Configuration Example 3 will be described.

FIG. 12 is a diagram illustrating a configuration example of the power amplification device according to Configuration Example 3. 12 includes a control unit 302, a power calculation unit 304, a first gain adjustment unit 310, a peak suppression unit 320, an adder 332, a second gain adjustment unit 334, a distortion compensation unit 340, and an amplifier 352. . The first gain adjustment unit 310 includes a first gain adjustment unit 311, a first gain adjustment unit 312, a first gain adjustment unit 313, and a first gain adjustment unit 314. First gain adjustment section 311 adjusts the gain of the transmission signal of carrier # 1. First gain adjustment section 312 adjusts the gain of the transmission signal of carrier # 2. First gain adjustment section 313 adjusts the gain of the transmission signal of carrier # 3. First gain adjustment section 314 adjusts the gain of the transmission signal of carrier # 4. The peak suppression unit 320 includes a peak suppression unit 321, a peak suppression unit 322, a peak suppression unit 323, and a peak suppression unit 324. The peak suppression unit 321 performs peak suppression processing on the signal whose gain has been adjusted by the first gain adjustment unit 311. The peak suppression unit 322 performs peak suppression processing on the signal whose gain has been adjusted by the first gain adjustment unit 312. The peak suppression unit 323 performs peak suppression processing on the signal whose gain has been adjusted by the first gain adjustment unit 313. The peak suppression unit 324 performs peak suppression processing on the signal whose gain has been adjusted by the first gain adjustment unit 314. The control unit 302 of the power amplification device 300 receives an instruction from the host device 2000. The transmission signal amplified by the amplifier 352 is output from the antenna 3000 toward the receiving device.

  The control unit 302 receives a gain adjustment value for each carrier from the higher-level device 2000. The control unit 302 calculates the first gain adjustment value in the first gain adjustment unit 310 and the second gain adjustment value in the second gain adjustment unit 334 based on the gain adjustment value for each carrier. The control unit 302 notifies the calculated first gain adjustment value and second gain adjustment value to the first gain adjustment unit 310 and the second gain adjustment unit 334, respectively. In addition, the control unit 302 acquires the average power of the signal of each carrier and the total of the average power from the power calculation unit 304. The total average power of each carrier may be calculated by the control unit 302. The control unit 302 notifies the peak suppression unit 320 of the total value of the average power of each carrier.

  The power calculation unit 304 acquires the average power of the transmission signal of each carrier after being output from the first gain adjustment unit 310. The power calculator 304 calculates the total average power of the transmission signals of each carrier. The power calculation unit 304 notifies the control unit 302 of the average power of the transmission signal of each carrier and the total of the average power of the transmission signals of each carrier. The power calculation unit 304 can be realized by a CPU, DSP, FPGA, or the like.

  The peak suppressing unit 320 suppresses the peak of the signal level so as not to exceed a predetermined level for each carrier. The peak suppression unit 320 receives the total of the average power of the transmission signals of each carrier from the control unit 302. The peak suppression unit 320 adds the PAPR set value and the total of the average power of each carrier received from the control unit 302 to obtain a new peak suppression threshold. The peak suppression unit 320 performs peak suppression on a PAPR signal exceeding the PAPR set value. The PAPR set value is set in advance. The peak suppression unit 320 suppresses the signal level peak so that it does not exceed the new peak suppression threshold. The peak suppression unit 320 outputs each signal subjected to the peak suppression processing to the adder 332.

(Operation example 3)
An operation example of the control unit 202 of the power amplifying apparatus 300 will be described.

FIG. 13 is a diagram illustrating an example of an operation flow of the control unit 302 of the power amplification device 300.
The control unit 302 of the power amplifying device 300 receives the gain adjustment value for each carrier from the higher-level device 2000. For example, the control unit 302 receives a gain adjustment value for each carrier as shown in FIG. 5 (S301).

  The control unit 302 receives, from the power calculation unit 304, the average power of the transmission signal of each carrier and the total of the average power of the transmission signal of each carrier (S302). Here, the transmission signal of each carrier is the transmission signal of each carrier after being output from first gain adjustment section 310.

The control unit 302 calculates a first gain adjustment value and a second gain adjustment value for each carrier (S303). The calculation method of the first gain adjustment value and the second gain adjustment value for each carrier is the same as that in the first operation example.

  The control unit 302 transmits the first gain adjustment value for each carrier to the first gain adjustment unit 310. The control unit 302 transmits the total average power of the transmission signals of the carriers to the peak suppression unit 320. The control unit 302 transmits the second gain adjustment value to the second gain adjustment unit 334 (S304).

  In first gain adjustment section 310, the gain of the transmission signal is adjusted for each carrier based on the first gain adjustment value. The operation of the gain adjustment unit 310 is the same as that of the gain adjustment unit 110.

  In peak suppression section 320, the peak suppression threshold is adjusted based on the PAPR set value and the total average power of transmission signals of each carrier received from control section 302. The peak suppression threshold is adjusted as follows.

Adjusted peak suppression threshold [dB]
= (Total of average power of transmission signals of each carrier) [dBm]
+ (PAPR set value) [dB] (8)
The second gain adjustment unit 334 adjusts the gain of the transmission signal that has been peak-suppressed and multiplexed based on the second gain adjustment value. The operation of the second gain adjustment unit 334 is the same as the operation of the second gain adjustment unit 134.

  In the power amplifying apparatus 300, since the amount corresponding to the threshold adjustment value is included in the sum of the average power of the transmission signals of the carriers, the threshold adjustment value need not be calculated.

(Modification 3)
In the configuration example 3, an example of a configuration in which transmission signals of a plurality of carriers are multiplexed and amplified is shown, but in the modification example 3, an example of a configuration in which a transmission signal of one carrier is amplified is shown.

  FIG. 14 is a diagram illustrating a configuration example of the power amplification device according to the third modification. 14 includes a control unit 1302, a power calculation unit 304, a first gain adjustment unit 1310, a peak suppression unit 1320, a second gain adjustment unit 1334, a distortion compensation unit 1340, and an amplifier 1352. The control unit 1302 of the power amplification device 1300 receives an instruction from the host device 2000. The transmission signal amplified by the amplifier 1352 is output from the antenna 3000 to the reception device. Since the signal amplified by the power amplifying apparatus 1300 is a signal of one carrier, it differs from the power amplifying apparatus 300 in that an adder is not included.

  Since there is one carrier, the first gain adjustment value is 0 dB. That is, the first gain adjustment unit 1310 does not perform gain adjustment.

Each of the above configurations can be implemented by combining them as much as possible.
(Operation and effect of the embodiment)
The power amplifying apparatus 100 multiplexes, amplifies and outputs the transmission signals of carrier # 1 to carrier # 4. The power amplifying apparatus 100 receives a gain adjustment value for each carrier from the host apparatus 2000. The power amplifying apparatus 100 calculates a first gain adjustment value for each carrier based on the gain adjustment value for each carrier. The power amplifying apparatus 100 calculates the second gain adjustment value based on the gain adjustment value for each carrier. The power amplifying apparatus 100 calculates a threshold adjustment value based on the gain adjustment value for each carrier. The first gain adjustment unit 110 adjusts the gain of the transmission signal for each carrier based on the first gain adjustment value for each carrier. The first gain adjustment value is a value corresponding to the difference between carriers of the gain adjustment value instructed from the higher-level device 2000. The peak suppression unit 120 determines a peak suppression threshold based on the threshold adjustment value and performs peak suppression. By using the threshold adjustment value, the peak suppression threshold becomes variable. The second gain adjustment unit 134 adjusts the gain of the transmission signal that has been peak-suppressed and synthesized based on the second gain adjustment value. The second gain adjustment value is the same value as the smallest absolute value of the gain adjustment value instructed from the host device 2000. When the gain adjustment values instructed from host device 2000 are all 0 or negative, the second gain adjustment value is the same value as the largest value of the gain adjustment values instructed from host device 2000.

  The power amplifying apparatus 100 performs carrier adjustment instructed by the host apparatus 2000 by the first carrier adjusting unit 110 and the second carrier adjusting unit 134. By reducing the adjustment performed by the first carrier adjustment unit 110, the signal is not reduced too much by the first carrier adjustment unit 110, and the peak suppression is easily performed by the peak suppression unit 120. Moreover, since the peak suppression unit 120 makes the peak suppression threshold smaller than the initial value of the peak suppression threshold by the threshold adjustment value, the peak suppression unit 120 is likely to perform peak suppression regardless of the average power of the transmission signal.

  According to the power amplifying apparatus 100, peak suppression is easily applied to a carrier signal of any average power level, so that the frequency of a transmission signal having a maximum amplitude or maximum power is increased. By increasing the frequency of the signal having the maximum amplitude or the maximum power, the time until the distortion compensation coefficient converges to the optimum value is shortened, and the occurrence of spurious is suppressed.

  In the power amplifying apparatus 200, the power calculation unit 204 acquires the average power of the transmission signal of each carrier before being input to the first carrier adjustment unit 210. The power calculation unit 204 calculates the total average power of the transmission signals of each carrier before being input to the first carrier adjustment unit 210. The power amplifying apparatus 200 can prevent a signal having a PAPR equal to or higher than the PAPR set value from being output based on the average power of the transmission signal of each carrier, the threshold adjustment value, and the PAPR set value. The electric amplifier 200 can prevent a signal having a PAPR equal to or higher than the PAPR set value from being output even when the power of the transmission signal is suppressed by an instruction from the host device 2000 or the like.

  In the power amplifying apparatus 300, the power calculation unit 304 acquires the average power of the transmission signal of each carrier after being output from the first carrier adjustment unit 310. The power calculation unit 304 calculates the total average power of the transmission signals of each carrier after being output from the first carrier adjustment unit 310. The power amplifying apparatus 300 can prevent a signal having a PAPR equal to or higher than the PAPR set value from being output based on the average power of the transmission signal of each carrier and the PAPR set value.

100 Power amplifier
102 Control unit
110 1st gain adjustment part
111-114 1st gain adjustment part
120 Peak suppressor
121-124 Peak suppressor
132 Adder
134 Second gain adjustment unit
140 Distortion compensation unit
142 multiplier
144 Distortion compensation coefficient calculation unit
152 amplifier
200 Power amplifier
202 Control unit
204 Power calculator
210 First gain adjuster
211-214 1st gain adjustment part
220 Peak suppressor
221-224 Peak suppression unit
232 Adder
234 Second gain adjustment unit
240 Distortion compensation unit
242 multiplier
244 Distortion compensation coefficient calculation unit
252 amplifier
300 Power amplifier
302 control unit
304 Power calculator
310 1st gain adjustment part
311-314 First gain adjustment unit
320 Peak suppressor
321-324 Peak suppression unit
332 Adder
334 Second gain adjustment unit
340 Distortion compensation unit
342 multiplier
344 Distortion compensation coefficient calculation unit
352 Amplifier 1010 Connector 1020 FPGA
1030 CPU
1040 DAC
1050 UP CONVERTER
1060 PA
1070 Circulator 1080 DOWN CONVERTER
1090 ADC
2000 Host device 3000 Antenna

Claims (3)

A first gain adjustment unit that adjusts gains of transmission signals of a plurality of carriers based on a first gain adjustment value for each carrier;
A peak suppression unit that performs peak suppression of transmission signals of the plurality of carriers that have been gain-adjusted by the first gain adjustment unit based on a threshold adjustment value based on the first gain adjustment value for each carrier and a predetermined peak suppression threshold When,
An adder for combining the transmission signals of the plurality of carriers;
A second gain adjustment unit that adjusts the gain of the transmission signal synthesized by the addition unit based on a second gain adjustment value;
A distortion compensation unit that performs distortion compensation on the transmission signal gain-adjusted by the second gain adjustment unit;
An amplifying unit for amplifying the transmission signal subjected to distortion compensation by the distortion compensating unit;
A power amplification device comprising: A power calculation unit that obtains an average power of transmission signals of the plurality of carriers before gain adjustment by the first gain adjustment unit, and calculates a sum of the average power;
The peak suppression unit is configured to adjust the gain by the first gain adjustment unit based on a threshold adjustment value based on a total of the average power calculated by the power calculation unit and a first gain adjustment value for each carrier. The power amplifying apparatus according to claim 1, wherein peak suppression is performed on a transmission signal of a carrier. A power calculation unit that obtains an average power of transmission signals of the plurality of carriers that have been gain-adjusted by the first gain adjustment unit, and calculates a total of the average power;
The said peak suppression part performs peak suppression of the transmission signal of the said some carrier by which the gain adjustment was carried out by the said 1st gain adjustment part based on the sum total of the said average power calculated by the said electric power calculation part. Power amplifier.

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