Modulation control device, modulation control method and program

Abstract

To provide a modulation control device, a modulation control method, and program, capable of restricting bit errors of a transmission signal even if temperature change occurs.SOLUTION: A modulation control device 10 according to one aspect of the embodiment includes an acquisition unit 11 for acquiring data of temperature during a predetermined period, and a setting unit 12 for setting signal constellation used for modulating a transmission signal so that the constellation used for modulating the transmission signal is changed over to different signal constellation during the predetermined period based on the temperature data.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present disclosure relates to a modulation control device, a modulation control method, and a program. [Background technology]

[0002] Techniques for improving the quality of communication are being researched.

[0003] For example, Patent Document 1 discloses a satellite communication system including a satellite station and a ground station. The satellite station includes a frequency compensation circuit that pre-compensates the frequency characteristics of an upconverter and an amplifier provided therein. The ground station includes a coefficient calculation unit that calculates filter coefficients used in the frequency compensation circuit, and a transmission unit that transmits the filter coefficients to the satellite station. Here, the coefficient calculation unit can select a frequency characteristic corresponding to the temperature of the satellite station, and calculate new filter coefficients using the selected frequency characteristic. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2017-184096 A Summary of the Invention [Problem to be solved by the invention]

[0005] When a transmitter digitally modulates a transmission signal and transmits the modulated transmission signal, temperature changes may occur, causing changes in the nonlinear characteristics of the amplifier that amplifies the transmission signal. The change in the nonlinear characteristics of the amplifier may cause phenomena such as gain suppression or memory effect in the transmission signal, which may result in bit errors in the transmission signal. The technology disclosed in Patent Document 1 performs frequency compensation based on the temperature on the receiving side, but does not take into account the effect on the transmission signal caused by the temperature on the transmitting side, and therefore cannot solve this problem.

[0006] One of the objectives that the embodiments of the present disclosure aim to achieve is to provide a modulation control device, a modulation control method, and a program capable of suppressing bit errors in a transmission signal even when there is a temperature change. It should be noted that this objective is only one of the objectives that the embodiments disclosed herein aim to achieve. Other objectives or problems and novel features will become apparent from the description of this specification or the accompanying drawings. [Means for solving the problem]

[0007] A modulation control device according to one aspect of the present embodiment includes an acquiring means for acquiring temperature data for a predetermined period of time, and a setting means for setting a signal constellation used for modulating a transmission signal based on the temperature data, such that the signal constellation used for modulating the transmission signal is switched to a different signal constellation within the predetermined period of time.

[0008] A modulation control method according to one aspect of the present embodiment is executed by a computer, and acquires temperature data for a predetermined period of time, and sets a signal constellation used for modulating a transmission signal based on the temperature data, such that the signal constellation used for modulating the transmission signal is switched to a different signal constellation within the predetermined period of time.

[0009] A program according to one aspect of the present embodiment causes a computer to acquire temperature data for a predetermined period of time, and set a signal constellation used for modulating a transmission signal based on the temperature data, such that the signal constellation used for modulating the transmission signal is switched to a different signal constellation within the predetermined period of time. Effect of the Invention

[0010] According to the present disclosure, it is possible to provide a modulation control device, a modulation control method, and a program that are capable of suppressing bit errors in a transmission signal even when there is a temperature change. [Brief description of the drawings]

[0011] [Figure 1] 1 is a block diagram showing an example of a modulation control device according to an embodiment; [Diagram 2] 4 is a flowchart illustrating an example of a process of the modulation control device according to the embodiment. [Diagram 3] FIG. 1 is a schematic diagram illustrating an example of a wireless communication system according to an embodiment. [Figure 4] FIG. 2 is a block diagram showing an example of a base station according to an embodiment. [Diagram 5] 1 is a graph showing an example of a nonlinear characteristic. [Figure 6] 1 is a graph showing an example of change in nonlinear characteristics due to temperature change. [Figure 7A] FIG. 2 is a diagram illustrating an example of a signal point arrangement according to an embodiment; [Figure 7B] FIG. 11 is a diagram showing another example of a signal point arrangement according to the embodiment. [Figure 8] FIG. 2 is a block diagram showing an example of a terminal according to an embodiment; [Figure 9A] 10 is a flowchart illustrating an example of a process of the information processing device according to the embodiment. [Figure 9B] 10 is a flowchart illustrating an example of a process of the information processing device according to the embodiment. [Figure 9C] 10 is a flowchart illustrating an example of a process of the information processing device according to the embodiment. [Figure 10] 11 is a flowchart illustrating an example of a process of a terminal according to the embodiment. [Figure 11] 2 is a block diagram showing an example of a hardware configuration of an apparatus according to an embodiment; DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] Hereinafter, the embodiments of the present disclosure will be described with reference to the drawings. Note that the following description and drawings in the embodiments are omitted and simplified as appropriate for clarity of explanation. For example, in each drawing, the same or corresponding elements are given the same reference numerals, and duplicate explanations are omitted as necessary for clarity of explanation. It goes without saying that the drawings referred to for explanation in each embodiment can also be applied to other embodiments. Furthermore, in this disclosure, unless otherwise specified, when "at least any of" is defined for multiple items, the definition may mean any one item, or any multiple items (including all items).

[0013] First embodiment [Configuration Description] Fig. 1 is a block diagram showing an example of a modulation control device. The modulation control device 10 includes an acquisition unit 11 and a setting unit 12. Each unit (means) of the modulation control device 10 is controlled by a control unit (controller) (not shown). The modulation control device 10 may be mounted in a transmitter that transmits a transmission signal to which the signal point arrangement is applied, or may be provided as a device separate from the transmitter. Each unit of the modulation control device 10 will be described below.

[0014] The acquiring unit 11 acquires temperature data for a predetermined period. The predetermined period is, for example, a period from the time of data acquisition into the future for which temperature changes are to be predicted. The length of the period can be any length, for example, one to several hours, one to several days, one to several weeks, one to several months, one year, etc.

[0015] The temperature data includes temperatures in a plurality of small intervals in a predetermined period. The temperature may be, for example, the air temperature or room temperature at a location where a transmitter that transmits a transmission signal by applying a signal point constellation set by the modulation control device 10 is installed. As an example, when the predetermined period is one day, the temperature data may include a numerical value of the temperature for each small interval, such as one minute or ten minutes. When the predetermined period is several months, the temperature data may include a numerical value of the temperature for each small interval, such as one day or one week. The numerical value of the temperature included in the temperature data is, for example, at least one of the maximum temperature, minimum temperature, and average temperature for one day or one week.

[0016] The modulation control device 10 may obtain the temperature data described above from an external device via a network such as the Internet. Alternatively, the modulation control device 10 may include a generating unit that generates temperature data. For example, the modulation control device 10 may derive temperature data by using an AI (Artificial Intelligence) model that has been trained in advance. This training is performed by inputting teacher data including information on the weather of a past date that serves as a sample and information on temperature data corresponding to the information (correct answer label) into the AI ​​model. The weather information is information related to the weather that is a factor in determining the temperature. This information includes, for example, at least any of the information on the sky state (e.g., sunny, rainy, etc.), temperature, humidity, air pressure, wind speed and wind direction, or weather chart at the location where the transmitter to which the signal point arrangement set by the modulation control device 10 is applied is installed. The information on the temperature data that serves as the correct answer label is information on the temperature or room temperature at the location where the transmitter is installed.

[0017] After the AI ​​model is trained using the teacher data, the acquisition unit 11 inputs information about the weather in a predetermined period to be predicted to the AI ​​model. The AI ​​model outputs temperature data in the predetermined period based on this input information. In this manner, the acquisition unit 11 can acquire temperature data. Any technique such as logistic regression or neural network can be used to train the AI ​​model.

[0018] However, the modulation control device 10 may use any algorithm instead of the AI ​​model. The modulation control device 10 can obtain temperature data for a predetermined period by inputting information about the weather for a predetermined period to be predicted into the algorithm.

[0019] The setting unit 12 sets the signal constellation used to modulate the transmission signal based on the temperature data acquired by the acquisition unit 11 so that the signal constellation used to modulate the transmission signal is switched to a different signal constellation within a predetermined period of time.

[0020] For example, the setting unit 12 may refer to the temperature data to identify the timing at which the magnitude relationship between the temperature and the predetermined threshold changes within a predetermined period of time. In other words, the setting unit 12 may identify at least one of the timing at which the temperature transitions from a state where the temperature is higher than the predetermined threshold to a state where the temperature is equal to or lower than the predetermined threshold, and the timing at which the temperature transitions from a state where the temperature is equal to or lower than the predetermined threshold to a state where the temperature is higher than the predetermined threshold.

[0021] However, the timing specified by the setting unit 12 is not limited to the above. As another example, the setting unit 12 may refer to temperature data to specify a timing at which the temperature changes by a predetermined threshold or more within a certain time period. The change in temperature indicates at least one of an increase in temperature and a decrease in temperature.

[0022] Furthermore, the setting unit 12 may use an AI model that has been trained in advance to identify the timing using temperature. This training is performed by inputting training data including past temperature data as samples and information (correct label) corresponding to the data that indicates the timing at which the signal point arrangement should be switched to another, into the AI ​​model. After the AI ​​model has been trained using the training data, the setting unit 12 inputs temperature data for a predetermined period to be predicted to the AI ​​model. Based on the input information, the AI ​​model outputs information indicating the timing at which the signal point arrangement should be switched in the predetermined period. In this way, the setting unit 12 can obtain information indicating the timing at which the signal point arrangement should be switched. Any technique such as logistic regression or neural network can be used to train the AI ​​model.

[0023] As yet another example, the setting unit 12 may estimate a change in the nonlinear characteristics of an amplifier that amplifies a transmission signal based on temperature data, and specify the timing at which the signal point arrangement should be switched within a predetermined period based on the estimation result. The setting unit 12 may use an AI model that has been trained in advance to specify this timing. This learning is performed by inputting training data including sample data indicating past changes in nonlinear characteristics and information (correct label) corresponding to the data indicating the timing at which the signal point arrangement should be switched to the AI ​​model. After the AI ​​model is trained using the training data, the setting unit 12 inputs data indicating the change in nonlinear characteristics during a predetermined period to be predicted to the AI ​​model. Based on this input information, the AI ​​model outputs information indicating the timing at which the signal point arrangement should be switched within a predetermined period. In this manner, the setting unit 12 can obtain information indicating the timing at which the signal point arrangement should be switched.

[0024] However, the setting unit 12 may use any algorithm instead of the AI ​​model. The setting unit 12 can obtain information indicating the timing to switch the signal point arrangement within a predetermined period by inputting data indicating a change in the nonlinear characteristics of the amplifier within a predetermined period into the algorithm.

[0025] The setting unit 12 sets the signal constellation so that the signal constellation used for modulating the transmission signal is switched to a different signal constellation at a timing according to the specified timing. The timing according to the specified timing may be the timing specified by the setting unit 12 itself, or may be a timing different from the specified timing. For example, the timing according to the specified timing may be a timing convenient for changing the signal constellation in a transmitter that modulates the transmission signal and transmits the transmission signal. As an example, when the transmitter is a transceiver capable of not only transmission but also reception, the timing closest to the specified timing among the timings at which the transmitter and receiver can simultaneously change the modulation setting of the transmission process and the demodulation setting of the reception process may be the timing according to the specified timing.

[0026] For example, the setting unit 12 may set the signal constellation used for modulating the transmission signal to the first signal constellation in a section corresponding to a period during which the temperature is higher than a predetermined threshold during a predetermined period. The setting unit 12 sets the signal constellation used for modulating the transmission signal to the second signal constellation in a section corresponding to a period during which the temperature is equal to or lower than a predetermined threshold during a predetermined period. Note that the section corresponding to a period during which the temperature is higher than or lower than a predetermined threshold is a section whose ends are at timings corresponding to the timings specified by the setting unit 12.

[0027] In this case, the second signal constellation is a signal constellation in which the signal points are arranged so that the interval between the signal points becomes wider as the strength of the transmission signal increases, compared to the first signal constellation. Specific examples of the first and second signal constellations will be described in the second embodiment.

[0028] When the temperature is high, the first signal constellation is used to suppress the occurrence of memory effects when the strength (i.e., power) of the transmitted signal is low, whereas when the temperature is low, the second signal constellation is used to suppress gain compression when the strength of the transmitted signal is high.

[0029] When there are multiple timings to be identified, the setting unit 12 can set the signal constellation so that the signal constellation used for modulating the transmission signal is switched to a different signal constellation at least in part of the multiple timings, as described above. For example, the setting unit 12 sets the signal constellation used for modulating the transmission signal to be switched from the second signal constellation to the first signal constellation at the timing when the temperature transitions from a state lower than a predetermined threshold to a state higher than a predetermined threshold during a predetermined period. The setting unit 12 may also set the signal constellation used for modulating the transmission signal to be switched back from the first signal constellation to the second signal constellation at the timing when the temperature transitions from a state higher than the predetermined threshold to a state lower than the predetermined threshold.

[0030] [Flow description] 2 is a flowchart showing an example of a typical process of the modulation control device 10, and an overview of the process of the modulation control device 10 will be described with reference to this flowchart. Note that the details of each process are as described above, and therefore will not be described here.

[0031] First, the acquisition unit 11 acquires temperature data for a predetermined period (step S11; acquisition step). The setting unit 12 sets a signal constellation used for modulating the transmission signal based on the temperature data so that the signal constellation used for modulating the transmission signal is switched to a different signal constellation within the predetermined period (step S12; setting step). The modulation control device 10 may output information on the signal constellation related to the predetermined period set in step S12 to another device.

[0032] [Effect description] As described above, the setting unit 12 sets the signal constellation used for modulating the transmission signal based on the temperature data so that the signal constellation used for modulating the transmission signal is switched to a different signal constellation within a predetermined period. This allows the modulation control device 10 to suppress the occurrence of phenomena such as gain suppression or memory effect in the transmission signal even if the nonlinear characteristics of the amplifier that amplifies the transmission signal change due to a temperature change. Therefore, the modulation control device 10 can suppress bit errors in the transmission signal even if there is a temperature change.

[0033] Furthermore, the setting unit 12 may set a signal constellation so as to switch the signal constellation used for modulating the transmission signal to a different signal constellation at a timing according to a timing at which the magnitude relationship between the temperature and a predetermined threshold changes during a predetermined period. This allows the modulation control device 10 to switch the signal constellation at a timing when the nonlinear characteristic is considered to change, thereby reliably suppressing the occurrence of phenomena such as gain suppression or memory effect in the transmission signal.

[0034] The setting unit 12 may set the signal constellation to be used to the first signal constellation in a section corresponding to a period during which the temperature is higher than a predetermined threshold during a predetermined period, and may set the signal constellation to be used to the second signal constellation in a section corresponding to a period during which the temperature is equal to or lower than the predetermined threshold. Here, the second signal constellation is a signal constellation in which the signal points are arranged so that the interval between the signal points becomes wider as the intensity of the transmission signal increases, as compared with the first signal constellation. Therefore, the modulation control device 10 can effectively suppress the occurrence of memory effect and gain suppression.

[0035] Embodiment 2 Hereinafter, the second embodiment will be described in detail with reference to the drawings. The second embodiment discloses a specific application example of the modulation control device described in the first embodiment, but the application example of the modulation control device shown in the first embodiment is not limited to the one shown below. Furthermore, the configurations and processes described below are examples and are not limited to these. All or any part of the configurations described in the second embodiment can be appropriately applied to the modulation control device described in the first embodiment, and it goes without saying that the drawings shown in the second embodiment can be appropriately applied to the first embodiment.

[0036] [Configuration Description] 3 is a schematic diagram showing an example of a wireless communication system. The wireless communication system S includes a base station 100, a terminal 200, an artificial satellite 300, and a receiving station 400. Two-way wireless communication is performed between the base station 100 and the terminal 200, between the terminal 200 and the artificial satellite 300, and between the artificial satellite 300 and the receiving station 400. The terminal 200 is a mobile body, and the wireless communication system S is capable of mobile communication. The receiving station 400 functions as a gateway connecting the artificial satellite 300 to a backhaul connected to the receiving station 400.

[0037] The transmitter device in each wireless communication executes adaptive modulation and coding (ACM) and compensation for nonlinearity occurring in the amplifier of the transmission signal as necessary. ACM is a technology that switches the modulation method and the coding method depending on whether the wireless communication line (hereinafter, also simply referred to as the line) is in good condition or not. By using ACM, the transmitter can change the error correction and multi-value conversion method in the transmission signal according to the line conditions. In addition, by the transmitter executing nonlinear compensation, the effect of multi-value conversion can be further improved, and wireless communication capacity can be increased.

[0038] However, when the transmitter executes the above process to increase the communication capacity, the process requires calculation, and the power consumption in the transmitter increases accordingly. Therefore, it is desirable to achieve both an increase in communication capacity and a reduction in power consumption in wireless communication. In the second embodiment, a method for increasing communication capacity and reducing power consumption by integrally controlling a plurality of processes executed inside the transmitter is described. More specifically, the transmitter can change various processes to be executed and reduce power consumption by comprehensively judging the line status, the power supply capacity available for processing, the temperature status at the location where the transmitter is installed, and the like. Hereinafter, the details of the base station 100 and the terminal 200 will be particularly described.

[0039] 4 is a block diagram showing an example of a base station. The base station 100 includes a required parameter calculation unit 101, a power supply estimation unit 102, a power calculation unit 103, a change prediction unit 104, a setting unit 105, a control unit 106, a nonlinear compensation unit 107, a multiplexing unit 108, a modulation / demodulation unit 109, and a transmission / reception unit 110. Hereinafter, the base station 100 will be described as a transmitter that transmits a transmission signal to a terminal 200. Note that the number of terminals 200 is not limited to one, and multiple terminals may be provided.

[0040] The required parameter calculation unit 101 obtains an index value indicating the state of the line connecting the base station 100 and the terminal 200, and calculates a required S / N (signal-noise ratio) that satisfies a parameter indicating the accuracy required for the transmission signal, using the index value. The index value indicating the state of the line may be, for example, Channel State Information (CSI), but examples of the index value are not limited to this. Also, the parameter indicating the accuracy is a value preset in the base station 100, and is a value indicating that the transmission signal should be transmitted at an error rate equal to or lower than this value. In this example, the parameter indicating the accuracy is BER (Bit Error Rate), but examples of the parameters used are not limited to this.

[0041] The required parameter calculation unit 101 calculates the required transmission power by using the calculated required S / N. The required transmission power refers to the power to be allocated to the transmission of a transmission signal. When the required BER value decreases, the noise ratio allowed in the required S / N decreases. In this case, compared to when the required BER value is high, at least one of the following occurs: the number of processes executed by the base station 100 increases, or the processing time becomes longer. Therefore, when the required BER value decreases, the required transmission power calculated by the required parameter calculation unit 101 becomes a higher value.

[0042] When the required BER is changed, the required parameter calculation unit 101 calculates a required S / N that satisfies the changed required BER. Then, the required parameter calculation unit 101 calculates a new required transmission power by using the calculated required S / N. In this way, the required parameter calculation unit 101 can calculate the required transmission power multiple times as necessary.

[0043] The power supply estimating unit 102 estimates the power supplied to the base station 100 and available to the base station 100. The power supply estimating unit 102 may estimate at least one of the power supplied from outside the base station 100, the power supplied to the base station 100 from a power generating device attached to the base station 100, or both, as the power available to the base station 100. The power supplied from outside the base station 100 or from a power generating device attached to the base station 100 may be constant regardless of time, or may change over time. An example of the latter is power derived from renewable energy. Renewable energy refers to energy derived from at least one of solar light, wind power, hydroelectric power, geothermal heat, solar heat, heat in the atmosphere, or other heat present in nature, or biomass.

[0044] For example, the power supply estimation unit 102 may derive data on the power supply by using an AI model that has been trained in advance. This training is performed by inputting training data including information related to the power supply on a past date as a sample and information on the power supply value corresponding to the information (correct answer label) into the AI ​​model. The information related to the power supply is information that is a factor that determines the power supply value. For example, when the power supply is derived from sunlight or solar heat, the information related to the power supply may include information on the sky state, such as sunny or rainy, in each small section (for example, every hour or every day) at the location where the base station 100 is installed. In addition, when the power supply is derived from wind power, the information related to the power supply may include information on the wind speed and wind direction in each small section at the location where the base station 100 is installed. The information on the power supply value that is the correct answer label is information on the power supply value supplied to the base station 100.

[0045] After the AI ​​model is trained using the teacher data, the power supply estimation unit 102 inputs information related to the power supply during a predetermined period to be predicted to the AI ​​model. The AI ​​model outputs data on the power supply during the predetermined period based on the input information. Any technique such as logistic regression or neural network can be used to train the AI ​​model.

[0046] However, the power supply estimation unit 102 may use any algorithm instead of the AI ​​model. The setting unit 12 can obtain data on the power supply during a predetermined period by inputting information related to the power supply during the predetermined period to be predicted into the algorithm.

[0047] The power calculation unit 103 calculates the power available to the nonlinear compensation unit 107 and the multiplexing unit 108 at each timing in the predetermined period (hereinafter also referred to as available power) using the data of power supply in the predetermined period estimated by the power supply estimation unit 102. Each timing in the predetermined period is a unit time for executing processes such as signal point arrangement, nonlinear compensation, and multiplexing, or a timing for setting a time when such processes can be switched. The power calculation unit 103 may calculate the available power by, for example, subtracting a power value (hereinafter also referred to as used power value) used in processes other than signal point arrangement, nonlinear compensation, and multiplexing from a power supply value indicated by the power supply data.

[0048] The power usage value may be, for example, a substantially constant value. The power calculation unit 103 can calculate the available power by subtracting the substantially constant value from the power supply value indicated by the power supply data.

[0049] As another example, the power usage value may change over time. The reason why the power usage value changes over time may be, for example, a change in the amount of communication due to a change in the number of terminals 200, or the necessity of nonlinear compensation for the wireless signal received by the base station 100 from the terminal 200, which changes over time. In such a case, the power calculation unit 103 may derive the power usage value for a predetermined period by using an AI model that has been trained in advance. This training is performed by inputting teacher data including information related to the power usage value of each small section (for example, every hour or every day) in the past as a sample and information (correct answer label) of the power usage value corresponding to the information, into the AI ​​model. The information related to the power usage value is information that is a factor that determines the power usage value. For example, the information related to the power usage value may include date information, information on the presence or absence of an event in the cell covered by the base station 100, and the like.

[0050] After the AI ​​model is trained using the teacher data, the power calculation unit 103 inputs information related to the power usage value in a predetermined period to be predicted to the AI ​​model. The AI ​​model outputs data on the power usage value in the predetermined period based on this input information. Any technique such as logistic regression or neural network can be used to train the AI ​​model. The power calculation unit 103 can calculate the available power at each timing using the power usage value calculated in this way.

[0051] However, the power calculation unit 103 may use any algorithm instead of the AI ​​model. The setting unit 12 can obtain data on the power consumption value in a predetermined period by inputting information related to the power consumption value in the predetermined period to be predicted into the algorithm.

[0052] Depending on the calculated available power, whether or not the nonlinear compensation unit 107 and the multiplexing unit 108 can perform multiplexing and nonlinear compensation, respectively, changes. In other words, the larger the available power, the higher the possibility of achieving both multiplexing and nonlinear compensation.

[0053] When the required parameter calculation unit 101 newly calculates the required transmission power, the power calculation unit 103 uses the newly calculated required transmission power to calculate the available power as described above. In this way, the power supply estimation unit 102 can execute the calculation of the available power multiple times as necessary.

[0054] Furthermore, power calculation section 103 can calculate the following powers based on the signal point arrangement set by setting section 105 at each timing within a predetermined period. A first power required for controlling the signal constellation and for performing nonlinear compensation according to the set signal constellation A second power required when the multiplexing unit 108 executes multiplexing The first power includes at least the power required for the modem 109 to set the signal constellation of the transmission signal to the signal constellation set by the setting unit 105, and the power required for the nonlinear compensation unit 107 to perform nonlinear compensation (hereinafter also referred to as the fourth power). Here, the first power is a value larger than the fourth power.

[0055] The first power required when the signal point arrangement control and nonlinear compensation are executed may be the net power required when the signal point arrangement control and nonlinear compensation are executed, or may be the power obtained by adding a predetermined margin to the required net power. The second power required when multiplexing is executed may be the net power required when multiplexing is executed, or may be the power obtained by adding a predetermined margin to the required net power. Similarly, the fourth power, which is the power required when nonlinear compensation is executed, may be the net power required when nonlinear compensation is executed, or may be the power obtained by adding a predetermined margin to the required net power. By calculating at least one of the first power, the second power, and the fourth power as described above, the power calculation unit 103 can further suppress the possibility that the power used for processing exceeds the available power when processing is actually executed.

[0056] The change prediction unit 104 obtains data on temperature during a predetermined period of time, which is the target of prediction, from outside the base station 100. The change prediction unit 104 predicts changes in the nonlinear characteristics of an amplifier (not shown) of the base station 100 during the predetermined period of time by using the temperature data. The amplifier of the base station 100 is a device that amplifies a transmission signal. Here, the change prediction unit 104 may derive changes in the nonlinear characteristics of the amplifier during the predetermined period of time, for example, by using an AI model that has been trained in advance. This learning is performed by inputting training data including sample data of past temperature and information (correct answer label) of changes in the nonlinear characteristics of the amplifier corresponding to the information, into the AI ​​model. After the AI ​​model has been trained using the training data, the change prediction unit 104 inputs data on temperature during a predetermined period of time, which is the target of prediction, into the AI ​​model. The AI ​​model outputs information on changes in the nonlinear characteristics of the amplifier during the predetermined period of time based on this input information. Any technique, such as logistic regression or neural network, can be used for training the AI ​​model.

[0057] However, the change prediction unit 104 may use any algorithm instead of an AI model. The change prediction unit 104 can obtain information on the change in the nonlinear characteristics of the amplifier within the predetermined period by inputting data on the temperature during the predetermined period, which is the prediction target, into the algorithm.

[0058] FIG. 5 is a graph showing an example of nonlinear characteristics at a certain temperature. The horizontal axis in the graph of FIG. 5 indicates the normalized input power of a transmission signal input to an amplifier, and the vertical axis indicates the normalized output power of a transmission signal output by the amplifier. FIG. 5 shows that when the input power is low, the dispersion of fluctuations occurs due to a memory effect in which the history of the transmission signal previously input to the amplifier remains in the amplifier. The memory effect occurs, for example, when the communication speed is 1 to 10 GPPS. FIG. 5 also shows that when the input power is high (especially when the input power is near the saturation point), gain suppression occurs, which means that the output power is difficult to increase. In other words, it is shown that nonlinearity due to different mechanisms occurs in the output of the amplifier when the input power is low and when it is high.

[0059] FIG. 6 is a graph showing an example of change in nonlinear characteristics due to temperature change. The horizontal and vertical axes of the graph in FIG. 6 show the same contents as the horizontal and vertical axes of the graph in FIG. 5. In FIG. 6, nonlinear characteristics at temperatures T1, T2, and T3 are shown. Here, the temperature levels are T1>T2>T3. In each of the temperatures T1 to T3, the memory effect is clearly manifested in the order of temperatures T1, T2, and T3, whereas the gain suppression is clearly manifested in the order of temperatures T3, T2, and T1. In this way, the nonlinear characteristics of the amplifier change according to temperature change. The change prediction unit 104 can predict the effect of the nonlinear characteristics on the transmission signal by grasping the prediction of the temperature change before the base station 100 determines the signal point arrangement.

[0060] Setting section 105 sets compensation processing that is considered optimal by using the effect on the transmission signal of the nonlinear characteristics predicted by change prediction section 104. Specifically, setting section 105 refers to the change in the nonlinear characteristics predicted by change prediction section 104 and sets, from among a plurality of signal point constellations, a signal point constellation to be used for modulating the transmission signal at each timing within a predetermined period.

[0061] 7A and 7B show examples of signal point constellations in 64APSK (Amplitude and phase-shift keying), respectively. The horizontal axis of FIG. 7A and FIG. 7B shows the in-phase component, and the vertical axis shows the quadrature component. FIG. 7A shows a signal point constellation in which the interval between signal points becomes wider as the power of the transmission signal, which is the input signal to the amplifier, becomes higher. For example, the interval between signal points "8" and "12" in FIG. 7A is narrow, but the interval between signal points "10" and "14" is wide. On the other hand, FIG. 7B shows a signal point constellation in which signal points are arranged so that the interval between signal points becomes equal, regardless of the power of the transmission signal, which is the input signal. In other words, the signal point constellation in FIG. 7A is a signal point constellation in which signal points are arranged so that the interval between signal points becomes wider as the strength of the transmission signal becomes higher, compared to the signal point constellation in FIG. 7B.

[0062] When the signal constellation of Fig. 7A is applied to a transmission signal, errors in the output transmission signal are less likely to occur when the power of the transmission signal input to the amplifier is large. Therefore, the signal constellation of Fig. 7A is suitable for correcting nonlinear distortion caused by the amplifier when the power of the transmission signal is large. On the other hand, when the power of the transmission signal is small, errors in the output transmission signal are more likely to occur when the signal constellation of Fig. 7A is applied, whereas errors in the output transmission signal are less likely to occur when the signal constellation of Fig. 7B is applied. Therefore, it is preferable to use the signal constellation of Fig. 7B when the power of the transmission signal is small.

[0063] Here, in the graph shown in Fig. 6, a description will be given of what kind of signal constellation is preferable for the nonlinear characteristics of each temperature. As described above, at temperature T1, the memory effect is clearly manifested, whereas the suppression of gain is less manifested. In other words, at temperature T1, when the power of the transmission signal, which is the input signal, is small, the transmission signal output from the amplifier is more likely to deteriorate. Therefore, at temperature T1, setting unit 105 selects the signal constellation of Fig. 7B, which is less likely to cause errors in the signal even when the power of the transmission signal is small.

[0064] On the other hand, at temperature T3, the suppression of gain is clearly observed, but the memory effect is not so observed. In other words, at temperature T3, when the power of the transmission signal, which is the input signal, is large, the transmission signal output from the amplifier is likely to deteriorate. Therefore, at temperature T3, setting unit 105 selects the signal point arrangement of FIG. 7A, which is less likely to cause errors in the signal even when the power of the transmission signal is large.

[0065] In the case of temperature T2, the setting unit 105 judges which of the effects of the gain suppression in the high power part and the memory effect in the low power part is more strongly expressed. Then, the setting unit 105 selects the signal point arrangement of FIG. 7A when the gain suppression is strongly expressed, and selects the signal point arrangement of FIG. 7B when the memory effect is strongly expressed. In addition, when performing the above judgment, the setting unit 105 may acquire the influence of each of the gain suppression and the memory effect on the deterioration of the BER characteristics. The BER characteristic deterioration is determined based on a required BER set in advance. The setting unit 105 compares the influence of each and specifies which of the two has a higher influence. Then, the setting unit 105 specifies whether the higher influence is the high power part or the low power part in the nonlinear characteristics, and selects the signal point arrangement of FIG. 7A or 7B in which an error is less likely to occur in that part. In addition, the setting unit 105 may perform the same judgment in the cases of temperatures T1 and T3 and select an appropriate signal point arrangement.

[0066] As described above, setting unit 105 can switch the signal point arrangement set for the transmission signal according to the temperature of the environment in which the amplifier is placed (i.e., the environment in which base station 100 is placed). Therefore, setting unit 105 contributes to suppressing bit errors in the transmission signal even when a temperature change occurs. Also, setting unit 105 can eliminate or suppress nonlinear compensation required for the transmission signal.

[0067] For example, setting section 105 may set, based on the prediction result of change prediction section 104, to use the signal point arrangement of Fig. 7B for modulating the transmission signal in an interval corresponding to a period during which the temperature is higher than a predetermined threshold. Also, based on the prediction result of change prediction section 104, setting section 105 may set, based on the prediction result of change prediction section 104, to use the signal point arrangement of Fig. 7A for modulating the transmission signal in an interval corresponding to a period during which the temperature is equal to or lower than a predetermined threshold.

[0068] The setting unit 105 refers to the nonlinear characteristics at each timing within a predetermined period and selects a signal constellation to be set at each timing using the above method. Based on the data of the selected signal constellation, the setting unit 105 specifies at what timing the signal constellation should be switched. Then, the setting unit 105 sets the signal constellation so that the signal constellation used for modulating the transmission signal is switched to a different signal constellation at a timing according to the specified timing. Here, the "timing according to the specified timing" refers to a timing immediately before the specified timing among timings at which the base station 100 can simultaneously change the modulation setting of the transmission process and the demodulation setting of the reception process.

[0069] Returning to FIG. 4, the description of the base station 100 continues. Based on the data of switching of the signal point arrangement within a predetermined period set by the setting unit 105, the control unit 106 judges whether or not at least one of multiplexing and nonlinear compensation is possible for the transmission signal with the available power at each timing. In the judgment, the control unit 106 performs the above judgment using the first power required for controlling the signal point arrangement and executing nonlinear compensation, the second power required when the multiplexing unit 108 executes multiplexing, and the available power, based on the signal point arrangement set by the setting unit 105. Then, the control unit 106 determines that at least one of the processes of multiplexing and nonlinear compensation, which is possible with the available power, is to be executed. Details of this process will be described later in the flow shown in FIGS. 9A to 9C.

[0070] When the base station 100 performs multiplexing and nonlinear compensation, the amount of calculations performed by the base station 100 increases, and therefore the power consumption of the base station 100 increases. In particular, multiplexing and nonlinear compensation consume a large amount of power compared to other processes on the transmission signal. Therefore, the control unit 106 takes into consideration the available power and the power required for each of multiplexing and nonlinear compensation, and controls to perform as much processing as possible on the transmission signal while preventing the power consumption required for processing from exceeding the available power.

[0071] When the required parameter calculation unit 101 newly calculates the required transmission power and the power supply estimation unit 102 newly calculates the available power, the control unit 106 can execute the above determination using the changed available power, the first power, and the second power. In this way, the control unit 106 can execute the determination multiple times as necessary.

[0072] When the control unit 106 instructs the nonlinear compensation unit 107 to perform nonlinear compensation, the nonlinear compensation unit 107 performs nonlinear compensation on the transmission signal output from the amplifier in accordance with the instruction. When the control unit 106 does not instruct the nonlinear compensation unit 107 to perform nonlinear compensation on the transmission signal.

[0073] When the control unit 106 instructs the multiplexing unit 108 to perform multiplexing, the multiplexing unit 108 performs multiplexing on the transmission signals output from the amplifiers in accordance with the instruction. When the control unit 106 does not instruct the multiplexing unit 108 to perform multiplexing, the nonlinear compensation unit 107 does not perform multiplexing on the transmission signals.

[0074] The modem unit 109 performs modulation processing on the transmission signal that is output from the amplifier and has been subjected to either nonlinear compensation or multiplexing as necessary. In this modulation processing, signal point arrangement for the transmission signal is controlled based on the signal point arrangement at each timing within a predetermined period set by the setting unit 105. The modem unit 109 can also perform demodulation processing on the signal from the terminal 200 that is received by the transmission / reception unit 110.

[0075] The transmitting / receiving unit 110 transmits the transmission signal modulated by the modem unit 109 to the terminal 200. The transmitting / receiving unit 110 can also receive signals from the terminal 200.

[0076] As an example, the required parameter calculation unit 101, the power supply estimation unit 102, the power calculation unit 103, the change prediction unit 104, the setting unit 105 and the control unit 106 may be realized as functions of a processor as a hardware configuration. The nonlinear compensation unit 107, the multiplexing unit 108, the modulation / demodulation unit 109 and the transmission / reception unit 110 may be realized as a signal processing circuit as a hardware configuration. An example of the base station 100 realized as a hardware configuration will be described later.

[0077] 8 is a block diagram showing an example of a terminal. Terminal 200 includes a transceiver 201, a modulation / demodulation unit 202, a control unit 203, and a nonlinear compensation unit 204. In the following description, terminal 200 is assumed to be a receiver that receives a transmission signal from base station 100.

[0078] The transceiver unit 201 receives a transmission signal transmitted from the transceiver unit 110 of the base station 100. The transceiver unit 201 can also transmit a signal to the base station 100.

[0079] The modem unit 202 performs demodulation processing on the signal received by the transmission / reception unit 201. The modem unit 202 can also perform modulation processing on the signal output from the amplifier of the terminal 200 and transmitted to the base station 100. In this modulation processing, the signal point arrangement for the transmission signal may be controlled based on the signal point arrangement at each timing within a predetermined period set by the terminal 200.

[0080] The control unit 203 judges whether or not nonlinear compensation has been performed in the base station 100 for the received signal demodulated by the modem unit 202. The control unit 203 may perform this judgment, for example, by detecting the BER of the signal to be judged and judging whether or not the detected BER is equal to or lower than a required BER.

[0081] When the control unit 203 determines that the received signal has not been subjected to nonlinear compensation, the nonlinear compensation unit 204 performs nonlinear compensation on the received signal. By performing this process, the terminal 200 can obtain accurate data of the received signal.

[0082] [Flow description] 9A to 9C are flowcharts showing an example of representative processing of base station 100, and an overview of the processing of base station 100 will be described with reference to this flowchart. In the following description, details of processing that have already been described will be omitted as appropriate.

[0083] First, the required parameter calculation unit 101 calculates a required S / N ratio using a required BER. Then, the required parameter calculation unit 101 calculates a required transmission power by using the calculated required S / N ratio. Next, the power supply estimation unit 102 estimates the power supplied to the base station 100 and available for the base station 100. The power calculation unit 103 calculates the available power at each timing during the predetermined period using the data on the power supply during the predetermined period estimated by the power supply estimation unit 102 (step S21; available power calculation step).

[0084] The change prediction unit 104 predicts a change in the nonlinear characteristics of the amplifier of the base station 100 within the predetermined period by using data on the temperature during the predetermined period that is the prediction target (step S22; nonlinear characteristics change prediction step).

[0085] The setting unit 105 uses the effect on the transmission signal of the nonlinear characteristics predicted by the change prediction unit 104 to select, from among a plurality of signal point constellations, a signal point constellation to be used for modulating the transmission signal at each timing within a predetermined period (step S23; signal point constellation selection step).

[0086] The power calculation unit 103 calculates, at each timing within a predetermined period, a first power required for executing control of the signal constellation and nonlinear compensation, and a second power required for the multiplexing unit 108 to execute multiplexing, based on the signal constellation set in step S23 (step S24; power usage calculation step).

[0087] At least one of the processes in steps S22 to S24 may be executed before the process in step S21, or may be executed simultaneously with the process in step S21.

[0088] The control unit 106 judges whether the first power calculated in step S24 is larger than the available power (step S25; nonlinear compensation judgment step). More specifically, the control unit 106 judges whether the first power is equal to or smaller than the available power at all timings within a predetermined period. In this way, the control unit 106 judges whether nonlinear compensation based on the signal point arrangement set in step S23 is possible.

[0089] If the first power is greater than the available power at any timing within the predetermined period (No in step S25), control unit 106 determines that nonlinear compensation based on the signal point arrangement set in step S23 is not possible. Control unit 106 also determines that there is no need to perform multiplexing on the transmission signal on which nonlinear compensation is not performed. Therefore, control unit 106 controls nonlinear compensation unit 107 not to perform nonlinear compensation and controls multiplexing unit 108 not to perform multiplexing (step S26; processing decision step). In this case, the control of the signal point arrangement set in step S23 is not performed on the transmission signal. Furthermore, nonlinear compensation on the transmission signal is performed by terminal 200 receiving the transmission signal.

[0090] On the other hand, if the first power is equal to or less than the available power at all timings (Yes in step S25), the control unit 106 derives the third power by adding the second power calculated in step S24 to the first power. Then, the control unit 106 determines whether the third power is equal to or less than the available power (step S27; multiplexing determination step). More specifically, the control unit 106 determines whether the third power is equal to or less than the available power at all timings within a predetermined period. In this way, the control unit 106 determines whether nonlinear compensation and multiplexing based on the signal point arrangement set in step S23 are possible.

[0091] If the third power is equal to or less than the available power at all timings (Yes in step S27), control unit 106 determines that nonlinear compensation and multiplexing based on the signal point arrangement set in step S23 are executable. Therefore, control unit 106 controls nonlinear compensation unit 107 to execute nonlinear compensation and multiplexing unit 108 to execute multiplexing (step S28; processing decision step). In this case, the signal point arrangement set in step S23 is executed on the transmission signal. Also, terminal 200 does not need to execute nonlinear compensation on the transmission signal to be received.

[0092] On the other hand, if the third power is greater than the available power at any timing within the predetermined period (No in step S27), the power calculation unit 103 calculates the fourth power, which is the power required when performing nonlinear compensation. Then, the control unit 106 determines whether or not the fifth power, which is obtained by subtracting the fourth power from the third power, is equal to or less than the available power (step S29). More specifically, the control unit 106 determines whether or not the fifth power is equal to or less than the available power at all timings within the predetermined period. In this way, when nonlinear compensation is not performed, the control unit 106 determines whether or not the control and multiplexing of the signal point arrangement set in step S23 are possible.

[0093] If the fifth power is greater than the available power at any timing within the predetermined period (No in step S29), control unit 106 determines that multiplexing is not possible, but nonlinear compensation based on the signal point arrangement set in step S23 is possible. Therefore, control unit 106 controls multiplexing unit 108 not to perform multiplexing, and controls nonlinear compensation unit 107 to perform nonlinear compensation (step S30; processing decision step). In this case, the signal point arrangement set in step S23 is performed on the transmission signal. Also, terminal 200 does not need to perform nonlinear compensation on the transmission signal to be received.

[0094] If the fifth power is equal to or less than the available power at all timings (Yes in step S29), the control unit 106 determines whether the BER of the transmission signal satisfies the required BER when the signal point arrangement and multiplexing are performed but nonlinear compensation is not performed (step S31; BER determination step). That is, the control unit 106 determines whether the BER of the transmission signal is equal to or less than the required BER. If nonlinear compensation is not performed, there is a possibility that the transmission signal does not satisfy the desired quality, so the control unit 106 performs this determination.

[0095] If the BER of the transmission signal satisfies the required BER (Yes in step S31), the control unit 106 controls the multiplexing unit 108 to perform multiplexing, and controls the nonlinear compensation unit 107 not to perform nonlinear compensation (step S32; processing decision step). In this case, the signal point arrangement set in step S23 is applied to the transmission signal. Moreover, the nonlinear compensation for the transmission signal is performed by the terminal 200 that receives the transmission signal.

[0096] If the BER of the transmission signal does not satisfy the required BER (No in step S31), the control unit 106 changes the required BER so that the BER of the transmission signal in step S31 is equal to or less than the required BER (step S33; required BER change step). Then, the required parameter calculation unit 101 calculates the required transmission power using the changed required BER as described in the explanation of step S21. The power supply estimation unit 102 calculates the available power using the newly calculated required transmission power (step S21). Thereafter, the base station 100 executes the process from step S22 onwards again using the changed required BER and the newly calculated available power. Note that when the process from step S22 onwards is executed again, at least one of the processes from step S22 to S24 may be omitted. This is because the values ​​calculated in these steps in the first flow loop can be diverted to the second flow loop.

[0097] 9A to 9C until the BER of the transmission signal satisfies the required BER and all processes that can be executed within the available power are executed. When the base station 100 reaches this state, the base station 100 ends the loop and determines the process to be executed.

[0098] Based on the control determined by the control unit 106 in steps S26, S28, S30, and S32, the nonlinear compensation unit 107 and the multiplexing unit 108 execute their respective processes. The modem unit 109 modulates the processed transmission signal, and the transceiver unit 110 transmits the modulated transmission signal to the terminal 200.

[0099] In step S25, control unit 106 may determine whether the first power is equal to or less than the available power for a period that is equal to or greater than a certain percentage of the predetermined period or a period that is equal to or greater than a certain length. Control unit 106 may also determine in step S27 or S29 whether the third power or the fifth power is equal to or less than the available power for a period that is equal to or greater than a certain percentage of the predetermined period or a period that is equal to or greater than a certain length. In this manner, base station 100 can still execute the flows shown in FIGS. 9A to 9C.

[0100] Furthermore, in step S29, control unit 106 may set, as the fourth power, power to be used for a portion of nonlinear compensation to be performed by terminal 200 among the nonlinear compensations performed on the transmission signal. In this case, if it is determined in step S29 that a portion of nonlinear compensation is not to be performed, control unit 106 determines whether or not the setting of the signal point arrangement and multiplexing in step S23 are possible. If it is determined No in step S29, control unit 106 controls multiplexing unit 108 not to perform multiplexing, and controls nonlinear compensation unit 107 to perform nonlinear compensation (step S30).

[0101] On the other hand, if the determination in step S29 is Yes, the control unit 106 executes the determination in step S31. If the BER of the transmission signal satisfies the required BER (Yes in step S31), the control unit 106 controls the multiplexing unit 108 to execute multiplexing. The control unit 106 also controls the nonlinear compensation unit 107 to not execute some nonlinear compensation processes and to execute the remaining nonlinear compensation processes (step S32; processing decision step). In this case, the nonlinear compensation processes for the transmission signal that are not executed in step S32 are executed by the terminal 200 that receives the transmission signal.

[0102] If the BER of the transmission signal does not satisfy the required BER (No in step S31), the control unit 106 executes the processes in steps S33 and after, the details of which are as described above.

[0103] 10 is a flowchart showing an example of a representative process of terminal 200, and an overview of the process of terminal 200 will be described with reference to this flowchart. In the following description, details of the process that have already been described will be omitted as appropriate.

[0104] First, the transmitting / receiving unit 201 receives a transmission signal transmitted from the transmitting / receiving unit 110 of the base station 100 (step S41; receiving step). The modem unit 202 executes demodulation processing on the signal received by the transmitting / receiving unit 201.

[0105] The control unit 203 judges whether or not the base station 100 has performed nonlinear compensation on the received signal demodulated by the modem unit 202 (step S42; judgment step). If the control unit 203 judges that the received signal has been nonlinearly compensated (Yes in step S42), the nonlinear compensation unit 204 does not perform nonlinear compensation on the received signal. On the other hand, if the control unit 203 judges that the received signal has not been nonlinearly compensated (No in step S42), the nonlinear compensation unit 204 performs nonlinear compensation on the received signal (step S43; nonlinear compensation step).

[0106] [Effect description] In the second embodiment, the change prediction unit 104 of the base station 100 sets a signal constellation used for modulating a transmission signal based on data on temperature during a predetermined period, so that the signal constellation used for modulating the transmission signal is switched to a different signal constellation within a predetermined period. This enables the base station 100 to suppress bit errors in the transmission signal even when there is a temperature change. The details of the reason for this are as described in the first embodiment.

[0107] Furthermore, the change prediction unit 104 may predict a change in the nonlinear characteristics of the amplifier within a predetermined period based on temperature data for the predetermined period. The setting unit 105 sets a signal constellation used for modulating the transmission signal based on the change in the nonlinear characteristics so that the signal constellation used for modulating the transmission signal is switched to a different signal constellation within the predetermined period. This allows the base station 100 to change the signal constellation at a timing when a change in the nonlinear characteristics of the amplifier occurs and a different nonlinear compensation method should be applied. Therefore, bit errors in the transmission signal can be reliably suppressed.

[0108] Furthermore, the control unit 106 can determine whether to perform at least one of nonlinear compensation and multiplexing using a first power required for controlling the set signal constellation and performing nonlinear compensation based on the signal constellation, a second power required for multiplexing performed on the transmission signal, and available power. Therefore, the base station 100 can simultaneously respond to at least one of an increase in communication capacity and a reduction in bit errors, while reducing power consumption.

[0109] Furthermore, when the first power is equal to or less than the available power, the third power is greater than the available power, and the fifth power is greater than the available power, the control unit 106 may determine to perform nonlinear compensation based on the set signal point arrangement but not to perform multiplexing. This allows the base station 100 to suppress bit errors in the transmission signal by performing nonlinear compensation, and to suppress power consumption.

[0110] Furthermore, the control unit 106 may determine that multiplexing is performed and at least a part of the nonlinear compensation process is not performed when the first power is equal to or less than the available power, the third power is greater than the available power, the fifth power is equal to or less than the available power, and the BER of the transmission signal satisfies a required BER. This allows the base station 100 to perform multiplexing corresponding to an increase in the communication capacity of the transmission signal and suppress power consumption.

[0111] Furthermore, when the first power is equal to or less than the available power, the third power is greater than the available power, the fifth power is equal to or less than the available power, and the BER of the transmission signal does not satisfy the required BER, the control unit 106 may change the required BER and execute the flow from step S21 again. In this way, the base station 100 changes the required BER only when necessary, and therefore the BER of the transmission signal can be kept as high as possible. Furthermore, the base station 100 can perform nonlinear compensation or multiplexing, whichever is feasible, while power consumption is suppressed, and therefore bit errors can be suppressed, and it is possible to accommodate an increase in communication capacity or suppress bit errors.

[0112] The present disclosure is not limited to the above-described embodiment, and can be modified as appropriate without departing from the spirit and scope of the present disclosure.

[0113] For example, in the second embodiment, the base station 100 can perform mobile communication with the terminal 200, which is a mobile body that can move relatively to the base station 100. However, the terminal 200 may be a terminal that is not a mobile body. In this case, the base station 100 performs fixed communication with the terminal 200. Moreover, the techniques described in each embodiment can be applied not only to wireless communication but also to wired communication.

[0114] The signal constellations that setting section 105 sets at each timing of a predetermined period are not limited to those shown in Fig. 7A and 7B. Setting section 105 may also select one signal constellation to be applied to a transmission signal from three or more signal constellations by the same method as that shown in the second embodiment.

[0115] For example, assume that there are three signal point constellations H1, H2, and H3 as signal point constellation candidates. Compared with signal point constellation H3, signal point constellations H1 and H2 are signal point constellations in which signal points are arranged so that the interval between signal points becomes wider as the intensity of the transmission signal increases. Signal point constellation H3 is a signal point constellation in which signal points are arranged so that the interval between signal points becomes even. Also, compared with signal point constellation H2, signal point constellation H1 is a signal point constellation in which signal points are arranged so that the interval between signal points becomes wider as the intensity of the transmission signal increases. In this case, setting unit 105 can select, for example, signal point constellation H3 for the nonlinear characteristic of temperature T1 in FIG. 6, signal point constellation H2 for the nonlinear characteristic of temperature T2, and signal point constellation H1 for the nonlinear characteristic of temperature T3.

[0116] In the second embodiment, the change prediction unit 104 may not predict the change in the nonlinear characteristics of the amplifier. In this case, the setting unit 105 may determine the timing to change the signal point arrangement by comparing the air temperature data with a predetermined threshold value, or by identifying the timing at which the temperature changes by more than the predetermined threshold value in a short section within a predetermined period. The setting unit 105 may also determine the timing to change the signal point arrangement by using a trained AI model. Details of these processes are as shown in the example of the first embodiment.

[0117] In the second embodiment, the terminal 200 may execute the same processing as the base station 100 described in the second embodiment. In this case, the base station 100 executes the same processing as the terminal 200 described in the second embodiment. Furthermore, the base station 100 and the terminal 200 may be capable of performing wireless communication in both uplink and downlink directions, and both the base station 100 and the terminal 200 may execute the processing related to transmission signals and the processing related to reception signals described in the second embodiment.

[0118] Furthermore, not only the base station 100 and the terminal 200, but also at least one of the artificial satellite 300 and the receiving station 400 in FIG. 3 may execute at least one of the processing related to the transmission signal and the processing related to the reception signal according to the second embodiment.

[0119] In the above-mentioned embodiment, this disclosure has been described as a hardware configuration, but this disclosure is not limited to this. In this disclosure, the processes or steps executed by at least any of the information processing devices, base stations, terminals, artificial satellites, and receiving stations described in the above-mentioned embodiment may be realized by causing a processor in a computer to execute a computer program.

[0120] 11 is a block diagram showing an example of the hardware configuration of an information processing device in which the processes of the devices in each of the above-described embodiments are executed. Referring to FIG. 11, the information processing device 90 includes a signal processing circuit 91, a processor 92, and a memory 93.

[0121] The signal processing circuit 91 is a circuit for processing signals in accordance with the control of the processor 92. Note that the signal processing circuit 91 may include a communication circuit for receiving a signal from a transmitting device.

[0122] The processor 92 is connected or coupled to the memory 93, and performs the processing of the device described in the above embodiment by reading and executing software or computer programs from the memory 93. Examples of the processor 92 include a CPU (Central Processing Unit), an MPU (Micro Processing Unit), an FPGA (Field-Programmable Gate Array), a DSP (Demand-Side Platform), and an ASIC (Application Specific Integrated Circuit). As the processor 92, one processor may be used, or multiple processors may be used in cooperation with each other.

[0123] The memory 93 is composed of a volatile memory, a non-volatile memory, or a combination thereof. The volatile memory may be, for example, a RAM (Random Access Memory) such as a DRAM (Dynamic Random Access Memory) or a SRAM (Static Random Access Memory). The non-volatile memory may be, for example, a ROM (Read Only Memory) such as a PROM (Programmable Random Only Memory) or an EPROM (Erasable Programmable Read Only Memory), a flash memory, or an SSD (Solid State Drive). As the memory 93, one memory may be used, or multiple memories may be used in cooperation with each other.

[0124] The memory 93 is used to store one or more instructions. Here, the one or more instructions are stored in the memory 93 as a group of software modules. The processor 92 can perform the processes described in the above-mentioned embodiments by reading and executing the group of software modules from the memory 93.

[0125] The memory 93 may include a memory built into the processor 92 in addition to a memory provided outside the processor 92. The memory 93 may also include a storage device disposed away from the processors constituting the processor 92. In this case, the processor 92 can access the memory 93 via an I / O (Input / Output) interface.

[0126] As described above, one or more processors included in each device in the above-mentioned embodiments execute one or more programs including a set of instructions for causing a computer to execute the algorithm described using the drawings. By performing this processing, the information processing described in each embodiment can be realized.

[0127] The program includes a set of instructions (or software code) that, when loaded into a computer, causes the computer to perform one or more functions described in the embodiments. The program may be stored in a non-transitory computer-readable medium or a tangible storage medium. By way of example and not limitation, the computer-readable medium or tangible storage medium includes random-access memory (RAM), read-only memory (ROM), flash memory, solid-state drive (SSD) or other memory technology, CD-ROM, digital versatile disk (DVD), Blu-ray® disk or other optical disk storage, magnetic cassette, magnetic tape, magnetic disk storage or other magnetic storage device. The program may be transmitted on a transitory computer-readable medium or communication medium. By way of example and not limitation, the transitory computer-readable medium or communication medium includes electrical, optical, acoustic, or other forms of propagated signals.

[0128] Although the present disclosure has been described above with reference to the embodiments, the present disclosure is not limited to the above. Various modifications that can be understood by a person skilled in the art can be made to the configuration and details of the present disclosure within the scope of the disclosure. Furthermore, each embodiment can be appropriately combined with other embodiments.

[0129] For example, some or all of the above-described embodiments may be described as, but are not limited to, the following supplementary notes. (Appendix 1) An acquisition means for acquiring temperature data for a predetermined period of time; and a setting means for setting a signal constellation used for modulating the transmission signal so that the signal constellation used for modulating the transmission signal is switched to a different signal constellation within the predetermined period based on the temperature data. Modulation control device. (Appendix 2) the setting means sets the signal constellation so as to switch the signal constellation used for modulating the transmission signal to a different signal constellation at a timing corresponding to a timing at which a magnitude relationship between the temperature and a predetermined threshold value changes during the predetermined period. 2. A modulation control device as claimed in claim 1. (Appendix 3) the setting means sets a signal constellation used for modulating the transmission signal to a first signal constellation in an interval corresponding to a period during which the temperature is higher than the predetermined threshold during the predetermined period, and sets a signal constellation used for modulating the transmission signal to a second signal constellation in an interval corresponding to a period during which the temperature is equal to or lower than the predetermined threshold during the predetermined period; The second signal constellation is a signal constellation in which signal points are arranged such that the interval between signal points becomes wider as the intensity of the transmission signal increases, compared to the first signal constellation. 3. A modulation control device as claimed in claim 2. (Appendix 4) The modulation control device further includes a change prediction means for predicting a change in a nonlinear characteristic of the amplifier within the predetermined period based on temperature data for the predetermined period, the setting means sets a signal constellation used for modulating the transmission signal so that the signal constellation used for modulating the transmission signal is switched to a different signal constellation within the predetermined period based on the change in the nonlinear characteristic. 4. A modulation control device according to any one of claims 1 to 3. (Appendix 5) The modulation control device further includes a control means for determining whether or not to execute at least one of nonlinear compensation and multiplexing based on the signal constellation set by the setting means, using a first power required for executing control of the signal constellation set by the setting means and nonlinear compensation according to the set signal constellation, a second power required for multiplexing performed on the transmission signal, and available power. 5. A modulation control device according to any one of claims 1 to 4. (Appendix 6) the control means, when the first power is equal to or less than the available power, a third power obtained by adding the second power to the first power is greater than the available power, and a fifth power obtained by subtracting a fourth power required for at least a part of the nonlinear compensation processing performed on the transmission signal from the third power is greater than the available power, determines to perform nonlinear compensation based on the signal point arrangement set by the setting means, but not to perform the multiplexing. 6. A modulation control device as claimed in claim 5. (Appendix 7) the control means determines, when the first power is equal to or less than the available power, a third power obtained by adding the second power to the first power is greater than the available power, a fifth power obtained by subtracting a fourth power required for at least a part of the nonlinear compensation processing performed on the transmission signal from the third power is equal to or less than the available power, and a parameter indicating accuracy of the transmission signal when the at least a part of the processing is not performed on the transmission signal satisfies a predetermined condition, that the nonlinear compensation and the multiplexing based on the signal point arrangement set by the setting means are performed in a state in which the part of the processing is not performed. 7. The modulation control device according to claim 5 or 6. (Appendix 8) the control means, when the first power is equal to or less than the available power, a third power obtained by adding the second power to the first power is greater than the available power, a fifth power obtained by subtracting a fourth power required for at least a part of the nonlinear compensation processing performed on the transmission signal from the third power is equal to or less than the available power, and a parameter indicating accuracy of the transmission signal in the case where the at least a part of the processing is not performed on the transmission signal does not satisfy a predetermined condition, changes the predetermined condition, changes the available power so as to satisfy the changed predetermined condition, and further determines whether or not to perform at least one of nonlinear compensation and multiplexing based on the signal point arrangement set by the setting means, using the first power, the second power, and the changed available power. 8. A modulation control device according to any one of claims 5 to 7. (Appendix 9) A transmitter; A receiver, The transmitter includes: An acquisition means for acquiring temperature data for a predetermined period of time; a setting means for setting a signal constellation used for modulating the transmission signal based on the temperature data so that the signal constellation used for modulating the transmission signal is switched to a different signal constellation within the predetermined period; a transmitting means for transmitting to the receiver the transmission signal modulated using the signal point arrangement set by the setting means, The receiver includes: receiving means for receiving the transmission signal from the transmitter; demodulation means for demodulating the transmission signal received by the receiving means; Communication systems. (Appendix 10) the setting means sets the signal constellation so as to switch the signal constellation used for modulating the transmission signal to a different signal constellation at a timing corresponding to a timing at which a magnitude relationship between the temperature and a predetermined threshold value changes during the predetermined period. 10. The communication system of claim 9. (Appendix 11) the setting means sets a signal constellation used for modulating the transmission signal to a first signal constellation in an interval corresponding to a period during which the temperature is higher than the predetermined threshold during the predetermined period, and sets a signal constellation used for modulating the transmission signal to a second signal constellation in an interval corresponding to a period during which the temperature is equal to or lower than the predetermined threshold during the predetermined period; The second signal constellation is a signal constellation in which signal points are arranged such that the interval between signal points becomes wider as the intensity of the transmission signal increases, compared to the first signal constellation. 11. The communication system of claim 10. (Appendix 12) The transmitter further comprises a change prediction means for predicting a change in a nonlinear characteristic of the amplifier within the predetermined period based on temperature data for the predetermined period, the setting means sets a signal constellation used for modulating the transmission signal so that the signal constellation used for modulating the transmission signal is switched to a different signal constellation within the predetermined period based on the change in the nonlinear characteristic. 12. A communication system according to any one of claims 9 to 11. (Appendix 13) The transmitter further comprises a control means for determining whether or not to execute at least one of nonlinear compensation and multiplexing based on the signal constellation set by the setting means, using a first power required for executing control of the signal constellation set by the setting means and nonlinear compensation according to the set signal constellation, a second power required for multiplexing performed on the transmission signal, and available power. 13. A communication system according to any one of claims 9 to 12. (Appendix 14) the control means, when the first power is equal to or less than the available power, a third power obtained by adding the second power to the first power is greater than the available power, and a fifth power obtained by subtracting a fourth power required for at least a part of the nonlinear compensation processing performed on the transmission signal from the third power is greater than the available power, determines to perform nonlinear compensation based on the signal point arrangement set by the setting means, but not to perform the multiplexing. 14. The communication system of claim 13. (Appendix 15) the control means determines, when the first power is equal to or less than the available power, a third power obtained by adding the second power to the first power is greater than the available power, a fifth power obtained by subtracting a fourth power required for at least a part of the nonlinear compensation processing performed on the transmission signal from the third power is equal to or less than the available power, and a parameter indicating accuracy of the transmission signal when the at least a part of the processing is not performed on the transmission signal satisfies a predetermined condition, that the nonlinear compensation and the multiplexing based on the signal point arrangement set by the setting means are performed in a state in which the part of the processing is not performed; The receiver includes: a nonlinear compensation unit that performs nonlinear compensation processing, which is at least a part of the processing, on the transmission signal received by the receiving unit; 15. The communication system according to claim 13 or 14. (Appendix 16) the control means, when the first power is equal to or less than the available power, a third power obtained by adding the second power to the first power is greater than the available power, a fifth power obtained by subtracting a fourth power required for at least a part of the nonlinear compensation processing performed on the transmission signal from the third power is equal to or less than the available power, and a parameter indicating accuracy of the transmission signal in the case where the at least a part of the processing is not performed on the transmission signal does not satisfy a predetermined condition, changes the predetermined condition, changes the available power so as to satisfy the changed predetermined condition, and further determines whether or not to perform at least one of nonlinear compensation and multiplexing based on the signal point arrangement set by the setting means, using the first power, the second power, and the changed available power. 16. A communication system according to any one of claims 13 to 15. (Appendix 17) Obtaining temperature data for a given period of time; setting a signal constellation used for modulating the transmission signal based on the temperature data such that the signal constellation used for modulating the transmission signal is switched to a different signal constellation within the predetermined period. A computer implemented modulation control method. (Appendix 18) setting a signal constellation such that a signal constellation used for modulating the transmission signal is switched to a different signal constellation at a timing corresponding to a timing at which a magnitude relationship between the temperature and a predetermined threshold value changes during the predetermined period; 18. The modulation control method of claim 17, wherein the modulation control method is computer-implemented. (Appendix 19) setting a signal constellation used for modulating the transmission signal to a first signal constellation in a section corresponding to a period during which the temperature is higher than the predetermined threshold during the predetermined period, and setting a signal constellation used for modulating the transmission signal to a second signal constellation in a section corresponding to a period during which the temperature is equal to or lower than the predetermined threshold during the predetermined period; The second signal constellation is a signal constellation in which signal points are arranged such that the interval between signal points becomes wider as the intensity of the transmission signal increases, compared to the first signal constellation. 19. The modulation control method of claim 18, wherein the modulation control method is computer-implemented. (Appendix 20) Further predicting a change in a nonlinear characteristic of the amplifier within the predetermined period based on the temperature data during the predetermined period; setting a signal constellation used for modulating the transmission signal such that the signal constellation used for modulating the transmission signal is switched to a different signal constellation within the predetermined period based on the change in the nonlinear characteristic; 20. A modulation control method according to any one of claims 17 to 19, implemented by a computer. (Appendix 21) further determining whether to execute at least one of nonlinear compensation or multiplexing based on the set signal constellation, using a first power required for controlling the set signal constellation and executing nonlinear compensation according to the set signal constellation, a second power required for multiplexing performed on the transmission signal, and available power; 21. A modulation control method according to any one of claims 17 to 20, implemented by a computer. (Appendix 22) determining to execute nonlinear compensation based on the set signal point arrangement but not to execute the multiplexing when the first power is equal to or less than the available power, a third power obtained by adding the second power to the first power is greater than the available power, and a fifth power obtained by subtracting a fourth power required for at least a part of the nonlinear compensation processing performed on the transmission signal from the third power is greater than the available power; 22. The modulation control method of claim 21, wherein the modulation control method is computer-implemented. (Appendix 23) determining, when the first power is equal to or less than the available power, a third power obtained by adding the second power to the first power is greater than the available power, a fifth power obtained by subtracting a fourth power required for at least a part of the nonlinear compensation processing performed on the transmission signal from the third power is equal to or less than the available power, and a parameter indicating accuracy of the transmission signal when the at least a part of the processing is not performed on the transmission signal satisfies a predetermined condition, to perform the nonlinear compensation and the multiplexing based on the set signal point arrangement in a state where the part of the processing is not performed. 23. The modulation control method of claim 21 or 22, implemented by a computer. (Appendix 24) when the first power is equal to or less than the available power, a third power obtained by adding the second power to the first power is greater than the available power, a fifth power obtained by subtracting a fourth power required for at least a part of the nonlinear compensation processing performed on the transmission signal from the third power is equal to or less than the available power, and a parameter indicating accuracy of the transmission signal when the at least a part of the processing is not performed on the transmission signal does not satisfy a predetermined condition, changing the predetermined condition, changing the available power so as to satisfy the changed predetermined condition, and further determining whether or not to perform at least one of nonlinear compensation and multiplexing based on the set signal point arrangement using the first power, the second power, and the changed available power. 24. A modulation control method according to any one of claims 21 to 23, implemented by a computer. (Appendix 25) Obtaining temperature data for a given period of time; setting a signal constellation used for modulating the transmission signal based on the temperature data such that the signal constellation used for modulating the transmission signal is switched to a different signal constellation within the predetermined period. A program that causes a computer to do something. (Appendix 26) setting a signal constellation such that a signal constellation used for modulating the transmission signal is switched to a different signal constellation at a timing corresponding to a timing at which a magnitude relationship between the temperature and a predetermined threshold value changes during the predetermined period; 26. The program according to claim 25, which causes a computer to execute the steps. (Appendix 27) setting a signal constellation used for modulating the transmission signal to a first signal constellation in a section corresponding to a period during which the temperature is higher than the predetermined threshold during the predetermined period, and setting a signal constellation used for modulating the transmission signal to a second signal constellation in a section corresponding to a period during which the temperature is equal to or lower than the predetermined threshold during the predetermined period; The second signal constellation is a signal constellation in which signal points are arranged such that the interval between signal points becomes wider as the intensity of the transmission signal increases, compared to the first signal constellation. 27. The program according to claim 26, which causes a computer to execute the steps. (Appendix 28) Further predicting a change in a nonlinear characteristic of the amplifier within the predetermined period based on the temperature data during the predetermined period; setting a signal constellation used for modulating the transmission signal such that the signal constellation used for modulating the transmission signal is switched to a different signal constellation within the predetermined period based on the change in the nonlinear characteristic; 28. The program according to any one of claims 25 to 27, which causes a computer to execute the steps. (Appendix 29) further determining whether to execute at least one of nonlinear compensation or multiplexing based on the set signal constellation, using a first power required for controlling the set signal constellation and executing nonlinear compensation according to the set signal constellation, a second power required for multiplexing performed on the transmission signal, and available power; 29. The program according to any one of appendices 25 to 28, which causes a computer to execute the steps. (Appendix 30) determining to execute nonlinear compensation based on the set signal point arrangement but not to execute the multiplexing when the first power is equal to or less than the available power, a third power obtained by adding the second power to the first power is greater than the available power, and a fifth power obtained by subtracting a fourth power required for at least a part of the nonlinear compensation processing performed on the transmission signal from the third power is greater than the available power; 30. The program according to claim 29, which causes a computer to execute the steps. (Appendix 31) determining, when the first power is equal to or less than the available power, a third power obtained by adding the second power to the first power is greater than the available power, a fifth power obtained by subtracting a fourth power required for at least a part of the nonlinear compensation processing performed on the transmission signal from the third power is equal to or less than the available power, and a parameter indicating accuracy of the transmission signal when the at least a part of the processing is not performed on the transmission signal satisfies a predetermined condition, to perform the nonlinear compensation and the multiplexing based on the set signal point arrangement in a state where the part of the processing is not performed. The program according to claim 29 or 30, which causes a computer to execute the steps. (Appendix 32) when the first power is equal to or less than the available power, a third power obtained by adding the second power to the first power is greater than the available power, a fifth power obtained by subtracting a fourth power required for at least a part of the nonlinear compensation processing performed on the transmission signal from the third power is equal to or less than the available power, and a parameter indicating accuracy of the transmission signal when the at least a part of the processing is not performed on the transmission signal does not satisfy a predetermined condition, changing the predetermined condition, changing the available power so as to satisfy the changed predetermined condition, and further determining whether or not to perform at least one of nonlinear compensation and multiplexing based on the set signal point arrangement using the first power, the second power, and the changed available power. 32. The program according to any one of claims 29 to 31, which causes a computer to execute the steps. [Explanation of symbols]

[0130] 10 Modulation control device 11 Acquisition Department 12 Setting section 100 base stations 101 Required parameter calculation unit 102 Power supply estimation section 103 Power Calculation Unit 104 Change Prediction Section 105 Setting section 106 Control section 107 Nonlinear compensation section 108 Multiplexer 109 Modulation and demodulation section 110 Transmitter / receiver 200 terminals 201 Transmitter / receiver 202 Modulation and demodulation section 203 Control Unit 204 Nonlinear compensation section 300 satellites 400 receiving stations S Wireless communication system

Claims

1. An acquisition means for acquiring temperature data for a predetermined period of time; and a setting means for setting a signal constellation used for modulating the transmission signal so that the signal constellation used for modulating the transmission signal is switched to a different signal constellation within the predetermined period based on the temperature data. Modulation control device.

2. the setting means sets the signal constellation so as to switch the signal constellation used for modulating the transmission signal to a different signal constellation at a timing corresponding to a timing at which a magnitude relationship between the temperature and a predetermined threshold value changes during the predetermined period. The modulation control device according to claim 1 .

3. the setting means sets a signal constellation used for modulating the transmission signal to a first signal constellation in an interval corresponding to a period during which the temperature is higher than the predetermined threshold during the predetermined period, and sets a signal constellation used for modulating the transmission signal to a second signal constellation in an interval corresponding to a period during which the temperature is equal to or lower than the predetermined threshold during the predetermined period; The second signal constellation is a signal constellation in which signal points are arranged such that the interval between signal points becomes wider as the intensity of the transmission signal increases, compared to the first signal constellation. The modulation control device according to claim 2 .

4. The modulation control device further includes a change prediction means for predicting a change in a nonlinear characteristic of the amplifier within the predetermined period based on temperature data for the predetermined period, the setting means sets a signal constellation used for modulating the transmission signal so that the signal constellation used for modulating the transmission signal is switched to a different signal constellation within the predetermined period based on the change in the nonlinear characteristic. A modulation control device according to any one of claims 1 to 3.

5. the modulation control device further comprises a control means for determining whether or not to execute at least one of nonlinear compensation and multiplexing based on the signal constellation set by the setting means, using a first power required for executing control of the signal constellation set by the setting means and nonlinear compensation according to the set signal constellation, a second power required for multiplexing performed on the transmission signal, and available power. A modulation control device according to any one of claims 1 to 3.

6. the control means, when the first power is equal to or less than the available power, a third power obtained by adding the second power to the first power is greater than the available power, and a fifth power obtained by subtracting a fourth power required for at least a part of the nonlinear compensation processing performed on the transmission signal from the third power is greater than the available power, determines to perform nonlinear compensation based on the signal point arrangement set by the setting means, but not to perform the multiplexing. The modulation control device according to claim 5 .

7. the control means determines, when the first power is equal to or less than the available power, a third power obtained by adding the second power to the first power is greater than the available power, a fifth power obtained by subtracting a fourth power required for at least a part of the nonlinear compensation processing performed on the transmission signal from the third power is equal to or less than the available power, and a parameter indicating accuracy of the transmission signal when the at least a part of the processing is not performed on the transmission signal satisfies a predetermined condition, that the nonlinear compensation and the multiplexing based on the signal point arrangement set by the setting means are performed in a state in which the part of the processing is not performed. The modulation control device according to claim 5 .

8. the control means, when the first power is equal to or less than the available power, a third power obtained by adding the second power to the first power is greater than the available power, a fifth power obtained by subtracting a fourth power required for at least a part of the nonlinear compensation processing performed on the transmission signal from the third power is equal to or less than the available power, and a parameter indicating accuracy of the transmission signal when the at least a part of the processing is not performed on the transmission signal does not satisfy a predetermined condition, changes the predetermined condition, changes the available power so as to satisfy the changed predetermined condition, and further determines whether or not to perform at least one of nonlinear compensation and multiplexing based on the signal point arrangement set by the setting means, using the first power, the second power, and the changed available power. The modulation control device according to claim 5 .

9. Obtaining temperature data for a given period of time; setting a signal constellation used for modulating the transmission signal based on the temperature data such that the signal constellation used for modulating the transmission signal is switched to a different signal constellation within the predetermined period. A computer implemented modulation control method.

10. Obtaining temperature data for a given period of time; setting a signal constellation used for modulating the transmission signal based on the temperature data such that the signal constellation used for modulating the transmission signal is switched to a different signal constellation within the predetermined period. A program that causes a computer to do something.

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