Management device, wireless base station, program, and management method

Abstract

Provided is a management device that manages a wireless base station equipped with a plurality of antennas, the wireless base station being a control target of a Radio Access Network (RAN) control function that controls a RAN function by executing an AI process (RAN Intelligent Controller (RIC)) or the like. The management device comprises: an acquisition unit that acquires a signal to be transmitted to the outside; a determination unit that, on the basis of the signal, determines a route through which the signal is transmitted to one antenna from among the plurality of antennas; and an amplification unit that has a plurality of amplifier groups arranged in parallel. The route is constituted of, from among the plurality of amplifier groups, one or more amplifier groups for amplifying the signal, and one switch from among a plurality of switches positioned between the plurality of amplifier groups and the plurality of antennas.

Description

Management Device, Radio Base Station, Program, and Management Method 【0001】 The present invention relates to a management device, a radio base station, a program, and a management method. 【0002】 Patent Document 1 describes an amplification device that can achieve high efficiency even when the circuit scale is not expanded and the dynamic range is wide. Patent Document 2 describes a Doherty amplifier that can suppress the oscillation phenomenon occurring between the first auxiliary amplification element and the second auxiliary amplification element. Patent Document 3 describes an amplification circuit that can efficiently amplify a signal with a large amplitude level variation. Patent Document 4 describes a line setting method in a wireless communication system that can suppress the PAPR (Peak-to-Average Power Ratio) low without being restricted by code selection. Patent Document 5 describes a high-frequency power amplification device that can obtain high power efficiency in a wide range of output power levels. Patent Document 6 describes a method for generating a frame format that can suppress the PAPR low without being restricted by code selection. Patent Document 7 describes a method for generating a frame format that can suppress the PAPR low without being restricted by code selection. Patent Document 8 describes a non-linear distortion compensation circuit for multi-carrier transmission that can reduce non-linear distortion and power consumption by a simple method. [Prior Art Documents] [Patent Documents] [Patent Document 1] Japanese Unexamined Patent Application Publication No. 2020-156024 [Patent Document 2] Japanese Patent No. 7166491 [Patent Document 3] Japanese Unexamined Patent Application Publication No. 2020-047984 [Patent Document 4] Japanese Unexamined Patent Application Publication No. 2013-055677 [Patent Document 5] Japanese Unexamined Patent Application Publication No. 2011-120142 [Patent Document 6] Japanese Unexamined Patent Application Publication No. 2011-087315 [Patent Document 7] Japanese Unexamined Patent Application Publication No. 2007-201854 [Patent Document 8] Japanese Unexamined Patent Application Publication No. 2005-252509 【0003】In mobile communication networks, including RAN (Radio Access Network), primary modulation (sometimes referred to as subcarrier modulation) standardized in mobile communications such as LTE (Long Term Evolution) and NR (New Radio) may include modulation schemes with a large number of bits per symbol, resulting in discontinuities in amplitude and phase. Therefore, the PAPR of the transmitted signal from a radio base station constituting a mobile communication network such as LTE or NR may be large. Conventionally, high-power transmission signals from radio base stations were achieved by increasing the EIRP (Equivalent Isotropic Radiation Power) of the antenna mounted on the radio base station using a high-gain amplifier. On the other hand, when an amplifier performs amplification near the upper limit of the linear region, clipping occurs, distorting the waveform of the output signal and significantly degrading the characteristics of the output signal. Therefore, in order to reliably perform amplification in an operating region where clipping does not occur, the amplifier must perform amplification with a certain margin above the upper limit of the linear region, that is, it must have a backoff. Amplifiers installed in wireless base stations capable of outputting transmit signals with a large PAPR must ensure a wide dynamic range, which is the range between the maximum and minimum signal amplitude, by having a backoff to perform amplification without clipping occurring in the high-power operating region. For this reason, conventional wireless base stations were equipped with Doherty amplifiers, which consist of a normal amplifier and a peak amplifier with higher gain than a normal amplifier connected in parallel, thereby achieving high output of the transmit signal of wireless base stations in digital modulation that needs to handle a larger PAPR. However, high-gain amplifiers such as Doherty amplifiers are very expensive devices. Furthermore, a drawback of installing high-gain amplifiers such as Doherty amplifiers in wireless base stations is that the design requirements of the wireless base station become stricter, such as the requirements for high efficiency to reduce power consumption and the requirements for heat dissipation design. 【0004】In the system according to this embodiment, for example, the RAN function can be run on a high-performance GPU (Graphics Processing Unit) server instead of a general-purpose server, thereby allowing the surplus computing resources to be utilized for AI (Artificial Intelligence) processing. Examples of AI processing include AI processing related to RAN control (sometimes referred to as RAN control AI processing) and AI processing unrelated to RAN control (sometimes referred to as non-RAN control AI processing). 【0005】 An example of AI-based RAN control processing is the RIC (RAN Intelligent Controller). The RIC is a technology that uses AI to optimize RAN wireless resources and automate RAN operations. The RIC includes Non-RT RIC and Near-RT RIC (Near-Real Time RIC). The Non-RT RIC is sometimes called Centralized RIC. The Non-RT RIC is located within the SMO (Service Management and Orchestration), which manages and orchestrates the RAN. The Non-RT RIC generates and notifies policies related to RAN control and transmits information to the Near-RT RIC. For example, a Non-RT RIC generates a trained model for RAN control by performing machine learning using data collected from the RAN, and sends it to a Near-RT RIC. A Near-RT RIC is sometimes called a Distributed RIC. Compared to a Non-RT RIC, a Near-RT RIC is located closer to the RAN nodes (RU (Radio Unit), DU (Distributed Unit), CU (Central Unit)) and performs control of the RAN nodes and resources. Compared to a Non-RT RIC, a Near-RT RIC performs processing with higher real-time capabilities. For example, a Near-RT RIC performs inference processing related to RAN control using the trained model obtained from a Non-RT RIC. RAN control AI processing is not limited to RICs. 【0006】 Non-RAN-controlled AI processing may correspond to so-called MEC (Multi-access Edge Computing) applications. Examples of non-RAN-controlled AI processing include, but are not limited to, monitoring AI execution processing that determines the situation within the imaging range of an input image, and response AI execution processing that outputs a response to an inquiry made by a user. 【0007】 In the system according to this embodiment, for example, a large number of amplifiers with low output characteristics are prepared to form an amplifier pooling, and the backoff required to output the transmission signal is determined by checking the characteristics of the signal in advance. A mechanism is then employed to select a route for outputting the transmission signal by flexibly changing the cascade connection from the amplifier pooling according to the determination result. This makes it possible to achieve backoff characteristics equivalent to or better than those when using amplifiers such as Doherty amplifiers, using less expensive amplifiers. 【0008】 According to one embodiment of the present invention, a management device for managing a wireless base station equipped with multiple antennas is provided. The management device may include an acquisition unit for acquiring a signal to be transmitted to the outside. The management device may include a determination unit for determining the route by which the signal is transmitted to one of the multiple antennas based on the signal. The management device may include an amplification unit having a plurality of amplifier groups arranged in parallel. The route may consist of one or more amplifier groups from the plurality of amplifier groups that amplify the signal, and one switch from a plurality of switches located between the plurality of amplifier groups and the plurality of antennas. 【0009】 In the management device, the decision unit may determine that the route is configured with two or more amplifier groups and one switch to amplify the signal when the signal satisfies predetermined high amplification conditions, and may determine that the route is configured with one amplifier group and one switch to amplify the signal when the signal does not satisfy the high amplification conditions. 【0010】In any of the above-mentioned management devices, the determination unit may determine that the route is configured with the two or more amplifier groups and the one switch when the modulation method of the signal satisfies predetermined modulation method conditions, and may determine that the route is configured with the one amplifier group and the one switch when the modulation method of the signal does not satisfy the modulation method conditions. 【0011】 In any of the above-mentioned management devices, the determination unit may determine that the route is configured with two or more amplifier groups and one switch when the number of user data to be transmitted the signal satisfies a predetermined user data quantity condition, and may determine that the route is configured with one amplifier group and one switch when the number of user data to be transmitted the signal does not satisfy the user data quantity condition. 【0012】 In any of the above-mentioned management devices, each of the plurality of amplifier groups may include n first amplifiers having a first gain, the n first amplifiers may be connected in series, and n may be an integer of 2 or more. 【0013】 In any of the above-mentioned management devices, each of the plurality of amplifier groups may include n-1 first amplifiers having a first gain and a second amplifier having a second gain that is higher than the first gain, the n-1 first amplifiers may be connected in series, and the second amplifier may amplify the signal amplified by the n-1 first amplifiers, where n is an integer of 2 or more. 【0014】 In any of the above-mentioned management devices, when the route is configured with one amplifier group that amplifies the signal and one switch, the decision unit may decide that the second amplifier included in the one amplifier group does not amplify the signal if the signal satisfies a predetermined low amplification condition, and may decide that the second amplifier included in the one amplifier group amplifies the signal if the signal does not satisfy the low amplification condition. 【0015】In any of the above-mentioned management devices, the plurality of amplifier groups may include one or more first amplifier groups and one or more second amplifier groups, each first amplifier group of the one or more first amplifier groups may include n first amplifiers having a first gain, the n first amplifiers may be connected in series, each second amplifier group of the one or more second amplifier groups may include n-1 first amplifiers having the first gain and a second amplifier having a second gain that is higher than the first gain, the n-1 first amplifiers may be connected in series, and the second amplifier may amplify the signal amplified by the n-1 first amplifiers, where n is an integer of 2 or more. 【0016】 In any of the above-mentioned management devices, the decision unit may, when the route is configured with one amplifier group that amplifies the signal and one switch, decide that one of the one or more first amplifier groups amplifies the signal if the signal satisfies a predetermined low amplification condition, and decide that one of the one or more second amplifier groups amplifies the signal if the signal does not satisfy the low amplification condition. 【0017】 According to one embodiment of the present invention, a wireless base station is provided. The wireless base station may include any of the management devices. The wireless base station may include the plurality of antennas. 【0018】 According to one embodiment of the present invention, a program is provided that, when executed by a computer, causes the computer to function as one of the management devices. 【0019】According to one embodiment of the present invention, a management method is provided that is performed by a computer managing a wireless base station equipped with multiple antennas. The management method may include an acquisition step of acquiring a signal to be transmitted to the outside. The management method may include a determination step of determining, based on the signal, a route through which the signal is transmitted to one of the multiple antennas. The route may consist of one or more amplifier groups that amplify the signal from a plurality of amplifier groups arranged in parallel, and one switch from a plurality of switches located between the plurality of amplifier groups and the plurality of antennas. 【0020】 It should be noted that the above summary of the invention does not enumerate all the necessary features of the present invention. Furthermore, subcombinations of these features may also constitute an invention. 【0021】 A schematic diagram of an example of system 10 is shown. A schematic diagram of an example of the configuration of a conventional wireless base station is shown. This is an explanatory diagram for explaining an example of a user data transmission method. This is an explanatory diagram for explaining an example of PAPR. A schematic diagram of an example of the configuration of wireless base station 300 is shown. This is an explanatory diagram for explaining an example of wireless base station 300 transmitting a signal. A schematic diagram of another example of the configuration of wireless base station 300 is shown. This is an explanatory diagram for explaining another example of wireless base station 300 transmitting a signal. This is an explanatory diagram for explaining another example of wireless base station 300 transmitting a signal. A schematic diagram of another example of the configuration of wireless base station 300 is shown. This is an explanatory diagram for explaining another example of wireless base station 300 transmitting a signal. This is an explanatory diagram for explaining another example of wireless base station 300 transmitting a signal. A schematic diagram of the functional configuration of the management device 350 is shown. This is an explanatory diagram for explaining an example of the processing flow of system 10. A schematic diagram of the hardware configuration of computer 1200 functioning as management device 350 is shown. 【0022】 The present invention will be described below through embodiments, but these embodiments are not intended to limit the scope of the claimed invention. Furthermore, not all combinations of features described in the embodiments are necessarily essential to the solution of the invention. 【0023】Figure 1 schematically shows an example of system 10. System 10 may include one or more wireless base stations 300 that constitute RAN 310. System 10 may include multiple distributed infrastructures 200. System 10 may include a management infrastructure 100 that manages the multiple distributed infrastructures 200. In system 10 according to this embodiment, for example, the management infrastructure 100 and the multiple distributed infrastructures 200 may cooperate to control RAN 310 and perform AI processing. 【0024】 RAN310 may be a virtualized vRAN (Virtual RAN), and system 10 may perform control of the vRAN. RAN310 may also be a physical RAN, and system 10 may perform control of the physical RAN. 【0025】 The AI ​​processing performed by system 10 may include RAN-controlled AI processing (sometimes referred to as RAN_AI). The AI ​​processing performed by system 10 may also include non-RAN-controlled AI processing (sometimes referred to as non-RAN_AI). 【0026】 The distributed infrastructure 200 may be data centers located in various locations. The distributed infrastructure 200 may be composed of multiple devices. The distributed infrastructure 200 may be implemented on a virtualization infrastructure consisting of multiple devices. The distributed infrastructure 200 may be implemented by a single device. In other words, the distributed infrastructure 200 may be a distributed device. 【0027】 The distributed infrastructure 200 may have one or more CPUs (Central Processing Units). The distributed infrastructure 200 may have one or more GPUs. The distributed infrastructure 200 may have multiple superchips, each connected to a CPU and a GPU by an interconnect. This interconnect may be memory consistent and capable of achieving high bandwidth and low latency. Thus, the distributed infrastructure 200 may have both CPU resources and GPU resources as computing resources. 【0028】The distributed infrastructure 200 includes, for example, an execution unit that includes a RAN control function for controlling the functions of RAN 310 and an application execution function for executing applications. The distributed infrastructure 200 may further include the functions of a wireless base station 300. 【0029】 The RAN control function controls the functions of RAN310, for example, by executing RAN_AI. The RAN control function may also control the functions of RAN310 by executing any other arbitrary processing. 【0030】 The RAN control function controls, for example, the wireless base station 300. The RAN control function controls the wireless base station 300 so that, for example, it uses an antenna to form a wireless communication area and provides mobile communication services to communication terminals 30 within the wireless communication area. 【0031】 The communication terminal 30 is, for example, a mobile phone such as a smartphone. The communication terminal 30 may also be a tablet device or a PC (Personal Computer). The communication terminal 30 may also be a so-called IoT (Internet of Things) device. The communication terminal 30 may include anything that falls under the so-called IoE (Internet of Everything). 【0032】 The application execution function may, for example, have the ability to execute AI applications. The application execution function may also have the ability to execute non-RAN_AI applications. The application execution function may execute any other application. 【0033】 The distributed infrastructure 200 is, for example, located on the core network. The term "on the core network" includes both the area inside and outside the core network. 【0034】The core network may conform to any mobile communication system. For example, the core network may conform to a 5G (5th Generation) communication system. The core network may conform to a 6G (6th Generation) communication system or later mobile communication systems. The core network may conform to a 3G (3rd Generation) communication system or an LTE communication system. 【0035】 The management infrastructure 100 may be a data center that manages multiple distributed infrastructures 200. The management infrastructure 100 may be composed of multiple devices. The management infrastructure 100 may be implemented on a virtualization infrastructure consisting of multiple devices. The management infrastructure 100 may be implemented by a single device. In other words, the management infrastructure 100 may be a management device. 【0036】 The management infrastructure 100 may be called the Core Brain, and the distributed infrastructure 200 may be called the Regional Brain. Note that Figure 1 illustrates a case where a single layer of the management infrastructure 100 is located below it, but this is not the only case. The distributed infrastructure 200 may have multiple layers. For example, if two layers of distributed infrastructure 200 are located below the management infrastructure 100, the management infrastructure 100 may be called the Core Brain, the distributed infrastructure 200 at the lower layer may be called the Regional Brain, and the distributed infrastructure 200 at the lower layer may be called the Sub-Regional Brain. 【0037】 Figure 2 schematically shows an example of a conventional wireless base station configuration. Here, we will mainly explain the configuration related to signal transmission at the wireless base station. 【0038】 The upper diagram in Figure 2 schematically shows an example of the configuration of the transmission function of a conventional wireless base station. The wireless base station may have a signal conversion function, an amplification function, and a radiation function. 【0039】The signal conversion function converts digital signals into analog signals. Note that the region before the signal conversion function converts digital signals into analog signals may be described as the analog signal region, and the region after the signal conversion function converts digital signals into analog signals may also be described as the analog signal region. The signal conversion function is, for example, a DAC (Digital-to-Analog Converter). 【0040】 The radio base station may generate a digital signal by subcarrier modulating one or more user data to generate a plurality of subcarrier signals and performing an inverse Fourier transform on the plurality of subcarrier signals. The radio base station may be capable of performing subcarrier modulation using a plurality of modulation schemes. Also, the radio base station may be able to set the modulation scheme of subcarrier modulation for each user data. 【0041】 For example, the binary phase-shift keying (BPSK) method, the quadrature PSK (QPSK) method, the 8-PSK method, the 16-quadrature amplitude modulation (16QAM) method, the 64QAM method, and the 256QAM method, etc., are exemplified as the modulation schemes of subcarrier modulation. The number of bits per symbol of the BPSK method is 1 bit, the number of bits per symbol of the QPSK method is 2 bits, the number of bits per symbol of the 8-PSK method is 3 bits, the number of bits per symbol of the 16QAM method is 4 bits, the number of bits per symbol of the 64QAM method is 6 bits, and the number of bits per symbol of the 256QAM method is 8 bits. 【0042】 The amplification function amplifies the analog signal converted by the signal conversion function. Note that the signal input to the amplification function may be described as the input signal, and the signal output by the amplification function may be described as the output signal. 【0043】 The amplification function is composed of, for example, a plurality of amplifier groups arranged in parallel. Each amplifier group of the plurality of amplifier groups may include a plurality of amplifiers. 【0044】 In the upper diagram of FIG. 2, an example in which an amplification function is constituted by N amplifier groups arranged in parallel is shown. N is an integer of 2 or more. 【0045】 The radiation function radiates radio waves that carry the signal amplified by the amplification function. Note that the signal carried by the radio waves radiated by the radiation function may be described as a transmission signal. 【0046】 The radiation function is constituted by a plurality of antennas. In the upper diagram of FIG. 2, an example in which the radiation function is constituted by N antennas is shown. 【0047】 In a conventional radio base station, the number of amplifier groups constituting the amplifier is equal to the number of antennas constituting the radiation function, and each amplifier group and each antenna correspond one-to-one. In the example shown in the upper diagram of FIG. 2, the signal carried by the radio waves radiated by the first antenna is the output signal amplified by the first amplifier group, the signal carried by the radio waves radiated by the second antenna is the output signal amplified by the second amplifier group, ···, the signal carried by the radio waves radiated by the (N - 1)-th antenna is the output signal amplified by the (N - 1)-th amplifier group, and the signal carried by the radio waves radiated by the N-th antenna is the output signal amplified by the N-th amplifier group. 【0048】 The lower diagram of FIG. 2 schematically shows an example of an amplifier group constituting the amplification function of a conventional radio base station. In the lower diagram of FIG. 2, an example of a X-th amplifier group including n amplifiers is shown. X is a positive integer satisfying 1 ≤ X ≤ N. n is an integer of 2 or more. 【0049】As shown in the lower part of Figure 2, n amplifiers are connected in series. The first stage amplifier of the n amplifiers amplifies the input signal, the second stage amplifier of the n amplifiers amplifies the signal amplified by the first stage amplifier, ..., the (n-1) stage amplifier of the n amplifiers amplifies the signal amplified by the (n-2) stage amplifier of the n amplifiers, and the nth stage amplifier of the n amplifiers amplifies the signal amplified by the (n-1) stage amplifier and outputs an output signal to the radiating function. Note that the amplifier that outputs an output signal to the radiating function may be referred to as the final stage amplifier, and amplifiers other than the final stage amplifier may be referred to as normal amplifiers. 【0050】 The final stage amplifier of each amplifier group is fixedly connected to one of the multiple antennas that constitute the radiation function. Fixed connection means that the connection target is connected in a way that makes it impossible to switch the connection destination. In the example shown in the upper part of Figure 2, the final stage amplifier of the first amplifier group is fixedly connected to the first antenna, the final stage amplifier of the second amplifier group is fixedly connected to the second antenna, ..., the final stage amplifier of the (N-1) amplifier group is fixedly connected to the (N-1) antenna, and the final stage amplifier of the N amplifier group is fixedly connected to the N antenna. 【0051】 The gains of the n amplifiers included in the Xth amplifier group satisfy the following relationship: (gain of the first stage amplifier) ​​= (gain of the second stage amplifier) ​​= ... = (gain of the (n-1)th stage amplifier) ​​<< (gain of the nth stage amplifier). The final stage amplifier is, for example, a Doherty amplifier. 【0052】 Because the gain of the final stage amplifier is significantly larger than that of a typical amplifier, the performance of the final stage amplifier is significantly higher than that of a typical amplifier. In conventional wireless base stations, a wide dynamic range of the transmitted signal has been ensured by employing very high-performance and expensive amplifiers, such as Doherty amplifiers, as the final stage amplifier. 【0053】Figure 3 is an explanatory diagram illustrating an example of a user data transmission method. Here, we mainly explain the case where the user data to be transmitted consists of x user data items: user data 1, user data 2, ..., user data x-1, and user data x. x is an integer greater than or equal to 2. 【0054】 The upper diagram in Figure 3 is an explanatory diagram for illustrating the OFDM (Orthogonal Frequency Division Multiplexing) scheme. As shown in the upper diagram of Figure 3, in the OFDM scheme, one user data occupies all subcarriers contained within the carrier. 【0055】 The lower diagram in Figure 3 is an explanatory diagram for illustrating the OFDMA (Orthogonal Frequency Division Multiple Access) scheme. As shown in the lower diagram of Figure 3, in the OFDMA scheme, multiple subcarriers containing multiple user data are shared within a single carrier. 【0056】 Figure 4 is an explanatory diagram illustrating an example of PAPR. P shown in Figure 4 Ａｖｅｒａｇｅ This is the average power of the transmitted signal. P is shown in Figure 4. Ｐｅａｋ P is the peak power of the transmitted signal. PAPR is the peak power of the transmitted signal relative to the average power of the transmitted signal. PAPR is P Ｐｅａｋ / P Ａｖｅｒａｇｅ It can be expressed as such. 【0057】 The PAPR of a transmitted signal tends to increase as the user data being transmitted is subcarrier modulated using a modulation scheme with a large number of bits per symbol. For example, among two transmitted signals with the same amount of user data, the PAPR of one transmitted signal that transmits user data subcarrier modulated using the 256QAM scheme will be greater than the PAPR of the other transmitted signal that transmits user data subcarrier modulated using the QPSK scheme. 【0058】The PAPR of a transmitted signal tends to increase as the number of user data being transmitted increases. For example, of two transmitted signals in which user data being transmitted is subcarrier modulated using the same modulation scheme, the PAPR of one transmitted signal with user data 1, user data 2, ..., user data a-1, and user data a (where a is a positive integer) is greater than the PAPR of the other transmitted signal with user data 1, user data 2, ..., user data b-1, and user data b (where b is a positive integer satisfying b < a). 【0059】 Figure 5 schematically shows an example of the configuration of a wireless base station 300. Here, we will mainly explain the parts of the configuration of the wireless base station 300 that differ from the configuration of a conventional wireless base station. 【0060】 The upper diagram of Figure 5 schematically shows an example of the configuration of the transmission function of the wireless base station 300. The wireless base station 300 may have a signal conversion function, a signal analysis function, a route determination function, an amplification function, a switching function, and a radiation function. 【0061】 The signal analysis function analyzes a signal. The signal to be analyzed is, for example, a digital signal generated by the wireless base station 300. The signal to be analyzed may also be an analog signal converted from the digital signal by the signal conversion function. 【0062】 The signal analysis function analyzes the signal to be analyzed in order to determine the amplification factor of the signal required for the wireless base station 300 to transmit a transmission signal. The signal analysis function analyzes the signal to be analyzed in order to determine the PAPR of the signal required for the wireless base station 300 to transmit a transmission signal. 【0063】 The signal analysis function analyzes the signal to be analyzed based on, for example, the modulation scheme of the subcarrier modulation of the signal to be analyzed. The signal analysis function analyzes the signal to be analyzed based on, for example, the number of user data included in the signal to be analyzed. The signal analysis function analyzes the signal to be analyzed based on, for example, both the modulation scheme of the subcarrier modulation of the signal to be analyzed and the number of user data included in the signal to be analyzed. 【0064】The routing function determines the route through which a signal intended for external transmission will travel. The signal intended for external transmission may also be referred to as the "transmission signal," and the route through which the transmission signal travels may be referred to as the "transmission route." An example of a routing function is a router. 【0065】 The route determination function determines, for example, the route by which the signal to be transmitted is transmitted to the radiating function as a transmission route. The route determination function also determines, for example, the route by which the signal to be transmitted is transmitted from the route determination function to the radiating function as a transmission route. 【0066】 The route determination function determines the transmission route based on, for example, the signal to be transmitted. The route determination function determines the transmission route based on, for example, the analysis results obtained by the signal analysis function that analyzes the signal to be transmitted. The signal to be transmitted may be the signal analyzed by the signal conversion function. 【0067】 The upper diagram of Figure 5 shows an example of a wireless base station 300 in which the route determination function is installed in the same device as the device that installs the signal analysis function. The wireless base station 300 may also install the route determination function in a different device from the device that installs the signal analysis function. 【0068】 The amplification function includes, for example, an amplifier pool composed of multiple amplifier groups arranged in parallel. The upper diagram of Figure 5 shows an example of a wireless base station 300 equipped with an amplification function having an amplifier pool composed of N amplifier groups arranged in parallel. 【0069】 For example, the number of amplifier groups constituting the amplification function is less than the number of antennas constituting the radiation function. The number of amplifier groups constituting the amplification function may also be the same as the number of antennas constituting the radiation function. In the upper part of Figure 5, an example of a wireless base station 300 is shown in which the number of amplifier groups constituting the amplification function is N and the number of antennas constituting the radiation function is M. M is an integer of 2 or more that satisfies N > M. 【0070】The switching function switches the transmission route. The switching function consists of multiple switches located between the amplification function and the radiation function. The upper diagram of Figure 5 shows an example of a wireless base station 300 equipped with a switching function consisting of M switches located between N amplifier groups that constitute the amplification function and M antennas that constitute the radiation function. 【0071】 The transmission route consists, for example, one or more amplifier groups that amplify the signal to be transmitted from among multiple amplifier groups that constitute the amplification function, and one switch from among multiple switches that constitute the switching function. The transmission route consists, for example, one amplifier group that amplifies the signal to be transmitted from among the multiple amplifier groups, and the one switch. The transmission route consists, for example, two or more amplifier groups that amplify the signal to be transmitted from among the multiple amplifier groups, and the one switch. 【0072】 The route determination function determines the transmission route by, for example, determining one or more amplifier groups. The route determination function determines the transmission route by, for example, determining one amplifier group. The route determination function determines the transmission route by, for example, determining two or more amplifier groups. The route determination function determines the transmission route by, for example, determining one switch. 【0073】 For example, an upper limit is set on the number of amplifier groups that amplify a single signal to be transmitted. In this case, the maximum number of amplifier groups that amplify a single signal to be transmitted is less than N. Alternatively, no upper limit may be set on the number of amplifier groups that amplify a single signal to be transmitted. In this case, the maximum number of amplifier groups that amplify a single signal to be transmitted is equal to N. 【0074】 The lower diagram of Figure 5 schematically shows an example of an amplifier group that constitutes the amplification function of the wireless base station 300. The lower diagram of Figure 5 shows an example of a Y-th amplifier group containing n amplifiers. Y is a positive integer satisfying 1 ≤ Y ≤ N. Here, we will mainly explain the differences between the amplifier group that constitutes the amplification function of the wireless base station 300 and the amplifier group that constitutes the amplification function of a conventional wireless base station. 【0075】The final stage amplifier of each amplifier group is not fixedly connected to any of the multiple antennas that constitute the radiation function. The final stage amplifier of each amplifier group is fluidly connected to one of the multiple antennas via one of the switches that constitute the switching function. Fluid connection means connecting the target in a way that allows the connection destination to be switched. 【0076】 For example, the gains of the n amplifiers included in the Y-th amplifier group satisfy the relationship: (gain of the first stage amplifier) ​​= (gain of the second stage amplifier) ​​= ... = (gain of the (n-1)-th stage amplifier) ​​= (gain of the n-th stage amplifier). In other words, the gains of all n amplifiers are the same. 【0077】 The statement that amplifiers have identical gains includes not only cases where the gains are exactly the same, but also cases where the error in the gains is within the range of manufacturing tolerances that occur during the manufacturing of the amplifiers. In other words, the statement that amplifiers have identical gains includes not only cases where the gains are exactly the same, but also cases where the gains are substantially the same. 【0078】 For example, the gain of the n amplifiers included in the amplifier group of the wireless base station 300 is about the same as the gain of the conventional amplifiers included in the amplifier group of a conventional wireless base station. Therefore, the gain of the final stage amplifier of the wireless base station 300 is significantly lower than the gain of the final stage amplifier of a conventional wireless base station. Consequently, the price of the final stage amplifier of the wireless base station 300 is significantly cheaper than the price of the final stage amplifier of a conventional wireless base station. 【0079】 Figure 6 is an explanatory diagram illustrating an example of a radio base station 300 transmitting a signal. Here, we mainly explain an example in which the radio base station 300 transmits a signal to the outside using the T-th antenna, one of the M antennas that constitute the radiation function. It is assumed that the route through which the signal to be transmitted reaches the T-th antenna includes the S-th switch, one of the M switches that constitute the switching function. T is a positive integer satisfying 1 ≤ T ≤ M, and S is a positive integer satisfying 1 ≤ S ≤ M. 【0080】The route determination function determines, for example, whether the signal to be transmitted satisfies predetermined high amplification conditions, and thereby determines one or more amplifier groups from among the N amplifier groups that constitute the amplification function to amplify the signal to be transmitted. The route determination function determines, for example, whether the signal to be transmitted satisfies predetermined multiple high amplification conditions, and thereby determines one or more amplifier groups from among the N amplifier groups to amplify the signal to be transmitted. 【0081】 The route determination function determines, for example, whether the signal to be transmitted satisfies a first high amplification condition, and then determines which of the N amplifier groups constituting the amplification function will amplify the signal to be transmitted. For example, if the route determination function determines that the signal to be transmitted does not satisfy the first high amplification condition, it decides that one of the N amplifier groups will amplify the signal to be transmitted. On the other hand, if the route determination function determines that the signal to be transmitted satisfies the first high amplification condition, it decides that two or more of the N amplifier groups will amplify the signal to be transmitted. 【0082】The route determination function determines, for example, whether the signal to be transmitted satisfies a second high amplification condition that is stricter than the first high amplification condition, and thereby determines which two or more amplifier groups out of the N amplifier groups that constitute the amplification function will amplify the signal to be transmitted. For example, if the route determination function determines that the signal to be transmitted satisfies the first high amplification condition but does not satisfy the second high amplification condition, it decides that two of the N amplifier groups will amplify the signal to be transmitted. On the other hand, if the route determination function determines that the signal to be transmitted satisfies the second high amplification condition, it decides that three or more of the N amplifier groups will amplify the signal to be transmitted. Similarly, the route determination function may use a third high amplification condition that is stricter than the second high amplification condition, a fourth high amplification condition that is stricter than the third high amplification condition, ..., an N-1 high amplification condition that is stricter than the N-2 high amplification condition, in order to determine that three of the N amplifier groups amplify the signal to be transmitted, four of the N amplifier groups amplify the signal to be transmitted, ..., N-1 of the N amplifier groups amplify the signal to be transmitted, and N amplifier groups amplify the signal to be transmitted. 【0083】 The upper diagram of Figure 6 schematically shows an example of the transmission route of a signal to be transmitted when one of the N amplifier groups amplifies the signal to be transmitted. Here, we assume that the P-th amplifier group among the N amplifier groups amplifies the signal to be transmitted. In this case, the transmission route of the signal to be transmitted consists of the P-th amplifier group and the S switch. P is a positive integer satisfying 1 ≤ P ≤ N. 【0084】 The wireless base station 300 controls, for example, the amplifiers from the first to the nth stage of the P amplifier group so that the P amplifier group amplifies the signal to be transmitted. The wireless base station 300 controls the S switch so that, for example, the P amplifier group is connected to the S switch in a flow manner, and the T antenna is also connected to the S switch in a flow manner. 【0085】The middle diagram in Figure 6 schematically shows an example of the transmission route of the signal to be transmitted when two of the N amplifier groups amplify the signal to be transmitted. Here, it is assumed that the P-th amplifier group and the Q-th amplifier group of the N amplifier groups amplify the signal to be transmitted. In this case, the transmission route of the signal to be transmitted consists of the P-th amplifier group, the Q-th amplifier group, and the S-switch. Q is a positive integer satisfying 1 ≤ Q ≤ N and Q ≠ P. 【0086】 The wireless base station 300 controls the amplifiers from the first to the nth stage of the P amplifier group and the amplifiers from the first to the nth stage of the Q amplifier group, respectively, so that the P amplifier group and the Q amplifier group amplify the signal to be transmitted. The wireless base station 300 controls the S switch, respectively, to fluidly connect the P amplifier group and the Q amplifier group to the S switch, and to fluidly connect the T antenna to the S switch. 【0087】 The lower diagram of Figure 6 schematically shows an example of a transmission route for a signal to be transmitted when three of the N amplifier groups amplify the signal to be transmitted. Here, it is assumed that the P, Q, and R amplifier groups among the N amplifier groups amplify the signal to be transmitted. In this case, the transmission route for the signal to be transmitted consists of the P, Q, and R amplifier groups and an S switch. R is a positive integer satisfying 1 ≤ R ≤ N, R ≠ P, and R ≠ Q. 【0088】 The wireless base station 300 controls the amplifiers from the first to the nth stage of the P amplifier group, the amplifiers from the first to the nth stage of the Q amplifier group, and the amplifiers from the first to the nth stage of the R amplifier group, respectively, so that the P amplifier group, the Q amplifier group, and the R amplifier group each amplify the signal to be transmitted. The wireless base station 300 controls the S switch so that the P amplifier group, the Q amplifier group, and the R amplifier group are connected to the S switch in a free-flowing manner, and the T antenna is also connected to the S switch in a free-flowing manner. 【0089】In conventional wireless base stations, the final stage amplifier of each amplifier group is fixedly connected to one of several antennas. Therefore, conventional wireless base stations cannot change the number of amplifier groups that amplify the signal to be transmitted. Consequently, conventional wireless base stations have been designed using the state when the PAPR of the transmitted signal is at its peak as the basis for design requirements, so that clipping does not occur even when the PAPR of the transmitted signal is at its peak. As a result, the design requirements for conventional wireless base stations were very strict. Furthermore, even when the amplification conditions for the signal to be transmitted are lenient, such as when the signal to be transmitted is subcarrier modulated using a modulation scheme with a small number of bits per symbol, such as BPSK or QPSK, or when the amount of user data included in the signal to be transmitted is small, conventional wireless base stations amplified the signal to be transmitted in the same way as when the amplification conditions for the signal to be transmitted were strict. Therefore, conventional wireless base stations sometimes wasted power when amplifying the signal to be transmitted. 【0090】In contrast, according to the system 10 of this embodiment, the wireless base station 300 can fluidly connect the final stage amplifier of each amplifier group to one of the multiple antennas via a switch included in the switching function, so that the number of amplifier groups that amplify the signal to be transmitted can be changed based on the signal to be transmitted. If the number of amplifier groups that amplify the signal to be transmitted is doubled, the power of the final transmitted signal will ideally double. Therefore, by making the number of amplifier groups that amplify the signal to be transmitted changeable, the system 10 of this embodiment can achieve a wide dynamic range of the transmitted signal using low-performance and inexpensive amplifiers, without using very high-performance and expensive amplifiers such as Doherty amplifiers that are installed in conventional wireless base stations. In particular, according to the system 10 of the embodiment shown in Figures 5 and 6, the gains of all n amplifiers included in each of the multiple amplifier groups that constitute the amplification function of the wireless base station 300 are the same. That is, the amplification function of the wireless base station 300 is composed of a single type of amplifier. Assuming that the price difference between amplifiers is relatively small, the fewer types of amplifiers that constitute the amplification function, the more likely it is that the manufacturing cost required to manufacture the wireless base station can be suppressed. Therefore, the system 10 according to the embodiment shown in Figures 5 and 6 can achieve a wide dynamic range of the transmitted signal at a particularly low cost. Furthermore, according to the system 10 according to this embodiment, the wireless base station 300 can change the number of amplifier groups that amplify the transmitted signal, decreasing the number of amplifier groups that amplify the transmitted signal when the amplification conditions for the transmitted signal are lenient, and increasing the number of amplifier groups that amplify the transmitted signal when the amplification conditions for the transmitted signal are strict. By flexibly changing the number of amplifier groups that amplify the transmitted signal according to the amplification conditions for the transmitted signal, the wireless base station 300 can amplify the transmitted signal while suppressing power waste compared to conventional wireless base stations. Therefore, the system 10 according to this embodiment can achieve a wide dynamic range of the transmitted signal with high power efficiency. As a result, the system 10 according to this embodiment can contribute to the realization of high-speed and high-power-efficient mobile communication. 【0091】Figure 7 schematically shows another example of the configuration of the wireless base station 300. Here, we will mainly explain the parts that differ from the configuration of the wireless base station 300 described above. 【0092】 The upper diagram of Figure 7 schematically shows an example of the configuration of the transmission function of the wireless base station 300. For example, each of the multiple amplifier groups that make up the amplifier pool includes two types of amplifiers. 【0093】 The lower part of Figure 7 schematically shows an example of an amplifier group that constitutes the amplification function of the wireless base station 300. For example, the gains of the n amplifiers included in the Y-th amplifier group satisfy the relationship (gain of the first stage amplifier) ​​= (gain of the second stage amplifier) ​​= ... = (gain of the (n-1)th stage amplifier) ​​< (gain of the nth stage amplifier). That is, the gains of the first to (n-1)th stage amplifiers are the same, and the gain of the nth stage amplifier is higher than the gains of the first to (n-1)th stage amplifiers. 【0094】 For example, the gain of the nth stage amplifier in the wireless base station 300 is lower than the gain of the final stage amplifier in a conventional wireless base station. Therefore, the price of the nth stage amplifier in the wireless base station 300 is cheaper than the price of the final stage amplifier in a conventional wireless base station. 【0095】 For example, a switch is placed between the gain of the (n-1)th stage amplifier and the gain of the nth stage amplifier. The route determination function determines the transmission route by, for example, determining whether the nth stage amplifier included in each of the one or more amplifier groups that amplify the signal to be transmitted, which constitute the amplification function, amplifies the signal to be transmitted. 【0096】 For example, if the route determination function determines that the nth stage amplifier does not amplify the signal to be transmitted, the wireless base station 300 controls the switch so that the nth stage amplifier does not amplify the signal to be transmitted. On the other hand, if the route determination function determines that the nth stage amplifier does amplify the signal to be transmitted, the wireless base station 300 controls the switch so that the nth stage amplifier amplifies the signal to be transmitted. 【0097】The upper part of the lower diagram in Figure 7 schematically shows an example of the switch state when the nth stage amplifier does not amplify the signal to be transmitted. In this case, the (n-1)th stage amplifier outputs the output signal to the radiating function, so the (n-1)th stage amplifier is the final stage amplifier. 【0098】 The lower panel of the lower section of Figure 7 schematically shows an example of the state of the switch when the nth stage amplifier amplifies the signal to be transmitted. In this case, the nth stage amplifier outputs an output signal to the radiating function, so the nth stage amplifier is the final stage amplifier. 【0099】 Figures 8 and 9 are explanatory diagrams illustrating another example of how the radio base station 300 transmits a signal. Here, we will mainly explain the differences from the previously described example of the radio base station 300 transmitting a signal. It is assumed that the radio base station 300 transmits the signal to be transmitted to the outside using the T antenna, and that the S switch is included in the route through which the signal to be transmitted to the T antenna. 【0100】 Figure 8 is an explanatory diagram illustrating another example in which the wireless base station 300 amplifies a signal using one of the N amplifier groups. Here, we mainly explain an example in which the route determination function determines that the signal to be transmitted does not satisfy the first high amplification condition. 【0101】 The route determination function determines the transmission route, for example, by determining whether the signal to be transmitted satisfies predetermined low amplification conditions. For example, if the route determination function determines that the signal to be transmitted does not satisfy the low amplification conditions, it decides that the nth stage amplifier in the amplifier group that amplifies the signal to be transmitted will amplify the signal to be transmitted. On the other hand, if the route determination function determines that the signal to be transmitted satisfies the low amplification conditions, it decides that the nth stage amplifier in the amplifier group that amplifies the signal to be transmitted will not amplify the signal to be transmitted. 【0102】The upper diagram of Figure 8 schematically shows an example of the transmission route of the signal to be transmitted when the nth stage amplifier of the P-th amplifier group, one of the N amplifier groups, does not amplify the signal to be transmitted. The wireless base station 300 controls the amplifiers from the 1st stage to the (n-1)th stage of the P-th amplifier group, for example, so that the P-th amplifier group amplifies the signal to be transmitted. The wireless base station 300 controls a switch located between the gain of the (n-1)th stage amplifier and the gain of the nth stage amplifier of the P-th amplifier group, for example, so that the nth stage amplifier of the P-th amplifier group does not amplify the signal to be transmitted. 【0103】 The lower diagram of Figure 8 schematically shows an example of the transmission route of the signal to be transmitted when the nth stage amplifier of the P-th amplifier group, one of the N amplifier groups, amplifies the signal to be transmitted. The wireless base station 300 controls the amplifiers from the 1st stage to the nth stage of the P-th amplifier group, for example, so that the P-th amplifier group amplifies the signal to be transmitted. The wireless base station 300 controls a switch located between the gain of the (n-1)th stage amplifier and the gain of the nth stage amplifier of the P-th amplifier group, for example, so that the nth stage amplifier of the P-th amplifier group amplifies the signal to be transmitted. 【0104】 Figure 9 is an explanatory diagram illustrating another example of a case where the wireless base station 300 amplifies a signal using two of the N amplifier groups. Here, we mainly explain an example where the route determination function determines that the signal to be transmitted satisfies the first high amplification condition. Note that the amplification ratio when the signal to be transmitted is amplified using two amplifier groups in the nth stage that do not amplify the signal to be transmitted is assumed to be higher than the amplification ratio when the signal to be transmitted is amplified using one amplifier group in the nth stage that does amplify the signal to be transmitted. 【0105】The route determination function determines the transmission route by determining, for example, whether the signal to be transmitted satisfies a second high amplification condition that is stricter than the first high amplification condition. For example, if the route determination function determines that the signal to be transmitted satisfies the first high amplification condition but does not satisfy the second high amplification condition, it determines that the nth stage amplifier in each of the two amplifier groups that amplify the signal to be transmitted will not amplify the signal to be transmitted, and that the two amplifiers will amplify the signal to be transmitted. In this case, the number of nth stage amplifiers that amplify the signal to be transmitted is 0. On the other hand, if the route determination function determines that the signal to be transmitted satisfies the second high amplification condition, it determines the transmission route by further determining whether the signal to be transmitted satisfies a third high amplification condition that is stricter than the second high amplification condition. 【0106】 For example, if the route determination function determines that the signal to be transmitted satisfies the second high amplification condition but does not satisfy the third high amplification condition, it decides that the nth stage amplifier in one of the two amplifier groups that amplify the signal to be transmitted will amplify the signal, thereby amplifying the signal by both amplifiers. In this case, the number of nth stage amplifiers that amplify the signal to be transmitted is one. On the other hand, if the route determination function determines that the signal to be transmitted satisfies the third high amplification condition, it determines the transmission route by further determining whether the signal to be transmitted satisfies the fourth high amplification condition, which is a stricter amplification condition than the third high amplification condition. 【0107】 For example, if the route determination function determines that the signal to be transmitted satisfies the third high amplification condition but does not satisfy the fourth high amplification condition, it determines that the nth stage amplifier in each of the two amplifier groups that amplify the signal to be transmitted will amplify the signal, thereby amplifying the signal with the two amplifiers. In this case, the number of nth stage amplifiers that amplify the signal to be transmitted is two. On the other hand, if the route determination function determines that the signal to be transmitted satisfies the fourth high amplification condition, it determines that three or more of the N amplifier groups will amplify the signal to be transmitted. 【0108】The route determination function may determine the transmission route when three of the N amplifier groups amplify the signal to be transmitted by sequentially using the fifth high amplification condition, which has stricter amplification requirements than the fourth high amplification condition, the sixth high amplification condition, which has stricter amplification requirements than the fifth high amplification condition, and the seventh high amplification condition, which has stricter amplification requirements than the sixth high amplification condition, in the same manner as when two of the N amplifier groups amplify the signal to be transmitted. Subsequently, the route determination function may determine the transmission route when four of the N amplifier groups amplify the signal to be transmitted by sequentially using the eighth high amplification condition, which has stricter amplification requirements than the seventh high amplification condition, the ninth high amplification condition, which has stricter amplification requirements than the eighth high amplification condition, ..., the third N-2 high amplification condition, which has stricter amplification requirements than the third N-3 high amplification condition, ..., and the transmission route when N amplifier groups amplify the signal to be transmitted. 【0109】 The upper diagram of Figure 9 schematically shows an example of the transmission route of the signal to be transmitted when the nth stage amplifier of the P amplifier group and the nth stage amplifier of the Q amplifier group do not amplify the signal to be transmitted. The wireless base station 300 controls, for example, the amplifiers from the first stage to the (n-1)th stage of the P amplifier group and the amplifiers from the first stage to the (n-1)th stage of the Q amplifier group so that the P amplifier group and the Q amplifier group amplify the signal to be transmitted. The wireless base station 300 controls, for example, a switch located between the gain of the (n-1)th stage amplifier of the P amplifier group and the gain of the nth stage amplifier so that the nth stage amplifier of the P amplifier group does not amplify the signal to be transmitted. The wireless base station 300 controls, for example, a switch located between the gain of the (n-1)th stage amplifier of the Q amplifier group and the gain of the nth stage amplifier so that the nth stage amplifier of the Q amplifier group does not amplify the signal to be transmitted. 【0110】The middle diagram in Figure 9 schematically shows an example of a transmission route for the signal to be transmitted when the nth stage amplifier of the P-th amplifier group, one of the N amplifier groups, amplifies the signal to be transmitted, and the nth stage amplifier of the Q-th amplifier group, one of the N amplifier groups, does not amplify the signal to be transmitted. The wireless base station 300 controls, for example, the amplifiers from the first to the nth stage of the P-th amplifier group and the amplifiers from the first to the (n-1)th stage of the Q-th amplifier group, respectively, so that the P-th amplifier group and the Q-th amplifier group amplify the signal to be transmitted. The wireless base station 300 controls, for example, a switch located between the gain of the (n-1)th stage amplifier of the P-th amplifier group and the gain of the nth stage amplifier so that the nth stage amplifier of the P-th amplifier group amplifies the signal to be transmitted. The wireless base station 300 controls, for example, a switch located between the gain of the (n-1)th stage amplifier of the Q-th amplifier group and the gain of the nth stage amplifier so that the nth stage amplifier of the Q-th amplifier group does not amplify the signal to be transmitted. 【0111】 The lower diagram of Figure 9 schematically shows an example of the transmission route of the signal to be transmitted when the nth stage amplifier of the P amplifier group and the nth stage amplifier of the Q amplifier group (among the N amplifier groups) amplify the signal to be transmitted. The wireless base station 300 controls, for example, the amplifiers from the first to the nth stage of the P amplifier group and the amplifiers from the first to the nth stage of the Q amplifier group, respectively, so that the P amplifier group and the Q amplifier group amplify the signal to be transmitted. The wireless base station 300 controls, for example, a switch located between the gain of the (n-1)th stage amplifier of the P amplifier group and the gain of the nth stage amplifier so that the nth stage amplifier of the P amplifier group amplifies the signal to be transmitted. The wireless base station 300 controls, for example, a switch located between the gain of the (n-1)th stage amplifier of the Q amplifier group and the gain of the nth stage amplifier so that the nth stage amplifier of the Q amplifier group amplifies the signal to be transmitted. 【0112】According to the system 10 shown in Figures 7 to 9, each amplifier group constituting the amplification function of the wireless base station 300 includes n-1 amplifiers from the 1st stage amplifier to the (n-1)th stage amplifier, and n amplifiers including an nth stage amplifier which has a higher gain compared to the gains of the (n-1)th amplifiers and a lower gain compared to the gain of the final stage amplifier of a conventional wireless base station, and a switch positioned between the gain of the (n-1)th stage amplifier and the gain of the nth stage amplifier. As a result, for example, when a signal is amplified using two of the N amplifier groups, there are three patterns for the amplification ratio of the signal to be transmitted: the amplification ratio pattern when the nth stage amplifier of the two amplifier groups does not amplify the signal to be transmitted, the amplification ratio pattern when the nth stage amplifier of one of the two amplifier groups amplifies the signal to be transmitted and the nth stage amplifier of the other amplifier group does not amplify the signal to be transmitted, and the amplification ratio pattern when the nth stage amplifier of the two amplifier groups amplifies the signal to be transmitted. Therefore, the system 10 shown in Figures 7 to 9 uses less expensive amplifiers compared to conventional wireless base stations, and compared to wireless base stations with the same number of amplifier groups and each amplifier group composed of only one type of amplifier, it is possible to realize a wireless base station in which the amplification factor of the signal to be transmitted can be adjusted particularly flexibly. 【0113】 Figure 10 schematically shows another example of the configuration of the wireless base station 300. Here, we will mainly explain the parts that differ from the configuration of the wireless base station 300 described above. 【0114】 The upper diagram of Figure 10 schematically shows an example of the configuration of the transmission function of the wireless base station 300. The amplification function has, for example, an amplifier pool composed of two types of amplifier groups. 【0115】 For example, each amplifier group in one of the two amplifier groups contains one type of amplifier, and each amplifier group in the other of the two amplifier groups contains two types of amplifiers. The upper diagram of Figure 10 shows an example of a wireless base station 300 in which the number of amplifier groups in one of the two amplifier groups is N1 and the number of amplifier groups in the other amplifier group is N2. N1 and N2 are positive integers. M is an integer of 2 or more that satisfies N1 + N2 > M. 【0116】 The lower part of Figure 10 schematically shows an example of an amplifier group that constitutes the amplification function of a wireless base station 300. For example, when 1 ≤ Y ≤ N1, the gains of the n amplifiers included in the Y-th amplifier group satisfy the relationship (gain of the first stage amplifier) ​​= (gain of the second stage amplifier) ​​= ... = (gain of the (n-1)-th stage amplifier) ​​= (gain of the n-th stage amplifier). The gain of the final stage amplifier in the Y-th amplifier group when 1 ≤ Y ≤ N1 is significantly lower than the gain of the final stage amplifier in a conventional wireless base station. Also, for example, when N1 + 1 ≤ Y ≤ N1 + N2, the gains of the n amplifiers included in the Y-th amplifier group satisfy the relationship (gain of the first stage amplifier) ​​= (gain of the second stage amplifier) ​​= ... = (gain of the (n-1)-th stage amplifier) ​​< (gain of the n-th stage amplifier). The gain of the final stage amplifier in the Y-th amplifier group when N1 + 1 ≤ Y ≤ N1 + N2 is lower than the gain of the final stage amplifier in a conventional wireless base station. 【0117】 The amplification function of the wireless base station 300 may have an amplifier pool composed of three or more amplifier groups. In this case, the types of amplifier groups and the types of gain of the final stage amplifier may match. 【0118】 Figures 11 and 12 are explanatory diagrams illustrating another example of how the wireless base station 300 transmits a signal. Here, we will mainly explain the differences from the previously described example of how the wireless base station 300 transmits a signal. It is assumed that the wireless base station 300 transmits the signal to be transmitted to the outside using the T antenna, and that the S switch is included in the route through which the signal to be transmitted to the T antenna. 【0119】 Figure 11 is an explanatory diagram illustrating another example in which the wireless base station 300 amplifies a signal using one of the N amplifier groups. Here, we mainly explain an example in which the route determination function determines that the signal to be transmitted does not satisfy the first high amplification condition. 【0120】The route determination function determines the transmission route, for example, by determining whether the signal to be transmitted satisfies predetermined low amplification conditions. For example, if the route determination function determines that the signal to be transmitted does not satisfy the low amplification conditions, it decides to select the P amplifier group to amplify the signal from among the N1+1 to N1+N2 amplifier groups. On the other hand, if the route determination function determines that the signal to be transmitted satisfies the low amplification conditions, it decides to select the P amplifier group to amplify the signal from among the 1st to N1st amplifier groups. 【0121】 The upper diagram of Figure 11 schematically shows an example of a transmission route for the signal to be transmitted when the P-th amplifier group, which amplifies the signal to be transmitted, is selected from the first to the N1st amplifier groups. The wireless base station 300 controls, for example, the first to nth stages of the P-th amplifier group so that the P-th amplifier group amplifies the signal to be transmitted. 【0122】 The lower part of Figure 11 schematically shows an example of a transmission route for the signal to be transmitted when the P-amplifier group that amplifies the signal to be transmitted is selected from the N1+1 to N1+N2 amplifier groups. The wireless base station 300 controls, for example, the amplifiers from the first to the nth stage of the P-amplifier group so that the P-amplifier group amplifies the signal to be transmitted. 【0123】 Figure 12 is an explanatory diagram illustrating another example in which the wireless base station 300 amplifies a signal using two amplifier groups out of N amplifier groups. Here, we mainly explain an example in which the route determination function determines that the signal to be transmitted satisfies the first high amplification condition. Note that the amplification ratio when the signal to be transmitted is amplified using two amplifier groups included in the first to N1 amplifier groups is assumed to be higher than the amplification ratio when the signal to be transmitted is amplified using one amplifier group included in the N1+1 to N1+N2 amplifier groups. 【0124】The route determination function determines the transmission route by determining, for example, whether the signal to be transmitted satisfies a second high amplification condition that is stricter than the first high amplification condition. For example, if the route determination function determines that the signal to be transmitted satisfies the first high amplification condition but does not satisfy the second high amplification condition, it decides that two amplifier groups included in the first to N1 amplifier groups will amplify the signal to be transmitted. On the other hand, if the route determination function determines that the signal to be transmitted satisfies the second high amplification condition, it determines the transmission route by further determining whether the signal to be transmitted satisfies a third high amplification condition that is stricter than the second high amplification condition. 【0125】 For example, if the route determination function determines that the signal to be transmitted satisfies the second high amplification condition but does not satisfy the third high amplification condition, it decides that two amplifier groups—one included in the first to N1 amplifier groups and one included in the N1+1 to N1+N2 amplifier groups—will amplify the signal to be transmitted. On the other hand, if the route determination function determines that the signal to be transmitted satisfies the third high amplification condition, it determines the transmission route by further determining whether the signal to be transmitted satisfies the fourth high amplification condition, which is a stricter amplification condition than the third high amplification condition. 【0126】 For example, if the route determination function determines that the signal to be transmitted satisfies the third high amplification condition but does not satisfy the fourth high amplification condition, it decides that two amplifier groups included in the N1+1 to N1+N2 amplifier groups will amplify the signal to be transmitted. On the other hand, if the route determination function determines that the signal to be transmitted satisfies the fourth high amplification condition, it decides that three or more amplifier groups out of the N amplifier groups will amplify the signal to be transmitted. 【0127】The route determination function may determine the transmission route when three of the N amplifier groups amplify the signal to be transmitted by sequentially using a fifth high amplification condition which has stricter amplification requirements than the fourth high amplification condition, a sixth high amplification condition which has stricter amplification requirements than the fifth high amplification condition, and a seventh high amplification condition which has stricter amplification requirements than the sixth high amplification condition, in the same manner as when two of the N amplifier groups amplify the signal to be transmitted. Furthermore, the route determination function may determine the transmission route when four of the N amplifier groups amplify the signal to be transmitted by sequentially using an eighth high amplification condition which has stricter amplification requirements than the seventh high amplification condition, a ninth high amplification condition which has stricter amplification requirements than the eighth high amplification condition, ..., a third N-2 high amplification condition which has stricter amplification requirements than the third N-3 high amplification condition, the transmission route when five of the N amplifier groups amplify the signal to be transmitted, ..., and the transmission route when all N amplifier groups amplify the signal to be transmitted. 【0128】 The upper diagram of Figure 12 schematically shows an example of the transmission route of the signal to be transmitted when the P amplifier group and Q amplifier group, which are included in the first to N1 amplifier groups, amplify the signal to be transmitted. The wireless base station 300 controls, for example, the amplifiers from the first to the nth stage of the P amplifier group and the amplifiers from the first to the nth stage of the Q amplifier group, respectively, so that the P amplifier group and Q amplifier group amplify the signal to be transmitted. 【0129】 The middle diagram in Figure 12 schematically shows an example of the transmission route of the signal to be transmitted when the P amplifier group included in the first to N1 amplifier groups and the Q amplifier group included in the N1+1 to N1+N2 amplifier groups amplify the signal to be transmitted. The wireless base station 300 controls, for example, the amplifiers from the first to the nth stage of the P amplifier group and the amplifiers from the first to the nth stage of the Q amplifier group, respectively, so that the P amplifier group and the Q amplifier group amplify the signal to be transmitted. 【0130】The lower diagram in Figure 12 schematically shows an example of the transmission route of the signal to be transmitted when the P amplifier group and Q amplifier group, which are included in the N1+1 amplifier group to the N1+N2 amplifier group, amplify the signal to be transmitted. The wireless base station 300 controls, for example, the amplifiers from the first to the nth stage of the P amplifier group and the amplifiers from the first to the nth stage of the Q amplifier group, respectively, so that the P amplifier group and the Q amplifier group amplify the signal to be transmitted. 【0131】 According to the system 10 shown in Figures 10 to 12, the amplification function of the wireless base station 300 is composed of multiple types of amplifier groups. For example, when the amplification function of the wireless base station 300 is composed of two types of amplifier groups, the first amplifier group to the N1st amplifier group and the N1+1st amplifier group to the N1+N2st amplifier group, there are three patterns for the amplification ratio of the signal to be transmitted when amplifying a signal using two of the N amplifier groups. These patterns include: the amplification ratio pattern when the two amplifier groups are selected from the first amplifier group to the N1st amplifier group; the amplification ratio pattern when one of the two amplifier groups is selected from the first amplifier group to the N1st amplifier group and the other amplifier group is selected from the N1+1st amplifier group to the N1+N2st amplifier group; and the amplification ratio pattern when the two amplifier groups are selected from the N1+1st amplifier group to the N1+N2st amplifier group. Furthermore, by configuring the amplification function of the wireless base station 300 with multiple types of amplifier groups, elements such as switches to increase the amplification rate patterns are unnecessary. Therefore, the system 10 shown in Figures 10 to 12 can realize a wireless base station at a lower cost that uses less expensive amplifiers compared to conventional wireless base stations, and has the same number of amplifier groups but uses only one type of amplifier for each amplifier group, while allowing for more flexible adjustment of the amplification rate of the signal to be transmitted. 【0132】Figure 13 schematically shows an example of the functional configuration of the management device 350. The management device 350 manages a wireless base station 300 equipped with multiple antennas. The management device 350 comprises an acquisition unit 354, a determination unit 356, an amplification unit 358, a radiation unit 362, a switching unit 364, and a control unit 366. However, it is not necessarily required that the management device 350 have all of these components. 【0133】 The acquisition unit 354 acquires the signal to be transmitted. The acquisition unit 354 acquires the signal to be transmitted, for example, by acquiring a digital signal generated by the wireless base station 300. The acquisition unit 354 acquires the signal to be transmitted, for example, by generating a digital signal from one or more user data. In this case, the acquisition unit 354 may have a function to subcarrier modulate one or more user data and a function to perform an inverse Fourier transform on the multiple subcarrier signals. 【0134】 The acquisition unit 354 acquires the signal to be transmitted, for example, by acquiring an analog signal converted from a digital signal by the signal conversion function of the wireless base station 300. The acquisition unit 354 acquires the signal to be transmitted, for example, by converting a digital signal to an analog signal. In this case, the acquisition unit 354 may have a signal conversion function. 【0135】 The determination unit 356 determines the transmission route. The determination unit 356 determines the transmission route based, for example, on the transmission target signal acquired by the acquisition unit 354. 【0136】 The decision unit 356 has, for example, a signal analysis function for the wireless base station 300. The decision unit 356 also has, for example, a route determination function for the wireless base station 300. 【0137】 The amplification unit 358 amplifies the signal to be transmitted acquired by the acquisition unit 354. The amplification unit 358 has, for example, a plurality of amplifier groups arranged in parallel. 【0138】The amplification unit 358 has, for example, the amplification function of the wireless base station 300 shown in Figure 5. In this case, each of the multiple amplifier groups constituting the amplification function includes, for example, n first amplifiers having a first gain, and these n first amplifiers are connected in series. In this case, the n first amplifiers having a first gain may be the first to nth stage amplifiers included in the Y amplifier group shown in the lower diagram of Figure 5. 【0139】 The amplification unit 358 has, for example, the amplification function of the wireless base station 300 shown in Figure 7. In this case, each of the plurality of amplifier groups constituting the amplification function includes, for example, n-1 first amplifiers having a first gain and a second amplifier having a second gain that is higher than the first gain, with the n-1 first amplifiers connected in series and the second amplifiers amplifying the signal amplified by the n-1 first amplifiers. In this case, the n-1 first amplifiers having a first gain may be the first to n-1 stage amplifiers included in the Y amplifier group shown in the lower part of Figure 7. The second amplifier having a second gain may be the nth stage amplifier included in the Y amplifier group shown in the lower part of Figure 7. Each of these amplifier groups may further include a switch positioned between the gain of the n-1 stage amplifier and the gain of the nth stage amplifier. 【0140】 The amplification unit 358 has, for example, an amplification function for the wireless base station 300 shown in Figure 10. In this case, the plurality of amplifier groups constituting the amplification function include, for example, one or more first amplifier groups and one or more second amplifier groups. Each of the one or more first amplifier groups includes, for example, n first amplifiers having a first gain, and the n first amplifiers are connected in series. Each of the one or more second amplifier groups includes, for example, n-1 first amplifiers having a first gain and a second amplifier having a second gain that is higher than the first gain, the n-1 first amplifiers are connected in series, and the second amplifiers amplify the signal amplified by the n-1 first amplifiers. 【0141】The one or more first amplifier groups may be the first to N1 amplifier groups that constitute the amplification function of the wireless base station 300 shown in Figure 10. In this case, the n first amplifiers having a first gain may be the first to nth stage amplifiers included in the Y amplifier group when 1 ≤ Y ≤ N1 as shown in the lower part of Figure 10. 【0142】 The one or more second amplifier groups may be the N1+1 to N1+N2 amplifier groups that constitute the amplification function of the wireless base station 300 shown in Figure 10. In this case, the n-1 first amplifiers having a first gain may be the first to n-1 stage amplifiers included in the Y amplifier group when N1+1 ≤ Y ≤ N1+N2 as shown in the lower part of Figure 10, and the second amplifier having a second gain may be the nth stage amplifier included in the Y amplifier group when N1+1 ≤ Y ≤ N1+N2 as shown in the lower part of Figure 10. 【0143】 The radiating unit 362 emits radio waves that carry the transmission signal. The radiating unit 362 has, for example, multiple antennas mounted on a radio base station 300. The radiating unit 362 has, for example, the radiating function of a radio base station. 【0144】 The switching unit 364 switches the transmission route. The switching unit 364 has, for example, a plurality of switches located between the amplification unit 358 and the radiating unit 362. The switching unit 364 has a switching function for the wireless base station 300. 【0145】 The determination unit 356 determines the transmission route, for example, based on high amplification conditions. The determination unit 356 determines the transmission route, for example, based on multiple high amplification conditions. 【0146】 For example, the determination unit 356 determines that if the signal to be transmitted satisfies the first high amplification condition, the transmission route is configured with two or more amplifier groups from among the multiple amplifier groups included in the amplification unit 358 that amplify the signal to be transmitted, and one switch from among the multiple switches included in the switching unit 364. On the other hand, if the signal to be transmitted does not satisfy the first high amplification condition, the determination unit 356 determines that the transmission route is configured with one amplifier group from among the multiple amplifier groups that amplifies the signal to be transmitted, and that one switch. 【0147】 For example, the determination unit 356 determines that if the modulation scheme of the signal to be transmitted satisfies a predetermined first modulation scheme condition, the transmission route is configured with two or more amplifier groups from among the multiple amplifier groups included in the amplification unit 358 that amplify the signal to be transmitted, and one switch from among the multiple switches included in the switching unit 364. On the other hand, if the modulation scheme of the signal to be transmitted does not satisfy the first modulation scheme condition, the determination unit 356 determines that the transmission route is configured with one amplifier group from among the multiple amplifier groups that amplifies the signal to be transmitted, and that one switch. 【0148】 The modulation scheme condition is, for example, that the number of bits per symbol of the modulation scheme of the signal to be transmitted is greater than a predetermined bit threshold. If the signal to be transmitted is modulated with multiple modulation schemes, the modulation scheme condition is, for example, that the number of bits per symbol of the modulation scheme with the largest number of bits per symbol among the multiple modulation schemes is greater than the bit threshold. If the signal to be transmitted is modulated with multiple modulation schemes, the modulation scheme condition may also be that the average number of bits per symbol of each modulation scheme is greater than the bit threshold. The modulation scheme condition may be an example of a high amplification condition. 【0149】 For example, the determination unit 356 determines that if the number of user data to be transmitted in the signal to be transmitted satisfies a predetermined first user data count condition, the transmission route will consist of two or more amplifier groups from the plurality of amplifier groups included in the amplification unit 358 and one switch from the plurality of switches included in the switching unit 364. On the other hand, if the number of user data to be transmitted in the signal to be transmitted does not satisfy the first user data count condition, the determination unit 356 determines that the transmission route will consist of one amplifier group from the plurality of amplifier groups and that one switch. 【0150】 The user data count condition is, for example, that the number of user data to be transmitted in the signal to be transmitted is greater than a predetermined user data count threshold. The user data count condition may be just one example of a high amplification condition. 【0151】For example, the determination unit 356 determines that if the signal to be transmitted satisfies both the first modulation scheme condition and the first user data count condition included in the first high amplification condition, the transmission route is configured with two or more amplifier groups from among the multiple amplifier groups included in the amplification unit 358 that amplify the signal to be transmitted, and one switch from among the multiple switches included in the switching unit 364. On the other hand, if the signal to be transmitted does not satisfy at least one of the first modulation scheme condition and the first user data count condition included in the first high amplification condition, the determination unit 356 determines that the transmission route is configured with one amplifier group from among the multiple amplifier groups that amplifies the signal to be transmitted, and that one switch. 【0152】 For example, the determination unit 356 determines that if the signal to be transmitted satisfies at least one of the first modulation scheme condition and the first user data number condition included in the first high amplification condition, the transmission route is configured with two or more amplifier groups from the plurality of amplifier groups included in the amplification unit 358 that amplify the signal to be transmitted and one switch from the plurality of switches included in the switching unit 364. On the other hand, if the signal to be transmitted does not satisfy both of the first modulation scheme condition and the first user data number condition included in the first high amplification condition, the determination unit 356 determines that the transmission route is configured with one amplifier group from the plurality of amplifier groups that amplifies the signal to be transmitted and that one switch. 【0153】When the amplification unit 358 has the amplification function of the wireless base station 300 shown in Figure 5, for example, when the signal to be transmitted satisfies the first high amplification condition, the determination unit 356 determines that the transmission route is configured with two or more amplifier groups that amplify the signal to be transmitted from among the N amplifier groups included in the amplification unit 358 and one switch from among the M switches included in the switching unit 364. Subsequently, the determination unit 356 may use a second high amplification condition which is stricter than the first high amplification condition, a third high amplification condition which is stricter than the second high amplification condition, a fourth high amplification condition which is stricter than the third high amplification condition, ..., an N-1 high amplification condition which is stricter than the N-2 high amplification condition, in order to determine a transmission route configured with two amplifier groups that amplify the signal to be transmitted from among the N amplifier groups and the one switch, a transmission route configured with three amplifier groups that amplify the signal to be transmitted from among the N amplifier groups and the one switch, ..., and a transmission route configured with N amplifier groups and the one switch. On the other hand, if the signal to be transmitted does not satisfy the first high amplification condition, the determination unit 356 determines that the transmission route is configured with one amplifier group from among the N amplifier groups that amplifies the signal to be transmitted and that one switch. 【0154】 When the amplification unit 358 has the amplification function of the wireless base station 300 shown in Figure 7, for example, when the signal to be transmitted satisfies the first high amplification condition, the determination unit 356 determines that the transmission route is configured with two or more amplifier groups that amplify the signal to be transmitted from among the N amplifier groups included in the amplification unit 358 and one switch from among the M switches included in the switching unit 364. In this case, the determination unit 356 determines the transmission route based, for example, on a second high amplification condition that is stricter than the first high amplification condition, a third high amplification condition that is stricter than the second high amplification condition, and a fourth high amplification condition that is stricter than the third high amplification condition. 【0155】For example, if the signal to be transmitted satisfies the first high amplification condition but does not satisfy the second high amplification condition, the determination unit 356 determines that the second amplifiers included in each of the two amplifier groups that amplify the signal to be transmitted from among the N amplifier groups will not amplify the signal to be transmitted, thereby determining the transmission route composed of the two amplifier groups and the one switch. For example, if the signal to be transmitted satisfies the second high amplification condition but does not satisfy the third high amplification condition, the determination unit 356 determines that the second amplifier included in one of the two amplifier groups will amplify the signal to be transmitted, and the second amplifier included in the other of the two amplifier groups will not amplify the signal to be transmitted, thereby determining the transmission route composed of the two amplifier groups and the one switch. For example, if the signal to be transmitted satisfies the third high amplification condition but does not satisfy the fourth high amplification condition, the determination unit 356 determines that the second amplifiers included in each of the two amplifier groups will amplify the signal to be transmitted, thereby determining the transmission route composed of the two amplifier groups and the one switch. 【0156】 For example, the determination unit 356 determines that if the signal to be transmitted satisfies the fourth high amplification condition, the transmission route is configured with three or more amplifier groups that amplify the signal to be transmitted from among the N amplifier groups included in the amplification unit 358 and the one switch. Subsequently, the determination unit 356 may use a fifth high amplification condition, which has stricter amplification requirements than the fourth high amplification condition; a sixth high amplification condition, which has stricter amplification requirements than the fifth high amplification condition; a seventh high amplification condition, which has stricter amplification requirements than the sixth high amplification condition; ... a third N-2 high amplification condition, which has stricter amplification requirements than the third N-3 high amplification condition, in order to determine a transmission route configured with three amplifier groups that amplify the signal to be transmitted from among the N amplifier groups and the one switch; a transmission route configured with four amplifier groups that amplify the signal to be transmitted from among the N amplifier groups and the one switch; ... and a transmission route configured with N amplifier groups and the one switch. 【0157】On the other hand, if the signal to be transmitted does not satisfy the first high amplification condition, the determination unit 356 determines that the transmission route is configured with one amplifier group from among the N amplifier groups that amplifies the signal to be transmitted and that one switch. In this case, the determination unit 356 may further determine the transmission route configured with the one amplifier group and that one switch based on a predetermined low amplification condition. 【0158】 For example, the determination unit 356 determines the transmission route consisting of the amplifier group and the switch by deciding that the second amplifier included in the amplifier group does not amplify the signal when the signal to be transmitted satisfies the low amplification condition. On the other hand, the determination unit 356 determines the transmission route consisting of the amplifier group and the switch by deciding that the second amplifier included in the amplifier group amplifies the signal when the signal to be transmitted does not satisfy the low amplification condition. 【0159】 For a signal to be transmitted to satisfy the low amplification condition, this includes, for example, that the modulation scheme of the signal to be transmitted satisfies predetermined modulation scheme conditions. The modulation scheme condition is, for example, that the number of bits per symbol of the modulation scheme of the signal to be transmitted is less than a predetermined bit threshold. If the signal to be transmitted is modulated with multiple modulation schemes, the modulation scheme condition is, for example, that the number of bits per symbol of the modulation scheme with the largest number of bits per symbol among the multiple modulation schemes is less than the bit threshold. If the signal to be transmitted is modulated with multiple modulation schemes, the modulation scheme condition may also be that the average number of bits per symbol of each of the multiple modulation schemes is less than the bit threshold. The modulation scheme condition is just one example of a low amplification condition. 【0160】 For a signal to be transmitted to satisfy the low amplification condition, this includes, for example, that the number of user data to be transmitted in the signal to be transmitted satisfies a predetermined user data count condition. The user data count condition is, for example, that the number of user data to be transmitted in the signal to be transmitted is less than a predetermined user data count threshold. The user data count condition may be just one example of the low amplification condition. 【0161】For example, the determination unit 356 determines the transmission route consisting of the amplifier group and the switch by deciding that the second amplifier included in the amplifier group will not amplify the signal if the signal to be transmitted satisfies both the modulation scheme condition and the user data count condition included in the low-high amplification condition. On the other hand, the determination unit 356 determines the transmission route consisting of the amplifier group and the switch by deciding that the second amplifier included in the amplifier group will amplify the signal if the signal to be transmitted does not satisfy at least one of the modulation scheme condition and the user data count condition included in the low-high amplification condition. 【0162】 For example, the determination unit 356 determines the transmission route consisting of the amplifier group and the switch by deciding that the second amplifier included in the amplifier group will not amplify the signal if the signal to be transmitted satisfies at least one of the modulation scheme conditions and the number of user data conditions included in the low-high amplification conditions. On the other hand, the determination unit 356 determines the transmission route consisting of the amplifier group and the switch by deciding that the second amplifier included in the amplifier group will amplify the signal if the signal to be transmitted does not satisfy both the modulation scheme conditions and the number of user data conditions included in the low-high amplification conditions. 【0163】 When the amplification unit 358 has the amplification function of the wireless base station 300 shown in Figure 10, for example, when the signal to be transmitted satisfies the first high amplification condition, the determination unit 356 determines that the transmission route is configured with two or more amplifier groups that amplify the signal to be transmitted from among the N amplifier groups included in the amplification unit 358 and one switch from among the M switches included in the switching unit 364. In this case, the determination unit 356 determines the transmission route based, for example, on a second high amplification condition which is stricter than the first high amplification condition, a third high amplification condition which is stricter than the second high amplification condition, and a fourth high amplification condition which is stricter than the third high amplification condition. 【0164】For example, if the signal to be transmitted satisfies the first high amplification condition but does not satisfy the second high amplification condition, the determination unit 356 determines that two amplifier groups from one or more first amplifier groups included in the N amplifier groups will amplify the signal to be transmitted, thereby determining a transmission route composed of the two amplifier groups and the one switch. For example, if the signal to be transmitted satisfies the second high amplification condition but does not satisfy the third high amplification condition, the determination unit 356 determines that one amplifier group from the one or more first amplifier groups will amplify the signal to be transmitted, and one amplifier group from one or more second amplifier groups included in the N amplifier groups will also amplify the signal to be transmitted, thereby determining a transmission route composed of the two amplifier groups and the one switch. For example, if the signal to be transmitted satisfies the third high amplification condition but does not satisfy the fourth high amplification condition, the determination unit 356 determines that two amplifier groups from one or more second amplifier groups will amplify the signal to be transmitted, thereby determining a transmission route composed of the two amplifier groups and the one switch. 【0165】 For example, the determination unit 356 determines that if the signal to be transmitted satisfies the fourth high amplification condition, the transmission route is configured with three or more amplifier groups that amplify the signal to be transmitted from among the N amplifier groups included in the amplification unit 358 and the one switch. Subsequently, the determination unit 356 may use a fifth high amplification condition, which has stricter amplification requirements than the fourth high amplification condition; a sixth high amplification condition, which has stricter amplification requirements than the fifth high amplification condition; a seventh high amplification condition, which has stricter amplification requirements than the sixth high amplification condition; ... a third N-2 high amplification condition, which has stricter amplification requirements than the third N-3 high amplification condition, in order to determine a transmission route configured with three amplifier groups that amplify the signal to be transmitted from among the N amplifier groups and the one switch; a transmission route configured with four amplifier groups that amplify the signal to be transmitted from among the N amplifier groups and the one switch; ... and a transmission route configured with N amplifier groups and the one switch. 【0166】On the other hand, if the signal to be transmitted does not satisfy the first high amplification condition, the determination unit 356 determines that the transmission route is configured with one amplifier group from among the N amplifier groups that amplifies the signal to be transmitted and that one switch. In this case, the determination unit 356 may further determine the transmission route configured with the one amplifier group and that one switch based on a predetermined low amplification condition. 【0167】 For example, the determination unit 356 determines a transmission route consisting of the amplifier group and the switch by deciding that one of the one or more first amplifier groups included in the N amplifier groups will amplify the signal to be transmitted if the signal to be transmitted satisfies the low amplification condition. On the other hand, the determination unit 356 determines a transmission route consisting of the amplifier group and the switch by deciding that one of the one or more second amplifier groups included in the N amplifier groups will amplify the signal to be transmitted if the signal to be transmitted does not satisfy the low amplification condition. 【0168】 For example, the determination unit 356 determines a transmission route consisting of the amplifier group and the switch by deciding that one of the one or more first amplifier groups amplifies the signal to be transmitted when the signal to be transmitted satisfies both the modulation scheme condition and the number of user data conditions included in the low-high amplification conditions. On the other hand, the determination unit 356 determines a transmission route consisting of the amplifier group and the switch by deciding that one of the one or more second amplifier groups amplifies the signal to be transmitted when the signal to be transmitted does not satisfy at least one of the modulation scheme condition and the number of user data conditions included in the low-high amplification conditions. 【0169】For example, the determination unit 356 determines a transmission route consisting of the amplifier group and the switch by deciding that one of the one or more first amplifier groups amplifies the signal to be transmitted if the signal to be transmitted satisfies at least one of the modulation scheme conditions and the number of user data conditions included in the low-high amplification conditions. On the other hand, the determination unit 356 determines a transmission route consisting of the amplifier group and the switch by deciding that one of the one or more second amplifier groups amplifies the signal to be transmitted if the signal to be transmitted does not satisfy both the modulation scheme conditions and the number of user data conditions included in the low-high amplification conditions. 【0170】 The control unit 366 controls the controlled object. For example, the control unit 366 controls the controlled object based on the transmission route determined by the determination unit 356. 【0171】 The control unit 366 controls, for example, the amplification unit 358. The control unit 366 controls, for example, one or more amplifier groups that constitute a transmission route among a plurality of amplifier groups included in the amplification unit 358. The control unit 366 controls, for example, the one or more amplifier groups so that they amplify the signal to be transmitted. 【0172】For example, if the amplification unit 358 has the amplification function of the wireless base station 300 shown in Figure 5, the control unit 366 controls the n first amplifiers included in each of the one or more amplifier groups so that the one or more amplifier groups amplify the signal to be transmitted. For example, if the amplification unit 358 has the amplification function of the wireless base station 300 shown in Figure 7, the control unit 366 controls the n-1 first amplifiers and switches located between the n-1 first amplifiers and second amplifiers included in each of at least one of the one or more amplifier groups so that the one or more amplifier groups amplify the signal to be transmitted, and controls the n-1 first amplifiers, second amplifiers and switches located between the n-1 first amplifiers and second amplifiers included in each of the remaining amplifier groups of the one or more amplifier groups. For example, if the amplification unit 358 has the amplification function of the wireless base station 300 shown in Figure 10, the control unit 366 controls n first amplifiers included in at least one first amplifier group among the one or more amplifier groups, and controls n-1 first and second amplifiers included in each of the remaining second amplifier groups among the one or more amplifier groups, so that the one or more amplifier groups amplify the signal to be transmitted. 【0173】 The control unit 366 controls, for example, the switching unit 364. The control unit 366 controls, for example, one switch among a plurality of switches included in the switching unit 364 that constitutes a transmission route. The control unit 366 controls, for example, the one switch so that each amplifier of one or more amplifier groups that constitute a transmission route among a plurality of amplifier groups included in the amplification unit 358 is fluidly connected to the one switch. The control unit 366 controls, for example, the one switch so that one antenna among a plurality of antennas included in the radiating unit 362 to which the signal to be transmitted is transmitted is fluidly connected to the one switch. 【0174】 The control unit 366 controls, for example, the radiating unit 362. The control unit 366 controls, for example, one antenna so that it radiates radio waves that carry the transmission signal. 【0175】Figure 14 is an explanatory diagram illustrating an example of the processing flow of system 10. Here, the starting state is defined as the state in which the wireless base station 300 has not yet acquired the signal to be transmitted. 【0176】 In step 102 (steps may be abbreviated as S), the acquisition unit 354 acquires the signal to be transmitted. In S104, the determination unit 356 determines the route by which the signal to be transmitted is transmitted to one of the multiple antennas mounted on the radio base station 300, based on the signal to be transmitted acquired by the acquisition unit 354 in S102. 【0177】 In S106, the control unit 366 controls one or more amplifier groups that constitute the route determined by the determination unit 356 in S104 so that each of them amplifies the signal to be transmitted. The one or more amplifier groups amplify the signal to be transmitted in accordance with the control of the control unit 366. 【0178】 In S108, the control unit 366 controls a single switch to connect the one or more amplifier groups and the single antenna to one of the multiple switches included in the switching unit 364 that constitutes the route determined by the determination unit 356 in S104. The single switch connects the one or more amplifier groups and the single antenna to the single switch in accordance with the control unit 366. The control unit 366 controls the single antenna to transmit the signal to be transmitted, amplified by the one or more amplifier groups in S106, as a transmission signal to one or more communication terminals 30. The single antenna radiates radio waves carrying the transmission signal in accordance with the control unit 366. One or more communication terminals 30 receive the transmission signal by receiving the radio waves radiated by the single antenna. After that, the process of the wireless base station 300 transmitting the transmission signal to one or more communication terminals 30 is completed. 【0179】Figure 15 schematically shows an example of the hardware configuration of a computer 1200 that functions as a management device 350. A program installed on the computer 1200 can cause the computer 1200 to function as one or more "parts" of the apparatus according to this embodiment, or to cause the computer 1200 to execute operations associated with the apparatus according to this embodiment or such one or more "parts", and / or to cause the computer 1200 to execute a process or a stage of such process according to this embodiment. Such a program may be executed by the CPU 1212 to cause the computer 1200 to execute specific operations associated with some or all of the blocks in the flowcharts and block diagrams described herein. 【0180】 The computer 1200 according to this embodiment includes a CPU 1212, RAM 1214, and a graphics controller 1216, which are interconnected by a host controller 1210. The computer 1200 also includes input / output units such as a communication interface 1222, a storage device 1224, a DVD drive 1226, and an IC card drive, which are connected to the host controller 1210 via an input / output controller 1220. The DVD drive 1226 may be a DVD-ROM drive and a DVD-RAM drive, etc. The storage device 1224 may be a hard disk drive and a solid-state drive, etc. The computer 1200 also includes legacy input / output units such as a ROM 1230 and a keyboard, which are connected to the input / output controller 1220 via an input / output chip 1240. 【0181】 The CPU 1212 operates according to the programs stored in the ROM 1230 and RAM 1214, thereby controlling each unit. The graphics controller 1216 acquires the image data generated by the CPU 1212 and stores it in the frame buffer provided in the RAM 1214 or within itself, so that the image data is displayed on the display device 1218. 【0182】The communication interface 1222 communicates with other electronic devices via a network. The storage device 1224 stores programs and data used by the CPU 1212 in the computer 1200. The DVD drive 1226 reads programs or data from the DVD-ROM 1227, etc., and provides them to the storage device 1224. The IC card drive reads programs and data from the IC card and / or writes programs and data to the IC card. 【0183】 The ROM 1230 stores boot programs and / or hardware-dependent programs of the computer 1200, which are executed by the computer 1200 when activated. The input / output chip 1240 may also connect various input / output units to the input / output controller 1220 via USB ports, parallel ports, serial ports, keyboard ports, mouse ports, etc. 【0184】 The program is provided on a computer-readable storage medium such as a DVD-ROM 1227 or an IC card. The program is read from the computer-readable storage medium and installed on a storage device 1224, RAM 1214, or ROM 1230, which are examples of computer-readable storage media, and executed by the CPU 1212. The information processing described within these programs is read by the computer 1200, resulting in coordination between the program and the various types of hardware resources described above. The apparatus or method may be configured to realize the operation or processing of information in accordance with the use of the computer 1200. 【0185】For example, when communication is performed between a computer 1200 and an external device, the CPU 1212 may execute a communication program loaded into the RAM 1214 and, based on the processing described in the communication program, instruct the communication interface 1222 to perform communication processing. Under the control of the CPU 1212, the communication interface 1222 reads transmission data stored in a transmission buffer area provided in a recording medium such as the RAM 1214, storage device 1224, DVD-ROM 1227, or IC card, transmits the read transmission data to the network, or writes received data received from the network to a reception buffer area or the like provided on the recording medium. 【0186】 Furthermore, the CPU 1212 may read all or necessary parts of a file or database stored on an external recording medium such as a storage device 1224, a DVD drive 1226 (DVD-ROM 1227), or an IC card into the RAM 1214, and perform various types of processing on the data in the RAM 1214. The CPU 1212 may then write the processed data back to the external recording medium. 【0187】 Various types of information, such as various types of programs, data, tables, and databases, may be stored on the recording medium and subjected to information processing. The CPU 1212 may perform various types of processing on the data read from the RAM 1214, including various types of operations, information processing, conditional judgments, conditional branching, unconditional branching, information retrieval / replacement, etc., as described throughout this disclosure and specified by the program instruction sequence, and write the results back to the RAM 1214. The CPU 1212 may also retrieve information in files, databases, etc., within the recording medium. For example, if a plurality of entries are stored in the recording medium, each having an attribute value of a first attribute associated with an attribute value of a second attribute, the CPU 1212 may search among the plurality of entries for an entry that matches the specified condition for the attribute value of the first attribute, read the attribute value of the second attribute stored in that entry, and thereby obtain the attribute value of the second attribute associated with the first attribute that satisfies a predetermined condition. 【0188】 The program or software module described above may be stored on or near the computer 1200 in a computer-readable storage medium. Alternatively, a recording medium such as a hard disk or RAM provided within a server system connected to a dedicated communication network or the Internet can be used as a computer-readable storage medium, thereby providing the program to the computer 1200 via the network. 【0189】 In this embodiment, blocks in the flowchart and block diagram may represent a stage in a process in which an operation is performed or a "part" of a device that has the role of performing an operation. A particular stage and "part" may be implemented by a dedicated circuit, a programmable circuit supplied with computer-readable instructions stored on a computer-readable storage medium, and / or a processor supplied with computer-readable instructions stored on a computer-readable storage medium. The dedicated circuit may include digital and / or analog hardware circuits, and may include integrated circuits (ICs) and / or discrete circuits. The programmable circuit may include reconfigurable hardware circuits, such as field-programmable gate arrays (FPGAs) and programmable logic arrays (PLAs), which include logical AND, logical OR, exclusive OR, negated AND, negated OR, and other logical operations, flip-flops, registers, and memory elements. 【0190】Computer-readable media may include any tangible device capable of storing instructions to be executed by a suitable device, and as a result, computer-readable media having instructions stored therein will comprise a product that includes instructions that can be executed to create means for performing operations specified in a flowchart or block diagram. Examples of computer-readable media may include electronic storage media, magnetic storage media, optical storage media, electromagnetic storage media, semiconductor storage media, etc. More specific examples of computer-readable media may include floppy disks (registered trademark), diskettes, hard disks, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), electrically erasable programmable read-only memory (EEPROM), static random access memory (SRAM), compact disk read-only memory (CD-ROM), digital multipurpose disc (DVD), Blu-ray (registered trademark) disc, memory stick, integrated circuit card, etc. 【0191】 Computer-readable instructions may include assembler instructions, instruction set architecture (ISA) instructions, machine instructions, machine-dependent instructions, microcode, firmware instructions, state setting data, or source code or object code written in any combination of one or more programming languages, including object-oriented programming languages ​​such as Smalltalk®, Java®, C++, and conventional procedural programming languages ​​such as the C programming language or similar programming languages. 【0192】Computer-readable instructions are provided locally or via a wide area network (WAN) such as a local area network (LAN) or the internet to the processor or programmable circuit of a programmable data processing device such as a computer, and may be executed to create means for performing operations specified in a flowchart or block diagram. Here, the computer may be a PC (personal computer), tablet computer, smartphone, workstation, server computer, general-purpose computer, or special-purpose computer, and may also be a computer system in which multiple computers are connected. Such a computer system in which multiple computers are connected is also called a distributed computing system and is a computer in a broad sense. In a distributed computing system, multiple computers execute a program by having each computer execute a part of the program and by passing data during program execution between computers as needed. 【0193】 Examples of processors include computer processors, central processing units (CPUs), processing units, microprocessors, digital signal processors, controllers, and microcontrollers. A computer may have one or more processors. In a multiprocessor system with multiple processors, each processor executes a portion of the program, and the processors collectively execute the program by passing program execution data between them as needed. For example, in the execution of multitasks, each of the multiple processors may execute a portion of each task in small chunks by switching tasks at each time slice. In this case, which part of a program each processor executes changes dynamically. Which part of a program each of the multiple processors executes may also be statically determined by multiprocessor-aware programming. 【0194】This invention can contribute to the realization of high-speed and power-efficient mobile communications, and therefore can contribute to achieving Sustainable Development Goal (SDG) 7, "Affordable and Clean Energy," and Goal 9, "Industry, Innovation, and Infrastructure." 【0195】 Although the present invention has been described above using embodiments, the technical scope of the present invention is not limited to the scope described in the above embodiments. It will be apparent to those skilled in the art that various modifications or improvements can be made to the above embodiments. It will be clear from the claims that such modified or improved forms may also be included in the technical scope of the present invention. 【0196】 It should be noted that the execution order of operations, procedures, steps, and stages in the devices, systems, programs, and methods shown in the claims, specifications, and drawings is not explicitly stated as "before" or "prior to," and that these can be performed in any order unless the output of a previous operation is used in a later operation. Even if the operation flow in the claims, specifications, and drawings is described using phrases such as "first," and "next," for convenience, this does not mean that it is mandatory to perform the operations in that order. 【0197】 10 System, 30 Communication terminal, 100 Management infrastructure, 200 Distributed infrastructure, 300 Wireless base station, 310 RAN, 350 Management device, 354 Acquisition unit, 356 Determination unit, 358 Amplification unit, 362 Radiation unit, 364 Switching unit, 366 Control unit, 1200 Computer, 1210 Host controller, 1212 CPU, 1214 RAM, 1216 Graphics controller, 1218 Display device, 1220 Input / Output controller, 1222 Communication interface, 1224 Storage device, 1226 DVD drive, 1227 DVD-ROM, 1230 ROM, 1240 Input / Output chip

Claims

1. A management device for managing a wireless base station equipped with multiple antennas, comprising: an acquisition unit for acquiring a signal to be transmitted to the outside; a determination unit for determining a route for the signal to be transmitted to one of the multiple antennas based on the signal; and an amplification unit having a plurality of amplifier groups arranged in parallel, wherein the route consists of one or more amplifier groups that amplify the signal from among the plurality of amplifier groups, and one switch from a plurality of switches located between the plurality of amplifier groups and the plurality of antennas.

2. The control device according to claim 1, wherein the determination unit determines that the route is composed of two or more amplifier groups and one switch for amplifying the signal when the signal satisfies predetermined high amplification conditions, and determines that the route is composed of one amplifier group and one switch for amplifying the signal when the signal does not satisfy the high amplification conditions.

3. The control device according to claim 2, wherein the determination unit determines that the route is configured with the two or more amplifier groups and the one switch when the modulation method of the signal satisfies predetermined modulation method conditions, and determines that the route is configured with the one amplifier group and the one switch when the modulation method of the signal does not satisfy the modulation method conditions.

4. The management device according to claim 2, wherein the determination unit determines that the route is configured with two or more amplifier groups and one switch when the number of user data to be transmitted the signal satisfies a predetermined user data number condition, and determines that the route is configured with one amplifier group and one switch when the number of user data to be transmitted the signal does not satisfy the user data number condition.

5. The control device according to any one of claims 1 to 4, wherein each of the plurality of amplifier groups includes n first amplifiers having a first gain, and the n first amplifiers are connected in series, where n is an integer of 2 or more.

6. The control device according to any one of claims 1 to 4, wherein each of the plurality of amplifier groups includes n-1 first amplifiers having a first gain and a second amplifier having a second gain that is higher than the first gain, the n-1 first amplifiers are connected in series, and the second amplifier amplifies the signal amplified by the n-1 first amplifiers, where n is an integer of 2 or more.

7. The control device according to claim 6, wherein, when the route is configured with one group of amplifiers that amplifies the signal and one switch, the determination unit determines that the second amplifier included in the group of amplifiers does not amplify the signal when the signal satisfies a predetermined low amplification condition, and determines that the second amplifier included in the group of amplifiers amplifies the signal when the signal does not satisfy the low amplification condition.

8. The control device according to any one of claims 1 to 4, wherein the plurality of amplifier groups includes one or more first amplifier groups and one or more second amplifier groups, each first amplifier group of the one or more first amplifier groups includes n first amplifiers having a first gain, the n first amplifiers are connected in series, each second amplifier group of the one or more second amplifier groups includes n-1 first amplifiers having the first gain and a second amplifier having a second gain that is higher than the first gain, the n-1 first amplifiers are connected in series, and the second amplifiers amplify the signal amplified by the n-1 first amplifiers, where n is an integer of 2 or more.

9. The control device according to claim 8, wherein, when the route is configured with one amplifier group for amplifying the signal and one switch, the determination unit determines that one of the one or more first amplifier groups amplifies the signal when the signal satisfies a predetermined low amplification condition, and determines that one of the one or more second amplifier groups amplifies the signal when the signal does not satisfy the low amplification condition.

10. A wireless base station comprising a management device according to any one of claims 1 to 9 and the plurality of antennas.

11. A program, when executed by a computer, that causes the computer to function as a management device according to any one of claims 1 to 9.

12. A management method performed by a computer managing a wireless base station equipped with multiple antennas, comprising: an acquisition step of acquiring a signal to be transmitted to the outside; and a determination step of determining a route for the signal to be transmitted to one of the multiple antennas based on the signal, wherein the route consists of one or more amplifier groups that amplify the signal from a plurality of amplifier groups arranged in parallel, and one switch from a plurality of switches located between the plurality of amplifier groups and the plurality of antennas.

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