A second device communicating with the first device

Abstract

To determine power of a radio signal, which is received at an antenna site, from a wireless device accurately in an aggregate station.SOLUTION: A first device disposed in a first site where an antenna is installed comprises: first adjustment means which adjusts a first signal of a radio frequency band from the antenna based on a value of a first gain and outputs a second signal; first transmission means to which the second signal is inputted and which transmits the second signal to a second site; first gain control means by which a first control signal is generated and outputted to the first adjustment means for controlling the value of the first gain, so that power of the second signal is settled in such a range as to be inputted to the first transmission means; and second transmission means which transmits a notification control signal indicating the value of the first gain or a value of the first control signal to the second site.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure provides: No. 1 site A second device communicating with the first device site No. 2 outfit Place Regarding. [Background technology]

[0002] In wireless communication systems such as mobile communication systems, Radio-over-Fiber (RoF) technology is used between an antenna site (or base station) and an aggregation station that connects to multiple antenna sites. An antenna site is a site where an antenna is located and transmits and receives radio signals to and from wireless devices (WDs) (also called user equipment (UE)) of the wireless communication system. An aggregation station is a site connected to the antenna site by a communication link and communicates with the WDs via the antenna site.

[0003] The antenna at the antenna site receives the radio signal transmitted by the WD and outputs a radio frequency signal (hereinafter referred to as an RF signal). When using RF, the antenna site generates modulated light based on the RF signal and transmits the modulated light via optical fiber to the central station. The central station demodulates the modulated light received via optical fiber to generate an RF signal.

[0004] There is a limit to the range of power (electrical power) of an RF signal that can be input to a device for generating modulated light (hereinafter referred to as a modulation device). Generally, the power of an RF signal output by an antenna based on a radio signal received from a WD can vary beyond the range that can be input to the modulation device depending on the position of the WD. For this reason, Non-Patent Document 1 discloses a configuration in which the gain of a power amplifier (hereinafter referred to as a PA) is adjusted according to the power of the RF signal from the antenna, thereby adjusting the power of the RF signal output by the PA to within the range that can be input to the modulation device. [Prior art documents] [Non-patent literature]

[0005] [Non-Patent Document 1] H. Yasuda et al., "Coverage Extension of 28 GHz Band Uplink Signals Inside Vehicle Using Analog Radio over Multi-Mode Fiber", in Proc. OECC 2022, Toyama, Japan, July 2022 Summary of the Invention [Problem to be solved by the invention]

[0006] In order for the central station to determine the transmission power of the radio signal to be transmitted to the WD and the beam direction of the radio signal to be transmitted to the WD, it may be necessary for the central station to refer to the power of the radio signal received from the WD, i.e., the RF signal. In the configuration described in Non-Patent Document 1, the power of the RF signal received by the central station is adjusted with a variable gain by the PA at the antenna site, so the central station cannot determine the power of the radio signal received from the WD, i.e., the RF signal before amplification by the PA, and cannot accurately determine the transmission power and beam direction of the radio signal to be transmitted to the WD.

[0007] Even when the antenna site and the central station are connected by a wireless link instead of RoF, the same problem occurs when the RF signal is amplified with a variable gain at the antenna site and transmitted to the central station.

[0008] The present disclosure provides: No. 1 The power of the wireless signal from the wireless device received at the site, Second Site The present invention provides a technology for accurately determining the above. [Means for solving the problem]

[0009] According to one aspect of the present disclosure, a first adjusting means for adjusting a first signal based on a value of a first gain and outputting a second signal; a first transmitting means for receiving the second signal and transmitting the second signal; a first gain control means for generating a first control signal for controlling the value of the first gain so that the power of the second signal is within a range that can be input to the first transmitting means and outputting the first control signal to the first adjusting means; and a second transmitting means for transmitting a notification control signal indicating the value of the first gain.The second device communicating with the first device includes a first receiving means for receiving and outputting the second signal from the first transmitting means, a second receiving means for receiving and outputting the notification control signal from the second transmitting means, a second adjusting means for adjusting the second signal based on a value of a second gain and outputting a third signal, and a second adjusting means for adjusting the value of the first gain indicated by the notification control signal. To the value and second gain control means for generating a second control signal for controlling the value of the second gain so that the value of the third gain of the third signal relative to the first signal falls within a predetermined range based on the second control signal and outputting the second control signal to the second adjustment means. the second gain control means has control information indicating a correspondence between a value of the second control signal and a value of the second gain, and generates the second control signal by using the control information to determine a value of the second control signal corresponding to the determined value of the second gain; the second device further comprises first generation means for determining a first gain value of the second gain of the second adjustment means when the first value is input to the second adjustment means by inputting a second control signal of a first value to the second adjustment means and measuring a power of an output of the second adjustment means when a test signal of known power is input to the first transmission means, and for determining a second gain value of the second gain of the second adjustment means when the second value is input to the second adjustment means by inputting a second control signal of a second value different from the first value to the second adjustment means and measuring a power of an output of the second adjustment means when a test signal of known power is input to the first transmission means; and for generating the control information based on the first value, the second value, the first gain value, and the second gain value. . [Effects of the Invention]

[0010] According to the present disclosure: No. 1 The power of the wireless signal from the wireless device received at the site, Second Site It is possible to make a highly accurate determination. [Brief explanation of the drawings]

[0011] [Figure 1] 1 is a diagram illustrating the configuration of a wireless communication system according to an embodiment. [Figure 2] FIG. 10 is a diagram showing the relationship between gain GX and gain GY. [Figure 3] FIG. 10 is a diagram illustrating that the total gain is not constant due to a difference in timing of the second control signal. [Figure 4] FIG. 10 is an explanatory diagram of a process for generating timing correction information. [Figure 5] FIG. 10 is an explanatory diagram of a process for generating control information. [Figure 6] 1 is a diagram illustrating the configuration of a wireless communication system according to an embodiment. [Figure 7] FIG. 2 is a diagram illustrating the configuration of a central station according to an embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0012] Hereinafter, the embodiments will be described in detail with reference to the accompanying drawings. Note that the following embodiments do not limit the scope of the invention as claimed, and not all combinations of features described in the embodiments are necessarily essential to the invention. Two or more features among the multiple features described in the embodiments may be arbitrarily combined. Furthermore, the same reference numerals are used for the same or similar components, and redundant explanations will be omitted.

[0013] First Embodiment 1 is a diagram showing the configuration of a wireless communication system according to this embodiment. An antenna 10 and a wireless unit (first device) are installed at an antenna site. The wireless unit includes an RF circuit 11, a PA 12, modulation devices (E / O) 13 and 14, and a gain control section 15.

[0014] The antenna 10 converts a radio signal received from a WD (not shown) into an RF signal and outputs it to the RF circuit 11. The RF circuit 11 performs processing such as filtering of the RF signal and outputs the processed RF signal (hereinafter referred to as a first RF signal) to the PA 12. The RF circuit 11 can also amplify the RF signal with a fixed gain. Since the amplification in the RF circuit 11 is performed with a fixed gain, the level of the RF signal can be determined from the level of the first RF signal.

[0015] PA 12 amplifies the first RF signal with a gain GX and outputs the amplified first RF signal (hereinafter, the amplified first RF signal will be referred to as the second RF signal) to E / O 13. The value of gain GX is controlled based on a first control signal input from gain control section 15. Gain control section 15 monitors the power of the second RF signal output by PA 12 and adjusts the value of the first control signal so that the power of the second RF signal is within a range that can be input to E / O 13. In the following description, the unit of gain is assumed to be dB.

[0016] As an example, the gain GX of PA12 is set by the voltage value of the first control signal. Gain control unit 15 outputs a notification control signal indicating a change over time in the voltage value of the first control signal to E / O 14. Note that the notification control signal may be a signal indicating a change over time in the value of the gain GX itself set in PA12, rather than the voltage value of the first control signal. In this case, first control information indicating the relationship between the voltage value of the first control signal and the value of the gain GX is stored in gain control unit 15. Gain control unit 15 can determine a change over time in the value of the gain GX from a change over time in the voltage value of the first control signal output to PA12, and generate a notification control signal.

[0017] E / O 13 transmits the first modulated light modulated with the second RF signal to the central station. E / O 14 transmits the second modulated light modulated with the notification control signal to the central station. Note that the configuration for transmitting the first modulated light and the second modulated light to the central station is arbitrary, and separate optical fibers can be used, or the first modulated light and the second modulated light can be multiplexed using any multiplexing method such as spatial multiplexing, wavelength multiplexing, or polarization multiplexing and then transmitted to the central station.

[0018] Note that the configuration may be such that the notification control signal is transmitted to the central station by a wireless signal rather than by light. Similarly, the second RF signal may also be transmitted to the central station by a wireless signal. In this case, E / Os 13 and 14 are wireless transmitters. Also, the configuration may be such that the second RF signal and the notification control signal are combined and transmitted to the central station by a wireless signal. In this case, only one wireless transmitter is required. The same applies to E / Os 13 and 14.

[0019] The aggregation station has a processing unit (second device). The processing unit has demodulators (O / E) 23 and 24, a PA 22, and a gain control unit 21. As shown in Fig. 1, the processing unit may have a generating unit 20 and a storage unit 25, but the generating unit 20 and the storage unit 25 will be described in the second embodiment and thereafter.

[0020] The O / E 23 demodulates the first modulated light received from the antenna site to generate a second RF signal and outputs the second RF signal to the PA 22. The O / E 24 demodulates the second modulated light received from the antenna site to generate a notification control signal and outputs the notification control signal to the gain control unit 21. When the antenna site and the aggregation station are connected by a wireless link, the O / Es 23 and 24 become wireless receivers. When there is only one wireless transmitter, there may be only one wireless receiver by providing a function to separate the second RF signal and the notification control signal from the demodulated signal. The same applies to the E / Os 13 and 14.

[0021] The PA22 amplifies the second RF signal with a gain GY and outputs the amplified second RF signal (hereinafter, the amplified second RF signal will be referred to as a third RF signal). The value of the gain GY is controlled based on a second control signal input from the gain control unit 21. For example, similar to the PA12, the gain GY of the PA22 is set by the voltage value of the second control signal.

[0022] When the notification control signal indicates a value of gain GX, second control information indicating the correspondence relationship between the voltage value of the second control signal and the value of gain GY is stored in gain control unit 21. Gain control unit 21 determines the value of gain GY by subtracting the value of gain GX indicated by the notification control signal from a predetermined value GT. Then, gain control unit 21 determines a voltage value corresponding to the determined value of gain GY based on the second control information, and outputs a second control signal of this voltage value.

[0023] The second control information may indicate a correspondence relationship between the voltage value of the second control signal and the value of gain GX indicated by the notification control signal. In this case, the second control information is set so that the sum of the value of gain GX indicated by the notification control signal and the value of gain GY determined by the voltage value of the second control signal corresponding to the value of gain GX is a predetermined value GT. In other words, the second control information in this case is obtained by replacing the value of gain GY in the second control information indicating the correspondence relationship between the voltage value of the second control signal and the value of gain GY with GX = GT - GY. Then, the gain control unit 21 determines a voltage value corresponding to the value of gain GX indicated by the notification control signal based on the second control information, and outputs a second control signal of this voltage value.

[0024] By setting the gain GY as described above, the sum of the gain GX and gain GY values ​​remains constant at the predetermined value GT regardless of time, as shown in Figure 2. This means that the gain GZ of the third RF signal relative to the first RF signal remains constant at the predetermined value GT regardless of time. Therefore, the central station can determine the power of the first RF signal, i.e., the received power of the radio signal from WD, based on the third RF signal.

[0025] When the notification control signal indicates the voltage value of the first control signal, second control information indicating the correspondence relationship between the voltage value of the first control signal and the voltage value of the second control signal is stored in gain control unit 21. Based on the second control information, gain control unit 21 outputs to PA 22 a second control signal having a voltage value corresponding to the voltage value of the first control signal indicated by the notification control signal. The second control information is created so that the gain GZ of the third RF signal relative to the first RF signal is constant at a predetermined value GT regardless of time.

[0026] It should be noted that PA12 and / or PA22 may not only amplify but also attenuate the input signal. That is, the gains GX and GY can be positive values ​​as well as negative values. In this way, PA12 and / or PA22 adjust the power of the input signal according to the set gain. For example, PA12 may only amplify the signal, and PA22 may only attenuate the signal. In this case, the predetermined value GT may be set to 0.

[0027] In this embodiment, the gain control unit 15 controls the gain GX based on the power of the second RF signal output by the PA 12. However, the gain control unit 15 may also be configured to control the gain GX based on the power of the first RF signal input to the PA 12. Specifically, the gain control unit 15 may determine the required gain GX value based on the power of the first RF signal and determine the voltage value of the first control signal based on first control information. The first control information may also indicate the relationship between the power of the first RF signal and the voltage value of the first control signal. In this case, the gain control unit 15 determines the voltage value corresponding to the power of the first RF signal based on the first control information and outputs the first control signal having the determined voltage value. For example, when the gain GX value is large due to communication with WD#1 at a long distance, if WD#2 at a short distance transmits a wireless signal, the level of the second RF signal may fall outside the input range of the E / O 13. By controlling the gain GX based on the power of the first RF signal, the gain GX can be quickly changed in response to fluctuations in the power of the first RF signal.

[0028] In the above description, the gains GX and GY of PA12 and PA22 are controlled by the voltage values ​​of the first control signal and the second control signal, respectively. However, PA12 and PA22 are not limited to those whose gains are controlled by the input voltage value. For example, PA12 and PA22 may be those whose gains are controlled by the input current value. Also, PA12 and PA22 may be those whose gains are controlled by the input digital value. In this case, the digital value may indicate the gain value itself.

[0029] In summary, the gain control unit 15 adjusts the value of the first control signal based on the power of the first RF signal or the second RF signal so that the power of the second RF signal falls within a predetermined range that can be input to the E / O 13. The value of the first control signal is correlated with the value of the gain GX of the PA 12. The gain control unit 15 The gain control unit 15 may have first control information for determining the value of the first control signal based on the power of the first RF signal or the second RF signal. The gain control signal may include first control information for determining the value of gain GX from the value of the first control signal generated based on the first control signal. The value of the first control signal may be a voltage value, a current value, a digital value, or the like. In the case of a digital value, the value of the first control signal may indicate the value of gain GX. Gain control unit 15 transmits a notification control signal indicating the value of the first control signal to the aggregate station.

[0030] The gain control unit 21 may have second control information indicating the correspondence relationship between the value of the notification control signal and the value of the second control signal. The value of the second control signal is correlated with the value of the gain GY of the PA 22. The second control information is created so that the sum of the gain GX of the PA 12 based on the value indicated by the notification control signal and the gain GY of the PA 22 based on the value of the second control signal corresponding to the value indicated by the notification control signal is a predetermined value GT. Therefore, the gain GZ of the third RF signal relative to the first RF signal is constant at the predetermined value GT regardless of time, and the central station can determine the received power of the radio signal from the WD.

[0031] Second Embodiment Next, the second embodiment will be described, focusing on differences from the first embodiment. In the first embodiment, the gain control unit 21 generates the second control signal based on the notification control signal and second control information. Note that, for example, the second control information is created based on typical characteristics of a system including a wireless unit and a processing unit. However, since the characteristics of individual systems vary, the second control information may not be optimal for each individual system. Furthermore, even optimal second control information at a certain time may become non-optimal due to aging. If a second control signal with a voltage value determined based on non-optimal second control information is output to the PA 22, the gain GZ of the third RF signal relative to the first RF signal will deviate from the predetermined value GT.

[0032] Furthermore, if the first time required for the second RF signal to travel from PA12 to PA22 does not match the second time from when gain control unit 15 sets the gain GX at PA12 to a value GX#1 until when gain control unit 21 sets the gain GY at PA22 to a value GY#1 (GX#1 + GY#1 = GT) based on the value GX#1, the sum GZ of the gain GX imparted to the second RF signal at PA12 and the gain GY imparted to the second RF signal at PA22 will not be the predetermined value GT. Figure 3 illustrates this situation. In Figure 3, the dotted line indicates the gain GX imparted to the second RF signal at PA12. The dashed line indicates the change in the value of gain GZ over time. Figure 3 illustrates the case where the second time is shorter than the first time. Because the first time and the second time may also differ from system to system, a process is required to match (synchronize) the first time and the second time.

[0033] For this reason, in this embodiment, calibration is performed on the wireless communication system shown in Fig. 1. The generation unit 20 generates correction information during the calibration and stores it in the storage unit 25. When generating a second control signal based on the notification control signal and the second control information, the gain control unit 21 corrects the voltage value of the second control signal and the output timing of the second control signal based on the correction information.

[0034] In this embodiment, the wireless communication system is designed so that the second time period is shorter than the first time period. In other words, as shown in Fig. 3, the wireless communication system is designed so that when the gain control unit 21 outputs the second control signal to the PA 22 without correcting / adjusting the timing, the second control signal will not be delayed behind the second RF signal.

[0035] The following first describes a method for generating timing correction information. To generate timing correction information, a test signal that periodically turns ON / OFF is input to PA12. FIG. 4A shows the relationship between the test signal output by PA12 and the gain GX. As shown in FIG. 4A, the gain GX during the OFF period of the test signal is larger than the gain GX during the ON period of the test signal. The gain control unit 21 controls the gain GY of PA22 based on the notification control signal. FIG. 4B shows a state in which the timing of the second control signal is ideal. As shown in FIG. 4B, the gain GY during the ON period of the test signal amplified by PA12 with a small gain GX is set larger than the gain GY during the OFF period of the test signal amplified with a large gain GX. Therefore, PA22 outputs the test signal shown in FIG. 4B.

[0036] On the other hand, Figure 4(C) shows a state in which the timing of the second control signal is not ideal. As shown in Figure 4(C), the timing of the test signal input to PA22 is later than the timing of the second control signal, so the amplitude of part of the test signal output by PA22 during the ON period is reduced. The generation unit 20 determines the period Δt during which the amplitude of the test signal output by PA22 during the ON period is reduced, and stores the period Δt in the storage unit 25 as timing correction information. The gain control unit 21 delays the output timing of the second control signal by the period Δt indicated by the correction information. This makes it possible to correct the timing discrepancy.

[0037] Next, a method for generating gain correction information will be described. First, a test signal with a constant power TP is input to PA12. The power TP of the test signal input to PA12 is set in the generating unit 20. Since the power of the test signal is constant, the value indicated by the notification control signal is also constant. The generating unit 20 acquires this constant value X indicated by the notification control signal from the gain control unit 21. The gain control unit 21 outputs a second control signal to PA22 based on the notification control signal and the second control information. Since the value indicated by the notification control signal is constant, the value of the second control signal is also constant Y. The generating unit 20 determines the value of the gain GZ from the input to PA12 to the output of PA22 by measuring the power RP of the test signal output by PA22. If the value of gain GZ differs from a predetermined value GT, the generating unit 20 notifies the gain control unit 21 of an increase or decrease in the value of the second control signal. For example, it is assumed that the larger the value of the second control signal, the larger the gain GY. In this case, if the value of gain GZ is greater than a predetermined value GT, the generating unit 20 notifies the gain control unit 21 to decrease the value of the second control signal, and if the value of gain GZ is less than the predetermined value GT, the generating unit 20 notifies the gain control unit 21 to increase or decrease the value of the second control signal until the value of gain GZ becomes the predetermined value GT.

[0038] When the value of the gain GZ reaches a predetermined value GT, the gain control unit 21 records the increase / decrease ΔY in the value of the second control signal at that time as a correction value in association with the value X indicated by the notification control signal. This process is repeated while changing the power TP of the test signal within the power level of the RF signal output from the antenna. This results in a corresponding correction value ΔY for each value of X indicated by the notification control signal. The generation unit 20 stores the correspondence between the value X indicated by the notification control signal and the correction value ΔY in the memory unit 25 as gain correction information.

[0039] During normal operation after calibration, the gain control unit 21 determines the value of the second control signal using the second control information based on the value indicated by the notification control signal. Then, the gain control unit 21 determines a correction value ΔY corresponding to the value indicated by the notification control signal by referring to the correction information, and changes the value of the second control signal determined based on the second control information by the correction value ΔY. This configuration allows the value of the gain GZ to approach a predetermined value GT.

[0040] In this embodiment, the second control information is left as is without being updated, and the gain correction information is stored in storage unit 25. However, it is also possible to configure the second control information to be updated based on the gain correction information. In this case, the second control information is updated by changing, by ΔY, the value of the second control signal corresponding to the value X indicated by the notification control signal in the second control information. In this case, during normal operation after calibration, gain control unit 21 simply determines the value of the second control signal using the second control information, based on the value indicated by the notification control signal.

[0041] In this embodiment, the correction value ΔY is calculated so that the gain GZ becomes the predetermined value GT, but the correction value ΔY may be calculated so that the gain GZ falls within a predetermined range including the predetermined value GT. Also, in the first embodiment, the second control information is created so that the gain GZ becomes the predetermined value GT, but the second control information may be created so that the gain GZ falls within a predetermined range including the predetermined value GT. Note that this predetermined range is determined based on the accuracy required to determine the received power of the wireless signal from the WD.

[0042] As described above, timing and gain correction information is obtained. Then, the timing of the second control signal is controlled based on the timing correction information. Furthermore, for the value indicated by the second control signal, the value determined by the second control information is corrected based on the gain correction information, or the second control information is updated based on the correction information. This configuration can prevent the gain GZ from deviating from the predetermined value GT, thereby enabling the aggregate station to accurately determine the received power of the radio signal from WD.

[0043] In this embodiment, it is assumed that the wireless communication system is designed so that the second time is shorter than the first time. This is because the timing of the second control signal generated based on the notification control signal can be delayed but cannot be advanced. However, if a variable delay circuit is provided between the O / E 23 and the PA 22 to provide a variable delay to the second RF signal, it is not necessary to design the wireless communication system so that the second time is shorter than the first time. In this case, if the timing of the second control signal is delayed by Δt, it is sufficient to provide a delay of Δt to the second RF signal. Whether the timing of the second control signal is early or late can be determined by the position where the amplitude of the ON period of the test signal becomes small. Specifically, as shown in FIG. 4(C), if the timing of the second control signal is early, the amplitude of the later portion of the ON period of the test signal at the output of the PA 22 becomes small. On the other hand, if the timing of the second control signal is late, the amplitude of the earlier portion of the ON period of the test signal at the output of the PA 22 becomes small.

[0044] As described above, the generating unit 20 measures the test signal only during calibration. Therefore, it is not necessary to always branch the third RF signal output by the PA22 and input it to the generating unit 20. For this reason, a switch may be provided on the output side of the PA22, and the output of the PA22 may be input to the generating unit 20 only during calibration. Furthermore, in this embodiment, a test signal that periodically turns ON / OFF is used to generate timing correction information, but it is also possible to use a test signal whose amplitude periodically changes between a first value and a second value smaller than the first value.

[0045] Third Embodiment Next, the third embodiment will be described, focusing on the differences from the first and second embodiments. A method for generating the first control information and the second control information will be described below. The first control information and the second control information can be generated, for example, by inputting test signals of various power levels to PA12 and measuring the power of the output of PA12 and the output of PA22 while changing the values ​​of the first control signal and the second control signal. However, such a method takes time. In this embodiment, a simpler method for generating the first control information and the second control information will be described.

[0046] FIG. 5(A) shows the first control information, and FIG. 5(B) shows the second control information indicating the relationship between the value of the second control signal and the value of the gain GY. First, a test signal with power TP is input to PA12 with the gain GY of PA22 fixed to 0 or with PA22 bypassed. Then, the value of the first control signal is set to, for example, the minimum value Xa that can be input to PA12. Based on the power RP of the test signal output by O / E 23, the generation unit 20 determines the value GX#a of the gain GX when the value of the first control signal is Xa. Next, the value of the first control signal is set to, for example, the maximum value Xb that can be input to PA12. Based on the power RP of the test signal at that time, the generation unit 20 determines the value GX#b of the gain GX when the value of the first control signal is Xb.

[0047] Next, the gain GX of PA12 is fixed to 0 and a test signal with power TP is input to PA12, or the test signal with power TP is input directly to E / O 13. Then, the value of the second control signal is set to, for example, the minimum value Ya that can be input to PA22. Based on the power RP of the test signal output by PA22, the generation unit 20 determines the value GY#a of the gain GY when the value of the second control signal is Ya. Next, the value of the second control signal is set to, for example, a value Yb that can be input to PA22. Based on the power RP of the test signal at that time, the generation unit 20 determines the value GY#b of the gain GY when the value of the second control signal is Yb.

[0048] The generation unit 20 determines the value of the gain GX when the value of the first control signal is different from Xa and Xb based on the characteristics of the PA12 (the curve in FIG. 5(A)). Similarly, the generation unit 20 determines the value of the gain GY when the value of the second control signal is different from Ya and Yb based on the characteristics of the PA22 (the curve in FIG. 5(B)). Note that the characteristics of the PA12 and PA22 can be determined from, for example, the specifications of the PA12 and PA22. Alternatively, representative characteristics can be determined based on actual measurement values ​​for a plurality of PA12s and used. The same applies to the PA22.

[0049] Furthermore, it is possible to determine the correspondence relationship between the value of the first control signal and the value of the second control signal for setting the gain GZ of the third RF signal relative to the first RF signal to a predetermined value GT based on the relationships shown in Figures 5(A) and 5(B). In other words, the second control information indicating the correspondence relationship between the value of the first control signal and the value of the second control signal can be generated based on the relationships shown in Figures 5(A) and 5(B).

[0050] <Fourth embodiment> Next, a fourth embodiment will be described, focusing on the differences from the above-mentioned embodiments. Fig. 6 is a configuration diagram of a wireless communication system according to this embodiment. The difference from the configuration shown in Fig. 1 is that a gain control unit 16 is provided instead of the gain control unit 15. The gain control unit 16 measures the gain GX based on the power of the first RF signal (input to PA12) and the power of the second RF signal (output from PA12), and transmits a notification control signal indicating the value of the measured gain GX to the central station.

[0051] For example, when the output of PA12 is saturated, the actual gain becomes smaller than the gain corresponding to the value of the first control signal. In this case, when the value of the first control signal is notified to the aggregate station, the gain of the third RF signal relative to the first RF signal does not become GT. In this embodiment, the value of the gain GX is actually measured, so that the gain of the third RF signal relative to the first RF signal can be prevented from deviating from GT. This allows the aggregate station to accurately determine the received power of the radio signal from WD. In this case, the second control information indicates the correspondence relationship between the value of the gain GX and the value of the second control signal.

[0052] Fifth Embodiment Generally, an aggregation station is connected to a plurality of antenna sites. If the generation unit 20 and the storage unit 25 shown in Fig. 1 are provided for each antenna site, the cost of the aggregation station will increase. In this embodiment, a configuration will be described in which one generation unit 20 and one storage unit 25 shown in Fig. 1 are provided for a plurality of antenna sites.

[0053] Fig. 7 is a configuration diagram of an aggregation station in this embodiment. Processing unit 200 communicates with one antenna site, and processing unit 201 communicates with another antenna site. Note that in Fig. 7, the aggregation station communicates with two antenna sites, but it can also communicate with three or more antenna sites.

[0054] As shown in Fig. 7, the generating unit 20 is configured to be able to receive the third RF signals output by the PAs 22 of the multiple processing units. The generating unit 20 is also configured to communicate with the gain control units 21 of the multiple processing units. Although not shown in Fig. 7 for the sake of simplicity, each gain control unit 21 is also configured to be able to access the storage unit 25.

[0055] This configuration allows the aggregation station to accurately determine the power of wireless signals received at the antenna site from wireless devices, thereby contributing to the achievement of Goal 9 of the United Nations' Sustainable Development Goals (SDGs), which is to "Build resilient infrastructure, promote sustainable industrialization, and foster innovation."

[0056] The invention is not limited to the above-described embodiment, and various modifications and variations are possible within the scope of the gist of the invention. [Explanation of symbols]

[0057] 12: PA, 13, 14: modulation device, 15: gain control section

Claims

1. A second device communicating with a first device, comprising: first adjustment means for adjusting a first signal based on a value of a first gain and outputting a second signal; first transmission means for receiving the second signal and transmitting the second signal; first gain control means for generating a first control signal for controlling the value of the first gain so that the power of the second signal is within a range that can be input to the first transmission means and outputting the first control signal to the first adjustment means; and second transmission means for transmitting a notification control signal indicating the value of the first gain, a first receiving means for receiving the second signal from the first transmitting means and outputting the second signal; second receiving means for receiving and outputting the notification control signal from the second transmitting means; a second adjusting means for adjusting the second signal based on a second gain value and outputting a third signal; a second gain control means for generating a second control signal for controlling the value of the second gain based on the value of the first gain indicated by the notification control signal so that the value of the third gain of the third signal relative to the first signal falls within a predetermined range, and outputting the second control signal to the second adjustment means; Equipped with the second gain control means has control information indicating a correspondence relationship between a value of the second control signal and a value of the second gain, and generates the second control signal by determining a value of the second control signal corresponding to the determined value of the second gain using the control information; The second device further includes first generation means that determines a first gain value of the second gain of the second adjustment means when the first value is input to the second adjustment means by inputting a second control signal of a first value to the second adjustment means and measuring the power of the output of the second adjustment means when a test signal of known power is input to the first transmission means, and determines a second gain value of the second gain of the second adjustment means when the second value is input to the second adjustment means by inputting a second control signal of a second value different from the first value to the second adjustment means and measuring the power of the output of the second adjustment means when a test signal of known power is input to the first transmission means, and generates the control information based on the first value, the second value, the first gain value, and the second gain value.

2. A second device communicating with a first device, comprising: first adjustment means for adjusting a first signal based on a value of a first gain and outputting a second signal; first transmission means for receiving the second signal and transmitting the second signal; first gain control means for generating a first control signal for controlling the value of the first gain so that the power of the second signal is within a range that can be input to the first transmission means and outputting the first control signal to the first adjustment means; and second transmission means for transmitting a notification control signal indicating the value of the first control signal, a first receiving means for receiving the second signal from the first transmitting means and outputting the second signal; second receiving means for receiving and outputting the notification control signal from the second transmitting means; a second adjusting means for adjusting the second signal based on a second gain value and outputting a third signal; a second gain control means for generating a second control signal to control the value of the second gain based on the value of the first control signal indicated by the notification control signal so that the value of the third gain of the third signal relative to the first signal falls within a predetermined range, and outputting the second control signal to the second adjustment means; Equipped with the second gain control means has control information indicating a correspondence relationship between a value of the first control signal and a value of the second control signal, and generates the second control signal by determining, using the control information, a value of the second control signal corresponding to the value of the first control signal indicated by the notification control signal; The second device further comprises: a first gain value of the first gain of the first adjustment means when the first value is input to the first adjustment means by inputting a first control signal of a first value to the first adjustment means and measuring the power of the output of the first receiving means when a test signal of known power is input to the first adjustment means; a second gain value of the first gain of the first adjustment means when the second value is input to the first adjustment means by inputting a first control signal of a second value different from the first value to the first adjustment means and measuring the power of the output of the first receiving means when a test signal of known power is input to the first adjustment means; and a correspondence relationship between the value of the first control signal and the value of the first gain is determined based on the first value, the second value, the first gain value, and the second gain value; a third gain value of the second gain of the second adjustment means when the third value is input to the second adjustment means by inputting a second control signal of a third value to the second adjustment means and measuring the output power of the second adjustment means when a test signal of known power is input to the first transmission means; a fourth gain value of the second gain of the second adjustment means when the fourth value is input to the second adjustment means by inputting a second control signal of a fourth value different from the third value to the second adjustment means and measuring the output power of the second adjustment means when a test signal of known power is input to the first transmission means; and a correspondence relationship between the value of the second control signal and the value of the second gain is determined based on the third value, the fourth value, the third gain value, and the fourth gain value; a second device comprising a first generating means for generating the control information based on a correspondence relationship between the value of the first control signal and the value of the first gain, and a correspondence relationship between the value of the second control signal and the value of the second gain.

3. A second device communicating with a first device, comprising: first adjustment means for adjusting a first signal based on a value of a first gain and outputting a second signal; first transmission means for receiving the second signal and transmitting the second signal; first gain control means for generating a first control signal for controlling the value of the first gain so that the power of the second signal is within a range that can be input to the first transmission means and outputting the first control signal to the first adjustment means; and second transmission means for transmitting a notification control signal indicating the value of the first gain, a first receiving means for receiving the second signal from the first transmitting means and outputting the second signal; second receiving means for receiving and outputting the notification control signal from the second transmitting means; a second adjusting means for adjusting the second signal based on a second gain value and outputting a third signal; a second gain control means for generating a second control signal for controlling the value of the second gain based on the value of the first gain indicated by the notification control signal so that the value of the third gain of the third signal relative to the first signal falls within a predetermined range, and outputting the second control signal to the second adjustment means; a storage means for storing correction information; Equipped with The second gain control means has control information indicating a correspondence between the value of the second control signal and the value of the second gain, and uses the control information to determine the value of the second control signal that corresponds to the determined value of the second gain, and corrects the value of the second control signal determined using the control information based on the correction information, thereby generating the second control signal.

4. 4. The second device according to claim 3, further comprising second generation means for determining the value of the third gain by inputting a test signal of known power to the first adjustment means, measuring the power of the test signal output by the second adjustment means when the second gain control means controls the value of the second gain with the second control signal generated based on the notification control signal and the control information, and generating the correction information by calculating a correction amount for the value of the second control signal to bring the determined value of the third gain within the predetermined range.

5. A second device communicating with a first device, comprising: first adjustment means for adjusting a first signal based on a value of a first gain and outputting a second signal; first transmission means for receiving the second signal and transmitting the second signal; first gain control means for generating a first control signal for controlling the value of the first gain so that the power of the second signal is within a range that can be input to the first transmission means and outputting the first control signal to the first adjustment means; and second transmission means for transmitting a notification control signal indicating the value of the first gain or the value of the first control signal, a first receiving means for receiving the second signal from the first transmitting means and outputting the second signal; second receiving means for receiving and outputting the notification control signal from the second transmitting means; a second adjusting means for adjusting the second signal based on a second gain value and outputting a third signal; a second gain control means for generating a second control signal to control the value of the second gain based on the value of the first gain indicated by the notification control signal or the value of the first control signal so that the value of the third gain of the third signal relative to the first signal falls within a predetermined range, and outputting the second control signal to the second adjustment means; a storage means for storing correction information; a second generation means for generating the correction information by inputting a test signal whose amplitude alternates between a first amplitude and a second amplitude smaller than the first amplitude to the first adjustment means and measuring the amplitude of the test signal output by the second adjustment means; Equipped with The second gain control means corrects the timing of outputting the second control signal to the second adjustment means based on the correction information.

6. The second device according to claim 5 , wherein the second generating means and the storing means are provided in common to a plurality of the second devices.

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