COMMUNICATION SYSTEM, COMMUNICATION DEVICE, AND COMMUNICATION METHOD

Abstract

The present invention reduces the impact of overreach interference when overreach interference occurs at the time of installation of communication devices. Provided is a communication system for performing wireless communication between a first communication device and a second communication device, wherein the first communication device performs measurement during a fixed period of an index indicating at least one of the modulation method and the coding rate used in wireless communication with the second communication device, calculates the amount of variation in the index in the fixed period on the basis of the measured indices, and determines the directivity of an antenna for performing wireless communication with the second communication device on the basis of the amount of variation in the index.

Description

[Technical Field]

[0001] The present disclosure relates to a communication system, a communication device, and a communication method. [Background technology]

[0002] A backhaul network connecting a base station and a core network may be configured by connecting multiple fixedly installed communication devices in multiple stages, either wired or wirelessly. When wireless communication between two communication devices and wireless communication between two other communication devices use the same frequency, overreach interference may occur depending on the relative positions of the communication devices, resulting in degradation of communication quality (Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2002-10340 Summary of the Invention [Problem to be solved by the invention]

[0004] As described above, overreach interference deteriorates the quality of communication between communication devices. Therefore, if overreach interference occurs when installing communication devices, it is preferable to reduce the impact of the overreach interference.

[0005] An object of the present disclosure is to provide a technology for reducing the influence of overreach interference when overreach interference occurs when a communication device is installed. [Means for solving the problem]

[0006] A communication system according to one embodiment of the present disclosure is a communication system that performs wireless communication between a first communication device and a second communication device, wherein the first communication device measures an index indicating at least one of a modulation method and a coding rate used for wireless communication with the second communication device for a certain period of time, calculates the amount of fluctuation of the index over the certain period based on the measured index, and determines the directivity of an antenna that performs wireless communication with the second communication device based on the amount of fluctuation of the index.

[0007] A communication device according to one aspect of the present disclosure is a communication device that performs wireless communication with a partner communication device, and includes: an antenna that performs wireless communication with the partner communication device; and a processor that measures an index indicating at least one of a modulation method and a coding rate used for wireless communication with the partner communication device over a certain period of time, calculates a fluctuation amount of the index over the certain period based on the measured index, and determines the directivity of the antenna based on the fluctuation amount of the index.

[0008] A communication method according to one embodiment of the present disclosure is a communication method for performing wireless communication between a first communication device and a second communication device, in which the first communication device measures an index indicating at least one of a modulation method and a coding rate used for wireless communication with the second communication device for a certain period of time, calculates a fluctuation amount of the index over the certain period based on the measured index, and determines a directivity of an antenna for performing the wireless communication with the first communication device based on the fluctuation amount of the index.

[0009] These comprehensive or specific aspects may be realized as a system, an apparatus, a method, an integrated circuit, a computer program, or a recording medium, and may be realized as a system, an apparatus, a method, an integrated circuit, a computer program, or a recording medium. It may be realized by any combination of a computer program and a recording medium. [Effects of the Invention]

[0010] According to the present disclosure, when overreach interference occurs when a communication device is installed, the influence of the overreach interference can be reduced. [Brief explanation of the drawings]

[0011] [Figure 1] FIG. 1 is a diagram showing an example of the configuration of a communication system according to an embodiment of the present invention. [Figure 2] FIG. 1 is a block diagram showing a configuration example of a communication device according to an embodiment of the present invention. [Figure 3A] FIG. 10 is a diagram showing a case where a reference sector is selected as a communication sector in the antenna according to the present embodiment. [Figure 3B] FIG. 10 is a diagram showing a case where the left sector is selected as the communication sector in the antenna according to the present embodiment. [Figure 3C] FIG. 10 is a diagram showing a case where the right sector is selected as the communication sector in the antenna according to the present embodiment. [Figure 4] FIG. 1 is a diagram showing an example of an MCS (Modulation Coding Scheme) expected value table according to the present embodiment. [Figure 5] 10 is a flowchart illustrating an example of processing in a communication device. [Figure 6] Flowchart showing an example of a sector change process DETAILED DESCRIPTION OF THE INVENTION

[0012] Hereinafter, embodiments of the present disclosure will be described in detail with appropriate reference to the drawings. However, more detailed description than necessary may be omitted. For example, detailed descriptions of well-known matters and redundant descriptions of substantially identical configurations may be omitted. This is to avoid unnecessary redundancy in the following description and to facilitate understanding by those skilled in the art. Note that the accompanying drawings and the following description are provided to enable those skilled in the art to fully understand the present disclosure, and are not intended to limit the subject matter described in the claims.

[0013] (Embodiment 1) <Communication system configuration> 1 is a diagram showing an example of the configuration of a communication system 1 according to the present embodiment. In the following description, when distinguishing between communication devices, a reference symbol with an alphabetical character added after a number is used, such as communication devices 10A and 10B. When not distinguishing between communication devices, a reference symbol with an alphabetical character added after a number is used, such as communication device 10. Numerical references only are used.

[0014] As shown in Fig. 1, a communication system 1 may be configured as a backhaul system by connecting multiple communication devices 10 in multiple stages via wired or wireless communication. A backhaul refers to a network configuration formed by one communication device at a time. A backhaul system refers to a system formed by multiple backhauls.

[0015] 1, it is assumed that communication devices 10A, 10B, 10C, and 10D have already been installed. It is also assumed that communication device 10A and communication device 10B are connected via wireless communication, communication device 10B and communication device 10C are connected via wired communication, and communication device 10C and communication device 10D are connected via wireless communication. As a result, a backhaul system capable of bidirectional data communication is configured between communication device 10A and communication device 10D.

[0016] For wireless communication, a radio signal in the 60 GHz band, which is an example of the millimeter wave band, may be used. This enables high-speed wireless communication. However, the frequency band used for wireless communication is not limited to the millimeter wave band and may be any frequency band. When the 60 GHz band is used, two communication devices 10 may transmit and receive wireless signals by selecting one of channels CH1 to CH4. For example, as shown in FIG. 1, communication devices 10A and 10B select CH2 to transmit and receive wireless signals, and communication devices 10C and 10D select CH3 to transmit and receive wireless signals. The radio signals between communication devices 10A and 10B and the radio signals between communication devices 10C and 10D do not interfere with each other because they are on different channels. Note that in the present disclosure, the term "channel" is used to distinguish between bands used in wireless communication.

[0017] Here, consider the case where the backhaul system is extended by further installing communication device 10E and communication device 10F, connecting communication device 10E and communication device 10D via wired communication, and connecting communication device 10F and communication device 10E via wireless communication.

[0018] In this case, communication device 10E and communication device 10F select a channel from channels CH1 to CH4 that is different from CH3 used by adjacent communication device 10C and communication device 10D. When using the 60 GHz band, CH1 and CH4 may not satisfy the transmission spurious requirement, and communication device 10E and communication device 10F may select CH2. However, if CH2 is selected, communication device 10F may be subject to interference (i.e., overreach interference) from a wireless signal that communication device 10A is transmitting to communication device 10B using the same CH2. This overreach interference degrades the reception quality at communication device 10F of the wireless signal transmitted from communication device 10E.

[0019] In this embodiment, a technology is described in which, when installing a communication device 10F, it is determined whether or not overreach interference is occurring, and if overreach interference is occurring, the antenna 11 of the communication device 10F is controlled to reduce the effects of the overreach interference.

[0020] <Configuration of communication device> Fig. 2 is a block diagram showing an example of the configuration of communication device 10 according to the present embodiment. Fig. 3A is a diagram showing a case where a reference sector is selected as a communication sector in antenna 11 according to the present embodiment. Fig. 3B is a diagram showing a case where a left sector is selected as a communication sector in antenna 11 according to the present embodiment. Fig. 3C is a diagram showing a case where a right sector is selected as a communication sector in antenna 11 according to the present embodiment.

[0021] The communication device 10 includes an antenna 11, a wireless communication circuit 12, a wired communication circuit 13, an input circuit 14, an output circuit 15, a memory 16, and a processor 17. However, the communication device does not necessarily need to include at least one of the wired communication circuit 13, the input circuit 14, and the output circuit 15.

[0022] The antenna 11 transmits and receives radio signals. As shown in FIG. 3A, the antenna 11 may be a sector antenna capable of selectively using multiple sectors with different directivities for communication. In this embodiment, as shown in FIG. 3A, the angle θ in a predetermined direction is set to 0 degrees, and a sector with angle θ = 0 degrees is referred to as a reference sector 30A. In addition, a sector in a direction where angle θ is positive is referred to as a right sector 30B, and a sector in a direction where angle θ is negative is referred to as a left sector 30C. The right sector 30B may be selectable in increments of plus 5 degrees, and the left sector 30C may be selectable in increments of minus 5 degrees. The antenna 11 may transmit and / or receive radio signals in a selected sector. Hereinafter, a sector selected to transmit and / or receive radio signals is referred to as a communication sector.

[0023] The antenna 11 may change the direction (angle) of directivity by beamforming. In this case, the direction of the beamforming directivity may correspond to a selected sector. That is, the selection of a communication sector may be interpreted as a change in the directivity of the antenna 11 by beamforming.

[0024] The wireless communication circuit 12 receives a wireless signal received by the antenna 11. The wireless communication circuit 12 demodulates the input wireless signal and outputs it to the processor 17. The wireless communication circuit 12 also modulates data input from the processor 17 to generate a wireless signal and outputs it to the antenna 11.

[0025] The wired communication circuit 13 transmits and receives signals to and from other communication devices 10 connected by wired communication. For example, an optical fiber cable, an Ethernet cable, or the like is connected to the wired communication circuit 13.

[0026] An input device is connected to the input circuit 14. Examples of the input device include a keyboard, a mouse, a touchpad, and a microphone. A user can operate the communication device 10 through the input device.

[0027] An output device is connected to the output circuit 15. Examples of the output device include a display and a speaker. A user can check the processing results and operating status of the communication device 10 through the output device.

[0028] The memory 16 stores data, programs, etc. for implementing the functions of the communication device 10 according to the present embodiment. The memory 16 may be implemented by a read-only memory (ROM), a random access memory (RAM), a non-volatile storage medium, or a combination thereof.

[0029] The processor 17 cooperates with at least one of the antenna 11, the wireless communication circuit 12, the wired communication circuit 13, the input circuit 14, the output circuit 15, and the memory 16 to realize the functions of the communication device 10 according to the present embodiment. For example, the processor 17 reads out a program from the memory 16 and executes it to realize the processing executed by the communication device 10, which will be described later. Therefore, the processes described in this embodiment mainly by the communication device 10 can be interpreted as processes mainly by the processor 17. Furthermore, the processor 17 may be interpreted as other terms such as a CPU (Central Processing Unit), a controller, an arithmetic circuit, or an integrated circuit.

[0030] Next, the process performed by the communication device 10 according to the present embodiment will be described.

[0031] <Detecting the distance between devices> The processor 17 of the communication device 10F performs test communication related to wireless communication with the communication device 10E, and detects the distance between the communication device 10E and the communication device 10F (hereinafter referred to as the inter-device distance). For example, the processor 17 of the communication device 10F detects the inter-device distance by the TOA (Time of Arrival) method using the arrival time of the wireless signal between the communication device 10E. However, the inter-device distance is not limited to being detected by the TOA method, and may be detected by other known methods. That is, it is only necessary to be able to obtain the inter-device distance in the communication device 10F, and the inter-device distance may be provided from an external device.

[0032] <Specification of MCS expected value> FIG. 4 is a diagram showing an example of an MCS expected value table according to the present embodiment.

[0033] As shown in FIG. 4, the memory 16 stores in advance an MCS expected value table, which is a table associating the distance between two communication devices 10 (hereinafter referred to as the inter-device distance) with the MCS value (hereinafter referred to as the MCS expected value) expected to be selected at the inter-device distance.

[0034] The MCS value is an index indicating the modulation method and the coding rate used for wireless communication. The correspondence between the MCS value, the modulation method, and the coding rate may be determined in advance according to the specification. Also, the MCS value may be read as an MCS index. Examples of the modulation method include QPSK, 16QAM, 64QAM, and 256QAM.

[0035] Generally, the larger the MCS value, the higher the spectral efficiency. However, the larger the MCS value, the more significantly it is affected by factors such as distance (attenuation), noise, and / or interference in the channel. Therefore, the communication device appropriately selects an appropriate MCS value according to the situation of distance (attenuation), noise, and / or interference in the channel. Thereby, the communication device 10 attempts to optimize the data transmission efficiency of the channel. In this embodiment, an example of reducing the overreach interference using the MCS value is shown, but in the present disclosure, an index indicating at least one of the modulation method and coding may be used instead of the MCS value.

[0036] When the inter-device distance is relatively far, selecting an MCS value smaller than the MCS value selected when the inter-device distance is relatively close may improve the data transmission efficiency. Thus, from the perspective of data transmission efficiency, there may exist an appropriate MCS value for the inter-device distance. That is, the expected MCS value corresponding to the inter-device distance may indicate the MCS value that two communication devices 10 installed at a distance corresponding to the inter-device distance would select when not considering the influence of other noise and / or interference, etc.

[0037] The processor 17 of the communication device 10F refers to the expected MCS value table and identifies the expected MCS value corresponding to the inter-device distance detected above.

[0038] <Calculation of MCS variation amount> The processor 17 of the communication device 10F measures the MCS value included in the radio signal transmitted from the communication device 10E for a certain period. The communication device 10E may determine the MCS value by a known method according to the channel situation between it and the communication device 10F.

[0039] The processor 17 calculates the variation amount of the MCS value (hereinafter referred to as the MCS variation amount) based on a plurality of MCS values measured for a certain period. The MCS variation amount is a value indicating the magnitude of the fluctuation of the MCS value over a certain period. The MCS variation amount may be calculated, for example, by any of the following (A1), (A2), and (A3).

[0040] (A1) The MCS variation amount may be the deviation of multiple MCS values ​​measured over a certain period of time. For example, if each MCS value measured over a certain period of time is xi, the number of MCS values ​​measured over that certain period of time is n, and the expected MCS value corresponding to the inter-device distance specified above is μ, the deviation σ of the MCS values ​​(where σ is a positive value) may be calculated using the following equation 1. In this case, communication device F may use the calculated deviation σ of the MCS values ​​as the MCS variation amount.

[0041]

number

[0042] (A2) The MCS variation may be the difference between the maximum and minimum MCS values ​​among the MCS values ​​measured over a certain period of time. For example, if the maximum MCS value over a certain period of time is "9" and the minimum MCS value is "2," the difference between "9" and "2" is "6." In this case, the communication device 10F may use the calculated difference "6" as the MCS variation.

[0043] (A3) The MCS variation may be a value obtained by dividing the length of a certain period by the longest period during which the MCS value remains the same. For example, if the length of the certain period is 60 seconds and the longest period during which the MCS value remains the same is 10 seconds, then dividing "60" by "10" yields "6." In this case, the communication device 10F may use the calculated "6" as the MCS variation.

[0044] That is, the larger the MCS fluctuation value, the greater the fluctuation of the MCS value, and the smaller the MCS fluctuation value, the less the fluctuation of the MCS value.

[0045] <Overreach interference determination> The processor 17 of the communication device 10F determines whether or not overreach interference is occurring based on the MCS variation amount. For example, the processor 17 determines that overreach interference is occurring when the MCS variation amount is equal to or greater than a predetermined threshold, and determines that overreach interference is not occurring when the MCS variation amount is less than the predetermined threshold. The threshold for this determination may be different for each of the above (A1), (A2), and (A3).

[0046] As described above, the communication device 10E selects an appropriate MCS value depending on the channel conditions. For example, when the communication device 10A in FIG. 1 is transmitting a radio signal, the radio signal interferes with the communication device 10F, so the communication device 10E may lower the MCS value. Also, when the communication device 10A is not transmitting a radio signal, the radio signal does not interfere with the communication device 10F, so the communication device 10E may raise the MCS value. In this way, when overreach interference occurs, the MCS value of the communication device 10E may fluctuate depending on the transmission conditions of the radio transmission in the communication device 10A. Therefore, the communication device 10F can determine whether or not overreach interference is occurring by the above-described determination process.

[0047] <Antenna Sector Selection> When the processor 17 of the communication device 10F determines that overreach interference is not occurring, it does not need to change the sector (communication sector) that transmits and / or receives radio signals in the antenna 11. For example, when the reference sector 30A is selected as the communication sector, if the processor 17 of the communication device 10F determines that overreach interference is not occurring, it leaves the communication sector as the reference sector 30A.

[0048] When determining that overreach interference is occurring, processor 17 may estimate the direction (angle) of communication device 10, which is the transmission source of the radio signal causing overreach interference. For example, processor 17 measures whether the amount of MCS fluctuation increases when the communication sector is changed to right sector 30B or left sector 30C. The variable range of angle θ for right sector 30B may be 0 degrees to +30 degrees. The variable range of angle θ for left sector 30C may be 0 degrees to -30 degrees.

[0049] If the MCS variation amount when changing to the right sector 30B (hereinafter referred to as the MCS variation amount of the right sector 30B) is larger than the MCS variation amount when changing to the left sector 30C (hereinafter referred to as the MCS variation amount of the left sector 30C), it is estimated that the direction of the communication device 10 that is the transmission source of the overreach interference radio signal is the direction (angle) of the right sector 30B as seen from the communication device 10F, as shown in FIG. 3B. In this case, the processor 17 may change the communication sector to the left sector 30C. For example, the processor 17 changes the communication sector to the left sector 30C, which is -10 degrees.

[0050] If the MCS variation amount of the left sector 30C is larger than that of the right sector 30B, as shown in FIG. 3C, it is estimated that the direction (angle) of the communication device 10, which is the transmission source of the overreach interference radio signal, as viewed from the communication device 10F is the direction (angle) of the left sector 30C. In this case, the processor 17 may change the communication sector to the right sector 30B. For example, the processor 17 changes the communication sector to the right sector 30B, which is +10 degrees.

[0051] As described above, by changing the communication sector to the left sector 30C or the right sector 30B, the SIR (Signal to Interference Ratio) between the radio signal (i.e., the desired signal) received from the communication device 10E and the interference signal is reduced in the antenna 11 of the communication device 10F, thereby improving the communication quality in the antenna 11 of the communication device 10F.

[0052] <Processing in communication device> FIG. 5 is a flowchart showing an example of processing in the communication device 10F.

[0053] In S101, the communication device 10F performs test communication with the communication device 10E to detect the distance between the devices.

[0054] In S102, the communication device 10F detects the inter-device distance to the communication device 10E based on the test communication result in S101.

[0055] In S103, the communication device 10F refers to the MCS expected value table and identifies the MCS expected value corresponding to the inter-device distance detected in S102.

[0056] In S104, the communication device 10F measures the MCS value in the reference sector 30A for a certain period of time. For example, the communication device 10F receives the MCS value transmitted from the communication device 10E for a certain period of time and records the MCS value received during the certain period in the memory 16. At this time, the communication device 10F may display the difference between the measured MCS value and the expected MCS value determined in S103 on a display in real time via the output circuitry 15. This allows the user to check in real time whether the quality of the wireless communication between the communication device 10F and the communication device 10E is poor compared to when the devices are spaced apart from each other at a normal distance.

[0057] In S105, the communication device 10F calculates the amount of MCS variation for the certain period of time using each MCS value measured for the certain period of time in S104. For example, the communication device 10F calculates the amount of MCS variation using any of the above methods (A1), (A2), or (A3).

[0058] In S106, the communication device 10F determines whether the MCS variation calculated in S105 is equal to or greater than a predetermined threshold.

[0059] If it is determined that the MCS variation amount is less than the predetermined threshold (S106: NO), the communication device 10F ends this process because the communication device 10F can receive the wireless signal transmitted from the communication device 10E with sufficient quality in the current communication sector (e.g., the reference sector 30A).

[0060] If it is determined that the MCS variation is equal to or greater than the predetermined threshold (S106: YES), the communication device 10F proceeds to the process of S107.

[0061] In S107, the communication device 10F executes a sector change process because, in this case, the current communication sector (for example, the reference sector 30A) is significantly affected by overreach interference and cannot receive the radio signal transmitted from the communication device 10E with sufficient quality.

[0062] Then, the communication device 10F ends this process.

[0063] 6 is a flowchart showing an example of the sector change process, which corresponds to details of the process of S107 in FIG.

[0064] In S201, the communication device 10F changes the communication sector for measurement to the right sector 30B.

[0065] In S202, the communication device 10F performs the same processing as S104 to S105 in FIG. The communication device 10F calculates the amount of MCS variation for the right sector 30B. Note that the communication device 10F may change the communication sector to the right sector 30B by a predetermined angle, and calculate the amount of MCS variation for the right sector 30B at each angle.

[0066] In S203, the communication device 10F changes the communication sector for measurement to the left sector 30C.

[0067] In S204, the communication device 10F performs the same processing as in S104 to S105 of FIG. The communication device 10F calculates the MCS variation amount for the left sector 30C. Note that the communication device 10F may change the communication sector to the left sector 30C by a predetermined angle, and calculate the MCS variation amount for the left sector 30C at each angle.

[0068] Alternatively, the communication device 10F may first execute S203 and S204, and then execute S201 and S202.

[0069] In S205, the communication device 10F determines whether the MCS variation amount for the right sector 30B calculated in S202 is greater than the MCS variation amount for the left sector 30C calculated in S204. Note that if the communication device 10F calculates the MCS variation amounts for multiple right sectors 30B at different angles and the MCS variation amounts for multiple left sectors 30C at different angles in the processes of S201 to S204, the communication device 10F may compare the largest MCS variation amounts to make the determination in S205. Alternatively, in this case, the communication device 10F may compare the average of the MCS variation amounts for multiple right sectors 30B at different angles with the average of the MCS variation amounts for multiple left sectors 30C at different angles to make the determination in S205.

[0070] If it is determined that the MCS variation amount of the right sector 30B is greater than the MCS variation amount of the left sector 30C (S205: YES), the communication device 10F determines the communication sector to be the left sector 30C in S206, and ends this process.

[0071] If it is determined that the MCS variation amount of the right sector 30B is equal to or less than the MCS variation amount of the left sector 30C (S205: NO), the communication device 10F determines the communication sector to be the right sector 30B in S207, and ends this process.

[0072] In addition, the communication device 10F may determine, in S205, whether the MCS variation amount of the left sector 30C calculated in S204 is greater than the MCS variation amount of the right sector 30B calculated in S202. In this case, if the communication device 10F determines that the MCS variation amount of the left sector 30C is greater than the MCS variation amount of the right sector 30B (S205: YES), the communication device 10F may determine, in S206, the right sector 30B as the communication sector and end this processing. In addition, if the communication device 10F determines that the MCS variation amount of the left sector 30C is equal to or less than the MCS variation amount of the right sector 30B (S205: NO), the communication device 10F may determine, in S207, the left sector 30C as the communication sector and end this processing.

[0073] In addition, as a process after S206 and S207, it is possible to determine whether the amount of fluctuation is within a predetermined value, and if the amount of fluctuation is not within the predetermined value, to treat the communication sector determined in S206 and S207 as the communication sector in S201 and to execute the process from S201 onwards again in a loop.

[0074] 5 and 6, when installing the communication device 10F, it is possible to determine whether or not overreach interference occurs in the communication device 10F. In addition, when overreach interference occurs, it is possible to reduce the influence of the overreach interference on the wireless communication between the communication device 10F and the communication device 10E.

[0075] <Modification> In the above description, the case where the communication device 10F receives the MCS value from the communication device 10E has been described. The communication device 10F may determine the MCS value itself based on the status of wireless communication with the communication device 10E, and measure the MCS value for a certain period of time.

[0076] Summary of the Disclosure The present disclosure may be expressed as follows.

[0077] <Expression 1> A communication system (1) for performing wireless communication between a first communication device (10F) and a second communication device (10E), wherein the first communication device measures an index (MCS value) indicating at least one of a modulation scheme and a coding rate used in wireless communication with the second communication device for a certain period of time, and calculates a fluctuation amount of the index (MCS fluctuation amount) for the certain period based on the measured index; Based on the amount of change in the index, the directivity of an antenna (11) that performs the wireless communication with the second communication device is determined. This allows the first communication device to appropriately determine the directivity of the antenna that communicates wirelessly with the second communication device based on the amount of change in the index.

[0078] <Expression 2> In the communication system according to Representation 1, the first communication device may decide to change the directivity of the antenna when the amount of change in the index is equal to or greater than a predetermined threshold. As a result, when the fluctuation amount of the index is greater than or equal to a predetermined threshold, i.e., when overreach interference is occurring, the first communication device can appropriately determine the directivity of the antenna that communicates wirelessly with the second communication device.

[0079] <Expression 3> In the communication system described in Expression 2, when the first communication device decides to change the directivity of the antenna, it may change the directivity of the antenna to a first angle (to the right sector) and calculate the amount of fluctuation of the index at the first angle, change the directivity of the antenna to a second angle that is an angle opposite to the first angle (to the left sector) and calculate the amount of fluctuation of the index at the second angle, compare the amount of fluctuation of the index at the first angle with the amount of fluctuation of the index at the second angle, and change the directivity of the antenna in the direction of the first angle or the second angle based on the result of the comparison. This allows the first communication device to compare the amount of change in the index when the antenna directivity is at the first angle with the amount of change in the index when the antenna directivity is at the second angle, and determine whether the amount of change in the index is greater for the first angle or the second angle. In other words, the first communication device can determine in which direction, at the first angle or the second angle, the source of the wireless signal that causes overreach interference is located.

[0080] <Expression 4> In the communication system described in Expression 3, the first communication device may change the directivity of the antenna to the direction of the second angle (left sector) when the amount of fluctuation of the index at the first angle is greater than the amount of fluctuation of the index at the second angle. This allows the first communication device to change the directivity of its antenna to a second angle opposite to the first angle in which the source of the wireless signal causing overreach interference is located, thereby reducing the effect of overreach interference and improving the quality of wireless communication between the first communication device and the second communication device.

[0081] <Expression 5> In the communication system according to expression 3 or 4, when the amount of change of the index at the first angle is equal to or less than the amount of change of the index at the second angle, the first communication device: The directivity of the antenna may be changed to the direction of the first angle (right sector). This allows the first communication device to change the directivity of the antenna to a first angle direction opposite to a second angle direction in which a source of a wireless signal causing overreach interference is present, thereby reducing the influence of overreach interference and improving the quality of wireless communication between the first communication device and the second communication device.

[0082] <Expression 6> In a communication system described in any one of Expressions 1 to 5, the first communication device measures the distance between itself and the second communication device, identifies an expected indicator (MCS expected value) which is the indicator expected at the measured distance, and the amount of fluctuation of the indicator may be calculated based on the identified expected indicator. This allows the first communication device to calculate the amount of fluctuation in the index over a certain period of time.

[0083] <Expression 7> In the communication system described in any one of Representations 1 to 5, the first communication device may calculate the difference between the maximum and minimum values ​​of the multiple indicators measured over the certain period as the amount of fluctuation of the indicator. This allows the first communication device to calculate the amount of fluctuation in the index over a certain period of time.

[0084] Although the embodiments have been described above with reference to the accompanying drawings, the present disclosure is not limited to such examples. It is clear that a person skilled in the art can conceive of various modifications, alterations, substitutions, additions, deletions, and equivalents within the scope of the claims, and it is understood that these also fall within the technical scope of the present disclosure. Furthermore, the components in the above-described embodiments may be combined in any manner without departing from the spirit of the invention.

[0085] This application is based on a Japanese patent application (Patent Application No. 2021-015669) filed on February 3, 2021, the contents of which are incorporated by reference into this application. [Industrial Applicability]

[0086] The technology of the present disclosure is useful for improving the quality of wireless communication. [Explanation of symbols]

[0087] 1. Communication Systems 10, 10A, 10B, 10C, 10D, 10E, 10F communication equipment 11 Antenna 12 Wireless communication circuit 13 Wired communication circuits 14 Input circuit 15 Output circuit 16 memory 17 processors 30A Reference Sector 30B Right Sector 30C left sector

Claims

1. A communication system for wirelessly communicating between a first communication device and a second communication device, The first communication device measuring, for a certain period of time, an index indicating at least one of a modulation scheme and a coding rate used in wireless communication with the second communication device; Calculating a fluctuation amount indicating the magnitude of fluctuation of the index by statistically processing the index measured over the certain period; If the amount of change is less than a predetermined threshold, it is determined not to change the directivity of the antenna that performs the wireless communication with the second communication device; If the amount of variation is equal to or greater than the threshold, it is determined to change the directivity of the antenna so as to reduce the amount of variation. Communication system.

2. When the first communication device determines to change the directivity of the antenna, changing the directivity of the antenna to a first angle and calculating a variation of the index at the first angle; changing the directivity of the antenna to a second angle that is an angle opposite to the first angle, and calculating a variation amount of the index at the second angle; comparing the amount of change of the index at the first angle with the amount of change of the index at the second angle; changing the directivity of the antenna toward the first angle or the second angle based on the result of the comparison; The communication system of claim 1 .

3. the first communication device changes the directivity of the antenna to a direction of the second angle when a fluctuation amount of the index at the first angle is greater than a fluctuation amount of the index at the second angle; The communication system according to claim 2 .

4. the first communication device changes the directivity of the antenna to a direction of the first angle when a fluctuation amount of the index at the first angle is equal to or less than a fluctuation amount of the index at the second angle; The communication system according to claim 2 .

5. The first communication device measuring the distance to the second communication device; identifying an expected indicator, the indicator being an expected indicator at the measured distance; The amount of fluctuation of the index calculated as the statistical processing is calculated based on the specified expected index. The communication system of claim 1 .

6. As a statistical process performed on the indexes, deviations in the plurality of indexes measured over at least the certain period are calculated. The communication system of claim 1 .

7. As a statistical process performed on the index, a value is calculated by dividing at least the length of the certain period by the longest period during which the plurality of indexes measured during the certain period remained the same consecutively. The communication system of claim 1 .

8. A communication device that performs wireless communication with another communication device, an antenna for wirelessly communicating with the other communication device; a processor that measures an index indicating at least one of a modulation method and a coding rate used in wireless communication with the other communication device for a certain period of time, calculates a fluctuation amount indicating a magnitude of flutter of the index by statistically processing the index measured for the certain period of time, and determines not to change the directivity of the antenna if the fluctuation amount is less than a predetermined threshold, and determines to change the directivity of the antenna so as to reduce the fluctuation amount if the fluctuation amount is equal to or greater than the threshold. Communication equipment.

9. A communication method for performing wireless communication between a first communication device and a second communication device, The first communication device measuring, for a certain period of time, an index indicating at least one of a modulation scheme and a coding rate used in wireless communication with the second communication device; Calculating a fluctuation amount indicating the magnitude of fluctuation of the index by statistically processing the index measured over the certain period; If the amount of change is less than a predetermined threshold, it is determined not to change the directivity of the antenna that performs the wireless communication with the second communication device; If the amount of variation is equal to or greater than the threshold, it is determined to change the directivity of the antenna so as to reduce the amount of variation. Communication method.

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