Base station device and communication method

Abstract

To provide a base station device and a communication method that are capable of efficiently restraining interference occurring between cells.SOLUTION: A base station device for performing radio communication with a plurality of terminal devices within a cell includes a storage unit for storing communication status information regarding a state of communication by the plurality of terminal devices; a first receiving unit for receiving, from an other first base station device corresponding to an other first cell, an interference notification indicating that interference is occurring in the other first cell, and a control unit that identifies, among the plurality of terminal devices, one or more terminal devices that are more likely to be a cause of the interference than the other terminal devices based on the interference notification received by the first receiving unit and the communication status information stored in the storage unit, and prioritizes scheduling of uplink signals for the identified one or more terminal devices over the scheduling of the uplink signals for the other terminal devices in regard to the scheduling of the uplink signals for the plurality of terminal devices.SELECTED DRAWING: Figure 6

Description

[Technical field]

[0001] The present invention relates to a base station device and a communication method. [Background technology]

[0002] In recent years, wireless communication systems (hereinafter also simply referred to as communication systems) have been constructed in which a large number of small cells (hereinafter also simply referred to as cells) are placed within a macrocell, for example, in order to cover areas where radio waves from the macrocell have difficulty reaching.

[0003] In such a wireless communication system, for example, various processes are executed to suppress interference occurring between small cells (see, for example, Patent Documents 1 and 2). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Special Publication No. 2014-535190 [Patent Document 2] JP 2014-030232 A Summary of the Invention [Problem to be solved by the invention]

[0005] Here, in the wireless communication system as described above, for example, when there are many terminal devices in each cell, the time required to execute each process becomes long, and it may not be possible to efficiently suppress interference occurring between cells.

[0006] Therefore, in one aspect, the present invention has an object to provide a base station apparatus and a communication method that enable efficient suppression of interference occurring between cells. [Means for solving the problem]

[0007] In one aspect of the embodiment, a base station device is a base station device that performs wireless communication with a plurality of terminal devices within a cell, and has a memory unit that stores communication status information regarding the state of communication by the plurality of terminal devices, a first receiver unit that receives an interference notification from another first base station device corresponding to the other first cell, indicating that interference is occurring in another first cell different from the cell, and a control unit that identifies one or more terminal devices among the plurality of terminal devices that are more likely to be at least one cause of interference than other terminal devices based on the interference notification received by the first receiver unit and the communication status information stored in the memory unit, and prioritizes the identified one or more terminal devices when scheduling uplink signals for the plurality of terminal devices. Effect of the Invention

[0008] According to one aspect, it is possible to efficiently suppress interference occurring between cells. [Brief description of the drawings]

[0009] [Figure 1] FIG. 1 is a diagram illustrating a configuration of a wireless communication system 10. As shown in FIG. [Diagram 2] FIG. 2 is a diagram illustrating the hardware configuration of the base station device 1. As shown in FIG. [Diagram 3] FIG. 3 is a diagram illustrating the hardware configuration of the terminal device 2. As shown in FIG. [Figure 4] FIG. 4 is a diagram illustrating the functions of the base station device 1 in the first embodiment. [Diagram 5] FIG. 5 is a diagram illustrating functions of the terminal device 2 in the first embodiment. [Figure 6] FIG. 6 is a sequence chart of the interference control process in the first embodiment. [Figure 7] FIG. 7 is a diagram for explaining a specific example of the interference notification 141. In FIG. [Figure 8] FIG. 8 is a diagram for explaining a specific example of the schedule notice 142. As shown in FIG. [Figure 9]FIG. 9 is a flowchart illustrating details of the interference control process in the first embodiment. [Figure 10] FIG. 10 is a flowchart illustrating details of the interference control process in the first embodiment. [Figure 11] FIG. 11 is a flowchart illustrating details of the interference control process in the first embodiment. [Figure 12] FIG. 12 is a diagram for explaining a specific example of the data retention amount information 131a. [Figure 13] FIG. 13 is a diagram illustrating a specific example of the state management information 131b. [Figure 14] FIG. 14 is a diagram for explaining a specific example of the scheduling history information 132. As shown in FIG. [Figure 15] FIG. 15 is a diagram for explaining a specific example of the data retention amount information 131a. [Figure 16] FIG. 16 is a diagram illustrating a specific example of the state management information 131b. [Figure 17] FIG. 17 is a diagram for explaining a specific example of the scheduling history information 132. As shown in FIG. [Figure 18] FIG. 18 is a diagram for explaining a specific example of the data retention amount information 131a. [Figure 19] FIG. 19 is a diagram illustrating a specific example of the state management information 131b. [Figure 20] FIG. 20 is a diagram for explaining a specific example of the scheduling history information 132. As shown in FIG. [Figure 21] FIG. 21 is a diagram for explaining a specific example of the scheduling history information 132. As shown in FIG. [Figure 22] FIG. 22 is a diagram for explaining a specific example of the data retention amount information 131a. [Diagram 23] FIG. 23 is a diagram illustrating a specific example of the state management information 131b. [Figure 24] FIG. 24 is a diagram for explaining a specific example of the data retention amount information 131a. [Diagram 25] FIG. 25 is a specific example for explaining the priority information 133. In FIG. [Figure 26] FIG. 26 is a specific example for explaining the priority information 133. In FIG. [Figure 27] FIG. 27 is a sequence chart of the interference control process in the first embodiment. [Figure 28] FIG. 28 is a diagram illustrating the first modified example. [Figure 29] FIG. 29 is a diagram for explaining a specific example of the interference notification 143. In FIG. [Diagram 30] FIG. 30 is a diagram illustrating the second modified example. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. However, such descriptions should not be interpreted in a limiting sense and do not limit the subject matter described in the claims. In addition, various changes, substitutions, and modifications can be made without departing from the spirit and scope of the present disclosure. In addition, different embodiments can be appropriately combined.

[0011] [Configuration of wireless communication system in the first embodiment] First, a description will be given of the configuration of the wireless communication system 10. Fig. 1 is a diagram for explaining the configuration of the wireless communication system 10. Below, a description will be given of the case where the wireless communication system 10 is a communication system compatible with the 5G communication standard.

[0012] 1, the wireless communication system 10 includes, for example, a base station device 1a, a base station device 1b, and a base station device 1c. The wireless communication system 10 also includes, for example, a terminal device 2a, a terminal device 2b, a terminal device 2c, a terminal device 2d, a terminal device 2e, and a terminal device 2f. Hereinafter, the base station device 1a, the base station device 1b, and the base station device 1c are collectively referred to as a base station device 1. Hereinafter, the terminal device 2a, the terminal device 2b, the terminal device 2c, the terminal device 2d, the terminal device 2e, and the terminal device 2f are collectively referred to as a terminal device 2.

[0013] Then, the base station device 1a, the base station device 1b, and the base station device 1c form, for example, a cell Ca, a cell Cb, and a cell Cc, respectively, as shown in Fig. 1. In the example shown in Fig. 1, the terminal device 2a, the terminal device 2b, and the terminal device 2c are each located, for example, in the cell Cb, and are wirelessly connected to the base station device 1b. The terminal device 2d is located, for example, in the cell Cc, and are wirelessly connected to the base station device 1c. Furthermore, the terminal device 2e and the terminal device 2f are each located, for example, in the cell Ca, and are wirelessly connected to the base station device 1a. Hereinafter, the cells Ca, Cb, and Cc are collectively referred to simply as cells C.

[0014] In the following description, it is assumed that two terminal devices 2 (terminal device 2e and terminal device 2f) are located in cell Ca, three terminal devices 2 (terminal device 2a, terminal device 2b, and terminal device 2c) are located in cell Cb, and one terminal device 2 (terminal device 2d) is located in cell Cc, but this is not limited thereto. Specifically, for example, other numbers of terminal devices 2 may be located in each of cell Ca, cell Cb, and cell Cc. In the following description, it is assumed that the wireless communication system 10 has three base station devices 1 (base station device 1a, base station device 1b, and base station device 1c), but this is not limited thereto. Specifically, for example, the wireless communication system 10 may have other numbers of base station devices 1.

[0015] Here, in the wireless communication system 10, for example, when there is a place where the placement density of the cells C is high, there is a possibility that interference occurs between the cells C. Specifically, in the wireless communication system 10, for example, in a cell Ca formed by the base station device 1a, there is a possibility that interference caused at least in part by an uplink signal transmitted from a terminal device 2a located in a cell Cb formed by the base station device 1b occurs.

[0016] Therefore, the wireless communication system 10 uses, for example, a technique for suppressing interference occurring between the cells C. Specifically, the wireless communication system 10 uses, for example, the technique described in FIG. 5 and the like of JP2014-204200A.

[0017] However, in the wireless communication system 10, for example, when there are many terminal devices 2 in each cell C, the time required to perform the process of suppressing interference occurring between the cells C (hereinafter also referred to as the interference suppression process) becomes long, and it may not be possible to efficiently suppress the interference occurring between the cells C.

[0018] Specifically, for example, each terminal device 2 may move between cells C or may disconnect a call as time passes. Therefore, in the wireless communication system 10, for example, if it takes a long time to execute the interference suppression process, it may not be possible to identify the terminal device 2 causing the interference. In this case, for example, the wireless communication system 10 may waste the execution of the process to identify the terminal device 2 causing the interference.

[0019] In response to this, in the wireless communication system 10, for example, the execution priority of the interference suppression process in each base station device 1 can be set higher than the execution priority of other processes (for example, processes for controlling communication with the terminal device 2) in each base station device 1, thereby making it possible to shorten the time required to execute the interference suppression process.

[0020] However, in each base station device 1, for example, due to the need to prevent processing delays in other processes, it may not be possible to set the execution priority of the interference suppression process to a sufficiently high level.

[0021] Therefore, the base station device 1 in this embodiment has, for example, a storage unit that stores communication state information regarding the state of communication by multiple terminal devices 2 in the cell C corresponding to the own device. Also, the base station device 1 has, for example, a receiver that receives an interference notification indicating that interference occurs in another cell C (hereinafter, also simply referred to as another cell C or another first cell C) different from the cell C corresponding to the own device from another base station device 1 (hereinafter, also simply referred to as another base station device 1 or another first base station device 1) corresponding to the other cell C. Also, the base station device 1, for example, identifies one or more terminal devices 2 that are more likely to be at least one of the causes of interference than the other terminal devices 2 based on the interference notification received by the receiver and the communication state information stored in the storage unit, among the multiple terminal devices 2 in the cell C corresponding to the own device, and prioritizes the identified one or more terminal devices 2 in scheduling of uplink signals for the multiple terminal devices 2 in the cell C corresponding to the own device.

[0022] That is, the base station device 1 in this embodiment narrows down in advance the terminal devices 2 that may be the cause of interference, for example, from the interference notification and the communication state information. Then, the base station device 1 prioritizes each of the one or more terminal devices 2 that have been determined to be the cause of interference, and determines whether each terminal device 2 is the cause of interference.

[0023] This allows the base station device 1 in this embodiment to, for example, reduce the number of terminal devices 2 for which uplink signal scheduling is required in the interference suppression process. In other words, the base station device 1 can, for example, reduce the number of terminal devices 2 for which uplink signal scheduling is required until identifying the terminal device 2 causing the interference. Therefore, the base station device 1 can, for example, reduce the processing load on a CPU (Central Processing Unit) associated with the execution of the interference suppression process, and can shorten the time required to execute the interference suppression process. Therefore, the base station device 1 can, for example, efficiently suppress interference occurring between cells C.

[0024] Specifically, the base station device 1 can increase the probability that the execution of the interference suppression process is completed before the terminal device 2 causing the interference moves between cells C or disconnects a call. Therefore, the base station device 1 can increase the accuracy of identifying the terminal device 2 causing the interference, and can efficiently suppress the interference occurring between cells C.

[0025] [Hardware configuration of communication system] Next, a description will be given of the hardware configuration of the wireless communication system 10. Fig. 2 is a diagram illustrating the hardware configuration of the base station device 1. Fig. 3 is a diagram illustrating the hardware configuration of the terminal device 2.

[0026] First, a description will be given of the hardware configuration of the base station device 1. As shown in Fig. 2, the base station device 1 includes, for example, a CPU (Central Processing Unit) 101, which is a processor, a memory 102, a communication circuit 103, and a storage device 104. Each unit is connected to each other via a bus 105.

[0027] The storage device 104 has, for example, a program storage area (not shown) that stores a program 110 for performing the interference control process. The storage device 104 also has, for example, a storage unit 130 (hereinafter also referred to as information storage area 130) that stores information used when performing the interference control process. The storage device 104 may be, for example, a hard disk drive (HDD) or a solid state drive (SSD).

[0028] The CPU 101 executes, for example, a program 110 loaded from the storage device 104 to the memory 102 to perform interference control processing.

[0029] The communication circuit 103 also includes a circuit for performing communication with the terminal device 2 via, for example, the antenna 103a via a wireless connection. The communication circuit 103 also includes a circuit for performing communication with, for example, another base station device 1 via a wired connection.

[0030] Next, a description will be given of the hardware configuration of the terminal device 2. As shown in Fig. 3, the terminal device 2 includes, for example, a CPU 201 which is a processor, a memory 202, a communication circuit 203, and a storage device 204. Each unit is connected to each other via a bus 205.

[0031] The storage device 204 has, for example, a program storage area (not shown) that stores a program 210 for performing the interference control process. The storage device 204 also has, for example, a storage unit 230 (hereinafter also referred to as information storage area 230) that stores information used when performing the interference control process. The storage device 204 may be, for example, an HDD or an SSD.

[0032] The CPU 201 executes, for example, a program 210 loaded from the storage device 204 to the memory 202 to perform interference control processing.

[0033] The communication circuit 203 also performs communication with the base station device 1 by wireless connection via, for example, an antenna 203a.

[0034] [Functions of the communication system in the first embodiment] Next, functions of the wireless communication system 10 in the first embodiment will be described. Fig. 4 is a diagram for explaining functions of the base station device 1 in the first embodiment. Fig. 5 is a diagram for explaining functions of the terminal device 2 in the first embodiment.

[0035] [Base station equipment functions] First, the functions of the base station device 1 will be described.

[0036] 4, the base station device 1 realizes various functions including a scheduling unit 111, a signal transmitting unit 112 (hereinafter also referred to as a first transmitting unit 112), a signal receiving unit 113 (hereinafter also referred to as a second receiving unit 113), a notification receiving unit 114 (hereinafter also referred to as a first receiving unit 114), an interference determination unit 115, and a notification transmitting unit 116 (hereinafter also referred to as a second transmitting unit 116) by organically cooperating with hardware such as a CPU 101 and a memory 102 and a program 110. Note that hereinafter, the scheduling unit 111 and the interference determination unit 115 are collectively referred to simply as a control unit.

[0037] 4, for example, communication state information 131 and scheduling history information 132 (hereinafter also referred to as history information 132) are stored in the information storage area 130. The communication state information 131 is, for example, information related to the state of communication in the terminal device 2. The scheduling history information 132 is, for example, information indicating the result (history) of scheduling by the scheduling unit 111.

[0038] First, the functions in the process of controlling communication with the terminal device 2 (hereinafter, also referred to as communication control process) will be described.

[0039] The scheduling unit 111 performs scheduling (radio resource allocation control) for uplink signals transmitted from a terminal device 2 located in a cell C corresponding to the own device, for example. The uplink signals include, for example, an uplink control signal and an uplink data signal. Specifically, the uplink control signal is, for example, a signal transmitted by a PUCCH (Physical Uplink Control CHannel). Also, the uplink data signal is, for example, a signal transmitted by a PUSCH (Physical Uplink Shared CHannel).

[0040] Furthermore, the scheduling unit 111 performs scheduling for downlink signals transmitted to a terminal device 2 located in a cell C corresponding to the own device, for example. The downlink signals include, for example, a downlink control signal and a downlink data signal. Specifically, the downlink control signal is, for example, a signal transmitted by a PDCCH (Physical Downlink Control CHannel). Furthermore, the downlink data signal is, for example, a signal transmitted by a PDSCH (Physical Downlink Shared CHannel).

[0041] Furthermore, the scheduling unit 111 generates, for example, scheduling history information 132. Then, the scheduling unit 111 stores, for example, the generated scheduling history information 132 in the information storage area .

[0042] The signal transmitting unit 112 transmits, for example, to the terminal device 2, a downlink control signal including the scheduling result by the scheduling unit 111 (the scheduling result for the uplink data signal).

[0043] Furthermore, the signal transmitting unit 112 transmits a downlink data signal to the terminal device 2, for example, by using the radio resources scheduled by the scheduling unit 111.

[0044] The signal receiving unit 113 receives, for example, an uplink data signal transmitted from the terminal device 2. That is, the signal receiving unit 113 receives, for example, an uplink data signal transmitted using the radio resource scheduled by the scheduling unit 111.

[0045] Furthermore, the signal receiving unit 113 receives, for example, an uplink control signal transmitted from the terminal device 2. That is, the signal receiving unit 113 receives, for example, an uplink control signal transmitted using the radio resource scheduled by the scheduling unit 111.

[0046] Then, the signal receiving unit 113 stores, for example, information included in the received uplink signal in the information storage area 130 as at least a part of the communication state information 131 .

[0047] Next, the interference suppression processing, which is performed when an interference notification is received from another base station device 1, will be described.

[0048] The notification receiving unit 114 receives, for example, an interference notification transmitted from another base station device 1. The interference notification is, for example, a notification indicating that interference occurs in a cell C of the other base station device 1 that transmitted the interference notification. In other words, the interference notification is, for example, a notification indicating that interference occurs in a cell C surrounding the cell C corresponding to the own device. Specifically, the notification receiving unit 114 receives the interference notification transmitted by using, for example, an X2 interface or an Xn interface defined in 3GPP (registered trademark) (Third Generation Partnership Project). Note that the interference notification includes, for example, a time when interference occurred in the cell C of the other base station device 1 that transmitted the interference notification (hereinafter, interference occurrence time). Then, the notification receiving unit 114 stores, for example, information related to the received interference notification in the information storage area 130 as at least a part of the communication state information 131.

[0049] For example, when the notification receiving unit 114 receives an interference notification from another base station device 1, the scheduling unit 111 identifies a terminal device 2 (hereinafter also referred to as a candidate terminal device 2) that may be the cause of interference among the terminal devices 2 located in the cell C corresponding to the own device, based on the interference notification received by the notification receiving unit 114 and the communication state information 131 stored in the information storage area 130. Then, the scheduling unit 111 prioritizes scheduling of uplink signals for the identified candidate terminal devices 2, for example.

[0050] The signal transmitting unit 112 transmits, for example, a downlink control signal including a result of scheduling by the scheduling unit 111 to the identified candidate terminal apparatus 2 .

[0051] Then, for example, when the candidate terminal device 2 receives a downlink control signal transmitted from the base station device 1, it transmits an uplink signal to the base station device 1 by using the radio resource specified in the received downlink control signal (the radio resource indicated by the scheduling result included in the downlink control signal).

[0052] The notification receiving unit 114 receives, for example, an interference identification notification transmitted from another base station device 1 (another base station device 1 that transmitted the interference notification). The interference identification notification is, for example, a notification indicating that one of the terminal devices 2 located in the cell C corresponding to the own device (the base station device 1 that received the interference identification notification) may be a cause of interference occurring in the cell C of the other base station device 1.

[0053] For example, when the notification receiving unit 114 receives an interference identification notification transmitted from another base station device 1, the interference determination unit 115 identifies a terminal device 2 (hereinafter also referred to as a specific terminal device 2) that may be the cause of interference from among the terminal devices 2 located in the cell C corresponding to the own device. Specifically, the interference determination unit 115 identifies the specific terminal device 2 by, for example, comparing the interference occurrence time included in the interference notification received by the notification receiving unit 114 with the scheduling history information 132 stored in the information storage area 130.

[0054] The signal transmission unit 112 transmits, for example, a control signal (hereinafter also referred to as a power control signal) for reducing the transmission power of the signal to a predetermined value to the specific terminal device 2 identified by the interference determination unit 115. That is, in this case, the base station device 1 performs control for eliminating the interference occurring in, for example, a cell C of another base station device 1.

[0055] In this case, when the specific terminal device 2 receives a power control signal transmitted from the base station device 1, for example, it reduces the transmission power of the signal to a predetermined value.

[0056] Next, a process of transmitting an interference notification to another base station device 1 (when interference occurring in the cell C corresponding to the own device is detected) among the interference suppression processes will be described.

[0057] The interference determination unit 115 estimates an interference level (hereinafter also simply referred to as an interference level) received from another cell C (hereinafter also referred to as another second cell C) located in the periphery of the cell C corresponding to the own device based on, for example, an uplink signal received by the signal receiving unit 113. Specifically, the interference determination unit 115 estimates the interference level at regular timing, for example, every several tens of milliseconds. Note that the interference determination unit 115 may estimate the interference level by using, for example, a user-specific reference signal (DM-RS: Demodulation Reference Signal) for PDSCH.

[0058] For example, when the interference determination unit 115 determines that the interference level is equal to or higher than a threshold, the notification transmission unit 116 transmits an interference notification to another base station device 1 (hereinafter also referred to as another second base station device 1) corresponding to another cell C. Specifically, for example, when there are multiple other cells C located in the periphery of the cell C corresponding to the own device, the notification transmission unit 116 transmits an interference notification to each of the multiple other base station devices 1 corresponding to each of the multiple other cells C.

[0059] Then, for example, when the signal receiving unit 113 receives an uplink signal transmitted from another cell C (terminal device 2 located in another cell C) after transmitting an interference notification to another base station device 1, the interference determination unit 115 identifies the other cell C that transmitted the received uplink signal based on the received uplink signal.

[0060] Furthermore, the notification transmission unit 116 transmits an interference identification notification to, for example, another base station device 1 corresponding to another cell C identified by the interference determination unit 115.

[0061] [Functions in terminal devices] Next, the functions of the terminal device 2 will be described.

[0062] As shown in FIG. 5, the terminal device 2 realizes various functions including a signal receiving unit 211, a signal transmitting unit 212, and a transmission power control unit 213 by organic cooperation between hardware such as a CPU 201 and a memory 202 and a program 210.

[0063] The signal receiving unit 211 receives, for example, a downlink data signal transmitted from the base station device 1. In addition, the signal receiving unit 211 receives, for example, a downlink control signal (for example, a power control signal) transmitted from the base station device 1.

[0064] The signal transmitting unit 212 transmits an uplink data signal to the base station device 1, for example, by using the radio resource indicated by the downlink control signal received by the signal receiving unit 211 (the radio resource indicated by the scheduling result by the scheduling unit 111). Also, the signal transmitting unit 212 transmits an uplink control signal to the base station device 1, for example, by using the radio resource indicated by the downlink control signal received by the signal receiving unit 211 (the radio resource indicated by the scheduling result by the scheduling unit 111).

[0065] For example, when the signal receiving unit 211 receives a power control signal, the transmission power control unit 213 reduces the transmission power of the signal to a predetermined value.

[0066] [Sequence chart of interference control processing in the first embodiment] Next, a sequence chart of the interference control process in the first embodiment will be described. FIG. 6 is a sequence chart of the interference control process in the first embodiment. Also, FIG. 7 and FIG. 8 explain the interference control process in the first embodiment. Note that, hereinafter, explanations of the terminal device 2e and the terminal device 2f (each terminal device 2 located in the cell Ca) will be omitted. Also, hereinafter, a case where interference occurs in the cell Ca explained in FIG. 1 etc. will be explained.

[0067] The interference determination unit 115 of the base station device 1a estimates the interference level that the cell Ca receives from the cell Cb or the cell Cc based on, for example, the uplink data signal received by the signal receiving unit 113 (S101). Similarly, the interference determination unit 115 of the base station device 1b estimates the interference level that the cell Cb receives from the cell Ca or the cell Cc based on, for example, the uplink data signal received by the signal receiving unit 113. Also, the interference determination unit 115 of the base station device 1c estimates the interference level that the cell Cc receives from the cell Ca or the cell Cb based on, for example, the uplink data signal received by the signal receiving unit 113.

[0068] Then, for example, if the notification transmitter 116 of the base station device 1a determines that the interference level estimated in the processing of S101 is equal to or greater than a threshold, it transmits an interference notification 141 to each of the base station device 1b and the base station device 1c (S102).

[0069] Specifically, in this case, the notification transmitter 116 of the base station device 1a transmits an interference notification 141 including, for example, an interference occurrence time as well as a time during which interference is intentionally caused to occur (hereinafter, interference occurrence scheduled time). The interference notification 141 will be specifically described below.

[0070] [Example of interference notification] Fig. 7 is a diagram for explaining a specific example of the interference notification 141. Specifically, Fig. 7 shows a specific example of the interference notification 141 when it is transmitted using the Xn interface.

[0071] As shown in Fig. 7, the interference notification 141 has, for example, items such as "Message Type" in which the message type of the interference notification 141 is set, "Global NG-RAN Node ID" in which identification information of the base station device 1 that is the transmission source of the interference notification 141 is set, "Interference time interval information" in which the interference occurrence time is set, and "Expected radio schedule interval offset" in which the expected interference occurrence time is set. Furthermore, the "Interference time interval information" has, for example, items such as "Start time" in which the start time of the interference occurrence time is set, and "End time" in which the end time of the interference occurrence time is set. Furthermore, the "Expected radio schedule interval offset" has, for example, items such as "Start time offset" in which the time from the time when the interference notification 141 is received to the start time of the expected interference occurrence time is set, and "End time offset" in which the time from the start time to the end time of the expected interference occurrence time is set.

[0072] Specifically, in the interference notification 141 shown in Fig. 7, for example, "17" is set as "Message Type" and "1" is set as "Global NG-RAN Node ID". Also, in the interference notification 141 shown in Fig. 7, for example, "SFN:0x1ED Subframe:0" is set as "Start time" in "Interference time interval information", and "SFN:0x251 Subframe:0" is set as "End time" in "Interference time interval information". Furthermore, in the interference notification 141 shown in Fig. 7, for example, "SFN:0x32 Subframe:0" is set as "Start time offset" in "Expected radio schedule interval offset", and "SFN:0x64 Subframe:0" is set as "End time offset" in "Expected radio schedule interval offset".

[0073] In addition, for example, UTC time or Radio frame timing may be set in the "Start time", "End time", "Start time offset" and "End time offset" in FIG.

[0074] Returning to FIG. 6, when the scheduling unit 111 of the base station device 1b receives the interference notification 141 transmitted in the process of S102, for example, based on the received interference notification 141 and the communication state information 131 stored in the information storage area 130, it identifies one or more candidate terminal devices 2 that may be the cause of interference among the terminal devices 2 located in the cell Cb, and prioritizes scheduling of uplink data signals for the identified one or more candidate terminal devices 2 (S103). Similarly, when the scheduling unit 111 of the base station device 1c receives the interference notification 141 transmitted in the process of S102, it identifies one or more candidate terminal devices 2 that may be the cause of interference among the terminal devices 2 located in the cell Cc, based on the received interference notification 141 and the communication state information 131 stored in the information storage area 130, and prioritizes scheduling of uplink data signals for the identified one or more candidate terminal devices 2.

[0075] Specifically, in this case, the scheduling unit 111 of the base station device 1b determines the priority of each terminal device 2 located in the cell Cb based on, for example, the communication state information 131 stored in the information storage area 130. Then, the scheduling unit 111 of the base station device 1b determines one or more candidate terminal devices 2 based on, for example, the determined priority. Thereafter, the scheduling unit 111 of the base station device 1b schedules the uplink data signal for each of the one or more candidate terminal devices 2 so that the uplink data signal is transmitted at the interference occurrence scheduled time included in the received interference notification 141. Similarly, in this case, the scheduling unit 111 of the base station device 1c determines the priority of each terminal device 2 located in the cell Cc based on, for example, the communication state information 131 stored in the information storage area 130. Then, the scheduling unit 111 of the base station device 1c determines one or more candidate terminal devices 2 based on, for example, the determined priority. Thereafter, the scheduling unit 111 of the base station device 1c schedules the uplink data signal for each of the one or more candidate terminal devices 2 so that the uplink data signal is transmitted at the scheduled interference occurrence time included in the received interference notification 141, for example.

[0076] The scheduling unit 111 of the base station device 1b may schedule the uplink data signal for each of the one or more candidate terminal devices 2 so that the uplink data signal is transmitted at a time different from the scheduled interference occurrence time included in the received interference notification 141. Similarly, the scheduling unit 111 of the base station device 1c may schedule the uplink data signal for each of the one or more candidate terminal devices 2 so that the uplink data signal is transmitted at a time different from the scheduled interference occurrence time included in the received interference notification 141.

[0077] Next, the notification transmitter 116 of the base station device 1b transmits, for example, a schedule notification 142 including the result of the scheduling performed in the process of S103 to the base station device 1a (the base station device 1 that transmitted the interference notification 141) (S104). Similarly, the notification transmitter 116 of the base station device 1c transmits, for example, a schedule notification 142 including the result of the scheduling performed in the process of S103 to the base station device 1a. The schedule notification 142 will be specifically described below.

[0078] [Examples of schedule notifications] Fig. 8 is a diagram for explaining a specific example of the schedule notification 142. Specifically, Fig. 8 is a specific example of the schedule notification 142 when it is transmitted using the Xn interface.

[0079] 8, the schedule notification 142 has, for example, items such as "Message Type" in which the message type of the schedule notification 142 is set, "Global NG-RAN Node ID" in which identification information of the base station device 1 that is the source of the schedule notification 142 is set, and "Radio schedule interval information" in which the scheduled interference occurrence time is set. Furthermore, the "Radio schedule interval information" has, for example, items such as "Start time" in which the time from the time when the schedule notification 142 is received to the start time of the scheduled interference occurrence time is set, and "End time" in which the time from the start time to the end time of the scheduled interference occurrence time is set.

[0080] Specifically, in the schedule notice 142 shown in Fig. 8, for example, "18" is set as the "Message Type" and "1" is set as the "Global NG-RAN Node ID." Also, in the schedule notice 142 shown in Fig. 8, for example, "SFN:0x32 Subframe:0" is set as the "Start time" in "Radio schedule interval information," and "SFN:0x64 Subframe:0" is set as the "End time" in "Interference time information."

[0081] In addition, for example, UTC time or Radio frame timing may be set in the "Start time" and "End time" in FIG.

[0082] 6, the signal transmission unit 112 of the base station device 1b transmits a downlink control signal including the scheduling result performed in the process of S103 to each terminal device 2 located in the cell Cb (S105). Similarly, the signal transmission unit 112 of the base station device 1c transmits a downlink control signal including the scheduling result performed in the process of S103 to each terminal device 2 located in the cell Cc.

[0083] Specifically, the signal transmission unit 112 of the base station device 1b transmits a downlink control signal including the scheduling result performed in the process of S103 to, for example, the terminal device 2a, the terminal device 2b, and the terminal device 2c. Similarly, the signal transmission unit 112 of the base station device 1c transmits a downlink control signal including the scheduling result performed in the process of S103 to, for example, the terminal device 2d.

[0084] Then, for example, when the signal receiving unit 211 of the signal transmitting unit 212 of the terminal device 2a, terminal device 2b, terminal device 2c, and terminal device 2d receives the downlink control signal transmitted in the processing of S105, the signal transmitting unit 212 transmits an uplink data signal by using the radio resource indicated by the received downlink control signal (the radio resource indicated by the scheduling result) (S106).

[0085] Specifically, the signal transmitters 212 of the terminal devices 2a, 2b, and 2c transmit uplink data signals to the base station device 1b, for example, in this case, while the signal transmitter 212 of the terminal device 2d transmits uplink data signals to the base station device 1c, for example.

[0086] Then, for example, when the interference determination unit 115 of the base station device 1a receives an uplink data signal transmitted from the cell Cb in the process of S106 (dotted line portion of S106), the interference determination unit 115 estimates the interference level received from the cell Cb (S107).

[0087] Specifically, the interference determination unit 115 of the base station device 1a identifies the cell C that is the source of the received uplink data signal, for example, by comparing the reception timing of the received uplink data signal with the scheduling results included in the schedule notices 142 transmitted from each of the base station devices 1b and 1c in the process of S104. More specifically, the interference determination unit 115 of the base station device 1a identifies, for example, the cell C corresponding to the base station device 1 that transmitted the schedule notice 142 indicating that the uplink data signal is being scheduled at the reception timing of the received uplink data signal, as the cell C that is the source of the received uplink data signal. Then, for example, when the interference determination unit 115 identifies cell Cb as cell C that is the source of the received uplink data signal, the interference determination unit 115 estimates the interference level received from the identified cell Cb.

[0088] That is, for example, when an uplink data signal transmitted from cell Cb to base station device 1b reaches base station device 1a, it can be determined that there is a possibility that terminal device 2, which is the cause of interference occurring in cell Ca, is located in cell Cb. Therefore, in this case, base station device 1a estimates, for example, the interference level of the uplink data signal transmitted from cell Cb.

[0089] Thereafter, for example, if the interference determination unit 115 estimates that the interference level from cell Cb is equal to or higher than a threshold, the notification transmission unit 116 of the base station device 1a transmits an interference identification notification to the base station device 1b corresponding to cell Cb (S108).

[0090] That is, in this case, the base station device 1a estimates that the terminal device 2 that may be the cause of interference occurring in the cell Ca is located in the cell Cb, and transmits an interference identification notification to the base station device 1b corresponding to the cell Cb.

[0091] Then, for example, when the interference determination unit 115 of the base station device 1b receives an interference identification notification from the base station device 1a, it identifies a specific terminal device 2 that may be the cause of the interference from among the terminal devices 2 located within the cell Cb (S109).

[0092] Specifically, the interference determination unit 115, for example, compares the interference occurrence time included in the interference notification 141 received in the processing of S102 with the scheduling history information 132 stored in the information storage area 130, and identifies the terminal device 2 that was performing scheduling at the interference occurrence time included in the interference notification 141 as a specific terminal device 2.

[0093] Thereafter, the signal transmitting unit 112 of the base station apparatus 1b transmits, for example, to the specific terminal apparatus 2 identified in the process of S109, a power control signal for reducing the transmission power of the signal to a predetermined value (S110).

[0094] [Details of interference control process in the first embodiment] Next, details of the interference control process in the first embodiment will be described. Figures 9 to 11 are flow chart diagrams for explaining details of the interference control process in the first embodiment. Also, Figures 12 to 26 are diagrams for explaining details of the interference control process in the first embodiment. Specifically, the details of the process of S103 will be explained below.

[0095] First, a specific example of the communication state information 131 and the scheduling history information 132 used in the process of S103 will be described. The communication state information 131 includes, for example, data retention amount information 131a indicating the amount of data (hereinafter also referred to as uplink retention amount) of uplink data waiting to be transmitted in the terminal device 2 (uplink data waiting to be transmitted to the base station device 1). The communication state information 131 also includes, for example, state management information 131b for managing the state of communication in the terminal device 2.

[0096] [Examples of data retention information] First, the data retention amount information 131a will be described. Fig. 12, Fig. 15, Fig. 18, Fig. 22, and Fig. 24 are diagrams for explaining specific examples of the data retention amount information 131a. In the following, the terminal device 2a, the terminal device 2b, and the terminal device 2c described in Fig. 1 etc. will also be written as "2a", "2b", and "2c", respectively. In the following, the cells Ca, Cb, and Cc described in Fig. 1 etc. will also be written as "Ca", "Cb", and "Cc", respectively.

[0097] The data retention amount information 131a shown in FIG. 12 and the like has, for example, items such as a "cell number" in which identification information of a cell C corresponding to a base station device 1 communicating with each terminal device 2 is set, a "user number" in which identification information of each terminal device 2 is set, and an "uplink retention amount" in which the uplink retention amount in each terminal device 2 is set.

[0098] Specifically, in the data retention amount information 131a shown in FIG. 12, the information in the second row has, for example, “Cb” set as the “cell number,” “2a” set as the “user number,” and “400 (bytes)” set as the “upstream retention amount.”

[0099] In addition, in the data retention amount information 131a shown in FIG. 12, the information in the fourth row has, for example, “Cb” set as the “cell number”, “2b” set as the “user number”, and “700 (bytes)” set as the “upstream retention amount”.

[0100] In addition, in the data retention amount information 131a shown in FIG. 12, the information in the sixth row has, for example, “Cb” set as the “cell number”, “2c” set as the “user number”, and “30,000 (bytes)” set as the “upstream retention amount”.

[0101] [Examples of state management information] Next, the state management information 131b will be described. Figures 13, 16, 19 and 23 are diagrams for explaining specific examples of the state management information 131b.

[0102] The state management information 131b shown in FIG. 13 and the like has, as items, for example, a "cell number" in which identification information of a cell C corresponding to the base station device 1 that communicates with each terminal device 2 is set, a "user number" in which identification information of each terminal device 2 is set, and an "uplink retention amount" in which an uplink retention amount in each terminal device 2 of information included in an uplink control signal transmitted from each terminal device 2 (hereinafter also referred to as report information) is set. In addition, the state management information 131b shown in FIG. 13 and the like has, as items, for example, a "report information reception time" in which a time at which report information (uplink control signal including report information) transmitted from each terminal device 2 is received is set, and an "average throughput" in which an average throughput of an uplink signal from each terminal device 2 to the base station device 1 is set. In addition, the state management information 131b shown in FIG. 13 and the like has, as items, for example, a "scheduling occurrence frequency" in which an occurrence frequency of scheduling of an uplink data signal from each terminal device 2 to the base station device 1 is set, and an "interference history" in which information indicating whether each terminal device 2 was a terminal device 2 that caused interference in the past is set. In the "interference history", for example, "Yes" is set, which indicates that each terminal device 2 was a terminal device 2 causing interference in the past, or "No" is set, which indicates that each terminal device 2 was not a terminal device 2 causing interference in the past. In the following description, it is assumed that "-" is set for items for which no information is set. Note that the uplink control signal including the report information is periodically transmitted from each terminal device 2 to the base station device 1.

[0103] Specifically, in the status management information 131b shown in FIG. 13, the information in the second row has, for example, the "cell number" set to "Cb," the "user number" set to "2a," the "uplink queue volume" set to "400 (bytes)," the "report information reception time" set to "SFN:0x24D Subframe:8," the "average throughput" set to "-," the "scheduling occurrence frequency" set to "-," and the "interference history" set to "none."

[0104] In addition, in the status management information 131b shown in FIG. 13, the information in the fourth row has, for example, the "cell number" set to "Cb", the "user number" set to "2b", the "uplink queue volume" set to "700 (bytes)", the "report information reception time" set to "SFN:0x24E Subframe:8", the "average throughput" set to "-", the "scheduling occurrence frequency" set to "-", and the "interference history" set to "none".

[0105] In addition, in the status management information 131b shown in FIG. 13, the information in the sixth row, for example, is set as the "cell number" to "Cb", as the "user number" to "2c", as the "uplink queue volume" to "30,000 (bytes)", as the "report information reception time" to "SFN:0x24E Subframe:8", as the "average throughput" to "-", as the "scheduling occurrence frequency" to "-", and as the "interference history" to "Yes".

[0106] [Example of scheduling history information] Next, a description will be given of the scheduling history information 132. Fig. 14, Fig. 17, Fig. 20, and Fig. 21 are diagrams for explaining specific examples of the scheduling history information 132.

[0107] The scheduling history information 132 shown in FIG. 14 and the like has, for example, items including a "scheduling time" in which the time when the scheduling of the uplink data signal from each terminal device 2 to the base station device 1 is performed is set, a "cell number" in which identification information of the cell C of the base station device 1 communicating with each terminal device 2 is set, a "user number" in which identification information of each terminal device 2 is set, and an "allocated resource" in which the amount of radio resources allocated by the scheduling for each terminal device 2 is set. The scheduling history information 132 shown in FIG. 14 and the like also has, for example, items including a "transmission type" in which information indicating whether or not a retransmission of the uplink data signal has been performed is set, and a "retransmission count" in which the number of retransmissions of the uplink data signal is set. In the "transmission type", for example, "new transmission" indicating that the transmission of the uplink data signal is not a retransmission, or "retransmission" indicating that the transmission of the uplink data signal is a retransmission is set.

[0108] Specifically, in the scheduling history information 132 shown in FIG. 14, the information in the second row has, for example, the "scheduling time" set to "SFN:0x24F Subframe:8", the "cell number" set to "Cb", the "user number" set to "2a", the "allocated resources" set to "400 (bytes)", the "transmission type" set to "new transmission" and the "number of retransmissions" set to "0".

[0109] In addition, in the scheduling history information 132 shown in FIG. 14, the information in the third row has, for example, the "scheduling time" set to "SFN:0x24F Subframe:8", the "cell number" set to "Cb", the "user number" set to "2c", the "allocated resources" set to "5,000 (bytes)", the "transmission type" set to "new transmission", and the "number of retransmissions" set to "0".

[0110] Then, when the data retention amount information 131a described in FIG. 12 and the status management information 131b described in FIG. 13 are stored in the information storage area 130, if scheduling corresponding to the second and third lines in the scheduling history information 132 described in FIG. 14 is performed, the scheduling unit 111 updates, for example, the value set for the "upstream retention amount" of the information in which the "user number" is "2a" (information in the second line) to "0 (bytes)", and updates the value set for the "upstream retention amount" of the information in which the "user number" is "2c" (information in the sixth line) to "25,000 (bytes)", as shown in the underlined portion in the data retention amount information 131a in FIG. 15.

[0111] That is, the result of subtracting "400 (bytes)" which is the "assigned resource" of the information on the second line in the scheduling history information 132 described in FIG. 14 from "400 (bytes)" which is the "upstream retention amount" of the information on the second line in the data retention amount information 131a described in FIG. 12 is "0 (bytes)". Therefore, as shown in the underlined portion in the data retention amount information 131a of FIG. 15, the scheduling unit 111 updates the value set in the "upstream retention amount" of the information (information on the second line) in which the "user number" is "2a" to "0 (bytes)". Also, the result of subtracting "5,000 (bytes)" which is the "assigned resource" of the information on the sixth line in the scheduling history information 132 described in FIG. 14 from "30,000 (bytes)" which is the "upstream retention amount" of the information on the sixth line in the data retention amount information 131a described in FIG. 12 is "25,000 (bytes)". Therefore, as shown in the underlined portion of the data retention amount information 131a in FIG. 15, the scheduling unit 111 updates the value set for the “upstream retention amount” of the information in which the “user number” is “2c” (information on the sixth line) to “25,000 (bytes)”.

[0112] Then, in this case, as shown in the underlined portion in the state management information 131b of Fig. 16, the scheduling unit 111 sets "14 (bits / sec)" calculated as the average throughput of the uplink data signal to be scheduled corresponding to the information on the second line in the scheduling history information 132 described in Fig. 14, for example, to "average throughput" in the second line of the state management information 131b. Also, in this case, as shown in the underlined portion in the state management information 131b of Fig. 16, the scheduling unit 111 sets "60 (bits / sec)" calculated as the average throughput of the uplink data signal to be scheduled corresponding to the information on the sixth line in the scheduling history information 132 described in Fig. 14, for example, to "average throughput" in the sixth line of the state management information 131b.

[0113] Thereafter, when scheduling corresponding to the fourth line is performed as shown in the underlined portion in the scheduling history information 132 of FIG. 17, the scheduling unit 111 updates the value set for the "upstream retention amount" of the information in which the "user number" is "2b" (information in the fourth line) to "300 (bytes)", as shown in the underlined portion in the data retention amount information 131a of FIG. 18.

[0114] That is, the result of subtracting "400 (bytes)", which is the "allocated resource" of the information on the fourth line in the scheduling history information 132 shown in Fig. 17, from "700 (bytes)", which is the "upstream retention amount" of the information on the fourth line in the data retention amount information 131a described in Fig. 15, is "300 (bytes)". Therefore, as shown in the underlined portion in the data retention amount information 131a in Fig. 18, the scheduling unit 111 updates the value set in the "upstream retention amount" of the information in which the "user number" is "2b" (information on the fourth line) to "300 (bytes)".

[0115] In this case, as shown in the underlined portion in the status management information 131b of FIG. 19, the scheduling unit 111 sets, for example, “13 (bits / sec)” calculated as the average throughput of the uplink data signal to be scheduled corresponding to the information on the fourth line in the scheduling history information 132 described in FIG. 17, to “average throughput” in the fourth line of the status management information 131b.

[0116] Thereafter, as shown in the underlined portion of the scheduling history information 132 in FIG. 20, when scheduling corresponding to the fifth line (scheduling corresponding to retransmission) is performed, the scheduling unit 111 does not update the data retention amount information 131a, for example.

[0117] Furthermore, as shown in the underlined portion in the scheduling history information 132 of FIG. 21, when scheduling corresponding to the sixth line is performed, the scheduling unit 111 updates, for example, the value set for the "upstream retention volume" of the information in which the "user number" is "2c" (information in the sixth line) to "22,000 (bytes)", as shown in the underlined portion in the data retention volume information 131a of FIG. 22.

[0118] That is, the result of subtracting "3,000 (bytes)" which is the "allocated resource" of the information on the sixth line in the scheduling history information 132 shown in Fig. 21 from "25,000 (bytes)" which is the "upstream retention amount" of the information on the sixth line in the data retention amount information 131a described in Fig. 18 is "22,000 (bytes)". Therefore, as shown in the underlined portion in the data retention amount information 131a in Fig. 22, the scheduling unit 111 updates the value set in the "upstream retention amount" of the information (information on the sixth line) in which the "user number" is "2b" to "22,000 (bytes)".

[0119] Thereafter, for example, when new notification information (uplink control signal including notification information) is received from the terminal device 2a, the scheduling unit 111 updates the state management information 131b according to information corresponding to the received notification information, for example, as shown in the underlined portion in the state management information 131b of FIG. 23.

[0120] Specifically, in this case, the scheduling unit 111 updates the "upstream retention volume" of the information having the "user number" of "2a" (information on the second line) to "200 (bytes)" and updates the "scheduling time" to "SFN:0x26D Subframe:8", as shown in the underlined portion of FIG. 23.

[0121] Then, as shown by the underlined portion in the accumulated data amount information 131a in FIG. 24, the scheduling unit 111 updates the accumulated data amount information 131a in accordance with information corresponding to the underlined portion in the status management information 131b in FIG. 23, for example.

[0122] Specifically, in this case, the scheduling unit 111 updates the "upstream retention amount" of the information (information on the second line) in which the "user number" is "2a" to "200 (bytes)" as shown in the underlined portion in FIG.

[0123] [Details of S103 processing] Next, the process of S103 will be described in detail. Figures 9 to 11 are flow charts for explaining the process of S103 in detail. The following description will be given on the assumption that the scheduling history information 132 described in Figure 21, the state management information 131b described in Figure 23, and the data retention amount information 131a described in Figure 24 are stored in the information storage area 130.

[0124] As shown in FIG. 9, the scheduling unit 111 waits until it receives, for example, an interference notification 141 from another base station device 1 (NO in S11).

[0125] Then, when an interference notification 141 is received from another base station device 1 (YES in S11), a history information detection process is performed (S12). The history information detection process will be described below.

[0126] [History information detection process] FIG. 10 is a flowchart illustrating the history information detection process.

[0127] As shown in FIG. 10, the scheduling unit 111 identifies the interference occurrence time included in the interference notification 141 received in the process of S11 (S21).

[0128] Specifically, for example, "SFN:0x1ED Subframe:0" and "SFN:0x251 Subframe:0" are set as the "Start time" and "End time" in the interference notification 141 shown in Fig. 7. Therefore, for example, when the interference notification 141 described in Fig. 7 is received in the process of S11, the scheduling unit 111 identifies the time from "SFN:0x1ED Subframe:0" to "SFN:0x251 Subframe:0" as the interference occurrence time.

[0129] Then, the scheduling unit 111 sets the first flag to, for example, "OFF" (S22).

[0130] Next, the scheduling unit 111, for example, refers to the scheduling history information 132 stored in the information storage area 130 and determines whether or not there is scheduling history information 132 corresponding to the time included in the interference occurrence time identified in the processing of S21 (S23).

[0131] As a result, if it is determined that there is scheduling history information 132 corresponding to the time included in the interference occurrence time identified in the processing of S21 (YES in S23), the scheduling unit 111 sets, for example, the first flag to "ON" (S24).

[0132] Specifically, in the scheduling history information 132 described in Fig. 21, for example, a time included in the period from "SFN:0x1ED Subframe:0" to "SFN:0x251 Subframe:0" is set as the "scheduling time" of the information in the second to sixth lines. Therefore, in this case, the scheduling unit 111 sets the first flag to "ON" in the process of S23, for example.

[0133] Then, after processing of S24, or if it is determined that there is no scheduling history information 132 corresponding to each time included in the interference occurrence time identified in processing of S21 (NO in S23), the scheduling unit 111, for example, terminates the history information detection process.

[0134] Returning to FIG. 9, the scheduling unit 111 determines, for example, whether or not the first flag is "ON" (S13).

[0135] As a result, if it is determined that the first flag is “ON” (YES in S13), the scheduling unit 111 identifies, for example, one terminal device 2 for which the terminal device selection process has not yet been performed in the process of S15 from among the terminal devices 2 corresponding to the scheduling history information 132 determined to exist in the process of S23 (S14).

[0136] Then, the scheduling unit 111 performs, for example, a terminal device selection process for the terminal device 2 identified in the process of S14 (S15). The terminal device selection process will be described below.

[0137] [Terminal device selection process] FIG. 11 is a flowchart illustrating the terminal device selection process.

[0138] As shown in FIG. 11, the scheduling unit 111 sets, for example, the second flag and the third flag to "OFF" (S31).

[0139] Then, the scheduling unit 111, for example, refers to the data retention amount information 131a stored in the information storage area 130, and identifies the upstream retention amount for the terminal device 2 identified in the process of S14 (S32).

[0140] Furthermore, the scheduling unit 111, for example, refers to the state management information 131b stored in the information storage area 130, and identifies the average throughput for the terminal device 2 identified in the process of S14 (S33).

[0141] Thereafter, the scheduling unit 111 calculates the frequency of upstream scheduling (hereinafter also simply referred to as the scheduling frequency) for the terminal device 2 identified in the processing of S14, for example, from the upstream congestion amount identified in the processing of S32 and the average throughput identified in the processing of S33 (S34).

[0142] Specifically, the scheduling unit 111 calculates the scheduling frequency for the terminal device 2 identified in the processing of S14, for example, by dividing the number (number of records) of scheduling history information 132 determined to exist in the processing of S23 by the interference occurrence time identified in the processing of S21.

[0143] Next, the scheduling unit 111 determines, for example, whether or not scheduling for the terminal device 2 identified in the processing of S14 is performed at the interference occurrence scheduled time (S35).

[0144] Specifically, for example, "SFN:0x32 Subframe:0" and "SFN:0x64 Subframe:0" are set in the "Start time offset" and "End time offset" in the interference notification 141 shown in Fig. 7. Therefore, for example, when the interference notification 141 described in Fig. 7 is received in the process of S11 and the timing at which the interference notification 141 is received is "SFN:0x400 Subframe:0", the scheduling unit 111 calculates the time from "SFN:0x432 Subframe:0" to "SFN:0x496 Subframe:0" as the expected interference occurrence time.

[0145] In addition, the scheduling unit 111 calculates the processing time (hereinafter also simply referred to as the scheduling processing time) for performing scheduling for the terminal device 2 identified in the processing of S14, for example, by dividing the upstream congestion amount identified in the processing of S32 by the average throughput identified in the processing of S33.

[0146] Furthermore, the scheduling unit 111 calculates the time interval (hereinafter also simply referred to as the scheduling interval) at which scheduling is performed for the terminal device 2 identified in the processing of S14, for example, by dividing the calculated scheduling processing time by the scheduling frequency calculated in the processing of S34.

[0147] Then, the scheduling unit 111 determines that, for example, if the time after the scheduling processing time has elapsed from the time when the interference notification 141 was received in the processing of S11 is included in the scheduled interference occurrence time and the scheduling interval is equal to or less than the scheduled interference occurrence time, scheduling for the terminal device 2 identified in the processing of S14 will be performed at the scheduled interference occurrence time.

[0148] As a result, when it is determined that scheduling for the terminal device 2 identified in the processing of S14 is performed at the interference occurrence scheduled time (YES in S35), the scheduling unit 111 sets, for example, the second flag to "ON" (S36).

[0149] In this case, the scheduling unit 111 may, for example, set “Interference History” of each piece of information regarding the terminal device 2 identified in the processing of S14 in the state management information 131b stored in the information storage area 130 to “Yes.”

[0150] Then, the scheduling unit 111, for example, refers to the state management information 131b stored in the information storage area 130 and determines whether or not the terminal device 2 identified in the processing of S14 has been identified in the past as a terminal device 2 that may be a cause of interference (S37).

[0151] Specifically, for example, when "Yes" is set in the "interference history" of each piece of information about the terminal device 2 identified in the processing of S14 among the state management information 131b stored in the information storage area 130, the scheduling unit 111 determines that the terminal device 2 identified in the processing of S14 has been identified as a terminal device 2 that may have been a cause of interference in the past. Also, for example, when "No" is set in the "interference history" of each piece of information about the terminal device 2 identified in the processing of S14 among the state management information 131b stored in the information storage area 130, the scheduling unit 111 determines that the terminal device 2 identified in the processing of S14 has not been identified as a terminal device 2 that may have been a cause of interference in the past.

[0152] As a result, if it is determined that the terminal device 2 identified in the processing of S14 was previously identified as the terminal device 2 causing interference (YES in S37), the scheduling unit 111 sets, for example, the third flag to “ON” (S38).

[0153] Then, after the processing of S38, or if it is determined that the terminal device 2 identified in the processing of S14 has not been identified in the past as a terminal device 2 that may have been a cause of interference (NO in S37), the scheduling unit 111, for example, terminates the terminal device selection processing.

[0154] In addition, the scheduling unit 111 also terminates the terminal device selection process, for example, when it determines in the process of S35 that scheduling for the terminal device 2 identified in the process of S14 will not be performed at the scheduled interference occurrence time (NO in S35).

[0155] Returning to FIG. 9, the scheduling unit 111 determines, for example, whether or not the second flag is "ON" (S16).

[0156] As a result, when it is determined that the second flag is "ON" (YES in S16), the scheduling unit 111 generates priority information 133 based on the third flag (S17). Then, the scheduling unit 111 stores the generated priority information 133 in the information storage area 130, for example. A specific example of the priority information 133 will be described below.

[0157] [Examples of priority information] 25 and 26 are specific examples illustrating the priority information 133. FIG.

[0158] The priority information 133 shown in FIG. 25 and the like has, as items, for example, a "cell number" in which identification information of the cell C in which the terminal device 2 identified in the processing of S14 is located, a "user number" in which identification information of the terminal device 2 identified in the processing of S14 is set, and an "interference history" in which information indicating whether or not the terminal device 2 identified in the processing of S14 has been determined to be a terminal device 2 that may be a cause of interference in the past is set. In addition, the priority information 133 shown in FIG. 25 and the like has, as an item, a "priority" in which the priority of the terminal device identified in the processing of S14 is set. In the "interference history", for example, the same information as the information set in the "interference history" for the terminal device 2 identified in the processing of S14 is set among the state management information 131b stored in the information storage area 130. In addition, in the "priority", for example, the higher the priority, the larger the value is set.

[0159] Specifically, in the priority information 133 shown in FIG. 25, the information in the first row has, for example, “Cb” set as the “cell number,” “2a” set as the “user number,” “Yes” set as the “interference history,” and “-” set as the “priority.”

[0160] Returning to FIG. 11, when it is determined in the process of S16 that the second flag is "OFF" (NO in S16), the scheduling unit 111 does not perform the process of S17, for example.

[0161] Then, the scheduling unit 111 determines, for example, whether or not all of the terminal devices 2 have been identified in the process of S14 (S18).

[0162] As a result, when it is determined that all the terminal devices 2 have not been identified in the process of S14 (NO in S18), the scheduling unit 111 performs, for example, the processes from S14 onwards again.

[0163] On the other hand, if it is determined in the processing of S14 that all terminal devices 2 have been identified (YES in S18), the scheduling unit 111 performs scheduling for each terminal device 2 (S19), for example, by referring to the priority information 133 generated in the processing of S17 (priority information 133 stored in the information storage area 130).

[0164] Furthermore, even if it is determined in the process of S13 that the first flag is "OFF" (NO in S13), the scheduling unit 111 similarly performs the process of S19.

[0165] Specifically, the priority information 133 when the process of S19 is performed includes, for example, information corresponding to each terminal device 2 in which the "second flag" is set to "ON" in the process of S36, as shown in FIG. 26. Also, as shown in FIG. 26, the "priority" of information in which "interference history" is set to "Yes" (for example, the information in the first row) is set to, for example, "2". Furthermore, as shown in FIG. 26, the "priority" of information in which "interference history" is set to "No" (for example, the information in the second and third rows) is set to, for example, "1". Therefore, in the process of S19, the scheduling unit 111 refers to the priority information 133 shown in FIG. 26, for example, and performs scheduling in the order of the terminal device 2 having the largest value set in the "priority".

[0166] More specifically, the scheduling unit 111 refers to the priority information 133 shown in FIG. 26, for example, identifies a predetermined number of terminal devices 2 in descending order of the value set for "priority", and performs scheduling for each of the identified predetermined number of terminal devices 2.

[0167] This allows the base station device 1 (scheduling unit 111) to reduce the number of terminal devices 2 that need to be scheduled in order to perform interference suppression processing in the processing of S103, for example. Therefore, the base station device 1 can reduce the processing load required to perform interference suppression processing, for example.

[0168] In this way, the base station device 1 in this embodiment has, for example, an information storage area 130 that stores communication state information 131 related to the state of communication by multiple terminal devices 2 in the cell C corresponding to the base station device. In addition, the base station device 1 has, for example, a notification receiving unit 114 that receives an interference notification 141 from another base station device 1 indicating that interference is occurring in another cell C different from the cell C corresponding to the base station device. In addition, the base station device 1 has, for example, a scheduling unit 111 that identifies one or more terminal devices 2 that may be at least one of the causes of interference among the multiple terminal devices 2 in the cell C corresponding to the base station device, based on the interference notification 141 received by the notification receiving unit 114 and the communication state information 131 stored in the information storage area 130, and schedules uplink signals for the multiple terminal devices 2 with priority given to the identified one or more terminal devices 2.

[0169] That is, the base station device 1 in this embodiment narrows down in advance the terminal devices 2 that may be the cause of interference, for example, from the interference notification 141 and the communication state information 131. Then, the base station device 1 prioritizes each of the one or more terminal devices 2 that have been determined to be the cause of interference, and determines whether or not each terminal device 2 is the cause of interference.

[0170] As a result, the base station device 1 in this embodiment can, for example, reduce the number of terminal devices 2 that need to perform uplink signal scheduling in the interference suppression process, and can shorten the time required to execute the interference suppression process. Therefore, the base station device 1 can, for example, efficiently suppress interference occurring between cells C.

[0171] Specifically, the base station device 1 can increase the probability that the execution of the interference suppression process is completed before the terminal device 2 causing the interference moves between cells C or disconnects a call. Therefore, the base station device 1 can increase the accuracy of identifying the terminal device 2 causing the interference, and can efficiently suppress the interference occurring between cells C.

[0172] [Interference control process in the second embodiment] Next, the interference control process in the second embodiment will be described. Figure 27 is a sequence chart diagram of the interference control process in the second embodiment. In addition, the case where interference occurs in the cell Ca described in Figure 1 etc. will be described below. In addition, the points different from the interference control process in the first embodiment will be described below.

[0173] The notification transmitting unit 116 of the base station device 1b, for example, identifies resource positions (hereinafter also referred to as predetermined resource positions) corresponding to each of the terminal devices 2a, 2b, and 2c (S201). The resource positions are, for example, positions of radio resources to be blanked in an uplink signal from the terminal device 2 to the base station device 1. Similarly, the notification transmitting unit 116 of the base station device 1c identifies, for example, a resource position corresponding to the terminal device 2d.

[0174] Specifically, the notification transmitter 116 of the base station device 1b identifies, for example, the resource position stored in the information storage area 130 of the base station device 1b. Also, the notification transmitter 116 of the base station device 1c identifies, for example, the resource position stored in the information storage area 130 of the base station device 1c.

[0175] Here, each resource position is, for example, a different position for each cell C. Therefore, each resource position may be, for example, centrally managed in another device (not shown) and notified to each base station device 1 from the other device.

[0176] Then, the notification transmitter 116 of the base station device 1b transmits a resource position notification including the resource position identified in the process of S201 to each of the terminal device 2a, the terminal device 2b, and the terminal device 2c (S202). Similarly, the notification transmitter 116 of the base station device 1c transmits a resource position notification to, for example, the terminal device 2d.

[0177] Thereafter, the interference determination unit 115 of the base station device 1a estimates the interference level that the cell Ca receives from the cell Cb or the cell Cc based on, for example, the uplink data signal received by the signal receiving unit 113 (S101). Similarly, the interference determination unit 115 of the base station device 1b estimates the interference level that the cell Cb receives from the cell Ca or the cell Cc based on, for example, the uplink data signal received by the signal receiving unit 113. Also, the interference determination unit 115 of the base station device 1c estimates the interference level that the cell Cc receives from the cell Ca or the cell Cb based on, for example, the uplink data signal received by the signal receiving unit 113.

[0178] Then, for example, if the notification transmitter 116 of the base station device 1a determines that the interference level estimated in the processing of S101 is equal to or greater than a threshold, it transmits an interference notification 141 to each of the base station device 1b and the base station device 1c (S102).

[0179] Specifically, in this case, the notification transmitter 116 of the base station device 1a transmits, for example, an interference notification 141 including the interference occurrence time.

[0180] That is, in the process of S102 in the second embodiment, unlike the process of S102 in the first embodiment, for example, an interference notification 141 that does not include a scheduled interference occurrence time is transmitted.

[0181] Next, when the scheduling unit 111 of the base station device 1b receives the interference notification 141 transmitted in the process of S102, for example, based on the received interference notification 141 and the communication state information 131 stored in the information storage area 130, it identifies one or more candidate terminal devices 2 that may be the cause of interference among the terminal devices 2 located in the cell Cb, and prioritizes scheduling of uplink data signals for the identified one or more candidate terminal devices 2 (S103). Similarly, when the scheduling unit 111 of the base station device 1c receives the interference notification 141 transmitted in the process of S102, it identifies one or more candidate terminal devices 2 that may be the cause of interference among the terminal devices 2 located in the cell Cc, based on the received interference notification 141 and the communication state information 131 stored in the information storage area 130, and prioritizes scheduling of uplink data signals for the identified one or more candidate terminal devices 2.

[0182] Specifically, in this case, the scheduling unit 111 of the base station device 1b determines the priority of each terminal device 2 located in the cell Cb based on, for example, the communication state information 131 stored in the information storage area 130. Then, the scheduling unit 111 of the base station device 1b determines one or more candidate terminal devices 2 based on, for example, the determined priority. Furthermore, in this case, the scheduling unit 111 of the base station device 1b schedules the uplink data signal for each of the one or more candidate terminal devices 2 so that the uplink data signal is scheduled at the interference occurrence scheduled time included in the received interference notification 141. Similarly, in this case, the scheduling unit 111 of the base station device 1c determines the priority of each terminal device 2 located in the cell Cc based on, for example, the communication state information 131 stored in the information storage area 130. Then, the scheduling unit 111 of the base station device 1c determines one or more candidate terminal devices 2 based on, for example, the determined priority. Furthermore, in this case, the scheduling unit 111 of the base station device 1c schedules the uplink data signal for each of the one or more candidate terminal devices 2 so that the uplink data signal is scheduled at the expected interference occurrence time included in the received interference notification 141.

[0183] Next, the signal transmission unit 112 of the base station device 1b transmits, for example, a downlink control signal including the scheduling result performed in the process of S103 and a downlink control signal instructing to blank the resource position notified in the process of S202 to each terminal device 2 located in the cell Cb (S105). Similarly, the signal transmission unit 112 of the base station device 1c transmits, for example, a downlink control signal including the scheduling result performed in the process of S103 and a downlink control signal instructing to blank the resource position notified in the process of S202 to each terminal device 2 located in the cell Cc.

[0184] Specifically, the signal transmission unit 112 of the base station device 1b transmits, for example, to each of the terminal devices 2a, 2b, and 2c, a downlink control signal including the scheduling result performed in the process of S103 and a downlink control signal instructing to blank the resource position notified in the process of S202. Similarly, the signal transmission unit 112 of the base station device 1c transmits, for example, to the terminal device 2d, a downlink control signal including the scheduling result performed in the process of S103 and a downlink control signal instructing to blank the resource position notified in the process of S202.

[0185] That is, in the process of S105 in the second embodiment, unlike the process of S105 in the first embodiment, for example, a downlink control signal for instructing to blank the resource position notified in the process of S202 is also transmitted. Also, in the second embodiment, unlike the first embodiment, for example, the process of S104 is not performed.

[0186] The downlink control signal for instructing to blank the resource position notified in the process of S202 may be, for example, in accordance with the DCI Format (DCI Format 0_0 or DCI Format 0_1) defined in 3GPP. In this case, the DCI Format may have, as an item, a "Blanking RE Indicator" to which "1" is set to instruct to blank the resource position notified in the process of S202, or "0" is set to instruct not to blank the resource position notified in the process of S202.

[0187] Then, for example, when the signal receiving unit 211 of each of the terminal devices 2a, 2b, 2c, and 2d receives the downlink control signal transmitted in the processing of S105, the signal transmitting unit 212 of each of the terminal devices 2a, 2b, 2c, and 2d transmits an uplink data signal with the resource position notified in the processing of S202 set to a blank state by using the radio resource indicated in the received downlink control signal (the radio resource indicated by the scheduling result) (S106).

[0188] Specifically, in this case, the signal transmitting units 212 of the terminal devices 2a, 2b, and 2c transmit, for example, to the base station device 1b, an uplink data signal in which the resource position notified in the process of S202 is set to a blank state. Also, in this case, the signal transmitting unit 212 of the terminal device 2d transmits, for example, to the base station device 1c, an uplink data signal in which the resource position notified in the process of S202 is set to a blank state.

[0189] Then, for example, when the interference determination unit 115 of the base station device 1a receives an uplink data signal transmitted from the cell Cb in the process of S106 (dotted line portion of S106), the interference determination unit 115 estimates the interference level received from the cell Cb (S107).

[0190] Specifically, the interference determination unit 115, for example, compares the blank resource position in the received uplink data signal with the resource position stored in the information storage area 130 of the base station device 1a to determine that the source of the received uplink data signal is cell Cb. In this case, the interference determination unit 115 then estimates, for example, the interference level received from cell Cb identified as the source of the received uplink data signal.

[0191] Thereafter, for example, if the interference determination unit 115 estimates that the interference level received from cell Cb is equal to or higher than a threshold, the notification transmission unit 116 of the base station device 1a transmits an interference identification notification to the base station device 1b corresponding to cell Cb (S108).

[0192] Furthermore, the interference determination unit 115 of the base station device 1b identifies a specific terminal device 2 that is the cause of the interference, from among the terminal devices 2 located within the cell Cb (S109).

[0193] Specifically, the interference determination unit 115 identifies the specific terminal device 2, for example, by comparing the interference occurrence time included in the interference notification 141 received in the processing of S102 with the scheduling history information 132 stored in the information storage area 130.

[0194] Thereafter, the signal transmitting unit 112 of the base station apparatus 1b transmits, for example, to the specific terminal apparatus 2 identified in the process of S109, a power control signal for reducing the transmission power of the signal to a predetermined value (S110).

[0195] As a result, the base station device 1b in this embodiment, like the first embodiment, can reduce the number of terminal devices 2 that need to schedule uplink data signals in the interference suppression process, and can shorten the time required to execute the interference suppression process. Therefore, the base station device 1b can efficiently suppress interference occurring between cells C, for example.

[0196] [First modified example of interference suppression processing] Next, a modified example of the interference suppression process in the first and second embodiments (hereinafter, also referred to as a first modified example) will be described. Fig. 28 is a diagram for explaining the first modified example.

[0197] In the first and second embodiments, the case where the CU (Central Unit) and the DU (Distributed Unit) in the base station device 1 are not separated (a single device) has been described, but the present invention is not limited to this. Specifically, the base station device 1 may be one in which, for example, the CU 11 and the DU 12 are different devices.

[0198] More specifically, when the DU 12 detects that interference occurs in the cell C corresponding to the DU 12, the DU 12 may transmit an interference notification 143 indicating that the interference has been detected to the CU 11 by using an F1 interface defined in 3GPP. Then, when the CU 11 receives the interference notification 143 from the DU 12, the CU 11 may transmit an interference notification 141 to another base station device 1 (another CU 11) by using an X2 interface or an Xn interface (S102 in FIG. 6 and FIG. 27).

[0199] Furthermore, when the CU 11 receives an interference notification 141 from another base station device 1 (another CU 11), for example, the CU 11 may transmit an interference notification 143 to the DU 12 by using the F1 interface.

[0200] In the first modified example, the notification receiving unit 114 and the notification transmitting unit 116 may be functions realized, for example, in the CU 11. In the first modified example, the scheduling unit 111, the signal transmitting unit 112, the signal receiving unit 113, and the interference determining unit 115 may be functions realized, for example, in the DU 12. A specific example of the interference notification 143 will be described below.

[0201] [Specific example of interference notification in the first modified example] Fig. 29 is a diagram for explaining a specific example of the interference notification 143. Specifically, Fig. 7 shows a specific example of the interference notification 143 when it is transmitted using the F1 interface.

[0202] 29, the interference notification 143 has, for example, items such as "Message Type" in which the message type of the interference notification 143 is set, "Transaction ID" in which identification information of the transaction corresponding to the interference notification 143 is set, and "Interference time interval information" in which the interference occurrence time is set. Furthermore, the "Interference time interval information" has, for example, items such as "Start time" in which the start time of the interference occurrence time is set, and "End time" in which the end time of the interference occurrence time is set.

[0203] Specifically, in the interference notification 143 shown in Fig. 29, for example, "19" is set as "Message Type" and "1" is set as "Transaction ID." Also, in the interference notification 143 shown in Fig. 29, for example, "SFN:0x1ED Subframe:0" is set as "Start time" in "Interference time interval information," and "SFN:0x251 Subframe:0" is set as "End time" in "Interference time interval information."

[0204] In addition, for example, UTC time or Radio frame timing may be set in the "Start time" and "End time" in FIG.

[0205] [Second modified example of interference suppression processing] Next, another modification of the interference suppression process in the first and second embodiments (hereinafter, also referred to as a second modification) will be described. Fig. 30 is a diagram for explaining the second modification.

[0206] In the first embodiment, the second embodiment, and the first modification, the case where each base station device 1 (each DU 12) communicates with each terminal device 2 located in one cell C has been described, but the present invention is not limited to this. Specifically, the base station device 1 (DU 12) may communicate with each terminal device 2 located in multiple cells C, for example.

[0207] Specifically, as shown in FIG. 30, the base station device 1 (DU 12) may communicate with, for example, terminal devices 2 (terminal device 2a, terminal device 2b, terminal device 2c, and terminal device 2d described in FIG. 1, etc.) located in each of cells Ca, Cb, and Cc described in FIG. 1, etc.

[0208] The interference determination unit 115 of the base station device 1 (DU12) may, for example, estimate the interference level that at least one of cell Ca, cell Cb, and cell Cc receives from another cell C based on the uplink data signal received by the signal receiving unit 113 (S101).

[0209] Furthermore, the notification transmitter 116 of the base station apparatus 1 (CU11) may transmit an interference notification 141 to other base station apparatuses 1 when it is determined that the interference level is equal to or higher than a threshold (S102).

[0210] Furthermore, for example, when the scheduling unit 111 of the base station device 1 (DU12) receives an interference notification 141 transmitted from another base station device 1, the scheduling unit 111 may identify one or more candidate terminal devices 2 that may be the cause of interference among the terminal devices 2 located in cells Ca, Cb, and Cc based on the received interference notification 141 and the communication status information 131 stored in the information storage area 130, and prioritize scheduling of uplink data signals for the identified one or more candidate terminal devices 2 (S103).

[0211] Furthermore, the notification transmission unit 116 of the base station device 1 (CU11) may, for example, transmit a schedule notification 142 including a scheduling result to another base station device 1 (the base station device 1 that is the source of the interference notification 141) (S104).

[0212] In addition, the signal transmission unit 112 of the base station device 1 (DU12) may, for example, transmit a downlink control signal including the scheduling result to each terminal device 2 (terminal device 2a, terminal device 2b, terminal device 2c, and terminal device 2d) located in cell Ca, cell Cb, and cell Cc (S105).

[0213] In addition, when the signal receiving unit 211 of the terminal device 2a, terminal device 2b, terminal device 2c, and terminal device 2d receives a downlink control signal transmitted from the base station device 1, the signal transmitting unit 212 may transmit an uplink data signal by using the radio resource indicated by the received downlink control signal (the radio resource indicated by the scheduling result) (S106).

[0214] Furthermore, the interference determination unit 115 of the base station device 1 (DU 12) may, for example, when receiving an uplink data signal transmitted from another cell C, estimate an interference level received from the other cell C (S107).

[0215] In addition, the notification sending unit 116 of the base station device 1 (CU11) may, for example, when the interference determination unit 115 estimates that the interference level from another cell C is equal to or higher than a threshold, send an interference identification notification to another base station device 1 corresponding to the other cell C (S108).

[0216] In addition, the interference determination unit 115 of the base station device 1 (DU12), for example, when receiving an interference identification notification from another base station device 1, may identify a specific terminal device 2 that may be the cause of interference from among the terminal devices 2 (terminal device 2a, terminal device 2b, terminal device 2c, and terminal device 2d) located in cells Ca, Cb, and Cc (S109).

[0217] Furthermore, the signal transmission unit 112 of the base station device 1 (DU 12) may transmit, for example, a power control signal for reducing the transmission power of the signal to a predetermined value to the specific terminal device 2 (S110).

[0218] The above embodiment can be summarized as follows:

[0219] (Appendix 1) A base station device that performs wireless communication with a plurality of terminal devices within a cell, a storage unit that stores communication status information regarding a state of communication between the plurality of terminal devices; a first receiving unit that receives an interference notification indicating that interference is occurring in another first cell different from the cell from another first base station device corresponding to the other first cell; and a control unit that identifies, among the plurality of terminal devices, one or more terminal devices that are more likely to be at least one cause of interference than other terminal devices based on the interference notification received by the first receiving unit and the communication state information stored in the storage unit, and prioritizes scheduling of uplink signals for the plurality of terminal devices for the identified one or more terminal devices. A base station device comprising:

[0220] (Appendix 2) Appendix 1 further states: a first transmission unit that transmits the result of the scheduling corresponding to each terminal device to each terminal device for which the control unit performed the scheduling among the plurality of terminal devices; A base station device comprising:

[0221] (Appendix 3) In Appendix 1: The interference notification includes an interference occurrence time indicating a time when the interference occurred, the communication state information includes past history information regarding the scheduling corresponding to each of the plurality of terminal devices, The control unit is Referring to the history information, it is determined whether or not the history information corresponding to the interference occurrence time included in the received interference notification exists; When it is determined that the history information corresponding to the interference occurrence time exists, the scheduling for the plurality of terminal devices is performed with a priority given to the one or more terminal devices. A base station device comprising:

[0222] (Appendix 4) In Appendix 1: The control unit is calculating, for each of the plurality of terminal devices, a priority indicating a degree of likelihood that each terminal device is at least one of the causes of interference based on the interference notification and the communication state information; identifying the one or more terminal devices based on the priority for each of the plurality of terminal devices; A base station device comprising:

[0223] (Appendix 5) In Appendix 4: the communication state information includes a data amount of the uplink signal awaiting transmission corresponding to each of the plurality of terminal devices, the control unit calculates the priority of each of the plurality of terminal devices such that the priority of a terminal device whose data amount is equal to or greater than a predetermined amount is higher than the priority of a terminal device whose data amount is less than the predetermined amount. A base station device comprising:

[0224] (Appendix 6) In Appendix 4: the communication state information includes information indicating whether each of the plurality of terminal devices is a specific terminal device that caused interference in a predetermined period in the past, the control unit calculates the priority of each of the plurality of terminal devices such that the priority of the specific terminal device is higher than the priority of terminal devices other than the specific terminal device; A base station device comprising:

[0225] (Appendix 7) Appendix 2 further states: a second transmission unit that transmits the result of the scheduling for each of the one or more terminal devices to the other first base station device; A base station device comprising:

[0226] (Appendix 8) In Appendix 7: The control unit determines whether interference occurs in the cell, When the control unit determines that the interference is occurring in the cell, the second transmission unit transmits the interference notification indicating that the interference is occurring in the cell to another second base station device. A base station device comprising:

[0227] (Appendix 9) Appendix 8 further states: a second receiving unit that receives the uplink transmitted from a terminal device in another second cell corresponding to the other second base station device; the first receiving unit receives a result of the scheduling transmitted from the other second base station device; The control unit determines whether or not the interference determined to occur in the cell is caused by a terminal device in the other second cell based on the result of the scheduling received by the first receiving unit and a reception timing of the uplink signal received by the second receiving unit; When the control unit determines that the cause of the interference determined to be occurring in the cell is a terminal device in the other second cell, the second transmission unit transmits an interference identification notification to the other second base station device indicating that the cause of the interference determined to be occurring in the cell is a terminal device in the other second cell. A base station device comprising:

[0228] (Appendix 10) In Appendix 2: The first transmission unit transmits, to each of the plurality of terminal devices, information instructing the terminal device to blank a predetermined resource position of an uplink signal to be transmitted according to a result of the scheduling. A base station device comprising:

[0229] (Appendix 11) In Appendix 10: The control unit determines whether interference occurs in the cell, When the control unit determines that the interference is occurring in the cell, the second transmission unit transmits the interference notification indicating that the interference is occurring in the cell to another second base station device. A base station device comprising:

[0230] (Appendix 12) Appendix 11 further states: a second receiving unit that receives the uplink transmitted from a terminal device in another second cell corresponding to the other second base station device; The control unit determines whether or not the cause of the interference determined to be occurring in the cell is a terminal device in the other second cell, based on whether or not the predetermined resource position of the uplink signal received by the second receiving unit is in the blank state; When the control unit determines that the cause of the interference determined to be occurring in the cell is a terminal device in the other second cell, the second transmission unit transmits an interference identification notification to the other second base station device indicating that the cause of the interference determined to be occurring in the cell is a terminal device in the other second cell. A base station device comprising:

[0231] (Appendix 13) A communication method in a base station device that performs wireless communication with a plurality of terminal devices within a cell, comprising: storing communication status information relating to a state of communication between the plurality of terminal devices in a storage unit; receiving an interference notification indicating that interference is occurring in another first cell different from the cell from another first base station device corresponding to the other first cell; Identifying one or more terminal devices among the plurality of terminal devices that are more likely to be at least one cause of interference than other terminal devices based on the received interference notification and the communication state information stored in the storage unit, and scheduling uplink signals for the plurality of terminal devices with a priority on the identified one or more terminal devices. A communication method comprising: [Explanation of symbols]

[0232] 1: Base station device 1a: Base station device 1b: Base station device 1c: Base station device 2: Terminal device 2a: Terminal device 2b: Terminal device 2c: Terminal device 2d: Terminal device 2e: Terminal device 2f: Terminal device 10: Wireless communication system 101: CPU 102: Memory 103: Communication circuit 104: Storage device 105: Bus 110: Program 130: Information storage area 201: CPU 202: Memory 203: Communication circuit 204: Storage device 205: Bus 210: Program 230: Information storage area

Claims

1. A base station device that performs wireless communication with a plurality of terminal devices within a cell, a storage unit that stores communication status information regarding a state of communication between the plurality of terminal devices; a first receiving unit that receives an interference notification indicating that interference is occurring in another first cell different from the cell from another first base station device corresponding to the other first cell; and a control unit that identifies, among the plurality of terminal devices, one or more terminal devices that are more likely to be at least one cause of interference than other terminal devices based on the interference notification received by the first receiving unit and the communication state information stored in the storage unit, and prioritizes scheduling of uplink signals for the plurality of terminal devices for the identified one or more terminal devices. A base station device comprising:

2. In claim 1, further comprising: a first transmission unit configured to transmit the result of the scheduling corresponding to each of the terminal devices to each of the terminal devices for which the control unit performed the scheduling, among the plurality of terminal devices; A base station device comprising:

3. In claim 1, The interference notification includes an interference occurrence time indicating a time when the interference occurred, the communication state information includes past history information regarding the scheduling corresponding to each of the plurality of terminal devices, The control unit is Referring to the history information, it is determined whether or not the history information corresponding to the interference occurrence time included in the received interference notification exists; When it is determined that the history information corresponding to the interference occurrence time exists, the scheduling for the plurality of terminal devices is performed with a priority given to the one or more terminal devices. A base station device comprising:

4. In claim 1, The control unit is calculating, for each of the plurality of terminal devices, a priority indicating a degree of likelihood that each terminal device is at least one of the causes of interference based on the interference notification and the communication state information; identifying the one or more terminal devices based on the priority of each of the plurality of terminal devices; A base station device comprising:

5. In claim 4, the communication state information includes a data amount of the uplink signal awaiting transmission corresponding to each of the plurality of terminal devices, the control unit calculates the priority of each of the plurality of terminal devices such that the priority of a terminal device whose data amount is equal to or greater than a predetermined amount is higher than the priority of a terminal device whose data amount is less than the predetermined amount. A base station device comprising:

6. In claim 4, the communication state information includes information indicating whether each of the plurality of terminal devices is a specific terminal device that caused interference in a predetermined period in the past, the control unit calculates the priority of each of the plurality of terminal devices such that the priority of the specific terminal device is higher than the priority of terminal devices other than the specific terminal device; A base station device comprising:

7. In claim 2, further comprising: a second transmission unit configured to transmit the result of the scheduling for each of the one or more terminal devices to the other first base station device; A base station device comprising:

8. In claim 2, The first transmission unit transmits, to each of the plurality of terminal devices, information instructing the terminal device to blank a predetermined resource position of an uplink signal to be transmitted in accordance with a result of the scheduling. A base station device comprising:

9. A communication method in a base station device that performs wireless communication with a plurality of terminal devices within a cell, comprising: storing communication status information relating to a state of communication between the plurality of terminal devices in a storage unit; receiving an interference notification indicating that interference is occurring in another first cell different from the cell from another first base station device corresponding to the other first cell; identifying one or more terminal devices among the plurality of terminal devices that are more likely to be at least one cause of interference than other terminal devices based on the received interference notification and the communication state information stored in the storage unit, and scheduling uplink signals for the plurality of terminal devices with a priority on the identified one or more terminal devices; A communication method comprising:

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