Control device, control method, communication system, and base station device

Abstract

To efficiently implement transmission power control for terminal devices.SOLUTION: A communication system includes a plurality of base station devices that form cells, a terminal device that performs wireless communication with the base station devices when located within their cells, and a control device that controls the base station devices, and the communication system controls, according to the value of path loss with the base station device with which the terminal device is communicating, the transmission power of the terminal device. The control device in the communication system includes a sharing unit that acquires from the base station device an interference measurement value measured when the base station device receives a signal from the terminal device, and a control unit that, when controlling the transmission power of a first terminal device that communicates with a first base station device, estimates a maximum amount of interference, which is the maximum amount of interference caused by the first terminal device to other base station devices other than the first base station device, and uses the maximum amount of interference to calculate a correction value to correct the transmission power of the first terminal device.SELECTED DRAWING: Figure 6

Description

[Technical field]

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

[0002] In a wireless communication system, a base station device establishes a communication area (hereinafter, sometimes referred to as a cell) in which wireless communication with a terminal device is possible. When a terminal device is located at a cell edge, the power of radio waves received by the base station device of its own cell in uplink communication is low, so that interference occurs with radio waves from terminal devices of other cells, resulting in, for example, a smaller signal-to-interference noise ratio (SINR) or a lower throughput. For this reason, in a wireless communication system, transmission power control (TPC) may be implemented to reduce interference from terminal devices of other cells.

[0003] One example of TPC is a technique called open-loop TPC (OLTPC). OLTPC is a TPC that reduces transmission power as a terminal device gets closer to a base station device of its own cell.

[0004] However, since a terminal device close to the base station device of its own cell is far from the base station device of other cells, the interference to the terminal device of other cells is small. In OLTPC, the transmission power is controlled to be reduced for a terminal device close to the base station device of its own cell even though the interference is small, which may result in a deterioration of throughput. On the other hand, in OLTPC, a terminal device located at the edge of a cell has high transmission power, but the interference to the terminal device of other cells is also large, so that the overall throughput may be improved by reducing the transmission power and reducing the interference.

[0005] Therefore, in addition to the control by OLPTC, interference to other cells may be suppressed by determining the transmission power using a correction value that takes into account the path loss in other cells.

[0006] A communication system that takes into consideration interference with other cells is described in, for example, the following documents. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] JP 2013-90164 A [Patent Document 2] JP 2010-166604 A [Non-patent literature]

[0008] [Non-Patent Document 1] M. Boussif, N. Quintero, FD Calabrese, C. Rosa, and J. Wigard, “Interference Based Power Control Performance in LTE Uplink”, in Proc. of 2008 IEEE International Symposium on Wireless Communication System, pp.698-702, 2008. Summary of the Invention [Problem to be solved by the invention]

[0009] However, the method of calculating or estimating the path loss in other cells used in calculating the correction value has not been decided. For example, if the path loss is measured for all combinations of terminal devices and base station devices, the measurement time and processing load will be large, and it may not be possible to guarantee real-time transmission power control.

[0010] Therefore, one disclosure provides a control device, a control method, a communication system, and a base station device that efficiently perform transmission power control of a terminal device. [Means for solving the problem]

[0011] A control device in a communication system having a plurality of base station devices that form a cell, a terminal device that performs wireless communication with the base station device when located within the cell, and a control device that controls the base station device, and controls the transmission power of the terminal device depending on the value of path loss with the base station device with which it is communicating, the control device having a sharing unit that acquires from the base station device an interference measurement value measured when the base station device receives a signal from the terminal device, and a control unit that, when controlling the transmission power of a first terminal device that communicates with a first base station device, estimates a maximum amount of interference, which is the maximum amount of interference caused by the first terminal device to base station devices other than the first base station device, and uses the maximum amount of interference to calculate a correction value to correct the transmission power of the first terminal device. Effect of the Invention

[0012] One aspect of the present invention makes it possible to efficiently control the transmission power of a terminal device. [Brief description of the drawings]

[0013] [Figure 1] FIG. 1 is a diagram showing an example of the configuration of a wireless communication system 10. As shown in FIG. [Diagram 2] FIG. 2 is a diagram illustrating an example of the configuration of the RIC 300. [Diagram 3] FIG. 3 is a diagram showing an example of the configuration of the wireless communication system 10. As shown in FIG. [Figure 4] FIG. 4 is a diagram illustrating an example of the configuration of the base station device 200. As shown in FIG. [Diagram 5] FIG. 5 is a diagram showing an example of a formula used in the OLTPC. [Figure 6] FIG. 6 is a diagram illustrating an example of a software configuration of the wireless communication system 10. As shown in FIG. [Figure 7] FIG. 7 is a diagram showing an example of interference in the wireless communication system 10. In FIG. [Figure 8] FIG. 8 is a diagram showing an example of an equation for calculating the second correction value. [Figure 9] FIG. 9 is a diagram showing an example of a processing flowchart of the transmission output control process S100 in the RIC 300. [Figure 10] FIG. 10 is a diagram showing an example of an equation used in the transmission power control. [Figure 11] FIG. 11 is a diagram showing an example of an equation used in the transmission power control. [Figure 12] FIG. 12 is a diagram illustrating an example of a software configuration of the wireless communication system 10 in a modification of the first embodiment. [Figure 13] FIG. 13 is a diagram illustrating an example of a software configuration of the wireless communication system 10 in the second embodiment. [Figure 14] FIG. 14 is a diagram showing an example of radio wave measurement in the terminal device 100-1 of the wireless communication system 10. In FIG. [Figure 15] FIG. 15 is a diagram showing an example of a process flowchart of the transmission power control S200 in the base station device 200. [Figure 16] FIG. 16 is a diagram showing an example of an equation used to calculate the second correction value. [Figure 17] FIG. 17 is a diagram illustrating an example of a software configuration of the wireless communication system 10 in a modified example of the second embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0014] [First embodiment] A first embodiment will be described.

[0015] <About the wireless communication system 10> 1 is a diagram showing an example of the configuration of a wireless communication system 10. The wireless communication system 10 includes a Radio access network Intelligent Controller (RIC) 300, base station devices 200-1 to 3, and terminal devices 100-1 to 3. The wireless communication system 10 is a system in which the RIC 300 performs transmission power control (TPC) of the terminal devices 100-1 to 3 via the base station devices 200-1 to 3.

[0016] The base station apparatuses 200-1 to 200-3 (hereinafter sometimes referred to as the base station apparatus 200) are apparatuses that perform wireless communication with the terminal apparatuses 100-1 to 100-3 (hereinafter sometimes referred to as the terminal apparatus 100), and are, for example, eNodeBs or gNodeBs. Further, the base station apparatus 200 may be composed of one unit, or may be composed of a plurality of units such as a CU (Central Unit) and a DU (Distributed Unit). Further, the base station apparatus 200 constitutes a communication area (cell) that is an area where the terminal apparatus 100 performs wireless communication with the self-apparatus. The base station apparatuses 200-1 to 200-3 respectively constitute cells C1 to C3. In FIG. 1, the cells C1 to C3 do not overlap, but may overlap.

[0017] The terminal apparatus 100 is a communication apparatus that wirelessly connects to the base station apparatus 200 and performs wireless communication, and is, for example, a wireless communication device such as a smartphone or a tablet terminal. Since the terminal apparatus 100-1 is located within the cell C1, it performs wireless communication with the base station apparatus 200-1. The terminal apparatus 100-2 performs wireless communication with the base station apparatus 200-2, and the terminal apparatus 100-3 performs wireless communication with the base station apparatus 200-3. Note that the terminal apparatuses 100-1 to 100-3 can each move. Further, the terminal apparatuses 100-1 to 100-3 may communicate with other base station apparatuses 200.

[0018] The RIC 300 is a control apparatus that controls the base station apparatus 200 and the terminal apparatus 100, and is, for example, a server machine or a computer. The RIC 300 performs transmission output control (TPC) of the terminal apparatus 100. The RIC 300 acquires the radio wave measurement results from the base station apparatus 200. The base station apparatus 200 receives signals from the terminal apparatuses 100 in its own cell or / and other cells, for example, and performs measurements. The measurement values include, for example, values related to received power (e.g., RSRP: Reference Signal Received Power) and values related to interference (e.g., signal-to-interference-plus-noise ratio: SINR). The RIC 300 performs transmission output control regularly or irregularly based on the measurement results.

[0019] <Configuration Example of RIC300> 2 is a diagram showing an example of the configuration of the RIC 300. The RIC 300 includes a CPU (Central Processing Unit) 310, a storage 320, a memory 330, and a communication circuit 340.

[0020] The storage 320 is an auxiliary storage device that stores programs and data, such as a flash memory, a hard disk drive (HDD), a solid state drive (SSD), etc. The storage 320 stores a transmission output control program 321 and a measurement data table 322.

[0021] The measured data table 322 is a table that stores measurement values ​​of the radio conditions measured by the base station device 200. The RIC 300 stores the measurement values ​​acquired from the base station device 200 in the measured data table 322 and refers to them in the transmission output control process.

[0022] The memory 330 is an area into which the programs stored in the storage 320 are loaded. The memory 330 may also be used as an area in which the programs store data.

[0023] The communication circuit 340 is a device that communicates with the base station device 200. The base station device 200 and the RIC 300 are connected via the communication circuit 340 by wire.

[0024] FIG. 3 is a diagram showing a configuration example of a wireless communication system 10. FIG. 3 shows an example of a wireless communication system defined by an open interface, and is an excerpt of "Figure 3.3.3-1: Flat Model" in "O-RAN.WG1.OAM-Architecture-v04.00". The RIC is standardized by, for example, the "O-RAN ALLIANCE", and is a device that controls and optimizes RAN functions. In FIG. 3, the RIC 300 is, for example, a "Non-Real Time RIC" or a "Near-Real Time RAN Intelligent Controller (RIC)". In FIG. 3, the base station device 200 is an "O-CU-CP", an "O-CU-UP", an "O-DU", and an "O-RU".

[0025] When the RIC 300 is a “Near-Real Time RAN Intelligent Controller (RIC)”, communication with the base station device 200 is performed over an E2 interface.

[0026] When the RIC 300 is a "Non-Real Time RIC", communication with the base station device 200 is performed via a "Near-Real Time RAN Intelligent Controller (RIC)". Communication between the RIC 300 and the "Near-Real Time RAN Intelligent Controller (RIC)" is performed on an A1 interface, and communication between the "Near-Real Time RAN Intelligent Controller (RIC)" and the base station device 200 is performed on an E2 interface.

[0027] Returning to FIG. 2, the CPU 310 is a processor that loads a program stored in the storage 320 into the memory 330, executes the loaded program, configures each unit, and realizes each process.

[0028] The CPU 310 executes the transmission power control program 321 to, for example, construct a control unit and a shared unit, and perform transmission power control processing. The transmission power control processing is processing for controlling the transmission power of the terminal device 100. In the transmission power control processing, the RIC 300 acquires radio measurement values ​​from each base station device 200, calculates the transmission power of the terminal device 100 based on the measurement values, and controls the transmission power of the terminal device 100 via the base station device 200.

[0029] <Example of configuration of base station device 200> 4 is a diagram showing an example of the configuration of the base station device 200. The base station device 200 includes a CPU 210, a storage 220, a memory 230, a communication circuit 240, and a wireless communication circuit 250.

[0030] The storage 220 is an auxiliary storage device such as a flash memory, a HDD, or an SSD that stores programs and data. The storage 220 stores a wireless communication program 221 and a radio wave measurement program 222.

[0031] The memory 230 is an area into which the programs stored in the storage 220 are loaded. The memory 230 may also be used as an area in which the programs store data.

[0032] The communication circuit 240 is a device that communicates with the RIC 300. The base station device 200 and the RIC 300 are connected by wire via the communication circuit 240.

[0033] The wireless communication circuit 250 is a device that performs wireless communication with the terminal device 100. The wireless communication circuit 250 has, for example, an antenna, and transmits and receives radio waves (signals) to and from the terminal device 100.

[0034] The CPU 210 is a processor that loads programs stored in the storage 220 into the memory 230, executes the loaded programs, configures each unit, and realizes each process.

[0035] The CPU 210 executes the wireless communication program 221 to construct, for example, a measurement unit, an acquisition unit, a control unit, and an estimation unit, and to perform wireless communication processing. The wireless communication processing is processing for controlling wireless communication with the terminal device 100. In the wireless communication processing, the base station device 200 instructs the terminal device 100 on transmission output and notifies the terminal device 100 of a correction value.

[0036] The CPU 210 executes the radio wave measurement program 222 to, for example, construct a measurement unit and perform radio wave measurement processing. In the radio wave measurement processing, the reception power and the degree of interference when signals are received from the terminal device 100 in the own cell and the terminal device 100 in another cell are measured.

[0037] <oltpc> The OLTPC and the correction means will now be described. Fig. 5 is a diagram showing an example of an equation used in the OLTPC and the correction means.

[0038] Equation (1) is a formula for calculating the transmission output of the terminal device 100 in OCTPC. P OL is the transmission output of the terminal device 100. max is the maximum transmission power of the terminal device 100. M is the number of resource blocks allocated to the terminal device 100. P0 is the target received power. α is a path loss compensation coefficient. PL is the path loss. P0 and α are notified in advance from the base station device 200 to the terminal device 100. PL is a value calculated from a reference signal received on the terminal device 100 side.

[0039] Equation (2) is a formula for calculating the transmission output when a correction value is present. Correction is the correction value.

[0040] Equation (3) is used to calculate the correction value. own is the path loss of the own cell, PL oth is the path loss of the adjacent cell (other cell) PL i I0 is an upper limit of any interference. psd is the transmission power per 1 RB (resource block) at the latest time when the terminal device 100 communicated. β and γ are weights (coefficients). i is the ID (identifier) ​​of the neighboring cell. N cell is the total number of adjacent cells. In addition, β+γ=1. Each value is expressed in dB.

[0041] As shown in formulas (1) to (3), the transmission output is calculated using the OLTPC and a correction means. Note that, in formula (2), an interference (interference) value is used, but in many cases, the RIC 300 cannot acquire (estimate, calculate) the value of interference from each terminal device 100 to each cell.

[0042] Therefore, the RIC 300 may substitute a second correction value calculated by a second correction value calculation method described below for the correction value.

[0043] <Software configuration> The following describes a software configuration of the wireless communication system 10. Fig. 6 is a diagram showing an example of a software configuration of the wireless communication system 10. Note that each unit is constructed by the processors of the base station device 200 and the RIC 300 executing a program.

[0044] The base station device 200 includes a communication unit 21, a scheduling unit 22, an interference measurement unit 23, a transmission power control unit 24, a data sharing unit 25, and a DB 26.

[0045] The communication unit 21 performs wireless communication with the terminal device 100. The communication unit 21 performs functions such as notifying parameters in transmission power control, receiving measurement values, and storing the received values ​​in the DB 26.

[0046] The scheduling unit 22 performs resource management for the terminal device 100, and controls the communication timing and resource blocks of the terminal device 100.

[0047] The interference measurement unit 23 measures the interference power from the terminal device 100 of another cell, and stores the measured interference power in the DB 26. The interference measurement unit 23 receives, for example, a pilot signal transmitted by the terminal device 100, and measures the interference power at the time of reception.

[0048] The transmission power control unit 24, following the instruction from the RIC 300, notifies the terminal device 100 using a TPC command or the like so that the terminal device 100 has the instructed transmission power.

[0049] The data sharing unit 25 transmits various data stored in the DB 26 to the data sharing unit 33 of the RIC 300 .

[0050] The DB 26 is a storage unit that stores various data.

[0051] The RIC 300 includes a transmission power correction value calculation unit 31, a maximum interference estimation unit 32, a data sharing unit 33, and a DB .

[0052] The transmission power correction value calculation unit 31 calculates a second correction value from the maximum interference of a certain terminal device 100. In addition, the transmission power correction value calculation unit 31 notifies the terminal device 100 of the second correction value.

[0053] The maximum interference estimation unit 32 estimates the maximum interference that a certain terminal device 100 causes to an adjacent cell.

[0054] The data sharing unit 33 stores in the DB 33 the data received from the base station device 200 and the data calculated and estimated by the own device.

[0055] The DB 33 is a storage unit that stores various data.

[0056] <Second correction value calculation method> A method for calculating the second correction value will be described. FIG. 7 is a diagram showing an example of interference in the wireless communication system 10. ij For example, I indicates the interference that the terminal device 100-i causes to the cell Cj. 12 ~I 52 The arrows in the figure indicate the interference that each terminal device 100 causes to an adjacent cell, and the thicker the arrow, the greater the interference. ij I ij The total interference amount (total interference power) of the cell Cj, which necessarily includes

[0057] 7, it is assumed that the terminal device 100-1 is located in cell C1, the terminal devices 100-2 to 100-4 are located in cell C2, and the terminal devices 100-5 to 7 are located in cell C3. It is assumed that the terminal device 100-1 is always in communication in cell C1, the terminal devices 100-2, 3, and 4 are in communication in that order in cell C2, and the terminal devices 100-5, 6, and 7 are in communication in that order in cell C3.

[0058] 8 is a diagram showing an example of an equation for calculating the second correction value. Hereinafter, the method for calculating the second correction value will be described with reference to FIGS.

[0059] The total amount of interference received by cell C2 and cell C3 is expressed by equations (11) and (12), respectively. The "or" in equations (11) and (12) indicates that the amounts vary depending on the timing.

[0060] RIC300 is a CI 12 and CI 13 Minimum value of (CI 12,min and CI 13,min ) is calculated using formulas (13) and (14). RIC300 is calculated by the CI 12 and CI 13 The minimum value of I 12 and I 13 It is considered that.

[0061] For example, I 12 But other I 52 , I 62 , and I 72 If CI is sufficiently larger than either 12,min I 12 Even if the above is not satisfied, if there are many terminal devices 100 and the CI 12 If there are many combinations of I i2 becomes small enough that CI 12,min I 12 As a result, the RIC300 can be approximated by CI 12,min and CI 13,min I 12 and I 13 It can be regarded as:

[0062] The RIC 300 calculates the maximum interference (CI 1、max The maximum interference is calculated as CI 12,min and CI 13,min In the case of Figure 7, I 12 I 13 Since it is larger than (thick arrow), CI 12,min It is calculated (estimated) as follows.

[0063] It is possible to estimate the path loss to the maximum interfering cell by subtracting the maximum interference from the transmission power of the terminal device 100-1. min This is expressed as:

[0064] The RIC 300 calculates the second correction value using the correction value calculation formula (3) in FIG. oth P.L. min is used (see equation (16)).

[0065] In calculating the correction value of the OLTPC, the RIC 300 calculates the correction value using only the maximum interference to adjacent cells, not the total value of the interference to each cell. As a result, even if it is not possible to measure all the interference in all cells, or if it takes time and processing to estimate the total value of the interference, it is only necessary to calculate the maximum interference, and therefore the correction value (second correction value) can be calculated efficiently.

[0066] <Transmission power control process> 9 is a diagram showing an example of a processing flowchart of the transmission output control process S100 in the RIC 300.

[0067] The transmission output control process S100 is a process executed after the terminal device 100 performs OLPTC (Equation (1) in FIG. 5), for example, and is a process for calculating and notifying a correction value.

[0068] The RIC 300 acquires measurement data in each cell (base station device 200) (S100-2). The measurement data is data stored in the base station device 200, and includes, for example, the degree of interference (SINR), received power (RSRP), a path loss estimate, the number of resource blocks, and the like. The measurement data is stored, for example, in association with time. The RIC 300 stores the acquired measurement data for each terminal device 100 (in association with each other).

[0069] If the number of measurements at the base station device 200 is not equal to or greater than the predetermined number (No in S100-3), the RIC 300 waits for the next measurement at the base station device 200 and acquires the measurement value (S100-2). The RIC 300 repeats this process until the number of measurements reaches the predetermined number.

[0070] If the number of measurements in the base station device 200 is equal to or greater than the predetermined number (Yes in S100-3), the RIC 300 estimates the path loss of the most interfering cell (S100-4).

[0071] The RIC 300 calculates a second correction value using the estimated path loss of the maximum interfering cell (S100-5), and performs transmission power control using the second correction value (S100-6). After that, the RIC 300 repeats this process periodically or irregularly.

[0072] The following describes transmission power control in the entire wireless communication system, including the above-described transmission output control process S100 in the RIC 300. Note that Figs. 10 and 11 are diagrams showing examples of equations used in transmission power control.

[0073] The terminal device 100 transmits a power headroom (PHR) to the base station device 200, for example, periodically. The PHR includes, for example, information on the transmission power margin of the terminal device 100. The base station device 200 can control the transmission power of the terminal device 100 by acquiring the PHR.

[0074] Upon receiving the PHR, the base station device 200 calculates the transmission power of the terminal device 100 using Equation 21. x,i (t) indicates the transmission output of the terminal device 100-i at time t. i (t) indicates the transmission power margin of the terminal device 100-i at time t. max,i (t) indicates the maximum transmission power of the terminal device 100-i at time t. The base station device 200 stores the transmission power of the terminal device 100 in association with the identifier (UEID) of the terminal device 100 and the time.

[0075] The base station apparatus 200 calculates the path loss to the own cell using equation (22). own,i (t) indicates the path loss to the own cell of the terminal device 100-i at time t. i (t) indicates the received power of the PUSCH etc. at the first transmission including the PHR from the terminal device 100-i at time t. The base station device 200 stores the path loss to the own cell of the terminal device 100 in association with the identifier (UEID) of the terminal device 100 and the time.

[0076] After performing the scheduling, the base station device 200 stores the time at which radio resources are allocated to the terminal device 100, the identifier of the resource block, and the identifier of the terminal device 100.

[0077] The base station device 200 measures interference power during communication, and stores the time, the resource block identifier, and the interference power corresponding to each resource block.

[0078] The base station device 200 transmits and shares these stored values ​​to the RIC 300. This sharing process corresponds to, for example, process S100-2 in FIG.

[0079] RIC300 is the CI at time t ij is calculated using equation (23). num,i (t) indicates the number of resource blocks allocated to the terminal device 100-i at time t. RB i (t) denotes a set of resource blocks allocated to the terminal device 100-i at time t. ij (t, k) denotes the amount of interference (interference power) of a resource block with an identifier k received by a cell Cj at time t.

[0080] The RIC300 is the minimum interference value CI ij,min is calculated using equation (24).

[0081] The RIC300 calculates the maximum interference value CI using equation (25). j,max Equation (25) is a formula for estimating the maximum interference amount (maximum interference power) from the minimum value of interference of each adjacent cell.

[0082] The RIC 300 acquires the latest transmission power, the latest path loss to the own cell, and the number of used resource blocks of the terminal device 100. The RIC 300 acquires these values ​​from, for example, stored measurement data.

[0083] The RIC 300 calculates the transmission power psd per resource block of the terminal device 100. i is calculated using equation (26).

[0084] And the RIC300 is the path loss PL oth,i is calculated using equation (27). A series of processes for calculating the path loss to the maximum interfering cell corresponds to, for example, process S100-4 in FIG.

[0085] RIC300 is the second correction value i ) is calculated using equation (28). PL oth,i is the path loss to the most interfering cell as described above.

[0086] The RIC 300 transmits the second correction value to the base station device 200. The base station device 200 notifies the terminal device 100 using a TPC command in accordance with the second correction value transmitted from the RIC 300 so that the terminal device 100 has a predetermined transmission power. Alternatively, the RIC 300 calculates the corrected target received power P0' from the second correction value using equation (29). The RIC 300 transmits the corrected target received power to the base station device 200. The base station device 200 notifies the terminal device 100 of the corrected target received power transmitted from the RIC 300 using RRC reconfiguration or the like, and controls the transmission power to be the predetermined transmission power.

[0087] <Modification> A description will now be given of a modified example of the first embodiment. Fig. 12 is a diagram showing an example of the software configuration of the wireless communication system 10 in the modified example of the first embodiment.

[0088] In the modification of the first embodiment, the base station device 200 has a transmission power correction value calculation unit 31 and a maximum interference estimation unit 32. The base station device 200 estimates the maximum interference and calculates the transmission power correction value. Note that the measurement data in each base station device 200 is shared in the DB 34 via the data sharing unit 33 of the RIC 300, as in the first embodiment.

[0089] [Second embodiment] A second embodiment will now be described. In the second embodiment, a base station device 200 uses measurement data in a terminal device 100 to estimate the sum of path losses to adjacent cells.

[0090] <Software configuration> A software configuration of the wireless communication system 10 in the second embodiment will be described. Fig. 13 is a diagram showing an example of a software configuration of the wireless communication system 10 in the second embodiment. Note that each unit is constructed by the processors of the base station device 200 and the terminal device 100 executing a program.

[0091] The base station apparatus 200 includes a communication unit 21, a transmission power control unit 24, a transmission power correction value calculation unit 31, a path loss estimation unit 41, and a DB .

[0092] The base station device 200 acquires the measurement data from the terminal device 100 via the communication unit 21 and stores it in the DB 26 .

[0093] The path loss estimation unit 41 estimates the sum of path losses to adjacent cells based on measurement data of the terminal device 100 .

[0094] The transmission power correction value calculation unit 31 calculates a second correction value from the estimated path loss sum.

[0095] The terminal device 100 includes a communication unit 11, a transmission power adjustment unit 12, an RSRP / SINR estimation unit 13, an RSRP / SINR notification unit 14, and a DB 15.

[0096] The communication unit 11 performs wireless communication with the base station device 200 .

[0097] The transmission power adjustment unit 12 adjusts the transmission power according to an instruction from the base station device 200 .

[0098] The RSRP / SINR estimation unit 13 receives a signal from the base station device 200 , measures or calculates (estimates) the RSRP and SINR, and stores the respective values ​​in the DB 15 .

[0099] The RSRP / SINR notification unit 14 notifies the base station device 200 in communication with the base station device 200 of the measurement data including the RSRP / SINR.

[0100] <Second correction value calculation method> A method of calculating the second correction value will be described. Fig. 14 is a diagram showing an example of radio wave measurement in a terminal device 100-1 of a wireless communication system 10. As shown in Fig. 14, the terminal device 100-1 is in communication with a base station device 200-1, and receives radio waves from adjacent base station devices 200-2 and 3 to perform measurements. The terminal device 100-1 measures or calculates, for example, RSRP and SINR when receiving a reference signal or a synchronization signal transmitted by the base station device 200. Note that the measurement data may include values ​​calculated (estimated) based on measurement values ​​and various data in addition to measurement values.

[0101] FIG. 15 is a diagram showing an example of a process flowchart of the transmission power control S200 in the base station device 200.

[0102] The transmission output control process S100 is a process executed after the terminal device 100 performs OLPTC (Equation (1) in FIG. 5), for example, and is a process for calculating and notifying a correction value.

[0103] The base station device 200 acquires measurement data of the terminal device 100 in its own cell (S200-2). The measurement data is data stored in the terminal device 100, and includes, for example, RSRP, SINR, and the like. The measurement data is stored in association with, for example, time. The base station device 200 stores the acquired measurement data for each terminal device 100 (in association with each other).

[0104] If the number of measurements by the terminal device 100 is not equal to or greater than the predetermined number (No in S200-3), the base station device 200 waits for the next measurement by the terminal device 100 and acquires measurement data (S200-2). The base station device 200 repeats this process until the number of measurements reaches the predetermined number.

[0105] If the number of measurements made by the terminal device 100 is equal to or greater than the predetermined number of times (Yes in S200-3), the base station device 200 estimates the total path loss to adjacent cells (S200-4).

[0106] The base station device 200 calculates a second correction value using the estimated path loss sum (S200-5), and performs transmission power control using the second correction value (S200-6). After that, the base station device 200 repeats this process periodically or irregularly.

[0107] 16 is a diagram illustrating an example of an equation used to calculate the second correction value. Estimation of the total path loss in the base station device 200 will be described.

[0108] The base station device 200 calculates the sum of path losses of adjacent cells PL based on the measurement data of the terminal device 100. oth Estimate.

[0109] The SINR can be expressed, for example, in dB units as shown in Equation (30), where N denotes thermal noise power and I denotes interference power.

[0110] The interference power I can be expressed, for example, as in equation (31). cell is the total number of neighbor cells, and i is the cell identifier. L,i denotes the downlink transmission power of the base station device 200 of the cell identifier i. i indicates the path loss between the base station device 200 and the terminal device 100 of the cell identifier i.

[0111] Assuming that the downlink transmit power of each cell is the same, PL oth can be expressed as equation (32).

[0112] In this way, the total path loss can be estimated from the RSRP, the SINR, the thermal noise power, and the downlink transmission power. The base station device 200 uses the estimated total path loss to calculate a transmission power correction value using, for example, equation (3).

[0113] It is assumed that the thermal noise power is a value at room temperature, and the downlink transmission power is a value of the own cell (own device).

[0114] <Modification> A modified example of the second embodiment will be described. Fig. 17 is a diagram showing an example of a software configuration of a wireless communication system 10 in a modified example of the second embodiment. Note that the software configuration of the terminal device 100 is the same as that of the second embodiment, and therefore will not be described.

[0115] In the modified example of the second embodiment, the RIC 300 includes a transmission power correction value calculation unit 31 and a path loss estimation unit 41. The RIC 300 estimates the total path loss and calculates the transmission power correction value. Note that the measurement data (measurement data of the terminal device 100) stored in each base station device 200 is shared in the DB 34 via the data sharing unit 33 of the RIC 300, as in the first embodiment.

[0116] In the modified example, by sharing the measurement data in the RIC 300, for example, it is possible to reduce the calculation cost in the base station device 200 and to support multiple vendors by using an open interface.

[0117] [Other embodiments] In each embodiment, the RIC 300 may be either "Non-Real Time RIC" or "Near-Real Time RAN Intelligent Controller (RIC)".

[0118] Also, to implement each embodiment, for example, the following interfaces (information elements) are added.

[0119] <Information elements from the base station device 200 to the RIC 300> · Transmission power information It includes the identifier of the terminal device 100, time, and transmission power.

[0120] · Path loss information It includes the identifier of the terminal device 100, time, and path loss.

[0121] · Scheduling information It includes the identifier of the terminal device 100, the identifier of the resource block, and time.

[0122] · Interference information It includes the identifier of the base station device, time, the identifier of the resource block, and interference power.

[0123] <Information elements from the RIC 300 to the base station device 200> · Transmission power correction value information It includes the identifier of the terminal device 100, the transmission power correction value (including the second correction value) or the transmission output considering the transmission power correction value.

[0124] The information elements are added, for example, in the E2 interface, A1 interface, or O1 interface in FIG. 3.

[0125] Summarizing below, it is as follows in the appendix.

[0126] (Appendix 1) A control device for controlling the base station devices, the control device being in a communication system including a plurality of base station devices constituting a cell, a terminal device that performs wireless communication with the base station devices when located within the cell, and the base station devices, the control device controlling the base station devices and controlling transmission power of the terminal device in accordance with a path loss value between the terminal device and the base station device in communication, a sharing unit that acquires from the base station device an interference measurement value measured when the base station device receives a signal from the terminal device; and a control unit that, when controlling the transmission power of a first terminal device that communicates with a first base station device, estimates a maximum amount of interference, which is the maximum amount of interference caused by the first terminal device to other base station devices other than the first base station device, and calculates a correction value for correcting the transmission power of the first terminal device using the maximum amount of interference. Control device.

[0127] (Appendix 2) When the maximum amount of interference is interference to a second base station device, the control unit regards a sum of interference to the second base station device as the maximum amount of interference, calculates a sum of path losses to the second base station device from the sum of interference to the second base station device, and calculates the correction value using the sum of path losses. 2. The control device according to claim 1.

[0128] (Appendix 3) The communication system is defined with an open interface; The control device includes a Near-Real Time RAN Intelligent Controller. 2. The control device according to claim 1.

[0129] (Appendix 4) The communication system is defined with an open interface; The control device includes a Non-Real Time RIC. 2. The control device according to claim 1.

[0130] (Appendix 5) The transmission power control includes OLPTC (Open-loop Transmission Power Control). 2. The control device according to claim 1.

[0131] (Appendix 6) A control device for controlling the base station devices, the control device being in a communication system including a plurality of base station devices constituting a cell, a terminal device that performs wireless communication with the base station devices when located within the cell, and the base station devices, the control device controlling the base station devices and controlling transmission power of the terminal device in accordance with a path loss value between the terminal device and the base station device in communication, a measurement unit that measures interference when a signal is received from the terminal device, transmits the measured interference measurement value to the control device, and stores the measured interference measurement value in the control device; A control unit that, when controlling the transmission power of a terminal device that communicates, estimates a maximum amount of interference that is the maximum amount of interference caused by the terminal device to other base station devices, calculates a correction value using the maximum amount of interference, and corrects the transmission power of the terminal device using the correction value. Base station equipment.

[0132] (Appendix 7) A communication system including a plurality of base station devices constituting a cell, a terminal device that performs wireless communication with the base station device when located within the cell, and a control device that controls the base station device, the communication system controlling a transmission power of the terminal device in accordance with a path loss value between the terminal device and the base station device in communication, The base station device transmits to the control device a measurement value of interference measured when receiving a signal from the terminal device; The control device stores the measured value, and when controlling the transmission power of the terminal device, estimates a maximum amount of interference that is the maximum amount of interference to a base station device other than the base station device with which the terminal device is communicating, and calculates a correction value for correcting the transmission power of the first terminal device using the maximum amount of interference; The base station device in communication controls the terminal device so that the transmission power is corrected using the correction value. Communication systems.

[0133] (Appendix 8) A control method for a communication system including a plurality of base station devices constituting a cell, a terminal device that performs wireless communication with the base station devices when located within the cell, and a control device that controls the base station devices, the control device controlling the base station devices, the control method comprising the steps of: acquiring, from the base station device, an interference measurement value measured when the base station device receives a signal from the terminal device; When controlling the transmission power of a first terminal device that communicates with a first base station device, a maximum amount of interference, which is the maximum amount of interference caused by the first terminal device to other base station devices other than the first base station device, is estimated, and a correction value for correcting the transmission power of the first terminal device is calculated using the maximum amount of interference. Control methods.

[0134] (Appendix 9) A base station device in a communication system includes a plurality of base station devices constituting a cell, and a terminal device that performs wireless communication with the base station device when the terminal device is located within the cell, the base station device controlling transmission power in accordance with a path loss value between the base station device and the terminal device in communication, an acquisition unit that acquires measurement data measured when the terminal device receives a signal from the base station device; and a control unit that, when controlling the transmission power of the terminal device during communication, estimates a sum of path losses for the other base station devices, including the path losses of the terminal device for the other base station devices, using the measurement data, and calculates a correction value for correcting the transmission power of the terminal device using the estimated sum of path losses. Base station equipment.

[0135] (Appendix 10) The measurement data includes a received power of the signal and a signal-to-interference-and-noise ratio calculated from the received power. 10. The base station apparatus of claim 9.

[0136] (Appendix 11) In the open interface, communication between the base station device and the control device is performed using any one of an E2 interface, an O1 interface, and an A1 interface. 5. The control device according to claim 3 or 4.

[0137] (Appendix 12) The control unit calculates an amount of interference using thermal noise power in the estimation, and estimates the sum of the path losses using the calculated amount of interference. 11. The base station apparatus of claim 10. [Explanation of symbols]

[0138] 10: Wireless communication systems 11: Communications Department 12: Transmission power adjustment unit 13:SINR estimation part 14:SINR Notification Department 21: Communications Department 22: Scheduling section 23: Interference measurement section 24: Transmission power control section 25: Data sharing section 31: Transmission power correction value calculation unit 32: Maximum interference estimator 33: Data sharing section 41: Path loss estimation unit 100: Terminal device 200:Base station equipment 210: CPU 220: Storage 221: Wireless communication program 222: Radio wave measurement program 230: Memory 240: Communication circuit 250: Wireless communication circuit 300:RIC 310: CPU 320: Storage 321: Transmission power control program 322: Measurement data table 330: Memory 340: Communication circuit< / oltpc>

Claims

1. A control device for controlling the base station devices, the control device being in a communication system including a plurality of base station devices constituting a cell, a terminal device that performs wireless communication with the base station devices when located within the cell, and the base station devices, the control device controlling the base station devices and controlling transmission power of the terminal device in accordance with a path loss value between the terminal device and the base station device in communication, a sharing unit that acquires from the base station device an interference measurement value measured when the base station device receives a signal from the terminal device; and a control unit that, when controlling the transmission power of a first terminal device that communicates with a first base station device, estimates a maximum amount of interference that is the maximum amount of interference caused by the first terminal device to other base station devices other than the first base station device, and calculates a correction value for correcting the transmission power of the first terminal device using the maximum amount of interference. Control device.

2. When the maximum amount of interference is interference to a second base station device, the control unit regards a sum of interference to the second base station device as the maximum amount of interference, calculates a sum of path losses to the second base station device from the sum of interference to the second base station device, and calculates the correction value using the sum of path losses. The control device according to claim 1.

3. The communication system is defined with an open interface; The control device includes a Near-Real Time RAN Intelligent Controller. The control device according to claim 1.

4. The communication system is defined with an open interface; The control device includes a Non-Real Time RIC. The control device according to claim 1.

5. The control of the transmission power includes OLPTC (Open-loop Transmission Power Control). The control device according to claim 1.

6. A control device for controlling the base station devices, the control device being in a communication system including a plurality of base station devices constituting a cell, a terminal device that performs wireless communication with the base station devices when located within the cell, and the base station devices, the control device controlling the base station devices and controlling transmission power of the terminal device in accordance with a path loss value between the terminal device and the base station device in communication, a measurement unit that measures interference when a signal is received from the terminal device, transmits the measured interference measurement value to the control device, and stores the measured interference measurement value in the control device; A control unit that, when controlling the transmission power of a terminal device that communicates, estimates a maximum amount of interference that is the maximum amount of interference caused by the terminal device to other base station devices, calculates a correction value using the maximum amount of interference, and corrects the transmission power of the terminal device using the correction value. Base station equipment.

7. A communication system including a plurality of base station devices constituting a cell, a terminal device that performs wireless communication with the base station device when located within the cell, and a control device that controls the base station device, the communication system controlling a transmission power of the terminal device in accordance with a path loss value between the terminal device and the base station device in communication, The base station device transmits to the control device a measurement value of interference measured when receiving a signal from the terminal device; The control device stores the measured value, and when controlling the transmission power of the terminal device, estimates a maximum amount of interference that is the maximum amount of interference to a base station device other than the base station device with which the terminal device is communicating, and calculates a correction value for correcting the transmission power of the terminal device using the maximum amount of interference; The base station device in communication controls the terminal device so that the transmission power is corrected using the correction value. Communication systems.

8. A control method for a communication system including a plurality of base station devices constituting a cell, a terminal device that performs wireless communication with the base station devices when located within the cell, and a control device that controls the base station devices, the control device controlling the base station devices, the control method comprising the steps of: acquiring, from the base station device, an interference measurement value measured when the base station device receives a signal from the terminal device; When controlling the transmission power of a first terminal device that communicates with a first base station device, a maximum interference amount, which is the maximum amount of interference caused by the first terminal device to other base station devices other than the first base station device, is estimated, and a correction value for correcting the transmission power of the first terminal device is calculated using the maximum interference amount. Control methods.

9. A base station device in a communication system includes a plurality of base station devices constituting a cell, and a terminal device that performs wireless communication with the base station device when the terminal device is located within the cell, the base station device controlling transmission power in accordance with a path loss value between the base station device and the terminal device in communication, an acquisition unit that acquires measurement data measured when the terminal device receives a signal from the base station device; and a control unit that, when controlling the transmission power of the terminal device during communication, estimates a sum of path losses for the other base station devices, including the path losses of the terminal device for the other base station devices, using the measurement data, and calculates a correction value for correcting the transmission power of the terminal device using the estimated sum of path losses. Base station equipment.

10. The measurement data includes a received power of the signal and a signal-to-interference-and-noise ratio calculated from the received power. The base station apparatus according to claim 9.

11. The control unit calculates an amount of interference using thermal noise power in the estimation, and estimates the sum of the path losses using the calculated amount of interference. The base station apparatus according to claim 10.

Images