JP2012085007A - Base station management server and base station device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a base station management server capable of reducing processing time required when an optimum combination of power parameters controlling transmission power of an uplink is selected for each base station device.SOLUTION: A base station management server comprises: a setting candidate information determination unit which outputs remaining combinations of power parameters while removing combinations of the power parameters with high probability of deteriorating communication quality for a plurality of base station devices from possible combinations of the power parameters for a plurality of base station devices based on information indicating communication conditions between the plurality of base station devices and respective terminal devices; and a communication quality calculation unit which calculates an estimation value of communication quality for each of the plurality of base station devices for each combination of the power parameters output by the setting candidate information determination unit.

Description

  The present invention relates to a base station management server and a base station apparatus.

  In LTE, transmission power P_PUSCH [mW] of an uplink data channel (PUSCH: Physical Uplink Shared Channel) of each terminal apparatus is determined according to the following equation (1) (Non-patent Document 1).

  Here, P_CMAX in Equation (1) is the maximum transmission power of the terminal, M_PUSCH is the number of allocated RBs notified from the base station to the terminal by PDCCH, and P_O_NOMINAL_PUSCH is notified by the RRC message from the base station Base station fixed offset. P_O_UE_PUSCH is a fixed offset of the terminal notified from the base station by the RRC message, and α is a path loss correction coefficient notified from the base station by the RRC message. Further, PL is a path loss estimated by the terminal, Δ_TF is a coefficient determined by a code block or the like, and f is a transmission power command notified from the base station to the terminal through PDCCH. Note that the correction coefficient α, the fixed offset P_O_NOMINAL_PUSCH, and the like are set for each base station apparatus.

The power parameters such as the correction coefficient α and the fixed offset P_O_NOMINAL_PUSCH can be set to different values for each base station apparatus, and the transmission power of each terminal apparatus changes depending on the power parameter setting in each base station apparatus. At this time, since not only the received power from the terminal device in the base station apparatus but also the interference power in the base station apparatus adjacent to the base station apparatus changes, each base station apparatus individually controls the power parameter and performs communication. It is difficult to set an optimal combination of power parameters for the entire system. Here, the optimal combination of power parameters is a combination of power parameters that maximizes the communication capacity in the communication system.
Therefore, the amount of change in received power and interference power is estimated by formulating changes in received power and interference power accompanying changes in power parameters, and the estimated value of communication quality in each base station apparatus is evaluated simultaneously. Thus, it is possible to set optimal power parameters in a plurality of base station apparatuses.

3GPP TS36.213 v9.2.0 2010-06 3GPP TS36.331 v9.3.0 2010-06

However, in order to obtain the optimum combination of power parameters, it is necessary to estimate the communication quality in each base station apparatus for each of a plurality of power parameter candidates and to select the optimum power parameter candidate from among them. Therefore, when the number of power parameter candidates is large, the range that each power parameter candidate can take, and when the number of base station apparatuses to be evaluated at the same time is large, the number of combinations of power parameter candidates to be evaluated Is a huge number.
For example, when the number of parameters is l, each parameter has equal m value ranges, and the number of base stations is n, it is necessary to calculate (m ^l ) ⁿ parameter candidates.

  Thus, in a communication system having a plurality of base station devices, when selecting a power parameter that optimizes the uplink communication quality for each base station device, the number of power parameter candidates, the base station device to be evaluated Depending on the number, the amount of calculation processing and the amount of data used in the calculation increase, and there is a problem that it takes a long time to select an optimal power parameter.

  The present invention has been made in view of the above situation, and an object of the present invention is to reduce the processing time required for selecting an optimal combination of power parameters for controlling uplink transmission power for each base station apparatus. It is an object of the present invention to provide a base station management server and a base station apparatus that can be reduced.

  In order to solve the above problem, the present invention provides a base station management server connected to a plurality of base station devices that control transmission power of a terminal device to be connected using a power parameter. Based on information indicating the communication status with the terminal device, a power parameter that is likely to reduce communication quality for the plurality of base station devices from a combination of power parameters that can be taken for the plurality of base station devices. For each of the plurality of base station apparatuses for each combination of power parameters output by the setting candidate information determining unit that outputs the remaining power parameter combinations and the setting candidate information determining unit. A base station management server comprising a communication quality calculation unit that calculates a value.

  Moreover, the present invention is the above-described invention, wherein the information indicating the communication status includes information indicating a level of communication quality between the base station device and the terminal device, and the setting candidate information determination unit includes: For each of the base station apparatuses, the communication quality of the base station apparatus is less than a predetermined first threshold, and the communication quality of the base station apparatus adjacent to the base station apparatus is higher than the first threshold. If the determination result is acceptable, the base station apparatus lowers the transmission power of the terminal apparatus with respect to the currently used power parameter combination, and the adjacent base station A combination of power parameters that increase the transmission power of the terminal apparatus in all apparatuses is excluded from possible combinations of power parameters.

  Further, the present invention is the above-described invention, wherein the information indicating the communication status includes information indicating a level of communication quality between the base station apparatus and the terminal apparatus and another base station apparatus connected to the base station apparatus. Information indicating the interference power received from the terminal device that is receiving, the setting candidate information determination unit, for each of the plurality of base station devices, the communication quality of the base station device is less than a predetermined first threshold Yes, it is determined whether the communication quality of an adjacent base station apparatus that gives interference equal to or higher than a predetermined power value to the base station apparatus is equal to or higher than a second threshold value that is higher than the first threshold value, and the determination result is passed A combination of power parameters that can be taken as a combination of power parameters that increase the transmission power of the terminal apparatus in the adjacent base station apparatus with respect to a combination of power parameters that are currently used. Characterized by excluding from allowed.

  Moreover, the present invention is the above-described invention, wherein the information indicating the communication status includes information indicating a level of communication quality between the base station device and the terminal device, and the setting candidate information determination unit includes: For each of the plurality of base station apparatuses, it is determined whether the communication quality of the base station apparatus is less than a predetermined threshold, and if the determination result is acceptable, the combination of power parameters currently used Thus, in the base station apparatus, a combination of power parameters for reducing the transmission power of the terminal apparatus is excluded from possible combinations of power parameters.

  Moreover, the present invention is the above-described invention, wherein the information indicating the communication status includes information indicating a level of communication quality between the base station device and the terminal device, and the setting candidate information determination unit includes: For each of the plurality of base station devices, it is determined whether the communication quality of the base station device is equal to or higher than a predetermined threshold, and if the determination result is acceptable, the combination of power parameters currently used Thus, in the base station apparatus, combinations of power parameters that increase the transmission power of the terminal apparatus are excluded from possible power parameter combinations.

  Further, the present invention is the above-described invention, wherein the information indicating the communication status includes information indicating the number of the terminal devices connected to each of the plurality of base station devices, and the setting candidate information determining unit Determines, for each of the plurality of base station devices, whether or not the number of the terminal devices connected to the base station device is less than a predetermined first threshold, The base station apparatus is characterized in that a combination of power parameters including other than the currently used power parameter is excluded from possible power parameter combinations.

  Further, the present invention is the above-described invention, wherein the information indicating the communication status includes information indicating the number of the terminal devices connected to each of the plurality of base station devices, the base station device and the terminal Information indicating the level of communication quality with the device, and the setting candidate information determination unit determines in advance, for each of the plurality of base station devices, the number of terminal devices connected to the base station device. It is determined whether the communication quality of the base station apparatus is less than a predetermined first threshold and the communication quality of the base station apparatus is equal to or higher than a predetermined second threshold. It is characterized in that combinations of power parameters including those other than the set power parameters are excluded from possible power parameter combinations.

  Also, the present invention is the above-described invention, wherein the information indicating the communication status includes information indicating the number of the terminal devices connected to each of the plurality of base station devices, and the setting candidate information determination unit Is a power parameter that is currently used in the base station apparatus that is not selected, selecting a predetermined number of base station apparatuses from the plurality of base station apparatuses in descending order of the number of connected terminal apparatuses. It is characterized in that combinations of power parameters including other than are excluded from possible combinations of power parameters.

  Further, according to the present invention, in the above-described invention, the setting candidate information determination unit further determines in advance a power parameter currently used in the plurality of base station apparatuses from a combination of possible power parameters. A combination of power parameters including a power parameter outside the specified range is excluded.

  The present invention is also a base station apparatus in a communication system including a plurality of base station apparatuses connected to a terminal apparatus by wireless communication, and is connected to the own apparatus based on information indicating a communication status with the terminal apparatus Setting candidates that exclude power parameter candidates that have a high possibility of lowering communication quality in the own device and output remaining power parameter candidates from possible candidates for power parameters that control transmission power of the terminal device For each power parameter output by the information reduction unit and the setting candidate information reduction unit, an estimated value of received power from a terminal device connected to the own device, and interference that the terminal device gives to another base station device A base station apparatus comprising a power estimation unit that calculates an estimated power value.

  Further, according to the present invention, in the invention described above, the information indicating the communication status includes information indicating a level of communication quality between the own device and the terminal device, and the setting candidate information reducing unit It is determined whether the communication quality between the device and the terminal device is less than a predetermined threshold value, and if the determination result is acceptable, the transmission power of the terminal device with respect to the currently used power parameter The power parameter that lowers the power consumption is excluded from possible power parameter candidates.

  Further, according to the present invention, in the invention described above, the information indicating the communication status includes information indicating a level of communication quality between the own device and the terminal device, and the setting candidate information reducing unit It is determined whether the communication quality between the device and the terminal device is equal to or higher than a predetermined threshold, and if the determination result is acceptable, the transmission power of the terminal device with respect to the currently used power parameter The power parameter that increases the power is excluded from the possible power parameter candidates.

  Further, in the present invention described above, in the above-described invention, the information indicating the communication status includes information indicating the number of the terminal devices connected to the own device, and the setting candidate information reducing unit is provided to the own device. It is determined whether the number of connected terminal devices is less than a predetermined first threshold, and if the determination result is acceptable, the power parameter that can take a power parameter other than the currently used power parameter It is excluded from the candidates.

  In the invention described above, the information indicating the communication status includes information indicating the number of the terminal devices connected to the own device, and communication quality between the own device and the terminal device. The setting candidate information reduction unit includes a number of the terminal devices connected to the own device being less than a predetermined first threshold, and the own device and the terminal device. It is determined whether the communication quality during the period is equal to or higher than a predetermined second threshold, and if the determination result is acceptable, it is excluded from power parameter candidates that can take power parameters other than the currently used power parameter It is characterized by that.

  Further, the present invention is the above-described invention, wherein the setting candidate information reduction unit is further out of a predetermined range with respect to a power parameter currently used in the own device, from possible power parameter candidates. The power parameter is excluded.

  According to the present invention, it is possible to reduce the processing time required for selecting an optimal combination of power parameters for controlling uplink transmission power. As a result, it is possible to appropriately set the power parameter in each base station apparatus.

It is a schematic block diagram which shows the structure of the communication system 1 in 1st Embodiment. It is a schematic block diagram which shows the structure of the communication system 2 in 2nd Embodiment.

  Hereinafter, a base station management server and a base station apparatus according to an embodiment of the present invention will be described with reference to the drawings.

(First embodiment)
FIG. 1 is a schematic block diagram showing a configuration of a communication system 1 in the first embodiment. As shown in the figure, the communication system 1 includes a plurality of base station devices 11-1 to 11-M (M is an integer of 2 or more) that performs wireless communication with a terminal device (not shown), and each base station device 11. -1 to 11-M and a base station management server 12 connected via a network 13.
Hereinafter, when any one or all of the base station apparatuses 11-1 to 11-M are shown, the base station apparatus 11 is referred to. In the present embodiment, by changing the value of the fixed offset P_O_NOMINAL_PUSCH and the value of the correction coefficient α in Expression (1) as a power parameter for controlling the transmission power of the terminal device connected to the base station device 11, A case where uplink communication quality is controlled in each base station apparatus 11 will be described as an example.

For each of a plurality of power parameter combination candidates, the base station device 11 receives an estimated value (estimated received power) of received power from a terminal device connected to the own device when the combination of the power parameters is applied, and An estimated value (estimated interference power) of interference power from the terminal device connected to the device to the base station device 11 to which the device is adjacent is calculated.
The base station management server 12 uses the estimated received power and estimated interference power calculated for each combination of power parameters by each base station apparatus 11 to use the signal to interference and noise ratio (SINR) in each base station apparatus 11. (Interference and noise power ratio) is estimated, a combination of power parameters satisfying a predetermined condition is selected based on the estimated SINR, and the selected power parameter is notified to each base station apparatus 11.

At this time, when calculating the estimated received power and the estimated interference power for each combination of power parameters, the base station apparatus 11 calculates the estimated received power and the traffic based on the user distribution, the traffic generation status, and the communication quality of the own apparatus. The combination of power parameters for calculating the estimated interference power is reduced. Thereby, the base station apparatus 11 reduces the amount of calculation processing and the amount of data when calculating the estimated received power and the estimated interference power.
Hereinafter, configurations of the base station management server 12 and the base station apparatus 11 in the present embodiment will be described.

The base station apparatus 11 includes a wireless communication unit 111, an input information acquisition unit 112, and a wireless power estimation unit 113.
The wireless communication unit 111 performs wireless communication with the terminal device by receiving a signal transmitted from the terminal device and transmitting the signal to the terminal device.

  The input information acquisition unit 112 acquires various types of input information used by the wireless power estimation unit 113 for calculating the estimated received power and the estimated interference power from the wireless communication unit 111 or from another base station device 11 via the network 13. To do. The input information includes setting information, setting candidate information, user distribution information, traffic information, communication quality information, radio resource allocation information, base station transmission power information, path loss information, measured power information, and statistical interval information.

The setting information is information indicating a power parameter currently used, and includes a fixed offset P_O_NOMINAL_PUSCH, which is a power parameter in the uplink, and a current setting value of the correction coefficient α.
The setting candidate information is information indicating possible values of each power parameter in the uplink in the base station apparatus 11. Specifically, a combination of any value in a setting candidate for fixed offset P_O_NOMINAL_PUSCH and any value in a setting candidate for correction coefficient α is shown. In LTE uplink transmission power control, the setting candidates (possible values) of the fixed offset P_O_NOMINAL_PUSCH are 151 integer values in the range of −126 to 24. Further, setting candidates (possible values) of the correction coefficient α are eight numerical values [0.0, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1.. 0] (Non-Patent Document 2). Therefore, there are 1208 (= 151 × 8) combinations of power parameters indicated by the setting candidate information at maximum.

The user distribution information indicates, for example, the number of terminal devices connected to each base station device 11 (number of connected users).
The traffic information indicates, for example, the average amount of uplink traffic and the average throughput in each base station apparatus 11.
The communication quality information is information indicating uplink communication quality in each base station apparatus 11 and is, for example, uplink SINR (Signal to Interference and Noise Ratio). Instead of SINR, information indicating communication quality such as IoT (Interference-over-thermal), MCS (Modulation Code Set), QCI (QoS Class Identifier) is used. Also good.

The radio resource allocation information is information indicating a radio resource allocation result of each terminal apparatus in each subframe determined by the radio scheduler in the past, and is configuration information indicating the allocation of radio resources allocated in the subframe, allocated radio It includes the number of resources M_PUSCH, coefficient Δ_TF, and transmission power command f.
The base station transmission power information includes information indicating the transmission power of the own device and information indicating the transmission power of the other base station device 11.
The path loss information indicates an estimated value PL of a path loss (propagation loss) between the own apparatus and the base station apparatus 11 adjacent to the own apparatus and a terminal apparatus connected to the own apparatus.

The measured power information is the received power measured per 1 RB (Resource Block) in the own device for a packet for which radio resource allocation is actually performed when the power parameter indicated by the setting information is used. Indicates the value.
The statistical interval information includes the estimated received power indicating the estimated value for the received power of the signal received by the wireless power estimation unit 113 from the terminal device connected to the own device, and the terminal device to which the own device is connected A predetermined statistical period I of radio resource allocation information used when calculating an estimated interference power indicating an estimated value for interference power given to the base station apparatus 11 is shown.

  The wireless power estimation unit 113 includes a setting candidate information reduction unit 114 and a power estimation unit 115, and the received power of the device itself when the power parameter is changed in the base station device 11 in the uplink of the communication system 1 and The interference power to the base station apparatus 11 adjacent to the own apparatus is estimated.

  Setting information, setting candidate information, user distribution information, traffic information, and communication quality information are input to the setting candidate information reduction unit 114 from the input information acquisition unit 112. Then, the setting candidate information reduction unit 114 has no influence on the search for the optimum power parameter from the input setting candidate information based on the user distribution information, traffic information, and communication quality information. The candidate with few is excluded and the remaining candidate among setting candidate information is output as estimation object setting candidate information. Specifically, the setting candidate information reduction unit 114 uses the combination of the fixed offset P_O_NOMINAL_PUSCH and the correction coefficient α included in the setting candidate information as the initial value of the estimation target setting candidate information, and affects the search for the optimal power parameter. The combinations that have no or little influence are excluded from the estimation target setting candidate information, and the remaining combinations are output as the estimation target setting candidate information.

For example, in Expression (1), when the set value of the fixed offset P_O_NOMINAL_PUSCH or the correction coefficient α is increased, the transmission power of the terminal apparatus connected to the base station apparatus 11 is increased, and the received power in the base station apparatus 11 is increased. To increase. At the same time, the interference power to the base station apparatus 11 adjacent to the base station apparatus 11 increases.
Conversely, if the fixed offset P_O_NOMINAL_PUSCH or the set value of the correction coefficient α is reduced, the received power of the base station apparatus 11 is reduced, and at the same time, the interference power to the adjacent base station apparatus 11 is reduced. Therefore, based on these behaviors, combinations of power parameters that are not likely to be optimal solutions (= lower communication quality) are excluded from the estimation target setting candidate information, thereby reducing the amount of calculation processing and data. Do.

  Hereinafter, a method of reducing the number of combinations included in the estimation target setting candidate information indicating the combination of power parameters that are targets for calculating the estimated reception power and the estimated interference power in the setting candidate information reduction unit 114 will be described.

(I) setting candidate information deletion unit 114, in its own device, it determines whether or not the average SINR is less than the set threshold value A ₁ determined in advance. If the average SINR is less than the set threshold value A ₁ which predetermined setting candidate information deletion unit 114, for a combination of power parameters indicated by the setting information, reducing the transmission power of the terminal device connected to the own device The combination of power parameters is excluded from the estimation target setting candidate information to reduce the number of combinations. Thereby, when a certain communication quality is not obtained in the own device, a combination of power parameters whose communication quality deteriorates by reducing the transmission power of the terminal device is excluded from the estimation target setting candidate information, and the estimation target setting candidate The number of combinations included in the information can be reduced. Here, the average SINR may be an average of SINRs in a predetermined period, or an average value of SINRs from the previous power parameter change to the present.

Specifically, one of the combinations of the fixed offset P_O_NOMINAL_PUSCH included in the estimation target setting candidate information and the correction coefficient α is equal to or less than the current value indicated by the setting information, and the other is less than the current value. A certain combination is excluded from the estimation target setting candidate information.
Instead of the average SINR, the SINR of the terminal device of the lower order x ₁ % set in advance in the CDF (Cumulative Distribution Function) of SINR acquired for each terminal device connected to the own device is set. You may make it compare with threshold value A1.

(Ii) setting candidate information deletion unit 114, in its own device, it determines whether or not the average SINR is equal predetermined set threshold value _{B 1} or more. If the average SINR is predetermined set threshold value B ₁ or more, setting candidate information deletion unit 114, for a combination of power parameters indicated by the setting information, increasing the transmit power of the terminal device connected to the own device The combination of power parameters is excluded from the estimation target setting candidate information to reduce the number of combinations. Thereby, when a certain communication quality is obtained in the own device, the estimation target setting candidate information is excluded from the estimation target setting candidate information by combining the power parameter combination that improves the communication quality by increasing the transmission power of the terminal device. The number of combinations included in can be reduced.

Specifically, one of the combinations of the fixed offset P_O_NOMINAL_PUSCH included in the estimation target setting candidate information and the correction coefficient α is greater than or equal to the current value indicated by the setting information, and the other is greater than the current value. The combination is excluded from the estimation target setting candidate information.
In addition, instead of the average SINR, the SINR of the terminal device of the lower x ₂ % predetermined in the CDF of the SINR acquired for each terminal device connected to the own device may be compared with the set threshold B. Good.

(Iii) setting candidate information deletion unit 114 determines the number of terminals connected to the own device indicated by the user profile information, whether a set threshold value D ₁ follows a predetermined. If the number of terminals connected to the own device is a predetermined setting threshold value _{D 1} or less, setting candidate information deletion unit 114, the estimated target configuration and fixed offset P_O_NOMINAL_PUSCH showing the setting information, other than the combination of the correction coefficient α By excluding the candidate information, only the combination indicated by the setting information is set as the estimation target setting candidate information. Thereby, when the number of terminals connected to the own device is equal to or less than a certain number, it is considered that the change in the combination of the power parameters in the own device contributes to the improvement of the communication quality and the like in the communication system 1 is low. Then, in the own device, by using only the combination indicated by the setting information as the estimation target setting candidate information, the number of combinations included in the estimation target setting candidate information can be reduced.

(Iv) setting candidate information deletion unit 114, the number of terminals connected to the user distribution information device itself, and the set threshold value D ₁ or less predetermined, and, in its own device, setting a threshold average SIRN is predetermined It is determined whether or not E is ₁ or more.
When it is equal to or smaller than the predetermined setting threshold D ₁ and the average SIRN is equal to or larger than the predetermined setting threshold E ₁ in the own device, the setting candidate information reduction unit 114 corrects with the fixed offset P_O_NOMINAL_PUSCH indicated by the setting information Except for the combination with the coefficient α, the estimation target setting candidate information is excluded, and only the combination indicated by the setting information is set as the estimation target setting candidate information. Thereby, when the number of connected terminals is less than a certain number and a certain communication quality is obtained in the own apparatus, the change of the combination of the power parameters improves the communication quality in the communication system 1 or the like. It is considered that the degree to contribute to is low. Then, in the own device, by using only the combination indicated by the setting information as the estimation target setting candidate information, the number of combinations included in the estimation target setting candidate information can be reduced.

With the method described above, the setting candidate information reduction unit 114 reduces the number of combinations of power parameters that are targets for calculating the estimated received power and the estimated interference power.
Here, the above-described set threshold values A ₁ , B ₁ , D ₁ , E ₁ , and x ₁ , x ₂ are predetermined values based on actually measured values or simulations.

In the above methods (i) to (ii), the value may be narrowed down to a value close to the value of the fixed offset P_O_NOMINAL_PUSCH indicated by the setting information and the value of the correction coefficient α. Here, the close value is a value within the range of front and rear F ₁ (F ₁ is an integer of 1 or more) for the fixed offset P_O_NOMINAL_PUSCH, and the step width G ₁ (G ₁ for the correction coefficient α). Is a value within an integer of 1 or more.
Specifically, in the above (i), the setting candidate information for the fixed offset P_O_NOMINAL_PUSCH and the correction coefficient α is −126 to 24, and [0.0, 0.4, 0.5, 0.6, 0, respectively. .7, 0.8, 0.9, 1.0] and the setting information is fixed offset P_O_NOMINAL_PUSCH = 10 and correction coefficient α = 0.7, the estimation target setting candidate information is fixed offset P_O_NOMINAL_PUSCH. Is a combination of “10 to 24” and a correction coefficient “0.7, 0.8, 0.9, 1.0”. Here, for example, assuming that F ₁ = 5 and G ₁ = 2, a combination of a fixed offset P_O_NOMINAL_PUSCH of “10 to 15” and a correction coefficient “0.7, 0.8, 0.9” is set as an estimation target. The candidate information may be narrowed down.

Further, in the above methods (i) to (iv), instead of SINR as an index indicating communication quality, the reciprocal of IoT, the MCS used in the terminal device connected to the own device, or the own device The QCI of the connected terminal device may be used.
In the methods (iii) to (iv) described above, the number of combinations included in the estimation target setting candidate information may be reduced using traffic information instead of the user distribution information. Specifically, the average traffic volume or average throughput indicated traffic information, if a preset threshold H ₁ predetermined, changing the combination of the power parameters of the device itself, the improvements such as the communication quality in the communication system 1 Assuming that the degree of contribution is low, only the combination indicated by the setting information may be used as the estimation target setting candidate information.

  The power estimation unit 115 receives radio resource allocation information, base station transmission power information, path loss information, measured power information, statistical section information, setting information, and estimation target setting candidate information from the input information acquisition unit 112. The power estimation unit 115 calculates an estimated value of the received power of the signal received from the terminal device connected to the own device based on each input information, and other terminal devices connected to the own device The estimated value of the interference power given to the base station apparatus 11 is calculated. Then, the power estimation unit 115 includes estimated received power information indicating an estimated value of received power, estimated interference power information indicating an estimated value of interference power, and information indicating a combination of power parameters when these estimated values are calculated. The estimated power information that is included is transmitted to the base station management server 12 via the network 13.

An example of a specific calculation method in the power estimation unit 115 is shown below.
First, the power estimation unit 115 is assigned radio resources among terminal devices connected to the own device (base station device 11 (x)) in the subframe (i) within the statistical period I indicated by the statistical interval information. For each terminal device (u), the estimated transmission power P_PUSCH (x, u, i) [mW], which is an estimated value of the transmission power for the current power parameter (setting information), is calculated using the following equation (2). To do.

  Next, for each combination indicated by the estimation target setting candidate information, the power estimation unit 115 uses the following equation (3) to estimate the transmission power P′_PUSCH (x, u, i) [ mW] is calculated.

Here, the fixed offset P′_O_NOMINAL_PUSCH and the correction coefficient α ′ are power parameters indicated by the estimation target setting candidate information.
Next, the difference (change amount) ΔP_PUSCH [dB] of the estimated transmission power when the power parameter is changed from the current setting value to the power parameter indicated by the estimation target setting candidate information is calculated using the following equation (4). .

  Moreover, the power estimation unit 115 uses the difference ΔP_PUSCH, the measurement information P_RX, and the following equation (5) to estimate the average received power P in the statistical period I for each terminal device (u) connected to the own device. '_RX (x, u) [mW] is calculated. N_assign (x, u) in Equation (5) is the number of subframes in which the base station apparatus 11 (x) has allocated radio resources to the terminal apparatus (u) in the statistical period I.

  Also, the power estimation unit 115 determines, from the terminal device (u) connected to the own device (base station device 11 (x)), the base station adjacent to the own device based on the current power parameter (setting information). Estimated interference power P_RX (x → y), which is an estimated value of interference power to apparatus 11 (y), is calculated using the following equation (6).

Here, N_I is the number of subframes in the statistical period I.
In addition, for each combination of power parameters indicated by the estimation target setting candidate information, the power estimation unit 115 uses the estimated transmission power P′_PUSCH (x, u, i) for the combination and the following equation (7): Estimated interference power P′_RX (x → y) is calculated. The estimated interference power P′_RX (x → y) is transmitted from the terminal device (u) connected to the own device (base station device 11 (x)) to the base station device 11 (y) adjacent to the own device. It is an estimated value of interference power.

  The power estimation unit 115 transmits a base station adjacent to the own device from the terminal device (u) connected to the own device (base station device 11 (x)) calculated by the equations (6) and (7). The estimated interference power information including the estimated value of the interference power to the device 11 (y) and the power parameter when each estimated value is calculated is transmitted to the base station management server 12 via the network 13.

  The base station management server 12 includes a communication quality calculation unit 121 and a parameter setting unit 122. For each base station apparatus 11, the communication quality calculation unit 121 selects a power parameter for the base station apparatus 11 from a combination of power parameters included in the estimated power information received from the base station apparatus 11, and sets all base stations A combination of power parameters for the station apparatus 11 is calculated. And the communication quality calculation part 121 uses the estimated power information received from each base station apparatus 11 for every combination of the calculated power parameter with respect to all the base station apparatuses 11, and estimates the communication quality in each base station apparatus 11. And the estimated communication quality information in which the calculated estimated value is associated with the combination of the power parameters when the estimated value is calculated is output to the parameter setting unit 122.

  The parameter setting unit 122 selects one combination of power parameters satisfying a predetermined selection condition from the estimated communication quality information calculated by the communication quality calculation unit 121, and each base station corresponding to the selected power parameter It transmits to the apparatus 11 and the electric power parameter of each base station apparatus 11 is updated. The selection condition is, for example, a condition such as “the SINR of each base station apparatus 11 is greater than or equal to a predetermined threshold”.

  Hereinafter, a method by which the communication quality calculation unit 121 calculates communication quality (SINR) will be described. The communication quality calculation unit 121 calculates a combination of power parameters of the base station apparatuses 11-1 to 11-M from a combination of power parameters included in the estimated power information received from each base station apparatus 11. And the communication quality calculation part 121 calculates the estimated value of SINR expected when the combination of the said power parameter is applied for every combination of the power parameter of the base station apparatuses 11-1 to 11-M. The estimated SINR value SINR ′ (x, u) is calculated by the following equation (8) for each terminal apparatus (u) connected to each base station apparatus 11 (x).

Here, P′_RX (x, u) is the estimated average received power calculated by the equation (5). P_N (x) is an average noise power in the base station apparatus 11 (x). P′_I (x) is interference power received from a terminal device connected to another base station device 11 in the base station device 11 (x).
The interference power P′I (x) [mW] is calculated by the following equation (9).

  Here, P_I_measured (x) [mW] is the interference power measured by the base station apparatus 11 (x) using DM-RS (Demodulation Reference Signal). ΔP_I_est (x) is expected when the base station apparatus 11 (x) changes the power parameter from the value (current value) indicated by the setting information to the value (candidate value) indicated by the setting candidate information. The amount of interference power change (estimated value, [mW]) is calculated by the following equation (10).

  When P′_I_est (x) uses a combination (candidate value) of the power parameters indicated by the setting candidate information, the base station device 11 (x) is connected to the other base station device 11 from the terminal device. The interference power received ([mW]) is calculated by the following equation (11).

  Further, P_I_est (x) is received by the base station apparatus 11 (x) from a terminal apparatus connected to another base station apparatus 11 when the combination (current value) of the power parameters indicated by the setting information is used. It is interference power ([mW]), and is calculated by the following equation (12).

Here, P_RX (y → x) indicates that the base station apparatus 11 (x) is connected to the base station apparatus 11 (y) when the current value of the power parameter is used in the base station apparatus 11 (y). Interference power received from the terminal device. Further, P′_RX (y → x) indicates that the base station apparatus 11 (x) is connected to the base station apparatus 11 (y) when the power parameter candidate value is used in the base station apparatus 11 (y). Interference power received from a terminal device. The interference powers P_RX (y → x) and P′_RX (y → x) are estimated interference powers calculated by the base station apparatus 11 (y) using the equations (6) and (7).
Further, NeighborList is a predetermined list of base station apparatuses 11 adjacent to the base station apparatus 11 (x).

  The communication quality calculation unit 121 calculates an estimated value of SINR in each base station apparatus 11 (x) for each combination of power parameters of all base station apparatuses 11 by the above method. Then, the communication quality calculation unit 121 outputs estimated communication quality information including the calculated estimated value and a combination of power parameters when the estimated value is calculated to the parameter setting unit 122.

As described above, in the present embodiment, the setting candidate information reduction unit 114 included in each base station apparatus 11 calculates the estimated received power and the estimated interference power according to the user distribution and traffic occurrence status. By reducing the number of parameter combinations, the amount of calculation processing and the amount of data required for the power estimation unit 115 to calculate the estimated received power and the estimated interference power can be reduced.
Thereby, it is possible to reduce the time required for each base station apparatus 11 to change the power parameter in cooperation, and to increase the system capacity by updating the power parameter according to the user distribution and the traffic occurrence situation. The time required for the change can be shortened. As a result, it becomes possible to update the power parameters corresponding to changes in the user distribution and traffic volume at short intervals.
In the present embodiment, the setting candidate information reduction unit 114 may use a combination of the methods (i) to (iv) described above.

(Second Embodiment)
FIG. 2 is a schematic block diagram showing the configuration of the communication system 2 in the second embodiment. The communication system 2 of this embodiment is a modification of the communication system 1 (FIG. 1) in the first embodiment, and the configuration of the base station management server 22 is different from the configuration of the base station management server 12 of the first embodiment. In the present embodiment, the same components as those in the first embodiment are denoted by the same reference numerals and description thereof is omitted.
As shown in FIG. 2, the base station management server 22 includes a communication quality estimation unit 221 and a parameter setting unit 122. The communication quality estimation unit 221 includes a setting candidate information determination unit 222 and a communication quality calculation unit 223.

  The setting candidate information determination unit 222 receives setting information, setting candidate information, user distribution information, traffic information, and communication quality information from each base station apparatus 11 via the network 13. The setting candidate information determination unit 222 determines the value of the fixed offset P_O_NOMINAL_PUSCH of the power parameter that can be taken for each base station apparatus 11 from the combination of the setting information received from each base station apparatus 11 and the power parameter included in the setting candidate information, The value of the correction coefficient α is acquired, and all combinations of the power parameters in all the base station apparatuses 11 selected one by one with the fixed offset P_O_NOMINAL_PUSCH and the correction coefficient α are calculated for each base station apparatus 11 to set the estimation target The initial value of candidate information. Then, the setting candidate information determination unit 222 does not affect the search for the optimum power parameter from the combination of the calculated power parameters of all base station apparatuses 11 based on the user distribution information, traffic information, and communication quality information. Alternatively, combinations that have little influence are excluded, and the remaining combinations are output to the communication quality calculation unit 223 as estimation target setting candidate information.

  Hereinafter, a method for reducing the number of combinations of power parameters (hereinafter referred to as estimation targets) for which the setting candidate information determination unit 222 calculates an estimated value of communication quality will be described. The setting candidate information determination unit 222 reduces the number of estimation targets by using any one of methods (I) to (VII) described below. Here, the fixed offset P_O_NOMINAL_PUSCH of the base station apparatus 11 (n) (n is an integer satisfying 1 ≦ n ≦ M) and the candidate elements of the setting candidate information of the correction coefficient α are p (n) and a (n). In the base station apparatus 11 (n), the currently set fixed offset P_O_NOMINAL_PUSCH and the correction coefficient α are p_t (n) and a_t (n) (current values).

(I) setting candidate information determination unit 222, for each base station apparatus 11, the average SINR is less than the set threshold value _{A 2} of the base station apparatus 11 (o), the interference power to the base station apparatus 11 (o) is It is determined whether or not there is a base station apparatus 11 (n) higher than a predetermined interference threshold. The average SINR in the base station apparatus 11 (o) is less than the set threshold value A _2, if the base station apparatus 11 (o) higher base station than the interference threshold interference power is predetermined with respect to the apparatus 11 (n) is present In addition, the setting candidate information determination unit 222 includes p (n) and a (n) in which the fixed offset P_O_NOMINAL_PUSCH and the correction coefficient α are both equal to or larger than p_t (n) and a_t (n) in all base station apparatuses 11 (n). P (o) and a in which either one of the fixed offset P_O_NOMINAL_PUSCH and the correction coefficient α is less than the currently set value and the other is less than the currently set value in the base station apparatus 11 (o) The combination of power parameters including (o) is excluded from the estimation targets, and the number of estimation targets is reduced.

That is, the average SINR in the base station apparatus 11 is less than the set threshold value A _2, if a high base station apparatus 11 than the interference threshold interference power predetermined for the base station apparatus 11 is present, the power currently used A base station connected to a terminal device that reduces transmission power of a terminal device connected to the base station device 11 and gives high interference to the base station device 11 with respect to a combination of parameters In the device 11, combinations of power parameters that increase the transmission power of the terminal device are excluded from the estimation targets. As a result, as is clear from the equation (1), the uplink transmission power is lowered in the base station apparatus 11 where a certain communication quality is not obtained, and the uplink in the base station apparatus 11 adjacent to the base station apparatus 11 The combination of the power parameters that increase the transmission power of can be excluded from the estimation targets, and the number of estimation targets can be reduced.
Instead of the average SINR, the SINR of the terminal device of the lower x ₃ % may be compared with the set threshold A _{2 in} the CDF of the SINR for each terminal device connected to the base station device 11. .

(II) setting candidate information determination unit 222, for each base station apparatus 11, the average SINR of the base station apparatus 11 (o) is less than the set threshold value _{B 2,} and the base station device 11 with respect to (o) the average SINR in the base station apparatus 11 (n) to provide high power interference than a predetermined interference threshold Te is equal to or preset threshold C ₂ or higher.
The average SINR in the base station apparatus 11 (o) is less than the set threshold value _{B 2,} and the average SINR of the base station apparatus 11 gives interference higher than the interference threshold power (n) to the base station apparatus 11 (o) If There is preset threshold _{C 2} or higher, setting candidate information determination unit 222, p in the base station apparatus 11 (n) (n) is smaller than P_T (n), and, a (n) is from A_t (n) A combination of small power parameters is set as an estimation target, and other combinations are excluded from the estimation targets to reduce the number of estimation targets.

That is, when there is a base station apparatus 11 having an average SINR less than the set threshold B ₂ and the average SINR of the base station apparatus 11 adjacent to the base station apparatus 11 is greater than or equal to the set threshold C ₂ , the currently used power parameter The combination of power parameters for increasing the transmission power of the terminal device connected to the adjacent base station device 11 is excluded from the estimation targets. Thereby, in the base station apparatus 11 which is adjacent to the base station apparatus 11 where a certain communication quality is not obtained and the certain communication quality is obtained, the transmission of the connected terminal apparatus is performed. A combination of power parameters for increasing power can be excluded from estimation targets, and the number of estimation targets can be reduced.
In addition, in the CDF of the SINR for each terminal device connected to the base station apparatus 11 in place of the average SINR, the SINR of the lower x ₄ % terminal device is compared with the setting threshold value B ₂ and the setting threshold value C _2. You may make it do.

  In addition, in this method, the base station apparatus 11 (n) in the “base station apparatus 11 (n) that gives interference with power higher than a predetermined interference threshold to the base station apparatus 11 (o)” is The condition determination may be facilitated as a base station apparatus 11 (n) adjacent to the station apparatus 11 (o) ”. Moreover, it is good also as "the base station apparatus 11 (n) in N circumferences adjacent to the base station apparatus 11 (o)." Here, when N is 0, the adjacent N-round base station apparatus 11 refers to a certain base station apparatus 11. When N is 1, a base station adjacent to the observed base station apparatus 11 It is the device 11. Further, when N is 2, the base station device 11 is adjacent to the base station device 11 that is adjacent to the adjacent one round of the base station device 11 of interest, and is other than the base station device 11 that is adjacent to the certain base station device 11 Of the base station apparatus 11. Further, the adjacent 3, 4,. A base station apparatus 11 located within a range of adjacent N laps is a base station apparatus 11 of N laps adjacent to a certain base station apparatus 11. N is a measured value or a numerical value determined in advance by simulation or the like.

(III) setting candidate information determination unit 222, for each base station apparatus 11 determines whether or not the average SINR of the base station apparatus 11 (n) is less than the set threshold _{D 2.} If the average SINR in the base station apparatus 11 (n) is less than the set threshold value _{D 2,} setting candidate information determination unit 222, is one of p in the base station apparatus 11 (n) (n) and a (n) A combination of power parameters that are equal to or less than the current value and the other is less than the current value can be excluded from the estimation targets, and the number of estimation targets can be reduced.
That is, if the average SINR is the base station apparatus 11 of less than the set threshold value D _2, power for a combination of power parameters currently used, decreasing the transmission power of the terminal devices connected to the base station apparatus 11 The parameter combination is excluded from the estimation target. As a result, for the base station apparatus 11 for which a certain communication quality is not obtained, a combination of power parameters for reducing the transmission power of the terminal apparatus connected to the base station apparatus 11 is excluded from the estimation target, and estimation is performed. The number of objects can be reduced.
Instead of the average SINR, the SINR of the terminal device of the lower x ₅ % may be compared with the setting threshold D _{2 in} the CDF of the SINR for each terminal device connected to the base station device 11. .

(IV) setting candidate information determination unit 222, for each base station apparatus 11 determines whether or not the average SINR of the base station apparatus 11 (n) is preset threshold _{E 2} or more. If the average SINR in the base station apparatus 11 (n) is preset threshold _{E 2} or more, setting candidate information determination unit 222, is one of p in the base station apparatus 11 (n) (n) and a (n) A combination of power parameters that are equal to or greater than the current value and the other is greater than the current value is excluded from the estimation targets, and the number of estimation targets is reduced.

That is, if the average SINR is preset threshold E ₂ or more base station apparatus 11, the electric power for a combination of power parameters currently used, increases the transmission power of the terminal devices connected to the base station apparatus 11 The parameter combination is excluded from the estimation target. As a result, for the base station apparatus 11 with a certain communication quality, the combination of power parameters including candidate values for improving the communication quality is excluded from the estimation targets, and the number of estimation targets can be reduced. it can.
Instead of the average SINR, the CDF of SINR for each terminal device connected to the base station apparatus 11, and the SINR of the lower _{x 6%} of the terminal device may be compared with a preset threshold _{E 2} .

(V) setting candidate information determination unit 222, for each base station apparatus 11, whether the number of terminal devices connected to the base station apparatus 11 (n) is the set threshold value G ₂ below a predetermined Determine whether. If the number of terminal devices connected to the base station apparatus 11 (n) is a set threshold _{G 2} or less, setting candidate information determination unit 222, P_T in the base station apparatus 11 (n) (n) and a_ (n ) Are excluded from the estimation targets.
That excludes the combination of the power parameters the number of the connected terminal device does not include the current value set threshold G ₂ following the base station apparatus 11 from the estimated target. Thereby, the base station apparatus 11 with a small number of connected terminal apparatuses considers that the contribution of improvement in the entire system is low even if the power parameter is updated, and reduces the power parameter candidate values for the base station apparatus 11. Thus, the number of estimation targets can be reduced.

(VI) setting candidate information determination unit 222, for each base station apparatus 11, and the number of terminal devices connected to the base station apparatus 11 (n) is a set threshold G ₂ or less, and the base station apparatus the average SINR of 11 (n) is equal to or preset threshold _{H 2} or more. The number of the base station apparatus 11 (n) to the connected terminal device is a set threshold value G ₂ or less, and, if the average SINR in the base station apparatus 11 (n) is preset threshold H ₂ or more, setting candidate information The determination unit 222 excludes from the estimation target a combination of power parameters that does not include the combination of p_t (n) and a_ (n) in the base station apparatus 11 (n).

  That is, only the current value is set as a power parameter candidate value for the base station apparatus 11 that has a certain communication quality and the number of connected terminal apparatuses is not more than a certain number. The combination of power parameters other than the current value is excluded from the estimation targets. As a result, the base station apparatus 11 having a certain communication quality and a small number of connected terminal apparatuses considers that the contribution of improvement in the entire system is low even if the power parameter is updated, and the base station apparatus 11 Only the current value can be used as a candidate value for the station apparatus 11, and the number of estimation targets can be reduced.

(VII) The setting candidate information determination unit 222 selects the upper I ₂ (I ₂ is an integer of 3 or more and M or less) base station apparatuses 11 having a large number of connected terminal apparatuses, and has not been selected. A combination of power parameters including other than the current value of each base station apparatus 11 (n) is excluded from the estimation targets, and the number of estimation targets is reduced.
Thereby, only the base station apparatus 11 that seems to have a high contribution degree of improvement in the entire system as a target for updating the power parameter, and only the current value as a candidate value for the base station apparatus 11 that seems to have a low contribution degree The number of estimation targets can be reduced.

Here, the set threshold values A ₂ , B ₂ , C ₂ , D ₂ , E ₂ , G ₂ , H ₂ , I ₂ , and x ₃ , x ₄ , x ₅ , x ₆ are measured values or simulations. It is a predetermined value based on the above.
In the above methods (I) to (VII), as in the first embodiment, the value of the fixed offset P_O_NOMINAL_PUSCH indicated by the setting information of each base station device 11 and the value of the correction coefficient α are close to each other. The power parameter combinations may be narrowed down. Thereby, by setting a value close to the current value as a candidate value, it is possible to reduce the number of estimation targets by excluding values that are likely to have large errors in the estimated value. Moreover, the accuracy of the estimated value of communication quality can be improved.

  Further, in the above methods (I) to (IV) and (VI), instead of SINR as an index indicating communication quality, the reciprocal of IoT is used in the terminal apparatus connected to each base station apparatus 11. You may make it use MCI or QCI of the terminal device connected to each base station apparatus 11. FIG.

In the above methods (V) to (VII), the number of combinations included in the estimation target setting candidate information may be reduced using traffic information instead of the user distribution information. Specifically, the average traffic volume or average throughput indicated traffic information, if a preset threshold H ₂ predetermined, changing the combination of the power parameters of the device itself, the improvements such as the communication quality in a communication system 2 Assuming that the degree of contribution is low, only the combination indicated by the setting information may be used as the estimation target setting candidate information.

Communication quality calculation section 223 receives from each base station apparatus 11 for each combination of power parameters of base station apparatuses 11-1 to 11-M indicated by the estimation target setting candidate information input from setting candidate information determination section 222. The estimated power information is used to calculate an estimated SINR value when the combination of the power parameters is applied. The method for calculating the estimated value of SINR is the same as the method in which the communication quality calculating unit 121 of the first embodiment calculates the estimated value of SINR, and thus the description thereof is omitted.
Further, the communication quality calculation unit 223 outputs the estimated communication quality information in which the calculated estimated SINR value is associated with the combination of the power parameters when the estimated value is calculated to the parameter setting unit 122.

As described above, in the present embodiment, the setting candidate information determination unit 222 provided in the base station management server 12 includes the power parameter for each base station apparatus 11 included in the setting candidate information received from each base station apparatus 11. From these combinations, a combination of power parameters in all base station apparatuses 11 in the communication system 2 is calculated as an initial value to be estimated.
For example, in the LTE uplink, a combination of power parameters indicated in the setting candidate information received from each base station apparatus 11 is included. Here, the maximum number of combinations of the fixed offset P_O_NOMINAL_PUSCH and the correction coefficient α is 1208 as described above. When the number of base station apparatuses 11 is M (M is an integer of 2 or more), there are a maximum of (1208 ^N ) combinations of estimation target power parameters for calculating an estimated value of communication quality.

The setting candidate information determination unit 222 is a combination of power parameters for calculating an estimated value of communication quality that is a maximum of (1208 ^N ) according to the user distribution, traffic occurrence status, and communication quality in each base station apparatus 11. The number is reduced, and the calculation processing amount and the data amount in the communication quality calculation unit 223 and the parameter setting unit 122 are reduced.
As a result, when searching for an optimal combination of power parameters for each base station apparatus 11 in uplink transmission power control, the number of combinations of power parameters is reduced based on user distribution information, traffic information, and communication quality information. By doing so, it is possible to reduce the amount of calculation processing and the amount of data necessary for selecting an appropriate combination of power parameters. In addition, power parameters corresponding to changes in user distribution and traffic volume can be updated at short intervals, and power parameters for avoiding interference between the base station apparatuses 11 are set to set the communication capacity of the communication system 2 as a whole. Can be improved.

In addition, in each base station apparatus 11 of the above-mentioned 2nd Embodiment, the setting candidate information reduction part 114 demonstrated the structure which reduces the number of the combination of the power parameter of the object which calculates estimated reception power and estimated interference power. However, the power estimation unit 115 may calculate the estimated received power and the estimated interference power for all possible combinations of the power parameters without providing the setting candidate information reduction unit 114.
In the second embodiment, the configuration candidate information determination unit 222 has been described with respect to the configuration information received from each base station apparatus 11 and the configuration for calculating the initial value of the estimation target configuration candidate information from the configuration candidate information. However, the initial value of the estimation target setting candidate information may be calculated from a combination of power parameters included in the estimated power information received from each base station apparatus 11.
In addition, the setting candidate information determination unit 222 may use a combination of the methods (I) to (VII) described above.

In the first and second embodiments described above, the communication quality calculation unit 121 (223) has described the configuration for calculating the estimated value of SINR. However, the present invention is not limited to this, and any other index may be used as long as it indicates communication quality. For example, SIR (Signal to Interference Ratio) or the like may be calculated.
Further, in the first and second embodiments described above, the configuration using the fixed offset P_O_NOMINAL_PUSCH and the correction coefficient α as the power parameter for controlling the transmission power of the terminal apparatus has been described. Other power parameters included in 1) may be added, or the transmission power of the terminal apparatus may be controlled using either a fixed offset or a correction coefficient.

In addition, the setting candidate information reduction unit 114 in the first and second embodiments described above may be provided as an independent device. In this case, each device may be provided in association with each base station device 11 or may be provided in association with a plurality of base station devices 11 to perform processing for each base station device 11 in a time division manner. May be. In addition, the setting candidate information determination unit 222 in the second embodiment described above may be provided as an independent device.
Further, in the first and second embodiments described above, the configuration for calculating the transmission power of the terminal device using Equation (1) used in LTE has been described. However, the calculation processing amount and the data amount in each embodiment are reduced. The method is not limited to this, and can be similarly applied to the case where the transmission power of the terminal apparatus is calculated using another calculation formula.

  The base station apparatus 11 and the base station management server 12 (22) described above may have a computer system inside. In this case, the processes of the above-described input information acquisition unit 112, setting candidate information reduction unit 114, power estimation unit 115, setting candidate information determination unit 222, and communication quality calculation unit 223 are recorded in a computer-readable form in a program format. The above processing is performed when the computer reads out and executes the program stored in the medium. Here, the computer-readable recording medium means a magnetic disk, a magneto-optical disk, a CD-ROM, a DVD-ROM, a semiconductor memory, or the like. Alternatively, the computer program may be distributed to the computer via a communication line, and the computer that has received the distribution may execute the program.

  DESCRIPTION OF SYMBOLS 1,2 ... Communication system 11, 11-1, 11-M ... Base station apparatus, 12, 22 ... Base station management server, 13 ... Network, 111 ... Wireless communication part, 112 ... Input information acquisition part, 113 ... Wireless Power estimation unit, 114 ... setting candidate information reduction unit, 115 ... power estimation unit, 121, 223 ... communication quality calculation unit, 122 ... parameter setting unit, 221 ... communication quality estimation unit, 222 ... setting candidate information determination unit

Claims (15)

In a base station management server connected to a plurality of base station devices that control transmission power of a terminal device to be connected using a power parameter,
Based on information indicating the communication status of each of the plurality of base station apparatuses with the terminal apparatus, communication quality for the plurality of base station apparatuses is determined from combinations of power parameters that can be taken for the plurality of base station apparatuses A setting candidate information determination unit that excludes combinations of power parameters that are likely to decrease and outputs combinations of remaining power parameters;
A base station management server, comprising: a communication quality calculation unit that calculates an estimated value of communication quality in each of the plurality of base station apparatuses for each combination of power parameters output by the setting candidate information determination unit. The information indicating the communication status includes information indicating the level of communication quality between the base station device and the terminal device,
The setting candidate information determination unit
For each base station apparatus, the communication quality of the base station apparatus is less than a predetermined first threshold value, and the communication quality of a base station apparatus adjacent to the base station apparatus is higher than a second threshold value that is higher than the first threshold value. If the determination result is acceptable, the base station apparatus lowers the transmission power of the terminal apparatus with respect to the currently used power parameter combination, and the adjacent base station apparatus The base station management server according to claim 1, wherein all combinations of power parameters that increase transmission power of the terminal device are excluded from possible combinations of power parameters. The information indicating the communication status includes information indicating the level of communication quality between the base station device and the terminal device, information indicating interference power received from a terminal device connected to another base station device, and Including
The setting candidate information determination unit
For each of the plurality of base station devices, adjacent base stations whose communication quality of the base station device is less than a predetermined first threshold value and which cause interference equal to or higher than a predetermined power value for the base station device When it is determined whether the communication quality of the device is equal to or higher than the second threshold value higher than the first threshold value, and the determination result is acceptable, the adjacent base station device determines the combination of power parameters currently used. The base station management server according to claim 1, wherein combinations of power parameters that increase transmission power of the terminal device are excluded from possible power parameter combinations. The information indicating the communication status includes information indicating the level of communication quality between the base station device and the terminal device,
The setting candidate information determination unit
For each of the plurality of base station devices, determine whether the communication quality of the base station device is less than a predetermined threshold, and if the determination result is acceptable, for the combination of power parameters currently used The base station management server according to claim 1, wherein combinations of power parameters for reducing transmission power of the terminal device in the base station device are excluded from possible power parameter combinations. The information indicating the communication status includes information indicating the level of communication quality between the base station device and the terminal device,
The setting candidate information determination unit
For each of the plurality of base station devices, determine whether the communication quality of the base station device is equal to or higher than a predetermined threshold, and if the determination result is acceptable, for the combination of power parameters currently used The base station management server according to claim 1, wherein combinations of power parameters that increase transmission power of the terminal device in the base station device are excluded from possible power parameter combinations. The information indicating the communication status includes information indicating the number of the terminal devices connected to each of the plurality of base station devices,
The setting candidate information determination unit
For each of the plurality of base station devices, it is determined whether the number of the terminal devices connected to the base station device is less than a predetermined first threshold, and if the determination result is acceptable, the base station The base station management server according to claim 1, wherein in the apparatus, combinations of power parameters including other than power parameters currently used are excluded from possible combinations of power parameters. The information indicating the communication status includes information indicating the number of the terminal devices connected to each of the plurality of base station devices, information indicating the level of communication quality between the base station device and the terminal devices, and Including
The setting candidate information determination unit
For each of the plurality of base station devices, the number of the terminal devices connected to the base station device is less than a predetermined first threshold, and the communication quality of the base station device is determined in advance. If it is determined whether the threshold value is 2 or more and the determination result is acceptable, the base station apparatus excludes combinations of power parameters including power parameters other than those currently used from possible power parameter combinations. The base station management server according to claim 1. The information indicating the communication status includes information indicating the number of the terminal devices connected to each of the plurality of base station devices,
The setting candidate information determination unit
From the plurality of base station devices, select a predetermined number of base station devices in order from the largest number of connected terminal devices, and other than the power parameters currently used in the base station devices not selected The base station management server according to claim 1, wherein a combination of included power parameters is excluded from possible combinations of power parameters. The setting candidate information determination unit further includes:
The power parameter combination including a power parameter outside a predetermined range with respect to a power parameter currently used in the plurality of base station apparatuses is excluded from possible power parameter combinations. The base station management server according to any one of claims 2 to 8. A base station device in a communication system comprising a plurality of base station devices connected to a terminal device by wireless communication,
Based on the information indicating the communication status with the terminal device, the power that is likely to lower the communication quality in the own device from the possible candidates for the power parameter for controlling the transmission power of the terminal device connected to the own device. A setting candidate information reduction unit that excludes parameter candidates and outputs remaining power parameter candidates;
For each power parameter output by the setting candidate information reduction unit, an estimated value of received power from a terminal device connected to the own device, and an estimated value of interference power that the terminal device gives to other base station devices, A base station apparatus comprising: a power estimation unit that calculates The information indicating the communication status includes information indicating the level of communication quality between the own device and the terminal device,
The setting candidate information reduction unit
It is determined whether the communication quality between the own device and the terminal device is less than a predetermined threshold, and if the determination result is acceptable, the transmission of the terminal device for the currently used power parameter The base station apparatus according to claim 10, wherein a power parameter for reducing power is excluded from possible power parameter candidates. The information indicating the communication status includes information indicating the level of communication quality between the own device and the terminal device,
The setting candidate information reduction unit
It is determined whether the communication quality between the own device and the terminal device is equal to or higher than a predetermined threshold, and if the determination result is acceptable, the transmission of the terminal device for the currently used power parameter The base station apparatus according to claim 10, wherein power parameters that increase power are excluded from possible power parameter candidates. The information indicating the communication status includes information indicating the number of the terminal devices connected to the own device,
The setting candidate information reduction unit
It is determined whether or not the number of the terminal devices connected to the own device is less than a predetermined first threshold value. If the determination result is acceptable, power parameters other than the currently used power parameter can be taken. The base station apparatus according to claim 10, wherein the base station apparatus is excluded from power parameter candidates. The information indicating the communication status includes information indicating the number of the terminal devices connected to the own device, and information indicating the level of communication quality between the own device and the terminal device,
The setting candidate information reduction unit
Whether the number of the terminal devices connected to the own device is less than a predetermined first threshold, and communication quality between the own device and the terminal device is equal to or higher than a predetermined second threshold The base station apparatus according to claim 10, wherein if the determination result is acceptable, the power parameter candidate other than the currently used power parameter is excluded from possible power parameter candidates. The setting candidate information reduction unit further includes:
The power parameter outside a predetermined range with respect to the power parameter currently used in the own device is excluded from possible power parameter candidates. 15. The base station apparatus as described in.

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