JP5378337B2 - Wireless communication system - Google Patents

Description

  The present invention relates to a wireless communication system.

  In LTE (Long Term Evolution), which is one of mobile phone communication standards, transmission power P_PUSCH [dBm] of an uplink data channel (PUSCH: Physical Uplink Shared Channel) from each terminal apparatus to a base station apparatus is 1) (non-patent document 1).

  Here, P_CMAX is the maximum transmission power of the terminal device. M_PUSCH is the number of allocated RBs (Resource Blocks) notified from the base station apparatus to the terminal apparatus through a downlink control channel (PDCCH; Physical Downlink Control Channel). P_O_NOMINAL_PUSCH is a fixed offset of the transmission power in the uplink notified from the base station apparatus to the terminal apparatus by an RRC (Radio Resource Control) message, and is set for each base station apparatus.

P_O_UE_PUSCH is a fixed offset of the transmission power in the uplink of the terminal device notified by the RRC message from the base station device, and may be different for each terminal device. α is a path loss correction coefficient notified from the base station apparatus by an RRC message. PL is a path loss estimated by the terminal device. Δ_TF is a coefficient determined by a code block or the like. f is a transmission power command notified from the base station apparatus to the terminal apparatus. The coefficient Δ_TF and the transmission power command f are calculated based on information notified from the base station apparatus to the terminal apparatus through the PDCCH.
The correction coefficient α and the fixed offset P_O_NOMINAL_PUSCH are set for each base station.

  In addition, the terminal device periodically or when a specific condition is satisfied, the received power information of the signal received from the connected base station device (hereinafter referred to as connected base station device) measured by the terminal device, Notifying the connected base station device of the received power information of signals received from adjacent base station devices other than the connected base station device. This notification is called MR information (Measurement Report;), and is mainly used for determination of handover conditions (Non-Patent Document 2).

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

  Since the transmission 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, the transmission power of each terminal apparatus is set according to the setting of the transmission power parameter set in the connected base station apparatus. Changes. Then, when the transmission power parameter is changed in a certain base station apparatus, the received power from the connected terminal apparatus changes, and the received power (interference) from the terminal apparatus in the base station apparatus adjacent to the base station apparatus. Electricity) also changes.

  Therefore, when simultaneously changing the parameters of a plurality of base station apparatuses that affect each other, it is difficult to estimate a change in characteristics. That is, when the transmission power parameter is changed at the same time in the adjacent base station apparatus, the received power from the connected terminal apparatus and the interference power from the unconnected terminal apparatus are both changed. It was difficult to guess.

In general, as a solution to the above, a computer simulation simulates user allocation, propagation path, traffic distribution, base station allocation, etc., and estimates the communication quality by changing parameters, or formulates these to communicate A method for estimating the quality can be considered.
However, when the results of computer simulation are applied to a system that actually operates, it is difficult to accurately simulate / formulate user arrangements, propagation paths, traffic distributions, etc. that vary in time series, and the estimation accuracy of communication quality is low. There was a case.

In addition, since the above method performs estimation in an environment assumed in advance by computer simulation, there is an unexpected interference (an unknown base station device that cannot manage parameters, interference due to illegal radio waves, etc.) In some cases, the estimation accuracy of the communication quality is lowered.
That is, in each base station device, the accuracy of the estimated received power that estimates the received power from the connected terminal device and the estimated interference power that estimates the interference power from the terminal device that is not connected, etc. is low. In some cases, the estimation accuracy of uplink communication quality is not sufficient.

  The present invention has been made to solve the above problem, and an object thereof is to provide a radio communication system capable of improving the estimation accuracy of uplink communication quality.

  In order to solve the above problem, the present invention is a wireless communication system comprising a plurality of base station devices that perform wireless communication with a terminal device, and a management server connected to the plurality of base station devices, The base station apparatus uses a first estimated transmission power which is an estimated value of the transmission power of the terminal apparatus when using a current setting value of a transmission power parameter for determining the transmission power of the terminal apparatus, and the setting value. Calculate a difference from the second estimated transmission power, which is an estimated value of the transmission power of the terminal device when using different candidate values of the transmission power parameter, and measure when the calculated difference and the set value are used A received power estimation unit that calculates the estimated received power by adding the received power from the terminal device, the terminal device that is performing wireless communication with the own device, and the other base station device adjacent to the own device Path loss between and before An interference power estimation unit that calculates an estimated interference power in the other base station apparatus based on the first estimated transmission power and the second estimated transmission power, and the management server, for each base station apparatus, Communication quality with the terminal device in the base station device from the estimated received power calculated in the base station device and the estimated interference power for the base station device calculated in the base station device adjacent to the base station device A wireless communication system comprising a communication quality estimation unit for calculating

  Further, the present invention is the above-described invention, wherein the base station device is a measurement result report notified from the terminal device that is in radio communication with the own device, and is adjacent to the own device. Based on the measurement result report indicating the received power of the signal received from the base station device, it is determined whether or not the terminal device that has transmitted the measurement result report is the target of the path loss calculation, and based on the measurement result report And a path loss estimation unit for calculating the path loss.

  Further, the present invention is the above-described invention, wherein the base station apparatus further performs the first estimated transmission based on allocation information indicating radio resources allocated according to the setting value and the setting value. A transmission power estimation unit is provided that calculates power and calculates the second estimated transmission power based on the allocation information and the candidate value.

  Further, the present invention is the above-described invention, wherein the base station device further includes terminal information indicating a communication state of the terminal device in the past communication between the terminal device and the terminal device, and the allocation information. And an allocation information correction unit that calculates allocation of radio resources corresponding to the candidate values from the correspondence relationship with the transmission power parameter, and the transmission power estimation unit allocates radio resources calculated by the allocation information correction unit The second estimated transmission power is calculated using.

  Further, the present invention provides the allocation information correction unit according to the above-described invention, wherein the allocation information correction unit, when an index indicating a degree of congestion of wireless communication between the own device and the terminal device is equal to or greater than a predetermined threshold value, The information is calculated as an assignment of a radio resource corresponding to the candidate value.

  Further, the present invention provides the communication quality estimation unit according to the invention described above, wherein the base station apparatus adjacent to the base station apparatus with respect to interference power measured in the base station apparatus for each base station apparatus. In the station apparatus, the difference between the estimated interference power calculated by the interference power estimation unit based on the first estimated transmission power and the estimated interference power calculated by the interference power estimation unit based on the second estimated transmission power is added. Then, an estimated value of interference power is calculated, and communication quality is calculated using the calculated estimated value.

  According to the present invention, it is possible to appropriately calculate the estimated received power and the estimated interference power in each base station apparatus when the transmission power parameter is changed, and improve the estimation accuracy of the communication quality of each base station apparatus Can be made.

It is the schematic which shows the structure of the radio | wireless communications system 1 in 1st Embodiment. It is a schematic block diagram which shows the structure of the base station apparatus 10 in this embodiment. It is a figure which shows an example of allocation information. It is a figure which shows the outline | summary of the estimated value of the interference power which the interference power estimation part 116 calculates. It is a schematic block diagram which shows the structure of the base station management server 20 in this embodiment. It is a schematic block diagram which shows the structure of the base station apparatus 50 in 2nd Embodiment. It is a schematic block diagram which shows the structure of the base station apparatus 60 in 3rd Embodiment. It is a figure which shows an example of the management table in the embodiment. It is a schematic block diagram which shows the structure of the base station apparatus 70 in 4th Embodiment.

  Hereinafter, a radio communication system according to an embodiment of the present invention will be described with reference to the drawings.

(First embodiment)
FIG. 1 is a schematic diagram illustrating a configuration of a wireless communication system 1 according to the first embodiment.
The wireless communication system 1 includes a plurality of base station devices 10, a terminal device 30 that is connected to each base station device 10 and performs wireless communication, and a base station management that is connected to each base station device 10 via a network 40. And a server 20.
Hereinafter, a case where the base station apparatus 10 and the terminal apparatus 30 perform wireless communication according to the LTE standard will be described as an example. Also, uplink transmission power control is performed by changing the correction coefficient α and the fixed offset P_O_NOMINAL_PUSCH using the correction coefficient α and the fixed offset P_O_NOMINAL_PUSCH as transmission power parameters.

In this embodiment, each base station apparatus 10 changes the reception power of the signal received from the connected terminal apparatus 30 when changing the transmission power parameter in the uplink from the terminal apparatus 30 to the base station apparatus 10. An estimated received power that is an estimated value is calculated. Also, each base station apparatus 10 calculates estimated interference power that is an estimated value of interference power received by the other base station apparatus 10 from the terminal apparatus 30 connected to the base station apparatus 10.
The base station management server 20 uses the estimated reception power calculated in each base station device 10 and the estimated interference power to change the transmission power parameter of each base station device 10 to each base station device 10. The estimated communication quality of the connected terminal apparatus 30 is calculated, and the transmission power parameter of each base station apparatus 10 is changed according to the calculated estimated communication quality.

Hereinafter, configurations of the base station apparatus 10 and the base station management server 20 will be described.
FIG. 2 is a schematic block diagram showing the configuration of the base station apparatus 10 in the present embodiment. As shown in the figure, the base station device 10 includes a wireless power estimation unit 11 that calculates estimated received power and estimated interference power when changing the transmission power parameter, a wireless communication unit 12 that communicates with the terminal device 30, A network communication unit 13 that communicates with another base station apparatus 10 and the base station management server 20 via the network 40 is provided.

The wireless power estimation unit 11 includes an input information acquisition unit 111, a setting candidate storage unit 112, a transmission power estimation unit 113, a path loss estimation unit 114, a reception power estimation unit 115, and an interference power estimation unit 116.
The input information acquisition unit 111 acquires various types of input information used for calculation of estimated received power and estimated interference power information from the wireless communication unit 12 or via the network communication unit 13. The input information includes MR (Measurement Report) information, base station transmission power information, setting information, allocation information, calculation section information, own station path loss information, and measurement information.
The MR information is information notified to the base station apparatus 10 to which the terminal apparatus 30 is connected, and is information including reception power information indicating the reception power measured by the terminal apparatus 30. The received power information includes information indicating received power of a signal received from the base station apparatus 10 to which the terminal apparatus 30 is connected and reception of a signal received from the base station apparatus 10 to which the terminal apparatus 30 is not connected. One or both of the information indicating the power is included.

The base station transmission power information is information including transmission power information indicating the transmission power of the own device and transmission power information indicating the transmission power of the adjacent base station device 10.
The setting information is information indicating transmission power parameters (correction coefficient α, fixed offset P_O_NOMINAL_PUSCH, fixed offset P_O_UE_PUSCH, etc.) currently set in the own device.
The allocation information is information indicating an allocation result of each radio resource (RB; Resource Block) of each terminal apparatus 30 in each subframe when the above setting information is set, and the arrangement of the RB allocated to the terminal apparatus 30 , Allocation information indicating the number of allocated RBs M_PUSCH, coefficient Δ_TF, and transmission power command f.

  FIG. 3 is a diagram illustrating an example of allocation information. The arrangement information and the number of assigned RBs M_PUSCH are information indicating the number of radio resources allocated based on the setting information in the calculation section I as shown in FIG.

Returning to FIG. 2, the calculated section information is predetermined information indicating a section in which the estimated transmission power is calculated.
The local station path loss information is information indicating an estimated value of the path loss between the local apparatus used when obtaining the above allocation information in the wireless communication unit 12 and the terminal apparatus connected to the local apparatus.
The measurement information is information indicating a received power value of the packet in each terminal device 30 that has received a packet in which a transmission power parameter indicated by the setting information is set and radio resource allocation is performed according to the setting.

  The setting candidate storage unit 112 stores in advance a plurality of setting candidate information combinations of transmission power parameters to be notified to each terminal device 30. The setting candidate information is information that combines parameter candidates that can be set in the base station, such as P_O_NOMINAL_PUSCH candidates, α candidates, and P_O_UE_PUSCH candidates that are transmission power parameters in the uplink.

  The transmission power estimation unit 113, based on the setting candidate information stored in the setting candidate storage unit 112, and the setting information, allocation information, calculation section information, and own station path loss information input from the input information acquisition unit 111, Estimation of transmission power of the terminal device 30 connected to the own device when the transmission power parameter (hereinafter referred to as setting value) indicated by the setting information is changed to the transmission power parameter (hereinafter referred to as setting candidate value) indicated by the setting candidate information. A value (estimated transmission power) is calculated. Also, the transmission power estimation unit 113 receives the estimated transmission power information in which the estimated transmission power value of each terminal device 30 is associated with the setting candidate information when the estimated value is calculated, as the received power estimation unit 115, And output to the interference power estimation unit 116. Here, the estimated transmission power calculated by the transmission power estimation unit 113 indicates the transmission power of each of the terminal devices 30 connected to the own device when the combination of the power parameters indicated by the setting information is set, and the setting candidate information. For each combination of transmission power parameters, the transmission power of each terminal device 30 connected to the own device when the combination of transmission power parameters is set.

A specific calculation method in the transmission power estimation unit 113 will be described below.
In each subframe (i) included in the calculation section I indicated by the calculation section information, the terminal apparatus 30 connected to the own apparatus (base station apparatus 10 (x)), to which the radio resource is allocated The estimated transmission power P_PUSCH (x, u, i) of 30 (u) is calculated by the following equation (2). The estimated transmission power P_PUSCH (x, u, i) [dBm] is the estimated transmission power when setting information that is the current transmission power parameter is set.
Here, x indicates any one of the base station apparatuses 10 in the wireless communication system 1, and u indicates any one of the terminal apparatuses 30 connected to the base station apparatus 10 (x). . Further, i indicates one of the subframes included in the calculation section I. For example, the estimated transmission power P_PUSCH (x, u, i) indicates an estimated value of transmission power in the subframe (i) by the terminal device 30 (u) connected to the base station device 10 (x).

  Similarly, in each subframe (i) included in the calculation section I indicated by the calculation section information, the terminal apparatus 30 connected to the own apparatus (base station apparatus 10 (x)), to which radio resources are allocated. The estimated transmission power P_PUSCH ′ (x, u, i) of the terminal device 30 (u) is calculated by the following equation (3). The estimated transmission power P′_PUSCH (x, u, i) [dBm] is the estimated transmission power when the transmission power parameter indicated by the setting candidate information is set.

Here, the fixed offset P_O_NOMINAL_PUSCH ′ and the correction coefficient α ′ are candidate values of the fixed offset P_O_NOMINAL_PUSCH and the correction coefficient α indicated by the setting candidate information.
The transmission power estimation unit 113 uses the estimated transmission power P_PUSCH (x, u, i) and P_PUSCH ′ (x, u, i) calculated by the equations (2) and (3), the setting information, and the setting candidate information. The associated estimated transmission power information is output to reception power estimation section 115 and interference power estimation section 116.

  Based on the MR information input from the input information acquisition unit 111 and the base station transmission power information, the path loss estimation unit 114 is connected to the base station device 10 disposed in the vicinity of the own device and the own device. Path loss information indicating a propagation loss with the terminal device 30 is output. In addition, the path loss estimation unit 114 uses the terminal device 30 that has notified the MR information including the received power information from the adjacent base station device 10 among the MR information acquired by the own device, as a target terminal device for calculating the path loss. 30.

  Specifically, the path loss estimator 114 uses the following equation (4) to determine whether the terminal device 30 (u) that is to calculate the path loss among the terminal devices 30 and the adjacent base station device 10 (y). A path loss PL (y, u) [dB] is calculated.

  Here, P_TX_eNB (y) is the transmission power of the adjacent base station apparatus 10 (y). RSRP (y, u) is the received power from the adjacent base station apparatus 10 (y) measured by the terminal apparatus 30 (u). The path loss estimation unit 114 calculates the path loss for each terminal device 30 for which the path loss is calculated using the equation (4), and includes the calculated path loss and information indicating the base station device 10 (y). The path loss information is output to the interference power estimation unit 116.

  When the reception power estimation unit 115 sets the transmission power parameter indicated by the setting candidate information based on the estimated transmission power information input from the transmission power estimation unit 113 and the measurement information input from the input information acquisition unit 111 The estimated value of the received power of the signal received from the terminal device 30 connected to the own device is calculated. Also, the received power estimation unit 115 sends estimated received power information in which the estimated value of the received power calculated is associated with the setting candidate information when the estimated value is calculated to the base station management server 20 through the network communication unit 13. Send.

A calculation method for estimating the received power in the received power estimation unit 115 will be described below.
The transmission power difference ΔP_PUSCH (x, u, i) [dB] when the transmission power parameter is changed from the transmission power parameter indicated by the setting information to the transmission power parameter indicated by the setting candidate information is calculated by the following equation (5). .

  Each terminal in each subframe (i) when the transmission power parameter is changed from the transmission power difference ΔP_PUSCH (x, u, i) accompanying the change of the transmission power parameter calculated by Expression (5) and the measurement information The estimated received power P′_RX (x, u, i) [mW] from the device 30 is calculated by the following equation (6).

  Here, P_RX (x, u, i) is the received power after antenna combination indicated by the measurement information. Note that the estimated average received power P_RX ′ [mW] for each terminal apparatus 30 may be calculated using the following equation (7) to obtain an estimated value of the received power.

  Here, N_assign (x, u) is the number of subframes to which the radio resource is allocated in the calculation section I by the terminal device 30 (u) connected to the base station device 10 (x).

  Based on the estimated transmission power information input from the transmission power estimation unit 113 and the adjacent base station path loss information input from the path loss estimation unit 114, the interference power estimation unit 116 determines a setting candidate from the transmission power parameter indicated by the setting information. When the transmission power parameter indicated by the information is changed, the adjacent base station apparatus 10 calculates an estimated value of the received power (interference power) of the signal received from the terminal apparatus 30 connected to the own apparatus. Further, the interference power estimation unit 116 transmits estimated interference power information in which the calculated estimated value is associated with the setting candidate information when the estimated value is calculated to the base station management server 20 through the network communication unit 13.

  FIG. 4 is a diagram showing an overview of the estimated value of interference power calculated by the interference power estimation unit 116. As shown in the figure, interference is received in the adjacent base station apparatus 10 (y) by a signal transmitted by the terminal apparatus 30 (u) connected to the own apparatus (x). The interference power estimation unit 116 determines the base station apparatus 10 (y) from the estimated transmission power of the terminal apparatus 30 (u) and the path loss between the terminal apparatus 30 (u) and the base station apparatus 10 (y). The estimated value of the interference power at is calculated.

A specific calculation method in the interference power estimation unit 116 will be described below.
The interference power estimation unit 116 is a terminal device 30 connected to the own device (x), and the path loss estimation unit 114 obtains the path loss information with the adjacent base station device 10 (y). The estimated interference power P_RX (x → y) [mW], which is an estimated value of the interference power from the terminal device 30 (u) to the adjacent base station device 10 (y) based on the setting information, is expressed by the following equation (8). Calculated by

Here, N_I is the number of subframes in the calculation interval I.
Similarly, the interference power estimation unit 116 estimates the interference power P_RX ′ (x → y) that is an estimated value of interference power from the terminal device 30 (u) to the adjacent base station device 10 (y) based on the setting candidate information. ) [MW] is calculated by the following equation (9).

  The interference power estimation unit 116 includes the estimated interference power P_RX (x → y) and P_RX ′ (x → y) calculated by the equations (8) and (9), and setting information and settings when the estimated interference power is calculated. The estimated interference power information associated with the candidate information is transmitted to the base station management server 20 through the network communication unit 13.

  FIG. 5 is a schematic block diagram showing the configuration of the base station management server 20 in the present embodiment. As shown in the figure, the base station management server 20 communicates with each base station apparatus 10 via a network 40 and an adjacent base station information storage unit 21 that stores a list of adjacent base station apparatuses 10. A communication quality estimation unit 23 that estimates the communication quality in each base station apparatus 10 based on the estimated received power information and the estimated interference power information calculated in the base station apparatus 10, and the communication quality And a base station control unit 24 that controls each base station device 10 based on the communication quality estimated by the estimation unit 23.

The adjacent base station information storage unit 21 stores a list of adjacent base station devices 10 for each base station device 10. The network communication unit 22 communicates with each base station device 10 via the network 40, and outputs the estimated received power information and the estimated interference power information received from each base station device 10 to the communication quality estimation unit 23. .
Based on the estimated received power information and the estimated interference power information input from the network communication unit 22 and the adjacent base station list stored in the adjacent base station information storage unit 21, the communication quality estimation unit 23 Communication quality in the station apparatus 10 is estimated.

Hereinafter, communication quality estimation by the communication quality estimation unit 23 will be described.
Here, a case where the index indicating the communication quality is SIR (Signal to Interference Ratio) will be described.
The communication quality estimation unit 23 uses the estimated received power information and the estimated interference power information input from the network communication unit 22 to transmit the transmission power indicated by the setting candidate information from the transmission power parameter (hereinafter, set value) indicated by the setting information. When the transmission power parameter is changed to a parameter (setting candidate value), an estimated value of SIR between each base station apparatus 10 and the terminal apparatus 30 connected to the base station apparatus 10 is calculated for each terminal apparatus 30. Further, the communication quality estimation unit 23 outputs the estimated communication quality information in which the estimated value of SIR is associated with the setting candidate information when the estimated value is calculated, to the base station control unit 24.

  The communication quality estimation unit 23 calculates an estimated communication quality SIR ′ (x, u, i) that is an estimated value of SIR for each subframe by the following equation (10).

  The estimated communication quality SIR ′ (x, u) for each terminal device 30 may be calculated by the following equation (11).

  Here, the estimated received power P′_RX is the estimated received power calculated in the base station apparatus 10 included in the estimated received power information. P′_I is an interference power value [mW] expressed by the following equation (12).

  In Expression (12), interference power P_I_measured [mW] is interference power measured by the base station apparatus 10 using DM-RS (Demodulation Reference Signal), and is expressed by the following Expression (13). Calculated.

Here, r is an identifier for identifying a resource block (RB). R is a set of RBs that can be allocated to the PUSCH in the base station apparatus 10 (x). N_PUSCH is the number of RBs that can be allocated to PUSCH. P_I_DMRS (x, i, r) is interference power in the subframe i in the calculation interval I and the resource block r included in the subframe i in the base station apparatus 10 (x).
Further, in Expression (12), the change amount ΔP_I_est [mW] is a change amount of interference power estimated when the setting value is changed to the setting candidate value. Further, the change amount ΔP_I_est is calculated by the following equation (14).

  Here, P′_I_est (x) and P_I_est (x) are calculated by the following equations (15) and (16).

  Here, when P_RX (y → x) is a set value in the base station apparatus 10 (y), the base station apparatus 10 (x) adjacent to the base station apparatus 10 (y) y) is an estimated value of interference power received from the terminal device 30 connected to the terminal device 30, and is a value included in the estimated interference power information calculated in the base station device 10 (y).

Further, P′_RX (y → x) indicates that when the setting candidate value is used in the base station apparatus 10 (y), the base station apparatus 10 (x) adjacent to the base station apparatus 10 (y) 10 (y) is an estimated value of interference power received from the terminal device 30 connected to the terminal device 30, and is a value included in the estimated interference power information calculated in the base station device 10 (y).
In addition, the Nightlist in Expressions (15) and (16) is the value of the base station device 10 arranged adjacent to the base station device 10 for each base station device 10 stored in the adjacent base station information storage unit 21. It is a list.

  As described above, the communication quality estimation unit 23 calculates the estimated value of SIR when the transmission power parameter is changed by using Expressions (10) to (16). Further, the communication quality estimation unit 23 outputs the estimated communication quality information in which the estimated value of SIR is associated with the setting candidate information when the estimated value is calculated, to the base station control unit 24.

The base station control unit 24 generates a control signal for controlling each base station apparatus 10 based on the communication quality estimated by the communication quality estimation unit 23 and transmits the control signal through the network communication unit 22.
For example, the base station control unit 24 uses the communication quality information calculated by the communication quality estimation unit 23 to set the setting candidate information for which the average SIR value of each terminal device 30 is equal to or greater than a predetermined threshold value to the base station. Select for each device 10. Then, the base station control unit 24 transmits a control signal for setting the transmission power parameter indicated by the selected setting candidate information to a new transmission output parameter to each base station device 10 through the network communication unit 22.

  According to the wireless communication system 1 of the present embodiment, in each base station apparatus 10, the transmission power estimation unit 113 sets the transmission power parameter for each subframe of each terminal apparatus 30 connected to the base station apparatus 10. A change amount ΔP_PUSCH (x, u, i) of the estimated value of transmission power when the current setting value is changed to the setting candidate value is calculated. Then, for each subframe of the terminal device 30, the received power estimation unit 115 and the measured value of the received power P_RX (x, u, i) indicated by the measurement information and the calculated change amount ΔP_PUSCH (x, u, i) ) And the estimated received power P′_RX (x, u, i) when the transmission power parameter is changed from the current setting value to the setting candidate value.

As described above, the estimated received power P′_RX (x, u, i) when the setting candidate value is applied is calculated using the actually measured received power P_RX (x, u, i). The received power can be estimated in accordance with the situation in which the system 1 is operated, and the accuracy of the estimated value of the received power in each base station apparatus 10 can be improved. That is, since the estimated received power P′_RX (x, u, i) is calculated based on the actual distribution of the terminal devices 30, the accuracy of the estimated value of the received power in each base station device 10 can be improved.
Further, since the received power is estimated including factors that are not parameterized in the computer simulation, the accuracy of the estimated value of the received power in each base station apparatus 10 can be improved.

  Further, the interference power estimation unit 116 is adjacent to the own device based on the estimated transmission power value of the terminal device 30 connected to the own device calculated by the transmission power estimation unit 113 and the path loss calculated from the MR information. The estimated value of the interference power with respect to the base station apparatus 10 is calculated. Thus, since the interference power is calculated based on the distribution of the actual terminal devices 30 by using the path loss calculated from the MR information in accordance with the situation in which the wireless communication system 1 is operated, each base station device 10 The accuracy of the estimated value of the interference power at can be improved. Also, since the interference power P_I_measured, which is an actual measurement value, is used in calculating the estimated value of the interference power, the interference power P′_I includes the factors that are not parameterized in the computer simulation, and estimates the interference power. As a result, the accuracy of the estimated value of the interference power in each base station apparatus 10 can be improved.

  Then, by improving the accuracy of the estimated value of the received power in each base station apparatus 10 and the estimated value of the interference power for each base station apparatus 10, the accuracy of the estimated value of communication quality calculated using these estimated values Can also be improved.

(Second Embodiment)
Next, a radio communication system according to the second embodiment will be described. In the wireless communication system according to the second embodiment, the base station apparatus is different from the base station apparatus 10 included in the wireless communication system 1 according to the first embodiment. Since the configuration of the base station management server is the same as that of the base station management server 20 (FIG. 5) of the first embodiment, the description thereof is omitted.

  FIG. 6 is a schematic block diagram showing the configuration of the base station device 50 in the second embodiment. As shown in the figure, the base station device 50 communicates with the terminal device 30 and a wireless power estimation unit 51 that calculates estimated reception power, estimated interference power, and estimated noise power when changing the transmission power parameter. A wireless communication unit 12 and a network communication unit 13 that communicates with another base station device 50 and the base station management server 20 via a network 40 are provided.

  The wireless power estimation unit 51 includes an input information acquisition unit 111, a setting candidate storage unit 112, a transmission power estimation unit 113, a path loss estimation unit 114, a reception power estimation unit 115, an interference power estimation unit 116, and a noise power estimation unit 517. ing. Further, the wireless power estimation unit 51 is different from the wireless power estimation unit 11 (FIG. 2) of the first embodiment in that a noise power estimation unit 517 is included. Hereinafter, the same reference numerals are given to the same components as those of the wireless power estimation unit 11 of the first embodiment, the description thereof will be omitted, and the noise power estimation unit 517 having a different configuration will be described.

  The noise power estimation unit 517 measures the noise power density, noise figure (NF), etc. based on the signal received by the wireless communication unit 12, and estimates the noise power per resource block. Is calculated. Also, the noise power estimation unit 517 transmits estimated noise power information indicating the calculated estimated noise power value to the base station management server 20 through the network communication unit 13. Measurements such as noise power density and noise figure (NF; Noise Figure) may be performed in a time zone in which communication with the terminal device 30 is not performed or hardly performed. Also, a predetermined set value may be used for the noise power density and the noise figure.

Since the base station apparatus 50 includes the noise power estimation unit 517, the communication quality estimation unit 23 of the base station management server 20 uses an SINR (Signal to Interference and Noise Ratio) as an index indicating the communication quality. Ratio) can be calculated.
Specifically, the communication quality estimation unit 23 can calculate the estimated value of SINR by using the following equations (17) and (18) instead of equations (10) and (11).

Here, P_N (x) is an estimated value of noise power calculated by the noise power estimation unit 517.
Thereby, the wireless communication system of the second embodiment can estimate the communication quality using SINR as an index, and in an environment where noise power has a large influence on the communication quality, the wireless communication system 1 of the first embodiment The accuracy of the estimated value of communication quality can be improved.
In the equation (12), when the interference power P′_I (x) becomes a negative value, it may be handled as “0”.

(Third embodiment)
Hereinafter, the radio | wireless communications system in 3rd Embodiment is demonstrated. In the wireless communication system according to the third embodiment, the base station apparatus is different from the base station apparatus 10 included in the wireless communication system 1 according to the first embodiment. Since the configuration of the base station management server is the same as that of the base station management server 20 (FIG. 5) of the first embodiment, the description thereof is omitted.

  FIG. 7 is a schematic block diagram showing the configuration of the base station device 60 in the third embodiment. As shown in the figure, the base station device 60 includes a wireless power estimation unit 61 that calculates estimated received power and estimated interference power when changing transmission parameters, and a wireless communication unit 12 that communicates with the terminal device 30. A network communication unit 13 that communicates with another base station device 60 and the base station management server 20 via the network 40 is provided.

  The wireless power estimation unit 61 includes an input information acquisition unit 111, a setting candidate storage unit 112, a transmission power estimation unit 613, a path loss estimation unit 114, a reception power estimation unit 115, an interference power estimation unit 116, and an allocation information correction unit 617. ing. Further, the wireless power estimation unit 61 has the allocation information correction unit 617 and the transmission power estimation unit 613 in place of the transmission power estimation unit 113 (FIG. 2). This is different from the wireless power estimation unit 11 of the embodiment. Hereinafter, the same reference numerals are given to the same components as those of the wireless power estimator 11 of the first embodiment, the description thereof is omitted, and the allocation information correction unit 617 and the transmission power estimator 613 which are different configurations. explain.

The allocation information correction unit 617 includes an allocation candidate information generation unit 618 and a management table storage unit 619. The allocation candidate information generation unit 618 calculates an average (simple average or smoothed average) of allocation information in the period indicated by the calculation section information for each terminal information and setting information input from the wireless communication unit 12. Also, the allocation candidate information generation unit 618 associates the terminal information and setting information when the average value is calculated with the allocation candidate information that is the calculated average value, and causes the management table storage unit 619 to store the association information.
The management table storage unit 619 stores a management table in which allocation candidate information calculated by the allocation candidate information generation unit 618 is associated with terminal information and setting information.
The terminal information includes, for example, downlink WideBand CQI, path loss between the own device and the terminal device 30, a difference in path loss between the adjacent base station device 60 and the terminal device 30 calculated by the own device and the path loss estimation unit 114, RSRP, RSRQ, RSSI, For example, the buffer amount.

  FIG. 8 is a diagram illustrating an example of a management table in the present embodiment. As shown in the figure, in the management table, terminal information (WideBand CQI in the figure) and the average value of the assignment information (number of assigned RBs in the figure) correspond to each setting information (correction coefficient α in the figure). It is attached. For example, the management table indicates that when WideBandCQI is 3 and the correction coefficient α is 0.8, five RBs are allocated on average from past allocation information (M_PUSCH = 5).

That is, the allocation information correction unit 617 is expected in the period indicated by the calculation interval information when given allocation information and terminal information are given from the correspondence relationship between the terminal information, the allocation information, and the past transmission power parameter. Allocation information calculated from past allocation information is stored.
Although FIG. 8 shows an example in which the number of RBs corresponding to the WideBand CQI and the correction coefficient α is calculated and stored, the present invention is not limited to this, and other combinations may be used. Further, the allocation information may be associated with the change amount of the setting information, and the offset amount with respect to the setting information may be stored in the management table storage unit 617.

Returning to FIG. 7, the transmission power estimation unit 613 is input from the setting candidate information stored in the setting candidate storage unit 112, the management table stored in the allocation information correction unit 617, and the input information acquisition unit 111. Connected to the own device when the transmission power parameter indicated by the setting information is changed to the transmission power parameter indicated by the setting candidate information (hereinafter, the setting candidate value) based on the setting information, the calculation section information, and the local station path loss information. The estimated value of the transmission power of the terminal device 30 is calculated. Also, the transmission power estimation unit 613 reads the allocation candidate information corresponding to the setting candidate value from the management table storage unit 619 when calculating the estimated value of the transmission power of the terminal device 30, and determines the transmission power of the terminal device 30. Used to calculate the estimated value.
Specifically, the transmission power estimation unit 613 calculates an estimated value [dBm] of transmission power using the following equation (19).

  Here, M_PUSCH ′ is allocation candidate information corresponding to the setting candidate value, and indicates allocation information expected when the setting candidate value is used.

  In the wireless power estimator 11 of the first embodiment and the wireless power estimator 51 of the second embodiment, allocation information corresponding to setting information is calculated when calculating an estimated value of transmission power when using the setting candidate information. Was used. On the other hand, in the wireless power estimation unit 61 of the present embodiment, the allocation information when the setting candidate information is used is transmitted using the allocation candidate information obtained by correcting the allocation information using statistical information based on past allocation information. Since the estimated power value is calculated, it is possible to calculate the estimated transmission power value in accordance with the actual operation, and to improve the accuracy of the estimated transmission power value.

  That is, the wireless power estimation unit 61 of this embodiment calculates allocation candidate information in which the allocation information correction unit 617 corrects the allocation information according to the setting candidate information, and the transmission power estimation unit 613 calculates the allocation candidate information calculated. Used to calculate the estimated value of the transmission power. Thereby, the wireless power estimation unit 61 can set the estimated value of the transmission power to a value in accordance with the operation of the wireless communication system, and can improve the accuracy of the estimated value of the transmission power.

  Further, by calculating the estimated received power information and the estimated interference power information from the past radio resource allocation information in each base station device 60, the base station management server 20 allows the user arrangement, traffic distribution, It is possible to estimate the communication quality following the environmental change such as station arrangement with high accuracy. Further, by taking into account the expected amount of change in the allocation information with respect to the measured value of the current transmission power parameter (setting information), it is possible to estimate with high accuracy even in unexpected interference.

  Note that the transmission power estimation unit 613 assigns an allocation candidate when an index (a radio resource usage rate, a generated traffic amount, etc.) indicating the degree of congestion with the terminal device 30 of the own device is equal to or greater than a predetermined threshold. You may make it calculate the estimated value of transmission power using the allocation information which the input information acquisition part 111 acquired, without using information. For example, when the usage rate of the radio resource of the own device or the generated traffic amount is high, that is, when it is congested, the number of RBs allocated to the radio resource for each terminal device 30 often does not change. The need to do is low. Therefore, the transmission power estimation unit 613 determines the necessity of correction based on the degree of congestion, and the processing amount in the wireless power estimation unit 61 can be reduced by omitting correction when it is congested.

(Fourth embodiment)
Hereinafter, the radio | wireless communications system in 3rd Embodiment is demonstrated. In the wireless communication system according to the third embodiment, the base station apparatus is different from the base station apparatus 10 included in the wireless communication system 1 according to the first embodiment. Since the configuration of the base station management server is the same as that of the base station management server 20 (FIG. 5) of the first embodiment, the description thereof is omitted.

  FIG. 9 is a schematic block diagram illustrating the configuration of the base station device 70 in the fourth embodiment. As shown in the figure, the base station device 70 includes a wireless power estimation unit 71 that calculates estimated received power and estimated interference power when changing transmission parameters, and a wireless communication unit 12 that communicates with the terminal device 30. A network communication unit 13 that communicates with another base station device 70 and the base station management server 20 via the network 40 is provided.

  The wireless power estimation unit 71 includes an input information acquisition unit 111, a setting candidate storage unit 112, a transmission power estimation unit 713, a path loss estimation unit 114, a reception power estimation unit 115, an interference power estimation unit 116, and a wireless scheduler 717. . Further, the wireless power estimation unit 71 includes a wireless scheduler 717, and a transmission power estimation unit 713 in place of the transmission power estimation unit 113 (FIG. 2) is the first embodiment. This is different from the wireless power estimation unit 11. Hereinafter, the same components as those of the wireless power estimation unit 11 of the first embodiment are denoted by the same reference numerals, description thereof is omitted, and the wireless scheduler 717 and the transmission power estimation unit 713 having different configurations will be described. .

  The radio scheduler 717 simulates (simulates) radio resource allocation in the radio communication unit 12, performs radio resource allocation based on setting information or setting candidate information input from the transmission power estimation unit 713, and determines the allocation result. Certain allocation candidate information is output to transmission power estimation section 713.

The transmission power estimation unit 713 receives the setting information based on the setting candidate information stored in the setting candidate storage unit 112 and the setting information, calculation section information, and own station path loss information input from the input information acquisition unit 111. When the transmission power parameter shown is changed to the transmission power parameter (hereinafter, setting candidate value) indicated by the setting candidate information, an estimated value of the transmission power of the terminal device 30 connected to the own device is calculated. Further, when calculating the estimated value of the transmission power of the terminal device 30, the transmission power estimation unit 713 uses the allocation candidate information corresponding to the setting candidate value input from the radio scheduler 717 as the estimated value of the transmission power of the terminal device 30. Used to calculate
Specifically, the transmission power estimation unit 713 calculates an estimated value [dBm] of transmission power using the following equation (20).

  Here, the number of assigned RBs M_PUSCH ′, the coefficient Δ_TF ′, and the transmission power command f ′ are radio resource allocation results calculated by the radio scheduler 717 based on the transmission power parameter indicated by the setting candidate value.

  In the wireless power estimation unit 71 of this embodiment, the wireless scheduler 717 simulates the wireless resource allocation of the wireless communication unit 12 to calculate allocation candidate information according to the setting candidate information, and the transmission power estimation unit 713 is calculated. The estimated value of transmission power is calculated using the allocation candidate information. Thereby, the radio | wireless power estimation part 71 can make the estimated value of transmission power into the value according to operation | movement of a radio | wireless communications system, and can improve the precision of the estimated value of transmission power.

In the above-described embodiments, the configuration in which the wireless power estimation unit 11 (51, 61, 71) is provided in each base station device 10 (50, 60, 70) has been described. It is good also as an independent apparatus provided for every (50, 60, 70).
Further, the noise power estimation unit 517 included in the base station device 50 of the second embodiment is provided in the base station device 60 of the third embodiment or the base station device 70 of the fourth embodiment, so that the base station management server SINR may be calculated as an index 20 represents communication quality.

  Further, in each of the above-described embodiments, the configuration candidate storage unit 112 included in the wireless power estimation unit 11 (51, 61, 71) has been described as previously storing configuration candidate information. However, the present invention is not limited to this. The setting candidate information may be distributed from the base station management server 20. Moreover, in each above-mentioned embodiment, although each base station apparatus 10 demonstrated the structure provided with the wireless power estimation part 11 (51, 61, 71), it is not restricted to this, Each wireless power estimation part 11 ( 51, 61, 71) may be configured as independent devices, or the base station management server 20 may include the wireless power estimation units 11 (51, 61, 71). In this case, various types of input information used for estimation of received power and interference power may be input to the wireless power estimation unit 11 (51, 61, 71) via the network 40.

  The base station apparatus 10 (50, 60, 70) described above may have a computer system therein. In that case, the above-described input information acquisition unit, setting candidate storage unit, transmission power estimation unit, path loss estimation unit, reception power estimation unit, interference power estimation unit, noise power estimation unit, allocation candidate information generation unit, management table storage unit, The process of each component of the wireless scheduler is stored in a computer-readable recording medium in the form of a program, and the above process is performed by the computer reading and executing this program. 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 ... Wireless communication system 10, 50, 60, 70 ... Base station apparatus 11, 51, 61, 71 ... Wireless power estimation part 12 ... Wireless communication part 13, 22 ... Network communication part 20 ... Base station management server 21 ... Adjacent base Station information storage unit 23 ... Communication quality estimation unit 24 ... Base station control unit 30 ... Terminal device 40 ... Network 111 ... Input information acquisition unit 112 ... Setting candidate storage units 113, 613, 713 ... Transmission power estimation unit 114 ... Path loss estimation unit 115: Received power estimation unit 116 ... Interference power estimation unit 517 ... Noise power estimation unit 617 ... Allocation information correction unit 618 ... Allocation candidate information generation unit 619 ... Management table storage unit 717 ... Radio scheduler

Claims (6)

A wireless communication system comprising a plurality of base station devices that perform wireless communication with a terminal device, and a management server connected to the plurality of base station devices,
The base station device
A first estimated transmission power that is an estimated value of the transmission power of the terminal device when using a current setting value of a transmission power parameter that determines the transmission power of the terminal device, and a transmission power parameter that is different from the setting value. The difference between the second estimated transmission power, which is an estimated value of the transmission power of the terminal device when using the candidate value, is calculated, and the calculated difference from the terminal device measured when using the set value A received power estimation unit that calculates the estimated received power by adding the received power;
Based on the path loss between the terminal device in wireless communication with the own device and the other base station device adjacent to the own device, the first estimated transmission power and the second estimated transmission power, An interference power estimation unit that calculates estimated interference power in another base station device, and
The management server
For each base station apparatus, from the estimated received power calculated in the base station apparatus and the estimated interference power for the base station apparatus calculated in the base station apparatus adjacent to the base station apparatus, A wireless communication system, comprising: a communication quality estimation unit that calculates communication quality with the terminal device. The base station device further includes:
A measurement result report notified from the terminal device that is performing radio communication with the own device, and based on the measurement result report indicating the received power of the signal received from the base station device adjacent to the own device. 2. A path loss estimation unit that determines whether or not the terminal device that has transmitted the result report is the target of the path loss calculation, and calculates the path loss based on the measurement result report. The wireless communication system according to 1. The base station device further includes:
The first estimated transmission power is calculated based on allocation information indicating radio resources allocated according to the setting value and the setting value, and the second estimation is performed based on the allocation information and the candidate value. The wireless communication system according to claim 1, further comprising: a transmission power estimation unit that calculates estimated transmission power. The base station device further includes:
Allocation of radio resources corresponding to the candidate value based on the correspondence relationship between the terminal information indicating the communication status of the terminal device, the allocation information, and the transmission power parameter in the past communication between the own device and the terminal device An allocation information correction unit for calculating
The radio communication system according to claim 3, wherein the transmission power estimation unit calculates the second estimated transmission power using radio resource allocation calculated by the allocation information correction unit. The allocation information correction unit
The allocation information is calculated as an allocation of radio resources corresponding to the candidate value when an index indicating a degree of congestion of radio communication between the own device and the terminal device is equal to or greater than a predetermined threshold value. The wireless communication system according to claim 4. The communication quality estimation unit
For each base station apparatus, the interference power estimation unit calculates the interference power measured in the base station apparatus based on the first estimated transmission power in the base station apparatus adjacent to the base station apparatus. A difference between the estimated interference power and the estimated interference power calculated by the interference power estimation unit based on the second estimated transmission power is added to calculate an estimated value of interference power, and the communication quality is calculated using the calculated estimated value. The wireless communication system according to any one of claims 1 to 5, wherein the wireless communication system is calculated.

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