KR102203818B1 - Interference control device and control method thereof - Google Patents

Abstract

The present invention controls the transmission power of a flexible neighboring cell having a neighboring relationship with a flexible reference cell that changes according to the location of a specific terminal (eg, SPID/ARP terminal), away from the existing CRS-IC function operation method. Then, by changing the handover position offset, a new method of interference control technology (function) that reduces cell interference to a cell (a dynamic reference cell) in which a specific terminal (eg, SPID/ARP terminal) is located is proposed.

Description

Interference control device and interference control method {INTERFERENCE CONTROL DEVICE AND CONTROL METHOD THEREOF}

The present invention relates to a technique for controlling inter-cell interference in an environment where coverage overlap between cells is mixed and traffic is high.

In the LTE system, the type of main terminal that accesses the base station and uses the LTE service by accessing the Core Network network through the base station is the subscriber's personal terminal (eg, smartphone, etc.).

On the other hand, as the number of subscribers increases since the LTE technology was commercialized, the service frequency continues to increase and the number of cells is also increasing, so that interference between cells due to overlapping coverage between cells is increasing.

Currently, as a method of minimizing inter-cell interference, the CRS-IC function that lowers the transmission power of neighboring cells based on the cell is used, but the CRS-IC function improves the performance of reducing inter-cell interference in areas with a lot of traffic. There is a drawback that it is not visible and real-time application is not guaranteed.

Considering that the interference of neighboring cells to the cell is high in urban areas with a lot of traffic, the disadvantage of the existing CRS-IC function is quite fatal.

Accordingly, in the present invention, a new interference control capable of guaranteeing real-time performance while exhibiting sufficient performance even in an area with high traffic by operating based on the terminal, deviating from the operation method of the existing CRS-IC function based on the cell. I would like to suggest a function.

The present invention was created in view of the above circumstances, and an object to be reached in the present invention is a new method of inter-cell interference control technology that operates based on a terminal in an environment where coverage overlap between cells is mixed and traffic is high ( Function).

An interference control apparatus according to a first aspect of the present invention for achieving the above object includes: a cell identification unit for identifying a cell in which a specific terminal is located; A neighboring cell checking unit that checks a neighboring cell having a predefined neighboring relationship with the cell; And a control unit for controlling the transmission power of the neighboring cell when the cell is checked to reduce interference of the neighboring cell to the cell, and an offset control unit for controlling a handover condition change offset according to a change in existing coverage (offset change unit). Includes.

Specifically, the specific terminal may be a terminal in which a specific factor value is set based on a Subscriber Profile ID (SPID) or Allocation and Retention Priority (ARP) set for each terminal.

Specifically, an offset changer configured to compensate for a coverage change according to the transmission power control of the neighboring cell by changing an offset value related to handover set in a terminal located in the cell when the transmission power of the neighboring cell is controlled. I can.

Specifically, the offset value is, in the process of comparing the signal reception strength of the serving cell and the signal reception strength of the target cell and reporting the comparison result for a handover attempt to the target cell, the signal reception strength and the target It may be an offset value used when comparing the signal reception strength of the cell.

Specifically, the offset value may be a value determined according to a degree to which the transmission power of the neighboring cell is changed.

Specifically, the neighboring cell identification unit checks a neighboring cell belonging to the relational list as a neighboring cell having a neighboring relationship with the cell, based on a relation list indicating a neighboring cell having a handover history for the cell. I can.

Specifically, the controller may attenuate the transmission power by adjusting a value of a pre-defined attenuation parameter for attenuation of the transmission power intensity for each of the neighboring cells.

Specifically, when the specific terminal is operating using a primary cell and a secondary cell, the neighboring cell identification unit checks the neighboring cells for each of the primary and secondary cells, and the control unit, An operation of controlling transmission power for a cell adjacent to the primary cell and a cell adjacent to the auxiliary cell may be performed, respectively.

Specifically, when the specific terminal is operating using two or more cells serving different frequency bands, the neighboring cell check unit checks the neighboring cells for each of the two or more cells, and the control unit, for each of the two or more cells. Each operation of controlling the transmission power can be performed for the confirmed neighboring cells.

In the interference control method performed in a base station according to a second aspect of the present invention for achieving the above object, the cell identification step of confirming a cell in which a specific terminal is located; A neighboring cell checking step of checking neighboring cells having a predefined neighboring relationship with the cell; And a control step of controlling the transmission power of the neighboring cell when the cell is checked, so that interference of the neighboring cell on the cell is reduced.

Specifically, the specific terminal may be a terminal in which a specific factor value is set based on a Subscriber Profile ID (SPID) or Allocation and Retention Priority (ARP) set for each terminal.

Specifically, an offset change step of changing an offset value related to handover set in a terminal located in the cell when controlling the transmission power of the neighboring cell to compensate for a coverage change according to the transmission power control of the neighboring cell is further included. can do.

Specifically, the offset value is, in the process of comparing the signal reception strength of the serving cell and the signal reception strength of the target cell and reporting the comparison result for a handover attempt to the target cell, the signal reception strength and the target It may be an offset value used when comparing the signal reception strength of the cell.

Specifically, the offset value may be a value determined according to a degree to which the transmission power of the neighboring cell is changed.

Specifically, in the neighboring cell checking step, a neighboring cell belonging to the relational list is converted to a neighboring cell having a neighboring relationship with the cell, based on a relation list indicating a neighboring cell with a handover history for the cell. I can confirm.

Specifically, the control step may control attenuation of transmission power by adjusting a value of a pre-defined attenuation parameter for attenuation of transmission power intensity for each of the neighboring cells.

Accordingly, according to the interference control apparatus and the interference control method of the present invention, from the operation method of the existing CRS-IC function based on the cell, the neighboring cell having a neighboring relationship with the cell in which a specific terminal is located is It is possible to realize a new inter-cell interference control technology (function) in a manner of controlling transmission power.

Accordingly, according to the present invention, it is possible to exhibit sufficient performance to reduce inter-cell interference even in an area with a large amount of traffic, and to ensure real-time performance by enabling flexible inter-cell interference control in real time. It derives an effect that can dramatically improve the quality deterioration problem caused by.

1 is an exemplary diagram showing a system environment to which the interference control technology (function) of the present invention is applied.
2 is a block diagram showing the configuration of an interference control apparatus according to an embodiment of the present invention.
3 is an exemplary view showing a situation in which transmission power and A3 offset values of neighboring cells are controlled/changed according to an embodiment of the present invention.
4 is a flowchart showing an operation flow of an interference control method (function) according to an embodiment of the present invention.

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

1 shows a system environment to which the interference control technology (function) of the present invention is applied.

Since LTE technology was commercialized, as subscribers increase, service frequencies continue to increase and the number of cells is also increasing, so inter-cell interference due to overlapping coverage between cells is increasing.

Thus, as can be seen in Figure 1, a plurality of cell coverage is operated by overlapping (overlapping) with each other.

As shown in FIG. 1, the cell operated by overlapping may be a cell by each RRU (Remote Radio Unit) operated by the same base station (100, DU (Digital Unit)), and operated by different base stations. It may be a cell by each RRU.

Accordingly, in an environment where the RRU installation interval is narrow, inter-cell interference due to overlapping coverage between cells will increase.

Currently, as a method for minimizing inter-cell interference, the CRS-IC function is used.

CRS-IC (Cell Specific Reference Signal-Interference Cancellation) is a technology that operates in units of DU. After setting the reference cell among the cells of each RRU operated by the DU and the neighboring cells of the cell, transmission of neighboring cells It operates in a manner that reduces the output by a set value to reduce interference to the reference cell.

As described above, the conventional CRS-IC function, which lowers the transmission power of neighboring cells in units of DUs based on the cell, is an operation technology in units of DUs, and thus prevents inter-cell interference in areas where there is a lot of traffic in which cells of different DUs overlap. It does not show the performance to reduce, and since the basic settings such as surrounding cells/transmission output settings are fixed, there is a disadvantage that the real-time application is not guaranteed.

Considering that the interference of neighboring cells to the cell is high in urban areas with a lot of traffic, the disadvantage of the existing CRS-IC function is quite fatal.

Accordingly, in the present invention, a new interference control capable of guaranteeing real-time performance while exhibiting sufficient performance even in an area with high traffic by operating based on the terminal, deviating from the operation method of the existing CRS-IC function based on the cell. I would like to suggest a function.

More specifically, to propose an interference control device that realizes the interference control function (method) of the present invention.

Hereinafter, an interference control apparatus according to an embodiment of the present invention will be described in detail with reference to FIG. 2.

As shown in FIG. 2, the interference control apparatus 200 of the present invention may include a cell check unit 210, a neighbor cell check unit 230, and a control unit 240.

Furthermore, the interference control apparatus 200 of the present invention may further include an offset change unit 240.

In addition to this, the interference control apparatus 200 of the present invention may further include a communication unit 250.

The interference control device 200 of the present invention may be a separate device that controls related functions in each base station by interlocking with each base station (100, DU), or may be the same device as each base station (100, DU). have.

Hereinafter, for convenience of description, it is assumed that the interference control apparatus 200 of the present invention is the same apparatus as the base station 100 (DU).

Here, the communication unit 250 includes, for example, an antenna system, an RF transceiver, one or more amplifiers, a tuner, one or more oscillators, a digital signal processor, a codec chipset, and a memory, but is not limited thereto. Any known circuit to be performed may be included.

Accordingly, the interference control device 200, based on the communication unit 250, communicates with other base stations (eg, X2 interface), or accesses/communicates with the terminal to use various types of services provided by the core network network. Make it possible.

All or at least a part of the configuration of the interference control apparatus 200 may be implemented in the form of a hardware module or a software module, or may be implemented in a form in which a hardware module and a software module are combined.

Here, the software module may be understood as, for example, an instruction executed by a processor that controls an operation in the interference control device 200, and such a command may have a form mounted in a memory in the interference control device 200. There will be.

As a result, the interference control apparatus 200 according to an embodiment of the present invention realizes the new type of interference control function proposed in the present invention through the above-described configuration, and hereinafter, the interference control apparatus 100 for realizing this Each of my components will be described in more detail.

In the following, it is assumed that the interference control device 200 of the present invention is the same device as the base station 100 (DU), and the present invention will be described by referring to the base station 100 (DU).

The cell check unit 210 serves to check a cell in which a specific terminal is located.

That is, the cell verification unit 210, if there is a specific terminal among the terminals connected to the base station (100, DU), the corresponding specific terminal is among the cells of each RRU operated by the base station (100, DU (Digital Unit)) It is to check which cell is located (connected).

Here, the specific terminal is a terminal that serves as an operation criterion for servicing the interference control function proposed in the present invention, and for example, a terminal of a subscriber defined as having relatively high importance among a number of subscribers (e.g., a terminal of a specific type). , VIP subscriber's terminal, etc.).

As a method of classifying such a specific terminal, in the present invention, an embodiment using a Subscriber Profile ID (SPID) or Allocation and Retention Priority (ARP) will be described.

For example, according to an embodiment of the present invention, a specific terminal may be a terminal in which a specific factor value is set based on a Subscriber Profile ID (SPID) or Allocation and Retention Priority (ARP) set for each terminal.

Network priority information is set in each terminal, and the network priority information may be included in a terminal profile identifier, that is, SPID, transmitted from a mobility management entity (MME) or a home terminal server (HSS).

For example, if the SPID set in the UE is 256, the UE has priority in the E-UTRAN, and if the SPID set in the UE is 255, it means that the UE has priority in the UTRAN.

Accordingly, in the present invention, an SPID factor value set in a terminal to be used as an operation reference terminal for servicing the interference control function of the present invention may be set as a specific SPID factor value.

On the other hand, ARP, in the situation of insufficient resources in the LTE network, if a new EPS bearer needs to be created, whether to delete the existing EPS bearer and create a new EPS bearer (create a new EPS bearer with a high priority ARP factor value) It is a factor that determines whether to reject the creation of a new EPS bearer or delete an existing EPS bearer with a low priority ARP factor value.

Accordingly, in the present invention, an ARP factor value set in a terminal to be used as an operation reference terminal for servicing the interference control function of the present invention may be set as a specific ARP factor value.

Accordingly, the cell verification unit 210 receives the identification number of the terminal, the SPID and ARP managed by the mapping from the core node (eg, MME, HSS, etc.) to the terminal connected to the base station (100, DU) to the terminal. You can check the set SPID and parameter values in ARP.

The cell identification unit 210 classifies a terminal having a predetermined specific SPID factor value or a specific ARP factor value among terminals connected to the base station 100, DU as a specific terminal, and the specific base station 100, DU ( Digital Unit)), you can check which cell is located (accessed) from the cells of each RRU.

Hereinafter, for convenience of explanation, it is assumed that the terminal 10 of FIG. 1 is a specific terminal.

The neighboring cell checker 220 serves to check the cell checked by the cell checker 210, that is, a cell in which the specific terminal 10 is located, and a neighboring cell having a predefined neighboring relationship.

Specifically, the neighboring cell identification unit 220 identifies a neighboring cell belonging to the relational list based on a relation list indicating a neighboring cell that has a handover history with respect to the cell in which the specific terminal 10 is located. It can be identified as a neighboring cell having a neighboring relationship with the cell in which the terminal 10 is located.

Specifically, according to the present invention, for each cell, neighbors related to handover whenever a handover occurs, such as when a terminal handovers from a corresponding cell to a neighboring cell or a terminal handovers to a corresponding cell from a neighboring cell. You can manage the relationship list by listing information about the cell.

Accordingly, the neighboring cell identification unit 220 identifies all neighboring cells belonging to the relation list based on the relation list of the cell in which the specific terminal 10 is located among the relation lists managed for each cell. It can be identified as a neighboring cell that has a neighboring relationship with the cell where this is located.

The control unit 230 controls the transmission output (especially, the transmission output of the cell reference signal) of the neighboring cell checked by the neighboring cell identification unit 220 when the cell identification unit 210 checks the cell where the specific terminal 10 is located. , It serves to reduce the interference of neighboring cells to the cell in which the specific terminal 10 is located.

In the present invention, unlike the existing CRS-IC function in which a reference cell and a neighboring cell are fixed on a per DU basis, since the cell in which a specific terminal serving as an operation reference is located becomes the reference cell, the terminal-based reference cell is flexible and thus flexible. A neighboring cell having a neighboring relationship with the reference cell is also dynamically determined.

That is, the control unit 230 operates in a manner of controlling the transmission power of a flexible neighboring cell having a neighboring relationship with the reference cell when checking the flexible reference cell in which the specific terminal 10 is located, As a reference, cell interference to a cell in which a specific terminal 10 is located is reduced.

In this case, as a method of controlling the transmission power of the neighboring cells, any method may be employed as long as it is a control method capable of attenuating or increasing the transmission power intensity of the neighboring cells.

According to an embodiment of the present invention, the control unit 230 may control attenuation of transmission power by adjusting a value of a pre-defined attenuation parameter for attenuation of the transmission power intensity for each of the surrounding cells checked by the neighboring cell identification unit 220. have.

In each cell, an attenuation parameter (eg, Atten) for attenuation of the transmit power intensity may be defined.

Accordingly, the control unit 230 may attenuate the transmission power by adjusting a parameter value of an attenuation parameter (eg, Atten) for each of the neighboring cells checked by the neighboring cell checker 220.

If there is a cell operated by another base station (DU) among the neighboring cells checked by the neighboring cell identification unit 220, the control unit 230 may use an attenuation parameter for the neighboring cell through inter-base station communication (e.g., X2 interface). Transmit power can be attenuated by adjusting the parameter value of (Example: Atten).

To explain an example, the parameter value of the attenuation parameter (eg, Atten) of each cell is set to an initial value (default value), and the control unit 230 attenuates each neighboring cell checked by the neighboring cell checker 220. By adjusting the parameter value of a parameter (eg, Atten) from the default value (eg, 0) to a specific parameter value (eg, 2dB) previously set by the operator, the transmission power can be attenuated and controlled.

To explain another example, the controller 230 sets the parameter value of the attenuation parameter (eg, Atten) for each neighboring cell checked by the neighboring cell checker 220 from the current value to a specific parameter value (+ 2dB), the transmission power can be attenuated.

As described above, in the present invention, by controlling the transmission power of neighboring cells by adjusting the parameter value of the attenuation parameter (e.g., Atten) defined in each cell, by realizing the immediate transmission power attenuation (downward) of the neighboring cell, a specific terminal Based on (10), it is possible to guarantee a real-time property in which inter-cell interference control is possible in real time for a cell in which a specific terminal 10 is located.

3 shows a situation in which transmission power of a neighboring cell is controlled according to an embodiment of the present invention.

As shown in FIG. 3, assuming that a specific terminal (SPID/ARP terminal) having a specific SPID factor value or a specific ARP factor value is located in the center cell, the center cell in which the SPID/ARP terminal is located is inter-cell interference. It becomes a flexible reference cell for control.

In addition, as shown in FIG. 3, it may be assumed that six outer cells are identified as a fluid surrounding cell having a neighboring relationship with a fluid reference cell.

In this case, in the present invention, the transmission power of the six outer cells identified as flexible neighboring cells is attenuated (downward) in real time, and as shown in the upper left -> right of FIG. 3, SPID/ARP based on the SPID/ARP terminal. It is possible to reduce the interference of neighboring cells to the central cell in which the terminal is located in real time.

On the other hand, as can be seen from FIG. 3, if the transmission power of the neighboring cell is attenuated, the coverage of the neighboring cell can be reduced. In this case, in terms of system operation, the central cell, that is, the flexible reference cell where a specific terminal is located, and the outer cell A situation in which normal handover cannot be performed may occur due to a change in the handover position condition between the flexible surrounding cells of the flexible reference cell.

The present invention further proposes a function of attenuating the transmission power of the neighboring cell so that even if the coverage of the neighboring cell is reduced, normal handover can be performed.

To this end, the offset changing unit 240 changes the offset value related to the handover set in the terminal located in the flexible reference cell when controlling the transmission power of the neighboring cell, so that the coverage change according to the transmission power control of the neighboring cell is compensated. Play a role.

That is, when described with reference to FIG. 3, the offset changing unit 240 performs a handover set in each of the terminals located in the flexible reference cell, that is, the center cell, when controlling the transmission power attenuation of the six outer cells identified as the flexible surrounding cells. By changing the related offset value, the coverage change according to the transmission power attenuation control of the neighboring cells (6 outer cells) is compensated.

Specifically, for each of the six outer cells (peripheral cells) identified as floating surrounding cells, the parameter value of the attenuation parameter (eg Atten) is adjusted from the default value (eg 0) to a specific parameter value (eg 2dB). Thus, it is assumed that the transmission power is attenuated.

In this case, the offset changing unit 240, when the coverage reduced by the transmission power attenuation control of the neighboring cells (6 outer cells) is smaller than a preset change value compared to the coverage before the attenuation control, the coverage according to the transmission power control It is recognized as a change, and an offset value related to handover set in all terminals located in the flexible reference cell, that is, the center cell, can be changed.

In this case, the offset value is, in the process of comparing the signal reception strength of the serving cell and the signal reception strength of the target cell and reporting the comparison result for a handover attempt to the target cell, the signal reception strength of the serving cell and the target cell It may mean an offset value used when comparing signal reception strengths, for example, an A3 offset value.

That is, when the signal reception strength of the target cell is greater than the signal reception strength of the serving cell by an offset value of A3 or more, the UE reports each signal reception strength measurement value (comparison result) to the base station and attempts handover to the target cell.

Here, the serving cell to which the changed offset value is applied refers to the cell previously identified by the cell identification unit 210, that is, the cell in which the specific terminal 10 is located, in other words, this time in which the specific terminal (SPID/ARP terminal) is located. It refers to a flexible reference cell for inter-cell interference control.

Accordingly, in the present invention, the offset changer 240 recognizes (confirms) the change in coverage of the neighboring cells (6 outer cells) according to the transmission power attenuation control of the neighboring cells (6 outer cells), the specific terminal 10 By changing the A3 offset value set in each terminal by transmitting a control message to change the A3 offset value to each terminal in which the cell in which the cell is located, that is, the flexible reference cell (eg, the center cell in FIG. 3) as a serving cell, the neighboring cell 6 This is to compensate for the coverage change, that is, coverage reduction according to the transmission power attenuation control of the outer cell).

In particular, the A3 offset value may be a value determined according to a degree to which the transmission power of a neighboring cell is changed.

Therefore, as described above, attenuation control of the transmission power by adjusting the parameter value of the attenuation parameter (e.g. Atten) from the default value (e.g. 0) to a specific parameter value (e.g. 2dB) for each of six outer cells (surrounding cells) Assuming one case and assuming that the A3 offset value is 3dB, the offset changer 240 offsets A3 to a mobile reference cell, that is, a terminal located in the center cell, according to the degree of change in the transmission power of the neighboring cell, that is, 2dB. You can change the value from 3dB to 1dB.

As described above, in the present invention, each terminal located in a flexible reference cell (central cell) according to the location of a specific terminal by compensating the coverage reduction according to the transmission power attenuation control of the neighboring cells (6 outer cells) with an A3 offset value, As shown in the lower left -> right of Fig. 3, even after the transmission power of the surrounding cells (6 outer cells) decreases due to the changed A3 offset value (e.g. 3dB -> 1dB), according to the same handover position conditions as before. You should be able to perform handover normally.

Meanwhile, as shown in the example at the bottom of FIG. 3, a specific terminal (SPID/ARP terminal) performs a normal handover and is located in a neighboring cell (eg, one of six outer cells) whose transmission power is attenuated (downward). Can be done.

In this way, when the location cell is changed according to the handover performed by a specific terminal (SPID/ARP terminal), the controller 230 attenuates the transmission power of the cell in which the specific terminal (SPID/ARP terminal) is newly located (downlink). ) It will return to the original state before control.

In addition, the cell identification unit 210 / surrounding cell identification unit 220 / control unit 230 is a flexible reference cell having a neighboring relationship with a flexible reference cell in which a specific terminal (SPID/ARP terminal) is newly located in the manner described above. It will control the attenuation (downward) of the transmission power of the surrounding cells in real time.

In addition, when the location cell of a specific terminal (SPID/ARP terminal) is changed as described above, the offset change unit 240 changes to the terminal located in the cell where the specific terminal (SPID/ARP terminal) was located before handover. When the set A3 offset value is restored, and the transmission power attenuation control for the flexible neighboring cell of the flexible reference cell in which a specific terminal (SPID/ARP terminal) is newly located is performed, the A3 set in the terminal located in the new reference cell The offset value will be changed according to the degree to which the transmit power of the neighboring cells is changed.

As described above, according to the present invention, a flexible neighboring cell having a neighboring relationship with a flexible reference cell that changes according to the location of a specific terminal (eg, SPID/ARP terminal), deviating from the operation method of the existing CRS-IC function. By controlling the transmission power of the device in real time, it is possible to realize a new type of interference control technology (function) that reduces cell interference to a cell (a dynamic reference cell) in which a specific terminal (eg, SPID/ARP terminal) is located.

For this reason, according to the present invention, regardless of the large and small amount of traffic, the performance of reducing cell interference with respect to the cell (dynamic reference cell) in which a specific terminal (eg, SPID/ARP terminal) is located is sufficiently guaranteed, and As a result, it is possible to control the interference between cells in a flexible manner, thereby ensuring real-time performance, resulting in an effect that can dramatically improve the quality deterioration problem caused by interference.

Meanwhile, in the above description, for convenience of description of the present invention, a cell in which a specific terminal is located is referred to as one single cell.

However, the above-described interference control technology (function) of the present invention, when a specific terminal simultaneously accesses a plurality of cells and uses a service provided by the Core Network network, the specific terminal accesses (locations) each of the plurality of cells. Each can be applied/performed independently.

An example is a case in which the specific terminal 10 is operating using a primary cell and a secondary cell, that is, a case in which CA (Carrier Aggregation) is being operated.

As described above, if the specific terminal 10 is in CA operation, the specific terminal 10 can simultaneously access one primary cell (P cell) and N auxiliary cells (S cells) defined in the CA operation.

In this case, the neighboring cell checking unit 220 checks each neighboring cell in a neighboring relationship for each of the primary cell (P cell) and the secondary cell (S cell) used by the specific terminal 10, and the control unit 230 is An operation of attenuating and controlling the transmission power of a neighboring cell of the cell P cell and a neighboring cell of the auxiliary cell S may be performed respectively.

In this case, in the present invention, for each of a primary cell (P cell) and a secondary cell (S cell) as a flexible reference cell that is changed according to the location of a specific terminal (10, e.g., SPID/ARP terminal), a neighbor relationship with the corresponding cell is established. Each of a plurality of cells to which a specific terminal (10, e.g., SPID/ARP terminal) is connected (location) to the interference control technology (function) of the present invention by controlling the transmission power attenuation control of the mobile neighboring cells in real time. Can be applied independently for

In addition, in the present invention, the interference control technology (function) of the present invention is independently applied to each of a plurality of cells (P cell/S cells) to which a specific terminal (10, e.g., SPID/ARP terminal) is connected (location). Accordingly, by changing the A3 offset value set in each terminal using the base cell (P cell) of a specific terminal (10, e.g., SPID/ARP terminal) as a serving cell, attenuation of the transmission power of neighboring cells to the base cell (P cell) Coverage reduction according to the control is compensated, and the A3 offset value set in each terminal having a secondary cell (S cell) of a specific terminal (10, e.g., SPID/ARP terminal) as a serving cell is changed to the primary cell (S cell). The coverage reduction according to the transmission power attenuation control of the neighboring cell is compensated.

Of course, in the present invention, if the specific terminal 10 is in CA operation, only the primary cell (P cell) of the primary cell (P cell) and the secondary cell (S cell) used by the specific terminal 10 The interference control technology (function) of the present invention may be applied, or the interference control technology (function) of the present invention may be applied only to an auxiliary cell (S cell).

Meanwhile, another example is a case in which a specific terminal 10 is operating using two or more cells serving different frequency bands, and in this case, the above-described CA operation may also be included.

In this case, the neighboring cell identification unit 220 checks neighboring cells for each cell of each frequency band used by the specific terminal 10, and the controller 230 checks the neighboring cells for each cell of each frequency band. Each of the operations of attenuating and controlling the transmission power can be performed.

In this case, in the present invention, for each frequency band cell as a flexible reference cell that is changed according to the location of a specific terminal 10 (e.g., SPID/ARP terminal), attenuation of the transmission power of the flexible neighboring cells having a neighboring relationship with the corresponding cell By controlling each control in real time, the interference control technology (function) of the present invention can be independently applied to each of a plurality of cells to which a specific terminal 10 (eg, SPID/ARP terminal) is connected (location).

Hereinafter, an interference control method according to an embodiment of the present invention will be described with reference to FIG. 4.

For convenience of explanation, when the interference control method of the present invention is described as being performed by the interference control apparatus 200, it will be described assuming that the interference control apparatus 200 is the same apparatus as the base station 100 (DU).

According to the interference control method of the present invention, the interference control apparatus 200 identifies a cell in which a specific terminal is located (S10).

For example, according to an embodiment of the present invention, a specific terminal may be a terminal in which a specific factor value is set based on a Subscriber Profile ID (SPID) or Allocation and Retention Priority (ARP) set for each terminal.

Accordingly, according to the interference control method of the present invention, the interference control apparatus 200 manages the mapping and the identification number of the terminal from the core node (eg, MME, HSS, etc.) for the terminal connected to the base station 100, DU. By receiving the SPID and ARP, you can check the SPID set in the terminal and the factor value in the ARP.

Accordingly, according to the interference control method of the present invention, the interference control apparatus 200 classifies a terminal having a predetermined SPID factor value or a specific ARP factor value among the terminals connected to the base station 100, DU as a specific terminal, It is possible to check which cell is located (accessed) among the cells of each RRU operated by the classified corresponding specific base station 100 (Digital Unit (DU)) (S10).

Hereinafter, for convenience of explanation, it is assumed that the terminal 10 of FIG. 1 is a specific terminal.

According to the interference control method of the present invention, the interference control apparatus 200 checks the cell identified in step S10, that is, a cell in which a specific terminal 10 is located and a neighboring cell having a predefined neighbor relationship (S20).

Specifically, according to the present invention, for each cell, neighbors related to handover whenever a handover occurs, such as when a terminal handovers from a corresponding cell to a neighboring cell or a terminal handovers to a corresponding cell from a neighboring cell. You can manage the relationship list by listing information about the cell.

Accordingly, the interference control device 200, based on the relationship list of the cell in which the specific terminal 10 is located, among the relationship list managed for each cell, the specific terminal 10 It can be identified as a neighboring cell having a neighboring relationship with the located cell (S20).

And, according to the interference control method of the present invention, the interference control device 200, when checking the cell in which the specific terminal 10 is located in step S10, the transmission power of the neighboring cell checked in step S20 (especially, the transmission power of the cell reference signal) By controlling (S30), the interference of neighboring cells to the cell in which the specific terminal 10 is located is reduced (S40).

In the present invention, unlike the existing CRS-IC function in which a reference cell and a neighboring cell are fixed on a per DU basis, since the cell in which a specific terminal serving as an operation reference is located becomes the reference cell, the terminal-based reference cell is flexible and thus flexible. A neighboring cell having a neighboring relationship with the reference cell is also dynamically determined.

That is, the interference control device 200 operates in a manner of controlling the transmission power of a flexible neighboring cell having a neighboring relationship with the reference cell when checking a flexible reference cell in which a specific terminal 10 is located, ), the cell interference to the cell in which the specific terminal 10 is located is reduced.

In this case, as a method of controlling the transmission power of the neighboring cells, any method may be employed as long as it is a control method capable of attenuating or increasing the transmission power intensity of the neighboring cells.

According to an embodiment of the present invention, the interference control device 200 adjusts a parameter value of a pre-defined attenuation parameter (eg, Atten) for attenuation of the transmit power intensity for each neighboring cell identified in step S20 to adjust the transmit power. Can control attenuation.

In this way, if the transmission power of neighboring cells is controlled by adjusting the parameter value of the attenuation parameter (e.g., Atten) defined in each cell to realize immediate transmission power attenuation (downward) of the neighboring cell, a specific terminal 10 With respect to the cell in which the specific terminal 10 is located based on ), it is possible to guarantee real-time performance in which inter-cell interference control is possible in real time.

On the other hand, as can be seen from FIG. 3, if the transmission power of the neighboring cell is attenuated, the coverage of the neighboring cell can be reduced. In this case, in terms of system operation, the central cell, that is, the flexible reference cell where a specific terminal is located, and the outer cell A situation in which normal handover cannot be performed may occur due to a change in the handover position condition between the flexible surrounding cells of the flexible reference cell.

The present invention further proposes a function of attenuating the transmission power of the neighboring cell so that even if the coverage of the neighboring cell is reduced, normal handover can be performed.

Referring to FIG. 3 in detail, according to the interference control method of the present invention, the interference control device 200 is located in a flexible reference cell, that is, a center cell, when controlling transmission power attenuation of six outer cells identified as flexible surrounding cells. By changing the offset value related to the handover set in each of the terminal to be performed, it is possible to compensate for the coverage change according to the transmission power attenuation control of the neighboring cells (6 outer cells).

In the following, for each of the six outer cells (peripheral cells) identified as floating surrounding cells, the parameter value of the attenuation parameter (eg, Atten) is adjusted from the default value (eg 0) to a specific parameter value (eg 2dB), It is assumed that the transmission power is attenuated.

In this case, the interference control device 200 recognizes (confirms) the change in coverage of the surrounding cells (6 outer cells) according to the transmission power attenuation control of the surrounding cells (6 outer cells) (S50 Yes), a flexible reference By sending a control message to change the A3 offset value to the cell, that is, the terminal located in the center cell, and changing the A3 offset value set in each terminal (S60), the transmission power attenuation control of the neighboring cells (6 outer cells) Coverage change, that is, coverage reduction can be compensated.

In particular, the A3 offset value may be a value determined according to a degree to which the transmission power of a neighboring cell is changed.

Therefore, as described above, attenuation control of the transmission power by adjusting the parameter value of the attenuation parameter (e.g. Atten) from the default value (e.g. 0) to a specific parameter value (e.g. 2dB) for each of six outer cells (surrounding cells) Assuming one case and assuming that the A3 offset value is 3dB, the interference control device 200 offsets A3 to a mobile reference cell, that is, a terminal located in the center cell, according to the degree of change in the transmission power of the neighboring cell, that is, 2dB. The value can be changed from 3dB to 1dB.

As described above, in the present invention, each terminal located in a flexible reference cell (central cell) according to the location of a specific terminal by compensating the coverage reduction according to the transmission power attenuation control of the neighboring cells (6 outer cells) with an A3 offset value, As shown in the lower left -> right of Fig. 3, even after the transmission power of the surrounding cells (6 outer cells) decreases due to the changed A3 offset value (e.g. 3dB -> 1dB), according to the same handover position conditions as before. You should be able to perform handover normally.

According to the interference control method of the present invention, the interference control apparatus 200 performs the above-described step S10 and subsequent steps unless the (specific) terminal-based interference control function of the present invention is turned off (S70 No). By continuing to repeat, the transmission power control of the flexible neighboring cell of the flexible reference cell that is changed according to the location of the specific terminal 10 will be performed.

As described above, according to the present invention, a flexible neighboring cell having a neighboring relationship with a flexible reference cell that changes according to the location of a specific terminal (eg, SPID/ARP terminal), deviating from the operation method of the existing CRS-IC function. By controlling the transmission power of the terminal in real time, it is possible to realize a new type of interference control technology (function) that reduces cell interference to a cell (a dynamic reference cell) in which a specific terminal (eg, SPID/ARP terminal) is located.

For this reason, according to the present invention, regardless of the large and small amount of traffic, the performance of reducing cell interference with respect to the cell (dynamic reference cell) in which a specific terminal (eg, SPID/ARP terminal) is located is sufficiently guaranteed, and As a result, it is possible to control the interference between cells in a flexible manner, thereby ensuring real-time performance, resulting in an effect that can dramatically improve the quality deterioration problem caused by interference.

The interference control method according to an embodiment of the present invention may be implemented in the form of program commands that can be executed through various computer means and recorded in a computer-readable medium. The computer-readable medium may include program instructions, data files, data structures, and the like alone or in combination. The program instructions recorded on the medium may be specially designed and configured for the present invention, or may be known and usable to those skilled in computer software. Examples of computer-readable recording media include magnetic media such as hard disks, floppy disks, and magnetic tapes, optical media such as CD-ROMs and DVDs, and magnetic media such as floptical disks. -A hardware device specially configured to store and execute program instructions such as magneto-optical media, and ROM, RAM, flash memory, and the like. Examples of program instructions include not only machine language codes such as those produced by a compiler but also high-level language codes that can be executed by a computer using an interpreter or the like. The above-described hardware device may be configured to operate as one or more software modules to perform the operation of the present invention, and vice versa.

Although the present invention has been described in detail with reference to preferred embodiments so far, the present invention is not limited to the above-described embodiments, and the technical field to which the present invention belongs without departing from the gist of the present invention claimed in the following claims. Anyone of ordinary skill in the art will say that the technical idea of the present invention extends to the range in which various modifications or modifications are possible.

According to the interference control apparatus and the interference control method of the present invention, in that a new method of inter-cell interference control technology (function) operating based on a terminal is realized, as it goes beyond the limitations of the existing technology, It is an invention that has industrial applicability because it is not only possible to market or sell a device to which it is applied, but also to the extent that it can be practically clearly implemented.

200: interference control device
210: cell verification unit 220: surrounding cell verification unit
230: control unit 240: offset change unit

Claims (16)

A cell identification unit that checks a cell in which a specific terminal in which a specific factor value is set is located;
A neighboring cell checking unit that checks a neighboring cell having a predefined neighboring relationship with the cell; And
And a control unit configured to control the transmission power of the neighboring cell when the cell in which the specific terminal is located, thereby reducing interference of the neighboring cell on the cell in which the specific terminal is located. The method of claim 1,
The specific terminal,
An interference control apparatus comprising a terminal in which a specific factor value is set based on a Subscriber Profile ID (SPID) or Allocation and Retention Priority (ARP) set for each terminal. The method of claim 1,
When controlling the transmission power of the neighboring cell, by changing the offset value related to the handover set in the terminal located in the cell, characterized in that it further comprises an offset changer to compensate for the coverage change according to the transmission power control of the neighboring cell. Interference control device. The method of claim 3,
The offset value is,
When the terminal compares the signal reception strength of the serving cell and the signal reception strength of the target cell and reports the comparison result for a handover attempt to the target cell, when comparing the signal reception strength of the serving cell and the signal reception strength of the target cell Interference control device, characterized in that the offset value to be used. The method of claim 4,
The offset value is,
Interference control apparatus, characterized in that the value is determined according to the degree to which the transmission power of the neighboring cell is changed. The method of claim 1,
The peripheral cell confirmation unit,
An interference control apparatus, characterized in that, based on a relation list indicating a neighboring cell having a handover history with respect to the cell, a neighboring cell belonging to the relational list is identified as a neighboring cell having a neighboring relationship with the cell. The method of claim 1,
The control unit,
For each of the neighboring cells, an interference control device for attenuating transmission power by adjusting a value of a predetermined attenuation parameter to attenuate transmission power intensity. The method of claim 1,
When the specific terminal is operating using a primary cell and a secondary cell,
The neighboring cell check unit checks neighboring cells for each of the primary and secondary cells,
Wherein the control unit performs an operation of respectively controlling a transmission power of a neighboring cell of the primary cell and a neighboring cell of the auxiliary cell. The method of claim 1,
When the specific terminal is operating using two or more cells serving different frequency bands,
The neighboring cell check unit checks the neighboring cells for each of the two or more cells,
The control unit, the interference control device, characterized in that each performing an operation of controlling the transmission power of the adjacent cells checked for each of the two or more cells. ◈ Claim 10 was abandoned upon payment of the set registration fee. In the interference control method performed in the base station,
A cell identification step of confirming a cell in which a specific terminal in which a specific factor value is set is located;
A neighboring cell checking step of checking neighboring cells having a predefined neighboring relationship with the cell; And
And a control step of controlling the transmission power of the neighboring cell when the cell in which the specific terminal is located, so that interference of the neighboring cell on the cell in which the specific terminal is located is reduced. ◈ Claim 11 was abandoned upon payment of the set registration fee. The method of claim 10,
The specific terminal,
An interference control method, characterized in that the terminal has a specific factor value set based on a Subscriber Profile ID (SPID) or Allocation and Retention Priority (ARP) set for each terminal. ◈ Claim 12 was abandoned upon payment of the set registration fee. The method of claim 10,
An offset changing step of changing an offset value related to a handover set in a terminal located in the cell when the transmission power of the neighboring cell is controlled, so that a coverage change according to the transmission power control of the neighboring cell is compensated. Interference control method. ◈ Claim 13 was abandoned upon payment of the set registration fee. The method of claim 12,
The offset value is,
When the terminal compares the signal reception strength of the serving cell and the signal reception strength of the target cell and reports the comparison result for a handover attempt to the target cell, when comparing the signal reception strength of the serving cell and the signal reception strength of the target cell Interference control method, characterized in that the offset value to be used. ◈ Claim 14 was abandoned upon payment of the set registration fee. The method of claim 13,
The offset value is,
Interference control method, characterized in that the value is determined according to the degree to which the transmission power of the neighboring cell is changed. ◈ Claim 15 was abandoned upon payment of the set registration fee. The method of claim 10,
The neighboring cell check step,
An interference control method, characterized in that, based on a relation list indicating a neighboring cell having a handover history with respect to the cell, a neighboring cell belonging to the relational list is identified as a neighboring cell having a neighboring relationship with the cell. ◈ Claim 16 was abandoned upon payment of the set registration fee. The method of claim 10,
The control step,
For each of the neighboring cells, the transmission power is attenuated and controlled by adjusting a predetermined attenuation parameter value for attenuation of the transmission power intensity.

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