KR102191085B1 - Cell control apparatus and control method for full duplex transmission - Google Patents

Abstract

The present invention proposes a cell control apparatus and a full-duplex transmission control method capable of solving additional interference caused by IBFD when using full-duplex transmission (IBFD) in an actual mobile communication environment in which several cells coexist.

Description

Cell control device and full-duplex transmission control method {CELL CONTROL APPARATUS AND CONTROL METHOD FOR FULL DUPLEX TRANSMISSION}

The present invention relates to a cell control device, and more particularly, a cell control device capable of solving additional interference caused by IBFD when using full-duplex transmission (IBFD) and full-duplex transmission control in an actual mobile communication environment where several cells coexist. It's about how.

In recent years, due to the development of wireless communication technology, the demand for wireless traffic continues to increase, and various technologies have emerged to meet the increasing demand for wireless traffic.

As one of these technologies, an In-Band Full Duplex (IBFD) technology that can perform transmission and reception using the same one frequency/time resource in two nodes is drawing attention.

In-Band Half Duplex (IBHD) is a method in which each node uses frequency and/or time resources separately for transmission and reception, whereas in the case of IBFD, two nodes have the same frequency for transmission and reception. /Time resources are used simultaneously.

At this time, in the case of IBFD, since transmission and reception are simultaneously performed through the same frequency/time resource, the signal transmitted by the node itself acts as interference (hereinafter, self-interference) when receiving the signal transmitted from the opposite node. In this case, since the node side already knows the signal it has transmitted, it is possible to remove self-interference caused by the transmission signal when receiving the signal by removing the interference in the analog/digital domain.

For this reason, in IBFD, when self-interference removal is complete, there is an advantage of securing up to two times the resource utilization rate compared to IBHD from the viewpoint of two nodes.

However, when the IBFD is applied (used) to an actual mobile communication environment in which several cells coexist, downlink interference due to a downlink signal transmitted from another adjacent cell during uplink in the cell side additionally occurs.

In addition, since downlink interference (hereinafter, additional interference caused by IBFD) received by the downlink signal from another cell adjacent to the cell during uplink causes a decrease in transmission capacity, the resource utilization rate when using IBFD is maximized. Even though the transmission capacity was increased by 2 times, the additional interference caused by IBFD may cause a situation in which the total transmission capacity suffers a loss compared to the use of IBHD.

Accordingly, in the present invention, in an actual mobile communication environment in which several cells coexist, when using full-duplex transmission (IBFD), it is intended to propose a method for solving the additional interference caused by IBFD.

The present invention was created in view of the above circumstances, and an object to be reached in the present invention is to solve additional interference caused by IBFD when using full-duplex transmission (IBFD) in an actual mobile communication environment in which several cells coexist. It is to provide a cell control device and a full-duplex transmission control method.

The cell control apparatus according to the first aspect of the present invention for achieving the above object, among cells adjacent to a specific cell, can cause downlink interference by full-duplex transmission (IBFD: In-Band Full Duplex) to the specific cell. A grouping unit for grouping interfering cell groups; A downlink interference checker configured to check the downlink interference from an interfering cell belonging to the interfering cell group to the specific cell; And a controller for controlling full-duplex transmission radio resources of the interfering cell group so that the downlink interference to the specific cell is reduced when the downlink interference is greater than or equal to a preset threshold.

Preferably, the interfering cell group may be grouped based on the signal strength of each of the adjacent cells measured in the specific cell among the adjacent cells.

Preferably, the downlink interference check unit, in some radio resources in which the interfering cell does not transmit a downlink signal among full-duplex transmission radio resources, a downlink interference-free signal measured in the specific cell (non-interference) Check the reception quality value, check the signal reception quality value of the full-duplex transmission situation measured in the specific cell in the full-duplex transmission radio resource, and receive the signal reception quality value in the full-duplex transmission situation and the downlink interference-free situation Based on the quality value, the downlink interference can be checked.

Preferably, the partial radio resources are divided into a full-band (Channel Bandwidth) of the full-duplex transmission radio resource or the full-band of the full-duplex transmission radio resource at regular intervals, in which the interfering cell receives only an uplink signal every preset confirmation period. It may be a part of one or more sub-carriers.

Preferably, when the downlink interference is greater than or equal to the threshold, the control unit accesses the specific cell among full-duplex transmission radio resources used by the at least some interfering cells for at least some interfering cells belonging to the interfering cell group. Checking the full-duplex transmission radio resource at the same location as the full-duplex transmission radio resource allocated to the terminal, and downlink control of the downlink transmission strength of the at least some interfering cells or blanking the downlink from the confirmed full-duplex transmission radio resource Can be controlled.

Preferably, when the downlink interference is greater than or equal to the threshold, the control unit accesses the specific cell among full-duplex transmission radio resources used by the at least some interfering cells for at least some interfering cells belonging to the interfering cell group. Checking the full-duplex transmission radio resource at the same location as the full-duplex transmission radio resource allocated to the terminal, downlink control of the downlink transmission strength of the at least some interfering cells from the checked full-duplex transmission radio resource, and downlink control of the downlink transmission strength Even after the downlink interference is equal to or greater than the threshold, blanking control of the downlink of the at least some interfering cells in the confirmed full-duplex transmission radio resource.

A method for controlling full-duplex transmission according to a second aspect of the present invention for achieving the above object is an interfering cell group in which a cell control apparatus, among cells adjacent to a specific cell, can cause downlink interference by full-duplex transmission to the specific cell. A grouping step of grouping; A downlink interference checking step of the cell control apparatus confirming the downlink interference that an interfering cell belonging to the interfering cell group affects the specific cell; And a control step of controlling, by the cell control apparatus, a full-duplex transmission radio resource of the interfering cell group so that, when the downlink interference is greater than or equal to a preset threshold, the downlink interference to the specific cell is reduced.

Preferably, in the downlink interference checking step, in some radio resources in which the interfering cell does not transmit a downlink signal among full-duplex transmission radio resources, the signal reception quality value of the downlink interference-free situation measured in the specific cell is determined. Check and, in the full-duplex transmission radio resource, check the signal reception quality value of the full-duplex transmission situation measured in the specific cell, and based on the signal reception quality value of the full-duplex transmission situation and the signal reception quality value of the downlink interference-free situation Thus, the downlink interference can be checked.

Preferably, the some radio resources are a plurality of sub-bands in which all bands of the full-duplex transmission radio resource or all bands of the full-duplex transmission radio resource are divided at regular intervals, in which the interfering cell receives only an uplink signal every preset confirmation period. It may be part of the carrier.

Preferably, in the controlling step, when the downlink interference is greater than or equal to the threshold, for at least some of the interfering cells belonging to the interfering cell group, the specific cell among full-duplex transmission radio resources used by the at least some interfering cells. The full-duplex transmission radio resource at the same location as the full-duplex transmission radio resource allocated to the access terminal may be checked, and the at least some interfering cells may be downlinked from the checked full-duplex transmission radio resource.

Preferably, in the controlling step, when the downlink interference is greater than or equal to the threshold, for at least some of the interfering cells belonging to the interfering cell group, the specific cell among full-duplex transmission radio resources used by the at least some interfering cells. Checking the full-duplex transmission radio resource at the same location as the full-duplex transmission radio resource allocated to the access terminal, downlink control of the downlink transmission strength of the at least some interfering cells in the checked full-duplex transmission radio resource, and downlink transmission strength Even after the control, if the downlink interference is equal to or greater than the threshold, the downlink of the at least some interfering cells may be blanked in the identified full-duplex transmission radio resource.

Accordingly, according to the cell control apparatus and the full-duplex transmission control method of the present invention, in an actual mobile communication environment in which several cells coexist, an effect of solving additional interference caused by IBFD when using full-duplex transmission (IBFD) is derived.

1 is a block diagram showing a situation in which additional interference occurs due to full-duplex transmission (IBFD) in a mobile communication environment to which the present invention is applied.
2 is a block diagram showing in detail the configuration of a cell control apparatus according to a preferred embodiment of the present invention.
3 is an exemplary diagram showing a frame structure proposed to check a signal reception quality value in a downlink interference-free situation in the present invention.
4 is an exemplary diagram for explaining an example of controlling a full-duplex transmission radio resource used in an interfering cell in the present invention.
5 is a control flowchart showing a method for controlling full-duplex transmission according to a preferred embodiment of the present invention.

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

1 shows a situation in which additional interference occurs due to full-duplex transmission (IBFD) in a mobile communication environment to which the present invention is applied.

As shown in FIG. 1, the mobile communication environment to which the present invention is applied is an environment in which several cells coexist.

For example, in FIG. 1, on the assumption that each of the six base stations 10, 20... 60 forms a single cell, it shows a mobile communication environment in which six cells C1, C2... C6 coexist. Are doing. However, this is only an example.

That is, the present invention may be applicable even in a mobile communication environment in which a variety of cells exist in various forms on the premise of a smaller number or a greater number of base stations capable of forming two or more cells.

In addition, in FIG. 1, it is shown that the terminal 1 is connected to the cell C1 of the base station 10, but this is also only an embodiment for convenience of description, and the other cells C2, C3...C6 It is obvious that the terminal can be accessed.

Here, the terminal collectively refers to a mobile or fixed user node such as a user equipment (UE) or a mobile station (MS).

In addition, the base station shown in FIG. 1 collectively refers to a network node that communicates with a terminal such as NodeB, eNodeB, Base Station, and Access Point.

In the half-duplex transmission (IBHD) technology, frequency and/or time resources are used by each node for transmission and reception.

That is, if the description is made on the assumption that the terminal 1 is connected to the cell C1 of the base station 10 in the mobile communication environment shown in FIG. 1, when applying (using) IBHD, frequency and/or time resources Is divided into downlink and uplink, and the signal transmitted from the base station 10, that is, the cell C1, is received by the terminal 1 through the downlink resource, and the signal transmitted by the terminal 1 is the uplink resource. It is received by the base station 10 of the cell (C1) through.

On the other hand, full-duplex transmission (IBFD) technology is a method in which each node simultaneously uses the same frequency/time resources for transmission and reception.

That is, assuming that the terminal 1 is connected to the cell C1 of the base station 10 in the mobile communication environment shown in FIG. 1, when the IBFD is applied (used), the base station 10, that is, the cell Each of (C1) and the terminal 1 uses the same frequency/time resource simultaneously for transmission and reception of mutual signals.

At this time, in the case of IBFD, since transmission and reception are simultaneously performed through the same frequency/time resource, the signal transmitted by the node (base station, terminal) itself interferes when receiving the signal transmitted from the other node (terminal, base station) , Self-interference). In this case, since the node (base station, terminal) already knows the signal it has transmitted, self-interference caused by the transmitted signal when receiving the signal can be eliminated through interference cancellation in the analog/digital domain.

For this reason, in the case of IBFD, when self-interference removal is complete, there is an advantage of securing up to twice the resource utilization rate compared to IBHD from the viewpoint of interconnected nodes (base stations, terminals).

However, when the IBFD is applied (used) to an actual mobile communication environment in which several cells coexist, downlink interference due to a downlink signal transmitted from another adjacent cell during uplink in the cell side additionally occurs.

For example, in the mobile communication environment shown in FIG. 1, if described from the viewpoint of the cell C1 of the base station 10, when applying (using) IBFD, another cell adjacent to the cell C1 during uplink, for example, C2, Downlink interference (dotted line) caused by downlink signals transmitted from C3, C4, C5, C6, etc. additionally occurs.

In addition, although not shown in Figure 1, if described from the viewpoint of the cell (C2) of the base station 20, when applying (using) IBFD, other cells adjacent to the cell (C2) side uplink during the uplink, for example, C1, C3 Downlink interference due to downlink signals transmitted from C4, C5, C6, etc. will additionally occur.

In this way, the downlink interference (hereinafter, additional interference by IBFD) received by the cell side due to the downlink signal of another cell adjacent to the cell during uplink causes a decrease in transmission capacity, so that the resource usage rate when using IBFD is up to twice. Even though the transmission capacity was increased by increasing it to, there may be a situation where the use of IBHD rather loses compared to the use of IBHD in terms of the total transmission capacity due to additional interference caused by IBFD.

Accordingly, in the present invention, in an actual mobile communication environment in which several cells coexist as shown in FIG. 1, when using full-duplex transmission (IBFD), it is intended to propose a method for solving the additional interference (downlink interference) caused by IBFD.

Hereinafter, with reference to FIG. 2, a cell control apparatus according to a preferred embodiment for realizing the scheme proposed in the present invention will be described.

As shown in Figure 2, the cell control apparatus 100 according to a preferred embodiment of the present invention, among cells adjacent to a specific cell, interference that may cause downlink interference by full-duplex transmission (IBFD) to the specific cell. A grouping unit 110 for grouping a cell group, a downlink interference checker 120 for checking the downlink interference that an interfering cell belonging to the interfering cell group exerts on the specific cell, and the downlink interference is preset If the threshold is greater than or equal to the threshold, the control unit 130 controls full-duplex transmission radio resources used by the interfering cell so that the downlink interference to the specific cell is reduced.

Here, the cell control device 100 of the present invention may be a separate full-duplex control device that controls a cell of each base station through interworking with a base station located in a mobile communication environment, or each base station located in a mobile communication environment. May be.

Hereinafter, for convenience of explanation, it is assumed that the cell control apparatus 100 of the present invention is the base station 10 of FIG. 1.

The grouping unit 110 groups interfering cell groups that can cause downlink interference by full-duplex transmission (IBFD) to a specific cell from among cells adjacent to a specific cell.

In this case, the specific cell is a cell to be improved in which downlink interference by IBFD is improved by the scheme proposed in the present invention.

Accordingly, as described above, assuming that the cell control apparatus 100 of the present invention is the base station 10 of FIG. 1, the specific cell will be the cell C1 formed by the base station 10.

In the following description, the cell C1 will be referred to as a specific cell.

That is, the grouping unit 110 groups a group of interfering cells that can cause downlink interference by IBFD to the cell C1 from among cells adjacent to a specific cell, that is, cell C1.

At this time, it is preferable that the interfering cell group is grouped based on the signal strength of each adjacent cell measured in the cell C1 among cells adjacent to the cell C1.

More specifically, for example, in the cell C1 formed by the cell control apparatus 100 (same as the base station 10) of the present invention, a signal (eg, pilot signal, CRS, etc.) transmitted from an adjacent cell is Can be received.

Accordingly, the cell control apparatus 100 (same as the base station 10) of the present invention can measure the signal strength of a signal (eg, a pilot signal, CRS, etc.) received from an adjacent cell.

For example, in the mobile communication environment as shown in FIG. 1, the cell control apparatus 100 (same as the base station 10) of the present invention is a cell (C2, C3, C4, C5) adjacent to the cell (C1). C6) Each signal strength will be measured.

Accordingly, according to an embodiment, the grouping unit 110, among adjacent cells (C2, C3, C4, C5, C6) whose signal strength is measured, has a measured signal strength greater than or equal to a preset set value (eg, C2). ,C3,C4) may be grouped into an interfering cell group capable of causing downlink interference by IBFD to the cell C1.

Alternatively, according to another embodiment, the grouping unit 110 includes a predetermined number sequentially selected from the cells having the largest measured signal strength among adjacent cells (C2, C3, C4, C5, C6) measuring signal strength. (Example: 3) cells (eg, C2, C3, C4) can be grouped into an interfering cell group that can cause downlink interference by IBFD to the cell (C1).

Hereinafter, it is assumed that the cell (C2, C3, C4) is grouped by the grouping unit 110 into an interfering cell group capable of causing downlink interference by IBFD to the cell C1, and the corresponding interfering cell group is I will define it as

Interfering cell group: {C1_C2,C3,C4}

The downlink interference checker 120 checks downlink interference caused by IBFD by an interfering cell belonging to the interfering cell group to a specific cell, that is, cell C1.

Here, the downlink interference by IBFD means additional interference from other adjacent cells that are received by the cell C1 during uplink as described above by using IBFD. Hereinafter, for convenience of explanation, the downlink interference by IBFD and the additional interference by IBFD will be used interchangeably with the same meaning.

Interfering cell groups grouped as described above: When describing by referring to {C1_C2, C3, C4}, the downlink interference confirmation unit 120 includes the interfering cells C2, C3 and C4 belonging to the interfering cell group. Downlink interference by IBFD on cell (C1), that is, additional interference by IBFD is checked.

Hereinafter, a process of confirming downlink interference caused by IBFD by the interfering cells C2, C3, and C4 on the cell C1 will be described in detail.

The downlink interference check unit 120, in some radio resources in which the interfering cells (C2, C3, C4) of the full-duplex transmission radio resources (hereinafter, IBFD radio resources) do not transmit a downlink signal, a specific cell, that is, a cell (C1). Check the signal reception quality value of the downlink interference-free situation (non-interference) measured in ).

At this time, some radio resources, the entire band (Channel Bandwidth) of the IBFD radio resource, or the entire band of the IBFD radio resource, in which the interfering cells (C2, C3, C4) receive only the uplink signal at a predetermined interval (T) It may be a part of a plurality of sub-carriers divided by.

The process for checking the signal reception quality value in the downlink interference-free situation will be described in more detail as follows.

First, the cell control apparatus 100 of the present invention includes a threshold (a) related to downlink interference by IBFD, a confirmation period (T) for confirming a signal reception quality value in a downlink interference-free situation, and some radio resources. It is preferable that the location information is previously set.

And, the cell control apparatus 100 of the present invention, when the interfering cell group for the cell (C1) is grouped in the grouping unit 110, the interfering cell group: the interfering cell (C2, C2, C4) belonging to the It is desirable to inform and notify the confirmation period (T) and location information of some radio resources in C3, C4).

In this case, each of the interfering cells (C2, C3, C4), which is notified of the confirmation period (T) and the location information of some radio resources from the cell control device 100, is the IBFD radio resource used by the cell control apparatus 100 for each confirmation period (T). In some radio resources according to the location information, downlink signals are not transmitted.

More specifically described with reference to FIG. 3, each of the interfering cells C2, C3, and C4 that received notification of the confirmation period T and the location information of some radio resources from the cell control apparatus 100 As in the embodiment, downlink resources may be unallocated in all bands of IBFD radio resources according to location information among IBFD radio resources for a predetermined period of time (t) every confirmation period (T), and only uplink resources may be allocated.

In this case, the entire band of the IBFD radio resource, in which only the uplink resource is allocated for each confirmation period (T), is a partial radio resource in which the interfering cell (C2, C3, C4) among the IBFD radio resources does not transmit a downlink signal, more specifically This will correspond to some radio resources that do not transmit downlink signals and receive only uplink signals.

On the other hand, each of the interfering cells (C2, C3, C4), which received notification of the confirmation period (T) and the location information of some radio resources from the cell control apparatus 100, is the confirmation period (T), as in the second embodiment of FIG. ), the entire band of the IBFD radio resource is divided into subcarriers having a certain interval for a certain period of time (t), and downlink resources are unallocated in some of the divided subcarriers according to location information (e.g., N). Only uplink resources can be allocated.

In this case, some (e.g., N) subcarriers of all bands of IBFD radio resources in which only uplink resources are allocated for each confirmation period (T), and interfering cells (C2, C3, C4) among the IBFD radio resources transmit downlink signals. It may correspond to some radio resources that do not transmit, and more specifically, some radio resources that receive only an uplink signal without transmitting a downlink signal.

In the case of the first embodiment or the second embodiment described above, the cell control apparatus 100 (same as the base station 10) of the present invention is a downlink of the interfering cells (C2, C3, C4) every confirmation period (T). In some radio resources without downlink interference due to IBFD received from an interfering cell (C2, C3, C4) because there is no signal, an uplink signal from an access terminal (e.g., terminal 1) connected to the cell C1 Based on this, the signal reception quality value (eg, SINR) of the cell C1 can be measured.

Accordingly, the downlink interference confirmation unit 120, for each of the above-described confirmation periods (T), of the cell (C1) measured in some radio resources without additional interference by IBFD among IBFD radio resources, that is, downlink interference by IBFD. A signal reception quality value (eg, SINR) can be checked as a signal reception quality value in a downlink interference free situation.

Hereinafter, for convenience of description, the signal reception quality value of the downlink interference-free situation checked by the downlink interference checking unit 120 will be referred to as SINR(b) in the downlink interference-free situation.

In addition, the downlink interference checking unit 120 checks a signal reception quality value of a full-duplex transmission situation measured in a specific cell, that is, a cell C1 in the IBFD radio resource.

More specifically, the interfering cells (C2, C3, C4), each of which is notified of the confirmation period (T) and location information of some radio resources from the cell control apparatus 100, is the first embodiment or the second embodiment of FIG. As in the embodiment, the downlink signal is not transmitted only in some radio resources according to the location information among the IBFD radio resources at each confirmation period (T), and the IBFD radio resource is used by allocating both uplink and downlink resources. .

Accordingly, the cell control apparatus 100 of the present invention (same as the base station 10), because there is a downlink signal of the interfering cells (C2, C3, C4), the IBFD received from the interfering cells (C2, C3, C4) In IBFD radio resources with downlink interference, the signal reception quality value (eg, SINR) of the cell (C1) is measured based on the uplink signal from the access terminal (eg, terminal (1)) connected to the cell (C1). can do.

Accordingly, the downlink interference checking unit 120 may check a signal reception quality value (eg, SINR) of the cell C1 measured in the IBFD radio resource as a signal reception quality value in a full-duplex transmission situation.

Hereinafter, for convenience of explanation, the signal reception quality value of the full-duplex transmission condition checked by the downlink interference checker 120 will be referred to as the SINR of the IBFD condition.

Accordingly, the downlink interference checking unit 120 is based on a signal reception quality value in a full-duplex transmission situation (SINR in an IBFD situation) and a signal reception quality value in a downlink interference-free situation (SINR(b) in a downlink interference-free situation). On the basis of it, downlink interference, that is, additional interference caused by IBFD can be checked.

For example, the downlink interference check unit 120 obtains a value (c) obtained by subtracting the SINR (b) of the downlink interference-free situation from the SINR in the IBFD situation, and the downlink that the cell C1 receives additionally due to the IBFD. It can be confirmed that it is link interference, that is, additional interference caused by IBFD.

That is, the downlink interference confirmation unit 120 does not take into account interference due to other factors, and only checks downlink interference that is additionally received from another adjacent cell (interfering cell) due to IBFD, that is, additional interference caused by IBFD. will be.

When the downlink interference (c) checked by the downlink interference checker 120 is greater than or equal to a preset threshold (a), the control unit 130 may reduce the downlink interference to a specific cell, that is, a cell C1. : Controls full-duplex transmission radio resources of {C1_C2,C3,C4}.

More specifically, when the downlink interference (c) checked by the downlink interference checker 120 is more than the threshold (a), the interference cell group: interference belonging to {C1_C2,C3,C4} Full-duplex transmission radio resources can be controlled for at least some interfering cells among the cells C2, C3, and C4.

Hereinafter, a case in which all of the interfering cells C2, C3, and C4 correspond to at least some of the interfering cells C2, C3, and C4 will be described.

In this case, the control unit 130 is the same as the IBFD radio resources allocated to a specific cell, that is, the access terminal (eg, terminal 1) of the cell C1, among the IBFD radio resources used by the interfering cells C2, C3, C4. Check the full-duplex transmission radio resources of the location.

For example, the control unit 130 determines the location (resource allocation location) of the IBFD radio resource allocated from the cell C1 to the access terminal (eg, terminal 1), and the base station 20, 30, 40 IBFD radio allocated from the cell (C1) to the access terminal (e.g., terminal 1) among the IBFD radio resources used by the interfering cells (C2, C3, C4) of the base station (20, 30, 40) through interworking with each IBFD radio resources in the same resource allocation location as the resource can be checked.

For example, as shown in FIG. 4, it is assumed that the resource allocation position d of the IBFD radio resource allocated to the access terminal (eg, terminal 1) in the cell C1 is confirmed.

In this case, the control unit 130 downlinks the downlink transmission strength of the interfering cells C2, C3, and C4 in the IBFD radio resource, that is, the IBFD radio resource (d), or the interfering cells C2, C3, Blanking of the downlink of C4) may be controlled.

Hereinafter, a process of controlling the IBFD radio resources of the interfering cells C2, C3, and C4 will be described in detail with reference to the interfering cell C2.

The controller 130 may downlink the downlink transmission strength of the interfering cell C2 by a preset unit strength from the above-described IBFD radio resource, that is, the IBFD radio resource d.

According to an example, the control unit 130 can downlink control the downlink transmission strength of the interfering cell C2 in the IBFD radio resource d by a predetermined unit strength through interworking with the base station 20. .

Of course, the control unit 130 controls the downlink transmission strength of the remaining interfering cells (C3, C4) in the IBFD radio resource (d) through interworking with the remaining base stations (30, 40) as much as a preset unit strength. can do.

According to another example, the control unit 130, the downlink transmission strength of the interfering cell (C2) in the IBFD radio resource (d) is not less than a predefined minimum transmission strength, the downlink of the interfering cell (C2). The link transmission strength can be controlled downlink as many times as the unit strength.

Of course, the controller 130 may downlink control the downlink transmission strength of the remaining interfering cells C3 and C4 several times as much as the unit strength within the minimum transmission strength limit.

At this time, the control unit 130 downlink control the downlink transmission strength of the interfering cells (C2, C3, C4) and then checks whether the downlink interference (c) of the cell (C1) to be checked again is greater than or equal to the threshold (a). Accordingly, if the downlink interference (c) of the cell (C1) is still above the threshold (a), the downlink transmission strength of the interfering cells (C3, C4) is once again controlled down, and the downlink interference of the cell (C1) ( c) is a method to stop downlink transmission strength downlink control of the interfering cells (C3, C4) if it is not above the threshold (a), and reduce the downlink transmission strength of the interfering cells (C3, C4) within the minimum transmission strength limit. It can be controlled down as many times as the unit strength.

The controller 130 may downlink the downlink transmission strength of the interfering cell C2 by a preset unit strength from the above-described IBFD radio resource, that is, the IBFD radio resource d.

On the other hand, the control unit 130 may control the blanking of the downlink of the interfering cell C2 in the above-identified IBFD radio resource, that is, the IBFD radio resource d.

According to an example, the control unit 130 may immediately control the downlink of the interfering cell C2 in the IBFD radio resource (d) through interworking with the base station 20.

Of course, the control unit 130 may immediately control the downlink of the remaining interfering cells C3 and C4 in the IBFD radio resource d through interworking with the remaining base stations 30 and 40.

According to another example, the control unit 130 downlink controls the downlink transmission strength of the interfering cells C2, C3, C4 in the IBFD radio resource d, and downlink transmission of the interfering cells C2, C3, C4 If the downlink interference (c) of the cell C1 is still greater than or equal to the threshold value (a) even after the intensity is down-controlled, the downlink of the interfering cells C2, C3, and C4 may be controlled for blanking.

According to another example, the control unit 130 controls the downlink transmission strength of the interfering cells (C2, C3, C4) several times as much as the unit strength within the minimum transmission strength limit as in the above example, If there is an interfering cell (eg, C3) for which downlink control is not possible due to a transmission strength limit, blanking control of the downlink of the interfering cell (eg, C3) may be performed.

If the cell (C1) controls the IBFD radio resources of the interfering cells (C2, C3, C4), which cause additional interference by the IBFD, from the perspective of the interfering cells (C2, C3, C4), downlink resources may be slightly damaged. However, additional interference caused by IBFD on the cell C1, that is, downlink interference caused by a downlink signal transmitted from another adjacent cell will be reduced.

Meanwhile, in the above-described examples, in order to reduce the downlink interference of the cell C1, the IBFD radio resources of all the interfering cells C2, C3, and C4 belonging to the interfering cell group: {C1_C2, C3, C4} are controlled. , In addition to this method, it is also possible to control the IBFD radio resources of some selected interfering cells among interfering cells (C2, C3, C4) belonging to the interfering cell group: {C1_C2, C3, C4}.

That is, interfering cell group: As at least some interfering cells to control IBFD radio resources among interfering cells (C2, C3, C4) belonging to {C1_C2, C3, C4}, some but not all of the interfering cells (C2, C3, C4) It is also possible that the selected interfering cell is applicable.

For example, the present invention provides an interfering cell group: a predetermined number of interfering cells (C2, C3, C4) that belong to {C1_C2, C3, C4}, sequentially selected from the interfering cells having the largest measured signal strength (e.g. : For only two) cells (eg, C2, C3), downlink transmission strength may be down-controlled or downlink blanking-controlled in the IBFD radio resource (d) checked as described above.

As described above, the cell control apparatus according to the present invention provides additional interference caused by IBFD when using full-duplex transmission (IBFD) in an actual mobile communication environment in which several cells coexist, that is, downlink received from other cells adjacent to the cell side. Link interference (hereinafter, additional interference caused by IBFD) can be solved, resulting in an effect of taking advantage of increasing the transmission capacity of full-duplex transmission (IBFD) as much as possible.

Hereinafter, a full-duplex transmission control method according to a preferred embodiment of the present invention will be described with reference to FIG. 5.

For convenience of explanation, the cell control apparatus 100 (base station 10 of FIG. 1) is referred to as in the above-described embodiment, and reference numerals of FIGS. 1 to 4 are referred to for description.

According to the full-duplex transmission control method according to the present invention, the cell control apparatus 100 (same as the base station 10 of FIG. 1) is a specific cell, that is, from a cell adjacent to the cell C1, to the cell C1 by IBFD. Interfering cell groups that may cause link interference are grouped (S100).

Hereinafter, it is assumed that cells (C2, C3, C4) are grouped into an interfering cell group capable of causing downlink interference by IBFD to the cell (C1) in step S100, and the corresponding interfering cell group is defined as follows. would.

Interfering cell group: {C1_C2,C3,C4}

In addition, according to the full-duplex transmission control method according to the present invention, the cell control apparatus 100 does not transmit a downlink signal from the interfering cells C2, C3, C4 of the IBFD radio resources every preset confirmation period (T). In some radio resources that are not available, check the signal reception quality value in the downlink interference free situation.

More specifically, the cell control apparatus 100 includes a threshold (a) related to downlink interference by IBFD, a confirmation period (T) for confirming a signal reception quality value in a downlink interference-free situation, and some radio resources. It is preferable that the location information of is set in advance.

Then, the cell control apparatus 100, if the interfering cell group for the cell (C1) is grouped in step S100, the interfering cell group: {C1_C2, C3, C4} to identify the interfering cells (C2, C3, C4) belonging to It is desirable to inform and notify the location information of the period (T) and some radio resources.

In this case, each of the interfering cells (C2, C3, C4), which is notified of the confirmation period (T) and the location information of some radio resources from the cell control device 100, is the IBFD radio resource used by the cell control apparatus 100 for each confirmation period (T). In some radio resources according to the location information, downlink signals are not transmitted.

More specifically described with reference to FIG. 3, each of the interfering cells C2, C3, and C4 that received notification of the confirmation period T and the location information of some radio resources from the cell control apparatus 100 As in the embodiment, downlink resources may be unallocated in all bands of IBFD radio resources according to location information among IBFD radio resources for a predetermined time (t) every confirmation period (T) and only uplink resources may be allocated (S110).

On the other hand, each of the interfering cells (C2, C3, C4), which received notification of the confirmation period (T) and the location information of some radio resources from the cell control apparatus 100, is the confirmation period (T), as in the second embodiment of FIG. ), the entire band of the IBFD radio resource is divided into subcarriers having a certain interval for a certain period of time (t), and downlink resources are unallocated in some of the divided subcarriers according to location information (e.g., N). Only uplink resources can be allocated (S110).

In the case of the first embodiment or the second embodiment described above, the cell control apparatus 100, for each confirmation period (T), does not have a downlink signal of the interfering cells C2, C3, C4, and thus the interfering cells C2 and C3 In some radio resources without downlink interference due to IBFD received from C4), signal reception quality of cell C1 based on uplink signal from access terminal (eg, terminal 1) connected to cell C1 A value (eg, SINR) can be measured (S120).

Accordingly, the cell control apparatus 100 receives a signal from the cell C1 measured in some radio resources without additional interference due to IBFD among IBFD radio resources, that is, downlink interference due to IBFD in each of the above-described confirmation periods (T). A quality value (eg, SINR) can be checked as a signal reception quality value in a downlink interference-free situation (S120).

Hereinafter, for convenience of explanation, the signal reception quality value in the downlink interference free situation will be referred to as SINR(b) in the downlink interference free situation.

In addition, the cell control apparatus 100 will periodically repeat the steps of checking the SINR(b) of the uplink interference-free situation for the cell C1 every confirmation period T, even if there is no separate description.

In addition, the cell control apparatus 100 checks the signal reception quality value of the full-duplex transmission situation measured in the cell C1 in the IBFD radio resource.

More specifically, the interfering cells (C2, C3, C4), each of which is notified of the confirmation period (T) and location information of some radio resources from the cell control apparatus 100, is the first embodiment or the second embodiment of FIG. As in the embodiment, the downlink signal is not transmitted only in some radio resources according to the location information among the IBFD radio resources at each confirmation period (T), and the IBFD radio resource is used by allocating both uplink and downlink resources. (S130).

Accordingly, the cell control apparatus 100, because there is a downlink signal of the interfering cell (C2, C3, C4), in the IBFD radio resource with downlink interference by IBFD received from the interfering cell (C2, C3, C4), A signal reception quality value (eg, SINR) of the cell C1 may be measured based on an uplink signal from an access terminal (eg, terminal 1) connected to the cell C1 (S140).

Accordingly, the cell control apparatus 100 may check the signal reception quality value (eg, SINR) of the cell C1 measured in the IBFD radio resource as the signal reception quality value in the full-duplex transmission situation (S140).

Hereinafter, for convenience of explanation, the signal reception quality value in the full-duplex transmission situation will be referred to as the SINR in the IBFD situation.

Thereafter, the cell control apparatus 100, the interfering cell group: {C1_C2, C3, C4} in the interfering cell (C2, C3, C4) to the cell (C1) by IBFD downlink interference by IBFD, that is, addition by Check for interference.

That is, the cell control apparatus 100 is based on a signal reception quality value in a full-duplex transmission situation (SINR in IBFD situation) and a signal reception quality value in a downlink interference-free situation (SINR(b) in a downlink interference-free situation). , Downlink interference, that is, additional interference due to IBFD can be confirmed (S150).

For example, the cell control apparatus 100 obtains a value (c) obtained by subtracting the SINR (b) in the downlink interference-free situation from the SINR in the IBFD situation (c), and the downlink interference that the cell C1 receives additionally due to the IBFD. That is, it can be confirmed that it is additional interference caused by IBFD (S150).

That is, the cell control apparatus 100 does not consider interference due to other factors, and only checks downlink interference that is additionally received from another adjacent cell (interfering cell) due to IBFD, that is, additional interference due to IBFD.

The cell control apparatus 100 determines whether the downlink interference (c) checked in step S150 is greater than or equal to a preset threshold (a) (S160).

When the downlink interference (c) checked in step S150 is greater than or equal to the threshold (a) (S160 Yes), the interfering cells (C2, C3, C4) to reduce downlink interference to the cell (C1). ) To control the IBFD radio resource used in (S170).

More specifically, when the downlink interference (c) is greater than or equal to the threshold (a), the cell control apparatus 100 is the access terminal of the cell (C1) among the IBFD radio resources used by the interfering cells (C2, C3, C4). (Example: Check the full-duplex transmission radio resource at the same location as the IBFD radio resource allocated to the terminal 1).

For example, the cell control apparatus 100 determines the location (resource allocation location) of the IBFD radio resource allocated from the cell C1 to the access terminal (eg, terminal 1), and the base station 20, 30, 40) Among the IBFD radio resources used by the interfering cells (C2, C3, C4) of the base station (20, 30, 40) through interworking with each, the cell (C1) allocated to the access terminal (e.g., terminal 1). IBFD radio resources in the same resource allocation location as IBFD radio resources can be checked.

For example, as shown in FIG. 4, it is assumed that the resource allocation position d of the IBFD radio resource allocated to the access terminal (eg, terminal 1) in the cell C1 is confirmed.

In this case, the cell control apparatus 100 downlinks the downlink transmission strength of the interfering cells C2, C3, and C4 from the above-identified IBFD radio resource, that is, the IBFD radio resource d, or The downlink of C3 and C4) can be controlled by blanking.

Hereinafter, a process of controlling the IBFD radio resources of the interfering cells C2, C3, and C4 will be described in detail with reference to the interfering cell C2.

The cell control apparatus 100 may downlink the downlink transmission strength of the interfering cell C2 by a predetermined unit strength from the above-identified IBFD radio resource, that is, the IBFD radio resource d.

According to an example, the cell control apparatus 100 performs downlink control of the downlink transmission strength of the interfering cell C2 in the IBFD radio resource d by one preset unit strength through interworking with the base station 20. I can.

Of course, the cell control device 100, through interworking with the remaining base stations 30 and 40, the downlink transmission strength of the remaining interfering cells C3 and C4 in the IBFD radio resource d is also once as much as a preset unit strength. You can control down.

According to another example, the cell control apparatus 100, within a limit in which the downlink transmission strength of the interfering cell C2 in the IBFD radio resource d is not less than a predefined minimum transmission strength, the interfering cell C2 The downlink transmission strength of can be downlinked as many times as the unit strength.

Of course, the cell control apparatus 100 can downlink control the downlink transmission strength of the remaining interfering cells C3 and C4 several times as much as the unit strength within the minimum transmission strength limit.

At this time, the cell control apparatus 100 controls downlink transmission strength of the interfering cells (C2, C3, C4) to determine whether the downlink interference (c) of the cell (C1), which is checked again, is greater than or equal to the threshold (a). According to the check result, if the downlink interference (c) of the cell (C1) is still above the threshold (a), the downlink transmission strength of the interfering cells (C3, C4) is once again controlled down, and the downlink of the cell (C1). If the interference (c) is not greater than the threshold (a), it is a method of stopping downlink transmission strength downlink control of the interfering cells (C3, C4), and downlink transmission of the interfering cells (C3, C4) within the minimum transmission strength limit. The intensity can be controlled downward as many times as the unit intensity.

The cell control apparatus 100 may downlink the downlink transmission strength of the interfering cell C2 by a predetermined unit strength from the above-identified IBFD radio resource, that is, the IBFD radio resource d.

Meanwhile, the cell control apparatus 100 may control the downlink of the interfering cell C2 by blanking from the above-identified IBFD radio resource, that is, the IBFD radio resource d.

According to an example, the cell control apparatus 100 may immediately control the downlink of the interfering cell C2 from the IBFD radio resource d through interworking with the base station 20.

Of course, the cell control apparatus 100 can immediately control the downlink of the remaining interfering cells (C3, C4) in the IBFD radio resource (d) through interworking with the remaining base stations (30, 40).

According to another example, the cell control apparatus 100 downlinks the downlink transmission strength of the interfering cells C2, C3, C4 in the IBFD radio resource d, and downlinks the interfering cells C2, C3, C4. Even after downlink control of the link transmission strength, if the downlink interference (c) of the cell (C1) is still greater than or equal to the threshold (a), the downlink of the interfering cells (C2, C3, C4) can be controlled for blanking.

According to another example, the cell control apparatus 100 is in the process of downlink control of the downlink transmission strength of the interfering cells (C2, C3, C4) as many times as the unit strength within the minimum transmission strength limit as in the above example. , If there is an interfering cell (eg, C3) in which downlink control is not possible due to the minimum transmission strength limit, blanking control of the downlink of the interfering cell (eg, C3) may be performed.

If the cell (C1) controls the IBFD radio resources of the interfering cells (C2, C3, C4), which cause additional interference by the IBFD, from the perspective of the interfering cells (C2, C3, C4), downlink resources may be slightly damaged. However, additional interference caused by IBFD on the cell C1, that is, downlink interference caused by a downlink signal transmitted from another adjacent cell will be reduced.

Then, after controlling the IBFD radio resource of the interfering cell as described above (S170), the cell control device 100 moves down the cell C1 unless the operation of the cell control device 100 is turned off (S180 No). After the step S130 is repeated to determine whether the link interference, that is, the additional interference caused by the IBFD is greater than or equal to the threshold (a).

As described above, the method for controlling full-duplex transmission according to the present invention provides additional interference caused by IBFD when using full-duplex transmission (IBFD) in an actual mobile communication environment in which several cells coexist, that is, received from other cells adjacent to the cell side. Downlink interference (hereinafter, additional interference caused by IBFD) can be solved, resulting in an effect of taking advantage of increasing the transmission capacity of full-duplex transmission (IBFD) as much as possible.

The method for controlling full-duplex transmission 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 in 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 the 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 cell control apparatus and the full-duplex transmission control method according to the present invention, in an actual mobile communication environment in which several cells coexist, additional interference caused by IBFD when using full-duplex transmission (IBFD) can be solved. As the limit is exceeded, the possibility of marketing or sales of the applied device is sufficient, as well as the degree to be practically obvious, so that it is an invention that has industrial applicability.

1: terminal 10,20,30,40,50,60: base station
100: cell control device
110: grouping unit 120: downlink interference confirmation unit
130: control unit

Claims (11)

A grouping unit for grouping a group of interfering cells capable of causing downlink interference to the specific cell from among cells adjacent to a specific cell by In-Band Full Duplex (IBFD);
A downlink interference checker configured to check the downlink interference from an interfering cell belonging to the interfering cell group to the specific cell; And
When the downlink interference is greater than or equal to a preset threshold, a control unit for controlling a full-duplex transmission radio resource of the interfering cell group to reduce the downlink interference to the specific cell,
The downlink interference confirmation unit,
In some radio resources in which the interfering cell does not transmit a downlink signal among full-duplex transmission radio resources, the signal reception quality value of a downlink interference-free situation (non-interference) measured in the specific cell and a full-duplex transmission radio resource, the Cell control apparatus, characterized in that to check the downlink interference based on the signal reception quality value of a full-duplex transmission situation measured in a specific cell. The method of claim 1,
The interfering cell group,
Among the adjacent cells, the cell control apparatus is grouped based on the signal strength of each of the adjacent cells measured in the specific cell. delete The method of claim 1,
Some of the radio resources,
A plurality of sub-carriers in which the interfering cell receives only an uplink signal every preset confirmation period, and divides the full band (Channel Bandwidth) of the full-duplex transmission radio resource or the full band of the full-duplex transmission radio resource at regular intervals. Cell control device, characterized in that a part of. A grouping unit for grouping a group of interfering cells capable of causing downlink interference to the specific cell from among cells adjacent to a specific cell by In-Band Full Duplex (IBFD);
A downlink interference checker configured to check the downlink interference from an interfering cell belonging to the interfering cell group to the specific cell; And
When the downlink interference is greater than or equal to a preset threshold, a control unit for controlling a full-duplex transmission radio resource of the interfering cell group to reduce the downlink interference to the specific cell,
The control unit,
When the downlink interference is greater than the threshold, full-duplex transmission radio resources allocated to the access terminal of the specific cell among full-duplex transmission radio resources used by the at least some interfering cells for at least some interfering cells belonging to the interfering cell group Check the full-duplex transmission radio resource at the same location as,
In the checked full-duplex transmission radio resource, downlink transmission strength of the at least some interfering cells is downlinked or downlink blanking is controlled. A grouping unit for grouping a group of interfering cells capable of causing downlink interference to the specific cell from among cells adjacent to a specific cell by In-Band Full Duplex (IBFD);
A downlink interference checker configured to check the downlink interference from an interfering cell belonging to the interfering cell group to the specific cell; And
When the downlink interference is greater than or equal to a preset threshold, a control unit for controlling a full-duplex transmission radio resource of the interfering cell group to reduce the downlink interference to the specific cell,
The control unit,
When the downlink interference is greater than the threshold, full-duplex transmission radio resources allocated to the access terminal of the specific cell among full-duplex transmission radio resources used by the at least some interfering cells for at least some interfering cells belonging to the interfering cell group Check the full-duplex transmission radio resource at the same location as,
Downlink control of the downlink transmission strength of the at least some interfering cells in the checked full-duplex transmission radio resource,
If the downlink interference is equal to or greater than the threshold value even after the downlink transmission strength is down-controlled, blanking control is performed on downlink of the at least some interfering cells in the checked full-duplex transmission radio resource. A grouping step of grouping, by the cell control apparatus, an interfering cell group capable of causing downlink interference by full-duplex transmission to the specific cell from among cells adjacent to the specific cell;
A downlink interference checking step of the cell control apparatus confirming the downlink interference that an interfering cell belonging to the interfering cell group affects the specific cell; And
And a control step of controlling, by the cell control apparatus, a full-duplex transmission radio resource of the interfering cell group so that the downlink interference to the specific cell is reduced when the downlink interference is greater than or equal to a preset threshold,
The downlink interference confirmation step,
In some radio resources in which the interfering cell does not transmit a downlink signal among full-duplex transmission radio resources, the signal reception quality value of a downlink interference-free situation (non-interference) measured in the specific cell and a full-duplex transmission radio resource, the A full-duplex transmission control method, characterized in that the downlink interference is checked based on a signal reception quality value of a full-duplex transmission situation measured in a specific cell. delete The method of claim 7,
Some of the radio resources,
Full-duplex transmission control, characterized in that the interfering cell receives only an uplink signal every preset confirmation period, and is part of a plurality of subcarriers that divide the full-duplex radio resource or the full-duplex radio resource at regular intervals. Way. A grouping step of grouping, by the cell control apparatus, an interfering cell group capable of causing downlink interference by full-duplex transmission to the specific cell from among cells adjacent to the specific cell;
A downlink interference checking step of the cell control apparatus confirming the downlink interference that an interfering cell belonging to the interfering cell group affects the specific cell; And
And a control step of controlling, by the cell control apparatus, a full-duplex transmission radio resource of the interfering cell group so that the downlink interference to the specific cell is reduced when the downlink interference is greater than or equal to a preset threshold,
The control step,
When the downlink interference is greater than the threshold, full-duplex transmission radio resources allocated to the access terminal of the specific cell among full-duplex transmission radio resources used by the at least some interfering cells for at least some interfering cells belonging to the interfering cell group Check the full-duplex transmission radio resource at the same location as,
In the checked full-duplex transmission radio resource, the downlink transmission strength of the at least some interfering cells is downlinked or downlink is controlled by blanking. A grouping step of grouping, by the cell control apparatus, an interfering cell group capable of causing downlink interference by full-duplex transmission to the specific cell from among cells adjacent to the specific cell;
A downlink interference checking step of the cell control apparatus confirming the downlink interference that an interfering cell belonging to the interfering cell group affects the specific cell; And
And a control step of controlling, by the cell control apparatus, a full-duplex transmission radio resource of the interfering cell group so that the downlink interference to the specific cell is reduced when the downlink interference is greater than or equal to a preset threshold,
The control step,
When the downlink interference is greater than the threshold, full-duplex transmission radio resources allocated to the access terminal of the specific cell among full-duplex transmission radio resources used by the at least some interfering cells for at least some interfering cells belonging to the interfering cell group Check the full-duplex transmission radio resource at the same location as,
Downlink control of the downlink transmission strength of the at least some interfering cells in the checked full-duplex transmission radio resource,
If the downlink interference is equal to or greater than the threshold value even after the downlink transmission strength is down-controlled, blanking control of downlink of the at least some interfering cells is performed in the checked full-duplex transmission radio resource.

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