KR101915114B1 - Base station and control method thereof - Google Patents

Abstract

In determining the auxiliary cell (SCell) of the CA terminal, the optimum auxiliary cell (SCell) considering the interference with the adjacent cell is determined to lower the influence of the intercell interference due to the use of the auxiliary cell (SCell) of the CA terminal A base station apparatus and a base station apparatus capable of improving throughput of a communication system are proposed.

Description

TECHNICAL FIELD [0001] The present invention relates to a base station apparatus and a base station apparatus,

The present invention relates to an operation method of a base station apparatus and a base station apparatus, and more particularly, to an operation method of an auxiliary cell (SCell) considering an interference with a neighboring cell in determining an auxiliary cell (SCell) of a CA (Carrier Aggregation) To an operation method of a base station apparatus and a base station apparatus capable of improving the throughput of a communication system by lowering the influence of intercell interference due to the use of the auxiliary cell (SCell) of the CA terminal.

In the existing LTE system, it is possible to support high-speed communication service by using a bandwidth of up to 20 MHz. However, as the type of communication service and the speed of transmission demand have become diverse, there is an increasing demand for faster speed communication systems.

In recent years, an IMT-advanced communication system capable of supporting a wider band than the existing 20 MHz band has emerged. In an IMT-advanced communication system, in a case where a plurality of frequency bands coexist, (CA) technology to support a wider bandwidth.

CA technology can acquire a wider frequency band through integration of multiple unit frequency bands (CCs), and since each unit frequency band (CC) is used as an LTE frequency band for LTE terminals, So as to maintain compatibility with the system.

A terminal supporting the CA function (hereinafter referred to as a CA terminal) firstly accesses a base station through a primary cell (PCell) of a base frequency band in which an initial connection among a plurality of frequency bands CC is designated, Accordingly, it is possible to simultaneously access the base station through a secondary cell (SCell) in the auxiliary frequency band, and to use communication services by integrating cells of various frequency bands, that is, PCell and SCell.

In this way, when the CA terminal accesses the base station simultaneously through the base cell (PCell) and at least one auxiliary cell (SCell) and uses the communication service utilizing the CA function, since a plurality of frequency bands are integrally used, A higher data transfer rate can be obtained.

However, when the CA terminal uses the auxiliary cell (SCell) to increase the data transmission speed, interference with the adjacent cell formed in the frequency band of the auxiliary cell (SCell) necessarily occurs. Therefore, The quality of the communication service of other terminals using the communication service may be lowered and the throughput of the communication system may be lowered.

Accordingly, in determining the auxiliary cell (SCell) of the CA terminal, the optimum auxiliary cell (SCell) considering the interference with the neighboring cell is determined, so that the intercell interference To improve the throughput of the communication system.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and it is an object of the present invention to provide a method of determining an optimal auxiliary cell (SCell) considering interference with a neighboring cell The present invention also provides a method of operating a base station apparatus and a base station apparatus capable of improving the throughput of a communication system by lowering the influence of intercell interference caused by the use of the auxiliary cell (SCell) of the CA terminal.

According to a first aspect of the present invention, there is provided a base station apparatus comprising: a connection unit connected to a terminal using a base cell of a base frequency band among a plurality of frequency bands; A candidate identifying unit for identifying a candidate frequency band that can be simultaneously connected to the basic frequency band, among the plurality of frequency bands; An interference amount checking unit for checking an interference amount for each of the candidate frequency bands; And a controller for determining to use a cell of a candidate frequency band having the smallest interference amount among the candidate frequency bands as an auxiliary cell of the terminal based on the interference amount for each of the candidate frequency bands.

Preferably, the control unit determines whether there is a candidate frequency band having a smaller interference amount than the frequency band of the auxiliary cell used by the terminal among the candidate frequency bands at a predetermined scheduling period, Band can change the auxiliary cell of the terminal.

Preferably, if it is determined that the data transmission rate to be transmitted to the terminal is lower than a specific transmission rate required through the basic cell and the auxiliary cell used by the terminal, The cell of the candidate frequency band having the smallest interference amount among the remaining candidate frequency bands other than the frequency band of the auxiliary cell can be additionally determined as the auxiliary cell of the terminal.

Preferably, the interference amount checking unit can check the amount of interference based on the radio environment measurement information provided from the terminal connected to the candidate frequency band for each of the candidate frequency bands.

Preferably, the interference amount checking unit calculates an interference amount for each of the plurality of frequency bands by a predetermined unit time based on a result of monitoring radio environment measurement information provided from a terminal connected to the frequency band, The interference amount of the unit time belonging to the time point of determining the auxiliary cell of the terminal for each of the candidate frequency bands and the unit time belonging to the predetermined unit time past section from the time point, And to check the amount of interference based on the determined amount of interference for each candidate frequency band.

Preferably, the unit time past interval may be set to be longer as the rate of change of the radio environment that is grasped based on the interference amount per unit time calculated for each of the plurality of frequency bands is greater.

Preferably, the radio environment measurement information may include a sounding reference signal (SRS).

According to a second aspect of the present invention, there is provided a method of operating a base station, the method comprising: connecting to a terminal using a base cell of a base frequency band among a plurality of frequency bands; A candidate identifying step of identifying, among the plurality of frequency bands, a candidate frequency band that the terminal can simultaneously access to the basic frequency band; An interference amount checking step of checking an interference amount for each of the candidate frequency bands; And an auxiliary cell determining step of determining, based on the interference amount for each of the candidate frequency bands, to use a cell of the candidate frequency band having the smallest interference amount among the candidate frequency bands as the auxiliary cell of the terminal.

Preferably, the mobile station checks whether there is a candidate frequency band with a smaller interference amount than the frequency band of the auxiliary cell used by the terminal among the candidate frequency bands at a predetermined scheduling period, And changing the auxiliary cell of the terminal.

Determining whether a data transmission rate to be transmitted to the terminal is lower than a specific transmission rate required through the basic cell and the auxiliary cell used by the terminal; If it is determined that the data transmission rate is equal to or lower than the specific transmission rate, among the candidate frequency bands other than the frequency band of the auxiliary cell used by the terminal, the cell of the candidate frequency band having the smallest interference amount, And further determining the cell as a supplementary cell.

Preferably, the interference amount checking step may check the amount of interference based on the radio environment measurement information provided from the terminal connected to the candidate frequency band for each of the candidate frequency bands.

According to the method of operation of the base station apparatus and the base station apparatus of the present invention, in determining the auxiliary cell (SCell) of the CA terminal, the optimum auxiliary cell (SCell) considering the interference with the adjacent cell is determined, (SCell), thereby improving the throughput of the communication system.

1 is a configuration diagram illustrating a communication system including a base station apparatus according to a preferred embodiment of the present invention.
2 is a block diagram illustrating a configuration of a base station apparatus according to a preferred embodiment of the present invention.
3 is a control flowchart of a communication system including a base station apparatus according to a preferred embodiment of the present invention.
4 is a flowchart illustrating an operation method of a base station apparatus according to an exemplary embodiment of the present invention.

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

1 is a diagram illustrating a communication system including a base station apparatus according to a preferred embodiment of the present invention.

As shown in FIG. 1, in the communication system including the base station apparatus 100 of the present invention, a plurality of frequency bands coexist in the same area.

For example, referring to FIG. 1, the base station apparatus 100 includes a plurality of frequency bands, for example, a first frequency band B1, a second frequency band B2, and a third frequency band B3 In the cell perspective, the base station apparatus 100 may be configured to include cells B1_a, B1_b ... B1_f according to the first frequency band, cells B2_a ... B2_c according to the second frequency band, It is possible to form cells B3_a ... B3_c according to the frequency band.

The present invention is related to a Carrier Aggregation (CA) technique adopted in an IMT-advanced communication system that has been introduced to support a wider band than the existing 20 MHz band.

Here, the CA technology can secure a wider frequency band through the integration of multiple unit frequency bands (CCs), and since each unit frequency band (CC) is used as an LTE frequency band for LTE terminals, So that compatibility with the system can be maintained.

Accordingly, the base station apparatus 100 according to the present invention can be applied to any one of frequency bands (e.g., a first frequency band, a second frequency band, and a third frequency band) A CA supporting base station capable of providing a communication service by integrating cells of two or more frequency bands into a communication service utilizing a CA function for a terminal functioning as a CA function, will be.

It is assumed that the terminal 10 shown in FIG. 1 is a terminal supporting the CA function.

That is, the terminal 10 is a terminal that can use a communication service utilizing the above-described CA function on the premise that it supports two or more frequency bands.

Hereinafter, for convenience of description, it is assumed that the terminal 10 is a terminal supporting both the first frequency band B1, the second frequency band B2, and the third frequency band B3.

When the terminal 10 is powered on, the terminal 10 is connected to the base station apparatus 100 through cells of one frequency band among a plurality of frequency bands.

At this time, since the terminal 10 supports the CA function, the initial connection is connected to the base station apparatus 100 through the designated frequency band. This frequency band is the basic frequency band, The cell of the fundamental frequency band used for connection corresponds to a primary cell (PCell).

The terminal 10 is connected to the base station apparatus 100 through the base cell (PCell) in the basic frequency band and then transmitted through a secondary cell (SCell) of at least one auxiliary frequency band It is possible to simultaneously access the base station apparatus 100 and to use communication services by integrating cells of various frequency bands, that is, PCell and SCell.

At this time, when the terminal 10 accesses the base station apparatus 100 through the base cell (PCell), the base station apparatus 100 designates a candidate frequency band that the terminal 10 can use as an auxiliary cell (SCell) ), And then determines which candidate frequency band cell should be used as a supplementary cell (SCell).

The terminal 10 is connected to the base station 100 through the base cell 100 and then transmitted to the base station 100 through at least one auxiliary cell SCell determined by the base station 100 By using the communication service that utilizes the CA function using the simultaneous connection, a plurality of frequency bands are integrated, so that a higher data transmission rate can be obtained than when one frequency band is used.

However, when the terminal 10 or the CA terminal uses the auxiliary cell SCell to increase the data transmission speed, the interference with the adjacent cell formed in the frequency band of the auxiliary cell SCell necessarily occurs. Therefore, There is a problem that the communication service quality of other terminals using the communication service as well as the neighboring cells is deteriorated, thereby causing a problem that the throughput of the communication system is lowered.

Accordingly, in determining the auxiliary cell (SCell) of the CA terminal, the optimum auxiliary cell (SCell) considering the interference with the neighboring cell is determined, so that the intercell interference To improve the throughput of the communication system.

To this end, the base station apparatus 100 according to the present invention is connected to a terminal 10 using a basic cell basic cell (PCell) of a fundamental frequency band among a plurality of frequency bands, 10 confirms a candidate frequency band that can be concurrently connected to the basic frequency band, and then checks the interference amount for each candidate frequency band.

The base station apparatus 100 then determines to use the cell of the candidate frequency band having the smallest interference amount among the candidate frequency bands as the auxiliary cell SCell of the terminal 10 based on the interference amount for each candidate frequency band ).

Hereinafter, a configuration of a base station apparatus according to a preferred embodiment of the present invention will be described in detail with reference to FIG. For convenience of explanation, reference will be made to the above-mentioned reference numerals.

Prior to the description, a basic cell (PCell) and at least one auxiliary cell (SCell) used by the CA terminal, for example, the terminal 10 in the CA function operation are cells formed in different frequency bands.

In other words, if the terminal 10 uses the cell of the second frequency band B2 as the basic cell PCell, it may be understood that the second frequency band B2 is used as the basic cell PCell, 10 may use the third frequency band B3 as the auxiliary cell SCell if the cell of the third frequency band B3 is used as the auxiliary cell SCell.

A base station apparatus 100 according to the present invention includes a connection unit 110 for connecting to a terminal 10 using a basic cell of a basic frequency band among a plurality of frequency bands, A candidate identifying unit 120 for identifying candidate frequency bands capable of being simultaneously connected to the basic frequency band, an interference amount checking unit 130 for checking an interference amount for each of the candidate frequency bands, And a control unit (140) for determining to use a cell of the candidate frequency band having the smallest interference amount among the candidate frequency bands as the auxiliary cell of the terminal (10).

Here, the plurality of frequency bands provided by the base station apparatus 100 are described as being the first frequency band B1, the second frequency band B2 and the third frequency band B3, as shown in Fig. The base station apparatus 100 includes cells B1_a, B1_b ... B1_f according to the first frequency band, cells B2_a ... B2_c according to the second frequency band, cells B3_a ... B3_c are formed.

As described above, the base station apparatus 100 is capable of providing communication services utilizing the CA function, that is, a CA supporting base station (BS) capable of providing communication services by integrating cells of two or more frequency bands, would.

The connection unit 110 connects to the terminal 10 using the basic cell (PCell) of the fundamental frequency band among the plurality of frequency bands B1, B2, and B3.

At this time, it is assumed that the terminal 10 is assumed to be a terminal supporting the CA function, and the basic frequency band to which the initial connection is designated is the second frequency band B2.

That is, when the terminal 10 is powered on, the terminal 10 is connected to the base station apparatus 100 through the cell of the second frequency band B2 in which the initial connection is designated, and is connected to the communication system such as the location registration and the radio resource allocation The connection procedure is performed.

At this time, the cell of the fundamental frequency band, that is, the second frequency band B2 used for initial connection with the base station apparatus 100 by the terminal 10 corresponds to the basic cell PCell.

Hereinafter, for convenience of explanation, the terminal 10 uses the cell B2_b of the cells B2_a ... B2_c in the second frequency band B2 as the base cell (PCell) It is assumed that they are connected. Therefore, the base cell (PCell) of the terminal 10 mentioned below will be the cell B2_b.

The candidate confirming unit 120 identifies a candidate frequency band that can be simultaneously connected to the basic frequency band, i.e., the second frequency band B2, among the plurality of frequency bands B1, B2, and B3.

More specifically, in the above-described connection procedure execution process in which the terminal 10 accesses the base station apparatus 100 via the basic cell (PCell), the base station apparatus 100 determines whether or not the base station 100 (PCell), as well as frequency band combination information (CA Capability) capable of simultaneous access in the terminal 10 can be grasped.

The candidate identifying unit 120 determines whether the terminal 10 is connected to the basic frequency band, that is, the second frequency band B2, based on the frequency band combination information (CA Capability) of the terminal 10, Identify possible candidate frequency bands.

As a result, the candidate frequency band means a frequency band that the terminal 10 can use at the same time as the basic frequency band, that is, the second frequency band B2, and can use the auxiliary frequency band.

At this time, the candidate frequency band may be identified as a single number, or two or more may be identified.

For example, in the frequency band combination information (CA Capability) of the terminal 10, if only the first frequency band B1 is confirmed as a frequency band in which the terminal 10 can be concurrently connected to the second frequency band B2, The confirmation unit 120 can identify a single first frequency band B1 as a candidate frequency band.

On the other hand, in the frequency band combination information (CA Capability) of the terminal 10, the terminal 10 can simultaneously access the first frequency band B1 and the third frequency band B3 , The candidate identifying unit 120 can identify two or more of the first frequency band B1 and the third frequency band B3 as candidate frequency bands.

Hereinafter, it is assumed that the first frequency band B1 and the third frequency band B3 are confirmed as the candidate frequency bands.

In this case, the candidate identifying unit 120 determines whether the terminal 10 is a candidate frequency band that can be concurrently connected to the fundamental frequency band, that is, the second frequency band B2, in the first frequency band B1 and the third frequency band B3 ).

Of course, the base station apparatus 100 provides the terminal 10 with information on the candidate frequency bands, that is, the first frequency band B1 and the third frequency band B3, I.e., the first frequency band B1 and the third frequency band B3, which are usable as the first frequency band B3.

The interference amount checking unit 130 checks the amount of interference for each candidate frequency band.

That is, the interference amount checking unit 130 checks the interference amount for each of the candidate frequency bands, for example, the first frequency band B1 and the third frequency band B3 identified by the candidate checking unit 120. [

More specifically, the interference amount verifying unit 130 determines the interference amount based on the radio environment measurement information provided from the terminal connected to the candidate frequency band for each of the candidate frequency bands, for example, the first frequency band B1 and the third frequency band B3 The amount of interference can be confirmed based on this.

At this time, the radio environment measurement information preferably includes a sounding reference signal (SRS).

Hereinafter, a process of checking the amount of interference for each of the candidate frequency bands, for example, the first frequency band B1 and the third frequency band B3 will be described with reference to a more specific embodiment.

The interference amount checking unit 130 calculates the interference amount for each of the plurality of frequency bands B1, B2, and B3 by the predetermined unit time based on the result of monitoring the wireless environment measurement information provided from the terminal connected to the frequency band .

More specifically, basically, the base station apparatus 100 transmits radio environment measurement information provided from a terminal connected to the corresponding frequency band to each of a plurality of frequency bands B1, B2, and B3 provided by the base station apparatus 100 continuously .

Hereinafter, the first frequency band B1 among the plurality of frequency bands B1, B2, and B3 will be described for convenience of explanation.

The base station apparatus 100 may continuously monitor the radio environment measurement information provided from the terminal connected to the first frequency band B1.

A terminal connected to the first frequency band B1 is a cell in the first frequency band B1 formed by the base station apparatus 100, for example, cells B1_a, B1_b ... B1_f, (CA terminal, terminal that does not support the CA function (hereinafter referred to as CA non-terminal terminal)) connected to at least one of the terminals B2, B2_a, B2_c, B3_a ... B3_c.

The terminal connected to the base station apparatus 100 through the cells B1_a, B1_b, ... B1_f, B2_a ... B2_c, B3_a ... B3_c of the first frequency band B1 is generally connected (I.e., the radio environment measurement information) to the base station apparatus 100 (reporting).

At this time, the radio environment measurement information provided to the base station apparatus 100 includes a sounding reference signal SRS.

Therefore, the base station apparatus 100 transmits radio environment measurement information, particularly sounding information, provided from an unspecified terminal (CA terminal or CCA-compliant terminal) connected to the first frequency band B1 to the first frequency band B1 The reference signal SRS can be continuously monitored.

In this manner, the base station apparatus 100 is provided with, for each of a plurality of frequency bands B1, B2, and B3 provided by itself, including the first frequency band B1, Wireless environment measurement information, in particular sounding reference signal (SRS), can be monitored.

Based on the result of monitoring the radio environment measurement information, particularly the sounding reference signal SRS, for each of the plurality of frequency bands B1, B2, and B3 as described above, It is possible to calculate the amount of interference (hereinafter referred to as interference amount per unit time (TTI)) by time (TTI).

For example, to describe the first frequency band B1, the interference amount checking unit 130 monitors the radio environment measurement information, particularly the sounding reference signal SRS, with respect to the first frequency band B1 as described above And calculates the interference amount per unit time (TTI) of the first frequency band B1 on the basis of the result.

In this case, the interference amount checking unit 130 calculates the interference amount per unit time (TTI) according to a predetermined calculation algorithm, and the interference amount per unit time (TTI) calculated according to the calculation algorithm is the reception level of the sounding reference signal SRS It is preferable that the interference amount is calculated as a smaller value and the interference amount is calculated as a larger value as the reception level of the sounding reference signal SRS is lower.

In this way, the interference amount checking unit 130 can calculate the interference amount per unit time (TTI) for each of a plurality of frequency bands B1, B2, and B3 including the first frequency band B1.

The interference amount checking unit 130 determines the interference amount based on the candidate frequency bands B1 to B3 and the third frequency band B1 to B2 in the interference amount calculated for each of the plurality of frequency bands B1, The interfering amount of the unit time to which the time for determining the auxiliary cell (SCell) of the terminal 10 belongs per unit time B3 and the interfering amount of the unit time belonging to the past unit time set from the time point.

For example, if the first frequency band B1 is referred to, the interference amount checking unit 130 calculates the interference amount for each of the frequency bands B1, B2, and B3 based on the calculated interference amount per unit time (TTI) Check the interference amount per unit time (TTI) for one frequency band (B1).

The interference amount check unit 130 determines the time point at which the auxiliary cell SCell of the terminal 10 is determined, that is, the current time n, from the interference amount per unit time (TTI) for the first frequency band B1 The interference amount of the unit time (TTI, n) belonging and the interference amount of the unit time (nt) belonging from the present time (n) to the predetermined unit time past period (t) are checked.

The interference amount checking unit 130 calculates the interference amount of each of the frequency bands B1, B2, and B3 based on the calculated interference amount per unit time (TTI) 3 interference amount per unit time (TTI) with respect to the frequency band (B3).

The interference amount checking unit 130 determines the time at which the auxiliary cell SCell of the terminal 10 is determined, that is, the current time n, from the interference amount per unit time (TTI) for the third frequency band B3 The interference amount of the unit time (TTI, n) belonging and the interference amount of the unit time (nt) belonging from the present time (n) to the predetermined unit time past period (t) are checked.

The interfering amount check unit 130 determines interference amounts of the unit times determined as described above, that is, the current unit time (TTI, n), for each of the candidate frequency bands, i.e., the first frequency band B1 and the third frequency band B3 It is possible to confirm the interference amount based on the interference amount and the interference amount of the past unit time (nt).

More specifically, the interference amount checking unit 130 can check the interference amount of the first frequency band B1 and the interference amount S of the third frequency band B3 according to the following equation (1).

Equation 1.

S (B1) = a * S (B 1, n-t) + S (B 1, n)

Here, S (B1) means the interference amount of the first frequency band B1 and S (B3) means the interference amount of the third frequency band B3.

Here, n denotes a unit time (TTI) to which a current time point for determining a supplementary cell (SCell) of the terminal 10 belongs, and t denotes a unit amount of time from the current point of time (n) , And a denotes a weight value.

Here, a and t are changeable by the operator of the communication system.

Particularly, as the radio environment change rate, which is grasped based on the interference amount per unit time (TTI) calculated for each of the frequency bands B1, B2, and B3, is set longer and smaller It is desirable to set it to be short and reflect the change of the radio environment efficiently.

That is, the interference amount check unit 130 applies the weight a to the interference amount S (B1, nt) of the past unit time nt confirmed with respect to the first frequency band B1, as in the above-described Equation 1 The interference amount S (B1, n) of the current unit time (TTI, n) can be confirmed as the interference amount of the first frequency band B1.

The interference amount check unit 130 applies the weight a to the interference amount S (B3, nt) of the past unit time nt confirmed for the third frequency band B3 as in the above-described equation (1) The result of adding the interference amount S (B3, n) of the current unit time (TTI, n) to the interference amount of the third frequency band B3.

Based on the candidate frequency bands identified by the interference amount checking unit 130, that is, the interference amounts S (B1) and S (B3) for the first frequency band B1 and the third frequency band B3, It is determined to use the cell of the candidate frequency band having the smallest interference amount among the first frequency band B1 and the third frequency band B3 as the auxiliary cell SCell of the terminal 10.

Hereinafter, for ease of explanation, it is assumed that the interference amount S (B3) of the third frequency band B3 is smaller than the interference amount S (B1) of the first frequency band B1.

In this case, the control unit 140 confirms the third frequency band B3 as the candidate frequency band having the smallest interference amount among the first frequency band B1 and the third frequency band B3, and the third frequency band B3 To be used as the auxiliary cell (SCell) of the terminal (10).

That is, the control unit 140 activates the cell of the third frequency band B3 together with the basic cells PCell and B2_b in the terminal 10 as an auxiliary cell SCell, 10 to connect to the base station apparatus 100 using the cell of the third frequency band B3 (for example, B3_b) as the auxiliary cell SCell in the CA function operation.

As described above, the base station apparatus 100 according to the present invention transmits a cell in a candidate frequency band having the smallest interference amount determined for each candidate frequency band to the terminal 10 (i.e., the CA terminal) initially connected through the base cell (PCell) (SCell), it is possible to determine the optimal auxiliary cell (SCell) considering the interference with the adjacent cell in determining the auxiliary cell (SCell) of the CA terminal.

Furthermore, the base station apparatus 100 may change the supplementary cell SCell so that the CA terminal can use the optimal supplementary cell SCell every scheduling period even after determining the supplementary cell SCell of the CA terminal as described above It is possible.

On the contrary, if the terminal 10 using the basic cells (PCell, B2_b) is activated as described above, the cells in the third frequency band B3 are used as the auxiliary cells SCell As follows.

The control unit 140 controls the frequency band of the third frequency band B3 of the auxiliary cell SCell used by the terminal 10 among the candidate frequency bands B1 and B3 every predetermined scheduling period, It is determined whether there is a candidate frequency band with a smaller interference amount than the frequency band B3.

Here, the scheduling period may be the same as or different from the unit time (TTI) for calculating the above-mentioned interference amount.

The radio environment changes unpredictably. Therefore, after the interference amount of the third frequency band B3 is confirmed to be smaller than the interference amount of the first frequency band B1 as described above, the interference amount of the first frequency band B1 becomes the third May be smaller than the interference amount of the frequency band B3.

If the amount of interference of the first frequency band B1 is smaller than the amount of interference of the third frequency band B3, the control unit 140 controls the third frequency b3 of the auxiliary cell SCell used by the terminal 10, It is confirmed that there is a candidate frequency band with a smaller interference amount than the band B3, that is, the first frequency band B1.

In this case, the control unit 140 can change the auxiliary cell (SCell) of the terminal 10 to the cell of the candidate frequency band having the smaller interference amount, that is, the cell of the first frequency band B1.

That is, the control unit 140 performs inter-frequency handover of the terminal 10 so that the candidate frequency band having a smaller interference amount, that is, the first frequency band B1, becomes the sub frequency band of the terminal 10, (E.g., B1_c) in the first frequency band B1 as a spare cell (SCell) to connect to the base station device 100. [

Of course, if the interference amount of the third frequency band B3 is smaller than the interference amount of the first frequency band B1, the control unit 140 controls the third terminal of the auxiliary cell SCell used by the terminal 10, It is confirmed that there is no candidate frequency band with smaller interference amount than the frequency band B3. In this case, the terminal 10 will continue to use the cell of the third frequency band B3 as the auxiliary cell SCell.

As described above, the base station apparatus 100 of the present invention can determine whether or not the CA terminal is the best candidate based on the amount of interference of the candidate frequency band that changes occasionally at every scheduling period, even after determining the terminal 10, The auxiliary cell (SCell) may be changed to use the auxiliary cell (SCell).

Furthermore, the base station apparatus 100 may improve the data transmission rate by further determining the auxiliary cell (SCell) when the data rate of the CA terminal is lower than or equal to a specific transmission rate required by the CA function.

On the contrary, if the terminal 10 using the basic cells (PCell, B2_b) is activated as described above, the cells in the third frequency band B3 are used as the auxiliary cells SCell As follows.

First, when the terminal 10 uses the basic cells (PCell, B2_b) and one auxiliary cell (SCell) as described above, it corresponds to the 2-band CA function.

In this case, the control unit 140 controls the data transmission rate to be transmitted to the terminal 10 through the basic cell (PCell, B2_b) and the auxiliary cell (SCell, for example, B3_b) It is possible to confirm the data transmission rate to be transmitted to the terminal 10 operating by the CA function.

The control unit 140 then determines whether or not the data transmission rate of the identified terminal 10 is lower than or equal to the required specific transmission rate.

In this case, the specific transmission rate may be a fixed transmission rate requested by the terminal 10 in the CA function operation, or may be a variable transmission rate depending on the communication service used by utilizing the CA function in the terminal 10 have.

If it is determined that the data transmission rate of the terminal 10 is equal to or lower than the required transmission rate, the control unit 140 controls the third frequency band of the auxiliary cell SCell used by the terminal 10, The cell of the candidate frequency band having the smallest interference amount among the remaining candidate frequency bands other than the candidate frequency band B3 can be further determined by the auxiliary cell SCell of the terminal 10. [

If the candidate frequency band is the first frequency band B1 and the third frequency band B3 as described above, the third frequency band B3 of the auxiliary cell SCell used by the terminal 10 The candidate frequency band is only the first frequency band B1.

The control unit 140 further activates the cell of the first frequency band B1 to the auxiliary cell SCell of the terminal 10 so as to allow the terminal 10 to operate in the first frequency band B1 (For example, B1_c) as an auxiliary cell (SCell) to connect to the base station apparatus 100. [

Of course, if there are a plurality of candidate frequency bands other than the third frequency band B3 of the auxiliary cell SCell used by the terminal 10, the controller 140 selects the smallest frequency band among the several remaining candidate frequency bands The cell of the candidate frequency band (e.g., B1) will be additionally determined as the auxiliary cell (SCell) of the terminal 10. [

If the remaining frequency band other than the third frequency band B3 of the auxiliary cell SCell used by the terminal 10 is several, the controller 140 determines that the data transmission rate of the terminal 10 is a specific transmission The supplementary cell SCell of the terminal 10 can be additionally determined in the same manner as described above until the speed exceeds the speed.

As described above, the base station apparatus of the present invention determines an optimal supplementary cell (SCell) considering interference with neighboring cells in determining the supplementary cell (SCell) of the CA terminal, The influence of inter-cell interference due to use can be lowered, thereby improving the overall throughput of the communication system.

Hereinafter, an operation method of the base station apparatus according to the present invention will be described with reference to FIG. 3 and FIG. For convenience of description, reference will be made to the reference numerals of FIGS. 1 to 2 described above.

First, with reference to FIG. 3, a control flow of a communication system including a base station apparatus according to the present invention will be described.

The terminal 10 is powered on or handed over and connected to the base station apparatus 100 through a base cell (PCell) of a basic frequency band (S10).

The terminal 10 supports the CA function and the terminal 10 uses the cell B2_b of the second frequency band B2 as the basic cell PCell for the sake of convenience of description, As shown in FIG. Therefore, the base cell (PCell) of the terminal 10 mentioned below will be the cell B2_b.

The base station apparatus 100 of the present invention is configured to transmit the base station apparatus 10 with a base frequency band that is a candidate frequency band that can be simultaneously accessed with the second frequency band B2, (S20).

Hereinafter, it is assumed that the first frequency band B1 and the third frequency band B3 are confirmed as the candidate frequency bands.

The base station apparatus 100 provides the terminal 10 with information on the candidate frequency bands B1 and B3 (S30) That is, the first frequency band B1 and the third frequency band B3 that can be used as the first frequency band B3 (Step S35).

In step S40, the base station apparatus 100 checks the amount of interference for each of the candidate frequency bands, for example, the first frequency band B1 and the third frequency band B3.

Accordingly, the base station apparatus 100 determines a candidate frequency band having the smallest interference amount among the candidate frequency bands, that is, the first frequency band B1 and the third frequency band B3, based on the interference amount for each candidate frequency band identified in step S40 It is determined to be the auxiliary frequency band of the terminal 10 (S50).

The base station apparatus 100 then activates (S60) the cell of the auxiliary frequency band determined in step S50, for example, the third frequency band B3 as the auxiliary cell SCell of the terminal 10 The terminal 10 can access the base station 100 by using the cell of the third frequency band B3 (for example, B3_b) as the auxiliary cell SCell in operation S70.

Hereinafter, an operation method of the base station apparatus according to the preferred embodiment of the present invention will be described in more detail with reference to FIG.

Basically, the method of operation of the base station apparatus 100 according to the present invention calculates an interference amount per unit time (TTI) for each of a plurality of frequency bands B1, B2, and B3 provided by the base station apparatus 100 (S100).

More specifically, the method of operation of the base station apparatus 100 according to the present invention is a method for operating the base station apparatus 100 according to the present invention, for each of a plurality of frequency bands B1, B2, and B3 provided by the base station apparatus 100, Environmental monitoring information can be continuously monitored.

Hereinafter, the first frequency band B1 among the plurality of frequency bands B1, B2, and B3 will be described for convenience of explanation.

The operation method of the base station apparatus 100 according to the present invention can continuously monitor the radio environment measurement information provided from the terminal connected to the first frequency band B1.

A terminal connected to the first frequency band B1 is a cell in the first frequency band B1 formed by the base station apparatus 100, for example, cells B1_a, B1_b ... B1_f, (CA terminal, terminal that does not support the CA function (hereinafter referred to as CA non-terminal terminal)) connected to at least one of the terminals B2, B2_a, B2_c, B3_a ... B3_c.

The terminal connected to the base station apparatus 100 through the cells B1_a, B1_b, ... B1_f, B2_a ... B2_c, B3_a ... B3_c of the first frequency band B1 is generally connected (I.e., the radio environment measurement information) to the base station apparatus 100 (reporting).

At this time, the radio environment measurement information provided to the base station apparatus 100 includes a sounding reference signal SRS.

The method of operation of the base station apparatus 100 according to the present invention is a method of operating the base station apparatus 100 provided from an unspecified terminal (CA terminal, CCA non-support terminal) connected to the first frequency band B1 with respect to the first frequency band B1 Wireless environment measurement information, in particular the sounding reference signal (SRS), can be continuously monitored.

In this way, the method of operation of the base station apparatus 100 according to the present invention is such that, for each of a plurality of frequency bands B1, B2, B3 provided by itself including the first frequency band B1, And can monitor the radio environment measurement information, particularly the sounding reference signal SRS,

The method of operation of the base station apparatus 100 according to the present invention is a method of monitoring radio environment measurement information and sounding reference signal SRS for each of a plurality of frequency bands B1, B2, and B3 as described above (Hereinafter referred to as an interference amount per unit time (TTI)) for each predetermined unit time (TTI).

For example, when the first frequency band B1 is referred to, the operation method of the base station apparatus 100 according to the present invention is such that the radio environment measurement information, particularly the sounding reference signal (TTI) of the first frequency band B1 on the basis of the result of monitoring the SRS.

Herein, the method of operation of the base station 100 according to the present invention is a method of calculating an interference amount per unit time (TTI) according to a predetermined calculation algorithm, wherein the interference amount per unit time (TTI) It is preferable that the higher the reception level of the signal SRS is, the smaller the interference amount is, and the lower the reception level of the sounding reference signal SRS is, the larger the interference amount is calculated.

In this manner, the method of operation of the base station apparatus 100 according to the present invention is such that, for each of a plurality of frequency bands B1, B2, B3 including the first frequency band B1, Can be calculated.

Thereafter, the terminal 10 is powered on or handed over and connected to the base station 100 through a base cell (PCell) of a basic frequency band (S110).

The terminal 10 supports the CA function and the terminal 10 uses the cell B2_b of the second frequency band B2 as the basic cell PCell for the sake of convenience of description, As shown in FIG. Therefore, the base cell (PCell) of the terminal 10 mentioned below will be the cell B2_b.

The method of operation of the base station apparatus 100 according to the present invention is based on the frequency band combination information (CA Capability) of the terminal 10 so that the terminal 10 can access the base frequency band, A possible candidate frequency band is confirmed (S120).

Hereinafter, it is assumed that the first frequency band B1 and the third frequency band B3 are confirmed as the candidate frequency bands.

The method of operation of the base station 100 according to the present invention then checks the amount of interference for each candidate frequency band, e.g., the first frequency band B1 and the third frequency band B3 determined in step S120.

For example, the operation of the base station apparatus 100 according to the present invention may be realized by calculating the unit of the frequency band B1, B2, B3 for each of the frequency bands B1, B2, B3 through step S100, The interference amount per unit time (TTI) with respect to the first frequency band B1 is confirmed at the interference amount per time (TTI).

The method of operation of the base station apparatus 100 according to the present invention is a method of determining the timing at which the auxiliary cell SCell of the terminal 10 is determined from the interference amount per unit time TTI for the first frequency band B1 The interference amount of the unit time (TTI, n) to which the current time (n) belongs and the interference amount of the unit time (nt) belonging from the current time (n) to the predetermined unit time past section (t) are checked.

The operation method of the base station apparatus 100 according to the present invention may further include the step of determining whether a unit of the frequency band B1, The interference amount per unit time (TTI) with respect to the third frequency band B3 is checked at the interference amount per time (TTI).

The method of operation of the base station apparatus 100 according to the present invention is a method of determining the timing at which the auxiliary cell SCell of the terminal 10 is determined from the interference amount per unit time TTI for the third frequency band B3 The interference amount of the unit time (TTI, n) to which the current time (n) belongs and the interference amount of the unit time (nt) belonging from the current time (n) to the predetermined unit time past section (t) are checked.

The method of operation of the base station apparatus 100 according to the present invention will now be described with respect to the candidate frequency bands B1 to B3 and the third frequency band B3, (TTI, n) and the interference amount of the past unit time (nt) (S130).

More specifically, an operation method of the base station apparatus 100 according to the present invention is a method of operating the base station apparatus 100 according to the above-described equation (1), in which the interference amount S (B1, nt) of the past unit time nt confirmed for the first frequency band B1 ) To the interference amount S (B1, n) of the current unit time (TTI, n) by applying the weight (a) to the first frequency band B1 as the interference amount of the first frequency band B1.

The method of operation of the base station apparatus 100 according to the present invention is characterized in that the interference amount S (B3, nt) of the past unit time (nt) checked against the third frequency band B3 is added to the interference amount S (B3, n) of the current unit time (TTI, n) by applying the above-described interference amount S (B3, n) to the interference amount of the third frequency band B3.

The method of operation of the base station apparatus 100 according to the present invention further includes the steps of determining interference frequencies S (B1) and S (B1) for the first frequency band B1 and the third frequency band B3, The candidate frequency band having the smallest amount of interference among the first frequency band B1 and the third frequency band B3 is determined as the sub frequency band of the terminal 10 based on the frequency bands B3 and B3 at step S140.

The method of operation of the base station apparatus 100 according to the present invention further includes determining whether to use the cell of the sub frequency band B3 determined in step S140 as the auxiliary cell SCell of the terminal 10 The base station apparatus 100 can be connected to the terminal 10 using the cell of the third frequency band B3 (for example, B3_b) as the auxiliary cell SCell in the CA function operation (S150) do.

The method of operation of the base station apparatus 100 according to the present invention is similar to that of step S130 even after determining the supplementary cell SCell of the CA terminal as described above, the candidate frequency band, for example, the first frequency band B1, And the third frequency band B3 (S160).

The operation method of the base station apparatus 100 according to the present invention is the same as the operation of the auxiliary cell SCell used by the terminal 10 among the candidate frequency bands B1 and B1 and the third frequency band B3 It is checked whether there is a candidate frequency band with a smaller interference amount than the third frequency band B3 (S170).

If the amount of interference in the first frequency band B1 is smaller than the amount of interference in the third frequency band B3, the method of operation of the base station apparatus 100 according to the present invention is not limited to the assistance It is confirmed that there is a candidate frequency band having a smaller interference amount than the third frequency band B3 of the cell SCell, that is, the first frequency band B1 (Yes in S170).

In this case, the operation method of the base station apparatus 100 according to the present invention can change the auxiliary cell SCell of the terminal 10 to the cell of the candidate frequency band having the smaller interference amount, that is, the first frequency band B1 (S180 ).

That is, the method of operation of the base station 100 according to the present invention is a method of operating the terminal 10 so that the candidate frequency band having a smaller interference amount, that is, the first frequency band B1, Inter-frequency Handover) to allow the terminal 10 to access the base station 100 by using a cell (e.g., B1_c) of the first frequency band B1 as a supplementary cell (SCell).

If the interference amount of the third frequency band B3 is smaller than the interference amount of the first frequency band B1, the operation method of the base station apparatus 100 according to the present invention is not limited to the method It is confirmed that there is no candidate frequency band having a smaller interference amount than the third frequency band B3 of the auxiliary cell SCell (S170 No). In this case, the terminal 10 continues to operate as the auxiliary cell SCell in the third frequency band B3) will be used.

The method of operation of the base station apparatus 100 according to the present invention is transmitted to the terminal 10 through the base cell (PCell, B2_b) and the auxiliary cell (SCell, for example, B3_b) That is, whether the data transmission rate to be transmitted to the terminal 10 operating in the 2-Band CA function is equal to or less than the required specific transmission rate (S190).

If it is determined that the data transmission rate of the terminal 10 is less than or equal to the specific transmission rate required (S190, Yes), the operation of the base station apparatus 100 according to the present invention is such that the terminal 10 The cell of the candidate frequency band having the smallest interference amount among the remaining candidate frequency bands other than the third frequency band B3 of the used auxiliary cell SCell can be additionally determined as the auxiliary cell SCell of the terminal 10 ).

If the candidate frequency band is the first frequency band B1 and the third frequency band B3 as described above, the third frequency band B3 of the auxiliary cell SCell used by the terminal 10 The candidate frequency band is only the first frequency band B1.

The method of operating the base station apparatus 100 according to the present invention further includes activating the cell of the first frequency band B1 with the auxiliary cell SCell of the terminal 10 at step S200, (B1_c) of the first frequency band B1 to be used as a supplementary cell (SCell) to connect to the base station device 100. [

Of course, if there are a plurality of candidate frequency bands other than the third frequency band B3 of the auxiliary cell SCell used by the terminal 10, the operation method of the base station apparatus 100 according to the present invention may include a plurality of The cell of the candidate frequency band having the smallest interference amount among the candidate frequency bands will be additionally determined as the auxiliary cell (SCell) of the terminal 10.

The method of operation of the base station apparatus 100 according to the present invention is the same as that of the base station apparatus 100 according to the first embodiment except that the terminal 10 does not terminate the CA function operation or use the communication service through the CA function (S210 No) The terminal 10 can use and add the optimal auxiliary cell SCell repeatedly based on the interferences of the candidate frequency bands B1 and B3 that change occasionally.

As described above, in the method of operating the base station apparatus according to the present invention, in determining the auxiliary cell (SCell) of the CA terminal, the optimum auxiliary cell (SCell) considering the interference with the adjacent cell is determined, Cell interference due to the use of a cell (SCell) is lowered, thereby improving the overall throughput of the communication system.

The method of operating the base station according to an embodiment of the present invention may be implemented in the form of a program command 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 those specially designed and constructed for the present invention or may be available to those skilled in the art of computer software. Examples of computer-readable media include magnetic media such as hard disks, floppy disks and magnetic tape; optical media such as CD-ROMs and DVDs; magnetic media such as floppy disks; Magneto-optical media, and hardware devices specifically configured to store and execute program instructions such as ROM, RAM, flash memory, and the like. Examples of program instructions include machine language code such as those produced by a compiler, as well as high-level language code that can be executed by a computer using an interpreter or the like. The hardware devices described above may be configured to operate as one or more software modules to perform the operations of the present invention, and vice versa.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments, but, on the contrary, It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims.

According to the operation method of the base station apparatus and the base station apparatus according to the present invention, in determining the auxiliary cell (SCell) of the CA terminal, the optimum auxiliary cell (SCell) considering the interference with the adjacent cell is determined, It is possible to improve the throughput of the communication system by reducing the influence of the intercell interference due to the use of the SCell. Therefore, as the technology overcomes the limit of the existing technology, But it is an invention that is industrially applicable because it can be practically carried out clearly.

10: Terminal
100: base station device
110: connection unit 120: candidate confirmation unit
130: interference amount checking unit 140:

Claims (11)

A connection unit for connecting to a terminal using a basic cell of a basic frequency band among a plurality of frequency bands;
A candidate identifying unit for identifying a candidate frequency band that can be simultaneously connected to the basic frequency band, among the plurality of frequency bands;
An interference amount checking unit for checking an interference amount for each of the candidate frequency bands; And
And a controller for determining to use a cell of a candidate frequency band having the smallest interference amount among the candidate frequency bands as an auxiliary cell of the terminal based on the interference amount for each of the candidate frequency bands,
Wherein the interference amount checking unit comprises:
The amount of interference is determined based on the interference amount of the unit time to which the time for determining the auxiliary cell of the terminal belongs and the interference amount of the unit time belonging to the previous unit time period from the time point,
Wherein the unit time past period includes:
Wherein the base station apparatus is set longer as the rate of change of the radio environment is larger. The method according to claim 1,
Wherein,
The method comprising: checking whether a candidate frequency band having a smaller interference amount than the frequency band of the auxiliary cell being used by the terminal is present in the candidate frequency band every predetermined scheduling period, To the base station apparatus. The method according to claim 1,
Wherein,
When it is determined that the data transmission rate to be transmitted to the terminal is lower than a specific transmission rate required through the basic cell and the auxiliary cell used by the terminal,
Wherein the cell of the candidate frequency band having the smallest interference amount among the remaining candidate frequency bands other than the frequency band of the auxiliary cell used by the terminal is determined as the auxiliary cell of the terminal. The method according to claim 1,
Wherein the interference amount checking unit comprises:
And the interference amount is confirmed based on the radio environment measurement information provided from the terminal connected to the candidate frequency band for each of the candidate frequency bands. delete delete 5. The method of claim 4,
The wireless environment measurement information includes:
And a sounding reference signal (SRS). A connection step of connecting to a terminal using a basic cell of a fundamental frequency band among a plurality of frequency bands;
A candidate identifying step of identifying, among the plurality of frequency bands, a candidate frequency band that the terminal can simultaneously access to the basic frequency band;
An interference amount checking step of checking an interference amount for each of the candidate frequency bands; And
And an auxiliary cell determining step of determining to use a cell of a candidate frequency band having the smallest interference amount among the candidate frequency bands as an auxiliary cell of the terminal based on the interference amount for each of the candidate frequency bands,
In the interference amount checking step,
The interference amount is checked based on the interference amount of the unit time to which the time of determining the auxiliary cell of the terminal belongs and the interference amount of the unit time belonging to the previous unit time period from the time point,
Wherein the unit time past period includes:
Wherein a larger value of the rate of change of the radio environment is set. 9. The method of claim 8,
The method comprising: checking whether a candidate frequency band having a smaller interference amount than the frequency band of the auxiliary cell being used by the terminal is present in the candidate frequency band every predetermined scheduling period, Further comprising the step of modifying the base station apparatus. 9. The method of claim 8,
Determining whether a data transmission rate to be transmitted to the terminal is lower than a specific transmission rate required through the basic cell and the auxiliary cell used by the terminal;
If it is determined that the data transmission rate is equal to or lower than the specific transmission rate, among the candidate frequency bands other than the frequency band of the auxiliary cell used by the terminal, the cell of the candidate frequency band having the smallest interference amount, Further comprising the step of determining the additional cell as an auxiliary cell. 9. The method of claim 8,
In the interference amount checking step,
And the interference amount is confirmed based on radio environment measurement information provided from a terminal connected to the candidate frequency band for each of the candidate frequency bands.

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