KR20130055498A - Method for scheduling resource block in wireless communicatoin system and apparatus thereof - Google Patents

Abstract

PURPOSE: A wireless resource scheduling method of a wireless communication system and a device thereof are provided to reduce interference by allocating resources through a cooperative scheduling of a wireless resource in an adjacent cell. CONSTITUTION: A reception unit(210) receives a signal strength value of an uplink from a terminal through a plurality of wireless signal processing devices. A determination unit(220) determines whether each terminal is located inside a cell or the boundary of the cell based on a signal strength value received from the reception unit. A priority setting unit(230) sets priority for each terminal based on the location of the terminal in the cell. [Reference numerals] (210) Reception unit; (220) Determination unit; (230) Priority setting unit; (240) Resource allocation unit

Description

TECHNICAL FIELD OF THE INVENTION A radio resource scheduling method and apparatus therefor in a wireless communication system.

The present invention relates to a radio resource scheduling method and apparatus therefor in a wireless communication system.

In general, resources in a wireless communication system can be classified into frequency resources and time resources, and optimal allocation of such resources is very important for improving the performance of a wireless communication system.

FIG. 1 is a diagram illustrating an example of resource allocation in an orthogonal frequency division multiplexing (OFDM) system. In detail, FIG. 1 illustrates allocation of a frequency resource and a time resource in a grid form to a user.

In such a wireless communication system, there is a need for a method of maximizing overall network performance by minimizing cell-to-cell interference and increasing resource reuse rate through common resource management between cells.

To this end, as shown in FIG. 2, a reuse method of reusing the same resource is used in an area inside a cell, and a resource coordination method of using different resources between cells is used in a cell boundary area. do.

However, when a fixed allocation of resources in the cell boundary region reduces the number of available resources, there is a need for a method for efficiently using them.

It is an object of the present invention to provide a radio resource scheduling method and apparatus for maximizing radio capacity in a wireless communication system.

Scheduling method according to an aspect of the present invention,

Determining, by a scheduling apparatus that manages radio resources in common, whether the terminal is located in a cell boundary region through a signal received from the terminal; And setting the priority of the terminal to be higher than the priority of the terminal located inside the cell instead of the cell boundary region when it is determined that the terminal is located in the cell boundary region.

Here, in the determining step, it is determined whether the terminal is located in the cell boundary region by receiving the signal strength value of the uplink from the terminal through a plurality of radio signal processing apparatus.

In addition, when the absolute value of the difference between the signal strength value received from the terminal through the two wireless signal processing device is less than the threshold value, it characterized in that the terminal is determined to be located in the cell boundary region.

In addition, when the ratio of the signal strength value received from the terminal through the two radio signal processing apparatus is larger than the threshold value and less than the inverse of the threshold value, it characterized in that the terminal is determined to be located in the cell boundary region.

Further, in the setting step, the priority of the terminal located in the cell boundary region is set in priority in proportion to the number of cells that affect the interference located in the cell boundary region.

The method may further include allocating radio resources to terminals having priority set after the setting, and in the allocating step, wireless at an edge of radio resources for a terminal located in the cell boundary region. The resource is characterized in that the allocation.

Further, in the allocating step, the terminal located inside the cell may be allocated from the radio resource among the radio resources.

In addition, a radio resource is allocated to a terminal located inside the cell through a water filling method.

Scheduling apparatus according to another aspect of the present invention,

A scheduling apparatus for commonly managing radio resources allocated to terminals, the scheduling apparatus comprising: a receiver configured to receive an uplink signal strength value from a terminal through a plurality of wireless signal processing apparatuses; A determination unit determining whether each terminal is located inside a cell or in a cell boundary region based on the signal strength value of each terminal received by the receiver; And a priority setting unit that sets a priority for each terminal based on whether the terminal is located inside a cell or a cell boundary region determined by the determination unit, wherein the priority setting unit is located at a cell boundary region. It is characterized in that the priority of the terminal when it is determined to set higher than the priority of the terminal located inside the cell, not the cell boundary region.

Here, the determination unit confirms the number of cells that affect the interference when the terminal is located in the cell boundary region, the priority setting unit confirms the priority of the terminal located in the cell boundary region by the determination unit It is characterized in that it is set in proportion to the number of cells affecting interference to the terminal.

The apparatus may further include a resource allocator configured to allocate radio resources according to the priorities of the terminals set by the priority setter.

The resource allocator may be configured to allocate a radio resource located at an edge from among radio resources to a terminal located in a cell boundary region.

The resource allocator may be configured to allocate a radio resource among the radio resources to a terminal located inside the cell.

According to the present invention, by allocating resources through cooperative scheduling of radio resources between adjacent cells in the boundary region of cells, it is possible to reduce interference and increase data transmission efficiency.

In addition, performance can be improved by reusing all frequency resources in the cell region.

1 is a diagram illustrating an example of resource allocation in an OFDM system.
2 is a diagram illustrating a concept of allocating resources through a cooperative scheme in general.
3 is a schematic structural diagram of a network according to an embodiment of the present invention.
4 illustrates a concept of setting a cell boundary region according to an embodiment of the present invention.
FIG. 5 is a diagram illustrating a concept of resource allocation for terminals located in a cell boundary region according to an embodiment of the present invention.
FIG. 6 is a diagram illustrating a concept of resource allocation for terminals located in an inner cell area according to an embodiment of the present invention.
FIG. 7 is a diagram illustrating an example of allocating resources for three adjacent cells centering on a terminal according to an embodiment of the present invention.
8 is a diagram illustrating a principle of allocating radio resources to a terminal located in a cell boundary area according to an embodiment of the present invention.
9 is a diagram illustrating a principle of allocating radio resources to a terminal located in an inner cell area according to an embodiment of the present invention.
10 is a block diagram of a digital signal processing apparatus according to an embodiment of the present invention.

DETAILED DESCRIPTION Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art may easily implement the present invention. The present invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. In the drawings, parts irrelevant to the description are omitted in order to clearly describe the present invention, and like reference numerals designate like parts throughout the specification.

Throughout the specification, when a part is said to "include" a certain component, it means that it can further include other components, without excluding other components unless specifically stated otherwise. Also, the terms " part, "" module," and " module ", etc. in the specification mean a unit for processing at least one function or operation and may be implemented by hardware or software or a combination of hardware and software have.

In this specification, a terminal includes a mobile station (MS), a mobile terminal (MT), a subscriber station (SS), a portable subscriber station (PSS), a user equipment , An access terminal (UE), an access terminal (AT), and the like, and may include all or some functions of a terminal, a mobile terminal, a subscriber station, a mobile subscriber station, a user equipment,

In this specification, a base station (BS) includes an access point (AP), a radio access station (RAS), a node B, an evolved NodeB (eNodeB) A base station (BTS), a mobile multihop relay (MMR) -BS, or the like, and may perform all or a part of functions of an access point, a radio access station, a Node B, an eNodeB, a base transceiver station, .

Now, a radio resource scheduling method and apparatus thereof according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

3 is a schematic structural diagram of a network according to an embodiment of the present invention.

Referring to FIG. 3, a network according to an embodiment of the present invention includes a radio signal processing unit (RU) 100, a digital signal processing unit (DU) 200, and a core system 300. do. The wireless signal processing apparatus 100 and the digital signal processing apparatus 200 constitute a signal processing system of wireless communication.

The wireless signal processing apparatus 100 converts and amplifies a digital signal received from the digital signal processing apparatus 200 into a radio frequency (RF) signal according to a frequency band as a part of processing a wireless signal. A plurality of wireless signal processing apparatuses 100, 110, 120 and 130 are connected to the digital signal processing apparatus 200, and each wireless signal processing apparatus 100 is installed in a service area, that is, a cell. The wireless signal processing apparatus 100 and the digital signal processing apparatus 200 may be connected by an optical cable.

The digital signal processing apparatus 200 performs a process of encrypting and decrypting a wireless digital signal, and is connected to the core system 300. Unlike the wireless signal processing apparatus 100, the digital signal processing apparatus 200 is not installed in a service area but is mainly installed in a central office of a communication company, and is a virtualized base station. The digital signal processing apparatus 200 transmits and receives signals to and from a plurality of radio signal processing apparatuses 100.

The existing communication base station includes a processing unit corresponding to each of the wireless signal processing apparatus 100 and the digital signal processing apparatus 200 in one physical system, and one physical system is installed in the service target area. On the other hand, the system according to the present invention physically separates the wireless signal processing device 100 and the digital signal processing device 200, and only the wireless signal processing device 100 is installed in the service area.

The core system 300 processes connection between the digital signal processing apparatus 200 and the external network, and includes an exchange (not shown) and the like.

Now, a method of determining whether a cell is bordered or not will be described.

First, two wireless signal processing apparatuses 110 and 120 located in each adjacent cell measure the signal strength of the uplink received from the terminal and transmit it to the digital signal processing apparatus 200. Then, the digital signal processing apparatus 200 based on the signal strength value A received from the wireless signal processing apparatus 110 and the signal strength value B received from the wireless signal processing apparatus 120. Evaluate. That is, when the absolute value of the difference between the signal strength value A and the signal strength value B is less than or equal to the threshold value T as shown in Equation 1, it is determined that the terminal is a terminal located in the boundary region of the two cells. Here, Equation 1 corresponds to a dB-based equation.

[Equation 1]

| A-B | ≤T

Alternatively, in the case of the general strength-based equation, as shown in Equation 2, when the ratio of the signal strength value A and the signal strength value B is greater than T and less than 1 / T, the corresponding UE is located at the boundary region of the two cells. It is determined that the terminal.

&Quot; (2) "

T <A / B <1 / T (0 <T <1)

Here, the threshold value T may be variously determined according to the capacity and needs of the wireless communication system.

As described above, as shown in FIG. 4, the boundary area may be set for each cell 10. At this time, scheduling for resource allocation is performed on a cell inner (inner) region 11 and a cell boundary (outer) region, and when a resource is allocated to a user in the cell boundary region, another cell that interferes at this time is allocated. Scheduling proceeds in consideration of the user.

The digital signal processing apparatus 200 allocates frequency and time resources that can be used by a cell in a cell boundary region for each cell through cooperative scheduling. For example, as shown in FIG. 5, the digital signal processing apparatus 200 includes a terminal A 410 and a terminal B 420 in a cell boundary region 13 between two cells 10 and 20. Allocate resources differently.

On the other hand, the digital signal processing apparatus 200, as shown in the accompanying FIG. 6, the terminal C (430) and the terminal D (located in the inner region (11, 21) of each cell of the two cells (10, 20) For 440, the same resource is allocated for reuse.

Resource allocation as described above will be described with reference to the case where three cells 10, 20, and 30 are adjacent as shown in FIG.

If three wireless signal processing apparatuses 110, 120, and 130 located in the three cells α, β, and γ are referred to as A, B, and C, respectively, the signal strengths received from the terminal 450 are | AB | ≤ T and | A-C | ≤ T, but | B-C | > T, three cells (α, β, γ) uses a cooperative method using different resources for the terminal 450.

Here, the cell α is determined to be located in the region where the cell β and the cell γ form a boundary area, respectively, but it is determined that the terminal 450 is not in the boundary region for the cell β and the cell γ.

Therefore, since time and frequency resources used by cell α to transmit data to terminal 450 interfere with the corresponding terminal 450 in cell β and cell γ, resource allocation is scheduled so that the same resource cannot be used.

In addition, time and frequency resources used by the cell β to transmit data to the terminal 450 cannot be used because they interfere with the terminal 450 in the cell α and different data to other terminals using the same resource in the cell γ. Is scheduled to be available.

In addition, time and frequency resources used by cellγ to transmit data to the terminal 450 cannot be used because they interfere with the terminal 450 in the cell α, and different data to other terminals using the same resource in the cell β. Is scheduled to be available.

Meanwhile, in the embodiment of the present invention, when scheduling for resource allocation, the terminal in the cell boundary region is set to increase the priority of the terminal in the cell boundary region for resource allocation. That is, when allocating a resource to a terminal located in a cell boundary region, other cell resource allocations that are affected by the corresponding terminal also affect the resource allocation. At this time, since the terminal in the border region affects the resource to other cells, the priority is given as in Equation 3 below.

&Quot; (3) &quot;

Priority_outer =

Priority_internal =

Here, the priority_outer indicates the priority of the terminal in the boundary area, and the priority_inner indicates the priority of the terminal in the cell.

In the equation (3), if there is a cell that primarily affects interference to the UE, the priority is smaller than that of the UE which is not, but the priority for resource allocation is set to be high, and the cell affecting interference to the UE. The higher the number, the lower the priority_out value, but the higher the priority for resource allocation.

In this way, if the priority is given, the digital signal processing apparatus 200 allocates resources from a user having a high priority according to the given priority.

Hereinafter, a method of allocating resources to users by the digital signal processing apparatus 200 will be described.

First, the digital signal processing apparatus 200 which performs a common resource management function for managing resources for cells in common, selects N names to be linked to each cell from the users having the highest priority among users. Here, N represents the maximum number of scheduling users per transmission time interval (TTI).

As such, when N persons including users linked to one cell are selected, further selection of the corresponding cell is stopped. If the number is not N, scheduling is performed such that the number of users is divided into frequency resources.

Next, if the user is located in the cell boundary region, the resource allocation order for the selected N names is allocated as much as necessary from the radio resource located at the edge among the radio blocks (Resource Block, RB). When the user is inside the cell, the radio resources are allocated as many as necessary from the middle (central) radio resources among the radio resources. The reason for allocating the radio resource at the edge to the user in the cell boundary region is that assigning the radio resource at the center makes continuity difficult for resource allocation of the linked cell. That is, a large amount of data transmission is likely to be caused by a user inside the cell, and a large amount of data transmission is possible only by allocating continuous radio resources for such a user. The concept of allocating the frequency resources to the users (terminals) in the cell boundary region from the edge frequency in terms of frequency, and the center frequencies to the users (terminals) inside the cell are shown in FIG. 8.

On the other hand, after the resource allocation of the users in the cell boundary region to the users inside the cell, the resources are allocated using the remaining radio resources, that is, the resources in the middle, such as water filling method (Water Filling) Can be used. In other words, the signal to noise ratio (SNR) is allocated from a good radio resource, and even the radio resources that can be used when allocating transmittable power. Since the water filling method is well known to those skilled in the art, a detailed description thereof will be omitted. An example of allocating radio resources to users inside a cell is shown in FIG. Referring to FIG. 9, an example in which user A is allocated 1 to 7 times among frequency resources and user B is allocated 8 to 13 times is shown.

As described above, by allocating resources through cooperative scheduling of radio resources between adjacent cells in the boundary region of the cells, it is possible to reduce interference and increase data transmission efficiency. In addition, performance can be improved by reusing all frequency resources in the cell region.

Now, the digital signal processing apparatus 200 corresponding to radio resource scheduling according to an embodiment of the present invention will be described in detail with reference to FIG. 10.

10 is a block diagram of a digital signal processing apparatus 200 according to an embodiment of the present invention.

Referring to FIG. 10, the digital signal processing apparatus 200 includes a receiver 210, a determiner 220, a priority setter 230, and a resource allocator 240.

The receiver 210 receives a signal strength value of uplink determined by a signal received from each terminal from the wireless signal processing apparatus 100.

The determination unit 220 performs an operation such as Equation 1 or Equation 2 based on the signal strength value of each terminal received by the receiver 210 to determine whether each terminal is located inside a cell or in a boundary region between cells. Judge whether In addition, when the terminal is located in the cell boundary region, the number of cells affecting interference for the terminal is checked.

The priority setting unit 230 sets the priority for each terminal according to Equation 3 based on whether it is located inside the cell of the terminal or the cell boundary region determined by the determination unit 220.

The resource allocator 240 allocates a radio resource to each terminal according to the priorities of the terminals set by the priority setting unit 230. In this case, terminals having a higher priority, that is, terminals located in a cell boundary region, are allocated from radio resources at the edge among radio resources. After the resource allocation for the terminals located in the cell boundary area is completed, the terminals located inside the cell are allocated from the radio resource among the radio resources.

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, It belongs to the scope of right.

Claims (13)

Determining, by a scheduling apparatus that manages radio resources in common, whether the terminal is located in a cell boundary region through a signal received from the terminal; And
If it is determined that the terminal is located in a cell boundary region, setting the priority of the terminal to be higher than that of a terminal located inside a cell instead of the cell boundary region.
Scheduling method comprising a. The method of claim 1,
In the determining, the scheduling method, characterized in that receiving the uplink signal strength value from the terminal through a plurality of wireless signal processing device to determine whether the terminal is located in a cell boundary region. The method of claim 2,
And determining that the terminal is located in a cell boundary area when an absolute value of a difference between signal strength values received from the terminal through two radio signal processing apparatuses is equal to or less than a threshold value. The method of claim 2,
And determining that the terminal is located in a cell boundary area when a ratio of signal strength values received from the terminal through two radio signal processing apparatuses is greater than a threshold value and less than an inverse of the threshold value. The method of claim 1,
In the setting step,
The priority method of a terminal located in the cell boundary region is set in a priority order in proportion to the number of cells affecting interference in the terminal located in the cell boundary region. The method of claim 1,
After the setting step,
Allocating a radio resource for the terminals set priority, further comprising:
In the allocating step,
Scheduling method for allocating the radio resources at the edge of the radio resources to the terminal located in the cell boundary region. The method according to claim 6,
In the allocating step,
Scheduling method for allocating the radio resources in the middle of the radio resources for the terminal located inside the cell. The method of claim 7, wherein
Scheduling method for allocating radio resources to the terminal located in the cell through a water filling method. In the scheduling apparatus for managing the radio resources allocated to the terminals in common,
A receiver which receives a signal strength value of an uplink from a terminal through a plurality of wireless signal processing apparatuses;
A determination unit determining whether each terminal is located inside a cell or in a cell boundary region based on the signal strength value of each terminal received by the receiver; And
It includes a priority setting unit for setting the priority for each terminal based on whether the position of the terminal inside the cell or the cell boundary region determined by the determination unit,
And the priority setting unit sets the priority of the terminal when the terminal is determined to be located in the cell boundary region to be higher than the priority of the terminal located inside the cell instead of the cell boundary region. 10. The method of claim 9,
The determination unit checks the number of cells that affect the interference when the terminal is located in the cell boundary area,
And the priority setting unit sets the priority of a terminal located at a cell boundary in proportion to the number of cells that have an interference effect on the terminal identified by the determination unit. 10. The method of claim 9,
And a resource allocating unit for allocating radio resources according to the priorities of the terminals set by the priority setting unit. The method of claim 11,
And the resource allocator allocates the radio resources at the edge of the radio resources to the terminal located in the cell boundary region. The method of claim 12,
The resource allocating unit is a scheduling apparatus, characterized in that for allocating the radio resources in the middle of the radio resources to the terminal located inside the cell.

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