KR20170001152A - Method and Device for Obtaing Inforamtion of Interference Source in Wireless Communication System - Google Patents

Abstract

Disclosed is technology about a method and apparatus for obtaining interference source information without cooperation between cells based on a control signal of an adjacent cell. The disclosed method for obtaining interference source information includes the steps of: receiving control signals of at least one or more adjacent cells; obtaining the interference source information by decoding the control signals; and transmitting the interference source information to a base station of a linked cell including the apparatus for obtaining the interference source information.

Description

TECHNICAL FIELD [0001] The present invention relates to a method and apparatus for acquiring interference source information in a wireless communication system,

The present invention relates to a method and apparatus for acquiring interference source information in a wireless communication system, and more particularly, to a method and apparatus for acquiring interference source information without inter-cell cooperation based on a control signal of an adjacent cell.

Wireless communication systems, such as cellular systems, require high frequency efficiency to accommodate the rapid growth of mobile traffic. To this end, the LTE (Long Term Evolution) system, which is the latest cellular system, uses the same frequency band between cells, and also uses a small cell such as a pico cell and a femtocell, Macro cell) to improve the efficiency of frequency reuse.

In the LTE environment with high frequency reuse, severe inter-cell interference is experienced in the inter-cell boundary region. In particular, in the case of a UE located in a cell boundary area, the performance of the uplink / downlink decreases due to interference between the neighboring cell BS and a user adjacent to the neighboring cell BS. In order to solve this problem, a method of removing interference using information of an interference source such as an adjacent cell is being studied.

In the conventional method, the interferer information is mainly acquired by the base station through cooperation with the adjacent cell or provided from the terminal. A related prior art document is Korean Patent Publication No. 2014-0129982.

However, additional resources are required to transmit and receive information between cells or between cells and terminals, and as the number of cells and terminals increases, resources to be input must be increased. Therefore, it is necessary to study the method of acquiring the information of the interferer without inter-cell cooperation.

The present invention provides a method and apparatus for acquiring interferer information without inter-cell cooperation based on a control signal of a neighboring cell in a wireless communication system.

According to an aspect of the present invention, there is provided a method for acquiring interference source information of an interference source information acquisition apparatus in a wireless communication system, the method comprising: receiving control signals of at least one neighboring cell; Decoding the control signal to obtain interference source information; And transmitting the interferer information to a base station of an associated cell including the interferer information obtaining apparatus.

According to another aspect of the present invention, there is provided a method for acquiring interference source information of a base station in a wireless communication system, the method comprising: receiving control signals of at least one neighboring cell; And decoding the control signal to obtain interference source information, wherein the step of receiving the control signal of the neighboring cell includes receiving the uplink signal from the base station and transmitting the downlink signal to the neighboring cell And receiving the control signal in a full duplex communication environment.

According to another aspect of the present invention, there is provided an apparatus for obtaining interference source information in a wireless communication system, the apparatus comprising: a control signal receiving unit receiving a control signal of at least one adjacent cell; A decoding unit decoding the control signal to obtain interference source information; And an information transmission unit for transmitting the interference source information to a base station of an associated cell including the interference source information acquisition apparatus.

According to the present invention, it is possible to acquire the interferer information without cooperation among the cells by using the interferer information acquiring device that receives the control signal of the adjacent cell and acquires the interferer information.

Also, according to the present invention, it is possible to provide an interferer information acquisition method that can be used in both a Frequency Division Duplex (FDD) environment, a TDD (Time Division Duplex) environment, and a Full Duplex environment.

Also, according to the present invention, each cell can independently perform interference control in a next generation wireless communication environment in which the number of cells is increased, so that a more improved channel capacity can be obtained.

1 is a diagram illustrating a wireless communication system in an FDD communication environment.
2 is a view for explaining an interference source information acquisition apparatus in a wireless communication system according to an embodiment of the present invention.
3 is a diagram for explaining a method of acquiring interference source information according to an embodiment of the present invention.
4 is a diagram for explaining a method of acquiring interference source information in a TDD environment.
5 is a flowchart of a method for acquiring interference source information according to another embodiment of the present invention.
6 is a diagram for explaining a method of acquiring interference source information in a full-duplex communication environment.

While the invention is susceptible to various modifications and alternative forms, specific embodiments thereof are shown by way of example in the drawings and will herein be described in detail. It should be understood, however, that the invention is not intended to be limited to the particular embodiments, but includes all modifications, equivalents, and alternatives falling within the spirit and scope of the invention. Like reference numerals are used for like elements in describing each drawing.

The present invention proposes a method and apparatus for acquiring interferer information using a downlink control signal of a neighboring cell in a wireless communication system.

When a terminal transmits a signal to a base station (hereinafter, referred to as an uplink band) or receives a signal from a base station (hereinafter, referred to as a downlink band), the terminal grants permission for transmission and reception, Band, signal format, and so on. The base station transmits the control signal including the above-described control information to the terminal using the downlink band.

The control signal includes RS (Reference Signal) information which is information on a pilot signal for channel estimation, scrambling code information which is information on a code for reducing interference between users, information on modulation of a signal and information on channel coding (CRC) information, which is information on a code for detecting a signal error, TPC information (Transmit Power Control), which is information on transmission power, and a rank of a transmission signal, Rank indicator information which is information and resource block information which is information on which resource block exists a signal, and the like.

The control information included in the control signal may vary according to the wireless communication system. For example, in a LTE environment, a control signal of a cell, that is, a base station may be transmitted through a PDCCH, which is a downlink control channel.

A control signal is transmitted, and uplink and downlink are set and data is transmitted and received. Interference occurs between adjacent cells, and information on a neighboring cell, that is, an interference source is required in order to avoid or eliminate interference. As a result, the control information included in the control signal of the adjacent cell becomes the interference source information, and the base station or the wireless terminal performs interference avoidance or interference cancellation using the interference source information. The present invention relates to a method and an apparatus for acquiring interference source information, not an invention relating to interference avoidance or interference cancellation, and a method for acquiring the interference source information will be mainly described below.

The downlink control signal may be received and decoded by a base station or an interference source information acquisition apparatus newly proposed by the present invention. Alternatively, the base station may directly receive a control signal according to whether a neighboring cell and a base station transmit downlink signals at the same time, The decoding unit can receive the control signal. That is, the communication environment may be different depending on whether the communication environment is an FDD (frequency division duplex) environment, a TDD (time division duplex) environment, or a full duplex environment.

Hereinafter, embodiments according to the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 shows a wireless communication system in an FDD communication environment, and FIG. 2 is a view for explaining an interference source information acquisition apparatus in a wireless communication system according to an embodiment of the present invention.

In FIG. 1, an interference source information acquisition method of the interference source information acquisition apparatus 100 included in the first cell 110 is described as an embodiment. The second cell 120 and the third cell 130 are adjacent cells of the first cell 110 and serve as interference sources. Hereinafter, the first cell 110 is referred to as an associated cell, and the second cell 120 and the third cell 130 adjacent to the associated cell are referred to as neighboring cells.

2, the apparatus 100 for acquiring interference source information according to the present invention includes a control signal receiving unit 210, a decoding unit 220, and an information transmitting unit 230.

The control signal receiving unit 210 receives control signals of at least one of the neighboring cells 120 and 130. 1, a base station of a neighboring cell 120 or 130 transmits a control signal using a downlink band, and a control signal receiving unit 210 receives a control signal of a neighboring cell 120 or 130 .

The decoding unit 220 may decode the control signal to obtain the interferer information, and may perform decoding using the ID information of the neighboring cells 120 and 130 with respect to the control signal. More specifically, the decoding unit 220 generates a pilot signal for the control signal using the ID information, and performs channel estimation with the base stations BS2 and BS3 of the neighboring cells 120 and 130 using the pilot signal. And decoding can be performed based on the estimated channel.

At this time, the decoding unit 220 may perform decoding by selecting a decoding target among control signals of the adjacent cells according to a predetermined rule. For example, the decoding unit 220 may randomly select an object to be decoded according to the size of the channel. When the size of the channel between the interference source information obtaining apparatus 100 and the second cell 120 is larger than that of the third cell 130, the interference source information obtaining apparatus 100 controls the second cell 120 The signal can be first selected and decoded.

Since the decoding capacity may be different depending on the resources of the interferer information obtaining apparatus 100, the decoding unit 220 may perform decoding selectively or sequentially according to the priority order. As a result, the decoding unit 220 may determine the number of times of decoding according to resources of the interferer information obtaining apparatus 100, and may perform decoding on at least one control signal based on the number of times of decoding.

The decoding unit 220 may decode the control signal of the second cell 120 and then control the control of the third cell 130 if the resource is enough to perform the decoding of the control signal of the third cell 130. [ It is possible to repeatedly perform decoding on the signal. Here, the resource of the interferer information obtaining apparatus 100 may include a processing capacity and a speed, and the decoding unit 220 may determine the number of decoding by further considering the number of neighboring cells, the decoding delay time, and the like.

1, not only the neighboring cells 120 and 130, but also the base station BS1 of the associated cell 110 transmit control signals. Therefore, the control signal receiving unit 210 receives the control signal, It is possible to further receive the control signal. The control signal of the associated cell 110 is unnecessary and the control signals of the adjacent cells 120 and 130 can be transmitted with high reliability To receive, the control signal of the associated cell 110 needs to be removed.

The decoding unit 220 removes the control signal of the associated cell 110 from the signal including the control signals of the associated cell 110 and the neighboring cells 120 and 130 using the ID information of the associated cell 110 . More specifically, the decoding unit 220 generates a pilot signal for the control signal of the associated cell 110 using the ID information, and performs channel estimation with the base station BS1 of the associated cell 110 using the pilot signal do. By performing decoding based on the estimated channel, the control signal of the associated cell 110 can be removed.

The information transmission unit 230 transmits the decoded interference source information to the base station BS1 of the association cell 110. [ The interference source information obtaining apparatus 100 may be connected to the base station BS1 via a wired or wireless backhaul network and the information transmitting unit 230 may transmit the interference source information to the base station BS1 through the backhaul network.

In the uplink environment, the base station BS1 can perform interference avoidance or cancellation on the uplink signal of the interferer using the interferer information. Or in a downlink environment, the base station BS1 transmits the interferer information together with the downlink data to the terminal UE1, and the terminal UE1 uses interference source information to avoid interference avoidance or removal of the downlink signal of the interferer Can be performed. At this time, the interferer information may be transmitted in the control signal region or the data region of the downlink signal.

As a result, according to the present invention, it is possible to acquire the interferer information without loading according to inter-cell cooperation by using the interferer information acquiring device that receives the control signal of the adjacent cell and acquires the interferer information. Then, through the interference cancellation using the obtained interference source information, the channel capacity decrease phenomenon due to the interference can be solved.

3 is a diagram for explaining a method of acquiring interference source information according to an embodiment of the present invention.

The interference source information obtaining apparatus according to the present invention receives control signals of at least one neighboring cell (S310) and decodes the control signals to obtain interference source information (S320). Then, the interference source information is transmitted to the base station of the associated cell including the interference source information obtaining apparatus (S330).

The interference source information obtaining apparatus can perform decoding by selecting a decoding target among the received control signals according to predetermined rules and using ID information on a neighbor cell of the selected control signal. That is, the interference source information obtaining apparatus can perform decoding according to the priority order, and the interference source information obtaining apparatus can determine the number of times of decoding according to the resource of the interference source information obtaining apparatus.

The number of adjacent cell control signals to be decoded may be determined according to the number of decoding times and the interference source information obtaining apparatus may perform decoding on at least one control signal based on the number of decoding times. Here, the resource of the interferer information obtaining apparatus may include a processing capacity and a speed of the interferer information obtaining apparatus.

On the other hand, the interference source information obtaining apparatus can further receive the control signal of the associated cell, and by using the ID information of the associated cell, the control signal of the associated cell is removed from the signal including the control signal of the associated cell and the adjacent cell .

3 may be utilized by receiving a control signal of a neighboring cell in an environment in which adjacent cells and associated cells simultaneously transmit a downlink signal among the FDD environment or a TDD environment described later.

FIG. 4 is a view for explaining a method of acquiring interference source information in a TDD environment, and FIG. 5 is a flowchart of a method of acquiring interference source information according to another embodiment of the present invention.

In the TDD environment, since the uplink / downlink transmission time is set for each cell, four scenarios as shown in [Table 1] can occur.

Neighbor cell downlink
Associated cell downlink Neighbor cell downlink
Associated cell uplink Adjacent cell uplink
Associated cell downlink Adjacent cell uplink
Associated cell uplink

If both the neighboring cell and the associated cell are the downlink environment or both are the uplink environment, the interference source information can be obtained and the interference avoiding / removing can be performed like the FDD environment described above. That is, the interference source information acquisition apparatus acquires the downlink control signal of the neighboring cell and transmits the interference source information to the base station of the associated cell. In the uplink state, the base station can perform interference avoidance or cancellation on the uplink signal of the interferer using the interferer information. Also, in the downlink situation, the base station transmits the interferer information together with the downlink data to the terminal, and the terminal can perform interference avoidance or cancellation on the downlink signal of the interferer using the interferer information.

However, in an environment where the adjacent cell downlink / uplink cell uplink environment, i.e., the association cell base station receives the uplink signal and the neighboring cell base station transmits the downlink signal, the base station of the associated cell transmits the downlink control signal The base station of the associated cell can directly acquire the interference source information without the interference source information acquisition apparatus. Hereinafter, a method for acquiring the interferer information by the base station BS1 of the associated cell in the neighbor cell downlink / uplink cell uplink environment will be described as an embodiment.

The base station BS1 of the association cell 410 receives control signals of at least one of the neighboring cells 420 and 430, decodes the control signal, and acquires interference source information. The base station BS1 acquires the interferer information similar to the interferer information acquisition apparatus of Fig.

However, since the base station BS1 receives the uplink signal of the associated cell terminal UE1, unlike the interference source information acquisition apparatus of FIG. 2, it is necessary to remove the uplink signal from the received signal. In addition, since the base station BS1 directly acquires the interference source information, it is not necessary to transmit the interference source information to the base station.

The base station BS1 can perform interference avoidance or cancellation on the uplink signal of the interferer using the interferer information.

Meanwhile, according to the embodiment, an interference source information acquisition apparatus similar to that of FIG. 2 can be used in the neighbor cell downlink / uplink cell uplink environment, and the interference source information acquisition apparatus acquires the interference source information instead of the base station BS1 . In the neighbor cell downlink / uplink cell uplink environment, the interferer information acquisition apparatus 400 receives the uplink signal of the associated cell terminal without receiving the control signal of the associated cell base station, . ≪ / RTI >

In the neighbor cell uplink / downlink cell downlink environment, the base station BS1 includes the interference source information in the downlink signal and transmits the downlink signal to the terminal UE1. The terminal UE1 uses the interference source information to increase the interference source Interference cancellation or elimination to the link signal can be performed.

5, the association BS BS1 receives control signals of at least one neighboring cell 420 and 430 (S510), decodes the control signals, and acquires interference source information (S520) )do. At this time, the associated cell base station BS1 transmits the downlink signal to the neighboring cell 420 or 430 in an environment where the base station BS1 receives the uplink signal and the neighboring cell 420 or 430 transmits the downlink signal, or in a full duplex communication environment 420, and 430, respectively.

The associated cell BS1 determines the number of times of decoding according to the resource of the BS1 and performs decoding on at least one control signal based on the number of times of decoding. The associated cell base station BS1 may decode the control signal selected according to the decoding priority and may decode the control signal by the number of adjacent cells 420 and 430 corresponding to the number of decoding times.

Meanwhile, the associated cell base station BS1 can further receive the uplink signal of the UE1. Since the associated cell BS1 transmits and receives control information to and from the UE1 and the uplink is allocated to the cell BS1, the associated cell BS BS1 uses the control information for the neighboring cells 420, The uplink signal can be removed from the signal including the uplink signal and the control signal of the uplink signal.

6 is a diagram for explaining a method of acquiring interference source information in a full-duplex communication environment.

As shown in FIG. 6, in the full-duplex communication environment, the base station can transmit and receive signals. Thus, the associated cell base station BS1 may receive the direct interferer information by receiving the downlink control signal of the associated cell 610, as described in FIG. 4 and FIG.

However, in the full-duplex communication environment, since the uplink / downlink interference signal is continuously received from the neighbor cells 620 and 630 in addition to the downlink control signal, the associated cell base station BS1 receives the uplink signal of the associated cell terminal UE1 And simultaneously performs an operation of estimating and removing the uplink interference signal of the neighboring cell terminals UE5 and US6 from the previous interference source information.

Meanwhile, although the case where the base station uses the full-duplex communication mode is described as an embodiment in FIG. 6, the present invention can be applied to an environment in which the terminal also uses the full-duplex communication mode. Also, the present invention can be applied to an environment in which the base station and the terminal selectively use the FD mode and the HD (Half Duplex) mode depending on the situation.

The above-described technical features may be implemented in the form of program instructions 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 embodiments 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 device may be configured to operate as one or more software modules to perform the operations of the embodiments, and vice versa.

As described above, the present invention has been described with reference to particular embodiments, such as specific elements, and specific embodiments and drawings. However, it should be understood that the present invention is not limited to the above- And various modifications and changes may be made thereto by those skilled in the art to which the present invention pertains. Accordingly, the spirit of the present invention should not be construed as being limited to the embodiments described, and all of the equivalents or equivalents of the claims, as well as the following claims, belong to the scope of the present invention .

Claims (11)

A method for acquiring interference source information of an interference source information acquisition apparatus in a wireless communication system,
Receiving control signals of at least one neighboring cell;
Decoding the control signal to obtain interference source information; And
Transmitting the interferer information to a base station of an associated cell including the interferer information obtaining apparatus
And an interferer.
The method according to claim 1,
The step of acquiring the interferer information
Selecting a decoding target among the control signals according to a predetermined rule; And
Performing decoding using ID information on a neighbor cell of the selected control signal
And an interferer.
The method according to claim 1,
The step of acquiring the interferer information
Determining a number of times of decoding according to resources of the interference source information obtaining apparatus; And
Performing decoding on at least one control signal based on the number of decoding steps
And an interferer.
The method of claim 3,
The resource of the interference source information acquiring device
And a processing capacity and a speed of the interference source information obtaining apparatus
Interference source information acquisition method.
The method according to claim 1,
The step of receiving the control signal
Further receiving a control signal of the associated cell,
The step of acquiring the interferer information
Removing the control signal of the associated cell from the signal including the control signal of the associated cell and the adjacent cell using the ID information of the anchor-
Further comprising the steps of:
The method according to claim 1,
The step of receiving the control signal of the adjacent cell
And receiving the control signal in an environment in which the neighboring cell and the associated cell simultaneously transmit downlink signals
Interference source information acquisition method.
A method for acquiring interference source information of a base station in a wireless communication system,
Receiving control signals of at least one neighboring cell; And
And decoding the control signal to obtain interferer information,
The step of receiving the control signal of the adjacent cell
The base station receives the uplink signal and receives the control signal in an environment in which the neighboring cell transmits a downlink signal or in a full duplex communication environment
Interference source information acquisition method.
8. The method of claim 7,
The step of acquiring the interferer information
Determining a number of times of decoding according to resources of the base station; And
Performing decoding on at least one control signal based on the number of decoding steps
And an interferer.
9. The method of claim 8,
The resource of the interference source information acquiring device
And a processing capacity and a speed of the interference source information obtaining apparatus
Interference source information acquisition method.
The method according to claim 6,
Further comprising receiving an uplink signal from a terminal assigned an uplink with the base station,
The step of acquiring the interferer information
Removing the uplink signal from the signal including the control signal of the adjacent cell and the uplink signal using the control information for the UE
Further comprising the steps of:
An interference source information obtaining apparatus in a wireless communication system,
A control signal receiving unit receiving a control signal of at least one adjacent cell;
A decoding unit decoding the control signal to obtain the interference source information; And
An information transmission unit for transmitting the interference source information to a base station of an associated cell including the interference source information obtaining apparatus,
And an interferer.

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