WO2015012663A1

WO2015012663A1 - Method and apparatus for transmitting/receiving channel quality information in wireless communication system

Info

Publication number: WO2015012663A1
Application number: PCT/KR2014/006887
Authority: WO
Inventors: 김은용; 맹승주; 박명희; 한승희
Original assignee: 삼성전자 주식회사
Priority date: 2013-07-26
Filing date: 2014-07-28
Publication date: 2015-01-29
Also published as: KR20150012708A

Abstract

The present invention relates to a method and an apparatus for transmitting/receiving channel quality information in a wireless communication system. A method for transmitting a reference signal by a BS in a wireless communication system according to the present invention comprises the steps of: identifying index information on a current subframe; determining whether the subframe is a predetermined subframe; transmitting a reference signal in the subframe when the identified subframe is not the predetermined subframe based on a result of the determination, and not transmitting the reference signal when the identified subframe is the predetermined subframe.

Description

Method and apparatus for transmitting and receiving channel quality information in wireless communication system

The present invention relates to a wireless communication system, and more particularly to a method for transmitting and receiving channel quality information in a wireless communication system.

In general, wireless communication systems have been developed to provide voice services while guaranteeing user activity. However, wireless communication systems are gradually expanding to not only voice but also data services, and to the extent that they can provide high speed data services. However, in the wireless communication system in which a service is currently provided, a shortage of resources and users require faster services, and thus, a more advanced mobile communication system is required.

In response to these demands, one of the systems being developed as a next-generation mobile communication system, a specification work for Long Term Evolution (LTE) is underway in the 3GPP (The 3rd Generation Partnership Project). LTE is a technology that implements high speed packet-based communication. To this end, various methods are discussed. For example, the network structure can be simplified to reduce the number of nodes located on the communication path, or the wireless protocols can be as close to the wireless channel as possible.

On the other hand, the base station transmits a reference signal to the terminal so that the terminal can estimate the downlink channel quality, the terminal measures the reference signal and reports the channel quality information to the base station. In this case, the more accurately the terminal measures downlink channel quality, the base station can more efficiently and accurately allocate radio resources for the terminal.

Accordingly, there is a need for a study on a method for allowing a base station and a terminal to estimate downlink channel quality of a terminal through mutual cooperation.

The present invention has been made in accordance with the above needs, and the base station cooperates to clearly determine whether the terminal should report the instantaneous channel quality or the average channel quality, and the terminal accordingly It is an object of the present invention to provide a method and apparatus for generating and reporting channel quality information according to a set method.

In the wireless communication system of the present invention for achieving the above object, the method for transmitting a reference signal of a base station includes: checking index information of a current subframe, determining whether the subframe is a predetermined subframe, and the determination As a result, the method may further include transmitting a reference signal in the subframe when the identified subframe is not a predetermined subframe and not transmitting the reference signal when the identified subframe is a predetermined subframe. It features.

In addition, in the wireless communication system of the present invention, the method for reporting channel quality information of a terminal includes: checking index information of a current subframe, performing measurement on the identified subframe, and determining the identified subframe in advance If the subframe and the measurement result is less than or equal to a predetermined threshold, setting to generate instantaneous channel quality information for the subframe and subframes coming after the subframe, and a channel generated according to the setting method Reporting the quality information to the base station.

In addition, in the wireless communication system of the present invention, the base station transmitting a reference signal checks a transceiver for transmitting and receiving a signal with the terminal, and index information for the current subframe, and determines whether the subframe is a predetermined subframe, And a controller configured to transmit a reference signal in the subframe when the determined subframe is not a predetermined subframe and to not transmit the reference signal when the determined subframe is a predetermined subframe. It is characterized by.

In the wireless communication system of the present invention, a terminal reporting channel quality information checks a transceiver for transmitting and receiving a signal to and from a base station, and index information for a current subframe, and performs measurement on the identified subframe. If the identified subframe is a predetermined subframe and the measurement result is less than or equal to a preset threshold, it is set to generate instantaneous channel quality information for the subframe and subframes coming after the subframe. And controlling the controller to report the channel quality information generated accordingly.

According to the present invention, the terminal can robustly determine whether to report the instantaneous channel quality. In addition, the base station can receive various types of channel quality reports as necessary, and as a result, it is possible to expect the capacity improvement effect of the wireless communication system.

1 is a diagram illustrating examples of various kinds of channel qualities.

2 is a diagram illustrating an example of transmitting a CSI-RS (reference signal) by alternating TP combinations for measuring various kinds of channel quality.

3 is a diagram illustrating an example in which no TP transmits a reference signal at a time when a base station receives various types of channel qualities reported from a terminal.

4 is a flowchart illustrating an operation sequence of a base station according to an embodiment of the present invention.

5 is a flowchart illustrating an operation sequence of a terminal according to an embodiment of the present invention.

6 is a flowchart illustrating an operation sequence of a terminal according to an embodiment of the present invention.

7 is a block diagram illustrating an internal structure of a base station according to an embodiment of the present invention.

8 is a block diagram showing the internal structure of a terminal according to an embodiment of the present invention.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. At this time, it should be noted that the same components in the accompanying drawings are represented by the same reference numerals as possible. In addition, detailed descriptions of well-known functions and configurations that may blur the gist of the present invention will be omitted.

The present invention described below relates to a method and apparatus for enabling a channel quality estimation scheme to be determined in a broadband wireless communication system. In particular, the present invention relates to a method and apparatus for allowing a terminal to determine a downlink channel quality estimation method through cooperation of a base station and a terminal.

The present invention relates to a downlink of a broadband wireless communication system, and more particularly, to a method of determining a downlink channel quality estimation method in a terminal. The present specification describes the 3GPP LTE (3rd Generation Partnership Project, Long-Term Evolution) wireless communication system standard, but it can be extended to other communication systems.

In a typical cellular communication system, each cell consists of one transmission point (TP), and the TP plays a role of transmitting a downlink signal from a base station to a terminal. On the other hand, the channel quality for the downlink is the most accurate and reliable way that the UE directly measures and reports to the base station. To this end, the terminal measures downlink channel quality for the serving cell (or for the cell to which the terminal belongs) by using a radio resource for a designated channel quality measurement, and reports channel quality information to the base station through uplink. do. Then, the scheduler of the base station performs radio resource allocation for the terminal based on the channel quality information received from the terminal.

If the scheduler of the base station can know the various types of downlink channel quality according to various environments (for example, various TP combinations), it can be used for scheduling to improve the performance of the wireless network.

An example of the various types of channel quality will be described with reference to FIG. 1. In this case, various kinds of channel quality may refer to radio channel quality between a terminal and a base station according to a combination of at least one TP (base station). For example, various types of channel quality may include channel quality between the terminal and the serving base station, channel quality between the terminal and the neighbor base station 1, channel quality between the terminal and the serving base station and the neighbor base station 1, and the like.

1 is a diagram illustrating examples of various types of channel quality.

As shown in (a) of FIG. 1, the base station and the terminal may consider channel quality when receiving a signal transmitted from TP # 0 and channel quality when receiving a signal transmitted from TP # 1 as shown in (b). have.

According to the method, the base station allocates periodic radio resources for one channel quality measurement purpose to the terminal. The base station may transmit a reference signal using alternating TP combinations for which channel quality measurement is to be performed while using the radio resource for the one channel quality measurement purpose. According to an embodiment of the present invention, the reference signal may be a channel state information reference signal (CSI RS).

2 is a diagram illustrating an example of transmitting a CSI-RS (reference signal) by alternating TP combinations for measuring various types of channel quality.

Specifically, FIG. 2 is an example of reference signal transmission for a case in which channel quality for TP # 0 and channel quality for TP # 1 are to be measured. The terminal measures the instantaneous channel quality by using a radio resource for channel quality measurement. The terminal reports the channel quality to the base station according to a method set by the base station (periodic reporting or aperiodic reporting).

Then, the base station can distinguish and manage which TP combination is the channel quality from the timing at which the terminal reports the channel quality, and utilize the finally collected channel quality information in performing radio resource allocation.

However, according to the above method, if it is necessary to report various types of channel quality, the terminal must measure and report instantaneous channel quality. The reason is that the terminal does not know the fact that the TP combinations are being transmitted alternately or does not know the exact order even if they know that the TP combinations are being transmitted alternately. If the terminal that does not know the order reports the value of filtering (or averaging) the channel quality without reporting the instantaneous channel quality information, the channel quality information according to various TP combinations becomes mixed channel quality information. This is because the base station cannot find out the exact channel quality information for each TP combination.

However, it may not be assumed that the terminal always reports instantaneous channel quality information. In situations where multiple kinds of channel qualities are not reported (i.e. when TP combinations do not alternately transmit reference signals), the UE can filter channel qualities more accurately by filtering the channel qualities instead of measuring the instantaneous channel qualities. Can be estimated.

The present invention has been proposed to clarify the operation of the terminal. According to the present invention, the base station cooperates to clearly determine whether the terminal should report various types of channel quality, that is, whether instantaneous channel quality should be reported.

The terminal clearly performs the determination with the help of the base station and determines a channel quality measurement method according to the intention of the base station. That is, the terminal generates an instantaneous channel quality or an average (filtered) channel quality according to the intention of the base station and reports it to the base station.

The present invention also has another object to minimizing performance degradation of the system in achieving the above object.

As described above, the present invention relates to a technology for determining whether a terminal should report various types of channel quality through cooperation of a base station and a terminal.

According to the present invention, the base station allocates periodic radio resources for one channel quality measurement purpose to the terminal.

If the base station is a base station that receives only one channel quality from the terminal, the base station transmits a reference signal using one TP combination to measure channel quality using radio resources for the one channel quality measurement purpose.

If the base station is a base station that receives various kinds of channel quality from the terminal (or the terminal wants to report the instantaneous channel quality), the base station is a radio resource only for the one channel quality measurement purpose And transmits the reference signal (CSI-RS) alternately among the TP combinations for which the channel quality measurement is to be performed. Do not send.

FIG. 3 is a diagram illustrating an example in which no TP transmits a reference signal at a time when a base station receives various types of channel quality reports from a terminal.

3 illustrates an example in which no TP transmits a reference signal only when an index value of a subframe is greater than or greater than 0 and less than 5 in a modulo 100 operation.

The terminal measures the received power of the reference signal for a subframe meeting the specific condition, and compares the measured received power with a preset threshold. The terminal determines whether the base station transmits a reference signal at a corresponding subframe based on the comparison result, and determines whether to report the instantaneous channel quality or the average channel quality based on this.

That is, when it is determined that the base station transmits the reference signal at a time when the specific condition is satisfied, the terminal determines that the base station is a base station that receives only one channel quality from the terminal. Accordingly, the terminal may generate and report channel quality information that has been filtered. Generating the filtered channel quality information may mean generating channel quality information measured for the current subframe and channel quality information obtained by averaging channel quality information accumulated up to now.

Meanwhile, according to another embodiment of the present invention, when the terminal determines that the base station receives only one channel quality from the terminal, it is not necessary to perform filtering. For example, the fast-moving terminal may detect that the channel changes rapidly, so it may not necessarily need to perform filtering in this case.

On the other hand, when the terminal determines that the base station has not transmitted the reference signal at the time that satisfies the specific condition, the terminal determines that the base station is a base station that receives a plurality of channel quality reports from the terminal. Accordingly, the terminal does not perform filtering, that is, generates instantaneous channel quality information and reports it to the base station. Generating and reporting the instantaneous channel quality information may mean generating and reporting only the channel quality information measured instantaneously for the current subframe.

In addition, when the terminal determines that the base station is a base station that receives a plurality of channel quality reports from the terminal as described above, the instantaneous channel quality information is generated to the base station by generating the instantaneous channel quality information for the sub-frame that will be measured later report.

The base station that reports various types of channel quality from the terminal already knows that the reference signal is not transmitted at a subframe satisfying the specific condition. Therefore, even when the terminal reports the channel quality information measured from the radio resource for the channel quality measurement purpose at a time when the specific condition is satisfied, the base station can know that the channel quality information reported from the terminal is meaningless. Accordingly, the base station may not utilize the channel quality information reported from the terminal at the time that satisfies the specific condition in the radio resource allocation to the terminal.

According to an embodiment of the present invention, information on a condition for determining a subframe for not transmitting the CSI-RS may be used in advance between the base station and the terminal. Alternatively, the base station may inform the terminal of the information through at least one of system information, higher layer signaling, for example, radio resource control (RRC) signaling, and physical layer signaling.

In the LTE system, CSI-RS is a reference signal used only for measuring channel quality for use in radio resource allocation. In other words, CSI-RS is not used for cell search or data demodulation for handover. Accordingly, not transmitting the CSI-RS at a time satisfying a specific condition as in the present invention does not affect other operations of the system. In addition, the overhead of the radio resources occupied by the CSI-RS is very low, and among them, only the CSI-RS of the time that satisfies some specific conditions is used, so the ratio of wasted radio resources will be very small.

4 is a flowchart illustrating an operation sequence of a base station according to an embodiment of the present invention. It is assumed that the base station illustrated in FIG. 4 is a base station that receives various types of channel quality from the terminal.

First, the base station checks the current subframe index in step S410. In operation S420, the base station determines whether the identified subframe index is an index for a predetermined subframe. According to an embodiment of the present invention, the predetermined subframe index may be an index of greater than or equal to 0 and less than 5 in a modulo 100 operation, but is not necessarily limited to this method.

As a result of the determination, when the current subframe is a predetermined subframe, the base station proceeds to step S440 and does not transmit a reference signal, for example, CSI-RS, in the subframe.

On the other hand, if the current subframe is not a predetermined subframe as a result of the determination, the base station proceeds to step S430 and transmits a reference signal at a predetermined position of the subframe.

In operation S450, the base station may receive channel quality information from the terminal. The channel quality information may include channel quality indicator information. The channel quality information may further include precoding matrix indicator information and rank indicator information.

In step S460, the base station determines whether the channel quality information received from the terminal is channel quality information for a predetermined subframe.

As a result of the determination, if the received channel quality information is for a predetermined subframe, the base station proceeds to step S470 and ignores the corresponding channel quality information. This is because, since the base station did not transmit the reference signal in a predetermined subframe, the channel quality information measured and reported by the terminal will be meaningless.

On the other hand, if the received channel quality information is not for a predetermined subframe, the base station proceeds to step S480 to report the channel quality information to the scheduler, so that the scheduler utilizes the radio resource allocation. That is, in a subframe other than the predetermined subframe, the base station transmits a reference signal for channel measurement to the terminal in the corresponding subframe, and the channel quality information reported by the terminal is a measurement result of the reference signal transmitted by the base station. Because.

First, in step S510, the terminal checks the current subframe index. In operation S520, the terminal determines whether the identified subframe index is an index for a predetermined subframe. According to an embodiment of the present invention, the predetermined subframe index may be an index of greater than or equal to 0 and less than 5 in a modulo 100 operation, but is not necessarily limited to this method.

Subsequently, in step S530, the terminal performs measurement on the identified subframe. Here, performing the measurement on the subframe may mean measuring the received signal strength.

In operation S540, the terminal determines whether the received signal strength measurement result is greater than or equal to a predetermined threshold value. If the received signal strength measurement result is greater than or equal to the threshold, it means that the base station has transmitted the reference signal in the corresponding subframe, and below the threshold may mean that the base station has not transmitted the reference signal in the corresponding subframe.

If the received signal strength measurement result is not equal to or greater than a predetermined threshold value, the terminal proceeds to step S550 and sets not to perform filtering when generating channel quality information on the current subframe and the subsequent subframe. This means that the measurement result of the received signal strength is not more than a predetermined threshold value, indicating that the base station has not transmitted the reference signal in the corresponding subframe, since the base station is a base station that reports various types of channel quality from the terminal. This is because the channel quality should be reported.

Meanwhile, in step S550, according to another embodiment of the present invention, when the measurement result of the predetermined subframe is less than or equal to the threshold value, the terminal will need to inform the base station that the terminal has grasped the intention of the base station. To this end, the UE may intentionally generate the best quality channel quality information and report it to the base station even if the reference signal measurement result in the corresponding subframe is not good.

Then, when the base station receives the best quality channel quality information from the terminal for a subframe in which the base station does not transmit the reference signal, it can know that the terminal has understood its intention.

In the above description, the terminal transmits the best quality channel quality information. However, this is only an example. For example, the terminal may transmit channel quality information above a certain threshold under the above conditions.

On the other hand, if the received signal strength measurement result is more than a predetermined threshold value, the terminal proceeds to step S560 is set to generate the channel quality information according to the set operation. For example, the terminal may be configured to generate filtered channel quality information. This may mean that the channel quality information measured for the current subframe and the channel quality information obtained by averaging the previously accumulated channel quality information are generated.

The terminal proceeds to step S570, and reports the channel quality information generated according to the method set in the previous step to the base station.

Meanwhile, in FIG. 5, when the determination result of step S540 indicates that the subframe measurement result is not greater than or equal to a preset threshold value, instantaneous channel quality information is generated.

On the other hand, according to another embodiment of the present invention, when a subframe having a received power that is not more than a preset threshold is detected more than a set number (or more than a set ratio, in one embodiment more than 7 times of 10 measurements) In addition, instantaneous channel quality information may be generated.

In detail, FIG. 6 is a flowchart illustrating a process of determining whether to generate filtered channel quality information when the terminal generates instantaneous channel quality information.

First, the terminal may detect that an arbitrary event has occurred in step S610. In operation S620, the terminal may determine whether the detected event is a preset event. The preset event may include, for example, at least one of a handover attach.

When the preset event is a handover, the handover may mean a handover from a base station that reports various types of channel quality from the terminal to a base station that receives only one channel quality from the terminal.

In addition, when the preset event is a connection, the connection may mean a connection to a base station that receives only one channel quality reported from the terminal.

As a result of the determination, when a preset event is detected, the terminal proceeds to step S630 to perform filtering when generating channel quality information. That is, average channel quality information is generated.

On the other hand, if the detected event is not a preset event as a result of the determination, the terminal proceeds to step S640 and does not perform filtering when generating channel quality information. That is, instantaneous channel quality information is generated.

In step S650, the terminal reports the generated channel quality information to the base station.

In FIG. 6, an example of handover or connection has been described with respect to a case in which a terminal generating instantaneous channel quality information generates filtered channel quality information again.

Meanwhile, according to another embodiment of the present invention, the terminal may periodically determine whether to generate instantaneous channel quality information or to generate filtered channel quality information. In this case, the terminal may determine this based on the received power in the predetermined subframe.

7 is a block diagram showing the internal structure of a base station according to an embodiment of the present invention.

As shown in FIG. 7, the base station may include a transceiver 710 for transmitting and receiving a signal to and from a terminal, and a controller 720 for controlling a signal flow between internal blocks of the base station.

More specifically, the control unit 720 of the base station according to an embodiment of the present invention may further include a detailed block as follows.

The CSI-RS transmission TP set determination unit 730 determines whether to use the radio resource for each channel quality measurement purpose to measure the channel quality of the TP set (TP combination). The CSI-RS transmission TP set determination unit 730 instructs the CSI-RS transmission unit 740 of TP #n to transmit the CSI-RS for each TP of the determined TP set. For example, when the radio resource for channel quality measurement is to be used to measure the channel quality when receiving a signal transmitted from TP # 1, the CSI-RS transmission TP aggregation determination unit 730 may determine the CSI of TP # 1. Instructs the RS transmitter to transmit the CSI-RS.

According to an exemplary embodiment of the present invention, the CSI-RS transmission TP set determination unit 730 does not instruct CSI-RS transmission to any TP at a time (subframe) that satisfies a specific condition. In the resource, the CSI-RS may be controlled from being transmitted from any TP.

When the terminal reports the channel quality periodically (or aperiodically), the channel quality information separator 750 separates which TP combination the channel quality corresponds to. For example, when separated by the channel quality of TP # 1, the quality information separator 750 transmits the channel quality information to the channel quality manager 760 for the channel of TP # 1.

The radio resource allocator 770 may receive channel quality for various TP combinations and use the radio resource allocation to the terminal.

In the above description, the controller 720 includes separate detailed blocks, and the functions performed by the detailed blocks are different, but are not necessarily limited thereto. For example, the controller 720 itself may perform a function performed by the CSI-RS transmission TP set determiner 730.

As shown in FIG. 8, the terminal may include a

transceiver

810a and 810b for transmitting and receiving a signal to and from a base station, and a controller 820 for controlling a signal flow between internal blocks of the terminal.

More specifically, the control unit 820 of the terminal according to an embodiment of the present invention may further include a detailed block as follows.

The CSI-RS receiver 830 measures instantaneous downlink channel quality or instantaneous CSI-RS received power value or both from radio resources (reference signal, CSI-RS) for every channel quality measurement purpose.

The CSI-RS untransmitted subframe calculator 840 determines whether it is a subframe that satisfies a specific condition and informs the channel quality estimation method determiner 850.

The channel quality estimation method determiner 850 transmits the CSI-RS from the base station by using an instantaneous downlink channel quality or an instantaneous CSI-RS received power value or both at a subframe satisfying a specific condition. Judge whether or not. If it is determined that the base station transmits the CSI-RS in any TP at a time when the specific condition is satisfied, the channel quality estimation method determiner 850 filters the channel quality to the channel quality estimator 860. To instruct.

If it is determined that the base station has not transmitted the CSI-RS in any TP at the time that satisfies the specific condition, the channel quality estimation method determiner 850 does not filter the channel quality to the channel quality estimator 860 immediately. Instructs to measure channel quality.

The channel quality estimator 860 estimates the channel quality according to the instruction of the channel quality estimation method determiner 850, and transfers this value to the channel quality information transmitter 870. The channel quality information transmitter 870 reports the downlink channel quality to the base station through a periodic (or aperiodic) uplink report channel designated by the base station.

In the above description, the controller 820 includes separate detailed blocks, and the functions performed by the detailed blocks are different, but are not necessarily limited thereto. For example, the controller 820 may perform a function performed by the CSI-RS receiver 830.

According to the embodiment of the present invention described above, the terminal can robustly determine whether to report the instantaneous channel quality. In addition, the base station can receive various types of channel quality reports as necessary, and as a result, it is possible to expect the capacity improvement effect of the wireless communication system.

The embodiments of the present invention disclosed in the specification and the drawings are only specific examples to easily explain the technical contents of the present invention and aid the understanding of the present invention, and are not intended to limit the scope of the present invention. It will be apparent to those skilled in the art that other modifications based on the technical idea of the present invention can be carried out in addition to the embodiments disclosed herein.

Claims

In the method of transmitting a reference signal of a base station in a wireless communication system,

Identifying index information for the current subframe;

Determining whether the subframe is a predetermined subframe; And

And as a result of the determination, transmitting the reference signal in the subframe when the identified subframe is not a predetermined subframe and not transmitting the reference signal when the identified subframe is a predetermined subframe. Reference signal transmission method, characterized in that.
The method of claim 1,

Receiving channel quality information from a terminal;

Determining whether the received channel quality information is channel quality information for the predetermined subframe; And

And if the received channel quality information is channel quality information for the predetermined subframe, ignoring the channel quality information.
The method of claim 2,

And if the received channel quality information is not the channel quality information for the predetermined subframe, allocating a radio resource for the terminal by using the channel quality information. .
The method of claim 1,

And transmitting the information on the predetermined subframe to the terminal.
The method of claim 4, wherein

The information on the predetermined subframe is transmitted to the terminal through at least one of system information, higher layer signaling or a physical layer signal.
The method of claim 1, wherein the reference signal,

And a channel state information reference signal.
In the method for reporting channel quality information of a terminal in a wireless communication system,

Identifying index information for the current subframe;

Performing measurements on the identified subframes;

If the checked subframe is a predetermined subframe and the measurement result is equal to or less than a preset threshold, setting to generate instantaneous channel quality information for the subframe and subframes coming after the subframe; And

And reporting the channel quality information generated according to the setting method to the base station.
The method of claim 7, wherein

Setting to generate average channel quality information when the measurement result is equal to or greater than a preset threshold value; And

And reporting the channel quality information generated according to the setting method to the base station.
The method of claim 7, wherein

Determining whether a predetermined event occurs while generating and reporting the instantaneous channel quality information;

Setting to generate average channel quality information when a predetermined event occurs as a result of the determination; And

And reporting the channel quality information generated according to the setting method to the base station.
The method of claim 9, wherein the preset event,

Channel quality information reporting method comprising a handover (attach) or attach (attach).
The method of claim 7, wherein the channel quality information generating step,

And when the checked subframe is a predetermined subframe and the measurement result is equal to or less than a predetermined threshold value, generating channel quality information indicating a quality equal to or greater than a predetermined threshold value.
A base station transmitting a reference signal in a wireless communication system,

Transmitting and receiving unit for transmitting and receiving a signal with the terminal; And

Check index information of a current subframe, determine whether the subframe is a predetermined subframe, and if the determined subframe is not a predetermined subframe, transmit a reference signal in the subframe, and And a controller for controlling not to transmit the reference signal when the identified subframe is a predetermined subframe.
The method of claim 12, wherein the control unit,

When receiving the channel quality information from the terminal, it is determined whether the received channel quality information is channel quality information for the predetermined subframe, and if the received channel quality information is channel quality information for the predetermined subframe, the channel A base station characterized by ignoring quality information.
The method of claim 13, wherein the control unit,

And if the received channel quality information is not channel quality information for the predetermined subframe, controlling to allocate radio resources for the terminal using the channel quality information.
The method of claim 12, wherein the control unit,

The base station characterized in that to control to transmit the information about the predetermined subframe to the terminal.
The method of claim 15,

And the information on the predetermined subframe is transmitted to the terminal through at least one of system information, higher layer signaling, or physical layer signal.
The method of claim 12, wherein the reference signal,

And a channel state information reference signal.
A terminal for reporting channel quality information in a wireless communication system,

Transmitting and receiving unit for transmitting and receiving a signal with the base station; And

Confirm the index information on the current subframe, perform measurement on the identified subframe, and if the checked subframe is a predetermined subframe and the measurement result is less than or equal to a preset threshold, the subframe and the subframe And a controller configured to generate instantaneous channel quality information for subframes coming after the frame and to report the channel quality information generated according to the set method to the base station.
The method of claim 18, wherein the control unit,

And setting the average channel quality information when the measurement result is greater than or equal to a preset threshold value, and controlling to report the channel quality information generated according to the set method to the base station.
The method of claim 18, wherein the control unit,

While generating and reporting the instantaneous channel quality information, it is determined whether or not a predetermined event occurs, and when the predetermined event occurs, the average channel quality information is set to be generated, and the channel quality generated according to the set method Terminal for controlling the reporting of information to the base station.
The method of claim 20, wherein the preset event,

Terminal comprising a handover (attach) or attach (attach).
The method of claim 18, wherein the control unit,

And when the checked subframe is a predetermined subframe and the measurement result is less than or equal to a preset threshold, controlling to generate channel quality information indicating a quality greater than or equal to the set threshold.