KR101448651B1 - Method For Transmitting Information Using Channel Quality Indicator - Google Patents

Abstract

A method for transmitting information using a channel quality indicator is disclosed. In this method, a first channel quality indicator and a second channel quality indicator, which can indicate a combination of channel quality indicator within a predetermined range, are transmitted, wherein the first channel quality indicator is a reference value and the second channel quality indicator is a first channel quality indicator In the form of a difference value with the quality indicator. At this time, if the specific combination of the reference value and the difference value does not indicate the channel quality indicator combination within the predetermined range, the specific combination is set to indicate additional information, and the transmitter can flexibly transmit the additional information have.

CQI, Additional Information

Description

[0001] The present invention relates to a method for transmitting information using a channel quality indicator,

The present invention relates to channel quality information in a mobile communication system. Specifically, in a situation where a channel quality indicator is transmitted in a differential manner to reduce feedback amount of channel quality information, a combination of a reference value and a differential value can be represented A combination of channel quality indicators that can not be represented in this case represents specific information, so that additional information can be efficiently transmitted.

First, a channel quality indicator (CQI) for indicating channel quality information to be handled by the present invention will be outlined.

In order to efficiently communicate, it is essential that the receiver informs the channel information in a feedback manner. In general, the downlink channel information is sent uplink and the uplink channel information is downlinked. Such channel information is referred to as a channel quality indicator, that is, a channel quality indicator (CQI). These CQIs can be generated in various ways.

For example, there are a method of quantizing and transmitting a channel state as it is, a method of calculating and transmitting a signal-to-interference-and-noise ratio (SINR), and a method of indicating a state in which a channel is actually applied, such as a modulation coding scheme (MCS).

Among the various CQI generation methods, in many cases, CQIs are generated based on MCS, so let's examine this in more detail. An example of this is CQI generation for a transmission scheme such as HSDPA in 3GPP (3rd Generation Partnership Project). In this way, if the CQI is generated based on the MCS, the MCS includes the modulation scheme, the coding scheme, and the coding rate. Therefore, the CQI needs to be changed according to the modulation method and the coding method, so at least one CQI per codeword unit is required.

If MIMO is applied to the system, the number of required CQIs also changes. That is, since a MIMO system generates multiple channels using multiple antennas, usually multiple codewords are available. Therefore, multiple CQIs must be used. When a plurality of CQIs are used, the amount of control information is proportionally increased.

1 is a conceptual diagram of generation and transmission of a CQI.

As shown in FIG. 1, the UE 100 measures a downlink channel quality and reports a selected CQI value to the base station 200 through an uplink control channel. The base station 200 performs downlink scheduling (terminal selection, resource allocation, etc.) according to the reported CQI. Here, the CQI value includes a signal to interference and noise ratio (SINR), a carrier to interference and noise ratio (CINR), a bit error rate (BER), a frame error rate (FER) In the case of a MIMO system, RI (Rank Information), PMI (Precoding Matrix Information), and the like may be added as information reflecting the channel state.

Meanwhile, in a mobile communication system, a link adaptation is used to maximize a channel capacity of a channel, and a modulation and coding set (MCS) and a transmission power are adjusted according to a given channel. do. In order to perform link adaptation in the base station, the user must inevitably feed back the channel quality information to the base station.

If the frequency band used by the system has a bandwidth that exceeds the coherence bandwidth, the channel will show a sudden change within one bandwidth. Particularly, in a multi-carrier system such as OFDM (Orthogonal Frequency Division Multiplexing), a plurality of sub-carriers exist in a given bandwidth, and a modulated symbol is transmitted through each sub- A channel is transmitted for each subcarrier.

Therefore, since the amount of feedback of channel information in a multi-carrier system having a large number of sub-carriers increases sharply, there is a continuing demand for reduction of control overhead of such control signals.

In order to reduce the overhead, there is a differential transmission scheme in which one CQI value is transmitted as a reference value and another one or more CQI values are transmitted in a form of a difference from the reference value when transmitting CQI values for two or more channels among the proposed methods . However, there is no discussion as to whether there is a case in which the original CQI value indicates a combination exceeding the range of the possible combination according to the differential transmission method of the CQI value.

According to an embodiment of the present invention, in order to reduce the amount of feedback of the channel quality information, a combination of a reference value and a difference value may be represented in a situation where a channel quality indicator is transmitted in a differential manner. It is desirable to provide a method for efficiently transmitting additional information by setting a combination of channel quality indicators that can not be represented in this case to indicate specific information.

In one embodiment of the present invention for solving the above problems, among the first channel quality indicator and the second channel quality indicator that can indicate a combination of channel quality indicators within a predetermined range, Wherein the second channel quality indicator is transmitted in the form of a difference value with the first channel quality indicator, and the specific combination of the reference value and the difference value indicates a combination of channel quality indicators in the predetermined range And the specific combination is set to indicate additional information when the channel quality indicator is not used.

According to another aspect of the present invention, there is provided a channel quality indicator comprising a first channel quality indicator and a second channel quality indicator, Transmitting, as a reference value, the second channel quality indicator in the form of a difference value from the first channel quality indicator; And transmitting additional information through a specific combination of the reference value and the difference value that does not indicate a combination of channel quality indicators within the predetermined range.

In this case, the channel quality indicator combination within the predetermined range may be a combination indicating a value within a predetermined range in which the first channel quality indicator and the second channel quality indicator are both not negative; The first channel quality indicator and the second channel quality indicator may both be 0 or a combination indicating a positive value within a predetermined range.

Further, the additional information may indicate an emergency status indicator.

Meanwhile, in a specific embodiment, the channel quality indicator combination within the predetermined range includes a first combination in which one of the first channel quality indicator and the second channel quality indicator indicates 0, In addition to the combination, one of the first channel quality indicator and the second channel quality indicator may be set to indicate an additional combination indicating zero.

According to the embodiments of the present invention as described above, it is possible to reduce the control information transmission overhead according to the differential CQI transmission scheme and to transmit the additional information using an unclear combination that may occur in the differential CQI transmission scheme The control information can be efficiently transmitted.

Hereinafter, preferred embodiments according to the present invention will be described in detail with reference to the accompanying drawings. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The following detailed description, together with the accompanying drawings, is intended to illustrate exemplary embodiments of the invention and is not intended to represent the only embodiments in which the invention may be practiced. For example, the following description will be made by way of a specific example applied to the 3GPP LTE (Third Generation Partnership Project) Long Term Evolution (LTE) system described above. However, the present invention is not limited to 3GPP LTE systems, It can be applied to any communication system in which feedback of information is required.

The following detailed description includes specific details in order to provide a thorough understanding of the present invention. However, those skilled in the art will appreciate that the present invention may be practiced without these specific details. In some instances, well-known structures and devices are omitted or shown in block diagram form around the core functions of each structure and device in order to avoid obscuring the concepts of the present invention. In the following description, the same components are denoted by the same reference numerals throughout the specification.

As described above, in an embodiment of the present invention, a combination of a channel quality indicator that can not be represented by a combination of a reference value and a difference value in a situation where a channel quality indicator is transmitted in a differential manner to reduce feedback amount of channel quality information In this case, the combination of the channel quality indicator that can not be represented in this case represents the specific information, thereby efficiently transmitting the additional information.

To this end, various methods that can be considered to reduce overhead in CQI generation and transmission, including a technique of first transmitting the above-described CQI in a differential mode, will be described in more detail.

First, a method of changing the unit of the CQI transmission is possible in order to reduce the CQI transmission overhead. For example, in the OFDM scheme, channel information transmitted for each subcarrier is grouped into one subcarrier group, and the channel information is transmitted on a per group basis. That is, in the OFDM scheme using 2048 subcarriers, when 12 subcarriers are collected into one subcarrier group, a total of 171 subcarrier groups are formed, so that the actual amount of channel information is reduced from 2048 to 171.

In the following description of the present invention, when a frequency band is divided into subcarriers as in the OFDM scheme, one or a plurality of subcarriers are grouped into one group, and the CQIs are reported in units of subcarrier groups The basic unit of the method is defined as a " CQI subcarrier group "or a" CQI subband. &Quot; On the other hand, when the frequency bands are not distinguished as in each subcarrier, the entire frequency band is divided into some frequency bands, and the CQI is generated on the basis of the divided frequency bands. Quot; CQI subband ". Such CQI subbands are also referred to hereinafter simply as "subbands ".

Next, a method of generating the CQI by compressing the channel information is possible. For example, in the OFDM scheme, channel information for each subcarrier is compressed using a specific compression scheme and transmitted. As the compression method, methods such as DCT (Discrete Cosine Transform) may be considered.

Also, a method of generating a CQI by selecting a corresponding frequency band for generating channel information is possible. For example, in the OFDM scheme, not the channel information is transmitted for every sub-carrier, but a Best-M scheme in which the best M number of sub-carriers or sub-carrier groups are selected and transmitted may be possible.

When transmitting the CQI by selecting the frequency band, the actual transmitted part can be roughly divided into two parts. The first is the CQI value part and the second is the CQI index part.

2 is a diagram for explaining a method of generating a CQI by selectively setting a CQI subband in the frequency domain.

In the graph shown at the top of FIG. 2, the horizontal axis represents the frequency axis and the vertical axis represents the CQI value in each frequency domain. In the top graph of FIG. 2, the horizontal axis is divided into subband units in which a plurality of subcarriers are grouped, and an index is allocated to each subband.

The frequency - selective CQI scheme consists of three parts. The first step is to select a frequency band for CQI generation, i.e., a CQI subband. The second step is to generate and transmit CQI values of the selected frequency bands by manipulation. The third step is to transmit the index of the selected frequency band, i.e. CQI subbands

In FIG. 2, an example of a method of selecting a CQI subband in a first step is an example of a Best-M scheme and a threshold-based scheme.

Best-M scheme is a method for selecting M CQI subbands having good channel conditions. In the example shown in FIG. 2, Best-3 scheme is used to select CQI subbands of indexes 5, As shown in Fig. The threshold-based scheme is a technique for selecting a CQI subband having a channel state higher than a predetermined threshold. In the example of FIG. 2, the CQI sub-index of the index 5 or 6 higher than the threshold T Band is selected.

Meanwhile, FIG. 2 shows an example of an individual transmission method and an average transmission method as an example of a method of generating and transmitting CQI values in a second step. The individual transmission scheme is a method of transmitting all the CQI values of the CQI subband selected in the first step. Accordingly, when the number of the selected CQI subbands increases, the CQI values to be transmitted are also increased in the individual transmission scheme. Meanwhile, the average transmission method is a method of transmitting an average of CQI values of the selected CQI subbands. Therefore, the average transmission method is advantageous in that the CQI value to be transmitted is one regardless of the number of the selected CQI subbands, but the accuracy is lowered by transmitting the average of several CQI subbands. Here, the method for calculating the average may be an arithmetic average method or an average method considering the channel capacity.

In FIG. 2, the CQI generation and transmission method in the second step is described as an example in which the CQI subbands 5, 6, and 9 are selected by the Best-3 scheme in the first step. That is, in the second step, CQI values 7, 6, and 5 of each of the subbands 5, 6, and 9 are separately generated and transmitted. When the average transmission method is used, subbands 5 and 6 And 9 are generated / transmitted, where the arithmetic mean of 6 CQI values is generated / transmitted.

In FIG. 2, as an example of a method of transmitting an index of a CQI subband in a third step, a bitmap index scheme and a general combination index scheme are shown as an example. The bitmap index scheme is a scheme of assigning one bit to every CQI subband and assigning 1 when the corresponding CQI subband is used and 0 when not using the CQI subband. it means. This bitmap index scheme has the disadvantage of requiring the number of bits as many as the total CQI subbands, but has an advantage that it can always be expressed through a constant number of bits regardless of how many CQI subbands are used. On the other hand, the combination index scheme determines how many CQI subbands are used, and indicates a case in which combinations of CQI subbands used in the total CQI subbands are mapped to respective indexes. More specifically, if there are N total CQI subbands and M CQI subband indices among the N are used for CQI generation, the total number of possible combinations is the same as in the following case.

The number of bits for expressing the number in the case of Equation (1) can be determined by Equation (2) below.

)In the example of FIG. 2, since three CQI subbands are selected from a total of 11 CQI subbands, the number of possible CQI subbands is ₁₁ C ₃ = 165, and the number of bits for representing 165 CQI subbands is 8 bits. (

)

On the other hand, the number of CQIs may increase as transmission to various dimensions is possible.

First, the increase of the CQI in the spatial dimension is as follows. In MIMO, when multiple codewords are transmitted through multiple layers, multiple CQIs are required. For example, in 3GPP LTE, up to two codewords can be used in MIMO, thereby requiring two CQIs. If one CQI is composed of 4 bits and the codeword is 2, the CQI should be composed of 8 bits in total. The CQI is transmitted by all the users who need to know the channel status, and therefore, the CQI occupies a large portion from the viewpoint of the entire radio resources. Therefore, it is preferable in terms of channel capacity to reduce the CQI to a minimum amount.

Second, the increase of the CQI in the frequency dimension is as follows. The above-mentioned CQI is about a case where each user transmits a CQI for one frequency band. If the receiving side selects a frequency band that exhibits the best channel state and transmits the CQI only for the selected frequency band and the transmitting side performs the service through the selected frequency band, the CQI is transmitted only for one band . Such a case is suitable for a single user environment, but is not suitable for a multi-user case, so a more efficient method is needed.

The problems occurring in the scheduling process when the CQI is transmitted in only one preferred band will be described in more detail as follows. There is no problem if the frequency bands preferred by the multi users do not overlap each other. However, a problem occurs when a plurality of users select the best frequency channel at the same time as the best channel environment. In this case, users other than the user whose transmission is selected by the transmitting side can not receive signals through the corresponding frequency band. Here, if each user transmits only one preferred frequency band, users who are not selected by the transmitting side are essentially blocked from receiving the service.

Therefore, in order to solve such a problem and effectively obtain the multi-user diversity gain, CQI transmission for various frequency bands is required. When the CQI corresponding to the plurality of frequency bands is transmitted, the amount of CQI transmission information corresponding to the selected frequency band increases. For example, if three CQIs and a frequency band indicator are transmitted in the order of good channel state, the transmission amount of the CQI is tripled, and additional transmission is performed for the indicator for indicating the selected frequency band. .

Third, an increase in CQI can be considered in consideration of both space and frequency. That is, a plurality of CQIs are required in the spatial dimension, and a case in which a plurality of CQIs are required in the frequency dimension may also be considered.

Fourth, an increase in CQI in other dimensions can be considered. For example, when a CDMA (Code Division Multiple Access) scheme is used, a change in signal strength and interference amount is generated for each spreading code, and CQI for each spreading code can be considered. Therefore, an increase in the CQI in the code dimension can be considered. In addition, it is possible to consider the increase of CQI in various dimensions.

The concept of differential CQI (Delta CQI) has been introduced to reduce the transmission of CQI. That is, one CQI normally transmits while the other CQI transmits only the difference from the first CQI. That is, a method similar to Differential Modulation in the modulation and demodulation method is used.

Based on the above description, a method of transmitting a CQI based on a difference scheme will be described below.

We have discussed the case where multiple CQIs are needed in various dimensions. In the case where a plurality of CQIs are required in this way, the above-described concept of differential CQI can be used to reduce the amount of CQI transmission. That is, one CQI is selected as a reference and the reference CQI is transmitted normally, while other CQIs only transmit the difference from the reference CQI. Here, when a plurality of CQIs are represented by a difference scheme, generally, a large number of bits are allocated to the CQI reference value, and a relatively small number of bits are allocated to the difference value, thereby reducing the transmission amount of the entire transmitted CQI.

The above-described differential CQI transmission scheme can be used not only when two or more CQIs are spatially transmitted but also when a plurality of CQIs are transmitted in various dimensions. Hereinafter, for convenience of description, description will be made with respect to two CQIs spatially transmitted within a range in which the generality is not lost.

In the embodiment to be described below, one CQI denotes a reference CQI, and the other CQIs are represented by a difference from a reference CQI. For convenience of description, the reference CQI is denoted by " CQI 1 "in the following embodiments, and the other CQI is denoted by" CQI 2 ". Further, the definition of the difference value (?) Is assumed as the form of "reference value-target value" as follows.

△ = CQI 1 - CQI 2

However, the definition of the difference value can also be defined in the form of "target value-reference value", in which case Δ = CQI 2 - CQI 1. However, in any case, since the contents can be arbitrarily selected by the system designer, only the definition of Equation (3) will be used in the following embodiments to avoid confusion.

In the following embodiments, it is assumed that 4 bits are allocated to CQI 1, which is a reference CQI, to represent values from 0 to 15, and CQI 2, which is a target CQI, is represented through a difference value. Specifically, it is assumed that 3 bits are allocated to CQI 2 to represent values from -4 to 3.

It should be noted here that the definition of the difference value is? = CQI 1 - CQI 2. CQI 2 = CQI 1 -? Is satisfied by the definition of the difference value. For example, if reference CQI 1 is 7 and? Is 3, CQI 2 = CQI 1-? = 7 - 3 = 4. As another example, if CQI 1 is 8 and? Is -2, CQI 2 = CQI 1 -? = 8 - (-2) = 10.

The overall combinations that can be represented through CQI 1 and CQI 2 according to the above definition are as follows.

FIG. 3 is a diagram illustrating a total combination that can be represented through a differential CQI transmission scheme, and is a diagram for explaining the concept of a CQI combination that can not be used according to an aspect of the present invention.

3, the horizontal axis represents the value of CQI 1 and the vertical axis represents the value of CQI 2. A specific case will be described as an example. The CQI 1 value is a reference value, and 4 bits are allocated as described above, and can represent any value from 0 to 15. If the CQI 1 value is 7, the CQI 2 value is a 3-bit difference value type and can represent a value from -4 to 3, which is the value in the range indicated by A in FIG. The overhead reduction effect for CQI transmission can be obtained by using such a difference scheme.

However, if it is assumed that 0 to 15 can be defined by allocating 4 bits to each CQI originally, the shaded B and C regions in FIG. 3 are portions in which the actual CQI value can not be defined. That is, when CQI 1 is 12 and? Is -4, CQI 2 = CQI 1 -? = 12 - (- 4) = 16, This corresponds to a case in which a CQI value that does not exist actually exists due to the use of a difference scheme. Also, when CQI 1 is 2 and? Is 3, CQI 2 = CQI 1 -? = 2 - 3 = -1.

That is, if a CQI is represented by a difference method, a portion indicating a portion in which a CQI value is not defined may be generated.

Therefore, according to an embodiment of the present invention, a method using a differential CQI transmission scheme eliminates a case where a combination in which an actual CQI value is not defined is eliminated and used.

FIG. 4 is a view showing the removal of portions B and C in FIG. 3; FIG.

As shown in FIG. 3, when CQI is defined and used, CQI 1 is 4 bits, and the difference value is 3 bits, so that a total of 128 combinations can be represented. However, when the system using the differential CQI transmission scheme according to the present embodiment shows a combination in which the actual CQI value is not defined (B and C in FIG. 3), the 16 combinations are eliminated and a total of 112 combinations This will remain. In this way, it is possible to eliminate the ambiguity that may occur in the CQI analysis by deleting a CQI combination that does not exist.

On the other hand, another embodiment of the present invention proposes a method of additionally limiting the case where it is not preferable to generate the actual CQI in addition to the portions B and C of FIG.

For example, if a CQI value is 0 in a specific system, it is assumed that the corresponding CQI is regarded as a value equal to "out of range" In FIG. 4, a part where one CQI is 0 indicates that transmission is impossible in one of the two channels.

FIG. 5 is a diagram showing a portion where only one CQI value is 0 in FIG. 4 as shaded.

Specifically, FIG. 5 shows portions where only one CQI value is 0 in FIG. 4 as E and F, respectively. In FIG. 5, it is to be noted that both CQIs are not included in E and F areas in the case of all 0s. Specific reasons for using such a setting will be described below.

If two CQIs are set to be transmitted as shown in FIG. 4, it is assumed that the channel of the corresponding user is maintained to use two channels as a whole. Therefore, if the channel is maintained for only one channel for a specific time instant, it can be regarded as a case where the channel is rapidly deteriorated. Therefore, when the available channels drop rapidly from two to one in the CQI reporting step without adjusting the number of channels through the feedback of the rank index (RI) or the like, it is preferable not to schedule the channel to the user It is advantageous in terms of system capacity.

On the other hand, if both CQIs are 0, no transmission is possible for the corresponding channel, so that the channel assignment is not performed at all in the scheduler. Accordingly, in the case of a scheduler, when only one of the reported CQIs is 0, it is preferable not to allocate a channel as in the case where both CQIs are 0s. Therefore, when only one CQI is set to be 0, it is determined that both CQIs are reported as being 0, and when only one CQI is 0, it is possible to cancel.

Fig. 6 is a view showing a form in which E and F regions are removed in Fig. 5. Fig.

In other words, the case where only one of the two CQIs is 0 is removed, and all cases where 0 is included in the CQI value are shown as cases where the CQI is 0, thereby unnecessary combinations can be additionally eliminated. That is, in FIG. 6, seven combinations out of the 112 combinations shown in FIG. 5 are additionally deleted, leaving only a total of 105 CQI combinations. By eliminating the unnecessary CQI combination, there is an advantage of reducing the search space in the CQI analysis.

However, in a preferred embodiment of the present invention as well as a passive method of reducing the search space as described above, the efficiency of information transmission is improved by transmitting additional information through a specific combination indicating a combination that does not exist in an actual CQI combination I suggest.

In other words, it is considered that the CQI combination deleted in FIGS. 4 to 6 is used to indicate other control information. For example, it is possible to use the deleted CQI combination (CQI 1, CQI 2) = (0, 1, -1) as an emergency indicator or the like. Here, the emergency status indicator may be control information informing that the channel status is suddenly changed to require more frequent channel reporting, or may be a call signal for a specific emergency response. However, the additional information to be transmitted through the combination as described above is not particularly limited, and any control signal and / or data may be transmitted. That is, in a differential CQI transmission scheme, a combination that is not defined as a combination of actual CQIs is negotiated between transmitting and receiving sides in advance to indicate specific information, and the CQI transmitting side can artificially transmit additional information by transmitting such a CQI combination.

Thus, by allocating the deleted CQI combination which is not defined in the actual CQI value for other additional information transmission, the information transmission efficiency can be improved.

On the other hand, another embodiment of the present invention proposes a method of positively using the above-described additional information for adjusting the number of channels.

In the description with reference to FIG. 5 and FIG. 6, when the number of usable channels suddenly drops from two to one, the case of excluding from the scheduling is considered. This is because the general system does not consider the case of suddenly changing the number of used channels without adjusting the rank.

However, it is desirable to allow a sudden change in the number of channels when considering a system that positively uses a change according to the number of channels in the CQI reporting step. Therefore, in the present embodiment, a method of actively expanding and using a CQI of only one channel deleted in the examples of FIGS. 5 and 6 is also proposed. In other words, in FIG. 5, instead of deleting E and F regions, a combination corresponding to regions B and C in the description related to FIG. 3 is used as a combination for a case where the CQI for any one channel is 0 It is considered to be used in addition.

For example, (CQI 1, CQI 2) = (0, 1, -1) is deleted from the embodiment related to FIG. 3 (CQI 1, As shown in FIG. There are various methods for associating the actually deleted combination with the combination of only one CQI.

FIG. 7 is a diagram for explaining a method of setting the combination of the B and C regions in FIG. 3 to correspond to the combination of the G and H regions according to another embodiment of the present invention.

In FIG. 7, the extended portions are shown by G and H in comparison with FIG. That is, FIG. 7 shows a total of 128 CQI combinations including extended portions. By thus expanding the case where one CQI is 0, there is an advantage of enabling fast channel adaptation.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The foregoing description of the preferred embodiments of the present invention has been presented for those skilled in the art to make and use the invention. It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or scope of the present invention as defined by the following claims It can be understood that

Accordingly, the present invention is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

According to the information transmission method according to the embodiments of the present invention as described above, it is possible to efficiently transmit additional information in a system using a differential CQI transmission scheme, and this scheme can be applied not only to the 3GPP LTE system, And can be applied to the mobile communication system in the same manner.

1 is a conceptual diagram of generation and transmission of a CQI.

2 is a diagram for explaining a method of generating a CQI by selectively setting a CQI subband in the frequency domain.

FIG. 3 is a diagram illustrating a total combination that can be represented through a differential CQI transmission scheme, and is a diagram for explaining the concept of a CQI combination that can not be used according to an aspect of the present invention.

FIG. 4 is a view showing the removal of portions B and C in FIG. 3; FIG.

FIG. 5 is a diagram showing a portion where only one CQI value is 0 in FIG. 4 as shaded.

Fig. 6 is a view showing a form in which E and F regions are removed in Fig. 5. Fig.

FIG. 7 is a diagram for explaining a method of setting combinations of regions B and C in FIG. 3 corresponding to combinations of G and H regions according to another embodiment of the present invention.

Claims (6)

A method for transmitting information using a channel quality indicator, Wherein the first channel quality indicator and the second channel quality indicator are capable of indicating a combination of channel quality indicator within a predetermined range, the first channel quality indicator and the second channel quality indicator, In the form of a difference value, Wherein when the specific combination of the reference value and the difference value does not represent the channel quality indicator combination within the predetermined range, the specific combination is set to indicate additional information. A method of transmitting information using a channel quality indicator (CQI) Wherein the first channel quality indicator and the second channel quality indicator are capable of indicating a combination of channel quality indicator within a predetermined range, the first channel quality indicator and the second channel quality indicator, Transmitting in the form of a difference value; And And transmitting additional information through a specific combination of the reference value and the difference value that do not represent the channel quality indicator combination within the predetermined range. 3. The method according to claim 1 or 2, Wherein the combination of channel quality indicators within the predetermined range is a combination indicating a value within a predetermined range in which the first channel quality indicator and the second channel quality indicator are both not negative. 3. The method according to claim 1 or 2, Wherein the combination of channel quality indicators in the predetermined range is a combination in which the first channel quality indicator and the second channel quality indicator are both 0 or both of which indicate a positive value within a predetermined range. 3. The method according to claim 1 or 2, Wherein the additional information indicates an emergency condition indicator. The method of claim 3, Wherein the channel quality indicator combination in the predetermined range includes a first combination in which one of the first channel quality indicator and the second channel quality indicator indicates 0, Each of said specific combinations being redefined to be included in a second combination wherein either said first channel quality indicator and said second channel quality indicator are represented by 0, Wherein the channel quality indicator combination within the predetermined range further comprises the second combination, Wherein the first combination and the second combination are combinations in which the first channel quality indicator and the second channel quality indicator represent values within different ranges, Information transmission method.

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