KR20080111378A - A method for transmitting channel quality information of frequency sub-band in a wideband multi-carrier communication system - Google Patents

Abstract

A method for transmitting channel quality information about unit frequency band in a broadband multi carrier transmission system is provided to use limited uplink resource efficiently in the broadband multi carrier transmission system and to reduce control information overhead in a mobile communication system. Downlink signal is received from a base station(S30). The channel quality about one or more unit frequency bands based on the downlink signal is measured(S31). The channel quality information about the corresponding unit frequency band and unit frequency band information is periodically received(S32). The transmission cycle of the unit frequency band information and transmission cycle of the channel quality information are independent from each other.

Description

A method for transmitting channel quality information of frequency sub-band in a wideband multi-carrier communication system in a wideband multicarrier communication system

This document relates to a wideband multi-carrier communication system, more specifically. In a wideband multi-carrier communication system, a method for transmitting channel quality information for a unit frequency band.

In the mobile communication system, the channel capacity is maximized, and a link adaptation scheme is used to efficiently transmit data to users. In order to apply this link adaptation scheme, the base station feeds back channel quality information on the received downlink signal to the base station.

Link control techniques that can be used for efficient data transmission include Adaptive Modulation & Coding (AMC), Hybrid Automatic Request (HARQ), and Power Control. Among them, AMC refers to a channel adaptive transmission scheme in which a base station determines a modulation scheme and a code rate based on feedback information received from terminals and adjusts the data rate accordingly. As an example of AMC, when the base station determines a modulation and coding selection (MCS) based on the CQI information fed back from the terminal and transmits it to the terminal, the terminal transmits data using a modulation scheme and coding scheme specified in the MCS. Can be.

Each terminal transmits channel quality information for all frequency bands for efficient resource allocation. In a multi-carrier system, since the channel quality is different for each frequency band where data is transmitted, the entire frequency band is divided into several unit frequency bands. Channel quality information is sent for each frequency band. Since there are several terminals in one base station, if the information on the entire band is fed back to each terminal, the control information overhead for efficiently allocating resources will increase drastically.

In the prior art as described above, an object of the present invention is to provide a method for transmitting channel quality information for a unit frequency band in a wideband multi-carrier communication system.

In the wideband multi-carrier communication system according to an embodiment of the present invention for achieving the above object, a method for transmitting channel quality information for a unit frequency band, receiving a downlink signal from a base station, the downlink signal Measuring channel quality for one or more unit frequency bands based on the step and periodically transmitting unit frequency band information and the channel quality information for the unit frequency band using the measured channel quality, The transmission period of the unit frequency band information and the transmission period of the channel quality information are determined independently of each other.

The transmission period of the unit frequency band information may be determined to be larger than the transmission period of the channel quality information.

The unit frequency band information and the channel quality information may be individually coded and transmitted.

The unit frequency band information and the channel quality information may be divided and transmitted in one or more subframes.

The unit frequency band information and the channel quality information may be transmitted through at least one of an uplink shared channel and an uplink control channel.

The channel quality information may be channel quality information of one or more unit frequency bands having higher channel quality among unit frequency bands included in all bands.

The channel quality information may be average channel quality information of all bands or a plurality of selected unit frequency bands.

The channel quality information may be a value relative to the average channel quality for all bands or a plurality of selected unit frequency bands.

The unit frequency band information may be an index or a bitmap allocated for each unit frequency band.

Further, in a wideband multi-carrier communication system according to another embodiment of the present invention, the method for transmitting channel quality information for a unit frequency band, receiving a downlink signal from a base station, at least one based on the downlink signal Measuring channel quality for a unit frequency band, individually coding unit frequency band information and channel quality information for a corresponding unit frequency band by using the measured channel quality, and for each unit frequency band information and the channel Transmitting the quality information.

The unit frequency band information may be transmitted through the same or previous subframe as the channel quality information for the unit frequency band.

The unit frequency band information and the channel quality information are periodically transmitted, and the transmission period of the unit frequency band information and the transmission period of the channel quality information may be independently determined.

The transmission period of the unit frequency band information may be determined to be larger than the transmission period of the channel quality information.

The unit frequency band information and the channel quality information may be divided and transmitted in one or more subframes.

The unit frequency band information and the channel quality information may be transmitted through at least one of an uplink shared channel and an uplink control channel.

Through the embodiments disclosed in this document, channel quality information on a unit frequency band may be transmitted in a wideband multicarrier communication system.

In addition, in a broadband multi-carrier communication system, a limited uplink resource can be efficiently used when a terminal transmits (reports) downlink channel quality information used for base station scheduling and the like to uplink.

In addition, it is possible to reduce the control information overhead in the mobile communication system and to convey the channel state as accurately as possible. In addition, the downlink scheduling gain can be increased as a result.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. The detailed description set forth below in conjunction with the appended drawings is intended to explain exemplary embodiments of the present invention and is not intended to represent the only embodiments in which the present invention may be practiced.

1 is a diagram illustrating an example of a method for transmitting channel quality information by a terminal to a base station in a mobile communication system.

As shown in FIG. 1, the terminal 11 receives a downlink signal from the base station 10 and measures the downlink channel state. In this case, the downlink signal may be a pilot signal or a reference signal. Then, the channel state measurement result is transmitted back to the base station 10 as channel quality information (CQI). And, in the case of a MIMO system, RI (Rank Information), PMI (Precoding Matrix Information), etc. may be added as control information reflecting the channel state.

The base station 10 may select a terminal to receive downlink data through downlink scheduling according to the channel quality information reported from the terminal 11 or perform radio resource allocation for the selected terminal. In particular, the channel quality information fed back by the terminal 11 uses the channel capacity in the mobile communication system at the base station 10 to maximize the link adaptation (link) for efficiently transmitting data to users. This can be very useful when you want to perform the adaptation technique.

Channel quality information can be generated in various ways. For example, a method of quantizing the measured channel state as it is, signal to interference and noise ratio (SINR) of the channel, carrier to interference and noise ratio (CINR), bit error rate (BER), frame error rate (FER), etc. Or a channel such as MCS (Modulation and Coding Selection) level information that can inform a modulation method and / or a coding rate for performing the link adaptation method described above. There are ways to tell the status of this actual application.

If the channel quality information is generated based on the MCS, specifically, the MCS includes a modulation scheme, a coding scheme, a code rate thereof, and the like. Therefore, when the modulation scheme and the coding scheme are changed, the channel quality information must also change accordingly. Therefore, when a plurality of codewords are transmitted, at least one channel quality information is transmitted for each codeword that can be regarded as a modulation scheme and a coding unit. Do.

In addition, the channel quality information may vary in the channel measurement range and / or report range according to the type of the signal or the type of the channel. For example, a communication channel between a base station and a terminal may be classified into a data traffic channel and a control channel for controlling the same. Channel quality information may be different when the frequency band and the space band in which each of these two channels are transmitted are different.

That is, in general, in a multi-carrier system, the control channel often uses frequency diversity and spatial diversity over the entire band, so that the channel quality information for the control channel feeds back the entire frequency band by measuring the channel quality. In the case of channels, frequency band scheduling and spatial multiplexing are used to divide the frequency band and measure and feed back channel quality information divided by the divided bands.

In another aspect, when the terminal reports the downlink channel quality to the base station, only one channel quality information may be calculated and fed back for the entire frequency band of the system, but as described above, in the case of the broadband mobile communication system, in particular, the broadband multi-carrier system However, since the same channel quality is not guaranteed over all bands, system performance may be deteriorated when one channel quality information of all bands is transmitted.

Accordingly, in the broadband mobile communication system, the system frequency band is divided into a plurality of unit frequency bands, and the channel quality for each unit frequency band is measured to transmit all or part of the plurality of channel quality information determined for the unit frequency band. Method can be used. The basic unit of the unit frequency band for measuring channel quality and generating channel quality information may be referred to as a CQI subband or a CQI subband.

According to the present invention, as the transmission bandwidth is widened, for example, to 10 MHz and 20 MHz in the broadband mobile communication system, the amount of channel quality information to be fed back increases accordingly, thereby allowing the terminal to efficiently transmit downlink channel quality information to the base station. It is about a method. In the present invention described through the following embodiments, when the terminal transmits downlink channel quality information to the base station, the channel quality information is segmented and the update or transmission period is independently determined in consideration of the amount of time variation of each segmented information. We propose a method to minimize system and user losses even if the information is delivered in the same amount of information.

The control information including the channel quality information described above may be transmitted as a physical layer control signal. The transmission to the physical layer control signal is punctured or multiplexed with data symbols or bits of the shared data channel according to the presence or absence of a shared data channel (DL-SCH) allocated to the corresponding terminal to be transmitted upward. Or a reserved control channel such as a physical uplink control channel (PUCCH).

The case where channel quality information is generated based on MCS among the various channel quality information generating methods described above will be described in more detail.

2 is a view for explaining an example of a method for transmitting channel quality information of a unit frequency band in a wideband multicarrier system.

FIG. 2 illustrates a case in which a CQI subband is assumed to be a unit of 3RB in a multi-carrier system when 24 resource blocks (RBs), which are scheduling basic units, are configured to be included in a 5 MHz frequency band. In this case there will be eight CQI subbands. For example, if 5-bit feedback is given as channel quality information for each CQI subband, 40 bits per terminal (= 5X8) are transmitted in the uplink. Since there are a plurality of terminals in the system, the amount of control information transmitted in the uplink will increase according to the number of terminals. This large amount of information puts a strain on limited uplink resources.

Accordingly, in the transmission of such channel quality information, it is necessary to reduce the amount of uplink feedback information of all terminals by selectively transmitting a transmission band or adjusting an update period according to a channel change in a frequency domain or a time domain. An example of a method of selectively transmitting a transmission band in the frequency domain may be a method of selecting a CQI subband and selectively transmitting only channel quality information of the selected CQI subband.

In particular, FIG. 2 illustrates a case where the method is applied to the Best-M scheme, which is a technique for selecting and transmitting a subband having a higher M quality from among a plurality of CQI subbands included in all frequency bands. That is, unlike the case where the terminal transmits the channel quality information of the entire CQI subbands, the terminal may transmit the M channel quality information selected from the channel quality information of the entire CQI subbands or average channel quality information for the selected frequency domain. have.

When the terminal transmits M channel quality information selected from the channel quality information of all CQI subbands, it is preferable to inform the selected unit frequency band information, that is, information on the selected CQI subband. That is, if the base station needs to know which CQI subband channel quality information is transmitted, the CQI subband may receive the channel quality information and reflect it in effective downlink scheduling. When transmitting the channel quality information, such unit frequency band information may be transmitted as bit map information or index information allocated to each unit frequency band.

For the downlink shared channel (DL-SCH), the terminal generates channel quality information for each CQI subband consisting of 3RB. In this case, an index is sequentially assigned to each CQI subband, and an index of 0 to 7 is allocated. And, when transmitting the MCS level in the channel quality information, it is assumed that the MCS level for each CQI subband is determined as shown in FIG. In this case, the CQI subbands having the top three channel qualities, that is, the CQI subbands corresponding to index 0, index 3, and index 7 and the channel quality information of each CQI subband according to the above-described Best-3 scheme, are used. Will be sent as 5, 6, 7.

3 is a flowchart illustrating an example of a method for transmitting channel quality information in a wideband multi-carrier system according to an embodiment of the present invention.

First, the terminal receives a downlink signal from the base station in step S30. In this case, the downlink signal that can be received may be a pilot signal or a reference signal.

The terminal measures the downlink channel quality based on the downlink signal received in step S31. The terminal may generate channel quality information by measuring channel quality for each unit frequency band. In operation S32, all or selected portions of the channel quality information generated for each unit frequency band may be transmitted.

In the case of transmitting only the channel quality information of the selected unit frequency band, it is preferable to transmit not only the channel quality information but also the information of the unit frequency band as described above. The base station may effectively reflect this in downlink scheduling when it knows which unit frequency band the received channel quality information is.

The channel quality information will be fed back at an appropriate interval in consideration of the correlation between performance degradation and feedback overhead. For example, if the change of the channel quality information is slow in the time domain, feeding back the channel quality information in every subframe will have less gain in performance improvement than the amount of information. Information can be sent. In addition, when transmitting not only the actual channel quality information but also additional information, for example, the above-described unit frequency band information as the channel quality information, it may be desirable to feed back information at an appropriately set period for each information.

According to the present embodiment, in the case of transmitting the unit frequency band information and the channel quality information for the unit frequency band as described above in step S32, the transmission period for each of them may be set independently of each other. In other words, the transmission period for the unit frequency band information and the transmission period for the channel quality information may be set differently.

For example, the transmission period of the unit frequency band information may be determined to be larger than the transmission period of the channel quality information and fed back. In this case, a unit frequency band having a large period and a good channel condition is selected and informed, and channel quality information of the selected unit frequency band is transmitted for a predetermined period, compared with the case of transmitting unit frequency band information for each channel quality information transmission. This may reduce overhead of uplink control information.

According to the present embodiment, each information may be transmitted together or separately by determining the transmission period of the unit frequency band information and the transmission period of the channel quality information independently. As in the above example, when the transmission period of the unit frequency band information is determined to be larger than the transmission period of the channel quality information and fed back, the unit frequency band information is transmitted together with the channel quality information, but the unit frequency band information is not transmitted. If not, only the channel quality information of the unit frequency band according to the transmitted unit frequency band information may be transmitted.

In the present embodiment, the unit frequency band information and the channel quality information are transmitted among control information. However, if there is additionally or alternatively transmitted information, the present embodiment is extended and applied, and the transmission period between these information is also extended. It may be determined independently.

4 is a diagram illustrating an experimental result comparing the effects of different transmission cycles of unit frequency band information and channel quality information in transmitting channel quality information in a broadband multi-carrier system according to an exemplary embodiment of the present invention. .

In independently determining the transmission period according to the present embodiment, the transmission period of the unit frequency band information may be set longer than the transmission period of the channel quality information. That is, the selection of the Best-M unit frequency band and the feedback period of the unit frequency band information according to this can be made long, and the transmission period of the channel quality information in this band can be made short.

FIG. 4 compares the effects of different transmission periods of unit frequency band information and channel quality information when transmitting channel quality information using Best-2. In particular, FIG. 4 (a) shows an experimental result for a case where the transmission period is varied with CI = 1, CI = 6, CI = 12, and CI = 24 for the unit frequency band information CI, and FIG. (b) shows the results of experiments in the case where the transmission period is varied with CV = 1, CV = 6, CV = 12 and CV = 24 for the channel quality information CV.

The decrease in performance as the transmission period of the unit frequency band information shown in FIG. 4 (a) becomes longer is shown to be less than the decrease in performance as the transmission period of the channel quality information shown in FIG. 4 (b) becomes longer. Can be. Therefore, it is more efficient with the same amount of information than the method of feeding back both information at the same period because it transmits by increasing the proportion of relatively sensitive information such as channel quality information than less sensitive information such as unit frequency band information. It will be possible to control the channel information.

5 is a view for explaining an example of a method for transmitting channel quality information in a broadband multi-carrier system according to an embodiment of the present invention.

FIG. 5 is a diagram illustrating a relative period of transmitting unit frequency band information and channel quality information for a corresponding unit frequency band in a method of selecting some unit frequency bands and transmitting channel quality information for the selected unit frequency band. to be.

Referring to FIG. 5, the transmission periods of the unit frequency band information and the channel quality information are determined independently of each other, but considering the experimental results confirmed through FIG. 4, the transmission period of the channel quality information having a more sensitive effect on performance is relatively higher. You can see an example that determines the shorter value.

FIG. 5A illustrates an example including a case in which transmission periods of unit frequency band information and transmission periods of channel quality information are independently determined, but transmitted in the same time period. The transmission period of the unit frequency band information, that is, the CQI sub-band index is 6 subframes, and the transmission period of the channel quality information CQI value is 3 subframes. The transmission period of the unit frequency band information is set twice as large as the transmission period of the channel quality information.

In (a) of FIG. 5, unit frequency band information and channel quality information may be transmitted together in the same time period, that is, in the same subframe, and only channel quality information may be transmitted. If only the channel quality information is transmitted, the channel quality information for the same unit frequency band as the selected unit frequency band announced through the previously transmitted unit frequency band information will be transmitted.

In addition, (b) of FIG. 5 determines the transmission period of the unit frequency band information and the transmission period of the channel quality information independently of each other, while the unit frequency band information and the channel quality information for the unit frequency band are mutually exclusive. Only shows how to transfer.

In FIG. 5 (b), the unit frequency band information of the selected unit frequency band, that is, the CQI sub-band index, is transmitted, and then the channel quality information (CQI value) of the unit frequency band is 2. An example of determining the transmission period of the unit frequency band and the transmission period of the channel quality information independently from each other through the method of transmitting more than one time. Even in this case, it can be described that the transmission period of the unit frequency band information is set relatively larger than the transmission period of the channel quality information.

According to the present embodiment, the unit frequency band information and the channel quality information may be transmitted through different channels by applying a signaling method independently of each other. That is, the unit frequency band information and the channel quality information may be signaled in the same way, or may be signaled in different ways. In each method, the unit frequency band information or the channel quality information may be transmitted in one subframe or may be divided and transmitted in several subframes.

6 is a flowchart illustrating an example of a method for transmitting channel quality information in a wideband multi-carrier system according to an embodiment of the present invention.

First, the terminal receives a downlink signal from the base station in step S60. In this case, the downlink signal that can be received may be a pilot signal or a reference signal as described above.

The terminal measures the downlink channel quality based on the downlink signal received in step S61. The terminal may generate channel quality information by measuring channel quality for each unit frequency band. In addition, all or selected portions of the channel quality information generated for each unit frequency band may be transmitted. In the case of transmitting only the channel quality information of the selected unit frequency band, it is preferable to transmit not only the channel quality information but also the information of the unit frequency band as described above.

According to the present embodiment, in transmitting the selected unit frequency band information and the channel quality information for the selected unit frequency band in this way, it may be coded and transmitted separately from each other in step S62. In other words, in case of transmitting the unit frequency band information and the channel quality information for the unit frequency band, coding for them may be performed.

In addition, by separately coding the unit frequency band information and the channel quality information may be coded by applying different coding schemes or coding rates. According to an embodiment of the present invention, as the unit frequency band information and the channel quality information are transmitted through the same or different signaling methods, each may be transmitted through different channels or different subframes, in which case each may be individually coded. And transmit, but may be transmitted after coding with a coding scheme or a coding rate independently of each other.

In operation S63, all or selected portions of the unit frequency band information coded separately from each other and the channel quality information generated for each unit frequency band may be transmitted.

Although the present embodiment has been described as transmitting unit frequency band information and channel quality information among control information, in addition to this, if there is additionally or alternatively transmitted information, the present embodiment can be extended and applied so that the transmission period between these information can be extended. It may be determined independently.

The channel quality information can be signaled in two ways, for example. When a shared data channel is allocated, a type A method of sending a physical layer control signal using a channel such as a physical uplink shared channel (PUSCH) and a reserved physical such as a physical uplink control channel (PUCCH) for faster update. This is a type B method of transmitting control channel.

Table 1 below shows various embodiments of transmitting unit frequency band information and channel quality information in consideration of the above-described signaling and coding method.

Type A : Type B : Allocate shared data channel and transmit as physical layer control signal Transmission on reserved physical control channel (PUCCH) Case 1 CQI sub-band index Channel Quality Information (CQI Value) Index information is transmitted in a type A method, and value is transmitted in a type B method. Two pieces of information are transmitted in an exclusive time period. Case 2 Value Index Index information is transmitted using Type B and Value is transmitted using Type A. Both information is transmitted in an exclusive time period (each of which can be divided into several subframes). Case 3 Index Value Individual coding / transmission of Index and Value information by Type B method Two information is transmitted in an exclusive time period (each can be divided and transmitted in several subframes) Case 4 Index Value Individual coding / transmission of Index and Value information by Type A method Two information is transmitted in an exclusive time period (each can be divided and transmitted in several subframes) Case 5 Index, Value Individual coding / transmission of index and value information using Type A method Two information can be transmitted in the same time interval (splitting transmission is possible in several subframes) Case 6 Index + Value Joint coding / transmission when sending index and value information in type A method Both information can be transmitted in the same time interval (divided transmission is possible in several subframes)

The unit frequency band information and the channel quality information may be transmitted by applying a signaling method independently of each other. That is, this shows the method of transmitting the unit frequency band information and the channel quality information through different signaling methods, that is, different channels, as shown in case 1 and case 2 of Table 1.

In particular, case 1 of Table 1 shows a method in which a shared data channel is allocated, unit frequency band information is transmitted through a physical layer control signal, and channel quality information is transmitted through a reserved physical control channel. On the contrary, case 2 of Table 1 shows a method of transmitting unit frequency band information as a physical layer control signal and transmitting channel quality information to a reserved physical control channel.

In this case, the same time interval transmission may be possible by the method of FIG. 5 (a) or FIG. 5 (b), or may be possible only in a time interval that is mutually exclusive.

Alternatively, the unit frequency band information and the channel quality information may be applied to the same signaling method, but transmitted in mutually exclusive time periods. This shows how the unit frequency band information and the channel quality information are transmitted only in mutually exclusive time periods in the manner shown in case 3 and case 4 of Table 1.

In particular, case 3 of Table 1 shows a method of transmitting both unit frequency band information and channel quality information to a reserved physical control channel. Case 4 of Table 1 shows a method of transmitting both unit frequency band information and channel quality information as physical layer control signals. It is assumed that transmission is possible only in mutually exclusive time periods. When transmitting in mutually exclusive time periods, individual coding according to the present embodiment will be applied.

Meanwhile, the unit frequency band information and the channel quality information may include a case in which the same signaling method is applied to each other but transmitted in the same time period. The method shown in case 5 and case 6 of Table 1 shows a method of transmitting both unit frequency band information and channel quality information as a physical layer control signal.

Case 5 of Table 1 shows a method of including the same time interval transmission but separately coding unit frequency band information and channel quality information even when transmitting in the same time interval. Case 6 of Table 1 shows a method of coding and transmitting a joint coding scheme including unit frequency band information and channel quality information when the same time period is transmitted but transmitted in the same time period.

If the amount of control information that can be transmitted through the method of transmitting the reserved physical control channel can be extended to transmit the unit frequency band information and the channel quality information in the same time period, the unit frequency band information and the channel quality are not shown in Table 1. Information may also be transmitted on a reserved physical control channel in the same time period. In this case, of course, separate coding and / or joint coding may also be applied.

Of course, although the case of coding and transmitting together with each other including the same time interval transmission is possible, in case of transmitting the unit frequency band information and the channel quality information in independent transmission periods according to the present embodiment, an individual coding method and / or an exclusive time period The inter-transmission method should be applied together.

In the above-described embodiments, in the same or mutually exclusive time period transmission, the unit frequency band information and the channel quality information may be transmitted in one subframe in one transmission, but are transmitted in a plurality of subframes. Could be

In the above-described embodiments, the transmitted channel quality information is a method of quantizing the measured channel state as it is, the signal to interference and noise ratio (SINR) of the channel, the carrier to interference and noise ratio (CINR). ), A bit error rate (BER), a frame error rate (FER), or a value converted into transmittable data, and the like, and a modulation method and / or a coding rate for performing the link adaptation method described above. It may be transmitted in various ways, such as a method for notifying a state in which a channel is actually applied, such as Modulation and Coding Selection (MCS) level information capable of indicating.

In addition, according to the method of transmitting the channel quality information, the channel quality value for the corresponding frequency band may be transmitted, or may be transmitted as an average value for a plurality of frequency bands or a relative value for the average value. For example, when the channel quality information is transmitted using the BEST-M scheme, the channel quality information for the unit frequency band having the upper M good channel quality will be transmitted. In addition, when transmitting a value relative to an average value, delta-CQI (ΔCQI), the channel quality information includes average channel quality information of all or some selected unit frequency bands and average channel quality information of each or all selected unit frequency bands. Relative values for may be sent.

In this document, embodiments of the present invention have been described based on data transmission / reception relations between a base station and a terminal. Here, the base station has a meaning as a terminal node of the network that directly communicates with the terminal. The specific operation described as performed by the base station in this document may be performed by an upper node of the base station in some cases. That is, it is obvious that various operations performed for communication with a terminal in a network composed of a plurality of network nodes including a base station may be performed by the base station or other network nodes other than the base station. A 'base station' may be replaced by terms such as a fixed station, a Node B, an eNode B (eNB), an access point, and the like. In addition, the term "terminal" may be replaced with terms such as a user equipment (UE), a mobile station (MS), a mobile subscriber station (MSS), and the like.

It is obvious that the claims may be combined to form an embodiment by combining claims that do not have an explicit citation relationship in the claims or as new claims by post-application correction.

It will be apparent to those skilled in the art that the present invention can be embodied in other specific forms without departing from the spirit and essential features of the present invention. Accordingly, the above detailed description should not be interpreted as limiting in all aspects and should be considered as illustrative. The scope of the invention should be determined by reasonable interpretation of the appended claims, and all changes within the equivalent scope of the invention are included in the scope of the invention.

1 is a diagram for explaining an example of a method for transmitting channel quality information by a terminal to a base station in a mobile communication system.

2 is a view for explaining an example of a method for transmitting channel quality information of a unit frequency band in a wideband multicarrier system.

3 is a flowchart for explaining an example of a method for transmitting channel quality information in a wideband multicarrier system according to an embodiment of the present invention.

4 is a view showing an experimental result comparing the effects of different transmission cycles of unit frequency band information and channel quality information in transmitting channel quality information in a wideband multicarrier system according to an embodiment of the present invention.

FIG. 5 is a diagram illustrating a relative period of transmitting unit frequency band information and channel quality information for a corresponding unit frequency band in a method of selecting some unit frequency bands and transmitting channel quality information for the selected unit frequency band. .

6 is a flowchart illustrating an example of a method for transmitting channel quality information in a wideband multi-carrier system according to an embodiment of the present invention.

Claims (15)

In a wideband multi-carrier communication system, a method for transmitting channel quality information for a unit frequency band, Receiving a downlink signal from a base station; Measuring channel quality for at least one unit frequency band based on the downlink signal; And Periodically transmitting unit frequency band information and channel quality information for the corresponding unit frequency band by using the measured channel quality. Including, wherein the transmission period of the unit frequency band information and the transmission period of the channel quality information are independent of each other. The method of claim 1, And the transmission period of the unit frequency band information is larger than the transmission period of the channel quality information. The method of claim 1, And the unit frequency band information and the channel quality information are separately coded and transmitted. The method of claim 1, And the unit frequency band information and the channel quality information are divided and transmitted in at least one subframe. The method of claim 1, And the unit frequency band information and the channel quality information are transmitted through at least one of an uplink shared channel and an uplink control channel. The method of claim 1, The channel quality information is channel quality information transmission method, characterized in that the channel quality information for one or more unit frequency bands having a higher channel quality of the unit frequency bands included in all bands. The method of claim 1, And the channel quality information is average channel quality information for all bands or a plurality of selected unit frequency bands. The method of claim 1, The channel quality information, characterized in that the relative value for the average channel quality for all bands or a plurality of selected unit frequency bands, channel quality information transmission method. The method of claim 1, And the unit frequency band information is one of an index and a bitmap allocated for each unit frequency band. In a wideband multi-carrier communication system, a method for transmitting channel quality information for a unit frequency band, Receiving a downlink signal from a base station; Measuring channel quality for at least one unit frequency band based on the downlink signal; Individually coding unit frequency band information and channel quality information for the corresponding unit frequency band by using the measured channel quality; And Transmitting the unit frequency band information and the channel quality information. Channel quality information transmission method comprising a. The method of claim 10, And the unit frequency band information is transmitted through the same or previous subframe as the channel quality information for the unit frequency band. The method of claim 10, The unit frequency band information and the channel quality information are periodically transmitted, and the transmission period of the unit frequency band information and the transmission period of the channel quality information are determined independently of each other, channel quality information transmission method. The method of claim 12, And the transmission period of the unit frequency band information is larger than the transmission period of the channel quality information. The method of claim 10, And the unit frequency band information and the channel quality information are divided and transmitted in at least one subframe. The method of claim 10, And the unit frequency band information and the channel quality information are transmitted through at least one of an uplink shared channel and an uplink control channel.

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