KR101556142B1 - Method For Transmitting Channel Quality Indicator - Google Patents

Method For Transmitting Channel Quality Indicator Download PDF

Info

Publication number
KR101556142B1
KR101556142B1 KR1020080104649A KR20080104649A KR101556142B1 KR 101556142 B1 KR101556142 B1 KR 101556142B1 KR 1020080104649 A KR1020080104649 A KR 1020080104649A KR 20080104649 A KR20080104649 A KR 20080104649A KR 101556142 B1 KR101556142 B1 KR 101556142B1
Authority
KR
South Korea
Prior art keywords
cqi
transmitted
cqis
carriers
transmitting
Prior art date
Application number
KR1020080104649A
Other languages
Korean (ko)
Other versions
KR20100020884A (en
Inventor
김봉회
노동욱
이대원
노유진
Original Assignee
엘지전자 주식회사
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority to US8870708P priority Critical
Priority to US61/088,707 priority
Application filed by 엘지전자 주식회사 filed Critical 엘지전자 주식회사
Priority claimed from US12/461,253 external-priority patent/US20100041344A1/en
Publication of KR20100020884A publication Critical patent/KR20100020884A/en
Application granted granted Critical
Publication of KR101556142B1 publication Critical patent/KR101556142B1/en

Links

Images

Abstract

In a system using multiple carrier bands (legacy system band), a method of transmitting a CQI for the entire carrier band is disclosed. In order to provide sufficient information to the scheduler, the CQIs for all the carrier bands are generated and transmitted in the same manner, or a predetermined preferred number of carrier bands are selected, and only the CQI of the selected carrier band is transmitted to efficiently use the control signal resources . Further, by simply extending the CQI transmission method for each carrier band, the system scalability can be facilitated.
Figure R1020080104649
CQI, Multi-Carrier

Description

[0001] METHOD FOR TRANSMITTING CHANNEL QUALITY INDICATOR [0002]

The present invention relates to a method of transmitting a channel quality indicator (CQI) in a mobile communication system, and more particularly, to a method of efficiently generating and transmitting a channel quality indicator in a system for performing communication using a plurality of legacy system bands It is about.

 For efficient communication, the receiver side is required to feed back the channel information to the transmitter side. In general, the channel information of the downlink is sent uplink, and the channel information of the uplink is sent downlink. Such channel information is referred to as a channel quality indicator, i.e., a CQI. These CQIs can be generated in various ways.

For example, a method of quantizing and transmitting a channel state as it is, a method of calculating and transmitting SINR (Signal to Interference and Noise Ratio), and a method of indicating a state in which a channel is actually applied, such as a Modulation Coding Scheme .

Among the various CQI generation methods, in practice, CQIs are generated based on MCS. An example of this is CQI generation for a transmission scheme such as HSDPA in 3GPP. 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 according to the modulation scheme and the coding scheme. Therefore, the CQI needs to be changed according to the modulation scheme and the coding scheme, 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, a plurality of codewords are usually 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 CQI generation and transmission.

The UE measures the downlink quality and reports the selected CQI value to the base station through the uplink control channel. The BS performs downlink scheduling (UE selection, resource allocation, etc.) according to the reported CQI. Here, the CQI value includes a SINR, a Carrier to Interference and Noise Ratio (CINR), a Bit Error Rate (BER), a Frame Error Rate (FER) In the case of the MIMO system, RI (Rank Information) and PMI (Precoding Matrix Information) can be added as information reflecting the channel state.

The mobile communication system adjusts the MCS and the transmission power according to a given channel using link adaptation to maximize the channel capacity of the channel. In order to perform such link adaptation at the base station, the user must feed back the channel quality information to the base station.

If the frequency band used by the system exceeds the coherence bandwidth, the channel will show a sudden change within the bandwidth used. 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-carrier , And optimal channel transmission is that channel information for each subcarrier is transmitted. Therefore, in a multi-carrier system having a large number of sub-carriers, the amount of feedback of channel information is rapidly increased. Therefore, various methods have been proposed to reduce the control overhead of such control signals.

On the other hand, the number of CQIs increases the number of transmissions in various dimensions, resulting in a large overhead.

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, requiring two CQIs. If the CQI of one codeword is composed of N bits and the number of codewords is two, the CQI must be composed of a total of 2 * N bits. 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 corresponds to only one frequency band. If the receiving side selects a frequency band that exhibits the best channel state, transmits only the selected frequency, and the transmitting side performs the service through the frequency band selected in the CQI, the CQI is required in only 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 required. 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 selected user can not use the corresponding frequency band. Here, if each user transmits only one preferred frequency band, the users who are not selected before are blocked from the opportunity of 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.

We have looked at cases where multiple CQIs are needed in various dimensions. If multiple CQIs are needed, the concept of differential CQI (Delta 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. That is, a method similar to Differential Modulation in the modulation and demodulation method is used. 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 correct CQI.

On the other hand, in the next generation mobile communication system, a plurality of carriers (a plurality of frequency allocation bands (FAs)) are allocated to a specific layer above the physical layer in order to efficiently use multi-band or multi- A technology managed by a corresponding entity has been proposed.

2 (a) and 2 (b) are diagrams for conceptually explaining a method of transmitting and receiving a multi-band RF-based signal in terms of a transmitting side and a receiving side.

PHY n, PHY 1, PHY n-2 and PHY n-1 in FIG. 2A and FIG. 2B represent multi-bands according to the present invention. Each of the bands represents a specific service according to a predetermined frequency policy. (FA) size to allocate to the base station. For example, PHY0 (RF carrier 0) may have a size of a frequency band allocated for general FM radio broadcasting, and PHY1 (RF carrier 1) may have a frequency band size allocated for mobile communication. However, in the following description, in order to secure a wider system bandwidth in a next generation mobile communication system such as 3GPP LTE-A, a case where a system band of 20 MHz allocated for an existing system, for example, 3GPP LTE system, . As described above, each frequency band may have different frequency band sizes depending on the characteristics of the respective frequency bands. However, in the following description, it is assumed that each frequency band FA has a constant size for convenience of explanation. Each of the frequency allocation bands as described above avoids confusion with the concept of "multi-carrier" widely used in a system using a plurality of subcarriers as in the conventional OFDM-based communication system, May be referred to as a "Legacy System band" in view of using a plurality of system bands. In addition, each legacy system band may be represented by a carrier frequency for use in baseband signals in each frequency band, where each frequency band is referred to as a "carrier frequency band" Quot;

In order to transmit a signal through multiple bands as shown in FIG. 2 (a) and to receive signals through multiple bands as shown in FIG. 2 (b), all transmitters / receivers use an RF module . In Fig. 2, "MAC" is determined by the base station regardless of DL and UL.

Briefly, the present technique is based on the assumption that a given number of specific layer entities, in the example of FIG. 2, one MAC entity (hereinafter simply referred to as "MAC" And transmitting / receiving signals. Also, the RF carriers managed in a particular entity need not be contiguous with each other. Therefore, according to this technology, there is an advantage that it is more flexible in terms of resource management.

For example, the following frequency uses are assumed.

3 is a diagram illustrating an example of frequency allocation in a multi-band supporting communication method.

In Fig. 3, FA0 to FA7 can be managed by RF0 to RF7. In the example of FIG. 3, it is assumed that FA0, FA2, FA3, FA6, and FA7 are already allocated to existing specific communication services. On the other hand, it is assumed that available RF1 (FA1), RF4 (FA4), and RF5 (FA5) can be effectively managed by one MAC (MAC # 5). Here, since the RF carriers constituting one MAC may not be adjacent to each other as described above, frequency resources can be more effectively managed. However, the MAC for managing a plurality of RF carriers may be two or more as described above.

When the channel quality indicator is transmitted in a communication system using a plurality of carriers and a plurality of legacy system bands as described above, an increase in overhead due to channel quality indicator transmission is predicted. At present, there is no specific method for transmitting the channel quality indicator in a system using such a plurality of carriers, and it is necessary to specify a method for efficiently performing the method.

According to an aspect of the present invention, there is provided a method for efficiently transmitting a channel quality indicator in a system using a plurality of carriers.

According to an aspect of the present invention, there is provided a method for transmitting a channel quality indicator by a user equipment in a system that performs communication using a plurality of legacy system bands, Receiving a signal; And transmitting a channel quality indicator for each of the plurality of legacy system bands using the same channel quality indicator transmission mode for each legacy system band, wherein the channel quality indicator for each legacy system band is transmitted through an uplink shared channel When transmitting the entire channel quality indicator for each legacy system band and transmitting the channel quality indicator for each legacy system band through an uplink control channel, the channel quality indicator for each legacy system band is divided into a predetermined number And transmits the channel quality indicator in units of a predetermined number of channels.

According to another aspect of the present invention, there is provided a method of transmitting a channel quality indicator by a user equipment in a system that performs communication using a plurality of legacy system bands, Receiving a signal through a band; And transmitting a channel quality indicator for a predetermined number of legacy system bands of the plurality of legacy system bands, wherein the channel quality indicator for the specific number of legacy system bands is transmitted on an uplink shared channel Transmitting the entire channel quality indicator for the specific number of legacy system bands, transmitting a channel quality indicator for the specific number of legacy system bands through the uplink control channel, and transmitting the specific number of legacy system bands When the uplink control channel capacity is insufficient to transmit the entire channel quality indicator for the predetermined number of legacy system bands, the channel quality indicator for the predetermined number of legacy system bands is sequentially transmitted in units of a predetermined number. .

The channel quality indicator transmission method may further include receiving a control signal for requesting transmission of the channel quality indicator. When the channel quality indicator is transmitted after receiving the control signal, And may be transmitted on the uplink shared channel.

Also, in a transmission mode requiring transmission of a wideband channel quality indicator among the channel quality indicator transmission mode through the uplink shared channel or the uplink control channel, the channel quality indicator for each legacy system band is used as the wideband channel quality indicator Can be used.

In addition, the method may further include transmitting information on the predetermined number of legacy system bands in the method of selecting a predetermined number of legacy system bands and transmitting the channel quality indicator. In this case, the information on the selected legacy system band may be transmitted in bitmap format or may be transmitted directly to each legacy system band.

In addition, a method of selecting a preferred number of legacy system bands and transmitting a channel quality indicator is provided. The channel quality indicator for a legacy system band not selected as a preferred number of legacy system bands among the plurality of legacy system bands, May be transmitted in the form of a wideband channel quality indicator on a predetermined cycle basis.

According to the channel quality indicator transmission method according to each embodiment of the present invention as described above, system performance can be improved by minimizing the performance degradation of the scheduler while minimizing overhead in a system using a plurality of legacy system bands .

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.

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, an embodiment of the present invention proposes a method of efficiently generating and transmitting a CQI in a system for transmitting a signal using a plurality of carriers. In a system for transmitting using a plurality of carriers, an independent control signal can be transmitted for each carrier.

FIG. 4 shows an example of configuring a wideband system using five carriers.

For example, assuming that the 20 MHz band is transmitted on one carrier in FIG. 4, 100 MHz can be transmitted using five carriers, and an independent control signal can be transmitted every 20 MHz. Such a system can be easily implemented by simply expanding the control channel designed for the 20 MHz system. However, when considering CQI transmission, CQI / PMI / RI must be independently transmitted every 20 MHz, so that the amount of control information increases in proportion to the number of carriers used. It is difficult to efficiently use the system resources since many resources must be allocated to transmit them.

In order to efficiently support the scheduling operation, it is required to report channel information of a band corresponding to all carriers. Although the following description can be applied to both the downlink and the uplink, a CQI transmission method for downlink data transmission will be described as an example.

First, in an embodiment of the present invention, a method of transmitting all the channel information of each carrier is proposed. In a system using N carriers, a CQI corresponding to a band of each carrier may be transmitted through an uplink shared channel or an uplink control channel. In the case of a 3GPP LTE system, a CQI may be transmitted on a PUSCH or a PUCCH.

At this time, in the present embodiment, it is assumed that the CQI generation method used in the system is applied to all the carriers using only one. Here, the CQI generation method may be differently defined according to the channel type for CQI transmission, and various CQI transmission modes may exist in each channel.

Various methods that can be used for CQI generation and transmission are described below.

As the amount of channel transmission increases, the following method can be used as a generation method for reducing the amount of information of the channel quality indicator in order to reduce the waste of the control signal.

First, it is a method of changing the unit of channel information transmission. For example, channel information transmitted for each subcarrier in an orthogonal multi-carrier scheme (OFDM) is grouped into a plurality of subcarriers, and channel information is transmitted on a per group basis. That is, when 12 subcarriers are grouped into a single subcarrier group in an orthogonal multi-carrier scheme using 600 subcarriers, a total of 50 subcarrier groups are formed, so that the actual amount of channel information is reduced from 600 to 50 do.

In the following description, when a frequency band is divided into integer sub-carriers such as an orthogonal multi-carrier scheme (OFDM), one or a plurality of sub-carriers are grouped into one group and divided into sub- (CQI subcarrier group) or a CQI subband (CQI subband). If the frequency bands are not divided as in each subcarrier, the entire frequency band is divided into a plurality of frequency bands, and the CQI is generated on the basis of the divided frequency bands. The frequency bands divided for generating the CQI are divided into CQI Subband.

Secondly, the channel quality indicator is generated by compressing the channel information. For example, in the orthogonal multi-carrier scheme, channel information for each subcarrier is compressed using a compression scheme and transmitted. As the compression method, methods such as DCT (Discrete Cosine Transform) may be considered.

Third, it is a method of generating a CQI by selecting a corresponding frequency band for generating channel information. For example, in the orthogonal multi-carrier scheme, not the channel information is transmitted for every sub-carrier, but a Best-M scheme for selecting and transmitting the best M sub-carrier or sub-carrier group.

When transmitting the CQI that selects and transmits 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.

5 is a diagram illustrating techniques for selecting a CQI subband in the frequency domain to generate a CQI.

The frequency - selective CQI scheme consists of three parts. The first is a method of selecting a frequency band for generating a CQI, that is, a CQI subband. And the second is a method of generating and transmitting CQI values of the selected frequency bands by manipulation. And the third is a method of transmitting the index of the selected frequency band, i.e., CQI subbands.

In FIG. 5, Best-M and Threshold-based methods are cited as examples of how to select the CQI subband first. The Best-M scheme is a method of selecting M CQI subbands having good channel states. In the example of FIG. 5, the best-3 scheme is used to select CQI subbands of indexes 5, 6 and 9 with good channel conditions . In addition, the threshold-based scheme selects a CQI subband having a channel state higher than a predetermined threshold. In this case, a CQI subband with indexes 5 and 6 higher than the threshold is selected.

Meanwhile, as an example of a method of generating and transmitting CQI values, an individual transmission method and an average transmission method are described. The individual transmission method is a method of transmitting all the CQI values of the CQI subband selected in the first step. Therefore, in the individual scheme, as the number of the selected CQI subbands increases, the number of CQI values to be transmitted also increases. Meanwhile, the average transmission method is a method of transmitting an average value of the 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. In the average transmission method, the average value may be an arithmetic average or an average considering the channel capacity.

Third, examples of a method of transmitting an index of a CQI subband include a bitmap index scheme and a general combination index scheme. The bitmap index scheme refers to a method of allocating one bit for every CQI subband and indicating which CQI subband is used by assigning 1 when the corresponding CQI subband is used and 0 when not used. do. This bitmap indexing scheme can be represented by a constant number of bits, regardless of how many CQI subbands are used, while requiring as many bits as the total CQI subband.

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 a total of N CQI subbands and M CQI subbands are used among the N, then the total number of possible combinations is the same as in the following case.

Figure 112008073902733-pat00001

The number of bits for expressing the number in the case of Equation (1) can be determined as follows.

Figure 112008073902733-pat00002

In the example of FIG. 5, since three CQI subbands are selected from 11 CQI subbands in total, the number of possible CQI subbands is 165 (= 11 C 3 ), and the number of bits for representing 165 CQI subbands is 8 to be

Figure 112008073902733-pat00003
.

A transmission mode that can be used for CQI transmission will be described in more detail as follows.

Scheduling method Periodic CQI transmission Nonperiodic CQI transmission Frequency non-selective PUCCH - Frequency selective PUCCH PUSCH

As shown in Table 1, the CQI may be transmitted using a physical uplink control channel (PUCCH) at a period determined by an upper layer, or may be periodically transmitted using a physical uplink shared channel (PUSCH) Lt; / RTI > When the CQI is transmitted on the PUSCH, it is possible to select only the frequency.

Hereinafter, the case of transmitting the CQI according to the CQI transmission request and the case of periodically transmitting the CQI will be described separately.

1) Transmission of CQI / PMI / RI through PUSCH after receiving CQI transmission request control signal

In this case, a control signal requesting transmission of the CQI is received. Table 2 below shows the mode when CQI / PMI / RI is transmitted through PUSCH.


PMI feedback type
PMI non-transfer
Single PMI Multiple PMI
PUSCH CQI feedback type Wideband
(Broadband CQI)


Mode 1-2
UE Select (UE Selected)
(Subband CQI)
Mode 2-0

Mode 2-2
Higher layer-configured
(Subband CQI)
Mode 3-0
Mode 3-1

The transmission mode of Table 2 is selected in an upper layer, and CQI / PMI / RI are all transmitted through the same PUSCH sub-frame.

Each transmission mode will be described below.

First, "Mode 1-2" selects a precoding matrix on the assumption that data is transmitted through only the corresponding subband for each subband. The terminal generates the CQI by assuming the precoding matrix selected in advance for the system band or the whole band (set S) designated by the upper layer. The UE transmits the CQI and the PMI value of each subband. The size of each subband may vary depending on the size of the system band.

Next, in "Mode 2-0 ", the UE selects the M subbands preferred for the system band or the band (set S) specified by the higher layer. The terminal generates one CQI value on the assumption that it transmits data for the selected M subbands. The terminal additionally generates one CQI (Wideband CQI) value for the system band or set S. When there are a plurality of codewords for the selected M subbands, a CQI value for each codeword is defined as a differential format. At this time, the difference CQI can be a value obtained by subtracting the wideband CQI index from the index corresponding to the CQI value for the selected M subbands. The terminal transmits information on the location of the selected M subbands, one CQI value for the selected M subbands, and the CQI value generated for the entire band or set S. At this time, the size and the M value of the subband can be changed according to the size of the system band.

Next, in "Mode 2-2 ", the UE simultaneously selects a single precoding matrix for M preferred subbands and M preferred subbands on the assumption that data is transmitted through M preferred subbands. The CQI values for the M preferred subbands are defined per codeword. The terminal additionally generates a wideband CQI value for the system band or set S. In addition, the terminal transmits information on the positions of M preferred subbands, one CQI value for the selected M subbands, a single precoding matrix index for M preferred subbands, and a wideband CQI value. At this time, the subband size and the M value may vary depending on the size of the system band.

Also, in "Mode 3-0 ", the terminal generates a wideband CQI value. The terminal generates a CQI value for each subband on the assumption that data is transmitted through each subband. In this case, even if RI> 1, the CQI value represents only the CQI value for the first codeword.

Finally, in "Mode 3-1", a single precoding matrix is generated for the system band or set S. The terminal assumes a single precoding matrix generated for each subband and generates a subband CQI for each codeword. In addition, the terminal assumes a single precoding matrix and generates a wideband CQI. The CQI values of each subband are expressed in a differential format. In addition, the size of the subbands may vary depending on the size of the system band.

2) Transmission of CQI / PMI / RI periodically via PUCCH

In this case, the CQI information is periodically transmitted through the PUCCH. When the control signal for transmitting the user data is received, the CQI can be transmitted through the PUSCH. PUSCH, the CQI / PMI / RI contents are generated and transmitted by one of the transmission modes defined in Table 3 below.

PMI feedback type PMI non-transfer
Single PMI
PUCCH CQI feedback type Wideband
(Broadband CQI)
Mode 1-0
Mode 1-1
UE Select (UE Selected)
(Subband CQI)
Mode 2-0
Mode 2-1

In the case of Mode 2-0 and Mode 2-1 in Table 3, the BP (bandwidth part) is a set of subbands located consecutively in the frequency domain, and can cover the system band or the set S. The size of each subband, the size of the BP, and the number of BPs may vary depending on the size of the system band. Also, CQIs are transmitted in ascending order in the frequency domain for each BP so as to cover the system band or set S.

In this type of CQI transmission, there are four transmission types according to transmission combinations of CQI / PMI / RI as follows.

(1) Type 1: Transmit the subband CQI of Mode 2-0, Mode 2-1.

(2) Type 2: Broadband CQI and PMI are transmitted.

(3) Type 3: RI is transmitted.

(4) Type 4: Broadband CQI is transmitted.

When RI and wideband CQI / PMI are transmitted, they are transmitted in subframes having different periods and offsets. When RI and wideband CQI / PMI are to be transmitted in the same subframe, CQI / PMI is not transmitted.

Among the transmission schemes, the transmission period of the wideband CQI / PMI and the subband CQI is P, and has the following characteristics.

The broadband CQI / PMI has a period of H * P. At this time, H = J * K + 1, J is the number of BP (bandwidth parts), and K is the total number of cycles of BP. That is, the wideband CQI / PMI is transmitted in {0, H, 2H, ...}. In addition, the J * K time point other than the time of transmitting the wideband CQI / PMI transmits the subband CQI.

The transmission period of RI is M times the broadband CQI / PMI period and has the following characteristics.

The offset of RI and broadband CQI / PMI is O. Broadband CQI / PMI is not transmitted when RI and broadband CQI / PMI are transmitted in the same subframe. All the above parameters P, H, K, and O are determined and signaled by the upper layer.

Each of the transmission modes shown in Table 3 will be described below.

First, when an RI is transmitted in "Mode 1-0", an RI is generated for a system band or set S, and the RI is transmitted through a type 3 report. When transmitting a CQI, it transmits a wideband CQI.

Next, when transmitting an RI in "Mode 1-1", RI is generated for system band or set S, and report of type 3 is transmitted. When transmitting the CQI / PMI, a single precoding matrix is selected assuming the most recently transmitted RI. A Type 2 report comprising a wideband CQI, a single precoding matrix, and a differential wideband CQI.

Next, when transmitting the RI in "Mode 2-0", the RI is generated for the system band or set S, and the type 3 report is transmitted. When a broadband CQI is transmitted, a broadband CQI is generated assuming the most recently transmitted RI, and a type 4 report is transmitted. When transmitting a CQI for a selected subband, the UE selects the most preferred subband for J BPs composed of N subbands, and transmits a Type 1 report. Type 1 reporting may require one or more subframes depending on the BP.

Finally, when transmitting an RI in "Mode 2-1", it creates an RI for the system band or set S, and sends a Type 3 report. When a broadband CQI is transmitted, a broadband CQI is generated assuming the most recently transmitted RI, and a type 4 report is transmitted. If the CQI for the selected subbands is transmitted, the UE calculates a single CQI value for the selected subbands in the BP, assuming the most recently transmitted PMI / RI for the J BPs composed of Nj, It is assumed that a single precoding matrix is used for the most recently transmitted RI and the selected subband, and the CQI difference of the codeword is generated and transmitted using the Type 1 report.

Each of the CQI transmission modes and types described above may be referred to differently depending on the system, and the name of the transmission mode described above may be expressed using another term indicating the same / similar transmission mode.

Among the various CQI transmission methods, the CQI transmission method used in the present embodiment proposes that each CQI for the entire carrier band is transmitted using the same transmission scheme for each carrier band. For example, if the CQI is generated using the Mode 1 - 2 among the CQI transmission modes for the PUSCH in the first carrier, it is assumed that Mode 1-2 is used among the CQI transmission modes for the PUSCH in all other carriers. Here, the CQI generation method may be defined differently for the case of transmitting the CQI after receiving the CQI transmission request and the method of periodically transmitting the CQI.

In the following description, the CQI corresponding to the j-th carrier is denoted as CQI j , and the CQI of the system corresponding to N carriers is denoted as {CQI 1 , .., CQI N }.

First, a case in which transmission is performed using a PUSCH after receiving a CQI transmission request control signal will be described.

In this embodiment, by using the specific CQI generation method selected from the Mode 1-2, Mode 2-0, Mode 2-2, Mode 3-0, and Mode 3-1, which is the CQI transmission mode through the PUSCH, It is proposed that all CQIs of the system corresponding to the entire carrier are transmitted using the PUSCH after the CQI is generated. In this case, the wideband CQI / PMI is a CQI / PMI value corresponding to the band of the carrier. RI may be a value corresponding to the corresponding carrier band or a value corresponding to the entire carrier band.

Next, a case in which the CQI is periodically transmitted using the PUCCH will be described.

In the present embodiment, a CQI corresponding to each carrier is generated using a CQI generation method selected from among Mode 1-0, Mode 1-1, Mode 2-0, and Mode 2-1, which is a CQI transmission mode through a PUCCH, Thereby generating the CQI of the system corresponding to the entire carrier. However, when the CQI is transmitted using the PUCCH, all CQIs may not be transmitted at one time because the amount of CQIs that can be transmitted at one transmission time is restricted. Therefore, in the present embodiment, it is possible to set the CQI of each carrier to be sequentially transmitted. That is, each CQI can be sequentially transmitted from CQI 1 at each transmission time with respect to the entire CQIs of {CQI 1 , ..., CQI N }. At this time, transmission of the CQI j (j = 1, ..., N) can follow the transmission methods of Mode 1-0, Mode 1-1, Mode 2-0, and Mode 2-1.

Meanwhile, another embodiment of the present invention proposes a method of selecting a preferred specific carrier band among a plurality of carrier bands and transmitting the CQI.

That is, in the case of a system using N carriers, it is desirable to secure a CQI corresponding to the entire carrier band for scheduling. However, in order to transmit them, resources should be allocated in proportion to the number of carriers. In order to reduce this, if a preferred carrier band is selected and the CQI corresponding to the selected carrier band is transmitted, resources for control signal transmission can be efficiently utilized. That is, it is proposed to transmit information on the preferred carrier L, {CQI b1 , .., CQI bL } among the entire CQI, {CQI 1 , ..., CQI N }. At this time, it is assumed that N is equal to or greater than bL.

Meanwhile, in the CQI transmission method according to the present embodiment, it is also proposed to define the CQI transmission method according to whether or not to transmit the CQI after receiving the control signal for the CQI transmission request as follows.

First, a method of transmitting a CQI transmission request signal using a PUSCH after receiving the CQI transmission request control signal will be described. And transmits the CQIs for the selected L carrier bands, i.e., {CQI b1 , ..., CQI bL }, all at one transmission time through the PUSCH. In this case, the generation of the wideband CQI / PMI means a CQI / PMI value corresponding to only the band of the selected corresponding carrier.

On the other hand, it is a principle that the CQIs related to the carrier band (s) other than the selected L carriers are basically not transmitted, but it is possible to partially transmit the CQI information for the band corresponding to the carrier which is not additionally selected. At this time, it is proposed to transmit a wideband CQI / PMI value as the partial CQI information.

On the other hand, RI may be a value corresponding to the corresponding carrier band or a value corresponding to the entire carrier band. In this case, transmission of the CQI j (j = b1, ..., bL) is performed by one of PUSCH transmission modes Mode 1-2, Mode 2-0, Mode 2-2, Mode 3-0, You can choose to use it.

Next, a method of periodically transmitting the CQI using the PUCCH will be described.

CQIs for selected L carriers {CQI b1 , ..., CQI bL } are transmitted through the PUCCH. At this time, transmission of the CQI j (j = b1, ..., bL) can be selected by using one of the PUCCH transmission modes Mode 1-0, Mode 1-1, Mode 2-0, and Mode 2-1 .

Also in this embodiment, although it is a principle that CQIs relating to the carrier band (s) other than the L carriers selected are basically not transmitted, it is a principle to partially transmit CQI information for a band corresponding to a carrier which is not additionally selected It is possible. At this time, it is proposed to transmit a wideband CQI / PMI value as the partial CQI information.

When the CQI is transmitted using the PUCCH, the amount of the CQI that can be transmitted at one transmission time is restricted, so that all the information of the selected CQI may not be transmitted at one time. If all the CQIs can not be transmitted at once, the CQI is divided and transmitted several times. At this time, the positions of the L carriers selected at the beginning are divided by the entire CQI, and are fixed without changing during the transmission time.

As an example, it is possible to transmit the CQI of the selected carrier in order. That is, it is proposed to sequentially transmit {CQI b1 , ..., CQI bL } from CQI b1 . Additionally, information about the location of the selected carrier can be additionally transmitted.

As another example, it is also possible to consider a method of transmitting the CQIs of the selected carriers evenly over several time periods. That is, a part of each CQI can be transmitted for each {CQI b1 , ..., CQI bL }.

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.

The channel quality indicator transmission method according to each embodiment of the present invention as described above can be applied to various next generation mobile communication systems using a plurality of carrier bands (a plurality of legacy system bands).

1 is a conceptual diagram of CQI generation and transmission.

2 (a) and 2 (b) are diagrams for conceptually explaining a method of transmitting and receiving a multi-band RF-based signal in terms of a transmitting side and a receiving side.

3 is a diagram illustrating an example of frequency allocation in a multi-band supporting communication method.

FIG. 4 shows an example of configuring a wideband system using five carriers.

5 is a diagram illustrating techniques for selecting a CQI subband in the frequency domain to generate a CQI.

Claims (13)

  1. A method for transmitting a channel quality indicator by a user equipment in a system for performing communication using a plurality of carriers,
    Selecting a number of carriers that is one or more than a total number of carriers among a plurality of carriers;
    Selecting one generation mode from a plurality of CQI generation modes;
    Generating first CQIs corresponding to each of the selected carriers using the selected generation mode;
    Generating a second CQI corresponding to at least one of the unselected carriers using a wideband CQI generation mode; And
    And transmitting the first CQI corresponding to each of the selected carriers and the second CQI corresponding to at least one of the unselected carriers to the base station through an uplink shared channel or an uplink control channel,
    When the first and second CQIs are transmitted aperiodically, the first and second CQIs are combined and transmitted,
    Wherein when the first and second CQIs are periodically transmitted, the first and second CQIs are transmitted in different subframes.
  2. The method according to claim 1,
    Further comprising receiving a control signal requesting transmission of the first CQI if the first and second CQIs are transmitted aperiodically,
    Wherein the first and second CQIs are combined and transmitted after the control signal is received.
  3. delete
  4. delete
  5. delete
  6. delete
  7. delete
  8. delete
  9. The method according to claim 1,
    If the first and second CQIs are transmitted aperiodically, transmitting a rank indicator together with the combined first and second CQIs.
  10. 10. The method of claim 9,
    Wherein the rank indicator comprises a value corresponding to a particular carrier among the plurality of carriers.
  11. 11. The method of claim 10,
    Wherein the rank indicator comprises a value corresponding to all of the plurality of carriers.
  12. The method according to claim 1,
    Wherein when the first and second CQIs are transmitted aperiodically, the combined first and second CQIs are transmitted on an uplink shared channel.
  13. The method according to claim 1,
    Wherein when the first and second CQIs are transmitted periodically, the first and second CQIs corresponding to the plurality of carriers are transmitted on an uplink control channel.
KR1020080104649A 2008-08-13 2008-10-24 Method For Transmitting Channel Quality Indicator KR101556142B1 (en)

Priority Applications (2)

Application Number Priority Date Filing Date Title
US8870708P true 2008-08-13 2008-08-13
US61/088,707 2008-08-13

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US12/461,253 US20100041344A1 (en) 2008-08-13 2009-08-05 Method for transmitting channel quality indicators

Publications (2)

Publication Number Publication Date
KR20100020884A KR20100020884A (en) 2010-02-23
KR101556142B1 true KR101556142B1 (en) 2015-09-30

Family

ID=42091537

Family Applications (1)

Application Number Title Priority Date Filing Date
KR1020080104649A KR101556142B1 (en) 2008-08-13 2008-10-24 Method For Transmitting Channel Quality Indicator

Country Status (1)

Country Link
KR (1) KR101556142B1 (en)

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2013062363A1 (en) * 2011-10-27 2013-05-02 엘지전자 주식회사 Method and apparatus for managing quality of service of uplink in wireless communication system

Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20070026810A1 (en) 2005-08-01 2007-02-01 Love Robert T Channel quality indicator for time, frequency and spatial channel in terrestrial radio access network

Patent Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20070026810A1 (en) 2005-08-01 2007-02-01 Love Robert T Channel quality indicator for time, frequency and spatial channel in terrestrial radio access network

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
표준문서(3GPP TS 36.213 V8.3.0 ,2008-05.)

Also Published As

Publication number Publication date
KR20100020884A (en) 2010-02-23

Similar Documents

Publication Publication Date Title
US8116262B2 (en) Methods and systems for enabling feedback in wireless communication networks
US10051613B2 (en) Method for transmitting channel state information in wireless access system
US8792834B2 (en) Communication scheme for channel quality information
KR101481166B1 (en) Method for transmitting feedback data in multiple antenna system
CN102356580B (en) Configuration information for periodic feedback transmission on a physical uplink shared channel (PUSCH) of
JP4384223B2 (en) Method for allocating subchannels in orthogonal frequency division multiple access cellular communication systems
US8509161B2 (en) Systems and methods for OFDMA and SC-FDMA switching
KR101548338B1 (en) Methods and systems for conveying scheduling information of overlapping co-scheduled users in an ofdma-mu-mimo system
EP2135398B1 (en) Method and apparatus for transmission within a multi-carrier communication system
US8811353B2 (en) Rank and PMI in download control signaling for uplink single-user MIMO (UL SU-MIMO)
JP5130592B2 (en) Method and apparatus for providing channel quality and precoding metric feedback in an orthogonal frequency division multiplexing communication system
KR101094575B1 (en) Downlink control channel signaling in wireless communication systems
US8457235B2 (en) Method of transmitting feedback data in multiple antenna system
CN101606339B (en) A method and apparatus for achieving transmit diversity and spatial multiplexing using antenna selection based on feedback information
CN101615984B (en) Method and device of periodic CQI feedback under carrier polymerization
KR101357936B1 (en) Uplink feedback channel reporting mechanism in wireless systems
JP5714608B2 (en) Method and system for enabling resource block bundling in an LTE advanced system
US8184544B2 (en) Method of transmitting feedback data in a multiple antenna system
US20120099452A1 (en) Method, Terminal and Network System for Reporting Buffer Status Report
RU2433536C2 (en) Efficient uplink feedback in wireless communication system
JP2014060772A (en) Transmitting uplink control information over data channel or over control channel
EP2129159B1 (en) Base station, communication terminal, transmission method, and reception method for resource block scheduling
KR101587680B1 (en) Carrier aggregation
WO2011043328A1 (en) Wireless base station device, mobile terminal device and wireless communication method
US20100227565A1 (en) Transmission of channel quality data in wireless communication systems

Legal Events

Date Code Title Description
A201 Request for examination
E902 Notification of reason for refusal
E701 Decision to grant or registration of patent right
GRNT Written decision to grant
FPAY Annual fee payment

Payment date: 20180814

Year of fee payment: 4