KR102425065B1 - Method and apparatus for csi measurement and reporting in wireless communication system - Google Patents

Abstract

The present disclosure relates to a communication technique that converges a 5G communication system for supporting a higher data rate after a 4G system with IoT technology, and a system thereof. The present disclosure provides intelligent services (eg, smart home, smart building, smart city, smart car or connected car, healthcare, digital education, retail business, security and safety related services, etc.) based on 5G communication technology and IoT-related technology. ) can be applied to The present invention discloses a method for supporting repeated CSI-RS resource transmission in a mobile communication system.

Description

Method and apparatus for measuring and reporting channel state information in mobile communication system {METHOD AND APPARATUS FOR CSI MEASUREMENT AND REPORTING IN WIRELESS COMMUNICATION SYSTEM}

Unlike the existing LTE, NR (New Radio), a new 5G communication, communicates based on a beam. This is because NR supports a band of 6 GHz or higher, which is higher than the existing LTE band, and since there are not many existing systems in this band, more bands can be secured. However, in order to support a band of 6 GHz or higher, unlike the band used in the existing LTE, many things must be considered, and one of them is pathloss as the band increases. As the band used for wireless communication increases, the path attenuation occurring in the corresponding band increases, and according to the path attenuation, the coverage supported by the corresponding base station decreases when based on the same transmission power. Therefore, in order to overcome such path attenuation, it is necessary to support a beam that transmits the transmission power by concentrating the transmission power in the direction that the base station wants to transmit. A method is needed to select and manage it. To this end, the UE reports channel state and beam management related information based on CRI and L1-RSRP. For this, a definition of reporting priority is required.

Efforts are being made to develop an improved 5G communication system or pre-5G communication system in order to meet the increasing demand for wireless data traffic after commercialization of the 4G communication system. For this reason, the 5G communication system or the pre-5G communication system is called a system after the 4G network (Beyond 4G Network) communication system or the LTE system after (Post LTE). In order to achieve a high data rate, the 5G communication system is being considered for implementation in a very high frequency (mmWave) band (eg, such as a 60 gigabyte (60 GHz) band). In order to alleviate the path loss of radio waves and increase the propagation distance of radio waves in the very high frequency band, in the 5G communication system, beamforming, massive MIMO, and Full Dimensional MIMO (FD-MIMO) are used. ), array antenna, analog beam-forming, and large scale antenna technologies are being discussed. In addition, for network improvement of the system, in the 5G communication system, an evolved small cell, an advanced small cell, a cloud radio access network (cloud radio access network: cloud RAN), an ultra-dense network (ultra-dense network) , Device to Device communication (D2D), wireless backhaul, moving network, cooperative communication, Coordinated Multi-Points (CoMP), and interference cancellation Technology development is underway. In addition, in the 5G system, the advanced coding modulation (ACM) methods FQAM (Hybrid FSK and QAM Modulation) and SWSC (Sliding Window Superposition Coding), and advanced access technologies FBMC (Filter Bank Multi Carrier), NOMA (non orthogonal multiple access), and sparse code multiple access (SCMA) are being developed.

On the other hand, the Internet is evolving from a human-centered connection network where humans create and consume information to an Internet of Things (IoT) network that exchanges and processes information between distributed components such as objects. Internet of Everything (IoE) technology, which combines big data processing technology through connection with cloud servers, etc. with IoT technology, is also emerging. In order to implement IoT, technology elements such as sensing technology, wired and wireless communication and network infrastructure, service interface technology, and security technology are required. , M2M), and MTC (Machine Type Communication) are being studied. In the IoT environment, an intelligent IT (Internet Technology) service that collects and analyzes data generated from connected objects and creates new values in human life can be provided. IoT is a field of smart home, smart building, smart city, smart car or connected car, smart grid, health care, smart home appliance, advanced medical service, etc. can be applied to

Accordingly, various attempts are being made to apply the 5G communication system to the IoT network. For example, technologies such as sensor network, machine to machine (M2M), and MTC (Machine Type Communication) are implemented by 5G communication technologies such as beamforming, MIMO, and array antenna. will be. The application of a cloud radio access network (cloud RAN) as the big data processing technology described above is an example of the convergence of 5G technology and IoT technology.

Unlike the existing LTE, NR (New Radio), a new 5G communication, communicates based on a beam. This is because NR supports a band of 6 GHz or higher, which is higher than the existing LTE band, and since there are not many existing systems in this band, more bands can be secured. However, in order to support a band of 6 GHz or higher, unlike the band used in the existing LTE, many things must be considered, and one of them is pathloss as the band increases. As the band used for wireless communication increases, the path attenuation occurring in the corresponding band increases, and according to the path attenuation, the coverage supported by the corresponding base station decreases when based on the same transmission power. Therefore, in order to overcome such path attenuation, it is necessary to support a beam that transmits the transmission power by concentrating the transmission power in the direction that the base station wants to transmit. A method is needed to select and manage it. To this end, the UE reports channel state and beam management related information based on CRI and L1-RSRP. For this, a definition of reporting priority is required.

Unlike the existing LTE, NR (New Radio), a new 5G communication, communicates based on a beam. This is because NR supports a band of 6 GHz or higher, which is higher than the existing LTE band, and since there are not many existing systems in this band, more bands can be secured. However, in order to support a band of 6 GHz or higher, unlike the band used in the existing LTE, many things must be considered, and one of them is pathloss as the band increases. As the band used for wireless communication increases, the path attenuation occurring in the corresponding band increases, and according to the path attenuation, the coverage supported by the corresponding base station decreases when based on the same transmission power. Therefore, in order to overcome such path attenuation, it is necessary to support a beam that transmits the transmission power by concentrating the transmission power in the direction that the base station wants to transmit. A method is needed to select and manage it. To this end, the UE reports channel state and beam management related information based on CRI and L1-RSRP. For this, a definition of reporting priority is required.

The present invention for solving the above problems is a control signal processing method in a wireless communication system, the method comprising: receiving a first control signal transmitted from a base station; processing the received first control signal; and transmitting a second control signal generated based on the processing to the base station.

As described above, the present invention proposes a reporting priority required when reporting channel state and beam management related information based on UE DL CRI and L1-RSRP.

1 is a diagram illustrating a radio resource configuration of an LTE system.
2 is a diagram illustrating feedback timings of RI and wCQI in the case of N _pd =2, M _RI =2, N _OFFSET,CQI =1, N _OFFSET,RI =-1.
3 shows RI, sCQI, wCQI feedback timing for the case of N _pd =2, M _RI =2, J = 3 (10 MHz), K = 1, N _{OFFSET, CQI} = 1, N _{OFFSET, RI} = -1. It is a drawing showing.
4 shows PTI = 0 for the case of N _pd =2, M _RI =2, J = 3 (10 MHz), K = 1, H' = 3, N _{OFFSET, CQI} = 1, N _{OFFSET, RI} = -1 It is a diagram showing the feedback timing in the case of .
5 shows PTI = 1 for the case of N _pd =2, M _RI =2, J = 3 (10 MHz), K = 1, H' = 3, N _{OFFSET, CQI} = 1, N _{OFFSET, RI} = -1 It is a diagram showing the feedback timing in the case of .
6 is a diagram illustrating periodic channel state reporting supported by UEs in which CSI-RSs of 12 or more ports are configured in Rel-13 and Rel-14.
7 is a diagram illustrating a radio resource configuration of data such as eMBB, URLLC, and mMTC in the NR system.
8 is a diagram showing an embodiment in which a synchronization signal is transmitted in the 5G communication system under consideration in the present invention.
9 is a diagram showing an embodiment in which a PBCH is transmitted in the 5G communication system under consideration in the present invention.
10 is a diagram exemplifying assuming that each service is multiplexed in time and frequency resources in the NR system.
11 is a diagram illustrating that the base station and the terminal allow flexible configuration through resource configuration, CSI report configuration, and CSI measurement configuration in NR, and channel state reporting operates based on this.
12 is a diagram illustrating a method of triggering a link in a trigger measurement setting according to the aperiodic channel state report triggering method 1;
13 is a diagram illustrating an instruction order of a bitmap for aperiodic channel state report trigger method 1;
14 is a diagram illustrating a method of triggering a channel status report setup in a trigger measurement setup according to aperiodic channel status report triggering method 2;
15 is a diagram illustrating an indication order of a bitmap for aperiodic channel state report triggering method 2;
16 is a diagram illustrating indirectly indicating an aperiodic CSI-RS using the aperiodic CSI-RS indication field.
17 is a diagram illustrating hybrid beamforming.
18 is a diagram illustrating beam sweeping operations of a terminal and a base station in time resources.
19 is a diagram illustrating transmission of a long PUCCH having a long period.
20 is a diagram exemplifying assuming a situation when a short PUCCH (format 2) and a long PUCCH (format 4) collide.
21 illustrates an operation based on hybrid CSI in which NP CSI-RS and UE specific BF CSI-RS are combined.
22 illustrates an operation based on hybrid CSI in which cell specific CSI-RS and UE specific BF CSI-RS are combined.
23 is a diagram illustrating that interference resources are configured for each CSI-RS resource for channel measurement.
24 is a diagram illustrating that a plurality of interference resources are configured in a CSI-RS resource for channel measurement.
25 is a diagram illustrating a process in which the UE calculates the total interference by summing the interference measured from a plurality of interference resources.
26 is a flowchart illustrating an operation of a base station in the present invention.
27 is a flowchart illustrating an operation of a terminal in the present invention.
28 is a block diagram illustrating an internal structure of a terminal according to an embodiment of the present invention.
29 is a block diagram illustrating an internal structure of a base station according to an embodiment of the present invention.

The present invention relates to a general wireless mobile communication system, and in particular, a reference signal in a wireless mobile communication system to which a multiple access scheme using a multi-carrier such as OFDMA: Orthogonal Frequency Division Multiple Access is applied. It is about how to map Signal).

The current mobile communication system is developing into a high-speed, high-quality wireless packet data communication system to provide data services and multimedia services, away from the initial voice-oriented service provision. To this end, various standardization organizations such as 3GPP, 3GPP2, and IEEE are working on the 3rd generation evolutionary mobile communication system standard applying multiple access method using multi-carrier. Recently, various mobile communication standards such as 3GPP's Long Term Evolution (LTE), 3GPP2's Ultra Mobile Broadband (UMB), and IEEE's 802.16m have provided high-speed, high-quality wireless packet data transmission services based on multiple access methods using multi-carriers. was developed to support

Existing 3rd generation mobile communication systems such as LTE, UMB, and 802.16m are based on the multi-carrier multiple access method, and to improve transmission efficiency, Multiple Input Multiple Output (MIMO, multiple antennas) is applied and beam- It has the characteristics of using various techniques such as forming (beamforming), Adaptive Modulation and Coding (AMC, adaptive modulation and coding) method, and channel sensitive (channel sensitive) scheduling method. The above various technologies improve transmission efficiency through methods such as concentrating transmission power transmitted from multiple antennas or adjusting the amount of transmitted data according to channel quality, and selectively transmitting data to users with good channel quality. Improve system capacity performance. Since most of these techniques operate based on channel state information between a base station (eNB: evolved Node B, BS: Base Station) and a UE (User Equipment, MS: Mobile Station), the eNB or UE is a base station and a terminal. It is necessary to measure the channel state between the two, and in this case, a Channel Status Indication reference signal (CSI-RS) is used. The aforementioned eNB means a downlink transmission and uplink reception device located at a predetermined place, and one eNB performs transmission/reception for a plurality of cells. In one mobile communication system, a plurality of eNBs are geographically distributed, and each eNB performs transmission/reception for a plurality of cells.

Existing 3G and 4G mobile communication systems such as LTE/LTE-A utilize MIMO technology that transmits using a plurality of transmit/receive antennas to increase data rates and system capacity. The MIMO technology uses a plurality of transmit/receive antennas to spatially separate and transmit a plurality of information streams. In this way, spatially separating and transmitting a plurality of information streams is called spatial multiplexing. In general, the number of information streams to which spatial multiplexing can be applied depends on the number of antennas of the transmitter and receiver. In general, the number of information streams to which spatial multiplexing can be applied is called the rank of the transmission. In the case of MIMO technology supported by standards up to LTE/LTE-A Release 11, spatial multiplexing is supported when there are 16 transmit antennas and 8 receive antennas, and a rank of up to 8 is supported.

In the case of NR (New Radio access technology), a 5G mobile communication system currently being discussed, the design goal of the system is to support various services such as eMBB, mMTC, and URLLC mentioned above. The time and frequency resources can be flexibly transmitted by minimizing the reference signal that is used and allowing the transmission of the reference signal to be transmitted aperiodically.

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

In describing the embodiments, descriptions of technical contents that are well known in the technical field to which the present invention pertains and are not directly related to the present invention will be omitted. This is to more clearly convey the gist of the present invention by omitting unnecessary description.

For the same reason, some components are exaggerated, omitted, or schematically illustrated in the accompanying drawings. In addition, the size of each component does not fully reflect the actual size. In each figure, the same or corresponding elements are assigned the same reference numerals.

Advantages and features of the present invention, and a method of achieving them will become apparent with reference to the embodiments described below in detail in conjunction with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, but may be implemented in various different forms, and only these embodiments allow the disclosure of the present invention to be complete, and common knowledge in the art to which the present invention pertains. It is provided to fully inform the possessor of the scope of the invention, and the present invention is only defined by the scope of the claims. Like reference numerals refer to like elements throughout.

At this time, it will be understood that each block of the flowchart diagrams and combinations of the flowchart diagrams may be performed by computer program instructions. These computer program instructions may be embodied in a processor of a general purpose computer, special purpose computer, or other programmable data processing equipment, such that the instructions performed by the processor of the computer or other programmable data processing equipment are not described in the flowchart block(s). It creates a means to perform functions. These computer program instructions may also be stored in a computer-usable or computer-readable memory that may direct a computer or other programmable data processing equipment to implement a function in a particular manner, and thus the computer-usable or computer-readable memory. It is also possible for the instructions stored in the flowchart block(s) to produce an article of manufacture containing instruction means for performing the function described in the flowchart block(s). The computer program instructions may also be mounted on a computer or other programmable data processing equipment, such that a series of operational steps are performed on the computer or other programmable data processing equipment to create a computer-executed process to create a computer or other programmable data processing equipment. It is also possible that instructions for performing the processing equipment provide steps for performing the functions described in the flowchart block(s).

Additionally, each block may represent a module, segment, or portion of code that includes one or more executable instructions for executing specified logical function(s). It should also be noted that in some alternative implementations it is also possible for the functions recited in the blocks to occur out of order. For example, it is possible that two blocks shown in succession are actually performed substantially simultaneously, or that the blocks are sometimes performed in the reverse order according to the corresponding function.

At this time, the term '~ unit' used in this embodiment means software or hardware components such as FPGA or ASIC, and '~ unit' performs certain roles. However, '-part' is not limited to software or hardware. '~unit' may be configured to reside on an addressable storage medium or may be configured to refresh one or more processors. Thus, as an example, '~' denotes components such as software components, object-oriented software components, class components, and task components, and processes, functions, properties, and procedures. , subroutines, segments of program code, drivers, firmware, microcode, circuitry, data, databases, data structures, tables, arrays, and variables. The functions provided in the components and '~ units' may be combined into a smaller number of components and '~ units' or further separated into additional components and '~ units'. In addition, components and '~ units' may be implemented to play one or more CPUs in a device or secure multimedia card.

And, in describing the present invention, if it is determined that a detailed description of a related known function or configuration may unnecessarily obscure the gist of the present invention, the detailed description thereof will be omitted. In addition, the terms described below are terms defined in consideration of functions in the present invention, which may vary according to intentions or customs of users and operators. Therefore, the definition should be made based on the content throughout this specification.

Hereinafter, in this specification, the NR system and the LTE (Long Term Evolution) system and the LTE-A (LTE-Advanced) system have been described as examples, but the present invention does not add or subtract other communication systems using licensed and unlicensed bands. can be applied without

FIG. 1 shows radio resources of 1 subframe and 1 RB, which are the minimum units that can be scheduled in downlink in an LTE/LTE-A system.

The radio resource shown in FIG. 1 consists of one subframe on the time axis and one RB on the frequency axis. Such radio resources consist of 12 subcarriers in the frequency domain and 14 OFDM symbols in the time domain to have a total of 168 unique frequencies and time positions. In LTE/LTE-A, each natural frequency and time position of FIG. 1 is referred to as a resource element (RE).

A plurality of different types of signals as follows may be transmitted to the radio resource shown in FIG. 1 .

1. CRS (Cell Specific RS): A reference signal periodically transmitted for all terminals belonging to one cell and can be commonly used by a plurality of terminals.

2. DMRS (Demodulation Reference Signal): A reference signal transmitted for a specific terminal and transmitted only when data is transmitted to the corresponding terminal. DMRS may consist of a total of 8 DMRS ports. In LTE/LTE-A, ports 7 to 14 correspond to DMRS ports, and ports maintain orthogonality so as not to cause interference with each other using CDM or FDM.

3. PDSCH (Physical Downlink Shared Channel): This is a data channel transmitted through downlink, which is used by the base station to transmit traffic to the UE and is transmitted using REs in which a reference signal is not transmitted in the data region of FIG. 1 .

4. CSI-RS (Channel Status Information Reference Signal): A reference signal transmitted for terminals belonging to one cell is used to measure the channel state. A plurality of CSI-RSs may be transmitted to one cell.

5. Other control channels (PHICH, PCFICH, PDCCH): ACK/NACK transmission for providing control information necessary for the UE to receive the PDSCH or operating HARQ for uplink data transmission

In addition to the above signals, in the LTE-A system, muting may be set so that CSI-RSs transmitted by other base stations can be received without interference by terminals of the corresponding cell. The muting may be applied at a position where CSI-RS can be transmitted, and in general, the UE receives a traffic signal by skipping the corresponding radio resource. In the LTE-A system, muting is another term, also called zero-power CSI-RS. This is because, due to the nature of muting, it is applied to the location of the CSI-RS and transmission power is not transmitted.

In FIG. 1, the CSI-RS is to be transmitted using a part of the positions indicated by A, B, C, D, E, E, F, G, H, I, J according to the number of antennas for transmitting the CSI-RS. can Muting can also be applied to some of the positions indicated by A, B, C, D, E, E, F, G, H, I, and J. In particular, the CSI-RS may be transmitted in 2, 4, or 8 REs according to the number of transmitting antenna ports. When the number of antenna ports is 2, the CSI-RS is transmitted in half of the specific pattern in FIG. 1, and when the number of antenna ports is 4, the CSI-RS is transmitted over the entire specific pattern, and when the number of antenna ports is 8, two patterns are used. CSI-RS is transmitted. On the other hand, muting is always done in one pattern unit. That is, muting can be applied to a plurality of patterns, but cannot be applied to only a part of one pattern when the CSI-RS and the position do not overlap. However, only when the position of the CSI-RS and the position of the muting overlap, it can be applied only to a part of one pattern. When the CSI-RS for two antenna ports is transmitted, the CSI-RS transmits a signal of each antenna port in two REs connected in the time axis, and the signal of each antenna port is divided by an orthogonal code. Also, when CSI-RSs for four antenna ports are transmitted, two additional REs are used in addition to CSI-RSs for two antenna ports, and signals for two additional antenna ports are transmitted in the same manner. The same is true when CSI-RSs for 8 antenna ports are transmitted. In the case of CSI-RS supporting 12 and 16 antenna ports, three CSI-RS transmission positions for the existing 4 antenna ports are combined or two CSI-RS transmission positions for 8 antenna ports are combined.

In addition, the UE may be allocated CSI-IM (or IMR, interference measurement resources) together with the CSI-RS, and the resource of the CSI-IM has the same resource structure and location as the CSI-RS supporting 4port. The CSI-IM is a resource for a terminal receiving data from one or more base stations to accurately measure interference from an adjacent base station. For example, if it is desired to measure the amount of interference when the neighboring base station transmits data and the amount of interference when it does not transmit data, the base station configures a CSI-RS and two CSI-IM resources, and one CSI-IM The signal is always transmitted and the other CSI-IM prevents the neighboring base station from always transmitting the signal, thereby effectively measuring the amount of interference of the neighboring base station.

Table 1 below shows the RRC (Radio Resource Control) field configuring the CSI-RS configuration.

Table 1 RRC configuration to support periodic CSI-RS in CSI process

The configuration for reporting the channel state based on the periodic CSI-RS in the CSI process can be classified into four types as shown in Table 1. The CSI-RS config is for setting the frequency and time location of the CSI-RS RE. Here, the number of ports of the corresponding CSI-RS is set through setting the number of antennas. Resource config sets the RE location in the RB, and Subframe config sets the period and offset of the subframe. Table 2 is a table for setting Resource config and Subframe config currently supported by LTE.

Table 2 Resource config and Subframe config settings

(a) Resource config setting

(b) Subframe config setting

It is possible for the terminal to check the frequency and time position, and the period and offset through Table 2 above. Qcl-CRS-info sets quasi co-location information for CoMP. The CSI-IM config is for setting the frequency and time location of the CSI-IM for measuring interference. Since CSI-IM is always set based on 4 ports, there is no need to set the number of antenna ports, and Resource config and Subframe config are set in the same way as CSI-RS. The CQI report config exists to set how to report the channel status using the CSI process. The configuration includes periodic channel status report configuration, aperiodic channel status report configuration, PMI/RI report configuration, RI reference CSI process configuration, and subframe pattern configuration.

The subframe pattern is for setting a measurement subframe subset for supporting a channel and interference measurement that have different temporal characteristics in the channel and interference measurement received by the UE. Measurement subframe subset was first introduced in eICIC (Enhanced Inter-Cell Interference Coordination) to reflect and estimate ABS (Almost Blank Subframe) and other interference characteristics of non-ABS general subframes. Thereafter, in eIMTA (enhanced Interference Mitigation and Traffic Adaptation), two IMRs are set and measured to measure different channel characteristics between a subframe that always operates in DL and a subframe that can be dynamically switched from DL to UL. developed in an improved form. Tables 3 and 4 show the measurement subframe subset for eICIC and eIMTA support.

Table 3 Measurement subframe subset settings for eICIC

CQI-ReportConfig-r10 ::= SEQUENCE {

cqi-ReportAperiodic-r10 CQI-ReportAperiodic-r10 OPTIONAL, -- Need ON

nomPDSCH-RS-EPRE-Offset INTEGER (-1..6),

cqi-ReportPeriodic-r10 CQI-ReportPeriodic-r10 OPTIONAL, -- Need ON

pmi-RI-Report-r9 ENUMERATED {setup} OPTIONAL, -- Cond PMIRIPCell

csi-SubframePatternConfig-r10 CHOICE {

release NULL,

setup SEQUENCE {

csi-MeasSubframeSet1-r10 MeasSubframePattern-r10,

csi-MeasSubframeSet2-r10 MeasSubframePattern-r10

}

} OPTIONAL -- Need ON

}

Table 4 Measurement subframe subset settings for eIMTA

CQI-ReportConfig-v1250 ::= SEQUENCE {

csi-SubframePatternConfig-r12 CHOICE {

release NULL,

setup SEQUENCE {

csi-MeasSubframeSets-r12 BIT STRING (SIZE (10))

}

} OPTIONAL, -- Need ON

cqi-ReportBoth-v1250 CQI-ReportBoth-v1250 OPTIONAL, -- Need ON

cqi-ReportAperiodic-v1250 CQI-ReportAperiodic-v1250 OPTIONAL, -- Need ON

altCQI-Table-r12 ENUMERATED {

allSubframes, csi-SubframeSet1,

csi-SubframeSet2, spare1} OPTIONAL -- Need OP

}

The eICIC measurement subframe subset supported by LTE is set using csi-MeasSubframeSet1-r10 and csi-MeasSubframeSet2-r10. MeasSubframePattern-r10 referenced by the corresponding field is shown in Table 5 below.

Table 5 MeasSubframePattern

-- ASN1START

MeasSubframePattern-r10 ::= CHOICE {

subframePatternFDD-r10 BIT STRING (SIZE (40)),

subframePatternTDD-r10 CHOICE {

subframeConfig1-5-r10 BIT STRING (SIZE (20)),

subframeConfig0-r10 BIT STRING (SIZE (70)),

subframeConfig6-r10 BIT STRING (SIZE (60)),

...

},

...

}

-- ASN1STOP

In the field, it means subframe #0 from the left MSB, and when it is 1, it indicates that it is included in the corresponding measurement subframe subset. Unlike the eICIC measurement subframe subset that sets each subframe set through each field, the eIMTA measurement subframe set uses one field to indicate 0 as the first subframe set and 1 as the second subframe set. Therefore, in eICIC, the corresponding subframe may not be included in two subframe sets, but in the case of the eIMTA subframe set, there is a difference that it must always be included in one subframe set of the two.

In addition to this, there is a codebook subset restriction that sets the power ratio between _PDSCH and CSI-RS RE required for the UE to generate a channel state report, and which codebook is to be used. For PC and codebook subset restriction, each field means setting for each subframe subset by the pC- _AndCBSRList field including two PC-AndCBSR fields in Table 7 below in the form of a list.

Table 6 p-C-AndCBSRList

CSI-Process-r11 ::= SEQUENCE {

...

p-C-AndCBSRList-r11 SEQUENCE (SIZE (1..2)) OF P-C-AndCBSR-r11,

...

}

Table 7 P-C-AndCBSR

P-C-AndCBSR-r11 ::= SEQUENCE {

p-C-r11 INTEGER (-8..15),

codebookSubsetRestriction-r11 BIT STRING

}

_The PC may be defined as in Equation 1 below, and a value between -8 and 15 dB may be designated.

[Equation 1]

The base station can variably adjust the CSI-RS transmission power for various purposes such as improving the channel estimation accuracy, and the UE can adjust the transmission power to be used for data transmission through the notified _PC how low or high compared to the transmission power used for channel estimation. can know For the above reason, it is possible for the UE to calculate and report the correct CQI to the base station even if the base station varies the CSI-RS transmission power.

In the cellular system, the base station must transmit a reference signal to the terminal in order to measure the downlink channel state. In the case of 3GPP's LTE-A (Long Term Evolution Advanced) system, the terminal measures the channel state between the base station and itself using CRS or Channel Status Information Reference Signal (CSI-RS) transmitted by the base station. do. In the channel state, several factors should be basically considered, and this includes the amount of interference in the downlink. The amount of interference in the downlink includes an interference signal and thermal noise generated by an antenna belonging to an adjacent base station, and is important for the UE to determine the downlink channel condition. As an example, when a signal is transmitted from a base station having one transmit antenna to a terminal having one receive antenna, the terminal uses a reference signal received from the base station to receive energy per symbol in downlink and in a section for receiving the corresponding symbol. At the same time, it is necessary to determine the amount of interference to be received and determine Es/Io. The determined Es/Io is converted to a data rate or a value corresponding thereto, and is notified to the base station in the form of a channel quality indicator (CQI), so that the base station transmits the data to the terminal at a certain data rate in the downlink. to be able to decide whether

In the case of the LTE-A system, the terminal feeds back information on the downlink channel state to the base station so that it can be utilized for downlink scheduling of the base station. That is, the terminal measures the reference signal transmitted by the base station in the downlink and feeds back the information extracted thereto to the base station in the form defined by the LTE/LTE-A standard. In LTE/LTE-A, there are three main types of information fed back by the UE.

l Rank Indicator (RI): the number of spatial layers that the UE can receive in the current channel state

l Precoder Matrix Indicator (PMI): An indicator for the precoding matrix preferred by the UE in the current channel state

l Channel Quality Indicator (CQI): The maximum data rate that the terminal can receive in the current channel state (data rate). CQI may be replaced with SINR, a maximum error-correcting code rate and modulation scheme, and data efficiency per frequency that can be used similarly to the maximum data rate.

The RI, PMI, and CQI are related to each other and have meaning. For example, the precoding matrix supported by LTE/LTE-A is defined differently for each rank. Therefore, when RI has a value of 1, the PMI value and when RI has a value of 2, the PMI value is interpreted differently even if the value is the same. Also, it is assumed that the rank value and PMI value notified to the base station are applied by the base station even when the terminal determines the CQI. That is, when the terminal notifies the base station of RI_X, PMI_Y, and CQI_Z, when the rank is RI_X and the precoding is PMI_Y, it means that the terminal can receive the data rate corresponding to CQI_Z. In this way, when the UE calculates the CQI, it is assumed which transmission method to perform to the base station, so that optimized performance can be obtained when actual transmission is performed using the transmission method.

In LTE/LTE-A, the periodic feedback of the terminal is set to one of the following four feedback modes (feedback mode or reporting mode) depending on what information is included:

● Reporting mode 1-0 (wideband CQI with no PMI): RI, wideband CQI (wCQI)

● Reporting mode 1-1 (wideband CQI with single PMI):: RI, wCQI, PMI

● Reporting mode 2-0 (subband CQI with no PMI):: RI, wCQI, narrowband (subband) CQI (sCQI)

Reporting mode 2-1 (subband CQI with single PMI):: RI, wCQI, sCQI, PMI

The feedback timing of each information for the four feedback modes is determined by values such as N _pd , N _OFFSET,CQI , M _RI , and N _OFFSET,RI transmitted as a higher layer signal. In feedback mode 1-0, the transmission period of wCQI is N _pd , and the feedback timing is determined with subframe offset values of N _OFFSET,CQI . In addition, the RI transmission period is N _{pd ·} M _RI , and the offset is N _OFFSET,CQI + N _OFFSET,RI .

2 is a diagram illustrating feedback timings of RI and wCQI in the case of N _pd =2, M _RI =2, N _OFFSET,CQI =1, N _OFFSET,RI =-1. In FIG. 3 , each timing indicates a subframe index.

Feedback mode 1-1 has the same feedback timing as mode 1-0, except that wCQI and PMI are transmitted together in wCQI transmission timing.

In feedback mode 2-0, the feedback period for sCQI is N _pd and the offset value is N _OFFSET,CQI . And the feedback period for wCQI is H·N _pd , and the offset value is N _OFFSET,CQI like the offset value of sCQI. Here, it is defined as H=J·K+1, where K is transmitted to the upper level signal and J is a value determined according to the system bandwidth.

For example, the value of J for a 10 MHz system is defined as 3. As a result, the wCQI is transmitted by replacing it once every H sCQI transmissions. And the period of RI is M _RI· H _· N _pd , and the offset is N _OFFSET,CQI + N _OFFSET,RI .

3 shows RI, sCQI, wCQI feedback timing for the case of N _pd =2, M _RI =2, J = 3 (10 MHz), K = 1, N _{OFFSET, CQI} = 1, N _{OFFSET, RI} = -1. It is a drawing showing.

Feedback mode 2-1 has the same feedback timing as mode 2-0, except that PMI is transmitted together in wCQI transmission timing.

The above-described feedback timing is a case where the number of CSI-RS antenna ports is 4 or less, and in the case of a UE allocated with CSI-RS for 8 antenna ports, two pieces of PMI information must be fed back differently from the feedback timing. For 8 CSI-RS antenna ports, feedback mode 1-1 is again divided into two submodes. In the first submode, RI is transmitted with the first PMI information and the second PMI information is transmitted with wCQI. Here, the feedback period and offset for wCQI and the second PMI are defined as N _pd and N _OFFSET,CQI , and the feedback period and offset values for the RI and first PMI information are M _RI N _pd and N _OFFSET,CQI +N _OFFSET , respectively. _{, which is defined as RI} . Here, if the precoding matrix corresponding to the first PMI is W1 and the precoding matrix corresponding to the second PMI is W2, the terminal and the base station share information that the precoding matrix preferred by the terminal is determined as W1W2.

는 CSI-RS 안테나 포트 개수가 4인 경우와 같이 정의된다. In the case of feedback mode 2-1 for eight CSI-RS antenna ports, feedback of precoding type indicator (PTI) information is added. PTI is fed back together with RI, the period is M _RI· H _· N _pd , and the offset is defined as N _OFFSET,CQI +N _OFFSET,RI . When the PTI is 0, the first PMI, the second PMI, and the wCQI are all fed back, and the wCQI and the second PMI are transmitted together at the same timing, the period of which is N _pd , and the offset is given as N _OFFSET,CQI . Also, the period of the first PMI is H'·N _pd , and the offset is N _OFFSET,CQI . Here, H' is transmitted as a higher-order signal. On the other hand, when the PTI is 1, the PTI is transmitted together with the RI, the wCQI and the second PMI are transmitted together, and the sCQI is additionally fed back at a separate timing. In this case, the first PMI is not transmitted. Periods and offsets of PTI and RI are the same as when PTI is 0, and sCQI is defined as period N _pd offset is N _OFFSET,CQI . In addition, wCQI and the second PMI are fed back with a period of H N _{pd and} an offset of N _{OFFSET and CQI} .

is defined as in the case where the number of CSI-RS antenna ports is 4.

4 and 5 are for the case of N _pd =2, M _RI =2, J = 3 (10 MHz), K = 1, H' = 3, N _{OFFSET, CQI} = 1, N _{OFFSET, RI} = -1, respectively. It is a diagram showing feedback timing in the case of PTI=0 and PTI=1.

6 is a diagram illustrating a structure of a periodic channel state reporting time point for a CSI-RS port of 12 or more ports for a 2-D array antenna supported by Rel-13 and Rel-14.

LTE Rel-13 and Rel-14 support NP (non-precoded) CSI-RS to support more than 12 CSI-RS ports for 2-D array antennas. In the NP CSI-RS, 8, 12, 16 or more CSI-RS ports are supported in one subframe by utilizing positions for the existing CSI-RS. This field is set in CSI-RS-ConfigNZP-EMIMO. The UE may use this to identify and receive a location for a CSI-RS resource. In addition, in BF CSI-RS, csi-RS-ConfigNZPIdListExt-r13 and csi-IM-ConfigIdListExt-r13 are used to bundle individual CSI-RS resources that may differ in the number of CSI-RS ports, subframe and codebook subset restriction, etc. It is used as BF CSI-RS. In order to support a 2D antenna in the NP CSI-RS, a new 2D codebook is required, which may vary according to an antenna for each dimension and an oversampling factor, and a codebook configuration. If the PMI bit of the 2-D codebook is analyzed, all bits for i2 (W2) report are 4 bits or less, and the existing channel state reporting method can be used. However, in the case of i11/i12, the PMI bit increases as follows for N1, N2, O1, O2, and codebookConfig supported as shown in Table 8 below.

Table 8 PMI overhead analysis of 2D codebook

Based on the above table, it can be confirmed that (N1,N2,O1,O2) = (2,4,8,8) and i1 when Config is 1 should transmit 10 bits at the maximum. . In the case of PUCCH format 2 used for the existing periodic channel state reporting, the Reed-Muller code used for channel coding can be transmitted up to 13 bits, but in the case of extended CP, HARQ ACK/NACK of 2 bits must be supported, so it is actually a normal CP situation. The payload size that can be transmitted is 11 bits. In order to support such a payload size, both the wideband CQI mode and the subband CQI mode report using three independent CSI reporting points shown in FIG. 6 .

LTE/LTE-A supports not only periodic feedback of the terminal but also aperiodic feedback. When the base station wants to obtain aperiodic feedback information of a specific terminal, the base station performs specific aperiodic feedback on the aperiodic feedback indicator included in downlink control information (DCI) for uplink data scheduling of the corresponding terminal to perform uplink data scheduling of the corresponding terminal. When the corresponding terminal receives an indicator configured to perform aperiodic feedback in the nth subframe, the corresponding terminal performs uplink transmission including aperiodic feedback information in data transmission in the n+kth subframe. Here, k is a parameter defined in the 3GPP LTE Release 11 standard, which is 4 in frequency division duplexing (FDD) and is defined as in Table 9 in time division duplexing (TDD).

Table 9 k value for each subframe number n in TDD UL/DL configuration

When the aperiodic feedback is configured, the feedback information includes RI, PMI, and CQI as in the case of periodic feedback, and the RI and PMI may not be fed back according to the feedback configuration. And the CQI may include both wCQI and sCQI or may include only wCQI information.

In LTE/LTE-A, a codebook subsampling function is provided for periodic channel state reporting. In LTE/LTE-A, the periodic feedback of the terminal is transmitted to the base station through the PUCCH. Since the amount of information that can be transmitted through PUCCH at one time is limited, various feedback objects such as RI, wCQI, sCQI, PMI1, wPMI2, sPMI2 are transmitted to PUCCH through subsampling, or two or more pieces of feedback information are encoded together. be (joint encoding) and may be transmitted as PUCCH. For example, when the number of CSI-RS ports configured by the base station is 8, RI and PMI1 reported in submode 1 of PUCCH mode 1-1 may be joint-encoded as shown in Table 11. Based on Table 9, RI composed of 3 bits and PMI1 composed of 4 bits are joint-encoded with a total of 5 bits. Submode 2 of PUCCH mode 1-1 jointly encodes PMI1 composed of 4 bits and PMI2 composed of another 4 bits into a total of 4 bits as shown in Table 10. Since the subsampling level is larger compared to submode 1 (4->3 for submode 1, 8->4 for submode 2), more precoding indexes cannot be reported. As another example, when the number of CSI-RS ports configured by the base station is 8, PMI2 reported in PUCCH mode 2-1 may be subsampled as shown in Table 11. Referring to Table 11, PMI2 is reported as 4 bits when the associated RI is 1. However, since the differential CQI for the second codeword must be additionally reported together when the associated RI is 2 or more, it can be seen that PMI2 is subsampled to 2 bits and reported.

Table 9: Joint encoding of RI and i ₁ for PUCCH mode 1-1 submode 1

Table 10: Joint encoding of RI, i ₁ and i ₂ for PUCCH mode 1-1 submode 2

Table 11: PUCCH mode 2-1 codebook subsampling

7 is a diagram illustrating a state in which data such as eMBB, URLLC, mMTC, etc., which are services considered in the NR system, are allocated in frequency-time resources together with FCR (Forward Compatiable Resource).

When URLLC data is generated and transmission is required while eMBB and mMTC are allocated in a specific frequency band and transmitted, the eMBB and mMTC are allocated in advance and URLLC data is transmitted. Among the above services, since short delay time is particularly important for URLLC, URLLC data may be allocated and transmitted to a part of resources allocated with eMBB, and the eMBB resource may be known to the terminal in advance. To this end, eMBB data may not be transmitted in a frequency-time resource where eMBB data and URLLC data overlap, and thus eMBB data transmission performance may be lowered. That is, in the above case, eMBB data transmission failure may occur due to URLLC allocation. In this case, the length of a transmission time interval (TTI) used for URLLC transmission may be shorter than the TTI length used for eMBB or mMTC transmission.

In the process of the terminal accessing the wireless communication system, a synchronization signal is used to obtain synchronization with a cell in the network. More specifically, the synchronization signal means a reference signal transmitted by the base station for time and frequency synchronization and cell search when the terminal is initially connected. In LTE, signals such as PSS (Primary Synchronization Signal) and SSS (Secondary Synchronization Signal) are may be sent for synchronization.

8 is a diagram showing an embodiment in which a synchronization signal is transmitted in the 5G communication system under consideration in the present invention.

In FIG. 8 , the synchronization signal 8-01 may be transmitted at intervals of a predetermined period 8-04 on the time axis 8-02. Also, the synchronization signal 8-01 may be transmitted within a constant synchronization signal transmission bandwidth 8-03 on the frequency axis 8-03. The synchronization signal may map a special sequence to subcarriers within the transmission bandwidth (8-03) to indicate a cell number (Cell ID). A cell number may be mapped to one or a combination of a plurality of sequences, and thus, the terminal may detect the number of a cell to which the terminal intends to access by detecting a sequence used for a synchronization signal. The sequence used for the synchronization signal may use a sequence having a constant amplitude zero auto correlation (CAZAC) characteristic, such as a Zadoff-Chu sequence or a Golay sequence, or a pseudo random noise sequence such as an M-sequence or a Gold sequence. In the present invention, it is assumed that the aforementioned synchronization signal is used for the synchronization signal, but the present invention is not limited to a specific signal. The synchronization signal 8-01 may be configured using one OFDM symbol or may be configured using a plurality of OFDM symbols. When configured using a plurality of OFDM symbols, sequences for a plurality of different synchronization signals may be mapped to each OFDM symbol. For example, similarly to LTE, a Primary Synchronization Signal (PSS) may be generated using three Zadoff-Chu sequences, and a Secondary Synchronization Signal (SSS) may be generated using a Gold sequence. The PSS of one cell may have three different values according to the physical layer cell ID of the cell, and three cell IDs in one cell ID group correspond to different PSSs. Accordingly, the UE can detect one cell ID group among three cell ID groups supported by LTE by detecting the PSS of the cell. The UE additionally detects the SSS among 168 cell IDs reduced from 504 through the cell ID group confirmed through the PSS, and finally knows the cell ID to which the corresponding cell belongs.

As described above, the UE synchronizes with a cell in the network, acquires a cell number (Cell ID), and finds cell frame timing. Once this is successful, the UE should receive important cell system information. This is information that is repeatedly broadcast by the network, and is information that the terminal needs to know in order to access the cell and generally operate properly in the cell. In LTE, system information is transmitted through two different transmission channels, and a limited amount of system information called MIB (Master information block) is transmitted using PBCH (Physical broadcast channel) and corresponds to SIB (System information block). A major part of the system information to be transmitted is transmitted using a physical downlink shared channel (PDSCH). More specifically, the system information included in the MIB in the LTE system includes a downlink transmission bandwidth, a physical hybrid ARQ indicator channel (PHICH) configuration information, and a system frame number (SFN).

9 is a diagram showing an embodiment in which a PBCH is transmitted in the 5G communication system under consideration in the present invention. In FIG. 9 , the PBCH 9-01 may be transmitted at intervals of a predetermined period (9-04) on the time axis (9-02). Also, the PBCH 9-01 may be transmitted within a constant PBCH transmission bandwidth 9-03 on the frequency axis 9-03. The PBCH may transmit the same signal at regular intervals (9-04) in order to improve coverage and combine them to receive it. In addition, by applying a transmission technique such as TxD (Transmit diversity) and one DMRS port-based precoder cycling using multiple antenna ports, a diversity gain can be obtained without additional information about the transmission technique used at the receiving end. can do. In the present invention, it is assumed that the aforementioned PBCH is used for the PBCH, but the present invention is not limited to a specific structure. Similar to the current LTE system, the PBCH 9-01 may be configured using a plurality of OFDM symbols for time-frequency domain resources, or may be configured scattered across time-frequency domain resources. The UE needs to receive and decode the PBCH in order to receive system information, and in the LTE system, channel estimation for the PBCH is performed using the CRS.

10 is a diagram exemplifying assuming that each service is multiplexed in time and frequency resources in the NR system. The base station may allocate the CSI-RS to all bands or a plurality of bands in order to secure initial channel state information to the UE. Such full-band or multi-band CSI-RS may be disadvantageous in optimizing system performance because it requires a large amount of reference signal overhead. may be essential. After such full-band or multi-band CSI-RS transmission, each service may be provided with different requirements for each service, and accordingly, the accuracy of necessary channel state information and the need to update may also vary. Accordingly, after the base station secures the initial channel state information, the base station can trigger the subband CSI-RS for each service in the corresponding band according to the occurrence of a need for each service. Although the CSI-RS transmission for each service is exemplified at one time in FIG. 10, CSI-RSs for a plurality of services may be transmitted if necessary.

Compared with the above-mentioned LTE CSI-RS transmission and CSI reporting configuration, the types of CSI-RS transmission and CSI reporting configuration supported by NR may be different. Unlike LTE, NR enables more flexible channel status report configuration than LTE through resource configuration, channel measurement configuration, and channel status report configuration required to support channel status report. 11 is a diagram illustrating resource configuration, channel measurement configuration, and channel status report configuration required to support channel status reporting in NR. Resource setting, channel measurement setting, and channel status report setting may include the following setting information.

● CSI reporting setting: It is possible to set on, off, etc. of reporting parameters (eg, RI, PMI, CQI, etc.) required for channel state reporting. In addition, the type of channel status report (eg, Type I: low resolution channel status report, indirect (implicit) report type, or Type II: high resolution channel status report, linear combination type channel status report) It can be set in the form of reporting the eigen vector, covariance matrix, etc. directly using setting), report method (periodic, aperiodic, semi-persistent, aperiodic and semi-persistent can be set as one parameter), codebook setting information, PMI type (full band/partial band), channel status report type (implicit /explicit or Type I/Type II), channel quality report format (CQI/RSRP), and resource configuration for channel status report may be supported.

● Resource setting: A setting that includes setting information for a reference signal required for channel state measurement. A CSI-RS resource for channel measurement and an Interference Measurement Resource (CSI-IM) resource for interference measurement may be configured, and a plurality of resource configurations may exist for this purpose. In addition, the transmission type (periodic, aperiodic, semi-permanent) of the reference signal, the transmission period and offset of the reference signal, etc. can also be set.

● Channel measurement setup: Set up mapping or connection between channel status report setup and resource setup. For example, when there are N channel state report settings and M resource settings, L links for setting mapping between the plurality of channel state report settings and resource settings may be included in the channel measurement setting. In addition, the reference signal setting and the association setting of the reporting time (for example, when the reference signal is transmitted in n subframes or slots, the reporting time is D0-0, D1-0, D2-1, D3-2 and D3-3 It can be set using parameters like

NR supports semi-persistent reference signal transmission and channel state information in addition to periodic and aperiodic channel state reporting supported by LTE. In this case, the NR periodic and semi-persistent channel state information may not support subband reporting among the aforementioned reporting modes. PUCCH used in periodic and semi-persistent channel state reporting has a limited amount of report that can be transmitted. Therefore, as mentioned above, in LTE, the UE selects and uploads subbands of some of the bandwidth parts. However, since the report on this selective subband contains extremely limited information, the usefulness of the information is not great. Therefore, by not supporting such a report, it is possible to reduce the complexity of the terminal and increase the efficiency of the report. In addition, since subband reporting is not supported, PMI may not be reported in NR periodic channel state information reporting, or only one PMI corresponding to a wideband or partial band may be transmitted.

The following reporting modes may be supported in the NR aperiodic channel state information reporting.

● Reporting mode 1-2 (wideband CQI with multiple PMI): RI, wideband CQI (wCQI), multiple wideband and narrowband PMI

● Reporting mode 2-0 (subband CQI with no PMI):: RI, wCQI, narrowband CQI (sCQI) of the band selected by the UE

● Reporting mode 2-2 (subband CQI with multiple PMIs):: RI, wCQI, sCQI, multiple wideband and narrowband PMIs

● Reporting mode 3-0 (subband CQI with no PMI):: RI, wCQI, all-band narrowband (subband) CQI (sCQI)

● Reporting mode 3-2 (subband CQI with multiple PMIs):: RI, wCQI, full band subband CQI (sCQI), multiple wideband and narrowband PMIs

Like the periodic channel state report, reporting modes 2-0 and 2-2 select and report one of the subbands of the bandwidth part of the terminal, and may not be supported in NR due to the low efficiency of the report. In addition, in the periodic channel state report in LTE, it was determined using the PMI/RI report setting and the CQI setting of the corresponding channel state reporting mode setting, and in the case of the aperiodic channel state report, the channel state reporting mode was directly set. In the NR, the PMI/RI report configuration and CQI report configuration may be provided in each of the above-mentioned channel state report configuration.

As mentioned above, in NR, two types of channel state reporting having a low spatial resolution and a high spatial resolution are supported as follows. Table 12-1 and Table 12-2 below show these two types of channel state reporting and reporting overhead required for each report type.

Table 12-1: Type I Channel Status Reporting

Type 1 single panel codebook

- For two CSI-RS ports, NR supports the following Type 1 codebook

- For 4 or more CSI-RS ports, NR supports Type 1 codebooks for ranks 1 to 8 below

, B는 L 개의 오버 샘플링된 2D DFT 빔으로 구성된다. 랭크 1 및 2에 관해, L 값은

중 하나로 설정될 수 있다. W₂는 빔 선택을 수행하고 (L=4인 경우에만), 2개의 polarization들 사이에서 QPSK co-phasing을 수행한다.The codebook assumes a W=W ₁ W ₂ precoder structure, where

, B consists of L oversampled 2D DFT beams. For ranks 1 and 2, the L value is

It can be set to one of W ₂ performs beam selection (only when L=4), and QPSK co-phasing between two polarizations.

- 1D/2D antenna port layouts (N ₁ , N ₂ ) and oversampling factors (O ₁ , O ₂ ) (cf. Rel.13/14 LTE Class A codebooks) are supported as follows.

Regarding -L=4, the following beam group (B) patterns are supported.

Table 12-2: Type II Channel Status Reporting

Type 2 single panel codebook

-NR supports Type 2 Cat 1 CSI for rank 1 and 2

PMI is used for spatial channel information feedback.

The UE assumes the following precoder structure for the PMI codebook for channel state reporting.

-

중 하나의 값으로 설정될 수 있다.L value is

It can be set to one of the values.

b _k1,k2 is an oversampled 2D DFT beam.

: 빔 i 및 polarization r 및 레이어 l에 대한 와이드밴드 빔 진폭 스케일링 팩터

: wideband beam amplitude scaling factor for beam i and polarization r and layer l

: 빔 i 및 polarization r 및 레이어 l에 대한 서브밴드 빔 진폭 스케일링 팩터

: subband beam amplitude scaling factor for beam i and polarization r and layer l

: 빔 i 및 polarization r 및 레이어 l에 대한 빔 결합 계수 (위상)

: Beam coupling coefficient (phase) for beam i and polarization r and layer l

Set by selecting between QPSK (2-bit) and 8PSK (3-bit).

Amplitude Scaling Mode: Choose between WB+SB (Uneven Bit Allocation) and WB-only

Table 12-3: Reporting Overhead for Type I Channel Status Reporting

Table 12-4: Reporting Overhead for Type II Channel Status Reporting

As described above, the Type I channel state report can report the channel state to the base station through RI, PMI, CQI, CSI-RS Resource Indicator (CRI), etc. based on a codebook like the existing LTE. On the other hand, Type II report can provide a higher form of resolution through more PMI reporting overhead to implicit CSI similar to Type I report, and this PMI report is used for the precoder, beam, Co It can be made through a linear combination such as -phase. In addition, in order to directly report the channel state, it can be reported in an explicit CSI format different from the existing one, and a representative example of this may be a method of reporting the covariance matrix of the channel. In addition, a form in which implicit and explicit are combined is also possible. For example, the covariance matrix of the channel is reported as PMI, but CQI or RI may also be reported together.

As mentioned above, Type II requires high reporting overhead. Therefore, such a report may not be suitable for periodic channel state reporting where the number of reportable bits is not large. On the other hand, in the case of aperiodic channel state reporting, since the corresponding channel state report is supported through a PUSCH that can support a lot of reporting overhead, Type II reporting requiring such a high reporting overhead can only be supported for aperiodic channel state reporting. have.

In addition, Type II may be supported for semi-persistent channel state reporting. In NR, the semi-persistent channel state report requires a relatively high UE complexity because it supports dynamic activation/deactivation compared to the periodic channel state report.

In the LTE channel state report, as mentioned in Table 1, the base station sets the reference signal and report-related settings to the terminal based on the CSI process through higher layer settings. Based on this, in the case of periodic channel state reporting, it is reported to a preset reporting time and resource, and in the case of aperiodic channel state reporting, a preset setting through a trigger in DCI transmitted by the base station through a downlink control signal information will be reported.

In NR, as mentioned in FIG. 11, channel state report configuration, resource configuration, and a link connecting them exist in the channel measurement configuration. In the case of periodic and semi-persistent channel status reporting, the channel status may be reported periodically or semi-persistently by the channel status report configuration according to the RRC configuration of the base station and the DCI or MAC CE-based activation/deactivation signal. . In the case of aperiodic channel status report, the channel status report can be triggered using the following method.

- Aperiodic Channel Status Report Trigger Method 1: Trigger based on a link within the measurement setup

- Aperiodic channel status report trigger method 2: Trigger based on the channel status report setting in the measurement setup

Aperiodic channel status report triggering method 1 is a triggering method based on the link in the measurement setup. 12 is a diagram illustrating a method of triggering a link in a trigger measurement setting according to the aperiodic channel state report triggering method 1;

In FIG. 12 , the base station may set a link triggered for each trigger field as RRC in advance for aperiodic channel state reporting. In this case, the base station may directly set the link ID in the trigger setting in order to set the triggered link. As another example, the base station may be configured using a bitmap of links of all cells configured for the terminal. In this case, the instruction order of the bitmap may be arranged in an ascending order or a descending order based on a cell ID, a link ID, and the like. 13 is a diagram illustrating an instruction order of such a bitmap.

As shown in FIG. 13, cell IDs are first sorted, and after sorting, based on the link IDs within the same cell ID, the cell IDs can be arranged in ascending order from MSB to LSB. In FIG. 13, it is exemplified that cell IDs are prioritized, but link IDs may be prioritized and sorted, or they may be sorted in descending order.

Aperiodic channel status report triggering method 2 is a triggering method based on the channel status report setting in the measurement setting. 14 is a diagram illustrating a method of triggering a channel status report setup in a trigger measurement setup according to aperiodic channel status report triggering method 2;

In FIG. 14 , the base station may set the channel state report setting triggered for each trigger field to RRC in advance for aperiodic channel state reporting. In this case, the base station may directly set the channel status report configuration ID in the trigger configuration in order to set the triggered channel status report configuration. As another example, the base station may be configured using a bitmap of channel state report settings of all cells configured for the terminal. In this case, the instruction order of the bitmap may be arranged in an ascending order or a descending order based on a cell ID, a channel state report setting ID, and the like. 15 is a diagram illustrating an instruction order of such a bitmap.

As shown in FIG. 15, cell IDs are first sorted, and after sorting, MSB to LSB can be arranged in ascending order based on the channel state report ID within the same cell ID. In FIG. 15, it is exemplified that cell IDs are prioritized, but the channel status report IDs may be prioritized and sorted, or they may be sorted in descending order.

As mentioned above, the base station reports the aperiodic channel state to the base station through DCI using the trigger fields as shown in Tables 13-1, 13-2, and 13-3 below to trigger the link based on the link. can do.

Table 13-1: Link-based aperiodic channel status report indication field

Table 13-2: Link-based aperiodic channel status report indication field

Table 13-3: Link-based aperiodic channel status report indication field

In Table 13-1, the base station does not trigger an aperiodic channel state report to the terminal by using the indication field, or can trigger all links of the cell. Links triggered for channel state reporting through RRC configuration can be triggered as described in trigger method 1 above. The trigger field used in Table 13-2 excludes the case where it is not triggered. In this case, a non-triggered option may exist in the preset of the trigger field that can be set such as '001'. It is possible to provide flexibility in the configuration of the base station by increasing the degree of freedom except for the aperiodic channel state report configuration that reports all links of one cell used in Table 13-3. In this case, as in Table 13-2 mentioned above, a non-triggered option may exist in the preset of a trigger field that can be set, such as '000'.

As mentioned above, in order for the base station to trigger based on the channel state report setting, the aperiodic channel state to the terminal by DCI using the trigger fields shown in Tables 13-4, 13-5, and 13-6 below to the base station can be reported.

Table 13-4: Aperiodic channel status report indication field based on CSI channel status report configuration

Table 13-5: Aperiodic channel status report indication field based on CSI channel status report configuration

Table 13-6: Aperiodic channel status report indication field based on CSI channel status report configuration

In Table 13-4, the base station does not trigger aperiodic channel status report to the terminal using the indication field, or can trigger all channel status report settings of the corresponding cell, and the bit '010' after '001' ', the channel state report settings triggered for the channel state report through the RRC setting in advance can be triggered as described in trigger method 2 above. The trigger field used in Table 13-5 excludes the case where it is not triggered, and in this case, a non-triggered option may exist in the preset of the trigger field that can be set, such as '001'. It is possible to provide flexibility in the configuration of the base station by increasing the degree of freedom except for the aperiodic channel status report configuration that reports all the channel status report configurations of one cell used in Table 13-6. In this case, as in Table 13-5 mentioned above, a non-triggered option may exist in the preset of a trigger field that can be set, such as '000'.

Aperiodic CSI-RS for channel measurement and interference measurement may be indirectly indicated by using the indication field. 16 is a diagram illustrating indirectly indicating an aperiodic CSI-RS using the aperiodic CSI-RS indication field.

In FIG. 16, the base station triggers a channel state report by using a link. At this time, if the resource supported for channel measurement in the resource setting connected to the link is periodic CSI-RS, the aperiodic channel status report is estimated based on the channel measured in the existing periodic CSI-RS resource, and the corresponding If the resource supported for channel measurement in the resource configuration connected to the link is an aperiodic CSI-RS, the aperiodic channel state report can be estimated based on the channel measured in the aperiodically configured CSI-RS resource. In this case, the aperiodic channel state report trigger and the aperiodic CSI-RS may always be transmitted in the same slot or subframe. In addition, as mentioned above, it is also possible to be triggered through the channel state report configuration rather than the link.

In this case, in order to support such a channel state report, a resource for measuring a preferred signal and interference may be set to the UE through the resource setting shown in FIG. 11 . The following RRC parameters may be considered for resource configuration.

Table 14: Example resource settings fields

Based on the resource configuration, NR may support beam measurement, reporting, and management. In NR MIMO, a large number of antennas such as 1024 are supported and a high frequency band such as 30 GHz is supported. Wireless communication using such millimeter waves exhibits high straightness and high path loss due to the characteristics of the corresponding band. need. 17 is a diagram illustrating such a hybrid beamforming system.

In FIG. 17, the base station and the terminal include an RF chain and a phase shifter for digital beamforming and analog beamforming. The analog beamforming method at the transmitting side is a method of concentrating a signal transmitted from each antenna in a specific direction by changing the phase of a signal transmitted from each antenna through a phase shifter using a plurality of antennas. For this purpose, an array antenna in a form in which a plurality of antenna elements are aggregated is used. If such transmission beamforming is used, it is possible to increase the propagation distance of a signal, and since the signal is hardly transmitted in any direction other than the corresponding direction, there is an advantage in that interference to other users is greatly reduced. Similarly, the receiving side can also perform receive beamforming by using the receiving array antenna, which also concentrates the reception of radio waves in a specific direction to increase the sensitivity of the received signal coming in that direction and receives the signal coming in the direction other than the corresponding direction. Interfering signals can be blocked by excluding them from the signal.

On the other hand, since the wavelength of the radio wave becomes shorter as the transmission frequency increases, for example, in the case of configuring the antenna at half-wavelength intervals, the array antenna may be configured with more element antennas in the same area. Accordingly, since a communication system operating in a high frequency band can obtain a relatively higher antenna gain compared to using the beamforming technique in a low frequency band, it is advantageous to apply the beamforming technique.

In this beamforming technology, in addition to applying analog beamforming technology to obtain a higher antenna gain, hybrid beamforming is applied to digital precoding used to obtain a high data rate effect in an existing multi-antenna system. beamforming) is used. In this case, when a beam is formed through analog beamforming and one or more analog beams are formed, digital precoding similar to that applied in the existing multi-antenna is applied and transmitted in the baseband to receive a more reliable signal or to achieve a higher system capacity. can be expected In the present invention, when a base station and a terminal support analog, digital, or hybrid beamforming, a method for measuring beam quality according to the beam switching capability of the corresponding base station and the terminal, and reporting and using the corresponding information is proposed.

The most important thing in applying the beamforming is to select a beam direction optimized for the corresponding base station and the terminal. In order to select an optimized beam direction, the base station and the terminal may support beam sweeping using a plurality of time and frequency resources. 18 is a diagram illustrating beam sweeping operations of a terminal and a base station in time resources.

In FIG. 18 , a terminal or a base station transmits a reference signal using a different beam for a time resource for beam selection of the corresponding terminal or base station. At this time, the base station or terminal that has received the reference signal measures the quality of the reference signal based on CSI, Reference Signals Received Power (RSRP), Reference Signals Received Quality (RSRQ), etc. One or a plurality of transmit or receive beams can be selected depending on the number of beams. Although FIG. 17 shows that a reference signal based on a different beam is transmitted through a different time resource, the same may be applied to a frequency, a cyclic shift, a code resource, and the like. In this case, as shown in FIG. 18 , a plurality of transmit beams may be transmitted for transmit beam sweeping, and one transmit beam may be repeatedly applied and transmitted for receive beam sweeping.

Beam management operations such as beam sweeping are also performed in the channel state reporting framework (resource configuration, CSI reporting configuration, CSI measurement configuration, link, etc.) mentioned in FIGS. 11 to 16, and periodic, semi-persistent, and aperiodic CSI-RS transmission. and channel state report/beam report.

In supporting the channel state report or beam report, in NR, a CSI-RS resource set for repeated transmission of a plurality of beams for transmission beam sweeping and one transmission beam for reception beam sweeping in resource configuration. It is possible to configure a plurality of CSI-RS resources in the can be provided.

Table 15: CSI-RS resource set settings

In Table 15, ResourceSetConfigList is a setting that allows a plurality of CSI-RS resource sets to be set. A plurality of CSI-RS resource sets may be configured in the corresponding configuration, and individual CSI-RS resource sets are individually configured through ResourceSetConfig. In the corresponding ResourceSetConfig, the settings of ResourceSetConfigId, CSI-RS-ResourceConfigList, and CSI-RS ResourceRepetitionConfig exist. In this case, the ResourceSetConfigId sets an ID for configuring the CSI-RS resource set, and the CSI-RS-ResourceConfigList is a CSI set in the corresponding CSI-RS resource set based on the IDs of the CSI-RS resources described in Table 14 above. - By setting the ID of the RS resources, it is possible to indicate the CSI-RS resource set in the CSI-RS resource set. CSI-RS ResourceRepetitionConfig determines whether CSI-RS resources configured in the corresponding CSI-RS resource set are transmitted based on different beams for transmission beam sweeping, or whether individual CSI-RS resources are the same CSI-RS. You can set whether to support resource repetition. At this time, the CSI-RS ResourceRepetitionConfig may be expressed as BeamRepetitionConfig or the like to indicate whether the CSI-RS resource set supports the same beam or not.

At this time, in configuring the repetition of CSI-RS resources in the corresponding CSI-RS resource set configuration, each CSI-RS resource can be configured only with 1 port CSI-RS or 1 port or 2 port CSI-RS resources. can In the transmission beam sweeping and reception beam sweeping described in FIG. 18, in the case of the corresponding transmission beam, the number may be as large as 1024, as described above, and this number becomes larger when the reception beam sweeping is considered. do. Therefore, by limiting the number of corresponding antenna ports to resources up to 1 port or 2 ports for setting the CSI-RS resource required for the corresponding sweeping, overhead required for reference signal transmission can be reduced and beam management can be supported efficiently. have.

For the above-mentioned Type I and Type II channel status report and beam management information report of the UE, the UE may report using PUSCH and PUCCH. In NR, in the case of PUCCH, two transmission types of PUCCH, a short duration PUCCH (short PUCCH) having a short period and a long duration PUCCH, a long PUCCH (PUCCH) having a long period, may be supported. 19 is a diagram illustrating transmission of a long PUCCH having a long period.

Such a long PUCCH may be transmitted through a minimum of 3 to a maximum of 14 OFDM symbols within one slot, and may be transmitted by aggregating a plurality of slots. The first purpose of this long PUCCH is to transmit a lot of information at once. In order to transmit such a large amount of information, it is possible to secure a lot of resources on the time axis by allowing up to 14 OFDM symbols to be transmitted within a slot, and in addition, it is possible to combine additional slots. In addition, as shown in FIG. 14, it is also possible to add more frequency resources by transmitting using more PRBs on the frequency axis. Through these relatively many time and frequency resources, the long PUCCH can support the terminal to transmit more information to the base station at once.

Another purpose of the long PUCCH is to enable the UE to secure coverage necessary for uplink control information (UCI) transmission. Unlike the base station, the terminal is transmitted with relatively low power compared to the base station for reasons of implementation space, battery, and the like. In addition, unlike downlink planned through cell planning in advance, in the case of uplink, interfering terminals may vary dynamically depending on the distribution and use of users, and in the worst case, other terminals may be located nearby and may experience high interference. have. Accordingly, such a terminal experiences a low Signal to Noise and Interference Ratio (SINR). In this case, the additional allocation of frequency resources lowers the energy per bit of the signal transmitted by the terminal, and accordingly, the same information is transmitted to several time resources to secure coverage of the terminal transmitted signal, thereby maintaining the energy per bit while maintaining the overall transmission of the signal. power can be increased. Accordingly, by repeatedly transmitting the same signal to a plurality of allocated time resources, it is possible to support the terminal to secure coverage of the corresponding signal. In addition, by supporting the DFT-S OFDM waveform exhibiting a low Peak-to-Average Power Ratio (PAPR) characteristic, it is possible to increase the uplink transmission efficiency of the UE.

Compared to the long PUCCH, the short PUCCH allows a small amount of information to be efficiently transmitted using a small number of resources. To this end, UCI can be transmitted in a small number of OFDM symbols (eg, one or two OFDM symbols), and is based on a CP-OFDM waveform for efficient data transmission. Although such short PUCCH transmission can be efficiently transmitted using CP-OFDM and a small number of OFDM symbols, UEs having a relatively good uplink channel state may transmit, and the UE is located at a cell boundary or is nearby uplink. If the quality of the uplink channel is not good enough due to the location of a terminal supporting link transmission at the same time, the corresponding transmission may not be supported.

Based on the short PUCCH and the long PUCCH, the PUCCH formats shown in Table 16 below are supported in NR.

Table 15: PUCCH format of NR

In this case, among the PUCCH formats, PUCCH formats 2, 3, and 4 may be used for channel state reporting. At this time, in the case of PUCCH format 2 based on short PUCCH, only periodic or semi-persistent channel state reporting is supported using only Type I CSI. In addition, by supporting only wideband or partial band channel state information reporting that reports only one PMI and CQI, the base station can easily monitor the channel state based on a small amount of information.

Long PUCCH-based PUCCH formats 3 and 4 are the same as format 2 in that only periodic or semi-persistent channel state reporting is supported, but subband reporting that reports Type II CSI and PMI and CQI for each subband is supported. It differs from PUCCH format 2 in that it is. Also, there is a difference that format 4 supports multiplexing between terminals using OCC in addition to format 3 .

When a report based on these PUSCHs and PUCCHs does not allow the UE to report a plurality of channel states, or when the amount of information that can be transmitted based on PUCCH and PUSCH is insufficient, the rest or all should be dropped except for one. can 20 is a diagram exemplifying assuming a situation when short PUCCH (format 2) and long PUCCH (format 4) collide among them.

In the collision of these different transmission type-based reports as exemplified in FIG. 20 (collision of PUCCH and PUSCH-based reports) and the collision of the same transmission type (collision of PUCCH and PUCCH or collision of PUSCH and PUSCH), the UE excludes one In order to drop some of the rest or all, the following priorities can be considered.

- Priority determination method 1: Determined based on the time transmission type of the channel status report

- Priority determination method 2: Determination based on the transmission channel and channel format (PUCCH or PUSCH, etc.) of the corresponding channel state report

- Priority determination method 3: Determined according to the type of channel state information report

- Priority determination method 4: Determined according to the corresponding codebook type

- Priority determination method 5: Determined according to the number of PMI reports

- Priority determination method 6: Determination and determination based on channel state report configuration ID or CSI-RS ID

Priority determination method 1 is a method of determining based on a time transmission type. Table 16 is a table showing that the base station sets the time transmission type of the channel state information through RRC when setting the channel state report to the terminal.

Table 16: Time transmission type setting of channel status report

As shown in Table 16, the UE can receive the time transmission type of the corresponding channel state report set from the base station through the CSI reporting setting in the RRC field or the RRC field provided in the CSIReportConfig. This setting may be set to aperiodic, semi-persistent transmission using PUCCH, semi-persistent transmission using PUSCH, periodic transmission, and the like. In this case, priority may be considered in case of collision according to such a transmission type. For example, when aperiodic transmission collides with periodic transmission or semi-persistent transmission, aperiodic transmission may be prioritized. In the case of aperiodic transmission, detailed information is triggered according to the needs of the base station, and it contains a lot of information (Type II CSI, subband report information, etc.) that is urgent compared to the channel state information previously set through RRC or MAC CE. . Accordingly, in the case of a collision, the UE may preferentially report aperiodic channel state information. Similarly, it is also possible for the terminal to transmit the semi-persistent transmission with priority when the semi-persistent transmission and the periodic transmission collide. In the case of semi-persistent transmission, a relatively large amount of information (eg, subband report information) can be contained, and accordingly, semi-persistent transmission, which can be freely activated and deactivated, is preferentially transmitted, thereby efficiently operating a communication system.

Priority determination method 2 is a method of determining according to which transmission channel and format (PUSCH or PUCCH and PUCCH format) the corresponding channel state information or beam management information is transmitted. Table 17 below is a field showing the PUCCH format and resource configuration required for the base station to configure the channel state report to the terminal.

Table 17: PUCCH format and resource settings for channel status reporting

As mentioned above, the short PUCCH-based PUCCH format 2 supports a low coverage and a low amount of information, but can deliver information quickly through a small amount of time and frequency resources. However, in the case of long PUCCH-based PUCCH formats 3 and 4, high coverage can be supported through repeated transmission, and subbands requiring a lot of information or Type II channel state information reporting can be supported through a large amount of resources. Therefore, when format 2 and format 3 or 4 collide, format 3 or 4 based channel state information reporting that requires more information and resources is prioritized so that the base station secures more information and high coverage-based PUCCH report. can do. In addition, it is also possible to give priority to PUSCH-based transmission supporting more information even when PUSCH and PUCCH collide.

In addition, when PUCCH formats 3 and 4 collide, it is possible to prioritize PUCCH format 3 . In the case of PUCCH format 4, since a plurality of terminals multiplex and transmit through OCC, the reporting performance of the corresponding PUCCH may not be high. Accordingly, by preferentially transmitting PUCCH format 3, which can secure better coverage, the base station can reliably acquire channel state information.

In addition, it is also possible to give priority to PUCCH format 4 on the contrary. In the case of PUCCH format 4, since the base station can efficiently use resources according to multiplexing of the terminal, it enables efficient support with fewer resources than when the PUCCH format 3 is used. Accordingly, it is possible to enable the base station to efficiently support radio resources by preferentially transmitting PUCCH format 4.

In addition, in the case of priorities between PUCCH formats 3 and 4, the base station may set an RRC setting to set which of the corresponding formats has a higher priority. As mentioned above, since there are advantages according to each format transmission, the base station can be flexibly set and used according to the situation of the corresponding system.

Priority determination method 3 is a method of determining according to the type of the corresponding channel state information. Table 18 below shows a field in which the base station sets the channel state report to the UE or sets the information used for the corresponding channel state report in CSIReportConfig in the RRC.

Table 18: Information Settings Fields Used for Channel Status Reporting

As shown above, according to the information setting field, CRI/RI/PMI/CQI-based report, CRI/RI/i1-based report, CRI/RI/i1/CQI-based report, CRI/RI/CQI-based report, CRI/RSRP Based reporting, SSB index/RSRP-based reporting, CRI/RI/LI/PMI/CQI-based reporting, etc. can be configured. By allowing the UE to set priorities and report according to such a setting, it is possible to efficiently report the channel state and the beam management information.

For example, CQI-based reporting groups (CRI/RI/PMI/CQI, CRI/RI/i1, CRI/RI/i1/CQI, CRI/RI/CQI, CRI/RI/LI/PMI/CQI, etc.) and RSRP It can be divided into base reporting groups (CRI/RSRP or SSB index/RSRP) to support CQI-based reporting to take precedence when two groups collide. This is because the CQI-based report includes more information such as RI/PMI/CQI and requires more terminal complexity for this calculation.

Conversely, it is also possible to support RSRP-based reporting to take precedence. This is because, if the beam-based report possessed by the base station is not accurate, it is impossible to properly transmit control signals and data to the terminal.

In addition, it is also possible to determine the priority between the CQI-based reporting group and the RSRP-based reporting group differently depending on the time transmission type of the priority determination method 1 mentioned above. For example, in the case of periodic and semi-persistent channel and beam management information reporting, information of a CQI-based reporting group that requires more information and calculation amount for monitoring may be more useful. In particular, since the beam information changes relatively less frequently, it is preferable to give priority to the information of the CQI-based reporting group in the case of periodic and semi-persistent channel and beam management information reporting for channel monitoring. However, in the case of aperiodic channel state and beam management information reporting, the base station determines that beam information for transmitting control information and data to the terminal is not accurate and triggers it urgently, so that it may be requested more urgently than CQI information. Therefore, the information of the RSRP-based reporting group can be transmitted in preference to the CQI-based reporting group.

In addition, if there is a collision within the RSRP-based reporting group, CRI/RSRP reporting may take precedence over SSB index/RSRP reporting. This is because CSI-RS-based CRI reporting requires additional reference signal overhead through CSI-RS and can generate more accurate information through a wider band.

In addition, in the case of information including i2 (CRI/RI/PMI/CQI, etc.) and information not including i2 (CRI/RI/i1/CQI or CRI/RI/i1, etc.) in the CQI-based reporting group, i2 is You can make the included information take precedence. This is because, in the case of information not including i2, the base station considers that the mobile station has a fast moving speed and cycles the precoder to obtain and report the average CQI value. It is possible.

Conversely, it is also possible to prioritize information not including i2. In the case of CRI/RI/i1, based on many CSI-RS ports or resource-based NP (non-precoded) CSI-RS or cell-specific BF (beamformed) CSI-RS-based operation and small CSI-RS ports, It is for supporting operation based on hybrid CSI based on one UE specific BF CSI-RS. 21 and 22 show such hybrid CSI-based operation.

The NP CSI-RS of FIG. 21 that requires many CSI-RS ports (eg, 32 ports) allows the UE to report precoding information and CQI by calculating accurate information based on many CSI-RS ports. Although it has the advantage of being there, it requires a lot of reference signal overhead. The Cell-specific BF CSI-RS of FIG. 22 also calculates accurate information based on many CSI-RS resources (eg, 64), and uses beam information and corresponding PMI through CRI (CSI-RS Resource Indicator). Although it has the advantage of being able to report information such as and CQI, it requires a lot of reference signal overhead. Conversely, UE-specific BF CSI-RS has the advantage of reporting channel state information based on a small number of CSI-RS ports (eg, 4 ports) and resources (eg, 1), but It is possible to secure prior beam or channel information through SRS, NP CSI-RS, or cell-specific BF CSI-RS. Accordingly, the pre-beam or channel information is acquired through the long period-based NP CSI-RS or the cell-specific BF CSI-RS, and the channel information is acquired in the corresponding beam through the short period-based UE-specific BF CSI-RS. Through this method, it is possible to reduce the reference signal overhead and efficiently acquire the channel state information. At this time, in the case of CRI/RI/i1, for this hybrid-based operation, the terminal is used to transmit approximate beam direction information. Accordingly, a lot of overhead-based information can be solved by giving priority to general CQI information.

Additionally, the above-mentioned priority according to the presence or absence of i1 may be applied differently between CRI/RI/i1/CQI and CRI/RI/i1. For example, CRI/RI/i1 has a higher priority than CRI/RI/PMI/CQI, and CRI/RI/i1/CQI has a lower priority than CRI/RI/PMI/CQI .

In addition, in the case of information including PMI (CRI/RI/PMI/CQI, etc.) and information not including PMI (CRI/RI/CQI) within a CQI-based reporting group, information including PMI may be prioritized. This is because the information including the PMI contains direction information, so more information can be provided to the base station.

Conversely, it is also possible to give preference to information that does not include PMI. This is because, in the case of information not including PMI, for TDD-based operation, channel state information is obtained in advance through SRS, so that information with higher accuracy than PMI can be provided.

In addition, in the case of reporting between information including LI (CRI/RI/LI/PMI/CQI, etc.) and information not including LI (CRI/RI/PMI/CQI, etc.), the UE selects a more preferred layer for PTRS transmission. Since LI information for indicating is additionally transmitted, the information reported by the LI may be prioritized over the reporting of information not reported by the LI.

The priority determination method 4 determines differently according to the codebook type. As mentioned above, NR supports two types of channel state reporting codebooks, Type I/Type II. Table 19 below shows the RRC field for setting the Type I and Type II channel state reporting codebooks.

Table 19: RRC Fields for Type I and Type II Channel Status Reporting Codebook Settings

At this time, the Type II channel status report is always reported assuming a sub-band, and the relative amplitude and phase difference for combining are reported together for combining the main beam and the sub-beam in a form in which several beams are combined instead of one beam. will do The relative amplitude and phase difference can be additionally reported in the subband along with the amplitude and phase difference of the entire band. In this case, the presence or absence of the subband phase difference can be set by RRC. In addition, in the case of a beam for combining, up to four beams can be combined, and the number of beams actually used for combining can also be set by RRC.

As described above, the Type II channel status report requires a lot of UE complexity compared to the Type I channel status report, and thus includes a lot of information. Accordingly, by allowing the terminal to prioritize the Type II channel state report, the base station can preferentially obtain more information. In addition, such a report may be made within the CQI-based reporting group mentioned in the priority determination method 3 above.

Priority determination method 5 is to determine according to the CSI report configuration or the PMI type configuration of CSIReportConfig. Table 20 shows the RRC field for configuring the PMI type.

Table 20: RRC Fields for Type I and Type II Channel Status Reporting Codebook Settings

As shown in Table 20, the base station gives priority to the terminal according to whether a corresponding PMI report is reported on a full-band basis or a plurality of reports for each subband. Since the subband report reports PMI for each subband, it is based on more UE calculation complexity and contains a lot of information. Accordingly, by prioritizing information reported for each subband, the base station can preferentially obtain more information. In addition, such a report may be made within the CQI-based reporting group mentioned in the priority determination method 3 above.

Priority determination method 6 is to determine based on the CSI report configuration or CSIReportConfig or the ID of the CSI-RS or Cell connected to the CSI report configuration. The base station may assign a low ID to the UE in the case of a more important cell (eg, a primary cell), and may assign a high ID to a relatively less important cell (eg, a secondary cell). Therefore, the CSI report configuration with a low ID or CSI report configuration or CSIReportConfig or a report with the ID of the CSI-RS or Cell connected to the CSI reporting configuration have priority over the CSI report configuration, thereby solving the collision situation of the channel state report.

In addition, the priority determination methods 1 and 3 can be combined to be used as in Equation 2 below.

[Equation 2]

Aperiodic RSRP > Aperiodic Type II > Aperiodic Type I > Semi-persistent Type II > Semi-persistent Type I > Semi-persistent RSRP > Periodic Type I > Periodic RSRP

As mentioned above, this is to obtain urgent beam-related information in the case of aperiodic RSRP-based information, and in the case of semi-persistent and periodic RSRP, CQI-based reporting may be given priority. Priority differentiation of such RSRP-based information can also be applied differently depending on whether PUCCH or PUSCH is used within the semi-persistent channel state report. Equation 2-1 is an equation showing that different priorities are applied within the semi-persistent report.

[Equation 2-1]

Aperiodic RSRP > Aperiodic Type II > Aperiodic Type I > PUSCH-based semi-persistent RSRP > PUSCH-based semi-persistent Type II > PUSCH-based semi-persistent Type I > PUCCH-based semi-persistent Type II > PUCCH-based semi-persistent Type I > PUCCH-based Semi-persistent RSRP > Periodic Type I > Periodic RSRP

Semi-persistent channel status report has different methods of activation and deactivation depending on whether the corresponding channel status report uses PUCCH or PUSCH. When PUSCH is used, DCI is used to activate and deactivate SPS (semi-persistent scheduling), whereas when PUCCH is used, it is activated using MAC CE. Therefore, the PUSCH-based semi-persistent report can be triggered faster using DCI, and the RSRP report based on this can be quickly requested from the base station like the aperiodic RSRP report. Therefore, it can be used to obtain urgent beam information, such as an aperiodic RSRP report. However, in the case of PUCCH-based semi-persistent RSRP reporting, since it is activated and deactivated using MAC CE, a longer delay time is required for activation and deactivation, and thus it is difficult to use to obtain urgent beam information. Therefore, in case of semi-persistent PUSCH report, it is possible to give priority to RSRP report and to give priority to Type II information in case of semi-persistent PUCCH report.

In addition to this, it is also possible to use as in Equation 3 below.

[Equation 3]

Aperiodic Type II > Aperiodic RSRP > Aperiodic Type I > Semi-persistent Type II > Semi-persistent Type I > Semi-persistent RSRP > Periodic Type I > Periodic RSRP

This should take precedence over any information because aperiodic Type II CSI contains a lot of information, and is to proceed with RSRP-based reporting and Type I reporting for the beam afterwards. Beam information is very important information, and aperiodic RSRP information is preferred over Type I because it is used to obtain urgent information, but Type II is preferred over RSRP because it requires a lot of calculation complexity and reporting overhead. can Equation 3 may also be extended as shown in Equation 3-1 below according to which channel is used for the semi-persistent channel state report.

[Equation 3-1]

Aperiodic Type II > Aperiodic RSRP > Aperiodic Type I > PUSCH-based semi-persistent Type II > PUSCH-based semi-persistent RSRP > PUSCH-based semi-persistent Type I > PUCCH-based semi-persistent Type II > PUCCH-based semi-persistent Type I > PUCCH-based Semi-persistent RSRP > Periodic Type I > Periodic RSRP

In addition, it is also possible to support, as in Equation 4, which supports priority in the same way as semi-persistent and periodic even in aperiodic, based on the amount of information.

[Equation 4]

Aperiodic Type II > Aperiodic Type I > Aperiodic RSRP > Semi-persistent Type II > Semi-persistent Type I > Semi-persistent RSRP > Periodic Type I > Periodic RSRP

Also, in the same time transmission type, more information can be acquired by giving Type II priority over Type I.

An additional priority may be given based on the above equations. When reports having the same priority (eg, periodic Type I and periodic Type I) collide, it may be determined based on the PUCCH format of Priority Determination Method 2 . For example, when PUCCH format 2 of periodic Type I and PUCCH format 3 reporting of periodic Type I collide, PUCCH format 3 information may be transmitted with priority.

In addition, based on Equations 2, 2-1, 3, 3-1, and 4, it can be additionally determined based on the PMI form of the priority determination method 5. For example, when the periodic Type I full-band PMI report collides with the periodic Type I subband PMI report, the subband PMI report may be transmitted with priority.

It is also possible to apply the priority determination methods 2 and 5 at once based on Equations 2, 2-1, 3, 3-1, and 4 above. It is also possible to apply the determination method 5 if the priority is the same even after applying the determination method 2, or to apply the determination method 2 if the determination method 5 is the same priority after applying the priority 5.

In addition, if the priorities are the same even after the above method, the priority may be additionally determined based on the ID of the priority determination method 6 .

A resource for interference measurement may be configured for the above-mentioned channel state reporting operation and beam management operation. For such interference measurement, the interference measurement method of FIGS. 23 and 24 may be used.

The interference measurement method of FIG. 23 is a method of separately measuring an interference measurement resource for each channel measurement resource. As mentioned above, in NR, different beams can be supported for each CSI-RS resource for beam management and reporting. have. Accordingly, by supporting different interference measurement resources for each CSI-RS resource, it is possible to correctly apply and measure different interference for each beam.

The interference measurement method of FIG. 24 is a method of placing a plurality of interference measurement resources in one channel measurement resource. When a plurality of beams and MU-MIMO transmission are supported, interference situations that may occur to the UE vary. In this case, when all the interference measurement resources are allocated for each corresponding interference situation, the overhead for the interference measurement becomes excessive. Accordingly, the base station can reduce the number of interference measurement resources by summing the interference transmitted from a plurality of resources and measuring the interference as interference for generating channel report state information. 25 is a diagram illustrating a process in which the UE calculates the total interference by summing the interference measured from the plurality of interference resources.

As mentioned above, both of the interference measurement methods of FIGS. 23 and 24 have advantages. Therefore, in order for the terminal to simultaneously support the methods of FIGS. 23 and 24, the following method may be considered.

- Interference measurement setting method 1: RRC setting support for interference measurement for each channel measurement resource and setting of a plurality of interference measurement resources

- Interference measurement setting method 2: Interference measurement method classification according to the number of channel measurement resources

- Interference measurement setting method 3: RRC setting support for classifying interference measurement resources for each channel measurement resource

- Interference measurement setting method 4: Classification of interference measurement method according to whether or not it is repeated

- Interference measurement setting method 5: Interference measurement method classification according to the report information of the channel state report

Interference measurement configuration method 1 is a method of supporting RRC configuration for interference measurement for each channel measurement resource and configuration of a plurality of interference measurement resources. Through RRC, the UE may consider the corresponding operation by allowing the UE to configure whether to support one interference resource or a plurality of interference resources for each CSI-RS resource for channel measurement through RRC. At this time, when it is set to use one interference resource for each CSI-RS resource, the number of CSI-RS resources set in the CSI-RS set for channel resource measurement and the CSI-RS resource set in the CSI-RS set for interference measurement may be the same number of

Interference measurement setting method 2 is a method of classifying interference measurement methods according to the number of channel measurement resources. When there is only one channel measurement resource, it may be a case in which detailed MU-MIMO or CoMP related information is additionally acquired based on one beam determined through information obtained in advance. Accordingly, in this case, measurement may be required in consideration of a plurality of interference resources in one channel measurement resource. However, when a plurality of channel measurement resources are configured, it is for beam information acquisition, and in this case, an interference resource may be required for each beam. Accordingly, in this case, the interference resource for each beam can be supported by configuring a plurality of interference resources. In this case, the number of CSI-RS resources configured in the CSI-RS set for channel resource measurement may be the same as the number of CSI-RS resources configured in the CSI-RS set for interference measurement.

Interference measurement configuration method 3 is a method of supporting RRC configuration for classifying interference measurement resources for each channel measurement resource. By supporting the same number of bitmaps as the number of channel measurement resources for RRC configuration, resources to be used for interference measurement for each channel resource may be set as bitmaps. For example, 1 may mean a used interference resource and 0 may mean an unused interference resource. In this case, the size of the bitmap may be equal to the number of configured interference measurement resources. In addition, in order to support the use of different beams, overlapping of interference resource settings used for each channel measurement resource is not allowed or the UE may ignore it. For example, the base station may not configure or the terminal may ignore that the CSI-RS resources 0 and 1 use the interference measurement resource 0 at the same time.

Interference measurement setting method 4 is a method of classifying an interference measurement method according to whether or not it is repeated. As mentioned above, the base station may repeatedly transmit the beam to support the reception beam change of the terminal, and for this purpose, the repeating transmission of the CSI-RS may be configured in the CSI-RS resource. In this case, since the UE must use a different reception beam for each resource, the interference resource may be always set for each resource or the interference measurement resource may be designated by RRC through the interference measurement setting method 3 . When interference resources are configured for each resource, as mentioned above, the number of CSI-RS resources configured in the CSI-RS set for channel resource measurement is the same as the number of CSI-RS resources configured in the CSI-RS set for interference measurement. can

Interference measurement setting method 5 is a method of classifying an interference measurement method according to report information of a channel state report. As mentioned above, in the case of RSRP-based reporting, the analog beam is highly likely to be different as information for beam management, and in CQI-based reporting, digital beam management can be supported based on a predetermined analog beam. Therefore, in RSRP-based reporting, interference resources are configured for each resource, and in CQI-based reporting, interference of the configured interference resources is collected and regarded as one interference to generate a channel report.

In order to support the interference measurement configuration method, both NZP (Non-Zero Power) CSI-RS and ZP (Zero Power) CSI-RS may be considered and configured. When the NZP CSI-RS is configured, the UE measures a channel from the NZP CSI-RS and uses it as interference. When the ZP CSI-RS is configured, the terminal can measure the power of interference transmitted from other base stations and terminals in a state in which the signal for the corresponding terminal is muted, and use it to generate a channel state report. Only one of the ZP CSI-RS and NZP CSI-RS for the interference measurement may be configured, or both types may be configured. For this support, an NZP CSI-RS set for channel measurement, an NZP CSI-RS set for interference measurement, and a ZP CSI-RS set for interference measurement exist in the channel state report configuration in RRC or in the resource configuration connected to CSIReportConfig. can In this case, the number of channel measurement resources configured above may be the number of NZP CSI-RS resources configured and indicated by RRC to be used for a corresponding report in the NZP CSI-RS set for channel measurement. In addition, the meaning that the number of channel measurement resources and the number of interference resources are the same can be individually applied to the ZP CSI-RS set and the NZP CSI-RS set for interference measurement, and the number of resources directly set in the interference CSI-RS set or It may be the number of CSI-RSs indicated and configured to be used for corresponding measurement and reporting as RRC in the set.

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

Referring to FIG. 26 , the UE receives measurement configuration and resource configuration information in step 2610 . Such information may include information on a reference signal for channel measurement. For example, the reference signal type, the number of ports of the reference signal, the codebook type, N1 and N2, which are the number of antennas per dimension, O1, O2, which are the oversampling factors for each dimension, one subframe config and location for transmitting a plurality of CSI-RSs A plurality of resource configs for setting up, codebook subset restriction related information, CSI report related information, CSI-process index, candidate number for timing indication between aperiodic channel status report trigger and aperiodic channel status report, and transmit power information ( At least one of P _C ) can be identified. Thereafter, the terminal configures one piece of feedback configuration information through the channel state report setting used in the corresponding measurement setting in step 2620 . The information includes PMI/CQI report status, cycle and offset, RI cycle and offset, CRI cycle and offset, wideband/subband status, submode, channel status report type, timing indication between aperiodic channel status report trigger and aperiodic channel status report Candidate numbers for , etc. may be set. When the terminal receives the reference signal based on the corresponding information in step 2040, it estimates a channel between the base station antenna and the reception antenna of the terminal based on this. In step 2640, the UE generates feedback information rank, PMI, and CQI using the received feedback setting based on the estimated channel, and may select an optimal CRI based thereon. Thereafter, the terminal transmits the feedback information to the base station at a predetermined feedback timing according to the feedback setting of the base station or the timing indication between the aperiodic channel state report trigger and the aperiodic channel state report trigger and the aperiodic channel state report in step 2650, and the channel feedback Complete the creation and reporting process.

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

Referring to FIG. 27, in step 2710, the base station transmits a reference signal for measuring a channel and configuration information for a channel state report configuration to the terminal. In the configuration information, at least one of the type of each reference signal, time, frequency resource location, service type, supported feedback type, and measurement subset may be set, and based on this, the number of ports for the reference signal in order to transmit the reference signal; N1 and N2, which are the number of antennas for each dimension, O1, O2, which are oversampling factors for each dimension, one subframe config for transmitting multiple reference signals and a plurality of resource configs to set the location, codebook subset restriction related information, CSI reporting related It may include at least one of information, CSI-process index, and transmit power information ( _PC ). Thereafter, the base station transmits feedback configuration information based on at least one CSI-RS to the terminal in step 7120 . In the corresponding information, PMI/CQI period and offset, RI period and offset, CRI period and offset, wideband/subband or not, submode, candidate number for timing indication between aperiodic channel state report trigger and aperiodic channel state report, etc. to be set. can Thereafter, the base station transmits the configured CSI-RS to the terminal. The terminal estimates a channel for each antenna port and estimates an additional channel for a virtual resource based on this. The UE determines the feedback, generates CRI, PMI, RI, and CQI corresponding thereto, and transmits the generated CRI, PMI, RI, and CQI to the base station. Accordingly, the base station receives the feedback information from the terminal at a predetermined timing in step 2730, and uses it to determine the channel state between the terminal and the base station.

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

Referring to FIG. 28 , the terminal includes a communication unit 2810 and a control unit 2820 . The communication unit 2810 performs a function of transmitting or receiving data from the outside (eg, a base station). Here, the communication unit 2810 may transmit feedback information to the base station under the control of the control unit 2820 . The controller 2820 controls the state and operation of all components constituting the terminal. Specifically, the control unit 2820 generates feedback information according to information allocated from the base station. Also, the controller 2820 controls the communication unit 2810 to feed back the generated channel information to the base station according to timing information allocated from the base station. To this end, the controller 2820 may include a channel estimator 2830 . The channel estimator 2830 determines the location of the corresponding resource in time and frequency resources through the service and feedback information received from the base station, and checks the necessary feedback information through the CSI-RS and feedback allocation information related thereto. A channel is estimated using the received CSI-RS based on the feedback information. In FIG. 28 , an example in which the terminal includes the communication unit 2810 and the control unit 2820 has been described, but the present invention is not limited thereto, and various configurations may be further provided according to functions performed in the terminal. For example, the terminal may further include a display unit for displaying the current state of the terminal, an input unit to which a signal such as performing a function from a user is input, a storage unit for storing data generated in the terminal, and the like. In addition, although it is illustrated that the channel estimator 2830 is included in the controller 2820 above, the present invention is not limited thereto. The controller 2820 may control the communication unit 2810 to receive configuration information for each of at least one or more reference signal resources from the base station. Also, the control unit 2820 may control the communication unit 2810 to measure the at least one reference signal and receive feedback setting information for generating feedback information according to the measurement result from the base station.

In addition, the controller 2820 may measure at least one or more reference signals received through the communication unit 2810 and generate feedback information according to the feedback setting information. In addition, the controller 2820 may control the communication unit 2810 to transmit the generated feedback information to the base station at a feedback timing according to the feedback setting information. In addition, the controller 2820 may receive the CSI-RS from the base station, generate feedback information based on the received CSI-RS, and transmit the generated feedback information to the base station. At this time, the control unit 2820 selects each precoding matrix for each antenna port group of the base station and further selects one additional precoding matrix based on the relationship between the antenna port groups of the base station. have.

In addition, the controller 2820 may receive the CSI-RS from the base station, generate feedback information based on the received CSI-RS, and transmit the generated feedback information to the base station. In this case, the controller 2820 may select one precoding matrix for all antenna port groups of the base station. In addition, the control unit 2820 receives the feedback configuration information from the base station, receives the CSI-RS from the base station, generates feedback information based on the received feedback configuration information and the received CSI-RS, and the generated Feedback information may be transmitted to the base station. In this case, the controller 2820 may receive feedback configuration information corresponding to each antenna port group of the base station and additional feedback configuration information based on the relationship between the antenna port groups.

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

Referring to FIG. 29 , the base station includes a control unit 2910 and a communication unit 2920 . The control unit 2910 controls the state and operation of all components constituting the base station. Specifically, the controller 2910 allocates a CSI-RS resource for channel estimation and related configuration for the UE to acquire resource information to the UE, and allocates a feedback resource and a feedback timing to the UE. To this end, the controller 2910 may further include a resource allocator 2930 . In addition, feedback setting and feedback timing are allocated so that feedback from multiple terminals does not collide, and feedback information set at the corresponding timing is received and interpreted. The communication unit 2920 performs a function of transmitting and receiving data, a reference signal, and feedback information to the terminal. Here, the communication unit 2920 transmits the CSI-RS to the UE through the allocated resources under the control of the control unit 2910 and receives feedback on channel information from the UE. In addition, a reference signal is transmitted based on CRI, rank, PMI partial information, CQI, etc. obtained from the channel state information transmitted by the UE.

In the above description, the resource allocator 2930 is illustrated as being included in the controller 2910 , but the present invention is not limited thereto. The controller 2910 may control the communication unit 2920 to transmit configuration information for each of the at least one or more reference signals to the terminal, or may generate the at least one or more reference signals. Also, the controller 9310 may control the communication unit 2920 to transmit feedback setting information for generating feedback information according to the measurement result to the terminal. Also, the controller 2910 may control the communication unit 2920 to transmit the at least one reference signal to the terminal and receive feedback information transmitted from the terminal at a feedback timing according to the feedback setting information. Also, the controller 2910 may transmit feedback configuration information to the terminal, transmit a CSI-RS to the terminal, and receive feedback information generated based on the feedback configuration information and the CSI-RS from the terminal. . In this case, the controller 2910 may transmit feedback configuration information corresponding to each antenna port group of the base station and additional feedback configuration information based on the relationship between the antenna port groups. Also, the controller 2910 may transmit a beamformed CSI-RS to the terminal based on the feedback information, and receive feedback information generated based on the CSI-RS from the terminal. According to the above-described embodiment of the present invention, it is possible to prevent the base station having a large number of transmit antennas having a two-dimensional antenna array structure from allocating excessive feedback resources to transmit the CSI-RS and increasing the channel estimation complexity of the terminal. In addition, the terminal can effectively measure all channels for a large number of transmit antennas, configure it as feedback information, and notify the base station.

Claims (20)

A method of a terminal in a communication system, comprising:
Receiving, from the base station, one or more CSI (channel state information) reporting configuration;
when two CSI reports overlap in a time domain resource based on the one or more CSI report settings, identifying one of the two CSI reports having a higher priority; and
Transmitting the identified CSI report to the base station,
The priority of the CSI report is based on at least one of a time domain transmission type of the CSI report or a report quantity type of the CSI report,
In the identification of the priority, the time domain transmission type takes precedence over the report amount type,
The report amount type is characterized in that it relates to whether the CSI report includes a reference signal received power (RSRP) report. According to claim 1,
The priority according to the time domain transmission type is a non-periodic CSI report, semi-persistent (semi-persistent) CSI report, characterized in that the higher in the order of the periodic CSI report. According to claim 1,
The priority according to the report amount type is the CSI report including the RSRP report, characterized in that the higher in the order of the CSI report not including the RSRP report. According to claim 1,
The priority method, characterized in that the CSI report associated with a low number of cell identifiers is higher in the order of the CSI report associated with a high number of cell identifiers. According to claim 1,
The method, characterized in that the priority is high in the order of a CSI report associated with a low number of CSI reporting configuration identifiers and a CSI report associated with a high number of CSI reporting configuration identifiers. A method of a base station in a communication system, comprising:
Transmitting one or more CSI (channel state information) reporting configuration to the terminal; and
When two CSI reports overlap in a time domain resource based on the one or more CSI report settings, receiving one of the two CSI reports from the terminal having a higher priority,
The priority of the CSI report is based on at least one of a time domain transmission type of the CSI report or a report quantity type of the CSI report,
In the identification of the priority, the time domain transmission type takes precedence over the report amount type,
The report amount type is characterized in that it relates to whether the CSI report includes a reference signal received power (RSRP) report. 7. The method of claim 6,
The priority according to the time domain transmission type is a non-periodic CSI report, semi-persistent (semi-persistent) CSI report, characterized in that the higher in the order of the periodic CSI report. 7. The method of claim 6,
The priority according to the report amount type is the CSI report including the RSRP report, characterized in that the higher in the order of the CSI report not including the RSRP report. 7. The method of claim 6,
The priority method, characterized in that the CSI report associated with a low number of cell identifiers is higher in the order of the CSI report associated with a high number of cell identifiers. 7. The method of claim 6,
The method, characterized in that the priority is high in the order of a CSI report associated with a low number of CSI reporting configuration identifiers and a CSI report associated with a high number of CSI reporting configuration identifiers. In the terminal of a communication system,
transceiver; and
connected to the transceiver,
Receive one or more CSI (channel state information) report configuration from the base station,
When two CSI reports overlap in a time domain resource based on the one or more CSI report settings, identify one of the two CSI reports having a higher priority,
A control unit for transmitting the identified CSI report to the base station,
The priority of the CSI report is based on at least one of a time domain transmission type of the CSI report or a report quantity type of the CSI report,
In the identification of the priority, the time domain transmission type takes precedence over the report amount type,
The report amount type is a terminal, characterized in that it relates to whether the CSI report includes a reference signal received power (RSRP) report. 12. The method of claim 11,
The priority according to the time domain transmission type is a terminal, characterized in that aperiodic CSI report, semi-persistent (semi-persistent) CSI report, characterized in that the higher in the order of the periodic CSI report. 12. The method of claim 11,
The priority according to the report amount type is the CSI report including the RSRP report, and the CSI report not including the RSRP report is higher in the order of the terminal. 12. The method of claim 11,
The priority is a terminal, characterized in that the highest in the order of a CSI report associated with a low number of cell identifiers and a CSI report associated with a high number of cell identifiers. 12. The method of claim 11,
The priority is a CSI report associated with a low number of CSI reporting configuration identifiers, the terminal, characterized in that the higher in the order of CSI reports associated with a high number of CSI reporting configuration identifiers. In a base station of a communication system,
transceiver; and
connected to the transceiver,
One or more CSI (channel state information) report settings are transmitted to the terminal,
When two CSI reports overlap in a time domain resource based on the one or more CSI report settings, a control unit for receiving one of the two CSI reports having a higher priority from the terminal,
The priority of the CSI report is based on at least one of a time domain transmission type of the CSI report or a report quantity type of the CSI report,
In the identification of the priority, the time domain transmission type takes precedence over the report amount type,
The reporting amount type is a base station, characterized in that it relates to whether the CSI report includes a reference signal received power (RSRP) report. 17. The method of claim 16,
The base station, characterized in that the priority according to the time domain transmission type is high in the order of aperiodic CSI report, semi-persistent CSI report, and periodic CSI report. 17. The method of claim 16,
The priority according to the report amount type is the CSI report including the RSRP report, the base station, characterized in that the higher in the order of the CSI report not including the RSRP report. 17. The method of claim 16,
The priority is a CSI report associated with a low number of cell identifiers, the base station, characterized in that the higher in the order of the CSI report associated with a high number of cell identifiers. 17. The method of claim 16,
The priority is a CSI report associated with a low number of CSI reporting configuration identifiers, the base station, characterized in that the highest in the order of CSI reports associated with a high number of CSI reporting configuration identifiers.

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