Device and method for csi reporting in wireless communication system

Abstract

The present disclosure relates to a 5G or 6G communication system for providing higher data transmission rates beyond a previous 4G communication system, such as LTE. A method performed by a terminal in a wireless communication system may comprise the steps of: receiving, from a base station, information for triggering the transmission of an indicator for a change in channel state; transmitting, to the base station, at least one indicator for the change in the channel state on the basis of the information for triggering the transmission of the indicator; and transmitting, to the base station, a measurement report except for data for at least one parameter of which the value has not changed among one or more parameters, wherein the information for triggering the transmission includes information about at least one parameter for the indicator among a plurality of parameters associated with the channel state, and the at least one indicator may indicate whether the value of the at least one parameter has changed.

Description

Device and method for performing CSI reporting in a wireless communication system

[0001] The present disclosure relates to a wireless communication system (or mobile communication system). Specifically, the present disclosure relates to a device and method for performing CSI reporting in a wireless communication system.

[0002] Looking back at the evolution of wireless communication over successive generations, technologies have primarily been developed for human-facing services such as voice, multimedia, and data. With the commercialization of the 5G (5th Generation) communication system, an explosive increase in connected devices is expected to be connected to communication networks. Examples of networked objects include vehicles, robots, drones, home appliances, displays, smart sensors installed in various infrastructures, construction equipment, and factory equipment. Mobile devices are also expected to evolve into diverse form factors, such as augmented reality glasses, virtual reality headsets, and holographic devices. In the 6G (6th Generation) era, efforts are being made to develop improved 6G communication systems to connect hundreds of billions of devices and objects and provide diverse services. For this reason, 6G communication systems are often referred to as "beyond 5G."

[0003] The 6G communication system, expected to be realized around 2030, will have a maximum transmission speed of terabytes (i.e., 1,000 gigabits) per second (bps) and a wireless latency of 100 microseconds (μsec). In other words, compared to 5G, the transmission speed in a 6G communication system will be 50 times faster and the wireless latency will be reduced to one-tenth.

[0004] To achieve these high data rates and ultra-low latency, 6G communication systems are being considered for implementation in the terahertz (THz) band (e.g., from 95 gigahertz (GHz) to 3 terahertz (THz)). Compared to the millimeter wave (mmWave) band introduced in 5G, the terahertz band is expected to have more severe path loss and atmospheric absorption, making it more important to develop technologies that can guarantee signal reach, or coverage. Key technologies to ensure coverage include Radio Frequency (RF) components, antennas, new waveforms that offer better coverage than Orthogonal Frequency Division Multiplexing (OFDM), beamforming, and multiple antenna transmission technologies such as massive Multiple-Input and Multiple-Output (MIMO), Full Dimensional MIMO (FD-MIMO), array antennas, and large-scale antennas. In addition, new technologies such as metamaterial-based lenses and antennas, high-dimensional spatial multiplexing using Orbital Angular Momentum (OAM), and Reconfigurable Intelligent Surface (RIS) are being discussed to improve the coverage of terahertz band signals.

[0005] In addition, in order to improve frequency efficiency and system network, 6G communication systems are developing full duplex technology that utilizes the same frequency resources at the same time for uplink and downlink; network technology that integrates satellites and HAPS (High-Altitude Platform Stations); network structure innovation technology that supports mobile base stations and enables optimization and automation of network operation; dynamic spectrum sharing technology through collision avoidance based on spectrum usage prediction; AI-based communication technology that utilizes AI (Artificial Intelligence) from the design stage and internalizes end-to-end AI support functions to realize system optimization; and next-generation distributed computing technology that realizes services with complexity that exceeds the limits of terminal computing capabilities by utilizing ultra-high-performance communication and computing resources (Mobile Edge Computing (MEC), cloud, etc.). In addition, efforts are being made to further strengthen connectivity between devices, further optimize networks, promote softwareization of network entities, and increase the openness of wireless communications through the design of new protocols to be used in 6G communication systems, the implementation of hardware-based security environments, the development of mechanisms for the safe use of data, and the development of technologies for maintaining privacy.

[0006] Research and development of these 6G communication systems are expected to enable a new level of hyper-connected experience through the hyper-connectivity of 6G communication systems, which encompass not only connections between things but also connections between people and things. Specifically, 6G communication systems are expected to enable services such as truly immersive eXtended Reality (XR), high-fidelity mobile holograms, and digital replicas. Furthermore, services such as remote surgery, industrial automation, and emergency response, which are provided through 6G communication systems through enhanced security and reliability, will be applied in diverse fields such as industry, medicine, automobiles, and home appliances.

[0007] The bit width of the channel state information (CSI) report transmitted by a terminal to a base station may vary based on configuration information. Furthermore, PMI may have various bit widths depending on the number of subbands, the number of antenna ports, the number of oversamples, the number of ranks, and / or the codebook type. Consequently, the overhead of CSI reporting in a multi-user MIMO (multi-input, multi-output) system may increase, and the terminal may consume a significant amount of radio resources to perform CSI reporting.

[0008] According to one embodiment, a method performed by a terminal in a wireless communication system includes the steps of: receiving, from a base station, information for triggering transmission of an indicator for a change in a channel state; transmitting, to the base station, at least one indicator for the change in the channel state based on the information for triggering the transmission of the indicator; and transmitting, to the base station, a measurement report in which data for one or more parameters of which a value has not changed among the at least one parameter is excluded, wherein the information for triggering the transmission includes information for at least one parameter for the indicator among a plurality of parameters associated with the channel state, and the at least one indicator can indicate whether a value of the at least one parameter has changed.

[0009] According to one embodiment, in a wireless communication system, a terminal includes a transceiver and a controller coupled with the transceiver, wherein the controller is configured to receive, from a base station, information for triggering transmission of an indicator for a change in a channel state, and to transmit to the base station at least one indicator for the change in the channel state based on the information for triggering the transmission of the indicator, and to transmit to the base station a measurement report in which data for one or more parameters whose values ​​among the at least one parameter have not changed is excluded, wherein the information for triggering the transmission includes information for at least one parameter for the indicator among a plurality of parameters associated with the channel state, and the at least one indicator can indicate whether a value of the at least one parameter has changed.

[0010] A method performed by a base station in a wireless communication system includes the steps of transmitting, to a terminal, information for triggering an indicator for a change in a channel state, receiving, from the terminal, at least one indicator for the change in the channel state based on the information for triggering the indicator, and receiving, from the terminal, a measurement report in which data for one or more parameters whose values ​​among the at least one parameter have not changed are excluded, wherein the information for triggering the indicator may include information for at least one parameter for the indicator among a plurality of parameters associated with the channel state, and the at least one indicator may indicate whether a value of the at least one parameter has changed.

[0011] According to one embodiment, in a wireless communication system, a base station includes a transceiver and a controller coupled with the transceiver, wherein the controller is configured to transmit, to a terminal, information for triggering an indicator for a change in a channel state, receive from the terminal at least one indicator for the change in the channel state based on the information for triggering the indicator, and receive from the terminal a measurement report in which data for one or more parameters whose values ​​among the at least one parameter have not changed are excluded, wherein the information for triggering the indicator includes information for at least one parameter for the indicator among a plurality of parameters associated with the channel state, and the at least one indicator can indicate whether a value of the at least one parameter has changed.

[0012] In one embodiment, simplified CSI reporting may reduce or minimize uplink resources for CSI reporting.

[0013] In one embodiment, simplified CSI reporting can save energy at the terminal and free uplink resources for other data transmissions.

[0014] In addition, various effects may be provided directly or indirectly through the present disclosure.

[0015] FIG. 1 illustrates a wireless communication system according to one embodiment of the present disclosure.

[0016] Figure 2 is a drawing for explaining the structure of a terminal according to one embodiment.

[0017] FIG. 3 is a drawing for explaining the structure of a base station according to one embodiment.

[0018] FIG. 4 is a diagram illustrating a terminal transmitting a CSC (channel state change) indicator according to one embodiment.

[0019] FIG. 5 is a diagram illustrating an operation of a terminal transmitting a measurement report to a base station excluding data for at least one parameter indicated from the base station according to one embodiment.

[0020] FIG. 6 is a diagram illustrating a terminal transmitting an indicator for a channel state according to one embodiment.

[0021] FIG. 7 is a diagram illustrating a method for a terminal to obtain an indicator of a change in channel status based on a plurality of measurement reports according to one embodiment.

[0022] FIG. 8 is a diagram illustrating a method for a base station to transmit information to trigger an indicator for a change in channel conditions according to one embodiment.

[0023] FIG. 9 is a diagram illustrating a method for a MAC layer of a base station to count CSC instances and activate a CSC indicator for at least one parameter or deactivate an activated CSC indicator according to an embodiment.

[0024] FIG. 10 is a diagram illustrating fields of a CSC indicator according to one embodiment.

[0025] FIG. 11 is a diagram illustrating types of CSC indicators according to one embodiment.

[0026] FIG. 12 is a diagram illustrating a base station allocating uplink resources for simplified CSI reporting and a terminal performing CSI reporting according to one embodiment.

[0027] FIG. 13 is a diagram illustrating a method for exchanging CSC indicators and capability information for simplified CSI reporting between a base station and a terminal according to one embodiment.

[0028] In connection with the description of the drawings, the same or similar reference numerals may be used for identical or similar components.

[0029] Hereinafter, various embodiments of the present invention will be described with reference to the attached drawings. However, this is not intended to limit the present invention to specific embodiments, and it should be understood that the present invention encompasses various modifications, equivalents, and / or alternatives of the embodiments.

[0030] FIG. 1 illustrates a wireless communication system according to one embodiment of the present disclosure.

[0031] FIG. 1 illustrates some of the nodes utilizing a wireless channel in a wireless communication system, including a base station (110), a first terminal (120), and / or a second terminal (130). Although FIG. 1 illustrates only one base station, this is merely an example. The wireless communication system of FIG. 1 may further include other base stations identical or similar to the base station (110).

[0032] The base station (110) is a network infrastructure that provides wireless access to terminals (120, 130). The base station (110) may have coverage defined as a certain geographical area based on the distance at which a signal can be transmitted. In addition to the base station, the base station (110) may be referred to as an 'access point (AP)', 'eNodeB (eNB)', 'gNodeB (gNB)', '5G node (5th generation node)', 'wireless point', 'transmission / reception point (TRP)', or other terms having equivalent technical meanings.

[0033] The first terminal (120) and the second terminal (130) are each devices used by a user and can communicate with the base station (110) via a wireless channel. At least one of the first terminal (120) or the second terminal (130) can be operated without the user's intervention. For example, at least one of the first terminal (120) or the second terminal (130) may be a device that performs machine type communication (MTC) and may not be carried by the user. Each of the first terminal (120) and the second terminal (130) may be referred to as a terminal, or other terms having equivalent technical meanings, such as 'user equipment (UE),' 'mobile station,' 'subscriber station,' 'customer premises equipment (CPE),' 'remote terminal,' 'wireless terminal,' 'electronic device,' or 'user device.'

[0034] The base station (110), the first terminal (120), and the second terminal (130) can transmit and / or receive wireless signals in the millimeter wave (mmWave) band (e.g., 28 GHz, 30 GHz, 38 GHz, 60 GHz). At this time, in order to improve channel gain, the base station (110), the first terminal (120), and / or the second terminal (130) can perform beamforming.

[0035] Beamforming may include transmit beamforming and / or receive beamforming. That is, the base station (110), the first terminal (120), and / or the second terminal (130) may impart directionality to the transmit signal or the receive signal. To impart directionality to the receive signal, the base station (110) and / or the terminals (120, 130) may select serving beams (112, 113, 121, 131) through a beam search or beam management procedure. After the serving beams (112, 113, 121, 131) are selected, subsequent communication may be performed through resources that are in a quasi-co-located (QCL) relationship with the resources that transmitted the serving beams (112, 113, 121, 131).

[0036] The base station (110), the first terminal (120), and the second terminal (130) of the present disclosure may each be a transmitting apparatus, a transmitting node, a receiving apparatus, and / or a receiving node. For example, the base station (110) may transmit an RF (radio frequency) signal to the first terminal (120). The base station (110) may receive the RF signal from the first terminal (120). As another example, the first terminal (120) may transmit an RF signal to the base station (110) or the second terminal (130). The first terminal (120) may receive the RF signal from the base station (110) or the second terminal (130).

[0037] Figure 2 is a drawing for explaining the structure of a terminal according to one embodiment.

[0038] Referring to FIG. 2, a terminal (200) according to one embodiment may include a transceiver (210), a memory (220), and / or a processor (230). Although the terminal (200) is described in the present disclosure as including a transceiver (210), a memory (220), and / or a processor (230), this is merely an example. For example, the terminal (200) may further include other components in addition to the transceiver (210), the memory (220), and the processor (230).

[0039] According to one embodiment, the transceiver (210), memory (220), and processor (230) may be implemented or formed as separate chips. However, this is merely an example, and the transceiver (210), memory (220), and / or processor (230) may be implemented or formed as a single chip.

[0040] According to one embodiment, the transceiver (210) may include at least one transmitter and / or at least one receiver. For example, the transceiver (210) may include an RF transmitter for amplifying and up-converting the frequency of a transmitted signal. The transceiver (210) may include an RF receiver for down-converting the frequency of a received signal and amplifying low-noise.

[0041] The configurations of the transceiver (210) described in the present disclosure are merely examples, and the configuration of the transceiver (210) is not limited to an RF transmitter and an RF receiver. For example, the transceiver (210) may further include a coupler to ensure isolation between the RF transmitter and the RF receiver.

[0042] According to one embodiment, the transceiver (210) can transmit or receive a signal to the processor (230). For example, the transceiver (210) can transmit or deliver an RF signal received through a wireless communication channel to the processor (230). The transceiver (210) can receive or deliver an RF signal from the processor (230).

[0043] According to one embodiment, the transceiver (210) may be referred to as a UE transmitter or a UE receiver.

[0044] According to one embodiment, the transceiver (210) may transmit a signal to a base station (e.g., base station (110) of FIG. 1) or a network entity (e.g., user plane function (UPF) entity) or receive a signal from the base station or network entity. In one embodiment, the transmitted or received signal may include a control signal and data.

[0045] According to one embodiment, the memory (220) may include or store programs and data required for the operations of the terminal (200). For example, the memory (220) may be a non-transitory memory, and a program stored in the non-transitory memory may be organically combined with a hardware configuration of the terminal (200) (e.g., a processor (230) or a transceiver (210)). The memory (220) may store control information or data including a signal acquired by the terminal (200). In one embodiment, the memory (220) may include a read-only memory (ROM), a random access memory (RAM), a hard disk, a CD-ROM, a DVD, and / or a storage medium.

[0046] According to one embodiment, the processor (230) may include one processor or multiple processors. For example, the processor (230) may include a communication processor. For example, the processor (230) may include a communication processor and / or an application processor.

[0047] According to one embodiment, the processor (230) may control a series of processes performed by the terminal (200). For example, the transceiver (210) may receive a data signal including control information transmitted by a base station or network entity. The processor (230) may process the received control signal and data signal.

[0048] The term "processor" in the present disclosure may be replaced with various terms referring to a configuration that executes or performs operations of the terminal (200). For example, the term "processor" may be replaced with a controller or a computing circuit.

[0049] The terminal (200) of the present disclosure may correspond to the first terminal (120) and / or the second terminal (130) of FIG. 1.

[0050] FIG. 3 is a drawing for explaining the structure of a base station according to one embodiment.

[0051] Referring to FIG. 3, a base station (300) according to one embodiment may include a transceiver (310), a memory (320), and / or a processor (330). Although the base station (300) is described in the present disclosure as including a transceiver (310), a memory (320), and / or a processor (330), this is merely an example. For example, the base station (300) may further include other components in addition to the transceiver (310), the memory (320), and the processor (330).

[0052] According to one embodiment, the transceiver (310), memory (320), and processor (330) may be implemented or formed as separate chips. However, this is merely an example, and the transceiver (310), memory (320), and / or processor (330) may be implemented or formed as a single chip.

[0053] According to one embodiment, the transceiver (310) may include at least one transmitter and / or at least one receiver. For example, the transceiver (310) may include an RF transmitter for amplifying and up-converting the frequency of a transmitted signal. The transceiver (310) may include an RF receiver for down-converting the frequency of a received signal and amplifying low-noise.

[0054] The configurations of the transceiver (310) described in the present disclosure are merely examples, and the configuration of the transceiver (310) is not limited to an RF transmitter and an RF receiver. For example, the transceiver (310) may further include a coupler to ensure isolation between the RF transmitter and the RF receiver.

[0055] According to one embodiment, the transceiver (310) may transmit or receive a signal to the processor (330). For example, the transceiver (310) may transmit or deliver an RF signal received via a wireless communication channel to the processor (330). The transceiver (310) may receive or deliver an RF signal from the processor (230).

[0056] According to one embodiment, the transceiver (310) may be referred to as a base station transmitter or a base station receiver.

[0057] According to one embodiment, the transceiver (310) may transmit a signal to the terminal (200) or receive a signal from the terminal (200). In one embodiment, the transmitted or received signal may include a control signal and data.

[0058] According to one embodiment, the memory (320) may include programs and data required for the operations of the base station (300). For example, the memory (320) may be a non-transitory memory, and a program stored in the non-transitory memory may be organically combined with a hardware configuration of the base station (300) (e.g., a processor (330) or a transceiver (310)). The memory (320) may store control information or data including a signal acquired by the base station (300). In one embodiment, the memory (320) may include a read-only memory (ROM), a random access memory (RAM), a hard disk, a CD-ROM, a DVD, and / or a storage medium.

[0059] According to one embodiment, the processor (330) may include one processor or multiple processors. For example, the processor (330) may include a communication processor. For example, the processor (330) may include a communication processor and / or an application processor.

[0060] According to one embodiment, the processor (330) may control a series of processes performed by the base station (300). For example, the transceiver (310) may receive a data signal including control information transmitted by the base station or a network entity. The processor (330) may process the received control signal and data signal.

[0061] The term "processor" in the present disclosure may be replaced with various terms referring to a configuration that executes or performs operations of the base station (300). For example, the term "processor" may be replaced with a controller or a computing unit.

[0062] FIG. 4 is a diagram illustrating a terminal transmitting a CSC (channel state change) indicator according to one embodiment.

[0063] Referring to FIG. 4, a wireless communication system according to one embodiment may include a base station (401) and / or a terminal (402). For example, the base station (401) may correspond to the base station (300) of FIG. 3, and the terminal (402) may correspond to the terminal (200) of FIG. 2.

[0064] According to one embodiment, the terminal (402) may receive configuration information from the base station (401) at step 411. For example, the base station (401) may transmit configuration information including information about a CSI (channel state information) report (or measurement report) to the terminal (402).

[0065] According to one embodiment, the configuration information may include information on a plurality of parameters that are associated with a channel state between a base station (401) and a terminal (402) and are subject to a measurement report. For example, the plurality of parameters associated with the channel state between the base station (401) and the terminal (402) may include a layer indicator (LI), a channel quality indicator (CQI), a precoding matrix indicator (PMI), and / or a rank indicator (RI). The base station (401) may indicate a plurality of parameters that are subject to a measurement report (e.g., a CSI report) through the configuration information, and the terminal (402) may include data on the plurality of parameters included in the configuration information in a CSI report (or a measurement report) and transmit the same to the base station (401).

[0066] For example, the configuration information (e.g., CSI-ReportConfig) transmitted in step 411 may include at least one of the information elements (IEs) included in [Table 1]. The configuration information may include information (e.g., reportQuantity) on parameters that are targets of CSI reporting (or measurement reporting). For example, the parameters that are targets of CSI reporting may include at least one of cri-RI-PMI-CQI, cri-RI-LI-PMI-CQI, cri-RI-i1, cri-RI-i1-CQI, cri-RI-CQI, cri-RSRP, ssb-index-RSRP, cri-SINR, or ssb-index-SINR.

[0067]

[0068] [Table 2] shows the relationships among the parameters subject to CSI reporting. For example, reported parameters (e.g., reporting parameters) can be calculated or obtained based on other parameters (e.g., dependencies). However, the parameters subject to CSI reporting are not limited to those listed in [Table 2].

[0069]

[0070] According to one embodiment, the configuration information transmitted in step 411 may include information enabling transmission of a CSC indicator. For example, the configuration information may include information for enabling the CSC indicator by the terminal (402). For example, the terminal (402) may transmit to the base station (401) based on the information enabling the CSC indicator.

[0071] According to one embodiment, the configuration information may include at least some of the information elements (IEs) included in [Table 3]. For example, the configuration information for configuring CSI reporting (or measurement reporting) may include information for enabling the terminal (402) to transmit a CSC indicator (e.g., simplifiedReportMode). The information for enabling the transmission of the CSC indicator may include configuration information for the CSC indicator (e.g., CSC-indicatorConfig).

[0072] As another example, the configuration information for setting up CSI reporting may include information for enabling simplified reporting of the terminal (402) (e.g., simplifiedReportMode), and the information for enabling simplified reporting may include configuration information for the CSC indicator (e.g., CSC-indicatorConfig).

[0073]

[0074] According to one embodiment, the configuration information for the CSC indicator (e.g., CSC-indicatorConfig) may include information about the initial CSC indicator field. For example, the configuration information for the CSC indicator may include information about at least one parameter included in the CSC indicator (e.g., CSCindicatorParameter). For example, the configuration information for the CSC indicator may indicate to the terminal (402) multiple parameters (e.g., RI, CRI, CQI, PMI) to be included in the CSC indicator, as shown in [Table 4].

[0075]

[0076] According to one embodiment, at least one parameter included in the CSC indicator can be changed by the base station (401). For example, based on configuration information for the CSC indicator, at least one parameter included in the CSC indicator can be determined as first parameters (e.g., RI, CRI, CQI, PMI) (or initial parameters). The terminal (402) can transmit information on whether each of the first parameters (or initial parameters) has been changed to the base station (401) through the CSC indicator. In this case, the base station (401) can change at least one parameter included in the CSC indicator from the first parameters to second parameters (e.g., CQI, PMI). The base station (401) can transmit information on the second parameters to the terminal (402) through a downlink control information (DCI) or a radio resource control (RRC) message. The terminal (402) can transmit information on whether each of the second parameters has changed to the base station (401) via a CSC indicator.

[0077] According to one embodiment, the base station (401) may transmit configuration information including information about a CSC indicator to the terminal (402) when specified conditions (e.g., capability information, mobility, presence of obstacles, frequency of channel changes) are satisfied. For example, the base station (401) may transmit configuration information including information about a CSC indicator to the terminal (402) based on whether the terminal (402) has the capability to perform a CSC indicator and / or a simplified CSI report. In another example, the base station (401) may transmit configuration information including information about a CSC indicator to the terminal (402) when the mobility of the terminal (402) is less than or equal to a specified value. When the mobility of the terminal (402) is low, the time correlation may be relatively high, so that the possibility of changes in a plurality of parameters may be low. In this case, the base station (401) can identify that the consumption of wireless resources can be reduced by utilizing the CSC indicator, and can transmit configuration information including information about the CSC indicator to the terminal (402).

[0078] For another example, when there is no other object (e.g., an obstacle) within a specified distance from the terminal (402) (e.g., a line of sight (LOS) condition), the base station (401) may transmit configuration information including information about a CSC indicator to the terminal (402). When there is no other object within a specified distance from the terminal (402), the possibility of changing a plurality of parameters may be low, and the base station (401) may transmit configuration information including information about a CSC indicator to the terminal (402) in order to reduce consumption of radio resources. For another example, when the frequency of channel changes between the terminal (402) and the base station (401) is less than a specified value, the base station (401) may transmit configuration information including information about a CSC indicator to the terminal (402).

[0079] According to one embodiment, the terminal (402) may receive a CSI RS (reference signal) at step 413. For example, the base station (401) may transmit at least one CSI RS to the terminal (402) on at least one resource.

[0080] According to one embodiment, the terminal (402) may transmit a CSI report to the base station (401) based on the CSI RS received in step 415. For example, the terminal (402) may identify information about a channel state between the terminal (402) and the base station (401) based on at least one received CSI-RS. For example, the information about the channel state may include data about a plurality of parameters. The terminal (402) may transmit at least one CSI report including data about a plurality of parameters to the base station (401). For example, the plurality of parameters may be configured for the terminal (402) based on the configuration information of step 411.

[0081] According to one embodiment, the base station (401) may perform CSC indicator handling at step 417. For example, the base station (401) may determine whether the terminal (402) transmits the CSC indicator and / or whether to transmit a simplified CSI report based on a plurality of CSI reports (or measurement reports) transmitted by the terminal (402). For example, a simplified CSI report may be referred to as a CSI report that does not include data for at least some of at least one parameter included in the CSC indicator. As another example, a simplified CSI report may be referred to as a CSI report in which data for at least some of at least one parameter included in the CSC indicator is omitted or excluded.

[0082] For example, the base station (401) may identify at least one parameter among the plurality of parameters that has not changed more than a specified number of times based on the plurality of CSI reports transmitted by the terminal (402). The base station (401) may determine to transmit information about the at least one parameter to the terminal (402) so that the terminal (402) may report, via a CSC indicator, whether the value of the at least one parameter has changed.

[0083] For example, the MAC (medium access control) layer of the base station (401) can identify whether a CSC instance is received more than a specified number of times for a plurality of parameters from the PHY (physical) layer. The MAC layer can identify at least one parameter among the plurality of parameters for which a CSC instance is received more than a specified number of times, and can determine to have the terminal (402) report through a CSC indicator whether the value of the at least one identified parameter changes.

[0084] In this case, the base station (401) can transmit a message (or an activation message) requesting a CSC indicator for at least one parameter to the terminal (402). Based on receiving the message requesting the CSC indicator, the terminal (402) can report whether the value of at least one parameter changes through the CSC indicator, and the terminal (402) can perform a simplified CSI report for one or more parameters whose values ​​do not change among the at least one parameter. That is, in the simplified CSI report, data for one or more parameters whose values ​​do not change among the at least one parameter may be omitted.

[0085] In one example, a CSC instance may be generated based on a plurality of CSI reports (e.g., the CSI reports received in step 415). For example, the base station (401) may identify whether a plurality of parameters included in the plurality of CSI reports have changed. If a first parameter (e.g., CQI) among the plurality of parameters has changed, the CSC instance for the first parameter may not be delivered to the MAC layer, and if the first parameter has not changed, the CSC instance for the first parameter may be delivered to the MAC layer. Similarly, if a second parameter (e.g., RI) among the plurality of parameters has changed, the CSC instance for the second parameter may not be delivered to the MAC layer, and if the second parameter has not changed, the CSC instance for the second parameter may be delivered to the MAC layer.

[0086] That is, the MAC layer of the base station (401) can determine whether a CSC instance has been received a specified number of times or more for each of the plurality of parameters, and can determine whether to request a report through a CSC indicator for each of the plurality of parameters. For example, if a specified number of CSC instances have been received for a first parameter (e.g., CQI), the MAC layer of the base station (401) can request the terminal (402) to report whether the value of the first parameter has changed through the CSC indicator. On the other hand, if a specified number of CSC instances have not been received for a second parameter (e.g., RI), the MAC layer of the base station (401) can request the terminal (402) not to report the second parameter through the CSC indicator.

[0087] According to one embodiment, the terminal (402) may receive the first CSI RS at step 419. For example, the base station (401) may transmit the first CSI RS to the terminal (402) on at least one resource for channel estimation.

[0088] According to one embodiment, the terminal (402) can identify a channel state and determine a first CSC indicator in step 421. For example, the terminal (402) can identify the channel state based on the first CSI RS and determine the first CSC indicator to transmit to the base station (401). For example, the terminal (402) can identify a first channel state corresponding to the first time point based on the first CSI RS received at the first time point, and can identify an initial channel state corresponding to the initial time point based on a CSI RS received at an initial time point prior to the first time point (e.g., a CSI RS received at step 413).

[0089] The terminal (402) may compare the first channel state and the initial channel state to determine the first CSC indicator. For example, the first CSC indicator may include information on whether the value of at least one parameter has changed at the first point in time compared to the initial point in time. For example, if the parameter value of at least one parameter has not changed, the field value of the first CSC indicator may be 0, and if the parameter value of at least one parameter has changed, the field value of the first CSC indicator may be 1. However, the field values ​​are merely examples, and the present disclosure is not limited thereto. For example, if the parameter value has changed, the field value of the first CSC indicator may be 0, and if the parameter value has not changed, the field value of the first CSC indicator may be 1. As another example, if the parameter value has not changed, the field value of the first CSC indicator may be set to “true.”

[0090] According to one embodiment, the operation of comparing channel states by the terminal (402) may substantially correspond to the operation of comparing a plurality of parameter values ​​associated with the channel states. For example, the terminal (402) may compare a plurality of parameter values ​​associated with a first channel state with a plurality of parameter values ​​associated with an initial channel state. For example, the terminal (402) may determine that the first parameter (e.g., CQI) value has changed at the first time point if the difference between the value of the first parameter (e.g., CQI) at the first time point and the value of the first parameter (e.g., CQI) at the initial time point is greater than or equal to a threshold value. In other words, the terminal (402) may determine that the channel state has changed.

[0091] As another example, the terminal (402) may determine that the second parameter (e.g., RI) value has changed at the first time point if the difference between the second parameter (e.g., RI) value at the first time point and the second parameter value at the initial time point is greater than or equal to a threshold value. In other words, the terminal (402) may determine that the channel state has changed.

[0092] According to one embodiment, the terminal (402) may transmit a first CSC indicator in step 423. For example, the terminal (402) may transmit the first CSC indicator determined in step 421 to the base station (401). For example, the first CSC indicator may have a field value of “0” for a first parameter (e.g., CQI). In this case, the base station (401) may identify that the value of the first parameter (e.g., CQI) has not substantially changed between the initial time point and the first time point. In another example, the first CSC indicator may have a field value of “1” for a second parameter (e.g., RI). In this case, the base station (401) may identify that the value of the second parameter has changed between the initial time point and the first time point.

[0093] According to one embodiment, the terminal (402) may transmit a first CSI report (or measurement report) at step 425. For example, the first CSI report may be a simplified report.

[0094] For example, the terminal (402) may transmit the first CSI report in response to the first CSI RS based on the request for simplified CSI reporting (or the activation message for the CSC indicator) received from the base station (401) at step 417. For example, the terminal (402) may be configured to transmit measurement reports for a plurality of parameters (e.g., CQI, PMI, RI, and / or LI) through the configuration information of step 411. The terminal (402) may receive information about at least one parameter (e.g., CQI) among the plurality of parameters as the activation message of the CSC indicator at step 417. In this case, the terminal (402) may transmit to the base station (401) a CSI report excluding data of one or more parameters whose values ​​have not changed among at least one parameter (e.g., CQI). That is, the terminal (402) can identify a parameter whose value has changed among at least one parameter transmitted from the base station (401) and a parameter whose value has not changed (e.g., an unstable parameter) among the parameters. The terminal (402) can transmit a CSI report that excludes data about the parameter whose value has not changed among at least one parameter. That is, the terminal (402) can transmit a CSI report that includes data about the parameter whose value has changed among at least one parameter.

[0095] For example, the terminal (402) may transmit to the base station (401) a first CSI report that does not include data for a parameter for which no change is indicated by the first CSC indicator among at least one parameter.

[0096] According to one embodiment, when the terminal (402) transmits a CSI report excluding data for one or more parameters whose values ​​have not changed among at least one parameter, the base station (401) may reduce or minimize radio resources used for the CSI report. The newly secured radio resources, which are omitted for data for one or more parameters whose values ​​have not changed, may be used to transmit other data between the terminal (402) and the base station (401) on a physical uplink shared channel (PUSCH).

[0097] According to one embodiment, the base station (401) can perform CSC indicator and CSI report monitoring and resetting in step 427. For example, the base station (401) can monitor values ​​(e.g., field values) reported through the CSC indicator and reset the type of parameter reported through the CSC indicator based on the values. For example, the base station (401) can monitor CSI reports and reset the CSI reports based on the values ​​of the parameters reported through the CSI reports. That is, the base station (401) can reset the type of parameter that is the target of the CSI report (or the type of parameter that is the target of omission).

[0098] For example, the base station (401) can change the type of at least one parameter that is the target of reporting through the CSC indicator through an RRC (radio resource control) message (e.g., an RRC reconfiguration message). However, in the present disclosure, the type of at least one parameter that is reported through the CSC indicator can be changed in various ways. For example, the base station (401) can change the type of at least one parameter that is the target of reporting through a MAC control element (CE) and / or downlink control information (DCI).

[0099] For example, the base station (401) can transmit information (or a deactivation message) to deactivate transmission of a CSC indicator for at least one parameter and simplified CSI reporting via an RRC message. That is, the base station (401) can transmit information to the terminal (402) requesting that the terminal include data for one or more parameters omitted from the simplified CSI report in the CSI report and transmit it. The terminal (402) can transmit a CSI report including data for one or more parameters to the base station (401) based on the information requesting that data for one or more parameters be transmitted.

[0100] According to one embodiment, the terminal (402) may receive a second CSI RS from the base station (401) at step 429. For example, the base station (401) may transmit the second CSI RS to the terminal (402) on at least one resource. For example, the terminal (402) may receive the second CSI RS at a third time point.

[0101] According to one embodiment, the terminal (402) may transmit a second CSC indicator in step 431. For example, the terminal (402) may transmit the second CSC indicator based on the second CSI RS. For example, the terminal (402) may identify a first channel state identified based on the first CSI RS and a second channel state identified based on the second CSI RS. The terminal (402) may compare the first channel state and the second channel state and transmit the second CSC indicator to the base station (401). For example, the terminal (402) may identify at least one first parameter identified based on the first CSI RS and at least one second parameter identified based on the second CSI RS. The terminal (402) may compare the values ​​of the at least one first parameter and the values ​​of the at least one second parameter to determine whether a difference is greater than or equal to a threshold value. The terminal (402) can identify that the value of at least one parameter has changed at a third time point compared to a first time point if the difference for each of at least one parameter is greater than or equal to a threshold value.

[0102] According to one embodiment, when the value of at least one parameter (e.g., CQI) changes, it may be referred to as a change in the channel state between the base station (401) and the terminal (402).

[0103] According to one embodiment, the terminal (402) may transmit a second CSI report at step 433. For example, the terminal (402) may transmit a second CSI report (e.g., a simplified report) based on the second CSI RS. For example, the second CSI report may omit data for one or more parameters whose values ​​have not changed among at least one parameter. For example, the second CSI report may omit data for one or more parameters whose values ​​have been indicated as not changing by the second CSC indicator among at least one parameter.

[0104] For example, if the base station (401) transmits a message to the terminal (402) to deactivate or release the simplified CSI report in step 427, the terminal (402) may transmit a second CSI report including data for a plurality of parameters. That is, the terminal (402) may transmit a second CSI report including data for one or more parameters whose values ​​have not changed among at least one parameter to the base station (401).

[0105] According to one embodiment, the base station (401) can monitor whether the channel condition changes through the CSC indicator, and adaptively (or flexibly) determine the parameters to be reported through the CSC indicator based on the monitoring, thereby reducing or minimizing the consumption of radio resources. Similarly, the base station (401) can monitor the channel condition and adaptively determine the parameters to be omitted through the simplified CSI report or the parameters to be reported through the simplified CSI report based on the monitoring, thereby reducing or minimizing the consumption of radio resources.

[0106] Although the transmission of the first CSC indicator and the transmission of the first CSI report are described as separate operations in FIG. 4 of the present disclosure, this is merely an example. For example, the first CSC indicator and the first CSI report may be included in a single message and transmitted from the terminal (402) to the base station (401).

[0107] In the present disclosure, a plurality of parameters for CSI reporting indicated based on configuration information and at least one parameter included in the CSC indicator may be substantially identical. However, the present disclosure is not limited thereto, and at least one parameter included in the CSC indicator may be included in the plurality of parameters for CSI reporting.

[0108] FIG. 5 is a diagram illustrating an operation of a terminal transmitting a measurement report to a base station excluding data for one or more parameters whose values ​​have changed among at least one parameter indicated from the base station according to one embodiment.

[0109] Referring to FIG. 5, a terminal (402) according to an embodiment may receive information for triggering transmission of an indicator (e.g., a CSC indicator) for a change in channel status from a base station (401) in step 501. For example, the base station (401) may transmit to the terminal (402) information for triggering the terminal (402) to transmit an indicator (e.g., a CSC indicator) indicating whether a channel status has changed and / or a simplified CSI report. As another example, the base station (401) may transmit to the terminal (402) a message (or an activation message) for activating the terminal (402) to transmit the CSC indicator and / or the simplified CSI report.

[0110] In the present disclosure, a simplified CSI report may be referred to as a CSI report that excludes data for one or more parameters whose values ​​have not changed among at least one parameter. For example, if a terminal (402) is instructed in the configuration information to perform CSI reporting for a plurality of parameters (e.g., CQI, PMI, RI), the base station (401) may then instruct the terminal (402) to report for at least one parameter (e.g., CQI, PMI) through a CSC indicator based on information for triggering an indicator for a channel change. In this case, the terminal (402) may transmit to the base station (401) a simplified CSI report that does not include data for one or more parameters (e.g., CQI) whose values ​​have not changed among the at least one parameter (e.g., CQI, PMI).

[0111] According to one embodiment, the terminal (402) may transmit at least one indicator (e.g., a CSC indicator) for a change in channel status based on the information that triggers transmission to the base station (401) in step 503. For example, the configuration information may include configuration information for an indicator for a change in channel status (e.g., CSC-indicatorConfig), and the terminal (402) may transmit at least one indicator to the base station (401) based on the configuration information for the indicator. In this case, the at least one indicator for a change in channel status may correspond to a CSI RS transmitted by the base station (401). That is, the terminal (402) may transmit an indicator for a change in channel status and / or a CSI report (or a measurement report) in response to the base station (401) transmitting a CSI RS.

[0112] For example, the base station (401) can transmit a first CSI RS to the terminal (402) at a first time point and a second CSI RS at a second time point before the first time point. The terminal (402) can transmit a first CSC indicator based on the first CSI RS and can transmit a second CSC indicator based on the second CSI RS.

[0113] In one example, the first CSC indicator may indicate whether there is a difference between the first channel state at the first time point and the second channel state at the second time point. That is, the first CSC indicator may indicate whether the channel state has changed at the first time point compared to the second time point. In this case, the first CSC indicator may indicate whether there has been a change for each of at least one parameter. For example, if the CQI value has changed at the first time point compared to the second time point, the CQI field value of the first CSC indicator may be “1”, and if the CQI value has not changed at the first time point compared to the second time point, the CQI field value may be “0”. For example, if the RI value has changed at the first time point compared to the second time point, the RI field value of the first CSC indicator may be “1”, and if the RI value has not changed at the first time point compared to the second time point, the RI field value may be “0”.

[0114] According to one embodiment, the terminal (402) may transmit to the base station (401) a measurement report that excludes data for one or more parameters whose values ​​have not changed among at least one parameter in step 505. For example, the terminal (402) may transmit to the base station (401) a simplified CSI report (or simplified measurement report), and the simplified CSI report may not include data for one or more parameters whose values ​​have not changed among at least one parameter. For example, the at least one parameter may be a parameter that is the target of a report via a CSC indicator.

[0115] A request for a measurement report excluding data for at least one parameter described in FIG. 5 of the present disclosure may substantially correspond to the simplified CSI report request of FIG. 4.

[0116] Although CQI and RI are described as examples of parameters subject to CSI reporting in FIG. 5 of the present disclosure, this is merely an example. For example, parameters subject to CSI reporting may include CQI, RI, CRI, and / or PMI. As another example, although CQI is described as an example of parameters omitted from CSI reporting, this is merely an example. For example, parameters omitted from CSI reporting may include CQI, RI, CRI, and / or PMI. Furthermore, when data regarding PMI is omitted, the data regarding PMI may be distinguished by layer, and may be omitted from all layers or only from some layers.

[0117] FIG. 6 is a diagram illustrating a terminal transmitting an indicator for a channel state according to one embodiment.

[0118] Referring to FIG. 6, a terminal (402) according to one embodiment may receive a first CSI RS from a base station (401) at step 601. For example, the terminal (402) may receive a first CSI RS corresponding to a first time point from the base station (401).

[0119] According to one embodiment, the terminal (402) may compare first values ​​for at least one parameter (e.g., CQI, RI) identified based on the first CSI RS in step 602 with second values ​​for at least one parameter (e.g., CQI, RI) identified based on a second CSI RS received prior to the first CSI RS. For example, the terminal (402) may receive the second CSI RS corresponding to a second time point prior to the first time point, and obtain second values ​​for each of the at least one parameter (e.g., CQI, RI) based on the second CSI RS. The terminal (402) may obtain first values ​​for each of the at least one parameter (e.g., CQI, RI) based on the first CSI RS. In this case, the terminal (402) may compare the first values ​​and the second values ​​and identify whether there is a difference between the first values ​​and the second values.

[0120] According to one embodiment, at least one parameter (e.g., CQI, RI) may be a parameter indicated by the base station (401) among a plurality of parameters (e.g., QCI, CRI, RI, and / or PMI) that are subject to CSI reporting. For example, the at least one parameter may be a parameter reported via a CSC indicator in step 417 of FIG. 4.

[0121] According to one embodiment, the terminal (402) can identify whether a channel condition has changed by comparing a difference between the first values ​​and the second values ​​with a threshold value. If the difference between the first values ​​and the second values ​​is less than or equal to the threshold value, the terminal (402) can identify that at least one parameter has not changed at the first time point compared to the second time point. For example, if the difference between a first CQI value corresponding to the first time point and a second CQI value corresponding to the second time point is less than or equal to the threshold value, the terminal (402) can identify that the CQI value has not changed at the first time point compared to the second time point. If the difference between a first PMI value corresponding to the first time point and a second PMI value corresponding to the second time point is less than or equal to the threshold value, the terminal (402) can identify that the PMI value has not changed at the first time point compared to the second time point. For example, the terminal (402) can identify that the channel condition between the base station (401) and the terminal (402) has not changed if the value of at least one parameter has not changed.

[0122] The terminal (402) can identify that at least one parameter has changed at the first time point compared to the second time point if the difference between the first values ​​and the second values ​​exceeds a threshold value. For example, if the difference between the first CQI value corresponding to the first time point and the second CQI value corresponding to the second time point exceeds a threshold value, the terminal (402) can identify that the CQI value has changed at the first time point compared to the second time point. If the difference between the first PMI value corresponding to the first time point and the second PMI value corresponding to the second time point exceeds a threshold value, the terminal (402) can identify that the PMI value has changed at the first time point compared to the second time point. For example, the terminal (402) can identify that the channel state between the base station (401) and the terminal (402) has changed if the value of at least one parameter has changed.

[0123] According to one embodiment, the terminal (402) may transmit an indicator indicating whether a channel condition has changed based on the comparison result in step 605. For example, the terminal (402) may identify whether each of the plurality of parameters has changed at a first time point compared to a second time point based on the comparison result between the first values ​​and the second values. For example, the terminal (402) may identify that a CQI value has changed and a PMI value has not changed. In this case, the terminal (402) may transmit a CSC indicator including a CQI field having a value of “0” and a PMI field having a value of “1” to the base station (401).

[0124] Step 601 described in FIG. 6 of the present disclosure may correspond to step 419 of FIG. 4. Step 603 of FIG. 6 may correspond to step 421 of FIG. 4. Step 605 of FIG. 6 may correspond to step 423 of FIG. 4. However, the correspondence between FIG. 4 and FIG. 6 described above is merely an example, and the present disclosure is not limited thereto.

[0125] FIG. 7 is a diagram illustrating a method for a terminal to obtain an indicator of a change in channel status based on a plurality of measurement reports according to one embodiment.

[0126] Referring to FIG. 7, a terminal (402) according to an embodiment may receive multiple CSI RSs from a base station (401) on at least one resource. The terminal (402) may identify or obtain multiple CSI reports (701) based on the received multiple CSI RSs. For example, the terminal (402) may receive a first CSI RS at a first time point and identify a first CSI report (701-1) based on the first CSI RS. For example, the terminal (402) may receive a second CSI RS at a second time point and identify a second CSI report (701-2) based on the second CSI RS. For example, the terminal (402) may receive a third CSI RS at a third time point and identify a third CSI report (701-3) based on the third CSI RS. For example, the terminal (402) can receive the nth CSI RS at the nth point in time and identify the nth CSI report (701-n) based on the nth CSI RS.

[0127] According to one embodiment, the terminal (402) can compare the last identified CSI report and the second-to-last identified CSI report among the plurality of CSI reports (701). For example, the terminal (402) can compare the n-1-th CSI report (701-n-1) corresponding to the n-1-th time point and the n-th CSI report (701-n) corresponding to the n-th time point. For example, the terminal (402) can compare the first values ​​of the plurality of parameters included in the n-1-th CSI report (701-n-1) and the second values ​​of the plurality of parameters included in the n-th CSI report (701-n).

[0128] According to one embodiment, the terminal (402) can identify the nth CSC indicator (703-n) based on the comparison result of the n-1th CSI report (701-n-1) and the nth CSI report (701-n). For example, the terminal (402) can compare the first values ​​and the second values ​​parameter by parameter, and if the difference between the first values ​​and the second values ​​parameter by parameter is less than a threshold value, the terminal can determine the field value for the parameter as “0”. For example, the terminal (402) can compare the first values ​​and the second values ​​parameter by parameter, and if the difference between the first values ​​and the second values ​​parameter by parameter is greater than or equal to a threshold value, the terminal can determine the field value for the parameter as “1”.

[0129] For example, the terminal (402) may determine the field value of the CSC for the first parameter as “0” when the difference between the first value and the second value of the first parameter (e.g., CQI) is less than a threshold value. For example, the terminal (402) may determine the field value of the CSC for the first parameter as “1” when the difference between the first value and the second value of the first parameter (e.g., CQI) is greater than or equal to the threshold value.

[0130] According to one embodiment, the terminal (402) can identify multiple CSC indicators (703) based on the CSI reports. For example, the terminal (402) can identify the first CSC indicator (703-1) by comparing the first CSI report (701-1) and the second CSI report (701-2). For example, the terminal (402) can identify the second CSC indicator (703-2) by comparing the second CSI report (701-2) and the third CSI report (701-3).

[0131] According to one embodiment, the threshold values ​​for each of the plurality of parameters (e.g., CQI, CRI, PMI, and / or RI) may be different. For example, the threshold value of a first parameter (e.g., CQI) for determining a CSC field value may be different from the threshold value of a second parameter (e.g., RI) for determining a CSC field value.

[0132] According to one embodiment, information about threshold values ​​for each of the plurality of parameters may be included in configuration information transmitted from the base station (401) to the terminal (402). For example, the configuration information may include configuration information for a CSC indicator (e.g., CSC-indicatorConfig), and the configuration information for the CSC indicator (e.g., CSC-indicatorConfig) may include information about threshold values ​​for each parameter for determining a CSC field based on CSI reports.

[0133] Although the present disclosure has described that the field value is indicated as 0 when there is no change in the value of the parameter, and as 1 when there is a change in the value of the parameter, this is only an example. For example, the field value may be indicated as 1 when there is no change in the value of the parameter, and as 0 when there is a change in the value of the parameter.

[0134] FIG. 8 is a diagram illustrating a method for a base station to transmit information to trigger an indicator for a change in channel conditions according to one embodiment.

[0135] Referring to FIG. 8, a base station (401) according to an embodiment may receive a plurality of measurement reports including data for at least one parameter in step 801. For example, the base station (401) may transmit a plurality of CSI RSs to the terminal (402), and the base station (401) may receive a plurality of CSI reports (or a plurality of measurement reports) from the terminal (402) in response to each of the plurality of CSI RSs.

[0136] For example, the plurality of measurement reports may not be simplified CSI reports. That is, the plurality of measurement reports may be reports transmitted by the terminal (402) before the CSC indicator and simplified CSI reporting are activated. For another example, the plurality of measurement reports received by the base station (401) in step 801 may correspond to the CSI report received in step 415 of FIG. 4. For another example, the plurality of measurement reports received by the base station (401) in step 801 may be CSI reports that include data for a plurality of parameters (e.g., CQI, CRI, RI, and / or PMI). That is, the plurality of measurement reports may include measurement values ​​for all of the plurality of parameters (e.g., CQI, CRI, RI, and / or PMI) that are configured based on configuration information (e.g., reportQuantity).

[0137] In one embodiment, the base station (401) may identify at least one parameter that does not change more than a specified number of consecutive times based on the plurality of measurement reports in step 803. For example, the base station (401) may identify at least one parameter that does not change more than a specified number of consecutive times among the plurality of parameters included in the plurality of measurement reports. In one example, the identified at least one parameter may be included in a CSC indicator.

[0138] For example, the base station (401) may sequentially receive a first CSI report, a second CSI report, and a third CSI report from the terminal (402). The base station (401) may identify first values ​​for a plurality of parameters (e.g., CQI, CRI, RI, PMI) included in the first CSI report, and may identify second values ​​for a plurality of parameters (e.g., CQI, CRI, RI, PMI) included in the second CSI report. The base station (401) may identify third values ​​for a plurality of parameters (e.g., CQI, CRI, RI, PMI) included in the third CSI report. In this case, the first CSI report may be a response to the first CSI RS transmitted at the first initial time point, the second CSI report may be a response to the second CSI RS transmitted at the second initial time point, and the third CSI report may be a response to the third CSI RS transmitted at the third initial time point. The first values ​​may correspond to a first initial time point at which the first CSI RS is received, the second values ​​may correspond to a second initial time point at which the second CSI RS is received, and the third values ​​may correspond to a third initial time point at which the third CSI RS is received.

[0139] In one example, a first value for a first parameter (e.g., CQI) among the first values ​​may have a difference less than or equal to a threshold value from a second value for the first parameter (e.g., CQI) among the second values. Similarly, a third value for a first parameter (e.g., CQI) among the third values ​​may have a difference less than or equal to a threshold value from the second value. In this case, the base station (401) may identify that the value of the first parameter (e.g., CQI) has not changed consecutively for a specified number of times (e.g., twice). (That is, since there is no change between the first value and the second value, one time may be counted, and since there is no change between the second value and the third value, two times may be counted.)

[0140] In one example, the fourth value for the second parameter (e.g., RI) among the first values ​​may have a difference less than or equal to a threshold value from the fifth value for the second parameter (e.g., RI) among the second values. On the other hand, the sixth value for the second parameter (e.g., RI) among the third values ​​may have a difference greater than or equal to a threshold value from the fifth value. In this case, the base station (401) may identify that the value of the second parameter (e.g., RI) has not changed less than a specified number of times (e.g., twice). That is, the base station (401) may identify that the value of the second parameter has not been maintained continuously for a specified number of times.

[0141] In one example, the base station (401) may identify a first parameter (e.g., CQI) among a plurality of parameters as at least one parameter to be included in the CSC indicator, and may identify a second parameter (e.g., RI) as a parameter not to be included in the CSC indicator. That is, the base station (401) may request reporting through the CSC indicator for the first parameter (e.g., CQI) that is a stable parameter, and may request data transmission through a CSI report rather than the CSC indicator for the second parameter (e.g., RI) that is an unstable parameter.

[0142] According to one embodiment, the base station (401) may transmit information indicating at least one parameter that is subject to reporting via the CSC indicator in step 805. For example, the base station (401) may transmit a message activating transmission of the CSC indicator, and the message may include information indicating at least one parameter that is subject to reporting via the CSC indicator.

[0143] According to one embodiment, information indicating at least one parameter may be transmitted from the base station (401) to the terminal (402) via RRC signaling, MAC CE, or downlink control information (DCI). For example, the base station (401) may transmit information indicating at least one parameter to the terminal (402) via an RRC message. As another example, the base station (401) may activate a CSC indicator and / or simplified CSI reporting to the terminal (402) via DCI including information indicating at least one parameter.

[0144] According to one embodiment, the base station (401) can minimize or reduce unnecessary resource waste by performing CSC indicators and simplified CSI reporting only for at least one parameter (e.g., stable parameter or semi-static parameter) that has not changed more than a specified number of consecutive times. For example, if CSC indicators and simplified CSI reporting are performed even for unstable parameters, the base station (401) may have to request data transmission from the terminal (402) again for parameters omitted from the simplified CSI reporting and may have to allocate resources for data transmission. On the other hand, if the base station (401) according to one embodiment performs CSC indicators and simplified CSI reporting only for at least one parameter that has not changed more than a specified number of consecutive times, unnecessary radio resource consumption can be reduced.

[0145] In FIG. 8 of the present disclosure, the counting of the number of times that the value of a parameter (e.g., CQI) does not change by the base station (401) may substantially correspond to the counting of CSC instances by the base station (401) in FIG. 9, which will be described later.

[0146] Information indicating at least one parameter described in FIG. 8 of the present disclosure may be information that substantially activates transmission of a CSC indicator. For example, when information indicating at least one parameter is transmitted to a terminal (402), the terminal (402) may, in response to a CSI RS, inform the base station (401) via the CSC indicator whether the value of at least one parameter has changed.

[0147] Additionally, the information indicating at least one parameter described in FIG. 8 of the present disclosure may be information that activates a substantially simplified CSI report (or a CSI report that excludes data for one or more parameters whose values ​​have not changed among at least one parameter). For example, when the information indicating at least one parameter is transmitted to the terminal (402), the terminal (402) may transmit, in response to the CSI RS, a CSI report that excludes data for one or more parameters whose values ​​have not changed among the at least one parameter, to the base station (401).

[0148] The step 801 of the base station (401) of FIG. 8 of the present disclosure receiving multiple measurement reports may correspond to the step 415 of FIG. 4 in which the terminal (402) transmits a CSI report. Steps 803 to 805 of FIG. 8 may correspond to the step of handling a CSC indicator of step 417 of FIG. 4. However, the above-described correspondence relationship is merely an example, and the present disclosure is not limited thereto.

[0149] FIG. 9 is a diagram illustrating a method for a MAC layer of a base station to count CSC instances and activate a CSC indicator for at least one parameter or deactivate an activated CSC indicator according to an embodiment.

[0150] Referring to FIG. 9, a protocol of a base station (401) according to an embodiment may include a MAC layer and a PHY layer. For a stable parameter (e.g., a parameter whose value has not changed) among a plurality of parameters, the MAC layer may receive a CSC instance from the PHY layer.

[0151] According to one embodiment, before the CSC indicator and / or the simplified CSI reporting is activated, the PHY layer of the base station (401) may receive multiple CSI reports from the terminal (402). If the values ​​of each of the multiple parameters do not change (e.g., are stable) based on the multiple CSI reports, a CSC instance may be transmitted from the PHY layer to the MAC layer. For example, when comparing a first CSI report and a second CSI report, if a first parameter (e.g., CQI) among the multiple parameters (e.g., CQI, RI) does not change, the MAC layer may receive a CSC instance for the first parameter from the PHY layer. In another example, when comparing the first CSI report and the second CSI report, if a second parameter (e.g., RI) among the multiple parameters (e.g., CQI, RI) changes, the MAC layer may not receive a CSC instance for the second parameter from the PHY layer.

[0152] According to one embodiment, the base station (401) (or MAC layer) can identify at least one parameter among a plurality of parameters (e.g., CQI, RI) for which CSC instances have been received consecutively a specified number of times or more. The base station (401) can transmit information about the identified at least one parameter to the terminal (402), thereby requesting the terminal (402) to report whether the value of the at least one parameter has changed through a CSC indicator and to perform simplified CSI reporting for one or more parameters among the at least one parameter whose value has not changed.

[0153] According to one embodiment, the specified number of times can be set by the base station (401) to the terminal (402) through configuration information. For example, referring to [Table 5], the configuration information can include configuration information for a CSC indicator (e.g., CSC-indicatorConfig). The configuration information for the CSC indicator (e.g., CSC-indicatorConfig) can include information for a CSC instance (e.g., CSCinstanceConfig), and the information for the CSC instance can include information for a specified number of times (e.g., counterThreshold).

[0154]

[0155] According to one embodiment, after the CSC indicator and / or the simplified CSI reporting is activated, the PHY layer of the base station (401) may receive the CSC indicator from the terminal (402). If the value of at least one parameter does not change (e.g., is stable) based on the CSC indicator, the CSC instance may be transmitted from the PHY layer to the MAC layer. For example, if the first CSC indicator indicates that a first parameter (e.g., CQI) among the at least one parameter (e.g., CQI, RI) does not change (e.g., when the field of CQI is 0), the CSC instance may be transmitted from the PHY layer to the MAC layer. For example, if the first CSC indicator indicates that a second parameter (e.g., RI) among the at least one parameter (e.g., CQI, RI) has changed (e.g., when the field of RI is 1), the CSC instance may not be transmitted from the PHY layer to the MAC layer.

[0156] According to one embodiment, after the CSC indicator and / or simplified CSI reporting is activated, the base station (401) may deactivate the CSC indicator and / or simplified CSI reporting using the CSC instance.

[0157] For example, the base station (401) (or MAC layer) may receive a first CSC instance (911). The MAC layer may monitor the CSC instance for a first time (or time window) (921) after receiving the first CSC instance (911). That is, the MAC layer may expect the next CSC instance to be received during the first time (921).

[0158] If no CSC instance is received during the first time (921), the field value of the CSC indicator for at least one parameter is “1”, so the base station (401) can identify that the value of at least one parameter has changed. In this case, the base station (401) (or the MAC layer) can request the terminal (402) to deactivate the CSC indicator and / or simplified CSI reporting for at least one parameter via an RRC message, MAC CE, or DCI. That is, the base station (401) can request the terminal (402) not to report through the CSC indicator whether the value of at least one parameter has changed, but to perform CSI reporting including data for at least one parameter.

[0159] In one embodiment, the base station (401) (or the MAC layer) may use the CSC instance to (re)enable the CSC indicator and / or the simplified CSI reporting. For example, the MAC layer may receive the second CSC instance (912) and identify the count as 1. The MAC layer may receive the third CSC instance (913) within a second time (922) after the second CSC instance (912) is received. In this case, the MAC layer may identify the count as 2.

[0160] When the number of times a CSC instance is received consecutively (e.g., consecutively without at least one parameter changing) is greater than a specified number of times (e.g., 2 times), the MAC layer may transmit a message (or an activation message) requesting the terminal (402) to transmit a CSC indicator for at least one parameter.

[0161] In one embodiment, the MAC layer may increment the count by one if a CSC instance is received, and set the count to zero if no CSC instance is received.

[0162] According to one embodiment, the time (or time window) at which a CSC instance is expected to be received can be set by the base station (401) to the terminal (402) through configuration information. For example, referring to [Table 5], the configuration information can include configuration information for a CSC indicator (e.g., CSC-indicatorConfig). The configuration information for the CSC indicator (e.g., CSC-indicatorConfig) can include information for a CSC instance (e.g., CSCinstanceConfig), and the information for the CSC instance can include information for a specified number of times (e.g., expectedTimeWindow).

[0163] In one embodiment, when the value of one or more parameters changes or a message for a measurement report including data for one or more parameters is received from the terminal (402), the base station (401) may transmit a message (e.g., a deactivation message) requesting transmission of a measurement report including data for one or more parameters. For example, the base station (401) may identify whether the value of at least one parameter has changed by counting the CSC instances described above. When the value of a first parameter among the at least one parameter has changed, the base station (401) may stop reporting to the terminal (402) through the CSC indicator since the first parameter is no longer a stable parameter and request the terminal (402) to report data through the CSI report.

[0164] For example, the base station (401) may receive a message (e.g., a deactivation request message) from the terminal (402) indicating that reporting via CSI reporting is required for one or more parameters. Based on receiving the deactivation request message, the base station (401) may request the terminal (402) to stop reporting via the CSC indicator for one or more parameters and to report data via CSI reporting. That is, the terminal (402) may compare the values ​​of one or more parameters and identify that the values ​​of one or more parameters have changed. In this case, the terminal (402) may determine that a CSI report including data for one or more parameters is required and may transmit a deactivation request message to the base station (401).

[0165] According to one embodiment, the deactivation message transmitted by the base station (401) to the terminal (402) may be applied to each of at least one parameter. For example, the base station (401) may identify that the value of a first parameter (e.g., CQI) among at least one parameter (e.g., CQI, RI) has changed, and may identify that the value of a second parameter (e.g., RI) has not changed. In this case, the base station (401) may transmit a message (e.g., a deactivation message) to the terminal (402) requesting that reporting via the CSC indicator be stopped only for the second parameter (e.g., RI) among the at least one parameter.

[0166] That is, the deactivation message can be applied individually to at least one parameter.

[0167] FIG. 10 is a diagram illustrating fields of a CSC indicator according to one embodiment.

[0168] Referring to FIG. 10, a CSC indicator (1001) according to an embodiment may include fields for at least one parameter (e.g., CRI, PMI). For example, the CSC indicator (1001) may include a 1-bit field for at least one parameter. For example, the CSC indicator (1001) may include a 1-bit first field (1011) for CRI, and a bit value of the first field (1011) of 0 may indicate that the CRI value has not changed compared to before, and a bit value of the first field (1011) of 1 may indicate that the CRI value has changed compared to before.

[0169] For example, the CSC indicator (1001) may include a 1-bit field for each of the indices (1020) included in the PMI. For example, the CSC indicator (1001) may include a 1-bit second field (1022) for the index of the beam in azimuth dimension of i1, and a bit value of the second field (1022) of 0 may indicate that the beam index in azimuth dimension has not changed compared to before, and a bit value of the second field (1022) of 1 may indicate that the beam index in azimuth dimension has changed compared to before.

[0170] In one embodiment, at least one parameter may be based on information about multiple parameters included in the configuration information (e.g., reportQuantity) and / or wideband / narrowband. For example, at least one parameter included in the CSC indicator (1001) may be at least one of the multiple parameters included in the configuration information.

[0171] According to one embodiment, the type and / or number of indices (1020) included in the PMI may be determined based on the codebook type. For example, the codebook type may include type 1 - single panel, type 1 - multi panel, type 2, and / or enhanced type 2. For example, a type 1 codebook may use predefined metrics (e.g., a pre-determined table) and may be for single-user multi-input multi-output (MIMO) (SU-MIMO). For example, a type 2 codebook may use a mathematical formula with multiple parameters and may be for multi-user MIMO (MU-MIMO).

[0172] According to one embodiment, the PMI indices or PMI parameters to be reported for each type of codebook may be as shown in [Table 6]. However, [Table 6] is only an example, and the present disclosure is not limited thereto.

[0173]

[0174]

[0175] FIG. 11 is a diagram illustrating types of CSC indicators according to one embodiment.

[0176] Referring to FIG. 11, a first indicator (1101) of a first type according to an embodiment may have a field value for each of at least one parameter (e.g., CRI, RI, CQI). For example, the first indicator (1101) may include a 1-bit CRI value, a 1-bit RI value, and a 1-bit CQI value. For example, the first indicator (1101) of the first type may correspond to a case where information on parameters to be targets of CSI reporting included in the configuration information (e.g., reportQuantity) is cri-Ri-CQI.

[0177] According to one embodiment, the second indicator (1102) of the second type may have field values ​​for each of at least one parameter (e.g., CRI, RI, CQI, PMI). For example, the second indicator (1102) may include a 1-bit CRI value, a 1-bit RI value, and a 1-bit CQI value. For example, the second indicator (1102) may include a 1-bit value for each of a plurality of indices included in the PMI.

[0178] The second type of second indicator (1102) of FIG. 11 may correspond to the CSC indicator (1001) of FIG. 10.

[0179] According to one embodiment, the third indicator (1103) of the third type may have field values ​​for each of at least one parameter (e.g., CRI, RI, CQI, PMI). For example, the third indicator (1103) of the third type may include, for each layer, a plurality of indices included in the PMI. For example, the PMI field (1120) of the second indicator (1102) of the second type may include all of the plurality of indices listed. On the other hand, the PMI field (1130) of the third indicator (1103) of the third type may include a plurality of indices divided by layer.

[0180] According to one embodiment, the base station (401) can variably change at least one parameter included in the CSC indicator to the terminal (402). For example, the base station (401) can configure the terminal (402) to omit at least some of at least one parameter (e.g., CRI, PMI) included in the CSC indicator. As another example, the base station (401) can add at least one parameter included in the CSC indicator.

[0181] According to one embodiment, fields may be omitted in units of upper parameters in the second indicator (1102) of the second type based on the configuration or control of the base station (401). For example, the field (1140) of the i2 parameter may be omitted in the second indicator (1102) of the second type based on the configuration or control of the base station (401).

[0182] According to one embodiment, fields may be omitted in units of sub-parameters in the third indicator (1103) of the third type based on the configuration or control of the base station (401). For example, the first fields (1151) of the fields of the i1 parameter and the second fields (1152) of the fields of the i2 parameter may be omitted based on the configuration or control of the base station (401).

[0183] According to one embodiment, a parameter omitted from a CSC indicator may be a parameter whose value changes (e.g., an unstable parameter). For example, the base station (401) may identify that the value of at least one parameter reported via the CSC indicator has changed. In this case, the base station (401) may request that reporting via the CSC indicator for the parameter whose value has changed be omitted. In this case, the value of the parameter whose value has changed may be reported to the base station (401) via a CSI report.

[0184] FIG. 12 is a diagram illustrating a base station allocating uplink resources for simplified CSI reporting and a terminal performing CSI reporting according to one embodiment.

[0185] Referring to FIG. 12, a terminal (402) according to an embodiment may identify buffered UL (uplink) data in step 1201. For example, the terminal (402) may transmit to the base station (401) a simplified CSI report excluding one or more parameters (e.g., CQI, PMI) whose values ​​have not changed among at least one parameter. In one example, the at least one parameter may be a parameter included in a CSC indicator.

[0186] According to one embodiment, while the terminal (402) is performing a simplified CSI report, the base station (401) may transmit a message to the terminal (402) to deactivate (or release) the simplified CSI report when it identifies that the channel condition has changed.

[0187] In this case, the terminal (402) may need to transmit more data for one or more parameters (e.g., CQI, PMI) than the simplified CSI report in the CSI report, and the terminal (402) may need to request resource allocation for the data to be additionally transmitted from the base station (401).

[0188] According to one embodiment, the terminal (402) may transmit a scheduling request (SR) to the base station (401) for resources to transmit data for one or more parameters (e.g., CQI, PMI) in step 1203. For example, the terminal (402) may request additional resources from the base station (401) in addition to the resources allocated for simplified CSI reporting.

[0189] According to one embodiment, the base station (401) may allocate UL resources to the terminal (402) in step 1205. For example, the base station (401) may allocate additional UL resources to transmit data of one or more parameters (e.g., CQI, PMI) to the terminal (402).

[0190] According to one embodiment, the terminal (402) may transmit data for one or more parameters (e.g., CQI, PMI) to the base station (401) based on the additional UL resources allocated in step 1206. For example, the terminal (402) may transmit data for one or more parameters (e.g., CQI, PMI) to the base station (401) in addition to data for the parameters (e.g., RI, CRI) that were transmitted in the simplified CSI report.

[0191] According to one embodiment, the terminal (402) may transmit a BSR (buffer status report) to the base station (401) while transmitting data. As another example, the terminal (402) may transmit only data without a BSR.

[0192] According to one embodiment, the base station (401) may allocate UL resources for CSI reporting to the terminal (402) in step 1207, and the terminal (402) may transmit the CSI report to the base station (401) in step 1208. For example, the terminal (402) may transmit data for multiple parameters (e.g., CQI, CRI, PMI, RI) without BSR based on the allocated UL resources.

[0193] According to one embodiment, the terminal (402) may receive an activation message for a simplified CSI report from the base station (401) while performing a CSI report including data for all of a plurality of parameters (e.g., CQI, CRI, PMI, RI) to the base station (401). In this case, the terminal (402) may perform only a CSI report excluding data for one or more parameters (e.g., CQI, CRI) among the plurality of parameters (e.g., CQI, CRI, PMI, RI). Accordingly, some of the UL resources allocated by the base station (401) before the terminal (402) receives the activation message may not be used. For example, one or more parameters (e.g., CQI, CRI) may be parameters whose values ​​have not changed among at least one parameter (e.g., CQI, CRI, RI) that is a target of a report through a CSC indicator.

[0194] In one embodiment, the terminal (402) may request the base station (401) to reallocate unused resources when some of the UL resources are unused, in order to efficiently utilize the radio resources. As another example, the terminal (402) may not request reallocation from the base station (401) even if some of the UL resources are unused, as requesting reallocation and receiving new resources may incur delay or latency. In this case, the terminal (402) may perform simplified CSI reporting based on the allocated resources before receiving the activation message.

[0195] Similarly, when the base station (401) activates the CSC indicator, the base station (401) may receive a UL resource allocation request for the CSC indicator from the terminal (402) and allocate the UL resources. In addition, when the base station (401) deactivates the CSC indicator, the UL resources for the CSC indicator are no longer needed, so the base station (401) may receive a request for reallocation of the UL resources for the CSC indicator from the terminal (402). In this case, the base station (401) may reallocate the UL resources for the CSC indicator to be used for other data transmission. In addition, when the base station (401) deactivates the CSC indicator, even if the UL resources for the CSC indicator are not used, a delay or latency may occur if the terminal (402) requests reallocation. Accordingly, the terminal (402) may not request reallocation of the UL resources for the CSC indicator.

[0196] According to one embodiment, the base station (401) can monitor the size of the CSC indicator and / or CSI report without an SR request from the terminal (402), and can allocate UL resources via DCI. For example, when the base station (401) transmits a message activating the CSC indicator to the terminal (402), the base station (401) can identify a first resource required for the CSC indicator and a second resource required for simplified CSI reporting. The base station (401) can newly allocate UL resources to the terminal (402) based on the first resource and the second resource, even if there is no SR from the terminal (402).

[0197] As another example, when the base station (401) transmits a message to the terminal (402) to deactivate the CSC indicator, the base station (401) may identify a third resource required for CSI reporting for both the first resource used for the CSC indicator and a plurality of parameters. The base station (401) may allocate new UL resources to the terminal (402) based on the first resource and the third resource, even if there is no SR from the terminal (402).

[0198] Activation or deactivation of the CSC indicator described in FIG. 12 of the present disclosure can be applied to each parameter associated with a channel state, and uplink resource allocation can be newly performed for each parameter. For example, the base station (401) can request the terminal (402) to report a first parameter (e.g., CQI) through the CSC indicator, and in this case, the base station (401) can identify that uplink resource allocation is required by receiving an SR or monitoring the size of the CSC indicator, and can perform uplink resource allocation.

[0199] FIG. 13 is a diagram illustrating a method for exchanging CSC indicators and capability information for simplified CSI reporting between a base station and a terminal according to one embodiment.

[0200] Referring to FIG. 13, according to an embodiment, a base station (401) may transmit a capability information request (e.g., UECapabilityEnquiry) when a terminal (402) is connected (or camped on, or attached) to the base station (401) at step 1310. For example, the base station (401) may inquire whether the terminal (402) is capable of transmitting an indicator (e.g., a CSC indicator) regarding a change in channel status. For example, when the terminal (402) performs an initial connection to the base station (401), the base station (401) may transmit a capability information request to the terminal (402).

[0201] For example, [Table 7] may be an IE for a capability inquiry request transmitted to a terminal (402), and information for inquiring whether the terminal (402) has the capability to transmit an indicator for a change in channel status may be included in [Table 7]. However, this is only an example, and a capability information request (e.g., UECapabilityEnquiry) transmitted by a base station (401) may include only a portion of the information in [Table 7], and may further include additional IEs.

[0202]

[0203] According to one embodiment, the terminal (402) may transmit capability information (e.g., UECapabilityInformation) of the terminal (402) in response to the capability information request at step 1320. For example, the capability information of the terminal (402) may include information on whether the terminal (402) is capable of transmitting an indicator of a change in channel status (e.g., a CSC indicator).

[0204] For example, [Table 8] may be an IE for capability information transmitted by the terminal (402), and information on whether the terminal (402) can transmit an indicator for a change in channel status may be included in [Table 8]. However, this is only an example, and the capability information transmitted by the terminal (402) may include only a portion of the information in [Table 8], and may further include additional IEs.

[0205]

[0206] According to one embodiment, whether the base station (401) transmits information for enabling a CSC indicator to the terminal (402) may be determined based on whether the terminal (402) is capable of transmitting the CSC indicator. For example, the base station (401) may identify whether the terminal (402) is capable of transmitting the CSC indicator and / or the simplified CSI report based on capability information transmitted by the terminal (402). If the terminal (402) is capable of transmitting the CSC indicator and / or the simplified CSI report, the base station (401) may set information for enabling the CSC indicator (e.g., CSC-indicatorConfig) to the terminal (402). As another example, the base station (401) may not set information for enabling the CSC indicator to the terminal (402) if the terminal (402) is not capable of transmitting the CSC indicator and / or the simplified CSI report.

[0207] According to one embodiment, a method performed by a terminal in a wireless communication system includes the steps of: receiving, from a base station, information for triggering transmission of an indicator for a change in a channel state; transmitting, to the base station, at least one indicator for the change in the channel state based on the information for triggering the transmission of the indicator; and transmitting, to the base station, a measurement report in which data for one or more parameters of which a value has not changed among the at least one parameter is excluded, wherein the information for triggering the transmission includes information for at least one parameter for the indicator among a plurality of parameters associated with the channel state, and the at least one indicator can indicate whether a value of the at least one parameter has changed.

[0208] According to one embodiment, the method further comprises the step of receiving configuration information including information for enabling the indicator for the change in the channel state, wherein the at least one indicator is transmitted based on the information for enabling the indicator, and the step of transmitting the at least one indicator may comprise the steps of: receiving, from the base station, a first channel state information reference signal (CSI RS); comparing first values ​​for the at least one parameter identified based on the first CSI RS with second values ​​for the at least one parameter identified based on a second CSI RS received prior to the first CSI RS; and transmitting an indicator indicating whether the channel state has changed based on a result of the comparison.

[0209] According to one embodiment, the method may further include the step of receiving a message requesting transmission of the measurement report including the data for the one or more parameters from the base station when the value of the one or more parameters changes or a message for a measurement report including the data for the one or more parameters is transmitted to the base station.

[0210] According to one embodiment, the method may further include a step of transmitting the measurement report based on information about the resource received in response to a scheduling request (SR) for a resource for the measurement report including the data, when the SR is transmitted to the base station, and a step of transmitting the measurement report based on the information about the resource received from the base station based on at least one of a size of the at least one indicator or a size of the measurement report.

[0211] According to one embodiment, the method further comprises the steps of receiving, from the base station, a request for capability information for the transmission of the indicator when performing an initial connection to a cell of the base station, and transmitting, to the base station, the capability information, wherein the at least one indicator includes a field of 1 bit for each of the at least one parameter, and wherein the plurality of parameters associated with the channel state can be changed via downlink control information (DCI) or radio resource control (RRC) signaling.

[0212] According to one embodiment, in a wireless communication system, a terminal includes a transceiver and a controller coupled with the transceiver, wherein the controller is configured to receive, from a base station, information for triggering transmission of an indicator for a change in a channel state, and to transmit to the base station at least one indicator for the change in the channel state based on the information for triggering the transmission of the indicator, and to transmit to the base station a measurement report in which data for one or more parameters whose values ​​among the at least one parameter have not changed is excluded, wherein the information for triggering the transmission includes information for at least one parameter for the indicator among a plurality of parameters associated with the channel state, and the at least one indicator can indicate whether a value of the at least one parameter has changed.

[0213] According to one embodiment, the controller is configured to receive configuration information including information for enabling the indicator for the change in the channel state, and the at least one indicator is transmitted based on the information for enabling the indicator, and the controller is configured to receive, from the base station, a first channel state information reference signal (CSI RS), compare first values ​​for the at least one parameter identified based on the first CSI RS with second values ​​for the at least one parameter identified based on a second CSI RS received prior to the first CSI RS, and transmit an indicator indicating whether the channel state has changed based on a result of the comparison.

[0214] According to one embodiment, the controller may be configured to receive a message requesting transmission of the measurement report including the data for the one or more parameters from the base station when the value of the one or more parameters changes or when a message for a measurement report including the data for the one or more parameters is transmitted to the base station.

[0215] According to one embodiment, the controller may be configured to transmit the measurement report based on information about the resource received in response to the SR (scheduling request) for the resource for the measurement report including the data when the SR is transmitted to the base station, and to transmit the measurement report based on the information about the resource received from the base station based on at least one of a size of the at least one indicator or a size of the measurement report.

[0216] According to one embodiment, the controller is configured to receive, from the base station, a request for capability information for the transmission of the indicator when performing an initial connection to a cell of the base station, and to transmit the capability information to the base station, wherein the at least one indicator includes a field of 1 bit for each of the at least one parameter, and the plurality of parameters associated with the channel state can be changed via downlink control information (DCI) or radio resource control (RRC) signaling.

[0217] A method performed by a base station in a wireless communication system includes the steps of transmitting, to a terminal, information for triggering an indicator for a change in a channel state, receiving, from the terminal, at least one indicator for the change in the channel state based on the information for triggering the indicator, and receiving, from the terminal, a measurement report in which data for one or more parameters whose values ​​among the at least one parameter have not changed are excluded, wherein the information for triggering the indicator may include information for at least one parameter for the indicator among a plurality of parameters associated with the channel state, and the at least one indicator may indicate whether a value of the at least one parameter has changed.

[0218] According to one embodiment, the at least one indicator indicates whether the at least one parameter associated with the channel state has changed, and the step of transmitting the information for triggering the indicator may include the step of receiving a plurality of measurement reports including data for the at least one parameter, and the step of transmitting the information for the at least one parameter if, based on the plurality of measurement reports, the at least one parameter has not changed more than a specified number of consecutive times.

[0219] According to one embodiment, the method may further include the step of transmitting a message requesting the terminal to transmit the measurement report including the data for the one or more parameters when the value of the one or more parameters changes or a message for a measurement report including the data for the one or more parameters is received from the terminal.

[0220] According to one embodiment, the method may further include the step of transmitting information about the resource in response to a scheduling request (SR) for a resource for the measurement report including the data when the SR is received from the terminal, and the step of transmitting the information about the resource received from the base station based on at least one of a size of the at least one indicator or a size of the measurement report.

[0221] According to one embodiment, the method further includes the step of requesting capability information of the terminal for transmission of the indicator from the terminal when the terminal performs an initial connection, and the step of receiving the capability information of the terminal from the terminal, wherein the information for enabling the indicator is determined based on the capability information, and wherein the at least one indicator includes a field of 1 bit for each of the at least one parameter, and the plurality of parameters associated with the channel state can be changed through downlink control information (DCI) or radio resource control (RRC) signaling.

[0222] According to one embodiment, in a wireless communication system, a base station includes a transceiver and a controller coupled with the transceiver, wherein the controller is configured to transmit, to a terminal, information for triggering an indicator for a change in a channel state, receive from the terminal at least one indicator for the change in the channel state based on the information for triggering the indicator, and receive from the terminal a measurement report in which data for one or more parameters whose values ​​among the at least one parameter have not changed are excluded, wherein the information for triggering the indicator includes information for at least one parameter for the indicator among a plurality of parameters associated with the channel state, and the at least one indicator can indicate whether a value of the at least one parameter has changed.

[0223] In one embodiment, the at least one indicator may indicate whether the at least one parameter associated with the channel state has changed, and the controller may be configured to receive a plurality of measurement reports including data for the at least one parameter, and to transmit the information for the at least one parameter if, based on the plurality of measurement reports, the at least one parameter has not changed more than a specified number of consecutive times.

[0224] According to one embodiment, the controller may be configured to transmit a message requesting the terminal to transmit the measurement report including the data for the one or more parameters when the value of the one or more parameters changes or when a message for a measurement report including the data for the one or more parameters is received from the terminal.

[0225] According to one embodiment, the controller may be configured to transmit information about the resource in response to a scheduling request (SR) for a resource for the measurement report including the data when the SR is received from the terminal, and to transmit the information about the resource received from the base station based on at least one of a size of the at least one indicator or a size of the measurement report.

[0226] According to one embodiment, the controller is configured to request capability information of the terminal for transmission of the indicator from the terminal when the terminal performs an initial connection, and to receive the capability information of the terminal from the terminal, wherein the information for enabling the indicator is determined based on the capability information, and wherein the at least one indicator includes a field of 1 bit for each of the at least one parameter, and the plurality of parameters associated with the channel state can be changed through downlink control information (DCI) or radio resource control (RRC) signaling.

[0227] Meanwhile, the present specification and drawings disclose preferred embodiments of the present invention. Although specific terms have been used, they are used in a general sense only to easily explain the technical contents of the present invention and to assist in understanding the invention, and are not intended to limit the scope of the present invention. It will be apparent to those skilled in the art that other modified examples based on the technical concept of the present invention are possible in addition to the embodiments disclosed herein.

Claims

1. In a method performed by a terminal in a wireless communication system, A step of receiving, from a base station, information for triggering transmission of an indicator for a change in channel status, wherein the information for triggering the transmission includes information on at least one parameter for the indicator among a plurality of parameters associated with the channel status; transmitting to the base station at least one indicator for the change in the channel state based on the information for triggering the transmission of the indicator, the at least one indicator indicating whether the value of the at least one parameter has changed; and A method comprising the step of transmitting to the base station a measurement report excluding data for one or more parameters whose values ​​among the at least one parameter have not changed.

2. In claim 1, Further comprising a step of receiving configuration information including information for enabling the indicator for the change in the channel state, wherein said at least one indicator is transmitted based on said information for enabling said indicator, The step of transmitting at least one of the above instructions comprises: A step of receiving a first CSI RS (channel state information reference signal) from the base station, A step of comparing first values ​​for the at least one parameter identified based on the first CSI RS with second values ​​for the at least one parameter identified based on a second CSI RS received before the first CSI RS, and A method comprising the step of transmitting an indicator indicating whether the channel state has changed based on the comparison result.

3. In claim 1, A method further comprising the step of receiving a message requesting transmission of the measurement report including the data for the one or more parameters from the base station when the value of the one or more parameters changes or a message for a measurement report including the data for the one or more parameters is transmitted to the base station.

4. In claim 3, When a scheduling request (SR) for a resource for the measurement report including the data is transmitted to the base station, a step of transmitting the measurement report based on information about the resource received in response to the SR; and A method further comprising the step of transmitting the measurement report based on the information about the resource received from the base station based on at least one of the size of the at least one indicator or the size of the measurement report.

5. In a wireless communication system, at the terminal, transceiver; and A controller coupled with the above transceiver, The above controller: Receive information from a base station for triggering transmission of an indicator for a change in channel status, wherein the information for triggering the transmission includes information on at least one parameter for the indicator among a plurality of parameters associated with the channel status, Transmitting to the base station at least one indicator for the change in the channel state based on the information for triggering the transmission of the indicator, is configured to transmit to the base station a measurement report excluding data for one or more parameters whose values ​​among the at least one parameter have not changed; A terminal in which at least one indicator indicates whether the value of at least one parameter has changed.

6. In claim 5, The above controller: is configured to receive configuration information including information for enabling the indicator for the change in the channel state; wherein said at least one indicator is transmitted based on said information for enabling said indicator, The above controller: From the above base station, a first CSI RS (channel state information reference signal) is received, Compare first values ​​for the at least one parameter identified based on the first CSI RS with second values ​​for the at least one parameter identified based on a second CSI RS received before the first CSI RS, A terminal configured to transmit an indicator indicating whether the channel status has changed based on the comparison result.

7. In claim 5, The above controller: A terminal configured to receive a message requesting transmission of the measurement report including the data for the one or more parameters from the base station when the value of the one or more parameters changes or a message for a measurement report including the data for the one or more parameters is transmitted to the base station.

8. In claim 7, The above controller: When a scheduling request (SR) for a resource for the measurement report including the above data is transmitted to the base station, the measurement report is transmitted based on information about the resource received in response to the SR, A terminal configured to transmit the measurement report based on the information about the resource received from the base station based on at least one of the size of the at least one indicator or the size of the measurement report.

9. In a method performed by a base station in a wireless communication system, A step of transmitting information to a terminal for triggering an indicator for a change in a channel state, wherein the information for triggering the indicator includes information on at least one parameter for the indicator among a plurality of parameters associated with the channel state; A step of receiving, from the terminal, at least one indicator for the change in the channel state based on the information for triggering the indicator, the at least one indicator indicating whether the value of the at least one parameter has changed; and A method comprising the step of receiving, from the terminal, a measurement report excluding data for one or more parameters whose values ​​among the at least one parameter have not changed.

10. In claim 9, wherein said at least one indicator indicates whether said at least one parameter associated with said channel state has changed, The steps for transmitting the above information to trigger the above indicator are: receiving a plurality of measurement reports including data for at least one parameter; and A method comprising the step of transmitting the information about the at least one parameter, if the at least one parameter has not changed more than a specified number of consecutive times based on the plurality of measurement reports.

11. In claim 9, A method further comprising the step of transmitting a message requesting the terminal to transmit the measurement report including the data for the one or more parameters when the value of the one or more parameters changes or a message for a measurement report including the data for the one or more parameters is received from the terminal.

12. In claim 11, When a scheduling request (SR) for a resource for the measurement report including the data is received from the terminal, a step of transmitting information about the resource in response to the SR; and A method further comprising the step of transmitting the information about the resource received from the base station based on at least one of the size of the at least one indicator or the size of the measurement report.

13. In a wireless communication system, at a base station, transceiver; and A controller coupled with the above transceiver, The above controller: Transmitting information to a terminal for triggering an indicator for a change in channel status, wherein the information for triggering the indicator includes information on at least one parameter for the indicator among a plurality of parameters associated with the channel status, Receive from the terminal at least one indicator for the change in the channel state based on the information for triggering the indicator, wherein the at least one indicator indicates whether the value of the at least one parameter has changed, A base station configured to receive, from the terminal, a measurement report excluding data for one or more parameters whose values ​​have not changed among the at least one parameter.

14. In claim 13, wherein said at least one indicator indicates whether said at least one parameter associated with said channel state has changed, The above controller: Receiving a plurality of measurement reports including data for at least one parameter; A base station configured to transmit the information about the at least one parameter if the at least one parameter does not change more than a specified number of times consecutively based on the plurality of measurement reports.

15. In claim 13, The above controller: A base station configured to transmit a message requesting the terminal to transmit the measurement report including the data for the one or more parameters when the value of the one or more parameters changes or a message for a measurement report including the data for the one or more parameters is received from the terminal.

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