Method and device for interference-based information reporting in wireless communication system

Abstract

The present disclosure relates to a 5G or 6G communication system for supporting higher data transmission rates beyond the previous 4G communication system, such as LTE. The method performed by a terminal in a wireless communication system according to an embodiment of the present disclosure comprises the steps of: calculating a difference value between an interference amount when receiving n-th information and an interference amount when receiving (n-1)-th information; and transmitting interference change-related information to a base station when the difference value exceeds a first threshold value. The interference change-related information is used for link adaptation, and the interference change-related information includes at least one of a first indicator indicating whether interference is changed, a second indicator indicating the difference value, or the difference value.

Description

Method and device for interference-based information reporting in wireless communication systems

[0001] The present disclosure relates to a method and apparatus for interference-based information 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 5G (5th-generation) communication systems, 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 expected to evolve into diverse form factors, including augmented reality glasses, virtual reality headsets, and holographic devices. In the 6th-generation (6G) 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 per second (i.e., 1,000 gigabits per second) 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, while 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 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 experience more severe path loss and atmospheric absorption, making it more crucial to ensure signal reach, or coverage, in this band. Key technologies to ensure coverage include radio frequency (RF) components, antennas, new waveforms that offer better coverage than OFDM (orthogonal frequency division multiplexing), 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 surfaces (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 for uplink and downlink at the same time; network technology that integrates satellites and high-altitude platform stations (HAPS); 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 artificial intelligence (AI) 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 (the next 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 (Truly Immersive 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 find application in diverse fields such as industry, medicine, automobiles, and home appliances.

[0007] The present disclosure proposes a method and device for a terminal to report additional information to a base station based on an interference level.

[0008] The present disclosure proposes a method and device for instantaneous reporting or statistical reporting when a terminal reports additional information to a base station based on an interference level.

[0009] According to one embodiment of the present disclosure, a method of a terminal in a wireless communication system includes the steps of: calculating a difference value between an interference amount when receiving an nth piece of information and an interference amount when receiving an n-1th piece of information; and transmitting interference change-related information to a base station when the difference value exceeds a first threshold; wherein the interference change-related information is used in link adaptation, and the interference change-related information includes at least one of a first indicator indicating whether interference has changed, a second indicator indicating the difference value, and the difference value.

[0010] According to one embodiment of the present disclosure, a method of a base station in a wireless communication system includes the steps of: receiving interference change-related information from a terminal when a difference value between an interference amount when an nth piece of information is received from the terminal and an interference amount when an n-1th piece of information is received exceeds a first threshold value; and performing link adaptation based on the interference change-related information; wherein the interference change-related information includes at least one of a first indicator indicating whether interference has changed, a second indicator indicating the difference value, and the difference value.

[0011] According to one embodiment of the present disclosure, in a wireless communication system, a terminal includes a transceiver; and at least one processor; wherein the at least one processor is configured to calculate a difference value between an interference amount when an nth piece of information is received and an interference amount when an n-1th piece of information is received, and transmit interference change-related information to a base station when the difference value exceeds a first threshold value, wherein the interference change-related information is used in link adaptation, and the interference change-related information includes at least one of a first indicator indicating whether interference has changed, a second indicator indicating the difference value, and the difference value.

[0012] According to one embodiment of the present disclosure, in a wireless communication system, a base station includes a transceiver; and at least one processor; wherein the at least one processor is configured to receive interference change-related information from a terminal when a difference value between an interference amount when an nth piece of information is received by a terminal and an interference amount when an n-1th piece of information is received exceeds a first threshold value, and to perform link adaptation based on the interference change-related information, wherein the interference change-related information includes at least one of a first indicator indicating whether interference has changed, a second indicator indicating the difference value, and the difference value.

[0013] The method and device according to the embodiment of the present disclosure can improve the performance of link adaptation performed at a base station through additional information reporting by a terminal when channel conditions change rapidly.

[0014] The method and device according to the embodiment of the present disclosure can improve the performance of link adaptation performed at a base station through statistical reporting on current channel information of a terminal.

[0015] Figure 1 is a flowchart illustrating a terminal channel status measurement and reporting procedure.

[0016] FIG. 2 is a diagram illustrating an operation for performing link adaptation in a wireless communication system.

[0017] Figure 3 is a diagram explaining OLRC (outer loop rate control) during link adaptation of a wireless communication system.

[0018] FIG. 4 is a diagram illustrating a scenario in which the SINR prediction of a base station is delayed when the SINR of a terminal side suddenly changes in a wireless communication system.

[0019] FIG. 5 is a diagram illustrating a change in the predicted SINR of a base station when applying instantaneous reporting according to one embodiment of the present invention.

[0020] FIG. 6 is a diagram illustrating a change in the predicted SINR of a base station when applying a statistical report according to one embodiment of the present invention.

[0021] FIG. 7 is a drawing illustrating an example of measuring relative interference according to one embodiment of the present invention.

[0022] FIG. 8 is a diagram illustrating an example of an operation for instantaneous reporting according to one embodiment of the present invention.

[0023] FIG. 9 is a diagram illustrating an example of a physical uplink control channel (PUCCH) resource set for instantaneous reporting according to one embodiment of the present invention.

[0024] FIG. 10 is a diagram illustrating a change in the predicted SINR of a base station when applying instantaneous reporting using True or False values ​​according to one embodiment of the present invention.

[0025] FIG. 11 is a diagram explaining a change in the predicted SINR of a base station when applying an instantaneous report that divides the difference in interference level into L stages according to one embodiment of the present invention.

[0026] FIG. 12 is a diagram illustrating a change in the predicted SINR of a base station when applying an instantaneous report that reports a difference value of an interference level according to one embodiment of the present invention.

[0027] FIG. 13 is a diagram illustrating an operation of periodically reporting statistical information on channel conditions according to one embodiment of the present invention.

[0028] FIG. 14 is a diagram illustrating an operation of aperiodically reporting statistical information on channel conditions according to one embodiment of the present invention.

[0029] Figure 15 is a flowchart illustrating the operation of a terminal according to one embodiment of the present invention.

[0030] Figure 16 is a flowchart illustrating the operation of a base station according to one embodiment of the present invention.

[0031] Figure 17 is a structural diagram showing the structure of a terminal according to one embodiment of the present invention.

[0032] FIG. 18 is a structural diagram showing the structure of a base station according to one embodiment of the present invention.

[0033] Hereinafter, preferred embodiments of the present disclosure will be described in detail with reference to the attached drawings. It should be noted that, where possible, identical components are represented by identical reference numerals throughout the attached drawings. Furthermore, detailed descriptions of well-known functions and configurations that may obscure the gist of the present disclosure will be omitted.

[0034] In describing the embodiments in this specification, descriptions of technical details that are well known in the technical field to which the present disclosure pertains and are not directly related to the present disclosure will be omitted. This is to avoid obscuring the gist of the present disclosure by omitting unnecessary explanations and to convey the gist more clearly.

[0035] For the same reason, some components in the attached drawings are exaggerated, omitted, or schematically depicted. Furthermore, the dimensions of each component do not entirely reflect its actual size. Identical or corresponding components in each drawing are assigned the same reference numbers.

[0036] The advantages and features of the present disclosure, and methods for achieving them, will become clearer with reference to the embodiments described below in detail together with the accompanying drawings. However, the present disclosure is not limited to the embodiments disclosed below and may be implemented in various different forms. These embodiments are provided only to ensure that the disclosure of the present disclosure is complete and to fully inform those skilled in the art of the scope of the disclosure, and the present disclosure is defined only by the scope of the claims. Like reference numerals refer to like elements throughout the specification.

[0037] At this time, it will be understood that each block of the processing flow diagrams and combinations of the flow diagrams can be performed by computer program instructions. These computer program instructions can be installed in a processor of a general-purpose computer, a special-purpose computer, or other programmable data processing equipment, so that the instructions executed by the processor of the computer or other programmable data processing equipment create a means for performing the functions described in the flow diagram block(s). These computer program instructions can also be stored in a computer-available or computer-readable memory that can direct a computer or other programmable data processing equipment to implement the functions in a specific manner, so that the instructions stored in the computer-available or computer-readable memory can also produce a manufactured item that includes an instruction means for performing the functions described in the flow diagram block(s). Since the computer program instructions may be installed on a computer or other programmable data processing device, a series of operational steps may be performed on the computer or other programmable data processing device to create a computer-executable process, and the instructions that cause the computer or other programmable data processing device to perform the steps for performing the functions described in the flowchart block(s) may also provide steps for performing the functions described in the flowchart block(s).

[0038] Additionally, each block may represent a module, segment, or portion of code that contains one or more executable instructions for performing a specific logical function(s). It should also be noted that in some alternative implementation examples, the functions described in the blocks may occur out of order. For example, two blocks depicted in succession may actually be executed substantially concurrently, or the blocks may sometimes be executed in reverse order, depending on their respective functions.

[0039] Here, the term '~ unit' used in the present embodiment means software or hardware components such as FPGA (field programmable gate array) or ASIC (application specific integrated circuit), and the '~ unit' performs certain roles. However, the '~ unit' is not limited to software or hardware. The '~ unit' may be configured to be on an addressable storage medium and may be configured to play one or more processors. Accordingly, as an example, the '~ unit' includes components such as software components, object-oriented software components, class components, and task components, processes, functions, properties, procedures, subroutines, segments of program code, drivers, firmware, microcode, circuits, data, databases, data structures, tables, arrays, and variables. The functions provided within the components and '~ units' may be combined into a smaller number of components and '~ units' or further separated into additional components and '~ units'. Additionally, components and '~parts' may be implemented to regenerate one or more CPUs within a device or secure multimedia card.

[0040] In embodiments of the present disclosure, a base station is an entity that performs resource allocation for a terminal, and may be at least one of a gNode B, a gNB, an eNode B, an eNB, a Node B, a BS, a radio access unit, a base station controller, or a node on a network. In addition, the base station may be a gNB that provides network access to the terminal(s) through a network of backhaul and access links in an NR system.

[0041] In addition, the terminal may include a user equipment (UE), a mobile station (MS), a cellular phone, a smartphone, a computer, or various devices capable of performing communication functions. In the present disclosure, downlink (DL) refers to a wireless transmission path of a signal transmitted from a base station to a terminal, and uplink (UL) refers to a wireless transmission path of a signal transmitted from a terminal to a base station.

[0042] In addition, although the LTE or LTE-A system may be described below as an example, the embodiments of the present disclosure may also be applied to other communication systems with similar technical backgrounds or channel types. For example, this may include the 5th generation mobile communication technology (5G, new radio, NR) or 6G developed after LTE-A, and the 5G or 6G described below may also include the existing LTE, LTE-A, and other similar services. In addition, the present disclosure may be applied to other communication systems with some modifications within a range that does not significantly deviate from the scope of the present disclosure, as determined by a person having skilled technical knowledge.

[0043] Terms used in the following description to refer to signals, channels, control information, network entities, and device components are provided for convenience of explanation. Furthermore, terms used in the following description to identify nodes, messages, interfaces between network entities, and various pieces of information are provided for convenience of explanation. Therefore, the present disclosure is not limited to the terms described below, and other terms having equivalent technical meanings may be used.

[0044] Additionally, while this disclosure describes various embodiments using terminology used in certain communication standards (e.g., 3rd Generation Partnership Project (3GPP)), these are merely illustrative examples. The various embodiments of this disclosure can be easily modified and applied to other communication systems.

[0045] Figure 1 is a flowchart illustrating a terminal channel status measurement and reporting procedure.

[0046] Referring to FIG. 1, in step 100, a terminal may transmit an SRS (sounding reference signal). In step 105, a base station may measure a channel state of an uplink based on the SRS and determine at least one downlink beam candidate to be used in a downlink based on a direction and delay according to the measured channel state. In order to determine a size and a phase of the downlink beam candidate, the base station transmits a CSI-RS (channel state information-reference signal) to the terminal using a beamformed port reflecting the uplink beam candidate in step 110. The base station may trigger a CSI report simultaneously with or prior to transmitting the CSI-RS. The terminal may receive the CSI-RS by considering configuration information for measuring and reporting a channel state that the base station previously sent. In step 120, the terminal may report CSI (channel state information) reflecting the downlink beam candidate to the base station using the received CSI-RS. The base station that receives the above CSI uses it to determine which terminals to transmit to, at what data transmission rate to transmit, and what precoding to apply in relation to downlink transmission.

[0047] The terminal transmits downlink channel status information (CSI) back to the base station, allowing the base station to utilize it for downlink scheduling. The terminal can measure the reference signal (CSI-RS) transmitted by the base station on the downlink and feed back the extracted information to the base station. The information transmitted back by the terminal can include the following three types of information: RI, PMI, and CQI.

[0048] 1) RI (Rank Indicator): This indicator provides information on the recommended value for the rank used for transmission, i.e. the number of layers desired to be used for downlink transmission to the terminal.

[0049] 2) PMI (Precoder Matrix Indicator): This indicator provides information about the precoding matrix desired to be used for DL-SCH transmission.

[0050] 3) CQI (Channel Quality Indicator): The maximum data rate (i.e., modulation and coding scheme (MCS)) that a terminal can receive under the current channel conditions. CQI can also be replaced with SINR (signal-to-noise ratio), maximum error correction coding rate, modulation scheme, and data efficiency per frequency, which can be utilized similarly to the maximum data rate.

[0051] With the advancement of LTE, 5G, and 6G, the impact of interference and noise on channels is becoming increasingly significant. Link adaptation technology adaptively improves channel issues based on wireless link conditions. Link adaptation technology is required to ensure error-free data transmission by applying appropriate parameters based on wireless link conditions, as the radio conditions between the wireless terminal and the base station constantly change over time, especially for wireless terminals moving in real time or at cell edges.

[0052] Link adaptation algorithm is a technology that provides a data rate suitable for the channel environment by dynamically adjusting the MCS (modulation and coding scheme) level and / or rate-related parameters according to the wireless channel environment. The parameters for link adaptation operation are predefined. Generally, link adaptation algorithm through HARQ ACK (Acknowledgement) / NACK (Negative Acknowledgement) feedback and link adaptation algorithm through CSI feedback are applied in 4G LTE / 5G NR, and the above algorithm method can be continuously used in HARQ-based communication systems.

[0053] In link adaptation, a network transceiver may select a defined set of modulation techniques and coding schemes based on an estimate of the instantaneous quality of the downlink channel to each wireless terminal (e.g., UE). Channel information is typically reported by the terminal and may include a signal-to-interference-and-noise ratio (SINR) measured or estimated by the terminal. In the present disclosure, for convenience of explanation, the channel state information is described as SINR, but the channel state information is not limited thereto.

[0054] Active research on broadband wireless communication systems has been underway since LTE Release 8 / 9. In these broadband wireless communication systems, the modulation scheme and error correction coding rate for the data to be transmitted are determined to suit the channel environment before transmission. The MCS level for downlink transmission in these broadband wireless communication systems can be implemented in various ways depending on the method, but the following methods are representative examples.

[0055] FIG. 2 is a diagram illustrating an operation for performing link adaptation in a wireless communication system.

[0056] Referring to Figure 2, the operation for performing link adaptation includes an adaptive modulation and coding (AMC) method and an outer loop rate control (OLRC) method.

[0057] First, the AMC method refers to determining the MCS solely based on the CQI information contained in the CSI transmitted by the terminal. That is, when the terminal transmits CQI feedback to the base station, the base station can convert the CQI information transmitted by the terminal into SINR using a predetermined value through CQI-SINR Conversion.

[0058] However, since the criteria for CQI reported by each terminal are ambiguous and inaccurate, and information is not continuously reported, there is a problem that it is difficult to detect channel changes using only CQI.

[0059] The OLRC method is related to an algorithm of a base station for correcting problems caused by the above AMC, and refers to a method of receiving a response signal for downlink data, i.e., an ACK / NACK signal, and making additional corrections to the estimated SINR.

[0060] For example, when the base station receives an ACK signal, it adjusts the estimated SINR upward, and when it receives a NACK signal, it adjusts the estimated SINR downward to determine the estimated SINR. Then, the base station detects the MCS level corresponding to the determined SINR by referring to an MCS decision table including MCS level information for each preset channel state. Then, the base station transmits downlink data to the terminal using the detected MCS level. Then, continuous SINR correction is performed based on the response signal of the corresponding downlink data. In this process, by adjusting the size of the SINR correction amount (AckStepSize / NackStepSize) according to the ACK / NACK signal, the BLER (block error rate) of the data transmitted from the base station can converge to a target BLER of a certain value.

[0061] Figure 3 is a diagram explaining OLRC (outer loop rate control) during link adaptation of a wireless communication system.

[0062] Referring to Fig. 3, the base station can correct the SINR value estimated from the CQI using the HARQ ACK / NACK report received from the terminal. For example, if the base station receives a NACK, the estimated SINR can be adjusted downward by NackStepSize (300). Alternatively, if the base station receives an ACK, the estimated SINR can be adjusted upward by AckStepSize (310). The base station can continuously track the channel even in sections where it does not receive a CQI. Accordingly, if the base station receives multiple ACKs or NACKs, the final estimated SINR can be derived as shown in Equation 1 below.

[0063] [Mathematical Formula 1]

[0064] SINRwithOLRC=SINR + OLRC OFFSET

[0065] OLRCOFFSET = OLRC OFFSET + ACK count × AckStepSize - NACK count × NackStepSize

[0066] That is, OLRC OFFSET is not determined by a single HARQ ACK / NACK reporting, but is a parameter that is continuously updated for each UE each time a report is received. For example, when multiple ACK / NACKs are received at once, the base station calculates the number of ACKs × AckStepSize - number of NACKs × NackStepSize as in the above mathematical expression 1. OFFSET It can be updated by applying it to parameters.

[0067] Meanwhile, if sudden SINR changes occur between CQI reporting periods, these changes can be compensated for by applying an OLRC offset to the SINR currently predicted by the base station based on CQI. However, if the OLRC method sets a constant SINR compensation value based on the ACK / NACK signal, a large gap may occur between the terminal's actual SINR and the base station's predicted SINR.

[0068] FIG. 4 is a diagram illustrating a scenario in which the SINR prediction of a base station is delayed when the SINR of a terminal side suddenly changes in a wireless communication system.

[0069] Referring to FIG. 4, it can be seen that there is a time difference between the SINR (hereinafter, actual SINR) (400) that the terminal actually experiences as a result of PDSCH decoding and the SINR (hereinafter, predicted SINR) (410) that the base station predicts based on the terminal's CQI report to determine the MCS for performing link adaptation. In other words, this is a scenario where the base station's SINR prediction is delayed even if the SINR experienced by the terminal suddenly changes.

[0070] When the channel condition improves and the actual SINR of the terminal increases rapidly (425) after the base station receives the first CQI report (420), the base station performs an SINR correction operation by the preset AckStepSize when applying the OLRC method through ACK, so there is a delay in the predicted SINR reflecting the actual SINR. Accordingly, there is a problem in that the base station cannot sufficiently increase the MCS level even though it can process the signal based on a relatively high MCS level by performing link adaptation.

[0071] Afterwards, when the base station receives the second CQI report (430) and before receiving the third CQI report (440), if the channel condition deteriorates and the actual SINR of the terminal drops sharply (445), the base station performs an SINR correction operation by the preset NackStepSize when applying the OLRC method through NACK until receiving the third CQI report (440), so there is a delay in the predicted SINR reflecting the actual SINR. Accordingly, the base station processes the signal based on a relatively high MCS level compared to the current channel condition, which causes a problem in that the BLER (block error rate) increases.

[0072] Accordingly, a method of shortening the cycle of CQI reporting can be considered, but this will significantly increase the usage of downlink resources for CSI-RS, and a method is needed to improve the problem of CQI reporting itself, in that the standard for the CQI value reported by each terminal is ambiguous and inaccurate.

[0073] Accordingly, the present disclosure aims to improve the above-described problematic situation through additional information reporting of the terminal, and specifically proposes the following two measures.

[0074] Method 1. Link adaptation of base stations through instantaneous reporting information from terminals

[0075] Method 2. Base station link adaptation through statistical reporting information from terminals.

[0076] Method 1 involves the terminal observing the current channel conditions each time it receives downlink data transmission and reporting any significant changes in channel conditions compared to the previous transmission to the base station via uplink control information. The base station can then perform link adaptation by receiving this information and making additional corrections to the OLRC offset.

[0077] Method 2 involves the terminal continuously monitoring changes in the current channel conditions whenever it receives downlink data and reporting this information to the base station periodically or aperiodically via uplink control information. The base station can then perform link adaptation by receiving this information and adjusting the OLRC parameters (AckStepSize / NackStepSize) to match the current channel conditions.

[0078] FIG. 5 is a diagram illustrating a change in the predicted SINR of a base station when applying instantaneous reporting according to one embodiment of the present invention.

[0079] Figure 5 (a) is a case where the instantaneous reporting of the terminal described in the above method 1 is not applied, and Figure 5 (b) is a case where the instantaneous reporting of the terminal is applied.

[0080] Referring to (a) of Fig. 5, it can be seen that there is a time difference between the SINR (hereinafter, actual SINR) (500) that the terminal actually experiences as a result of PDSCH decoding and the SINR (hereinafter, predicted SINR) (505) that the base station predicts based on the CQI report of the terminal to determine the MCS. That is, in Fig. 5 (a), even when the actual SINR (500) that the terminal experiences drops sharply, the base station only performs SINR correction through NACK using the OLRC method, so it takes a considerably long time to reflect the actual SINR (500) in the predicted SINR (505).

[0081] However, referring to (b) of FIG. 5, by applying the instantaneous reporting of the terminal corresponding to the above method 1, the terminal can detect the actual SINR (520) that the current channel condition has deteriorated rapidly compared to the previous transmission even before the second CQI report (535) after the first CQI report (530) and report an additional signal to the base station (540). Thereafter, the base station can rapidly reflect the actual SINR (520) by significantly lowering the predicted SINR (525) through an additional offset based on the additional signal (545). Accordingly, when the SINR suddenly drops, the base station can quickly improve the problem of a significant increase in BLER by processing the signal based on a relatively high MCS level compared to the current channel condition, thereby increasing the throughput of the system. In the case of FIG. 5, an example of a rapid drop in SINR is shown, but a case where the SINR increases rapidly can also be improved through the same method.

[0082] FIG. 6 is a diagram illustrating a change in the predicted SINR of a base station when applying a statistical report according to one embodiment of the present invention.

[0083] Figure 6 (a) is a case where the statistical report described in the above method 2 of the terminal is not applied, and Figure 5 (b) is a case where the statistical report of the terminal is applied.

[0084] Referring to (a) of FIG. 5, a large channel condition change exists between the first CQI report (610) and the second CQI report (620) of the terminal, so that the SINR (hereinafter, actual SINR) (600) actually experienced by the terminal as a result of PDSCH decoding varies greatly, but the SINR (hereinafter, predicted SINR) (605) predicted by the base station based on the CQI report of the terminal to determine the MCS does not immediately reflect this. In other words, the base station must use the OLRC method even when a large channel condition change exists, but the current OLRC parameters (AckStepSize / NackStepSize) do not match the channel condition, so the base station continuously fails to predict the channel condition.

[0085] However, referring to (b) of FIG. 6, if there is a large channel condition change between the first CQI report (630) and the second CQI report (635) of the terminal, and the actual SINR (620) experienced by the terminal changes greatly, the base station can receive a report of the current large channel condition even before the second CQI (635) report from the terminal by applying the statistical report of the terminal corresponding to the above method 2. Accordingly, the base station can greatly adjust the adjustment size of the predicted SINR (625), AckStepSize / NackStepSize, so that the predicted SINR (625) can quickly reflect the actual SINR (620) using the OLRC method. Conversely, if the channel change is very small as illustrated in FIG. 6, the base station that received the statistical channel condition report can adjust the AckStepSize / NackStepSize smaller, so that a more detailed SINR prediction is possible using the OLRC method.

[0086] Below, the above methods 1 and 2 are described in detail.

[0087] In the above method 1, the terminal can observe the current channel conditions each time it receives downlink data transmission, and if the interference amount measured by the terminal itself has changed drastically compared to the previous transmission, it can report additional information to the base station through uplink control information (UCI).

[0088] To perform the above operation, at least one of the following new fields may be added to the uplink control information (UCI):

[0089] A. True / False (1 bit) for sudden changes in interference per TB (time block)

[0090] B. The difference in interference between the current downlink data transmission and the previous downlink data transmission is at a certain level. Fields to report based on judgment ( bit)

[0091] C. Difference value of interference between the current downlink data transmission and the previous downlink data transmission

[0092] D. Interference amount of current downlink data transmission

[0093] E. SINR (SINR demodulation) inferred by the terminal through the DM-RS of the PDCSCH received by the terminal

[0094] In the above method 2, the terminal can observe and update changes in the current channel conditions whenever it receives downlink data transmission, and report additional information to the base station through uplink control information (UCI) periodically or non-periodically.

[0095] To perform the above operation, at least one of the following new fields may be added to the uplink control information (UCI):

[0096] 1. Variance and standard deviation of current channel interference

[0097] 2. Variance and standard deviation of SINR inferred by the terminal through DM-RS of PDSCH (physical downlink shared channel) transmission

[0098] Both the above methods 1 and 2 have in common that the terminal observes the current channel state and then sends additional information to the base station. The current channel state can be measured using various indicators, but in the present disclosure, it refers to the SINR received by the terminal as a result of decoding downlink data transmission, or the amount of interference received during transmission. The SINR received as a result of decoding downlink data transmission can be calculated using a method using DM-RS. The amount of interference received during transmission can be measured in various ways depending on the implementation method of the terminal, and the present disclosure proposes a relative interference measurement method as an example, but is not limited thereto.

[0099] FIG. 7 is a drawing illustrating an example of measuring relative interference according to one embodiment of the present invention.

[0100] Figure 7 (a) is a diagram schematically illustrating an algorithm for measuring relative interference by a terminal, and Figure 7 (b) is an example of a measurement result of relative interference.

[0101] Referring to (a) of Fig. 7, each time a terminal receives a downlink data transmission from a base station, the terminal can calculate and store the relative interference amount, interference variance, and standard deviation.

[0102] Referring to (a) of FIG. 7, when the terminal receives the nth downlink data (receiving PDSCH), the terminal can calculate and store the nth relative interference amount (Interference(n)) as the difference between the SINR (SINR_for_CQI(n))(710) estimated by the previous CSI-RS (700) and the SINR (SINR_Demodulation(n))(730) estimated based on the DM-RS (725) of the PDSCH (720).

[0103] Additionally, the terminal calculates the channel interference variance (Variance_Interference) using the variance of the relative interference amount (Interference) accumulated over a certain period, and can also calculate and store the channel interference standard deviation (Std_Interference) using the same method.

[0104] Referring to (b) of FIG. 7, for example, the relative interference (Interference(n)) (750) when the terminal receives downlink data at time t1 after the first CQI report (740) can be calculated as the difference between the SINR (SINR_for_CQI(n)) estimated by the CSI-RS at the time of the first CQI report (740), which is the immediately preceding CQI report, and the SINR (SINR_Demodulation(n)) estimated based on the DM-RS of the PDSCH received at time t1.

[0105] The mathematical expression 2 below expresses the calculation process of the nth relative interference amount (Interference(n)), channel interference variance (Variance_Interference), and channel interference standard deviation (Std_Interference) in a formula.

[0106] [Equation 2]

[0107] Interference(n)=SINR_for_CQI(n)-SINR_Demodulation(n)

[0108] Variance_Interference=Var(Interference(end-windowsize+1:end))

[0109] Std_Interference=Std(Interference(end-windowsize+1:end))

[0110] By using the same method, the variation of the channel state can be measured using SINR (SINR_Demodulation), which is the result of decoding downlink data transmission rather than interference, and the variance of SINR_Demodulation (Variance_SINR_Demodulation) and the standard deviation of SINR_Demodulation (Std_SINR_Demodulation) are as shown in the following mathematical expression 3.

[0111] [Equation 3]

[0112] Variance_SINR_Demodulation=Var(SINR_Demodulation(end-windowsize+1:end))

[0113] Std_SINR_Demodulation=Std(SINR_Demodulation(end-windowsize+1:end))

[0114] The terminal can help improve the link adaptation of the base station by performing operations such as methods 1 and 2 based on the relative interference amount and channel state variation (variance or standard deviation) described above.

[0115] FIG. 8 is a diagram illustrating an example of an operation for instantaneous reporting according to one embodiment of the present invention.

[0116] Figure 8 is a drawing illustrating an example of an operation for an instantaneous report corresponding to the previously described method 1.

[0117] Referring to Fig. 8, whenever a terminal receives downlink data transmission, the terminal can observe the current (D(n)) channel condition and, if the interference measured by the terminal itself has changed drastically compared to the previous transmission (D(n-1)), report additional information to the base station through uplink control information. Fig. 8 illustrates a situation in which, unlike the previous downlink data transmission, the current transmission experiences strong interference and the terminal fails to decode the PDSCH. In this case, the terminal can confirm that the interference has significantly increased compared to the previous transmission and report additional information that can assist in link adaptation together with the HARQ ACK / NACK signal. Fig. 8 is an example in which the interference has drastically increased compared to the previous transmission, causing the channel condition to deteriorate rapidly from the terminal's perspective. However, even in cases in which the interference has drastically decreased compared to the previous transmission, causing the channel condition to improve rapidly, the terminal can report additional information that can assist in link adaptation together with the HARQ ACK / NACK signal.

[0118] Below, we describe a method for a terminal to verify that the interference has significantly increased compared to the previous transmission. In the following, we assume that the interference is calculated using the relative interference (Interference) described in FIG. 7. In one embodiment, the difference in interference between the current (nth) downlink data transmission and the previous (n-1th) transmission (Difference_Interference(n)) can be calculated using the following mathematical expression 4.

[0119] [Equation 4]

[0120]

[0121] Depending on the calculated value, the terminal can perform different actions as follows.

[0122] As an example, In this case, the terminal can generate UCI bits including HARQ + SR (if necessary) + CSI Report (if necessary) and report uplink control to the base station by utilizing Short PUCCH or Long PUCCH without reporting additional information.

[0123] As an example, In this case, the uplink control report can be made to the base station by configuring UCI bits including specific additional information in HARQ + SR (if required) + CSI Report (if required) using RRC or other predefined PUCCH resource set.

[0124] FIG. 9 is a diagram illustrating an example of a physical uplink control channel (PUCCH) resource set for instantaneous reporting according to one embodiment of the present invention.

[0125] Figure 9 shows multiple PUCCH resource sets set in RRC. If only HARQ ACK / NACK reporting is performed using the short PUCCH format, Here is an example of sending HARQ ACK / NACK + additional information using Long PUCCH format and more resources.

[0126] Below, Fig. 10, Fig. 11, and Fig. 12 This is a diagram illustrating an example of additional information candidates to be reported. Therefore, in order to perform the above operation, it is possible to propose adding the following new fields to the uplink control information (UCI). The terminal can select one or more of these fields as additional information and report them for each uplink control information transmission.

[0127] FIG. 10 is a diagram illustrating a change in the predicted SINR of a base station when applying instantaneous reporting using True or False values ​​according to one embodiment of the present invention.

[0128] Figure 10 shows a case where the interference amount measured by the terminal itself in the above method 1 changes rapidly, i.e., In this case, it is about reporting True / False about sudden change in interference amount per TB (time block) to the base station, and the difference in interference amount is at a certain level. When judging by this, the case where L=1 can be included in the report.

[0129] In one embodiment, the terminal may transmit 1 bit H-ARQ + 1 bit T / F + SR reporting using PUCCH format 0 or 1.

[0130] (a) and (b) of Fig. 10 show that the terminal Here are two examples of cases where the 1-bit T / F value reports “1” indicating True.

[0131] Referring to (a) of FIG. 10, in one embodiment, when the interference amount is sharply reduced compared to the previous transmission and the difference in the channel interference amount exceeds α, the terminal may report “1”, which is a value indicating True, together with the ACK. This is when the SINR (hereinafter, actual SINR) (1000) actually experienced by the terminal as a result of PDSCH decoding sharply increases. In this case, the base station that has received the report of “1”, which is a value indicating True, together with the ACK may provide an additional OLRC correction value based on the reported information for the predicted SINR (hereinafter, predicted SINR) (1005) based on the CQI report of the terminal in order to determine the MCS.

[0132] Referring to (b) of Fig. 10, in one embodiment, the amount of interference increases rapidly compared to the previous transmission, resulting in a difference in the amount of channel interference. If it exceeds , the terminal can report “1”, which is a value indicating True, along with a NACK. This is when the actual SINR (1010) experienced by the terminal drops sharply. In this case, the base station that receives the “1”, which is a value indicating True, along with the NACK can provide an additional OLRC correction value based on the reported information for the predicted SINR (1015).

[0133] As illustrated in (a) and (b) of Fig. 10, a base station that receives additional information about changes in interference can provide additional OLRC correction values ​​for predicted SINRs (1005 and 1015) and quickly anticipate channel changes. Although the additional information reporting method of Fig. 10 may make it difficult for a base station to estimate an appropriate OLRC correction value based on the information alone, uplink resources can be saved by reporting only 1 bit and using fewer UCI bits.

[0134] FIG. 11 is a diagram explaining a change in the predicted SINR of a base station when applying an instantaneous report that divides the difference in interference level into L stages according to one embodiment of the present invention.

[0135] Figure 11 shows a case where the interference amount measured by the terminal itself in the above method 1 changes rapidly, i.e., In this case, the difference in interference amount to the base station is at a certain level. This is a drawing explaining the case of L=4 when judged by the report.

[0136] In one embodiment, the terminal , and when L=4, the critical value After deciding on one of the levels from 1 to 4 as follows: It can be reported to the base station in bits.

[0137] (1) Difference_Inteference< If so, report HARQ + “00”,

[0138] (2) Difference_Inteference< If so, report HARQ + “01”,

[0139] (3) Difference_Inteference< If so, report HARQ + “10”,

[0140] (4) If Difference_Inteference, report HARQ + “11”.

[0141] In one embodiment, the base station may determine and apply the size of the OLRC correction value based on a value indicating the level of Difference_Inteference. For example, the base station may increase the size of the OLRC correction value as the level of Difference_Inteference increases.

[0142] (a) and (b) of Fig. 11 show that the terminal In case of , the threshold value Here are four examples of cases where one of the levels from 1 to 4 is determined and reported.

[0143] Referring to (a) of Fig. 11, in one embodiment, the amount of interference is drastically reduced compared to the previous transmission, so that the difference in the amount of channel interference is exceeds, In this case, the terminal may report “11” with ACK. This means that the SINR (hereinafter, actual SINR) (1100) that the terminal actually experiences as a result of PDSCH decoding This is the case where the signal level rapidly increases beyond 1110. In this case, the base station that has received “11” along with ACK adds an additional OLRC correction value based on the reported information for the predicted SINR (hereinafter, predicted SINR) (1105) based on the CQI report of the terminal to determine the MCS. It can be decided and applied.

[0144] In one embodiment, the difference in channel interference is such that the amount of interference is drastically reduced compared to the previous transmission. exceeds, Difference_Inteference< In this case, the terminal can report “01” with ACK. This is when the actual SINR (1100) experienced by the terminal increases sharply compared to the previous transmission (1115). In this case, the base station that has received the “01” value with the ACK adds an additional OLRC correction value based on the reported information for the predicted SINR (1105). It can be decided and applied.

[0145] Referring to (b) of Fig. 11, in one embodiment, the amount of interference increases rapidly compared to the previous transmission, resulting in a difference in the amount of channel interference. exceeds, In this case, the terminal may report “11” with NACK. This is when the actual SINR (1120) experienced by the terminal is rapidly reduced (1130). In this case, the base station that has received “11” with NACK may add an additional OLRC correction value based on the reported information for the predicted SINR (1125). It can be decided and applied.

[0146] In one example, the amount of interference increases rapidly compared to the previous transmission, resulting in a difference in channel interference. exceeds, In this case, the terminal can report “01” with NACK. This is when the actual SINR (1120) experienced by the terminal is drastically lowered compared to the previous transmission (1135). In this case, the base station that has received the “01” value along with the NACK adds an additional OLRC correction value based on the reported information for the predicted SINR (1125). It can be decided and applied.

[0147] The reporting method illustrated in Fig. 11 requires more uplink resources, but can differentially apply additional OLRC correction values ​​depending on the level reported to the base station, and can quickly and accurately predict channel changes.

[0148] FIG. 12 is a diagram illustrating a change in the predicted SINR of a base station when applying an instantaneous report that reports a difference value of an interference level according to one embodiment of the present invention.

[0149] Figure 12 shows a case where the interference amount measured by the terminal itself in the above method 1 changes rapidly, i.e., In this case, it is a diagram explaining how to report the difference value of the interference amount (Difference_Interference) itself to the base station.

[0150] In one embodiment, the base station may differentially apply additional OLRC correction values ​​proportional to the difference in interference amount with the reported previous transmission.

[0151] Referring to (a) of Fig. 12, in one embodiment, the interference amount is drastically reduced compared to the previous transmission, so that the difference in channel interference amount is If it exceeds , the terminal can report the difference value of the interference amount (Difference_Interference) itself together with the ACK. This is when the SINR (hereinafter, actual SINR) (1200) actually experienced by the terminal as a result of PDSCH decoding increases sharply (1210 and 1215). In this case, the base station that has received the report of the difference value of the interference amount (Difference_Interference) itself together with the ACK determines the MCS based on the predicted SINR (hereinafter, predicted SINR) (1205) based on the CQI report of the terminal. Additional OLRC correction values ​​can be applied.

[0152] Referring to (b) of Fig. 12, in one embodiment, the amount of interference increases rapidly compared to the previous transmission, resulting in a difference in the amount of channel interference. If it exceeds , the terminal can report the difference value of the interference (Difference_Interference) itself along with the NACK. This is when the actual SINR (1220) experienced by the terminal drops sharply (1230 and 1235). In this case, the base station that has received the difference value of the interference (Difference_Interference) itself along with the NACK reports the predicted SINR (1225) based on the reported information. Additional OLRC correction values ​​can be applied.

[0153] A reporting method such as the above-described Figure 12 requires more uplink resources by using many UCI bits, but the base station can quickly and accurately predict channel changes and provide an OLRC correction value appropriate for the channel changes.

[0154] Below are the threshold values ​​used in the above operation examples. class Explains how to set up .

[0155] In one embodiment, the terminal has a threshold value class can be determined. In this case, the terminal may not inform the base station of the threshold value, or may inform the base station of the threshold value through RRC and UCI. In one embodiment, the base station may determine the threshold value. class can be determined. In this case, the base station can inform the terminal of the threshold value through RRC and DCI, and thus, examples of RRC and DCI / UCI additional fields are as shown in Table 1 below.

[0156]

[0157] Below, the above method 2, i.e., adjusting the OLRC parameters of the base station through the statistical reporting information of the terminal, is described.

[0158] Whenever a terminal receives downlink data transmission, it can observe and update the current channel conditions (e.g., variance and standard deviation of interference, variance and standard deviation of SINR), and report additional information to the base station through uplink control information periodically or aperiodically. Below are examples of candidate additional information to be reported, and therefore, the following new fields are proposed to be added to the uplink control information (UCI). At least one of the following can be selected and reported as additional information in the UCI.

[0159] (1) Variance (Variance_Interference) and standard deviation (Std_Interference) of the current channel interference

[0160] (2) Variance (Variance_SINR_Demodulation) and standard deviation (Std_SINR_Demodulation) of SINR inferred by the terminal through DM-RS of PDSCH transmission

[0161] In the following Figures 13 and 14, a method for a terminal to report the selected additional information is described.

[0162] FIG. 13 is a diagram illustrating an operation of periodically reporting statistical information on channel conditions according to one embodiment of the present invention.

[0163] Referring to (a) of FIG. 13, in one embodiment, in steps 1310 and 1315, the terminal may report channel condition change information to the base station at regular intervals using Long PUCCH (1310, 1315).

[0164] Referring to (b) of FIG. 13, in one embodiment, a terminal may transmit an SR (scheduling request) to a base station and then report using PUSCH. More specifically, in step 1320, the terminal may transmit the SR to the base station. In step 1325, the base station may perform resource allocation to the terminal via DCI. In step 1330, the terminal may report channel condition change information using the allocated resources. After a certain period, the terminal and the base station may perform the same operations as in steps 1320, 1325, and 1330 in steps 1340, 1345, and 1350.

[0165] FIG. 14 is a diagram illustrating an operation of aperiodically reporting statistical information on channel conditions according to one embodiment of the present invention.

[0166] Figure 14 shows a method of operating observation of channel condition fluctuations in a window manner and reporting when there is a difference greater than a certain level between the variance value of indicators (interference, SINR, etc.) for previously reported channel conditions and the same.

[0167] Referring to Figure 14, at step 1410, the terminal may transmit an SR to the base station. At step 1415, the base station may perform resource allocation to the terminal via DCI. At step 1420, the terminal may report channel condition change information using the PUSCH.

[0168] Figure 15 is a flowchart illustrating the operation of a terminal according to one embodiment of the present invention.

[0169] Referring to FIG. 15, in step 1510, the terminal can calculate the difference value between the interference amount when receiving the nth information and the interference amount when receiving the n-1th information.

[0170] In step 1520, if the difference value exceeds the first threshold, the terminal may transmit interference change-related information to the base station. In one embodiment, the interference change-related information may be used during link adaptation. In one embodiment, the interference change-related information may include at least one of a first indicator indicating whether interference has changed, a second indicator indicating the difference value, and the difference value.

[0171] In one embodiment, the interference amount upon receiving the nth information may be the difference between a first interference amount measured based on the nth received PDSCH (physical downlink shared channel) and a second interference amount measured based on a CSI-RS (channel state information-reference signal) received immediately before receiving the PDSCH.

[0172] In one embodiment, the interference change-related information may include the first interference amount. In one embodiment, the terminal may transmit the interference amount at the time of receiving the nth information and the variance value for at least one interference amount at the time of receiving the information during a predetermined time prior to receiving the nth information.

[0173] In one embodiment, the second indicator indicating the difference value may include at least one third indicator indicating the difference value divided into sections.

[0174] Figure 16 is a flowchart illustrating the operation of a base station according to one embodiment of the present invention.

[0175] Referring to FIG. 16, in step 1610, if the difference value between the interference amount when the nth information is received from the terminal and the interference amount when the n-1th information is received exceeds a first threshold, the base station may receive interference change-related information from the terminal. In step 1620, the base station may perform link adaptation based on the interference change-related information. In one embodiment, the interference change-related information may include at least one of a first indicator indicating whether interference has changed, a second indicator indicating the difference value, and the difference value.

[0176] In one embodiment, the interference amount upon receiving the nth information may be the difference between a first interference amount measured based on the nth received PDSCH (physical downlink shared channel) and a second interference amount measured based on a CSI-RS (channel state information-reference signal) received immediately before receiving the PDSCH.

[0177] In one embodiment, the interference change related information may include the first interference amount. In one embodiment, the base station may receive the interference amount at the time of receiving the nth information and the variance value for at least one interference amount at the time of receiving information during a predetermined time prior to receiving the nth information.

[0178] In one embodiment, the second indicator indicating the difference value may include at least one third indicator indicating the difference value divided into sections.

[0179] Figure 17 is a structural diagram showing the structure of a terminal according to one embodiment of the present invention.

[0180] According to FIG. 17, the terminal may include a transceiver (1710), a memory (1720), and a control unit (1730). However, the components of the terminal are not limited to the examples described above, and in embodiments, the terminal may include more or fewer components than the components illustrated. In addition, the transceiver (1710), the control unit (1730), and the memory (1720) may be implemented in the form of a single chip.

[0181] The transceiver (1710) can transmit and receive signals with a base station. Here, the signals can include control information and data. To this end, the transceiver (1710) can be configured with an RF transmitter that up-converts and amplifies the frequency of a transmitted signal, and an RF receiver that low-noise amplifies and frequency-converts a received signal. However, this is only one embodiment of the transceiver (1710), and the components of the transceiver (1710) are not limited to the RF transmitter and RF receiver. In addition, the transceiver (1710) can receive a signal through a wireless channel and output it to the control unit (1730), and transmit the signal output from the control unit (1730) through the wireless channel. In addition, the transceiver (1710) may be equipped with an RF transceiver for the first wireless communication technology and an RF transceiver for the second wireless communication technology separately, or may perform physical layer processing according to the first wireless communication technology and the second wireless communication technology with one transceiver.

[0182] The memory (1720) can store programs and data necessary for the operation of the terminal. In addition, the memory (1720) can store control information or data included in signals transmitted and received by the terminal. The memory (1720) can be configured as a storage medium or a combination of storage media, such as a ROM, a RAM, a hard disk, a CD-ROM, and a DVD. In addition, there can be multiple memories (1720).

[0183] The control unit (1730) may control a series of processes to enable the terminal to operate according to the embodiments of the present disclosure described above. The control unit (1730) may include at least one processor, and the series of processes to enable the terminal to operate may be performed by each of at least one processor belonging to the control unit, or by a combination thereof.

[0184] The above at least one processor can calculate a difference value between the interference amount when the nth information is received and the interference amount when the n-1th information is received.

[0185] The at least one processor may transmit interference change-related information to the base station if the difference value exceeds a first threshold. In one embodiment, the interference change-related information may be used during link adaptation. In one embodiment, the interference change-related information may include at least one of a first indicator indicating whether interference has changed, a second indicator indicating the difference value, and the difference value.

[0186] In one embodiment, the interference amount upon receiving the nth information may be the difference between a first interference amount measured based on the nth received PDSCH (physical downlink shared channel) and a second interference amount measured based on a CSI-RS (channel state information-reference signal) received immediately before receiving the PDSCH.

[0187] In one embodiment, the interference change related information may include the first interference amount. In one embodiment, the at least one processor may transmit the interference amount at the time of receiving the nth information and the variance value for at least one interference amount at the time of receiving the information during a predetermined time prior to receiving the nth information.

[0188] In one embodiment, the second indicator indicating the difference value may include at least one third indicator indicating the difference value divided into sections.

[0189] FIG. 18 is a structural diagram showing the structure of a base station according to one embodiment of the present invention.

[0190] According to FIG. 18, the base station may include a transceiver (1810), a memory (1820), and a control unit (1830). However, the components of the base station are not limited to the examples described above, and in embodiments, the base station may include more or fewer components than the components illustrated. In addition, the transceiver (1810), the memory (1820), and the control unit (1830) may be implemented in the form of a single chip.

[0191] The transceiver (1810) can transmit and receive signals with the terminal. Here, the signals can include control information and data.

[0192] The memory (1820) can store programs and data required for the operation of the base station. In addition, the memory (1820) can store control information or data included in signals transmitted and received by the base station. The memory (1820) can be configured as a storage medium or a combination of storage media, such as a ROM, a RAM, a hard disk, a CD-ROM, and a DVD. In addition, there can be multiple memories (1820).

[0193] The control unit (1830) may control a series of processes to enable the base station to operate according to the embodiments of the present disclosure described above. The control unit (1830) may include at least one processor, and the series of processes to enable the base station to operate may be performed by at least one process belonging to the control unit, or a combination thereof.

[0194] The at least one processor may receive interference change-related information from the terminal when the difference value between the interference amount when the nth piece of information is received and the interference amount when the n-1th piece of information is received exceeds a first threshold value. The at least one processor may perform link adaptation based on the interference change-related information. In one embodiment, the interference change-related information may include at least one of a first indicator indicating whether interference has changed, a second indicator indicating the difference value, and the difference value.

[0195] In one embodiment, the interference amount upon receiving the nth information may be the difference between a first interference amount measured based on the nth received PDSCH (physical downlink shared channel) and a second interference amount measured based on a CSI-RS (channel state information-reference signal) received immediately before receiving the PDSCH.

[0196] In one embodiment, the interference change related information may include the first interference amount. In one embodiment, the at least one processor may receive the interference amount upon receiving the nth information and the variance value for at least one interference amount upon receiving information during a predetermined time prior to receiving the nth information.

[0197] In one embodiment, the second indicator indicating the difference value may include at least one third indicator indicating the difference value divided into sections.

[0198] The methods according to the embodiments described in the claims or specification of the present disclosure may be implemented in the form of hardware, software, or a combination of hardware and software. If implemented in software, a computer-readable storage medium storing one or more programs (software modules) may be provided. The one or more programs stored in the computer-readable storage medium are configured for execution by one or more processors within an electronic device. The one or more programs include instructions that cause the electronic device to execute the methods according to the embodiments described in the claims or specification of the present disclosure.

[0199] These programs (software modules, software) may be stored in random access memory, non-volatile memory including flash memory, read only memory (ROM), electrically erasable programmable read only memory (EEPROM), magnetic disc storage device, compact disc ROM (CD-ROM), digital versatile discs (DVDs) or other forms of optical storage device, magnetic cassette. Or, they may be stored in a memory configured as a combination of some or all of these. In addition, each configuration memory may be included in multiple numbers.

[0200] Additionally, the program may be stored in an attachable storage device that is accessible via a communication network such as the Internet, an intranet, a local area network (LAN), a wide local area network (WLAN), a storage area network (SAN), or a combination thereof. Such a storage device may be connected to a device performing an embodiment of the present disclosure via an external port. Additionally, a separate storage device on the communication network may be connected to a device performing an embodiment of the present disclosure.

[0201] In the specific embodiments of the present disclosure described above, components included in the invention are expressed in the singular or plural form, depending on the specific embodiment presented. However, the singular or plural expressions are selected to suit the presented situation for convenience of explanation, and the present disclosure is not limited to singular or plural components. Components expressed in the plural form may be composed of singular elements, or components expressed in the singular form may be composed of plural elements.

[0202] While the detailed description of this disclosure has described specific embodiments, it should be understood that various modifications are possible without departing from the scope of this disclosure. Therefore, the scope of this disclosure should not be limited to the described embodiments, but should be defined not only by the scope of the claims described below, but also by equivalents thereof.

Claims

1. In a terminal method in a wireless communication system, A step of calculating the difference value between the interference amount when receiving the nth information and the interference amount when receiving the n-1th information; and a step of transmitting interference change related information to a base station when the above difference value exceeds a first threshold value; The above interference change related information is used during link adaptation, and A method characterized in that the interference change related information includes a first indicator indicating whether or not there is an interference change, a second indicator indicating the difference value, and at least one of the difference values.

2. In the first paragraph, the amount of interference when receiving the nth information is A method characterized in that the difference is between a first interference amount measured based on the nth received PDSCH (physical downlink shared channel) and a second interference amount measured based on a CSI-RS (channel state information-reference signal) received immediately before receiving the PDSCH.

3. A method according to claim 2, characterized in that the interference change related information includes the first interference amount.

4. In paragraph 2, A method further comprising: a step of transmitting a dispersion value for an interference amount when receiving the nth information and at least one interference amount when receiving information during a predetermined time before receiving the nth information.

5. In paragraph 1, the second indicator indicating the difference value is, A method characterized by including at least one third indicator that divides the above difference value into intervals.

6. In a method of a base station in a wireless communication system, A step of receiving interference change-related information from a terminal when the difference value between the interference amount when receiving the nth information and the interference amount when receiving the n-1th information exceeds the first threshold value; and A step of performing link adaptation based on the above interference change related information; A method characterized in that the interference change related information includes a first indicator indicating whether or not there is an interference change, a second indicator indicating the difference value, and at least one of the difference values.

7. In the 6th paragraph, the amount of interference when receiving the nth information is A method characterized in that the difference is between a first interference amount measured based on the nth received PDSCH (physical downlink shared channel) and a second interference amount measured based on a CSI-RS (channel state information-reference signal) received immediately before receiving the PDSCH.

8. In paragraph 7, the interference change related information is: A method characterized by including the first interference amount.

9. In paragraph 7, A method further comprising: a step of receiving a variance value for an interference amount when receiving the nth information and at least one interference amount when receiving information during a predetermined time before receiving the nth information.

10. In paragraph 6, the second indicator indicating the difference value is, A method characterized by including at least one third indicator that divides the above difference value into intervals.

11. In a terminal in a wireless communication system, Transmitter and receiver; and comprising at least one processor; wherein the at least one processor comprises: Calculate the difference between the interference amount when receiving the nth information and the interference amount when receiving the n-1th information, and If the above difference value exceeds the first threshold, it is configured to transmit interference change related information to the base station, The above interference change related information is used during link adaptation, and A terminal characterized in that the interference change related information includes a first indicator indicating whether or not there is an interference change, a second indicator indicating the difference value, and at least one of the difference values.

12. In the 11th paragraph, the amount of interference when receiving the nth information is The difference between the first interference amount measured based on the nth received PDSCH (physical downlink shared channel) and the second interference amount measured based on the CSI-RS (channel state information-reference signal) received immediately before receiving the PDSCH, The above interference change related information includes the first interference amount, and A terminal characterized by including at least one third indicator that divides the above difference value into sections.

13. In the 12th paragraph, at least one processor, A terminal configured to transmit a dispersion value for an interference amount when receiving the nth information and at least one interference amount when receiving information during a predetermined time prior to receiving the nth information.

14. In a base station in a wireless communication system, Transmitter and receiver; and comprising at least one processor; wherein the at least one processor comprises: If the difference value between the interference amount when the terminal receives the nth information and the interference amount when the terminal receives the n-1th information exceeds the first threshold value, interference change-related information is received from the terminal, and It is configured to estimate the channel state based on the above interference change related information, A base station, characterized in that the interference change related information includes a first indicator indicating whether or not there is an interference change, a second indicator indicating the difference value, and at least one of the difference values.

15. In the 14th paragraph, the amount of interference when receiving the nth information is A base station characterized in that the difference is between a first interference amount measured based on the nth received PDSCH (physical downlink shared channel) and a second interference amount measured based on a CSI-RS (channel state information-reference signal) received immediately before receiving the PDSCH.

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