Method and apparatus for transmitting uplink control signals in a wireless cellular communication system

Abstract

This disclosure relates to communication technologies and systems for integrating IoT technology with 5G communication systems that support higher data transmission rates than 4G systems. This disclosure can be applied to smart services (e.g., smart homes, smart buildings, smart cities, smart cars or connected cars, healthcare, digital education, retail businesses, security and safety-related services, etc.) based on 5G communication technology and IoT-related technologies. This invention relates to wireless communication systems. More specifically, a method and apparatus are disclosed for a terminal to transmit control signals associated with uplink data transmission when the terminal performs uplink transmission.

Description

[0001] This application is a divisional application of the invention patent application filed on September 29, 2017, with application number 201780072784.0 and entitled "Method and apparatus for transmitting uplink control signals in a wireless cellular communication system". Technical Field

[0002] This disclosure relates to wireless communication systems. More specifically, this disclosure relates to methods and apparatus for a terminal to transmit control signals related to uplink data transmission during uplink transmission. Background Technology

[0003] To meet the increasing demand for wireless data services following the commercialization of 4G communication systems, efforts are underway to develop improved 5G or pre-5G communication systems. For this reason, 5G or pre-5G communication systems are referred to as super-4G network communication systems or post-LTE systems.

[0004] To achieve high data transmission rates, 5G communication systems are considered to be implemented in millimeter-wave bands (e.g., the 60 GHz band). To reduce radio wave loss and increase transmission distance in the millimeter-wave band, beamforming, massive MIMO, full-dimensional MIMO (FD-MIMO), array antennas, analog beamforming, and massive MIMO technologies are being discussed in 5G communication systems.

[0005] In addition, to improve the network of the system, technologies such as improved small cells, advanced small cells, cloud radio access network (cloud RAN), ultra-dense networks, device-to-device communication (D2D), wireless backhaul, mobile networks, cooperative communication, cooperative multipoint (CoMP), and receive interference cancellation are being developed in 5G communication systems.

[0006] In addition, hybrid FSK and QAM modulation (FQAM) and sliding window superposition coding (SWSC), improved filter bank multicarrier (FBMC), non-orthogonal multiple access (NOMA) and sparse code multiple access (SCMA) are being developed as advanced coding and modulation (ACM) schemes in 5G communication systems.

[0007] Simultaneously, the internet has evolved from a human-centric network connecting the generation and consumption of information to the Internet of Things (IoT), where information is exchanged and processed between distributed components such as objects. The Internet of Everything (IoE) technology is emerging, where big data processing technologies are combined with cloud server connectivity and IoT technologies. To realize IoT, technological elements such as sensing technologies, wired / wireless communication and network infrastructure, service interface technologies, and security technologies are required. Therefore, technologies for connecting objects, such as sensor networks, machine-to-machine (M2M), and machine-type communication (MTC), have recently been researched. In the IoT environment, intelligent internet technology (IT) services can be provided, creating new value for human life through the collection and analysis of data generated from connected objects. IoT can be applied to fields such as smart homes, smart buildings, smart cities, smart cars or connected cars, smart grids, healthcare, smart appliances, and advanced medical services through the integration and combination of existing information technology (IT) and various industries.

[0008] Therefore, various attempts are underway to apply 5G communication systems to IoT. For example, 5G communication technologies such as sensor networks, machine-to-machine (M2M), and machine-type communication (MTC) are being implemented through schemes such as beamforming, MIMO, and array antennas. The application of cloud radio access networks (cloud RAN), as a big data processing technology, can be seen as an example of the convergence between 5G and IoT technologies.

[0009] In wireless communication systems, specifically in traditional LTE systems, when performing uplink transmissions, the terminal uses the MCS, transmission resources, TTI length, etc., allocated by the base station without making any changes. However, even without scheduling in the uplink transmission grant from the base station, a method may still be needed for the terminal to perform uplink transmissions. Summary of the Invention

[0010] Technical issues

[0011] This disclosure will provide a method and apparatus that provide various services within a short delay time by means of a rapid feedback report as a result of an initial transmission.

[0012] Furthermore, this disclosure provides a method and apparatus for simultaneously providing different types of services. More specifically, this disclosure provides a method and apparatus for effectively providing different types of services within the same time interval by obtaining received information suitable for the characteristics of each service when simultaneously providing different types of services through embodiments.

[0013] Furthermore, this disclosure provides a method for estimating interference information using the same framework as RS configuration and transmission and reception methods.

[0014] Technical solution

[0015] A method of a user equipment according to an embodiment of the present disclosure includes: receiving data from a base station, and when decoding of some data fails, sending a NACK of some data to the base station in a second TTI prior to a first transmission time interval (TTI) in which an acknowledgment (ACK) or a negative ACK (NACK) of the data is to be transmitted.

[0016] A user equipment according to an embodiment of the present disclosure includes: a transceiver configured to transmit and receive signals; and a controller configured to receive data from a base station, and, when decoding of some data fails, to send a NACK of some data to the base station in a second TTI prior to a first transmission time interval (TTI) in which an acknowledgment (ACK) or a negative ACK (NACK) of the data is to be transmitted.

[0017] A method for a base station according to an embodiment of the present disclosure includes: sending data to a user equipment; receiving a NACK for some data from the user equipment during a second TTI prior to a first transmission time interval (TTI) in which an acknowledgment (ACK) or a negative ACK (NACK) for transmitting the data is to be transmitted; and retransmitting the data to the user equipment in response to the received NACK.

[0018] A base station according to an embodiment of the present disclosure includes: a transceiver configured to transmit and receive signals; and a controller configured to: transmit data to a user equipment, receive a NACK for some data from the user equipment in a second TTI prior to a first transmission time interval (TTI) in which an acknowledgment (ACK) or a negative ACK (NACK) for transmitting the data is to be transmitted when the user equipment fails to decode some data, and retransmit the data to the user equipment in response to the received NACK.

[0019] A method of a user equipment according to an embodiment of the present disclosure includes: receiving configuration information related to uplink transmission from a base station, and transmitting uplink data to the base station in a resource area determined based on the configuration information without uplink authorization.

[0020] A user equipment according to an embodiment of the present disclosure includes: a transceiver configured to transmit and receive signals, and a controller configured to: receive configuration information related to uplink transmission from a base station, and transmit uplink data to the base station in a resource area determined based on the configuration information without uplink authorization.

[0021] A method for a base station according to an embodiment of the present disclosure includes: sending configuration information related to uplink transmission to a user equipment, and receiving uplink data from the user equipment in a resource area determined based on the configuration information without uplink authorization.

[0022] A base station according to an embodiment of the present disclosure includes: a transceiver configured to transmit and receive signals; and a controller configured to transmit configuration information related to uplink transmission to a user equipment, and to receive uplink data from the user equipment in a resource area determined based on the configuration information without uplink authorization.

[0023] A method of a user equipment according to an embodiment of the present disclosure includes: receiving information related to the transmission of a reference signal (RS) from a base station, identifying an RS resource configured with a combination of multiple reference signal (RS) groups based on the information, and receiving an RS on the RS resource, wherein each of the multiple RS groups is determined based on the smallest unit of two adjacent resource elements (REs) in a symbol.

[0024] A user equipment according to an embodiment of the present disclosure includes: a transceiver configured to transmit and receive signals; and a controller configured to: receive information related to the transmission of reference signals (RS) from a base station, identify, based on the information, an RS resource configured with a combination of multiple groups of reference signals (RS), and receive RS on the RS resource, wherein each of the multiple groups of RS is determined based on the smallest unit of two adjacent resource elements (REs) in a symbol.

[0025] A method for base stations according to embodiments of the present disclosure includes: sending information related to reference signal (RS) transmission to a user equipment, identifying RS resources configured with a combination of multiple reference signal (RS) groups based on the information, and transmitting RS based on the RS resources, wherein each of the multiple RS groups is determined based on the smallest unit of two adjacent resource elements (REs) in a symbol.

[0026] A base station according to an embodiment of the present disclosure includes: a transceiver configured to transmit and receive signals; and a controller configured to transmit information related to reference signal (RS) transmission to a user equipment, identify RS resources configured with a combination of multiple reference signal (RS) groups based on the information, and transmit RS based on the RS resources, wherein each of the multiple RS groups is determined based on the smallest unit of two adjacent resource elements (REs) in a symbol.

[0027] Beneficial technical effects

[0028] According to embodiments of this disclosure, effective uplink transmission between the BS and the UE can be performed by providing an operational method for the UE to send control information about uplink transmission.

[0029] Furthermore, according to another embodiment of this disclosure, different types of services can be used in a communication system to efficiently transmit data. Additionally, the embodiment provides a method in which data transmission between homogeneous or heterogeneous services can coexist. Therefore, the requirements of each service can be met, and transmission time delays can be reduced, or at least one of frequency-time and spatial resources and transmission power can be used efficiently.

[0030] Furthermore, according to another embodiment of this disclosure, coordination among multiple TRPs or beams becomes possible because the UE measures the channel through different TRPs or beams. For example, the UE can receive at least one RS among DLCSI-RS, UL CSI-RS (SRS), and DMRS through one or more resources, and can generate channel state information regarding scenarios where the UE independently transmits and receives signals using each TRP or beam through the received RS, or scenarios where the UE cooperatively transmits and receives signals using two or more TRPs or beams, and can report this information to the BS. In this case, the UE can measure interference in various transmission and reception scenarios using the interference measurement methods provided in this disclosure, and can incorporate the measured interference into the generation of channel state information. Furthermore, the BS can configure and notify QCL information between RSs according to the environment using the QCL signaling methods provided in this disclosure. The UE can receive QCL information, can compensate for time / frequency offsets of RSs transmitted peripherally on time and frequency resources, and can improve channel estimation performance. Attached Figure Description

[0031] Figure 1A This is a diagram illustrating the downlink time-frequency domain transmission architecture of an LTE or LTE-A system.

[0032] Figure 1B This is a diagram illustrating the uplink time-frequency domain transmission architecture of an LTE or LTE-A system.

[0033] Figure 1C This is a diagram showing the status of eMBB, URLLC, and mMTC data already allocated in the frequency-time resources of a communication system.

[0034] Figure 1D This is a diagram showing the status of eMBB, URLLC, and mMTC data already allocated in the frequency-time resources of a communication system.

[0035] Figure 1EThis is a diagram illustrating a self-contained structure in which uplink and downlink exist within a subframe of a communication system.

[0036] Figure 1F This is a diagram showing the state of the initial transmission result fed back in a self-contained structure on time division duplex (TDD).

[0037] Figure 1G This is a diagram showing the state of rapid feedback of the results of some initial transfers performed on a self-contained TDD structure.

[0038] Figure 1H This is a diagram showing the feedback of the results of the initial transmission and some rapid feedback of the results of the initial transmission on the state of the same resource in the self-contained structure of TDD.

[0039] Figure 1I This is a diagram showing the state of feedback of the initial transmission results in frequency division duplex (FDD).

[0040] Figure 1J This is a diagram showing the state of rapid feedback of the results of some initial transfers performed in the FDD.

[0041] Figure 1K This is a diagram showing the feedback state of the results of performing some initial transmissions differently in an FDD.

[0042] Figure 1L This is a diagram showing the feedback of the results of the initial transmission and some rapid feedback of the results of the initial transmission in the state of using the same resources in FDD.

[0043] Figure 1M This is a diagram showing the status of time-frequency resources used to report both rapid feedback and feedback together.

[0044] Figure 1N This is a diagram illustrating the operation of the UE according to embodiment (2-1).

[0045] Figure 10 This is a diagram illustrating the operation of the UE according to embodiment (2-2).

[0046] Figure 1P This is a diagram illustrating the operation of the UE according to embodiment (2-3).

[0047] Figure 1Q This is a diagram illustrating the operation of the UE according to embodiment (2-4).

[0048] Figure 1R This is a diagram illustrating the operation of the UE according to embodiments (2-5).

[0049] Figure 1SThis is a diagram illustrating the BS operation according to embodiment (2-6).

[0050] Figure 1T This is a diagram illustrating the BS operation according to embodiment (2-7).

[0051] Figure 1U This is a block diagram illustrating the structure of a UE according to an embodiment.

[0052] Figure 1V This is a block diagram illustrating the structure of the BS according to an embodiment.

[0053] Figure 2A It is a diagram illustrating the basic structure of the time-frequency domain (i.e., the radio resource area in which data or control channels are transmitted in the downlink) in an LTE system or similar system.

[0054] Figure 2B This is a diagram illustrating the basic structure of the time-frequency domain (i.e., the radio resource region in which data or control channels are transmitted in the uplink) in an LTE-A system.

[0055] Figure 2C It is a diagram showing the state of data allocation for eMBB, URLLC and mMTC in frequency-time resources (i.e., services considered in 5G or NR systems).

[0056] Figure 2D It is a diagram showing the state of data (i.e., services considered in 5G or NR systems) orthogonally allocated in frequency-time resources for eMBB, URLLC and mMTC.

[0057] Figure 2E This is a diagram showing the time and frequency resource areas in which the UE can perform unlicensed uplink transmissions.

[0058] Figure 2F This is a diagram illustrating BS operation according to an embodiment of the present disclosure.

[0059] Figure 2G This is a diagram illustrating UE operation according to an embodiment of the present disclosure.

[0060] Figure 2H This is a block diagram illustrating the structure of a UE according to an embodiment.

[0061] Figure 2I This is a block diagram illustrating the structure of a UE according to an embodiment.

[0062] Figure 3A This is a diagram illustrating the downlink time-frequency domain transmission architecture of an LTE or LTE-A system based on conventional technology.

[0063] Figure 3BThis is a diagram illustrating the uplink time-frequency domain transmission architecture of an LTE or LTE-A system based on conventional technology.

[0064] Figure 3C This is a diagram showing the PRB structure of an LTE-A system.

[0065] Figure 3D This is a diagram illustrating the CSI-RS power boost of an LTE-A system.

[0066] Figure 3E This is a diagram illustrating the PRB structure of an NR system according to an embodiment (4-1) of this disclosure.

[0067] Figure 3F This is a diagram illustrating an example of IM resource configuration according to an embodiment of (4-2) of this disclosure.

[0068] Figure 3G This is a diagram illustrating an example of network coordination.

[0069] Figure 3H This is a diagram illustrating an example of a QCL configuration based on single-point transmission.

[0070] Figure 3I This is a diagram illustrating an example of a QCL configuration based on multipoint transmission.

[0071] Figure 3J This is a flowchart illustrating an embodiment (4-3) of the present disclosure.

[0072] Figure 3K This is a diagram illustrating examples of OFDM symbols used for NR CSI-RS transmissions in this disclosure, avoiding OFDM symbols used for NR DMRS and NRPDCCH transmissions, as well as OFDM symbols used for LTE CRS transmissions.

[0073] Figure 3L This is a diagram illustrating OFDM symbols used for NR CSI-RS transmissions in this disclosure, avoiding other examples of OFDM symbols used for NR DMRS and NRPDCCH transmissions, and OFDM symbols used for LTE CRS transmissions.

[0074] Figure 3M This is a diagram illustrating an example of coexistence between various signals (such as NR CSI-RS / NR DMRS / LTE CRS) through sub-grouping of the NR CSI-RS resources of this disclosure.

[0075] Figure 3NA , 3NB 3NC and 3ND are diagrams illustrating examples of CSI-RS port mapping of CSI-RS resources according to embodiments of the present disclosure.

[0076] Figure 3OA , 3OB 3OC, 3OD, and 3OE are diagrams illustrating examples of CSI-RS port mapping of CSI-RS resources according to embodiments of the present disclosure. Detailed Implementation

[0077] In the following, embodiments of the present disclosure are described in detail with reference to the accompanying drawings. Furthermore, in describing the present disclosure, detailed descriptions of related known functions or configurations are omitted if they would unnecessarily obscure the key points of the disclosure. Additionally, the terminology described below has been defined by consideration of its functionality in the present disclosure and may vary depending on the intent or practice of the user or operator.

[0078] The advantages and features of this disclosure, as well as methods for achieving these advantages and features, will become more apparent from the embodiments described in detail with reference to the accompanying drawings. However, this disclosure is not limited to the disclosed embodiments, but can be implemented in a variety of different ways. The embodiments provided are for the purpose of completing this disclosure and are intended to allow those skilled in the art to fully understand the scope of this disclosure. This disclosure is defined by the scope of the claims. Throughout the drawings, the same reference numerals will be used to refer to the same or similar elements.

[0079] <First Embodiment>

[0080] Embodiments of this disclosure are described in detail below with reference to the accompanying drawings.

[0081] In describing the embodiments, descriptions of well-known content in the field to which this disclosure pertains and in fields not directly related to this disclosure have been omitted in order to make the essential points of this disclosure clearer.

[0082] For the same reason, some elements are enlarged, omitted, or shown schematically in the accompanying drawings. Furthermore, the dimensions of each element do not accurately reflect its actual size. Identical or similar elements are assigned the same reference numerals in the drawings.

[0083] The advantages and features of this disclosure, as well as methods for achieving these advantages and features, will become clearer from the embodiments described in detail with reference to the accompanying drawings. However, this disclosure is not limited to the disclosed embodiments, but can be implemented in various different ways. The embodiments provided are only for completing the disclosure and to allow those skilled in the art to understand the scope of this disclosure. This disclosure is defined by the scope of the claims. Throughout the drawings, the same reference numerals will be used to refer to the same or similar elements.

[0084] In this disclosure, it will be understood that each block of a flowchart illustration and combinations of blocks in a flowchart illustration can be executed by computer program instructions. These computer program instructions can be mounted on a processor of a general-purpose computer, a special-purpose computer, or other programmable data processing apparatus, such that the instructions, which are executed by the processor of the computer or other programmable data processing apparatus, create means for performing the functions specified in one or more flowchart blocks. These computer program instructions can also be stored in a computer-usable or computer-readable storage medium, which can instruct the computer or other programmable data processing apparatus to act in a particular manner, such that the instructions stored in the computer-usable or computer-readable storage medium produce an article of writing containing instruction means that implement the functions specified in one or more flowchart blocks. The computer program instructions can also be loaded onto a computer or other programmable data processing apparatus, causing a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer-executed process, such that the instructions executing the computer or other programmable apparatus provide steps for performing the functions described in one or more flowchart blocks.

[0085] Furthermore, each block in the flowchart can represent a module, segment, or portion of code, containing one or more executable instructions for implementing one or more specified logical functions. It should also be noted that in some alternative implementations, the functions marked in a block may occur out of order. For example, two blocks shown consecutively may actually execute substantially simultaneously, or these blocks may sometimes execute in reverse order, depending on the functions involved.

[0086] In this context, the term "unit" as used in this embodiment refers to a software or hardware component, such as a field-programmable gate array (FPGA) or application-specific integrated circuit (ASIC), and the "unit" performs a specific task. A "unit" can advantageously be configured to reside on an addressable memory medium and to operate on one or more processors. Therefore, a "unit" can include, for example, components such as software components, object-oriented software components, class components and task components, processes, functions, attributes, processes, subroutines, program code segments, drivers, firmware, microcode, circuits, data, databases, data structures, tables, arrays, and variables. The functionality provided in components and "units" can be combined into fewer components and "units," or can be further divided into additional components and "units." Furthermore, components and "units" can be implemented to operate on one or more CPUs in a device or secure multimedia card. Additionally, in one embodiment, a "unit" can include one or more processors.

[0087] Wireless communication systems have deviated from providing initial voice-oriented services and evolved to provide high-speed and high-quality packet data services (e.g., communication standards such as 3GPP's High-Speed ​​Packet Access (HSPA), 3GPP2's Long Term Evolution (LTE) or Evolved Universal Terrestrial Radio Access (E-UTRA), Advanced LTE (LTE-A), LTE-Pro, High-Speed ​​Packet Data (HRPD), IEEE's Ultra Mobile Broadband (UMB), and 802.16e broadband wireless communication systems). Furthermore, 5G or New Radio (NR) communication standards are emerging as 5G wireless communication systems.

[0088] As described above, in a 5G-enabled wireless communication system, at least one of the following services can be provided to a terminal: enhanced mobile broadband (eMBB), massive machine-type communication (mMTC), and ultra-reliable low-latency communication (URLLC). These services can be provided to the same terminal within the same time interval. In one embodiment, eMBB can be a service aimed at high-speed transmission of large amounts of data, mMTC can be a service aimed at minimizing terminal power and facilitating access for multiple terminals, and URLLC can be a service aimed at high reliability and low latency, but is not limited to these. These three types of services can be a primary scenario in LTE systems or post-LTE systems such as 5G / New Radio and Next Radio (NR). In one embodiment, a method for the coexistence of mMBB and URLLC or a method for the coexistence of mMTC and URLLC, and apparatus for using them are described.

[0089] If a base station has scheduled data corresponding to eMBB service for a terminal within a given transmission time interval (TTI), then when a situation arises where URLLC data must be transmitted within the TTI, the base station may not transmit some of the eMBB data in the frequency band where eMBB data has already been scheduled and transmitted, but instead transmit the generated URLLC data in that frequency band. The terminal that has been scheduled for eMBB and the terminal that has been scheduled for URLLC can be the same terminal or different terminals. In this case, the possibility of eMBB data corruption increases because some of the scheduled and transmitted eMBB data is not transmitted. Therefore, in the above situation, it is necessary to determine a method for processing signals received by a terminal that has been scheduled for eMBB or a terminal that has been scheduled for URLLC, and a signal reception method. Therefore, in one embodiment, a method for coexistence between heterogeneous services capable of transmitting information based on services is described when information based on eMBB and URLLC is scheduled by sharing some frequency bands or the entire frequency band, when information based on mMTC and URLLC is scheduled simultaneously, when information based on mMTC and eMBB is scheduled simultaneously, or when information based on eMBB, URLLC, and mMTC is scheduled simultaneously.

[0090] In the following, embodiments of the present disclosure are described in detail with reference to the accompanying drawings. Furthermore, in describing the present disclosure, details of related known functions or configurations that would unnecessarily obscure the essential points of the disclosure are omitted. Additionally, the terms described below have been defined by consideration of the functions in the present disclosure and may vary depending on the intent or practice of the user or operator. Therefore, each term should be defined based on the entirety of the specification. In the following, a base station is the entity that performs resource allocation for a terminal and may be at least one of an eNode B, Node B, BS, radio access unit, BS controller, and nodes on a network. A terminal may include a user equipment (UE), a mobile station (MS), a cellular phone, a smartphone, a computer capable of performing communication functions, and a multimedia system. In this disclosure, downlink (DL) refers to the radio transmission path of a signal transmitted from the BS to the UE, and uplink (UL) refers to the radio transmission path of a signal transmitted from the UE to the BS. Furthermore, embodiments of the invention are described below using LTE or LTE-A systems as examples; however, embodiments of the invention can be applied to other communication systems with similar technical backgrounds or channel configurations. For example, 5G mobile communication technology (New Radio (NR)) developed after LTE-A can be included in other communication systems. Furthermore, based on the assessment of those skilled in the art, embodiments of this disclosure can also be applied to other communication systems with modifications without significantly departing from the scope of this disclosure.

[0091] LTE systems (a representative example of broadband wireless communication systems) employ Orthogonal Frequency Division Multiplexing (OFDM) in the downlink (DL) and Single-Carrier Frequency Division Multiple Access (SC-FDMA) in the uplink (UL). The uplink refers to the radio link through which a terminal (or User Equipment (UE)) or mobile station (MS) transmits data or control signals to a base station (BS or eNode B). The downlink refers to the radio link through which the BS transmits data or control signals. This multiple access scheme is a method of allocating or managing time-frequency resources on which each user carries data or control information to distinguish between user data or control information, ensuring that time-frequency resources do not overlap, i.e., establishing orthogonality.

[0092] When decoding failure occurs during the initial transmission, the LTE system employs a Hybrid Automatic Repeat Request (HARQ) scheme, retransmitting the corresponding data at the physical layer. According to the HARQ scheme, when the receiver fails to decode the data accurately, it sends a negative acknowledgment (NACK) to the transmitter, notifying it of the decoding failure, allowing the transmitter to retransmit the corresponding data at the physical layer. The receiver combines the retransmitted data with the previously failed decoding data, thereby improving data reception performance. Furthermore, when the receiver successfully decodes the data, it sends an acknowledgment (ACK) to the transmitter, notifying it of successful decoding, allowing the transmitter to transmit new data.

[0093] To meet the increasing demand for wireless data services following the commercialization of 4G communication systems, efforts are underway to develop improved 5G or near-5G communication systems. For this purpose, 5G or near-5G communication systems are referred to as super-4G network communication systems or post-LTE systems. To achieve high data transmission rates, 5G communication systems are considered to be implemented in millimeter-wave bands (e.g., the 60GHz band). To reduce radio wave loss and increase transmission distance in the millimeter-wave band, beamforming, massive MIMO, full-dimensional MIMO (FD-MIMO), array antennas, analog beamforming, and massive MIMO technologies are being discussed in 5G communication systems. Furthermore, to improve the network of the system, technologies such as improved small cells, advanced small cells, cloud radio access networks (cloud RAN), ultra-dense networks, device-to-device (D2D) communication, wireless backhaul, mobile networks, cooperative communication, coordinated multipoint (CoMP), and receive interference cancellation are being developed in 5G communication systems. In addition, hybrid FSK and QAM modulation (FQAM) and sliding window superposition coding (SWSC), improved filter bank multicarrier (FBMC), non-orthogonal multiple access (NOMA) and sparse code multiple access (SCMA) are being developed as advanced coding and modulation (ACM) schemes in 5G systems.

[0094] Simultaneously, the Internet has evolved from a human-centric network of connections where information is generated and consumed to the Internet of Things (IoT), where information is exchanged and processed between distributed elements such as objects. The Internet of Everything (IoE) technology, which combines big data processing with IoT technology through connections to cloud servers, is emerging. To realize the IoT, technological elements such as sensing technology, wired / wireless communication and network infrastructure, service interface technology, and security technology are required. Therefore, technologies such as sensor networks, machine-to-machine (M2M) and machine-type communication (MTC) for connections between objects have recently been studied. In the IoT environment, intelligent Internet of Things (IT) services can be provided, where new value is created for human life by collecting and analyzing data generated from connected objects. The IoT can be applied to fields such as smart homes, smart buildings, smart cities, smart cars or connected cars, smart grids, healthcare, smart appliances, and advanced medical services through the convergence and combination of existing information technology (IT) and various industries.

[0095] Therefore, various attempts are underway to apply 5G communication systems to IoT. For example, 5G communication technologies such as sensor networks, machine-to-machine (M2M), and machine-type communication (MTC) are being implemented through schemes such as beamforming, MIMO, and array antennas. The application of cloud radio access networks (cloud RAN), as a big data processing technology, can be seen as an example of the convergence between 5G and IoT technologies.

[0096] As mentioned above, in a communication system, multiple services can be provided to a user. To provide multiple such services to a user, a method and apparatus are needed to provide each service, tailored to its characteristics, within the same time interval. Furthermore, a given service may require a faster transmission time than other services. That is, a given service requires a shorter transmission time.

[0097] Embodiments described herein have been proposed to address the above-mentioned problems, and methods and apparatus for providing different types of services simultaneously have been provided.

[0098] Figure 1A It is a diagram showing the basic structure of the frequency domain (i.e., the radio resource area in an LTE system or similar system in which data or control channels are transmitted in the downlink).

[0099] refer to Figure 1A The horizontal axis represents the time domain, and the vertical axis represents the frequency domain. The smallest transmission unit in the time domain is an OFDM symbol, N. symbOFDM symbols 1a02 are aggregated to configure one time slot 1a06, and two time slots are aggregated to configure one subframe 1a05. The length of a time slot is 0.5 milliseconds, and the length of a subframe is 1.0 millisecond. Furthermore, radio frame 1a14 is a time-domain time period configured with 10 subframes. The smallest transmission unit in the frequency domain is a subcarrier, and the bandwidth of the entire system transmission bandwidth is configured to a total of N. BW One subcarrier 1a04. However, this detailed digital value can be applied differently.

[0100] In the time-frequency domain, the basic unit of a resource is a resource element (RE) 1a12, which can be indicated by a symbol index and a subcarrier index. A resource block (RB) 1a08 (or a physical resource block (PRB)) can be defined as N in the time domain. symb A consecutive OFDM symbol 1a02 and N in the frequency domain RB There are N consecutive subcarriers 1a10. Therefore, in one time slot, one RB 1a08 can contain N symb ×N RB Each RE 1a12. Typically, the smallest frequency domain allocation unit for data is an RB; in LTE systems, typically N... symb =7, N RB =12, and N BW and N RB The data rate is proportional to the bandwidth of the system transmission band. The data rate increases proportionally to the number of RBs scheduled in the terminal. LTE systems can define and operate six transmission bandwidths. In the case of FDD systems, where downlink and uplink are divided and operated by frequency, the downlink and uplink transmission bandwidths can be different. The channel bandwidth indicates the RF bandwidth corresponding to the system transmission bandwidth. Table 1 shows the correspondence between the defined channel bandwidth and the system transmission bandwidth in an LTE system. For example, in an LTE system with a 10MHz channel bandwidth, the transmission bandwidth can be configured with 50 RBs.

[0101] [Table 1]

[0102] <![CDATA[Channel bandwidth BW Channel [MHz]]]> 1.4 3 5 10 15 20 <![CDATA[Transmission Bandwidth Configuration N RB > 6 15 25 50 75 100

[0103] Downlink control information can be transmitted within the first N OFDM symbols of a subframe. In one embodiment, typically N = {1, 2, 3}. Therefore, the value of N can be variably applied to each subframe depending on the amount of control information to be transmitted in the current subframe. The transmitted control information may include a control channel transmission interval indicator indicating how many OFDM symbols to transmit control information, scheduling information about downlink or uplink data, and information about HARQ ACK / NACK.

[0104] In LTE systems, scheduling information for downlink or uplink data is delivered from the BS to the UE via downlink control information (DCI). DCI is defined according to various formats and can indicate whether the information is scheduling information for uplink data (UL grant) or downlink data (DL grant), whether the information is a compact DCI with a smaller control information size, whether spatial multiplexing using multiple antennas is applied, and whether the information is a DCI for power control, etc. For example, DCI format 1 (i.e., scheduling control information for downlink data (DL grant)) may contain at least one of the following control information:

[0105] - Resource Allocation Type 0 / 1 Flag: Indicates whether the resource allocation method is Type 0 or Type 1. In Type 0, resources are allocated in units of Resource Block Groups (RBGs) using a bitmap method. In LTE systems, the basic unit of scheduling is an RB, represented as a time-frequency domain resource. An RBG contains multiple RBs and becomes the basic unit of scheduling in the Type 0 method. In Type 1, a set number of RBs are allocated within an RBG.

[0106] - Resource Block Allocation: Indicates the Resource Block (RB) allocated to data transmission. The resource is determined based on system bandwidth and resource allocation method.

[0107] - Modulation and coding scheme (MCS): Indicates the modulation scheme used for data transmission and the size of the transport block (TB) (i.e., the data to be transmitted).

[0108] -HARQ procedure number: The procedure number indicating the HARQ.

[0109] - New data indicator: Indicates whether the transmission is a HARQ initial transmission or a retransmission.

[0110] - Redundant version: Indicates a redundant version of HARQ.

[0111] - Transmission Power Control (TPC) Commands for Physical Uplink Control Channel (PUCCH): Indicates the transmission power control commands used for PUCCH (i.e., the uplink control channel).

[0112] DCI can be transmitted via channel coding and modulation processes on the Physical Downlink Control Channel (PDCCH) (or control information, and they are used interchangeably below) or the Enhanced PDCCH (EPDCCH) (or enhanced control information, and they are used interchangeably below) (i.e., the downlink physical control channel).

[0113] Typically, the DCI is independently scrambled for each UE using a given Radio Network Temporary Identifier (RNTI) (or UE ID). After Cyclic Redundancy Check (CRC) is added to the DCI and it undergoes channel coding, the DCI can be configured with each individual PDCCH and transmitted. In the time domain, the PDCCH is mapped and transmitted during the control channel transmission interval. The frequency domain mapping position of the PDCCH can be determined by each UE's ID and can be spread and transmitted throughout the entire system transmission bandwidth.

[0114] Downlink data can be transmitted on the Physical Downlink Shared Channel (PDSCH) (i.e., the physical channel used for downlink data transmission). The PDSCH can be transmitted after the control channel transmission interval. Based on the DCI transmitted via the PDCCH, the detailed mapping position of the PDSCH in the frequency domain and scheduling information such as the modulation scheme are determined.

[0115] The BS informs the UE of the modulation scheme applied to the PDSCH to be transmitted and the transmission (transmission block size (TBS)) of the data to be transmitted by using the MCS in the control information configured for DCI. In one embodiment, the MCS can be configured with 5 bits or more or less than 5 bits. The TBS corresponds to the size before the data transmission block (TB) to be transmitted by the BS, where the channel coding for error correction is applied.

[0116] The modulation schemes supported in LTE systems include Quadrature Phase Shift Keying (QPSK), Quadrature Amplitude Modulation (16QAM), and 64QAM. The modulation order (Qm) corresponds to 2, 4, and 6, respectively. That is, in the case of QPSK modulation, 2 bits can be transmitted per symbol; in the case of 16QAM modulation, 4 bits can be transmitted per symbol; and in the case of 64QAM modulation, 6 bits can be transmitted per symbol. Furthermore, depending on system modifications, 256QAM or higher modulation methods can be used.

[0117] Figure 1B This is a diagram illustrating the basic structure of the time-frequency domain (i.e., the radio resource area in which data or control channels are transmitted in the uplink) in an LTE-A system.

[0118] refer to Figure 1B The horizontal axis represents the time domain, and the vertical axis represents the frequency domain. The smallest transmission unit in the time domain is SC-FDMA symbol 1b02, and N symb UL One SC-FDMA symbol can be aggregated to configure one time slot 1b06. Furthermore, two time slots are aggregated to configure one subframe 1b05. The smallest transmission unit in the frequency domain is a subcarrier. The entire system transmission bandwidth 1b04 is configured with a total of N... BW N subcarriers.BW It can have a value proportional to the system's transmission bandwidth.

[0119] In the time-frequency domain, the basic unit of a resource is a resource element (RE) 1b12, which can be defined as an SC-FDMA symbol index and subcarrier index. A resource block pair (RB pair) 1b08 can be defined as N in the time domain. symb UL A consecutive SC-FDMA symbol and N in the frequency domain SC RB N consecutive subcarriers. Therefore, an RB is configured with N symb UL ×N SC RB One RE. Typically, the smallest unit of transmission for data or control information is the RB unit. The PUCCH is mapped to the frequency domain corresponding to one RB and transmitted during one subframe.

[0120] In LTE systems, the timing relationship between PDSCH (the physical channel used for downlink data transmission), PUCCH, or PUSCH (the uplink physical channel in which HARQ ACK / NACK corresponding to PDCCH / EPDDCH containing semi-persistent schedule release (SPS release) is transmitted) can be defined. For example, in an LTE system operating under Frequency Division Duplex (FDD) conditions, the HARQ ACK / NACK corresponding to the PDSCH transmitted in the (n-4)th subframe or the PDCCH / EPDCCH containing SPS release can be transmitted as PUCCH or PUSCH in the nth subframe.

[0121] In LTE systems, downlink HARQ employs an asynchronous HARQ method with variable data transmission timing. That is, when the UE receives a HARQ NACK feedback for the initial transmission data sent by the BS, the BS freely determines the transmission timing of the retransmitted data based on scheduling operations. As a result of decoding the received data in response to the HARQ operation, the UE can buffer data identified as erroneous and can execute a combination with the next retransmitted data.

[0122] When the UE receives a PDSCH containing downlink data transmitted by the BS in subframe n, the UE transmits uplink control information containing downlink data, either HARQ ACK or NACK, to the BS via PUCCH or PUSCH in subframe n+k. In this case, k can be defined differently depending on the FDD or Time Division Duplex (TDD) configuration of the LTE system and its subframe configuration. For example, in the case of an FDD LTE system, k is fixed at 4. In the case of a TDD LTE system, k can be changed depending on the subframe configuration and subframe number. Furthermore, when data transmission is performed over multiple carriers, the value of k can be applied differently based on the TDD configuration of each carrier.

[0123] In LTE systems, unlike downlink HARQ, uplink HARQ employs a synchronous HARQ method with fixed data transmission timing. That is, the uplink / downlink timing relationship between the Physical Uplink Shared Channel (PUSCH) (i.e., the physical channel used for uplink data transmission), the PDCCH (i.e., the downlink control channel preceding PUSCH), and the Physical Hybrid Indicator Channel (PHICH) (i.e., the physical channel in which downlink HARQ ACK / NACK corresponding to PUSCH are transmitted) can be transmitted and received according to the following rules.

[0124] When the UE receives a PDCCH containing uplink scheduling control information sent by the BS, or a PHICH in which the BS sends downlink HARQ ACK / NACK in subframe n, the UE sends uplink data corresponding to the control information via PUSCH in subframe n+k. In this case, k can be defined differently depending on the FDD or Time Division Duplex (TDD) configuration of the LTE system. For example, in the case of an FDD LTE system, k can be fixed at 4. In the case of a TDD LTE system, k can be changed depending on the subframe configuration and subframe number. Furthermore, when data transmission is performed over multiple carriers, the value of k can be applied differently depending on the TDD configuration of each carrier.

[0125] Furthermore, when the UE receives a PHICH containing information related to downlink HARQ ACK / NACK from the BS in subframe i, the PHICH corresponds to the PUSCH sent by the UE in subframe ik. In this case, k can be defined differently depending on whether the LTE system is FDD or TDD and its configuration. For example, in the case of an FDD LTE system, k is fixed at 4. In the case of a TDD LTE system, k can be changed depending on the subframe configuration and subframe number. Moreover, when data transmission is performed over multiple carriers, the value of k can be applied differently depending on the TDD configuration of each carrier.

[0126] The wireless communication system has already been described based on the LTE system. However, the content of this disclosure is not limited to the LTE system and can be applied to various wireless communication systems, such as NR and 5G. Furthermore, in one embodiment, if the content is applied to other wireless communication systems, the value of k can be changed and applied in systems using FDD and corresponding modulation schemes.

[0127] Figure 1C and 1D The diagram shows the status of data allocation for eMBB, URLLC, and mMTC (i.e., services considered in 5G or NR systems) in frequency-time resources.

[0128] from Figure 1C and Figure 1D This allows us to see the methods for allocating frequency and time resources for information transmission in each system.

[0129] first, Figure 1C The diagram illustrates the status of eMBB, URLLC, and mMTC data across the entire system frequency band 1c00. If URLLC data 1c03, 1c05, and 1c07 are generated and need to be transmitted when eMBB 1c01 and mMTC 1c09 are allocated and transmitted in a given frequency band, the portion of eMBB 1c01 and mMTC 1c09 already allocated can be empty or not transmitted, while URLLC data 1c03, 1c05, and 1c07 can be transmitted. URLLC data (1c03, 1c05, and 1c07) can be allocated to a portion of resource 1c01 that has already been allocated and transmitted for eMBB because the latency time spent by URLLC during this service period must be reduced. If URLLC is additionally allocated and transmitted within the URLLC of the already allocated eMBB resource, eMBB data can be avoided in redundant frequency and time resources. Therefore, the transmission performance of eMBB data may be degraded. That is, in this case, eMBB data transmission failure may occur due to URLLC allocation.

[0130] exist Figure 1D In this system, the entire frequency band 1d00 can be divided and used to transmit services and data in subbands 1d02, 1d04, and 1d06. Information related to subband configuration can be predetermined and transmitted from the BS to the UE via higher signaling. Alternatively, subband-related information can be randomly allocated by the BS or network nodes, and services can be assigned to the UE without transmitting separate subband configuration information. Figure 1D The diagram shows the states where subband 1d02 is used for eMBB data transmission, subband 1d04 is used for URLLC data transmission, and subband 1d06 is used for mMTC data transmission.

[0131] Throughout this embodiment, the transmission time interval (TTI) for URLLC transmission can be shorter than the TTI for eMBB or mMTC transmission. Furthermore, responses to information related to URLLC can be sent faster than responses to information related to eMBB or mMTC. Therefore, information can be sent and received with low latency.

[0132] The eMBB service described below is referred to as a first-type service, and the eMBB data is referred to as first-type data. The first-type service or first-type data is not limited to eMBB and may correspond to situations requiring high-speed data transmission or broadband transmission. Furthermore, the URLLC service is referred to as a second-type service, and the URLLC data is referred to as second-type data. The second-type service or second-type data is not limited to URLLC and may correspond to other systems requiring low latency or high reliability transmission, or other systems requiring both low latency and high reliability. Furthermore, the mMTC service is referred to as a third-type service, and the mMTC data is referred to as third-type data. The third-type service and third-type data are not limited to mMTC and may correspond to situations requiring low speed, low coverage, or low power. Additionally, when describing embodiments, the first-type service may or may not include the third-type service.

[0133] The structure of the physical layer channel used for each type to transmit three types of service data can be different. For example, at least one of the following can be different: the length of the transmission time interval (TTI), the frequency resource allocation unit, the structure of the control channel, and the data mapping method.

[0134] The above has described three types of services and three types of data, but there can be many more types of services and corresponding data. Even in such cases, the content of this disclosure can still be applied.

[0135] To describe the methods and apparatus presented in one embodiment, the terms "physical channel" and "signal" from conventional LTE or LTE-A systems may be used. However, the content of this disclosure can be applied to wireless communication systems other than LTE and LTE-A systems.

[0136] As described above, the embodiments present detailed methods for defining the sending and receiving operations of a UE and a BS for UEs of first-type, second-type, and third-type services or data transmission and operation, wherein different types of services or data are scheduled within the same system. In this disclosure, first-type, second-type, and third-type UEs refer to UEs for which first-type, second-type, and third-type services have been scheduled. In one embodiment, the first-type UE, second-type UE, and third-type UE may be the same UE or different UEs.

[0137] In the following embodiments, at least one of the uplink scheduling signal and the downlink data signal is referred to as the first signal. Furthermore, in this disclosure, at least one of the uplink data signal for uplink scheduling authorization and the HARQ ACK / NACK for downlink data signals is referred to as the second signal. In one embodiment, among the signals from the BS to the UE, the signal awaiting a response from the UE may be the first signal, and the response signal from the UE corresponding to the first signal may be the second signal. Furthermore, in one embodiment, the service type of the first signal may be at least one of eMBB, URLLC, and mMTC, and the service type of the second signal may also correspond to at least one of these.

[0138] In the following embodiments, the TTI length of the first signal is a time value associated with the transmission of the first signal and can indicate the duration of transmission of the first signal. Furthermore, in this disclosure, the TTI length of the second signal is a time value associated with the transmission of the second signal and can indicate the duration of transmission of the second signal. The TTI length of the third signal is a time value associated with the transmission of the third signal and can indicate the duration of transmission of the third signal. Additionally, in this disclosure, the second signal transmission timing is information about when the UE transmits the second signal and when the BS receives the second signal, and can be referred to as the second signal transmission and reception timing.

[0139] The contents of this disclosure can be applied to FDD and TDD systems.

[0140] In the following, and in this disclosure, higher signaling refers to a method for a BS to send signals to a UE using a downlink data channel of the physical layer, or a method for a UE to send signals to a BS using an uplink data channel of the physical layer. Higher signaling may also be referred to as RRC signaling, PDCP signaling, or MAC control element (MAC CE).

[0141] The contents of this disclosure can be applied to FDD and TDD systems.

[0142] Figure 1E This is a diagram illustrating a self-contained structure in which uplink and downlink exist within a subframe of a communication system.

[0143] exist Figure 1EIn this disclosure, an uplink 1e04, a downlink 1e00, and a protection period 1e02 required for handover between them are configured within a subframe. The protection period 1e02 is configured to handle the time required for the handover from downlink to uplink between the BS and UE, as well as the time required for transmission time alignment between the BS and UE. Therefore, the protection period 1e02 can have different time values ​​depending on the performance of the UE and BS, and the distance between the UE and BS. Furthermore, the roles of uplink 1e04 and downlink 1e00 can be changed, and their durations can differ from those shown in the figure. In this disclosure, conditions including downlink 1e00, protection period 1e02, and uplink 1e04 are considered.

[0144] Figure 1F This is a diagram showing the state of the initial transmission result fed back in a self-contained structure on time division duplex (TDD).

[0145] Figure 1F Case 1f08 is illustrated, where, in the case that the initial transmission occurs as downlink 1f00 in the nth subframe, slot, or transmission time interval (TTI), the UE reports the decoding result of the corresponding initial downlink transmission 1f06 using the (n+2)th uplink resource 1f04. That is, the UE can determine the decoding result of the initial downlink transmission after the downlink in the nth subframe, slot, or TTI has been terminated. Furthermore, the feedback for the corresponding nth downlink initial transmission result can be n+1, n+3, or n+4 instead of n+2. The corresponding diagram is drawn under the assumption of n+2. The values ​​described below are merely examples described in this disclosure and can be applied to different values. Two types of decoding results are reported: successful or failed initial transmissions.

[0146] Figure 1G This is a diagram showing the state of rapid feedback of the results of some initial transfers performed on a self-contained TDD structure.

[0147] Figure 1GCase 1g10 is illustrated, in which, in order to provide notification of feedback transmission results faster than those in the nth subframe, time slot, or transmission interval, the UE reports some results (1g08) of the initial transmission of the nth information link via uplink resources in the (n+1)th subframe or time slot. The corresponding scenario can be described as follows: The initial transmission of the nth downlink is then configured as a transport block 1g00, and a transport block is configured to have several code block units. The UE determines that the decoding of the corresponding transport block has been successful only when the decoding of all corresponding code blocks is successful, and reports this to the BS. When at least one of the corresponding code blocks fails during decoding, the UE determines that the decoding of the corresponding transport block has failed, and reports the decoding result to the BS. Therefore, during the nth downlink transmission interval, rather than after the nth downlink transmission interval, if the UE fails to decode the initial code block of the nth downlink initial transmission data 1g00, and this failure occurs during the decoding of the corresponding transmission block, the UE can report the decoding failure result of the corresponding transmission block to the BS, regardless of the decoding results of subsequent code blocks. Therefore, in Figure 1F If a feedback result report for the initial transmission of the nth downlink has already been executed through the (n+2)th uplink resource, then in Figure 1G When a failure occurs in the initial transmission of the nth downlink, the corresponding feedback result report can be executed earlier using the (n+1)th uplink resources. In other words, compared to... Figure 1F Compared to the previous scenario, the corresponding result can be notified one or two subframes, time slots, or transmission intervals in advance. In this case, to provide notification of the nth downlink decoding result (1g10) via the (n+1)th uplink resource, a set of code blocks 1g08 for configuring a certain interval (1g06) of the nth downlink initial transmission and a transmission block 1g00 in the initial transmission need to be pre-configured. Therefore, the certain interval 1g06 of the initial transmission needs to be pre-configured by considering several values ​​(such as the performance of the UE and BS and the distance between the UE and BS). Furthermore, it should be noted that the corresponding operation is easy only when the code blocks for configuring a transmission block are configured via frequency first mapping rather than time first mapping. When the decoding of the corresponding portion 1g06 of the initial transmission fails, an uplink fast report 1g10 at the (n+1)th position for the result of the portion 1g06 of the nth downlink initial transmission occurs. If the decoding of the corresponding portion 1g06 of the initial transmission is successful, an uplink fast report 1g10 at the (n+1)th position does not occur. The reason is that although the decoding of part of the initial 1g06 transmission was successful, the decoding of the remaining parts may have failed. Therefore, reporting the successful decoding of part of the initial 1g06 transmission is meaningless. Thus, in this situation, as... Figure 1FIn this disclosure, the UE provides notification of the decoding result via the (n+2)th uplink after the initial transmission on the nth downlink has completely terminated. In this disclosure, the nth faster feedback report can be notified via the nth uplink resources instead of the (n+1)th uplink resources. Furthermore, it is assumed that a portion of the initial transmission on the nth downlink determined for the faster feedback report is first-type data, and the remaining data is second-type data. That is, it is assumed that a certain set of code blocks configured for a transport block used for the initial transmission is first-type data, and the remaining set of code blocks is second-type data. Furthermore, a transport block can be divided into three or four types instead of two types, and feedback reports can be executed differently. The method for dividing first-type and second-type data can be determined based on values ​​such as the UE's decoding processing capability, the size of the corresponding transport block, and the distance between the UE and the BS. The corresponding information can be dynamically shared between the UE and the BS in advance via control information, or semi-statically shared between the UE and the BS by obtaining system information. Furthermore, if the value (i.e., the criterion for distinguishing between the first and second types of data) can be a value previously shared between the UE and the BS, then the BS and UE can assume that they can implicitly calculate and understand this value to autonomously determine its operation. For example, assuming the UE receives α (i.e., the size of a transport block (TB)), the UE can calculate the size of the first type of data as α × β, define it as the corresponding value, and operate accordingly. In this case, β is a value between 0 and 1 and is considered as a reference value for reporting the decoding result through the corresponding uplink resources by processing the first type of data. Furthermore, the UE can calculate the second type of data as α × (1 - β), define it as the corresponding value, and operate accordingly. In cases where various transport block sizes exist, the UE and BS can pre-select one of the various β values ​​based on the UE's decoding processing capabilities and can notify the UE of the selected value, or the UE can autonomously select one of the various β values ​​and report it to the BS. Alternatively, besides this method, it is possible to pre-determine the size of the first type of data as an absolute value and share it between the BS and the UE.

[0148] According to this method, the feedback report for the first type of data on the nth downlink only provides notification of decoding failure for the corresponding data on the (n+1)th uplink, while the feedback reports for the first and second types of data on the nth downlink provide notifications of decoding success and failure for the corresponding data on the (n+2)th uplink. Therefore, when the BS receives a decoding failure in the (n+1)th uplink resource, it can retransmit the transport block for initial transmission much faster than if the BS receives a decoding failure in the (n+2)th uplink resource. For example, if the UE reports a failure in the (n+1)th feedback, the BS can perform a retransmission for the corresponding transport block in the (n+3)th feedback. If the UE reports a failure in the (n+2)th feedback, the BS can perform a retransmission for the corresponding transport block in the (n+4)th feedback.

[0149] For feedback reports of Type 1 data on the nth downlink, a different method is used to provide notifications of successful and failed decoding of the corresponding data on the (n+1)th uplink. For feedback reports of Type 2 data on the nth downlink, a different method is used to provide notifications of successful and failed decoding of the corresponding data on the (n+2)th uplink. If such a method is used, when the UE reports a failure in the (n+1)th iteration, the BS can perform a retransmission of Type 1 data in the (n+3)th iteration. When the UE reports a failure in the (n+2)th iteration, the BS can perform a retransmission of Type 2 data in the (n+4)th iteration. In other words, in the above case, the method of the UE dividing a transport block into Type 1 data and Type 2 data and sending each feedback result report to the BS via the uplink in different subframes, time slots, or TTIs, and the BS performing each retransmission based on the corresponding feedback result, is considered.

[0150] In addition to the retransmission operation used for the initial transmission, this method can be executed as a retransmission operation for retransmission.

[0151] Figure 1H It is a diagram showing the state of the results of the initial transmission and the rapid feedback of a portion of the results of the initial transmission on the self-contained structure of TDD using the same resources.

[0152] Figure 1HCase 1h10 is illustrated, where the feedback result of the initial transmission 1h04 of the downlink (1h00) in the nth subframe, time slot, or TTI is reported as uplink 1h14 in the n+2nd subframe, time slot, or TTI. Furthermore, the figure illustrates case 1h12, where the rapid feedback result of a portion 1h08 of the initial transmission of the downlink (1h06) in the n+1th subframe, time slot, or TTI is reported as uplink 1h14 in the n+2nd subframe, time slot, or TTI. Various methods can be used to support the feedback reporting for each transmission in the nth and n+1th subframes as uplink 1h14 in the n+2nd subframe, time slot, or TTI. First, if the UEs are the same or different, different feedback time and frequency resources can be used to notify the feedback of the nth transmission and the feedback of the n+1th transmission. Furthermore, if the UEs are the same, the same feedback time and frequency resources can be used to group and notify the feedback of the nth transmission and the feedback of the n+1th transmission. In other words, if the feedback from the nth transmission and the (n+1)th transmission are successful, a success feedback is notified in the (n+2)th uplink transmission. If at least one of the feedbacks from the nth transmission and the (n+1)th transmission fails, a failure feedback is notified in the (n+2)th uplink transmission. Before the initial transmission, the corresponding relevant information can be directly notified to the UE via control information. Alternatively, the UE can implicitly perform the corresponding operation through the corresponding resource relationships. That is, if two or more transmission reports overlap in the (n+2)th uplink, the UE can, depending on the conditions, use the same resources for each report or perform all reports at once. Alternatively, if the (n+1)th first-type data report only provides a failure notification, the resources used for the first-type data are used to transmit the nth downlink transmission report. For example, if when the first-type data report fails, the resources used for the first-type data report are... Figure 1M The first time-frequency resource 1m02 is used when there is no failure in the reporting of the first type of data. Figure 1M When the second time-frequency resource 1m04 is used, the BS can detect the feedback result report of the first type of data through energy detection in the corresponding two resource areas. Furthermore, when the feedback result of the (n+1)th type of downlink data fails, the feedback result report for the initial transmission of the nth downlink is executed through the first time-frequency resource 1m02. Alternatively, when the feedback result of the (n+1)th type of downlink data succeeds, it is reported through the second time-frequency resource 1m04. The corresponding first and second time-frequency resources can be configured differently based on different time or frequency locations.

[0153] Figure 1I This is a diagram showing the state of feedback of the initial transmission results in frequency division duplex (FDD).

[0154] Figure 1ICase 1i02 is illustrated, where the decoding result of the corresponding transport block is fed back as the (n+4)th uplink 1i08 relative to transport block 1i04 transmitted on the nth downlink 1i00. When the UE receives the transport block on the nth downlink, it decodes the code block configured for the transport block transmitted on the corresponding nth downlink using its own decoder 1106. Different values ​​other than n+4 can be applied to report the corresponding decoding result via the uplink. This is determined based on the performance of the BS and UE, as well as the distance between the BS and UE.

[0155] Figure 1J This is a diagram showing the state of rapid feedback of the results of a portion of the initial transfer performed in the FDD.

[0156] Figure 1J Case 1j04 is illustrated, where the UE, for a transport block transmitted in the n+3 uplink 1j04 for the nth downlink 1j00, only reports the decoding result of the first type of data 1j06, i.e., some code blocks of the configured transport block 1j08. In this case, the corresponding report may only report the decoding failure of a portion of the transport block 1j04, or it may report both success and failure. Based on the performance of the UE and BS, the distance between the UE and BS, and the size of the portion of the transport block 1j04, the n+2 and n+1 values, which are faster than n+3, can be used as feedback transmission reports. This is determined based on the UE's decoding processing capability, the size of the configured first type of data, and the distance between the UE and BS. Furthermore, if the value (i.e., the standard for dividing the first type of data and the second type of data (i.e., the data other than the first type of data in the transport block)) is a value previously shared between the UE and BS, then the BS and UE can assume that they can implicitly calculate and understand this value to autonomously determine the corresponding value. For example, assuming the UE receives α (i.e., the size of a transport block (TB)), the UE can calculate the size of the first type of data as α × β, define it as a corresponding value, and operate on it. In this case, β is a value between 0 and 1 and is considered as a reference value for reporting the decoding result through the corresponding uplink resources by processing the first type of data. Furthermore, the UE can calculate the second type of data as α × (1 - β), define it as a corresponding value, and operate on it. Given various transport block sizes, the UE and BS can pre-select one of the various β values ​​based on the UE's decoding processing capabilities and can notify the UE of the selected value, or the UE can autonomously select one of the various β values ​​and report it to the BS. Alternatively, besides this method, it is feasible to pre-determine the size of the first type of data as an absolute value and share it between the BS and the UE. Information sharing between the UE and the BS can be performed using a dynamic method via control information and a semi-static method via control information broadcasting.

[0157] Figure 1K This is a diagram showing the state of feedback as a result of performing a portion of the initial transmission differently in an FDD.

[0158] Figure 1K The illustration shows a scenario where the decoding results of transport block 1k10 transmitted in downlink 1k00 are reported via uplink 1k04 (n+3rd and n+4th uplinks), respectively (1k02, 1k12). In this case, the portion of downlink transport block 1k10 reported via uplink 1k04 is referred to as first-type data 1k06, and the remaining portion reported via uplink 1k04 is referred to as second-type data 1k08. In this scenario, the data decoding results reported in uplink 1k04 and uplink 1k05 are categorized as success or failure and reported accordingly. The BS performs first-type data retransmission or second-type data retransmission in different subframes, time slots, or TTIs based on the feedback results received via each uplink resource. The size of the first-type and second-type data is determined based on the performance of the UE and BS, as well as the distance between them. Furthermore, the UE and BS can explicitly learn about the size of the corresponding first-type and second-type data in advance through signaling exchange, or implicitly through different reference values. The reference value can be determined based on the timing advance value or the UE performance value. Therefore, the BS determines which values ​​the UE has set for the first type of data and the second type of data, and has reported feedback from the (n+3)th or (n+4)th uplink based on these values, and determines the data to be retransmitted based on this determination.

[0159] Figure 1L This is a diagram showing the feedback of the results of the initial transfer in FDD and the rapid feedback of the results of a portion of the initial transfer using the same resources.

[0160] Figure 1LThe following scenario illustrates a feedback result report 1l02 for the nth downlink (1l00) transport block and a feedback result report 1l08 for a portion of the n+1th downlink (1l01) transport block, occurring in the (n+4)th uplink 1l04. Various methods can be used to support feedback reports for the corresponding downlink transmissions in the nth and (n+1)th downlinks via the (n+4)th uplink 1l14. First, if the UEs are the same or different, different feedback time and frequency resources can be used to notify the feedback for the nth downlink transmission and the feedback for the (n+1)th downlink transmission differently. Alternatively, if the UEs are the same, the same feedback time and frequency resources can be used to group and notify the feedback for the nth downlink transmission and the feedback for the (n+1)th downlink transmission. That is, when both the feedback for the nth downlink transmission and the feedback for the (n+1)th downlink transmission are successful, a feedback indicating success can be notified in the (n+4)th uplink transmission. When a failure occurs in at least one of the nth downlink transmission and the (n+1)th downlink transmission, feedback indicating the failure is notified in the (n+4)th uplink transmission. The relevant information can be directly notified to the UE via control information before the initial transmission, or the UE can implicitly perform the corresponding operation through corresponding resource relationships. That is, when two or more transmission reports overlap in the (n+4)th uplink, they can be performed differently or simultaneously using the same resources, depending on the conditions. Alternatively, if the (n+1)th first type of data report only provides a failure notification, the resources used for the first type of data are used to transmit the nth downlink transmission report. For example, if the first type of data report fails in... Figure 1M Use the first time-frequency resource 1m02 and when the first type of data is reported as not having failed. Figure 1M Using the second time-frequency resource 1m04, the BS can detect the feedback result report of the first type of data through energy detection in the corresponding two resource areas. Furthermore, when the feedback result of the (n+1)th type of first-downlink data fails, the feedback result of the initial transmission of the nth downlink is reported via the first time-frequency resource 1m02. Alternatively, when the feedback result of the (n+1)th type of first-downlink data is successful, it is reported via the second time-frequency resource 1m04. The corresponding first and second time-frequency resources can be configured differently based on different time or frequency positions within the (n+1)th uplink subframe, time slot, or TTI.

[0161] Figure 1M This is a diagram showing the status of time-frequency resources used for reporting rapid feedback and feedback together.

[0162] Figure 1MA method for reporting feedback on two initial transmissions as described above is illustrated. In the case where the first feedback method only reports the failure of the corresponding transmission, and the second feedback method reports both the success and failure of the corresponding transmission, when the UE provides notification of the second feedback result via the first time-frequency resource 1m02, it implicitly provides notification of the failure of the first feedback result. Furthermore, when the UE provides notification of the second feedback result via the second time-frequency resource 1m04, it implicitly provides notification of the success of the second feedback result. Therefore, the BS can decode the feedback result via the first and second time-frequency resources and can determine both the first and second feedback results simultaneously.

[0163] [(1-1) Example]

[0164] Figure 1N This is a diagram illustrating the operation of the UE according to embodiment (2-1).

[0165] exist Figure 1N In this process, the UE sequentially decodes the first type of data and determines whether to report the decoding result of the second type of data based on the corresponding result. That is, when the decoding result of the first type of data fails, a feedback report can be executed immediately based solely on the result of the first type of data, because the transmission of the corresponding transport block ultimately reports decoding failure to the BS. In this scenario, assuming that although the decoding of the first type of data fails and the UE reports a failure for the corresponding transport block, the decoding of the second type of data is still performed. Although the decoding of the corresponding second type of data reappears in subsequent retransmissions, the decoding operation is incorporated into the soft combination method.

[0166] Specifically, the UE first performs decoding of the first type of data (1n00). When decoding of the first type of data fails (1n02), the UE encodes the second type of data (1n06) and sends decoding failure information about the first type of data to the BS through the allocated uplink resources (1n10). When decoding of the first type of data succeeds (1n02), the UE encodes the second type of data (1n04) and, based on the decoding result of the second type of data, sends success information about the success of the first and second types of data and failure information about the second type of data to the BS through the allocated uplink resources (1n08).

[0167] [(1-2) Examples]

[0168] Figure 10 This is a diagram illustrating the operation of the UE according to embodiment (2-2).

[0169] exist Figure 10In this process, the UE sequentially decodes the first type of data and determines whether to report the decoding result of the second type of data based on the corresponding result. That is, when the decoding result of the first type of data fails, since the transmission of the corresponding transport block eventually reports a decoding failure to the BS, a feedback report can be executed immediately based solely on the result of the first type of data. In this scenario, assuming that although the decoding of the first type of data fails and the UE reports a failure of the corresponding transport block, the decoding of the second type of data is not executed. For feedback reports based on the uplink resources allocated for the corresponding first type, the UE may not execute the decoding of the second type of data simultaneously. In this case, the UE executes the decoding of the second type of data after reporting the decoding result of the first type.

[0170] Specifically, the UE first performs decoding of the first type of data (1o00). When decoding of the first type of data fails (1o02), the UE sends decoding failure information about the first type to the BS through the allocated uplink resources (1o06). When decoding of the first type of data succeeds (1o02), the UE encodes the second type of data (1o04), and based on the decoding result of the second type of data, sends success information about the first and second types of data or failure information about the second type to the BS through the allocated uplink resources (1o08).

[0171] [(1-3) Examples]

[0172] Figure 1P This is a diagram illustrating the operation of the UE according to embodiment (2-3).

[0173] exist Figure 1P In the process, the UE first performs decoding of the first type of data. If decoding of the first type of data fails, the UE expects to retransmit a transport block containing both the first type of data and the second type of data in the downlink transmission in subsequent operations. If decoding of the first type of data succeeds but decoding of the second type of data fails, the UE expects to retransmit a transport block containing both the first type of data and the second type of data in the downlink transmission in subsequent operations.

[0174] In summary, the UE fails at least in decoding either the first type of data or the second type of data (1p02, 1p04), and then receives data containing both the first and second types of data again in the subsequently configured downlink resources (1p06). When the UE succeeds in decoding either the first type of data or the second type of data, it receives the next new data in the subsequently configured downlink resources (1p08).

[0175] [(1-4) Examples]

[0176] Figure 1QThis is a diagram illustrating the operation of the UE according to embodiment (2-4).

[0177] Figure 1Q The process of a UE decoding each data type and feeding back the result is illustrated when the downlink transport block has been divided into first-type data and second-type data.

[0178] Specifically, the UE sequentially decodes the first type of data (1q00) and the second type of data (1q02). The UE feeds back the decoding result of the first type of data (1q04) through the corresponding configured uplink resources, and feeds back the decoding result of the second type of data (1q06) through the corresponding configured uplink resources.

[0179] [(1-5) Examples]

[0180] Figure 1R This is a diagram illustrating the operation of the UE according to embodiments (2-5).

[0181] Figure 1R The following scenario illustrates a situation where the UE decodes each piece of data and returns the result, and the corresponding subsequent operation is included in a case where one of the downlink transport blocks has been divided into first type data and second type data.

[0182] Specifically, in Figure 1R In the process, the UE first performs decoding of both Type 1 and Type 2 data (1r00). When both Type 1 and Type 2 data decoding are successful (1r02, 1r04), the UE reports success information regarding the Type 1 and Type 2 data to the BS (1r08). Furthermore, the UE receives the next new data via subsequently configured downlink resources (1r16). When Type 1 data decoding is successful (1r02) and Type 2 data decoding fails (1r04), the UE sends success information regarding Type 1 data and failure information regarding Type 2 data to the BS (1r10). Furthermore, the UE receives Type 2 data again via subsequently configured downlink resources (1r18). When Type 1 data decoding fails (1r02) and Type 2 data decoding is successful (1r06), the UE sends failure information for Type 1 data and success information for Type 2 data to the BS (1r12). Furthermore, the UE receives Type 1 data again via subsequently configured downlink resources (1r20). When decoding of both the first type of data and the second type of data fails (1r02, 1r06), the UE sends failure information about the first and second types of data to the BS (1r14). Furthermore, the UE then receives both the first and second types of data again via subsequently configured downlink resources (1r22).

[0183] [(1-6) Examples]

[0184] Figure 1S This is a diagram illustrating the BS operation according to embodiment (2-6).

[0185] Figure 1S The diagram illustrates the adaptive retransmission of Type 1 and Type 2 data when the BS receives feedback from the UE for Type 1 data and Type 2 data, respectively. Specifically, when the BS receives feedback as failed Type 1 data, it transmits a transport block containing both Type 1 and Type 2 data in the subsequent downlink allocated resources, regardless of the reception of Type 2 data feedback. If the BS does not receive feedback for Type 1 data but receives feedback as failed Type 1 and Type 2 data, it transmits a transport block containing both Type 1 and Type 2 data in the subsequent downlink allocated resources. If the BS does not receive feedback for Type 1 data but receives feedback as successful Type 1 and Type 2 data, it transmits a new transport block in the subsequent downlink allocated resources.

[0186] Specifically, the BS transmits a transport block configured with first type data and second type data in the downlink (1s00). Subsequently, when the BS receives a failure to decode the first type data (1s02) or a failure to decode the second type data (1s04), the BS retransmits the transport block containing the first type data and the second type data in subsequent operations (1s06). When the BS receives a success message for decoding the first type data (1s02) or the second type data (1s04), the BS sends the next new data (1s08).

[0187] [(1-7) Examples]

[0188] Figure 1T This is a diagram illustrating the BS operation according to embodiment (2-7).

[0189] Figure 1TThe illustration shows a scenario where the BS receives feedback for type 1 data and feedback for type 2 data differently. The BS first receives feedback for type 1 data, and then receives feedback for type 2 data. Based on the feedback results for type 1 data, the BS transmits only type 1 data in the corresponding allocated downlink resources, regardless of the feedback results. Similarly, based on the feedback results for type 2 data, the BS transmits only type 2 data in the corresponding allocated downlink resources. That is, this corresponds to an operation where, in the initial transmission, a transport block containing both type 1 and type 2 data is sent to the UE, but retransmissions are performed based on the corresponding results in different downlink resources.

[0190] Specifically, the BS sends a transport block (1t00) containing first type data and second type data. When the BS receives a successful decoding report of the first type data and second type data from the UE (1t02, 1t04), the BS determines that the transmission of the first type data and second type data is successful (1t08). Furthermore, the BS sends the next new data using the subsequently configured downlink resources (1t16). When the BS receives a report from the UE indicating successful decoding of the first type data (1t02) and a report indicating failed decoding of the second type data (1t04), the BS determines that the transmission of the first type data is successful and that the transmission of the second type data has failed (1t10). Furthermore, the BS retransmits the second type data using the subsequently configured downlink resources (1t18). When the BS receives a report from the UE indicating failed decoding of the first type data (1t02) and a report indicating successful decoding of the second type data (1t06), the BS determines that the transmission of the first type data has failed and that the transmission of the second type data is successful (1t12). Furthermore, the BS retransmits the first type data using the subsequently configured downlink resources (1t20). When the BS receives a failure report from the UE for decoding of both Type 1 and Type 2 data (1t02, 1t06), the BS determines that the transmission of both Type 1 and Type 2 data has failed (1t14). Furthermore, the BS retransmits both Type 1 and Type 2 data using subsequently configured downlink resources (1t22).

[0191] Figure 1U This is a block diagram illustrating the structure of a UE according to an embodiment.

[0192] refer to Figure 1UThe UE disclosed herein may include a UE receiver 1u00, a UE transmitter 1u04, and a UE processor 1u02. In one embodiment, the UE receiver 1u00 and the UE transmitter 1u04 may be collectively referred to as a transceiver. The transceiver can transmit signals to and receive signals from the BS. The signals may contain control information and data. For this purpose, the transceiver may be configured with an RF transmitter and an RF receiver, the RF transmitter being configured to up-convert and amplify the frequency of the transmitted signal, and the RF receiver being configured to amplify the received signal with low noise and down-convert the frequency, etc. Moreover, the transceiver can receive signals via a radio channel, transmit signals to the UE processor 1u02, and transmit signals output by the UE processor 1u02 via a radio channel. The UE processor 1u02 can control a series of processes to cause the UE to operate according to the embodiment. For example, the UE processor 1u02 can control the UE receiver 1u00 to receive a signal containing second signal transmission timing information from the BS and interpret the second signal transmission timing. Thereafter, the UE receiver 1u04 can transmit the second signal according to the timing.

[0193] Figure 1V This is a block diagram illustrating the structure of the BS according to an embodiment.

[0194] refer to Figure 1V In one embodiment, the BS may include at least one of a BS receiver 1v01, a BS transmitter 1v05, and a BS processor 1v03. In one embodiment of this disclosure, the BS receiver 1v01 and the BS transmitter 1v05 may be collectively referred to as a transceiver. The transceiver can transmit signals to and receive signals from the UE. The signals may include control information and data. For this purpose, the transceiver may be configured with an RF transmitter and an RF receiver, the RF transmitter being configured to up-convert and amplify the frequency of the transmitted signal, and the RF receiver being configured to amplify the received signal with low noise and down-convert the frequency. Furthermore, the transceiver can receive signals via a radio channel, output signals to the BS processor 1v03, and transmit signals output by the UE processor 1v03 via a radio channel. The BS processor 1v03 can control a series of processes that cause the BS to operate according to embodiments of this disclosure. For example, the BS processor 1v03 can control the determination of a second signal transmission timing and generate second signal transmission timing information to be sent to the UE. Subsequently, the BS transmitter 1v05 can send timing information to the UE, and the BS receiver 1v01 can receive the second signal according to the timing.

[0195] Furthermore, according to one embodiment of this disclosure, the BS processor 1v03 can be controlled to generate downlink control information (DCI) that includes second signal transmission timing information. In this case, the DCI can indicate that it is second signal transmission timing information.

[0196] The embodiments of this disclosure disclosed in the specification and accompanying drawings have been suggested as examples to facilitate the description of the technical content of this disclosure and to aid in understanding it, and are not intended to limit the scope of this disclosure. That is, other modifications based on the technical spirit of this disclosure can be practiced, as will be apparent to those skilled in the art to which this disclosure pertains. Furthermore, the embodiments described can be combined and operated if desired. For example, some of embodiments 1-1, 1-2, and 1-3 of this disclosure can be combined, and the BS and UE operate based on them. Moreover, the embodiments have been presented based on NR systems, and other modifications based on the technical spirit of the embodiments can be applied to other systems, such as FDD or TDD LTE systems.

[0197] Furthermore, preferred embodiments of this disclosure are disclosed in this specification and accompanying drawings. Although specific terms have been used, they are used in their ordinary sense to readily describe the technical content of this disclosure and to aid in understanding it, but are not intended to limit the scope of this disclosure. Other examples of modifications based on the technical spirit of this disclosure are possible in addition to the disclosed embodiments, and will be apparent to those skilled in the art to which this disclosure pertains.

[0198] <Second Embodiment>

[0199] Embodiments of this disclosure are described in detail below with reference to the accompanying drawings.

[0200] In describing the embodiments, descriptions of content that is well-known in the art to which this disclosure pertains and is not directly related to this disclosure have been omitted in order to make the essential points of this disclosure clearer.

[0201] For the same reason, some elements are enlarged, omitted, or shown schematically in the accompanying drawings. Furthermore, the dimensions of each element do not accurately reflect its actual size. Identical or similar elements are assigned the same reference numerals in the drawings.

[0202] The advantages and features of this disclosure, as well as the methods for achieving these advantages and features, will become more apparent from the embodiments described in detail with reference to the accompanying drawings. However, this disclosure is not limited to the disclosed embodiments, but can be implemented in a variety of different ways. The embodiments are provided merely to complete the disclosure and to allow those skilled in the art to understand its scope. This disclosure is defined by the scope of the claims. Throughout the drawings, the same reference numerals will be used to denote the same or similar elements.

[0203] In this disclosure, it will be understood that each block of a flowchart illustration and combinations of blocks in a flowchart illustration can be executed by computer program instructions. These computer program instructions can be mounted on a processor of a general-purpose computer, a special-purpose computer, or other programmable data processing apparatus, such that the instructions, which are executed by the processor of the computer or the other programmable data processing apparatus, create means for performing the functions specified in one or more flowchart blocks(s). These computer program instructions can also be stored in a computer-usable or computer-readable storage medium, which can instruct the computer or other programmable data processing apparatus to function in a particular manner, causing the instructions stored in the computer-usable or computer-readable storage medium to produce an article of writing containing instruction means for implementing the functions specified in one or more flowchart blocks(s). The computer program instructions can also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a process executed by the computer, such that the instructions of the computer or other programmable apparatus provide steps for performing the functions described in one or more flowchart blocks(s).

[0204] Furthermore, each block in the flowchart diagram may represent a module, segment, or portion of code, containing one or more executable instructions for implementing one or more specified logical functions. It should also be noted that in some alternative implementations, the functions marked in the blocks may occur out of order. For example, two blocks shown consecutively may actually execute substantially simultaneously, or these blocks may sometimes execute in reverse order, depending on the functions involved.

[0205] In this context, the term "unit" as used in this embodiment refers to a software or hardware component, such as a field-programmable gate array (FPGA) or application-specific integrated circuit (ASIC), and the "unit" performs a specific task. A "unit" can advantageously be configured to reside on an addressable memory medium and to operate on one or more processors. Therefore, a "unit" can include, for example, components (such as software components, object-oriented software components, class components, and task components), processes, functions, attributes, processes, subroutines, program code segments, drivers, firmware, microcode, circuits, data, databases, data structures, tables, arrays, and variables. The functionality provided in components and "units" can be combined into fewer components and "units," or can be further divided into additional components and "units." Furthermore, components and "units" can be implemented to operate on the CPU of one or more devices or secure multimedia cards. Additionally, in one embodiment, a "unit" can include one or more processors.

[0206] Wireless communication systems have deviated from providing initial voice-oriented services and evolved into broadband wireless communication systems that provide high-speed, high-quality packet data services (e.g., communication standards), such as 3GPP's High-Speed ​​Packet Access (HSPA), 3GPP2's Long Term Evolution (LTE) or Evolved Universal Terrestrial Radio Access (E-UTRA), LTE-Advanced (LTE-A), LTE-Enhanced, High-Speed ​​Packet Data (HRPD), IEEE's Ultra Mobile Broadband (UMB), and 802.16e. Furthermore, 5G, or New Radio (NR), communication standards are emerging as 5G wireless communication systems.

[0207] As described above, in a 5G-enabled wireless communication system, at least one of the following services can be provided to a terminal: enhanced mobile broadband (eMBB), massive machine-type communication (mMTC), and ultra-reliable low-latency communication (URLLC). These services can be provided to the same terminal within the same time interval. In all the following embodiments of this disclosure, eMBB can be a service aimed at high-speed transmission of large amounts of data, mMTC can be a service aimed at minimizing terminal power and allowing access from multiple terminals, and URLLC can be a service aimed at high reliability and low latency, but is not limited thereto. Furthermore, in all the following embodiments of this disclosure, it can be assumed that the TTI of the URLLC service is shorter than that of the eMBB and mMTC services, but is not limited thereto. These three types of services can be the main scenarios in LTE systems or post-LTE systems (such as 5G / New Radio and Next Radio (NR)).

[0208] In the following, embodiments of the present disclosure are described in detail with reference to the accompanying drawings. Furthermore, in describing the present disclosure, descriptions of relevant known functions or configurations that would unnecessarily obscure the essential points of the disclosure are omitted. Additionally, the terms described below have been defined by consideration of the functions in the present disclosure and may vary depending on the intent or practice of the user or operator. Therefore, each term should be defined based on the entire contents of this specification. In the following, a base station is the entity that configures some or all of the control information bars of the UE and allocates resources, and may be at least one of an eNode B, Node B, BS, radio access unit, BS controller, transmit and receive point (TRP), or node on a network. A terminal may include a user equipment (UE), a mobile station (MS), a cellular phone, a smartphone, a computer capable of performing communication functions, and a multimedia system.

[0209] In this disclosure, downlink (DL) refers to the radio transmission path of a signal from the BS to the UE, and uplink (UL) refers to the radio transmission path of a signal from the UE to the BS. Furthermore, embodiments of the invention are described below using LTE or LTE-A systems as examples, but embodiments of the invention can be applied to other communication systems with similar technical backgrounds or channel configurations. For example, 5G mobile communication technology (New Radio (NR)) developed after LTE-A can be included in other communication systems. Moreover, it is certain that embodiments of this disclosure can be applied to other communication systems with certain modifications without significantly departing from the scope of this disclosure, based on the judgment of a person skilled in the art.

[0210] LTE systems, a representative example of broadband wireless communication systems, employ Orthogonal Frequency Division Multiplexing (OFDM) in the downlink (DL) and Single-Carrier Frequency Division Multiple Access (SC-FDMA) in the uplink (UL). The uplink refers to the radio link through which a terminal (or User Equipment (UE)) or mobile station (MS) transmits data or control signals to a base station (BS or eNode B). The downlink refers to the radio link through which the BS transmits data or control signals. This multiple access scheme is a method of allocating or managing time-frequency resources, where each user carries data or control information on those resources to differentiate between user data or control information, ensuring that time-frequency resources do not overlap, i.e., establishing orthogonality.

[0211] When decoding failure occurs during the initial transmission, the LTE system employs a Hybrid Automatic Repeat Request (HARQ) scheme, retransmitting the corresponding data at the physical layer. According to the HARQ scheme, when the receiver fails to decode the data accurately, it sends a negative acknowledgment (NACK) to the transmitter, allowing the transmitter to retransmit the corresponding data at the physical layer. The receiver combines the retransmitted data with the previously failed-to-decode data, thereby improving data reception performance. Furthermore, when the receiver successfully decodes the data, it sends an acknowledgment (ACK) to the transmitter, allowing the transmitter to transmit new data.

[0212] Figure 2A It is a diagram illustrating the basic structure of the time-frequency domain (i.e., the radio resource area in which data or control channels are transmitted in the downlink) in an LTE system or similar systems.

[0213] refer to Figure 2A The horizontal axis indicates the time domain, and the vertical axis indicates the frequency domain. The smallest transmission unit in the time domain is an OFDM symbol, N. symbOFDM symbols 2a-102 are aggregated to configure one time slot 2a-106, and two time slots are aggregated to configure one subframe 2a-105. The time slot length is 0.5 milliseconds, and the subframe length is 1.0 millisecond. Furthermore, radio frame 2a-114 is a time-domain segment configured with 10 subframes. The smallest transmission unit in the frequency domain is a subcarrier, and the bandwidth of the entire system transmission bandwidth is configured to a total of N. BW There are 2a-104 subcarriers. However, these detailed values ​​can be applied variably.

[0214] In the time-frequency domain, the basic unit of a resource is a resource element (RE) 2a-112, which can be indicated by OFDM symbol indices and subcarrier indices. A resource block (RB) 2a-108 (or physical resource block (PRB)) can be defined as N in the time domain. symb A series of consecutive OFDM symbols 2a-102 and N in the frequency domain RB There are N consecutive subcarriers 2a-110. Therefore, in one time slot, one RB 2a-108 can contain N symb ×N RB Each RE 2a-112. Typically, the smallest frequency domain allocation unit for data is an RB. In LTE systems, typically N symb =7, N RB =12, and N BW and N RB The data rate is proportional to the bandwidth of the system transmission band. The data rate increases proportionally to the number of RBs scheduled in the UE. An LTE system can define and operate six transmission bandwidths. In the case of an FDD system where the downlink and uplink are frequency-divided and operated, the downlink and uplink transmission bandwidths can be different. The channel bandwidth indicates the RF bandwidth corresponding to the system transmission bandwidth. Table 2a shows the correspondence between the system transmission bandwidth and the channel bandwidth defined in the LTE system. For example, in an LTE system with a 10MHz channel bandwidth, the transmission bandwidth can be configured with 50 RBs.

[0215] [Table 2a]

[0216]

[0217] Downlink control information can be transmitted within the first N OFDM symbols of a subframe. In one embodiment, typically N = {1, 2, 3}. Therefore, the value of N can be variably applied to each subframe depending on the amount of control information to be transmitted in the current subframe. The transmitted control information may include a control channel transmission interval indicator indicating how many OFDM symbols to transmit control information, scheduling information about downlink or uplink data, and information about HARQ ACK / NACK.

[0218] In LTE systems, scheduling information for downlink or uplink data is delivered from the BS to the UE via downlink control information (DCI). DCI is defined according to various formats and can vary depending on the format, indicating whether the information is scheduling information for uplink data (UL grant) or downlink data (DL grant), whether the information is a compact DCI with a smaller control information size, whether spatial multiplexing using multiple antennas is applied, and whether the information is a DCI for power control, etc. For example, DCI format 1, i.e., scheduling control information for downlink data (DL grant), can contain at least one of the following control information.

[0219] - Resource Allocation Type 0 / 1 Flag: Indicates whether the resource allocation method is Type 0 or Type 1. In Type 0, resources are allocated in Resource Block Group (RBG) units using a bitmap method. In LTE systems, the basic unit of scheduling is an RB, represented as time-domain and frequency-domain resources. An RBG is configured with multiple RBs and becomes the basic unit of scheduling in the Type 0 method. In Type 1, a set number of RBs are allocated within an RBG.

[0220] - Resource Block Allocation: Indicates the Resource Blocks (RBs) allocated for data transmission. The represented resource is determined based on system bandwidth and resource allocation method.

[0221] - Modulation and coding scheme (MCS): Indicates the modulation scheme used for data transmission and the size of the transport block (TB) (i.e., the data to be transmitted).

[0222] -HARQ procedure number: The procedure number indicating the HARQ.

[0223] - New data indicator: Indicates whether the transmission is a HARQ initial transmission or a retransmission.

[0224] - Redundant version: Indicates a redundant version of HARQ.

[0225] - Transmission Power Control (TPC) Commands for Physical Uplink Control Channel (PUCCH): Indicates the transmission power control commands used for PUCCH (i.e., the uplink control channel).

[0226] DCI can be transmitted via channel coding and modulation processes on the Physical Downlink Control Channel (PDCCH) (or control information, and they are used interchangeably below) or the Enhanced PDCCH (EPDCCH) (or enhanced control information, and they are used interchangeably below) (i.e., the downlink physical control channel).

[0227] Typically, for each UE, the DCI is scrambled independently using a given Radio Network Temporary Identifier (RNTI) (or UE ID). After Cyclic Redundancy Check (CRC) is added to the DCI and it undergoes channel coding, the DCI can be configured with each independent PDCCH and transmitted. In the time domain, the PDCCH is mapped and transmitted during the control channel transmission interval. The frequency domain mapping position of the PDCCH can be determined by each UE's ID and can be spread and transmitted throughout the entire system transmission bandwidth.

[0228] Downlink data can be transmitted on the Physical Downlink Shared Channel (PDSCH) (i.e., the physical channel used for downlink data transmission). The PDSCH can be transmitted after the control channel transmission interval. Based on the DCI transmitted via the PDCCH, the detailed mapping position of the PDSCH in the frequency domain and scheduling information such as the modulation scheme are determined.

[0229] The BS informs the UE of the modulation scheme applied to the PDSCH to be transmitted and the size of the data to be transmitted (Transmission Block Size (TBS)) by configuring the MCS in the DCI control information. In one embodiment, the MCS may be configured with 5 bits or more or less. The TBS corresponds to the size before the channel coding for error correction is applied to the data transmission block (TB) to be transmitted by the BS.

[0230] The modulation schemes supported in LTE systems include Quadrature Phase Shift Keying (QPSK), Quadrature Amplitude Modulation (16QAM), and 64QAM. The modulation order (Qm) corresponds to 2, 4, and 6, respectively. That is, in the case of QPSK modulation, 2 bits can be transmitted per symbol; in the case of 16QAM, 4 bits can be transmitted per symbol; and in the case of 64QAM, 6 bits can be transmitted per symbol. Furthermore, depending on system modifications, modulation schemes of 256QAM or higher can be used.

[0231] Figure 2B This is a diagram illustrating the basic structure of the time-frequency domain (i.e., the radio resource region in which data or control channels are transmitted in the uplink) in an LTE-A system.

[0232] refer to Figure 2B The horizontal axis indicates the time domain, and the vertical axis indicates the frequency domain. The smallest transmission unit in the time domain is SC-FDMA symbol 2b-202, and N symb UL Several SC-FDMA symbols can be aggregated to configure a time slot 2b-206. Furthermore, two time slots are aggregated to configure a subframe 2b-205. The smallest transmission unit in the frequency domain is a subcarrier. The entire system transmission bandwidth 2b-204 is configured with a total of N... BW N subcarriers.BW It can have a value proportional to the system's transmission bandwidth.

[0233] In the time-frequency domain, the basic unit of a resource is a resource element (RE) 2b-212, which can be defined as an SC-FDMA symbol index and subcarrier index. Resource block pairs (RB pairs) 2b-208 can be defined as N in the time domain. symb UL A consecutive SC-FDMA symbol and N in the frequency domain SC RB N consecutive subcarriers. Therefore, an RB is configured with N symb UL ×N SC RB One RE. Typically, the smallest unit of transmission for data or control information is the RB unit. The PUCCH is mapped to the frequency domain corresponding to one RB and transmitted during one subframe.

[0234] In LTE systems, the timing relationship between PDSCH (i.e., the physical channel for downlink data transmission), PUCCH, or PUSCH (i.e., the uplink physical channel in which HARQ ACK / NACK corresponding to PDCCH / EPDDCH containing semi-persistent schedule release (SPS release) is transmitted) can be defined. For example, in an LTE system operating under Frequency Division Duplex (FDD) conditions, the HARQ ACK / NACK corresponding to the PDSCH transmitted in the (n-4)th subframe or the PDCCH / EPDCCH containing SPS release can be transmitted as PUCCH or PUSCH in the nth subframe.

[0235] In LTE systems, downlink HARQ employs an asynchronous HARQ method with variable data retransmission timing. That is, when the UE receives a HARQ NACK feedback for the initial transmission data sent by the BS, the BS freely determines the transmission timing of the retransmitted data based on scheduling operations. As the decoding result of the data received in response to the HARQ operation, the UE can buffer data identified as erroneous and can execute a combination with the next retransmitted data.

[0236] When the UE receives a PDSCH containing downlink data transmitted by the BE in subframe n, the UE transmits uplink control information containing downlink data, either HARQ ACK or NACK, to the BS via PUCCH or PUSCH in subframe n+k. In this case, k can be defined differently depending on the LTE system's FDD or Time Division Duplex (TDD) configuration and its subframe configuration. For example, in an FDD LTE system, k is fixed at 4. In a TDD LTE system, k can be changed depending on the subframe configuration and subframe number. Furthermore, when data transmission is performed over multiple carriers, the value of k can be applied differently based on the TDD configuration of each carrier.

[0237] In LTE systems, unlike downlink HARQ, uplink HARQ employs a synchronous HARQ method with fixed data transmission timing. That is, the uplink / downlink timing relationship between the Physical Uplink Shared Channel (PUSCH) (i.e., the physical channel used for uplink data transmission), the PDCCH (i.e., the downlink control channel preceding the PUSCH), and the Physical Hybrid Indicator Channel (PHICH) (i.e., the physical channel in which downlink HARQ ACK / NACK corresponding to the PUSCH is transmitted) can be determined using the following rules.

[0238] When the UE receives a PDCCH containing uplink scheduling control information sent by the BS, or a PHICH in which the BS sends downlink HARQ ACK / NACK in subframe n, the UE sends uplink data corresponding to the control information via PUSCH in subframe n+k. In this case, k can be defined differently depending on the FDD or Time Division Duplex (TDD) configuration of the LTE system. For example, in the case of an FDD LTE system, k can be fixed at 4. In the case of a TDD LTE system, k can be changed depending on the subframe configuration and subframe number. Furthermore, when data transmission is performed over multiple carriers, the value of k can be applied differently depending on the TDD configuration of each carrier.

[0239] Furthermore, when the UE receives a PHICH containing information related to downlink HARQ ACK / NACK from the BS in subframe i, the PHICH corresponds to the PUSCH sent by the UE in subframe ik. In this case, k can be defined differently depending on whether the LTE system is FDD or TDD and its configuration. For example, in the case of an FDD LTE system, k is fixed at 4. In the case of a TDD LTE system, k can be changed depending on the subframe configuration and subframe number. Moreover, when data transmission is performed over multiple carriers, the value of k can be applied differently depending on the TDD configuration of each carrier.

[0240] The wireless communication system has already been described based on the LTE system, and the content of this disclosure is not limited to the LTE system and can be applied to various wireless communication systems, such as NR and 5G. Furthermore, in one embodiment, if the content is applied to other wireless communication systems, FDD and the corresponding modulation scheme can be used to change the k value and apply it to the system.

[0241] Figure 2C and 2D The diagram illustrates the status of data allocation for eMBB, URLLC, and mMTC in frequency-time resources (i.e., services considered in 5G or NR systems).

[0242] from Figure 2C and 2D This shows the methods for allocating frequency and time resources for information transmission in each system.

[0243] first, Figure 2C This diagram illustrates the status of eMBB, URLLC, and mMTC data within the entire system frequency band 2c-300. If, while eMBB 2c-301 and mMTC 2c-309 are allocated and transmitted in a given frequency band, URLLC data 2c-303, 2c-305, and 2c-307 are generated and need to be transmitted, the portion of eMBB 2c-301 and mMTC 2c-309 already allocated can be empty or not transmitted, while URLLC data 2c-303, 2c-305, and 2c-307 can be transmitted. URLLC data (2c-303, 2c-305, and 2c-307) can be allocated to a portion of the already allocated and transmitted eMBB resource 2c-301 because it is necessary to reduce the latency incurred by URLLC during service. If URLLC is additionally allocated and transmitted within the already allocated eMBB resource, eMBB data can be avoided in redundant frequency-time resources. Therefore, it may reduce the transmission performance of eMBB data. In other words, in this situation, eMBB data transmission failure may occur due to URLLC allocation.

[0244] exist Figure 2D In this system, the entire 2D-400 frequency band can be divided and used to transmit services and data in subbands 2D-402, 2D-404, and 2D-406. Information related to subband configuration can be predetermined and transmitted from the BS to the UE via higher signaling. Alternatively, the BS or network node can randomly allocate subband-related information and assign services to the UE without transmitting individual subband configuration information. Figure 2DThe diagram shows the states where subband 2d-402 is used for eMBB data transmission, subband 2d-404 is used for URLLC data transmission, and subband 2d-406 is used for mMTC data transmission.

[0245] Throughout this embodiment, it can be assumed that the Transmission Time Interval (TTI) for URLLC transmission is shorter than the TTI for eMBB or mMTC transmission, but the TTI length for URLLC transmission can be the same as the TTI length for eMBB or mMTC transmission. Furthermore, responses to information related to URLLC can be transmitted faster than responses to information related to eMBB or mMTC. Therefore, information can be sent and received with low latency.

[0246] The eMBB service described below is referred to as a first type service, and the eMBB data is referred to as first type data. The first type service or first type data is not limited to eMBB and can correspond to situations requiring high-speed data transmission or broadband transmission. Furthermore, the URLLC service is referred to as a second type service, and the URLLC data is referred to as second type data. The second type service or second type data is not limited to URLLC and can correspond to other systems requiring low latency or high reliability transmission, or other systems requiring both low latency and high reliability. Furthermore, the mMTC service is referred to as a third type service, and the mMTC data is referred to as third type data. The third type service or third type data is not limited to mMTC and can correspond to situations requiring low speed, wide coverage, or low power. Additionally, when describing embodiments, the first type service may or may not include the third type service.

[0247] The structure of the physical layer channel used for each type to transmit at least one of the three types of service, control information, or data can be different. For example, at least one of the transmission time interval (TTI) length, frequency resource allocation unit, control channel structure, and data mapping method can be different. In this case, three different types of service, control information, and data have been described, but more types of service, control information, and data may exist. In this case, the contents of this disclosure can be applied. Furthermore, in embodiments of this disclosure, based on the determination of those skilled in the art, without departing significantly from the scope of this disclosure, the control information and data used for service may not be divided and described, and this disclosure can be applied by considering the inclusion of control information in the data used for service.

[0248] To describe the methods and apparatus presented in one embodiment, the terms "physical channel" and "signal" from conventional LTE or LTE-A systems may be used. However, the content of this disclosure can be applied to wireless communication systems other than LTE and LTE-A systems.

[0249] As described above, the embodiments present detailed methods for defining the transmission and reception operations of a UE and a BS for first-type, second-type, and third-type services or data transmission, and for UEs operating within the same system where different types of services, control information, or data are scheduled. In this disclosure, first-type, second-type, and third-type UEs refer to UEs where first-type, second-type, and third-type services or data have been scheduled. In one embodiment, the first-type, second-type, and third-type UEs may be the same UE or different UEs. Furthermore, in this embodiment, for UEs supporting transmission and reception of one or more service types, the content of this disclosure can be applied to situations where at least one of the first-type, second-type, and third-type services operates in the same cell or carrier, or where each service type operates in different cells or carriers.

[0250] In the following embodiments, at least one of the uplink scheduling grant signal and the downlink data signal is referred to as the first signal. Furthermore, in this disclosure, at least one of the uplink data signal used for uplink scheduling configuration and the response signal (or HARQ ACK / NACK signal) used for the downlink data signal is referred to as the second signal. In one embodiment, among the signals from the BS to the UE, the signal awaiting a response from the UE may be the first signal, and the response signal from the UE corresponding to the first signal may be the second signal. Furthermore, in one embodiment, the service type of the first signal may be at least one of eMBB, URLLC, and mMTC, and the service type of the second signal may also correspond to that at least one.

[0251] In the following embodiments, the TTI length of the first signal is a time value associated with the transmission of the first signal and can indicate the length of time the first signal is transmitted. Furthermore, in this disclosure, the TTI length of the second signal is a time value associated with the transmission of the second signal and can indicate the length of time the second signal is transmitted. The TTI length of the third signal is a time value associated with the transmission of the third signal and can indicate the length of time the third signal is transmitted. Furthermore, in this disclosure, the transmission and reception timing of the first, second, or third signal pertains to when the UE transmits the first, second, or third signal, when the BS receives the first, second, or third signal, or when the BS transmits a response or feedback (e.g., ACK / NACK information) to the received signal. This information can be referred to as the transmission and reception timing of the first, second, or third signal. In this case, the first, second, or third signal can be considered as a signal for a first type of service, a second type of service, or a third type of service. In this case, at least one of the TTI lengths of the first, second, or third signal and the transmission and reception timings of the first, second, or third signal can be configured differently. For example, the TTI length of the first signal is the same as the TTI length of the second signal, but it can be configured to be longer than the TTI length of the third signal. As another example, the transmission and reception timing of the first or second signal is configured as n+4, but the transmission and reception timing of the third signal can be configured to be shorter than that transmission and reception timing, for example, n+2.

[0252] Furthermore, in the following embodiments, it is assumed that when the BS transmits the first signal in the nth TTI, and the UE transmits the second signal in the (n+k)th TTI, the timing at which the BS notifies the UE of transmitting the second signal is the same as the value k that the BS notifies the UE of. Alternatively, it is assumed that when the BS transmits the first signal in the nth TTI, and the UE transmits the second signal in the (n+t+a)th TTI, the timing at which the BS notifies the UE of transmitting the second signal is either previously defined or the same as the offset value a of the value t derived by the BS to the UE according to the previously defined method. In this case, the value of t can be predefined as various values ​​other than t=4 as described in this disclosure, or it can be derived using the previously defined method.

[0253] In addition to FDD and TDD systems, the techniques proposed in this disclosure can also be applied to new types of duplex modes (e.g., LTE frame structure type 3).

[0254] In the following description, within this disclosure, higher signaling refers to a method by which the BS transmits signals to the UE using the downlink data channel of the physical layer, or a method by which the UE transmits signals to the BS using the uplink data channel of the physical layer. Higher signaling may also be referred to as RRC signaling, PDCP signaling, or MAC control element (MAC CE).

[0255] In the following, in one embodiment of this disclosure, an uplink transmission resource allocation method for reducing the delay between uplink transmission configuration information transmission and configured uplink transmissions is described when providing one or more services including eMBB, mMTC, and URLLC to a UE. Furthermore, in one embodiment of this disclosure, a BS and UE performing uplink transmissions via a licensed band or an unlicensed band are assumed and described; however, embodiments of this disclosure can be applied regardless of whether the band is licensed or unlicensed.

[0256] Typically, the BS configures (schedules) a given Transmission Time Interval (TTI) and frequency resource area, enabling the UE to transmit uplink data or control information corresponding to eMBB, mMTC, URLLC, etc. For example, the BS can configure a given TTI and frequency resource area for a given UE in subframe n via the downlink control channel, allowing the UE to perform uplink transmission in subframe n+k (k ≥ 0). In other words, the BS can send uplink transmission configuration information to the UE, which needs to perform uplink transmission via the downlink control channel in subframe n. A UE that has received the uplink transmission configuration information can use the time and frequency resource area configured in the uplink transmission configuration information to send uplink data or control information to the BS (or another UE). In this case, a UE with data or control information to be transmitted via the uplink can send a scheduling request to the BS, or request the BS to send the uplink transmission configuration information to the UE through a random access procedure.

[0257] In other words, uplink transmission for a public UE can consist of the following three steps. This three-step uplink transmission is merely an example, and uplink transmissions with more or fewer steps than those described in this example are also possible.

[0258] Step 1: A UE having data or control information to be transmitted via the uplink requests uplink transmission configuration from the BS through valid uplink resources in which uplink transmission configuration requests can be transmitted. In this case, at least one of the time resources or frequency resources in which uplink transmission configuration can be requested can be predefined or configured via higher-layer signals.

[0259] Step 2: The BS, having received the uplink transmission configuration request from the UE, configures the uplink transmission by sending uplink transmission configuration information to the UE via the downlink control channel.

[0260] Step 3: UEs with uplink transmission configured by the BS use the uplink transmission configuration information configured by the BS to perform uplink transmission.

[0261] In other words, when a UE with data or control information to be transmitted via the uplink performs uplink information, a transmission delay of a given time or longer occurs. For example, in a UE with uplink transmission data at time n, if the uplink transmission configuration request resource is configured with a 5-millisecond cycle time, a maximum delay of 5 milliseconds may occur when transmitting the uplink transmission configuration request information. Furthermore, if a transmission delay (e.g., 1 millisecond) is required between the uplink configuration control information reception timing and the configured uplink transmission start time, a minimum transmission delay of 6 milliseconds or longer is unavoidable when the UE begins uplink transmission. In known LTE systems, the minimum transmission delay between the uplink configuration control information reception timing and the configured link transmission start time is 4 milliseconds. Therefore, this disclosure proposes a method to reduce uplink transmission delay by having the UE attempt to perform uplink signal transmission operations to perform uplink transmission without receiving separate uplink transmission configuration information from the BS.

[0262] Therefore, this disclosure describes a method for performing uplink transmissions without a separate uplink transmission configuration from the BS when the UE attempts to perform an uplink transmission, using radio resources previously configured by the BS or transmitted via a broadcast channel with higher-layer signals or system information (e.g., a system information block (SIB)). It also describes a method for changing pre-configured radio resources so that the BS can perform transmissions without uplink transmissions.

[0263] Typically, in uplink signal transmission within a UE, after receiving configuration or scheduling information about uplink transmission from the BS, the configured uplink transmission can be executed using the time and frequency resources configured by the BS through the UE's uplink transmission configuration information.

[0264] In BS and UE performing wireless communication in an unlicensed band—in other words, in BS and UE occupying the unlicensed band after performing a channel access procedure (or carrier sensing (LBT) or channel sensing) and being able to transmit signals as described above—UEs that have been configured for uplink transmission by the BS can perform a channel access procedure on the configured unlicensed band and can perform the configured uplink transmission only if it is determined that the unlicensed band is idle. Wireless communication operation in the unlicensed band is described in more detail below.

[0265] BS and UE performing wireless communication in unlicensed frequency bands may, after performing a channel access procedure, transmit or not transmit signals based on the result of the channel access procedure, which is predefined depending on the frequency band, country, etc., or defined in the wireless communication standard used by the corresponding BS and UE to coexist with other wireless devices. For example, the BS or UE needs to sense the channel for performing wireless communication during fixed intervals (or times) or time periods (or periods) that vary according to predetermined rules (e.g., measuring the strength of the received signal and comparing it to a threshold). If the channel is determined to be idle during the set time period (e.g., during this time period, when the strength of the signal received by the BS or UE (or the transmitting device) is less than a predefined or rule-set threshold), the BS or UE can use the channel to perform communication. If the channel is determined not to be idle during the set time period (e.g., during this time period, when the strength of the received signal is greater than a predefined or rule-set threshold), the BS or UE does not use the channel to perform communication. Therefore, the BS and UE performing uplink transmission through the three steps described above perform a channel access procedure for uplink control information and data transmission in steps 1 and 3. In step 2, the BS performs a channel access procedure for downlink transmission. Therefore, if the UE uses the method described above, which allows uplink transmission without receiving separate uplink transmission configuration information from the BS, to perform wireless communication over an unlicensed frequency band, the UE can perform uplink transmission more efficiently because it only requires a channel access procedure in step 3. In the following, in this disclosure, the UE performing uplink transmission without receiving separate uplink transmission configuration information from the BS, as described above, is referred to as unlicensed transmission. In this case, in addition to performing uplink transmission without the configuration of the entire uplink transmission configuration information from the BS, unlicensed transmission includes: at least one of a plurality of predefined configuration information regarding uplink transmission between the BS and the UE (e.g., some or all of the information regarding time or frequency resources enabling unlicensed transmission (e.g., start frequency information enabling unlicensed transmission)); configuration for the UE to receive information or to receive information from the BS via a higher-layer signal; configuration for the UE to receive system information transmitted via a broadcast channel sent by the BS or to receive system information from the BS; or configuration for the UE to receive information or to receive information from the BS via a downlink control channel.

[0266] A BS or UE operating in an unlicensed frequency band can perform different channel access procedures based on the uplink transmission method configured by the BS. The BS and UE (or transmission equipment operating in the unlicensed frequency band) need to perform channel sensing operations or channel access procedures on the unlicensed frequency band before transmitting downlink or uplink signals. In this case, the requirements for the channel access procedure may depend on predefined frequency bands, countries, etc., or may be defined in the corresponding wireless communication standard.

[0267] Typically, the channel access procedure in a transmission device attempting to transmit signals through an unlicensed frequency band includes the following steps: During a configuration period, the strength of the received signal in the unlicensed frequency band is measured according to predefined rules for the unlicensed frequency band where the signal will be transmitted. The availability of the unlicensed frequency band is checked by comparing the measured signal strength with a threshold configured according to the previously defined rules. When the received signal strength during the set time period is less than the configured threshold, the transmission device can determine that the unlicensed frequency band is idle and transmit the signal through the corresponding unlicensed frequency band. When the received signal strength during the set time period is greater than the configured threshold, the transmission device can determine that the unlicensed frequency band is occupied by another device and will not transmit the signal through the corresponding unlicensed frequency band. The channel access procedure can be repeated until the unlicensed frequency band is determined to be idle.

[0268] The UE can perform channel sensing operations when it attempts to transmit uplink signals over an unlicensed frequency band using at least one of the following methods.

[0269] - Method 1 (or Type 1): Uplink signal transmission after sensing unlicensed frequency band channels during a variable time period

[0270] - Method 2 (or Type 2): Uplink signal transmission after sensing unlicensed frequency band channels during a fixed time period

[0271] Method 3: Uplink signal transmission without channel sensing

[0272] A UE whose uplink signal transmission is configured in an unlicensed frequency band (as in Method 1) can perform channel sensing operations on the unlicensed frequency band in which uplink signal transmission is configured during a channel sensing period prior to the configured uplink signal transmission. In this case, the channel sensing period can be randomly selected during the UE's contention period or can be configured by the BS. Furthermore, the channel sensing period can include a fixed interval and one or more variable intervals. In this case, the channel sensing period can include variable intervals without a fixed interval, or it can include only a single variable interval. Furthermore, Method 1 is generally a method of continuously performing channel sensing operations on the unlicensed frequency band in which uplink signal transmission is configured at a given timing. In Method 1, for example, the channel sensing operation can be performed at a location where, for example, the channel sensing operation can be terminated immediately before the start of the first symbol transmitted as the channel sensing period transmission in the uplink subframe in which uplink signal transmission is configured, or the channel sensing operation can be performed at the start timing of the last OFDM symbol in the subframe preceding the uplink subframe in which uplink signal transmission is configured. In this scenario, a channel occupancy signal can be transmitted until the start of the first symbol transmitted in the uplink subframe in which uplink signal transmission has been configured. Furthermore, channel sensing operation can be performed in the first OFDM / or SC-FDMA symbol in the uplink subframe in which uplink signal transmission has been configured. In this scenario, channel sensing operation can be performed in the first OFDM / or SC-FDMA symbol in the configured uplink subframe. In the above scenario, channel sensing operation can be performed at a position immediately preceding the start of the second OFDM or SC-FDMA symbol in the uplink subframe, or at the start timing of the first OFDM or SC-FDMA symbol in a subframe of the uplink subframe in which uplink signal transmission has been configured. In this scenario, a channel occupancy signal can be transmitted immediately preceding the start of the second symbol transmitted in the uplink subframe in which uplink signal transmission has been configured.

[0273] A UE whose uplink signal transmission is configured in an unlicensed frequency band (as in Method 2) can perform channel sensing operations on the unlicensed frequency band where uplink signal transmission is configured during a fixed channel sensing period prior to the configured uplink signal transmission. In this case, when the end timing of the channel sensing operation is earlier than the transmission timing of the configured uplink signal, the UE can send an occupation signal to occupy the channel from the end timing of the channel sensing operation to the transmission timing of the uplink signal. In this case, if the channel sensing operation is terminated immediately before the transmission timing of the uplink signal, the occupation signal may not be sent. In this scenario, the occupation signal can be any of an implementation signal, a preamble signal (e.g., PRACH), or an SRS signal, which may be transmitted differently depending on the UE's implementation. Method 2 is a method for performing channel sensing operations on an unlicensed frequency band where uplink signal transmission is typically configured during a fixed channel sensing period at a fixed timing. In method 2, for example, the channel sensing operation can be performed at a position that terminates the channel sensing operation immediately before the start of the first symbol transmitted in the uplink subframe (in which uplink signal transmission has been configured), or at the start timing of the last OFDM symbol in the subframe preceding the uplink subframe in which uplink signal transmission has been configured. In this case, the channel occupancy signal can be transmitted only before the start of the first symbol transmitted in the uplink subframe in which uplink signal transmission has been configured. Furthermore, the channel sensing operation can be performed on the first OFDM / or SC-FDMA symbol in the uplink subframe in which uplink signal transmission has been configured. In the above case, the channel sensing operation can be performed at a position that can be terminated immediately before the start of the second OFDM or SC-FDMA symbol in the uplink subframe, or at the start timing of the first OFDM or SC-FDMA symbol in the subframe of the uplink subframe in which uplink signal transmission has been configured. In this case, the channel occupancy signal can be sent only at the moment before the start of the transmission of the second symbol in the uplink subframe that has been configured for uplink signal transmission.

[0274] In method 3, the UE transmits uplink signals in an uplink subframe in which uplink signal transmission is configured, without a separate channel sensing operation.

[0275] The BS can configure the UE's uplink transmission method through system information transmission via higher-layer signals or broadcast channels, or through downlink control channels. In this scenario, the UE's uplink transmission method can be divided into licensed transmission methods and unlicensed transmission methods. Licensed transmission methods are used when the UE receives uplink transmission configuration information from the BS and performs uplink transmission based on the received configuration. Unlicensed transmission methods are used when the UE performs uplink transmission even without receiving separate uplink transmission configuration information from the BS. In this case, the UE does not operate solely based on either licensed or unlicensed transmission methods, but it can support both. For example, when a UE configured with unlicensed transmission methods receives uplink transmission configuration information from the BS via the downlink control channel, the UE can perform uplink transmission using the most recently received uplink transmission configuration information from the BS, according to the licensed transmission method. In this case, the UE can perform uplink transmission using only some of the most recently received uplink transmission configuration information from the BS.

[0276] The BS can configure the uplink transmission method relative to the UE within the BS or cell via higher-layer signals. The method for the BS to configure the UE's uplink transmission method relative to the UE via higher-layer signals is as follows: The BS can configure the cell's uplink transmission method as an unlicensed transmission method relative to the UE by adding a field regarding the UE's uplink transmission method to the RRC configuration information (e.g., an unlicensed UL transmission field) for a given BS or cell (or SCell or Transmit and Receive Point (TRP)) and setting the field value to true. In this case, a UE that has received a false RRC field value can determine that the cell's uplink transmission method is configured as a license-based transmission method for receiving uplink control information from the BS and transmitting uplink control information. The classification of RRC fields and uplink transmission methods is merely an example, but this disclosure is not limited thereto.

[0277] A BS (Base Station) can transmit uplink transmission methods in a BS or cell to one or more UEs via a broadcast channel, using system information. In this scenario, the BS uses a broadcast channel to transmit or configure uplink transmission methods relative to a UE via system information transmission, as follows: The BS or cell (or SCell or Transmit and Receive Point (TRP)) can periodically or non-periodically transmit (or broadcast) information about the corresponding cell's system information (e.g., Master Information Block (MIB) or System Information Block (SIB)) to one or more UEs. In this scenario, a broadcast channel means a channel that can be received by multiple UEs via a previously defined single identifier (e.g., System Information RNTI). In this scenario, in addition to the configuration of the uplink transmission methods for the cell, the system information may also include configuration information about unlicensed transmission methods, such as at least one of time and frequency resource information with unlicensed transmission capability. If the uplink transmission method of the cell is configured as a license-based transmission method, it may not include time and frequency resource information with unlicensed transmission capability, or even if time and frequency resource information is included, the UE may ignore time and frequency resource information with unlicensed transmission capability.

[0278] The BS can configure the UE's uplink transmission method through its downlink control channel. The method by which the BS configures the UE's uplink transmission method through its downlink control channel is as follows: The BS can add an uplink transmission method field to the control channel and transmit it in the common control channel (or cell-specific search space) or group common control channel (or group-specific search space) within the BS's downlink control channel that configures the UE's uplink transmission method. In this case, the common control channel or group common control channel means that all UEs in a given group or group receive the same control information (hereinafter, common control information) from the BS through an identifier previously defined in the given UE and configured by the BS (e.g., group RNTI or CC-RNTI). For example, the BS can configure the uplink transmission method of UEs included in a group by adding a field about the group's uplink transmission method to the information about uplink transmission transmitted in the group common control channel. For example, when a field is set to 1 by adding an uplink transmission method or type field or a field that transmits information about the existence of uplink transmission configuration (e.g., a 1-bit field), a UE that has received a control channel can perform uplink transmission to the BS or cell as an unlicensed transmission method. In this case, when the field is set to 0, a UE that has received a control channel can perform uplink transmission to the BS or cell as a licensed transmission method. In this case, the added field and the method of configuring the field are merely examples and can be configured as a 1-bit or more-bit field. For example, the UE's uplink transmission method can be divided into an unlicensed transmission method, a licensed transmission method, and a mixture of unlicensed and licensed transmission methods by adding a 2-bit field.

[0279] A UE configured with the unlicensed transmission method described above for uplink transmission can select at least one of the variables related to uplink transmission (e.g., time resource region, frequency resource region, MCS, PMI, and RI), and can transmit that variable. For example, such as Figure 3EAs shown, a BS already configured with an unlicensed transmission method in the UE can use one of the various configuration methods described in the embodiments to configure periodic time resource area information with unlicensed uplink transmission capability in the UE. The UE can select variables that need to be configured additionally when performing uplink transmission, such as the frequency resource area where uplink transmission is actually performed, in addition to the configured time-domain information with unlicensed transmission capability, and can transmit variables. In this case, the BS can pre-configure candidate values ​​or set values ​​in the UE that can be selected from uplink transmission-related variables that can be selected by the UE, such as MCS sets (QPSK, 16QAM), frequency start area information with unlicensed transmission capability, and configuration values ​​that belong to the configured candidate group and can be used by the UE for uplink transmission. In this case, the example of previously configuring time resource areas and randomly selecting frequency resources is only one example, and the UE can select some or all variables required for uplink transmission, including variables other than those required for uplink transmission.

[0280] As described above, if at least one of the transmission configuration information for unlicensed transmission (e.g., time, frequency resource area, MCS, DMRS sequence, DMRS cyclic shift information, subframe structure with unlicensed transmission capability, or the number of symbols or minimum number of symbols for unlicensed transmission) is predefined between the BS and the UE, then the UE can be configured with this information or can receive this information through higher-layer signals transmitted by the BS, or the UE can be configured with this information by receiving system information (e.g., MIB) transmitted through a broadcast channel or through a downlink time channel (e.g., SIB) transmitted by the BS. The BS cannot dynamically change the configuration information related to unlicensed transmission (e.g., the 1-millisecond unit or minimum unit for transmitting data or control signals). For example, in a TDD-based system, if there is a UE configured for unlicensed transmission, the BS cannot dynamically change the uplink and downlink subframes based on the UE's unlicensed transmission configuration values. More specifically, assuming the BS has configured a time resource region in the UE capable of unlicensed transmission within a 10-millisecond cycle time via a higher-layer signal or SIB, the BS cannot use subframes of the resource region configured for uplink unlicensed transmission in the UE as downlink transmissions. Similarly, in a system operating in an unlicensed frequency band, assuming the BS has configured a time resource region in the UE capable of uplink unlicensed transmission via a higher-layer signal or SIB according to the BS's or UE's channel access procedure, the BS cannot effectively use the unlicensed transmission resources because it cannot predict the outcome of the BS and UE's channel access procedure. Therefore, this disclosure proposes various methods to effectively modify at least one of the multiple uplink unlicensed transmission information configured by the BS. By using at least one of the various methods proposed in this disclosure, the BS can more effectively use the unlicensed transmission resources configured in the UE and can control unlicensed transmission within the pre-configured unlicensed transmission resources.

[0281] In this disclosure, for ease of description, the smallest unit of downlink and uplink transmission between the BS and the UE is represented as a time slot. In other words, the BS can transmit the downlink control channel to the UE in each time slot. Furthermore, in this disclosure, for ease of description, the following describes the configuration and changes related to unlicensed transmission configuration information and time resources; however, the methods proposed in this disclosure can also be applied to the configuration and changes of information related to unlicensed transmission information, including frequency resources in addition to time resources. Moreover, the inventions proposed in Embodiments 2-1 and 2-2 are not limited to the individual embodiments and can be applied to the inventions proposed throughout this disclosure. In other words, some or all of the embodiments in Embodiment 2-1 and some or all of the embodiments in Embodiment 2-2 can be used to solve the problems to be solved in this disclosure.

[0282] [Example 2-1]

[0283] This embodiment relates to a method by which a BS notifies a UE via a downlink control channel whether unlicensed transmission in a time slot is permitted or information about time slots with unlicensed transmission capability can be provided.

[0284] A given UE, a group of UEs, or all UEs configured to perform unlicensed transmission by the BS can be notified of information about a time slot with unlicensed transmission capability via the downlink control channel in time slot n. More specifically, the BS can notify the given UE, the group of UEs, or all UEs configured to perform unlicensed transmission by the BS of information about a resource with unlicensed transmission capability in time slot n or a given time slot immediately preceding time slot n (e.g., a time slot immediately preceding time slot n with the nearest downlink control channel transmission capability), or time slot n and a time slot immediately preceding time slot n with the nearest downlink control channel transmission capability, using one of four methods. In this case, in addition to the selected method of these four types, at least one of these four types of methods can also be used to notify the UE of information about a resource with unlicensed transmission capability.

[0285] Method 1) Time slot (time slot n), where transmission is used to deliver a downlink control channel containing a common control signal indicating whether unlicensed transmission is feasible, or

[0286] Method 2) The subsequent k1 time slots (e.g., from time slot n to time slot n+k1) include time slots in which downlink control channels for delivering common control signals containing whether unlicensed transmission is feasible, or

[0287] Method 3) In the time slot following k2 (e.g., time slot n+k2), a downlink control channel is transmitted to deliver a common control signal containing whether unlicensed transmission is feasible, or

[0288] Method 4) The subsequent k1 time slots (from time slot n+k2 to time slot n+k2+k1), including time slots after k2, transmit downlink control channels for delivering common control signals indicating whether unlicensed transmission is feasible. For at least one of these four methods, the UE that has received control information can be notified of time slots with unlicensed transmission capability. In this case, k1 can be applied to k1 consecutive time slots or k1 discontinuous time slots. In other words, in the case of consecutive time slots, k1 time slots mean k1 consecutive time slots, regardless of the configuration for the transmission direction of the time slots; that is, regardless of whether k1 time slots are downlink transmission time slots or uplink transmission time slots. In this case, the UE does not perform unlicensed transmission on time slots that are configured to have unlicensed transmission capability and on time slots determined to be downlink transmission time slots by blind detection of the downlink control channel received from the BS or by reference signals. In the case of non-contiguous time slots, the UE may use only k1 time slots belonging to the time slot and determined as uplink transmission time slots, or may use only k1 time slots belonging to the time slots pre-configured by the UE as time slots with unlicensed transmission capability and time slots determined as uplink transmission time slots within the time slots.

[0289] If the UE has been configured with previously defined resources (or time slots) with unlicensed transmission capability, either through higher-layer signals from the BS or through the SIB, then when the UE receives information about the time slots (or resources) with unlicensed transmission capability from the BS via the downlink control channel as described above, the UE can compare the previously defined time slots with unlicensed transmission capability or those received through higher-layer signals or the SIB with the time slots with unlicensed transmission capability received from the BS via the downlink control channel, and can perform unlicensed transmission only on the two commonly configured time slots.

[0290] The k1 time slot used for unlicensed transmissions operating in unlicensed frequency bands can be a time slot on which the BS has actually performed downlink transmissions or simply on which the UE has actually performed uplink transmissions. That is, the time slot used for channel access procedures may not be included in the k1 time slot.

[0291] The UE can be configured with information about time slots capable of unlicensed transmission, or can receive information about time slots capable of unlicensed transmission, through a common control signal that can be transmitted by the BS via the downlink control channel. In this case, the information about time slots capable of unlicensed transmission can be transmitted from the BS to the UE through at least one method in a 1-bit field or bitmap within the common control signal. Method 4) is described using a bitmap. The BS can use k1 bits or a bitmap of length k1 in the common control signal to notify the UE whether unlicensed transmission of time slot k1 is feasible. Alternatively, the BS can send information about the start time slot and the last time slot capable of unlicensed transmission to the UE. In this case, at least one of four methods for notifying the UE of time slots capable of unlicensed transmission via the common control signal can be pre-defined between the BS and the UE, or the BS can select one of the four types and configure the selected method in the UE via a higher-layer signal.

[0292] [Example 2-2]

[0293] This embodiment relates to a method for a time slot with unlicensed transmission capability, whereby the UE determines whether unlicensed transmission is feasible, or relative to a situation where the BS does not notify the UE via the downlink control channel whether unlicensed transmission in the time slot is feasible or has unlicensed transmission capability.

[0294] The BS can configure a given UE, a group of UEs, or all UEs to enable unlicensed transmission of uplink transmission methods via system information (such as higher-layer signals or SIBs). In this scenario, the UE configured to perform unlicensed transmission can be configured with or can receive from the BS configuration information related to unlicensed transmission (e.g., time or slot information with unlicensed transmission capability, or cyclic time or frequency allocation information (RB or subband information or interleaving index information or symbol count for unlicensed transmission), or minimum symbol count for unlicensed transmission to determine the effective slot for unlicensed transmission, channel access procedure type, priority for the channel access procedure or DMRS sequence, cyclic shift and MCS information for unlicensed transmission, at least one of these) and system information (such as higher-layer signals or SIBs that perform configuration to enable unlicensed transmission methods), or via system information (such as higher-layer signals different from configuration information) or SIBs. In this scenario, at least one of the configuration information related to unlicensed uplink transmission can be configured as one or more values, a set, or a candidate set. For example, in the case of MCS, the BS can configure modulation candidate groups that can be used by the UE for unlicensed transmission. The UE can select a candidate group and perform unlicensed transmission. In the case of MCS, there is only one configuration piece of information related to unlicensed transmission that can be configured as a candidate group. This disclosure can also be applied to situations where the configuration values ​​required by the MCS to perform unlicensed uplink transmission are configured as candidate groups.

[0295] For example, an unlicensed transmission method has been configured in the UE (such as...). Figure 2E The BS (Base Station) configures periodic time resource area information or time slot information with unlicensed uplink transmission capability in the UE. If the UE needs uplink transmission in the configured time domain with unlicensed transmission capability, in addition to the configured time information, the UE can select variables that need to be configured when performing unlicensed uplink transmission (e.g., the frequency resource area and MCS where the actual uplink transmission is performed), and can perform unlicensed transmission. In this case, the UE is not configured with a periodic time resource area with unlicensed uplink transmission capability, but can be configured with an aperiodic time resource area. Furthermore, the frequency domain information with unlicensed transmission capability can be fixed or the same in the configured time resource area with unlicensed uplink transmission capability, or it can change according to the unlicensed uplink transmittable time resource area. In this case, the starting point of the unlicensed transmittable frequency domain can be fixed or the same in the configured time resource area with unlicensed uplink transmission capability. In other words, the frequency domain of unlicensed transmission can vary depending on the time domain of unlicensed transmission, but the starting point of the frequency domain of unlicensed transmission can be configured the same.

[0296] However, as mentioned above, in systems where downlink and uplink transmissions can be dynamically changed in time slots or multiple time slots or subframe units (hereinafter referred to as dynamic TDD systems), or in systems operating in unlicensed frequency bands, the BS can use pre-configured unlicensed transmission areas for downlink information transmission. Specifically, the BS can use at least some of the time and frequency resource areas pre-configured as unlicensed transmission areas for downlink control information transmission or downlink data information transmission to transmit downlink control information, such as synchronization signals, system information, or reference signals. Therefore, if the BS performs downlink signal transmission in a pre-configured unlicensed transmission area or time slot, and a UE configured with unlicensed transmission performs unlicensed uplink transmission, downlink and uplink signal transmission and reception cannot be performed correctly.

[0297] Typically, downlink control information transmission from the BS is more important than unlicensed uplink transmission from the UE. As mentioned above, UEs configured to perform dynamic TDD operation or configured to transmit downlink and uplink information from the BS in unlicensed frequency bands need to determine the feasibility of unlicensed transmission in the corresponding time slot before unlicensed transmission.

[0298] The method used by the UE to determine whether unlicensed transmission in time slot n is feasible is as follows.

[0299] Method 1: When the UE receives time slot structure information about one or more time slots from the BS, it determines whether unlicensed transmission is feasible based on the received time slot structure information.

[0300] Method 2: When information configured by the BS regarding the downlink control signal transmission time or time slot exists, determine whether unlicensed transmission is feasible based on the configured downlink control signal transmission time information.

[0301] Method 3: Determine whether unlicensed transmission is feasible after performing the channel access procedure in all time slots, regardless of whether the time slot is configured as an uplink transmission time slot or a downlink and uplink transmission time slot.

[0302] Method 1 is described in more detail below. The BS can transmit common control information to one or more UEs, a group of UEs, or all UEs in time slot n via a common control channel through a downlink control channel. When the common control information receives time slot structure information about one or more time slots, such as the transmission architecture for time slot n or time slot n+1 or time slot n and n+1 (e.g., at least one number of symbols or downlink transmission symbols or uplink transmission symbols or the number of symbols in the guard period or the number of symbols in which uplink control signals are transmitted or the length of the configuration information of the corresponding time slot configuration) or information about the transmission direction (downlink or uplink or empty subframe or unknown time slot or subframe), the UE can determine whether to perform unlicensed transmission in time slot n based on the received information.

[0303] The following describes a detailed example. In a UE that has received configuration information about time slot n transmitted via common control information, if time slot n has been configured as an uplink transmission time slot, or if the number of valid uplink data transmission symbols in time slot n configured via common control information is equal to or greater than the number of symbols for unlicensed transmission pre-configured via unlicensed transmission configuration information, or if the number of valid uplink data transmission symbols in time slot n is greater than a given threshold pre-configured via unlicensed transmission configuration information, then the UE may perform unlicensed transmission. If time slot n has been configured as a downlink transmission time slot, or if the number of valid uplink data transmission symbols in time slot n configured via common control information is less than the number of symbols for unlicensed transmission pre-configured via unlicensed transmission configuration information, or if the number of valid uplink data transmission symbols in time slot n is less than a given threshold pre-configured via unlicensed transmission configuration information, then the UE may not perform unlicensed transmission.

[0304] Another example is described below. The BS can send time slot structure information (e.g., at least one number of symbols, downlink transmission symbols, uplink transmission symbols, or the number of symbols in a guard period, or the number of symbols in which uplink control signals are transmitted, or the length of configuration information corresponding to the time slot configuration) or transmission direction information (downlink, uplink, empty subframe, unknown time slot, or subframe) to one or more UEs via the common control channel in time slot n. For example, the BS can notify the UE in time slot n via common control information that time slots n and n+1 are downlink transmission time slots, and time slots n+k to n+k+m are uplink transmission time slots. In this case, an uplink transmission time slot means a licensed uplink transmission time slot (hereinafter referred to as an uplink transmission time slot) in which a UE that has received uplink control information (UL license) from the BS performs uplink transmission based on the received UL license information. In this scenario, a UE configured for unlicensed transmission can determine, based on common control information, that a time slot other than the following time slots is a time slot with unlicensed transmission capability: a downlink or uplink transmission time slot, or a time slot between a downlink transmission time slot and an uplink transmission time slot notified via common control information, or a time slot before the uplink transmission start time slot following the last downlink transmission time slot in the downlink transmission time slots notified via common control information. In this scenario, if a time slot determined to be a time slot with unlicensed transmission capability is determined to be a time slot configured for downlink transmission through at least one of system information (such as higher-layer signals, MIB, and SIB), common control information, or information on candidate time slots with downlink transmission capability, then the UE may not perform unlicensed transmission in that time slot. An LTE system is described in more detail as an example. The BS can transmit at least one of the following to the UE in subframe n via a common control channel (DCI scrambled with Group-RNTI or CC-RNTI): downlink transmission subframe information, start subframe information regarding the start of uplink subframes, and uplink subframe time information. In this case, the common control information transmitted in subframe n indicates, in addition to information related to the signal transmission direction (downlink or uplink), the number of symbols used for downlink signal transmission in one or more downlink subframes (e.g., subframe n+1) containing subframe n. Furthermore, the common control information may include the initial uplink transmission subframe (uplink subframe offset) and uplink transmission subframe time information based on the subframe n in which the common control information is transmitted. In this case, the UE can determine that subframes with unlicensed transmission capability are those following the last downlink transmission subframe in the downlink transmission subframe information transmitted from the common control information, and those preceding the first uplink transmission subframe transmitted from the common control information.

[0305] If, as described above, an unlicensed transmission slot is determined based on downlink and uplink transmission slot information without any indicator information regarding unlicensed transmission slots, the common control information (CCI) contains information about one uplink transmission slot. Therefore, in this scenario, although the BS does not attempt to perform licensed transmissions, it inevitably provides notification that at least one slot is a licensed uplink transmission slot. In other words, at least one slot cannot be used for at least one unlicensed uplink transmission. To address this issue, the BS can notify the UE configured for unlicensed transmission that some or all of the uplink transmission slots transmitted via the CCI are slots with unlicensed transmission capability or valid unlicensed transmission slots by adding a new field (e.g., a 1-bit unlicensed indication or autonomous UL indication) to the CCI. For example, if a new 1-bit string is added to the CCI, and the bit information is set to 0, the UE will not perform unlicensed transmissions in any of the uplink transmission slots indicated in the CCI. If the bit information is set to 1, the UE can determine that it can perform unlicensed transmission in all uplink transmission slots indicated in the common control information. If a new 2-bit bit string has been added to the common control information, and the bit information is set to 00, the UE can determine that it does not perform unlicensed transmission in all uplink transmission slots indicated in the common control information. If the bit information is set to 11, the UE can determine that it can perform unlicensed transmission in all uplink transmission slots indicated in the common control information. If the bit information is set to 01 or 10, the UE can determine that it can perform unlicensed transmission in some uplink transmission slots indicated in the common control information. In this case, the information about the slots in which unlicensed transmission can be performed can be predefined in the bit information 01 or 10, or the slot information corresponding to each bit information can be configured through higher-layer signals, or the information can be configured differently based on the uplink transmission slot period (or length). For example, a UE that has received bit information 01 can determine that it can perform unlicensed transmission in the first K or last K time slots of the indicated uplink transmission time slot period. A UE that has received bit information 10 can determine that it can perform unlicensed transmission in the first M or last K time slots of the indicated uplink transmission time slot period.

[0306] In this scenario, compared to the above scenario, based on the method previously defined between the BS and UE, or the method configured by the BS via higher-layer signals, even without adding new fields to the common control information (e.g., a 1-bit unlicensed indication or an autonomous UL indication), a time slot can be determined as a time slot with unlicensed transmission capability or an unlicensed transmission valid time slot. For example, if the BS sends information to the UE regarding a subframe or time slot with uplink transmission capability via the UL duration and offset fields in the common control information, then when the UL duration indication X (e.g., X = 1), the UE, having received this information, can perform unlicensed transmission during the uplink transmission subframe or time slot period transmitted via the common control information. When the UL duration is greater than X, the UE does not perform unlicensed transmission during the uplink transmission subframe or time slot period transmitted via the common control information. In this scenario, the UE can be configured to perform or not perform unlicensed transmission during the uplink transmission subframe or time slot period transmitted via the common control information and at the X value, based on the X value from the higher-layer signals from the BS.

[0307] In this scenario, if the BS sends information to the UE regarding subframes or time slots with uplink transmission capability via the UL duration and offset fields in the common control information, the UE, having received this information, can determine that it can perform unlicensed transmission throughout the entire uplink transmission subframe or time slot period transmitted via the common control information. In this case, the UE can be configured, via higher-layer signals from the BS, to perform or not perform unlicensed transmission throughout the entire uplink transmission subframe or time slot period transmitted via the common control information.

[0308] Method 2 is described in more detail below. The BS can configure information in the UE regarding the time slots in which downlink control signals (e.g., synchronization signals, system information (MIB and / or SIB), reference signals, and discovery signals) are transmitted, via higher-layer signals or other system information (MIB and / or SIB), or the time slots or times in which control signals are transmitted can be predefined between the BS and the UE. In this case, the discovery signal includes at least one synchronization signal. In this case, the frequency location, in addition to the timing of downlink control signal transmission, can be predefined or configured in the UE via higher-layer signals. For example, in current LTE FDD systems, the synchronization signal has been predefined to be transmitted in six RBs at the center of the system bandwidth in the sixth and seventh symbols of subframes 0 and 5. Furthermore, in current LTE FDD systems, the discovery signal can be transmitted in up to five consecutive subframes (e.g., in a 40-millisecond cycle time) with one synchronization signal (PSS / SSS) and five reference signals (CRS port 0). In this scenario, the UE is configured with discovery signal-related settings, such as discovery signal transmission cycle time and discovery signal transmission interval, via higher-layer signals from the BS.

[0309] Therefore, the UE can determine whether unlicensed transmission is feasible in time slot n by comparing the time and frequency domains (where downlink control signals previously defined or configured by the BS as described above are transmitted) with pre-configured time and frequency domains with unlicensed transmission capability. For example, if the time and frequency domains of downlink control signals previously defined between the UE and the BS as described above, or configured in the UE via higher-layer signals or system information from the BS, partially or entirely overlap with a region with unlicensed transmission capability, then the UE will not perform unlicensed transmission in the entire time and frequency domains where unlicensed transmission is configured, or can use the remaining regions other than the overlapping regions to perform unlicensed transmission. For example, if time slot n is a time slot previously defined for transmitting periodically transmitted downlink control signals (such as asynchronous signals or discovery signals), and if the UE is pre-configured to perform unlicensed transmission in time slots n-1, n, n+1, and n+2, then the UE does not perform unlicensed transmission in all time slots of n-1, n, n+1, and n+2, or it can perform unlicensed transmission in time slots n-1, n+1, and n+2 other than time slot n in which downlink control signals are transmitted. As another example of method 2, uplink unlicensed transmission can be performed in time slots following those in time slots n-1, n, n+1, and n+2, which are pre-configured for unlicensed transmission and are subsequently used for transmission of the BS's downlink control signals. This method is effective for systems operating in unlicensed frequency bands. That is, in the case of unlicensed frequency bands, the actual transmission timing of the BS's downlink control channel can vary depending on the outcome of the channel access procedure. In other words, the BS can transmit control signals (e.g., discovery signals) in time slot n-1 or time slot n+1 instead of time slot n. In the above scenario, the BS's control information transmission is relatively more important than the UE's unlicensed transmission. Therefore, if the BS's downlink control signal transmission area and the BS's unlicensed transmission area overlap as described above, the UE can perform unlicensed transmission after the time slot in which the BS's downlink control signals are transmitted. In this case, in other words, the UE can determine the time or time slot after receiving the downlink control signal transmitted by the BS as the interval with unlicensed transmission capability and can perform unlicensed transmission. The above example is described in more detail. The UE can be configured with information about time, time slot, or subframe (where downlink control signals (such as synchronization signals or discovery signals) can be transmitted from the BS via higher-layer signals), or this information can be predefined between the BS and the UE. The discovery signal is described as an example.The BS can configure discovery signal configuration (discovery signal measurement timing configuration (DMTC)) information in the UE, which includes timing information for transmitting discovery signals via higher-layer signals (at least one of discovery signal transmission cycle time and period, discovery signal start timing (offset)). In this case, the BS can transmit the discovery signal within a time (slot or subframe) configured with a discovery signal configuration that has discovery signal transmission capability (e.g., 6 milliseconds). In this case, if the discovery signal is transmitted via an unlicensed frequency band, the BS can transmit the discovery signal within a subframe of the configured interval with discovery signal transmission capability. In other words, if the discovery signal is transmitted via an unlicensed frequency band, the transmission time of the discovery signal can vary based on the outcome of the channel access process within the configured discovery signal transmission interval. In this case, the BS's downlink control signal transmission is relatively more important than the UE's unlicensed transmission in the discovery signal. Therefore, the UE can determine that the entire discovery signal transmission interval configured by the BS is not valid for unlicensed transmission or can receive the discovery signal sent by the BS in the discovery signal transmission interval configured by the BS, can determine that unlicensed transmission is valid in the subsequent time (slot or subframe), and can perform unlicensed transmission.

[0310] In other words, the UE can determine the transmission interval of downlink control signals (e.g., periodically transmitted downlink control signals such as synchronization signals or discovery signals) previously defined with the BS or configured via higher-layer signals as an interval in which unlicensed transmission is invalid, and can not perform pre-configured unlicensed transmission, or can determine unlicensed transmission as valid in the remaining time interval of the downlink control signal transmission interval, excluding the time interval in which the downlink control signals are actually transmitted, and can perform unlicensed transmission. In this case, the UE can determine unlicensed transmission as valid in the remaining time interval after the time interval in which the downlink control signals are actually transmitted in the downlink control signal transmission interval, and can perform unlicensed transmission. In this case, the downlink control signals may include downlink control signals such as CSI-RS and phase tracking RS (PT-RS). In this case, unlicensed transmission can be rate-matched with the portion transmitting downlink control signals, or the portion transmitting downlink control signals during unlicensed transmission can be punctureed and transmitted.

[0311] Method 3 is described in more detail below. In this scenario, Method 3 can be applied to all systems operating in both licensed and unlicensed frequency bands. The channel access procedure in a system operating in a licensed frequency band can have one or more different configurations compared to the channel access procedure performed in an unlicensed frequency band. For example, in the channel access procedure in a licensed frequency band, the received signal threshold used to determine whether channel access is feasible can be set differently than in the unlicensed frequency band. Furthermore, the channel access procedure may include performing reference signal detection by the BS or UE. In this case, the UE can receive configuration information regarding channel access operation from the BS via unlicensed transmission configuration information.

[0312] In Method 3, the UE needs to perform a channel access operation in time slot n before executing unlicensed transmission. To determine the feasibility of unlicensed transmission through the channel access procedure as in Method 3, the position of the downlink signal transmission start timing or symbol in time slot n, the start timing or symbol of licensed uplink signal transmission and the license, and the start timing or symbol of unlicensed uplink signal transmission can be configured differently. For example, the downlink signal and licensed uplink signal transmission in time slot n can be configured to start at symbol index 0, and the unlicensed uplink signal transmission can be predefined or configured via downlink control signals to start at symbol index 1. In this case, the UE attempting to perform unlicensed uplink signal transmission performs a channel access operation before the unlicensed transmission begins, and can perform or not perform unlicensed transmission based on the result of the channel sensing operation. For example, when a given reference value or a larger received signal strength is measured during the channel sensing operation, the UE can determine that the time slot has been used for the BS's downlink or for another UE's licensed uplink transmission, and can choose not to perform unlicensed transmission. In other words, by configuring the start timing of unlicensed uplink signal transmission later than the start timing of downlink signal transmission and licensed uplink signal transmission as described above, there is an effect that unlicensed uplink transmission is not performed during the time (time slot or subframe) when transmitting downlink-based or licensed uplink signals. In this case, downlink signal transmission, licensed uplink signal transmission, and unlicensed uplink signal transmission can be classified as described above by differently configuring the configuration information (e.g., at least one of LBT priority, delay period, maximum contention window size (CWS), and CWS change requirements) of at least one of the channel access procedures for downlink signal transmission, licensed uplink signal transmission, and unlicensed uplink signal transmission (so that downlink transmission and licensed transmission are performed earlier than unlicensed transmission).

[0313] In this scenario, the timing or symbol position for performing channel access operations to determine the feasibility of unlicensed transmission can be predefined between the BS and UE, or the BS can deliver or configure the timing or symbol position to the UE via downlink control information. In this scenario, the BS can configure or instruct the UE to use the unlicensed uplink transmission start timing or symbol within the unlicensed transmission slot. For example, an unlicensed transmission in slot n can be configured to begin from the k-th symbol of slot n (e.g., symbol index #1). In this scenario, the UE can perform the channel access procedure before that k-th symbol. In this scenario, the position of the unlicensed transmission start symbol can be predefined, or it can be included in the unlicensed transmission configuration information and configured via higher-layer signals or SIBs. In this scenario, the position of the unlicensed transmission start symbol can be included in and transmitted via common control signals transmitted through the BS's downlink control channel. If the downlink signal transmission start timing and the license-based uplink transmission start timing are defined or configured as k-m1 and k-m2 respectively via higher-layer signals or SIBs (m1>0, m2>0, m1 and m2 can be the same or different), then a UE configured to perform unlicensed transmission in slot n can perform channel sensing operations in the band prior to the unlicensed transmission start timing (e.g., symbol k-1) in the region with unlicensed transmission capability, and can perform or not perform unlicensed transmission based on the result of the channel sensing operations.

[0314] Another example is described. The start symbol of the unlicensed transmission for the UE can vary depending on the channel access procedure that the UE needs to perform for the unlicensed transmission. For example, after the channel access procedure of method 1 (or type 1) for transmitting uplink signals, the start timing or symbol of the unlicensed transmission after sensing the unlicensed frequency band during a variable time period can be predefined or configured by higher-layer signals to be the time or symbol after the start timing or symbol of the unlicensed transmission after sensing the unlicensed frequency band during a fixed time interval, following the channel access procedure of method 2 (or type 2) for transmitting uplink signals, or it can be indicated based on downlink control information.

[0315] Typically, the scenario where the UE transmits uplink signals by executing a Type 1 channel access procedure corresponds to the scenario where the UE has already been configured or scheduled by the BS to transmit uplink signals by executing a Type 1 channel access procedure, but the BS is not occupying unlicensed frequency bands. In this case, the BS may be executing a channel access procedure for downlink signal transmission, or it may not be executing a channel access procedure, as downlink signal transmission is unnecessary. If a UE that has configured a time slot or subframe n for unlicensed transmission attempts to execute a Type 1 channel access procedure and performs unlicensed transmission, the BS's channel access procedure may fail due to the UE's unlicensed transmission when the BS executes the channel access procedure to transmit downlink signals in the time slot or subframe n. Typically, the BS's downlink signal transmission is given priority over the UE's unlicensed transmission. Furthermore, the BS's downlink signal transmission typically begins from the first symbol of the time slot or subframe. Therefore, to prevent the BS's channel access procedure from failing due to the UE's unlicensed transmission as described above, the UE's unlicensed transmission can begin after the first symbol of the time slot or subframe. For example, the start time of unlicensed uplink transmission can be configured as the second symbol of an uplink transmission slot or subframe, giving priority to downlink signal transmission or licensed uplink signal transmission by the BS. In other words, the start time of unlicensed uplink transmission sent by the UE through a Type 1 channel access procedure can be configured to be later than the start time of downlink signal transmission or licensed uplink signal transmission by the BS, thus giving priority to downlink signal transmission and licensed uplink signal transmission.

[0316] Typically, if a UE transmits uplink signals via a Type 2 channel access procedure, and if a BS occupies an unlicensed frequency band via a Type 1 channel access procedure and transmits or indicates an uplink transmission interval configured by the BS in the unlicensed frequency band (relative to the UE via the common control channel in the occupied unlicensed frequency band), and if the UE, having received uplink transmission interval information from the BS via the common control channel, performs uplink transmission within the configured uplink transmission interval, then the UE transmits uplink signals via a Type 2 channel access procedure. In this case, the uplink transmission interval information transmitted or indicated by the BS to the UE via the common control channel is based on licensed uplink transmission interval information. If the UE can determine the interval with unlicensed uplink transmission capability through downlink transmission interval information and license-based uplink transmission interval information transmitted in the common control channel (e.g., determining that the interval immediately following the uplink transmission interval starting from the last downlink transmission interval is an interval with unlicensed uplink transmission capability according to the method proposed in Method 1), then the interval with unlicensed uplink transmission capability does not conflict between the BS's downlink signal transmission and license-based uplink transmission and unlicensed uplink transmission. Therefore, the UE can use the Type 2 channel access procedure to perform unlicensed uplink signal transmission. In this case, the UE can receive information about the time period with unlicensed uplink transmission capability from the BS alone through the common control channel. In this case, the UE can use the Type 2 channel access procedure to perform unlicensed uplink signal transmission. In other words, in the interval with unlicensed uplink transmission capability configured or determined as described above, there is no conflict between the BS's downlink signal transmission and license-based uplink transmission and unlicensed uplink transmission. Therefore, the unlicensed uplink transmission start timing or symbol sent by the UE can be configured to be equal to or faster than the unlicensed uplink transmission start timing or symbol sent by the UE through a type 1 channel access procedure. For example, the start timing or symbol of the unlicensed transmission through a type 2 channel access procedure can be an uplink transmission slot or subframe boundary or the first symbol, or the unlicensed signal can be transmitted after the timing X required for performing the type 2 channel access procedure within the first symbol (e.g., X + timing adjustment (TA) value after the unlicensed signal transmission or 25 microseconds after the symbol 0 start time), and the unlicensed uplink transmission start time sent by the UE through a method 1 channel access procedure can be the second symbol of the uplink transmission slot or subframe.

[0317] In this scenario, the unlicensed uplink transmission start time or symbol sent by the UE through a Type 1 or Type 2 channel access procedure is merely an example. The unlicensed transmission start time or symbol sent by the UE through a Type 1 or Type 2 channel access procedure can be predefined between the BS and the UE, or the unlicensed transmission start time or symbol can be configured by higher-layer signals from the BS or indicated by downlink control information. In this scenario, the downlink control information can be downlink control information transmitted to activate at least one of the unlicensed transmissions of the UE configured by the BS through higher-layer signals, or it can be common control information transmitted through the downlink common control channel.

[0318] For example, the unlicensed transmission start time or symbol sent by the UE through a Type 1 channel access procedure can be predefined between the BS and the UE, or configured via higher-layer signals from the BS. The unlicensed transmission start time or symbol sent by the UE through a Type 2 channel access procedure can be indicated by the BS via downlink control information. In this case, the UE can apply the unlicensed transmission start time or symbol indicated in the most recently received downlink control information to the unlicensed transmission sent by the UE through a Type 2 channel access procedure. If the UE has already received one or more downlink control messages in the same time slot or subframe, the UE can apply the unlicensed transmission start time or symbol indicated in the common control information to the unlicensed transmission sent by the UE through a Type 2 channel access procedure. In this case, the unlicensed transmission start time or symbol sent by the UE through a Type 2 channel access procedure can be predefined between the BS and the UE, or configured via higher-layer signals from the BS. If the UE has been informed of the unlicensed transmission start time or symbol via downlink control information, the UE may apply the unlicensed transmission start time or symbol indicated in the most recently received downlink control information to unlicensed transmissions sent by the UE through a type 2 channel access procedure. If the UE has already received one or more downlink control messages in the same time slot or subframe, the UE may apply the unlicensed transmission start time or symbol indicated in the common control information to unlicensed transmissions sent by the UE through a type 2 channel access procedure.

[0319] In this scenario, the unlicensed transmission end time or end symbol, the time or symbol preceding the last symbol, time slot, or subframe in which the unlicensed transmission terminates, can be predefined differently depending on the type of signal access procedure, or can be configured by the BS. For example, an unlicensed transmission sent by the UE through a Type 1 channel access procedure can be predefined or configured by the BS such that it only transmits up to the symbol preceding the last symbol of the unlicensed transmission time slot or subframe. For example, in the case of a subframe containing 14 symbols, unlicensed transmission can be performed up to the 13th symbol (or symbol index 12) in the subframe. In this case, the last symbol (or symbol index 13) of the subframe can be used by the BS to perform a downlink channel access procedure, or by a UE configured with license-based uplink signal transmission to perform a channel access procedure. Unlicensed transmissions sent by the UE through a Type 2 channel access procedure can be configured by higher-layer signals for unlicensed transmission, or can be included in and indicated in an unlicensed transmission activation signal, or can be included in and indicated in common control information transmitted through the common control channel. For example, in the case of a subframe containing 14 symbols, unlicensed transmission can be performed up to the 13th symbol (or symbol index 12) in the subframe, or it can be configured or instructed to perform up to the 14th symbol (or symbol index 13) in the subframe. If the UE is indicated with an unlicensed transmission end time or symbol via downlink control information, the UE can apply the unlicensed transmission end time or symbol indicated in the most recently received downlink control information to the unlicensed transmission sent by the UE through a type 2 channel access procedure. If the UE has already received one or more downlink control messages in the same time slot or subframe, the UE can apply the unlicensed transmission end time or symbol indicated in the common control information to the unlicensed transmission sent by the UE through a type 2 channel access procedure. In this case, if the unlicensed transmission is a continuous transmission in two or more time slots or subframes, the start time or symbol of the unlicensed transmission is applied to the first time slot or subframe in which the unlicensed transmission is performed, and the end time or symbol of the unlicensed transmission is applied to the last time slot or subframe in which the unlicensed transmission is performed.

[0320] The following describes the process described in this disclosure. Figure 2FThe proposed method for configuring unlicensed uplink signal transmission resources for a BS (Base Station). In operation 2f-601, the BS can configure one of the uplink transmission methods (e.g., licensed uplink transmission, unlicensed uplink transmission, or a combination of licensed and unlicensed uplink transmission methods) for uplink transmission of the BS or cell in the UE via at least one of higher-layer signals, a broadcast channel, or a downlink control channel. In operation 2f-602, the BS can configure additional variables required for uplink transmission based on the uplink transmission method configured in operation 2f-601. For example, the BS can use at least one of higher-layer signals, a broadcast channel, or a downlink control channel to send configuration information about at least one of the time resource region and frequency resource region in which the configured unlicensed uplink transmission can be performed to the UE configured with the unlicensed uplink transmission method, or configure it in the UE. In this case, operation 2f-602 can be included in operation 2f-601 and can be configured or transmitted to the UE. In Operation 2f-602, in addition to the time and frequency resource areas, some or all of the variables required for the uplink transmission configuration can be configured, including the MCS, information (cyclic shift), and the TTI length that the UE can use for unlicensed uplink transmission, DMRS-related information for unlicensed transmission, the unlicensed transmission start symbol within the time slot, channel access procedure-related configuration information for unlicensed transmission, or candidate values ​​that the UE can select relative to the variable values. In this case, if the uplink transmission configuration is for unlicensed frequency bands, then in Operation 2f-602, the BS can configure the variables related to the uplink channel access procedure differently depending on the uplink transmission method configured in Operation 2f-601. If downlink control signal or downlink data signal transmission is required in the unlicensed transmission resource area configured by the BS in operation 2f-603, or if it is determined that licensed uplink transmission is necessary, then in operation 2f-605, the BS can configure the corresponding time slot so that the common control information transmitted through the downlink control channel is not used as an unlicensed time slot, or it can reconfigure resources with unlicensed transmission capability.

[0321] The following describes the application of this disclosure. Figure 2GThe proposed method is a channel access procedure configuration method based on the UE's uplink signal transmission method. In operation 2g-701, the UE can configure one of the uplink transmission methods (e.g., licensed uplink transmission, unlicensed uplink transmission, or a combination of licensed and unlicensed uplink transmission) for uplink transmission to the BS or cell via at least one method from higher-layer signals, broadcast channels, or downlink control channels. In operation 2g-702, the UE can further configure variable values ​​required for uplink transmission based on the uplink transmission method configured from the BS in operation 2g-701. For example, a UE configured with an unlicensed uplink transmission method can be configured or can receive configuration information regarding at least one of a time resource region and a frequency resource region, in which unlicensed uplink transmission configured by the BS can be performed. In this case, operation 2g-702 can be included in operation 2g-701 and configured from the BS. In this scenario, during Operation 2g-702, in addition to configuring time and frequency resource areas, the UE can configure some or all of the variables required for uplink transmission configuration. These variables include the MCS, information (cyclic shift), and TTI length that the UE can use for unlicensed uplink transmission, DMRS-related information for unlicensed transmission, the unlicensed transmission start symbol within the time slot, channel access procedure-related configuration information for unlicensed transmission, or candidate values ​​for variable values ​​that the UE can select. In this scenario, at least one of the variables related to the uplink channel access procedure configured in Operation 2g-702 can be configured differently based on at least one of the uplink transmission method, uplink transmission frequency band, or frame structure type of the frequency band in which uplink transmission is performed, configured in Operation 2g-701. If the uplink transmission method configured by the BS in operation 2g-701 and determined in operation 2g-703 is a licensed method, then in operation 2g-704, in addition to the uplink transmission method configured in operation 2g-702, the UE may receive some or all of the uplink transmission methods or all the configurations required for uplink transmission configured in operation 2g-702, or may receive uplink configuration information in which at least one variable value received in operation 2g-702 is configured as a new variable value via the BS's downlink control channel. In operation 2g-703, the UE may determine whether unlicensed transmission is feasible in time slot n based on the uplink transmission method received from the BS. If unlicensed transmission is determined to be feasible in time slot n in operation 2g-703, then in operation 2g-704, the UE may perform uplink transmission using a pre-configured unlicensed uplink transmission configuration. In this case, the UE can select some variables required for uplink transmission.For example, if in operation 2g-703 it is determined that unlicensed transmission in time slot n is not feasible, then if time slot n is used for downlink signaling or licensed uplink signaling, or if the channel access procedure has not been terminated, the UE may not perform unlicensed uplink signaling. If in operation 2g-705 the UE receives the uplink transmission configuration for time slot n via the BS's downlink control channel in time slot n or before time slot n—in other words, a UE configured with licensed uplink transmission in time slot n can perform uplink transmission in operation 2g-707 based on the newly received uplink transmission configuration from the BS's downlink control channel.

[0322] The following describes the application of this disclosure. Figure 2GAnother example of the proposed channel access procedure configuration method based on the UE's uplink signal transmission method. In operation 2g-701, the UE can be configured to use unlicensed uplink transmission to the BS or cell via at least one of higher-layer signals from the BS, a broadcast channel, or a downlink control channel. In this case, if the unlicensed uplink transmission is an activation signal for unlicensed transmission configured via the downlink control channel from the BS (e.g., upon receiving a DCI scrambled with a given RNTI, when the DCI indicates activation of unlicensed transmission), the corresponding method can be configured differently to perform unlicensed transmission or to perform unlicensed uplink transmission without receiving a separate activation signal. In operation 2g-702, the UE can be configured with the variable values ​​required for unlicensed uplink transmission configured from the BS in operation 2g-701. For example, in Operation 2g-702, a UE configured with an unlicensed uplink transmission method can be configured with time resource area information (at least one of unlicensed resource cycle time, offset, and time period information) from the BS, which allows for the execution of the configured unlicensed uplink transmission, and information about the frequency resource area via higher-layer signals from the BS. Additionally, in Operation 2g-702, the UE can be configured with Radio Network Temporary Identifier (RNTI) information (e.g., GF-RNTI) that scrambles downlink control information transmitted for unlicensed transmission activation. In Operation 2g-702, a UE configured with unlicensed uplink transmission in an unlicensed frequency band can also be configured with information about the channel access procedure, such as channel access procedure or type information and priority category, start / end time symbol information for the unlicensed uplink transmission, and at least one of information related to MCS, HARQ procedure ID, DMRS (e.g., cyclic shift, OCC), and transmit power control (TPC). If the configured unlicensed transmission requires receiving an unlicensed transmission activation indication signal from the BS, then at least one piece of configuration information can be included in and indicated in the unlicensed transmission activation indication signal. In this case, if the unlicensed transmission activation indication information includes information indicating the uplink transmission time (e.g., timing offset), and this information is not used to identify the validity of the unlicensed transmission activation, the UE can determine, based on the time it receives the unlicensed transmission activation indication information within the unlicensed transmission cycle time configured via higher-layer signals, to periodically configure the unlicensed transmission resources for a period after the indicated uplink transmission time. For example, if the UE receives the unlicensed transmission activation indication information at time n, and the value of the field indicating the uplink transmission time in the unlicensed transmission activation information indicates k, then the UE can determine that the unlicensed transmission resources have been configured according to the cycle time T configured via higher-layer signals starting from time n+k.For example, the UE can determine that times n+k, n+k+T, and n+k+2T will be configured as unlicensed transmission resources. The UE can determine that unlicensed transmission resources have been configured within this cycle time before receiving downlink control information in which resources indicate the release (or deactivation) of individual unlicensed transmissions. In this case, k can be used as an additional offset value, applied to an absolute value, a predefined value, or a configured value. In Operation 2g-703, having determined that time n (slot or subframe n) is the unlicensed uplink transmission slot or subframe configured from the BS in the above operation and that unlicensed transmission is necessary, the UE determines whether unlicensed uplink transmission can be performed within time n. In this scenario, if time n is not a downlink control signal transmission interval configured via a predefined downlink control signal or higher-layer signal from the BS, or if, during operation 2g-707, the UE receives time slot or subframe structure (e.g., the number and location information of downlink or uplink transmission symbols) or transmission direction information (e.g., downlink or uplink) regarding time n via the downlink control channel from the BS and determines based on this information that time n has been configured as an unlicensed uplink transmission interval, then the UE transmits unlicensed uplink signals using the unlicensed transmission configuration value configured via the higher-layer signal and the unlicensed transmission configuration value indicated by the unlicensed transmission activation signal. When the unlicensed transmission configuration value configured via the higher-layer signal and the unlicensed transmission configuration value indicated by the unlicensed transmission activation signal differ, the UE can perform unlicensed transmission based on the unlicensed transmission configuration value indicated by the unlicensed transmission activation signal. If time n is a downlink control signal transmission interval configured via a previously defined downlink control signal or a higher-layer signal from the BS, or if the UE receives slot or subframe structure information (e.g., the number and location information of downlink or uplink transmission symbols) or transmission direction information (e.g., downlink or uplink) about time n via the downlink control channel from the BS and determines based on the received information that time n is not configured as an unlicensed uplink transmission interval (e.g., if time n is a downlink transmission slot or a licensed uplink transmission slot), then the UE does not perform the configured unlicensed transmission. If the UE has already configured licensed uplink transmission in time n during operation 2g-705, then during operation 2g-707, the UE transmits uplink signals based on the licensed uplink transmission configuration configured in operation 2g-705. UEs that have not configured licensed uplink transmission in time n during operation 2g-705 do not perform uplink signal transmission in time n.In this scenario, if the UE has already determined in operation 2g-703 that time n has been configured as an unlicensed uplink transmission interval, but licensed uplink transmission has been configured in time n, then the UE will send uplink signals in time n according to the licensed uplink transmission configuration, and may not perform unlicensed transmission.

[0323] To implement the embodiments, each of the UE and BS may include a transmitter, a receiver, and a processor. Embodiments have shown transmission and reception methods for the BS and UE to determine the timing of transmission and reception of a second signal and perform corresponding operations. The transmitter, receiver, and processor can perform these operations. In one embodiment, the transmitter and receiver may be referred to as transceivers capable of performing all functions, and the processor may be referred to as a controller.

[0324] Figure 2H This is a block diagram illustrating the structure of a UE according to an embodiment.

[0325] refer to Figure 2H The UE disclosed herein may include a UE receiver 2h-800, a UE transmitter 2h-804, and a UE processor 2h-802. In one embodiment, the UE receiver 2h-800 and the UE transmitter 2h-804 may generally be referred to as transceivers. The transceivers can transmit signals to and receive signals from the BS. These signals may contain control information and data. For this purpose, the transceivers may be configured with an RF transmitter and an RF receiver, the RF transmitter being configured to up-convert and amplify the frequency of the transmitted signal, and the RF receiver being configured to amplify the received signal with low noise and down-convert the frequency, etc. Furthermore, the transceivers can measure the strength of the signal received via a radio channel and output the measured signal to the UE processor 2h-802. The UE processor 2h-802 can perform a channel access operation by comparing the strength of the received signal with a pre-configured threshold, and can transmit the signal output by the UE processor 2h-802 via the radio channel based on the result of the channel access operation. Furthermore, the transceiver can receive signals via a radio channel, transmit signals to the UE processor 2h-802, and also transmit signals output by the UE processor 2h-802 via a radio channel. The UE processor 2h-802 can control a series of processes to enable the UE to operate according to the embodiment. For example, the UE processor 2h-802 can control the UE receiver 2h-800 to receive a signal containing second signal transmission timing information from the BS and interpret the second signal transmission timing. Subsequently, the UE receiver 2h-804 can transmit the second signal at that timing.

[0326] Figure 2I This is a block diagram illustrating the structure of the BS according to an embodiment.

[0327] refer to Figure 2I In one embodiment, the BS may include at least one of a BS receiver 2i-901, a BS transmitter 2i-905, and a BS processor 2i-903. In one embodiment of this disclosure, the BS receiver 2i-901 and the BS transmitter 2i-905 may generally be referred to as transceivers. The transceivers can transmit signals to and receive signals from the UE. The signals may include control information and data. For this purpose, the transceivers may be configured with an RF transmitter and an RF receiver, the RF transmitter being configured to up-convert and amplify the frequency of the transmitted signal, and the RF receiver being configured to amplify the received signal with low noise and down-convert the frequency. Furthermore, the transceivers can receive signals via a radio channel, output signals to the BS processor 2i-903, and transmit signals output by the BS processor 2i-903 via a radio channel. The BS processor 2i-903 can control a series of processes that cause the BS to operate according to embodiments of this disclosure. For example, the BS processor 2i-903 can control the determination of a second signal transmission timing and generate second signal transmission timing information to be sent to the UE. Subsequently, the BS transmitter 2i-905 can send the timing information to the UE, and the BS receiver 2i-901 can receive the second signal at that timing. Alternatively, the BS processor 2i-903 can configure the UE's uplink transmission method, enabling it to use at least one of an unlicensed method or a licensed method. The BS transmitter 2i-905 can send configuration information about uplink transmission to the UE, which includes the uplink channel access procedure defined based on the configured uplink transmission method.

[0328] Furthermore, according to one embodiment of this disclosure, the BS processor 2i-903 can be controlled to generate downlink control information (DCI) that includes second signal transmission timing information. In this case, the DCI can indicate that it is second signal transmission timing information.

[0329] The embodiments of this disclosure disclosed in the specification and accompanying drawings have been suggested as examples to readily describe the technical content of this disclosure and aid in understanding it, and are not intended to limit the scope of this disclosure. That is, other modifications based on the technical spirit of this disclosure can be practiced, as will be apparent to those skilled in the art to which this disclosure pertains. Furthermore, embodiments can be combined and operated if desired. For example, embodiments of this disclosure can be combined so that the BS and UE operate based on them. Moreover, embodiments have been presented based on NR systems, and other modifications based on the technical spirit of the embodiments can be applied to other systems, such as FDD or TDD LTE systems.

[0330] Furthermore, preferred embodiments of this disclosure are disclosed in this specification and accompanying drawings. Although specific terms have been used, they are used in their ordinary sense to readily describe the technical content of this disclosure and aid in understanding it, but are not intended to limit the scope of this disclosure. Other examples of modifications based on the technical spirit of this disclosure are possible in addition to the disclosed embodiments, and will be apparent to those skilled in the art to which this disclosure pertains.

[0331] <Third Embodiment>

[0332] Wireless communication systems have deviated from providing initial voice-oriented services and evolved to provide high-speed, high-quality packet data services (e.g., communication standards such as 3GPP's High-Speed ​​Packet Access (HSPA), Long Term Evolution (LTE) or Evolved Universal Terrestrial Radio Access (E-UTRA), LTE-Advanced (LTE-A), LTE-Pro, 3GPP2's High-Speed ​​Packet Data (HRPD), IEEE's Ultra Mobile Broadband (UMB), and 802.16e's broadband wireless communication systems). Furthermore, 5G or New Radio (NR) communication standards are emerging as 5G wireless communication systems.

[0333] LTE systems (a representative example of broadband wireless communication systems) employ Orthogonal Frequency Division Multiplexing (OFDM) in the downlink (DL) and Single-Carrier Frequency Division Multiple Access (SC-FDMA) in the uplink (UL). The uplink refers to the radio link through which a terminal (or User Equipment (UE)) or mobile station (MS) transmits data or control signals to a base station (BS or eNode B). The downlink refers to the radio link through which the BS transmits data or control signals. This multiple access scheme is a method of allocating or managing time-frequency resources, on which each user carries data or control information to differentiate between user data or control information, ensuring that time-frequency resources do not overlap, i.e., establishing orthogonality.

[0334] When decoding failure occurs during the initial transmission, the LTE system employs a Hybrid Automatic Repeat Request (HARQ) scheme, retransmitting the corresponding data at the physical layer. According to the HARQ scheme, when the receiver fails to decode the data accurately, it sends a negative acknowledgment (NACK) to the transmitter, notifying it of the decoding failure, allowing the transmitter to retransmit the corresponding data at the physical layer. The receiver combines the retransmitted data with the previously failed data, thereby improving data reception performance. Furthermore, when the receiver decodes the data accurately, it sends an acknowledgment (ACK) to the transmitter, notifying it of successful decoding, allowing the transmitter to send new data.

[0335] In wireless communication networks containing multiple cells, transmit / receive points (TRPs), or beams, coordination between cells, TRPs, or beams can significantly impact the overall network transmission efficiency. For coordination between cells, TRPs, or beams, the UE needs to be able to perform channel and interference estimation across multiple cells, TRPs, or beams. Key scenarios considered in systems such as 5G / NR (New Radio, Next Radio) after LTE (e.g., indoor hotspots) typically involve high-density and highly integrated networks. Therefore, compared to LTE, the number of cells, TRPs, or beams that can be coordinated for a single UE increases, leading to increased complexity in channel and interference estimation.

[0336] This disclosure outlines a CSI framework for network coordination. First, it provides configuration and transmission methods for DL ​​CSI-RS, UL CSI-RS (SRS), and DMRS for effective channel estimation. The BS enables the UE to measure various channel conditions via multiple TRPs or beams based on these methods. Furthermore, this disclosure discusses interference measurement methods and channel state generation methods corresponding to various interference conditions. The BS can instruct the UE to generate CSI for network coordination based on channel and interference estimates and report it to the BS. Finally, a QCL signaling method is provided to support various coordination node geometries and dynamic transmission scheme changes.

[0337] More specifically, this disclosure provides methods for configuring, transmitting, and receiving RSs (such as downlink (DL) channel state information reference signals (CRI-RS), uplink (UL) CSI-RS or sounding reference signals (SRS), demodulation reference signals (DMRS)) capable of various channel and interference estimations across multiple cells, TRPs, or beams. The UE generates channel state information (CSI) for each network coordination scenario based on the estimated channel and interference information and reports it to the BS. In this scenario, the BS can signal the quasi-cooperative positioning (QCL) information provided in this disclosure to the UE to provide a standard for time / frequency offset correction of RSs transmitted peripherally in time / frequency resources (such as aperiodic RSs or subband RSs). The UE can appropriately improve channel estimation performance through each RS.

[0338] Figure 3A This is a diagram illustrating the downlink time-frequency domain transmission architecture of an LTE or LTE-A system based on conventional technology.

[0339] refer to Figure 3A The horizontal axis represents the time domain, and the vertical axis represents the frequency domain. The smallest transmission unit in the time domain is an OFDM symbol, N. symbOFDM symbols 3a-102 are aggregated to configure one time slot 3a-106, and two time slots are aggregated to configure one subframe 3a-105. The length of a time slot is 0.5 milliseconds, and the length of a subframe is 1.0 millisecond. Furthermore, radio frame 3a-114 is a time-domain segment configured with 10 subframes. The smallest transmission unit in the frequency domain is a subcarrier, and the bandwidth of the entire system transmission bandwidth is configured to a total of N. BW 3a-104 subcarriers.

[0340] In the time-frequency domain, the basic unit of a resource is a resource element (RE) 3a-112, which can be indicated by OFDM symbol indices and subcarrier indices. A resource block (RB) 3a-108 (or physical resource block (PRB)) can be defined as N in the time domain. symb A series of consecutive OFDM symbols 3a-102 and N in the frequency domain RB There are N consecutive subcarriers 3a-110. Therefore, an RB 3a-108 can contain N symb ×N RB Each RE 3a-112. Typically, the smallest frequency domain allocation unit for data is an RB. In LTE systems, typically N symb =7, N RB =12, and N BW and N RB The data rate is proportional to the system transmission bandwidth. The data rate increases proportionally to the number of RBs scheduled in the UE. LTE systems define and operate six transmission bandwidths. In the case of FDD systems, where downlink and uplink are divided and operated by frequency, the downlink and uplink transmission bandwidths can be different. Channel bandwidth indicates the RF bandwidth corresponding to the system transmission bandwidth. Table 3a shows the correspondence between channel bandwidth and system transmission bandwidth defined in LTE systems. For example, in an LTE system with a 10MHz channel bandwidth, the transmission bandwidth is configured with 50 RBs.

[0341] [Table 3a]

[0342]

[0343] Downlink control information is transmitted within the first N OFDM symbols of a subframe. Typically, N = {1, 2, 3}. Therefore, the value of N changes in each subframe depending on the amount of control information to be transmitted in the current subframe. The control information includes a control channel transmission interval indicator indicating how many OFDM symbols to transmit control information, scheduling information regarding downlink or uplink data, and information regarding HARQ ACK / NACK.

[0344] In LTE systems, scheduling information for downlink or uplink data is delivered from the BS to the UE via downlink control information (DCI). DCIs are defined in various formats, and the specific DCI format applied and operated depends on factors such as whether the information is scheduling information for uplink data (UL grant) or downlink data (DL grant), whether the information is a compact DCI with a small control information size, whether spatial multiplexing using multiple antennas is applied, and whether the information is a DCI for power control. For example, DCI format 1 (i.e., scheduling control information for downlink data (DL grant)) may contain at least one of the following control information.

[0345] - Resource Allocation Type 0 / 1 Flag: Provides notification of whether the resource allocation method is Type 0 or Type 1. In Type 0, resources are allocated in Resource Block Group (RBG) units using a bitmap method. In LTE systems, the basic unit of scheduling is an RB, represented as time-domain and frequency-domain resources. An RBG is configured with multiple RBs and becomes the basic unit of scheduling in the Type 0 method. In Type 1, a set number of RBs are allocated within an RBG.

[0346] - Resource Block Allocation: Provides notification of RBs allocated to data transmission. The represented resource is determined based on system bandwidth and resource allocation method.

[0347] - Modulation and Coding Scheme (MCS): Provides information on the modulation scheme used for data transmission and the size of the transport block (TB) (i.e., the data to be transmitted).

[0348] -HARQ Procedure Number: Provides notification of the HARQ procedure number.

[0349] - New data indicator: Provides notification of whether the transmission is a HARQ initial transmission or a retransmission.

[0350] - Redundant Version: Provides notifications for redundant versions of HARQ.

[0351] - Transmission Power Control (TPC) Commands for Physical Uplink Control Channel (PUCCH): Provides notifications for transmission power control commands for PUCCH (i.e., the uplink control channel).

[0352] DCI is transmitted via channel coding and modulation processes on the Physical Downlink Control Channel (PDCCH) (or control information, which are used interchangeably below) or Enhanced PDCCH (EPDCCH) (or enhanced control information, which are used interchangeably below) (i.e., downlink physical control channel).

[0353] Typically, the DCI is scrambled independently for each UE using a given Radio Network Temporary Identifier (RNTI) (or UE ID). After Cyclic Redundancy Check (CRC) is added to the DCI and it undergoes channel coding, the DCI can be configured with each individual PDCCH and transmitted. In the time domain, the PDCCH is mapped and transmitted during the control channel transmission interval. The frequency domain mapping position of the PDCCH is determined by each UE's ID and is extended across the entire system transmission bandwidth.

[0354] Downlink data is transmitted on the Physical Downlink Shared Channel (PDSCH) (i.e., the physical channel used for downlink data transmission). The DCI transmitted via the PDCCH provides notification of the detailed mapping location of the PDSCH in the frequency domain and scheduling information (such as modulation schemes).

[0355] In the control information used to configure DCI, the BS informs the UE of the modulation scheme applied to the PDSCH to be transmitted and the size of the data to be transmitted (Transmission Block Size (TBS)) via a 5-bit MCS. The TBS corresponds to the size before the channel coding for error correction is applied to the data transmission block (TB) to be transmitted by the BS.

[0356] The modulation schemes supported in LTE systems include Quadrature Phase Shift Keying (QPSK), Quadrature Amplitude Modulation (16QAM), and 64QAM. The modulation order (Qm) corresponds to 2, 4, and 6, respectively. That is, in the case of QPSK modulation, 2 bits can be transmitted per symbol; in the case of 16QAM modulation, 4 bits can be transmitted per symbol; and in the case of 64QAM modulation, 6 bits can be transmitted per symbol.

[0357] Figure 3B This is a diagram illustrating the uplink time-frequency domain transmission architecture of an LTE or LTE-A system based on conventional technology.

[0358] refer to Figure 3B The horizontal axis represents the time domain, and the vertical axis represents the frequency domain. The smallest transmission unit in the time domain is the SC-FDMA symbol 3b-202, and N symb UL SC-FDMA symbols are aggregated to configure one time slot 3b-206. Furthermore, two time slots are aggregated to configure one subframe 3b-205. The smallest transmission unit in the frequency domain is a subcarrier. The entire system transmission bandwidth 3b-204 is configured with a total of N... BW N subcarriers. BW It has a value proportional to the system's transmission bandwidth.

[0359] In the time-frequency domain, the basic unit of a resource is a resource element (RE) 3b-212, defined as the SC-FDMA symbol index and subcarrier index. Resource block pairs (RB pairs) 3b-208 can be defined as N in the time domain. symb UL A consecutive SC-FDMA symbol and N in the frequency domain SC RB N consecutive subcarriers. Therefore, an RB is configured with N symb UL ×N SC RB One RE. Typically, the smallest unit of transmission for data or control information is the RB unit. The PUCCH is mapped to the frequency domain corresponding to one RB and transmitted during one subframe.

[0360] In LTE systems, the timing relationships between PDSCH (the physical channel used for downlink data transmission), PUCCH, and PUSCH (the uplink physical channels in which HARQ ACK / NACK (which correspond to PDCCH / EPDDCH containing semi-persistent schedule release (SPS release)) and PUSCH are defined. For example, in an LTE system operating under Frequency Division Duplex (FDD), the HARQ ACK / NACK corresponding to the PDSCH transmitted in the (n-4)th subframe or the PDCCH / EPDCCH containing SPS release is transmitted as PUCCH or PUSCH in the nth subframe.

[0361] In LTE systems, downlink HARQ employs an asynchronous HARQ method with variable data transmission timing. That is, when the UE receives a HARQ NACK feedback for the initial transmission data sent by the BS, the BS freely determines the transmission timing of the retransmitted data based on scheduling operations. As a result of decoding the received data used for HARQ operations, the UE buffer is identified as erroneous data and combined with the next retransmitted data.

[0362] When the UE receives a PDSCH containing downlink data transmitted by the BS in subframe n, the UE transmits uplink control information containing downlink data, either HARQ ACK or NACK, to the BS via PUCCH or PUSCH in subframe n+k. In this case, k is defined differently depending on whether the LTE system uses FDD or Time Division Duplex (TDD) and its subframe configuration. For example, in an FDD LTE system, k is fixed at 4. In a TDD LTE system, k can be changed depending on the subframe configuration and subframe number.

[0363] In LTE systems, unlike downlink HARQ, uplink HARQ employs a synchronous HARQ method with fixed data transmission timing. That is, the uplink / downlink timing relationship between the Physical Uplink Shared Channel (PUSCH) (i.e., the physical channel used for uplink data transmission), the PDCCH (i.e., the downlink control channel preceding PUSCH), and the Physical Hybrid Indicator Channel (PHICH) (i.e., the physical channel where downlink HARQ ACK / NACK corresponding to PUSCH are transmitted) is fixed according to the following rules.

[0364] When the UE receives a PDCCH containing uplink scheduling control information sent by the BS, or a PHICH in which the BS sends downlink HARQ ACK / NACK in subframe n, the UE sends uplink data corresponding to the control information via PUSCH in subframe n+k. In this case, k is defined differently depending on whether the LTE system uses FDD or Time Division Duplex (TDD) and its configuration. For example, in the case of an FDD LTE system, k is fixed at 4. In the case of a TDD LTE system, k can be changed depending on the subframe configuration and subframe number.

[0365] Furthermore, when the UE receives a PHICH carrying downlink HARQ ACK / NACK from the BS in subframe i, the PHICH corresponds to the PUSCH sent by the UE in subframe ik. In this case, k can be defined differently depending on whether the LTE system is FDD or TDD and its configuration. For example, in the case of an FDD LTE system, k is fixed at 4. In the case of a TDD LTE system, k can be changed depending on the subframe configuration and subframe number.

[0366] The wireless communication system has already been described based on the LTE system. However, the content of this disclosure is not limited to the LTE system and can be applied to various wireless communication systems, such as NR and 5G. For example, in NR, besides N... RB Beyond 12, the number of subcarriers per PRB can be defined as N. RB =16. Furthermore, in LTE, the uplink waveform is limited to, for example... Figure 3B SC-FDMA in NR, but not limited to this, and can be applied in the uplink, such as Figure 3A OFDMA can be selectively applied, or both OFDMA and SC-FDMA can be used. Therefore, in the following description of this disclosure, although the description is given based on a configuration value, it is clear that this is for ease of description and not for restrictive application.

[0367] In mobile communication systems, time, frequency, and power resources are limited. Therefore, allocating more resources to the reference signal may reduce the absolute amount of data transmitted, as this reduces the resources available for transmission on the traffic channel (data traffic channel). In this case, the performance of channel measurement and estimation may improve, but the overall system capacity performance may decrease due to the reduced absolute amount of data transmitted.

[0368] Therefore, an appropriate allocation is needed between resources used for reference signals and resources used for traffic channel transmission to achieve optimal performance in terms of overall system capacity.

[0369] Figure 3C This is a diagram showing the radio resources of one subframe and one resource block (RB) (i.e., the smallest unit that can be scheduled in the downlink in an LTE / LTE-A system).

[0370] Figure 3C The radio resource shown contains one subframe on the time axis and one resource block (RB) on the frequency axis. Such a radio resource contains 12 subcarriers in the frequency domain and 14 OFDM symbols in the time domain, forming a total of 168 unique frequency and time locations. In LTE / LTE-A, Figure 3C Each unique frequency and time location in the array is called a resource element (RE).

[0371] In the radio resources shown in Figure 3, such as Figure 3C As shown, multiple signals of different types can be transmitted.

[0372] 1. Cell-Specific RS (CRS): This is a reference signal that is periodically transmitted for all UEs belonging to a cell and can be shared by multiple UEs.

[0373] 2. Demodulation Reference Signal (DMRS): This is a reference signal transmitted for a given UE and is transmitted when data is transmitted to the corresponding UE. The DMRS can contain a total of 8 DMRS ports. In LTE / LTE-A, ports 7 to 14 correspond to the DMRS ports. The ports use CDM or FDM to maintain orthogonality in order to prevent interference.

[0374] 3. Physical Downlink Shared Channel (PDSCH): This is the data channel transmitted in the downlink and is used by the BS to send service E to the UE, and utilizes the data within it. Figure 3C The data area does not transmit the reference signal RE.

[0375] 4. Channel State Information Reference Signal (CSI-RS): This is a reference signal transmitted to UEs belonging to a cell and used to measure channel state. Multiple CSI-RS signals can be transmitted within a single cell.

[0376] 5. Other control channels (PHICH, PCFICH, PDCCH): They provide the control information necessary for the UE to receive PDSCH and are used for ACK / NACK transmission to operate HARQ for uplink data transmission.

[0377] In addition to signal transmission, mute can be configured in LTE-A systems to allow a UE in a corresponding cell to receive CSI-RS transmitted by another BS without interference. Mute can be applied where CSI-RS can be transmitted. Typically, the UE receives the service signal by skipping the corresponding radio resources. In LTE-A systems, mute is also referred to as zero-power CSI-RS. This is because, in terms of mute, constellation mute is also applied to the location of CSI-RS and does not transmit transmit power.

[0378] exist Figure 3C Depending on the number of antennas transmitting CSI-RS, the transmission may utilize locations indicated by A, B, C, D, E, E, F, G, H, I, and J. Furthermore, mute may also be applied to locations indicated by A, B, C, D, E, E, F, G, H, I, and J. Specifically, CSI-RS may be transmitted across 2, 4, or 8 REs, depending on the number of antenna ports used for transmission. Figure 3C In this configuration, when the number of antenna ports is 2, CSI-RS is transmitted in half of a given mode. When the number of antenna ports is 4, CSI-RS is transmitted in all given modes. When the number of antenna ports is 8, CSI-RS is transmitted using both modes. Conversely, mute is always configured using a single mode unit. That is, mute can be applied to multiple modes, but it cannot be applied to only some modes when the mute location does not overlap with the CSI-RS location. However, mute can be applied to some modes only when the CSI-RS location and the mute location overlap.

[0379] If CSI-RS is transmitted for two antenna ports, the signal for each antenna port is transmitted in two REs connected on the time axis, and the signals for each antenna port are divided by orthogonal codes. Furthermore, if CSI-RS for four antenna ports is transmitted, the signals for the remaining two antenna ports are transmitted using the same method by further utilizing two REs, in addition to the CSI-RS for the two antenna ports mentioned above. The same applies when transmitting CSI-RS for eight antenna ports.

[0380] BS can increase the transmission power of CSI-RS to improve channel estimation accuracy. If CSI-RS with four or eight antenna ports (APs) is transmitted, a given CSI-RS port is transmitted only in the CSI-RS RE at the predetermined location and not in other OFDM symbols within the same OFDM symbol. Figure 3D This is a diagram illustrating an example of CSI-RS RE mapping for the nth and (n+1)th PRBs when the BS sends 8 CSI-RSs. Figure 3D As shown, if the CSI-RS RE position of AP 15 or 16 is... Figure 3D The inspection mode is the same. Therefore, for the remaining APs 17-22 indicated by the diagonal pattern, the transmission power of APs 15 or 16 is not used in the CSI-RS RE. Thus, if... Figure 3D As indicated, in APs 15 or 16, the transmission power intended for subcarriers 3, 8, and 9 can be used on subcarrier 2. This natural power boost, compared to the transmission power of AP 15 used in the data RE, allows the power of the CSI-RS port 15 transmitted via subcarrier 2 to be configured to a maximum of up to 6dB. The current 2 / 4 / 8-port CSI-RS mode achieves a natural power boost of 0 / 2 / 6dB per port, and each AP can use its entire available power (full power utilization) to transmit CSI-RS.

[0381] In addition, CSI-IM (or IMR, Interference Measurement Resource) and CSI-RS can be allocated to the UE. The CSI-IM resource has the same resource structure and location as the CSI-RS, which supports four ports. The CSI-IM is a resource that enables a UE receiving data from one or more BSs to accurately measure interference from neighboring BSs. If a neighboring BS wants to measure the amount of interference when it is transmitting data and when it is not transmitting data, the BS can configure CSI-RS and two CSI-IM resources such that the neighboring BS always transmits signals in one CSI-IM and never transmits signals in the other CSI-IM, thereby enabling efficient measurement of the interference from neighboring BSs.

[0382] In LTE-A systems, the BS can notify the UE of CSI-RS configuration information via higher-layer signaling. The CSI-RS configuration includes the index of the CSI-RS configuration information, the number of ports included in the CSI-RS, the CSI-RS transmission cycle time, the transmission offset, CSI-RS resource configuration information, the CSI-RS scrambling ID, QCL information, etc.

[0383] In cellular systems, the BS needs to send reference signals to the UE to measure the downlink channel state. In the case of 3GPP Advanced Long Term Evolution (LTE-A) systems, the UE uses the CRS or Channel State Information Reference Signal (CSI-RS) sent by the BS to measure the channel state between the BS and the UE. Several factors need to be considered in the channel state. These factors include the amount of interference in the downlink. The amount of interference in the downlink includes interference signals and thermal noise caused by antennas belonging to adjacent BSs. The amount of interference is important for the UE to determine the downlink channel conditions. As an example, if a BS with one transmit antenna sends a signal to a UE with one receive antenna, the UE needs to use the reference signal received from the BS to determine the energy of each symbol that can be received in the downlink, the amount of interference that will be received simultaneously during the period in which the corresponding symbol is received, and determine the Es / Io. The determined Es / Io is converted into a data transmission rate or corresponding value and notified to the BS in the form of a Channel Quality Indicator (CQI). Therefore, the BS can determine at what data transmission rate it will perform transmissions to the UE in the downlink.

[0384] In LTE-A systems, the UE feeds back information about the downlink channel state to the BS, enabling the BS to use this information for downlink scheduling. That is, the UE measures the reference signal transmitted by the BS in the downlink and feeds back information extracted from the reference signal to the BS in the form defined in the LTE / LTE-A standard. In LTE / LTE-A, the information fed back by the UE basically includes the following three types.

[0385] • Rank Indicator (RI): The number of spatial layers that the UE can receive in the current channel state.

[0386] • Precoding Matrix Indicator (PMI): An indicator of the precoding matrix preferred by the UE under the current channel condition.

[0387] • Channel Quality Indicator (CQI): The maximum data rate at which the UE can receive data under the current channel conditions. CQI can be replaced by SINR, which can be used similarly to maximum data rate, maximum error correction code rate, modulation scheme, data efficiency per frequency, etc.

[0388] RI, PMI, and CQI are related and meaningful. As an example, the precoding matrix supported in LTE / LTE-A is defined differently for each rank. Therefore, the PMI value when RI has a value of 1 and the PMI value when RI has a value of 2 are interpreted differently, even though they have the same value. Furthermore, it is assumed that when the UE determines the CQI, the rank and PMI values ​​relative to the BS, as notified by the UE, have already been applied in the BS. That is, this means that if the UE notifies the BS of RI_X, PMI_Y, and CQI_Z, then when the rank is RI_X and the precoding is PMI_Y, the UE can receive the data rate corresponding to CQI_Z. If the UE assumes which transmission method it will perform against the BS when calculating the CSI as described above, it can achieve optimized performance when it performs the actual transmission using the corresponding transmission method.

[0389] In the following, embodiments of the present disclosure are described in detail with reference to the accompanying drawings. Furthermore, in describing the present disclosure, details of known functions or configurations that would unnecessarily obscure the essential points of the disclosure are omitted. Additionally, the terms described below have been defined by consideration of the functions in the present disclosure and may vary depending on the intent or practice of the user or operator. Therefore, each term should be defined based on the entirety of the specification. In the following, a base station is the entity that performs resource allocation for a terminal and may be at least one of an eNode B, Node B, BS, radio access unit, BS controller, and nodes on a network. A terminal may include a user equipment (UE), a mobile station (MS), a cellular phone, a smartphone, a computer capable of performing communication functions, and a multimedia system. In this disclosure, downlink (DL) refers to the radio transmission path of a signal transmitted from the BS to the UE, and uplink (UL) refers to the radio transmission path of a signal transmitted from the UE to the BS. Furthermore, embodiments of the invention are described below using LTE or LTE-A systems as examples; however, embodiments of the invention can be applied to other communication systems with similar technical backgrounds or channel configurations. For example, 5G mobile communication technology (New Radio (NR)) developed after LTE-A can be included in other communication systems. Furthermore, based on the assessment of those skilled in the art, embodiments of this disclosure can also be applied to other communication systems with modifications without significantly departing from the scope of this disclosure.

[0390] The contents of this disclosure can be applied in FDD and TDD systems.

[0391] In this disclosure, higher-layer signaling refers to a signal transmission method that uses the downlink data channel of the physical layer from the BS to the UE, or uses the uplink data channel of the physical layer from the UE to the BS, and may be referred to as RRC signaling, PDCP signaling, or MAC control element (MAC CE).

[0392] As mentioned above, in order to perform network coordination, such as signal transmission or interference management, through multiple cells, TRPs, or beams, at least the following three functions need to be satisfied.

[0393] The primary function is channel estimation for multiple cells, TRPs, or beams (or combinations thereof). Unlike LTE CSI-RS, which is always wideband based on a given cycle time and time offset, in NR, CSI-RS can be transmitted non-periodically and in subbands by taking into account various factors such as forward compatibility.

[0394] The following detailed examples of performing one or more combinations of methods are described in this disclosure.

[0395] Examples are described below in this disclosure by way of several embodiments, but these are not independent and one or more embodiments may be applied simultaneously or in combination.

[0396] [(3-1) Example: RS RE mapping method]

[0397] (3-1) The embodiments provide detailed examples of the RS RE mapping method. Figure 3E This diagram illustrates the RE structure within a PRB when it is configured with 16 subcarriers (vertical axis) and 14 OFDM (or SC-FDMA) symbols (horizontal axis). In this case, an OFDM symbol is configured with 8 RS RE subgroups. In this case, an RS RE subgroup is the smallest unit of RS configuration within the same OFDM symbol, consisting of two adjacent REs, and can be defined by various names, such as component RS RE mode or component RS resource. In this disclosure, for ease of description, the 8 RS RE subgroups present in the Xth OFDM symbol are labeled by {AX, BX, ..., HX}. For example, the 8 RS RE subgroups from A0 3e-501 to H0 3e-502 exist in OFDM symbol 0. In this case, an orthogonal coverage code (OCC) of length 2 is applied to each RS RE subgroup. Depending on ([1 1] or [1 -1]), up to two ports (e.g., port a and port a+1) can be multiplexed (or assigned) with a single RS RE subgroup.

[0398] In this scenario, the RS RE subgroup (i.e., the smallest unit of RS configuration) is configured with two adjacent REs on the frequency axis within the OFDM symbol. In the aforementioned next-generation communication systems, NR-based systems, or 5G systems, it makes more sense to define two adjacent REs on the frequency axis as a single RS configuration unit, as described above. In next-generation communication systems, using two adjacent REs on the frequency axis to define RS configuration units can be advantageous compared to using two adjacent REs on the time axis, because this is because different transmission time intervals (TTIs) of varying lengths are considered depending on several different values. That is, defining two or more adjacent REs on the frequency axis as RS configuration units is not a simple choice, but rather an embodiment designed to derive technically advanced results. Furthermore, the advantages of the proposed method can be equally applied to LTE / LTE-A systems, as such RS configuration methods can be used identically in LTE / LTE-A systems, in addition to next-generation communication systems.

[0399] In this example, the BS can signal multiple pieces of information, such as a symbol index (or what can be understood as a resource configuration index), where the RS is transmitted in relation to RS transmissions, time-domain and frequency-domain aggregation levels, comb indexes, or frequency-domain measurement constraint information.

[0400] First, the BS informs the UE at which position on the timeline the RS will be transmitted by transmitting the symbol index (or resource configuration index) X of the RS to the UE.

[0401] RS resources (i.e., the units that actually transmit RS) are configured as combinations of RS RE subgroups. Within an RS resource, an RS antenna port is extended and transmitted via an OCC having the same length as the number of REs contained and transmitted within the RS resource. This facilitates interference management between RSs by providing various RS modes as needed. For this purpose, the BS can notify the UE of the "aggregation level" via higher-layer signaling or L1 signaling. The aggregation level can be configured with an extended time-domain aggregation level indicating an extension on the time axis and an extended frequency-domain aggregation level indicating an extension on the frequency axis (in practice, the aggregation level can be defined using various terms such as replication level, number of (sub)time units within the CSI-RS resource, etc.).

[0402] like Figure 3EIn this configuration, if a PRB contains 16 subcarriers, the frequency domain aggregation level is determined to be a value of {1, 2, 4, or 8} (if a PRB contains 12 subcarriers, the aggregation level value is less than 8). The UE knows how many RS RE subgroups to group to form an RS resource based on the configured aggregation level. For example, when the aggregation level is 1, each RS RE subgroup is interpreted as a separate RS resource. Conversely, when the aggregation level is 2, two adjacent RS RE subgroups are grouped to form an RS resource. Figure 3E In this case, AX and BX are grouped to define the first RS resource. {CX, DX}, {EX, FX}, and {GX, HX} define the second, third, and fourth RS resources, respectively. As another example, when the aggregation level is 8, a total of eight RS RE subgroups from AX to HX are grouped to configure one RS resource. This variable RS resource structure helps control interference environments attributable to various factors, such as UL-DL interference attributable to dynamic TDD and interference attributable to multiple numerical values ​​(e.g., different subcarrier spacings).

[0403] Using only frequency-domain aggregation presents the risk that channel estimation performance may degrade in cases where the RS power is critical for UEs due to coverage issues (such as noise-constrained environments). To address this issue, time-domain aggregation can be used to transmit RS across one or more OFDM symbols. For example, if time-domain aggregation can reach a maximum of two symbols, the time-domain aggregation level is determined to be one of {1 or 2} (the range of this value increases if time-domain aggregation can be extended to more than two symbols). If time-domain aggregation can reach a maximum of four symbols, the time-domain aggregation level is determined to be one of {1, 2, or 4}.

[0404] If the aggregation level is a value greater than 1, it's important to note that OCC can also be extended when performing aggregation. For example, suppose... Figure 3EIn Example 1 (3e-503), A4 and B4 are grouped to form R0. In this case, the OCC-2 of A4 ([1 1] or [1 -1]) and the OCC-2 of B4 ([1 1] or [1 -1]) are extended to OCC-4 based on the RS port index in which R0 is transmitted. If RS ports a to a+3 are transmitted in the four REs of R0 = [A4 B4], the first two ports are combined with the OCCs of A4 and B4, while the latter half (B4) has no OCC sign conversion. That is, the OCC-4 of RS ports a and a+1 becomes [1 1 1 1] and [1 -1 1 -1]. In contrast, in the last two ports, the OCCs of A4 and B4 are combined after the OCC sign conversion of the latter half (B4). That is, the OCC-4 of RS ports a+2 and a+3 becomes [1 1 -1 -1] and [1 -1 -1 1]. Despite Figure 3E The temporal aggregation is applied as in Example 2 (3e-504), but the OCC extension method described above can be applied in the same way. In the case of 3e-504, in that example, the same OCC extension can be performed by replacing A4 and B4 with A7 and A8.

[0405] The OCC extension method can be extended to higher aggregation levels using a recursive function structure. Specifically, it extends the OCC of aggregation level N based on the OCC of aggregation level N / 2. An RS resource of aggregation level N contains two RS resources of aggregation level N / 2, and at most 2N RS resources can be reused. That is, assuming "a" is the smallest RS port index that can be transmitted in the corresponding RS resource of aggregation level N, then RS port a to RS port a+2N-1 are transmitted in the corresponding RS resource. RS ports that can be transmitted in the RS resource of aggregation level N can be divided into two groups: {a, a+1, ..., a+N-1} and {a+N, a+N+1, ..., a+2N-1}. When the port belongs to the first group, the OCC-N mode of the two RS resources of aggregation level N / 2 configured with the RS resource of aggregation level N is aggregated without sign conversion and extended to the OCC-2N mode of the RS resource of aggregation level N. In contrast, when the port belongs to the second group, after the sign of the second OCC-N mode of two RS resources with aggregation level N and aggregation level N / 2 is changed (or by multiplying the second OCC-N mode by -1), the second OCC-N mode is aggregated and expanded into an OCC-2N mode of RS resources with aggregation level N. The basic unit of the recursive function is the aforementioned RS RE subgroup.

[0406] For ease of description, the frequency domain and time domain aggregation levels have been shown as independent configuration values, but they can be defined as a single value when they are actually applied.

[0407] If both time-domain aggregation and frequency-domain aggregation are applied simultaneously, frequency-domain aggregation is performed earlier than time-domain aggregation. This is used to achieve overlap between a one-symbol-based RS mode and an extended RS mode in the time domain, i.e., transmission over two or more symbols. If frequency-domain aggregation is performed first, this function can still be performed because the mode within an OFDM symbol is maintained regardless of whether time-domain aggregation is applied.

[0408] The BS can adjust RS RE density by configuring comb transmission or measurement limits (MR) in the frequency domain. For example, if the BS configures comb transmission or measurement limits based on a repetition factor (RPF) of 2, the UE can allocate RS resources (i.e., Figure 3E The RS RE subgroups (or the final determined values ​​of aggregation) are divided into two distinct groups, and RS can be measured only in one of the two groups. If the UE partitions RS resources based on RS RE subgroups, it can configure two groups with a given interval, such as {AX, CX, EX, GX} and {BX, DX, FX, HX}. The advantage in this case is that both groups have the same RS RE transmission location regardless of the aggregation level. In contrast, if the UE partitions RS resources after aggregation, it can configure two groups, such as {AX, BX, EX, FX} and {CX, DX, GX, HX}, as in 3e-503. The advantage in this case is that RS interference management is facilitated because even OCC modes are precisely matched based on the aggregation level and RPF configuration.

[0409] exist Figure 3E Examples 3e-503 and 3e-504 illustrate RS resource configuration results based on RS transmission OFDM symbols, aggregation levels, and comb or frequency domain MR configurations. Specifically, 3e-503 is an example when configuring OFDM symbol number 4, frequency domain aggregation level 2, time domain aggregation level 1, and RPF=2. 3e-504 is an example when configuring OFDM symbol number 7, frequency domain aggregation level 1, time domain aggregation level 2, and RPF=2. In this embodiment, the process for configuring RS resources (such as 3e-503 or 3e-504) has been described; however, the results of this method, such as 3e-503 or 3e-504, can be stored in a storage medium when they are actually applied and can be implemented in a form for reference.

[0410] It is important to note that the aggregation level and comb or frequency domain MR configuration can be agreed to change over time (or at the location of RS transmission). For example, if multiple RS resources are configured in two or more OFDM symbols within a PRB, different aggregation levels and comb or frequency domain MR configuration values ​​can be applied based on the OFDM symbols. For instance, if RS is transmitted in OFDM symbols 1 and 8, it can be agreed that OFDM symbol 1 can have a high RS RE density by applying a low RPF value, and OFDM symbol 8 can have a low RS RE density by applying a high RPF value. This is used to ensure excellent channel estimation performance in the initial transmission phase where there is no already obtained channel estimation information, and to reduce the RS transmission burden in the middle or later stages of transmission by using the already obtained channel estimation information. In this example, it has been described that the RS RE density within the PRB can be different, but it is not limited to this. Obviously, the RS RE density can be extended to RS RE density configurations between different subframes or TTIs. Changes in aggregation level and comb or frequency domain MR configuration can be explicitly executed via higher-layer signaling or L1 signaling, or they can be defined and implicitly executed within the standard. If the aggregation level and comb or frequency domain MR configuration are explicitly changed via signaling, the BS can notify the UE whether the aggregation level and comb or frequency domain MR configuration will change over time. That is, the BS can selectively apply changes in RS RE density over time (applying RS RE density changes when necessary and using the same RSRE density in other cases).

[0411] The BS can be configured within the UE to transmit which RS in the RS resource configured as in the example. For instance, the BS can notify the UE via higher-layer signaling that the RS resource configured in this example is one of CSI-RS, SRS, or DMRS.

[0412] This example has been described based on non-zero power (NZP) CSI-RS, NZP SRS, and NZP DMRS (i.e., RS resources). However, the resource configuration method is not necessarily limited to NZP RS configuration. The same method can be applied to the resource configuration of zero power (ZP) CSI-RS, ZPSRS, and ZPDMRS for PDSCH rate matching.

[0413] As mentioned above, up to 2N RS ports can be multiplexed via OCC and transmitted within an RS resource of aggregation level N. Assuming 2N RS ports {a, a+1, ..., a+2N-1} are transmitted within an RS resource, the value of port index a must indeed be the same across all PRBs in the full band. This is to support scenarios where the TRP or beam differs for each subband where the transmitted RS ports are transmitted.

[0414] According to this example, the UE can identify and receive RS resources based on at least one configuration of RS transmission OFDM symbols, aggregation level, and comb type or frequency domain MR. If some configuration values ​​are notified to the UE via higher-layer signaling or L1 signaling, there may be a problem where the UE, having not received the relevant signaling, cannot find the accurate location of the RS resource. To minimize this problem, initial values ​​for the configuration values ​​can be agreed upon. If no relevant signaling exists, the UE can use this initial value and estimate the location of the RS resource. For example, if the UE has not yet received signaling information related to the frequency domain aggregation level, it can be agreed that the UE uses the highest aggregation level (in the frequency domain). Figure 3E In the case of 8), although the aggregation level cannot be precisely matched due to the lack of signaling, an average effect can be obtained.

[0415] In this example, a method for configuring RS resources as basic units using RS RE subgroups configured with two adjacent REs (two adjacent subcarriers) on the frequency axis has been described. However, it is clear that extension methods can be applied based on different forms of basic patterns. For example, there exists a fixed form of minimum RS pattern, and some of the methods described above can be applied based on the minimum RS pattern when additional extensions are added.

[0416] For example, an example can be performed based on an RS RE subgroup configured with two adjacent REs (two adjacent OFDM symbols) on the time axis, or an RS RE subgroup configured with four REs present in two adjacent subcarriers and two adjacent OFDM symbols, or an RS RE subgroup configured with eight REs present in two adjacent subcarriers and four adjacent OFDM symbols. In this case, the RS RE subgroup can be the same as the CDM group. For example, if an RS RE subgroup with two REs is used, CDM-2 can be applied to each RS RE subgroup. If an RS RE subgroup with four REs is used, CDM-4 can be applied to each RS RE subgroup. If an RS RE subgroup with eight REs is used, CDM-8 can be applied to each RS RE subgroup.

[0417] [(3-2) Example: Interference Measurement Configuration]

[0418] In this embodiment, an interference measurement method for network coordination is described.

[0419] In the NR (5G) CSI framework, a flexible interference measurement method is needed to handle various radio transmission environments, such as variable TTIs and multiple values. If the TTI is long or the subcarrier spacing (SCS) is small, the system's resource allocation (RA) unit or the time unit for precoding changes becomes longer because the change unit in the time axis becomes longer. Conversely, if the TTI is short or the subcarrier spacing is large, the system's RA unit or the time unit for precoding changes becomes shorter because the change unit in the time axis becomes shorter. Since the TTI or subcarrier spacing can be configured based on the channel conditions of each UE, it can be inferred that several types of interference can vary within a cell in various time units. This means that unlike LTE, which operates within a single TTI and a single subcarrier spacing (in most cases), interference variations in NR can be very large. DL-UL interference or UL-DL interference, attributable to dynamic TDD, is another factor that can amplify these interference variations.

[0420] By taking these characteristics into account, it is important that the interference measurement (IM) method in NR has the following two functions:

[0421] In NR, the resolution of the Information Management Module (IM) needs to be designed by considering the minimum time or frequency granularity between multiple possible interferences. That is, even if the time unit of a given UE's data / control transmission is long (when the TTI is long or the SCS is short), if the time unit of interference changes is short, the IM needs to have a short time unit for estimation.

[0422] To perform accurate interference measurements under various interference conditions, it is necessary to support 1) signal-based interference extraction schemes and 2) puncture-based interference (power) measurement schemes.

[0423] Figure 3F This is a diagram illustrating an example where interference occurs when the TTI of the serving TRP and the TTI of the interfering TRP are different. Figure 3F This implies that although the desired channel TTI is long, if the interference TTI is short, the variations in SNIR can be several within a single TTI. Assuming that only one of the three IM resources 3f-602, 3f-603, and 3f-604 is used within a single TTI 3f-601 in which data is transmitted, then interference is measured only when the interfering TRP in Figure 3 is not transmitting, for 3f-602 and 3f-604, and only when the interfering TRP in Figure 3 is transmitting. Therefore, it may be difficult to measure the interference impact on 3f-601. To address this problem, the following two schemes can be considered.

[0424] The first approach is to enable the UE to use a sufficient number of IM resources for statistical measurements of interference. As an example of this approach, the BS can configure measurement limits with different values ​​for channel estimation and interference estimation. For instance, a short measurement window can be used by considering CSI-RS beamformation when performing channel estimation, but a longer measurement window can be used to obtain statistics when performing interference estimation. Another example of this approach is that IM resources can be configured with smaller cell intervals than RS resources (e.g., RS resources are configured per subframe, while IM resources are configured in slot cells or mini-slot cells (e.g., 2 or 4 OFDM symbols)). Reference Figure 3F An S resource is configured in 3f-601, while an IM resource is configured in each of 3f-602, 3f-603 and 3f-604 based on the interference time unit.

[0425] The second approach is to provide high-resolution IM resources for accurate and timely interference measurements. This can be understood as a second example similar to the first approach. That is, IM resources are configured with smaller cell intervals than RS resources (e.g., RS resources are configured per subframe, while IM resources are configured with slot or mini-slot cells (e.g., 2 or 4 OFDM symbols)). Reference Figure 3F An RS resource is configured in 3f-601, while an IM resource is configured in each of 3f-602, 3f-603, and 3f-604 based on interference.

[0426] For interference measurement, two schemes can be considered as described above: 1) a signal-based interference extraction scheme and 2) a tag-based interference (power) measurement scheme. The signal-based interference extraction scheme measures one of the predetermined signals, such as CSI-RS or DMRS, and treats the measured signal as interference. In this case, the BS transmits a signal for actual interference measurement. The corresponding signal can be used for various purposes, such as, in addition to measuring interference signals loaded onto the corresponding signal after estimation (CSI-RS-based IM, DMRS-based IM, DMRS-based CQI, etc.), the UE also generates new interference hypotheses by combining the measured interference signals. Meanwhile, in the tag-based interference measurement case, the serving TRP can not transmit the actual signal in the corresponding resource after IM resource configuration. In this case, the UE can measure the power of the actual interference in the tagged corresponding resource and incorporate the measured power into the generation of the CSI. According to embodiment 3-1, a single framework can support DL CSI-RS / ULCSI-RS / DMRS configuration and can change the feedback configuration or feedback content depending on the aforementioned IM usage.

[0427] [(3-3) Implementation Plan: QCL Signaling]

[0428] This embodiment provides a quasi-cooperative positioning (QCL) configuration method based on various network coordination environments. Figure 3G An example of a network coordination scenario is shown. (Reference) Figure 3G A single cell (gNB) can have multiple TRPs. In this case, TRPs can be distinguished by CSI-RS resources (or CSI-RS ports). For example, a UE can... Figure 3G The UE is configured with four CSI-RS resources, A, B, C, and D. In this scenario, RS resources A and B are transmitted at TRP 1, and RS resources C and D are transmitted at TRP 2. The UE can report its preferred subset of all RS resource sets to the BS via the CSI-RS Resource Indicator (CRI) and can transmit and receive data based on the beam direction applied to the corresponding resource. If the UE has selected resources A and C for transmission at different TRPs, the CSI-RS transmitted in the corresponding resources can have the same QCL attributes, such as delay shift, delay spread, Doppler shift, Doppler spread, and AoD propagation. Furthermore, unlike LTE-A, in NR, CSI-RS can be transmitted in subbands. In this case, QCL support for another RS ​​may be necessary for time or frequency offset compensation. In other words, in NR, in addition to DMRS, it may be necessary to consider QCL support for various RS (such as subband CSI-RS), and flexible QCL configuration is necessary by taking into account various transmission scenarios.

[0429] Figure 3H An example of QCL signaling that can be considered in single-point transmission is shown. References Figure 3H If a single beam is used to transmit CSI-RS due to a small channel angular spread, the CSI-RS and DMRS used for data transmission can share all QCL attributes. In contrast, if the channel angular spread is large and one or more main paths exist, channel estimation can be performed using two or more CSI-RS beams, sharing QCL attributes across all CSI-RS port groups, and DMRS port groups may not be feasible (e.g., angle of departure (AoD)). In this case, it is necessary to configure unshared given QCL attributes to be shared between some CSI-RS port groups and DMRS port groups (in... Figure 3H In a multibeam diagram, AoD information is shared only between the CSI-RS and DMRS corresponding to the upper path and the CSI-RS and DMRS corresponding to the lower path.

[0430] Figure 3I An example of QCL signaling that can be considered in multipoint transmission is shown. Figure 3IFor ease of description, only a single beam is shown (when the angular spread is small), and references can be made to... Figure 3H The description is used to express multibeams. (Reference) Figure 3I For transmission schemes such as coherent joint (JT), a DMRS and a CSI-RS port can be transmitted at multiple TRPs within the same frequency / time resource. It is understood that the RS port is shared between TRPs. In this case, the DMRS can share CSI-RS and QCL attributes. As another example, for transmission schemes such as incoherent JT, multiple CSI-RS and DMRS ports can be transmitted at different TRPs within separate frequency / time resources. In this case, unlike the previous example, RSs transmitted through the same TRP or the same beam can share QCL attributes, but if they are transmitted through different TRPs or different beams, they should not share QCL attributes.

[0431] Therefore, when performing time / frequency offset compensation on an externally transmitted RS on the time / frequency axis, all environmental factors (such as...) need to be considered. Figure 3G , 3H (and 3I). To this end, the BS can configure the QCL master and QCL slave sets via higher-level signaling. The QCL master set transmits in a sufficiently wide frequency band from which QCL attributes can be extracted. The duration between RS REs is configured with a sufficiently short RS ID. For example, if such RSs are 4, the BS can define the QCL master set as follows.

[0432] QCL MASTER_SET ={RS ID#1, RS ID#2, RS ID#3, RS ID#4}

[0433] QCL slave sets are transmitted in narrowband, where time / frequency offset compensation is performed based on QCL attributes extracted from the master set or configured with the ID of an RS having a long duration between RS REs. If such RSs are 3, then the BS can define the QCL slave set as follows.

[0434] QCL SLAVE_SET ={RS ID#5, RS ID#6, RS ID#7}

[0435] In this example, RS ID#N is the ID of the signaling, such as at least one DL CSI-RS, UL CSI-RS (SRS), or DMRS.

[0436] The BS can configure at least one QCL subgroup based on QCL master and slave sets, and can notify the UE of this QCL subgroup via higher-layer signaling. In this case, each QCL subgroup is configured with master and slave configuration components. The master and slave components in a QCL subgroup are indicators of the master-slave relationship of QCL attributes between the QCL master set and the QCL slave set. Assume that the Nth QCL subgroup is configured as follows.

[0437]

[0438] UE receives QCL SUBGROUP#N The RSs indicated by RS IDs #1, #2, and #3 and the RS indicated by RS ID #5 are known to be contained in the same QCL subgroup A. Therefore, the UE can correct the time / frequency offset of the RS indicated by RS ID #5 by estimating the QCL attributes of the RSs indicated by RS IDs #1, #2, and #3. Similarly, the UE can receive the QCL... SUBGROUP#N The UE knows that the RS indicated by RS ID#4 and the RS indicated by RS ID#6 are contained in the same QCL subgroup B. Therefore, the UE can correct the time / frequency offset of the RS indicated by RS ID#6 by estimating the QCL attributes in the RS indicated by RS ID#4. The UE knows that RS ID#7 is not contained in any QCL subgroup because of SUBGROUP. SLAVE The value is NAN. Therefore, the RS indicated by RS ID#7 becomes an independent RS in the QCL perspective.

[0439] The BS can notify the UE via L1 signaling that it will use QCL. SUBGROUP Which location in the configuration is this configuration? For example, if there is a network coordination scenario requiring four different QCL configurations, then the BS configures four QCL subgroups (QCL...). SUBGROUP#1 QCL SUBGROUP#2 QCL SUBGROUP#3 QCL SUBGROUP#4 Afterwards, the UE can receive 2 bits of L1 signaling and, based on the configuration (QCL) SUBGROUP#1 QCL SUBGROUP#2 QCL SUBGROUP#3 QCL SUBGROUP#4 Which of the following determines whether to correct the time / frequency offset?

[0440] The execution order of Example 3-3 is as follows: Figure 3J It was arranged as in (3j-01, 3j-03, 3j-05).

[0441] [(3-4) Example: OFDM symbol location for CSI-RS transmission]

[0442] Examples 3-1, 3-2, or 3-3 can be applied based on CSI-RS transmitted via OFDM symbols at various locations within a time slot containing CSI-RS. The time slot containing CSI-RS can be determined through higher-layer configured CSI-RS timing information (e.g., CSI-RS subframe / time slot configuration including periodicity and offset information) in the case of aperiodic CSI-RS or semi-persistent CSI-RS. In the case of aperiodic CSI-RS, the time slot containing CSI-RS can be a time slot spaced apart from a DCI that triggers aperiodic CSI-RS transmission at given time intervals. This embodiment provides various examples of OFDM symbol locations for CSI-RS transmission within a time slot containing CSI-RS.

[0443] Figure 3K This is a diagram illustrating examples of OFDM symbols used for NR CSI-RS transmissions, OFDM symbols used for NR DMRS and NR PDCCH transmissions, and OFDM symbols used for LTE CRS transmissions.

[0444] exist Figure 3K In the first example, to avoid using resource 3k-00 for PDCCH transmission, resource 3k-01a for DMRS transmission, and resource 3k-02 for LTE CRS transmission, non-zero power (NZP) or zero power (ZP) CSI-RS can be transmitted / configured in the 6th, 7th, 13th, and 14th OFDM symbols 3k-03 within a time slot containing 14 OFDM symbols. If a time slot contains 7 or fewer OFDM symbols, the corresponding OFDM symbol numbering can therefore be changed. In this case, detailed RE mode configurations for NZP CSI-RS or ZP CSI-RS, ZPSRS within 3k-03 can be configured according to Embodiments 3-1 and 3-2. In this example, it is assumed that resource 3k-01a for DMRS transmission is transmitted in the 3rd, 4th, 9th, and 10th OFDM symbols. This is used to provide higher-layer MIMO transmission or accurate DMRS channel estimation for high-speed UEs. If CSI-RS is transmitted in 3k-03, the advantage is that the UE's CSI-RS reception structure becomes simpler and rate matching becomes easier, because the CSI-RS mode is the same between a 14-symbol time slot and a 7-symbol mini-time slot. However, if a large number or more of the 24 CSI-RS ports are transmitted using three or more OFDM symbols, the disadvantage is reduced channel estimation accuracy due to phase drift, because one CSI-RS is transmitted in six or more OFDM symbol TTIs.

[0445] exist Figure 3KIn the second example, to avoid using resource 3k-00 for PDCCH transmission, resource 3k-01b for DMRS transmission, and resource 3k-02 for LTE CRS transmission, NZP or ZP CSI-RS can be transmitted / configured in the 10th, 11th, 13th, and 14th OFDM symbols 3k-04 within a time slot containing 14 OFDM symbols. If a time slot contains 7 or fewer OFDM symbols, the corresponding OFDM symbol numbering can therefore be changed. In this case, detailed RE mode configurations for NZP CSI-RS or ZP CSI-RS, ZP SRS within 3k-04 can be configured according to Embodiments 3-1 and 3-2. In this example, it is assumed that resource 3k-01b for DMRS transmission is transmitted in the 3rd, 4th, and 9th OFDM symbols. This is used to provide higher-layer MIMO transmission or accurate DMRS channel estimation for high-speed UEs and also to adjust RS overhead. The advantage of transmitting CSI-RS in 3k-04 is that although CSI-RS ports are transmitted within a single CSI-RS resource, many CSI-RS ports can be transmitted in a short period of time. It is robust to transmission over channels that change over time, and the LTE UE can perform rate matching on most NR CSI-RS resources. However, the disadvantage is that it is detrimental to faster CSI feedback because the CSI-RS resources are located in the latter half of the time slot.

[0446] exist Figure 3K In the third example, to avoid using resource 3k-00 for PDCCH transmission, resource 3k-01b for DMRS transmission, and resource 3k-02 for LTE CRS transmission, NZP or ZP CSI-RS can be transmitted / configured in OFDM symbols 3k-05 (6th, 7th, 10th, 11th, 13th, and 14th) within a time slot containing 14 OFDM symbols. If a time slot contains 7 or fewer OFDM symbols, the corresponding OFDM symbol numbering can therefore be changed. In this case, detailed RE mode configurations for NZP CSI-RS or ZP CSI-RS, ZP SRS within 3k-05 can be configured according to Embodiments 3-1 and 3-2. In this example, it is assumed that resource 3k-01b for DMRS transmission is transmitted in OFDM symbols 3, 4th, and 9th. This is used to provide higher-layer MIMO transmission or accurate DMRS channel estimation for high-speed UEs and also to adjust RS overhead. In various scenarios, 3k-05 can support either 3k-03 or 3k-04 relative to CSI-RS resources, and the advantages of 3k-03 or 3k-04 can be appropriately adopted depending on the situation. However, as mentioned above, the increased number of scenarios increases the complexity of UE and BS implementation.

[0447] exist Figure 3K In the fourth example, to avoid using resource 3k-00 for PDCCH transmission, resource 3k-01c for DMRS transmission, and resource 3k-02 for LTE CRS transmission, NZP or ZP CSI-RS can be transmitted / configured in OFDM symbols 3k-06 (4th, 6th, 7th, 10th, 11th, 13th, and 14th) within a time slot containing 14 OFDM symbols. If a time slot contains 7 or fewer OFDM symbols, the corresponding OFDM symbol numbering can therefore be changed. In this case, detailed RE mode configurations for NZP CSI-RS or ZP CSI-RS, ZP SRS within 3k-06 can be configured according to Embodiments 3-1 and 3-2. In this example, it is assumed that resource 3k-01c for DMRS transmission is transmitted in the 3rd and 9th OFDM symbols. This is to minimize RS overhead. The advantages and disadvantages of 3k-06 are similar to those of the third example (3k-05), and their detailed description is omitted. The choice between 3k-05 and 3k-06 can be explicitly indicated by higher-layer signaling or L1 signaling, or implicitly determined by the BS's DMRS mode configuration. Implicitly indicating this choice means that the available CSI-RS resources can vary when the BS indicates different DMRS modes (such as 3k-01b or 3k-01c), allowing the UE to use different DMRS modes.

[0448] exist Figure 3KIn the fifth example, to avoid using resource 3k-00 for PDCCH transmission, resource 3k-01b for DMRS transmission, and resource 3k-02 for LTE CRS transmission, NZP or ZP CSI-RS can be transmitted / configured in the 6th, 7th, 10th, and 11th OFDM symbols 3k-07 within a time slot containing 14 OFDM symbols. If a time slot contains 7 or fewer OFDM symbols, the corresponding OFDM symbol numbering can therefore be changed. In this case, detailed RE mode configurations for NZP CSI-RS or ZP CSI-RS, ZP SRS within 3k-07 can be configured according to Embodiments 3-1 and 3-2. In this example, it is assumed that resource 3k-01b for DMRS transmission is transmitted in the 3rd, 4th, and 9th OFDM symbols. This is used to provide higher-layer MIMO transmission or accurate DMRS channel estimation for high-speed UEs and also to adjust RS overhead. If CSI-RS is transmitted in 3k-07, the number of OFDM symbols required for transmission of CSI-RS resources containing 24 or more CSI-RS ports is less than 6, which is between 3k-03 and 3k-04. The advantage is that the LTE UE can perform rate matching on most NR CSI-RS resources. However, LTE PSS / SSS / PBCH may be difficult to avoid because NZP or ZP CSI-RS may not be configured in the 13th or 14th OFDM symbols. Potential disadvantages include faster PDSCH decoding affecting the UE.

[0449] exist Figure 3KIn the sixth example, to avoid using resource 3k-00 for PDCCH transmission and resource 3k-01a for DMRS transmission, NZP or ZP CSI-RS can be transmitted / configured in the 5th, 6th, 7th, and 8th OFDM symbols 3k-08 within a time slot containing 14 OFDM symbols. If a time slot contains 7 or fewer OFDM symbols, the corresponding OFDM symbol numbering can therefore be changed. In this case, detailed RE mode configurations of NZP CSI-RS or ZP CSI-RS, ZP SRS within 3k-08 can be configured according to Embodiments 3-1 and 3-2. In this example, it is assumed that resource 3k-01a for DMRS transmission is transmitted in the 3rd, 4th, 9th, and 10th OFDM symbols. This is used to provide higher-layer MIMO transmission or accurate DMRS channel estimation for high-speed UEs. The impact of time-varying channel conditions can be minimized because a CSI-RS resource can be transmitted in consecutive OFDM symbols, regardless of the number of CSI-RS ports transmitted when transmitting CSI-RS in 3k-08. However, a drawback in this case is that it is difficult to avoid conflicts with OFDM symbols in which LTE CRS 3k-02 is transmitted.

[0450] Figure 3L This is a diagram illustrating other examples where OFDM symbols used for NR CSI-RS transmissions avoid those used for NR DMRS and NR PDCCH transmissions, as well as OFDM symbols used for LTE CRS transmissions. However, in Figure 3L In the example, some OFDM symbols used for DMRS transmission can be shared for CSI-RS transmission.

[0451] exist Figure 3LIn the first example, to avoid using resource 3l-00 for PDCCH transmission and resource 3l-02 for LTE CRS transmission, NZP or ZP CSI-RS can be transmitted / configured in the 3rd, 4th, 6th, and 7th OFDM symbols 3l-03 within a time slot configured with 14 OFDM symbols. If a time slot contains 7 or fewer OFDM symbols, the corresponding OFDM symbol numbering can therefore be changed. In this case, detailed RE mode configurations for NZP CSI-RS or ZP CSI-RS, ZP SRS within 3l-03 can be configured according to Embodiments 3-1 and 3-2. In this example, it is assumed that resource 3l-01a for DMRS transmission is transmitted in the 3rd and 4th OFDM symbols. This is used to support simultaneous transmission of DL / UL within a time slot or to support faster PDSCH decoding for the UE. DMRS and CSI-RS can be TDM / FDM / CDM in the first two OFDM symbols of the four OFDM symbols in 31-03 and 31-04.

[0452] exist Figure 3L In the second example, to avoid using resource 31-00 for PDCCH transmission and resource 31-02 for LTE CRS transmission, NZP or ZP CSI-RS can be transmitted / configured in the 6th, 7th, 10th, and 11th OFDM symbols 31-05 of a time slot with 14 OFDM symbols. If a time slot contains 7 or fewer OFDM symbols, the corresponding OFDM symbol numbering can therefore be changed. In this case, the detailed RE mode configuration of NZP CSI-RS or ZP CSI-RS, ZP SRS within 31-05 can be configured according to Embodiments 3-1 and 3-2. In this example, it is assumed that resource 31-01b for DMRS transmission is transmitted in the 3rd, 4th, 9th, and 10th OFDM symbols. This is used to provide higher-layer MIMO transmission or accurate DMRS channel estimation for high-speed UEs. DMRS and CSI-RS can be transmitted via TDM / FDM / CDM in the third OFDM symbol 31-06 of the four OFDM symbols in 31-05. If CSI-RS is transmitted in 31-05, the advantage is that although CSI-RS ports are transmitted within a single CSI-RS resource, many CSI-RS ports can be transmitted in a short period, thus making transmission robust to time-varying channels. The advantage is that when the number of DMRS REs used is small, both DMRS and CSI-RS can be transmitted in a short time.

[0453] exist Figure 3LIn the third example, to avoid using resource 3l-00 for PDCCH transmission and resource 3l-02 for LTE CRS transmission, NZP or ZP CSI-RS can be transmitted / configured in OFDM symbols 3l-07 (6th, 7th, 10th, 11th, 13th, and 14th) within a time slot containing 14 OFDM symbols. If a time slot contains 7 or fewer OFDM symbols, the corresponding OFDM symbol numbering can therefore be changed. In this case, detailed RE mode configurations for NZP CSI-RS or ZP CSI-RS, ZP SRS within 3l-07 can be configured according to Embodiments 3-1 and 3-2. In this example, it is assumed that resource 3l-01b for DMRS transmission is transmitted in OFDM symbols 3, 4th, 9th, and 10th. This is used to provide higher-layer MIMO transmission or accurate DMRS channel estimation for high-speed UEs. DMRS and CSI-RS can be transmitted via TDM / FDM / CDM in the third OFDM symbol 31-08 of the six OFDM symbols in 31-07. If CSI-RS is transmitted in 31-07, the advantage is that although CSI-RS ports are transmitted within a single CSI-RS resource, many CSI-RS ports can be transmitted in a short period, thus making transmission robust to time-varying channels. If the number of DMRS REs used is small, the advantage is that both DMRS and CSI-RS can be transmitted in a short time.

[0454] Figure 3M This is a diagram illustrating an example of how sub-packets of NR CSI-RS resources can coexist between various signals, such as NR CSI-RS / NR DMRS / LTE CRS.

[0455] exist Figure 3MIn the first example, to avoid using resource 3m-00 for PDCCH transmission and resource 3m-01 for DMRS transmission, NZP or ZP CSI-RS can be transmitted / configured in the 5th, 6th, 7th, and 8th OFDM symbols 3m-03 and 3m-04 of a time slot with 14 OFDM symbols. If a time slot contains 7 or fewer OFDM symbols, the corresponding OFDM symbol numbering can therefore be changed. In this case, detailed RE mode configurations of NZP CSI-RS or ZP CSI-RS, ZP SRS within 3m-03 and 3m-04 can be configured according to Embodiments 3-1 and 3-2. In this example, it is assumed that resource 3m-01 for DMRS transmission is transmitted in the 3rd, 4th, 9th, and 10th OFDM symbols. This is used to provide higher-layer MIMO transmission or accurate DMRS channel estimation for high-speed UEs. In this example, 3m-04, which has the potential to conflict with LTE CRS, has a lower priority than 3m-03, which does not have the potential to conflict with other signals. For example, when configuring CSI-RS resources with a small number or fewer of the eight CSI-RS ports, 3m-03 can be used first. If a large number or more of the eight CSI-RS ports are configured, 3m-04 can be used in addition to 3m-03. In this case, if LTE CRS and NR CSI-RS are transmitted together in 3m-04, the BS can apply separate CSI-RS power boosts on 3m-04 and 3m-03, and can send information about the separate CSI-RS power boosts to the UE through two power boost information parameters Pc.

[0456] exist Figure 3MIn the second example, to avoid using resources for PDCCH transmission and DMRS transmission (resource 3m-00), NZP or ZP CSI-RS can be transmitted / configured in OFDM symbols 3m-05 and 3m-06 of a time slot with 14 OFDM symbols. If a time slot contains 7 or fewer OFDM symbols, the corresponding OFDM symbol numbering can therefore be changed. In this case, detailed RE mode configurations of NZP CSI-RS or ZP CSI-RS, ZP SRS within 3m-05 and 3m-06 can be configured according to Embodiments 3-1 and 3-2. In this example, 3m-06, which has the potential to conflict with LTE CRS, has a lower priority than 3m-05, which does not have the potential to conflict with other signals. For example, when configuring CSI-RS resources with a small number or fewer of 8 CSI-RS ports, 3m-05 can be used first. When configuring CSI-RS resources with a large number or more ports out of 8, 3m-06 can be used in addition to 3m-05. In this case, if LTE CRS and NR CSI-RS are transmitted together in 3m-06, the BS can apply separate CSI-RS power boosts on 3m-06 and 3m-05, and can send information about the separate CSI-RS power boosts to the UE through two power boost information parameters Pc.

[0457] exist Figure 3MIn the third example, to avoid using resource 3m-00 for PDCCH transmission and resource 3m-01 for DMRS transmission, NZP or ZP CSI-RS can be transmitted / configured in OFDM symbols 3m-07, 3m-08, 3m-09, and 3m-10 within a time slot containing 14 OFDM symbols. If a time slot contains 7 or fewer OFDM symbols, the corresponding OFDM symbol numbering can therefore be changed. In this case, detailed RE mode configurations of NZP CSI-RS or ZP CSI-RS, ZPSRS within 3m-07, 3m-08, 3m-09, and 3m-10 can be configured according to Embodiments 3-1 and 3-2. In this example, 3m-08, which may conflict with LTE CRS, or 3m-09, which needs to be multiplexed with DMRS, has a lower priority than 3m-07 or 3m-10, which do not have the potential to conflict with other signals. For example, when configuring CSI-RS resources with a small number or fewer of the eight CSI-RS ports, 3m-07 or 3m-10 can be used first. When configuring a large number or more of the eight CSI-RS ports, 3m-08 and 3m-09 can be used in addition to 3m-07 and 3m-10. In this case, the BS may apply individual CSI-RS power boosts to CSI-RS transmission locations 3m-07, 3m-08, 3m-09, and 3m-10 depending on several reasons (such as coexistence with LTE CRS or DMRS), and can send information about the individual CSI-RS power boosts to the UE through multiple power boost information parameters Pc. Specifically, for CSI acquisition, the NZP UE-specific CSI-RS configuration does not use 3m-10, but it can be used for ZP CSI-RS or cell-specific NZP CSI-RS for time / frequency tracking.

[0458] [(3-5) Examples: CSI-RS Port and Resource Mapping]

[0459] Figure 3NA , 3NB 3NC, 3ND, 3OA, 3OB, 3OC, 3OD, and 3OE are diagrams illustrating examples of CSI-RS port mappings for CSI-RS resources according to embodiments.

[0460] refer to Figure 3NA , 3NB3NC and 3ND, 3n-00 indicates two PDCCH OFDM symbols, two front-loaded DMRS, and one or more additional DMRS OFDM symbols. According to 3n-00, CSI-RS can be transmitted in OFDM symbols {5, 6, 7, 8, 13, 14}. In this case, if UL and DL coexist in a time slot, the actual number of CSI-RS OFDM symbols used can be appropriately adjusted based on the Guard Period (GP) and PUCCH symbols. For example, if one GP OFDM symbol and one PUCCH OFDM symbol are configured, then OFDM symbols {13, 14} are not configured as CSI-RS resources.

[0461] In environments such as 3n-00, 36 two-port CSI-RS resources can be defined as 3n-10 for two-port CSI-RS transmission. To avoid conflicts with LTE CRS, configurations {0, 1, 2, 3, 4, 5, 18, 19, 20, 21, 22, 23} are not used in 3n-10. In the case of four-port CSI-RS, a total of 18 CSI-RS resources can be defined based on four adjacent REs on the frequency / time axis, as in 3n-30. In this case, a CDM-4 can be applied, or two CDM-Ts of length 2 can be applied to a four-port CSI-RS resource. To avoid conflicts with LTE CRS, the CSI-RS resource can be defined as a new mode, as in 3n-40, where the 5th and 8th OFDM symbols are not used. In the case of 8-port CSI-RS, a total of 6 CSI-RS resources can be defined based on 8 adjacent REs on the time and frequency axes, as in 3n-50. In this case, one CDM-8 can be applied, or two CDM-Ts of length 4 can be applied to one 8-port CSI-RS resource. To avoid conflicts with LTE CRS, the 7th OFDM symbol can be empty, and the CSI-RS resource can be defined as in 3n-60. In the case of 24-port CSI-RS, three CSI-RS resources containing 24 REs can be defined as in 3n-70 or 3n-80. CDM-2, CDM-4, ​​or CDM-8 can be applied to each CSI-RS resource. In the case of CDM-2, CDM-T is applied to 2 adjacent REs on the time axis. In the case of CDM-4, ​​CDM-T / F is applied to 4 adjacent REs on the time and frequency axes. In the case of CDM-8, CDM-T / F is applied to 8 adjacent REs on the time and frequency axes. To avoid conflicts with LTE CRS, two CSI-RS resources in which the 5th and 8th OFDM symbols are not used can be defined as in 3n-80.

[0462] refer to Figure 3OA , 3OBIn 3OC, 3OD, and 3OE, 3o-00 indicates three PDCCH OFDM symbols, two preload DMRS, and one or more additional DMRS OFDM symbols. According to 3o-00, CSI-RS can be transmitted in the {6th, 7th, 8th, 9th, 13th, 14th}th OFDM symbols. In this case, if UL and DL coexist in a time slot, the actual number of CSI-RS OFDM symbols used can be appropriately adjusted based on the Guard Period (GP) and PUCCH symbols. For example, if one GPOCCH OFDM symbol and one PUCCH OFDM symbol are configured, the {13th, 14th}th OFDM symbol is not configured as a CSI-RS resource.

[0463] In environments such as 3o-00, 36 two-port CSI-RS resources can be defined as in 3o-10 for two-port CSI-RS transmission. To avoid conflicts with LTE CRS, the OFDM symbol can be empty, and CSI-RS resources can be defined as in 3o-20. In the case of four-port CSI-RS, a total of 18 CSI-RS resources can be defined based on four REs adjacent on the time and frequency axes, as in 3o-30. In this case, a CDM-4 can be applied, or two CDM-Ts of length 2 can be applied to a four-port CSI-RS resource. To avoid conflicts with LTE CRS, the eighth OFDM symbol can be empty, and the CSI-RS resource can be defined as in 3o-40. In the case of eight-port CSI-RS, a total of six CSI-RS resources can be defined based on eight REs adjacent on the time and frequency axes, as in 3o-50. In this scenario, a single CDM-8 can be applied, or two CDM-Ts of length 4 can be applied to an 8-port CSI-RS resource. To avoid conflicts with LTE CRS, the 8th OFDM symbol can be left empty, and the CSI-RS resource can be defined as in 3o-60. In the case of a 24-port CSI-RS, three CSI-RS resources containing 24 REs can be defined as 3o-70 or 3o-80. CDM-2, CDM-4, ​​or CDM-8 can be applied to each CSI-RS resource. In the case of CDM-2, CDM-T is applied to two adjacent REs on the time axis. In the case of CDM-4, ​​CDM-T / F is applied to four adjacent REs on the time and frequency axes. In the case of CDM-8, CDM-T / F is applied to eight adjacent REs on the time and frequency axes. To avoid conflicts with LTE CRS, the 8th OFDM symbol can be empty, and the CSI-RS resource can be defined as in 3o-80.

[0464] Additionally, for ports 8, 12, 16, 24, and 32, which are not described in this example, CSI-RS resources can be defined according to the aggregation method described above.

[0465] [(3-6) Examples: CDM Configuration Method for CSI-RS Transmission]

[0466] The BS can indicate whether to apply CDM and CDM group modes for each CSI-RS resource via higher-layer signaling. For example, the BS can provide higher-layer signaling to the UE, causing the UE to apply at least one of {CDM disabled, CDM-2, CDM-4, ​​CDM-8}. CDM signaling can be implicitly defined based on CSI-RS transmission conditions. For example, the UE can determine whether to apply CDM based on the number of configured CSI-RS ports or the CSI-RS RE mode. In this case, when the number of CSI-RS ports is 2, 4, or less, or when all CSI-RS ports are transmitted in one OFDM symbol, the UE can agree to use CDM disabled. As another example, the UE can determine whether to apply CDM based on the purpose of the CSI-RS transmission. In this scenario, if CSI-RS is used for time / frequency tracking purposes (when it is configured by MIB or SIB) or for beam management purposes (when sub-time units are configured, i.e., when CSI-RS OFDM symbols and data OFDM symbols have...

Claims

1. A method performed by a terminal in a wireless communication system, the method comprising: receiving, from a base station, a control message including first information configuring a grant-free uplink transmission and second information about a period of the grant-free uplink transmission; receiving, from the base station, a downlink control information (DCI) activating the grant-free uplink transmission, the DCI including information for an offset identifying the grant-free uplink transmission; transmitting, to the base station, a first transmission according to the grant-free uplink transmission in a first slot identified by the offset; and transmitting, to the base station, a plurality of second transmissions according to the grant-free uplink transmission in a plurality of second slots occurring after the first slot with the period based on the second information. The grant-free uplink transmission is configured by the control message to be performed based on the DCI activating the grant-free uplink transmission.

2. The method of claim 1, wherein, The control message further includes third information about a radio network temporary identifier (RNTI) for the grant-free uplink transmission, and 3. The method of claim 1, wherein, wherein the DCI is scrambled with the RNTI for the grant-free uplink transmission. The plurality of second transmissions are transmitted until the grant-free uplink transmission is released.

4. The method of claim 1, wherein, 5.A method performed by a base station in a wireless communication system, the method comprising: transmitting, to a terminal, a control message including first information configuring a grant-free uplink transmission and second information about a period of the grant-free uplink transmission; transmitting, to the terminal, a downlink control information (DCI) activating the grant-free uplink transmission, the DCI including information for an offset for the grant-free uplink transmission; receiving, from the terminal, a first transmission according to the grant-free uplink transmission in a first slot based on the offset; and receiving, from the terminal, a plurality of second transmissions according to the grant-free uplink transmission in a plurality of second slots occurring after the first slot with the period based on the second information. The grant-free uplink transmission is configured by the control message to be performed based on the DCI activating the grant-free uplink transmission.

6. The method of claim 5, wherein, The control message further includes third information about a radio network temporary identifier (RNTI) for the grant-free uplink transmission, 7. The method of claim 5, wherein, wherein the DCI is scrambled with the RNTI for the grant-free uplink transmission, and wherein the plurality of second transmissions are received until the grant-free uplink transmission is released. 8.A terminal in a wireless communication system, the terminal comprising: a transceiver; and a controller coupled to the transceiver and configured to: receive, from a base station, a control message including first information configuring a grant-free uplink transmission and second information about a period of the grant-free uplink transmission; receive, from the base station, a downlink control information (DCI) activating the grant-free uplink transmission, the DCI including information for an offset identifying the grant-free uplink transmission; ​ in a first time slot identified based on the offset, transmitting a first transmission to the base station according to the grant-free uplink transmission; and based on the second information, in a plurality of second time slots occurring after the first time slot with the periodicity, transmitting a plurality of second transmissions to the base station according to the grant-free uplink transmission.

9. The terminal according to claim 8, wherein The grant-free uplink transmission is configured by the control message to be performed based on the DCI activating the grant-free uplink transmission.

10. The terminal of claim 8, wherein, The control message further includes third information about a radio network temporary identifier (RNTI) for the grant-free uplink transmission, and wherein the DCI is scrambled with the RNTI for the grant-free uplink transmission.

11. The terminal of claim 8, wherein, The plurality of second transmissions are transmitted until the grant-free uplink transmission is released. 12.A base station of a wireless communication system, the base station comprising: a transceiver; and a controller coupled to the transceiver and configured to: transmit, to a terminal, a control message including first information configuring a grant-free uplink transmission and second information about a periodicity of the grant-free uplink transmission; transmit, to the terminal, a downlink control information (DCI) activating the grant-free uplink transmission, the DCI including information of an offset for the grant-free uplink transmission; receive, from the terminal, a first transmission according to the grant-free uplink transmission in a first time slot based on the offset; and based on the second information, receive, from the terminal, a plurality of second transmissions according to the grant-free uplink transmission in a plurality of second time slots occurring after the first time slot with the periodicity.

13. The base station of claim 12, wherein, The grant-free uplink transmission is configured by the control message to be performed based on the DCI activating the grant-free uplink transmission.

14. The base station of claim 12, wherein, The control message further includes third information about a radio network temporary identifier (RNTI) for the grant-free uplink transmission, wherein the DCI is scrambled with the RNTI for the grant-free uplink transmission.

15. The base station of claim 12, wherein, The plurality of second transmissions are received until the grant-free uplink transmission is released.

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