Method and apparatus for resource allocation for network coordination

Abstract

The present disclosure relates to a communication technique and a system for integrating a 5G (5th generation) or pre-5G communication system with IoT technology to support higher data transmission rates than those of 4G (4th generation) communication systems such as LTE (Long Term Evolution). The present disclosure may be applied to intelligent services (e.g., smart homes, smart buildings, smart cities, smart cars or connected cars, healthcare, digital education, retail, security and safety-related services, etc.) based on 5G communication technology and IoT-related technology. According to various embodiments of the present invention, a method and apparatus for allocating time and frequency resources to provide services smoothly are provided.

Description

Technology Field

[0001] The present invention relates to a wireless communication system, and more specifically, to a method and apparatus for allocating time and frequency resources to provide services smoothly. Background Technology

[0002] Efforts are being made to develop improved 5G communication systems or pre-5G communication systems to meet the increasing demand for wireless data traffic following the commercialization of 4G communication systems. For this reason, 5G communication systems or pre-5G communication systems are referred to as communication systems beyond 4G networks or systems after LTE systems.

[0003] To achieve high data transmission rates, 5G communication systems are being considered for implementation in the mmWave band (e.g., the 60 GHz band). To mitigate path loss and increase the transmission distance of radio waves in the mmWave band, beamforming, massive MIMO, full-dimensional MIMO (FD-MIMO), array antenna, analog beamforming, and large-scale antenna technologies are being discussed for 5G communication systems.

[0004] In addition, to improve the network of the system, technologies such as advanced small cell, advanced small cell, cloud radio access network (cloud RAN), ultra-dense network, Device to Device communication (D2D), wireless backhaul, moving network, cooperative communication, Coordinated Multi-Points (CoMP), and interference cancellation are being developed in 5G communication systems. Furthermore, in 5G systems, advanced coding modulation (ACM) methods such as Hybrid FSK and QAM Modulation (FQAM) and Sliding Window Superposition Coding (SWSC), as well as advanced access technologies such as Filter Bank Multi Carrier (FBMC), Non-Orthogonal Multiple Access (NOMA), and Spare Code Multiple Access (SCMA), are being developed.

[0005] 5G systems are considering support for a wider variety of services compared to existing 4G systems. For example, the most representative services may include enhanced mobile broadband (eMBB), ultra-reliable and low-latency communication (URLLC), massive machine-type communication (mMTC), and evolved multimedia broadcast / multicast service (eMBMS). Furthermore, a system providing the aforementioned URLLC service may be referred to as a URLLC system, and a system providing eMBB service may be referred to as an eMBB system. Additionally, the terms "service" and "system" may be used interchangeably.

[0006] Among these, URLLC services are being newly considered in 5G systems, unlike existing 4G systems, and require the satisfaction of ultra-high reliability (e.g., packet error rate of about 10⁻⁵) and low latency (e.g., about 0.5 msec) conditions compared to other services. To satisfy these strict requirements, URLLC services may require the application of a transmission time interval (TTI) shorter than that of eMBB services, and various operational methods utilizing this are being considered.

[0007] Meanwhile, the Internet is evolving from a human-centered network where humans generate and consume information into an IoT (Internet of Things) network where distributed components, such as objects, exchange and process information. IoE (Internet of Everything) technology, which combines IoT with Big Data processing technologies through connections with cloud servers, is also emerging. To implement IoT, technological elements such as sensing technology, wired and wireless communication and network infrastructure, service interface technology, and security technology are required; consequently, technologies such as sensor networks, Machine-to-Machine (M2M) communication, and Machine-Type Communication (MTC) are currently being researched to facilitate the connection of objects. In an IoT environment, intelligent IT services that create new value for human life by collecting and analyzing data generated from connected objects can be provided. Through the convergence and integration of existing IT technologies with various industries, IoT can be applied to fields such as smart homes, smart buildings, smart cities, smart or connected cars, smart grids, healthcare, smart home appliances, and advanced medical services.

[0008] Accordingly, various attempts are being made to apply 5G communication systems to IoT networks. For example, technologies such as sensor networks, Machine to Machine (M2M), and Machine Type Communication (MTC) are being implemented using 5G communication techniques such as beamforming, MIMO, and array antennas. The application of cloud RAN as a big data processing technology, as previously described, can also be considered an example of the convergence of 5G and IoT technologies. The problem to be solved

[0009] One embodiment of the present invention aims to provide a method and apparatus for allocating time and frequency resources to provide services smoothly in a wireless communication system.

[0010] The technical problems to be solved by the present invention are not limited to those mentioned above, and other technical problems not mentioned will be clearly understood by those skilled in the art to which the present invention belongs from the description below. means of solving the problem

[0011] The present invention, for solving the above-mentioned problems, is characterized in that a method for processing a control signal in a wireless communication system comprises: a step of receiving a first control signal transmitted from a base station; a step of processing the received first control signal; and a step of transmitting a second control signal generated based on the processing to the base station. Effects of the invention

[0012] According to one embodiment of the present invention, time and frequency resources can be efficiently allocated in a wireless communication system.

[0013] The effects obtainable from the present invention are not limited to those mentioned above, and other unmentioned effects will be clearly understood by those skilled in the art from the description below. Brief explanation of the drawing

[0014] FIG. 1 is a diagram showing the time-frequency domain transmission structure of the LTE, LTE-A, NR, or similar wireless communication system of the present invention. FIG. 2 is a diagram illustrating the frame, subframe, and slot structure in the 5G of the present invention. FIG. 3 illustrates an example of a bandwidth portion configuration according to one embodiment of the present invention. FIG. 4 is a drawing illustrating an example of bandwidth portion indication and change according to an embodiment of the invention. FIG. 5 is a diagram illustrating an example of setting a control area of ​​a downlink control channel according to an embodiment of the present invention. FIG. 6 is a diagram illustrating an example of PDSCH frequency axis resource allocation according to one embodiment of the present invention. FIG. 7 is a diagram illustrating an example of time axis resource allocation of NR according to an embodiment of the present invention. FIG. 8 is a diagram illustrating an example of time-axis resource allocation according to the subcarrier intervals of a data channel and a control channel according to an embodiment of the present invention. FIG. 9 is a diagram illustrating a base station and terminal protocol stack when performing single cell, carrier aggregation, and dual connectivity according to an embodiment of the present invention. FIG. 10 is a diagram illustrating an example of cooperative communication antenna port configuration and resource allocation according to an embodiment of the present invention. FIG. 11 is a drawing illustrating an example of a cooperative communication DCI configuration according to an embodiment of the present invention. FIG. 12 is a drawing illustrating an example of a stepwise FD-RA according to an embodiment of the present invention. FIG. 13 is a drawing illustrating a PDCCH monitoring occasion according to a PDSCH mapping type according to an embodiment of the present invention. FIG. 14 is a diagram illustrating a method for monitoring two or more PDSCHs according to one embodiment of the present invention. FIG. 15 is a diagram illustrating another example of a method for monitoring two or more PDSCHs according to one embodiment of the present invention. FIG. 16 is a block diagram illustrating the structure of a terminal according to one embodiment of the present invention. FIG. 17 is a block diagram illustrating the structure of a base station according to one embodiment of the present invention. FIG. 18 is a diagram illustrating an example of a bitmap for RBG-TRP relationships and RBG assignment according to an embodiment of the present invention. Specific details for implementing the invention

[0015] Hereinafter, embodiments of the present invention will be described in detail with reference to the attached drawings.

[0016] In describing the embodiments, technical details that are well known in the technical field to which the present invention belongs and are not directly related to the present invention are omitted. This is intended to convey the essence of the present invention more clearly without obscuring it by omitting unnecessary explanations.

[0017] For the same reason, some components in the attached drawings have been exaggerated, omitted, or schematically depicted. Additionally, the size of each component does not entirely reflect its actual dimensions. Identical or corresponding components in each drawing have been assigned the same reference number.

[0018] The advantages and features of the present invention and the methods for achieving them will become clear by referring to the embodiments described below in detail together with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below but can be implemented in various different forms. The embodiments of the present disclosure are provided merely to make the present disclosure complete and to fully inform those skilled in the art of the scope of the invention, and the present disclosure is defined only by the scope of the claims. Throughout the specification, the same reference numerals refer to the same components.

[0019] At this point, it will be understood that each block of the process flow diagrams and combinations of the flow diagrams can be executed by computer program instructions. Since these computer program instructions can be loaded into the processor of a general-purpose computer, a special-purpose computer, or other programmable data processing equipment, the instructions executed through the processor of the computer or other programmable data processing equipment create means to perform the functions described in the flow diagram block(s). Since these computer program instructions can also be stored in computer-available or computer-readable memory that can be directed toward the computer or other programmable data processing equipment to implement the function in a specific way, the instructions stored in computer-available or computer-readable memory can also produce a manufactured item containing means of instruction to perform the function described in the flow diagram block(s). Since computer program instructions can be loaded onto a computer or other programmable data processing equipment, instructions that execute a computer or other programmable data processing equipment by performing a series of operation steps on the computer or other programmable data processing equipment to create a process executed by the computer may also provide steps for executing the functions described in the flowchart block(s).

[0020] Additionally, each block may represent a module, segment, or part of code containing one or more executable instructions for executing a specific logical function(s). It should also be noted that in some alternative execution examples, the functions mentioned in the blocks may occur out of order. For instance, two blocks described in succession may actually be executed substantially simultaneously, or the blocks may be executed in reverse order depending on the corresponding function.

[0021] In this embodiment, the term "part" used refers to a software or hardware component such as an FPGA (Field Programmable Gate Array) or an ASIC (Application Specific Integrated Circuit), and the "part" performs certain roles. However, the meaning of "part" is not limited to software or hardware. The "part" may be configured to reside in an addressable storage medium or may be configured to run one or more processors. Accordingly, according to some embodiments, the "part" includes components such as software components, object-oriented software components, class components, and task components, as well as processes, functions, attributes, procedures, subroutines, segments of program code, drivers, firmware, microcode, circuits, data, databases, data structures, tables, arrays, and variables. The functions provided within the components and "parts" may be combined into a smaller number of components and "parts" or further separated into additional components and "parts." In addition, the components and 'parts' may be implemented to utilize one or more CPUs within the device or secure multimedia card. Furthermore, according to some embodiments, the 'parts' may include one or more processors.

[0022] The operating principle of the present invention will be described in detail below with reference to the attached drawings. In describing the present invention below, if it is determined that a detailed description of related known functions or configurations may unnecessarily obscure the essence of the present invention, such detailed description will be omitted. Furthermore, the terms described below are defined considering their functions in the present invention, and these may vary depending on the intentions or conventions of the user or operator. Therefore, such definitions should be based on the content throughout this specification. Hereinafter, a base station is an entity that performs resource allocation for terminals and may be at least one of a gNode B, eNode B, Node B, BS (Base Station), wireless access unit, base station controller, or a node on a network. A terminal may include a UE (User Equipment), MS (Mobile Station), cellular phone, smartphone, computer, or a multimedia system capable of performing communication functions. Of course, it is not limited to the above examples.

[0023] The present disclosure describes a technology for a terminal to receive broadcast information from a base station in a wireless communication system. The present invention relates to a communication technique and a system that fuses a 5G communication system with IoT technology to support a higher data transmission rate than that of a 4G system. The present disclosure can be applied to intelligent services (e.g., smart home, smart building, smart city, smart car or connected car, healthcare, digital education, retail, security and safety-related services, etc.) based on 5G communication technology and IoT-related technology.

[0024] Terms used in the following description to refer to broadcast information, control information, communication coverage, state changes (e.g., events), network entities, messages, and device components are examples provided for the convenience of explanation. Accordingly, the present invention is not limited to the terms described below, and other terms having equivalent technical meanings may be used.

[0025] For the convenience of the following explanation, some terms and names defined in the 3GPP LTE (3rd generation partnership project long term evolution) standard may be used. However, the present invention is not limited by the above terms and names and can be applied in the same way to systems conforming to other standards.

[0026] Wireless communication systems are evolving from providing early voice-oriented services to broadband wireless communication systems that provide high-speed, high-quality packet data services, such as communication standards like 3GPP’s HSPA (High Speed ​​Packet Access), LTE (Long Term Evolution or E-UTRA (Evolved Universal Terrestrial Radio Access)), LTE-Advanced (LTE-A), LTE-Pro, 3GPP2’s HRPD (High Rate Packet Data), UMB (Ultra Mobile Broadband), and IEEE’s 802.16e.

[0027] As a representative example of a broadband wireless communication system, the LTE system employs the Orthogonal Frequency Division Multiplexing (OFDM) method for the downlink (DL) and the Single Carrier Frequency Division Multiple Access (SC-FDMA) method for the uplink (UL). The uplink refers to a wireless link through which a terminal (User Equipment (UE) or Mobile Station (MS)) transmits data or control signals to a base station (eNode B, or base station (BS)), and the downlink refers to a wireless link through which a base station transmits data or control signals to a terminal. The above multiple access method distinguishes the data or control information of each user by allocating and operating time-frequency resources to be transmitted for each user so that they do not overlap, that is, so that orthogonality is established.

[0028] As a future communication system following LTE, that is, a 5G communication system, it must be able to freely reflect the diverse requirements of users and service providers, and therefore, services that satisfy these diverse requirements must be supported. Services being considered for the 5G communication system include Enhanced Mobile BroadBand (eMBB), Massive Machine Type Communication (mMTC), and Ultra Reliability Low Latency Communication (URLLC).

[0029] According to some embodiments, eMBB aims to provide data transmission speeds that are higher than those supported by existing LTE, LTE-A, or LTE-Pro. For example, in a 5G communication system, eMBB must be able to provide a peak data rate of 20 Gbps in the downlink and a peak data rate of 10 Gbps in the uplink from the perspective of a single base station. At the same time, it must provide an increased user-perceived data rate. To satisfy these requirements, improvements in transmission and reception technologies are required, including enhanced Multi-Input Multi-Output (MIMO) transmission technology. Additionally, the data transmission speed required by the 5G communication system can be satisfied by using a frequency bandwidth wider than 20 MHz in the 3–6 GHz or higher frequency bands instead of the 2 GHz band currently used by LTE.

[0030] At the same time, mMTC is being considered to support application services such as the Internet of Things (IoT) in 5G communication systems. To efficiently provide IoT, mMTC may require support for the connection of a large number of terminals within a cell, improved terminal coverage, enhanced battery life, and reduced terminal costs. Since IoT provides communication functions by attaching to various sensors and devices, a large number of terminals within a cell (e.g., 1,000,000 terminals / km²) 2It must be able to support mMTC. In addition, due to the nature of the service, terminals supporting mMTC are likely to be located in dead zones where cells cannot cover, such as building basements, so they may require wider coverage compared to other services provided by the 5G communication system. Terminals supporting mMTC must consist of low-cost devices, and since it is difficult to frequently replace the device's battery, a very long battery life may be required.

[0031] Finally, URLLC is a mission-critical cellular-based wireless communication service used for remote control of robots or machinery, industrial automation, unmanned aerial vehicles, remote health care, and emergency alerts; it must provide communication that offers ultra-low latency and ultra-reliability. For example, services supporting URLLC must satisfy an air interface latency of less than 0.5 milliseconds and simultaneously have a packet error rate of 10⁻⁵ or less. Therefore, for services supporting URLLC, 5G systems must provide a Transmit Time Interval (TTI) smaller than other services, and design specifications are required to allocate a wide range of resources in the frequency band. However, the aforementioned mMTC, URLLC, and eMBB are merely examples of different service types, and the service types to which the present disclosure applies are not limited to the examples mentioned above.

[0032] The services considered in the aforementioned 5G communication system must be provided by converging with one another based on a single framework. In other words, for efficient resource management and control, it is desirable for each service to be integrated into a single system for control and transmission rather than operated independently.

[0033] In addition, although embodiments of the present invention are described below using LTE, LTE-A, LTE Pro, or NR systems as examples, embodiments of the present invention may be applied to other communication systems having similar technical backgrounds or channel types. Furthermore, embodiments of the present invention may be applied to other communication systems with some modifications made at the judgment of a person with skilled technical knowledge, without significantly departing from the scope of the present invention.

[0035] The frame structure of the 5G system will be explained in more detail below with reference to the drawings.

[0036] FIG. 1 is a diagram illustrating the basic structure of the time-frequency domain, which is a wireless resource domain where data or control channels are transmitted in the 5G system of the present invention.

[0037] In FIG. 1, the horizontal axis represents the time domain, and the vertical axis represents the frequency domain. In the time and frequency domains, the basic unit of a resource is a resource element (RE, 1-01), which can be defined as one OFDM (Orthogonal Frequency Division Multiplexing) symbol (1-02) on the time axis and one subcarrier (1-03) on the frequency axis. In the frequency domain (For example, 12) consecutive REs can form a single resource block (Resource Block, RB, 1-04).

[0038] FIG. 2 is a diagram illustrating a slot structure considered in the 5G system of the present invention.

[0039] FIG. 2 illustrates an example of a frame (2-00), subframe (2-01), and slot (2-02) structure. One frame (2-00) can be defined as 10ms. One subframe (2-01) can be defined as 1ms, and thus one frame (2-00) can be composed of a total of 10 subframes (2-01). One slot (2-02, 2-03) can be defined as 14 OFDM symbols (i.e., the number of symbols per slot ( )=14). One subframe (2-01) may be composed of one or more slots (2-02, 2-03), and the number of slots (2-02, 2-03) per one subframe (2-01) may vary depending on the setting value μ (2-04, 2-05) for the subcarrier spacing. In one example of FIG. 2, cases where μ=0 (2-04) and μ=1 (2-05) are shown as the setting value for the subcarrier spacing. When μ=0 (2-04), one subframe (2-01) may be composed of one slot (2-02), and when μ=1 (2-05), one subframe (2-01) may be composed of two slots (2-03). That is, the number of slots per one subframe ( ) may vary, and accordingly, the number of slots per frame ( ) may vary. Depending on each subcarrier spacing setting μ and It can be defined by [Table 1] below.

[0040] [Table 1]

[0041]

[0042] In NR, a single component carrier (CC) or serving cell can be composed of up to 250 or more serving cells (RBs). Therefore, if a terminal always receives the entire serving cell bandwidth, as in LTE, the terminal's power consumption can be severe. To address this, the base station can support the terminal in changing the reception area within the cell by setting one or more bandwidth parts (BWPs). In NR, the base station can set an 'initial BWP,' which is the bandwidth of CORESET #0 (or common search space, CSS), to the terminal via the MIB. Subsequently, the base station sets the terminal's initial BWP (first BWP) through RRC signaling and can notify at least one BWP setting information that can be indicated via the DCI in the future. Afterward, the base station can indicate which band the terminal will use by announcing the BWP ID via the DCI. If the terminal fails to receive the DCI from the currently allocated BWP for a certain period of time or longer, the terminal reverts to the 'default BWP' and attempts to receive the DCI.

[0043] FIG. 3 is a diagram illustrating an example of a setting for a bandwidth portion in a 5G communication system according to an embodiment of the present invention.

[0044] FIG. 3 shows an example in which the terminal bandwidth (3-00) is set to two bandwidth parts, namely bandwidth part #1 (3-05) and bandwidth part #2 (3-10). The base station may set one or more bandwidth parts for the terminal and may set the information in [Table 2] below for each bandwidth part.

[0045] [Table 2]

[0046]

[0048] In addition to the above configuration information, various parameters related to the bandwidth portion may be configured for the terminal. The above information may be transmitted by the base station to the terminal via upper-layer signaling, such as RRC signaling. Among the one or more configured bandwidth portions, at least one bandwidth portion may be activated. Whether a configured bandwidth portion is activated may be transmitted semi-statically from the base station to the terminal via RRC signaling, or dynamically via MAC CE (control element) or DCI.

[0049] The settings for the bandwidth portion supported by the above 5G communication system can be used for various purposes.

[0050] For example, if the bandwidth supported by the terminal is smaller than the system bandwidth, this can be supported through the above-mentioned bandwidth portion setting. For instance, by setting the frequency position of the bandwidth portion (setting information 1) in Table 2 above to the terminal, the terminal can transmit and receive data at a specific frequency position within the system bandwidth.

[0051] As another example, a base station may set multiple bandwidth portions for a terminal for the purpose of supporting different numerologies. For instance, to support data transmission and reception using both a 15 kHz subcarrier interval and a 30 kHz subcarrier interval for a terminal, two bandwidth portions may be configured to use subcarrier intervals of 15 kHz and 30 kHz, respectively. Different bandwidth portions can be FDMed, and if data transmission and reception is to be performed using a specific subcarrier interval, the bandwidth portion configured for that subcarrier interval may be activated.

[0052] As another example, a base station may set bandwidth portions with different bandwidth sizes for the purpose of reducing the power consumption of the terminal. For instance, if a terminal supports a very large bandwidth, such as 100 MHz, and always transmits and receives data using that bandwidth, it can cause very high power consumption. In particular, in a situation where there is no traffic, it is very inefficient from a power consumption perspective for the terminal to perform unnecessary monitoring of downlink control channels using the large 100 MHz bandwidth. Therefore, to reduce the power consumption of the terminal, the base station may set a bandwidth portion with a relatively smaller bandwidth, such as 20 MHz, for the terminal. In a situation where there is no traffic, the terminal can perform monitoring operations in the 20 MHz bandwidth portion, and when data is generated, it can transmit and receive data using the 100 MHz bandwidth portion according to the instructions of the base station.

[0054] FIG. 4 is a diagram illustrating a method for changing dynamic settings for a bandwidth portion according to an embodiment of the present invention.

[0055] As explained in [Table 2] above, the base station can set one or more bandwidth portions for the terminal, and through the settings for each bandwidth portion, it can provide information regarding the bandwidth of the bandwidth portion, the frequency position of the bandwidth portion, the numerology of the bandwidth portion, etc. FIG. 4 shows an example in which two bandwidth portions, Bandwidth Part #1 (BPW#1, 4-05) and Bandwidth Part #2 (BWP#2, 4-10), are set within the terminal bandwidth (4-00) for a terminal. Among the set bandwidths, one or more bandwidth portions may be activated, and FIG. 4 considers an example in which one bandwidth portion is activated. In FIG. 4, Bandwidth Part #1 (4-02) is activated among the bandwidth portions set in Slot #0 (4-25), and the terminal can monitor the PDCCH in the control area #1 (4-45) set in Bandwidth Part #1 (4-05) and can transmit and receive data (4-55) in Bandwidth Part #1 (4-05). Depending on which of the configured bandwidth portions is activated, the control area where the terminal receives the PDCCH may differ, and accordingly, the bandwidth where the terminal monitors the PDCCH may differ.

[0056] The base station may additionally transmit an indicator to the terminal for changing the configuration of a bandwidth portion. Here, changing the configuration of a bandwidth portion can be considered equivalent to the operation of activating a specific bandwidth portion (e.g., changing the activation from bandwidth portion A to bandwidth portion B). The base station may transmit a Configuration Switching Indicator to the terminal in a specific slot, and after receiving the Configuration Switching Indicator from the base station, the terminal may determine the bandwidth portion to be activated by applying the changed configuration according to the Configuration Switching Indicator from a specific point in time and perform monitoring of the PDCCH in the control area configured in the activated bandwidth portion.

[0057] In FIG. 4, the base station may transmit a Configuration Switching Indication (4-15) in slot #1 (4-30) to the terminal, instructing it to change the activated bandwidth portion from the existing bandwidth portion #1 (4-05) to bandwidth portion #2 (4-10). After receiving the indication, the terminal may activate bandwidth portion #2 (6-10) according to the content of the indication. At this time, a Transition Time (4-20) may be required for changing the bandwidth portion, and accordingly, the timing for changing and applying the activated bandwidth portion may be determined. FIG. 4 illustrates a case where a transition time (4-20) of one slot is required after receiving the Configuration Switching Indication (4-15). Data transmission and reception may not be performed during the said transition time (4-60). Accordingly, in slot #2 (4-35), bandwidth portion #2 (4-10) is activated, and the operation of transmitting and receiving control channels and data to and from the corresponding bandwidth portion can be performed.

[0058] The base station may pre-configure one or more bandwidth portions for the terminal using upper layer signaling (e.g., RRC signaling), and may instruct activation by a configuration change indicator (4-15) that maps to one of the bandwidth portion settings pre-configured by the base station. For example, a log2N-bit indicator may select and indicate one of N pre-configured bandwidth portions. [Table 3] below shows an example of indicating configuration information for a bandwidth portion using a 2-bit indicator.

[0059] [Table 3]

[0060]

[0062] The setting change indicator (4-15) for the bandwidth portion described above can be transmitted from the base station to the terminal in the form of MAC (Medium Access Control) CE (Control Element) signaling or L1 signaling (e.g., common DCI, group-common DCI, terminal-specific DCI).

[0063] The timing of when the bandwidth portion activation is applied according to the bandwidth portion setting change indicator (4-15) described above is as follows. The timing of when the setting change is applied may be determined by a predefined value (e.g., applied after N (≥1) slots after receiving the setting change indicator), or by the base station setting it to the terminal via upper layer signaling (e.g., RRC signaling), or by being transmitted as part of the content of the setting change indicator (4-15). Alternatively, it may be determined by a combination of the above methods. The terminal may apply the changed setting from the time obtained by the above method after receiving the bandwidth portion setting change indicator (4-15).

[0065] In the following, the downlink control channel in a 5G communication system will be explained in more detail with reference to the drawings.

[0066] FIG. 5 is a diagram illustrating an example of a control area (Control Resource Set, CORESET) in which a downlink control channel is transmitted in a 5G wireless communication system according to an embodiment of the present invention.

[0067] FIG. 5 shows an example in which two control areas (control area #1 (5-01), control area #2 (5-02)) are set within a bandwidth portion (5-10) of the terminal on the frequency axis and one slot (5-20) on the time axis. The control areas (5-01, 5-02) can be set in a specific frequency resource (5-03) within the entire terminal bandwidth portion (5-10) on the frequency axis. On the time axis, they can be set with one or more OFDM symbols and can be defined as the control area length (Control Resource Set Duration, 5-04). In the example of FIG. 5, control area #1 (5-01) is set to a control area length of 2 symbols, and control area #2 (5-02) is set to a control area length of 1 symbol.

[0068] The control domain in 5G described above can be configured by the base station to the terminal through upper-layer signaling (e.g., System Information, MIB (Master Information Block), RRC (Radio Resource Control) signaling). Configuring the control domain to the terminal means providing information such as the control domain identifier (Identity), the frequency location of the control domain, and the symbol length of the control domain. For example, it may include the information in [Table 4].

[0069] [Table 4]

[0070]

[0072] In the above [Table 4], the tci-StatesPDCCH (simply named TCI state) configuration information may include information on one or more SS (Synchronization Signal) / PBCH (Physical Broadcast Channel) block indices or CSI-RS (Channel State Information Reference Signal) indices that are in a QCL (Quasi Co Located) relationship with the DMRS transmitted in the corresponding control area.

[0074] The following describes the methods for allocating time and frequency resources for data transmission in NR.

[0075] In addition to the frequency domain resource candidate allocation through the above-mentioned BWP indication, NR provides the following detailed frequency domain resource allocation methods (frequency domain resource allocation, FD-RA).

[0076] FIG. 6 is a diagram illustrating an example of PDSCH frequency axis resource allocation according to one embodiment of the present invention.

[0077] FIG. 6 is a diagram illustrating three frequency axis resource allocation methods, type 0 (6-00), type 1 (6-05), and dynamic switch (6-10), which can be configured through the upper layer in NR.

[0078] If the terminal is configured to use only resource type 0 through upper-layer signaling (6-00), some DCI (downlink control information) that allocates PDSCH to the terminal is N RBG It has a bitmap composed of bits. The conditions for this will be explained again later. In this case, N RBGThis refers to the number of RBG (resource block group) determined as shown in [Table 5] below according to the BWP size assigned by the above BWP indicator and the upper layer parameter rbg-Size, and data is transmitted to the RBG indicated as 1 by the above bitmap.

[0079] [Table 5]

[0080]

[0081] If the terminal is configured to use only resource type 1 through upper layer signaling (6-05), some DCI (downlink control information) that assigns PDSCH to the terminal is It has frequency axis resource allocation information consisting of bits. The conditions for this will be explained later. Through this, the base station can set the starting VRB (virtual RB) (6-20) and the length (6-25) of the frequency axis resources continuously allocated from it. Each of the above VRBs is mapped 1:1 with the PRB through a specific rule.

[0082] If the terminal is configured to use both resource type 0 and resource type 1 through upper layer signaling (6-10), some DCI (downlink control information) that allocates PDSCH to the terminal has frequency axis resource allocation information consisting of bits of the larger value (6-35) between the payload (6-15) for setting resource type 0 and the payload (6-20, 6-25) for setting resource type 1. The conditions for this will be explained later. At this time, one bit is added to the beginning part (MSB) of the frequency axis resource allocation information within the DCI; if it is 0, it indicates that resource type 0 is used, and if it is 1, it indicates that resource type 1 is used.

[0084] FIG. 7 is a diagram illustrating an example of time axis resource allocation of NR according to an embodiment of the present invention.

[0085] Referring to FIG. 7, the base station has a subcarrier spacing of the data channel and control channel configured in the upper layer ( , It is possible to indicate the time axis position of a PDSCH resource according to the OFDM symbol start position (7-00) and length (7-05) within a slot that are dynamically indicated through the ), scheduling offset (K0) value and DCI.

[0086] FIG. 8 is a diagram illustrating an example of time-axis resource allocation according to the subcarrier interval of a data channel and a control channel according to an embodiment of the present invention.

[0087] Referring to Fig. 8, when the subcarrier spacing of the data channel and the control channel is the same (8-00, Since the slot numbers of the data and control channels are the same, it can be seen that the base station and terminal generate a scheduling offset in accordance with the predetermined slot offset K0. On the other hand, when the subcarrier spacing of the data channel and the control channel is different (8-05, Since the slot numbers of data and control are different, it can be seen that the base station and terminal generate a scheduling offset based on the subcarrier interval of the PDCCH and the predetermined slot offset K0.

[0089] In order to efficiently receive control channels at the terminal, NR provides various forms of DCI (downlink control information) formats according to purpose, as shown in [Table 6] below.

[0090] [Table 6]

[0091]

[0093] For example, a base station may use DCI format 0_0 or DCI format 0_1 ​​to schedule PDSCH to a cell.

[0094] When DCI format 0_1 ​​is transmitted with a CRC scrambled by a C-RNTI (Cell Radio Network Temporary Identifier), CS-RNTI (Configured Scheduling RNTI), or new-RNTI, it includes at least the following information:

[0095] ● Identifier for DCI formats (1 bit): Always set to 1 as the DCI format indicator

[0096] ● Frequency domain resource assignment (N RBG bits or bits): Indicates frequency axis resource allocation, and when DCI format 1_0 is monitored in the UE-specific search space is the size of the active DL BWP, and in other cases is the size of the initial DL BWP. N RBG is the number of resource block groups. For detailed methods, refer to the frequency axis resource allocation above.

[0097] ● Time domain resource assignment (0~4 bits): Instructs the allocation of time-axis resources according to the above description.

[0098] ● VRB-to-PRB mapping(1 bit): 0 indicates non-interleaved, and 1 indicates interleaved VRP-to-PRB mapping.

[0099] ● Modulation and coding scheme (5 bits): Indicates the modulation order and coding rate used for PDSCH transmission.

[0100] ● New data indicator (1 bit): Indicates whether the PDSCH is an initial transmission or a retransmission depending on whether it is toggled.

[0101] ● Redundancy version (2 bits): Indicates the redundancy version used for PDSCH transmission.

[0102] ● HARQ process number (4 bits): Indicates the HARQ process number used for PDSCH transmission.

[0103] ● Downlink assignment index (2 bits): DAI indicator

[0104] ● TPC command for scheduled PUCCH (2 bits): PUCCH power control indicator

[0105] ● PUCCH resource indicator (3 bits): A PUCCH resource indicator that indicates one of the 8 resources set to the upper layer.

[0106] ● PDSCH-to-HARQ_feedback timing indicator(3 bits): HARQ feedback timing indicator, which indicates one of the 8 feedback timing offsets set to the upper layer.

[0107] When DCI format 1_1 is transmitted with a CRC scrambled by a C-RNTI (Cell Radio Network Temporary Identifier), CS-RNTI (Configured Scheduling RNTI), or new-RNTI, it includes at least the following information:

[0108] ● Identifier for DCI formats (1 bit): Always set to 1 as the DCI format indicator

[0109] ● Carrier indicator (0 or 3 bits): Indicates the CC (or cell) to which the PDSCH assigned by the corresponding DCI is transmitted.

[0110] ● Bandwidth part indicator (0 or 1 or 2 bits): Indicates the BWP to which the PDSCH assigned by the corresponding DCI is transmitted.

[0111] ● Frequency domain resource assignment (payload determined according to the above frequency domain resource assignment): Instructs frequency domain resource assignment, and is the size of the active DL BWP. For details on the method, refer to the frequency axis resource allocation above.

[0112] ● Time domain resource assignment (0 ~ 4 bits): Instructs time domain resource allocation according to the above description.

[0113] ● VRB-to-PRB mapping (0 or 1 bit): 0 indicates non-interleaved VRP-to-PRB mapping, and 1 indicates interleaved VRP-to-PRB mapping. It is 0 bit if the frequency axis resource allocation is set to resource type 0.

[0114] ● PRB bundling size indicator (0 or 1 bit): 0 bit if the upper layer parameter prb-BundlingType is not set or is set to 'static', and 1 bit if it is set to 'dynamic'.

[0115] ● Rate matching indicator (0 or 1 or 2 bits): Indicates the rate matching pattern.

[0116] ● ZP CSI-RS trigger(0 or 1 or 2 bits): An indicator that triggers the aperiodic ZP CSI-RS.

[0117] ● For transport block 1:

[0118] ■ Modulation and coding scheme (5 bits): Indicates the modulation order and coding rate used for PDSCH transmission.

[0119] ■ New data indicator (1 bit): Indicates whether the PDSCH is an initial transmission or a retransmission depending on whether it is toggled.

[0120] ■ Redundancy version (2 bits): Indicates the redundancy version used for PDSCH transmission.

[0121] ● For transport block 2:

[0122] ■ Modulation and coding scheme (5 bits): Indicates the modulation order and coding rate used for PDSCH transmission.

[0123] ■ New data indicator (1 bit): Indicates whether the PDSCH is an initial transmission or a retransmission depending on whether it is toggled.

[0124] ■ Redundancy version (2 bits): Indicates the redundancy version used for PDSCH transmission.

[0125] ● HARQ process number (4 bits): Indicates the HARQ process number used for PDSCH transmission.

[0126] ● Downlink assignment index (0 or 2 or 4 bits): DAI indicator

[0127] ● TPC command for scheduled PUCCH (2 bits): PUCCH power control indicator

[0128] ● PUCCH resource indicator (3 bits): A PUCCH resource indicator that indicates one of the 8 resources set to the upper layer.

[0129] ● PDSCH-to-HARQ_feedback timing indicator(3 bits): HARQ feedback timing indicator, which indicates one of the 8 feedback timing offsets set to the upper layer.

[0130] ● Antenna port (4 or 5 or 6 bits): Indicates DMRS port and CDM group without data.

[0131] ● Transmission configuration indication (0 or 3 bits): TCI indicator.

[0132] ● SRS request (2 or 3 bits): SRS transmission request indicator

[0133] ● CBG transmission information (0 or 2 or 4 or 6 or 8 bits): An indicator indicating whether code block groups within the allocated PDSCH are transmitted. 0 means that the corresponding CBG is not transmitted, and 1 means that it is transmitted.

[0134] ● CBG flushing out information (0 or 1 bit): An indicator indicating whether previous CBGs are corrupted; 0 means that they may be corrupted, and 1 means that they can be used when receiving a retransmission (combinable).

[0135] ● DMRS sequence initialization (0 or 1 bit): DMRS scrambling ID selection indicator

[0137] The maximum number of different sizes of DCIs that a terminal can receive per slot in the cell is 4. The maximum number of different sizes of DCIs scrambled with C-RNTI that a terminal can receive per slot in the cell is 3.

[0139] FIG. 9 is a diagram illustrating the structure of a base station and a terminal wireless protocol when performing single cell, carrier aggregation, and dual connectivity according to an embodiment of the present invention.

[0140] Referring to Fig. 9, the wireless protocol of the next-generation mobile communication system consists of NR SDAP (Service Data Adaptation Protocol 9-25, 9-70), NR PDCP (Packet Data Convergence Protocol 9-30, 9-65), NR RLC (Radio Link Control 9-35, 9-60), and NR MAC (Medium Access Control 9-40, 9-55) at the terminal and the NR base station, respectively.

[0141] The main functions of NR SDAP (9-25, 9-70) may include some of the following functions.

[0142] - User data transfer function (transfer of user plane data)

[0143] - Mapping function between a QoS flow and a DRB for both DL and UL for uplink and downlink

[0144] - Marking QoS flow ID for uplink and downlink (marking QoS flow ID in both DL and UL packets)

[0145] - Function to map reflective QoS flow to data bearers for the uplink SDAP PDUs.

[0146] Regarding the SDAP layer device, the terminal may receive a setting via an RRC message indicating whether to use the header of the SDAP layer device or the functions of the SDAP layer device for each PDCP layer device, bearer, or logical channel. If the SDAP header is configured, the terminal may be instructed to update or reset the mapping information for the QoS flow of the uplink and downlink and the data bearer using the NAS reflective QoS and AS reflective QoS 1-bit indicators of the SDAP header. The SDAP header may include QoS flow ID information indicating QoS. The QoS information may be used for data processing priority, scheduling information, etc., to support smooth service.

[0147] The main functions of NR PDCP (9-30, 9-65) may include some of the following functions.

[0148] - Header compression and decompression features (ROHC only)

[0149] - User data transfer function (Transfer of user data)

[0150] - Sequential delivery function (In-sequence delivery of upper layer PDUs)

[0151] - Out-of-sequence delivery of upper layer PDUs

[0152] - Reordering function (PDCP PDU reordering for reception)

[0153] - Duplicate detection function (Duplicate detection of lower layer SDUs)

[0154] - Retransmission of PDCP SDUs

[0155] - Encryption and decryption functions (Ciphering and deciphering)

[0156] - Timer-based SDU discard in uplink.

[0157] In the above, the reordering function of the NR PDCP device refers to a function of reordering PDCP PDUs received from a lower layer in order based on the PDCP SN (sequence number), and may include a function of transmitting data to an upper layer in the reordered order, or a function of transmitting immediately without considering the order, may include a function of recording lost PDCP PDUs by reordering, may include a function of reporting the status of lost PDCP PDUs to the transmitting side, and may include a function of requesting retransmission of lost PDCP PDUs.

[0158] The main functions of NR RLC(9-35, 9-60) may include some of the following functions.

[0159] - Data transfer function (Transfer of upper layer PDUs)

[0160] - Sequential delivery function (In-sequence delivery of upper layer PDUs)

[0161] - Out-of-sequence delivery of upper layer PDUs

[0162] - ARQ function (Error Correction through ARQ)

[0163] - Concatenation, segmentation, and reassembly functions of RLC SDUs

[0164] - Re-segmentation function (Re-segmentation of RLC data PDUs)

[0165] - Reordering function (Reordering of RLC data PDUs)

[0166] - Duplicate detection

[0167] - Error detection function (Protocol error detection)

[0168] - RLC SDU discard function

[0169] RLC re-establishment function

[0170] In the above, the in-sequence delivery function of the NR RLC device refers to the function of delivering RLC SDUs received from a lower layer to an upper layer in sequence; it may include a function to reassemble and deliver them if a single RLC SDU is received divided into multiple RLC SDUs; it may include a function to rearrange received RLC PDUs based on an RLC SN (sequence number) or PDCP SN (sequence number); it may include a function to record lost RLC PDUs after rearranging the order; it may include a function to report the status of lost RLC PDUs to the transmitting side; it may include a function to request retransmission of lost RLC PDUs; if there are lost RLC SDUs, it may include a function to deliver only the RLC SDUs prior to the lost RLC SDU to the upper layer in sequence; or if a predetermined timer has expired even if there are lost RLC SDUs, it may include a function to deliver all RLC SDUs received before the timer started to the upper layer in sequence; or It may include a function that delivers all RLC SDUs received up to the present to the upper layer in order once a predetermined timer has expired, even if there are lost RLC SDUs. Additionally, the RLC PDUs mentioned above may be processed in the order they are received (regardless of the order of sequence numbers, but in the order of arrival) and delivered to the PDCP device out of order (out-of-sequence delivery). In the case of segments, segments stored in a buffer or to be received later may be received, reconstructed into a single complete RLC PDU, processed, and then delivered to the PDCP device.The above NR RLC layer may not include a concatenation function, and the function may be performed in the NR MAC layer or replaced with the multiplexing function of the NR MAC layer.

[0171] In the above, the out-of-sequence delivery function of the NR RLC device refers to a function of delivering RLC SDUs received from a lower layer directly to an upper layer regardless of order. It may include a function of reassembling and delivering them when a single RLC SDU is received divided into multiple RLC SDUs, and may include a function of storing the RLC SN or PDCP SN of the received RLC PDUs and sorting the order to record the lost RLC PDUs.

[0172] The NR MAC (9-40, 9-55) can be connected to multiple NR RLC layer devices configured in a terminal, and the main functions of the NR MAC may include some of the following functions.

[0173] - Mapping function (Mapping between logical channels and transport channels)

[0174] - Multiplexing and demultiplexing functions (Multiplexing / demultiplexing of MAC SDUs)

[0175] - Scheduling information reporting function

[0176] - HARQ function (Error correction through HARQ)

[0177] - Priority handling between logical channels of one UE

[0178] - Priority handling between UEs by means of dynamic scheduling

[0179] - MBMS service identification function

[0180] - Transport format selection function

[0181] - Padding

[0182] The NR PHY layer (9-45, 9-50) can perform the operation of channel coding and modulating upper layer data, creating OFDM symbols and transmitting them to the wireless channel, or demodulating OFDM symbols received through the wireless channel and channel decoding them to transmit them to the upper layer.

[0183] The detailed structure of the above wireless protocol structure may vary depending on the carrier (or cell) operation method. For example, when a base station transmits data to a terminal based on a single carrier (or cell), the base station and the terminal use a protocol structure that has a single structure for each layer, such as 9-00. On the other hand, when a base station transmits data to a terminal based on Carrier Aggregation (CA) using multiple carriers in a single TRP, the base station and the terminal use a protocol structure that has a single structure up to the RLC, such as 9-10, but multiplexes the PHY layer through the MAC layer. As another example, when a base station transmits data to a terminal based on Dual Connectivity (DC) using multiple carriers in multiple TRPs, the base station and the terminal use a protocol structure that has a single structure up to the RLC, such as 9-20, but multiplexes the PHY layer through the MAC layer.

[0184] In LTE and NR, a terminal has a procedure to report the capabilities supported by the terminal to the corresponding base station while connected to the serving base station. In the description below, this is referred to as UE capability (reporting). The base station may transmit a UE capability enquiry message requesting capability reporting to the connected terminal. The above message may include a request for terminal capability specific to each RAT type. The request for each RAT type may include information on the requested frequency band. Furthermore, the UE capability enquiry message may request multiple RAT types within a single RRC message container, or it may transmit to the terminal multiple UE capability enquiry messages containing requests for each RAT type. That is, the UE capability enquiry may be repeated multiple times, and the terminal may construct corresponding UE capability information messages and report them multiple times. In next-generation mobile communication systems, terminal capability requests can be made for NR, LTE, EN-DC, and MR-DC. For reference, while the above UE capability enquiry message is generally sent initially after the terminal establishes a connection, the base station may request it under any conditions when necessary.

[0185] In the above step, the terminal that receives a request for a UE capability report from the base station configures the terminal capability according to the RAT type and band information requested from the base station. The method by which the terminal configures the UE capability in the NR system is summarized below.

[0186] 1. If the terminal receives a list of LTE and / or NR bands from the base station via a UE capability request, the terminal configures a band combination (BC) for EN-DC and NR stand-alone (SA). That is, it constructs a candidate list of BCs for EN-DC and NR SA based on the bands requested from the base station via FreqBandList. Additionally, the bands have priority in the order listed in the FreqBandList.

[0187] 2. If the base station requests a UE capability report by setting the “eutra-nr-only” flag or the “eutra” flag, the terminal completely removes NR SA BCs from the above-mentioned list of configured BC candidates. This operation may occur only when the LTE base station (eNB) requests “eutra” capability.

[0188] 3. Subsequently, the terminal removes fallback BCs from the candidate list of BCs configured in the above step. Here, a fallback BC refers to a case where at least one band corresponding to a SCell has been removed from a super set BC; this step can be omitted because the super set BC can already cover the fallback BC. This step also applies to MR-DC, meaning it applies to LTE bands as well. The BCs remaining after this step constitute the final “candidate BC list.”

[0189] 4. The terminal selects the BCs to be reported by selecting BCs that match the requested RAT type from the final “Candidate BC List” above. In this step, the terminal constructs the supportedBandCombinationList in a predetermined order. That is, the terminal constructs the BCs and UE capabilities to be reported according to the pre-set order of rat-Type (nr -> eutra-nr -> eutra). Additionally, it constructs a featureSetCombination for the constructed supportedBandCombinationList and constructs a list of “Candidate Feature Set Combinations” from the Candidate BC List from which the list of fallback BCs (containing capabilities of the same or lower level) has been removed. The “Candidate Feature Set Combinations” above include feature set combinations for both NR and EUTRA-NR BCs and can be obtained from the feature set combinations of the UE-NR-Capabilities and UE-MRDC-Capabilities containers.

[0190] 5. Additionally, if the requested rat Type is eutra-nr and has an influence, featureSetCombinations is included in both the UE-MRDC-Capabilities and UE-NR-Capabilities containers. However, the NR feature set is included only in UE-NR-Capabilities.

[0191] After the terminal capability is configured, the terminal transmits a UE capability information message containing the UE capability to the base station. Based on the UE capability received from the terminal, the base station then performs appropriate scheduling and transmission / reception management for the terminal.

[0193] Referring to the descriptions related to the PDSCH transmission and reception procedures, such as the DCI structure, PDSCH time / frequency resource allocation, and wireless protocol structure mentioned above, NR in Release 15 focuses on allocating PDSCHs transmitted from a single transmission point; therefore, additional specification support is required for cooperative communication where a single terminal receives PDSCHs transmitted from multiple points. For example, since the control information includes separate frequency and time axis resource allocation information corresponding to each PDSCH, a method to expand or process this information is required to allocate two or more PDSCHs.

[0194] The present invention improves cooperative communication efficiency by providing a time and frequency resource allocation method for efficiently allocating the plurality of PDSCHs to a single terminal.

[0195] Embodiments of the present invention will be described in detail below with reference to the accompanying drawings. Furthermore, in describing the present invention, specific descriptions of related functions or configurations are omitted if it is determined that such detailed descriptions would unnecessarily obscure the essence of the invention. Additionally, terms used below are defined considering their functions in the present invention, and these may vary depending on the intentions or conventions of the user or operator. Therefore, their definitions should be based on the content throughout this specification.

[0196] Hereinafter, the base station is an entity that performs resource allocation for terminals and may be at least one of a gNode B, gNB, eNode B, Node B, BS (Base Station), wireless access unit, base station controller, or a node on a network. The terminal may include a UE (User Equipment), MS (Mobile Station), cellular phone, smartphone, computer, or a multimedia system capable of performing communication functions. Furthermore, although embodiments of the present invention are described below using NR or LTE / LTE-A systems as examples, embodiments of the present invention may be applied to other communication systems having similar technical backgrounds or channel types. Additionally, embodiments of the present invention may be applied to other communication systems through some modifications made at the judgment of a person with skilled technical knowledge, without significantly departing from the scope of the present invention.

[0197] The content of this invention is applicable to FDD and TDD systems.

[0198] In the present invention, upper signaling is a signal transmission method transmitted from a base station to a terminal using a downlink data channel of the physical layer, or from a terminal to a base station using an uplink data channel of the physical layer, and may also be referred to as RRC signaling, PDCP signaling, or a MAC (medium access control) control element (MAC CE).

[0199] In the present invention, when determining whether cooperative communication is applied, the terminal may use various methods, such as the PDCCH(s) that allocate the PDSCH to which cooperative communication is applied having a specific format, or the PDCCH(s) that allocate the PDSCH to which cooperative communication is applied including a specific indicator indicating whether cooperative communication is applied, or the PDCCH(s) that allocate the PDSCH to which cooperative communication is applied being scrambled with a specific RNTI, or assuming the application of cooperative communication in a specific section indicated to an upper layer. For convenience of explanation thereafter, the case in which the terminal receives a PDSCH to which cooperative communication is applied based on conditions similar to those above will be referred to as the NC-JT case.

[0200] In the present invention, determining the priority between A and B may be described in various ways, such as selecting the one with a higher priority according to a predetermined priority rule and performing the corresponding action, or omitting (omitting or dropping) the action for the one with a lower priority.

[0201] In the following, the present invention describes the above examples through a number of embodiments, but these are not independent, and one or more embodiments may be applied simultaneously or in combination.

[0203] <1st Embodiment: Multiple DCI reception for NC-JT>

[0204] Unlike existing systems, 5G wireless communication systems can support not only services requiring high transmission speeds but also services requiring very short transmission delays and high connection density. In a wireless communication network comprising multiple cells, TRPs (transmission and reception points), or beams, coordinated transmission between each cell, TRP, or / and beam is one of the key technologies that can satisfy the various service requirements by increasing the signal strength received by the terminal or efficiently performing interference control between each cell, TRP, or / and beam.

[0205] Joint Transmission (JT) is a representative transmission technology for the aforementioned cooperative communication. Through this technology, a single terminal can be supported across different cells, TRPs, and / or beams, thereby increasing the signal strength received by the terminal. Meanwhile, since the characteristics of the channels between each cell, TRP, and / or beam and the terminal can differ significantly, it is necessary to apply different precoding, MCS, resource allocation, etc., to the links between each cell, TRP, and / or beam and the terminal. In particular, in the case of Non-Coherent Joint Transmission (NC-JT), which supports non-coherent precoding between each cell, TRP, and / or beam, the configuration of individual DL transmission information for each cell, TRP, and / or beam becomes important. Meanwhile, such individual DL transmission information settings for each cell, TRP or / and beam are a major factor in increasing the payload required for DL ​​DCI transmission, which can adversely affect the reception performance of the PDCCH (physical downlink control channel) transmitting DCI. Therefore, to support JT, it is necessary to carefully design the tradeoff between the amount of DCI information and the PDCCH reception performance.

[0206] FIG. 10 is a diagram illustrating a Joint Transmission (JT) technique according to an embodiment of the present invention and examples of wireless resource allocation by TRP according to the situation.

[0207] In FIG. 10, 10-00 is a diagram illustrating a Coherent Joint Transmission (C-JT) that supports coherent precoding between each cell, TRP, or / and beam. In the C-JT, the same data (PDSCH) is transmitted from TRP A (10-05) and TRP B (10-10), and joint precoding is performed from multiple TRPs. This means that the same DMRS ports (e.g., DMRS ports A and B in both TRPs) are transmitted from TRP A (10-05) and TRP B (10-10) for receiving the same PDSCH. In this case, the terminal will receive one DCI information for receiving a single PDSCH that is demodulated by DMRS ports A and B.

[0208] FIG. 10-20 illustrates a Non-Coherent Joint Transmission (NC-JT) that supports non-coherent precoding between each cell, TRP or / and beam. In the case of NC-JT, different PDSCHs are transmitted from each cell, TRP or / and beam, and individual precoding may be applied to each PDSCH. This means that different DMRS ports (e.g., DMRS port A in TRP A and DMRS port B in TRP B) are transmitted for receiving the different PDSCHs from TRP A (10-25) and TRP B (10-30). In this case, the terminal will receive two types of DCI information for receiving PDSCH A, which is demodulated by DMRS port A, and PDSCH B, which is demodulated by the other DMRS port B.

[0209] For example, in the case of NC-JT, it is possible to consider various wireless resource allocations according to FIG. 5b, such as when the frequency and time resources used by multiple TRPs are identical (10-40), when the frequency and time resources used by multiple TRPs do not overlap at all (10-45), or when some of the frequency and time resources used by multiple TRPs overlap (10-50). In particular, in the case of 10-50, it can be seen that the DCI payload required for resource allocation information increases linearly with the number of TRPs. Such an increase in the DL DCI payload poses a risk of adversely affecting the reception performance of the PDCCH (physical downlink control channel) transmitting the DCI, or significantly increasing the complexity of DCI blind decoding at the terminal as described above. Therefore, the present invention provides a method for allocating PDSCH time and frequency resources to efficiently support NC-JT.

[0210] To support NC-JT, DCIs of various forms, structures, and relationships can be considered to allocate multiple PDSCHs simultaneously to a single terminal.

[0211] FIG. 11 is a drawing illustrating four examples of DCI designs for NC-JT support according to one embodiment of the present invention.

[0212] In FIG. 11, case #1 (11-00) illustrates an example in which (N-1) different PDSCHs are transmitted from (N-1) additional TRPs (TRP#1 to TRP#(N-1)) in addition to the serving TRP (TRP#0) used for single PDSCH transmission, and control information for the PDSCHs transmitted from the additional TRPs is transmitted in the same form (same DCI format) as the control information for the PDSCHs transmitted from the serving TRP. That is, the terminal obtains control information for the PDSCHs transmitted from different TRPs (TRP#0 to TRP#(N-1)) through DCIs (DCI#0 to DCI#(N-1)) that all have the same DCI format and the same payload. While case #1 has the advantage of fully guaranteeing the freedom of control (assignment) for each PDSCH, it has the disadvantage that reception performance may be degraded due to differences in coverage per DCI when each DCI is transmitted from a different TRP.

[0213] In FIG. 11, case #2 (11-05) illustrates an example in which (N-1) different PDSCHs are transmitted from (N-1) additional TRPs (TRP#1 to TRP#(N-1)) other than the serving TRP (TRP#0) used for a single PDSCH transmission, and control information for the PDSCH transmitted from the additional TRPs is transmitted in a different form (different DCI format or different DCI payload) than the control information for the PDSCH transmitted from the serving TRP. For example, DCI#0, which transmits control information for PDSCH transmitted from a serving TRP (TRP#0), includes all information elements of DCI format 1_0 to DCI format 1_1, but 'shortened' DCIs (sDCI#0 to sDCI#(N-2)) that transmit control information for PDSCHs transmitted from cooperative TRPs (TRP#1 to TRP#(N-1)) may include only some of the information elements of DCI format 1_0 to DCI format 1_1. Therefore, in the case of sDCI, which transmits control information for PDSCHs transmitted from cooperative TRPs, it is possible to have a smaller payload compared to normal DCI (nDCI) that transmits PDSCH-related control information transmitted from a serving TRP, or to include reserved bits corresponding to the number of bits missing compared to nDCI. The above case #2 has the disadvantage that the degrees of freedom for each PDSCH control (assignment) may be limited depending on the contents of the information element included in the sDCI, but it has the advantage that the probability of coverage differences between DCIs is reduced because the reception performance of the sDCI is superior to that of the nDCI.

[0214] In FIG. 11, case #3 (11-10) illustrates another example in which (N-1) different PDSCHs are transmitted from (N-1) additional TRPs (TRP#1 to TRP#(N-1)) in addition to the serving TRP (TRP#0) used for a single PDSCH transmission, and control information for the PDSCH transmitted from the additional TRPs is transmitted in a different form (different DCI format or different DCI payload) than the control information for the PDSCH transmitted from the serving TRP. For example, in the case of DCI#0 transmitting control information for PDSCH transmitted from a serving TRP (TRP#0), it includes all information elements of DCI format 1_0 to DCI format 1_1, and in the case of control information for PDSCHs transmitted from cooperative TRPs (TRP#1 to TRP#(N-1)), it is possible to collect and transmit only some of the information elements of DCI format 1_0 to DCI format 1_1 into a single 'secondary' DCI (sDCI). For example, the sDCI may contain at least one piece of HARQ-related information such as frequency domain resource assignment, time domain resource assignment, and MCS of cooperative TRPs. In addition, for information not included in the sDCI, such as a BWP indicator or carrier indicator, it is possible to follow the DCI of the serving TRP (DCI#0, normal DCI, nDCI).The above case #3 has the disadvantage that the degree of freedom for each PDSCH control (assignment) may be limited depending on the contents of the information element included in the sDCI, but it has the advantage that the reception performance of the sDCI can be adjusted and the complexity of DCI blind decoding of the terminal is reduced compared to case #1 or #2.

[0215] In FIG. 11, case #4 (11-15) illustrates an example in which, in a situation where (N-1) different PDSCHs are transmitted from (N-1) additional TRPs (TRP#1 to TRP#(N-1)) other than the serving TRP (TRP#0) used for single PDSCH transmission, control information for the PDSCHs transmitted from the additional TRPs is transmitted in the same DCI (long DCI, lDCI) as the control information for the PDSCHs transmitted from the serving TRP. That is, the terminal obtains control information for the PDSCHs transmitted from different TRPs (TRP#0 to TRP#(N-1)) through a single DCI. Case #4 has the advantage that the terminal's DCI blind decoding complexity does not increase, but it has the disadvantage of low freedom in PDSCH control (assignment), such as the number of cooperating TRPs being limited by the long DCI payload limit.

[0216] In the following description and embodiments, sDCI may refer to various auxiliary DCIs, such as shortened DCI, secondary DCI, or normal DCI (DCI format 1_0 to 1_1 described above) containing PDSCH control information transmitted from a cooperative TRP, and unless a specific limitation is specified, the description may be similarly applied to the various auxiliary DCIs.

[0217] In the following description and embodiments, cases #1, #2, and #3, in which one or more DCIs (PDCCHs) are used for NC-JT support, are classified as multiple PDCCH-based NC-JT, and case #4, in which a single DCI (PDCCH) is used for NC-JT support, is classified as single PDCCH-based NC-JT.

[0218] The following description and embodiments provide detailed methods for allocating time and frequency resources for the multiple PDCCH-based and single PDCCH-based NC-JTs.

[0219] In the embodiments of the present invention, “Cooperative TRP” can be replaced with various terms such as “Cooperative panel” or “Cooperative beam” in actual application.

[0220] In the embodiments of the present invention, the phrase “when NC-JT is applied” can be interpreted in various ways depending on the situation, such as “when a terminal receives one or more PDSCHs simultaneously in one BWP,” “when a terminal receives PDSCHs based on two or more TCI indications simultaneously in one BWP,” or “when the PDSCHs received by the terminal are associated with one or more DMRS port groups,” but for the convenience of explanation, it has been used as a single expression.

[0221] In the present invention, the wireless protocol structure for NC-JT can be used in various ways depending on the TRP deployment scenario. For example, when there is no or small backhaul delay between cooperative TRPs, it is possible to use a structure based on MAC layer multiplexing similar to 9-10 in Fig. 9 (CA-like method). On the other hand, when the backhaul delay between cooperative TRPs is large enough to be non-negligible (e.g., when more than 2 ms is required for CSI exchange or scheduling information exchange between cooperative TRPs), it is possible to secure delay-robust characteristics by using a structure independent of each TRP starting from the RLC layer, similar to 9-20 in Fig. 9 (DC-like method).

[0223] <Second Embodiment: FD-RA for NC-JT>

[0224] In this embodiment, a frequency domain resource allocation (FD-RA) method considering NC-JT is described.

[0225] According to the above description, the number of bits for a conventional single PDSCH FD-RA may require a payload of 15 bits or more depending on the number of PRBs in the BWP, and if this is simply extended, the number of FD-RA payloads required when allocating N>1 PDSCHs for NC-JT may be 15*N bits or more, which can place a significant burden on DCI transmission.

[0226] To resolve this issue, the following methods can be used when using the same FD-RA payload as release 15 NR within a single PDCCH:

[0227] ● Method 1: In the case of type 0, which indicates whether resources for the corresponding band are allocated through a bitmap for a defined RB group (RBG), it is possible to agree to change the RGB size according to the number of PDSCHs allocated by the PDCCH. The number of PDSCHs allocated by the PDCCH can be indicated to the terminal by various methods, such as explicitly indicating it by a specific field value within the DCI transmitted by the PDCCH, or implicitly determining it based on the number or state of TCI states or QCL information within the DCI transmitted by the PDCCH (e.g., how many QCL information is included / indicated). [Table 7] is an example of a method for determining the RGB size based on the number of PRBs included in the band portion when the maximum number of PDSCHs that the terminal can be allocated through a single PDSCH is 2 due to the terminal's UE capability signaling and the base station's upper layer settings. Referring to [Table 7], if it can be determined by the above condition or method that the number of PDSCHs allocated by a DCI is one (condition A), one of the values ​​{2, 4, 8, 16} or {4, 8, 16, 16} is used according to the upper layer configuration of the base station (configuration 1 or configuration 2). On the other hand, if it can be determined by the above condition or method that the number of PDSCHs allocated by a DCI is two (condition B), the RGB size is doubled compared to the single PDSCH situation according to the upper layer configuration of the base station (configuration 1 or configuration 2) and one of the values ​​{4, 8, 16, 32} or {8, 16, 32, 32} is used. Through this, FD-RA can be performed on up to two PDSCHs without increasing the conventional FD-RA payload.The above method can be similarly extended even when a DCI can allocate three or more PDSCHs. In this method, all FD-RA bits are divided into subgroups according to the number of allocated PDSCHs and can be mapped to each PDSCH according to the signaling order of the TCI state (or QCL information) within the corresponding DCI.

[0229] [Table 7]

[0230]

[0232] ● Method 1-1: Alternatively, for the above RBGs, it is possible to assume a fixed TRP allocation per RBG. For example, n RBGs within a BWP, i.e. In resource allocation for, the even-numbered RBG, for example is specified for use in TRP 0 and odd-numbered RGBs, for example It is possible to designate it for use in TRP 1. Which of the above RBGs is assigned to the terminal can be indicated by the RBG bitmap within the DCI described above, and the size of the RBG bitmap can be the same as that of release 15 NR. An example of the relationship between RBG and TRP and the bitmap for RBG assignment is shown in FIG. 18. The above method can be similarly extended even when a DCI can assign three or more PDSCHs.

[0234] If a larger FD-RA payload than release 15 NR is used within a single PDCCH, the following methods can be used:

[0235] ● Method 2: For FD-RA type 0 or type 1, it is possible to agree to change the FD-RA payload size according to the number of PDSCHs allocated by the corresponding PDCCH. The number of PDSCHs allocated by the corresponding PDCCH can be indicated to the terminal by various methods, such as explicitly indicating it by a specific field value within the DCI transmitted by the PDCCH, or implicitly determining it by the number or state of TCI states or QCL information within the DCI transmitted by the PDCCH (e.g., based on how much QCL information is included / indicated). In this method, the RGB size based on the number of PRBs included in the band portion is used in the same way as in the past, and the FD-RA payload is linearly increased according to the maximum number of PDSCHs that the terminal can be allocated through a single PDSCH based on the terminal's UE capability signaling and the base station's upper layer settings, thereby performing different FD-RAs on different PDSCHs. At this time, all FD-RA bits are divided into subgroups according to the number of allocated PDSCHs, and it is possible to map them to each PDSCH according to the signaling order of the TCI state (or QCL information) within the corresponding DCI.

[0236] ● Method 3: In the case of type 0, which indicates whether resources are allocated for the corresponding band through a bitmap for a defined RB group (RBG), it is possible to select additional RGB configurations based on the number of PDSCHs allocated by the PDCCH. The number of PDSCHs allocated by the PDCCH can be indicated to the terminal by various methods, such as explicitly indicating a specific field value within the DCI transmitted by the PDCCH, or implicitly determining the number or state of TCI states or QCL information within the DCI transmitted by the PDCCH (e.g., based on how many QCL information is included / indicated). [Table 8] is an example of a method for determining the RGB size based on the number of PRBs included in the band portion when the maximum number of PDSCHs that the terminal can be allocated through a single PDSCH is two or more due to the terminal's UE capability signaling and the base station's upper layer settings. Referring to [Table 8], if it can be determined by the above condition or method that the number of PDSCHs allocated by a DCI is one (condition A), one of the values ​​{2, 4, 8, 16} or {4, 8, 16, 16} is used according to the upper layer setting of the base station (configuration 1 or configuration 2). On the other hand, if it can be determined by the above condition or method that the number of PDSCHs allocated by a DCI is two (condition B), one of the values ​​for the newly determined RGB size (in this example, {4, 8, 16, 32} …) is used according to the upper layer setting of the base station (configuration 3 or configuration 4 or …). Through this, FD-RA can be performed on two or more PDSCHs while appropriately increasing the conventional FD-RA payload.In this method, all FD-RA bits are divided into subgroups according to the number of allocated PDSCHs, and it is possible to map them to each PDSCH according to the signaling order of the TCI state (or QCL information) within the corresponding DCI.

[0238] [Table 8]

[0239]

[0241] ● Method 4: In the case of type 1, which provides resource allocation information through the starting position of the VRB and the allocated VRB length, it is possible to reduce the FD-RA payload for multiple PDSCHs by introducing a stepwise FD-RA. FIG. 12 is a diagram illustrating an example of a stepwise FD-RA according to an embodiment of the present invention. Referring to FIG. 12, it is possible to select an FD-RA method having different steps depending on the number of PDSCHs allocated by the PDCCH. The number of PDSCHs allocated by the PDCCH can be indicated to the terminal by various methods, such as explicitly indicating by a specific field value within the DCI transmitted by the PDCCH, or implicitly determining the number or state of TCI states or QCL information within the DCI transmitted by the PDCCH (e.g., depending on how many QCL information is included / indicated). According to FIG. 12, when the number of PDSCHs allocated by the PDCCH is one, frequency resources are allocated through a single-step FD-RA (12-00). On the other hand, if the number of PDSCHs allocated by the PDCCH is two or more, it is possible to allocate frequency resources through a two-stage FD-RA (12-05). In the two-stage FD-RS (12-05), the first stage (12-10) indicates information regarding the union of frequency axis resources occupied by the multiple PDSCHs based on the starting VRB and length. In the two-stage FD-RS (12-05), the second stage (12-15) sequentially indicates information regarding each frequency axis resource occupied by the multiple PDSCHs based on the starting VRB and length. At this time, the payload required in each stage is as [Equation 1] in the first stage (12-10) and as [Equation 2] in the second stage. In [Equation 1] is the number of PRBs within the BWP indicated by the DCI within the corresponding PDCCH, and in [Equation 2] is the VRB length indicated in the first step (12-10) above and is the number of PDSCH assigned by the corresponding DCI. Although VRBs in Fig. 12 are depicted as being composed of consecutive PRBs, it should be noted that this is for the convenience of explanation and the actual mapping with PRBs may vary according to predetermined rules.

[0242] [Mathematical Formula 1]

[0243]

[0244] [Mathematical Formula 2]

[0245]

[0247] Methods 1 to 4 of the present embodiment are not mutually exclusive and may be cross-supported depending on the conditions. For example, it may be agreed that Method 1 be used for FD-RA type 0 and Method 4 be used for FD-RA type 1. Various other combinations are possible, but not all possibilities are listed in order not to obscure the gist of the explanation.

[0248] In the case of type 1, which provides resource allocation information through the starting position of the VRB and the allocated VRB length, the FD-RA payload is already compressed in a form that indicates the index of the available VRB starting position and length combinations, so it becomes very difficult to include additional information when maintaining the conventional FD-RA payload. Therefore, if a DCI that directs NC-JT operation—that is, assigns one or more PDSCHs to at least one or more identical OFDM symbols—has the same FD-RA payload as the FD-RA payload of release 15 NR and uses type 1 FD-RA, the terminal may agree to understand that the DCI assigns the same FD-RA to all of the one or more PDSCHs.

[0250] <Third Embodiment: TD-RA for NC-JT>

[0251] In this embodiment, a time domain resource allocation (TD-RA) method considering NC-JT is described.

[0252] According to the above description, the number of bits for a conventional single PDSCH TD-RA can range from 0 to 4 bits depending on the configuration. If this is simply extended, the number of FD-RA payloads required to allocate N > 1 PDSCHs for NC-JT can be 4*N bits or more. Although this is not a significant increase compared to FD-RA, TD-RA requires careful design as it is intertwined with various issues such as DMRS RE patterns, PDSCH RE mapping, channel estimation, and control channel load balancing.

[0253] Considering the above problems, it is possible to use at least one of the following three methods for the SLIV and PDSCH mapping types among the information included in TD-RA.

[0254] ● Method 1: In this method, when a terminal simultaneously receives two or more PDSCHs that share at least some time and frequency resources, the SLIV and PDSCH mapping type for the two or more PDSCHs are all matched to reduce the complexity of implementing interference management, including interference measurement and interference cancellation between the two or more PDSCHs. In this case, the terminal can be guaranteed the same RE pattern for all PDSCHs that must be received simultaneously, thus simplifying the NC-JT reception operation including the interference management. At this time, to ensure the simplification of the implementation complexity of the terminal, it may be promised that “if the two or more PDSCHs that share at least some time and frequency resources are assigned to have different SLIV values ​​or different PDSCH mapping type values, none of these PDSCHs will be received” or “if the two or more PDSCHs that share at least some time and frequency resources are assigned to have different SLIV values ​​or different PDSCH mapping type values, only the PDSCH with the highest priority among these PDSCHs will be received.” In this case, the priority among PDSCHs can be determined in various ways, such as the PDSCH with the smallest k0 value, the PDSCH with the smallest TCI state ID, or the PDSCH with the smallest HARQ process ID.

[0255] ● Method 2: In this method, in order to reduce the complexity of terminal implementation when a terminal simultaneously receives two or more PDSCHs that share at least some time and frequency resources, and to distribute the PDCCH transmission burden of the base station (PDCCH load balancing), it is possible to allow the SLIV values ​​for the two or more PDSCHs to match, but the PDSCH mapping types to have different values. FIG. 13 is a diagram illustrating PDCCH monitoring occasions according to PDSCH mapping types according to an embodiment of the present invention. Referring to FIG. 13, in the case of PDSCH mapping type A, only the first three OFDM symbols within the slot can be designated as PDCCH monitoring occasions (13-00), whereas in the case of PDSCH mapping type B, all OFDM symbols within the slot can be designated as PDCCH monitoring occasions (13-05). This means that by appropriately allocating the PDSCH mapping types of NC-JT PDSCHs according to the network traffic load, it is possible to prevent PDCCH transmissions from being concentrated on some symbols within the slot. The present method is particularly suitable for multiple PDCCH-based NC-JTs where two or more PDCCH transmissions are required for NC-JT allocation. In order to ensure the simplification of implementation complexity of the terminal, it may be promised “not to receive any of the PDSCHs when two or more PDSCHs sharing at least some time and frequency resources are allocated to have different SLIV values” or “to receive only the PDSCH with the highest priority among the PDSCHs when two or more PDSCHs sharing at least some time and frequency resources are allocated to have different SLIV values.”In this case, the priority among PDSCHs can be determined in various ways, such as the PDSCH with the smallest k0 value, the PDSCH with the smallest TCI state ID, or the PDSCH with the smallest HARQ process ID.

[0256] ● Method 3: In this method, when a terminal simultaneously receives two or more PDSCHs that share at least some time and frequency resources, no constraints are placed on the SLIV values ​​and PDSCH mapping types for the said two or more PDSCHs in order to maximize scheduling degrees of freedom and throughput performance. In this case, the DMRS RE patterns within the said two or more PDSCHs may not match, and the DMRS RE of one PDSCH may collide with the PDSCH RE of another PDSCH, thereby degrading the DMRS channel estimation performance. To resolve this, if the SLIV values ​​or PDSCH mapping types for the said two or more PDSCHs are different, it is necessary to rate match the PDSCH RE located at the DMRS RE of another PDSCH.To this end, when the SLIV values ​​or PDSCH mapping types for the two or more PDSCHs are different, the terminal can be guaranteed not to perform additional operations (e.g., successive interference cancellation in DMRS RE) when performing DMRS channel estimation for NC-JT PDSCH demodulation by “receiving one additional SLIV value and performing PDSCH RE rate matching for a DMRS RE location determined by linking it with conventional DMRS port and CDM group without data indication information” or “performing PDSCH RE rate matching for a DMRS RE location determined by linking a pair of additional DMRS port number indication information and an additional SLIV value” or “performing PDSCH RE rate matching based on signaling indicating whether PDSCH RE rate matching is applied at the symbol level” or “performing PDSCH RE rate matching based on the RE-level rate matching signal of release 15 NR”.

[0258] Considering the above problems, it is possible to use at least one of the following two methods for k0 among the information included in TD-RA.

[0259] ● Method 4: In this method, when a terminal simultaneously receives two or more PDSCHs that share at least some time and frequency resources, the k0 values ​​for all said two or more PDSCHs are made identical to reduce the implementation complexity regarding processing time management and PDSCH dropping rules for preparing to receive said two or more PDSCHs. In this case, the terminal can be guaranteed the same processing time for all said PDSCHs to be received simultaneously, thus simplifying pipeline management for NC-JT PDSCH reception. At this time, to ensure the simplification of the terminal's implementation complexity, it may be agreed, for example, that “NC-JT capable UE can be allocated with up to 2 (or >2 per the UE capability signaling) PDSCHs on the same OFDM symbol(s), if the k0 values ​​of all the PDSCHs are identical. Otherwise, UE may assume that the PDSCH with the minimum k0 value is allocated on that OFDM symbol(s) only.” FIG. 14 is a diagram illustrating a brief example thereof and illustrates a method for monitoring two or more PDSCHs according to an embodiment of the invention. Referring to FIG. 14, if two different PDSCHs share at least some of the same time and frequency resources, the terminal considers it a single TRP transmission if the k0 values ​​of the two PDSCHs are different, and performs a corresponding operation (e.g., receiving only one PDSCH with the highest priority) (14-00).On the other hand, if two different PDSCHs allocated to a terminal share at least some of the same time and frequency resources, if the k0 values ​​of these two PDSCHs are the same, it is considered as an NC-JT transmission and the corresponding operation (e.g., receiving all of the PDSCHs) is performed (14-05).

[0260] ● Method 5: In this method, when a terminal simultaneously receives two or more PDSCHs that share at least some time and frequency resources, it is possible to impose a threshold on the difference between the k0 values ​​of the two or more PDSCHs to reduce the implementation complexity regarding processing time management and PDSCH dropping rules for preparing to receive said two or more PDSCHs. The threshold value(s) may be predetermined, but they may also be announced to the terminal through upper-layer signaling. That is, the terminal determines that two or more PDSCHs that share some time and frequency resources are allocated by DCIs transmitted within a given time interval as NC-JT. In this case, to ensure the simplification of the terminal's implementation complexity, for example, “NC-JT capable UE can be allocated with up to 2 (or >2) PDSCHs on the same OFDM symbol(s), if the value of It can be agreed that all the PDSCHs are less than the given threshold. Otherwise, the UE may assume that the PDSCH with the minimum k0 value is allocated on that OFDM symbol(s) only. Specifically, if two different PDSCHs share at least some of the same time and frequency resources, and the difference between the k0 values ​​of these two PDSCHs is greater than the value of the threshold, the terminal considers it a single TRP transmission and performs the corresponding action (e.g., receiving only the PDSCH with the highest priority). On the other hand, if two different PDSCHs allocated to the terminal share at least some of the same time and frequency resources, and the difference between the k0 values ​​of these two PDSCHs is less than the value of the threshold, the terminal considers it an NC-JT transmission and performs the corresponding action (e.g., receiving all of the PDSCHs).

[0261] ● Method 6: In the present method, when a terminal simultaneously receives two or more PDSCHs that share at least some time and frequency resources, it is possible to determine whether to apply NC-JT based on HARQ process ID values ​​for the two or more PDSCHs in order to reduce the complexity of implementation regarding processing time management and PDSCH dropping rules for preparing to receive the two or more PDSCHs. As an example, FIG. 15 is a diagram illustrating another example of a method for monitoring two or more PDSCHs according to an embodiment of the present invention. Referring to FIG. 15, if two or more PDSCHs that share some time and frequency resources are assigned to have different (same) HARQ process IDs, the terminal considers this to be an NC-JT transmission and performs a corresponding operation (e.g., receiving all of the PDSCHs). On the other hand, if the two or more PDSCHs are assigned to have the same (different) HARQ process IDs, the terminal determines this to be a single TRP transmission and performs a corresponding operation (e.g., receiving only the PDSCH with the highest priority).

[0263] In the present embodiment, methods 1 through 6 are not mutually exclusive, and it is possible to use a combination of one or more methods depending on the conditions. For example, it is possible to apply method 1 to the SLIV and PDSCH mapping types and method 4 to the k0 value. Various other combinations are possible, but not all possibilities are listed in order not to obscure the gist of the explanation.

[0265] <Fourth Embodiment: UE capability signaling for NC-JT reception and resource allocation method therefrom>

[0266] In this embodiment, a time and frequency domain resource allocation method considering the NC-JT-related UE capability signaling of a terminal is described.

[0267] The terminal may perform a UE capability report including at least one of the following methods to inform the base station whether NC-JT PDSCH reception is possible.

[0268] ● Method 1: The terminal may report to the base station whether it can receive only a single PDSCH associated with a single TCI state (or QCL information) or whether it can simultaneously receive multiple PDSCHs associated with multiple TCI states (or QCL information).

[0269] ● Method 2 (UE capability on NC-JT with overlapped PDSCHs): In the above Method 1, for a terminal capable of simultaneous reception of multiple PDSCHs associated with multiple TCI states (or QCL information), if the frequency resources indicated by the FD-RA values ​​of each PDSCH being simultaneously received (or the time resources or DMRS patterns indicated by the TD-RA values) match each other, the terminal may report to the base station whether simultaneous reception can be supported.

[0270] ● Method 3 (UE capability on NC-JT with non-overlapped PDSCHs): In the above Method 1, for a terminal capable of simultaneous reception of multiple PDSCHs associated with multiple TCI states (or QCL information), if the frequency resources indicated by the FD-RA values ​​of each PDSCH being simultaneously received (or the time resources or DMRS patterns indicated by the TD-RA values) match each other, the terminal may report to the base station whether simultaneous reception can be supported.

[0271] ● Method 4 (UE capability on NC-JT with partially overlapped PDSCHs): In the above Method 1, for a terminal capable of simultaneous reception of multiple PDSCHs associated with multiple TCI states (or QCL information), if the frequency resource indicated by the FD-RA value of each PDSCH being simultaneously received (or the time resource or DMRS pattern indicated by the TD-RA value) partially matches, the terminal may report to the base station whether simultaneous reception can be supported.

[0273] If the terminal reports to the base station that it supports NC-JT based on overlapped PDSCH according to Method 2 above and reports that NC-JT based on non-overlapped PDSCH or partially overlapped PDSCH is unavailable according to Method 3 or 4, the base station needs to ensure that the FD-RA (or TD-RA) fields within different PDCCH DCIs to which the terminal assigns NC-JT PDSCHs have the same value. If the terminal is instructed to receive PDSCHs assigned by different FD-RA (or TD-RA) fields, the terminal may not perform reception of the entire PDSCH, or may receive only the PDSCH with the highest priority among the PDSCHs.

[0275] If the terminal reports to the base station that it supports NC-JT based on non-overlapped PDSCH according to Method 3 above and reports that NC-JT based on overlapped PDSCH or partially overlapped PDSCH is unavailable according to Method 2 or 4, the base station needs to ensure that the FD-RA (or TD-RA) fields within the different PDCCH DCIs to which the terminal assigns NC-JT PDSCHs have different values. If the terminal is instructed to receive a PDSCH transmitted from a partially overlapping frequency (or time) resource, the terminal may not perform reception of the entire PDSCH, or may receive only the PDSCH with the highest priority among the PDSCHs.

[0277] FIG. 16 is a block diagram illustrating the structure of a terminal according to one embodiment of the present invention.

[0278] Referring to FIG. 16, the terminal may be composed of a transceiver (16-00, 16-10) and a processing unit (16-05) including memory and a processor. The transceiver (16-00, 16-10) and the processing unit (16-05) of the terminal may operate according to the communication method of the terminal described above. However, the components of the terminal are not limited to the examples described above. For example, the terminal may include more components or fewer components than the components described above. In addition, the transceiver (16-00, 16-10) and the processing unit (16-05) may be implemented in the form of a single chip.

[0279] The transceiver (16-00, 16-10) can transmit and receive signals with a base station. Here, the signal may include control information and data. To this end, the transceiver (16-00, 16-10) may be composed of an RF transmitter that up-converts and amplifies the frequency of a transmitted signal, and an RF receiver that low-noise amplifies a received signal and down-converts the frequency. However, this is merely one embodiment of the transceiver (16-00, 16-10), and the components of the transceiver (16-00, 16-10) are not limited to an RF transmitter and an RF receiver.

[0280] Additionally, the transmitting and receiving unit (16-00, 16-10) receives a signal through a wireless channel and outputs it to the processing unit (16-05), and can transmit the signal output from the processing unit (16-05) through a wireless channel.

[0281] The processing unit (16-05) can store programs and data necessary for the operation of the terminal. Additionally, the processing unit (16-05) can store control information or data included in signals obtained from the terminal. The processing unit (16-05) may include a memory composed of a storage medium such as ROM, RAM, hard disk, CD-ROM, and DVD, or a combination of storage media. Furthermore, the processing unit (16-05) may be electrically connected to the receiving unit (16-00) and the transmitting unit (16-10), and the processing unit (16-05) may include at least one processor.

[0282] Additionally, the processing unit (16-05) can control a series of processes to enable the terminal to operate according to the above-described embodiment. According to some embodiments, the processing unit (16-05) can control the components of the terminal to receive a DCI composed of two layers and receive multiple PDSCHs simultaneously.

[0284] FIG. 17 is a block diagram illustrating the structure of a base station according to one embodiment of the present invention.

[0285] Referring to FIG. 17, a base station may be composed of a transceiver (17-00, 17-10) and a processing unit (17-05) including memory and a processor. According to the communication method of the base station described above, the transceiver (17-00, 17-10) and the processing unit (17-05) of the base station may operate. However, the components of the base station are not limited to the examples described above. For example, the base station may include more components or fewer components than the components described above. In addition, the transceiver (17-00, 17-10) and the processing unit (17-05) may be implemented in the form of a single chip.

[0286] The transceiver (17-00, 17-10) can transmit and receive signals with a terminal. Here, the signal may include control information and data. To this end, the transceiver (17-00, 17-10) may be composed of an RF transmitter that up-converts and amplifies the frequency of a transmitted signal, and an RF receiver that low-noise amplifies a received signal and down-converts the frequency. However, this is merely one embodiment of the transceiver (17-00, 17-10), and the components of the transceiver (17-00, 17-10) are not limited to an RF transmitter and an RF receiver.

[0287] Additionally, the transmitting and receiving unit (17-00, 17-10) receives a signal through a wireless channel and outputs it to the processing unit (17-05), and can transmit the signal output from the processing unit (17-05) through a wireless channel.

[0288] The processing unit (17-05) can store programs and data necessary for the operation of the base station. Additionally, the processing unit (17-05) can store control information or data included in signals obtained from the base station. The processing unit (17-05) may include a memory composed of a storage medium such as ROM, RAM, hard disk, CD-ROM, and DVD, or a combination of storage media. Furthermore, the processing unit (17-05) may be electrically connected to the receiving unit (17-00) and the transmitting unit (17-10), and the processing unit (17-05) may include at least one processor.

[0289] The processing unit (17-05) can control a series of processes to enable the base station to operate according to the embodiments of the present invention described above. According to some embodiments, the processing unit (17-05) can control each component of the base station to configure two layers of DCIs containing allocation information for a plurality of PDSCHs and to transmit them.

[0291] Meanwhile, the embodiments of the present invention disclosed in this specification and drawings are merely specific examples provided to facilitate the explanation of the technical content of the present invention and to aid in understanding the present invention, and are not intended to limit the scope of the present invention. That is, it is obvious to those skilled in the art that other variations based on the technical concept of the present invention are possible. Furthermore, each of the above embodiments may be combined and operated as needed. For example, parts of Embodiments 1 and 2 of the present invention may be combined to operate a base station and a terminal.

Claims

Claim 1 A method for a terminal of a communication system comprises: transmitting capability information of the terminal to a base station regarding a method for receiving multiple physical downlink shared channels (PDSCH); receiving a physical downlink control channel (PDCCH) from the base station that includes a single downlink control information (DCI) indicating two transmission configuration indicator (TCI) states and resource allocation information for the two PDSCHs; and receiving the two PDSCHs based on the two TCI states and the resource allocation information, wherein the two PDSCHs are associated with a demodulation reference signal (DMRS) port group, and when the capability information indicates that the method supports receiving multiple PDSCHs that do not overlap in the time domain, each of the two TCI states indicated by the single DCI is associated with two PDSCHs having non-overlapping time domain resource allocations. Claim 2 A method according to claim 1, wherein, when the capability information indicates that it supports a method for receiving multiple non-overlapping PDSCHs in the frequency domain, each of the two TCI states indicated by the single DCI is respectively associated with two PDSCHs having non-overlapping frequency domain resource allocations. Claim 3 A method according to claim 2, wherein when the two PDSCHs are received such that they do not overlap in the frequency domain, a specific number of first PRBs (physical resource blocks) correspond to a first TCI state and the remaining PRBs correspond to a second TCI state. Claim 4 delete Claim 5 A method according to claim 1, wherein when the two PDSCHs are received such that they do not overlap in the time domain, the two PDSCHs correspond to the same number of symbols and the same PDSCH mapping type. Claim 6 A method of a base station of a communication system comprising: receiving capability information of a terminal regarding a method for receiving multiple physical downlink shared channels (PDSCH) from the terminal; indicating two transmission configuration indicator (TCI) states to the terminal and transmitting a physical downlink control channel (PDCCH) including a single downlink control information (DCI) that includes resource allocation information for the two PDSCHs; and transmitting the two PDSCHs based on the two TCI states and the resource allocation information, wherein the two PDSCHs are associated with a demodulation reference signal (DMRS) port group, and when the capability information indicates that a method for receiving multiple PDSCHs that do not overlap in the time domain is supported, each of the two TCI states indicated by the single DCI is respectively associated with two PDSCHs having non-overlapping time domain resource allocations. Claim 7 In claim 6, a method characterized in that, when the capability information indicates that it supports a method for receiving multiple non-overlapping PDSCHs in the frequency domain, each of the two TCI states indicated by the single DCI is associated with two PDSCHs having non-overlapping frequency domain resource allocations. Claim 8 A method according to claim 7, wherein when the two PDSCHs are received such that they do not overlap in the frequency domain, a specific number of first PRBs (physical resource blocks) correspond to a first TCI state and the remaining PRBs correspond to a second TCI state. Claim 9 delete Claim 10 A method according to claim 6, wherein when the two PDSCHs are received such that they do not overlap in the time domain, the two PDSCHs correspond to the same number of symbols and the same PDSCH mapping type. Claim 11 A terminal of a communication system comprising: a transceiver; and a control unit configured to receive the two PDSCHs based on the two TCI states and the resource allocation information, wherein the two PDSCHs are associated with a single DMRS (demodulation reference signal) port group, and wherein the capability information indicates that the terminal supports a method for receiving multiple PDSCHs that do not overlap in the time domain, and wherein each of the two TCI states indicated by the single DCI is associated with two PDSCHs that have non-overlapping time domain resource allocations. Claim 12 A terminal according to claim 11, wherein, when the capability information indicates that it supports a method for receiving multiple non-overlapping PDSCHs in the frequency domain, each of the two TCI states indicated by the single DCI is respectively associated with two PDSCHs having non-overlapping frequency domain resource allocations. Claim 13 A terminal according to claim 12, characterized in that when the two PDSCHs are received so as not to overlap in the frequency domain, a specific number of first PRBs (physical resource blocks) correspond to a first TCI state and the remaining PRBs correspond to a second TCI state. Claim 14 delete Claim 15 A terminal according to claim 11, characterized in that when the two PDSCHs are received so as not to overlap in the time domain, the two PDSCHs correspond to the same number of symbols and the same PDSCH mapping type. Claim 16 A base station of a communication system comprising: a transceiver; and a control unit configured to receive capability information of a terminal regarding a method for receiving multiple physical downlink shared channels (PDSCH) from the terminal, indicate two transmission configuration indicator (TCI) states to the terminal, transmit a physical downlink control channel (PDCCH) including a single downlink control information (DCI) containing resource allocation information for the two PDSCHs, and transmit the two PDSCHs based on the two TCI states and the resource allocation information, wherein the two PDSCHs are associated with a demodulation reference signal (DMRS) port group, and when the capability information indicates that a method for receiving multiple PDSCHs that do not overlap in the time domain is supported, each of the two TCI states indicated by the single DCI is respectively associated with two PDSCHs having non-overlapping time domain resource allocations. Claim 17 A base station according to claim 16, wherein, when the capability information indicates that it supports a method for receiving multiple non-overlapping PDSCHs in the frequency domain, each of the two TCI states indicated by the single DCI is respectively associated with two PDSCHs having non-overlapping frequency domain resource allocations. Claim 18 A base station according to claim 17, characterized in that when the two PDSCHs are received so as not to overlap in the frequency domain, a specific number of first PRBs (physical resource blocks) correspond to a first TCI state and the remaining PRBs correspond to a second TCI state. Claim 19 delete Claim 20 A base station according to claim 16, characterized in that when the two PDSCHs are received so as not to overlap in the time domain, the two PDSCHs correspond to the same number of symbols and the same PDSCH mapping type.

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