Method and apparatus for indicating dynamic waveform switching mode in wireless communication system

Abstract

The present disclosure relates to a 5th-Generation (5G) or 6th-Generation (6G) communication system for supporting higher data rates. Disclosed is a method performed by a terminal in a wireless communication system, comprising: receiving downlink control information (DCI) from a base station; identifying whether the DCI includes a dynamic waveform indicator; and transmitting an uplink signal to the base station through a physical uplink shared channel (PUSCH) based on the uplink waveform indicated by the dynamic waveform indicator in a case where the DCI includes the dynamic waveform indicator.

Description

Technical Field

[0001] The present disclosure generally relates to wireless communication systems, and more particularly, to a method and apparatus for indicating dynamic waveform switching in a wireless communication system. Background Art

[0002] The 5th generation (5G) mobile communication technology defines a wide frequency band, enabling high transmission rates and new services, and can be implemented not only in frequency bands below 6 gigahertz (GHz) (such as 3.5 GHz), but also in frequency bands above 6 GHz called millimeter waves (mmWave) including 28 GHz, 39 GHz, etc. In addition, the 6th generation (6G) mobile communication technology (referred to as the ultra-5G system) has been considered to be implemented in the terahertz (THz) frequency band (e.g., 95 GHz to 3 THz frequency band) in order to achieve a transmission rate fifty times faster than that of the 5G mobile communication technology and an ultra-low latency one-tenth of that of the 5G mobile communication technology.

[0003] At the beginning of the development of 5G mobile communication technology, in order to support services and meet the performance requirements related to enhanced mobile broadband (eMBB), ultra-reliable low-latency communication (URLLC), and massive machine type communication (mMTC), standardization has been carried out on the following aspects: beamforming and massive multiple-input multiple-output (MIMO), for reducing radio wave path loss in mmWave and increasing radio wave transmission distance; supporting parameter sets (operating multiple subcarrier spacings), for efficiently utilizing mmWave resources and dynamically operating time slot formats; initial access technology, for supporting multi-beam transmission and broadband; definition and operation of bandwidth parts (BWPs); new channel coding methods, such as low-density parity-check (LDPC) codes for large data transmission and polar codes for highly reliable transmission of control information; layer 2 (L2) preprocessing; and network slicing, for providing dedicated networks dedicated to specific services.

[0004] Currently, considering the services to be supported by 5G mobile communication technology, discussions on the improvement and performance enhancement of the initial 5G mobile communication technology are underway, and physical layer standardization has been carried out on technologies such as the following: vehicle-to-everything (V2X), for assisting autonomous vehicle driving decisions based on information about the location and status of the vehicle sent by the vehicle and for enhancing user convenience; new radio unlicensed (NR-U), aiming to make system operations comply with various regulatory requirements in unlicensed frequency bands; NR user equipment (UE) power saving; non-terrestrial network (NTN), i.e., UE-satellite direct communication, for providing coverage in areas where communication with terrestrial networks is unavailable; and positioning.

[0005] In addition, standardization has been underway in the field of air interface architecture / protocols for technologies such as industrial Internet of Things (IIoT) to support new services through interoperability and integration with other industries; integrated access and backhaul (IAB) to provide nodes for network service area expansion by supporting wireless backhaul links and access links in an integrated manner; mobility enhancements including conditional handover and dual active protocol stack (DAPS) handover; and two-step random access (2-step RACH for NR) to simplify the random access process. Standardization has also been underway in the field of system architecture / services for items such as 5G service-based architecture or service-based interfaces to combine network function virtualization (NFV) and software-defined network (SDN) technologies; and mobile edge computing (MEC) to receive services based on UE positioning.

[0006] With the commercialization of such 5G mobile communication systems, the number of devices connected to the communication network is expected to grow exponentially. Therefore, enhanced functions and performance of 5G mobile communication systems and integrated operation of connected devices are expected to be required. For this purpose, new research has been arranged in combination with the following: extended reality (XR) to efficiently support augmented reality (AR), virtual reality (VR), mixed reality (MR), etc.; 5G performance improvement and complexity reduction by leveraging artificial intelligence (AI) and machine learning (ML); AI service support; metaverse service support; and drone communication.

[0007] In addition, such development of 5G mobile communication systems will not only be used as a basis for developing the following: new waveforms to provide coverage in the THz band for 6G mobile communication technologies; multi-antenna transmission technologies such as full-dimensional MIMO (FD-MIMO), array antennas, and massive antennas; metamaterial-based lenses and antennas to improve the coverage of THz band signals; high-dimensional spatial multiplexing technologies using orbital angular momentum (OAM); and reconfigurable intelligent surfaces (RIS), but also the following are being developed: full-duplex technologies to increase the frequency efficiency of 6G mobile communication technologies and improve the system network; AI-based communication technologies to achieve system optimization by leveraging satellites and AI from the design phase and internalizing end-to-end AI support functions; and next-generation distributed computing technologies to achieve services at a complexity level exceeding the UE operation capacity limit by leveraging ultra-high-performance communication and computing resources.

[0008] Disclosure

[0009] Technical Problem

[0010] An object of the present disclosure is to at least solve the above problems and / or disadvantages and at least provide the following advantages.

[0011] Accordingly, one aspect of the present disclosure is to provide a method and apparatus for indicating dynamic waveform switching in a wireless communication system to support dynamic waveform switching.

[0012] Technical solution

[0013] According to an aspect of the present disclosure, a method performed by a terminal in a wireless communication system includes: receiving downlink control information (DCI) from a base station; identifying whether the DCI includes a dynamic waveform indicator; and in the case where the DCI includes the dynamic waveform indicator, sending an uplink signal to the base station via a physical uplink shared channel (PUSCH) based on the uplink waveform indicated by the dynamic waveform indicator.

[0014] According to an aspect of the present disclosure, a method performed by a base station in a wireless communication system includes: sending DCI to a terminal; and in the case where the DCI includes the dynamic waveform indicator, receiving an uplink signal from the terminal via the PUSCH based on the uplink waveform indicated by the dynamic waveform indicator.

[0015] According to an aspect of the present disclosure, a terminal in a wireless communication system includes a transceiver and a controller connected to the transceiver, the controller being configured to: receive DCI from a base station; determine whether the DCI includes a dynamic waveform indicator; and in the case where the DCI includes the dynamic waveform indicator, send an uplink signal to the base station via the PUSCH based on the uplink waveform indicated by the dynamic waveform indicator.

[0016] According to an aspect of the present disclosure, a base station in a wireless communication system includes a transceiver and a controller connected to the transceiver, the controller being configured to: send DCI to a terminal; and in the case where the DCI includes the dynamic waveform indicator, receive an uplink signal from the terminal via the PUSCH based on the uplink waveform indicated by the dynamic waveform indicator.

[0017] Beneficial effects

[0018] According to an embodiment of the present disclosure, by defining a signal transmission method of a base station in a wireless communication system, dynamic coverage can be provided based on the location and signal state of a terminal. Brief description of the drawings

[0019] The above and other aspects, features, and advantages of certain embodiments of the present disclosure will become more apparent from the following detailed description in conjunction with the drawings, in which:

[0020] Figure 1 Shows the basic structure of a time-frequency resource region in a 5G system according to an embodiment;

[0021] Figure 2 Shows the time-domain mapping structure and beam scanning operation of a synchronization signal according to an embodiment;

[0022] Figure 3 Shows a random access procedure according to an embodiment;

[0023] Figure 4 Shows a process in which a UE reports UE capability information to a base station according to an embodiment;

[0024] Figure 5 Shows a control resource set (CORESET) which is a time-frequency resource to which a physical downlink control channel (PDCCH) is mapped according to an embodiment;

[0025] Figure 6 Shows an example in which a downlink control information (DCI) and a demodulation reference signal (DMRS) are mapped to a resource element group (REG), where REG is a basic unit of a downlink control channel, according to an embodiment;

[0026] Figure 7 Shows a base station beam allocation configured according to a transmission configuration indicator (TCI) state according to an embodiment;

[0027] Figure 8 Shows a hierarchical signaling method for dynamically allocating PDCCH beams by NR according to an embodiment;

[0028] Figure 9 Shows a transport channel control element (MAC CE) signaling structure for a PDCCH DMRS according to an embodiment;

[0029] Figure 10 Shows a method for a base station and a UE to transmit and receive data by considering a DL data channel and rate matching resources according to an embodiment;

[0030] Figure 11 Shows an aperiodic channel state information (CSI) reporting method when a CSI-RS offset is 0 according to an embodiment;

[0031] Figure 12 Shows an aperiodic CSI reporting method when a CSI-RS offset is 1 according to an embodiment;

[0032] Figure 13 Shows a transmission block diagram for transmission signal generation in a 5G communication system according to an embodiment;

[0033] Figure 14 Shows a UE operation procedure related to type 1 transform precoding determination according to an embodiment;

[0034] Figure 15 Shows a UE operation procedure related to type 2 transform precoding determination according to an embodiment;

[0035] Figure 16 shows a UE operation procedure related to type 3 transform precoding determination according to an embodiment;

[0036] Figure 17 shows a branching method of dynamic waveform indication according to an embodiment, which is performed by schematically showing the overall application of transform precoding according to three PUSCH types affected by transform precoding;

[0037] Figure 18 shows a method of DCI-based signaling from a base station to a UE for dynamic waveform indication according to an embodiment;

[0038] Figure 19 shows resource allocation type 0 of frequency domain resource allocation (FDRA) according to an embodiment;

[0039] Figure 20 shows resource allocation type 1 of FDRA according to an embodiment;

[0040] Figure 21 shows a transmitter and a receiver of a UE according to an embodiment;

[0041] Figure 22 is a block diagram of the structure of a UE according to an embodiment; and

[0042] Figure 23 is a block diagram showing the structure of a base station according to an embodiment. Detailed implementation

[0043] Hereinafter, embodiments of the present disclosure will be described with reference to the accompanying drawings. When a detailed description of related well-known functions or configurations may unnecessarily obscure the essence of the present disclosure, they may be omitted. In addition, the terms used hereinafter are defined in consideration of the functions in the present disclosure and may have different meanings depending on the intention, habit, etc. of the user or operator. Therefore, the terms should be defined based on the description throughout this specification.

[0044] The advantages and features of the present disclosure and the method of achieving them can be more easily understood by referring to the following detailed description of the embodiments of the present disclosure and the accompanying drawings. However, the embodiments of the present disclosure may have different forms and should not be construed as limited to the descriptions set forth herein. Rather, these embodiments of the present disclosure are provided to make the present disclosure thorough and complete and to fully convey the concept of the present disclosure to those of ordinary skill in the art. Throughout this specification, like reference numerals denote like elements.

[0045] In this document, depending on the specific embodiments presented, the elements included in this disclosure are represented in singular or plural forms. However, the choice of singular or plural representation is for the convenience of description in the presented situation, and this disclosure is not limited to elements in singular or plural forms. That is, elements represented in plural forms can be configured as a single element, or elements represented in singular forms can be configured as multiple elements.

[0046] In the embodiments, the term 'unit' refers to a software component or a hardware component, such as a field-programmable gate array (FPGA) or an application-specific integrated circuit (ASIC), and performs a specific function. However, the term unit is not limited to software or hardware. A unit can be constructed in an addressable storage medium or can be constructed to operate one or more processors. Thus, for example, the term unit can refer to components such as software, object-oriented software, classes, and task components, and can include processes, functions, attributes, procedures, subroutines, program code segments, drivers, firmware, microcode, circuits, data, databases, data structures, tables, arrays, or variables. The functions provided by components and units can be associated with a smaller number of components and units or can be divided into additional components and units. Components and units can be embodied as one or more central processing units (CPUs) in a reproduction device or a secure multimedia card, and a unit can include at least one processor.

[0047] For convenience of description, terms used herein for identifying access nodes, terms for representing network entities, terms for representing interfaces between network entities, various types of identification information, etc. are described. Thus, the terms used in this disclosure are not restricted, and other terms representing objects with the same technical meaning can be used.

[0048] In this document, physical channels and signals can be used interchangeably with data or control signals. For example, the physical downlink shared channel (PDSCH) indicates the physical channel through which data is transmitted but can be used to indicate data. That is, in this document, the transmitted physical channel can indicate the transmission of data or signals through the physical channel.

[0049] In this disclosure, higher layer signaling refers to a signal transmission method used for a base station to send signals to a terminal by using the DL data channel of the physical layer or for a terminal to send signals to a base station by using the UL data channel of the physical layer, such as through radio resource control (RRC) signaling or media access control (MAC) control element (CE).

[0050] For ease of description, the present disclosure uses terms and names defined in the 3rd Generation Partnership Project (3GPP) NR mobile communication standard, but is not limited to these terms and names and can be equivalently applied to systems conforming to other standards. A terminal herein may refer to a mobile phone, a smart phone, an Internet of Things (IoT) device, a sensor, or other wireless communication devices.

[0051] Hereinafter, a base station is an entity that allocates resources to a terminal and may be at least one of the following: gNodeB, gNB, eNode B, eNB, Node B, BS, a radio access unit, a base station controller, and a node on the network. A terminal may include a UE, a mobile station (MS), a cellular phone, a smart phone, a computer, or a multimedia system capable of performing communication functions. The present disclosure is not limited to the above examples.

[0052] To handle the rapidly increasing mobile data traffic in recent years, the initial standards for the next-generation communication system, 5G system, or new radio access technology (NR) after Long-Term Evolution (LTE) (or Evolved Universal Terrestrial Radio Access (E-UTRA)) and LTE-Advanced (LTE-A) (or E-UTRA evolution) have been completed. In addition to existing mobile communication systems focusing on traditional voice / data communication, the 5G system aims to meet various services and requirements, such as enhanced mobile broadband (eMBB) services for improving existing voice / data communication, ultra-reliable and low-latency communication (URLLC) services, and massive machine type communication (MTC) supporting communication between multiple things.

[0053] Compared with traditional LTE and LTE-A systems where the system transmission bandwidth per carrier is limited to a maximum of 20 MHz, the 5G system mainly aims to provide ultra-high-speed data services of up to several Gbps with an ultra-wide bandwidth much wider than that of traditional LTE and LTE-A systems. Accordingly, ultra-high frequency bands from several GHz to a maximum of 100 GHz (where it is relatively easy to ensure ultra-wide bandwidth) are considered candidate frequencies for the 5G system. Additionally, the broadband frequency of the 5G system can be ensured by frequency relocation or allocation between frequency bands included in several hundred MHz to several GHz used in traditional mobile communication systems.

[0054] The wavelength of radio waves in the ultra-high frequency band is several millimeters and is also referred to as millimeter wave (mmWave). However, the path loss of radio waves increases proportionally with the frequency band in the ultra-high frequency band, thereby reducing the coverage of the mobile communication system.

[0055] To overcome the drawback of reduced coverage in the super high frequency band, beamforming technology is applied to increase the propagation distance of radio waves by concentrating the radiation energy of radio waves at a specific target point using multiple antennas. That is, the beamforming signal has a relatively narrow beam width and concentrates the radiation energy within the narrow beam width to increase the propagation distance of radio waves. The beamforming technology can be applied to each of the transmitter and the receiver. In addition to the effect of increasing coverage, the beamforming technology also reduces interference in areas other than the beamforming direction. To perform proper beamforming, a method for accurately measuring the transmit / receive beam and feeding back the measurement is required. The beamforming technology can be applied to the control channel or data channel corresponding one-to-one between a specific UE and a base station. In addition, the beamforming technology can also be applied to the common signals sent by the base station to multiple UEs in the system, such as synchronization signals, physical broadcast channels (PBCH), control channels carrying system information, and data channels, in order to increase coverage. When the beamforming technology is applied to the common signals, the beam scanning technology can be further applied to the common signals to send signals by switching the beam direction. Therefore, the common signals can reach UEs located anywhere within the cell.

[0056] Another requirement of the 5G system is ultra-low latency services with a transmission latency of approximately 1 ms between the transmitter and the receiver. As a method for reducing the transmission latency, it is necessary to design the frame structure based on shorter transmission time intervals (TTIs) than those in LTE and LTE-A. The TTI is the basic time unit for scheduling. In traditional LTE and LTE-A systems, the TTI is the length of one subframe, i.e., 1 ms. For example, 0.5 ms, 0.25 ms, 0.125 ms, etc., which are shorter than those in traditional LTE and LTE-A systems, can be used as the short TTIs to meet the requirements of ultra-low latency services in the 5G system.

[0057] Figure 1 Shows the basic structure of the time-frequency resource region in the 5G system according to an embodiment. That is, Figure 1 Shows the basic structure of the time-frequency resource region, which is the radio resource region carrying data or control channels in the 5G system.

[0058] In Figure 1 it, the horizontal axis represents the time domain and the vertical axis represents the frequency domain. In the 5G system, the smallest transmission unit in the time domain is the orthogonal frequency division multiplexing (OFDM) symbol. A number of symbols 102 can together form a time slot 106, and A number of time slots can together form a subframe 105. Ten subframes each with a length of 1.0 ms can together form a 10 ms frame 114. The smallest transmission unit in the frequency domain is the subcarrier, and the bandwidth of the entire system transmission bandwidth can be totally composed of NBW It is composed of subcarriers 104.

[0059] The basic resource unit in the time - frequency domain is a resource element (RE) 112, which can be represented by an OFDM symbol index and a subcarrier index. A resource block (RB or physical resource block (PRB)) can be defined as a number of consecutive subcarriers 110 in the frequency domain. In a 5G system, and the data rate can increase proportionally to the number of RBs scheduled for the UE.

[0060] In a 5G system, the base station can map data based on RBs, and the RBs included in one time slot are usually scheduled for a specific UE. That is to say, in a 5G system, the basic time unit for scheduling can be a time slot, and the basic frequency unit for scheduling can be an RB.

[0061] The number of OFDM symbols is determined according to the length of the cyclic prefix (CP) added to each symbol to prevent inter - symbol interference. For example, when normal CP is applied, and when extended CP is applied, Compared with the conventional CP, the extended CP is applied to systems with longer propagation distances, so that the orthogonality between symbols can be maintained. In the case of the conventional CP, the ratio between the CP length and the symbol length remains constant, so the overhead of the CP can remain constant regardless of the sub - carrier spacing. That is to say, when the sub - carrier spacing is small, the symbol length can increase, and correspondingly, the CP length can also increase. On the contrary, when the sub - carrier spacing is large, the symbol length can decrease, and correspondingly, the CP length can also decrease. The symbol length and the CP length can be inversely proportional to the sub - carrier spacing.

[0062] A 5G system can support various frame structures by adjusting the sub - carrier spacing to meet various services and requirements. For example, for the operating band, a larger sub - carrier spacing is more beneficial for recovering the phase noise of the high - frequency band. For the transmission time, as the sub - carrier spacing increases, the symbol length in the time domain decreases. Therefore, the time - slot length decreases, which is beneficial for supporting ultra - low - latency services such as URLLC. For the cell size, because a larger cell can be supported with a larger CP length, a larger cell can be supported with a smaller sub - carrier spacing. A cell conceptually refers to the area covered by a BS in mobile communication.

[0063] The subcarrier spacing, CP length, etc. are basic information for OFDM transmission / reception, and smooth transmission / reception can be achieved only when the base station and the UE recognize them as common values. Table 1 below shows the relationship between the subcarrier spacing configuration μ, subcarrier spacing Δf, and CP length supported by the 5G system.

[0064] Table 1

[0065] μ <![CDATA[Δf = 2 μ ·15[kHz]]]> Cyclic Prefix 0 15 Normal 1 30 Normal 2 60 Normal, Extended 3 120 Normal 4 240 Normal

[0066] Table 2 below shows the number of symbols per time slot for each subcarrier spacing configuration μ in the case of normal CP. The number of time slots per frame and the number of time slots per subframe

[0067] Table 2

[0068]

[0069] Table 3 below shows the number of symbols per time slot for each subcarrier spacing configuration μ in the case of extended CP. The number of time slots per frame and the number of time slots per subframe

[0070] Table 3

[0071]

[0072] In the initial introduction stage of the 5G system, it is expected to coexist with or operate in a dual-mode manner with traditional LTE / LTE-A systems at least. Therefore, traditional LTE / LTE-A can provide stable system operation for the UE, while the 5G system can provide advanced services for the UE. Accordingly, the frame structure of the 5G system needs to include at least the frame structure or basic parameter set (subcarrier spacing = 15 kHz) of LTE / LTE-A.

[0073] For example, when comparing the frame structure with subcarrier spacing configuration μ = 0 (hereinafter referred to as frame structure A) and the frame structure with subcarrier spacing configuration μ = 1 (hereinafter referred to as frame structure B), in frame structure B, compared with frame structure A, the subcarrier spacing and the size of the RB are increased by a factor of two, and the time slot length and symbol length are reduced by half. In the case of frame structure B, two time slots can form a subframe, and 20 subframes can form a frame.

[0074] When the frame structure of a 5G system is standardized, basic parameter sets such as subcarrier spacing, CP length, and slot length can have an integer multiple relationship according to different frame structures, thus providing high scalability. To indicate a reference time unit independent of the frame structure, a subframe with a fixed length of 1 ms can be defined.

[0075] The frame structure can be applied to various corresponding scenarios. Considering the cell size, when the CP length increases, larger cells can be supported. Therefore, compared with Frame Structure B, Frame Structure A can support relatively large cells. Considering the operating band, when the subcarrier spacing increases, the recovery from phase noise in the high frequency band is simplified. Therefore, compared with Frame Structure A, Frame Structure B can support relatively high operating frequencies. Considering the service, since a shorter slot length (used as the basic time unit for scheduling) is more favorable for supporting ultra-low latency services such as URLLC, Frame Structure B may be more suitable for URLLC services compared with Frame Structure A.

[0076] Hereinafter, the uplink (UL) may refer to the radio link for sending data or control signals from the UE to the base station, and the downlink (DL) may refer to the radio link for sending data or control signals from the base station to the UE.

[0077] In the initial access operation when the UE first accesses the system, the UE can establish DL time / frequency synchronization from the synchronization signal sent by the base station through cell search and can obtain the cell identifier (ID). In addition, the UE can receive the physical broadcast channel (PBCH) by using the obtained cell ID and can obtain the master information block (MIB) as the basic system information from the PBCH. In addition, the UE can receive the system information block (SIB) sent by the base station to obtain cell common transmission / reception related control information. The cell common transmission / reception related control information may include random access related control information, paging related control information, common control information for various physical channels, etc.

[0078] The synchronization signal is a reference signal for cell search, and a subcarrier spacing suitable for the channel environment (such as phase noise, etc.) can be applied for each frequency band. Different subcarrier spacings can be applied to data or control channels based on the service type to support various services as described above.

[0079] Figure 2 The time domain mapping structure and beam scanning operation of the synchronization signal according to an embodiment are shown.

[0080] For ease of explanation, the following elements can be defined.

[0081] The primary synchronization signal (PSS) is used as a reference for DL time / frequency synchronization and provides certain information about the cell ID.

[0082] The secondary synchronization signal (SSS) serves as a reference for DL time / frequency synchronization and provides some residual information about the cell ID. Additionally, the SSS can serve as a reference signal for demodulation of the PBCH.

[0083] The physical broadcast channel (PBCH) provides the master information block (MIB), which is the basic system information required for the transmission or reception of the UE's data channels and control channels. The basic system information may include search space-related control information indicating radio resource mapping information of the control channel, scheduling control information for a separate data channel for system information transmission, information such as the system frame number (SFN), which is a frame unit index used as a timing reference.

[0084] The synchronization signal / PBCH block (SS / PBCH block) or SSB consists of N OFDM symbols and includes a combination of the PSS, SSS, and PBCH. In the case of a system applying beam scanning technology, the SS / PBCH block is the smallest unit to which beam scanning is applied. In a 5G system, N = 4. The base station can transmit up to L SS / PBCH blocks, and the L SS / PBCH blocks are mapped within a half-frame (0.5 ms). Additionally, the L SS / PBCH blocks are periodically repeated in units of a predetermined period P. The period P may be signaled by the base station to the UE. If there is no separate signaling for the period P, the UE applies a predetermined default value.

[0085] Figure 2 Shown is the application of beam scanning in units of SS / PBCH blocks over time according to an embodiment. In Figure 2 , UE1 205 receives the SS / PBCH block at time t1 201 using the beam transmitted in direction #d0 203 by beamforming applied to SS / PBCH block #0. Additionally, UE2 206 receives the SS / PBCH block at time t2 202 using the beam transmitted in direction #d4 204 by beamforming applied to SS / PBCH block #4. The UE can obtain the best synchronization signal from the base station through the beam transmitted in the direction where the UE is located. For example, it may be difficult for UE1 205 to obtain time / frequency synchronization and basic system information from the SS / PBCH block through the beam transmitted in direction #d4 at a location far from UE1.

[0086] In addition to the initial access procedure, the UE can also receive SS / PBCH blocks to determine whether the radio link quality of the current cell is maintained at a predetermined level or higher. Additionally, during the process of the UE performing a handover from the current cell to an adjacent cell, the UE can receive the SS / PBCH blocks of the adjacent cell to determine the radio link quality of the adjacent cell and obtain the time / frequency synchronization of the adjacent cell.

[0087] After the UE obtains the MIB and system information from the base station through the initial access procedure, the UE can perform a random access procedure to switch the link with the base station to the connected state (or RRC_CONNECTED state). When the random access procedure is completed, the UE is switched to the connected state, and one-to-one communication is enabled between the base station and the UE. Hereinafter, the random access procedure will be described in detail in Figure 3 .

[0088] Figure 3 shows a random access procedure according to an embodiment.

[0089] In step 310, the UE sends a random access preamble to the base station. During the random access procedure, the random access preamble, which is the first message sent by the UE, can be referred to as message 1. The base station can measure the transmission delay value between the UE and the base station based on the random access preamble and establish uplink synchronization. In this case, the UE can randomly select a random access preamble to be used from the set of random access preambles pre-given by the system information. Additionally, the initial transmission power of the random access preamble can be determined according to the path loss between the base station and the UE, which is measured by the UE. Additionally, the UE can send the random access preamble by determining the transmission beam direction of the random access preamble based on the synchronization signal received from the base station.

[0090] In step 320, the base station sends a UL transmission timing adjustment instruction to the UE based on the transmission delay value measured from the random access preamble received in step 310. Additionally, the base station can send the UL resources and power control instructions to be used by the UE as scheduling information. The control information for the UL transmission beam of the UE can be included in the scheduling information.

[0091] If the UE does not receive a random access response (RAR) (or message 2), which is the scheduling information as message 3, from the base station within a predetermined period in step 320, step 310 can be executed. If step 310 is executed again, the UE increases the random access preamble transmission power through a predetermined operation and sends the same random access preamble (power boost), thereby increasing the random access preamble reception probability of the base station.

[0092] In step 330, the UE sends UL data (Message 3) including the UE ID of the UE itself to the base station via the UL physical uplink shared channel (PUSCH) by using the UL resources allocated in step 320. The transmission timing of the UL data channel for transmitting Message 3 may follow the timing control instruction received from the base station in step 320. Additionally, the transmission power of the UL data channel for transmitting Message 3 may be determined by considering the power boost value of the random access preamble and the power control instruction received from the base station in step 320. The UL data channel for transmitting Message 3 may refer to the first UL data signal sent by the UE to the base station after the UE transmits the random access preamble.

[0093] In step 340, when it is determined that the UE has performed random access without colliding with another UE, the base station sends data (Message 4) including the ID of the UE that has sent UL data in step 330 to the corresponding UE. When receiving the signal sent by the base station in step 340, the UE may determine that the random access is successful. Additionally, the UE may send hybrid automatic repeat request acknowledgment (HARQ-ACK) information indicating whether Message 4 has been successfully received to the base station via the physical uplink control channel (PUCCH).

[0094] If the base station fails to receive the data signal from the UE due to a collision between the data sent by the UE in step 330 and the data of another UE, the base station may no longer perform any data transmission to the UE. Accordingly, when the UE fails to receive the data sent by the base station in step 340 within a predetermined period, it may be determined that the random access process has failed, and the process may start again from step 310.

[0095] When the random access process is successfully completed, the UE is switched to the connected state, and one-to-one communication can be performed between the base station and the UE. The base station may receive a report of UE capability information from the UE in the connected state and may adjust scheduling with reference to the UE capability information of the corresponding UE. The UE may notify the base station whether the UE itself supports a predetermined function, the maximum allowable value of the functions supported by the UE, etc. via the UE capability information. Accordingly, the UE capability information reported by each UE to the base station may be different values for each UE.

[0096] As an example, the UE may report UE capability information including at least a part of the following control information as the UE capability information.

[0097] - Control information related to the frequency bands supported by the UE.

[0098] - Control information related to the channel bandwidth supported by the UE.

[0099] - Control information related to the maximum modulation method supported by the UE.

[0100] - Control information related to the maximum number of beams supported by the UE.

[0101] - Control information related to the maximum number of layers supported by the UE.

[0102] - Control information related to the CSI report supported by the UE.

[0103] - Control information related to whether the UE supports frequency hopping.

[0104] - Bandwidth-related control information when carrier aggregation (CA) is supported.

[0105] - Control information related to whether cross-carrier scheduling is supported when CA is supported.

[0106] Figure 4 The process in which the UE reports UE capability information to the base station is shown.

[0107] In Figure 4 In step 410, the base station 402 may send a UE capability information request message to the UE 401. In response to the request for UE capability information from the base station, in step 420, the UE sends the UE capability information to the base station.

[0108] Through the above process, the UE connected to the base station is in the RRC_CONNECTED state, and the UE connected to the base station can perform one-to-one communication. On the contrary, the unconnected UE is in the RRC_IDLE state, and the operations of the UE in this state are classified as follows.

[0109] - Operations of the UE-specific discontinuous reception (DRX) cycle configured by a higher layer.

[0110] - Operations of receiving paging messages from the core network.

[0111] - Obtaining system information.

[0112] - Measurement operations related to neighboring cells and cell reselection.

[0113] In the 5G system, a new state of the UE called RRC_INACTIVE is defined to reduce the energy and time consumed by the UE's initial access. In addition to the operations performed by the UE in the RRC_IDLE state, the UE in the RRC_INACTIVE state also performs the following operations.

[0114] - Storage of access stratum (AS) information required for cell access.

[0115] - UE-specific DRX cycle operations configured through the RRC layer.

[0116] - Configuration of RAN-based notification areas (RNA) that can be used by the RRC layer during handover and periodic updates.

[0117] - Monitoring of RAN-based paging messages sent via I-RNTI.

[0118] Hereinafter, a scheduling method for the base station to send DL data to the UE or instruct the UE to send UL data will be described.

[0119] DCI is control information sent by the base station to the UE via DL and can include DL data scheduling information or UL data scheduling information for a predetermined UE. The base station can perform channel coding of DCI independently for each UE and then send the channel-coded DCI to each UE via PDCCH.

[0120] The base station can operate DCI for the UE to be scheduled by applying a specific DCI format, which is determined according to whether the DCI is scheduling information about DL data (e.g., DL allocation) or scheduling information about UL data (UL grant), whether the DCI is used for power control, etc.

[0121] The base station can send DL data to the UE via PDSCH, which is a physical channel for DL data transmission. The base station can notify the UE of scheduling information, such as specific mapping positions in the time domain and frequency domain of PDSCH, modulation scheme, HARQ-related control information, and power control information, in the DCI sent via PDCCH through the DCI related to the scheduling information for DL data.

[0122] The UE can send UL data to the base station via PUSCH, which is a physical channel for UL data transmission. The base station can notify the UE of scheduling information, such as specific mapping positions in the time domain and frequency domain of PUSCH, modulation scheme, HARQ-related control information, and power control information, in the DCI sent via PDCCH through the DCI related to the scheduling information for UL data.

[0123] Figure 5 A control resource set (CORESET), which is a time-frequency resource to which PDCCH is mapped according to an embodiment, is shown.

[0124] In Figure 5In it, a UE BWP 510 is configured on the frequency axis, and two control resource sets (control resource set #1 (501) and control resource set #2 (502)) are configured in one time slot (520) on the time axis. The control resource sets 501 and 502 can be configured as specific frequency resources 503 within the entire UE BWP 510 on the frequency axis. One or more OFDM symbols can be configured on the time axis, and this can be defined as the control resource set duration 504.

[0125] The control resource set #1 (501) can be configured with a control resource set length of 2 symbols, and the control resource set #2 (502) can be configured with a control resource set length of 1 symbol.

[0126] The base station can configure one or more CORESETs for the UE through higher layer signaling (e.g., system information, master information block (MIB), radio resource control (RRC) signaling). Configuring a CORESET for the UE means providing information such as the CORESET identifier, the frequency location of the CORESET, and the symbol length of the CORESET. The information provided by the base station to the UE to configure the CORESET can include certain information related to the information contained in Table 4 below.

[0127] Table 4

[0128]

[0129]

[0130] A CORESET can include RBs in the frequency domain and symbols in the time domain. The NR PDCCH can include one or more control channel elements (CCEs). One CCE can include six resource element groups (REGs), and a REG can be defined as one RB during one OFDM symbol. In a CORESET, the REGs can be indexed in time-first order, starting from the lowest RB in the first OFDM symbol of the CORESET with REG index 0.

[0131] To transmit PDCCH, an interleaving scheme and a non - interleaving scheme can be supported. The base station can configure for the UE, on a CORESET basis, whether to use the interleaving scheme or the non - interleaving scheme to transmit PDCCH through higher - layer signaling. Interleaving can be performed on a REG bundle basis. A REG bundle can be defined as a set of one or more REGs. The UE can determine the CCE - to - REG mapping scheme for the corresponding CORESET based on the interleaving or non - interleaving transmission scheme configured by the base station in the manner described in Table 5 below.

[0132] Table 5

[0133]

[0134] The base station can indicate configuration information to the UE through signaling, such as the symbols to which the PDCCH is mapped in a time slot and the transmission period of the PDCCH.

[0135] Figure 6 An example in which DCI and DMRS are mapped to REGs according to an embodiment is shown. REG is the basic unit of the DL control channel.

[0136] In Figure 6 , the basic unit of the DL control channel (i.e., REG 603) can include both the REs to which DCI is mapped and the regions to which DMRS 605 (reference signal for decoding DCI) is mapped. Additionally, three DMRS 605s can be transmitted within one REG 603.

[0137] According to the aggregation level (AL), the number of CCEs required to transmit PDCCH can be 1, 2, 4, 8, or 16, and different numbers of CCEs can be used for link adaptation of the DL control channel. For example, in the case of AL = L, one downlink control channel can be transmitted with L CCEs. In the absence of information about the DL control channel, the UE detects the signal, which is blind decoding. For blind decoding, a search space can be defined. The search space is a set of CCEs. The search space is the set of downlink control channel candidates including CCEs that the UE should attempt to decode under a given AL. There are various ALs in which 1, 2, 4, 8, and 16 CCEs are bundled to form a bundle, and thus the UE can have multiple search spaces. The set of search spaces can be defined as the set of search spaces for all configured ALs.

[0138] The search space can be classified into a common search space (CSS) and a UE-specific search space (USS). A specific UE group or all UEs can monitor the CSS of the PDCCH to receive cell-common control information, such as the dynamic scheduling of SIB or paging messages. For example, a UE can receive scheduling assignment information for the PDSCH used for system information reception by monitoring the CSS of the PDCCH. Since a specific UE group or all UEs should receive this PDCCH, the CSS can be defined as a set of preset CCEs. A UE can receive scheduling assignment information for UE-specific PDSCH or PUSCH by monitoring the USS of the PDCCH. The USS can be specifically defined for a UE as a function of the UE ID and various system parameters.

[0139] The base station can configure configuration information about the search space of the PDCCH for a UE through higher-layer signaling (e.g., SIB, MIB, or RRC signaling). For example, the base station can configure for a UE the number of PDCCH candidate groups for each ALL, the monitoring periodicity of the search space, the monitoring occasion in each symbol of the time slot for the search space, the search space type (CSS or USS), the combination of DCI format and RNTI to be monitored in the search space, and the CORESET index to be monitored in the search space. For example, the parameters for the PDCCH search space can include the information described in Table 6 below.

[0140] Table 6

[0141]

[0142]

[0143]

[0144]

[0145] According to the configuration information, the base station can configure one or more search space sets for a UE. The base station can configure search space set 1 and search space set 2 for a UE. In search space set 1, the UE can be configured to monitor DCI format A scrambled with X-RNTI in the CSS, and in search space set 2, the UE can be configured to monitor DCI format B scrambled with Y-RNTI in the USS.

[0146] According to the configuration information, there can be one or more search space sets in the CSS or USS. For example, search space set #1 and search space set #2 can be configured as CSS, and search space set #3 and search space set #4 can be configured as USS.

[0147] In CSS, the UE can monitor the following DCI formats and RNTI combinations, but the present disclosure is not limited to the following examples.

[0148] DCI formats 0_0 / 1_0 with CRC scrambled by C-RNTI, CS-RNTI, SP-CSI-RNTI, RA-RNTI, TC-RNTI, P-RNTI, SI-RNTI

[0149] DCI format 2_0 with CRC scrambled by SFI-RNTI

[0150] DCI format 2_1 with CRC scrambled by INT-RNTI

[0151] DCI format 2_2 with CRC scrambled by TPC-PUSCH-RNTI, TPC-PUCCH-RNTI. DCI format 2_3 with CRC scrambled by TPC-SRS-RNTI

[0152] DCI format 2_4 with CRC scrambled by CI-RNTI

[0153] DCI format 2_5 with CRC scrambled by AI-RNTI

[0154] DCI format 2_6 with CRC scrambled by PS-RNTI

[0155] DCI format 2_7 with CRC scrambled by PEI-RNTI

[0156] In USS, the UE can monitor the following DCI formats and RNTI combinations. The present disclosure is not limited to the following examples.

[0157] DCI formats 0_0 / 1_0 with CRC scrambled by C-RNTI, CS-RNTI, TC-RNTI

[0158] DCI formats 1_0 / 1_1 with CRC scrambled by C-RNTI, CS-RNTI, TC-RNTI

[0159] The above RNTIs can be defined and used as follows.

[0160] Cell RNTI (C-RNTI): UE-specific PDSCH or PUSCH scheduling

[0161] Temporary Cell RNTI (TC-RNTI): UE-specific PDSCH scheduling

[0162] Configured Scheduling RNTI (CS-RNTI): Semi-statically configured UE-specific PDSCH scheduling

[0163] Random Access RNTI (RA-RNTI): PDSCH scheduling in the random access phase

[0164] Paging RNTI (P-RNTI): PDSCH scheduling for paging transmission

[0165] System Information RNTI (SI-RNTI): PDSCH scheduling for system information transmission

[0166] Interruption RNTI (INT-RNTI): Used to indicate whether the PDSCH is punctured

[0167] Transmission Power Control RNTI for PUSCH (TPC-PUSCH-RNTI): Used to indicate the power control instruction for PUSCH

[0168] TPC RNTI for PUCCH (TPC-PUCCH-RNTI): Used to indicate the power control instruction for PUCCH

[0169] TPC RNTI for SRS (TPC-SRS-RNTI): Used to indicate the power control instruction for SRS

[0170] The above DCI formats can follow the definitions shown in Table 7 below.

[0171] Table 7

[0172]

[0173]

[0174] The search space for ALL in CORESET p and the search space set s can be represented by the following equation (1).

[0175]

[0176] In equation (1):

[0177] L: Aggregation level

[0178] nci: Carrier index

[0179] NCCE,p: Total number of CCEs present in control resource set p

[0180] Slot index

[0181] M (L) p.s,max: Number of PDCCH candidates at aggregation level L

[0182] ms,n CI = 0, …, M (L) p.s,max - 1: Index of PDCCH candidates at aggregation level L

[0183] i = 0, …, L - 1

[0184] Y p,-1 = n RNTI ≠ 0, A0 = 39827, A1 = 39829, A2 = 39839, and D = 65537

[0185] nRNTI: UE identifier

[0186] The value can correspond to 0 in CSS.

[0187] The value can correspond to a value that varies according to the UE ID (C - RNTI or the ID configured by the base station for the UE) and the time index in USS.

[0188] The base station can configure and indicate the TCI state related to the PDCCH (or PDCCH DMRS) through appropriate signaling. According to the above description, the base station can configure and indicate the TCI state related to the PDCCH (or PDCCH DMRS) through appropriate signaling. The TCI state indicates the quasi - co - location (QCL) relationship between the PDCCH (or PDCCH DMRS) and another RS or channel. The fact that the reference antenna port A (reference RS#A) and the target antenna port B (target RS#B) are quasi - co - located means that the UE is allowed to apply all or part of the large - scale channel parameters estimated at antenna port A to perform channel measurements at antenna port B. QCL may need to involve different parameters depending on the situation, including: time tracking affected by the average delay and delay spread, frequency tracking affected by the Doppler shift and Doppler spread, radio resource management (RRM) affected by the average gain, and beam management (BM) affected by the spatial parameters. Accordingly, NR supports the four types of QCL relationships shown in Table 8 below.

[0189] Table 8

[0190] QCL Type Large-Scale Characteristics A Doppler Shift, Doppler Spread, Mean Delay, Delay Spread B Doppler Shift, Doppler Spread C Doppler Shift, Mean Delay D Spatial Rx Parameter

[0191] Spatial RX parameters can be a general term that indicates a part or all of various parameters, including: angle of arrival (AoA), power angular spectrum (PAS) of AoA, angle of departure (AoD), PAS of AoD, transmit / receive channel correlation, transmit / receive beamforming, and spatial channel correlation.

[0192] The QCL relationship can be configured for the UE through the RRC parameters TCI-state and QCL-Info shown in Table 9 below. In Table 9 below, the base station can configure at least one TCI state for the UE to notify the UE of up to two QCL relationships (qcl-Type1 and qcl-Type2) related to the RS with the ID of the reference TCI state (i.e., the target RS). Each QCL information (QCL-Info) included in the TCI state includes the serving cell index and BWP index of the reference RS, the type and ID of the reference RS, and the QCL type, as shown in Table 8 above.

[0193] Table 9

[0194]

[0195]

[0196] Figure 7 Illustrated is the base station beam allocation configured according to the TCI state according to an embodiment.

[0197] In Figure 7 the base station can transmit information related to N different beams to the UE through N different TCI states. For example, when N = 3, the base station can allow the qcl-Type 2 parameters included in the three TCI states 700, 705, and 710 to be associated with the CSI-RS or SSB corresponding to different beams, and be configured as QCL type D to indicate that the antenna ports referring to different TCI states 700, 705, and 710 are associated with different spatial Rx parameters (i.e., different beams).

[0198] Specifically, the combinations of TCI states applied to the PDCCH DMRS antenna ports are shown in Table 10 below. In Table 10, the combinations in the fourth row are assumed by the UE before RRC configuration and cannot be configured after RRC connection.

[0199] Table 10

[0200]

[0201] The NR system supports a hierarchical signaling method as Figure 8 shown for the dynamic allocation of PDCCH beams.

[0202] Figure 8 Illustrated is the hierarchical signaling method for dynamically allocating PDCCH beams according to an embodiment.

[0203] In Figure 8Among them, the base station can configure N TCI states 805, 810, …, and 820 (800) for the UE through RRC signaling, and can configure some of the TCI states as the TCI state (825) for the CORESET. After the configuration, the base station can indicate to the UE, through MAC CE signaling, one of the TCI states 830, 835, and 840 for the CORESET (845). After this indication, the UE receives the PDCCH based on the beam information included in the TCI state indicated by the MAC CE signaling.

[0204] Figure 9 The TCI indication MAC CE signaling structure for PDCCH DMRS according to an embodiment is shown.

[0205] In Figure 9 Among them, the TCI indication MAC CE signaling for PDCCH DMRS consists of 2 bytes (16 bits), and includes a reserved bit 910 formed by one bit, a serving cell ID 915 formed by five bits, a BWP ID 920 formed by two bits, a CORESET ID 925 formed by two bits, and a TCI state ID 930 formed by six bits.

[0206] The base station can indicate, through MAC CE signaling, one TCI state in the list of TCI states included in the configuration of the CORESET. During the time interval from the start of this TCI state indication to the indication of another TCI state in the corresponding CORESET through another MAC CE signaling, the UE can assume that the same QCL information is applied to one or more search spaces connected to the CORESET.

[0207] In this PDCCH beam allocation method, it is difficult to indicate beam switching before the MAC CE signaling delay, and there is a deficiency in uniformly applying the same beam to each CORESET without considering the characteristics of the search space. Therefore, it is difficult to flexibly perform PDCCH beam management. Therefore, a more flexible PDCCH beam configuration and management method is provided below. In this article, certain distinguishable examples are provided, but these examples are not mutually exclusive and can be appropriately combined with each other according to the application situation.

[0208] The base station can configure one or more TCI states for the UE regarding a specific control resource set, and can activate one of the configured TCI states through a MAC CE activation instruction. For example, {TCI state #0, TCI state #1, TCI state #2} is configured as the TCI state for control resource set #1, and the base station can send an instruction through the MAC CE to the UE to activate the TCI state (assumed to be TCI state #0) related to control resource set #1. Based on the activation instruction related to the TCI state received through the MAC CE, the UE can correctly receive the DMRS in the control resource set based on the QCL information in the activated TCI state.

[0209] Regarding the control resource set (control resource set #0) configured with index 0, if the UE fails to receive the MAC CE activation instruction related to the TCI state of control resource set #0, the UE can assume that the DMRS transmitted in control resource set #0 is QCL with the SS / PBCH block identified in the initial access procedure or in the non-competitive random access procedure not triggered by a PDCCH instruction.

[0210] Regarding the control resource set (control resource set #X) configured with a non-zero index, if no TCI state related to control resource set #X is configured for the UE, or if one or more TCI states are configured for the UE but the UE fails to receive the MAC CE activation instruction to activate one of the TCI states, the UE can assume that the DMRS transmitted in control resource set #X is QCL with the SS / PBCH block identified in the initial access procedure.

[0211] In the 5G system, the scheduling information regarding the physical uplink shared channel (PUSCH) or the physical downlink shared channel (PDSCH) is transmitted from the base station to the UE through DCI. The UE can monitor the fallback DCI format and the non-fallback DCI format for the PUSCH or PDSCH. The fallback DCI format can be configured by fixed fields predefined between the base station and the UE, and the non-fallback DCI format can include configurable fields.

[0212] The DCI can undergo channel coding and modulation processes and is then transmitted via the PDCCH. A cyclic redundancy check (CRC) can be appended to the DCI message payload, and the CRC can be scrambled by an RNTI corresponding to the identity of the UE. Different types of RNTIs can be used according to the purpose of the DCI message (e.g., UE-specific data transmission, power control instruction, RAR message, etc.). That is, the RNTI is not explicitly transmitted but is transmitted after being included in the CRC calculation process. If the UE has received the DCI message transmitted on the PDCCH, the UE can identify the CRC by using the allocated RNTI, and if the CRC identification result is correct, the UE can identify that the message has been sent to the UE.

[0213] For example, the DCI scheduling the PDSCH for system information (SI) can be scrambled by the SI-RNTI. The DCI scheduling the PDSCH for the RAR message can be scrambled by the RA-RNTI. The DCI scheduling the PDSCH for the paging message can be scrambled by the P-RNTI. The DCI notifying the slot format indicator (SFI) can be scrambled by the SFI-RNTI. The DCI notifying the transmit power control (TPC) can be scrambled by the TPC-RNTI. The DCI scheduling the UE-specific PDSCH or PUSCH can be scrambled by the cell RNTI (C-RNTI).

[0214] DCI format 0_0 can be used for the fallback DCI scheduling the PUSCH, and in this case, the CRC can be scrambled by the C-RNTI. The DCI format 0_0 with the CRC scrambled by the C-RNTI can include the following information shown in Table 11 below.

[0215] Table 11

[0216]

[0217]

[0218]

[0219] DCI format 0_1 can be used for the non-fallback DCI scheduling the PUSCH, and in this case, the CRC can be scrambled by the C-RNTI. The DCI format 0_1 with the CRC scrambled by the C-RNTI can include the following information shown in Table 12 below.

[0220] Table 12

[0221]

[0222]

[0223]

[0224]

[0225]

[0226]

[0227] DCI format 1_0 can be used for scheduling the fallback DCI of the PDSCH, and in this case, the CRC can be scrambled by the C-RNTI. The DCI format 1_0 with the CRC scrambled by the C-RNTI may include the following information shown in Table 13 below.

[0228] Table 13

[0229]

[0230]

[0231] DCI format 1_1 can be used for scheduling the non-fallback DCI of the PDSCH, and in this case, the CRC can be scrambled by the C-RNTI. The DCI format 1_1 with the CRC scrambled by the C-RNTI may include the following information shown in Table 14 below.

[0232] Table 14

[0233]

[0234]

[0235]

[0236]

[0237]

[0238] Hereinafter, a method for allocating time domain resources for a data channel in a 5G communication system will be described.

[0239] The base station can configure a table related to time-domain resource allocation information for the UE through higher-layer signaling (e.g., RRC signaling) for PDSCH and PUSCH. The base station can configure a table consisting of up to 16 entries for PDSCH (maxNrofDL-Allocations = 16), and can configure a table consisting of up to 16 entries for PUSCH (maxNrofUL-Allocations = 16). The time-domain allocation information can include, for example: PDCCH to PDSCH slot timing (the time interval in terms of slots between the time point when the PDCCH is received and the time point when the PDSCH scheduled by the received PDCCH is transmitted, and this timing is indicated by K0) or PDCCH to PUSCH slot timing (the time interval in terms of slots between the time point when the PDCCH is received and the time point when the PUSCH scheduled by the received PDCCH is transmitted, and this timing is indicated by K2), information related to the position of the start symbol of the PDSCH or PUSCH scheduled in the slot and the scheduling length, the mapping type of the PDSCH or PUSCH, etc. For example, the UE can receive the information shown in Table 15 and Table 16 below from the base station.

[0240] Table 15

[0241]

[0242] Table 16

[0243]

[0244] The base station can indicate one of the entries in the table related to time-domain resource allocation information to the UE through L1 signaling (e.g., DCI) (for example, the base station can indicate one of the entries to the UE through the time-domain resource allocation field in DCI). The UE can obtain the time-domain resource allocation information related to PDSCH or PUSCH based on the DCI received from the base station.

[0245] Hereinafter, a method for allocating frequency-domain resources for data channels in a 5G communication system will be described.

[0246] In 5G, as methods for indicating frequency-domain resource allocation information for PDSCH and PUSCH, two types are supported, such as resource allocation type 0 and resource allocation type 1.

[0247] Resource Allocation Type 0

[0248] The base station can notify the UE of RB allocation information in the form of a bitmap for a resource block group (RBG). In this case, an RBG can include a set of consecutive virtual RBs (VRBs), and the size P of the RBG can be determined based on the value configured as a higher layer parameter (rbg-Size) and the value of the BWP size defined in Table 17 below.

[0249] Table 17

[0250] Bandwidth Part Size Configuration 1 Configuration 2 1-36 2 4 37-72 4 8 73-144 8 16 145-275 16 16

[0251] The total number N of RBGs in BWP i with size can be defined by the following equation (2). RBG can be defined by the following equation (2).

[0252] Equation (2)

[0253]

[0254] Each bit in the bitmap with bit size N RBG can correspond to each RBG. The indexes can be assigned to the RBGs in ascending order of frequency starting from the lowest frequency of the BWP. For the N RBG RBGs within the BWP, the RBGs from RBG#0 to RBG#(N RBG -1) can be mapped to the bits from the MSB to the LSB in the RBG bitmap. When a specific bit value in the bitmap is 1, the UE can determine that the RBG corresponding to the corresponding bit value is allocated. When a specific bit value in the bitmap is 0, the UE can determine that the RBG corresponding to the corresponding bit value is not allocated.

[0255] Resource Allocation Type 1

[0256] The base station can notify the UE of RB allocation information, including information about the starting position and length of consecutively allocated VRBs. In this case, interleaving or non-interleaving can be additionally applied to the consecutively allocated VRBs. The resource allocation field of resource allocation type 1 can include a resource indication value (RIV), and the RIV can include the starting point RB of the VRB start and the length L of the consecutively allocated RBs RBs . More specifically, the RIV within the BWP with size can be defined as follows.

[0257] ■ If then

[0258] ◆

[0259] ■ Otherwise

[0260] ◆

[0261] ■ Among them, L RBs ≥ 1 and should not exceed

[0262] To support non - grant - based transmission / reception for PDSCH or PUSCH, the base station can configure various transmission / reception parameters, as well as time and frequency transmission resources for PDSCH and PUSCH for the UE in a semi - static manner.

[0263] More specifically, to support DL semi - persistent scheduling (SPS), the base station can configure the following information shown in Table 18 for the UE via higher - layer signaling (e.g., RRC signaling).

[0264] Table 18

[0265]

[0266] DL SPS can be configured in the primary cell or secondary cell, and DL SPS can be configured in one cell within a cell group.

[0267] In 5G, for two types of non - grant - based (referred to as configured grant, grant - free, etc.) transmission methods for PUSCH, non - grant - based PUSCH transmission type 1 (type 1 PUSCH transmission using configured grant) and non - grant - based PUSCH transmission type 2 (type 2 PUSCH transmission using configured grant) are supported.

[0268] Type 1 PUSCH Transmission Using Configured Grant

[0269] In type 1 PUSCH transmission using configured grant, the base station can configure specific time / frequency resources 600 that allow non - grant - based PUSCH transmission for the UE via RRC signaling. For example, referring back Figure 6 , time - axis allocation information 601, frequency - axis allocation information (PRB) 602, periodicity information 603, etc. for resource 600 can be configured. In addition, the base station can configure various parameters for PUSCH transmission (e.g., frequency hopping, DMRS configuration, MCS table, MCS, resource block group (RBG) size, number of repeat transmissions, redundancy version (RV), etc.) for the UE via higher - layer signaling. The configuration information in Table 19 can be included.

[0270] Table 19

[0271]

[0272]

[0273]

[0274] When receiving configuration information for type 1 PUSCH transmission using configured grant from the base station, the UE may periodically send PUSCH to the configured resource 600 without approval from the base station. Various parameters required for PUSCH transmission (e.g., frequency hopping, DMRS configuration, MCS, RBG size, number of repeated transmissions, RV, precoding and number of layers, antenna port, frequency hopping offset, etc.) may follow the configured values notified by the base station.

[0275] Type 2 PUSCH Transmission Using Configured Grant

[0276] In type 2 PUSCH transmission using configured grant, the base station may configure some of the information about specific time / frequency resources 600 that allow PUSCH transmission based on non-approval (e.g., periodic information 603, etc.) to the UE through RRC signaling. Additionally, the base station may configure various parameters for PUSCH transmission (e.g., frequency hopping, DMRS configuration, MCS table, MCS, RBG size, number of repeated transmissions, redundancy version (RV), etc.) to the UE through higher layer signaling. The base station may configure the configuration information in Table 20 below to the UE through higher layer signaling.

[0277] Table 20

[0278]

[0279]

[0280] For the purpose of scheduling activation or scheduling release of DL SPS and UL grant type 2, the BS may send DCI including specific DCI field values to the UE.

[0281] The base station may configure a configured scheduling RNTI (CS-RNTI) to the UE, and the UE may listen for DCI formats scrambled with CS-RNTI in the CRC. When the CRC of the DCI format received by the UE is scrambled with CS-RNTI, the new data indicator (NDI) is set to "0", and the DCI field meets Table 21 below, the UE may regard the DCI as an instruction to activate the transmission / reception of DL SPS or UL grant type 2.

[0282] Table 21

[0283]

[0284] The base station can configure the configured scheduling RNTI (CS-RNTI) for the UE, and the UE can monitor the DCI format in which the CRC is scrambled with the CS-RNTI. When the CRC of the DCI format received by the UE is scrambled with the CS-RNTI, the NDI is set to "0", and when the DCI field meets Table 22 below, the UE can regard this DCI as an instruction to release the transmission / reception of DL SPS or UL grant type 2.

[0285] Table 22

[0286]

[0287]

[0288] The DCI indicating the release of DL SPS or UL grant type 2 follows the DCI format corresponding to DCI format 0_0 or DCI format 1_0, and DCI format 0_0 or DCI format 1_0 does not include the carrier indicator field (CIF). So, in order to receive the release instruction of DL SPS or UL grant type 2 for a specific cell, the UE should always monitor the PDCCH in the cell where DL SPS or UL grant type 2 is configured. Even if a specific cell is configured for cross-carrier scheduling, the UE should always monitor DCI format 1_0 or DCI format 0_0 in the corresponding cell to receive the release instruction of DL SPS or UL grant type 2 configured in the corresponding cell.

[0289] The UE can be configured with multiple cells or component carriers (CCs) from the base station and can be configured to perform cross-carrier scheduling on the cells configured for the UE. If cross-carrier scheduling is configured for a specific cell (cell A or the scheduled cell), the PDCCH monitoring for cell A may not be performed in cell A, but may be performed in other cells (cell B or the scheduling cell) indicated for cross-carrier scheduling. In this case, different parameter sets can be configured for the scheduled cell (cell A) and the scheduling cell (cell B). The parameter set can include subcarrier spacing, cyclic prefix, etc. When the parameter sets of cell A and cell B are different from each other, when the PDCCH of cell B schedules the PDSCH of cell A, the following minimum scheduling offset can be additionally considered between the PDCCH and the PDSCH.

[0290] Cross-Carrier Scheduling Method

[0291] When the subcarrier spacing μ of cell B B is less than the subcarrier spacing μ of cell A AWhen it is, the PDSCH can be scheduled to start from the subsequent PDSCH time slot corresponding to X symbols after the last symbol of the PDCCH received from cell B. Here, X can vary according to μ B and when μ B = 15 kHz, X can be defined as 4 symbols. When μ B = 30 kHz, X can be defined as 4 symbols, and when μ B = 60 kHz, X can be defined as 8 symbols.

[0292] When the subcarrier spacing μ B of cell B is greater than the subcarrier spacing μ A of cell A, the PDSCH can be scheduled to start from the time point corresponding to X symbols after the last symbol of the PDCCH received from cell B. Here, X can vary according to μ B and when μ B = 30 kHz, X can be defined as 4 symbols. When μ B = 60 kHz, X can be defined as 8 symbols, and when μ B = 120 kHz, X can be defined as 12 symbols.

[0293] When the time and frequency resources A for transmitting the symbol sequence A overlap with the time and frequency resources B, the rate matching operation or the puncturing operation can be regarded as an operation of transmitting and receiving the channel A considering the resource C where the resources A and B overlap.

[0294] Rate Matching Operation

[0295] Among all the resources A for transmitting the symbol sequence A to the UE, the base station can map and transmit the symbol sequence A only to the resource area except for the resource C, and the resource C corresponds to the area where the resources A and B overlap with each other. For example, when the symbol sequence A includes symbol #1, symbol #2, symbol #3, and symbol 4, the resource A includes resource #1, resource #2, resource #3, and resource #4, and the resource B includes resource #3 and resource #5, the base station can sequentially map the symbol sequence A to resource #1, resource #2, and resource #4 (i.e., the resources in resource A except for resource #3 corresponding to resource C), and can transmit the symbol sequence A. Therefore, the base station can map symbol #1, symbol #2, and symbol #3 to resource #1, resource #2, and resource #4 respectively, and can transmit these symbols.

[0296] The UE can determine Resource A and Resource B based on the scheduling information for Symbol Sequence A from the base station, and can thus determine Resource C, which is the region where Resource A and Resource B overlap with each other. The UE can receive Symbol Sequence A by assuming that Symbol Sequence A is mapped to the region of all of Resource A except for Resource C and is transmitted. For example, when Symbol Sequence A includes Symbol #1, Symbol #2, Symbol #3, and Symbol #4, Resource A includes Resource #1, Resource #2, Resource #3, and Resource #4, and Resource B includes Resource #3 and Resource #5, the UE can receive Symbol Sequence A by assuming that Symbol Sequence A is sequentially mapped to Resource #1, Resource #2, and Resource #4 (i.e., the resources in Resource A except for Resource #3 corresponding to Resource C). Therefore, the UE can assume that Symbol #1, Symbol #2, and Symbol #3 are respectively mapped to Resource #1, Resource #2, and Resource #4 and are transmitted, and can perform a series of subsequent receiving operations.

[0297] Puncturing Operation

[0298] Among all of Resource A where Symbol Sequence A is to be transmitted to the UE, when there is Resource C corresponding to the region where Resource A and Resource B overlap with each other, the base station can map Symbol Sequence A to all of Resource A, but may not perform the transmission of the resources corresponding to Resource C, and can perform the transmission of the resources in all of Resource A except for Resource C. For example, when Symbol Sequence A includes Symbol #1, Symbol #2, Symbol #3, and Symbol #4, Resource A includes Resource #1, Resource #2, Resource #3, and Resource #4, and Resource B includes Resource #3 and Resource #5, the base station can map Symbol Sequence A including Symbol #1, Symbol #2, Symbol #3, and Symbol #4 to Resource A including Resource #1, Resource #2, Resource #3, and Resource #4, and can only transmit the symbol sequence including Symbol #1, Symbol #2, and Symbol #4 corresponding to Resource #1, Resource #2, and Resource #4 (i.e., the resources in all of Resource A except for Resource #3 corresponding to Resource C), and may not transmit Symbol #3 mapped to Resource #3 corresponding to Resource C. Therefore, the base station can respectively map Symbol #1, Symbol #2, and Symbol #4 to Resource #1, Resource #2, and Resource #4, and can transmit these symbols.

[0299] The UE can determine Resource A and Resource B based on the scheduling information for Symbol Sequence A from the base station, and thus can determine Resource C, which is the overlapping area between Resource A and Resource B. The UE can receive Symbol Sequence A by assuming that Symbol Sequence A is mapped to all of Resource A but the symbols are transmitted only in the resources in Resource Area A except for Resource C. For example, when Symbol Sequence A includes Symbol #1, Symbol #2, Symbol #3, and Symbol 4, Resource A includes Resource #1, Resource #2, Resource #3, and Resource #4, and Resource B includes Resource #3 and Resource #5, the UE can assume that Symbol #1, Symbol #2, Symbol #3, and Symbol 4 are respectively mapped to Resource A including Resource #1, Resource #2, Resource #3, and Resource #4, but Symbol #3 mapped to Resource #3 corresponding to Resource C is not transmitted, and can receive the symbol sequence by assuming that Symbol #1, Symbol #2, and Symbol 4 corresponding to Resource #1, Resource #2, and Resource #4 (i.e., the resources in Resource A except for Resource #3 corresponding to Resource C) are mapped and transmitted. Therefore, the UE can assume that Symbol #1, Symbol #2, and Symbol 4 are respectively mapped to Resource #1, Resource #2, and Resource #4 and are transmitted, and can perform a series of subsequent receiving operations.

[0300] Figure 10 A method for a base station and a UE to transmit and receive data by considering a DL data channel and rate matching resources according to an embodiment is shown.

[0301] In Figure 10 it describes PDSCH 1001 and rate matching resources 1002. The base station can configure one or more rate matching resources 1002 for the UE through RRC signaling. The configuration information of the rate matching resources 1002 can include time-axis resource allocation information 1003, frequency-axis resource allocation information 1004, and periodicity information 1005. Hereinafter, the bitmap corresponding to the frequency-axis resource allocation information 1004 is referred to as the first bitmap, the bitmap corresponding to the time-axis resource allocation information 1003 is referred to as the second bitmap, and the bitmap corresponding to the periodicity information 1005 is referred to as the third bitmap. When some or all of the time and frequency resources of the scheduled data channel 1001 overlap with the configured rate matching resources 1002, the base station can perform rate matching on the data channel 1001 in some of the rate matching resources 1002 and can transmit the data channel, and the UE can perform reception and decoding after assuming that the data channel 1001 has been rate-matched in some of the rate matching resources 1002.

[0302] The base station can dynamically notify the UE through DCI (corresponding to the rate matching indicator in the above DCI format) whether the data channel will be rate matched in some of the configured rate matching resources. Specifically, the base station can select some of the configured rate matching resources, group the selected resources into rate matching resource groups, and use a bitmap method relative to the UE through DCI to indicate whether the data channel is rate matched in the case of each rate matching resource group. For example, when four rate matching resources RMR#1, RMR#2, RMR#3, and RMR#4 are configured, the base station can configure RMG#1 = {RMR#1, RMR#2}, and RMG#2 = {RMR#3, RMR#4} as rate matching groups, and use 2 bits in the DCI field relative to the UE to indicate whether rate matching is performed in each of RMG#1 and RMG#2. For example, when rate matching needs to be performed, the base station can indicate 1 to the UE, and when rate matching does not need to be performed, it can indicate 0.

[0303] As a method for configuring rate matching resources in the UE, 5G supports RB symbol-level and RE-level granularity. More specifically, the following configuration methods can be performed.

[0304] RB Symbol Level

[0305] The UE can configure up to four RateMatchPatterns for each BWP through higher layer signaling, and one RateMatchPattern can include the following.

[0306] As reserved resources in the BWP, there can be resources where the time and frequency resource regions of these reserved resources are configured as a combination of an RB-level bitmap and a symbol-level bitmap on the frequency axis. The reserved resources can span one or two time slots. A time domain pattern (periodicityAndPattem) can be additionally configured, including the time domain and frequency domain of each RB-level and symbol-level bitmap pair being repeated according to this time domain pattern.

[0307] It can include: the time domain and frequency domain resource regions configured by the control resource set in the BWP, and the resource regions corresponding to the time domain pattern configured by the search space configuration, and the corresponding resource regions are repeated according to this time domain pattern.

[0308] RE Level

[0309] The UE can be configured with the following information through higher layer signaling.

[0310] As the configuration information (Ite-CRS-ToMatchAround) of the RE corresponding to the LTE cell-specific reference signal or the common reference signal (CRS) pattern, it may include: the number of LTE CRS ports (nrofCRS-Ports) and the (multiple) LTE-CRS-vshift (v-shift) values, the position information (carrierFregDL) from the reference frequency point (e.g., reference point A) to the center subcarrier of the LTE carrier, the LTE carrier bandwidth size information (carrierBandwidthDL), and the subframe configuration information (mbsfn-SubframConfigList) corresponding to the multicast broadcast single frequency network (MBSFN). The UE can determine the positioning of the CRS in the NR time slot corresponding to the LTE subframe based on the above information.

[0311] It may include the configuration information of one or more zero-power (ZP) CSI-RS resource sets in the BWP.

[0312] CSI may include channel quality information (CQI), precoding matrix indicator (PMI), CSI-RS resource indicator (CRI), SS / PBCH block resource indicator (SSBRI), layer indicator (LI), rank indicator (RI), and / or L1 - reference signal received power (RSRP). The base station can control the time and frequency resources for the CSI measurement and reporting of the UE.

[0313] For CSI measurement and reporting, the UE can be configured by higher layer signaling: the setting information (CSI-ReportConfig) for N (≥1) CSI reports, the setting information (CSI-ResourceConfig) for M (≥1) RS transmission resources, and one or two trigger state list information (CSI-AperiodicTriggerStateList and CSI-SemiPersistentOnPUSCH-TriggerStateList).

[0314] The configuration information for the above CSI measurement and reporting can be more specifically shown in Tables 23 to 29 as follows.

[0315] Table 23

[0316]

[0317]

[0318]

[0319]

[0320]

[0321]

[0322]

[0323]

[0324]

[0325]

[0326] Table 24

[0327]

[0328]

[0329]

[0330] Table 25

[0331]

[0332]

[0333] Table 26

[0334]

[0335]

[0336] Table 27

[0337]

[0338] Table 28

[0339]

[0340]

[0341]

[0342]

[0343] Table 29

[0344]

[0345] Regarding CSI report configuration (CSI-ReportConfig), each CSI-ReportConfig can be associated with CSI resource configuration associated with the corresponding report configuration and one DL BWP identified by a higher layer parameter BWP identifier (bwp-id) given as CSI-ResourceConfig. As the time domain reporting operations for each CSI-ReportConfig, non-periodic, semi-persistent, and periodic types can be supported, and these types can be configured for the UE by the BS via a parameter reportConfigType configured from a higher layer. The semi-persistent CSI reporting method can support semi-persistent on PUCCH (semi-PersistentOnPUCCH) and semi-persistent on PUSCH (semi-PersistentOnPUSCH). In the periodic or semi-persistent CSI reporting method, the PUCCH or PUSCH resource on which the CSI is to be sent can be configured for the UE by the base station via higher layer signaling. The period and slot offset of the PUCCH or PUSCH resource on which the CSI is to be sent can be given by a parameter set of the UL BWP configured to send the CSI report. In the non-periodic CSI reporting method, the PUSCH resource on which the CSI is to be sent can be scheduled for the UE by the base station via L1 signaling (the above DCI format 0_1).

[0346] Regarding CSI resource configuration (CSI-ResourceConfig), each CSI resource configuration CSI-ReportConfig may include S (where S ≥ 1) CSI resource sets (given by the higher layer parameter csi-RS-ResourceSetList). The CSI resource set list may include non-zero power (NZP) CSI-RS resource sets and SS / PBCH block sets, or may include CSI interference measurement (CSI-IM) resource sets. Each CSI resource configuration may be located in the DL BWP identified by the higher layer parameter bwp-id, and may be associated with a CSI report configuration in the same DL BWP. The time domain operation of the CSI-RS resources in the CSI resource configuration may be configured by the higher layer parameter resourceType to be one of aperiodic, periodic, and semi-persistent. Regarding periodic or semi-persistent CSI resource configuration, the number of CSI-RS resource sets may be restricted to S = 1, and the configured periodicity and slot offset may be given by the parameter set of the DL BWP identified by bwp-id. One or more CSI resource configurations for channel or interference measurement may be configured by the base station for the UE via higher layer signaling, and may include CSI resources such as CSI-IM resources for interference measurement, NZP CSI-RS resources for interference measurement, and NZP CSI-RS resources for channel measurement.

[0347] Regarding the CSI-RS resource sets associated with a resource configuration having a higher layer parameter resourceType configured as aperiodic, periodic, or semi-persistent, the triggering state of a CSI report configuration having a reporType configured as aperiodic, and the resource configuration for channel or interference measurement on one or more component cells (CC) may be configured by the higher layer parameter CSI-AperiodicTriggerStateList.

[0348] The UE may use the PUSCH for aperiodic CSI reporting and may use the PUCCH for periodic CSI reporting. The UE may use the PUSCH when the reporting is triggered or activated by DCI, and use the PUCCH to perform semi-persistent CSI reporting after the reporting is activated by a MAC CE. As described above, the CSI resource configuration may also be configured as aperiodic, periodic, and semi-persistent. Based on Table 30 below, combinations of CSI report configuration and CSI resource configuration may be supported.

[0349] Table 30

[0350]

[0351] An aperiodic CSI report can be triggered by a CSI request field included in DCI format 0_1 (corresponding to the scheduling DCI for PUSCH). The UE can monitor the PDCCH, obtain DCI format 0_1, and obtain the scheduling information for PUSCH and the CSI request indicator. The CSI request indicator can be configured to have N TS (= 0, 1, 2, 3, 4, 5, or 6) bits, and can be determined by higher layer signaling (reportTriggerSize). One of the one or more aperiodic CSI report trigger states that can be configured by higher layer signaling (CSI-AperiodicTriggerStateList) can be triggered by the CSI request indicator.

[0352] When all bits in the CSI request field are 0, the bit value can indicate that no CSI report is requested.

[0353] If the number (M) of CSI trigger states configured in CSI-AperiodicTriggerStateList is greater than 2NTs - 1, then the M CSI trigger states can be mapped to 2NTs - 1 trigger states according to a predefined mapping relationship, and one of the 2NTs - 1 trigger states can be indicated by the CSI request field.

[0354] If the number (M) of CSI trigger states configured in CSI-AperiodicTriggerStateLite is less than or equal to 2NTs - 1, then one of the M CSI trigger states can be indicated by the CST request field.

[0355] Table 31 below shows the relationship between the CSI request indicator and the CSI trigger states that can be indicated by the corresponding indicator.

[0356] Table 31

[0357]

[0358] The UE can measure CSI resources in the CSI triggering state triggered by the CSI request field and then generate CSI (which includes at least one of the above-mentioned CQI, PMI, CRI, SSBRI, LI, RI, and L1-RSRP). The UE can send the obtained CSI by using the PUSCH scheduled by the corresponding DCI format 0_1. When one bit corresponding to the UL data indicator (UL-SCH indicator) in DCI format 0_1 indicates 1, the UE can multiplex the obtained CSI with UL data (UL-SCH) by using the PUSCH resources scheduled by DCI format 0_1, so as to send the multiplexed CSI and data. When one bit corresponding to the UL data indicator (UL-SCH indicator) in DCI format 0_1 indicates 0, the UE can map only the CSI to the PUSCH resources scheduled by DCI format 0_1 without UL data (UL-SCH), so as to send the CSI.

[0359] Figure 11 Fig. shows an aperiodic CSI reporting method when the CSI-RS offset is 0 according to an embodiment.

[0360] In Figure 11 UE can obtain DCI format 0_1 by listening to PDCCH 1101 and obtain the scheduling information of PUSCH 1105 and CSI request information from DCI format 0_1. The UE can obtain the resource information of the CSI-RS 1102 to be measured from the received CSI request indicator. The UE can determine the time point at which the UE should measure the resources of the CSI-RS 1102 to be sent based on the time point when DCI format 0_1 is received and the offset-related parameter (the above-mentioned aperiodicTriggeringOffset) in the CSI resource set configuration (for example, NZP CSI-RS resource set configuration (NZP-CSI-RS-ResourceSet)). More specifically, the UE can receive the offset value X 1103 of the parameter aperiodicTriggeringOffset in the NZP-CSI-RS resource set configuration from the base station through higher layer signaling, and the configured offset value X can be the offset between the time slot on which the DCI triggering the aperiodic CSI report is received and the time slot on which the CSI-RS resource is sent. For example, the value of the parameter aperiodicTriggeringOffset and the offset value X 1103 may have the mapping relationship shown in Table 32 below.

[0361] Table 32

[0362] aperiodicTriggeringOffset Offset X 0 0 Slot 1 1 Slot 2 2 Slots 3 3 Slots 4 4 Slots 5 16 Slots 6 24 Slots

[0363] Figure 11 illustrates an aperiodic CSI reporting method when the CSI-RS offset is 1 according to an embodiment. In Figure 11 , the above offset value X 1103 may be configured to 0. In this case, the UE may receive CSI-RS 1102 in the time slot (corresponding to the time slot 0 in Figure 11 ) in which the UE has received the DCI format 0_1 that triggers the aperiodic CSI report. Additionally, the UE may report CSI information based on the received CSI-RS measurement to the base station via PUSCH 1105. The UE may obtain scheduling information (information corresponding to each field of the above DCI format 0_1) of PUSCH 1105 for CSI reporting from the DCI format 0_1. For example, the UE may obtain information about the time slot in which PUSCH 1105 is to be transmitted from the time domain resource allocation information of PUSCH 1105 included in the DCI format 0_1. In Figure 11 , the UE may obtain 3 as the K2 value 1104 corresponding to the time slot offset value 1103 related to PDCCH to PUSCH, and accordingly, PUSCH 1105 is transmitted in time slot 3 1109, which is 3 time slots apart from time slot 0 1106 (i.e., the time point when PDCCH 1101 is received).

[0364] In Figure 12 , the UE may obtain the DCI format 0_1 by listening to PDCCH 1201, and obtain scheduling information and CSI request information of PUSCH 1205 from the DCI format 0_1. The UE may obtain resource information of the CSI-RS 1202 to be measured from the received CSI request indicator. In Figure 12 , the above offset value X 1203 related to CSI-RS is configured to 1. In this case, the UE may receive CSI-RS 1202 in the time slot (corresponding to time slot 0 1206 in Figure 12 ) in which the UE has received the DCI format 0_1 that triggers the aperiodic CSI report, and may report CSI information based on the received CSI-RS measurement to the base station via PUSCH 1205.

[0365] Figure 13 illustrates a transmission block diagram for transmission signal generation in a 5G communication system according to an embodiment.

[0366] In Figure 13In [the figure], the transmitter generates a codeword 1301 and then performs scrambling 1302. The scrambled signal 1302 is modulated (1303) according to a modulation scheme such as QPSK or QAM and mapped to a layer (1304). Depending on whether the mapped signal is cyclic prefix orthogonal frequency division multiplexing (CP-OFDM) or discrete Fourier transform spread orthogonal frequency division multiplexing (DFT-S-OFDM), if the mapped signal is CP-OFDM, the signal is immediately mapped to a resource (1306) after CP-OFDM processing, or if the mapped signal is DFT-S-OFDM, the signal undergoes transform precoding (1305) and then is mapped to a resource (1306). In this case, in the DL, only CP-OFDM is considered, and in the UL, both CP-OFDM and DFT-S-OFDM are considered. Generally, CP-OFDM is superior to DFT-S-OFDM in some aspects, such as more flexible natural allocation and receiver complexity. In particular, in a frequency selective channel, the high MCS demodulation performance of CP-OFDM is superior to that of DFT-S-OFDM. Therefore, it may be more desirable to implement high spectral efficiency based on the CP-OFDM waveform.

[0367] Meanwhile, if the peak-to-average power ratio (PAPR) is low, high power amplifier efficiency can be expected, so the low PAPR characteristic is an important factor to consider for the waveform. Since DFT-S-OFDM has a lower PAPR than CP-ODM, DFT-S-OFDM is superior to CP-OFDM in a power-constrained situation. In other words, when the UE uses a low MCS in a power-constrained situation, DFT-S-OFDM can provide a link performance gain. Therefore, DFT-S-OFDM may be more suitable for power-constrained scenarios.

[0368] In NR, for transmission and reception between the base station and the UE, CP-OFDM is used in the DL, and CP-OFDM and DFT-S-OFDM are used in the UL. Among them, the UL coverage is the bottleneck, so it is pre-informed via an RRC message which waveform to use. For example, as shown in Table 33 below, whether to apply transform precoding in PUSCH-Config, ConfiguredGrantConfig, Rach-ConfigCommon, and MsgA-PUSCH-Config is indicated to the UE via RRC.

[0369] Table 33

[0370]

[0371] However, since the speed of indicating whether to apply transform precoding to the UE via RRC is too slow compared to the speed at which the UE moves from the cell center to the boundary or from the boundary to the cell center, there may be certain cases where the coverage of the UE is not satisfied. To solve this problem, a method for indicating whether to apply transform precoding more dynamically than RRC is needed.

[0372] The following discloses a method for dynamically indicating DFT-s-OFDM with low PAPR characteristics and CP-OFDM with high spectral efficiency for the UL of a cellular network for the PUSCH (as a bottleneck channel among the uplink channels). What is provided below is a method for indicating dynamic waveform switching for the PUSCH, and this method can also be applied to other channels (e.g., PUCCH).

[0373] First Embodiment

[0374] The first embodiment describes each operation of the method for the base station to dynamically indicate that the UE applies transform precoding.

[0375] To indicate the application or non-application of transform precoding more dynamically than RRC, the following methods can be considered.

[0376] First, the base station can explicitly indicate whether to apply transform precoding via the uplink scheduling DCI. In this case, a new field can be added to the existing uplink scheduling DCI format, or an existing field can be reused. When adding a new field, an additional reserved bit in the existing uplink scheduling DCI format can be used to indicate whether to apply transform precoding through a field of at least 1 bit. When reusing an existing field in the UL scheduling DCI format, the field for other purposes can be reused as the field for indicating whether to apply transform precoding, or it can be used to determine whether to apply transform precoding through creating an implicit rule for scheduling information.

[0377] Similar to DCI format 2_X, it can be indicated via DCI whether to apply transform precoding, rather than for scheduling purposes.

[0378] In addition to this, a method for using MAC-CE instead of DCI to indicate dynamic waveform switching can also be used. In the case of using the method of indicating based on the UL scheduling DCI, transform precoding can be applied to the scheduled PUSCH resources indicated by the DCI. However, for the dynamic waveform switching indication based on DCI or MAC-CE that is not for scheduling purposes, since it is not clear when to apply transform precoding, it is necessary to additionally explicitly or implicitly indicate the application delay time or application timing.

[0379] In the following, for convenience, DCI is described, but the following description can also be applied to MAC-CE or other similar signaling.

[0380] Existing RRC-based semi-static waveform switching indication has at most two states of applying or not applying transform precoding. When using a dynamic waveform indication method to indicate whether to apply transform precoding, there are a total of four states, as shown in Table 34 below.

[0381] Table 34

[0382]

[0383] Table 34 relates to the case when RRC and dynamic waveform indication indicate not to apply transform precoding (Case A1). In this case, the UE determines not to apply transform precoding and transmits the UL signal on the scheduled PUSCH using CP-OFDM.

[0384] After that, it relates to the case when RRC and dynamic waveform indication indicate to apply transform precoding (Case B2). In this case, the UE determines to apply transform precoding and transmits the UL signal on the scheduled PUSCH using DFT-s-OFDM.

[0385] After that, it relates to the case when RRC and dynamic waveform indication provide different indications - the case when RRC indicates not to apply transform precoding but dynamic waveform indication indicates to apply transform precoding (Case A2), and the case when RRC indicates to apply transform precoding but dynamic waveform indication indicates not to apply transform precoding (Case B1). In both cases, the dynamic waveform indication can be preferentially applied because, compared with RRC, the dynamic waveform indication corresponds to the latest situation (for example, in Case A2, the dynamic waveform indication indicates to apply transform precoding, so the PUSCH is transmitted using DFT-s-OFDM, and in Case B1, the dynamic waveform indication indicates not to apply transform precoding, so the PUSCH is transmitted using CP-OFDM).

[0386] The base station can configure information about DCI-based dynamic waveform indication for the UE through RRC, and the UE can identify the corresponding DCI. For example, in existing operations, whether to apply transform precoding is indicated to the UE by RRC in PUSCH-Config, ConfiguredGrantConfig, Rach-ConfigCommon, and MsgA-PUSCH-Config, as shown in Table 33. When the signal-to-interference-plus-noise ratio (SINR) of the UE is unstable and dynamic coverage response is required, the base station can send DCI-based dynamic waveform indication to the UE. In the case of UL-scheduled DCI, the UE can identify the DCI and operate according to the dynamic waveform indication. If whether to apply transform precoding is indicated by DCI not for scheduling purposes (such as DCI format 2_X), additional signaling is required to indicate that the UE additionally monitors DCI format 2_X. Therefore, if an additional state for transform precoding is configured by RRC as shown in Table 35 below, the UE can pre-identify the additional state and monitor the corresponding DCI to determine whether to apply transform precoding.

[0387] Table 35

[0388]

[0389] Therefore, if transform precoding is enabled or disabled, the UE determines whether to apply transform precoding based on RRC according to existing operations. If transform precoding is in the both state, the UE can monitor the corresponding DCI and determine whether to finally apply transform precoding.

[0390] Obviously, the RRC message does not include information for dynamic waveform indication, and the UE can determine whether to apply transform precoding after monitoring the corresponding DCI.

[0391] The operation of the UE applying transform precoding in the existing PUSCH is determined differently according to random access, dynamic grant, configured grant, and scrambled RNTI shown in Table 33 and Table 35. This can be divided into the following three types.

[0392] - Type 1: RAR UL grant, fallback RAR UL grant, DCI format 0_0 with TC-RNTI

[0393] - Type 2: CS-RNTI (NDI = 1), C-RNTI, or MCS-C-RNTI or SP-CSI-RNTI

[0394] - Type 3: Configured grant

[0395] Figure 14Illustrates a UE operation procedure related to type 1 transform precoding determination according to an embodiment.

[0396] When the PUSCH type is type 1 (1401), the waveform to be used is determined based on msg3-transformPrecoder or msgA-transformPrecoder (1402) in RRC.

[0397] Figure 15 Illustrates a UE operation procedure related to type 2 transform precoding determination according to an embodiment.

[0398] When the PUSCH type is type 2 in step 1501, the transform precoding is determined in step 1502 according to whether the DCI format is 0_0. When the DCI format is 0_0 in step 1502, similar to type 1, the type 2 waveform is determined in step 1503 based on msg3-transformPrecoder or msgA-transformPrecoder. When the DCI format is not 0_0 in step 1502, the waveform in step 1504 depends on whether transformPrecoder is configured in PUSCH-Config. When transformPrecoder is not configured in PUSCH-Config in step 1504, the type 2 waveform is determined in step 1503 based on msg3-transformPrecoder or msgA-transformPrecoder. When transformPrecoder is configured, whether to apply transform precoding is determined in step 1505 according to the corresponding configuration.

[0399] Figure 16 Illustrates a UE operation procedure related to type 3 transform precoding determination according to an embodiment.

[0400] When the PUSCH type is type 3 in step 1601, the transform precoding is determined according to whether transformPrecoder is configured in configuredGrantConfig.

[0401] If transformPrecoder is not configured in step 1602, the type 3 waveform is determined in step 1603 based on msg3-transformPrecoder or msgA-transformPrecoder. When transformPrecoder is configured in step 1602, whether to apply transform precoding is determined in step 1604 according to the corresponding configuration.

[0402] Figure 17 It shows whether transform precoding is applied to three types of PUSCHs based on the impact of transform precoding according to an embodiment.

[0403] The existing operations regarding whether to apply transform precoding to the UE for each type are the same as those in Figures 14 to 16 . Type 1 is a PUSCH type related to random access, so it is inefficient to dynamically determine the application of transform precoding. Type 3 is configured grant, so it is not easy to change once the configuration is applied to prevent duplicate PUSCH resource allocation. Therefore, similarly, dynamic waveform indication may be inefficient. However, in type 2, the PUSCH resources are allocated by DCI, so dynamic waveform indication is the most efficient among the three types.

[0404] In Figure 17 , when the DCI format is 0_0 in step 1702, the type 2 waveform is determined in step 1703 according to msg3-transformPrecoder or msgA-transformPrecoder. If dynamic waveform indication is indicated by the DCI in 1704, then in step 1705, the UE determines the waveform according to the information indicated in the DCI in step 1706. When the DCI does not include dynamic waveform indication, then the existing traditional operations are performed in step 1707. That is, in the case of performing existing operations, the type 2 waveform is determined in step 1703 according to msg3-transformPrecoder or msgA-transformPrecoder. However, since the DCI format 0_0 operates in a fallback mode in step 1702, the fields within the DCI are expected to remain as they are, so the dynamic waveform will be implicitly indicated.

[0405] When the DCI format is not 0_0 in step 1702, the waveform in step 1708 depends on whether transformPrecoder is configured in PUSCH-Config. If dynamic waveform indication is indicated by the DCI in 1709, then in step 1705, the UE determines the waveform according to the information indicated in the DCI in step 1706, and when the DCI does not include dynamic waveform indication, the existing operations in step 1707 can be performed. That is, when the DCI does not include dynamic waveform indication, the waveform to be applied to type 2 is determined according to the determination result in 1708. Different from the DCI format 0_0 in step 1702, in the DCI formats 0_1 or 0_2, additional fields for dynamic waveform indication can be defined within the fields of the DCI, so the dynamic waveform can be indicated explicitly or implicitly.

[0406] Figure 18A method for DCI-based signaling from a base station to a UE for dynamic waveform indication according to an embodiment is shown.

[0407] In Figure 18 as described above, in step 1801, the base station may indicate the waveform to be used to the UE based on RRC via transformPrecoder. In step 1802, the UE may periodically send the measured channel state to the base station. For example, the UE may send the channel state when moving from the cell center to the boundary or from the boundary to the cell center. In this case, if it is determined that a coverage problem is expected and the waveform should be dynamically indicated to the UE, then in step 1803, the base station may allow the UE to determine the waveform for uplink transmission via DCI-based dynamic waveform indication.

[0408] Second Embodiment

[0409] The second embodiment describes the ambiguity of the number of field bits or the associated table affected by the dynamic waveform indication in the DCI format, and describes solutions to eliminate these ambiguities.

[0410] The following example assumes that DCI format 0_0 does not have an additional field for dynamic waveform indication due to the fallback mode, and DCI formats 0_1 and 0_2 are cases where dynamic waveform indication is explicitly present. In this case, when the UE decodes the DCI, depending on the dynamic waveform indication, due to the additional bits related to the dynamic waveform indication, the DCI size may be ambiguous, or the associated table may not be correctly interpreted.

[0411] In the current DCI formats 0_1 / 0_2, the information related to transform precoding may be represented by multiple bits, such as whether transform precoding is applied, as shown below.

[0412] - Precoding information and number of layers: 0,..., 6 bits

[0413] - Second precoding information: 0,..., 5 bits

[0414] - Antenna port: 2,..., 5 bits

[0415] - PTRS-DMRS association: 0, 2 bits

[0416] DMRS sequence initialization: 0 (transform precoder is enabled), 1 (transform precoder is disabled) bit

[0417] -Among them, for example, the DCI-related ambiguity of the antenna port will be described. As shown in Table 36 below, depending on whether transform precoding is applied, the DMRS type and length, and whether the π / 2 BPSK modulation scheme is used, the DCI-related ambiguity of the antenna port can be divided into a total of 8 cases.

[0418] Table 36

[0419]

[0420]

[0421] Among them, as shown in Table 36, the cases where (dmrs-Type, maxLength) are the same can be grouped, that is, there can be cases {1, 2, 5}, {3, 4, 6}, and {7} or {8}. In these cases, in cases {7} or {8}, there is only one type of (dmrs-Type, maxLength), so there is no ambiguity. On the other hand, in cases {1, 2, 5} or {3, 4, 6}, multiple cases occur, so there is ambiguity regarding the DCI size or which table should be recognized.

[0422] In cases {3, 4, 6}, regardless of the transform precoding, the number of bits of the antenna port is the same, that is, 4 bits. Therefore, even if there are additional bits for dynamic waveform indication, the total number of bits of the antenna port is 4 bits, and thus, if the conditions of the number of bits and (dmrs-Type, maxLength) are met, only {3, 4, 6} is applicable. Therefore, a method is needed to determine which table to recognize in cases {3, 4, 6}. As mentioned before, the final waveform is determined according to the dynamic waveform indication, so the UE can divide the cases into cases {3, 4} and case {6}, and recognize each table according to whether the transform precoding is applied. In cases {3, 4} where the transform precoding is applied, the table to be used can be determined according to whether the π / 2 BPSK modulation scheme is used.

[0423] In cases {1, 2, 5}, different from cases {3, 4, 6}, depending on whether RRC-based transform precoding is applied, the number of bits is different. Since the dynamic waveform indication is sent via DCI, the UE does not know the bits to be used according to the final waveform until the UE identifies the DCI. Therefore, the UE can use max(number of bits when transform precoder = enabled, number of bits when transform precoder = disabled) to determine the number of bits for the antenna port. That is, the UE assumes that the number of bits for the antenna port is 3 bits, and decoding is performed, and all three tables can be used by using {table when transform precoder = enabled} ∪ {table when transform precoder = disabled}, regardless of whether RRC-based transform precoding is applied. However, depending on whether transform precoding is indicated by the dynamic waveform indication, it can be classified as whether {1, 2} is applied or whether {5} is applied. In cases {1, 2} where transform precoding is applied, the table to be used can be determined according to whether the π / 2 BPSK modulation scheme is used.

[0424] Each table included in Table 36 and referred to for determining the number of bits for the antenna port can be determined according to the number of DMRS ports and DMRS CDM groups in Table 37 below.

[0425] Table 37

[0426]

[0427]

[0428]

[0429]

[0430]

[0431]

[0432]

[0433] Table 37 describes the antenna port and can be similarly applied to precoding information and number of layers, second precoding information, PTRS-DMRS association, DMRS sequence initialization, etc.

[0434] For frequency domain resource allocation (FDRA), there are two resource allocation types: 0 and 1. In the case of RA type 0, the frequency domain resource allocation can be represented as a bitmap RBG unit.

[0435] Figure 19 Shows resource allocation type 0 of FDRA according to an embodiment.

[0436] In Figure 19 , assuming that the BWP is a 20 MHz BWP and the carrier spacing is 30 kHz, a total of 51 RBs are required. Here, assuming that the size of an RBG is P = 4, there are a total of N RBG = 13 RBGs (1901). Assuming that resources have been allocated to RBGs 5 to 10 (1902) in the i-th BWP for the corresponding UE, the starting RB of the BWP is and The base station sends a bitmap consisting of 0000011111100 of 13 bits to the UE using RA type 0.

[0437] Figure 20 Fig. 13 shows resource allocation type 1 of FDRA according to an embodiment.

[0438] As Figure 20 shown, in the case of RA type 1, instead of sending the bitmap of the entire RBG unit, the starting point 2001 of the allocated RB and the resource allocation section 2002 can be configured. The resource allocation section 2002 can be allocated until the end of the BWP, so the maximum number of bits required to configure the starting point 2001 of the RB and the resource allocation section 2002 is 11 bits.

[0439] For the above two RA types, CP-OFDM can be used for both RA type 0 and 1, and DFT-s-OFDM can only be used for RA type 1. That is, RA type 0 can only be configured when transform precoding is not applied, and RA type 1 can be configured regardless of whether transform precoding is applied.

[0440] If dynamic waveform indication is used, only RA type 1 can be used. In this case, the scheduling flexibility may be reduced.

[0441] Alternatively, dynamic waveform indication can be used to dynamically indicate from RA type 0 to 1 or from RA type 1 to 0. Therefore, the problem of what reference should be used to determine the FDRA bit number arises. The solution to this is described with reference to Table 38 below.

[0442] Table 38

[0443]

[0444]

[0445] Referring to Table 38, if the RA type is not configured as RA type 0 or RA type 1 through RRC configuration and resourceAllocation = dynamicSwitch is configured, then the dynamic waveform indication is configured, and 1 bit of the MSB used for the RA type and the maximum number of bits required for RA type 0 and RA type 1 become the number of bits for FDRA. Similarly, for DCI-based dynamic waveform indication, the maximum number of bits required for RA type 0 and RA type 1 can be applied as the number of bits for FDRA. That is, in the case of DCI-based dynamic waveform indication, the number of bits required for FDRA can be bits. In this process, since the dynamic waveform indication will be implicitly or explicitly indicated using an additional field in the DCI, there is no need for 1 bit of the additional MSB.

[0446] Third Embodiment

[0447] The third embodiment describes the ambiguity in determining the modulation scheme and code rate due to the dynamic waveform indication, and discloses a method for resolving this ambiguity.

[0448] Table 39 below lists several cases for determining whether to apply transform precoding in NR and the MCS tables for each DCI format and each RNTI.

[0449] Table 39

[0450]

[0451]

[0452]

[0453]

[0454] Depending on whether transform precoding is applied in the second column, there may be 11 cases, and these cases can be classified into case number - D and case number - E respectively. Each MCS table is determined according to type 0 (random access), type 1 (dynamic grant), and type 2 (configured grant) described in the first embodiment and the DCI format scrambled with a specific RNTI present in the PDCCH scheduling the PUSCH according to the modulation scheme. Since each case number in case number - D and case number - E is in pairs, the MCS table to be used in the case number can be determined based on whether transform precoding is applied.

[0455] An example of this case is shown in Table 40 below.

[0456] Table 40

[0457]

[0458]

[0459] In Table 40, under other equivalent conditions, the cases {2, 4, 5, 7} and {8, 9, 10, 11} are paired according to whether transform precoding is applied, but the MCS table identifying the pair can be different for each modulation scheme and each code rate. Additionally, in the case of applying transform precoding, the π / 2 BPSK modulation scheme can be used, so the code rate can vary according to q in Table 40, and the spectral efficiency can also vary.

[0460] Even if a dynamic waveform indication is added to this case, the type 0 (random access), type 1 (dynamic grant), and type 2 (configured grant), as well as the MCS table configuration determined according to the modulation scheme and the DCI format scrambled with a specific RNTI present in the PDCCH scheduling the PUSCH, will not change. However, since only the application of transform precoding is different, the MCS table is ultimately determined according to the dynamic waveform indication. For example, if transformPrecoder = disabled is configured by RRC at case number = 2, the terminal can refer to the MCS table 5.1.3.1-3 indicated by 2-D. However, if a dynamic waveform indication is sent by DCI and the application of transform precoding is indicated, in the case of case number = 2, the UE can refer to the MCS table 6.1.4.1-2 indicated by 2-E. For reference, the MCS tables 5.1.3.1-2, 6.1.4.1-3, and 6.1.4.1-4 are referred to by case number-D or case number-E, so in this case, whether transform precoding is applied is irrelevant, which eliminates the ambiguity.

[0461] Fourth Embodiment

[0462] The fourth embodiment describes the PUSCH waveform switching in the case of retransmission due to HARQ.

[0463] If the waveform changes according to the initial transmission and retransmission, various ambiguities will be involved. The DCI format or RA type can change, and the MCS level can also change. Since the base station has scheduling restrictions for each condition, the base station must consider the waveform switching for the initial transmission and retransmission.

[0464] One way to solve this structural problem is to keep the waveforms of the initial transmission and the retransmission the same. In this case, during the HARQ retransmission period, the UE performs the retransmission on the assumption that it will continue to use the waveform for the initial PUSCH transmission.

[0465] However, the waveforms of the initial transmission and the retransmission may be determined differently. In this case, the UE does not expect that the scheduling is carried out in an RA type where transform precoding is not considered. However, the factors to be considered are disclosed below.

[0466] Table 41 below shows two cases where both the initial transmission and the retransmission are DCI format 0_1 or 0_2.

[0467] Table 41

[0468]

[0469]

[0470] As cases 1a and 1b, Table 41 uses the same DCI format, but each field included in the UL grant can be independently configured for each of the initial transmission and the retransmission. In other words, different from the initial transmission, link adaptation is possible during the retransmission. For example, (I MCS , RA type) can be configured as (20, RA type 1: 10 consecutive RBs) during the initial transmission and as (15, RA type 0: 30 non - consecutive RBs) during the retransmission. Thus, for the same transport block, when the RA type changes, the code rate also changes. In the above example, the UE can use CP - OFDM for the initial transmission and DFT - s - OFDM indicated by the dynamic waveform indication for the retransmission. In this case, when using DFT - s - OFDM, only RA type 1 can be used, and the use of DFT - s - OFDM can be indicated by considering the scheduling limit of the number of RBs that the BS can schedule on the PUSCH according to {α2, α3, α5} (which consists of integers) to be indicated.

[0471] In addition, case 1b is similar to case 1a and refers to the case where only the MCS level is I MCS ≥27 or 28 during the retransmission. In this case, the UE follows the previous UL grant without changing the RA type field, so the same RA type as the initial or previous transmission is applied.

[0472] Table 42 below shows the case where DCI format 0_1 or 0_2 is used for the initial transmission and DCI format 0_0 is used for the retransmission.

[0473] Table 42

[0474]

[0475]

[0476] Cases 2a and 2b are the cases when different DCI formats are used for initial transmission and retransmission. The DCI format 0_0 for retransmission operates in the fallback mode and is thus fixed to RA type 1. The corresponding DCI format does not include a dynamic waveform indication. During initial transmission, there may be a case where the waveform determined by the dynamic waveform indication is different from the waveform determined by RRC. For example, if DFT-s-OFDM is used during initial transmission and CP-OFDM is used according to the RRC configuration during retransmission, the PUSCH coverage may be very low. Therefore, if DCI format 0_0 (fallback mode) is used during retransmission, it may be reasonable to use the same waveform as in the initial or previous transmission. Other scheduling restrictions and the content related to I MCS are the same as those in cases 1a and 1b.

[0477] In case 2b where I MCS ≥ 27 or 28, the same RA type as in the initial or previous transmission is used, and thus there may be a conflict with the characteristics of DCI format 0_0 fixed to RA type 1. In other words, there is no problem when the initial transmission is RA type 1, but there is a problem when the initial transmission is RA type 0. Therefore, in the case of DCI format 0_0 during retransmission, it can be configured to use RA type 1 or the existing RA type.

[0478] Table 43 below shows the case where DCI format 0_0 is used for initial transmission and DCI format 0_1 or 0_2 is used for retransmission.

[0479] Table 43

[0480]

[0481]

[0482] Cases 3a and 3b are the cases when different DCI formats are used for initial transmission and retransmission. The DCI format 0_0 for initial transmission operates in the fallback mode and is fixed to RA type 1. In addition, as mentioned above, the corresponding DCI format does not include a dynamic waveform indication. During initial transmission, the waveform determined by the dynamic waveform indication and the waveform determined by RRC may be different. Different from cases 2a and 2b, CP-OFDM can be used through RRC configuration during initial transmission, and DFT-s-OFDM can be used through the dynamic waveform indication during retransmission to meet the PUSCH coverage. Other scheduling restrictions and the content related to IMCS The related content is the same as that in Cases 1a and 1b.

[0483] In which I MCS In Case 3b where I ≥ 27 or 28, the same RA type as the initial or previous transmission must be used, so the RA type for retransmission must be the same as DCI format 0_0 which is fixed to RA type 1.

[0484] Figure 21 The transmitter and receiver of a UE in a wireless communication system according to an embodiment are shown. For ease of description, devices not related to the present disclosure are not shown or described.

[0485] In Figure 21 a UE may include: a transmitter 2104 including a UL transmission processing block 2101, a multiplexer 2102, and a transmission RF block 2103; a receiver 2108 including a DL reception processing block 2105, a demultiplexer 2106, a reception RF block 2107, and a controller 2109. The controller 2109 may control the corresponding building blocks of the receiver 2108 to receive the data channel or control channel transmitted by the base station as described above, and control the corresponding building blocks of the transmitter 2104 to transmit a UL signal.

[0486] The UL transmission processing block 2101 in the transmitter 2104 of the UE may generate a signal to be transmitted by performing processes such as channel coding, modulation, etc. The signal may be multiplexed with other UL signals by the multiplexer 2102, signal - processed by the transmission RF block 2103, and then transmitted to the base station.

[0487] The receiver 2108 of the UE may demultiplex the signal received from the base station and distribute the resulting signal to the corresponding DL reception processing blocks. The DL reception processing block 2105 may obtain the control information or data transmitted by the base station by performing processes such as demodulation, channel decoding, etc. on the DL signal from the base station. The receiver 2108 of the UE may support the operation of the controller 2109 by applying the output result of the DL reception processing block to the controller 2109.

[0488] Figure 22 is a block diagram of the structure of a UE according to an embodiment.

[0489] In Figure 22 a UE may include a processor 2230, a transceiver 2210, and a memory 2220. However, the components of the UE are not limited to the above examples. For example, the UE may include more or fewer components than those described above. The processor 2230, the transceiver 2210, and the memory 2220 may be implemented as a single chip. Figure 22 The transceiver 2210 in Figure 21The transmitter 2104 and receiver 2108 in addition, Figure 22 The processor 2230 in may include Figure 21 The controller 2109 in.

[0490] The processor 2230 may control a series of processes such that the UE can operate according to the embodiments. For example, the components of the UE may be controlled to perform the transmission and reception methods of the UE according to whether the base station mode is the base station energy saving mode or the base station normal mode. The processor 2230 may include one or more processors and execute the UE transmission and reception methods in a wireless communication system applying carrier aggregation by executing programs stored in the memory 2220.

[0491] The transceiver 2210 may send signals to the base station or receive signals from the base station. The signals sent to or received from the base station may include control information and data. The transceiver 2210 may include an RF transmitter for up-converting and amplifying the frequency of the signals to be sent, and an RF receiver for low-noise amplifying the received signals and down-converting their frequencies. However, the transceiver 2210 and the components of the transceiver 2210 are not limited to the RF transmitter and the RF receiver. The transceiver 2210 may receive signals via a radio channel and output the signals to the processor 2230, and send the signals output from the processor 2230 via the radio channel.

[0492] The memory 2220 may store data and programs required for the operation of the UE. The memory 2220 may store control information or data included in the signals sent or received by the UE. The memory 2220 may be composed of a storage medium such as a read-only memory (ROM), a random access memory (RAM), a hard disk, a compact disc (CD)-ROM, and a digital versatile disc (DVD), or a combination thereof. In addition, the memory 2220 may include multiple memories. The memory 2220 may store programs for performing the transmission and reception operations of the UE according to whether the base station mode is the base station energy saving mode or the base station normal mode in the embodiments of the present disclosure described above.

[0493] Figure 23 is a block diagram showing the structure of a base station according to an embodiment.

[0494] As Figure 23 shown, the base station may include a processor 2330, a transceiver 2310, and a memory 2320. However, the components of the base station are not limited to the above examples. For example, the base station may include more or fewer components than those described above. The processor 2330, the transceiver 2310, and the memory 2320 may be implemented as a single chip.

[0495] The processor 2330 may control a series of processes such that the base station can operate according to the above embodiments. For example, the components of the base station may be controlled such that the base station executes a method of scheduling UEs according to whether the base station mode is the base station energy saving mode or the base station normal mode. The processor 2330 may include one or more processors and execute a method of scheduling UEs according to whether the base station mode of the present disclosure above is the base station energy saving mode or the base station normal mode by executing a program stored in the memory 2320.

[0496] The transceiver 2310 may send signals to or receive signals from UEs. The signals sent to or received from UEs may include control information and data. The transceiver 2310 may include an RF transmitter for up-converting and amplifying the frequency of the signal to be sent, and an RF receiver for low-noise amplifying the received signal and down-converting its frequency, and so on. However, the transceiver 2310 and the components of the transceiver 2310 are not limited to the RF transmitter and the RF receiver. The transceiver 2310 may receive signals via a radio channel and output the signals to the processor 2330, and send the signals output from the processor 2330 via the radio channel.

[0497] The memory 2320 may store data and programs required for the operation of the base station, and may store control information or data included in the signals sent or received by the base station. The memory 2320 may be composed of a storage medium such as ROM, RAM, hard disk, CD-ROM, and DVD, or a combination thereof. The memory 2320 may also include multiple memories. The memory 2320 may store a program for executing a method of scheduling UEs according to whether the base station mode in the embodiments of the present disclosure above is the base station energy saving mode or the base station normal mode.

[0498] It should be understood that combinations of blocks in a flowchart or process flow diagram can be performed 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 another programmable data processing apparatus, the instructions executed by the processor of the computer or another programmable data processing apparatus create means for performing the functions described in the (one or more) flowchart blocks. The computer program instructions can be stored in a computer-executable or computer-readable memory that can direct a computer or another programmable data processing apparatus to implement functions in a particular manner, and thus the instructions stored in the computer-executable or computer-readable memory can also produce an article of manufacture that includes means for performing the functions described in the (one or more) flowchart blocks. The computer program instructions can also be loaded into a computer or another programmable data processing apparatus, and thus, when a series of operations are performed in the computer or other programmable data processing apparatus, the instructions for operating the computer or other programmable data processing apparatus by generating a computer-executed process can provide operations for performing the functions described in the (one or more) flowchart blocks.

[0499] Additionally, each block may represent a module, segment, or portion of code that includes one or more executable instructions for performing the (one or more) specified logical functions. It should be noted that in some alternative implementations, the functions recited in the blocks may occur out of order. For example, two blocks shown in succession may in fact be executed substantially concurrently, or the blocks may sometimes be executed in the reverse order depending on the corresponding functions.

[0500] Although the present disclosure has been shown and described with reference to various embodiments thereof, those skilled in the art will understand that various changes in form and detail may be made therein without departing from the spirit and scope of the present disclosure as defined by the appended claims and their equivalents.

Claims

1. A method performed by a terminal in a wireless communication system, the method comprising: Receive downlink control information (DCI) from a base station; Identify whether the DCI includes a dynamic waveform indicator; and When the DCI includes the dynamic waveform indicator, send an uplink signal to the base station via a physical uplink shared channel (PUSCH) based on the uplink waveform indicated by the dynamic waveform indicator.

2. The method according to claim 1, wherein, When the DCI includes the dynamic waveform indicator, the resource allocation type for the PUSCH is not determined to be type 0, and the demodulation reference signal (DMRS) type for the PUSCH is not determined to be type 2.

3. The method according to claim 1, wherein, When cyclic prefix orthogonal frequency division multiplexing (CP-OFDM) is indicated by information included in a radio resource control (RRC) message and discrete Fourier transform spread orthogonal frequency division multiplexing (DFT-S-OFDM) is indicated by the dynamic waveform indicator, the resource allocation type for the PUSCH is determined to be type 1.

4. The method according to claim 3, wherein, When the CP-OFDM is indicated by the information included in the RRC message and the DFT-S-OFDM is indicated by the dynamic waveform indicator, the DMRS type for the PUSCH is determined to be type 1.

5. A method performed by a base station in a wireless communication system, the method comprising: Send downlink control information (DCI) to a terminal; and When the DCI includes a dynamic waveform indicator, receive an uplink signal from the terminal via a physical uplink shared channel (PUSCH) based on the uplink waveform indicated by the dynamic waveform indicator.

6. The method according to claim 5, wherein, When the DCI includes the dynamic waveform indicator, the resource allocation type for the PUSCH is not determined to be type 0, and the DMRS type for the PUSCH is not determined to be type 2.

7. The method according to claim 5, wherein, When CP-OFDM is indicated by information included in an RRC message and DFT-S-OFDM is indicated by the dynamic waveform indicator, the resource allocation type for the PUSCH is determined to be type 1.

8. The method according to claim 7, wherein, When the CP-OFDM is indicated by the information included in the RRC message and the DFT-S-OFDM is indicated by the dynamic waveform indicator, the DMRS type for the PUSCH is determined to be type 1.

9. A terminal in a wireless communication system, the terminal comprising: A transceiver; and A controller coupled to the transceiver and configured to: Receive downlink control information (DCI) from a base station, Identify whether the DCI includes a dynamic waveform indicator, and When the DCI includes a dynamic waveform indicator, based on the uplink waveform indicated by the dynamic waveform indicator, send an uplink signal to the base station via a physical uplink shared channel (PUSCH).

10. The terminal according to claim 9, wherein, When the DCI includes the dynamic waveform indicator, the resource allocation type for the PUSCH is not determined to be type 0, and the DMRS type for the PUSCH is not determined to be type 2.

11. The terminal according to claim 9, wherein, In the case where cyclic prefix orthogonal frequency division multiplexing (CP-OFDM) is indicated by information included in a radio resource control (RRC) message, if discrete Fourier transform spread orthogonal frequency division multiplexing (DFT-S-OFDM) is indicated by the dynamic waveform indicator, the resource allocation type for the PUSCH is determined to be type 1.

12. The terminal according to claim 11, wherein, In the case where the CP-OFDM is indicated by the information included in the RRC message and the DFT-S-OFDM is indicated by the dynamic waveform indicator, the DMRS type for the PUSCH is determined to be the type 1.

13. A base station in a wireless communication system, the base station comprising: Transceiver; And A controller, the controller being coupled to the transceiver and configured to: Send downlink control information (DCI) to a terminal, and In the case where the DCI includes a dynamic waveform indicator, based on the uplink waveform indicated by the dynamic waveform Indicator, receive an uplink signal from the terminal through a physical uplink shared channel (PUSCH).

14. The base station according to claim 13, wherein, In the case where the DCI includes the dynamic waveform indicator, the resource allocation type for the PUSCH is not determined to be type 0, and the demodulation reference signal (DMRS) type for the PUSCH is not determined to be type 2.

15. The base station according to claim 14, wherein, In the case where cyclic prefix orthogonal frequency division multiplexing (CP-OFDM) is indicated by information included in a radio resource control (RRC) message and discrete Fourier transform spread orthogonal frequency division multiplexing (DFT-S-OFDM) is indicated by the dynamic waveform indicator, the resource allocation type for the PUSCH is determined to be type 1, and the DMRS type for the PUSCH is determined to be type 1.

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