Method and apparatus for transmitting and receiving multicast and broadcast data in a wireless cellular communication system

Abstract

The disclosure relates to fusing a fifth generation (5G) communication system for supporting higher data rates beyond a fourth generation (4G) system with technologies for Internet of Things (IoT), and can be applied to smart services based on 5G communication technology and IoT-related technology. To do so, a method and device for transmitting groupcast / broadcast / multicast data and control information in downlink and uplink are provided. The method and device include features for: transmitting, to a user equipment (UE), configuration information for a multicast and broadcast service (MBS); encoding a first sequence of bits for the MBS based on channel coding; determining a transport block size (TBS) for limited buffer rate matching (LBRM) based on the configuration information; performing the LBRM on the encoded first sequence of bits based on the determined TBS; and transmitting, to the UE, a second sequence of bits determined based on the LBRM.

Description

Technical Field

[0001] This disclosure relates to a wireless communication system. More specifically, this disclosure relates to a method and apparatus for multicast, broadcast, or broadcast data communication. Background Technology

[0002] To meet the increased demand for wireless data services since the deployment of fourth-generation (4G) communication systems, efforts have been made to develop improved fifth-generation (5G) or near-5G communication systems. Therefore, 5G or near-5G communication systems are also referred to as "super-4G networks" or "post-LTE systems." 5G communication systems are considered to be implemented in higher frequency (millimeter (mm) wave) bands (e.g., the 60 GHz band) to achieve higher data rates. To reduce radio wave propagation loss and increase transmission distance, beamforming, massive MIMO, full-dimensional MIMO (FD-MIMO), array antennas, analog beamforming, and massive MIMO technologies have been discussed in 5G communication systems. Furthermore, improvements to the system network are being developed based on advanced small cells, cloud radio access networks (RAN), ultra-dense networks, device-to-device (D2D) communication, wireless backhaul, mobile networks, cooperative communication, coordinated multipoint (CoMP), and receiver interference cancellation. In 5G systems, hybrid frequency shift keying (FSK) and quadrature amplitude modulation (QAM) modulation (FQAM) and sliding window superposition coding (SWSC) have been developed as advanced coding and modulation (ACM), as well as filter bank multicarrier (FBMC), non-orthogonal multiple access (NOMA) and sparse code multiple access (SCMA) as advanced access technologies.

[0003] The Internet, a human-centric network of connections where humans generate and consume information, is now evolving into the Internet of Things (IoT), a distributed network of entities such as things that exchange and process information without human intervention. The Internet of Everything (IoE), a combination of IoT technology and big data processing technology connected to cloud servers, has emerged. Because IoT implementations have always required technological elements such as sensing technology, wired / wireless communication and network infrastructure, service interface technology, and security technology, sensor networks, machine-to-machine (M2M) communication, and machine-type communication (MTC) have recently been studied. Such an IoT environment can provide intelligent Internet technology services that create new value for human life by collecting and analyzing data generated in connected things. IoT can be applied to a wide range of fields, including smart homes, smart buildings, smart cities, smart cars or connected cars, smart grids, healthcare, smart appliances, and advanced medical services, through the integration and combination of existing information technology (IT) with various industrial applications.

[0004] Consistent with this, various attempts have been made to apply 5G communication systems to IoT networks. For example, technologies such as sensor networks, machine-type communication (MTC), and machine-to-machine (M2M) communication can be achieved through beamforming, MIMO, and array antennas. Cloud radio access networks (RAN), as an application of the aforementioned big data processing technologies, can also be considered an example of the convergence between 5G and IoT technologies.

[0005] Low-density parity-check (LDPC) codes can be used to efficiently transmit data in NR systems. Furthermore, there are two methods for transmitting parity bits generated by LDPC encoding: transmitting all parity bits generated by LDPC encoding is called full-buffered rate matching (FBRM), while limiting the number of parity bits that can be transmitted is called finite-buffered rate matching (LBRM).

[0006] The above information is presented as background information only to aid in understanding this disclosure. It is neither determined nor asserted whether any of the foregoing items may be applicable as prior art to this disclosure. Summary of the Invention

[0007] Technical issues

[0008] Base stations can provide multicast, broadcast, and multi-cast services by sending the same data to multiple terminals. In this scenario, frequency and time resources may be used inefficiently if services are provided to each terminal through separate data transmission and reception.

[0009] Technical solution

[0010] Various aspects of this disclosure are intended to address at least the problems and / or disadvantages mentioned above and to provide at least the advantages described below. Therefore, one aspect of this disclosure is to provide a method and apparatus for efficiently performing data transmission and reception to provide multicast and multicast services.

[0011] Additional aspects will be set forth in part in the following description and will become clear in part from the specification, or may be learned by practice of the presented embodiments.

[0012] According to one aspect of this disclosure, a data transmission method for a base station in a communication system is provided. The base station data transmission method includes: encoding data based on channel coding; determining a finite buffer rate matching (LBRM) to be applied to the encoded data; performing the LBRM on the encoded data based on a first configuration when the data transmission is for a single user equipment (UE), and performing the LBRM on the encoded data based on a second configuration when the data transmission is for multiple UEs; and transmitting a bit sequence determined based on the execution of the LBRM.

[0013] According to another aspect of this disclosure, a data receiving method for a UE in a communication system is provided. The data receiving method for the UE includes: decoding received data; identifying that an LBRM is applied to the decoded data; and, if the data transmission is for one UE, performing the LBRM on the decoded data based on a first configuration, and if the data transmission is for multiple UEs, performing the LBRM on the decoded data based on a second configuration.

[0014] According to another aspect of this disclosure, a base station in a communication system is provided. The base station includes: a transceiver; and at least one processor configured to: encode data based on channel coding; determine that a Load Balancing Reduction Mechanism (LBRM) is applied to the encoded data; perform the LBRM on the encoded data based on a first configuration if the data transmission is for a single UE, and perform the LBRM on the encoded data based on a second configuration if the data transmission is for multiple UEs; and transmit a bit sequence determined based on the execution of the LBRM via the transceiver.

[0015] According to another aspect of this disclosure, a UE in a communication system is provided. The UE includes: a transceiver; and at least one processor configured to: decode received data; identify that LBRM is applied to the decoded data; and, if the data transmission is for one UE, perform the LBRM on the decoded data based on a first configuration, and if the data transmission is for multiple UEs, perform the LBRM on the decoded data based on a second configuration.

[0016] According to another aspect of this disclosure, a method performed by a base station in a communication system is provided. The method of the base station includes: transmitting configuration information for a multicast and broadcast service (MBS) to at least one UE; encoding a first bit sequence for the MBS based on channel coding; determining a transport block size (TBS) for LBRM based on the configuration information; performing the LBRM on the encoded first bit sequence based on the determined TBS; and transmitting a second bit sequence determined based on the LBRM to the at least one UE.

[0017] According to another aspect of this disclosure, a method performed by a UE in a communication system is provided. The method of the UE includes: receiving configuration information of an MBS from a base station; demodulating a bit sequence for the MBS received from the base station; and decoding the demodulated bit sequence based on channel coding, wherein the bit sequence is determined based on an LBRM, wherein the LBRM is performed based on a TBS for the LBRM, and wherein the TBS is determined based on the configuration information.

[0018] According to another aspect of this disclosure, a base station in a communication system is provided. The base station includes: a transceiver; and at least one processor configured to: transmit configuration information of an MBS to at least one UE via the transceiver; encode a first bit sequence for the MBS based on channel coding; determine a TBS for LBRM based on the configuration information; perform the LBRM on the encoded first bit sequence based on the determined TBS; and transmit a second bit sequence determined based on the LBRM to the at least one UE via the transceiver.

[0019] According to another aspect of this disclosure, a terminal in a communication system is provided. The terminal includes: a transceiver; and at least one processor configured to: receive configuration information of an MBS from a base station via the transceiver; demodulate a bit sequence for the MBS received from the base station; and decode the demodulated bit sequence based on channel coding, wherein the bit sequence is determined based on an LBRM, wherein the LBRM is performed based on a TBS for the LBRM, and wherein the TBS is determined based on the configuration information.

[0020] Beneficial effects

[0021] According to this disclosure, LBRM-related parameters can be configured to effectively perform LBRM on downlink data used for multicast / multicast / broadcast, or LBRM-related parameters can be appropriately configured without setting parameters.

[0022] Other aspects, advantages, and salient features of this disclosure will become apparent to those skilled in the art from the following detailed description, which discloses various embodiments of the disclosure in conjunction with the accompanying drawings. Attached Figure Description

[0023] The above and other aspects, features, and advantages of certain embodiments of the present disclosure will become clearer from the following description taken in conjunction with the accompanying drawings, in which:

[0024] Figure 1 The time-frequency domain structure for downlink or uplink transmission in a fifth-generation (5G) (or new radio (NR) system) according to an embodiment of the present disclosure is shown.

[0025] Figure 2 A downlink control channel in a 5G wireless communication system according to an embodiment of the present disclosure is shown;

[0026] Figure 3 Examples of allocating enhanced mobile broadband (eMBB) data, ultra-reliable and low-latency communication (URLLC) data, and massive machine-type communication (mMTC) data to frequency-time resources in a communication system according to embodiments of the present disclosure are shown.

[0027] Figure 4 An example is shown of allocating eMBB data, URLLC data, and mMTC data to frequency-time resources in a communication system according to embodiments of the present disclosure;

[0028] Figure 5 An example is shown of segmenting a transport block into several code blocks and adding a cyclic redundancy check (CRC) according to an embodiment of the present disclosure;

[0029] Figure 6 The FBRM and LBRM related to LDPC encoding are shown according to embodiments of this disclosure;

[0030] Figure 7 The present disclosure illustrates synchronization signals and physical broadcast channels mapped to the frequency and time domains in a 5G system according to embodiments of the present disclosure.

[0031] Figure 8 The symbols within a time slot to which a Synchronization Signal / Physical Broadcast Channel (SS / PBCH) block is mapped, according to an embodiment of this disclosure, are shown;

[0032] Figure 9 The present invention illustrates the processing time of a UE in a 5G system when the UE receives a first signal and sends a second signal in response, according to an embodiment of the present disclosure, due to timing advance.

[0033] Figure 10Examples of scheduling and transmitting data according to time slots, receiving Hybrid Automatic Repeat Request-Affirmative Response (HARQ-ACK) feedback for corresponding data, and performing retransmissions based on the feedback are shown in a 5G system according to embodiments of the present disclosure.

[0034] Figure 11 This is an example of a base station sending the same control information and data to multiple UEs according to embodiments of the present disclosure;

[0035] Figure 12 This is a flowchart illustrating a method for applying LBRM when performing multicast or broadcast data transmission and reception according to embodiments of the present disclosure;

[0036] Figure 13 This is another flowchart illustrating a method of applying LBRM when performing multicast or broadcast data transmission and reception according to an embodiment of the present disclosure;

[0037] Figure 14 This is another flowchart illustrating a method of applying LBRM when performing multicast or broadcast data transmission and reception according to an embodiment of the present disclosure;

[0038] Figure 15 This is a flowchart illustrating a method for a UE to identify broadcast / multicast transmissions and apply LBRM accordingly, according to an embodiment of the present disclosure;

[0039] Figure 16 This is a block diagram illustrating the structure of a UE according to an embodiment of the present disclosure; and

[0040] Figure 17 This is a block diagram illustrating the structure of a base station according to an embodiment of the present disclosure.

[0041] Throughout the accompanying drawings, the same reference numerals are used to denote the same elements. Detailed Implementation

[0042] The following description, provided with reference to the accompanying drawings, is intended to aid in a full understanding of the various embodiments of this disclosure as defined by the claims and their equivalents. It includes various specific details to aid this understanding, but these details should be considered exemplary only. Therefore, those skilled in the art will recognize that various changes and modifications can be made to the various embodiments described herein without departing from the scope and spirit of this disclosure. Additionally, descriptions of well-known functions and constructions may be omitted for clarity and brevity.

[0043] The terms and words used in the following description and claims are not limited to their literal meaning, but are merely intended to achieve a clear and consistent understanding of this disclosure. Therefore, it will be clear to those skilled in the art that the following description of various embodiments of this disclosure is provided for illustrative purposes only and not to limit the disclosure as defined by the appended claims and their equivalents.

[0044] It should be understood that, unless the context clearly specifies otherwise, the singular forms “a,” “an,” and “the” include plural references. Thus, for example, a reference to “component surface” includes a reference to one or more such surfaces.

[0045] New Radio (NR) access technologies are being designed as the next generation of fifth-generation (5G) communication, enabling the free reuse of various services in time and frequency resources, and allowing for the dynamic or free allocation of waveforms, parameter sets, reference signals, etc., according to the needs of the corresponding service. To provide optimal service to User Equipment (UE) in wireless communication, it is crucial to optimize data transmission by measuring channel quality and interference; therefore, accurate channel state measurements are essential. However, unlike fourth-generation (4G) communication, where channel and interference characteristics do not change significantly with frequency resources, in the case of 5G channels, channel and interference characteristics change significantly with service, necessitating separate measurements to support subsets within the Frequency Resource Group (FRG). On the other hand, in NR systems, supported service types can be categorized into classes such as Enhanced Mobile Broadband (eMBB), Massive Machine-Type Communication (mMTC), and Ultra-Reliable and Low-Latency Communication (URLLC). eMBB can be considered a service designed for high-speed transmission of high-capacity data, mMTC a service designed to connect many UEs with minimal UE power, and URLLC a service designed for high reliability and low latency. Different requirements can be applied based on the service type associated with the UE.

[0046] In this way, multiple services can be provided to users in a communication system. To provide such multiple services to users, a method is needed that can provide each individual service according to its characteristics within the same time period, as well as a device using that method.

[0047] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the accompanying drawings.

[0048] In the following description of the embodiments, descriptions of technical details known in the art and not directly related to this disclosure may be omitted. This is to convey the subject matter of this disclosure more clearly without ambiguity by omitting unnecessary descriptions.

[0049] In the accompanying drawings, some elements may be exaggerated, omitted, or only briefly outlined. Similarly, the size of each element does not necessarily reflect its actual size. Throughout the drawings, the same or similar reference numerals are used to refer to the same or similar parts.

[0050] The advantages and features of this disclosure and its implementation methods will become clear from the following detailed description of the embodiments taken in conjunction with the accompanying drawings. However, this disclosure is not limited to the embodiments disclosed below, but can be implemented in various different ways. The embodiments are provided only to accomplish this disclosure and to fully inform those skilled in the art of the scope of this disclosure, and this disclosure is limited only by the scope of the claims. Throughout the specification, the same reference numerals are used to refer to the same parts.

[0051] It should be understood that the frames of a flowchart and combinations thereof can be executed by computer program instructions. These computer program instructions can be loaded onto a processor of a general-purpose computer, a special-purpose computer, or a programmable data processing device, and the instructions, executed by the processor of the computer or programmable data processing device, create means for performing the functions described in the frames of the flowchart. To implement the functions in a particular manner, the computer program instructions can also be stored in a computer-usable or readable storage medium suitable for use in a special-purpose computer or programmable data processing device, and for the computer program instructions stored in such a medium, it is possible to produce an article of art containing means for performing the functions described in the frames of the flowchart. Since the computer program instructions can be loaded onto a computer or programmable data processing device, when the computer program instructions are executed on the computer or programmable data processing device as a process having a series of operations, they can provide operations for performing the functions described in the frames of the flowchart.

[0052] Each box in a flowchart may correspond to a module, segment, or piece of code containing one or more operable instructions for performing one or more logical functions, or a portion thereof. It should also be noted that in some alternative cases, the functions described by the boxes may be run in a different order than listed. For example, depending on the corresponding functions, two boxes listed sequentially may be run substantially simultaneously or in reverse order.

[0053] Here, the terms "unit," "module," etc., used in the embodiments can refer to software components or hardware components, such as field-programmable gate arrays (FPGAs) or application-specific integrated circuits (ASICs) capable of performing functions or operations. However, "unit," etc., is not limited to hardware or software. Units, etc., can be configured to reside in addressable storage media or drive one or more processors. For example, units, etc., can refer to components such as: software components, object-oriented software components, class components or task components, processes, functions, attributes, procedures, subroutines, program code segments, drivers, firmware, microcode, circuits, data, databases, data structures, tables, arrays, or variables. The functionality provided by components and units can be a combination of smaller components and units, and it can be combined with other components and units to form larger components and units. Components and units can be implemented to drive one or more processors in a secure multimedia card or device. Similarly, in certain embodiments, a module or unit may include one or more processors.

[0054] In contrast to earlier wireless communication systems that only provided voice-oriented services, advanced broadband wireless communication systems such as 3GPP High-Speed ​​Packet Access (HSPA), LTE or Evolved Universal Terrestrial Radio Access (E-UTRA), LTE-Advanced (LTE-A), 3GPP2 High-Speed ​​Packet Data (HRPD), Ultra Mobile Broadband (UMB), and IEEE 802.16e-based systems can provide high-speed and high-quality packet data services. Furthermore, communication standards are being developed for 5G or NR (New Radio) systems, which are considered fifth-generation wireless communication systems.

[0055] As a representative example of a broadband wireless communication system, NR systems employ Orthogonal Frequency Division Multiplexing (OFDM) in both the downlink (DL) and uplink (UL). More specifically, cyclic prefix OFDM (CP-OFDM) is used in the downlink, while Discrete Fourier Transform Extended OFDM (DFT-S-OFDM) is used in the uplink along with CP-OFDM. The uplink refers to the radio link through which a terminal (e.g., a UE or mobile station (MS)) transmits data or control signals to a base station (BS, such as a Node B, evolved Node B (eNB), or next-generation Node B (gNodeB, gNB)), while the downlink refers to the radio link through which the base station transmits data or control signals to the UE. In such multiple access schemes, time-frequency resources used to carry user data or control information are allocated to each other in a non-overlapping manner (i.e., maintaining orthogonality) to identify the data or control information of a specific user.

[0056] NR systems employ Hybrid Automatic Repeat Request (HARQ) to retransmit data at the physical layer when a decoding error occurs during the initial transmission. HARQ allows a receiver that has failed to decode data to send a negative acknowledgment (NACK) to the transmitter, enabling the transmitter to retransmit the corresponding data at the physical layer. The receiver can combine the retransmitted data with previously received data that failed to decode, thereby improving data reception performance. When the data is correctly decoded, the receiver can send an acknowledgment (ACK) to the transmitter, indicating successful decoding, allowing the transmitter to send new data.

[0057] Figure 1 The time-frequency domain structure for downlink or uplink transmission in a 5G (or NR) system according to embodiments of the present disclosure is shown.

[0058] Reference Figure 1 The horizontal axis represents the time domain, while the vertical axis represents the frequency domain. In the time domain, the smallest transmission unit is an OFDM symbol, and N symb OFDM symbols 102 are grouped to form a time slot 106. The length of a subframe is defined as 1.0 ms, and a radio frame 114 is defined as 10 ms. In the frequency domain, the smallest transmission unit is a subcarrier, and the total system transmission bandwidth is determined by a total of N... BW Each subcarrier consists of 104 elements. A frame can be defined as 10 ms. A subframe can be defined as 1 ms, therefore a frame can consist of a total of 10 subframes. A time slot can be defined as 14 OFDM symbols (i.e., the number of symbols per time slot). A subframe can consist of one or more time slots, and the number of time slots per subframe can vary depending on the subcarrier spacing setting μ. Figure 2 The example illustrates the cases where the subcarrier spacing setting μ = 0 and μ = 1. When μ = 0, a subframe can consist of one time slot, while when μ = 1, a subframe can consist of two time slots. That is, the number of time slots per subframe... It can vary depending on the subcarrier spacing setting value μ, and the number of time slots per frame. This can be varied accordingly. It can be defined in Table 1 below, depending on the subcarrier spacing setting μ. and The value of .

[0059] [Table 1]

[0060]

[0061] Before establishing a Radio Resource Control (RRC) connection, the base station can configure an initial bandwidth portion (initial BWP) for initial access for the UE via the Master Information Block (MIB). More specifically, during the initial access phase, the UE can receive configuration information via the MIB regarding the system information required for receiving initial access (which may correspond to the remaining System Information (RMSI) or System Information Block 1 (SIB1)), including the control area (control resource set, CORESET) and search space in which the Physical Downlink Control Channel (PDCCH) can be transmitted. The control area and search space configured via the MIB can each be represented by ID 0. The base station can use the MIB to inform the UE of configuration information regarding control area #0, such as frequency allocation information, time allocation information, and parameter sets. The base station can also use the MIB to inform the UE of configuration information regarding control area #0, including the listening period and timing, i.e., configuration information regarding search space #0. The UE can consider the frequency range set by control area #0 obtained from the MIB as the initial BWP for initial access. In this case, the ID of the initial BWP can be considered as 0. The MIB may include the following information from Tables 2 and 3 below.

[0062] [Table 2]

[0063]

[0064] [Table 3]

[0065]

[0066]

[0067] In the method of configuring the bandwidth portion, the UE can receive configuration information about the initial bandwidth portion via the MIB during the initial access phase before establishing an RRC connection. More specifically, the UE can be configured with a control area of ​​the downlink control channel through the MIB of the Physical Broadcast Channel (PBCH), through which downlink control information (DCI) used for scheduling SIBs can be transmitted. Here, the bandwidth of the control area configured via the MIB can be regarded as the initial bandwidth portion, and the UE can receive the Physical Downlink Shared Channel (PDSCH) through which SIBs are transmitted via the configured initial bandwidth portion. In addition to receiving SIBs, the initial bandwidth portion can also be used for other System Information (OSI), paging, and random access. When one or more bandwidth portions are configured for the UE, the base station can instruct the UE to switch bandwidth portions by using the bandwidth portion indicator field in the DCI.

[0068] The basic unit of a resource in the time-frequency domain is a resource element (RE) 112, which can be represented by OFDM symbol indexes and subcarrier indexes. A resource block (RB, or physical resource block (PRB)) 108 is defined as N in the frequency domain. RB One consecutive subcarrier 110. Generally, the smallest unit of data transmission is the RB unit. Typically, in an NR system, N symb =14 and N RB =12, and N BW The data rate is proportional to the bandwidth of the system's transmission band. The data rate can be increased proportionally to the number of RBs scheduled for the UE.

[0069] In the case of an FDD system where the downlink and uplink are frequency-separated in an NR system, the downlink transmission bandwidth and uplink transmission bandwidth can be different from each other. Channel bandwidth represents the RF bandwidth corresponding to the system transmission bandwidth. Tables 4 and 5 show a portion of the correspondence between system transmission bandwidth, subcarrier spacing, and channel bandwidth defined in NR systems in frequency ranges below and above 6 GHz, respectively. For example, in an NR system with a subcarrier spacing of 30 kHz and a channel bandwidth of 100 MHz, the transmission bandwidth can consist of 273 RBs. In the following text, N / A can indicate a bandwidth-subcarrier combination not supported by the NR system. Table 4 below shows the configuration for FR1 (frequency range 1), and Table 5 below shows the configuration for FR2 (frequency range 2).

[0070] [Table 4]

[0071]

[0072] [Table 5]

[0073]

[0074] In NR systems, the frequency range can be divided into FR1 and FR2, as defined in Table 6 below.

[0075] [Table 6]

[0076] Frequency range specification Corresponding frequency range FR1 450MHz-7125MHz FR2 24250MHz-52600MHz

[0077] As mentioned above, the ranges of FR1 and FR2 can be varied and applied differently. For example, the frequency range of FR1 can be changed to a range from 450MHz to 6000MHz for different applications.

[0078] The following is a description of the 5G Synchronization Signal (SS) / PBCH block.

[0079] The SS / PBCH block can refer to a physical layer channel block that includes the primary SS (PSS), secondary SS (SSS), and PBCH (each represented below).

[0080] -PSS: Reference signal used for downlink time / frequency synchronization, which provides partial information about the cell ID.

[0081] -SSS: A reference signal used for downlink time / frequency synchronization, providing additional information about the cell ID not provided by the PSS. It can also be used as a reference signal for PBCH demodulation.

[0082] -PBCH: Provides the necessary system information required for transmitting and receiving data and control channels for the UE. This necessary system information may include search space-related control information indicating radio resource mapping information for the control channel, and scheduling control information for separate data channels for transmitting system information.

[0083] -SS / PBCH Blocks: SS / PBCH blocks are combinations of PSS, SSS, and PBCH. One or more SS / PBCH blocks can be sent within 5ms, and the sent SS / PBCH blocks can be identified by their index.

[0084] During the initial access phase, the UE can detect the PSS and SSS and decode the PBCH. The UE can obtain the MIB from the PBCH and can accordingly be configured with Control Area #0 (which may correspond to Control Area index 0). The UE can assume that the Demodulation Reference Signal (DMRS) transmitted in Control Area #0 is quasi-co-located (QCL) with the selected SS / PBCH block and perform listening to Control Area #0. The UE can receive system information through downlink control information transmitted in Control Area #0. The UE can obtain configuration information about the Random Access Channel (RACH) required for initial access from the received system information. The UE can send a Physical RACH (PRACH) to the base station considering the selected SS / PBCH index, and the base station can receive the PRACH and obtain information about the SS / PBCH block index selected by the UE. Through the above process, the base station can know that the UE has selected a specific SS / PBCH block and is listening to Control Area #0 associated with the selected one.

[0085] The following section will provide a detailed description of downlink control information (DCI) in 5G systems.

[0086] In 5G systems, DCI (Distributed Information Channel) is used to send uplink data (or Physical Uplink Shared Channel (PUSCH)) or downlink data (or Physical Downlink Shared Channel (PDSCH)) scheduling information from the base station to the UE. The UE can listen for either PUSCH or PDSCH in both fallback and non-fallback DCI formats. Fallback DCI formats may include predefined fixed fields between the base station and the UE, while non-fallback DCI formats may include configurable fields. In addition, there are various other DCI formats, and each format can indicate whether it is a DCI used for power control or a DCI used for notification slot format indicators (SFI).

[0087] DCI messages can be transmitted on the PDCCH (Physical Downlink Control Channel) after channel coding and modulation. Cyclic Redundancy Check (CRC) can be appended to the DCI message payload, and the CRC can be scrambled using a Radio Network Temporary Identifier (RNTI) corresponding to the UE's identifier. Different RNTIs can be used depending on the purpose of the DCI message, such as UE-specific data transmission, power control commands, random access responses, etc. That is, the RNTI is not explicitly transmitted but is transmitted by including it in the CRC calculation process. Upon receiving a DCI message transmitted on the PDCCH, the UE can check the CRC using the assigned RNTI and know that a DCI message has been sent to it if the CRC check result is correct. The PDCCH is mapped to the Control Resource Set (CORESET) configured for the UE and transmitted.

[0088] For example, the DCI for scheduling PDSCH used for System Information (SI) can be scrambled with SI-RNTI. The DCI for scheduling PDSCH used for Random Access Response (RAR) messages can be scrambled with RA-RNTI. The DCI for scheduling PDSCH used for paging messages can be scrambled with P-RNTI. The DCI for notifying Slot Format Indicator (SFI) can be scrambled with SFI-RNTI. The DCI for notifying Transmit Power Control (TPC) can be scrambled with TPC-RNTI. The DCI for scheduling UE-specific PDSCH or PUSCH can be scrambled with Cell RNTI (C-RNTI). Here, scrambling the DCI with the Radio Network Temporary Identifier (RNTI) value can mean that the RNTI value is added to the CRC bits appended to the DCI via an XOR operation (0+0=0, 1+0=1, 1+1=0). In the above context, the XOR operation can be a modulo-2 operation. If the number of bits in the DCI's CRC and the RNTI is different, the operation can be performed using LSB or MSB bits with more bits. For example, when the CRC of DCI is 24 bits and the RNTI is 16 bits, the RNTI can be scrambled using the 16-bit LSB of the CRC.

[0089] DCI format 0_0 can be used for backoff DCI scheduling of PUSCH, in which case the CRC can be scrambled with C-RNTI. For example, DCI format 0_0 with a CRC scrambled with C-RNTI can include the following information in Table 7 below.

[0090] [Table 7]

[0091]

[0092] DCI format 0_1 ​​can be used for non-back-off DCI of scheduled PUSCH, in which case CRC can be scrambled with C-RNTI. For example, DCI format 0_1 ​​with CRC scrambled with C-RNTI can include the following information in Table 8 below.

[0093] [Table 8]

[0094]

[0095]

[0096]

[0097] DCI format 1_0 can be used for the backoff DCI of the scheduled PDSCH, in which case the CRC can be scrambled with C-RNTI. For example, DCI format 1_0 with a CRC scrambled with C-RNTI can include the following information in Table 9 below.

[0098] [Table 9]

[0099]

[0100] DCI format 1_1 can be used for non-back-off DCI used to schedule PDSCH, in which case the CRC can be scrambled with C-RNTI. For example, DCI format 1_1 with a CRC scrambled with C-RNTI can include the following information in Table 10 below.

[0101] [Table 10]

[0102]

[0103]

[0104]

[0105] Next, we will give a description of the time-domain resource allocation of the data channel in the 5G communication system.

[0106] The base station can configure the UE using tables containing time-domain resource allocation information for the downlink data channel (PDSCH) and uplink data channel (PUSCH) via higher-layer signaling (e.g., RRC signaling). Tables containing up to maxNrofDL-Allocations = 16 entries can be set for the PDSCH, and tables containing up to maxNrofUL-Allocations = 16 entries can be set for the PUSCH. For example, the time-domain resource allocation information may include information about: PDCCH-to-PDSCH time slot timing (corresponding to the time interval in time slots between the time of receiving the PDCCH and the time of transmitting the PDSCH scheduled through the received PDCCH, denoted by K0), PDCCH-to-PUSCH time slot timing (corresponding to the time interval in time slots between the time of receiving the PDCCH and the time of transmitting the PUSCH scheduled through the received PDCCH, denoted by K2), the position and length of the starting symbol for scheduling the PDSCH or PUSCH in the time slot, and the PDSCH or PUSCH mapping type. For example, the information shown in Tables 11 and 12 below can be notified to the UE by the base station.

[0107] [Table 11]

[0108]

[0109] [Table 12]

[0110]

[0111] The base station can notify the UE of one of the entries in the table for time-domain resource allocation information via L1 signaling (e.g., DCI) (e.g., indicated by the "Time-Domain Resource Allocation" field of the DCI). The UE can obtain the time-domain resource allocation information of PDSCH or PUSCH based on the DCI received from the base station. The downlink control channel in the 5G communication system will now be described in more detail with reference to the accompanying drawings.

[0112] Figure 2 A downlink control channel in a 5G wireless communication system according to an embodiment of the present disclosure is shown.

[0113] Reference Figure 2 , Figure 2An example is shown where a UE bandwidth portion 210 is set on the frequency axis and two control regions (control region #1 201, control region #2 202) are set in a time slot 220 on the time axis. Control region 201 or 202 can be set at a specific frequency resource 203 on the frequency axis within the entire UE bandwidth portion 210. A control region can be set as one or more OFDM symbols on the time axis, and this can be defined as the control region length (control resource set duration, 204). Figure 2 In the example, control region #1 201 is set to a control region length of 2 symbols, while control region #2 202 is set to a control region length of 1 symbol.

[0114] In 5G, the aforementioned control regions can be configured by the base station to the UE via higher-level signaling (e.g., system information, MIB, RRC signaling). Configuring a control region to the UE means providing information such as the control region identifier, the frequency location of the control region, and the symbol length of the control region. For example, higher-level signaling may include the information shown in Table 13 below.

[0115] [Table 13]

[0116]

[0117]

[0118] In Table 13, the configuration information tsi-StatesPDCCH (referred to as Transmission Configuration Indication (TCI) status) may include information about one or more SS / PBCH block indices or Channel State Information Reference Signal (CSI-RS) indices relating to the Quasi-Co-location (QCL) relationship with the DMRS transmitted in the corresponding control area.

[0119] For example, DCI format 1_1, which serves as scheduling control information (DL license) for downlink data, may include the following control information.

[0120] - Carrier indicator: Indicates the carrier on which data scheduled by DCI is transmitted -0 or 3 bits.

[0121] - Identifier for DCI format: Indicates the DCI format, specifically, it is an indicator -1 bit used to distinguish whether the corresponding DCI is used for downlink or uplink.

[0122] - Bandwidth section indicator: Indicates whether there is a change in the bandwidth section - 0, 1 or 2 bits.

[0123] - Frequency domain resource allocation: indicates the resource allocation information for frequency domain resource allocation, and the resources represented vary depending on whether the resource allocation type is 0 or 1.

[0124] - Time-domain resource assignment: Resource assignment information indicating time-domain resource assignment. It can be a configuration of 1, 2, 3 or 4 bits that indicates higher-level signaling or a preset PDSCH time-domain resource assignment list.

[0125] -VRB-to-PRB mapping: Indicates the mapping relationship between virtual resource blocks (VRBs) and physical resource blocks (PRBs) -0 or 1 bit.

[0126] -PRB Bundle Size Indicator: Indicates the size of the bundle of physical resource blocks that are assumed to be applied with the same precoding -0 or 1 bit.

[0127] - Rate Matching Indicator: Indicates the applied rate matching group - 0, 1, or 2 bits in the rate matching group applied to the PDSCH configured by the higher layer.

[0128] -ZP CSI-RS trigger: Triggers zero-power CSI-RS-0, 1, or 2 bits.

[0129] - Transport Block (TB) related configuration information: indicates the modulation and coding scheme (MCS), new data indicator (NDI), and redundancy version (RV) used for one or two TBs.

[0130] - Modulation and Coding Scheme (MCS): Indicates the modulation scheme and coding rate used for data transmission. In other words, it indicates the coding rate value that informs the TBS and channel coding information along with information indicating Quadrature Phase Shift Keying (QPSK), 16QAM, 64QAM, or 256QAM.

[0131] - New data indicator: Indicates whether it is an initial HARQ transmission or a retransmission.

[0132] - Redundant version: Indicates a redundant version of HARQ.

[0133] -HARQ process number: Indicates the HARQ process number applied to PDSCH -4 digits.

[0134] - Downlink Assignment Index: An index used to generate a dynamic HARQ-ACK codebook when reporting HARQ-ACK for PDSCH - 0, 2, or 4 bits.

[0135] - TPC commands for scheduled PUCCH: Power control information for PUCCH applications used for HARQ-ACK reports about PDSCH - 2 bits.

[0136] -PUCCH Resource Indicator: Indicates information about the PUCCH resource used for HARQ-ACK reporting on PDSCH - 3 bits.

[0137] -PDSCH-to-HARQ_feedback timing indicator: Configuration information about the time slot in which the PUCCH for sending HARQ-ACK reports about the PDSCH is sent - 3 bits.

[0138] - Antenna Port: Indicates the antenna port of the PDSCH DMRS and information on DMRS CDM groups that do not transmit PDSCH in it - 4, 5, or 6 bits.

[0139] - Transmission configuration indication: Information indicating beam-related information for the PDSCH - 0 or 3 bits.

[0140] -SRS Request: Requests information for SRS transmission -2 bits.

[0141] -CBG Transmission Information: When block group-based retransmission is configured, this information indicates which block group (CBG) data is sent via PDSCH - 0, 2, 4, 6, or 8 bits.

[0142] -CBG flushing information: Information indicating whether the code block group previously received by the UE can be used for HARQ combination - bit 0 or 1.

[0143] -DMRS sequence initialization: Indicates the DMRS sequence initialization parameter -1 bit.

[0144] In the preceding text, for data transmission via PDSCH or PUSCH, time-domain resource assignment can be sent using information about the following: the time slot in which PDSCH / PUSCH is transmitted, the starting symbol position S within the corresponding time slot, and the number of symbols L to which PDSCH / PUSCH is mapped. Here, S can be the relative position from the start of the time slot, and L can be the number of consecutive symbols, and S and L can be determined according to the start and length indicator values ​​(SLIV) as defined in Equation 1 below.

[0145] [Formula 1]

[0146] If (L-1)≤7, then

[0147] SLIV = 14·(L-1) + S

[0148] otherwise

[0149] SLIV = 14·(14-L+1)+(14-1-S)

[0150] Where 0 < L ≤ 14-S.

[0151] In an NR system, information about the SLIV value, PDSCH / PUSCH mapping type, and the time slots in which PDSCH / PUSCH is transmitted can be configured for the UE in a single line via RRC configuration (e.g., this information can be set in the form of a table). Then, in the DCI time domain resource allocation, by indicating the index value in the table configured above, the base station can deliver information about the SLIV value, PDSCH / PUSCH mapping type, and the time slots in which PDSCH / PUSCH is transmitted to the UE.

[0152] In the NR system, PDSCH mapping is defined into types A and B. In PDSCH mapping type A, the first symbol in the DMRS symbol is located at the second or third OFDM symbol in the time slot. In PDSCH mapping type B, the first symbol in the DMRS symbol is located at the first OFDM symbol in the time domain resource allocated via PUSCH transmission.

[0153] Downlink data can be transmitted on the PDSCH, which serves as the physical channel for downlink data transmission. The PDSCH can be transmitted after the control channel transmission period, and scheduling information such as specific mapping positions and modulation schemes in the frequency domain are determined based on the DCI transmitted via the PDCCH.

[0154] By using the MCS (Modulation Scheme) within the control information that constitutes the DCI (Distributed Control Information), the base station informs the UE (User Equipment) of the modulation scheme applied to the PDSCH (Programmable Streaming Distributed Chip) to be transmitted and the size of the data to be transmitted (Transmission Block Size (TBS)). In one embodiment, the MCS may consist of 5 bits or more or fewer bits. The TBS corresponds to the size of the data (transmission block, TB) that the base station expects to transmit before applying channel coding for error correction.

[0155] In this disclosure, a transport block (TB) may include a media access control (MAC) header, a MAC control element, one or more MAC service data units (MAC SDUs), and padding bits. Alternatively, the TB may indicate a unit of data delivered from the MAC layer to the physical layer, or a MAC protocol data unit (MAC PDU).

[0156] The modulation scheme supported by the NR system is its modulation order (Q). m These correspond to 2, 4, 6, and 8 bits of Quadrature Phase Shift Keying (QPSK), 16-QAM, 64QAM, and 256QAM, respectively. In other words, QPSK modulation can transmit 2 bits per symbol, 16QAM modulation can transmit 4 bits per symbol, 64QAM modulation can transmit 6 bits per symbol, and 256QAM modulation can transmit 8 bits per symbol.

[0157] Figure 3 and Figure 4 Examples are shown of eMBB data, URLLC data, and mMTC data allocated on frequency-time resources as services considered in 5G or NR systems.

[0158] Able to refer to Figure 3 and Figure 4 Identify methods for allocating frequency and time resources for information transmission in each system.

[0159] Figure 3 An example of allocating eMBB data, URLLC data, and mMTC data across the entire system frequency bandwidth according to an embodiment of the present disclosure is shown.

[0160] Reference Figure 3 Data slices for eMBB, URLLC, and mMTC are allocated across the entire system frequency bandwidth 300. When URLLC data 303, 305, and 307 are generated and their transmission is necessary in a specific frequency band where eMBB 301 and mMTC 309 are already allocated, URLLC data 303, 305, and 307 can be transmitted by clearing portions already allocated to eMBB 301 and mMTC 309 or by not transmitting them. In the aforementioned service, URLLC requires reduced latency, and URLLC data 303, 305, and 307 can be allocated to portions of resource 301 allocated for eMBB and transmitted. Here, when URLLC is additionally allocated and transmitted through resources already allocated for eMBB, eMBB data cannot be transmitted on overlapping frequency-time resources, and the transmission performance of eMBB data will be correspondingly reduced. That is, in the above situation, eMBB data transmission may fail due to URLLC allocation.

[0161] Figure 4 An example of allocating eMBB data, URLLC data, and mMTC data by dividing system frequency bands according to embodiments of the present disclosure is shown.

[0162] Reference Figure 4 The entire system frequency band 400 can be divided into sub-bands 402, 404, and 406, each capable of being used for service and data transmission. Information related to sub-band configuration can be determined in advance and transmitted from the base station to the UE via higher-layer signaling. Alternatively, the base station or network node can decide to allocate sub-bands for service without separately sending sub-band configuration information to the UE. Figure 4 In this sub-band, sub-band 402 is used for eMBB data transmission 408, sub-band 404 is used for URLLC data transmission 410, 412 and 414, and sub-band 406 is used for mMTC data transmission 416.

[0163] To describe the methods and apparatus presented in this embodiment, the terms "physical channel" and "signal" in NR systems may be used. However, the content of this disclosure is applicable to wireless communication systems other than NR systems.

[0164] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. Descriptions of well-known functions and structures incorporated herein may be omitted to avoid obscuring the subject matter of the disclosure. The following terms are defined in regard to their function in this disclosure, and these terms may vary depending on the intent of the user, operator, or customer. Therefore, their meaning should be determined based on the overall content of this specification.

[0165] In the description, the term "downlink (DL)" refers to the radio transmission path through which the base station sends signals to the UE, while the term "uplink (UL)" refers to the radio transmission path through which the UE sends signals to the base station.

[0166] In the following description, embodiments of this disclosure will be described using an NR system as an example, and these can be applied to other communication systems with similar technical backgrounds or channel configurations. The subject matter of this disclosure is applicable to other communication systems without significant modifications that depart from the scope of this disclosure.

[0167] In this disclosure, the terms "physical channel" and "signal" in the relevant art may be used interchangeably with "data" or "control signal". For example, although PDSCH is a physical channel used to transmit data, PDSCH may be referred to as data in this disclosure.

[0168] In this disclosure, higher-layer signaling is a method for transmitting signals from a base station to a UE using a downlink data channel of the physical layer or from a UE to a base station using an uplink data channel of the physical layer, and may be referred to as RRC signaling or MAC control element (MAC CE).

[0169] Figure 5 An example of a process for segmenting a transport block into several code blocks and adding CRC according to an embodiment of the present disclosure is shown.

[0170] Reference Figure 5A CRC 503 can be added to the last or first part of a transport block (TB) 501 to be transmitted in the uplink or downlink. The CRC 503 can have 16 bits, 25 bits, a pre-fixed number of bits, or a variable number of bits depending on the channel conditions, and can be used to determine whether the channel coding was successful. The block obtained by adding the CRC 503 to the TB 501 can be segmented into several code blocks (CBs) 507, 509, 511, and 513 (505). Here, the maximum size of the code blocks can be determined in advance, in which case the last code block 513 can have a smaller size compared to the other code blocks 507, 509, and 511. However, this is only illustrative, and according to another example, 0, random values, or 1 can be inserted into the last code block 513 so that the last code block 513 has the same length as the other code blocks 507, 509, and 511.

[0171] Alternatively, CRC 517, 519, 521, and 523 can be added to code blocks 507, 509, 511, and 513 (515), respectively. CRC can have 16 bits, 24 bits, or a pre-fixed number of bits and can be used to determine whether channel coding was successful.

[0172] TB 501 and cyclic generator polynomials can be used to generate CRC 503, and cyclic generator polynomials can be defined in various ways. For example, for a 24-bit CRC and L=24, assuming the cyclic generator polynomial gCRC24A(D) = D24+D23+D18+D17+D14+D11+D10+D7+D6+D5+D4+D3+D+1, for TB data a0, a1, a2, a3, ..., a A-1 It can be done by a0D A+23 +a1D A+22 +…+a A-1 D 24 +p0D 23 +p1D 22 +…+p 22 D 1 +p 23 Divide by gCRC24A(D) until the remainder is 0 to determine the CRC values ​​p0, p1, p2, p3, ..., p L-1 In the example above, it is assumed that the CRC length L is 24 for illustration, but the CRC length L can be determined to have various lengths such as 12, 16, 24, 32, 40, 48, 64, etc.

[0173] After adding the CRC to the TB using this process, the TB+CRC can be segmented into N CBs 507, 509, 511, and 513. CRCs 517, 519, 521, and 523 can be added to the segmented CBs 507, 509, 511, and 513 (515), respectively. The CRCs added to the CBs can have a different length than the CRCs added to the TB, or different cyclic generator polynomials can be used for CRC generation. Additionally, the CRC 503 added to the TB and the CRCs 517, 519, 521, and 523 added to the code blocks can be omitted depending on the type of channel code applied to the code block. For example, when applying an LDPC code instead of a turbo code to the code block, the CRCs 517, 519, 521, and 523 to be added to individual code blocks can be omitted.

[0174] However, even when applying LDPC, CRC 517, 519, 521, and 523 can be added to the code block. Additionally, even when using polar codes, CRC can be added or omitted.

[0175] like Figure 5 As described, the maximum length of a code block is determined based on the type of channel coding applied to the TB to be transmitted, and the TB and the CRC to be added to it can be segmented into code blocks according to the maximum length of the code block.

[0176] In the LTE system of the relevant technology, the CRC for the CB is added to the segmented CB, and the data bits of the CB and CRC are encoded with the channel code to determine the coded bits, and the rate matching bits are determined for the coded bits as agreed in advance.

[0177] In NR systems, the TB size (TBS) for uplink and downlink can be calculated using the steps in [TBS Determination Procedure 1] below. However, the definitions of each key parameter in [TBS Determination Procedure 1] follow the 3GPP standard TS38.214.

[0178] [TBS Determination Process 1]

[0179] Step 1: Calculate N′ RE That is, the number of REs allocated to the PDSCH mapping in a PRB within the allocated resources.

[0180] N′ RE It can be done To calculate. Here, It is 12, and It can indicate the number of OFDM symbols assigned to the PDSCH. It is the number of REs occupied by DMRS in the same CDM group within a PRB. This is the number of REs in a PRB that are consumed by overhead and set by higher signaling, and can be set to one of 0, 6, 12, and 18. Then, N can be calculated as the total number of REs allocated to the PDSCH. RE N RE It is achieved by min(156, N′) RE )·n PRB Calculated, and n PRB This indicates the number of PRBs allocated to the UE.

[0181] Step 2: It can be done through N RE *R*Q m *v is used to calculate the number of temporary information bits N. info Here, R is the bitrate, and Q is the bitrate. m It is the modulation order, and information about this value can be sent using the MCS bit field of the DCI and a pre-agreed table. Furthermore, v is the number of layers assigned. If N info If the value is ≤3824, then TBS can be calculated using step 3 below. Otherwise, TBS can be calculated using step 4.

[0182] Step 3: can be done through formula and To calculate N′ info TBS can be defined as any value in Table 14 that is not less than N′. info The value closest to N′ info The value of .

[0183] [Table 14]

[0184] index TBS index TBS index TBS index TBS 1 24 31 336 61 1288 91 3624 2 32 32 352 62 1320 92 3752 3 40 33 368 63 1352 93 3824 4 48 34 384 64 1416 5 56 35 408 65 1480 6 64 36 432 66 1544 7 72 37 456 67 1608 8 80 38 480 68 1672 9 88 39 504 69 1736 10 96 40 528 70 1800 11 104 41 552 71 1864 12 112 42 576 72 1928 13 120 43 608 73 2024 14 128 44 640 74 2088 15 136 45 672 75 2152 16 144 46 704 76 2216 17 152 47 736 77 2280 18 160 48 768 78 2408 19 168 49 808 79 2472 20 176 50 848 80 2536 21 184 51 888 81 2600 22 192 52 928 82 2664 23 208 53 984 83 2728 24 224 54 1032 84 2792 25 240 55 1064 85 2856 26 256 56 1128 86 2976 27 272 57 1160 87 3104 28 288 58 1192 88 3240 29 304 59 1224 89 3368 30 320 60 1256 90 3496

[0185] Step 4: can be done through formula and To calculate N′ info It can pass through N′ info The value and the following [pseudocode 1] determine the TBS. In the following text, C corresponds to the number of code blocks included in a TB.

[0186] [Starting with pseudocode 1]

[0187]

[0188] [End of pseudocode 1].

[0189] However, the determination of the number of resources N for the parameter PSSCH (Physical Sidelink Shared Channel) required for TBS calculation in the sidelink of the 5G NR system can be performed in the same manner as [TBS Determination Procedure 2] in Table 15 below. REThe process is as follows. However, the definitions of each major parameter and the table numbers referenced in [TBS Determination Process 2] follow 3GPP standard TS 38.214. Similarly, like [TBS Determination Process 1], the TBS value for the sidelink can be determined in Table 15 below based on the resources allocated to PSSCH, MCS, control information, etc.

[0190] [Table 15]

[0191]

[0192]

[0193] When a CB is input to the LDPC encoder in an NR system, parity bits can be added and output. The number of parity bits can vary depending on the LDPC basemap. For a given input, the method of sending all parity bits generated by LDPC encoding is called full buffered rate matching (FBRM), while the method of limiting the number of parity bits that can be sent is called finite buffered rate matching (LBRM). When allocating resources for data transmission, the LDPC encoder output is made in the form of a circular buffer, and the bits generated in the buffer are repeatedly sent as many times as the allocated resources, where the length of the circular buffer can be called N. cb . Figure 6 This illustrates N, which involves segmenting a TB into one or more code blocks, applying channel coding, and determining the transmission of specified parity bits. cb Examples.

[0194] Figure 6 The FBRM and LBRM associated with LDPC encoding are shown according to embodiments of this disclosure.

[0195] Reference Figure 6 If the total number of parity bits generated by LDPC encoding is N, then in the FBRM method, N cb =N. In the LBRM method, N cb is min(N,N ref ), N ref Depend on Give, and be able to give R LBRM The score is determined to be 2 / 3. This is to obtain TBS. LBRM The above method for obtaining TBS can be used, which assumes the maximum number of layers and the maximum modulation order supported by the UE in the corresponding cell, with the maximum modulation order Q. m It is assumed to be 8 when it is configured to use an MCS table supporting 256QAM for at least one BWP in the cell; otherwise, Q... mAssumed to be 6 (64QAM), the bitrate is assumed to be the maximum bitrate of 948 / 1024, N RE Assumed to be 156·n PRB And n PRB Assumed to be n PRB，LBRM To perform the calculation. n can be given in Table 16 below. PRB，LBRM .

[0196] [Table 16]

[0197] Maximum number of PRBs for all BWP configurations across carriers <![CDATA[n PRB，LBRM ]]> Less than 33 32 33 to 66 66 67 to 107 107 108 to 135 135 136 to 162 162 163 to 217 217 Greater than 217 273

[0198] The maximum data rate supported by the UE in the NR system can be determined by the following formula 2.

[0199] [Equation 2]

[0200]

[0201] In Equation 2, J can be the number of carriers generated through carrier aggregation, Rmax = 948 / 1024. It can be the maximum number of floors. It can be the maximum modulation order, f (j) This can be a scaling exponent, and μ can refer to the subcarrier spacing. The UE can use one of 1, 0.8, 0.75, or 0.4 as f. (j) The value of μ is reported, and μ can be given in Table 17 below.

[0202] [Table 17]

[0203] μ <![CDATA[Δf=2 μ ·15[kHz]]]> Cyclic prefix 0 15 normal 1 30 normal 2 60 Normal, expansion 3 120 normal 4 240 normal

[0204] in addition, It is the average OFDM symbol length and can be calculated as and It is the maximum number of RBs in BW(j). Cost value OH (j) In the downlink of FR1 (band below 6 GHz), it can be given as 0.14, while in the uplink it is given as 0.18; and in the downlink of FR2 (band above 6 GHz), it can be given as 0.08, while in the uplink it is given as 0.10. Using Equation 2, the maximum data rate in the downlink of a cell with a frequency bandwidth of 100 MHz and a subcarrier spacing of 30 kHz can be calculated as shown in Table 18 below.

[0205] [Table 18]

[0206]

[0207] The actual data rate that can be measured by the UE during actual data transmission can be a value obtained by dividing the data volume by the data transmission time. This can be a value obtained by dividing the TBS by the TTI length for a 1TB transmission or by dividing the sum of the TBS by the TTI length for a 2TB transmission. For example, the maximum actual data rate in the downlink of a cell with a 100MHz frequency bandwidth at a 30kHz subcarrier spacing can be determined based on the number of allocated PDSCH symbols as shown in Table 19 below.

[0208] [Table 19]

[0209]

[0210] The table above identifies the maximum data rate supported by the UE, and the actual data rate is determined based on the allocated TBS. However, depending on scheduling information, the actual data rate may exceed the maximum data rate.

[0211] In wireless communication systems, particularly New Radio (NR) systems, the data rate that the UE can support can be agreed upon between the base station and the UE. This can be calculated using the maximum bandwidth, maximum modulation order, and maximum number of layers supported by the UE. However, the calculated data rate may differ from the value calculated based on the transport block size (TBS) and transmission time interval (TTI) length used for actual data transmission.

[0212] As a result, the UE may be assigned a TBS value greater than that corresponding to the data rate supported by the UE. To prevent this, the TBS that can be scheduled based on the data rate supported by the UE can be limited.

[0213] Figure 7 The present disclosure illustrates synchronization signals and physical broadcast channels mapped to the frequency and time domains in a 5G system according to embodiments of the present disclosure.

[0214] Reference Figure 7 The primary synchronization signal (PSS) 701, secondary synchronization signal (SSS) 703, and PBCH 705 are mapped onto four OFDM symbols. The PSS and SSS are mapped to 12 RBs, while the PBCH is mapped to 20 RBs. The 20 RBs are shown in the diagram based on the frequency band variation of the subcarrier spacing (SCS). Figure 7 In the table, the resource area in which PSS, SSS, and PBCH are sent can be called an SS / PBCH block. Alternatively, an SS / PBCH block can be called an SSB block.

[0215] Figure 8 The symbols within a time slot to which an SS / PBCH block is mapped are shown according to an embodiment of this disclosure.

[0216] Reference Figure 8 The subcarrier spacing can be set to 15kHz, 30kHz, 120kHz and 240kHz, and the location of the symbol where the SS / PBCH block (or SSB block) can be located can be determined based on the subcarrier spacing. Figure 8 The diagram shows the positions of symbols within a 1ms interval that can be transmitted as SSB blocks based on the subcarrier interval, and it is not always necessary to... Figure 8 SSB blocks are transmitted in the area shown. The location for transmitting SSB blocks can be configured in the UE via system information or dedicated signaling.

[0217] Since UEs are typically located far from the base station, signals transmitted by the UE are received by the base station after a propagation delay. The propagation delay is a value obtained by dividing the path of a radio wave from the UE to the base station by the speed of light, and it can typically be obtained by dividing the distance from the UE to the base station by the speed of light. In one embodiment, for a UE 100 km from the base station, a signal transmitted by that UE is received by the base station after approximately 0.34 milliseconds. Conversely, a signal transmitted by the base station is also received by the UE after approximately 0.34 milliseconds. As mentioned above, the arrival time of a signal transmitted by a UE at the base station can vary depending on the distance between the UE and the base station. Therefore, when multiple UEs at different locations transmit signals simultaneously, the arrival times of the signals at the base station may all be different. To solve this problem by ensuring that signals transmitted from multiple UEs arrive at the base station simultaneously, the timing for transmitting uplink signals can be set differently for each UE based on its location. This is called timing advance in 5G, NR, and LTE systems.

[0218] Figure 9 The present invention illustrates the processing time of a UE in a 5G system when the UE receives a first signal and sends a second signal in response, according to an embodiment of the present disclosure, due to timing advance.

[0219] Reference Figure 9This document provides a detailed description of the UE processing time based on the timing advance. When the base station sends an uplink scheduling grant (UL grant) or downlink control signals and data (DL grant and DL data) to the UE in time slot n 902, the UE can receive the uplink scheduling grant or downlink control signals and data in time slot n 904. Here, the UE can receive the signal later than the time the base station sends the signal by transmission delay time Tp 910. In this embodiment, when the UE receives the first signal in time slot n 904, it sends the corresponding second signal in time slot n+4 908. When the UE sends a signal to the base station, in order to ensure that the signal arrives at the base station at a specific time, the UE can send HARQ ACK / NACK for downlink data or uplink data at timing 906, which is a timing advance of TA 912 compared to time slot n+4, which is the timing of the signal received by the UE. Therefore, in this embodiment, the time for the UE to prepare to send uplink data after receiving uplink scheduling permission or to send HARQ ACK or NACK after receiving downlink data can be the time corresponding to the three time slots excluding TA914.

[0220] To determine the aforementioned timing, the base station can calculate the absolute value of the TA for a specific UE. The base station can calculate the absolute value of the TA by adding the change in the TA value transmitted via higher signaling to the TA value initially delivered to the UE during the random access phase for initial access, or by subtracting the change in the TA value transmitted via higher signaling from the TA value initially delivered to the UE during the random access phase for initial access. In this disclosure, the absolute value of the TA can be obtained by subtracting the start time of the nth TTI (Time Interval) for reception from the start time of the nth TTI (Time Interval) for transmission by the UE.

[0221] One of the key performance metrics for cellular wireless communication systems is packet data latency. For this purpose, in LTE systems, signal transmission and reception are performed in subframes with a transmission time interval (TTI) of 1 ms. LTE systems operating as described above can support UEs with transmission time intervals shorter than 1 ms (short TTI UEs). In 5G or NR systems, the transmission time interval can be even shorter than 1 ms. Short TTI UEs are suitable for latency-critical LTE-based voice (VoLTE) and remote control services. Additionally, short TTI UEs can be a means of implementing mission-critical Internet of Things (IoT) on a cellular basis.

[0222] In 5G or NR systems, when a base station transmits a PDSCH containing downlink data, the DCI indicator K1 value for scheduling the PDSCH corresponds to the timing information of the HARQ-ACK information sent by the UE for the PDSCH. The UE can send the HARQ-ACK information to the base station if it is not indicated to be transmitted earlier than the timing-advanced symbol L1. That is, the UE can send the HARQ-ACK information to the base station at the same or later timing as the timing-advanced symbol L1. However, if the HARQ-ACK information is indicated to be transmitted earlier than the timing-advanced symbol L1, the HARQ-ACK information may not be valid during the HARQ-ACK transmission from the UE to the base station.

[0223] The symbol L1 can be the cyclic prefix (CP) starting from the last time point of PDSCH in T. proc，1 The first symbol that follows. T can be calculated using Equation 3 as follows. proc，1 .

[0224] [Formula 3]

[0225] T proc，1 =((N1+d) 1，1 +d 1，2 (2048+144)·κ2 -μ )·T C

[0226] In Equation 3, N1 and d can be defined as follows: 1，1 d 1，2 , κ, μ and Tc.

[0227] - When sending HARQ-ACK information on PUCCH (Uplink Control Channel), d 1，1 =0; while when HARQ-ACK information is sent on PUSCH (uplink shared channel, data channel), d 1，1 =1.

[0228] - When the UE is configured with multiple active component carriers or carriers, the maximum timing difference between carriers can be considered in the transmission of the second signal.

[0229] - For PDSCH mapping type A, i.e., when the first DMRS symbol is located at the third or fourth symbol of the time slot, when the position index i of the last symbol of the PDSCH is less than 7, d 1，2 It is defined as 7-i.

[0230] - For PDSCH mapping type B, i.e., when the first DMRS symbol is located at the first symbol of the PDSCH, when the PDSCH has a length of 4 symbols, d1，2 =3, or when PDSCH has a length of 2 symbols, d 1，2 =3+d, where d is the number of overlapping symbols between the PDSCH and the PDCCH (including control signals) corresponding to the scheduling PDSCH.

[0231] -N1 is defined according to μ as shown in Table 20 below. μ = 0, 1, 2 and 3 refer to subcarrier spacing of 15 kHz, 30 kHz, 60 kHz and 120 kHz respectively.

[0232] [Table 20]

[0233]

[0234] - For the N1 values ​​presented in the table above, different values ​​can be used depending on the UE's capabilities.

[0235] - Other values ​​can be defined as follows.

[0236] T c =1 / (Δf) max ·N f ), Δf max =480·10 3 Hz, N f =4096, κ=T s / T c =64,T s =1 / (Δf) ref ·N f，ref ), Δf ref =15·10 3 Hz, N f，ref =2048

[0237] Additionally, in 5G or NR systems, when a base station sends control information including uplink scheduling permission, it can indicate a K2 value corresponding to information about the timing of the UE sending uplink data or PUSCH.

[0238] The UE may send the PUSCH to the base station when it is not indicated to be sent earlier than the L2 symbol which includes a timing advance. That is, the UE may send the PUSCH to the base station at the same or later timing as the L2 symbol which includes a timing advance. When the PUSCH is indicated to be sent earlier than the L2 symbol which includes a timing advance, the UE may ignore the uplink scheduling permission control information from the base station.

[0239] Symbol L2 can be the CP of the PUSCH symbol at time T from the last time point of the PDCCH including scheduling permission. proc，2 The first symbol to be sent then. T can be calculated as shown in Equation 4 below. proc，2 .

[0240] [Formula 4]

[0241] T proc，2 =((N2+d 2，1 (2048+144)·κ2 -μ )·T C

[0242] In Equation 4 above, N2 and d can be defined as follows: 2，1 , κ, μ and TC.

[0243] - When the first symbol among the symbols assigned to PUSCH includes only DMRS, d 2，1 =0, otherwise d 2，1 =1.

[0244] - When the UE is configured with multiple active component carriers or carriers, the maximum timing difference between carriers can be reflected in the transmission of the second signal.

[0245] -N2 is defined according to μ as shown in Table 21 below. μ = 0, 1, 2 and 3 refer to subcarrier spacing of 15 kHz, 30 kHz, 60 kHz and 120 kHz, respectively.

[0246] [Table 21]

[0247] μ <![CDATA[PUSCH preparation time N2 [symbols]]]> 0 10 1 12 2 23 3 36

[0248] - For the N2 values ​​presented in the table above, different values ​​can be used depending on the UE's capabilities.

[0249] - Other values ​​can be defined as follows.

[0250] T c =1 / (Δf) max ·N f ), Δf max =480.10 3 Hz, N f =4096, κ=T s / T c =64,T s =1 / (Δf) ref ·N f，ref ), Δf ref =15·10 3 Hz, N f，ref =2048

[0251] In 5G or NR systems, a Frequency Bandwidth Part (BWP) can be configured within a carrier, and a specific UE can be designated to perform transmission and reception within that configured BWP. This can be intended to reduce UE power consumption. A base station can configure multiple BWPs and switch active BWPs via control information. The time available for a UE to switch BWPs can be defined in Table 22A below.

[0252] [Table 22A]

[0253]

[0254] In Table 22A, frequency range 1 refers to the range of frequencies below or equal to 6 GHz, while frequency range 2 refers to the range of frequencies above or equal to 6 GHz. In this embodiment, type 1 and type 2 can be determined based on UE capabilities. In this embodiment, scenarios 1, 2, 3, and 4 are given in Table 22B below.

[0255] [Table 22B]

[0256]

[0257] Figure 10 Examples of scheduling and transmitting data (e.g., TB) according to time slots, receiving HARQ-ACK feedback for data, and performing retransmissions based on the feedback are shown according to embodiments of the present disclosure.

[0258] Reference Figure 10 TB1 is initially transmitted in time slot 0, and an ACK / NACK response is sent for it in time slot 4. If the initial transmission of TB1 fails and a NACK is received, a retransmission of TB1 can be performed in time slot 8. Here, the timing of sending the ACK / NACK response and performing the retransmission can be predetermined or determined based on values ​​indicated in control information and / or higher-level signaling.

[0259] Figure 10 An example is shown where TB1 through TB8 are scheduled and transmitted sequentially according to time slot 0. For example, this could indicate that HARQ procedure IDs 0 through 7 are assigned to TB1 through TB8 for transmission, respectively. If the number of HARQ procedure IDs available to the base station and UE is only 4, it may not be possible to transmit eight different TBs consecutively.

[0260] Figure 11 This is an example of a base station sending the same control information and data to multiple UEs according to embodiments of the present disclosure.

[0261] Reference Figure 11Base station 1101 can notify UEs 1103, 1105, 1107, and 1111 of the G1-RNTI for receiving multicast control information via SIB or pre-configuration information, and the UEs can use the G1-RNTI to receive multicast control information. Here, the G1-RNTI can be sent by CRC scrambling with multicast downlink control information (DCI). Figure 11 In this context, UE1109 can be a UE connected to base station 1101 and can be a UE that has received a C-RNTI from base station 1101. Similarly, UE1111 can be a UE connected to base station 1101 and can be a UE that has received a C-RNTI from base station 1101 and knows the G1-RNTI used for multicast. As described above, when the same control information and data are sent and one or more UEs are able to receive the sent control information and data, the control information and data can be referred to as multicast. Furthermore, when a C-RNTI or a UE-specific RNTI is given... Figure 11 A unicast is defined as a specific UE, such as UE 1109 or UE 1111, where only that specific UE is able to receive control information or data by using the RNTI value.

[0262] A UE can be configured to receive control and data channels for multicast from sender A and control and data channels for unicast from sender B. In this embodiment, sender A and sender B can be the same sender or different senders. In this disclosure, sender A and sender B can be a base station, a vehicle, or a UE. Here, when the sender is a base station, multicast and unicast data transmission can be sent from the base station, i.e., via a Uu link. When the sender is a vehicle or a regular UE, multicast and unicast transmission can be sidelink transmission. In this case, the sender can be a UE referred to as the leader node or anchor node in the group, and can be a UE capable of performing multicast transmissions to other UEs in the group and capable of receiving control information from another UE. Furthermore, this embodiment can be applied with modifications, as in the case where sender A is a vehicle and sender B is a base station. Although this embodiment is described under the assumption that sender A and sender B are the same sender, this embodiment can be applied with modifications even when they are different senders.

[0263] To receive control and data channels for multicast / broadcast / multicast, the UE can be configured with an RNTI value corresponding to a unique ID (used interchangeably with Group RNTI (G-RNTI), Group Common RNTI (GC-RNTI), Group Identifier, or MBSRNTI in the following description), or it can be received from a base station or another UE in the group (which could be the leader node). The UE can receive control channels for multicast using the G-RNTI value and can receive data channels based on it. In this embodiment, the control channel for data scheduling can be used interchangeably with the Physical Downlink Control Channel (PDCCH) or Physical Sidelink Control Channel (PSCCH), the data channel can be used interchangeably with the Physical Downlink Shared Channel (PDSCH) or Physical Sidelink Shared Channel (PSSCH), and the feedback channel can be used interchangeably with the Physical Uplink Control Channel (PUCCH) or PSCCH. Additionally, although the control information received by the UE for scheduling is described as DCI below, it may be referred to differently.

[0264] For example, G-RNTI can be used to transmit multicast data and control information for scheduling multicast data. Here, channel coding can be applied by scrambling the G-RNTI value or a portion thereof with the CRC of the control information (DCI). This RNTI can be different from the UE-specific RNTI used for unicast data transmission and can be configured for multiple UEs. This DCI can have a different format than the DCI used for unicast data scheduling.

[0265] When a UE sends data to multiple UEs, or when a base station sends the same data to multiple UEs, this can be referred to as multicast or multi-cast, and these terms can be used interchangeably. Additionally, in this disclosure, "data" can refer to a transport block transmitted on a shared channel such as PDSCH, PUSCH, or PSSCH. In the downlink or sidelink of a 5G NR system, FBRM can be considered to support multicast or multicast and broadcast services (MBS). However, the types of UEs receiving multicast or MBS services can be very diverse, so some UEs without sufficient internal buffers may have difficulties with soft buffering operations or may experience performance degradation. Therefore, in cases where some multicast or multicast services or broadcast services (hereinafter, for convenience, referred to as MBS) are provided, LBRM can be applied to stably provide services to a variety and many UEs.

[0266] In this context, an LBRM scheme suitable for MBS is provided for use in the downlink or sidelink.

[0267] First, the current PDSCH LBRM scheme in 5G NR is the same as that described in Table 23 below [Considering the existing rate matching configuration of PDSCH-LBRM]. However, the definitions of each major parameter and the table numbers referenced in [Considering the existing rate matching configuration of PDSCH-LBRM] follow 3GPP standard TS 38.212.

[0268] [Table 23]

[0269]

[0270]

[0271] Based on [considering the existing rate matching configuration of PDSCH-LBRM], in order to identify or determine TBS when applying LBRM. LBRM The maximum number of layers used for a TB is determined based on the parameter maxMIMO-Layers included in the PDSCH-ServingCellConfig of higher-layer signaling or by the maximum number of layers supported by the UE for PDSCH in the serving cell. However, this value does not exceed 4. Additionally, the modulation order is determined based on the parameter mcs-Table included in the pdsch-Config of higher-layer signaling or a preset value (e.g., 6). The above method may be suitable for LBRM for a specific UE, but it may not be suitable for LBRM considering services such as MBS for multiple UEs. Therefore, various embodiments of this disclosure propose LBRM schemes suitable for services such as MBS. When applying LBRM to data transmission supporting services such as MBS according to various embodiments of this disclosure, at least one of the first to fifth embodiments described below can be applied to determine the TBS. LBRM The method involves configuring parameters to be considered (e.g., the number of allocated layers, modulation order, and number of PRBs). According to various embodiments of this disclosure, a base station supporting services such as MBS can identify the same TBS when transmitting the same data to multiple UEs. LBRM To apply LBRM.

[0272] [First Embodiment]

[0273] The first embodiment of this disclosure relates to a method and apparatus for efficiently applying a downlink LBRM (PDSCH-LBRM, DL-SCH LBRM, or PCH LBRM) when performing multicast or multicast / broadcast data transmission to support services such as MBS. For convenience, it is referred to hereinafter as PDSCH-LBRM.

[0274] First, a method for applying LBRM by separately configured parameters when it is applied to multicast or multicast / broadcast is given, although it is similar to the method in Table 23 above [Existing Rate Matching Configuration Considering PDSCH-LBRM]. In [Existing Rate Matching Configuration Considering PDSCH-LBRM], parameters such as maxMIMO-Layers required to determine the maximum number of layers for a TB, the maximum number of layers for PDSCH supported by the UE in the serving cell, and the mcs-Table used to determine the modulation order are unicast-based parameters, and therefore may not be suitable for multicast or multicast / broadcast. Therefore, if an instruction to perform LBRM is received when multicast or multicast / broadcast is supported, the TBS can be identified or determined based on at least one parameter that is different from the parameters used in [Existing Rate Matching Configuration Considering PDSCH-LBRM] (i.e., parameters considering unicast configuration). LBRM .

[0275] Figure 12 This is a flowchart illustrating a method for applying LBRM when performing multicast or broadcast data transmission and reception according to embodiments of the present disclosure.

[0276] Refer to the example as a specific case Figure 12 In operation 1210, it is first determined whether an instruction for supporting PDSCH-LBRM has been received. If no instruction for supporting PDSCH-LBRM has been received, LBRM is not applied. If an instruction for supporting PDSCH-LBRM has been received, in operation 1220 it is identified whether the first required parameter has been configured. For example, when supporting unicast services, the first parameter may be the parameter maxMIMO-Layers included in the higher-layer signaling PDSCH-ServingCellConfigure. When supporting multicast or multicast / broadcast, the first parameter may refer to a different value. If the first parameter is configured, in operation 1230 the first parameter or its corresponding value can be determined as the X value, for example, the layer number used for determination in Table 23. If the first parameter is not configured, a second parameter can be identified, and in operation 1240 the second parameter or its corresponding value can be determined as the X value. Here, the X value may refer to a default value.

[0277] Here, in the case of unicast, the second parameter can be a parameter in higher-layer signaling corresponding to the maximum number of layers supported by the UE for PDSCH in the serving cell, while when multicast or multicast / broadcast is supported, the second parameter can refer to a different value. In other words, the first and second parameters used to perform PDSCH-LBRM can be equally applied to both unicast and multicast / broadcast scenarios, but at least one of them can be determined as a different parameter depending on the system.

[0278] Furthermore, if the first and second parameters have different values ​​for different UEs, it may be ambiguous which value the base station or UE uses to specify the parameter values ​​required for LBRM. In this case, different LBRM operations can be performed. Therefore, the first and second parameters can be set to the same value only for UEs receiving the same multicast or broadcast service. For example, the base station can determine the minimum of possible maxMIMO-Layers values ​​(e.g., the first parameter) or the minimum of possible maximum supported layers (e.g., the second parameter), and can configure each parameter to have the same value for all UEs in the same group. Alternatively, the base station can configure each parameter to a pre-configured value. (In this case, it can be delivered to each UE via signaling or parameters different from existing higher-layer signaling or parameters (e.g., maxMIMO-Layers_multicast)). That is, when the first or second parameter is configured the same for UEs receiving multicast or broadcast services (or when the first or second parameter is grouped for UEs), the UE can easily determine the parameters required for LBRM.

[0279] In addition, it is also possible to identify or determine the TBS used for multicast or broadcast. LBRM Required bitrate parameter R LBRM Set to a value other than 2 / 3. Additionally, TBS can be identified or determined in [TBS Determination Process 1]. LBRM At least one of the required parameters or variables must be subject to a constraint different from the existing unicast constraint. As a specific example, the maximum bitrate of LBRM, 948 / 1024, could also be set to a different value (e.g., a value less than 948 / 1024), and equation N could also be... RE =156·n PRB The value of 156 in the parameter is set to another value (e.g., a multiple of 12 and less than 156). This parameter configuration method applies not only to this embodiment but also to the following embodiments unless otherwise specified.

[0280] The LBRM used for MBS data transmission can be determined as shown in Table 24 below, for example.

[0281] [Table 24]

[0282]

[0283]

[0284] As another example, the LBRM used for MBS data transmission described above can be determined as shown in Table 25 below. In this method, when determining the maximum number of layers X, X is determined by the configured value, rather than by the smaller of the configured value and 4 as shown in Table 24. This is likely because MBS transmission does not support transmissions with four or more layers.

[0285] [Table 25]

[0286]

[0287]

[0288] In existing LBRM applications, specifically in [the existing rate matching configuration considering PDSCH-LBRM], it is possible to determine the appropriate rate matching configuration based on I. LBRM The value determines whether to apply LBRM or full buffered rate matching (FBRM). In this disclosure, LBRM can be achieved using N. cb =min(N, N) ref The method for performing rate matching is ), while FBRM can be performed using N. cb =N to perform rate matching. When higher-level parameters or parameter I LBRM When it is 0, this can indicate FBRM, i.e., N. cb =N; when I LBRM When it is 1, this can indicate LBRM, i.e., N. cb =min(N, N) ref ).

[0289] Perhaps MBS transmission could be restricted to cases where TBS is small. Since MBS will be sent to multiple UEs, this restriction could also support UEs with low capabilities. Therefore, LBRM and FBRM can be applied differently depending on the RNTI value. That is, when DCI detects mbs-RNTI for MBS data transmission and scheduling, I can be set. LBRM =0 (i.e., apply FBRM); when DCI detects a different RNTI (or, otherwise), I can be set. LBRM =1 (i.e., apply LBRM).

[0290] Perhaps I can set I in the BWP that performs data transfer. LBRM .

[0291] As another example, perhaps it's also possible to set I for each mbs-RNTI. LBRM For example, you can set mbs-RNTI-1 and mbs-RNTI-2 values ​​for MBS transmission, and you can also set the I corresponding to each RNTI value. LBRMFor the mbs-RNTI-1 value, I can be set. LBRM =0, while for the mbs-RNTI-2 value, ILBRM can be set to 1. Then, the base station and UE can set I for MBS data scheduled and transmitted using mbs-RNTI-1. LBRM =0 (i.e., apply FBRM), while I can be set for MBS data scheduled and sent using mbs-RNTI-2. LBRM =1 (i.e., apply LBRM). If there is no I in RNTI LBRM If set, it can be regarded as I LBRM =1. In other words, if I is set in the RNTI settings... LBRM If the value is 0, then FBRM can be applied; otherwise, LBRM can be applied.

[0292] [Second Embodiment]

[0293] As another example of a method for configuring parameters for LBRM in multicast or broadcast applications, pre-set values ​​(default (or preset) values ​​or integers, such as 1, 2, 3, 4) can be utilized.

[0294] For example, when receiving instructions to apply LBRM to multicast or broadcast applications, the TBS can be identified or determined. LBRM At least some necessary parameters are set to pre-configured values. Specifically, a specific integer such as X = 1 or 2 can be set, or a specific value can be committed to be set, such as a specific integer in the frequency domain or frequency band, or a value forced to the UE as the maximum number of layers. That is, this predetermined or pre-configured value depends on the frequency domain or frequency band. (Hereinafter, in this embodiment or subsequent embodiments, it may be assumed, but not limited to, that X = 1 is given. For example, integer values ​​such as X = 2, 3, or 4 can be set. In addition, in the following embodiments, the configuration can be completed by omitting the process of setting X to a preset value without being mentioned separately.)

[0295] When an LBRM application instruction is received while supporting multicast or broadcast services, the TBS is identified or determined. LBRM At least some of the necessary parameters can be set to pre-configured values ​​immediately without additional operation, but they can also be set in appropriate combination with the operation of other embodiments.

[0296] As a specific example, refer to Figure 13 and Figure 14 A method combined with the first embodiment is described.

[0297] Figure 13 and Figure 14 This is a flowchart illustrating a method for applying LBRM when performing multicast or broadcast data transmission and reception according to various embodiments of the present disclosure.

[0298] Reference Figure 13 In operation 1310, it is first determined whether an instruction for supporting PDSCH-LBRM has been received. If no instruction for supporting PDSCH-LBRM has been received, LBRM is not applied. If an instruction for supporting PDSCH-LBRM has been received, in operation 1320 it is identified whether the first required parameter has been configured. If the first parameter has been configured, in operation 1330 the first parameter or its corresponding value can be determined as, for example, the X value used to determine the number of layers in Tables 23 to 25. If the first parameter has not been configured, in operation 1350 a second parameter can be identified, and in operation 1360 the second parameter or its corresponding value can be determined as the X value. If the second parameter has also not been set, in operation 1370 the value of X can be set to a pre-configured value. This value can vary according to the frequency domain or frequency band.

[0299] Reference Figure 14 When it is difficult to set the second parameter or the maximum number of tiers for PDSCH supported by the UE in the serving cell for UEs in the same group (or when it is difficult to group UEs with the same maximum number of tiers), if not as in Figure 14 By setting the first parameter, regardless of the second parameter or the maximum number of tiers supported by the UE for PDSCH in the serving cell, at least some parameter values ​​required by LBRM can be set to pre-configured values ​​in operation 1440. For operations 1410 to 1430, refer to... Figure 13 Operations 1310 to 1330. Additionally, when the first parameter cannot be set similarly for a single UE, the X value can be determined as a pre-configured value regardless of whether the first or second parameter is used.

[0300] A pre-configured value can refer to a fixed integer value in the system, but it can also be an integer value that can be identified or determined by another higher-level parameter. For example, in the case of broadcast (or multicast / multicast), the X value can be determined based on higher-level signaling or parameter values ​​or their corresponding values ​​included in at least one of the Master Information Block (MIB) or System Information Block (SIB).

[0301] [Third Embodiment]

[0302] As another example of a parameter configuration method for LBRM in multicast or broadcast applications, a method for setting the maximum modulation order parameter may be necessary.

[0303] The base station can configure frequency resources (PRB) or BWPs for MBS data transmission to the UE. Additionally, the base station can configure resources for transmitting DCI (or PDCCH) for scheduling MBS data transmission; these resources can be in the form of a CORESET, i.e., a CORESET for MBS. In other words, the base station can allocate frequency and time resources for a CORESET for MBS to one or more UEs. Here, the CORESET configuration for MBS can include slot indexes, symbol indexes (or start symbol and length), and settings related to the frequency PRB.

[0304] For example, the modulation order can be determined by using different mcs-table configuration values ​​based on the RNTI. Additionally, currently in the unicast case, if the mcs-table is set for at least one DL BWP in the parameters corresponding to 256QAM (e.g., qam256), then the modulation order Q... m The modulation order is set to 8; otherwise, it is set to 6. However, specifying the modulation order value for the LBRM can be ambiguous when UEs receiving multicast or multicast / broadcast do not have the same mcs-table configuration. Therefore, it is easy to specify the modulation order value for the LBRM when the same mcs-table is set for UEs receiving the same multicast or multicast / broadcast (or when UEs with the same mcs-table configuration are grouped together). (In this case, it can be delivered to each UE via signaling or parameters that are different from existing higher-level signaling or parameters. For example: mcs-table_multicast).

[0305] Furthermore, currently, the modulation order used for LBRM in unicast is set to either a maximum of 8 or a minimum of 6 based on the setting value of the mcs-Table parameter. However, in multicast or broadcast / multicast scenarios, it can be set to different values. For example, when multicast or broadcast / multicast services are supported, if the mcs-Table_multicast value is fixed to a value corresponding to 64QAM as the maximum modulation scheme, the case where the modulation order is set to 8 as the LBRM parameter can be excluded. That is, the modulation order (Q) used as the LBRM parameter can be set to... m The value is set to 6. Furthermore, when multicast or broadcast services are supported, if the maximum modulation order is limited to a specific value regardless of the `mcs-Table_multicast` value, the modulation order used as an LBRM parameter can be determined to the corresponding specific modulation order. For example, it can be set to 6 when multicast or broadcast services always operate at 64QAM or lower; it can be set to 6 when operating at 16QAM or lower; and it can be set to 2 when operating at QPSK or lower.

[0306] As mentioned above, in order to apply LBRM in multicast / broadcast data transmission, TBS can be determined based on RNTI. LBRM Or it can be determined that in order to determine TBS LBRM Required parameters. The base station can configure a separate RNTI value for the UE for multicast / broadcast data transmission. In this disclosure, the RNTI used for multicast / broadcast can be referred to as MBS-RNTI. That is, when receiving DCI normally during DCI reception, if the RNTI value used for decoding (e.g., the RNTI value used for descrambling) is MBS-RNTI, the UE can use the modulation order set for multicast / broadcast transmission. Alternatively, when multicast or multicast / broadcast is supported, a different parameter configuration method than that used for unicast can be applied based on the RNTI. This can be an example of using RNTI to determine parameters when multiple RNTIs are configured for MBS.

[0307] [Fourth Embodiment]

[0308] Based on Table 23 [considering the existing rate matching configuration of PDSCH-LBRM], firstly based on n PRB，LBRM The value of n is determined according to predefined rules. PRB The value is used to determine the size of the allocated resource element, such as N. RE =156·n PRB Here, when multicast or broadcast / multicast services are supported, n is determined. PRB The method of value can vary.

[0309] For example, in cases where multicast / broadcast services are supported, this value can be determined as the number of PRBs configured for the MBS or based on a corresponding value. That is, the configured number of PRBs can generally apply to UEs belonging to the same group. This value can be the size of the BWP or its corresponding value.

[0310] As another example, based on the number of PRBs configured for MBS transport or the number of PRBs configured for MBS transport by BWP, n can be calculated as shown in Table 26 below. PRB，LBRM That is, for example, if the PRB of the BWP configured for MBS transport is set to 100 PRBs, then n PRB，LBRM =107 can be used to determine TBS LBRM n PRB .

[0311] [Table 26]

[0312]

[0313]

[0314] [Fifth Embodiment]

[0315] The fifth embodiment of this disclosure provides a method for selecting a rate matching configuration. Various embodiments of this disclosure provide a method for applying LBRM in multicast / broadcast data transmission, which may be referred to as "[LBRM applied to multicast / broadcast]", and this may differ from "[existing rate matching configuration taking into account PDSCH-LBRM]" in existing NR systems.

[0316] Figure 15 This is a flowchart illustrating a method by which a UE, according to an embodiment of the present disclosure, determines whether a broadcast / multicast (MBS) has been sent and applies LBRM accordingly when receiving control information or data.

[0317] Reference Figure 15 To perform TBS_LBRM calculation for the LBRM in operation 1500, parameter settings such as the maximum number of layers and the maximum modulation order for data transmission can be identified first in operation 1510, and it can be determined in operation 1520 whether broadcast / multicast (MBS) transmission exists. In the case of broadcast / multicast, suitable parameters can be determined in operation 1530 (based on [LBRM applied to multicast / broadcast]). In the case of unicast, parameters according to existing methods can be determined in operation 1540 (based on [considering the existing rate matching configuration of PDSCH-LBRM]). Here, operation 1510 can be skipped. TBS_LBRM calculation for the LBRM can be performed in operation 1550 using the determined parameters, and data reception can be performed by applying the LBRM.

[0318] Here, the following method can be used in operation 1520 to determine whether broadcast / multicast exists.

[0319] - Method 1: This is determined based on the RNTI value scrambled with the control information (DCI) of the scheduling data. That is, in the case of MBS transmission, LBRM is performed using [LBRM applied to multicast / broadcast]; in the case of non-MBS transmission, LBRM is performed using [existing rate matching configuration taking into account PDSCH-LBRM]. In this disclosure, performing LBRM may mean for the base station that it performs rate matching to map and transmit data (PDSCH) taking into account LBRM, and for the UE that it decodes the PDSCH according to the rate matching taking into account LBRM. The base station can configure the MBS-RNTI value for one or more UEs to implement MBS reception. Therefore, the DCI scrambled with MBS-RNTI can be determined as scheduled MBS transmission, and the corresponding PDSCH can be determined as for MBS; RNTI values ​​using C-RNTI, MCS-C-RNTI, TC-RNTI, CS-RNTI, SI-RNTI, RA-RNTI, MsgB-RNTI, or P-RNTI can be interpreted as not being MBS transmission. A base station can configure one or more MBS-RNTIs for a UE, where individual MBS-RNTIs can be used for different purposes and for data transmitted through different resources. The term MBS-RNTI is merely an example of an RNTI used for multicast / broadcast and can be referred to by various names.

[0320] - Method 2: The determination can be made based on the DCI format. For example, the base station can configure DCI format 2-x for MBS transmission and can set the corresponding configuration in a specific CORESET. Therefore, when DCI format 2-x is detected in the aforementioned CORESET, the UE can determine that the PDSCH scheduled by DCI format 2-x is for MBS.

[0321] -Method 3: The determination can be made based on the CORESET in which DCI (or PDCCH) scheduling data is sent.

[0322] - Method 4: In the case of a configured licensed transport (or semi-persistent scheduling (SPS) transport), the determination can be made based on the settings of the PDSCH sent accordingly.

[0323] Method 5: Determination can be made based on the configured HARQ procedure number. That is, the base station can pre-configure the HARQ procedure number for MBS to the UE. Subsequently, when a schedule is received with the corresponding HARQ procedure number, the UE can determine that the corresponding transmission is for MBS.

[0324] In the parameter configuration and determination methods considering LBRM proposed in the various embodiments of this disclosure, decoding is only possible when the base station and UE, or the transmitter and receiver, maintain the same or agreed settings. Furthermore, new configuration and determination methods can be derived by combining the parameter configuration and determination methods mentioned in the embodiments presented in this disclosure in various ways.

[0325] In order to implement the above embodiments of this disclosure, respectively in Figure 16 and Figure 17 The diagram illustrates a UE and a base station, each comprising a transmitter, a receiver, and a processor. The above embodiments describe methods for a UE or base station to transmit and receive multicast and unicast control information and data, and the receiver, processor, and transmitter of the base station and UE must each operate according to an embodiment used to perform the method. When this embodiment is applied to data transmission and reception in a sidelink, the base station in the following operations can be a UE performing transmission in the sidelink or a base station of related technologies. In the following operations, the UE can be a UE performing transmission or reception in the sidelink.

[0326] Figure 16 This is a block diagram illustrating the structure of a UE according to an embodiment of the present disclosure.

[0327] Reference Figure 16 The UE disclosed herein may include a receiver 1600, a transmitter 1604, and at least one processor 1602. The receiver 1600 and transmitter 1604 may be collectively referred to as transceivers in embodiments of this disclosure. The transceivers may transmit signals to and receive signals from a base station. Signals may include control information and data. For this purpose, the transceiver may include an RF transmitter for up-converting and amplifying the frequency of the signal to be transmitted, and an RF receiver for low-noise amplification of the received signal and down-converting its frequency. Additionally, the transceiver may receive signals via a wireless channel and output them to the processor 1602, and may also transmit signals output from the processor 1602 via a wireless channel. The processor 1602 may include a controller for controlling a series of processes that enable the UE to operate according to the above-disclosed embodiments.

[0328] A controller that controls the operation of a UE according to the various embodiments of the present disclosure described above may perform the following operations.

[0329] In a communication or broadcast system, a user equipment (UE) (or terminal) can receive signals corresponding to data transmitted from a transmitter or base station and perform appropriate decoding based on a channel coding scheme through a suitable demodulation process. To perform decoding, the UE must determine the exact same rate matching method used by the transmitter or base station. Therefore, the UE can determine whether to apply LBRM based on instructions for LBRM. Here, since the parameter settings for LBRM operation can vary depending on whether unicast (or data transmission to one UE) or multicast (or data transmission to multiple UEs) is used, operations for identifying whether unicast or multicast transmission is used can be added. Similarly, the UE can determine or identify whether unicast or multicast is used based on higher-level signaling or indicators transmitted separately from the base station. When it is necessary to perform an operation corresponding to the LBRM performed by the transmitter device in a unicast (or data transmission to one UE) scenario, the UE can perform the operation corresponding to the LBRM performed by the transmitter device based on a first configuration; when it is necessary to perform an operation corresponding to the LBRM performed by the transmitter device in a multicast (or data transmission to multiple UEs) scenario, the UE can perform the operation corresponding to the LBRM performed by the transmitter device based on a second configuration. Here, at least one of the parameters corresponding to the first configuration may be different from the parameter corresponding to the second configuration, or at least one of the values ​​of the parameters corresponding to the first configuration may be different from the value of the parameter corresponding to the second configuration. A specific scheme for the first configuration and the second configuration can be determined based on the first to fifth embodiments or appropriate combinations of their operations.

[0330] For reference and convenience, the operation performed by the receiver device (e.g., UE) according to the LBRM of the transmitter device (e.g., base station) can also be referred to as an LBRM operation. In other words, an LBRM operation in the receiver device means an operation corresponding to the LBRM of the transmitter device. Furthermore, although the LBRM operation performed in the base station is performed at the bit level, the operation performed by the receiver device according to the LBRM performed by the transmitter device can be performed based on the values ​​corresponding to the received signal generated or determined by demodulation. For example, if the likelihood ratio (LR) or log-likelihood ratio (LLR) value corresponding to the transmitted bit is determined based on the signal received by demodulation, the LBRM operation of the receiver device can be performed based on the LR or LLR value of each bit or other corresponding message values. Therefore, after performing LBRM in the receiver device as described above, the transmitted data can be determined or recovered by performing decoding of the channel code based on the values ​​(e.g., LR or LLR) corresponding to the bit sequence transmitted from the transmitter device, which can be determined or identified based on the LBRM.

[0331] Figure 17 This is a block diagram illustrating the structure of a base station according to an embodiment of the present disclosure.

[0332] Reference Figure 17 The base station disclosed herein may include a receiver 1701, a transmitter 1705, and at least one processor 1703. The receiver 1701 and transmitter 1705 may be collectively referred to as a transceiver in embodiments of this disclosure. The transceiver may transmit signals to and receive signals from the UE. The signals may include control information and data. For this purpose, the transceiver may include an RF transmitter for up-converting and amplifying the frequency of the signal to be transmitted, and an RF receiver for low-noise amplification of the received signal and down-converting its frequency. Additionally, the transceiver may receive signals via a wireless channel and output them to the processor 1703, and may also transmit signals output from the processor 1703 via a wireless channel. The processor 1703 may include a controller for controlling a series of processes that enable the base station to operate according to the above-disclosed embodiments.

[0333] According to the various embodiments of this disclosure described above, the controller that controls the operation of the base station can perform the following operations.

[0334] In a communication or broadcast system, a base station can first appropriately encode the data to be transmitted based on a channel coding scheme. Then, the base station can determine whether to perform LBRM on the encoded data. Here, since the parameter settings for LBRM operation can vary depending on whether unicast (or data transmission to a single UE) or multicast / multi-cast (or data transmission to multiple UEs) is used, operations for checking whether unicast or multicast / multicast transmission is used can be added. Additionally, the base station can indicate to the UE whether unicast or multicast / multicast is used via separate higher-layer signaling or indicators. When it is necessary to perform LBRM in the case of unicast (or data transmission to a single UE), the base station can perform LBRM based on a first configuration; when it is necessary to perform LBRM in the case of multicast / multicast (or data transmission to multiple UEs), the base station can perform LBRM based on a second configuration. Here, at least one of the parameters corresponding to the first configuration may be different from the parameter corresponding to the second configuration, or at least one of the values ​​of the parameter corresponding to the first configuration may be different from the value of the parameter corresponding to the second configuration. A specific scheme for the first and second configurations can be determined based on appropriate combinations of the first to fifth embodiments or their operations. After performing LBRM as described above, the base station can apply appropriate modulation to the bit sequence that can be determined or identified based on LBRM and send it to the UE (or terminal).

[0335] On the other hand, the embodiments disclosed in the specification and drawings are provided as specific examples to readily illustrate the subject matter of this disclosure and aid in understanding it, and are not intended to limit the scope of this disclosure. That is, it will be clear to those skilled in the art that other modifications can be made based on the technical content of this disclosure. Furthermore, the above embodiments can be combined with each other as needed. For example, the first and second embodiments can be applied in combination. In addition, other modified embodiments can be implemented based on the technical content related to LTE and 5G systems in the above embodiments.

[0336] Although this 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 this disclosure as defined by the appended claims and their equivalents.

Claims

1. A method performed by a base station in a wireless communication system, the method comprising: Send configuration information associated with the Physical Downlink Shared Channel (PDSCH) for multicast, wherein, when a parameter having a value indicating the maximum number of layers is configured in the configuration information, the maximum number of layers is equal to the value directly provided by the parameter, and wherein, when the parameter having the value indicating the maximum number of layers is not configured in the configuration information, the maximum number of layers is equal to 1; Based on the maximum number of layers, determine the transport block size (TBS) associated with the finite buffer rate matching LBRM of the PDSCH used for multicast; Based on the TBS execution rate matching associated with the LBRM of the PDSCH used for multicast; and After performing the rate matching, the PDSCH for multicast is sent.

2. The method according to claim 1, in, The TBS associated with the LBRM of the PDSCH used for multicast is also determined based on the number of Physical Resource Blocks (PRBs), and The number of PRBs is determined based on the size of the frequency resources used for multicast and broadcast services MBS.

3. The method according to claim 1, further comprising: Send downlink control information (DCI) in a specific format for scheduling multicast using the PDSCH.

4. The method according to claim 1, in, The TBS associated with the LBRM of the PDSCH used for multicast is also determined based on the maximum modulation order. Wherein, in the case that the information in the configuration information regarding the modulation and coding scheme MCS table corresponds to 64 quadrature amplitude modulation (QAM), the maximum modulation order is equal to 6, and Wherein, in the case that the information about the MCS table corresponds to 256 QAM, the maximum modulation order is equal to 8.

5. A method performed by a user equipment (UE) in a wireless communication system, the method comprising: Configuration information associated with the Physical Downlink Shared Channel (PDSCH) for multicast is received from the base station, wherein, when a parameter indicating a maximum number of layers is configured in the configuration information, the maximum number of layers is equal to the value directly provided by the parameter, and wherein, when the parameter indicating the maximum number of layers is not configured in the configuration information, the maximum number of layers is equal to 1; and Receive the PDSCH for multicast from the base station; The bit sequence included in the PDSCH used for multicast is rate-matched based on the transport block size TBS associated with the finite buffer rate matching LBRM. The TBS associated with the LBRM is determined based on the maximum number of layers.

6. The method according to claim 5, in, The TBS associated with the LBRM is also determined based on the number of Physical Resource Blocks (PRBs), and The number of PRBs is determined based on the size of the frequency resources used for multicast and broadcast services MBS.

7. The method according to claim 5, further comprising: Receive downlink control information (DCI) in a specific format from the base station for scheduling the PDSCH used for multicast.

8. The method according to claim 5, in, The TBS is also determined based on the maximum modulation order. Wherein, in the case that the information in the configuration information regarding the modulation and coding scheme MCS table corresponds to 64 quadrature amplitude modulation (QAM), the maximum modulation order is equal to 6, and Wherein, in the case that the information about the MCS table corresponds to 256 QAM, the maximum modulation order is equal to 8.

9. A base station in a wireless communication system, the base station comprising: transceiver; as well as At least one processor, said at least one processor being configured to: The transceiver transmits configuration information associated with the Physical Downlink Shared Channel (PDSCH) for multicast, wherein, when a parameter indicating a maximum number of layers is configured in the configuration information, the maximum number of layers is equal to the value directly provided by the parameter, and wherein, when the parameter indicating the maximum number of layers is not configured in the configuration information, the maximum number of layers is equal to 1. Based on the maximum number of layers, the transport block size (TBS) associated with the finite buffer rate matching LBRM of the PDSCH used for multicast is determined. Based on the TBS execution rate matching associated with the LBRM of the PDSCH used for multicast, and After performing the rate matching, the PDSCH for multicast is sent via the transceiver.

10. The base station according to claim 9, in, The TBS associated with the LBRM of the PDSCH used for multicast is also determined based on the number of Physical Resource Blocks (PRBs), and The number of PRBs is determined based on the size of the frequency resources used for multicast and broadcast services MBS.

11. The base station according to claim 9, in, The at least one processor is also configured to send downlink control information (DCI) in a specific format for scheduling the PDSCH used for multicast.

12. The base station according to claim 9, in, The TBS associated with the LBRM of the PDSCH used for multicast is also determined based on the maximum modulation order. Wherein, in the case that the information in the configuration information regarding the modulation and coding scheme MCS table corresponds to 64 quadrature amplitude modulation (QAM), the maximum modulation order is equal to 6, and Wherein, in the case that the information about the MCS table corresponds to 256 QAM, the maximum modulation order is equal to 8.

13. A user equipment (UE) in a wireless communication system, the UE comprising: transceiver; as well as At least one processor, said at least one processor being configured to: The transceiver receives configuration information associated with the Physical Downlink Shared Channel (PDSCH) for multicast from the base station, wherein, when a parameter indicating a maximum number of layers is configured in the configuration information, the maximum number of layers is equal to the value directly provided by the parameter, and wherein, when the parameter indicating the maximum number of layers is not configured in the configuration information, the maximum number of layers is equal to 1. The PDSCH for multicast is received from the base station via the transceiver. The bit sequence included in the PDSCH used for multicast is rate-matched based on the transport block size TBS associated with the finite buffer rate matching LBRM. The TBS associated with the LBRM is determined based on the maximum number of layers.

14. The UE according to claim 13, in, The TBS is also determined based on the number of Physical Resource Blocks (PRBs) and the maximum modulation order. The number of PRBs is determined based on the size of the frequency resources used for MBS (Multicast and Broadcast Services). Wherein, in the case that the information in the configuration information regarding the modulation and coding scheme MCS table corresponds to 64 quadrature amplitude modulation (QAM), the maximum modulation order is equal to 6, and Wherein, in the case that the information about the MCS table corresponds to 256 QAM, the maximum modulation order is equal to 8.

15. The UE according to claim 13, in, The at least one processor is also configured to receive downlink control information (DCI) in a specific format for scheduling the PDSCH used for multicast.

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