WO2022154639A1 - Method and device for providing multicasting and broadcasting service in communication system - Google Patents

Abstract

The present disclosure relates to a 5G or 6G communication system for supporting higher data transmission rates. A method performed by a terminal in a communication system according to the present disclosure comprises the steps of: receiving configuration information for a group common resource from a base station; receiving downlink control information (DCI) from the base station on the basis of the configuration information; confirming whether a group-common radio network temporary identifier (RNTI) was used for scrambling a cyclic redundancy check (CRC) attached to the DCI; and, if the group-common RNTI was used, determining an encoding rate and a modulation order on the basis of group-common modulation and coding scheme (MCS)-related information.

Description

Method and apparatus for providing multicasting and broadcasting in a communication system

The present disclosure relates to a mobile communication system, and more particularly, to a method of transmitting data to a plurality of terminals.

5G mobile communication technology defines a wide frequency band to enable fast transmission speed and new services. It can also be implemented in the very high frequency band ('Above 6GHz') called Wave). In addition, in the case of 6G mobile communication technology, which is called a system after 5G communication (Beyond 5G), in order to achieve transmission speed 50 times faster than 5G mobile communication technology and ultra-low latency reduced by one-tenth, Tera Implementations in the Terahertz band (such as, for example, the 95 GHz to 3 THz band) are being considered.

In the early days of 5G mobile communication technology, ultra-wideband service (enhanced Mobile BroadBand, eMBB), high reliability / ultra-low latency communication (Ultra-Reliable Low-Latency Communications, URLLC), large-scale mechanical communication (massive Machine-Type Communications, mMTC) Beamforming and Massive MIMO to increase the propagation distance and mitigate the path loss of radio waves in the ultra-high frequency band with the goal of service support and performance requirements, and efficient use of ultra-high frequency resources Supports various numerology (eg, operation of multiple subcarrier intervals) for New channel coding methods such as LDPC (Low Density Parity Check) code for data transmission and polar code for reliable transmission of control information, L2 pre-processing, dedicated dedicated to specific services Standardization of network slicing that provides a network has progressed.

At present, in consideration of the services that 5G mobile communication technology intends to support, discussions are underway for improvement and performance enhancement of the initial 5G mobile communication technology, and based on the vehicle's own location and status information NR-U (New Radio Unlicensed) for the purpose of operating systems that meet various regulatory requirements in V2X (Vehicle-to-Everything) to help autonomous vehicle driving judgment and increase user convenience ), NR terminal low power consumption technology (UE Power Saving), terminal-satellite direct communication for securing coverage in areas where communication with the terrestrial network is impossible, Non-Terrestrial Network (NTN), Positioning, etc. Physical layer standardization of technology is in progress.

In addition, the Intelligent Factory (Industrial Internet of Things, IIoT) for supporting new services through linkage and convergence with other industries, and IAB (Industrial Internet of Things), which provides nodes for network service area expansion by integrating wireless backhaul links and access links Integrated Access and Backhaul), Mobility Enhancement including Conditional Handover and Dual Active Protocol Stack (DAPS) handover, 2-step RACH for simplifying random access procedures Standardization of the air interface architecture/protocol field for technologies such as NR) is also in progress, and the 5G baseline for the grafting of Network Functions Virtualization (NFV) and Software-Defined Networking (SDN) technologies Standardization of the system architecture/service field for architecture (eg, Service based Architecture, Service based Interface), Mobile Edge Computing (MEC) receiving services based on the location of the terminal, etc. is also in progress.

When such a 5G mobile communication system is commercialized, connected devices, which are on an explosive increase, will be connected to the communication network. Accordingly, it is expected that the function and performance of the 5G mobile communication system will be strengthened and the integrated operation of the connected devices will be required. To this end, eXtended Reality (XR), artificial intelligence (Artificial Intelligence) to efficiently support augmented reality (AR), virtual reality (VR), mixed reality (MR), etc. , AI) and machine learning (ML) to improve 5G performance and reduce complexity, AI service support, metaverse service support, drone communication, etc.

In addition, the development of such a 5G mobile communication system is a new waveform (Waveform), Full Dimensional MIMO (FD-MIMO), and Array Antenna for guaranteeing coverage in the terahertz band of 6G mobile communication technology. , multi-antenna transmission technology such as large scale antenna, metamaterial-based lens and antenna to improve the coverage of terahertz band signals, high-dimensional spatial multiplexing technology using OAM (Orbital Angular Momentum), RIS ( Not only Reconfigurable Intelligent Surface technology, but also full duplex technology, satellite, and AI (Artificial Intelligence) for frequency efficiency improvement and system network improvement of 6G mobile communication technology are utilized from the design stage and end-to-end -to-end) Development of AI-based communication technology that realizes system optimization by internalizing AI support functions, and next-generation distributed computing technology that realizes services with complexity that exceed the limits of terminal computing power by utilizing ultra-high-performance communication and computing resources could be the basis for

The present disclosure provides a configuration method and apparatus for transmitting/receiving a group common physical downlink shared channel (PDSCH) and unicast PDSCH in a communication system.

The present disclosure provides a method and apparatus for transmitting/receiving a PDSCH retransmission of a group common PDSCH in a communication system.

According to various embodiments of the present disclosure, there is provided a method performed by a terminal in a communication system, the method comprising: receiving configuration information for a group common resource from a base station; receiving downlink control information (DCI) from the base station based on the configuration information; checking whether a group common radio network temporary identifier (RNTI) is used for scrambling of a cyclic redundancy check (CRC) attached to the DCI; and determining a code rate and a modulation order based on group common modulation and coding scheme (MCS) related information when the group common RNTI is used.

In addition, according to various embodiments of the present disclosure, in a method performed by a base station in a communication system, the method comprising: transmitting configuration information for a group common resource to a terminal; transmitting downlink control information (DCI) to the terminal based on the configuration information; and transmitting data based on the DCI. When a group common radio network temporary identifier (RNTI) is used for scrambling of a cyclic redundancy check (CRC) attached to the DCI, the MCS included in the DCI ( It is characterized in that the modulation and coding scheme index is determined based on group common modulation and coding scheme (MCS) related information.

In addition, according to various embodiments of the present disclosure, in a terminal in a communication system, a transceiver; and connected to the transceiver, receiving configuration information for a group common resource from a base station, receiving downlink control information (DCI) from the base station based on the configuration information, and attaching to the DCI It is checked whether a group common radio network temporary identifier (RNTI) is used for scrambling of a cyclic redundancy check (CRC), and when the group common RNTI is used, the code rate and It characterized in that it comprises a control unit for determining the modulation order.

In addition, according to various embodiments of the present disclosure, in a base station in a communication system, a transceiver; and connected to the transceiver, transmits configuration information for group common resources to the terminal, transmits downlink control information (DCI) to the terminal based on the configuration information, and based on the DCI a control unit for transmitting data, wherein when a group common radio network temporary identifier (RNTI) is used for scrambling of a cyclic redundancy check (CRC) attached to the DCI, a modulation and coding scheme (MCS) index included in the DCI It is characterized in that it is determined based on group common modulation and coding scheme (MCS) related information.

According to the present disclosure, when data is transmitted to a plurality of terminals through a common PDSCH and a unicast PDSCH in a communication system, the present disclosure provides a configuration method for the PDSCHs, thereby enabling more efficient data transmission/reception.

According to the present disclosure, by providing a method for transmitting and receiving PDSCH retransmission of a group common PDSCH, a terminal and a base station can smoothly communicate.

1 is a diagram illustrating a structure of a next-generation mobile communication system according to an embodiment of the present disclosure.

2 is a diagram illustrating a radio protocol structure of a next-generation mobile communication system according to an embodiment of the present disclosure.

3 is a diagram illustrating a basic structure of a time-frequency domain, which is a radio resource domain in which data or a control channel is transmitted in a 5G communication system according to an embodiment of the present disclosure.

4 is a diagram illustrating an example of a slot structure considered in a 5G system according to an embodiment of the present disclosure.

5 is a diagram illustrating an example of setting a bandwidth portion in a 5G communication system according to an embodiment of the present disclosure.

6 is a diagram for explaining carrier aggregation (CA) according to an embodiment of the present disclosure.

7 is a diagram illustrating an example of a cross-carrier scheduling method according to an embodiment of the present disclosure.

8 is a diagram illustrating an example of setting a control resource set (CORESET) of a downlink control channel in a wireless communication system according to an embodiment of the present disclosure.

9 is a diagram illustrating an example of a downlink data channel (Physical Downlink Shared Channel) processing in a wireless communication system according to an embodiment of the present disclosure.

10 is a diagram illustrating an example of a method of obtaining a size of a transport block in a wireless communication system according to an embodiment of the present disclosure.

11 is a diagram illustrating an operation of determining a modulation and coding scheme (mcs)-Table of a terminal according to an embodiment of the present disclosure.

12 is a diagram illustrating a DCI generation operation of a base station according to an embodiment of the present disclosure.

13 is a diagram illustrating an example of a downlink data channel of a terminal according to an embodiment of the present disclosure.

14 is a diagram illustrating an example of a method of obtaining the size of a transport block of a terminal according to an embodiment of the present disclosure.

15 is a diagram illustrating an example of a downlink data channel of a terminal according to an embodiment of the present disclosure.

16 is a diagram illustrating a structure of a terminal according to an embodiment of the present disclosure.

17 is a diagram illustrating a structure of a base station according to an embodiment of the present disclosure.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

In describing the embodiments, descriptions of technical contents that are well known in the technical field to which the present invention pertains and are not directly related to the present invention will be omitted. This is to more clearly convey the gist of the present invention by omitting unnecessary description.

For the same reason, some components are exaggerated, omitted, or schematically illustrated in the accompanying drawings. In addition, the size of each component does not fully reflect the actual size. In each figure, the same or corresponding elements are assigned the same reference numerals.

Advantages and features of the present invention and methods of achieving them will become apparent with reference to the embodiments described below in detail in conjunction with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, but may be implemented in various different forms, and only the embodiments of the present disclosure make the present disclosure complete, and common knowledge in the art to which the present invention pertains It is provided to fully inform those who have the scope of the invention, and the present disclosure is only defined by the scope of the claims. Like reference numerals refer to like elements throughout.

At this time, it will be understood that each block of the flowchart diagrams and combinations of the flowchart diagrams may be performed by computer program instructions. These computer program instructions may be embodied in a processor of a general purpose computer, special purpose computer, or other programmable data processing equipment, such that the instructions performed by the processor of the computer or other programmable data processing equipment are not described in the flowchart block(s). It creates a means to perform functions. These computer program instructions may also be stored in a computer-usable or computer-readable memory that may direct a computer or other programmable data processing equipment to implement a function in a particular manner, and thus the computer-usable or computer-readable memory. It may also be possible for the instructions stored in the flowchart block(s) to produce an article of manufacture containing instruction means for performing the function described in the flowchart block(s). The computer program instructions may also be mounted on a computer or other programmable data processing equipment, such that a series of operational steps are performed on the computer or other programmable data processing equipment to create a computer-executed process to create a computer or other programmable data processing equipment. It may also be possible for instructions to perform the processing equipment to provide steps for performing the functions described in the flowchart block(s).

Additionally, each block may represent a module, segment, or portion of code that includes one or more executable instructions for executing specified logical function(s). It should also be noted that in some alternative implementations it is also possible for the functions recited in the blocks to occur out of order. For example, two blocks shown one after another may in fact be performed substantially simultaneously, or it may be possible that the blocks are sometimes performed in a reverse order according to a corresponding function.

At this time, the term '~ unit' used in this embodiment means software or hardware components such as FPGA (Field Programmable Gate Array) or ASIC (Application Specific Integrated Circuit), and '~ unit' performs certain roles do. However, '-part' is not limited to software or hardware. '~unit' may be configured to reside on an addressable storage medium or may be configured to refresh one or more processors. Accordingly, according to some embodiments, '~ part' refers to components such as software components, object-oriented software components, class components, and task components, and processes, functions, properties, and programs. Includes procedures, subroutines, segments of program code, drivers, firmware, microcode, circuitry, data, databases, data structures, tables, arrays, and variables. The functions provided in the components and '~ units' may be combined into a smaller number of components and '~ units' or further separated into additional components and '~ units'. In addition, components and '~ units' may be implemented to play one or more CPUs in a device or secure multimedia card. Also, according to some embodiments, '~ unit' may include one or more processors.

Hereinafter, the operating principle of the present invention will be described in detail with reference to the accompanying drawings. In the following description of the present invention, if it is determined that a detailed description of a related well-known function or configuration may unnecessarily obscure the gist of the present invention, the detailed description thereof will be omitted. In addition, the terms described below are terms defined in consideration of functions in the present invention, which may vary according to intentions or customs of users and operators. Therefore, the definition should be made based on the content throughout this specification. Hereinafter, the base station is a subject performing resource allocation of the terminal, and may be at least one of a gNode B, an eNode B, a Node B, a base station (BS), a radio access unit, a base station controller, or a node on a network. The terminal may include a user equipment (UE), a mobile station (MS), a cellular phone, a smart phone, a computer, or a multimedia system capable of performing a communication function. Of course, it is not limited to the above example. Hereinafter, the present disclosure describes a technique for a terminal to receive broadcast information from a base station in a wireless communication system. The present disclosure relates to a communication technique that converges a 5 ^th generation (5G) communication system for supporting a higher data rate after a 4 ^th generation (4G) system with an Internet of Things (IoT) technology, and a system thereof. The present disclosure provides intelligent services (eg, smart home, smart building, smart city, smart car or connected car, healthcare, digital education, retail business, security and safety related services, etc.) based on 5G communication technology and IoT-related technology. ) can be applied to

A term referring to broadcast information, a term referring to control information, a term related to communication coverage, a term referring to a state change (eg, an event), and network entities used in the following description Terms referring to, terms referring to messages, terms referring to components of an apparatus, and the like are exemplified for convenience of description. Accordingly, the present invention is not limited to the terms described below, and other terms having equivalent technical meanings may be used.

For convenience of description below, some terms and names defined in 3GPP LTE (3rd generation partnership project long term evolution) standard or 3GPP NR (new radio or new radio access technology) may be used. However, the present invention is not limited by the above terms and names, and may be equally applied to systems conforming to other standards.

1 is a diagram illustrating a structure of a next-generation mobile communication system according to an embodiment of the present disclosure.

1, the radio access network of the next-generation mobile communication system (hereinafter NR or 5g) is a next-generation base station (new radio node B, hereinafter, NR gNB or NR base station) 110 and a next-generation radio core network (new radio core network, NR CN) 105 . A new radio user equipment (NR UE or terminal) 115 may access an external network through the NR gNB 110 and the NR CN 105 .

In FIG. 1 , the NR gNB 110 may correspond to an evolved node B (eNB) of the existing LTE system. The NR gNB is connected to the NR UE 115 through a radio channel, and can provide a more improved service than the existing Node B. In the next-generation mobile communication system, all user traffic may be serviced through a shared channel. Accordingly, an apparatus for scheduling by collecting status information such as buffer status, available transmission power status, and channel status of UEs is required, and the NR gNB 110 may be responsible for this. One NR gNB can control multiple cells. In a next-generation mobile communication system, a bandwidth greater than or equal to the current maximum bandwidth may be applied to implement ultra-high-speed data transmission compared to current LTE. In addition, beamforming technology may be additionally grafted by using orthogonal frequency division multiplexing (OFDM) as a radio access technology. In addition, an adaptive modulation & doding (AMC) scheme for determining a modulation scheme and a channel coding rate according to the channel state of the terminal may be applied.

The NR CN 105 may perform functions such as mobility support, bearer establishment, and QoS establishment. The NR CN is a device in charge of various control functions as well as a mobility management function for the terminal, and can be connected to a plurality of base stations. In addition, the next-generation mobile communication system may be interlocked with the existing LTE system, and the NR CN may be connected to the MME 125 through a network interface. The MME may be connected to the existing base station, the eNB 130 .

2 is a diagram illustrating a radio protocol structure of a next-generation mobile communication system according to an embodiment of the present disclosure.

Referring to FIG. 2, radio protocols of the next-generation mobile communication system are NR service data adaptation protocol (SDAP) 201 and 245, NR PDCP 205, 240, and NR RLC ( 210, 235), NR MAC (215, 230), and NR PHY (220, 225).

The main functions of the NR SDAPs 201 and 245 may include some of the following functions.

- Transfer of user plane data

- Mapping between a QoS flow and a DRB for both DL and UL for uplink and downlink

- Marking QoS flow ID in both DL and UL packets for uplink and downlink

- A function of mapping a reflective QoS flow to a data bearer for uplink SDAP PDUs (reflective QoS flow to DRB mapping for the UL SDAP PDUs).

For the SDAP layer device, the UE uses the header of the SDAP layer device for each PDCP layer device or for each bearer or for each logical channel as a radio resource control (RRC) message or whether to use the function of the SDAP layer device can be set. When the SDAP header is set, the terminal reflects the non-access stratum (NAS) quality of service (QoS) reflection setting 1-bit indicator (NAS reflective QoS) of the SDAP header and the access layer (access stratum, AS) QoS reflection As a set 1-bit indicator (AS reflective QoS), it can be instructed so that the UE can update or reconfigure mapping information for uplink and downlink QoS flows and data bearers. The SDAP header may include QoS flow ID information indicating QoS. The QoS information may be used as data processing priority, scheduling information, etc. to support a smooth service.

The main functions of the NR PDCPs 205 and 240 may include some of the following functions.

- Header compression and decompression (ROHC only)

- Transfer of user data

- In-sequence delivery of upper layer PDUs

- Out-of-sequence delivery of upper layer PDUs

- Order reordering function (PDCP PDU reordering for reception)

- Duplicate detection of lower layer SDUs

- Retransmission of PDCP SDUs

- Encryption and decryption function (Ciphering and deciphering)

- Timer-based SDU discard in uplink.

In the above description, the reordering function of the NR PDCP device may refer to a function of reordering PDCP PDUs received from a lower layer in order based on a PDCP sequence number (SN). The reordering function of the NR PDCP device may include a function of delivering data to a higher layer in the rearranged order, and may include a function of directly delivering data without considering the order, It may include a function of recording PDCP PDUs, a function of reporting a status on the lost PDCP PDUs to the transmitting side, and a function of requesting retransmission of the lost PDCP PDUs. .

The main functions of the NR RLCs 210 and 235 may include some of the following functions.

- Data transfer function (Transfer of upper layer PDUs)

- In-sequence delivery of upper layer PDUs

- Out-of-sequence delivery of upper layer PDUs

- ARQ function (Error Correction through ARQ)

- Concatenation, segmentation and reassembly of RLC SDUs

- Re-segmentation of RLC data PDUs

- Reordering of RLC data PDUs

- Duplicate detection

- Protocol error detection

- RLC SDU discard function (RLC SDU discard)

- RLC re-establishment function (RLC re-establishment)

In the above description, in-sequence delivery of the NR RLC device may refer to a function of sequentially delivering RLC SDUs received from a lower layer to a higher layer. When one RLC SDU is originally divided into several RLC SDUs and received, the in-sequence delivery function of the NR RLC device may include a function of reassembling it and delivering it.

In-sequence delivery of the NR RLC device may include a function of rearranging the received RLC PDUs based on an RLC sequence number (SN) or a PDCP sequence number (SN), and may be lost by rearranging the order It may include a function of recording the lost RLC PDUs, a function of reporting a status on the lost RLC PDUs to the transmitting side, and a function of requesting retransmission of the lost RLC PDUs. have.

The in-sequence delivery function of the NR RLC (210, 235) device may include a function of sequentially delivering only RLC SDUs before the lost RLC SDU to a higher layer when there is a lost RLC SDU. can In addition, the in-sequence delivery function of the NR RLC device includes a function of sequentially delivering all RLC SDUs received before the timer starts to a higher layer if a predetermined timer expires even if there are lost RLC SDUs. can do. In addition, the in-sequence delivery function of the NR RLC device may include a function of sequentially delivering all RLC SDUs received so far to a higher layer if a predetermined timer expires even if there are lost RLC SDUs. .

The NR RLC (210, 235) device may process the RLC PDUs in the order in which they are received, regardless of the sequence number (Out of sequence delivery), and deliver it to the NR PDCP (205, 240) device.

When the NR RLC (210, 235) device receives a segment, it receives the segments stored in the buffer or to be received later, reconstructs it into one complete RLC PDU, and then delivers it to the NR PDCP device. have.

The NR RLC layer may not include a concatenation function, and may perform a function in the NR MAC layer or may be replaced with a multiplexing function of the NR MAC layer.

In the above description, the out-of-sequence delivery function of the NR RLC device may refer to a function of directly delivering RLC SDUs received from a lower layer to a higher layer regardless of order. The out-of-sequence delivery function of the NR RLC device may include a function of reassembling and delivering when one RLC SDU is originally divided into several RLC SDUs and received. The out of sequence delivery function of the NR RLC device may include a function of storing the RLC SN or PDCP SN of the received RLC PDUs and arranging the order to record the lost RLC PDUs.

The NR MACs 215 and 230 may be connected to several NR RLC layer devices configured in one terminal, and the main function of the NR MAC may include some of the following functions.

- Mapping function (Mapping between logical channels and transport channels)

- Multiplexing/demultiplexing of MAC SDUs

- Scheduling information reporting function

- HARQ function (Error correction through HARQ (hybrid automatic repeat request))

- Priority handling between logical channels of one UE

- Priority handling between UEs by means of dynamic scheduling

- MBMS service identification

- Transport format selection

- Padding function

The NR PHY layers 220 and 225 channel-code and modulate the upper layer data, make an OFDM symbol and transmit it to the radio channel, or demodulate the OFDM symbol received through the radio channel, decode the channel, and deliver the operation to the upper layer. can be done

Hereinafter, the frame structure of the 5G system will be described in more detail with reference to the drawings.

3 is a diagram illustrating a basic structure of a time-frequency domain, which is a radio resource domain in which data or a control channel is transmitted in a 5G system.

3 , the horizontal axis represents the time domain, and the vertical axis represents the frequency domain. The basic unit of resources in the time and frequency domain is a resource element (RE) 301 as one orthogonal frequency division multiplexing (OFDM) symbol 302 on the time axis and one subcarrier (subcarrier) 303 on the frequency axis. can be defined. in the frequency domain

(for example, 12) consecutive REs may constitute one resource block (RB) 304 .

4 is a diagram illustrating an example of a slot structure considered in a 5G system.

4 shows an example of a structure of a frame 400 , a subframe 401 , and a slot 402 . One frame 400 may be defined as 10 ms. One subframe 401 may be defined as 1 ms, and therefore, one frame 400 may consist of a total of 10 subframes 401 . One slot (402, 403) may be defined as 14 OFDM symbols (that is, the number of symbols per slot (

)=14). One subframe 401 may consist of one or a plurality of slots 402 and 403, and the number of slots 402 and 403 per one subframe 401 is a set value μ(404, 405) for the subcarrier spacing. ) may vary depending on In the example of FIG. 4 , a case of μ=0 (404) and a case of μ=1 (405) are illustrated as subcarrier spacing setting values. When μ=0 (404), one subframe 401 may consist of one slot 402, and when μ=1 (405), one subframe 401 may consist of two slots 403. can be composed of That is, the number of slots per subframe (

) may vary, and accordingly, the number of slots per frame (

) may be different. According to each subcarrier spacing setting μ

and

may be defined in Table 1 below.

[Table 1]

Next, a bandwidth part (BWP) setting in the 5G communication system will be described in detail with reference to FIG. 5 .

5 is a diagram illustrating an example of setting a bandwidth portion in a 5G communication system.

5 shows an example in which the UE bandwidth 500 is set to two bandwidth parts, that is, a bandwidth part #1 (BWP#1) 501 and a bandwidth part #2 (BWP#2) 502. has been The base station may set one or a plurality of bandwidth portions to the terminal, and may set information as shown in Table 2 below for each bandwidth portion, for example. The following BWP may be referred to as BWP setting information.

[Table 2]

Of course, it is not limited to the above example, and in addition to the configuration information, various parameters related to the bandwidth portion may be configured in the terminal. The information may be transmitted from the base station to the terminal through higher layer signaling, for example, RRC signaling. At least one bandwidth portion among the set one or a plurality of bandwidth portions may be activated. Whether to activate the set bandwidth portion may be semi-statically transmitted from the base station to the terminal through RRC signaling or may be dynamically transmitted through downlink control information (DCI).

According to some embodiments, the terminal before the RRC connection may receive an initial bandwidth portion (initial BWP) for the initial connection from the base station through a master information block (MIB). More specifically, the UE may transmit a PDCCH for reception of system information (remaining system information; RMSI or system information block 1; may correspond to SIB1) required for initial access through the MIB in the initial access step. Setting information for a control resource set (CORESET) and a search space may be received. The control resource set and search space set by the MIB may be regarded as an identifier (identity, ID) 0, respectively. The base station may notify the terminal of configuration information such as frequency allocation information, time allocation information, and numerology for the control resource set #0 through the MIB. In addition, the base station may notify the terminal through the MIB of configuration information on the monitoring period and occasion for the control resource set #0, that is, configuration information on the search space #0. The UE may regard the frequency domain set as the control resource set #0 obtained from the MIB as an initial bandwidth portion for initial access. In this case, the identifier (ID) of the initial bandwidth portion may be regarded as 0.

The configuration of the bandwidth part supported by the 5G may be used for various purposes.

According to some embodiments, when the bandwidth supported by the terminal is smaller than the system bandwidth, this may be supported through the bandwidth part setting. For example, when the base station sets the frequency position (setting information 2) of the bandwidth portion to the terminal, the terminal can transmit/receive data at a specific frequency location within the system bandwidth.

Also, according to some embodiments, the base station may set a plurality of bandwidth portions to the terminal for the purpose of supporting different numerologies. For example, in order to support both data transmission and reception using a subcarrier interval of 15 kHz and a subcarrier interval of 30 kHz to a certain terminal, two bandwidth portions may be set to a subcarrier interval of 15 kHz and 30 kHz, respectively. Different bandwidth portions may be frequency division multiplexed, and when data is transmitted and received at a specific subcarrier interval, a bandwidth portion set for the corresponding subcarrier interval may be activated.

Also, according to some embodiments, for the purpose of reducing power consumption of the terminal, the base station may set a bandwidth portion having different sizes of bandwidths to the terminal. For example, when the terminal supports a very large bandwidth, for example, a bandwidth of 100 MHz and always transmits and receives data using the corresponding bandwidth, very large power consumption may occur. In particular, monitoring an unnecessary downlink control channel with a large bandwidth of 100 MHz in a situation without traffic may be very inefficient in terms of power consumption. For the purpose of reducing power consumption of the terminal, the base station may set a relatively small bandwidth portion for the terminal, for example, a bandwidth portion of 20 MHz. In a situation in which there is no traffic, the terminal may perform a monitoring operation in the 20 MHz bandwidth portion, and when data is generated, it may transmit/receive data in the 100 MHz bandwidth portion according to the instruction of the base station.

In the method of setting the bandwidth part, terminals before RRC connection (connected) may receive configuration information for the initial bandwidth part through the MIB in the initial access step. More specifically, the UE may receive a control resource set (CORESET) for a downlink control channel through which DCI scheduling SIB can be transmitted from the MIB of a physical broadcast channel (PBCH). The bandwidth of the control resource set set as the MIB may be regarded as an initial bandwidth portion, and the terminal may receive the PDSCH through which the SIB is transmitted through the configured initial bandwidth portion. The initial bandwidth portion may be utilized for other system information (OSI), paging, and random access in addition to the purpose of receiving the SIB.

6 is a diagram for explaining carrier aggregation (CA) according to an embodiment of the present disclosure.

Referring to FIG. 6 , when CA is configured ( 600 ), a primary cell (PCell) and a secondary cell (SCell) may be configured in the terminal.

PCell is included in PCC (primary component carrier), RRC connection establishment/re-establishment, measurement, mobility procedure, random access procedure and selection, system information acquisition, initial random access, security key change and non-access stratum (NAS) function etc. can be provided.

Since the UE performs system information monitoring through the PCell, the PCell is not deactivated, and the PCC in the UL is carried through a physical uplink control channel (PUCCH) for transmitting control information. In addition, only one RRC connection is possible between the UE and the PCell, and PDCCH/PDSCH/PUSCH (physical uplink shared channel)/PUCCH transmission is possible. Also, in the secondary cell group, a spcell of a secondary cell group (PSCell) may be configured and operated as the PCell. The operation for the PCell described below may also be performed by the PSCell.

A maximum of 31 SCells can be added, and when additional radio resource provision is required, the SCell can be configured through an RRC message message (eg, dedicated signaling). The RRC message may include a physical cell ID for each cell, and may include a DL carrier frequency (absolute radio frequency channel number: ARFCN). PDCCH/PDSCH/PUSCH transmission is possible through the SCell. Supports dynamic activation and deactivation procedures of SCell for battery conservation of UE through MAC layer.

Cross-carrier scheduling may mean allocating at least one (eg, PDCCH) of all L1 control channels or L2 control channels for at least one other CC (component carrier) to one CC. A carrier indicator field (CIF) may be used to transmit data information of another CC through the PDCCH of one CC.

Resources (PDSCH, PUSCH) for data transmission of the CC or resources (PDSCH, PUSCH) for data transmission of another CC may be allocated through control information transmitted through the PDCCH of one CC.

The n-bit CIF is added to the DCI format by applying the cross-carrier scheduling, the bit size may vary according to the higher layer configuration or the DCI format, and the position of the CIF in the DCI format may be fixed.

7 is a diagram illustrating an example of a cross-carrier scheduling method according to an embodiment of the present disclosure.

Referring to 710 of FIG. 7 , PDSCH or PUSCH for two CCs may be scheduled through the PDCCH 701 of one CC.

In addition, referring to 720 of FIG. 7 , when a total of four CCs are configured, the PDSCH or PUSCH of each CC may be scheduled using the PDCCHs 721 and 723 of the two CCs.

Each CC may be mapped to a CI (carrier indicator) value for CIF application, which may be transmitted from the base station to the terminal through a dedicated RRC signal as a UE-specific configuration.

Each PDSCH/PUSCH CC may be scheduled from one DL CC. Accordingly, the UE only needs to monitor the PDCCH for the DL CC for each PDSCH/PUSCH CC. The UE may monitor the PDCCH in the DL CC to obtain PUSCH scheduling information in the linked UL carrier. The UE may monitor the PDCCH in the DL CC to obtain PDSCH scheduling information in the linked DL carrier.

8 is a diagram illustrating an example of setting a control area (CORESET) of a downlink control channel in a wireless communication system according to an embodiment of the present disclosure.

Referring to FIG. 8 , in FIG. 8 , there are two control regions (control region #1 (CORESET #1) 801) in a bandwidth part 810 of the terminal on the frequency axis and one slot 820 on the time axis. An example in which #2 (CORESET #2) 802) is set is shown. The control regions 801 and 802 may be set in a specific frequency resource 803 within the entire terminal bandwidth portion 810 on the frequency axis. The control regions 801 and 802 may be set with one or a plurality of OFDM symbols on the time axis, which may be defined as a control resource set duration (804). In the example of FIG. 8 , the control region #1 801 is set to a control region length of two symbols, and the control region #2 802 is set to a control region length of one symbol.

The control region in 5G described above may be configured by the base station through higher layer signaling (eg, system information, MIB, RRC signaling) to the terminal. Setting the control region to the terminal means to provide the terminal with information such as a control region identity, a frequency position of the control region, and a symbol length of the control region. For example, the information in Table 3 may be included.

[Table 3]

The number of CCEs required to transmit the PDCCH may be 1, 2, 4, 8, or 16 according to an aggregation level (AL), and the number of different CCEs is based on link adaptation of the downlink control channel. can be used to implement For example, when AL=L, one downlink control channel may be transmitted through L CCEs. The UE must detect a signal (blind decoding) without knowing information about the downlink control channel, and a search space indicating a set of CCEs is defined for blind decoding. The search space is a set of downlink control channel candidates consisting of CCEs that the UE should attempt to decode on a given aggregation level, and various aggregations that make one bundle with 1, 2, 4, 8, or 16 CCEs Since there is a level, the terminal may have a plurality of search spaces. A search space set may be defined as a set of search spaces in all set aggregation levels.

The search space may be classified into a common search space and a UE-specific search space. A group of terminals or all terminals may search the common search space of the PDCCH in order to receive control information common to cells such as dynamic scheduling for system information or a paging message. For example, the PDSCH scheduling assignment information for transmission of the SIB including the operator information of the cell may be received by examining the common search space of the PDCCH. In the case of the common search space, since terminals of a certain group or all terminals need to receive the PDCCH, it may be defined as a set of promised CCEs. The UE-specific scheduling assignment information for PDSCH or PUSCH may be received by examining the UE-specific search space of the PDCCH. The UE-specific search space may be UE-specifically defined as a function of UE identity and various system parameters.

In 5G, the parameter for the search space for the PDCCH may be set from the base station to the terminal through higher layer signaling (eg, SIB, MIB, RRC signaling). For example, the base station is the number of PDCCH candidates in each aggregation level L, the monitoring period for the search space, the monitoring occasion in symbol units in the slot for the search space, the search space type (common search space or terminal-specific search space), A combination of a DCI format and a radio network temporary identifier (RNTI) to be monitored in the corresponding search space, a control resource set index for monitoring the search space, etc. may be set to the UE. For example, the parameter for the search space for the PDCCH may include, for example, at least a part of information as shown in Table 4 below.

[Table 4]

The base station may set one or a plurality of search space sets to the terminal. According to some embodiments, the base station may set the search space set 1 and the search space set 2 to the terminal. In search space set 1, the UE may be configured to monitor DCI format A scrambled with X-RNTI in the common search space, and in search space set 2, the UE uses DCI format B scrambled with Y-RNTI in the UE-specific search space. can be set to monitor.

According to the configuration information, one or a plurality of search space sets may exist in the common search space or the terminal-specific search space. For example, the search space set #1 and the search space set #2 may be set as the common search space, and the search space set #3 and the search space set #4 may be set as the terminal-specific search space.

In the common search space, a combination of the following DCI format and RNTI may be monitored. Of course, it is not limited to the following examples.

DCI format 0_0/1_0 with CRC (cyclic redundancy check) scrambled by C-RNTI, CS-RNTI, SP-CSI-RNTI, RA-RNTI, TC-RNTI, P-RNTI, SI-RNTI

DCI format 2_0 with CRC scrambled by SFI-RNTI

DCI format 2_1 with CRC scrambled by INT-RNTI

DCI format 2_2 with CRC scrambled by TPC-PUSCH-RNTI, TPC-PUCCH-RNTI

DCI format 2_3 with CRC scrambled by TPC-SRS-RNTI

In the UE-specific search space, a combination of the following DCI format and RNTI may be monitored. Of course, it is not limited to the following examples.

DCI format 0_0/1_0 with CRC scrambled by C-RNTI, CS-RNTI, TC-RNTI

DCI format 1_0/1_1 with CRC scrambled by C-RNTI, CS-RNTI, TC-RNTI

The specified RNTIs may follow the definitions and uses below.

C-RNTI (Cell RNTI): UE-specific PDSCH scheduling purpose

TC-RNTI (Temporary Cell RNTI): UE-specific PDSCH scheduling purpose

CS-RNTI (Configured Scheduling RNTI): semi-statically configured UE-specific PDSCH scheduling purpose

RA-RNTI (Random Access RNTI): Used for scheduling PDSCH in the random access phase

P-RNTI (Paging RNTI): Used for scheduling PDSCH in which paging is transmitted

SI-RNTI (System Information RNTI): Used for scheduling PDSCH in which system information is transmitted

INT-RNTI (Interruption RNTI): Used to indicate whether PDSCH is pucturing

TPC-PUSCH-RNTI (Transmit Power Control for PUSCH RNTI): Used to indicate power control command for PUSCH

TPC-PUCCH-RNTI (Transmit Power Control for PUCCH RNTI): Used to indicate power control command for PUCCH

TPC-SRS-RNTI (Transmit Power Control for SRS RNTI): Used to indicate power control command for SRS

In 5G, the search space of the aggregation level L in the control resource set p and the search space set s may be expressed as in Equation 1 below.

[Equation 1]

The value may correspond to 0 in the case of a common search space.

In the case of a terminal-specific search space, the value may correspond to a value that changes depending on the terminal's identity (C-RNTI or ID set for the terminal by the base station) and the time index.

Accordingly, the terminal may monitor the PDCCH in the control region configured by the base station, and may transmit/receive data based on the received control information.

In the 5G system, scheduling information for uplink data (or physical uplink data channel (PUSCH)) or downlink data (or physical downlink data channel (PDSCH)) may be transmitted from the base station to the terminal through DCI. The UE may monitor a DCI format for fallback and a DCI format for non-fallback for PUSCH or PDSCH. The DCI format for countermeasures may be composed of a fixed field predetermined between the base station and the terminal, and the DCI format for non-prevention may include a configurable field.

DCI may be transmitted through a PDCCH, which is a physical downlink control channel, through channel coding and modulation. A CRC is added to the DCI message payload, and the CRC may be scrambling based on the RNTI corresponding to the identity of the UE. Different RNTIs may be used according to the purpose of the DCI message, for example, UE-specific data transmission, a power control command, or a random access response. That is, the RNTI is not explicitly transmitted, but included in the CRC calculation process and transmitted. Upon receiving the DCI message transmitted on the PDCCH, the UE checks the CRC using the assigned RNTI. If the CRC check result is correct, the UE can know that the message has been transmitted to the UE.

For example, DCI scheduling PDSCH for system information (SI) may be scrambled with SI-RNTI. DCI scheduling a PDSCH for a random access response (RAR) message may be scrambled with an RA-RNTI. DCI scheduling a PDSCH for a paging message may be scrambled with a P-RNTI. DCI notifying a slot format indicator (SFI) may be scrambled with an SFI-RNTI. DCI notifying transmit power control (TPC) may be scrambled with TPC-RNTI. DCI for scheduling UE-specific PDSCH or PUSCH may be scrambled with C-RNTI (cell RNTI).

Meanwhile, in NR, various types of DCI formats may be provided as shown in Table 5 below for efficient reception of control information of the UE.

DCI format	Usage
0_0	Scheduling of PUSCH in one cell
0_1	Scheduling of PUSCH in one cell
0_2	Scheduling of PUSCH in one cell
1_0	Scheduling of PDSCH in one cell
1_1	Scheduling of PDSCH in one cell
1_2	Scheduling of PDSCH in one cell
2_0	Notifying a group of UEs of the slot format
2_1	Notifying a group of UEs of the PRB(s) and OFDM symbol(s) where UE may assume no transmission is intended for the UE
2_2	Transmission of TPC commands for PUCCH and PUSCH
2_3	Transmission of a group of TPC commands for SRS transmissions by one or more UEs

For example, the base station may use DCI format 1_0, DCI format 1_1, or DCI format 1_2 to allocate (scheduling) the PDSCH for one cell to the terminal. As another example, the base station may use DCI format 0_0, DCI format 0_1, or DCI format 0_2 to allocate (scheduling) a PUSCH for one cell to the terminal. DCI format 1_0 is C-RNTI Alternatively, when transmitted together with a CRC scrambled by CS-RNTI, MCS-C-RNTI, or new-RNTI, it may include, for example, at least the information shown in Table 6:

- Identifier for DCI formats(1 bits): Always set to 1 as a DCI format indicator - frequency domain resource assignment (N RBG bits or bits): indicates frequency axis resource allocation, and when DCI format 1_0 is monitored in the UE specific search space is the size of the active DL BWP, otherwise is the size of the initial DL BWP. N RBG is the number of resource block groups. For a detailed method, refer to the frequency axis resource allocation. - time domain resource assignment (0~4 bits): indicates time domain resource assignment of PDSCH. - VRB-to-PRB mapping (1 bit): 0 indicates Non-interleaved, 1 indicates interleaved VRP-to-PRB mapping. - Modulation and coding scheme (5 bits): indicates the modulation order and coding rate used for PDSCH transmission. - New data indicator (1 bit): indicates whether the PDSCH is initial transmission or retransmission depending on whether toggle. - Redundancy version (2 bits): indicates the redundancy version used for PDSCH transmission. - HARQ process number (4 bits): indicates the HARQ process number used for PDSCH transmission. - Downlink assignment index (2 bits): DAI indicator - TPC command for scheduled PUCCH (2 bits): PUCCH power control indicator - PUCCH resource indicator (3 bits): As a PUCCH resource indicator, it indicates one of eight resources configured as a higher layer. - PDSCH-to-HARQ_feedback timing indicator (3 bits): As a HARQ feedback timing indicator, it indicates one of eight feedback timing offsets set as a higher layer.

DCI format 1_1 is transmitted together with CRC scrambled by cell radio network temporary identifier (C-RNTI) or configured scheduling RNTI (CS-RNTI) or MCS-C-RNTI or new-RNTI, for example, at least the table It may include information such as 7.

- Identifier for DCI formats (1 bit): Always set to 1 as a DCI format indicator - Carrier indicator (0 or 3 bits): indicates the CC (or cell) to which the PDSCH allocated by the corresponding DCI is transmitted. - Bandwidth part indicator (0 or 1 or 2 bits): indicates the BWP through which the PDSCH allocated by the corresponding DCI is transmitted. - Frequency domain resource assignment (determining payload according to the frequency axis resource allocation): indicates frequency axis resource allocation, is the size of the active DL BWP. For a detailed method, refer to the frequency axis resource allocation. - Time domain resource assignment (0 ~ 4 bits): indicates time domain resource assignment according to the above description. - VRB-to-PRB mapping (0 or 1 bit): 0 indicates Non-interleaved, 1 indicates interleaved VRP-to-PRB mapping. It is 0 bit when frequency axis resource allocation is set to resource allocation type 0 or when interleaved VRB-to-PRB mapping is not set by an upper layer. - PRB bundling size indicator (0 or 1 bit): When the upper layer parameter prb-BundlingType is not set or is set to 'static', it is 0 bit, and when it is set to 'dynamic', it is 1 bit. - Rate matching indicator (0 or 1 or 2 bits): indicates the rate matching pattern. - ZP CSI-RS trigger (0 or 1 or 2 bits): an indicator for triggering aperiodic ZP CSI-RS. - For transport block 1: - Modulation and coding scheme (5 bits): indicates the modulation order and coding rate used for PDSCH transmission. - New data indicator (1 bit): indicates whether the PDSCH is initial transmission or retransmission depending on whether toggle. - Redundancy version (2 bits): indicates the redundancy version used for PDSCH transmission. - For transport block 2: - Modulation and coding scheme (5 bits): indicates the modulation order and coding rate used for PDSCH transmission. - New data indicator (1 bit): indicates whether the PDSCH is initial transmission or retransmission depending on whether toggle. - Redundancy version (2 bits): indicates the redundancy version used for PDSCH transmission. - HARQ process number (4 bits): indicates the HARQ process number used for PDSCH transmission. - Downlink assignment index (0 or 2 or 4 bits): DAI indicator - TPC command for scheduled PUCCH (2 bits): PUCCH power control indicator - PUCCH resource indicator (3 bits): As a PUCCH resource indicator, it indicates one of eight resources configured as a higher layer. - PDSCH-to-HARQ_feedback timing indicator (3 bits): As a HARQ feedback timing indicator, it indicates one of eight feedback timing offsets set as a higher layer. - Antenna port (4 or 5 or 6 bits): indicates DMRS port and CDM group without data. - Transmission configuration indication (0 or 3 bits): TCI indicator. - SRS request (2 or 3 bits): SRS transmission request indicator - CBG transmission information (0 or 2 or 4 or 6 or 8 bits): an indicator indicating whether to transmit code block groups in the allocated PDSCH. 0 means that the CBG is not transmitted, and 1 means that it is transmitted. - CBG flushing out information (0 or 1 bit): An indicator indicating whether previous CBGs are contaminated. If 0, it means that it may have been contaminated, and if 1, it means that it can be used when receiving retransmission (combinable). - DMRS sequence initialization (0 or 1 bit): DMRS scrambling ID selection indicator

When DCI format 1_2 is transmitted together with CRC scrambled by C-RNTI (cell radio network temporary identifier) or CS-RNTI (configured scheduling RNTI) or MCS-C-RNTI or new-RNTI, for example, at least the table It may include information such as 8.

- Identifier for DCI formats (1 bit): Always set to 1 as a DCI format indicator - Carrier indicator (0 or 1 or 2 or 3 bits): indicates the CC (or cell) to which the PDSCH allocated by the corresponding DCI is transmitted. - Bandwidth part indicator (0 or 1 or 2 bits): indicates the BWP through which the PDSCH allocated by the corresponding DCI is transmitted. - Frequency domain resource assignment (determining payload according to the frequency axis resource allocation): indicates frequency axis resource allocation, is the size of the active DL BWP. For a detailed method, refer to the frequency axis resource allocation. - Time domain resource assignment (0 ~ 4 bits): indicates time domain resource assignment according to the above description. - VRB-to-PRB mapping (0 or 1 bit): 0 indicates Non-interleaved, 1 indicates interleaved VRP-to-PRB mapping. If the vrb-ToPRB-InterleaverForDCI-Format1-2 setting parameter of the upper layer is not set, it is 0 bit. - PRB bundling size indicator (0 or 1 bit): 0 bit if the upper layer parameter prb-BundlingTypeForDCI-Format1-2 is not set or set to 'static', and 1 bit if set to 'dynamic'. - Rate matching indicator (0 or 1 or 2 bits): indicates the rate matching pattern. - ZP CSI-RS trigger (0 or 1 or 2 bits): an indicator for triggering aperiodic ZP CSI-RS. - Modulation and coding scheme (5 bits): indicates the modulation order and coding rate used for PDSCH transmission. - New data indicator (1 bit): indicates whether the PDSCH is initial transmission or retransmission depending on whether toggle. - Redundancy version (0 or 1 or 2 bits): indicates the redundancy version used for PDSCH transmission. - HARQ process number (0 or 1 or 2 or 3 or 4 bits): indicates the HARQ process number used for PDSCH transmission. - Downlink assignment index (0 or 1 or 2 or 4 bits): DAI indicator - TPC command for scheduled PUCCH (2 bits): PUCCH power control indicator - PUCCH resource indicator (0 or 1 or 2 or 3 bits): A PUCCH resource indicator, indicating one of the resources configured as a higher layer. - PDSCH-to-HARQ_feedback timing indicator (0 or 1 or 2 or 3 bits): As a HARQ feedback timing indicator, it indicates one of the feedback timing offsets set as a higher layer. - Antenna port (4 or 5 or 6 bits): indicates DMRS port and CDM group without data. - Transmission configuration indication (0 or 1 or 2 or 3 bits): TCI indicator. - SRS request(0 or 1 or 2 or 3 bits): SRS transmission request indicator - DMRS sequence initialization (0 or 1 bit): DMRS scrambling ID selection indicator - Priority indicator (0 or 1 bit): 0 bit if higher layer priorityIndicatorForDCI-Format1-2 parameter is not set, 1 bit if set

The maximum number of DCIs of different sizes that the UE can receive per slot in the corresponding cell is 4. The maximum number of DCIs of different sizes scrambled with C-RNTI per slot in the cell by the UE is 3. The base station provides the UE with time domain resources for a downlink data channel (PDSCH) and an uplink data channel (PUSCH). Allocation information (eg, may be information configured in the form of a table) may be configured through higher layer signaling (eg, RRC signaling). The base station can set resource allocation information (for example, composed of table-type information) consisting of a maximum of maxNrofDL-Allocations = 16 entries for the PDSCH, and a maximum of maxNrofUL-Allocations = 16 entries for the PUSCH ( Entry), resource allocation information (eg, table-type information) can be set. The time domain resource allocation information includes, for example, the PDCCH-to-PDSCH slot timing (corresponding to the time interval in slot units between the time when the PDCCH is received and the time when the PDSCH scheduled by the received PDCCH is transmitted, denoted by K0) or PDCCH-to-PUSCH slot timing (corresponding to the time interval in slot units between the time when the PDCCH is received and the time when the PUSCH scheduled by the received PDCCH is transmitted, denoted by K2), the PDSCH or PUSCH scheduled within the slot Information on the position and length of the start symbol, the mapping type of PDSCH or PUSCH, etc. may be included. For example, information as shown in Table 9 or Table 10 below may be notified from the base station to the terminal.

[Table 9]

[Table 10]

The base station may notify the UE of one of the entries in the table for the time domain resource allocation information through L1 signaling (eg, DCI) (eg, it may be indicated by the time domain resource allocation field in DCI). The UE may acquire time domain resource allocation information for the PDSCH or PUSCH based on the DCI received from the base station.

Hereinafter, a method of allocating a frequency domain resource for a data channel in a 5G communication system will be described.

In 5G, two types, resource allocation type 0 and resource allocation type 1, are supported as a method of indicating frequency domain resource allocation information for a downlink data channel (PDSCH) and an uplink data channel (PUSCH).

In resource allocation type 0, RB allocation information may be notified from the base station to the terminal in the form of a bitmap for a resource block group (RBG). In this case, the RBG may be composed of a set of consecutive VRBs, and the size P of the RBG is based on a value set as a higher layer parameter (rbg-Size) and a size value of the bandwidth part defined as shown in Table 11 below. can be determined by

[Table 11] Nominal RBG size P

size

the total number of RBGs in bandwidth part i (

) may be defined as follows.

, where

the size of the first RBG is

,

the size of last RBG is

if

and P otherwise,

the size of all other RBGs is P.

Each bit of the bit-sized bitmap may correspond to each RBG. RBGs may be indexed in the order of increasing frequency, starting from the lowest frequency position of the bandwidth part. within the bandwidth

For RBGs, from RBG#0 to RBG#(

) may be mapped from the MSB to the LSB of the RBG bitmap. When a specific bit value in the bitmap is 1, the UE can determine that the RBG corresponding to the bit value is allocated, and when the specific bit value in the bitmap is 0, the RBG corresponding to the bit value is not allocated. can judge

In resource allocation type 1, RB allocation information may be notified from the base station to the terminal as information on the start position and length of the continuously allocated VRBs. In this case, interleaving or non-interleaving may be additionally applied to consecutively allocated VRBs. The resource allocation field of resource allocation type 1 may consist of a resource indication value (RIV), and the RIV is the starting point of the VRB (

) and the length of consecutively allocated RBs (

) may consist of More specifically,

The RIV in the bandwidth part of the size may be defined as follows.

9 is a diagram illustrating an example of downlink data channel processing in a wireless communication system according to an embodiment of the present disclosure.

A scrambling process may be performed for each of one codeword or two codewords ( S901 ). length

a sequence of codewords q with

A scrambling sequence obtained through initialization as in Equation 3

A sequence scrambled through the same process as in Equation 2 using

can be obtained.

The value is set through the upper layer parameter, or otherwise as the cell ID value.

can be determined,

may mean an RNTI associated with PDSCH transmission.

sequence of scrambled bits

and using one of various modulation schemes supported by the wireless communication system.

A modulation symbol sequence with a length of

may be generated (902).

For each layer in v layers

Each modulation symbol may be mapped (903), which represents

same as Table 12 shows the relationship between the number of layers, the number of codewords, and the codeword-layer mapping.

[Table 12]

The modulation symbols mapped to the layer may be mapped to an antenna port as shown in Equation (4).

may be determined by information included in the DCI format (904).

[Equation 4]

completed the above process

Symbols may be mapped to REs that satisfy conditions that can be used for PDSCH transmission among REs in VRBs allocated for transmission (eg, mapping impossible to DM-RS resources, etc.) (905).

VRBs that have completed the above process may be mapped to PRBs through an interleaving mapping method or a non-interleaving mapping method ( 906 ). The mapping method may be indicated through the VRB-to-PRB mapping field in DCI. If there is no indication of the mapping method, it may mean a non-interleaving mapping method.

When a non-interleaving mapping method is used, VRB n may be mapped to PRB n except in specific cases. For example, in the specific case, VRB n of a PDSCH scheduled using DCI format 1_0 through a common search space is PRB

(

may include a case in which the DCI is mapped to the first PRB of the transmitted CORESET).

When the interleaving mapping method is used, RBs in the BWP are

RB bundles are divided into RB bundles, and the RB bundles may be mapped in the manner shown in Table 13.

RBs in BWP

One example of dividing into RB bundles may be as follows. starting point

within the BWP with

A set of RBs is

It is divided into RB bundles, and the RB bundles may be indexed in an increasing order. Here, L _i means a bundle size in BWP i, which may be transmitted to the UE by the higher layer parameter vrb-ToPRB-Interleaver. And, RB bundle 0 is

Consists of RBs, RB bundle

Is

If you are satisfied with

RBs, otherwise it may be composed of L _i RBs. And the remaining RB bundles may be composed of L _i RBs.

[Table 13]

According to an embodiment of the present disclosure, in the 5G NR system, the MCS index for the PDSCH, ie, the modulation order (or method) Qm and the target code rate R, may be determined through the following process.

[How to determine the MCS index table]

DCI with CRC scrambled by C-RNTI, MCS-C-RNTI, TC-RNTI, CS-RNTI, SI-RNTI, RA-RNTI, MSGB-RNTI, or P-RNTI (e.g., DCI format 1_0, DCI format 1_1, or DCI format 1_2) including PDCCH (PDCCH with DCI format 1_0, format 1_1, or format 1_2 with CRC scrambled by C-RNTI, MCS-C-RNTI, TC-RNTI, CS-RNTI, For PDSCH scheduled through SI-RNTI, RA-RNTI, MSGB-RNTI, or P-RNTI), or without corresponding PDCCH transmission, using the PDSCH configuration SPS-Config (or SPS configuration) provided in the upper layer For the scheduled PDSCH,

(a) When the upper layer parameter mcs-Table given by PDSCH-Config is set to 'qam256', and the PDSCH is scheduled by the PDCCH of DCI format 1_1 with CRC scrambled by C-RNTI (if the higher In layer parameter mcs-Table given by PDSCH-Config is set to 'qam256', and the PDSCH is scheduled by a PDCCH with DCI format 1_1 with CRC scrambled by C-RNTI), the UE determines the modulation order Qm and the target code rate R To do this, the MCS index I _MCS value of [Table 15] can be used.

(b) the condition of (a) is not established, and the UE is not configured by MCS-C-RNTI (UE is not configured with MCS-C-RNTI), higher layer parameter mcs given by PDSCH-Config -Table is set to 'qam64LowSE', and when the PDSCH is scheduled by the PDCCH in the UE-Specific search space with the CRC scrambled by the C-RNTI (if the UE is not configured with MCS) -C-RNTI, the higher layer parameter mcs-Table given by PDSCH-Config is set to 'qam64LowSE', and the PDSCH is scheduled by a PDCCH with a DCI format other than DCI format 1_2 in a UE-specific search space with CRC scrambled by C-RNTI), the UE may use the MCS index I _MCS value of [Table 16] to determine the modulation order Qm and the target code rate R.

(c) The conditions of (a) and (b) do not hold, and the UE is set by MCS-C-RNTI, and the PDSCH is scheduled by the PDCCH to which the CRC scrambled by the MCS-C-RNTI is applied. In this case (if the UE is configured with MCS-C-RNTI, and the PDSCH is scheduled by a PDCCH with CRC scrambled by MCS-C-RNTI), the UE determines the modulation order Qm and the target code rate R [Table 16] MCS index I _MCS value can be used.

(d) The conditions of (a), (b), (c) do not hold, and the UE is not set by the upper layer parameter mcs-Table given by SPS-Config, and the upper layer given by PDSCH-Config Parameter mcs-Table was set to 'qam256' (if the UE is not configured with the higher layer parameter mcs-Table given by SPS-Config, and the higher layer parameter mcs-Table given by PDSCH-Config is set to 'qam256 '),

(d-1) PDSCH is scheduled by PDCCH of DCI format 1_1 to which CRC scrambled by CS-RNTI is applied (if the PDSCH is scheduled by a PDCCH with DCI format 1_1 with CRC scrambled by CS-RNTI or),

(d-2) When the PDSCH is scheduled without the corresponding PDCCH transmission using the SPS-Config,

The UE may use the MCS index I _MCS value of [Table 15] to determine the modulation order Qm and the target code rate R.

(e) When the conditions of (a), (b), (c), (d) do not hold, and the upper layer parameter mcs-Table given by the UE SPS-Config is set to qam64LowSE (if the UE is configured with the higher layer parameter mcs-Table given by SPS-Config set to 'qam64LowSE'),

(e-1) PDSCH is scheduled by PDCCH to which CRC scrambled by CS-RNTI is applied (if the PDSCH is scheduled by a PDCCH with CRC scrambled by CS-RNTI or),

(e-2) when the PDSCH is scheduled without corresponding PDCCH transmission using SPS-Config (if the PDSCH is scheduled without corresponding PDCCH transmission using SPS-Config,),

The UE may use the MCS index I _MCS value of [Table 16] to determine the modulation order Qm and the target code rate R.

(f) When the conditions of (a), (b), (c), (d), and (e) do not hold, the UE determines the modulation order Qm and the target code rate R of [Table 14]. MCS index I _MCS value can be used.

MCS Index I MCS	Modulation Order Qm	Target code rate [R x 1024]	Spectral efficiency
0	2	120	0.2344
One	2	157	0.3066
2	2	193	0.3770
3	2	251	0.4902
4	2	308	0.6016
5	2	379	0.7402
6	2	449	0.8770
7	2	526	1.0273
8	2	602	1.1758
9	2	679	1.3262
10	4	340	1.3281
11	4	378	1.4766
12	4	434	1.6953
13	4	490	1.9141
14	4	553	2.1602
15	4	616	2.4063
16	4	658	2.5703
17	6	438	2.5664
18	6	466	2.7305
19	6	517	3.0293
20	6	567	3.3223
21	6	616	3.6094
22	6	666	3.9023
23	6	719	4.2129
24	6	772	4.5234
25	6	822	4.8164
26	6	873	5.1152
27	6	910	5.3320
28	6	948	5.5547
29	2	reserved
30	4	reserved
31	6	reserved

MCS Index I MCS	Modulation Order Qm	Target code rate [R x 1024]	Spectral efficiency
0	2	120	0.2344
One	2	193	0.3770
2	2	308	0.6016
3	2	449	0.8770
4	2	602	1.1758
5	4	378	1.4766
6	4	434	1.6953
7	4	490	1.9141
8	4	553	2.1602
9	4	616	2.4063
10	4	658	2.5703
11	6	466	2.7305
12	6	517	3.0293
13	6	567	3.3223
14	6	616	3.6094
15	6	666	3.9023
16	6	719	4.2129
17	6	772	4.5234
18	6	822	4.8164
19	6	873	5.1152
20	8	682.5	5.3320
21	8	711	5.5547
22	8	754	5.8906
23	8	797	6.2266
24	8	841	6.5703
25	8	885	6.9141
26	8	916.5	7.1602
27	8	948	7.4063
28	2	reserved
29	4	reserved
30	6	reserved
31	8	reserved

MCS Index I MCS	Modulation Order Qm	Target code rate [R x 1024]	Spectral efficiency
0	2	30	0.0586
One	2	40	0.0781
2	2	50	0.0977
3	2	64	0.1250
4	2	78	0.1523
5	2	99	0.1934
6	2	120	0.2344
7	2	157	0.3066
8	2	193	0.3770
9	2	251	0.4902
10	2	308	0.6016
11	2	379	0.7402
12	2	449	0.8770
13	2	526	1.0273
14	2	602	1.1758
15	4	340	1.3281
16	4	378	1.4766
17	4	434	1.6953
18	4	490	1.9141
19	4	553	2.1602
20	4	616	2.4063
21	6	438	2.5664
22	6	466	2.7305
23	6	517	3.0293
24	6	567	3.3223
25	6	616	3.6094
26	6	666	3.9023
27	6	719	4.2129
28	6	772	4.5234
29	2	reserved
30	4	reserved
31	6	reserved

10 is a diagram illustrating an example of a method of obtaining a size (transport block size, TBS) of a transport block in a wireless communication system according to an embodiment of the present disclosure. It is possible to obtain (determine, or calculate) the number of REs (N _RE ) of (1001). The UE is the number of REs allocated to PDSCH mapping in one PRB in the allocated resource.

can be obtained (calculated).

Is

can be calculated as From here,

is 12,

may indicate the number of OFDM symbols allocated to the PDSCH.

is the number of REs of DMRSs of the same CDM group within one PRB.

is the number of REs occupied by the overhead in the PRB as long as it is set by higher-order signaling, and may be set to one of 0, 6, 12, or 18 (if not set as higher-order signaling, it may be set to 0).

And, the total number of REs allocated to the PDSCH

can be calculated.

Is

is calculated based on

indicates the number of PRBs allocated to the UE.

The value can be calculated as above. Alternatively, information including the number of all cases that can be set as the value of N _RE (for example, it may be configured in the form of at least one or more tables) is stored,

,

,

,

,

In the stored information (eg, table) through at least one parameter value of

A value may be obtained.

And, the number of temporary information bits

can be obtained (computed) (1002). For example, the number of temporary information bits N _info is

can be calculated as Here, R denotes a code rate, Qm denotes a modulation order, and the information includes modulation and coding scheme (MCS) information included in control information (eg, DCI, RRC configuration information, etc.). can be determined based on Specifically, information (eg, an MCS index table of Tables 12, 13, 14, etc.) previously agreed on for the code rate and the modulation order may be used, and the code rate and the modulation order are the MCS information and the previously agreed upon order. It can be determined based on the available information. v may mean the number of allocated layers.

The value is calculated as above or information including the number of all cases (eg, in the form of at least one or more tables) is stored, and the stored information is stored through at least one parameter value among R, Qm, and v from information

A value may be obtained.

The terminal acquired (calculated)

A value of 3824 can be compared with the value of 3824 (1003).

different methods depending on whether the value of is less than or equal to 3824

and TBS may be obtained (computed) (1004).

In case of

Wow

through the formula of

can be calculated.

The value is calculated as above, or information about the number of all cases (eg, at least one table) is stored,

In the stored information through at least one parameter value of , n

A value may be obtained. TBS in Table 17

of values not less than

can be determined as the closest value to .

[Table 17]

In case of

Wow

through the formula of

can be calculated.

The value is calculated as above or information about the number of all cases (eg, at least one table) is stored,

, in the stored table through at least one parameter value of n

A value may be obtained. TBS

It can be determined through the value and the pseudo code included in Table 18 or another type of pseudo code that produces the same result. Or, the TBS stores information on the number of all cases (eg, at least one or more tables), R,

A TBS value may be obtained from the stored information through at least one parameter value among , C .

[Table 18]

The maximum data rate supported by the UE in the NR system may be determined through Equation (6).

[Equation 6]

In Equation 6, J is the number of carriers bundled by frequency aggregation, Rmax = 948/1024,

is the maximum number of layers,

is the maximum modulation order,

is the scaling exponent,

may mean a subcarrier spacing. the terminal

can be reported by setting it to one of 1, 0.8, 0.75, or 0.4,

can be given as in Table 19.

[Table 19]

is the average OFDM symbol length,

Is

can be calculated as

is the maximum number of RBs in BW(j).

As an overhead value, it may be given as 0.14 in the downlink of FR1 (band below 6 GHz) and 0.18 in the uplink, and as 0.08 in the downlink of FR2 (band above 6 GHz) and 0.10 in the uplink. For example, through Equation 6, the maximum data rate in downlink in a cell having a 100 MHz frequency bandwidth at a 30 kHz subcarrier interval may be as shown in Table 20 below.

[Table 20]

Meanwhile, the actual data rate representing the actual data transmission efficiency may be a value obtained by dividing the amount of transmitted data by the data transmission time. That is, it may be a value obtained by dividing the TBS in one TB transmission or the sum of two TBSs in two transmissions by a transmission time interval (TTI) length. The maximum actual downlink data rate in a cell having a 30 kHz subcarrier interval and a 100 MHz frequency bandwidth may be determined as shown in Table 21 below according to the number of allocated PDSCH symbols.

[Table 21]

Referring to the maximum data rate supported by the terminal as shown in Table 20 and the actual data rate according to the assigned TBS as shown in Table 21, there is a case where the actual data rate is greater than the maximum data rate supported by the terminal according to scheduling information. that can be checked

In a wireless communication system and an NR system, the data rate supportable of the terminal may be determined (calculated, obtained) between the base station and the terminal using the maximum frequency band, the maximum modulation order, the maximum number of layers, etc. supported by the terminal. However, the data rate supportable by the terminal may be different from the actual data rate calculated based on TBS and TTI, and in some cases, the base station transmits data having a TBS larger than the data rate supportable by the terminal to the terminal. can happen

According to an embodiment of the present disclosure, the base station may transmit data to the terminal in a 1:1 relationship (uni-cast) or may transmit data in a 1:N relationship (multi-cast, group-cast, broad -cast, etc.).

According to an embodiment of the present disclosure, a DCI to which a scrambled CRC (CRC generated using DCI information) is attached based on a group-common RNTI (RNTI) is a group-common PDCCH (PDCCH). can be transmitted through The DCI may schedule a group-common PDSCH (PDSCH). In this case, the RNTI used in Equation 3 of step 901 may be a group-common RNTI (RNTI), and the same value may be set for the group-common RNTI for the terminals of the group. Meanwhile, the group common RNTI of the present disclosure may be a newly defined RNTI for group communication, or an RNTI configured to be used for group communication among RNTIs configured in the terminal.

According to an embodiment of the present disclosure, a DCI-specific PDCCH (UE) to which a scrambled CRC (CRC generated using DCI information) is attached based on a UE-specific RNTI (eg, C-RNTI) per UE. -specific PDCCH). The DCI may schedule a group-common PDSCH (PDSCH). In this case, the RNTI used in Equation 3 of step 901 may be a group-common RNTI (RNTI), and the same value may be set for the terminals of the group. According to , the base station may configure an mcs-Table (eg, Table 14, Table 15, or Table 16) for group-common PDSCH (PDSCH) transmission to the terminal. Hereinafter, in the present disclosure, information on at least one modulation order and target code rate that can be determined according to at least one MCS index value may be referred to as mcs-Table information, but in other terms (eg, MCS-related information). It is self-evident that it can be called mcs-Table (mcs-Table or group common mcs-Table for group communication) for group common PDSCH (group-common PDSCH) transmission configured in the terminal is mcs-Table (or UE- It may be set separately from the specific mcs-Table). For example, the mcs-Table for group common PDSCH transmission may be defined (or designed) or configured in consideration of lower performance than the mcs-Table for unicast PDSCH. However, an embodiment of the present disclosure is not limited thereto, and the mcs-Table for group common PDSCH transmission may include at least one or at least a part of mcs-Table entries configured for unicast PDSCH.

According to an embodiment of the present disclosure, the mcs-Table configuration for group-common PDSCH (PDSCH) transmission may be included in the PDSCH configuration parameter in the BWP configuration parameter and configured for each BWP.

Specifically, configuration information for downlink BWP (BWP-Downlink) and configuration information for uplink BWP (BWP-Uplink) may be configured in the terminal. The downlink BWP may include configuration information for a downlink common BWP (BWP-DownlinkCommon) and a downlink dedicated BWP (BWP-DownlinkDedicated). The downlink common BWP is a cell-specific BWP, and the downlink common BWP configuration information may include parameters commonly applied to terminals located in the cell. The downlink-specific BWP is a UE-specific BWP, and the downlink-specific BWP configuration information may include a UE-specific (dedicated) parameter. Meanwhile, in the present disclosure, the BWP including the group common PDSCH may be referred to as a group common BWP. That is, the group common BWP may mean a BWP used for 1: multiple communication, such as multicast or broadcast. The group common BWP may be set in the terminal as a BWP separate from the previously configured BWP (legacy BWP), or some frequency resources of the BWP configured in the terminal may be set in the terminal as a group common BWP.

When configured in the terminal as a BWP separate from the legacy BWP, configuration information for the group common BWP is included in the downlink common BWP, or configuration information for the group common BWP may be defined separately. The configuration information for the group common BWP may include information on the group common PDCCH region and information on the group common PDSCH region.

When a specific frequency resource among BWPs set in the terminal is set in the terminal as the group common BWP, for example, the terminal may use all or part of the downlink common BWP as the group common BWP. Alternatively, some BWPs or frequency resources among a plurality of BWPs set in the terminal may be used as the group common BWP.

Therefore, according to an embodiment of the present disclosure, when the group common BWP is set as a BWP separate from the BWP of the terminal, or when a specific frequency resource among BWPs set in the terminal is set as the group common BWP, the group common BWP setting information The configuration for the mcs-Table may be included in the PDSCH configuration information included in .

According to an embodiment of the present disclosure, the mcs-Table configuration for group-common PDSCH (group-common PDSCH) transmission is included in the group common frequency resource configuration parameter for group-common PDSCH transmission in the PDSCH configuration parameter. It may be set for each common frequency resource.

The group common frequency resource may be configured with a part or all of the BWP, and in the present disclosure, the group common frequency resource may be configured with all or at least a part of the frequency resource of the group common BWP. Accordingly, the group common frequency resource may also be set as a part of the frequency resource configured in the terminal or a frequency resource separate from the frequency resource configured in the terminal, and the information for setting the group common frequency resource is included in the mcs-Table settings may be included.

According to an embodiment of the present disclosure, a DCI to which a scrambled CRC (CRC generated using DCI information) is attached based on a group-common RNTI (RNTI) is a group-common PDCCH (PDCCH). can be received through In order to determine the modulation order (Qm) and the target code rate R corresponding to the Modulation and Coding Scheme field (I _MCS ) included in the DCI, the UE may use the mcs-Table configured for group common PDSCH transmission. If the mcs-Table configured for the group common PDSCH transmission does not exist, the UE uses the mcs-Table configured for the unicast PDSCH to modulate the modulation and coding scheme field (I _MCS ) included in the DCI. The order Qm and the target code rate R may be determined. In this case, for the DCI to which the CRC scrambled based on the group common RNTI is attached, a DCI format defined separately for group communication or a DCI format previously defined for unicast communication may be used.

According to an embodiment of the present disclosure, when receiving a PDCCH scheduled through a group-specific search space, the UE receives a modulation order (Qm) corresponding to the Modulation and Coding Scheme field (I _MCS ) included in the DCI. ) and the target code rate R, the mcs-Table configured for group common PDSCH transmission may be used. If the mcs-Table configured for the group common PDSCH transmission does not exist, the UE uses the mcs-Table configured for the unicast PDSCH to modulate the modulation and coding scheme field (I _MCS ) included in the DCI. The order Qm and the target code rate R may be determined. Meanwhile, DCI transmitted through the group-specific search space may use a DCI format defined separately for group communication or a DCI format previously defined for unicast communication may be used.

According to an embodiment of the present disclosure, a DCI to which a scrambled CRC (CRC generated using DCI information) is attached based on a group-common RNTI (RNTI) is a group-common PDCCH (PDCCH). may be received through a group-specific search space of In order to determine the modulation order (Qm) and the target code rate R corresponding to the Modulation and Coding Scheme field (I _MCS ) included in the DCI, the UE may use the mcs-Table configured for group common PDSCH transmission. If the mcs-Table configured for the group common PDSCH transmission does not exist, the UE uses the mcs-Table configured for the unicast PDSCH to modulate the modulation and coding scheme field (I _MCS ) included in the DCI. The order Qm and the target code rate R may be determined.

11 is a diagram illustrating an operation of a terminal according to an embodiment of the present disclosure.

Referring to FIG. 11 , the terminal may receive configuration information from the base station. The configuration information may be received through RRC signaling, MIB, or SIB.

The setting information may include information on BWP, and in the present disclosure, the setting information may include information on mcs-Table and the like. As described above, the mcs-Table may include at least one of mcs-Table configured for unicast PDSCH or mcs-Table configured for group common PDSCH. The mcs-Table configured for the group common PDSCH may be configured for each BWP or group common frequency resource as described above. In this case, the detailed content of the configuration information for the BWP or the configuration information for the group common frequency resource is the same as described above, and will be omitted below.

The UE may monitor the PDCCH in at least one search space according to the above embodiments ( 1101 ). The search space may include a common search space. The common search space may include a group search space commonly set only to a specific group i for group communication. Also, the search space may include a UE-specific search space. The UE-specific search space may include a group search space commonly configured only for a specific group i for group communication.

More specifically, the group search space commonly set only to the group i can be obtained by setting the Yp,-1 value of Equation 1 to the group common RNTI and substituting it in Equation 1. The terminal included in the group may monitor the PDCCH in the group search space, and information included in the DCI received in the group search space may be used for group communication of the terminal.

Alternatively, the base station may transmit information on the group search space to the terminal. The base station may configure information on the PDCCH in which the group search space is located (or to be used for group communication) to the terminal through RRC signaling or SIB. In this case, time resource information and frequency resource information for the CORESET may be directly indicated through RRC signaling, MIB, or SIB. Alternatively, the time resource information and the frequency resource information for the PDCCH indicate any one of predetermined information (eg, information configured in the form of a table) through RRC signaling, MIB, or information included in SIB. can make it In addition, the CCE index of the common search space included in the PDCCH may be determined based on Equation 1 above.

As a result of monitoring of the terminal, DCI may be detected ( 1102 ). That is, the UE may receive DCI through the PDCCH as a result of monitoring the PDCCH.

When the DCI is received, the UE may check whether the RNTI used for scrambling the CRC of the DCI transmitted through the PDCCH is the first RNTI or the second RNTI (1103). As described above, the terminal included in group i may be assigned a group common RNTI (received through higher layer signaling, MIB, or SIB), and when the group common RNTI is assigned, step 1103 may be performed. . In the present disclosure, the second RNTI may refer to a group common RNTI, and the first RNTI may refer to an RNTI other than the group common RNTI configured in the UE. Meanwhile, in the present disclosure, step 1103 may be a step of confirming whether the RNTI used for scrambling the CRC of the DCI is the second RNTI. That is, the terminal may determine whether a scrambled CRC is attached based on the group common RNTI, and may determine whether scheduling information for group communication is received based on this.

However, when the group search space is a search space commonly set only to group i based on the group common RNTI, since the DCI received in the group search space is the group common DCI, step 1103 may be omitted.

Also, step 1103 may be changed to a step of determining whether the DCI is for group communication (or whether the DCI is group common or UE-specific).

If the RNTI is the first RNTI, the UE may use the first mcs-Table (or mcs-Table #1) (1104). That is, the UE may identify at least one of the modulation order (Qm) and the target code rate R corresponding to the value of the MCS index (I _MCS ) bit field included in the received DCI.

When the RNTI is the second RNTI, the UE may use the second mcs-Table (or mcs-Table #2) (1105). That is, the UE may check at least one of the modulation order (Qm) and the target code rate R corresponding to the MCS index (I _MCS ) value included in the received DCI.

The terminal determines the modulation order (Qm) and the target code rate R of the PDSCH scheduled by the DCI based on the confirmed at least one modulation order (Qm) and the target code rate R, and a subsequent operation, for example, determination of TBS etc. can be performed.

The first mcs-Table may correspond to an mcs-Table configured for a unicast PDSCH, and the second mcs-Table may correspond to an mcs-Table configured for a group common PDSCH.

12 is a diagram illustrating a DCI generation operation of a base station according to an embodiment of the present disclosure.

Referring to FIG. 12 , the base station may transmit configuration information to the terminal ( 1201 ). The configuration information may refer to information transmitted through RRC signaling, MIB, or SIB.

The setting information may include information on BWP, and in the present disclosure, the setting information may include information on mcs-Table and the like. As described above, the mcs-Table may be at least one of mcs-Table configured for unicast PDSCH or mcs-Table configured for group common PDSCH. The mcs-Table configured for the group common PDSCH may be configured for each BWP or group common frequency resource as described above. In this case, the detailed content of the configuration information for the BWP or the configuration information for the group common frequency resource is the same as described above, and will be omitted below.

Then, the base station may determine the type of DCI to transmit (1202). However, step 1202 may be omitted. Specific details will be described later.

Specifically, the base station may determine the type of DCI according to data to be transmitted through the PDSCH (or according to whether the data is for group communication, or whether the data is group common data or UE-specific data). For example, the type of DCI may be determined depending on whether data is transmitted to one terminal or data transmitted to terminals belonging to a specific group (ie, multiple terminals). The base station determines a modulation order (Qm) and a target code rate R of data to be transmitted through the PDSCH, and an MCS index (I _MCS ) for indicating the modulation order (Qm) and/or the target code rate R can be decided At this time, the MCS index uses different mcs-Tables according to the data (that is, whether data is transmitted for group communication or data for unicast transmission) or according to the determined DCI type. It may be determined, and specific details will be described later. However, as described above, the DCI type (or format) for group communication and the DCI type (or format) for unicast communication may be the same, and in this case, step 1202 may be omitted.

Alternatively, the base station may determine the type of DCI according to whether the DCI to be transmitted through the PDCCH is for group communication (or whether the DCI is group common or UE-specific) ( 1202 ). For example, the DCI may be for one UE (UE-specific) or a specific group (group-common). Therefore, the base station determines the modulation order (Qm) and the target code rate R of data to be transmitted through the PDSCH scheduled by the DCI, and the MCS index (I) for indicating the modulation order (Qm) and/or the target code rate R _MCS ) can be determined. In this case, the MCS index may be determined using different mcs-Tables according to the determined DCI type, and details will be described later. However, as described above, the DCI type (or format) for group communication and the DCI type (or format) for unicast communication may be the same, and in this case, step 1202 may be omitted.

When the determined DCI is UE-specific, the base station generates a DCI using the first mcs-Table (mcs-Table #1) (1203), generates a CRC using the generated DCI, and sets the CRC to the first The RNTI may be used to scramble ( 1205 ). The first mcs-Table may be an mcs-Table set in the UE for unicast PDSCH through the process of 1201, and the RNTI is a UE-specific RNTI (UE-specific RNTI), including, for example, a C-RNTI. can do. The base station may transmit the DCI and CRC generated as above through the PDCCH.

When the determined DCI type is group-common, the base station generates a DCI using the second mcs-Table (1204), generates a CRC using the generated DCI, and scrambles the CRC using a second RNTI. Can (1206). The second mcs-Table may be an mcs-Table set in the UE for the group common PDSCH through the process of 1201, and the RNTI may include a group common RNTI (RNTI). The base station may transmit the DCI and CRC generated as above through the PDCCH. The PDCCH may be transmitted by being mapped to a common search space or a group search space.

According to an embodiment of the present disclosure, a group-common PDSCH (PDSCH) may be used for retransmission of data transmitted through a group-common PDSCH (PDSCH).

According to an embodiment of the present disclosure, a UE-specific PDSCH scheduled through a UE-specific PDCCH (UE-specific PDCCH) for retransmission for data transmitted through a group-common PDSCH (PDSCH) ) can be used.

According to an embodiment of the present disclosure, a group common PDSCH (group-common PDSCH) scheduled through a UE-specific PDCCH (UE-specific PDCCH) for retransmission for data transmitted through a group-common PDSCH (PDSCH) PDSCH) may be used.

According to an embodiment of the present disclosure, whether retransmission for a TB transmitted through the group common PDSCH is determined by a first RNTI transmitted through the first PDCCH scheduling the first PDSCH (CRC generated using the first DCI) A first HARQ process number and a first New Data Indicator (NDI) value included in the first DCI using (used for scrambling 2 may be determined by the second HARQ process number and the second NDI value included in the second DCI (used for scrambling the CRC generated using DCI).

More specifically, regardless of whether the first RNTI and the second RNTI are the same, if the first HARQ process number and the second HARQ process number are the same, and the second NDI value is the same as the first NDI value, the second PDSCH is The data TB transmitted through the first PDSCH is determined by retransmission of the data TB transmitted through the first PDSCH, and a subsequent operation (eg, combining) may be performed accordingly. That is, even when the first RNTI and the second RNTI are different RNTIs (eg, a UE-specific RNTI and a UE common RNTI), the number of HARQ processes included in the DCI is the same, and the NDI value is not toggled. An operation for retransmission may be performed. Alternatively, when the first RNTI and the second RNTI are the same RNTI (eg, terminal common RNTI), the number of HARQ processes included in the DCI is the same, and when the NDI value is not toggled, transmitted through the second PDSCH Data may be understood as retransmission data. Meanwhile, if the second NDI value is different from the first NDI value (ie, toggled), the data TB transmitted through the second PDSCH may be understood as new data. The first RNTI may be, for example, a group common RNTI, and the second RNTI may be a UE-specific RNTI (C-RNTI). As another example, the first RNTI may be a group common RNTI, and the second RNTI may also be a group common RNTI. According to an embodiment of the present disclosure, the determination of whether to retransmit as in the above embodiment may be performed for each MAC entity.

13 is a diagram illustrating an example of a downlink data channel of a terminal according to an embodiment of the present disclosure.

Referring to FIG. 13 , the UE may monitor the PDCCH in at least one search space according to the above embodiments (not shown). The search space may include a common search space. The common search space may include a group search space commonly set only to a specific group i for group communication. Also, the search space may include a UE-specific search space. The UE-specific search space may include a group search space commonly set only to a specific group i for group communication.

As a result of the monitoring, the UE may receive the first DCI (DCI #1) scheduling the first PDSCH (PDSCH #1), in which the CRC is scrambled by the first RNTI (RNTI #1) (1301). The first RNTI (RNTI #1) may be a group common RNTI, and the first PDSCH (PDSCH #1) may correspond to a group common PDSCH.

In addition, the UE may receive a second DCI (DCI #2) scheduling the second PDSCH (PDSCH #2), in which the CRC is scrambled by the second RNTI (RNTI #2) (1302). The second RNTI (RNTI #2) may be a UE-specific RNTI (eg, C-RNTI), and the second PDSCH (PDSCH #2) may correspond to a UE-specific PDSCH.

Meanwhile, steps 1301 and 1302 may be changed according to an embodiment of the present disclosure. That is, the order of steps 1301 and 1302 is changed, or the terminal may receive the first DCI scrambled with the first RNTI in steps 1301 and 1302, or the terminal may scramble with the second RNTI in steps 1301 and 1302. The second DCI may be received. Alternatively, steps 1301 and 1302 may be changed to receiving the first DCI and the second DCI, respectively, and the first DCI and the second DCI may not be limited to a specific RNTI. And, as will be described later, the UE may determine whether to retransmit according to whether the NDI value is toggled for the same HARQ process number. At this time, when the NDI value is not toggled for the same HARQ process number, the UE may perform retransmission regardless of the RNTI associated with the DCI.

Specifically, the UE may compare the value of the HARQ process number of the second DCI (DCI #2) with the value of the HARQ process number of the first DCI (DCI #1). When the HARQ process number values of the two DCIs are the same, the UE compares the first NDI value included in the second DCI (DCI #2) with the second NDI value included in the first DCI (DCI #1). It may be determined whether the second NDI value is toggled (for example, from 0 to 1 or from 1 to 0) (1303).

According to whether the second NDI value is toggled, if it is toggled, the terminal may understand the data included in the second PDSCH scheduled by DCI #2 as a new transmission, and then proceed with processing ( 1304 ). The processing may include, for example, calculation of TBS, flush operation of a buffer corresponding to the HARQ process number, and the like.

The UE understands the data included in the second PDSCH scheduled by DCI #2 as retransmission of the first PDSCH #1, if not toggled, that is, if the value is the same according to whether the second NDI value is toggled, Thereafter, processing may proceed ( 1305 ). The processing may include, for example, calculating the TBS, combining LLR values of the first PDSCH #1 and the second PDSCH #2, and the like. That is, even if the value of the first RNTI scrambling the CRC of the first DCI scheduling the first PDSCH #1 is different from the value of the second RNTI scrambling the CRC of the second DCI scheduling the second PDSCH #2, the UE , it is possible to determine whether to retransmit or not based on whether the HARQ process number and the NDI value included in each DCI are toggled, and process the PDSCH later.

According to an embodiment of the present disclosure, the same operation as in FIG. 13 may be performed even when the first RNTI (RNTI #1) and the second RNTI (RNTI #2) of FIG. 13 are the same. If the reception and decoding of PDSCH #1 is successful, the UE may not perform the processing operation 1305 of the second PDSCH.

Accordingly, the operation of the base station may be as follows. The base station may transmit DCI through at least one search space according to embodiments. The search space may include a common search space. The common search space may include a group search space commonly set only to a specific group i for group communication. Also, the search space may include a UE-specific search space. The UE-specific search space may include a group search space commonly set only to a specific group i for group communication.

At this time, the base station may transmit the first DCI (DCI #1) scheduling the first PDSCH (PDSCH #1), in which the CRC is scrambled by the first RNTI (RNTI #1). The first RNTI (RNTI #1) may be a group common RNTI, and the first PDSCH (PDSCH #1) may correspond to a group common PDSCH. In addition, the base station may transmit a second DCI (DCI #2) scheduling the second PDSCH (PDSCH #2), in which the CRC is scrambled by the second RNTI (RNTI #2). The second RNTI (RNTI #2) may be a UE-specific RNTI (eg, C-RNTI), and the second PDSCH (PDSCH #2) may correspond to a UE-specific PDSCH. Meanwhile, the first DCI and the second DCI may not be limited to a specific RNTI.

In addition, when the base station intends to retransmit data transmitted in the first PDSCH in the second PDSCH, the NDI value is identically set for the same HARQ process number regardless of the RNTI values used in the first DCI and the second DCI. can be transmitted to the terminal. Meanwhile, when the base station wants to transmit new data in the second PDSCH, the NDI value included in the second DCI may be toggled and transmitted to the terminal.

According to an embodiment of the present disclosure, DCI transmitted through a UE-specific PDCCH (Scrambling CRC through UE-specific RNTI) indicating retransmission for a group-common PDSCH (PDSCH) The modulation order (Qm) corresponding to the modulation and coding scheme field (I _MCS ) and the mcs-Table used for determining the target code rate R may be determined through the MCS index table determination method of the above embodiment.

According to an embodiment of the present disclosure, transmitted through a group common PDCCH (group-common PDCCH, scrambling CRC through a group common RNTI) indicating retransmission for a group common PDSCH (group-common PDSCH) The mcs-Table used for determining the modulation order (Qm) and the target code rate R corresponding to the Modulation and Coding Scheme field (I _MCS ) included in DCI is the mcs-Table set for group common PDSCH transmission of the above embodiment. this can be used

Meanwhile, according to an embodiment of the present disclosure, the TBS may be determined using at least some of the mcs-Table and I _MCS values determined through the above embodiments.

Specifically, when the code rate indicated by the MCS index included in the DCI is reserved (or when the MCS index indicates reserved), the UE sets the value of the TBS scheduled by the DCI to that of the most recently transmitted TBS. It can be set equal to the value. In this case, the TB scheduled by the DCI may be a retransmission of the most recently transmitted TB or a TB for new transmission.

Specifically, according to an embodiment of the present disclosure, Table 15 is used as an mcs-Table for the value of the Modulation and Coding Scheme field (I _MCS ) in the first DCI, and I _MCS included in the first DCI received by the UE. When the value of is 28 or more and 31 or less (that is, when the MCS index included in the DCI indicates reserved), the size (TBS) of a TB scheduled through the first DCI is 0 or more and 27 or less in Table 15. value, or a value of 0 or more and 28 or less of Table 14, or an MCS index (I _MCS ) corresponding to a value of 0 or more and 28 or less of Table 16 (ie, MCS index that does not indicate code rate reserved). It may be the same as the TBS determined by the second DCI transmitted through the latest PDCCH (the latest PDCCH) transmitted for the TB.

According to an embodiment of the present disclosure, Table 14 or Table 16 is used as the mcs-Table for the value of the Modulation and Coding Scheme field (I _MCS ) in the first DCI, and I _MCS included in the first DCI received by the UE. When the value of is 29 or more and 31 or less (or when the MCS index indicates reserved), the size (TBS) of a TB scheduled through the first DCI is a value of 0 or more and 28 or less in Table 14, or a value in Table 16. The first transmitted through the most recent PDCCH (the latest PDCCH) transmitted for the same TB, including the MCS index (I _MCS ) corresponding to a value of 0 or more and 28 or less, or a value of 0 or more and 27 or less in Table 15 2 It may be the same as TBS determined by DCI.

14 is a diagram illustrating an example of a method of obtaining the size of a transport block of a terminal according to an embodiment of the present disclosure.

Referring to FIG. 14 , the UE may monitor the PDCCH in at least one search space according to the above embodiments (not shown). The search space may include a common search space. The common search space may include a group search space commonly set only to a specific group i for group communication. Also, the search space may include a UE-specific search space. The UE-specific search space may include a group search space commonly configured only for a specific group i for group communication.

As a result of the monitoring, the UE may receive the first DCI (DCI #1) scheduling the first PDSCH (PDSCH #1), in which the CRC is scrambled by the first RNTI (RNTI #1) (1401). The first RNTI (RNTI #1) may be a group common RNTI, and the first PDSCH (PDSCH #1) may correspond to a group common PDSCH.

In addition, the UE may receive a second DCI (DCI #2) scheduling the second PDSCH (PDSCH #2), in which the CRC is scrambled by the second RNTI (RNTI #2) (1402). The second RNTI (RNTI #2) may be a UE-specific RNTI (eg, C-RNTI), and the second PDSCH (PDSCH #2) may correspond to a UE-specific PDSCH.

The terminal, for example, mcs for determining the modulation order (Qm) and the target code rate R corresponding to the value of the MCS index (I _MCS ) included in the second DCI (DCI #2) through the process as shown in FIG. 11 . -Table can be determined (1403). For example, the mcs-Table may be determined based on mc used for scrambling of the received DCI. For example, when scrambled based on the second RNTI, the mcs-Table may correspond to an mcs-Table configured for the unicast PDSCH.

Meanwhile, steps 1401 and 1402 may be changed according to an embodiment of the present disclosure. That is, the order of steps 1401 and 1402 is changed, or the terminal may receive the first DCI scrambled with the first RNTI in steps 1401 and 1402, or the terminal may scramble with the second RNTI in steps 1401 and 1402. The second DCI may be received. Alternatively, steps 1401 and 1402 may be changed to receiving the first DCI and the second DCI, respectively, and the first DCI and the second DCI may not be limited to a specific RNTI. As will be described later, when the value of the MCS index included in the second DCI is equal to or greater than a predetermined value or a specific value, the UE transmits the TBS transmitted through the second PDSCH scheduled by the second DCI to the first scheduled by the first DCI. 1 It can be determined the same as the TBS transmitted through the PDSCH.

Specifically, the UE may determine whether the value of I _MCS included in the second DCI is greater than or equal to a specific value 1 (threshold value 1 or value 1) ( 1404 ). The specific value may be determined by the mcs-Table determined in step 1403 . For example, if the mcs-Table corresponds to Table 15, the specific value may correspond to 28, and if the mcs-Table corresponds to Table 14 or 16, the specific value may correspond to 29. In addition, when the group common mcs-Table is separately set, the specific value may be a value for which the target code rate and spectral efficiency of the mcs-Table are reserved.

According to process 1404, when the value of I _MCS included in the second DCI is greater than or equal to a specific value 1 (value 1) according to the process 1404, the UE determines that the TBS of the second PDSCH scheduled through the second DCI is mcs- corresponding to the first DCI. It can be determined to be the same as the TBS determined by the value of I _MCS included in the Table and the first DCI (1405). The mcs-Table corresponding to the first DCI may be an mcs-Table configured by the base station for group common PDSCH transmission.

When the mcs-Table corresponding to the first DCI is Table 15, the value of I _MCS included in the first DCI may have a value of 0 or more and 27 or less, and the mcs-Table corresponding to the first DCI is shown in Table 15. In the case of 14, the value of I _MCS included in the first DCI may have a value of 0 or more and 28 or less, and when the mcs-Table corresponding to the first DCI is Table 16, I _MCS included in the first DCI The value of the bit field may have a value of 0 or more and 28 or less. In addition, when the group common mcs-Table is separately configured, the value of I _MCS included in the first DCI may be a value in which the target code rate and spectral efficiency of the mcs-Table are not reserved.

According to the process 1404, when the value of I _MCS included in the second DCI is less than a specific value 1 (value 1), the terminal according to the mcs-Table corresponding to the second DCI and the value of I _MCS included in the second DCI A TBS may be determined (computed) (1406).

Accordingly, the operation of the base station may be as follows. The base station may transmit DCI in at least one search space according to embodiments. The search space may include a common search space. The common search space may include a group search space commonly set only to a specific group i for group communication. Also, the search space may include a UE-specific search space. The UE-specific search space may include a group search space commonly set only to a specific group i for group communication.

In this case, the base station may transmit a first DCI (DCI #1) scheduling the first PDSCH (PDSCH #1), in which the CRC is scrambled by the first RNTI (RNTI #1). The first RNTI (RNTI #1) may be a group common RNTI, and the first PDSCH (PDSCH #1) may correspond to a group common PDSCH. In addition, the UE may transmit a second DCI (DCI #2) scheduling the second PDSCH (PDSCH #2), in which the CRC is scrambled by the second RNTI (RNTI #2). The second RNTI (RNTI #2) may be a UE-specific RNTI (eg, C-RNTI), and the second PDSCH (PDSCH #2) may correspond to a UE-specific PDSCH.

In addition, the base station may determine the mcs-Table for determining the value of the modulation order (Qm) to be included in the second DCI and the MCS index (I _MCS ) corresponding to the target code rate R. For example, the base station may check whether the second DCI is a group common DCI or a unicast DCI. Alternatively, the base station may check whether the second PDSCH scheduled by the second DCI is a group common PDSCH or a unicast PDSCH. For example, in the case of group common DCI or group common PDSCH, the base station may determine the MCS index by using the mcs-Table configured for the group common PDSCH. Meanwhile, the first DCI and the second DCI may not be limited to a specific RNTI.

In addition, when the base station intends to transmit data having the same TBS as the TBS determined by the value of I _MCS included in the first DCI, the base station sets the value of the MCS index included in the second DCI to a specific value 1 (threshold value 1). Alternatively, it can be set to value 1) or higher. The specific value may be determined by the determined mcs-Table. For example, if the mcs-Table corresponds to Table 15, the specific value may correspond to 28, and if the mcs-Table corresponds to Table 14 or 16, the specific value may correspond to 29. In addition, when the group common mcs-Table is separately set, the specific value may be a value for which the target code rate and spectral efficiency of the mcs-Table are reserved.

On the other hand, when the base station wants to transmit data having a TBS different from the TBS determined by the value of the MCS index included in the first DCI or when new data is to be transmitted), the base station MCS index included in the second DCI The value of can be set to less than a specific value 1 (value 1).

According to an embodiment of the present disclosure, the scheduled instantaneous data rate is expressed by Equation (7). L denotes the number of OFDM symbols allocated to the PDSCH, and M denotes the number of TBs transmitted in the corresponding PDSCH.

Is

can be calculated as

denotes a subcarrier interval used for PDSCH transmission. In the mth TB,

Is

, where A is the size of the TB (TBS), C is the number of code blocks (CBs) included in the TB, and C' is the number of code blocks scheduled in the TB. In the case of CBG (code block group) retransmission, C and C' may be different.

is the largest integer not greater than x.

[Equation 7]

According to an embodiment of the present disclosure, the maximum data rate DataRateCC supported by the UE in one carrier or serving cell may be determined based on Equation 6 or calculated as Equation 8. Equation 8 shows an example of calculating the DataRateCC of the j-th serving cell. Since the parameters included in Equation 8 have been described in Equation 6, they are omitted here.

[Equation 8]

According to an embodiment of the present disclosure, the instantaneous data rate transmitted in the J serving cells is as shown in Equation (9).

[Equation 9]

According to an embodiment of the present disclosure, the actual instantaneous data rate in carriers or serving cells set in the terminal is determined by comparing the value of Equation 9 and the value of Equation 6 in the carriers or the serving cells. It may be checked whether the capability of the terminal is satisfied. The comparison may be a condition applied to all cases including initial transmission and retransmission. That is, when the value of Equation 9 (instantaneous data rate for the serving cell(s)) is less than or equal to the value of Equation 6 (the maximum data rate supported by the UE in the serving cell(s)), the UE selects the PDSCH HARQ-ACK information can be fed back by receiving and decoding. Otherwise (that is, when the instantaneous data rate for the serving cell(s) is greater than the maximum data rate supported by the UE in the serving cell(s)), the UE ignores the PDSCH scheduling information, or does not receive the PDSCH Otherwise, decoding of the PDSCH may not be performed, HARQ-ACK information may be set to NACK, or HARQ-ACK information may not be fed back.

According to an embodiment of the present disclosure, the base station checks the maximum data rate (value of Equation 6) supported by the terminal in the serving cell(s) for each of the terminals belonging to one group, and Check the minimum value (the minimum value among the values of Equation 6), and the value of the instantaneous data rate (Equation 9) for the serving cell(s) is the minimum value of the maximum data rate for each of the terminals belonging to the group (Equation 6) value) or less, the group common PDSCH to the group of the terminal may be scheduled through the group common PDCCH.

According to an embodiment of the present disclosure, the terminal has the instantaneous data rate (the value of Equation 9) for the serving cell(s) is the value of the maximum data rate supported by the terminal in the serving cell(s) (or to a plurality of terminals) If it is less than or equal to the value of the maximum data rate (the value of Equation 6), the UE may feed back HARQ-ACK information by receiving and decoding the group common PDSCH. It is possible to ignore scheduling information, do not receive group common PDSCH, do not perform group common PDSCH decoding, set HARQ-ACK information to NACK, or not feed back HARQ-ACK information.

According to an embodiment of the present disclosure, by comparing the value of Equation 7 and the value of Equation 8, the actual instantaneous data rate in one carrier or serving cell is determined by the capability of the terminal in the carrier or the serving cell. ) can be verified. The comparison may be a condition applied to retransmission. That is, when the value of the instantaneous data rate (value of Equation 7) in one carrier or serving cell is less than or equal to the maximum data rate (value in Equation 8) supported by the UE in one carrier or serving cell, the UE may receive and decode the PDSCH to feed back HARQ-ACK information. Otherwise, the UE ignores the PDSCH scheduling information, does not receive PDSCH, does not perform PDSCH decoding, sets HARQ-ACK information to NACK, or may not feed back HARQ-ACK information.

According to an embodiment of the present disclosure, the base station checks the maximum data rate value (the value of Equation 8) supported by the terminal in one carrier or serving cell for each of the terminals belonging to one group, and the terminal Check the minimum value of the maximum data rate for each of the terminals (the minimum value among the values of Equation 8 of each of the terminals), and the value of the instantaneous data rate (the value of Equation 7) in one carrier or serving cell is one carrier Or, in the serving cell, the group common retransmission PDSCH to the group of terminals is scheduled to be less than or equal to the minimum value (the minimum value of Equation 6) of the maximum data rate for the terminals belonging to the group through the group common PDCCH or the terminal specific PDCCH. can do.

According to an embodiment of the present disclosure, when the value of the instantaneous data rate in one carrier or serving cell is less than or equal to the minimum value of the maximum data rate for the terminals, the terminal receives the group common retransmission PDSCH and decode to feed back HARQ-ACK information. Otherwise, the terminal ignores the group common retransmission PDSCH scheduling information, does not receive the group common retransmission PDSCH, does not perform decoding of the group common retransmission PDSCH, or sets HARQ-ACK information to NACK, or , HARQ-ACK information may not be fed back.

According to an embodiment of the present disclosure, the base station identifies the terminals in the group that have fed back NACK for group common PDSCH transmission, and the value of the maximum data rate supported by the terminal in one carrier or serving cell for each of the terminals. (values of Equation 8 of each of the terminals), and the instantaneous data rates (values of Equation 7) in one carrier or serving cell for each of the terminals are the maximum data rates for each of the terminals UE-specific retransmission PDSCHs for each UE may be scheduled through UE-specific PDCCHs so as to be less than or equal to the value of Equation (8).

According to an embodiment of the present disclosure, the terminal has an instantaneous data rate (value of Equation 7) in one carrier or serving cell is less than the maximum data rate (value in Equation 8) in one carrier or serving cell. or equal to, the UE may receive and decode the UE-specific retransmission PDSCH transmitted as a retransmission for the group common PDSCH transmission to feed back HARQ-ACK information. Otherwise, the terminal ignores the information on scheduling the terminal-specific retransmission PDSCH transmitted as retransmission for the group common PDSCH transmission, or does not receive or decode the terminal-specific retransmission PDSCH transmitted as the retransmission for the group common PDSCH transmission, HARQ-ACK information may be set to NACK, or HARQ-ACK information may not be fed back.

There may be many cases in which retransmission cannot be scheduled according to the scheduling constraints of the base station or the operation of the terminal as in the above embodiments of the present disclosure.

According to an embodiment of the present disclosure, when the mcs-Table set in DCI for scheduling retransmission is Table 14 or Table 16, when the I _MCS value is a value of 29 to 31, in Table 15, the I _MCS value is 28 to 31 value, or a newly added mcs-Table (or an mcs-Table defined for group communication) is used and the I _MCS value included in the received DCI is reserved for the target code rate and spectral efficiency of the newly added mcs-Table. In the case of , the UE may understand the DCI as a DCI indicating retransmission. Also, even if a different I _MCS value is used, retransmission may be performed when the conditions according to the above embodiments are satisfied.

According to an embodiment of the present disclosure, when the base station retransmits a group-common PDSCH (PDSCH) transmitted to a terminal or a group of terminals, the scheduling restrictions (eg, , the comparison of the instantaneous data rate and the maximum data rate supported by the terminal or the comparison of the value of Equation 7 and the value of Equation 8) may be limited to a specific case.

For example, it can be limited only when the number of symbols L allocated to the retransmission group common PDSCH or the retransmission terminal specific PDSCH is less than the specific symbol number (eg, 7). That is, when the above condition is not satisfied, the scheduling constraints (for example, comparison of the instantaneous data rate and the maximum data rate supported by the terminal or comparison of the value of Equation 7 and the value of Equation 8) are considered. There may be ways not to do it.

As another example, it can be limited only when the number of symbols L allocated to a common retransmission group PDSCH or a retransmission terminal-specific PDSCH is smaller than the number L of symbols used for initial transmission of the group common PDSCH. That is, if the above condition is not satisfied, a method of not considering the scheduling constraints (a comparison of an instantaneous data rate and a maximum data rate supported by the terminal or a comparison of the value of Equation 7 and the value of Equation 8) may include

For another example, the number of symbols L allocated to the retransmission group common PDSCH or the retransmission terminal specific PDSCH is smaller than the number of symbols L used for the group common PDSCH initial transmission, and is smaller than the specific symbol number (eg, 7). It can be limited only to cases. That is, when the above condition is not satisfied, the scheduling constraints (for example, comparison of the instantaneous data rate and the maximum data rate supported by the terminal or comparison of the value of Equation 7 and the value of Equation 8) are considered. There may be ways not to do it.

For another example, the number of symbols L allocated to the retransmission group common PDSCH or the retransmission terminal specific PDSCH is the number of symbols L-x used for initial transmission of the group common PDSCH (x value is, for example, a fixed value such as 2 or 3) is applied or the base station may set it through higher level signaling.). That is, if the above condition is not satisfied, the scheduling constraint (a comparison of an instantaneous data rate and a maximum data rate supported by the terminal or a comparison of the value of Equation 7 and the value of Equation 8) is not considered. can

According to an embodiment of the present disclosure, when calculating the number of symbols used for PDSCH mapping or the number of symbols allocated for PDSCH transmission or the number of symbols used for PDSCH transmission in the above examples, a demodulation reference signal for PDSCH : DMRS) symbol may be included. That is, it may be counting all symbols for PDSCH transmission delivered through DCI or higher signaling indicating PDSCH mapping information.

15 is a diagram illustrating an example of a downlink data channel of a terminal according to an embodiment of the present disclosure.

Referring to FIG. 15 , the UE may monitor the PDCCH in at least one search space according to the above embodiments (not shown). The search space may include a common search space. The common search space may include a group search space commonly set only to a specific group i for group communication. Also, the search space may include a UE-specific search space. The UE-specific search space may include a group search space commonly set only to a specific group i for group communication.

As a result of the monitoring, the UE may receive the first DCI (DCI #1) scheduling the first PDSCH (PDSCH #1), in which the CRC is scrambled by the first RNTI (RNTI #1) (1501). The first RNTI (RNTI #1) may be a group common RNTI, and the first PDSCH (PDSCH #1) may correspond to a group common PDSCH.

In addition, the UE schedules a second PDSCH (PDSCH #2) corresponding to retransmission for the first PDSCH (PDSCH #1), in which the CRC is scrambled by the second RNTI (RNTI #2) (DCI # 2) can be received (1502). The second RNTI (RNTI #2) may be a UE-specific RNTI (eg, C-RNTI), and the second PDSCH (PDSCH #2) may correspond to a UE-specific PDSCH.

Meanwhile, steps 1501 and 1502 may be changed according to an embodiment of the present disclosure. That is, the order of steps 1501 and 1502 is changed, or the terminal may receive the first DCI scrambled with the first RNTI in steps 1501 and 1502, or the terminal may scramble with the second RNTI in steps 1501 and 1502. The second DCI may be received. Alternatively, steps 1501 and 1502 may be changed to receiving the first DCI and the second DCI, respectively, and the first DCI and the second DCI may not be limited to a specific RNTI. And, as described later, the UE may determine whether to process the second PDSCH according to information of time domain resource assignment.

The UE determines whether a specific condition is satisfied by using at least one of time resource assignment information included in the first DCI (hereinafter, information of time domain resource assignment) and time domain resource assignment information included in the second DCI. can (1503). The specific condition is, for example, "when the number of symbols L allocated to the second PDSCH through time domain resource assignment included in the second DCI is smaller than the specific number of symbols" or "time domain resource assignment included in the second DCI" When the number of symbols L allocated to the second PDSCH through is less than the number of symbols L allocated to the first PDSCH through time domain resource assignment included in the first DCI” or “time domain resource assignment included in the second DCI” When the number of symbols L allocated to the second PDSCH through The number of symbols L allocated to the second PDSCH through time domain resource assignment is the number of symbols L-x allocated to the first PDSCH through time domain resource assignment included in the first DCI (x value is, for example, fixed such as 2 or 3) value is applied, or the base station may set it through higher level signaling).

If a specific condition is not satisfied in the process 1503, the UE determines the scheduling constraint (eg, the result value of Equation 7 and the result value of Equation 8 for comparing the instantaneous data rate and the maximum data rate supported by the UE) The second PDSCH may be processed regardless of the comparison result of ( 1505 ).

If it is determined in step 1503 that a specific condition is satisfied, the UE may check whether the scheduling constraint is satisfied. That is, the terminal may check whether the instantaneous data rate (eg, the result value of Equation 7) is less than or equal to the maximum data rate supported by the terminal (eg, the result value of Equation 8) (1504) . If the instantaneous data rate (eg, the result value of Equation 7) is less than or equal to the maximum data rate supported by the UE (eg, the result value of Equation 8), the UE performs the processing of the second PDSCH Can (1505).

If the instantaneous data rate (eg, the result value of Equation 7) is greater than the maximum data rate supported by the UE (eg, the result value of Equation 8), the UE may ignore the second DCI ( 1506). That is, processing of the second PDSCH scheduled by the second DCI may not be performed.

Accordingly, the operation of the base station may be as follows. The base station may transmit DCI in at least one search space according to the above embodiments. The search space may include a common search space. The common search space may include a group search space commonly set only to a specific group i for group communication. Also, the search space may include a UE-specific search space. The UE-specific search space may include a group search space commonly set only to a specific group i for group communication.

At this time, the base station may transmit the first DCI (DCI #1) scheduling the first PDSCH (PDSCH #1), in which the CRC is scrambled by the first RNTI (RNTI #1). The first RNTI (RNTI #1) may be a group common RNTI, and the first PDSCH (PDSCH #1) may correspond to a group common PDSCH. In addition, the base station schedules a second PDSCH (PDSCH #2) corresponding to retransmission for the first PDSCH (PDSCH #1), in which the CRC is scrambled by the second RNTI (RNTI #2) (DCI # 2) can be transmitted. The second RNTI (RNTI #2) may be a UE-specific RNTI (eg, C-RNTI), and the second PDSCH (PDSCH #2) may correspond to a UE-specific PDSCH. Meanwhile, the first DCI and the second DCI may not be limited to a specific RNTI.

And, the base station may transmit data to the terminal.

At this time, if a specific condition is not satisfied based on at least one of the time domain resource assignment information included in the first DCI and the time domain resource assignment information included in the second DCI, regardless of the restrictions on scheduling The data may be processed. Accordingly, the base station may set information of time domain resource assignment included in the DCI in order to process the data regardless of scheduling restrictions. Meanwhile, when the specific condition is satisfied, the terminal may process the data based on the scheduling constraint. The specific condition is, for example, "when the number of symbols L allocated to the second PDSCH through time domain resource assignment included in the second DCI is smaller than the specific number of symbols" or "time domain resource assignment included in the second DCI" When the number of symbols L allocated to the second PDSCH through is less than the number of symbols L allocated to the first PDSCH through time domain resource assignment included in the first DCI” or “time domain resource assignment included in the second DCI” When the number of symbols L allocated to the second PDSCH through The number of symbols L allocated to the second PDSCH through time domain resource assignment is the number of symbols L-x allocated to the first PDSCH through time domain resource assignment included in the first DCI (x value is, for example, fixed such as 2 or 3) value is applied, or the base station may set it through higher level signaling).

According to an embodiment of the present disclosure, the terminal checks whether a scrambled CRC is attached based on the group common RNTI, and when it is checked whether scheduling information for group communication is received based on this, scheduling information for the group communication The bwp-InactivityTimer associated with the BWP to which the group common PDSCH scheduled by can (re)start. When the bwp-InactivityTimer expires, if the defaultDownlinkBWP is set, the BWP is changed to the defaultDownlinkBWP, and if not set, the BWP may be changed to the initialDownlinkBWP.

16 is a diagram illustrating a structure of a terminal according to an embodiment of the present disclosure.

Referring to FIG. 16 , the terminal may include a transceiver 1610 , a control unit 1620 , and a storage unit 1^30 . In the present invention, the controller may be defined as a circuit or an application specific integrated circuit or at least one processor.

The transceiver 1610 may transmit/receive signals to and from other network entities. The transceiver 1610 may receive, for example, configuration information from a base station, and the configuration information may be received through RRC signaling, MIB, or SIB. The setting information may include information on BWP and information on mcs-Table. The transceiver 1610 may receive DCI through a group common PDCCH or a group specific PDCCH. Also, the transceiver 1610 may receive data from the base station. The transceiver 1610 may receive new transmission data or retransmission data from the base station.

The controller 1620 may control the overall operation of the terminal according to the embodiment proposed in the present invention. For example, the controller 1620 may control a signal flow between blocks to perform an operation according to the above-described flowchart. For example, the controller 1620 may check whether the received DCI is for group communication. The controller 1620 may check whether the DCI is for group communication according to whether the CRC included in the DCI is scrambled based on the first RNTI or the second RNTI. In this case, the first RNTI and the second RNTI may each include either a UE-specific RNTI (eg, C-RNTI) or a group common RNTI. In addition, the controller 1620 may use different mcs-Tables according to whether the DCI is for group communication or unicast communication (or whether DCI is group common or UE-specific). That is, when DCI is UE-specific, the UE may check at least one of a modulation order and a target code rate using the first mcs-Table. In addition, when DCI is group common, the UE may check at least one of a modulation order and a target code rate using the second mcs-Table.

Also, even when receiving a DCI including a CRC scrambled with a different RNTI, the controller 1620 understands the received data as retransmission data when the number of the HARQ process included in the DCI is the same and the NDI value is not toggled. and perform subsequent actions. On the other hand, when the NDI value is toggled, the controller 1620 may understand the received data as new data.

In addition, when the code rate indicated by the MCS index included in DCI indicates that the target code rate and spectral efficiency values of the mcs-Table defined for unicast communication or mcs-Table defined for group communication are reserved, The controller 1620 may set the value of the TBS scheduled by the DCI to be the same as the value of the most recently transmitted TBS.

In addition, when the instantaneous data rate is less than or equal to the maximum data rate, the control unit 1620 receives and decodes the group common retransmission PDSCH or the UE specific retransmission PDSCH as retransmissions for the group common PDSCH or UE specific PDSCH, and HARQ-ACK information. can give feedback On the other hand, when the instantaneous data rate is greater than the maximum data rate, the control unit ignores the retransmission PDSCH scheduling information, does not receive the retransmission PDSCH, does not perform decoding of the retransmission PDSCH, or NACKs HARQ-ACK information or may not feed back HARQ-ACK information.

Also, when a specific condition is satisfied, the controller 1620 may not consider the scheduling constraint (a comparison between an instantaneous data rate and a maximum data rate). The above-described operation of the terminal may be controlled by the controller 1620, and detailed description thereof will be omitted.

The storage unit 1630 may store at least one of information transmitted and received through the transceiver 1610 and information generated through the control unit 1620 .

17 is a diagram illustrating a structure of a base station according to an embodiment of the present disclosure.

Referring to FIG. 17 , the base station may include a transceiver 1710 , a control unit 1720 , and a storage unit 1730 . In the present invention, the controller may be defined as a circuit or an application-specific integrated circuit or at least one processor.

The transceiver 1710 may transmit/receive signals to and from other network entities. The transceiver 1710 may transmit, for example, configuration information from the base station to the terminal, and the configuration information may be transmitted through RRC signaling, MIB, or SIB. The setting information may include information on BWP and information on mcs-Table. The transceiver 1710 may transmit DCI through a group common PDCCH or a group specific PDCCH. Also, the transceiver 1710 may transmit data to the terminal. The transceiver 1710 may transmit new transmission data or retransmission data to the terminal.

The controller 1720 may control the overall operation of the base station according to the embodiment proposed in the present invention. For example, the controller 1720 may control a signal flow between blocks to perform an operation according to the above-described flowchart. For example, the controller 1720 may generate a DCI according to an embodiment of the present disclosure. The controller 1720 may determine DCI according to whether data to be transmitted is for group communication (or whether the data is group common data or UE-specific data). Alternatively, the controller 1720 may determine the type of DCI according to whether the DCI to be transmitted is for group communication (or according to whether the DCI is a group common DCI or a UE-specific DCI). The controller 1720 may determine a modulation order and a target code rate of data to be transmitted through a PDSCH scheduled by DCI, and may determine an MCS index indicating the modulation order and the target code rate. The MCS index may be determined using different mcs-Tables according to the type of DCI. In addition, the controller 1720 may transmit the DCI including the MCS index to the terminal.

Also, the controller 1720 may transmit the first DCI and the second DCI. When data transmitted in the first PDSCH is to be retransmitted in the second PDSCH, the NDI value is set the same for the same HARQ process number regardless of the RNTI values used in the first DCI and the second DCI and transmitted to the terminal. can Also, when the controller 1720 intends to transmit data having the same TBS as data transmitted in the first PDSCH, the controller 1720 may set the value of the MCS index included in the second DCI to a specific value or more. In addition, when the controller 1720 intends to process data regardless of scheduling restrictions, the time domain resource assignment information included in the DCI may set not to satisfy (or satisfy) a specific condition. The above-described operation of the base station may be controlled by the controller 1720, and detailed description thereof will be omitted.

The storage unit 1730 may store at least one of information transmitted and received through the transceiver 1710 and information generated through the control unit 1720 .

Accordingly, according to various embodiments of the present disclosure, in a method performed by a terminal in a communication system, in a method performed by a terminal in a communication system, the method comprising: receiving configuration information for a group common resource from a base station; receiving downlink control information (DCI) from the base station based on the configuration information; checking whether a group common radio network temporary identifier (RNTI) is used for scrambling of a cyclic redundancy check (CRC) attached to the DCI; and determining a code rate and a modulation order based on group common modulation and coding scheme (MCS) related information when the group common RNTI is used.

In addition, according to various embodiments of the present disclosure, in a method performed by a base station in a communication system, the method comprising: transmitting configuration information for a group common resource to a terminal; transmitting downlink control information (DCI) to the terminal based on the configuration information; and transmitting data based on the DCI. When a group common radio network temporary identifier (RNTI) is used for scrambling of a cyclic redundancy check (CRC) attached to the DCI, the MCS included in the DCI ( It is characterized in that the modulation and coding scheme index is determined based on group common modulation and coding scheme (MCS) related information.

In addition, according to various embodiments of the present disclosure, in a terminal in a communication system, a transceiver; and connected to the transceiver, receiving configuration information for a group common resource from a base station, receiving downlink control information (DCI) from the base station based on the configuration information, and attaching to the DCI It is checked whether a group common radio network temporary identifier (RNTI) is used for scrambling of a cyclic redundancy check (CRC), and when the group common RNTI is used, the code rate and It characterized in that it comprises a control unit for determining the modulation order.

In addition, according to various embodiments of the present disclosure, in a base station in a communication system, a transceiver; and connected to the transceiver, transmits configuration information for group common resources to the terminal, transmits downlink control information (DCI) to the terminal based on the configuration information, and based on the DCI a control unit for transmitting data, wherein when a group common radio network temporary identifier (RNTI) is used for scrambling of a cyclic redundancy check (CRC) attached to the DCI, a modulation and coding scheme (MCS) index included in the DCI It is characterized in that it is determined based on group common modulation and coding scheme (MCS) related information.

On the other hand, in the drawings for explaining the method of the present invention, the order of description does not necessarily correspond to the order of execution, and the precedence relationship may be changed or may be executed in parallel.

Alternatively, the drawings for explaining the method of the present invention may omit some components and include only some components within a range that does not impair the essence of the present invention.

In addition, the method of the present invention may be implemented in a combination of some or all of the contents contained in each embodiment within a range that does not impair the essence of the invention.

Claims (15)

1. A method performed by a terminal in a communication system, comprising:

   Receiving configuration information for a group common resource from the base station;

   receiving downlink control information (DCI) from the base station based on the configuration information;

   checking whether a group common radio network temporary identifier (RNTI) is used for scrambling of a cyclic redundancy check (CRC) attached to the DCI; and

   and determining a code rate and a modulation order based on group common modulation and coding scheme (MCS) related information when the group common RNTI is used.
2. According to claim 1,

   If the group common RNTI is not used, further comprising determining a code rate and a modulation order based on UE-specific MCS-related information,

   The configuration information includes at least one of the group common MCS-related information or terminal-specific MCS-related information,

   The MCS-related information comprises information on a code rate and a modulation order corresponding to the MCS index.
3. According to claim 1,

   The DCI is a first DCI,

   When the second DCI is received, even when the RNTIs associated with the first DCI and the second DCI are different, when the NDI included in the second DCI is not toggled, data received from a resource scheduled by the second DCI is retransmission data.
4. 4. The method of claim 3,

   When the MCS index included in the second DCI is equal to or greater than a specific value, the size of data received in the resource scheduled by the second DCI is the same as the size of data received in the resource scheduled by the first DCI,

   When the number of symbols determined based on the time resource allocation information included in the second DCI does not satisfy a predetermined condition, scheduling by the second DCI even when the instantaneous data rate is greater than the maximum data rate supported by the terminal A method characterized in that the data received from the resource is processed.
5. A method performed by a base station in a communication system, comprising:

   transmitting configuration information for a group common resource to the terminal;

   transmitting downlink control information (DCI) to the terminal based on the configuration information; and

   Transmitting data based on the DCI,

   When a group common radio network temporary identifier (RNTI) is used for scrambling of a cyclic redundancy check (CRC) attached to the DCI, a modulation and coding scheme (MCS) index included in the DCI is a group common modulation and coding scheme (MCS) index. ) is determined based on the relevant information.
6. 6. The method of claim 5,

   When the group common RNTI is not used, the MCS index included in the DCI is determined based on UE-specific MCS-related information,

   The configuration information includes at least one of the group common MCS-related information or terminal-specific MCS-related information,

   The MCS-related information comprises information on a code rate and a modulation order corresponding to the MCS index.
7. 6. The method of claim 5,

   The DCI is a first DCI,

   When the second DCI is transmitted, when the NDI included in the second DCI is not toggled even when the RNTIs associated with the first DCI and the second DCI are different, data transmitted from a resource scheduled by the second DCI is retransmission data.
8. 8. The method of claim 7,

   When the MCS index included in the second DCI is equal to or greater than a specific value, the size of data transmitted in the resource scheduled by the second DCI is the same as the size of data received in the resource scheduled by the first DCI,

   When the number of symbols determined based on the time resource allocation information included in the second DCI does not satisfy a predetermined condition, scheduling by the second DCI even when the instantaneous data rate is greater than the maximum data rate supported by the terminal Method characterized in that the data transmitted from the resource is processed.
9. In a terminal in a communication system,

   transceiver; and

   connected to the transceiver,

   Receive configuration information for group common resources from the base station,

   Receive downlink control information (DCI) from the base station based on the configuration information,

   Check whether a group common radio network temporary identifier (RNTI) is used for scrambling of a cyclic redundancy check (CRC) attached to the DCI,

   and a controller for determining a code rate and a modulation order based on group common modulation and coding scheme (MCS) related information when the group common RNTI is used.
10. 10. The method of claim 9,

    If the group common RNTI is not used, further comprising determining a code rate and a modulation order based on UE-specific MCS-related information,

    The configuration information includes at least one of the group common MCS-related information or terminal-specific MCS-related information,

    The MCS-related information terminal, characterized in that it includes information on a code rate and modulation order corresponding to the MCS index.
11. 10. The method of claim 9,

    The DCI is a first DCI,

    When the second DCI is received, even when the RNTIs associated with the first DCI and the second DCI are different, when the NDI included in the second DCI is not toggled, data received from a resource scheduled by the second DCI is retransmission data.
12. 12. The method of claim 11,

    When the MCS index included in the second DCI is equal to or greater than a specific value, the size of data received in the resource scheduled by the second DCI is the same as the size of data received in the resource scheduled by the first DCI,

    When the number of symbols determined based on the time resource allocation information included in the second DCI does not satisfy a predetermined condition, scheduling by the second DCI even when the instantaneous data rate is greater than the maximum data rate supported by the terminal A terminal, characterized in that for processing the data received from the resource.
13. In a base station in a communication system,

    transceiver; and

    connected to the transceiver,

    Transmitting configuration information for group common resources to the terminal,

    Transmitting downlink control information (DCI) to the terminal based on the configuration information,

    A control unit for transmitting data based on the DCI,

    When a group common radio network temporary identifier (RNTI) is used for scrambling of a cyclic redundancy check (CRC) attached to the DCI, a modulation and coding scheme (MCS) index included in the DCI is a group common modulation and coding scheme (MCS) index. ) base station, characterized in that determined based on the related information.
14. 14. The method of claim 13,

    When the group common RNTI is not used, the MCS index included in the DCI is determined based on UE-specific MCS-related information,

    The configuration information includes at least one of the group common MCS-related information or terminal-specific MCS-related information,

    The MCS-related information is a base station, characterized in that it includes information on a code rate and a modulation order corresponding to the MCS index.
15. 17. The method of claim 16,

    The DCI is a first DCI,

    When the second DCI is transmitted, when the NDI included in the second DCI is not toggled even when the RNTIs associated with the first DCI and the second DCI are different, data transmitted from a resource scheduled by the second DCI is the retransmission data,

    When the MCS index included in the second DCI is equal to or greater than a specific value, the size of data transmitted in the resource scheduled by the second DCI is the same as the size of data received in the resource scheduled by the first DCI,

    When the number of symbols determined based on the time resource allocation information included in the second DCI does not satisfy a predetermined condition, scheduling by the second DCI even when the instantaneous data rate is greater than the maximum data rate supported by the terminal Base station, characterized in that the data transmitted from the resource is processed.

Images