WO2022019729A1

WO2022019729A1 - Method and device for transmitting and receiving control information and data in communication system using sidelink

Info

Publication number: WO2022019729A1
Application number: PCT/KR2021/009658
Authority: WO
Inventors: 여정호; 명세호; 김영범; 류현석; 박성진; 신철규; 최승훈
Original assignee: 삼성전자 주식회사
Priority date: 2020-07-24
Filing date: 2021-07-26
Publication date: 2022-01-27

Abstract

The present disclosure relates to: a communication technique for merging IoT technology with a 5G communication system for supporting a data transmission rate higher than that of a 4G system; and a system therefor. The present disclosure can be applied to intelligent services (for example, smart homes, smart buildings, smart cities, smart cars or connected cars, healthcare, digital education, retail, security- and safety-related services, and the like) on the basis of 5G communication technology and IoT-related technology. According to an embodiment of the present disclosure, provided is a method for a transmission terminal in a communication system. The method comprises the steps of: transmitting first sidelink control information (SCI) to a reception terminal; and transmitting second SCI and sidelink data to the reception terminal on the basis of the first SCI, wherein the number of coded modulation symbols for the transmission of the second SCI is based on the first SCI.

Description

Method and apparatus for transmitting and receiving control information and data in a communication system using a sidelink

The present disclosure generally relates to a wireless communication system, and more particularly, to an apparatus and method for transmitting and receiving data of a terminal through a sidelink in a wireless communication system.

Efforts are being made to develop an improved 5G communication system or pre-5G communication system in order to meet the increasing demand for wireless data traffic after commercialization of the 4G communication system. For this reason, the 5G communication system or the pre-5G communication system is called a 4G network after (Beyond 4G Network) communication system or an LTE system after (Post LTE) system. In order to achieve a high data rate, the 5G communication system is being considered for implementation in a very high frequency (mmWave) band (eg, such as a 60 gigabyte (60 GHz) band). In order to alleviate the path loss of radio waves and increase the propagation distance of radio waves in the ultra-high frequency band, in the 5G communication system, beamforming, massive MIMO, and Full Dimensional MIMO (FD-MIMO) are used. ), array antenna, analog beam-forming, and large scale antenna technologies are being discussed. In addition, for network improvement of the system, in the 5G communication system, an evolved small cell, an advanced small cell, a cloud radio access network (cloud RAN), and an ultra-dense network (ultra-dense network) , Device to Device communication (D2D), wireless backhaul, moving network, cooperative communication, Coordinated Multi-Points (CoMP), and reception interference cancellation Technology development is underway. In addition, in the 5G system, the advanced coding modulation (ACM) methods FQAM (Hybrid FSK and QAM Modulation) and SWSC (Sliding Window Superposition Coding), and advanced access technologies FBMC (Filter Bank Multi Carrier), NOMA (non orthogonal multiple access), and sparse code multiple access (SCMA) are being developed.

On the other hand, the Internet is evolving from a human-centered connection network where humans create and consume information to an Internet of Things (IoT) network that exchanges and processes information between distributed components such as objects. Internet of Everything (IoE) technology, which combines big data processing technology through connection with cloud servers, etc. with IoT technology, is also emerging. In order to implement IoT, technology elements such as sensing technology, wired and wireless communication and network infrastructure, service interface technology, and security technology are required. , M2M), and MTC (Machine Type Communication) are being studied. In the IoT environment, an intelligent IT (Internet Technology) service that collects and analyzes data generated from connected objects and creates new values in human life can be provided. IoT is a field of smart home, smart building, smart city, smart car or connected car, smart grid, health care, smart home appliance, advanced medical service, etc. can be applied to

Accordingly, various attempts are being made to apply the 5G communication system to the IoT network. For example, in technologies such as sensor network, machine to machine (M2M), and MTC (Machine Type Communication), 5G communication technology is implemented by techniques such as beam forming, MIMO, and array antenna. there will be The application of cloud radio access network (cloud RAN) as the big data processing technology described above can be said to be an example of convergence of 5G technology and IoT technology.

In addition, in the 5G system, FQAM (Hybrid Frequency Shift Keying and Quadrature Amplitude Modulation) and SWSC (Sliding Window Superposition Coding), which are advanced coding modulation (Advanced Coding Modulation, ACM) methods, and FBMC (Filter Bank Multi Carrier), an advanced access technology, ), Non Orthogonal Multiple Access (NOMA), and Sparse Code Multiple Access (SCMA) are being developed.

As a wireless communication system develops, such as a 5G system, it is expected to be able to provide various services. In order to smoothly provide related services in a communication system using a sidelink, such as V2X communication, in line with the development of such a communication system, a method of mapping sidelink control information to resources and determining a transport block size (TBS) A method needs to be devised.

As described above, there is a need to devise a method and apparatus for transmitting and receiving control information and data in a wireless communication system.

A method and apparatus for transmitting and receiving control information and data in a wireless communication system are provided through the present disclosure.

An embodiment of the present disclosure provides a method and apparatus for determining control information mapping in a sidelink. Since the mapping method of control information is determined according to the method and apparatus proposed in an embodiment of the present disclosure, the transmitting terminal and the receiving terminal can understand the mapping of control information transmitted and received with each other as the same mapping method.

In addition, a method and apparatus for determining a transport block size (TBS) for data transmission/reception in a sidelink are provided through an embodiment of the present disclosure. By determining the TBS according to the method and apparatus proposed in an embodiment of the present disclosure, the transmitting terminal and the receiving terminal can understand the TBS for a TB (transport block) that transmits and receives each other as the same TBS.

A method for a transmitting terminal to transmit a PSSCH in a wireless communication system according to an embodiment of the present disclosure includes: determining a resource for transmitting the PSSCH; determining scheduling parameters to be included in SCI based on the determined resource for transmitting the PSSCH; determining a value of a bit field of second control information and a transmission resource to which the second control information is mapped based on the determined scheduling parameters; Based on the determined scheduling parameters, the value of the bitfield of the second control information, and the transmission resource to which the second control information is mapped, the bitfield value of the first control information and the transmission resource to which the first control information is mapped determining; and transmitting the first control information, the second control information, and the PSSCH.

A method for decoding a PSSCH in a receiving terminal of a mobile communication system according to an embodiment of the present disclosure includes decoding first control information, and determining whether to decode the second control information according to a decoding result of the first control information determining, based on a decoding result of the first control information and a decoding result of the second control information, determining a PSSCH transmission resource, and decoding the PSSCH based on the PSSCH transmission resource can

A method of a first terminal in a communication system according to an embodiment of the present disclosure includes transmitting first sidelink control information (SCI) to a second terminal; and transmitting a second SCI and sidelink data to the second terminal based on the first SCI, wherein the number of coded modulation symbols for transmission of the second SCI is the It is characterized in that it is based on the first SCI.

A method of a second terminal in a communication system according to an embodiment of the present disclosure includes: receiving a first SCI from a first terminal; and receiving a second SCI and sidelink data from the first terminal based on the first SCI, wherein the number of coded modulation symbols for transmission of the second SCI is based on the first SCI characterized in that

A first terminal of a communication system according to an embodiment of the present disclosure includes: a transceiver; and connected to the transceiver, transmits a first SCI to a second terminal through the transceiver, and based on the first SCI, transmits a second SCI and sidelink data to the second terminal through the transceiver and a controller, wherein the number of coded modulation symbols for transmission of the second SCI is based on the first SCI.

A second terminal of a communication system according to an embodiment of the present disclosure includes: a transceiver; and connected to the transceiver, receiving a first SCI from a first terminal through the transceiver, and based on the first SCI, receiving a second SCI and sidelink data from the first terminal through the transceiver and a controller, wherein the number of coded modulation symbols for transmission of the second SCI is based on the first SCI.

According to various embodiments of the present disclosure, more efficient transmission and reception of control information and data may be achieved in a wireless communication system, particularly, in a communication system using a sidelink.

According to an embodiment of the present disclosure, since the mapping method of sidelink control information is determined, the transmitting terminal and the receiving terminal can understand the mapping of control information transmitted and received with each other as the same mapping method.

In addition, according to an embodiment of the present disclosure, since the transmitting and receiving terminals may have a common understanding of the size of a TB (transport block) when performing communication between terminals, smooth communication between terminals may be possible.

Effects obtainable in the present disclosure are not limited to the above-mentioned effects, and other effects not mentioned may be clearly understood by those of ordinary skill in the art to which the present disclosure belongs from the description below. will be.

1 is a diagram illustrating a wireless communication system according to an embodiment of the present disclosure.

2 is a diagram illustrating a configuration of a base station in a wireless communication system according to an embodiment of the present disclosure.

3 is a diagram illustrating a configuration of a terminal in a wireless communication system according to an embodiment of the present disclosure.

4 is a diagram illustrating a configuration of a communication unit in a wireless communication system according to an embodiment of the present disclosure.

5 is a diagram illustrating a resource structure in a time-frequency domain in a wireless communication system according to an embodiment of the present disclosure.

6A is a diagram illustrating an example of allocation of data for each service to a frequency-time resource in a wireless communication system according to an embodiment of the present disclosure.

6B is a diagram illustrating another example of allocating data for each service to a frequency-time resource in a wireless communication system according to an embodiment of the present disclosure.

7 is a diagram illustrating a data encoding method in a wireless communication system according to an embodiment of the present disclosure.

8 is a diagram illustrating a mapping of a synchronization signal and a broadcast channel in a wireless communication system according to an embodiment of the present disclosure.

9 is a diagram illustrating an example of arrangement of a synchronization signal/physical broadcast channel block (SSB) in a wireless communication system according to an embodiment of the present disclosure.

10A is a diagram illustrating transmittable symbol positions of an SSB according to a subcarrier interval in a wireless communication system according to an embodiment of the present disclosure.

10B is a diagram illustrating transmittable symbol positions of an SSB according to a subcarrier interval in a wireless communication system according to an embodiment of the present disclosure.

11 is a diagram illustrating an example of generation and transmission of parity bits in a wireless communication system according to an embodiment of the present disclosure.

12A is a diagram illustrating an example of groupcasting transmission in a wireless communication system according to an embodiment of the present disclosure.

12B is a diagram illustrating an example of hybrid automatic repeat request (HARQ) feedback transmission according to group casting in a wireless communication system according to an embodiment of the present disclosure.

13 is a diagram illustrating an example of unicasting transmission in a wireless communication system according to an embodiment of the present disclosure.

14A is a diagram illustrating an example of sidelink data transmission according to scheduling of a base station in a wireless communication system according to an embodiment of the present disclosure.

14B is a diagram illustrating an example of sidelink data transmission without scheduling of a base station in a wireless communication system according to an embodiment of the present disclosure.

15 is a diagram illustrating an example of a channel structure of a slot used for sidelink communication in a wireless communication system according to an embodiment of the present disclosure.

16A is a diagram illustrating a first example of a distribution of a feedback channel in a wireless communication system according to an embodiment of the present disclosure.

16B is a diagram illustrating a second example of distribution of a feedback channel in a wireless communication system according to an embodiment of the present disclosure.

17A is a diagram illustrating an example of a method in which resource allocation of a physical sidelink shared channel (PSSCH) is performed in units of subchannels according to an embodiment of the present disclosure.

17B is a diagram illustrating an example of a method in which resource allocation of a PSSCH is performed in units of subchannels according to an embodiment of the present disclosure.

18 is a flowchart illustrating a method for a transmitting terminal to determine values of bit fields of first control information and second control information according to an embodiment of the present disclosure.

19 is a flowchart illustrating a method for a receiving terminal to sequentially decode first control information and second control information, and to decode a PSSCH based on the first control information according to an embodiment of the present disclosure.

20 is a diagram illustrating an example in which a frequency domain is divided in units of subchannels in a given resource pool according to an embodiment of the present disclosure, and resource allocation for data transmission is allocated in units of subchannels.

21 is a diagram illustrating a demodulation reference signal (DMRS) of a sidelink control channel and data when the first three symbols are used for downlink in a slot according to an embodiment of the present disclosure.

22A is a diagram illustrating a pattern including one DMRS symbol according to an embodiment of the present disclosure.

22B is a diagram illustrating a pattern including two DMRS symbols according to an embodiment of the present disclosure.

22C is a diagram illustrating a pattern including three DMRS symbols according to an embodiment of the present disclosure.

22D is a diagram illustrating a pattern including four DMRS symbols according to an embodiment of the present disclosure.

23A is a diagram illustrating a modified example of a DMRS pattern according to an embodiment of the present disclosure.

23B is a diagram illustrating a modified example of a DMRS pattern according to an embodiment of the present disclosure.

23C is a diagram illustrating a modified example of a DMRS pattern according to an embodiment of the present disclosure.

24 is a diagram illustrating a mapping in a symbol to which a DMRS for decoding a PSSCH is mapped in sidelink data transmission/reception according to an embodiment of the present disclosure;

25 is a block diagram illustrating an internal structure of a terminal according to an embodiment of the present disclosure.

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

27 is a block diagram of a terminal according to an embodiment of the present disclosure;

28 is a block diagram of a base station according to an embodiment of the present disclosure.

29 is a diagram illustrating a method of transmitting second control information in a PSSCH according to an embodiment of the present disclosure.

30 is a diagram illustrating another example in which second control information is mapped according to an embodiment of the present disclosure.

31 is a diagram illustrating another example in which second control information is mapped according to an embodiment of the present disclosure.

32 is a diagram illustrating an embodiment of a symbol allocated to a PSSCH according to an embodiment of the present disclosure;

33 is a diagram illustrating an embodiment of a symbol allocated to a PSSCH according to an embodiment of the present disclosure.

34 is a diagram illustrating an embodiment in which second control information is mapped according to an embodiment of the present disclosure.

35 is a diagram illustrating a case in which a resource for mapping second control information is insufficient according to an embodiment of the present disclosure;

36 is a diagram illustrating an example in which second control information is mapped to all remaining REs when there are resource elements (REs) remaining in a resource block (RB) to which second control information is mapped according to an embodiment of the present disclosure. .

Hereinafter, embodiments of the present disclosure 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 disclosure pertains and are not directly related to the present disclosure will be omitted. This is to more clearly convey the gist of the present disclosure without obscuring the gist of the present disclosure 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 disclosure, 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 disclosure is not limited to the embodiments disclosed below, but may be implemented in various different forms, and only the present embodiments make the disclosure of the present disclosure complete, and common knowledge in the art to which the present disclosure belongs 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). Create 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 is also possible that the instructions stored in the flow chart block(s) 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 is also possible that instructions for performing the processing equipment 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 blocks to occur out of order. For example, two blocks shown one after another may be performed substantially simultaneously, or the blocks may sometimes be performed in the 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. '~' may be configured to reside on an addressable storage medium or may be configured to refresh one or more processors. Thus, as an example, '~' refers to components such as software components, object-oriented software components, class components, and task components, and processes, functions, properties, and procedures. , subroutines, segments of program code, drivers, firmware, microcode, circuitry, data, databases, data structures, tables, arrays, and variables. Functions provided within the elements and '~ units' may be combined into a smaller number of elements 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, in an embodiment, '~ unit' may include one or more processors.

A term that refers to a signal, a term that refers to a channel, a term that refers to control information, a term that refers to network entities, a term that refers to a component of a device, and a term that refers to an access node used in the following description Terms for identification, terms for messages, terms for interfaces between network objects, terms for various types of identification information, and the like are exemplified for convenience of description. Accordingly, the present disclosure is not limited to the terms described below, and other terms referring to objects having equivalent technical meanings may be used.

Hereinafter, in the present disclosure, a physical channel and a signal may be used interchangeably with a data or a control signal. For example, a physical downlink shared channel (PDSCH) (or PSSCH) is a term that refers to a physical channel through which data is transmitted, but the PDSCH (or PSSCH) may also be used to refer to data. That is, in the present disclosure, the expression 'transmitting a physical channel' may be interpreted equivalently to the expression 'transmitting data or a signal through a physical channel'.

Hereinafter, in the present disclosure, higher signaling refers to a signal transmission method in which a base station is transmitted to a terminal using a downlink data channel of a physical layer or from a terminal to a base station using an uplink data channel of a physical layer. Upper signaling may be understood as radio resource control (RRC) signaling or MAC control element (hereinafter, 'CE').

In addition, in the present disclosure, in order to determine whether a specific condition is satisfied (satisfied) or satisfied (fulfilled), an expression of more than or less than is used, but this is only a description to express an example, and more or less description is excluded not to do Conditions described as 'more than' may be replaced with 'more than', conditions described as 'less than', and conditions described as 'more than and less than' may be replaced with 'more than and less than'.

For convenience of description, the present disclosure uses terms and names defined in 3GPP 3rd Generation Partnership Project Long Term Evolution (LTE) or New Radio (NR) standards, or terms and names modified based on them. However, the present disclosure is not limited by the above-described terms and names, and may be equally applied to systems conforming to other standards. In particular, the present disclosure is applicable to 3GPP NR (5th generation mobile communication standard). In addition, 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 based on 5G communication technology and IoT-related technology) etc.) can be applied.

FIG. 1 is a diagram illustrating a base station 110 , a terminal 120 , and a terminal 130 as part of nodes using a wireless channel in a wireless communication system. 1 shows only one base station, other base stations that are the same as or similar to the base station 110 may be further included.

The base station 110 is a network infrastructure that provides wireless access to the

terminals

120 and 130 . The base station 110 has coverage defined as a certain geographic area based on a distance capable of transmitting a signal. In addition to the base station (base station), the base station 110 includes an 'access point (AP)', an 'eNodeB (eNodeB)', a '5G node (5th generation node)', a 'next generation nodeB' , gNB)', 'wireless point', 'transmission/reception point (TRP)', or other terms having an equivalent technical meaning.

Each of the terminal 120 and the terminal 130 is a device used by a user, and performs communication with the base station 110 through a wireless channel. The link from the base station 110 to the terminal 120 or the terminal 130 is downlink (DL), and the link from the terminal 120 or the terminal 130 to the base station 110 is uplink (UL). ) is referred to as In addition, the terminal 120 and the terminal 130 may perform communication through a mutual wireless channel. In this case, a device-to-device link (D2D) between the terminal 120 and the terminal 130 is referred to as a sidelink, and the sidelink may be mixed with a PC5 interface. In some cases, at least one of the terminal 120 and the terminal 130 may be operated without the user's involvement. That is, at least one of the terminal 120 and the terminal 130 is a device that performs machine type communication (MTC) and may not be carried by the user. Each of the terminal 120 and the terminal 130 is a 'user equipment (UE)', a 'mobile station', a 'subscriber station', a 'remote terminal other than the terminal (terminal)' )', 'wireless terminal', or 'user device' or other terms having an equivalent technical meaning.

The base station 110 , the terminal 120 , and the terminal 130 may transmit and receive radio signals in millimeter wave (mmWave) bands (eg, 28 GHz, 30 GHz, 38 GHz, and 60 GHz). In this case, in order to improve the channel gain, the base station 110 , the terminal 120 , and the terminal 130 may perform beamforming. Here, the beamforming may include transmit beamforming and receive beamforming. That is, the base station 110 , the terminal 120 , and the terminal 130 may impart directivity to a transmission signal or a reception signal. To this end, the base station 110 and the

terminals

120 and 130 may select the serving

beams

112, 113, 121, and 131 through a beam search or beam management procedure. . After the serving

beams

112, 113, 121, and 131 are selected, subsequent communication may be performed through a resource having a quasi co-located (QCL) relationship with the resource that has transmitted the serving

beams

112, 113, 121, 131. Can be performed. have.

If the large-scale characteristics of the channel carrying the symbol on the first antenna port can be inferred from the channel carrying the symbol on the second antenna port, then the first antenna port and the second antenna port are said to be in a QCL relationship. can be evaluated. For example, a wide range of characteristics include delay spread, Doppler spread, Doppler shift, average gain, average delay, spatial receiver parameter. may include at least one of

The configuration illustrated in FIG. 2 may be understood as a configuration of the base station 110 . Terms such as '... unit' and '... group' used below mean a unit that processes at least one function or operation, which may be implemented as hardware or software, or a combination of hardware and software. have.

Referring to FIG. 2 , the base station may include a wireless communication unit 210 , a backhaul communication unit 220 , a storage unit 230 , and a control unit 240 .

The wireless communication unit 210 performs functions for transmitting and receiving signals through a wireless channel. For example, the wireless communication unit 210 performs a conversion function between the baseband signal and the bit stream according to the physical layer standard of the system. For example, when transmitting data, the wireless communication unit 210 generates complex symbols by encoding and modulating the transmitted bit stream. In addition, when receiving data, the wireless communication unit 210 restores the received bit stream by demodulating and decoding the baseband signal.

In addition, the wireless communication unit 210 up-converts the baseband signal into a radio frequency (RF) band signal, transmits it through the antenna, and downconverts the RF band signal received through the antenna into a baseband signal. To this end, the wireless communication unit 210 may include a transmit filter, a receive filter, an amplifier, a mixer, an oscillator, a digital to analog converter (DAC), an analog to digital converter (ADC), and the like. Also, the wireless communication unit 210 may include a plurality of transmission/reception paths. Furthermore, the wireless communication unit 210 may include at least one antenna array composed of a plurality of antenna elements.

In terms of hardware, the wireless communication unit 210 may be composed of a digital unit and an analog unit, and the analog unit includes a plurality of sub-units according to operating power, operating frequency, etc. can be composed of The digital unit may be implemented by at least one processor (eg, a digital signal processor (DSP)).

The wireless communication unit 210 transmits and receives signals as described above. Accordingly, all or part of the wireless communication unit 210 may be referred to as a 'transmitter', a 'receiver', or a 'transceiver'. In addition, in the following description, transmission and reception performed through a wireless channel may be used to mean that the above-described processing is performed by the wireless communication unit 210 .

The backhaul communication unit 220 provides an interface for performing communication with other nodes in the network. That is, the backhaul communication unit 220 converts the bit string transmitted from the base station to another node, for example, another access node, another base station, upper node, core network, etc. into a physical signal, and converts the physical signal received from the other node. Convert to bit string.

The storage unit 230 stores data such as a basic program, an application program, and setting information for the operation of the base station. The storage unit 230 may be configured as a volatile memory, a non-volatile memory, or a combination of a volatile memory and a non-volatile memory. In addition, the storage unit 230 provides the stored data according to the request of the control unit 240 .

The controller 240 controls overall operations of the base station. For example, the control unit 240 transmits and receives a signal through the wireless communication unit 210 or through the backhaul communication unit 220 . In addition, the control unit 240 writes and reads data in the storage unit 230 . In addition, the control unit 240 may perform functions of a protocol stack required by the communication standard. According to another implementation example, the protocol stack may be included in the wireless communication unit 210 . To this end, the controller 240 may include at least one processor. According to an embodiment, the controller 240 may control the base station to perform operations according to an embodiment in an embodiment to be described later.

The configuration illustrated in FIG. 3 may be understood as a configuration of the terminal 120 . Terms such as '... unit' and '... group' used below mean a unit that processes at least one function or operation, which may be implemented as hardware or software, or a combination of hardware and software. have.

Referring to FIG. 3 , the terminal may include a communication unit 310 , a storage unit 320 , and a control unit 330 .

The communication unit 310 performs functions for transmitting and receiving signals through a wireless channel. For example, the communication unit 310 performs a function of converting between a baseband signal and a bit stream according to a physical layer standard of the system. For example, when transmitting data, the communication unit 310 generates complex symbols by encoding and modulating the transmitted bit stream. In addition, when receiving data, the communication unit 310 restores the received bit stream by demodulating and decoding the baseband signal. In addition, the communication unit 310 up-converts the baseband signal into an RF band signal, transmits the signal through the antenna, and downconverts the RF band signal received through the antenna into a baseband signal. For example, the communication unit 310 may include a transmit filter, a receive filter, an amplifier, a mixer, an oscillator, a DAC, an ADC, and the like.

Also, the communication unit 310 may include a plurality of transmission/reception paths. Furthermore, the communication unit 310 may include at least one antenna array composed of a plurality of antenna elements. In terms of hardware, the communication unit 310 may include a digital circuit and an analog circuit (eg, a radio frequency integrated circuit (RFIC)). Here, the digital circuit and the analog circuit may be implemented as one package. Also, the communication unit 310 may include a plurality of RF chains. Furthermore, the communication unit 310 may perform beamforming.

The communication unit 310 transmits and receives signals as described above. Accordingly, all or part of the communication unit 310 may be referred to as a 'transmitter', 'receiver', or 'transceiver'. In addition, in the following description, transmission and reception performed through a wireless channel may be used to mean that the above-described processing is performed by the communication unit 310 .

The storage unit 320 stores data such as a basic program, an application program, and setting information for the operation of the terminal. The storage unit 320 may be configured as a volatile memory, a non-volatile memory, or a combination of a volatile memory and a non-volatile memory. In addition, the storage unit 320 provides the stored data according to the request of the control unit 330 .

The controller 330 controls overall operations of the terminal. For example, the control unit 330 transmits and receives a signal through the communication unit 310 . In addition, the control unit 330 writes and reads data in the storage unit 320 . And, the control unit 330 may perform the functions of the protocol stack required by the communication standard. To this end, the controller 330 may include at least one processor or microprocessor, or may be a part of the processor. Also, a part of the communication unit 310 and the control unit 330 may be referred to as a communication processor (CP). According to an embodiment, the controller 330 may control the terminal to perform operations according to an embodiment in an embodiment to be described later.

4 is a diagram illustrating a detailed configuration of the wireless communication unit 210 of FIG. 2 or the communication unit 310 of FIG. 3 . Specifically, FIG. 4 is a diagram illustrating components for performing beamforming as a part of the wireless communication unit 210 of FIG. 2 or the communication unit 310 of FIG. 3 .

Referring to FIG. 4 , the wireless communication unit 210 or the communication unit 310 includes an encoding and modulation unit 402 , a digital beamforming unit 404 , a plurality of transmission paths 406-1 to 406-N, or analog It may include a beamformer 408 .

The encoding and modulation unit 402 performs channel encoding. For channel encoding, at least one of a low density parity check (LDPC) code, a convolution code, and a polar code may be used. The encoder and modulator 402 generates modulation symbols by performing constellation mapping.

The digital beamformer 404 performs beamforming on a digital signal (eg, modulation symbols). To this end, the digital beamformer 404 multiplies the modulation symbols by beamforming weights. Here, the beamforming weights are used to change the magnitude and phase of a signal, and may be referred to as a 'precoding matrix', a 'precoder', or the like. The digital beamformer 404 outputs digital beamformed modulation symbols to the plurality of transmission paths 406-1 to 406-N. In this case, according to a multiple input multiple output (MIMO) transmission technique, modulation symbols may be multiplexed or the same modulation symbols may be provided to a plurality of transmission paths 406-1 to 406-N.

The plurality of transmission paths 406 - 1 to 406 -N convert digital beamformed digital signals into analog signals. To this end, each of the plurality of transmission paths 406 - 1 to 406 -N may include an inverse fast fourier transform (IFFT) calculator, a cyclic prefix (CP) inserter, a DAC, and an up converter. The CP insertion unit is for an orthogonal frequency division multiplexing (OFDM) method, and may be excluded when another physical layer method (eg, filter bank multi-carrier (FBMC)) is applied. That is, the plurality of transmission paths 406 - 1 to 406 -N provide independent signal processing processes for a plurality of streams generated through digital beamforming. However, depending on the implementation method, some of the components of the plurality of transmission paths 406 - 1 to 406 -N may be used in common.

The analog beamformer 408 performs beamforming on an analog signal. To this end, the digital beamformer 404 multiplies the analog signals by beamforming weights. Here, the beamforming weights may be used to change the magnitude and phase of the signal. Specifically, the analog beamformer 440 may be variously configured according to a connection structure between the plurality of transmission paths 406 - 1 to 406 -N and antennas. For example, each of the plurality of transmission paths 406 - 1 to 406 -N may be connected to one antenna array. As another example, a plurality of transmission paths 406 - 1 to 406 -N may be connected to one antenna array. As another example, the plurality of transmission paths 406 - 1 to 406 -N may be adaptively connected to one antenna array or connected to two or more antenna arrays.

A wireless communication system, for example, 3GPP high speed packet access (HSPA), long term evolution (LTE) or evolved universal terrestrial radio access (E-UTRA), LTE-A (Advanced), 3GPP2 HRPD (high rate packet data), UMB (ultra mobile broadband), and IEEE 802.16e, such as communication standards, such as high-speed, high-quality packet data service is developing into a broadband wireless communication system. . In addition, as a 5G wireless communication system, a communication standard of 5G or NR (new radio) is being made.

The NR system employs an orthogonal frequency division multiplexing (OFDM) scheme in downlink (DL) and uplink. More specifically, a cyclic-prefix OFDM (CP-OFDM) scheme in downlink and a discrete Fourier transform spreading OFDM (DFT-S-OFDM) scheme in uplink along with CP-OFDM are adopted in the uplink. The uplink refers to a radio link through which the terminal transmits data or control signals to the base station, and the downlink refers to a radio link through which the base station transmits data or control signals to the user equipment. The multiple access method divides the data or control information of each user by allocating and operating the time-frequency resources in which the data or control information is transmitted for each user in general so that they do not overlap each other, that is, orthogonality is established.

The NR system employs a hybrid automatic repeat request (HARQ) method for retransmitting the corresponding data in the physical layer when a decoding failure occurs in the initial transmission. According to the HARQ scheme, when the receiver fails to correctly decode data, the receiver transmits a negative acknowledgment (NACK), which is information informing the transmitter of decoding failure, so that the transmitter can retransmit the data in the physical layer. . The receiver can improve data reception performance by combining data retransmitted by the transmitter with data that has previously failed to be decoded. In addition, when the receiver correctly decodes data, the transmitter can transmit new data by transmitting an acknowledgment (ACK), which is information informing the transmitter of decoding success, to the transmitter.

5 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 downlink or uplink.

In FIG. 5 , the horizontal axis represents the time domain, and the vertical axis represents the frequency domain. The minimum transmission unit in the time domain is an OFDM symbol, and N _symb OFDM symbols 502 are gathered to form one slot 506 . The length of the subframe is defined as 1.0ms, and the length of the radio frame 514 is defined as 10ms. The minimum transmission unit in the frequency domain is a subcarrier, and the bandwidth of the entire system transmission bandwidth is composed of a _{total of N BW subcarriers 504 .} Specific numerical values such as N _symb and N _BW may be variably applied depending on the system.

A basic unit of a resource in the time-frequency domain is a resource element (hereinafter, 'RE') 512, which may be represented by an OFDM symbol index and a subcarrier index. A resource block (RB, or physical resource block, hereinafter 'PRB') 508 consists of N _symb consecutive OFDM symbols 502 _{in the time domain and N RB} consecutive subcarriers 510 in the frequency domain. is defined Thus, one RB 508 includes N _symb ×N _RB REs 512 . In general, the minimum transmission unit of data is an RB. In the NR system, in general, N _symb =14, N _RB =12, and N _BW and N _RB are proportional to the bandwidth of the system transmission band. A data rate may increase in proportion to the number of RBs scheduled for the UE. In the NR system, in the case of a frequency division duplex (FDD) system in which downlink and uplink are divided by frequencies, the downlink transmission bandwidth and the uplink transmission bandwidth may be different from each other. The channel bandwidth represents a radio frequency (RF) bandwidth corresponding to the system transmission bandwidth. [Table 1] and [Table 2] show the correspondence between system transmission bandwidth, subcarrier spacing (SCS) and channel bandwidth defined in the NR system in frequency bands lower than 6 GHz and higher than 6 GHz represents a part of For example, an NR system having a 100 MHz channel bandwidth with a 30 kHz subcarrier spacing consists of 273 RBs. In [Table 1] and [Table 2], N/A may be a bandwidth-subcarrier combination not supported by the NR system.

채널대역폭 [MHz]Channel bandwidth [MHz]	SCS SCS	55	1010	2020	5050	8080	100100
전송 대역폭 구성 N_RB Transmission Bandwidth Configuration N _{R B}	15kHz15 kHz	2525	5252	106106	207207	N/AN/A	N/AN/A
	30kHz30 kHz	1111	2424	5151	133133	217217	273273
	60kHz60kHz	N/AN/A	1111	2424	6565	107107	135135

채널대역폭 [MHz]Channel bandwidth [MHz]	SCS SCS	5050	100100	200200	400400
전송 대역폭 구성 N_RB Transmission Bandwidth Configuration N _{R B}	60kHz60kHz	6666	132132	264264	N/AN/A
	120kHz120kHz	3232	6666	132132	264264

In the NR system, scheduling information for downlink data or uplink data may be transmitted from the base station to the terminal through downlink control information (hereinafter 'DCI'). DCI is defined in various formats, and whether it is an uplink grant that is scheduling information for uplink data or a downlink grant that is scheduling information for downlink data, and the size of control information according to each format. Whether it is a small compact DCI, whether spatial multiplexing using multiple antennas is applied, whether DCI for power control, etc. may be determined. For example, DCI format 1-1, which is scheduling control information for downlink data, may include at least one of items shown in Table 3 below.

항목Item	내용Contents
반송파 지시자carrier indicator	어떠한 주파수 반송파에서 전송되는지를 지시한다.It indicates on which frequency carrier it is transmitted.
DCI 포맷 지시자DCI format indicator	해당 DCI가 하향링크용인지 상향링크용인지 구분하는 지시자이다.This is an indicator for distinguishing whether the corresponding DCI is for downlink or uplink.
BWP(bandwidth part) 지시자BWP (bandwidth part) directive	어떠한 BWP에서 전송되는지를 지시한다.It indicates in which BWP it is transmitted.
주파수 영역 자원 할당Frequency domain resource allocation	데이터 전송에 할당된 주파수 영역의 RB를 지시한다. 시스템 대역폭 및 리소스 할당 방식에 따라 표현하는 리소스가 결정될 수 있다.Indicates an RB in a frequency domain allocated for data transmission. A resource to be expressed may be determined according to a system bandwidth and a resource allocation method.
시간 영역 자원 할당Time domain resource allocation	어느 슬롯의 어느 OFDM 심볼에서 데이터 관련 채널이 전송될지를 지시한다. It indicates in which OFDM symbol in which slot a data-related channel is to be transmitted.
VRB-to-PRB 매핑VRB-to-PRB mapping	가상 RB(virtual RB: VRB) 인덱스와 물리RB(physical RB: PRB) 인덱스를 어떤 방식으로 매핑할 것인지를 지시한다.It indicates how to map a virtual RB (VRB) index and a physical RB (PRB) index.
MCS(modulation and coding scheme)Modulation and coding scheme (MCS)	데이터 전송에 사용된 변조방식과 코딩 레이트를 지시한다. 즉, QPSK인지, 16QAM인지, 64QAM인지, 256QAM인지에 대한 정보와 함께 TBS 및 채널코딩 정보를 알려줄 수 있는 코딩 레이트 값을 지시할 수 있다.It indicates the modulation method and coding rate used for data transmission. That is, it is possible to indicate a coding rate value that can inform TBS and channel coding information together with information on whether it is QPSK, 16QAM, 64QAM, or 256QAM.
CBG 전송 정보(codeblock group transmission information)CBG transmission information (codeblock group transmission information)	CBG 재전송이 설정된 경우, 어느 CBG가 전송되는지에 대한 정보를 지시한다.When CBG retransmission is configured, information on which CBG is transmitted is indicated.
HARQ 프로세스 번호(process number)HARQ process number	HARQ 의 프로세스 번호를 지시한다.It indicates the process number of HARQ.
NDI(new data indicator)New data indicator (NDI)	HARQ 초기전송인지 재전송인지를 지시한다.Indicates whether the HARQ is initial transmission or retransmission.
RV(redundancy version)RV (redundancy version)	HARQ 의 중복 버전(redundancy version)을 지시한다. It indicates a redundant version of HARQ.
PUCCH(physical uplink control channel)를 위한 TPC(transmit power control command)Transmit power control command (TPC) for a physical uplink control channel (PUCCH)	상향링크 제어 채널인 PUCCH에 대한 전송 전력 제어 명령을 지시한다.It indicates a transmit power control command for the uplink control channel, PUCCH.

In [Table 3], in the case of PDSCH transmission, time domain resource assignment is information about a slot in which the PDSCH is transmitted and the start symbol position S in the slot and the number of symbols L to which the PDSCH is mapped. can Here, S may be a relative position from the start of the slot, L may be the number of consecutive symbols, and S and L are start and length indicator values defined as in [Table 4] below. SLIV) can be determined.

if (L-1)≤7 then
SLIV=14·(L-1)+S
else
SLIV=14·(14-L+11)+(14-1-S)
where 0<L≤14-S

In the NR system, information about the correspondence between the SLIV value and the PDSCH or physical uplink shared channel (PUSCH) mapping type and information on the slot in which the PDSCH or PUSCH is transmitted is configured in one row through the RRC setting ( configured). Thereafter, by using the time domain resource allocation of DCI, the base station indicates to the terminal an index value defined in the configured correspondence, information on the slot in which the SLIV value, the PDSCH or PUSCH mapping type, and the PDSCH or PUSCH are transmitted can pass

For the NR system, PDSCH or PUSCH mapping types are defined as type A and type B. In the case of PDSCH or PUSCH mapping type A, a demodulation reference signal (DMRS) symbol starts in the second or third OFDM symbol in the slot. In the case of PDSCH or PUSCH mapping type B, a DMRS symbol starts from the first OFDM symbol of a time domain resource allocated for PUSCH transmission.

DCI may be transmitted in a physical downlink control channel (PDCCH) that is a downlink control channel through channel coding and modulation. PDCCH may be used to refer to control information itself rather than a channel. In general, DCI is scrambled by using a specific radio network temporary identifier (RNTI) or terminal identifier independently for each terminal, and is configured as an independent PDCCH after adding a cyclic redundancy check (CRC) and channel coding, and being transmitted can The PDCCH may be mapped to a control resource set (CORESET) configured for the UE.

Downlink data may be transmitted in PDSCH, which is a physical channel for downlink data transmission. The PDSCH may be transmitted after the control channel transmission period, and scheduling information such as a specific mapping position and a modulation method in the frequency domain may be indicated by DCI transmitted through the PDCCH. Among the control information constituting DCI, through MCS, the base station notifies the terminal of the modulation scheme applied to the PDSCH to be transmitted and the size of data to be transmitted (eg, transport block size (TBS). In one embodiment, the MCS is It may be composed of 5 bits or more or fewer bits The TBS corresponds to the size before channel coding for error correction is applied to TB (transport block), which is data that the base station wants to transmit.

In the present disclosure, a transport block (TB) may include a medium access control (MAC) header, MAC CE, one or more MAC service data unit (SDU), and padding bits. Alternatively, TB may indicate a data unit or MAC protocol data unit (PDU) that is sent down from the MAC layer to the physical layer.

Modulation schemes supported by the NR system are QPSK (quadrature phase shift keying), 16 QAM (quadrature amplitude modulation), 64 QAM, and 256 QAM, and each modulation order (Qm) is 2, 4, 6 or It could be 8. That is, 2 bits per symbol for QPSK, 4 bits per symbol for 16 QAM, 6 bits per symbol for 64 QAM, and 8 bits per symbol for 256 QAM may be transmitted, 1024 When QAM is supported, 10 bits per one symbol of 1024 QAM may be mapped and transmitted.

In terms of services, the NR system is designed to allow various services to be multiplexed freely in time and frequency resources, and accordingly, waveform/numerology, reference signals, etc. are dynamically or as needed. can be freely adjusted. In order to provide an optimal service to a terminal in wireless communication, it is important to optimize data transmission through measurement of channel quality and interference, and accordingly, accurate channel state measurement is essential. However, unlike 4G communication, where the channel and interference characteristics do not change significantly depending on frequency resources, in the case of 5G channels, the channel and interference characteristics change greatly depending on the service, so it is a frequency resource group (FRG) dimension that can be measured separately. support of a subset of On the other hand, the NR system can divide the types of supported services into eMBB (enhanced mobile broadband), mMTC (massive machine type communications), and URLLC (ultra-reliable and low-latency communications). eMBB is a high-speed transmission of high-capacity data, mMTC is a service that minimizes terminal power and connects multiple terminals, and URLLC is a service that aims for high reliability and low latency. Different requirements may be applied according to the type of service applied to the terminal. Examples of resource distribution of each service are shown in FIGS. 6A and 6B below. Hereinafter, a method in which frequency and time resources are allocated for information transmission in each system will be described with reference to FIGS. 6A and 6B .

Referring to FIG. 6A , resources may be allocated for the eMBB 622 , the

URLLCs

612 , 614 , 616 , and the mMTC 632 in the entire system frequency band 610 . When URLLC (612, 614, 616) data is generated while eMBB (622) data and mMTC (632) data are allocated and transmitted in a specific frequency band, eMBB (622) and mMTC (632) data are already allocated for eMBB (622) and mMTC (632). URLLC (612, 614, 616) data can be transmitted without emptying the part or transmitting eMBB (622) data and mMTC (632). Since URLLC requires a reduction in delay time, a resource for transmitting

URLLC

612 , 614 , and 616 data may be allocated to a portion of the resource allocated to the eMBB 622 . Of course, when the

URLLCs

612, 614, 616 are additionally allocated and transmitted in the resource to which the eMBB 622 is allocated, the eMBB 622 data may not be transmitted in the overlapping frequency-time resource. 622) data transmission performance may be reduced. That is, in this case, the eMBB 622 data transmission failure may occur due to the allocation of resources for the

URLLCs

612 , 614 , and 616 . The method shown in FIG. 6A may be referred to as a preemption method.

FIG. 6B is a diagram illustrating an embodiment in which each service is provided in each of the

subbands

662 , 664 , and 666 obtained by dividing the entire system frequency band 660 . Specifically, subband 662 may be used for

URLLC

672, 674, 576 data transmission, subband 664 may be used for eMBB 682 data transmission, and subband 666 may be used for mMTC 692 data transmission. . Information related to the configuration of the

subbands

662 , 664 , and 666 may be predetermined, and the information may be transmitted from the base station to the terminal through higher level signaling. Alternatively, the base station or the network node may arbitrarily divide information related to the

subbands

662 , 664 , and 666 without transmitting additional subband configuration information to the terminal and provide services according thereto.

According to an embodiment, a length of a transmission time interval (TTI) used for URLLC transmission may be shorter than a length of a TTI used for eMBB or mMTC transmission. In addition, a response of URLLC-related information may be transmitted faster than eMBB or mMTC, and accordingly, a terminal using the URLLC service may transmit/receive information with a low delay response. In order to transmit the above-described three services or data, a structure of a physical layer channel used for each type may be different from each other. For example, at least one of a length of a TTI, an allocation unit of a frequency resource, a structure of a control channel, and a data mapping method may be different from each other.

Although the three services and three data types have been described above, more kinds of services and data types corresponding thereto may exist. Even in this case, various embodiments to be described later may be implemented.

7 is a diagram illustrating that one TB is segmented into several code blocks (CBs) and CRC is added.

Referring to FIG. 7 , a CRC 714 may be added to the rear or front end of one TB 712 to be transmitted in uplink or downlink. The CRC 714 may have a 16-bit or 24-bit, or a pre-fixed number of bits, or a variable number of bits according to channel conditions, and may be used in the receiver to determine whether channel coding is successful. A block to which the TB 712 and CRC 714 are added may be divided into a plurality of CBs 722-1, 722-2, 722-(N-1), and 722-N. It can be divided into predefined sizes of CBs, in which case the last CB 722-N is smaller in size than the other CBs, or has the same length as the other CBs by adding 0, a random value or 1 can be configured. In each of the divided CBs

CRCs 732-1, 732-2, 732-(N-1), and 732-N may be added. The CRCs 732-1, 732-2, 732-(N-1), and 732-N may have 16 bits or 24 bits or a pre-fixed number of bits, to determine whether channel coding is successful at the receiver. can be used for

A TB 712 and a cyclic generator polynomial may be used to generate the CRC 714 . The recursive polynomial can be defined in various ways. For example, the recursive generating polynomial g _CRC24A (D) = D ²⁴ +D ²³ +D ¹⁸ +D ¹⁷ +D ¹⁴ +D ¹¹ +D ¹⁰ +D ⁷ +D ⁶ +D ⁵ +D ^{4 for 24-bit CRC.} Assume +D ³ +D+1, and if L=24, TB data a ₀ ,a ₁ ,a ₂ ,a ₃ ,… ,a For _A-1 , CRC p ₁ ,p ₂ ,… ,p _L-1 is a ₀ D ^A+23 +a ₁ D ^A+22 +… +a _A-1 D ²⁴ +p ₀ D ²³ +p ₁ D ²² +… By dividing +p ₂₂ D ¹ +p ₂₃ by g _CRC24A (D), the remainder may be determined to be 0. In the above example, the CRC length L is described as being 24, but the length L may be defined differently, such as 12, 16, 24, 32, 40, 48, 64, and the like.

After adding CRC to TB as described above, the sum of TB and CRC may be divided into N CBs 722-1, 722-2, 722-(N-1), 722-N. CRCs 732-1, 732-2, 732-(N-1), and 732-N are added to each of the CBs 722-1, 722-2, 722-(N-1), and 722-N. can The CRC added to each CB may be generated based on a CRC of a different length or a different cyclic generation polynomial than when generating the CRC added to the TB. However, according to another embodiment, the CRC 714 added to the TB and the CRCs 732-1 added to the CBs 722-1, 722-2, 722-(N-1) and 722-N). 732-2, 732-(N-1), and 732-N) may be omitted depending on the type of channel code to be applied to the CB. For example, when a low density parity code (LDPC) code, not a turbo code, is applied to a CB, CRCs 732-1, 732-2, 732-(N-1), and 732-N are added to each CB. may be omitted. However, even when LDPC is applied, the CRCs 732-1, 732-2, 732-(N-1), and 732-N are the CBs 732-1, 732-2, 732-(N-1). ), 732-N). Also, even when a polar code is used, the CRC may be added or omitted.

As shown in FIG. 7 , the maximum length of one CB is determined according to the type of channel coding applied to the TB, and the TB and CRC added to the TB according to the maximum length of the CB can be divided into CBs. have. In the LTE system, CRC for CB is added to the divided CB, and the data bits and CRC of the CB are encoded with a channel code, and coded bits are determined accordingly, and each coded bit is as preset. The number of bits that are rate matched together may be determined.

8 is a diagram illustrating an example of a mapped result in the frequency and time domains of synchronization signals and a physical broadcast channel (PBCH) of the NR system. A primary synchronization signal (PSS) 802, a secondary synchronization signal (SSS) 806, and a PBCH 804 are mapped over four OFDM symbols, and the PSS 802 and SSS ( 806 may be mapped to 12 RBs, and PBCH 804 may be mapped to 20 RBs. A frequency bandwidth of 20 RBs according to subcarrier spacing (SCS) is shown in FIG. 8 . A set of PSS 802, SSS 806, and PBCH 804, or a resource region carrying PSS 802, SSS 806, and PBCH 804 is called an SS/PBCH block (SS block, SSB). may be referred to.

9 is a diagram illustrating an example of arrangement of an SSB in a wireless communication system according to an embodiment of the present disclosure.

9 is a diagram illustrating an example of an LTE system using a subcarrier spacing of 15 kHz and an NR system using a subcarrier spacing of 30 kHz as an example of which symbols are mapped to one SSB in a slot. 9, the SSBs of the NR system at

positions

902, 904, 906, 908 that do not overlap with cell-specific reference signals (CRSs) that are always transmitted in the LTE system ( 910, 912, 914, 916) may be transmitted. The design shown in FIG. 9 may be to enable the LTE system and the NR system to coexist in one frequency band.

10A and 10B are diagrams illustrating transmittable symbol positions of an SSB according to a subcarrier interval in a wireless communication system according to an embodiment of the present disclosure. FIG. 10A is a diagram illustrating symbol positions at which SSB can be transmitted within a 1 ms interval and FIG. 10B within a 5 ms interval. In the area where the SSB shown in FIGS. 10A and 10B can be transmitted, the SSB does not always have to be transmitted, and the SSB may or may not be transmitted according to the selection of the base station.

In the wireless communication system according to an embodiment, the size of the TB may be calculated through the following steps.

Step 1: The number of REs allocated to PDSCH mapping in one PRB in the allocated resource

to calculate

Is

can be calculated as From here,

is the number of subcarriers included in one RB (eg 12),

is the number of OFDM symbols allocated to the PDSCH,

is the number of REs in one PRB occupied by a demodulation reference signal (DMRS) of the same code division multiplexing (CDM) group,

denotes the number of REs (eg, set to one of 0, 6, 12, 18) occupied by an overhead in one PRB configured by higher-order signaling. Thereafter, the total number of REs allocated to the PDSCH

can be calculated.

Is

can be calculated as n _PRB means the number of PRBs allocated to the UE.

Step 2: Number of Temporary Information Bits

Is

can be calculated as Here, R denotes a code rate, Qm denotes a modulation order, and ν denotes the number of allocated layers. The coding rate and the modulation order may be transmitted using an MCS field included in the control information and a predefined correspondence relationship. if,

, the TBS may be calculated according to step 3 below, otherwise, according to step 4 below.

Step 3:

Wow

together with

can be calculated. Then, the TBS in [Table 5] below

of values not less than

can be determined as the closest value to .

Step 4:

Wow

Depending on the

can be calculated. Then, TBS

It can be determined through a value and a pseudo-code as shown in [Table 6] below.

When one CB is input to the LDPC encoder, parity bits may be added and output. In this case, the size of the parity bit may vary according to the LDPC base graph. According to a method of rate matching, all parity bits generated by LDPC coding may be transmittable or only some of the parity bits may be transmittable. A method of processing all parity bits generated by LDPC coding to be transmittable is referred to as 'full buffer rate matching (FBRM)', and a method of limiting the number of transmitable parity bits is 'LBRM (limited buffer rate matching)'. is referred to as When a resource is allocated for data transmission, an LDPC encoder output is input to a circular buffer, and bits of the buffer may be repeatedly transmitted as much as the allocated resource.

If the length of the circular buffer is N _cb and the number of all parity bits generated by LDPC coding is N, in the case of the FBRM method,

this can be In case of LBRM method,

,

may be determined to be 2/3.

The above-described method of determining the TBS may be used to determine . In this case, C is the actual number of code blocks of the scheduled TB during scheduling. In this case, the number of layers is assumed to be the maximum number of layers supported by the UE in the corresponding cell, the modulation order is assumed to be the maximum modulation order set for the UE in the corresponding cell, or 64-QAM if not set, and the coding rate is the maximum coding rate. The rate is assumed to be 948/1024, and N _RE is

is assumed,

Is

can be assumed.

may be defined as shown in [Table 7] below.

In the wireless communication system according to an embodiment, the maximum data rate supported by the terminal may be determined through the following [Equation 1].

In [Equation 1], J is the number of carriers bundled by carrier aggregation (CA), Rmax = 948/1024,

is the maximum number of layers of the carrier at index j,

is the maximum modulation order of the carrier at index j,

is the scaling factor of the carrier at index j,

is the subcarrier spacing.

is one of 1, 0.8, 0.75, and 0.4, and may be reported by the terminal,

can be given as shown in [Table 8] below.

here,

is the average OFDM symbol length,

can be calculated as

Is

is the maximum number of RBs in

is an overhead value, and may be given as 0.14 in downlink and 0.18 in uplink of FR1 (eg, bands below 6 GHz or 7.125 GHz), and 0.08 in downlink of FR2 (eg, bands exceeding 6 GHz or 7.125 GHz) , may be given as 0.10 in uplink. According to [Equation 1], the maximum data rate in the downlink in a cell having a 100 MHz frequency bandwidth at a 30 kHz subcarrier interval can be calculated as shown in [Table 9] below.

On the other hand, the actual data rate that the terminal can measure in actual data transmission may be a value obtained by dividing the amount of data by the data transmission time. This may be a value obtained by dividing the TBS (TB size) in 1 TB transmission or the sum of TBSs in 2 TB transmission by the TTI length. For example, the maximum actual data rate in downlink in a cell having a 100 MHz frequency bandwidth in a 30 kHz subcarrier interval may be determined as shown in [Table 10] below according to the number of allocated PDSCH symbols.

The maximum data rate supported by the terminal can be confirmed through [Table 9], and the actual data rate according to the allocated TBS can be confirmed through [Table 10]. In this case, depending on the scheduling information, there may be a case where the actual data rate is greater than the maximum data rate.

In a wireless communication system, particularly, in an NR system, a data rate that the terminal can support may be preset between the base station and the terminal. The data rate may be calculated using the maximum frequency band supported by the terminal, the maximum modulation order, the maximum number of layers, and the like. However, the calculated data rate may be different from a value calculated from a transport block size (TBS) and a transmission time interval (TTI) length of a TB used for actual data transmission. Accordingly, the terminal may be allocated a TBS that is larger than a value corresponding to the data rate supported by the terminal, and to prevent this, there may be restrictions on the TBS that can be scheduled according to the data rate supported by the terminal. It may be necessary to minimize this case and define the operation of the terminal in this case. In addition, when LBRM is applied in the communication system defined in the current NR, TBS _LBRM is determined based on the number of layers or ranks supported by the UE, and the process is inefficient or the parameter configuration is ambiguous. Alternatively, there is a problem in that it is difficult to stably apply LBRM in the terminal. Hereinafter, the present disclosure will describe various embodiments that can solve these problems.

11 is a diagram illustrating an example of a process of dividing data to be transmitted into code blocks, generating parity bits by applying channel coding to the divided CB, and determining and transmitting parity bits to be transmitted.

Referring to FIG. 11 , one CB is transmitted to the channel encoder 1102 , and data bits 1112 and

parity bits

1114 and 1116 may be generated by the channel encoder 1102 . For example, the channel encoder 1102 may perform encoding using LDPC, polar codes, or other channel codes. In this case, the amount of generated parity bits may vary according to the type and details of the channel code. If the total length of the bits 1110 generated by the encoding of the channel encoder 1102 is N bits, when all

parity bits

1114 and 1116 are transmitted, the receiver can store N bits of received information. Softbuffers or memory may be required. If the receiver uses a soft buffer having a size smaller than N bits, reception performance may be deteriorated.

In order to reduce the required soft buffer size, a method of determining not transmitted parity bits 1116 and not transmitting the determined parity bits 1116 may be used. That is, only the data bits 1112 and a portion 1114 of the parity bits are input to the transmit buffer 1120 and transferred to the soft buffer 1130 , so that they can be transmitted. That is, transmittable parity bits may be limited, and the limited amount may be the sum of the size of the data bits 1112 and the size of some of the parity bits 1114 , and may be referred to _{as N cb .} When N _cb is N, it means that transmittable parity bits are not limited, which means that all parity generated by the channel code can be transmitted/received without restriction within the allocated resource. As such, a method of processing all parity bits to be transferable may be referred to as full buffer rate matching (FBRM). On the other hand, N _cb is determined as N _cb =min(N,N _ref ),

In the method given by , the transmitable parity bits may be limited. As such, a method of limiting the number of transmittable parity bits is referred to as 'limited buffer rate matching (LBRM)'.

In the embodiments to be described below, the base station is a subject that performs resource allocation of the terminal, and may be a base station supporting both V2X communication and general cellular communication, or a base station supporting only V2X communication. That is, the base station may mean a gNB, an eNB, or a road site unit (RSU) or a fixed station. The terminal supports not only general user equipment (UE), mobile station, but also vehicle-to-vehicular (V2V) communication and vehicle-to-pedestrian communication (vehicular-to-pedestrian, V2P). A vehicle or pedestrian's handset (such as a smartphone), a vehicle-to-vehicular-to-infrastructure (V2I) communication that supports vehicle-to-network (V2N) communication. It may be one of an RSU equipped with supporting vehicle and terminal functions, an RSU equipped with a base station function, or an RSU equipped with a part of a base station function and a part of a terminal function.

In the V2X environment, data may be transmitted from one terminal to a plurality of terminals, or data may be transmitted from one terminal to one terminal. Alternatively, data may be transmitted from the base station to a plurality of terminals. However, the present disclosure is not limited thereto, and may be applied to various cases.

In a communication system using a sidelink, in order for a terminal to transmit/receive a sidelink signal, the terminal operates based on a resource pool already defined or set or preset between terminals. The resource pool may be a set of frequency and time domain resources that can be used for transmission and reception of sidelink signals. That is, in order to transmit and receive a sidelink signal, transmission and reception of a sidelink signal must be performed in a predetermined frequency-time resource, and such resource is defined as a resource pool. A resource pool may be defined for transmission and reception, respectively, and may be commonly defined and used for transmission and reception. In addition, terminals may set one or a plurality of resource pools and perform transmission/reception of a sidelink signal. Configuration information about the resource pool used for sidelink transmission and reception and other configuration information for sidelink are pre-installed when the terminal is produced, configured from the current base station, or other configuration information prior to accessing the current base station. It may be pre-configured from the base station or from another network unit, or it may be a fixed value (fixed), provisioned from the network, or self-constructed by the terminal itself.

In order to indicate the frequency domain resource of the resource pool, the base station may indicate the start index and length (eg, the number of PRBs) of PRBs belonging to the resource pool, but is not limited thereto, and one You can configure the resource pool of In addition, in order to indicate time domain resources of the resource pool, the base station may indicate indices of OFDM symbols or slots belonging to the resource pool in units of bitmaps. Alternatively, according to another method, the system may use a formula in a set of specific slots to define slots that satisfy the formula to belong to a corresponding resource pool. In setting the time domain resource, for example, the base station may inform which slots among the slots for a specific time belong to a specific resource pool using a bitmap, and in this case, corresponds to the resource pool of the time resource at every specific time. Whether or not to do so may be indicated according to the bitmap.

Meanwhile, a subchannel may be defined in units of resources on a frequency including a plurality of RBs. As an example, a subchannel may be defined as an integer multiple of an RB. The size of the subchannel may be set to be the same or different for each subchannel, and although one subchannel is generally composed of continuous PRBs, there is no limitation that it must be composed of continuous PRBs. A subchannel may be a basic unit of resource allocation for a physical sidelink shared channel (PSSCH) or a physical sidelink control channel (PSCCH). Accordingly, the size of the subchannel may be set differently depending on whether the corresponding channel is the PSSCH or the PSCCH. In addition, the term of a subchannel may be replaced with another term such as a resource block group (RBG) or a set of RBGs or a set of PRBs.

For example, 'startRBSubchannel', which is higher level signaling or configuration information, may indicate the start position of a subchannel on a frequency in the resource pool. For example, in the LTE V2X system, a resource block, which is a frequency resource belonging to a resource pool for PSSCH, may be determined in the same manner as in [Table 11] below.

- The resource block pool is

It consists of sub-channels. From here

It is given by a higher layer parameters numSubchannel (The resource block pool consists _subCH N sub-channels where N is given by higher layer parameter _subCH numSubchannel).
- subchannel m( m =0,1,…,

-1) consists of a set of n _subCHsize consecutive resource blocks with physical resource block number n _PRB = n _subCHRBstart + m * n _subCHsize + j. From here

and

are given by upper layer parameters ( startRBSubchannel and sizeSubchannel ) respectively (The sub-channel m for m =0,1,…, N _subCH -1 consists of a set of n _subCHsize contiguous resource blocks with the physical resource block number n _PRB = n _subCHRBstart + m * n _subCHsize + j for j =0,1,…, N _subCH -1 where n _subCHRBstart and n _subCHsize are given by higher layer parameters startRBSubchannel and sizeSubchannel , respectively).

For resource pool configuration, the granularity of resource allocation in the time domain may be a slot. In the present disclosure, the resource pool is exemplified as a non-contiguously allocated slot in time, but the resource pool may be continuously allocated in time, or it may be set in a symbol unit or a unit consisting of a plurality of symbols (eg, mini-slot). can

As another example, when 'startSlot', which is higher signaling or configuration information, indicates the start position of a slot in time in the resource pool, subframes that are time resources belonging to the resource pool for PSSCH in the LTE V2X system

can be determined in the same way as in [Table 12] below.

According to the procedure of [Table 12], first with the bitmap, a certain slot is included in the resource pool, except for at least one slot used for downlink among the slots (subframes in [Table 14]) for a specific period. is indicated, and among the slots indicated to belong to the resource pool, according to the bitmap information, which slot is actually included in the resource pool and used for sidelink transmission/reception may be indicated.

The sidelink control channel may be referred to as a physical sidelink control channel (PSCCH), and the sidelink shared channel or data channel may be referred to as a physical sidelink shared channel (PSSCH). In addition, a broadcast channel broadcast together with a synchronization signal may be referred to as a physical sidelink broadcast channel (PSBCH), and a channel for feedback transmission may be referred to as a physical sidelink feedback channel (PSFCH). However, PSCCH or PSSCH may be used for feedback transmission. Depending on the communication system, the above-described channels may be referred to as LTE-PSCCH, LTE-PSSCH, NR-PSCCH, NR-PSSCH, and the like. In the present disclosure, a sidelink may mean a link between terminals, and a Uu link may mean a link between a base station and a terminal.

Information transmitted in the sidelink includes sidelink control information (SCI), sidelink feedback control information (SFCI), sidelink channel state information (SCSI), and a transport channel. It may include a sidelink shared channel (SL-SCH).

The above-described information and transport channels may be mapped to physical channels as shown in [Table 13] and [Table 14] below.

TrCH (Transport channel)TrCH (Transport channel)	Physical ChannelPhysical Channel
SL-SCHSL-SCH	PSSCHPSSCH

Control informationcontrol information	Physical ChannelPhysical Channel
SCISCI	PSCCHPSCCH
SFCISFCI	PSFCHPSFCH
SCSISCSI	PSSCHPSSCH

Alternatively, when SCSI is transmitted through the PSFCH, transport channel-physical channel mapping as shown in [Table 15] and [Table 16] below may be applied.

Control informationcontrol information	Physical ChannelPhysical Channel
SCISCI	PSCCHPSCCH
SFCISFCI	PSFCHPSFCH
SCSISCSI	PSFCHPSFCH

Alternatively, when SCSI is transmitted to a higher layer and is transmitted using, for example, MAC CE, upper layer signaling corresponds to SL-SCH, so it may be transmitted through PSSCH, and below [Table 17] and [Table 18] Transport channel-physical channel mapping such as ] may be applied.

Control informationcontrol information	Physical ChannelPhysical Channel
SCISCI	PSCCHPSCCH
SFCISFCI	PSFCHPSFCH

When the CSI of the sidelink is transmitted through the MAC CE, the receiving terminal may transmit at least one of the following additional information to the transmitting terminal together.

- Information on the slot in which the sidelink CSI-RS used when measuring CSI is transmitted, for example, information on the timing at which the sidelink CSI-RS is transmitted

- Information on the frequency domain in which the CSI is measured, for example, information on the frequency domain in which the sidelink CSI-RS is transmitted. It may include an index of a subchannel, and the like.

- Information of rank indicator (rank indicator, RI), channel quality indicator (channel quality indicator, CQI)

- Information of the preferred precoding matrix

- Information about preferred beamforming

- ID information of the receiving terminal that has received the sidelink CSI-RS

- ID information of the transmitting terminal that has transmitted the sidelink CSI-RS

- ID information of a transmitting terminal transmitting sidelink CSI feedback information

- ID information of the receiving terminal receiving sidelink CSI feedback information

Referring to FIG. 12A , a terminal 1220 may transmit common data to a plurality of

terminals

1221a, 1221b, 1221c, and 1221d, ie, transmit data in a group casting method. The terminal 1220 and the

terminals

1221a, 1221b, 1221c, and 1221d may be devices that move like a vehicle. For group casting, at least one of separate control information (eg, sidelink control information (SCI)), a physical control channel (eg, physical sidelink control channel (PSCCH)), and data may be further transmitted.

12B is a diagram illustrating an example of HARQ feedback transmission according to group casting in a wireless communication system according to an embodiment of the present disclosure.

12B, the

terminals

1221a, 1221b, 1221c, 1221d that have received common data by group casting transmit information indicating success or failure of data reception to the terminal 1220 that has transmitted the data. have. Information indicating success or failure of data reception may include HARQ-ACK feedback. Data transmission and feedback operations as shown in FIGS. 12A and 12B are performed based on group casting. However, according to another embodiment, the data transmission and feedback operations illustrated in FIGS. 12A and 12B may also be applied to unicast transmission.

Referring to FIG. 13 , a first terminal 1320a transmits data to a second terminal 1320b. As another example, the data transmission direction may be reversed (eg, from the second terminal 1320b to the first terminal 1320a). Except for the first terminal 1320a and the second terminal 1320b,

other terminals

1320c and 1320d cannot receive data transmitted and received in a unicast manner between the first terminal 1320a and the second terminal 1320b. . Transmission and reception of data through unicast between the first terminal 1320a and the second terminal 1320b is mapped in a preset resource between the first terminal 1320a and the second terminal 1320b, or scrambling using a preset value Or, it may be transmitted using a preset value. Alternatively, control information related to data through unicast between the first terminal 1320a and the second terminal 1320b may be mapped to each other in a preset manner. Alternatively, data transmission/reception through unicast between the first terminal 1320a and the second terminal 1320b may include an operation of confirming mutually unique IDs. The terminals may be devices that move like a vehicle. At least one of separate control information, a physical control channel, and data may be further transmitted for unicast.

14A is a diagram illustrating a mode 1 in which a terminal receiving scheduling information from a base station transmits sidelink data. Although the present disclosure refers to a method of performing sidelink communication based on scheduling information as mode 1, it may be referred to as another name. Referring to FIG. 14A , a terminal 1420a (hereinafter referred to as a 'transmitting terminal') that intends to transmit data in the sidelink receives scheduling information for sidelink communication from the base station 1410 . Upon receiving the scheduling information, the transmitting terminal 1420a transmits sidelink data to another terminal 1420b (hereinafter referred to as a 'receiving terminal') based on the scheduling information. Scheduling information for sidelink communication is included in DCI, and the DCI may include at least one of the items shown in [Table 19] below.

항목Item	내용Contents
반송파 지시자carrier indicator	반송파 집성(carrier aggregation, CA)이 적용된 상황에서 다른 반송파의 사이드링크를 스케줄링하기 위한 목적으로 사용될 수 있다.It may be used for the purpose of scheduling a sidelink of another carrier in a situation where carrier aggregation (CA) is applied.
초기 전송을 위한 서브채널 할당의 가장 낮은 인덱스 (lowest index)The lowest index of subchannel allocation for initial transmission (lowest index)	초기 전송의 주파수 자원 할당을 위해 사용될 수 있다.It may be used for frequency resource allocation of initial transmission.
사이드링크 제어 정보에 포함될 정보Information to be included in sidelink control information	-주파수 자원 할당 정보. 초기전송과 재전송, 그리고 이 후의 N번 전송에 대한 자원할당 또는 자원 예약 정보를 포함할 수 있다. -초기전송과 재전송 사이의 시간 간격 정보- Frequency resource allocation information. It may include resource allocation or resource reservation information for initial transmission, retransmission, and subsequent N-th transmission. -Time interval information between initial transmission and retransmission
사이드링크 슬롯 구조에 대한 정보Information on sidelink slot structure	어떤 슬롯과 어떤 심볼들이 사이드링크에 사용될 수 있는지에 대한 정보를 포함할 수 있다.It may include information about which slots and which symbols can be used for sidelink.
HARQ-ACK/CSI피드백 타이밍 정보HARQ-ACK/CSI feedback timing information	사이드링크에서의 HARQ-ACK 또는 CSI 피드백을 기지국으로 전송하기 위한 타이밍 정보를 포함할 수 있다.It may include timing information for transmitting HARQ-ACK or CSI feedback in the sidelink to the base station.
수신자 IDRecipient ID	어떤 단말들이 수신할 지에 대한 ID 정보ID information on which terminals will receive
Priority 등의 QoS(Quality-of-Service) 정보QoS (Quality-of-Service) information such as priority	어떤 우선 순위의 데이터를 전송할 지에 대한 정보Information on which priority data to transmit

Scheduling may be performed for one-time sidelink transmission, or may be performed for periodic transmission or semi-persistent scheduling (SPS) or configured grant transmission. The scheduling method may be distinguished by an indicator included in DCI or by an RNTI or ID value scrambled to CRC added to DCI. DCI for sidelink transmission may further include a padding bit (eg, 0 bit) to have the same size as other DCI formats such as DCI for downlink scheduling or uplink scheduling.

The transmitting terminal 1420a receives DCI for sidelink scheduling from the base station 1410, transmits a PSCCH including sidelink scheduling information to the receiving terminal 1420b, and then transmits the PSSCH, which is data corresponding to the PSCCH. . The PSCCH, which is sidelink scheduling information, includes SCI, and the SCI may include at least one of items shown in [Table 20] below.

항목Item	내용Contents
HARQ 프로세스 번호(process number)HARQ process number	전송하는 데이터의 HARQ 관련 동작을 위한 HARQ 프로세스 IDHARQ process ID for HARQ related operation of data to be transmitted
NDI(new data indicator)New data indicator (NDI)	현재 전송하고 있는 데이터가 새로운 데이터인지에 대한 정보Information on whether the data currently being transmitted is new data
RV(redundancy version)RV (redundancy version)	데이터의 채널 코딩을 수행하여 매핑할 때 어떤 패리티 비트를 보내는 지에 대한 정보Information on which parity bits are sent when mapping by performing channel coding of data
Layer-1 소스(source) IDLayer-1 source ID	송신 단말의 물리계층에서의 ID 정보ID information in the physical layer of the transmitting terminal
Layer-1 목적지(destination) IDLayer-1 destination ID	수신 단말의 물리계층에서의 ID 정보ID information in the physical layer of the receiving terminal
PSSCH 스케줄링을 위한 주파수 도메인 자원 정렬(frequency-domain resource assignment for scheduling PSSCH)Frequency-domain resource assignment for scheduling PSSCH	전송하는 데이터의 주파수 영역 자원 설정 정보Frequency domain resource setting information of data to be transmitted
MCSMCS	변조 차수 및 부호화율 정보Modulation order and coding rate information
QoS 지시(indication)QoS indication	우선순위(Priority), 목표 레이턴시/딜레이, 목표 거리, 목표 에러율 등을 포함할 수 있다.It may include priority, target latency/delay, target distance, target error rate, and the like.
안테나 포트(들)(Antenna port(s))Antenna port(s)	데이터 전송을 위한 안테나 포트 정보Antenna port information for data transmission
DMRS 시퀀스 초기화(sequence initialization)DMRS sequence initialization	DMRS 수열의 초기화를 위한 ID 값 등의 정보를 포함할 수 있다.It may include information such as an ID value for initialization of the DMRS sequence.
PTRS-DMRS 연관(association)PTRS-DMRS association	PTRS 매핑에 대한 정보를 포함할 수 있다.It may include information about PTRS mapping.
CBGTICBGTI	CBG 단위 재전송을 위한 지시자로 활용될 수 있다.It may be used as an indicator for CBG unit retransmission.
자원 예약(resource reservation)resource reservation	자원 예약을 위한 정보Information for Reserving Resources
초기 전송 및 재전송 간의 시간 간격(Time gap between initial transmission and retransmission)Time gap between initial transmission and retransmission	초기 전송 및 재전송 간의 시간 간격 정보About the time interval between initial transmission and retransmission
재전송 인덱스(retransmission index)retransmission index	재전송을 구분하는 지시자Indicator to distinguish retransmissions
전송 포맷(transmission format)/캐스트 타입 지시자(cast type indicator)Transmission format / cast type indicator (cast type indicator)	전송 포맷 또는 유니캐스트/그룹캐스트/브로드캐스트의 구분 지시자Transport format or unicast/groupcast/broadcast distinction indicator
존(zone) IDzone ID	송신 단말의 위치 정보Location information of the transmitting terminal
NACK 거리(distance)NACK distance	수신 단말이 HARQ-ACK/NACK을 전송해야하는지 여부를 판단하는 기준 지시자Reference indicator for determining whether the receiving terminal should transmit HARQ-ACK/NACK
HARQ 피드백 지시(feedback indication) HARQ feedback indication	HARQ 피드백을 전송해야하는지 또는 전송하고 있는지에 대한 여부를 포함할 수 있다.It may include whether or not HARQ feedback should be transmitted or not.
PSSCH 스케줄링을 위한 시간 도메인 자원 정렬(time-domain resource assignment for scheduling PSSCH)Time-domain resource assignment for scheduling PSSCH	전송하는 사이드링크 데이터의 시간 영역 자원 정보Time domain resource information of sidelink data to be transmitted
두번째 SCI 지시(second SCI indication)Second SCI indication (second SCI indication)	2단계 제어정보인 경우 두 번째 SCI의 매핑 정보를 포함하는 지시자In case of step 2 control information, an indicator including mapping information of the second SCI
DMRS 패턴(pattern)DMRS pattern	DMRS 패턴 (예를 들어, DMRS가 매핑되는 심볼 위치) 정보DMRS pattern (eg, symbol position to which DMRS is mapped) information

Control information including at least one of the items shown in Table 20 may be included in one SCI or two SCIs in order to be delivered to the receiving terminal. A method of being divided into two SCIs and transmitted may be referred to as a two-stage SCI.

14B is a diagram illustrating a mode 2 in which the terminal transmits sidelink data without receiving scheduling information from the base station. Although this disclosure refers to a method of performing sidelink communication without scheduling information as mode 2, it may be referred to by other names. The terminal 1420a desiring to transmit data in the sidelink may transmit the sidelink scheduling control information and the sidelink data to the receiving terminal 1420b by determining it by itself without scheduling from the base station. In this case, as the sidelink scheduling control information, an SCI of the same format as the SCI used in mode 1 sidelink communication may be used. For example, the scheduling control information may include at least one of the items shown in [Table 20].

15 is a diagram illustrating an example of a channel structure of a slot used for sidelink communication in a wireless communication system according to an embodiment of the present disclosure. 15 is a diagram illustrating physical channels mapped to slots for sidelink communication. Referring to FIG. 15 , the preamble 1502 may be mapped before the start of the slot, that is, at the end of the previous slot. Thereafter, from the start of the slot, a PSCCH 1504 , a PSSCH 1506 , a gap 1508 , a physical sidelink feedback channel (PSFCH) 1510 , and a gap 1512 may be mapped.

Before transmitting a signal in the corresponding slot, the transmitting terminal transmits a signal with a preamble 1502 in one or more symbols. The preamble may be used so that the receiving terminal can correctly perform automatic gain control (AGC) for adjusting the strength of the amplification when the receiving terminal amplifies the power of the received signal. In addition, the preamble may or may not be transmitted depending on whether the transmitting terminal has transmitted the previous slot. That is, when the transmitting terminal transmits a signal to the same terminal in the previous slot (eg, slot #n-1) of the corresponding slot (eg, slot #n), transmission of the preamble 1502 may be omitted. The preamble 1502 is a 'synchronization signal', a 'sidelink sync signal', a 'sidelink reference signal', a 'midamble', an 'initial signal', a 'wake-up signal' or the like. It may be referred to as another term having an equivalent technical meaning.

The PSCCH 1504 including control information may be transmitted using symbols transmitted at the beginning of the slot, and the PSSCH 1506 scheduled by the control information of the PSCCH 1504 may be transmitted. PSCCH 1504 may be mapped to at least a part of SCI, which is control information. Thereafter, there may be a GAP 1508 , and a PSFCH 1510 , which is a physical channel for transmitting feedback information, may be mapped.

The UE may receive a preset position of a slot capable of transmitting the PSFCH. Receiving in advance means that the terminal is predetermined in the process of making it, or is transmitted when accessing a sidelink-related system, or is transmitted from the base station when accessing the base station, or is transmitted from another terminal.

Referring to FIG. 15 , the PSFCH 1510 may be located in the last part of the slot. By securing a gap 1508, which is an empty time of a certain time, between the PSSCH 1506 and the PSFCH 1510, the terminal that has transmitted or received the PSSCH 1506 receives or prepares the PSFCH 1510 for reception or transmission (eg : Send/receive conversion). After the PSFCH 1510 , a gap 1512 that is an empty period for a predetermined time may exist.

16A is a diagram illustrating a case in which a resource capable of transmitting and receiving a PSFCH is allocated in every slot. In FIG. 16A, an arrow indicates a slot of the PSFCH in which HARQ-ACK feedback information corresponding to the PSSCH is transmitted. Referring to FIG. 16A , HARQ-ACK feedback information for the PSSCH 1612 transmitted in slot #n may be transmitted in the PSFCH 1614 of slot #n+1. Since the PSFCH is allocated to every slot, the PSFCH may correspond to a slot including the PSSCH 1:1. For example, if the period of a resource capable of transmitting and receiving PSFCH is configured by a parameter such as 'periodicity_PSFCH_resource', in the case of FIG. 16A, periodicity_PSFCH_resource indicates 1 slot. Alternatively, the period may be set in msec units, and the period may be indicated by a value allocated to every slot according to the subcarrier interval.

16B is a diagram illustrating a case in which resources are allocated to transmit/receive PSFCH in every 4 slots. In FIG. 16B, an arrow indicates a slot of the PSFCH in which HARQ-ACK feedback information corresponding to the PSSCH is transmitted. Referring to FIG. 16B , only the last slot among the four slots may include the PSFCH. Similarly, only the last of the next 4 slots contains the PSFCH. Accordingly, HARQ-ACK feedback for the PSSCH 1622a of slot #n, the PSSCH 1622b of the slot #n+1, the PSSCH 1622c of the slot #n+2, and the PSSCH 1622d of the slot #n+3 The information may be transmitted on the PSFCH 1624 in slot #+4. Here, the slot index may be an index for slots included in the resource pool. That is, the four slots are not physically consecutive slots, but may be consecutively listed slots among slots included in a resource pool (or slot pool) used for sidelink communication between terminals. The reason that the HARQ-ACK feedback information of the PSSCH transmitted in the 4th slot is not transmitted in the PSFCH of the same slot is because the processing time is not short enough for the UE to finish decoding the PSSCH transmitted in the corresponding slot and transmit the PSFCH in the same slot. have.

When a UE transmits or receives a PSFCH, it is necessary to know the number of HARQ-ACK feedback bits included in the PSFCH so that transmission or reception can be performed correctly. The number of HARQ-ACK feedback bits included in the PSFCH and which PSSCH to include the HARQ-ACK bits may be determined based on at least one or a combination of two or more of the items shown in [Table 21] below.

Item

The period of the slot in which PSFCH can be transmitted and received according to parameters such as periodicity_PSFCH_resource

HARQ-ACK bundling or not. It may be a value determined through AND operation on the HARQ-ACK bits of the PSFCH transmitted in a predetermined number of slots before transmission and reception of the PSFCH.

The number of transport blocks (TB) included in the PSSCH

Whether code block group (CBG) unit retransmission is used and set

Whether HARQ-ACK feedback is enabled

Number of PSSCHs actually transmitted and received

Minimum processing time of UE for PSSCH processing and PSFCH transmission preparation

The terminal receiving the PSSCH in slot #n uses the smallest x among integers greater than or equal to K when a resource capable of transmitting the PSFCH is set or given in the slot #n+x, the HARQ-ACK feedback of the PSSCH is Information is transmitted using the PSFCH of slot #n+x. K may be a value preset by the transmitting terminal or a value set in a resource pool through which the corresponding PSSCH or PSFCH is transmitted. For K setting, each terminal may exchange its capability information with the transmitting terminal in advance. For example, K may be determined according to at least one of a subcarrier interval, a terminal capability, a setting value with a transmitting terminal, or a resource pool setting.

In Mode2 operation in the NR sidelink system, the transmitting terminal may select a resource after sensing, without pre-reserving a resource for initial transmission of one TB. Meanwhile, as a method of reserving resources for initial transmission, resources may be reserved using SCI for another TB, and this function may be enabled or disabled by (pre-)configuration (ie, transmission of TB1). SCI1 for controlling TB2 may reserve a resource for initial transmission of TB2). For example, when the corresponding function is enabled, reservation interval information is set in SCI1 when the previous TB (TB1) is transmitted, and the same frequency resource as the resource selected for transmitting the previous TB (TB1) is set as the reservation interval. After the interval may be reserved for the initial transmission of TB2.

As another method of reserving the initial transmission resource, in addition to the method of using SCI to control the aforementioned other TB, the method of reserving the initial resource for the corresponding TB using SCI through standalone PSCCH transmission This can be considered.

In addition, when performing initial transmission, retransmission resources for one and the same TB may be reserved using SCI at the time of initial transmission. In this case, the SCI may include time gap information and frequency resource allocation information between initial transmission and retransmission for the same TB and may be transmitted. At this time, when the same frequency allocation size for the initial transmission and retransmission resource for the same TB is always supported (the first method) and when the frequency allocation size for the initial transmission and the retransmission resource is allowed to be different (the second method) can be considered. In general, the case where the frequency allocation size for initial transmission and retransmission resources is allowed to be different has the advantage of more flexible resource selection, but in SCI including information on retransmission resources, it is This may become very complicated, and the performance of SCI may decrease (eg, coverage of SCI may decrease or receive error rate may increase) as the number of bits transmitted in SCI increases. Contrary to this, when the same frequency allocation size for initial transmission and retransmission resources is always supported, the flexibility of resource allocation is small, but it can be simplified to indicate information on retransmission resource reservation information in SCI. There is an advantage in that the performance of the SCI can be guaranteed by reducing the number of bits transmitted through the SCI. Therefore, each of the two methods described above has advantages and disadvantages.

As a method for complementing the advantages and disadvantages of the above two methods, the initial transmission resource is fixed to X sub-channels and transmitted, and the retransmission resource is transmitted through one or more sub-channels. can be considered. For example, consider a method of allowing different frequency allocation sizes for initial transmission and retransmission resources while supporting a method of indicating reservation of retransmission resources through SCI for one same TB during initial transmission as simply as possible. can According to this method, since the frequency allocation size of the initial transmission resource is always fixed, only the frequency allocation size for the retransmission resource needs to be indicated through the SCI. If there is more than one retransmission resource reserved for the same TB, the frequency allocation size of all retransmission resources may be equally limited. In addition, a method of limiting to one subchannel as a value of the number of subchannels X for an initial transmission resource (ie, a method of limiting X to 1) may be considered. However, the above is only an example, and in embodiments of the present disclosure, the value of X is not always limited to 1, and the value of X may be variously determined. When the initial transmission resource is transmitted with a fixed value of subchannel X, PSCCH and PSSCH are transmitted on X subchannels. At this time, SCI transmitted on PSCCH may reserve retransmission resources, in which case the subchannel for the retransmission resource. For the size of , Y subchannels may be allocated.

If, in the NR sidelink system, the same frequency allocation size for the initial transmission and retransmission resource for the same TB is always supported (hereinafter, the first method) and the initial transmission resource is fixed to X sub-channels In the case where two methods (hereinafter, the second method) are considered in which two methods can be transmitted through one or more subchannels and the retransmission resource is transmitted through one or more subchannels, which method is used among the two methods is indicated by 1-bit information in the SCI. can be This is to enable interpretation of resource reservation information included in the SCI. Hereinafter, when these two methods are considered, resource reservation information included in SCI is proposed in more detail. The following is an example of a method of indicating reservation information for initial transmission and one retransmission resource for a corresponding TB.

17A and 17B are diagrams illustrating an example of a method in which resource allocation of PSSCH is performed in units of subchannels according to an embodiment of the present disclosure. Referring to FIG. 17A, 17a-10 shows a method in which a PSCCH and a PSSCH are multiplexed. 17A and 17B , the PSCCH may be transmitted in a subchannel corresponding to the lowest subchannel index in a subchannel allocated for the PSSCH. A method in which the PSCCH is always included in a subchannel and transmitted in the NR sidelink may be considered. In this case, the method of transmitting the PSCCH in the subchannel may be determined according to the size of the configured subchannel. Also, a method of repeatedly transmitting the PSCCH in the PSSCH region according to the size of the subchannel may be considered (17a-40). Specifically, a method in which the PSCCH is included in a subchannel and transmitted using the first method in which the same frequency allocation size for initial transmission and retransmission resource for the same TB is always supported is shown in FIGS. 17a-20 and 17a- 30 is shown. In addition, the initial transmission resource is transmitted by being fixed in X sub-channels, and the PSCCH is included in the sub-channel and transmitted using the second method in which the retransmission resource can be transmitted through one or more sub-channels. Methods are shown at 17b-50 and 17b-60 of FIG. 17b. 17A and 17B , the UE may receive startRB-Subchannel, sizeSubchannel, and numSubchannel configuration as frequency configuration information for the resource pool. First, an example of indicating resource reservation information through SCI when a method in which the same frequency allocation size for initial transmission and retransmission resource for the same TB is always supported is used will be described. Specifically, the following method is a chain reservation method for indicating resource allocation for the current transmission and the next retransmission, and resource reservation information for the PSSCH indicated by the SCI in the slot tn allocated to the one pool may be determined as follows:

1) When the time gap (SFgap) between the current transmission and the next retransmission is 0 (when retransmission is not performed), the time and frequency allocation positions for the PSSCH are as follows (17a-20)

a) sub-channel(s) nsubCHstart, nsubCHstart +1,… , nsubCHstart +LsubCH-1 in slot tn

2) If the time gap (SFgap) between the current transmission and the next retransmission is not 0 (corresponding to the current transmission), the time and frequency allocation positions for the PSSCH are as follows

a) sub-channel(s) nsubCHstart, nsubCHstart +1,… , nsubCHstart +LsubCH-1 in slot tn (17a-20)

b) sub-channel (s) nsubCHstart (RE), nsubCHstart (RE) +1, ... , nsubCHstart(RE) +LsubCH-1 in slot tn+SFgap(17a-30)

3) When the time gap (SFgap) between the current transmission and the next retransmission is not 0 (corresponding to the next retransmission), the time and frequency allocation positions for the PSSCH are as follows

a) sub-channel(s) nsubCHstart, nsubCHstart +1,… , nsubCHstart +LsubCH-1 in slot tn-SFgap

b) sub-channel (s) nsubCHstart (RE), nsubCHstart (RE) +1, ... , nsubCHstart(RE) +LsubCH-1 in slot tn

The LsubCH indicates the length of a subchannel allocated to the PSSCH, and nsubCHstart and nsubCHstart (RE) indicate the start position of a subchannel allocated to the PSSCH for initial transmission and retransmission. nsubCHstart and nsubCHstart (RE) information may be included in the SCI.

Contrary to this, when a method for transmitting the initial transmission resource in X sub-channels is fixed and transmitting the retransmission resource to one or more sub-channels is used, the resource reservation information is indicated through SCI. An example will be described. Specifically, the following method is a chain reservation method for indicating resource allocation for the current transmission and the next retransmission, and resource reservation information for the PSSCH indicated by the SCI in the slot tn allocated to the original pool may be determined as follows:

1) When the time gap (SFgap) between the current transmission and the next retransmission is 0 (when retransmission is not performed), the time and frequency allocation positions for the PSSCH are as follows (17b-50)

a) sub-channel(s) nsubCHstart, nsubCHstart +1,… , nsubCHstart +X-1 in slot tn

a) sub-channel(s) nsubCHstart, nsubCHstart +1,… , nsubCHstart +X-1 in slot tn (17b-50)

b) sub-channel (s) nsubCHstart (RE), nsubCHstart (RE) +1, ... , nsubCHstart(RE) +LsubCH-1 in slot tn+SFgap(17b-60)

a) sub-channel(s) nsubCHstart, nsubCHstart +1,… , nsubCHstart +X-1 in slot tn-SFgap

X indicates the length of a subchannel allocated to the PSSCH for initial transmission, and LsubCH indicates the length of a subchannel allocated to the PSSCH during retransmission. As described above, a method in which X=1 is fixed may be considered. In addition, nsubCHstart and nsubCHstart (RE) indicate start positions of subchannels allocated to the PSSCH for initial transmission and retransmission, and nsubCHstart and nsubCHstart (RE) information may be included in the SCI.

When the frequency resource allocation information is indicated through the above two methods, the start position nsubCHstart of the subchannel allocated for the PSSCH for initial transmission is not separately indicated by the SCI, but is replaced with the value of the PSCCH resource m and may be used ( 17b). This may be supported when the PSCCH is capable of one-to-one connection in a region in which the PSSCH is transmitted. When only the start position nsubCHstart (RE) of the subchannel allocated to the PSSCH for retransmission is indicated by the SCI, the Resource Indication Value (RIV) may be defined as follows.

Here, N _subCH represents the total number of subchannels configured in the resource pool by the upper layer.

18 is a flowchart illustrating a method for a transmitting terminal to determine values of bit fields of first control information and second control information according to an embodiment of the present disclosure. Referring to FIG. 18, the transmitting terminal determines the resource to transmit the PSSCH through the above-described method such as channel occupancy and channel reservation (18-01). The transmitting terminal determines scheduling parameters to be included in the SCI based on the determined resource to transmit the PSSCH. The scheduling parameters may include frequency and time resources of PSSCH, MCS, RV, NDI, H17RQ process ID, and the like. The transmitting terminal determines values of the bit field of the second control information based on the determined scheduling parameter, and determines a transmission resource for where to map the second control information (18-03). Also, the transmitting terminal determines the bit field value of the first control information based on the transmission resource to which the scheduling parameter of the PSSCH, the bit field value of the second control information, and the second control information are mapped (18-05). This is because the first control information may include information for decoding the second control information. In addition, the transmitting terminal may determine a transmission resource to which the first control information is mapped based on the transmission resource to which the scheduling parameter of the PSSCH, the bit field value of the second control information, and the second control information are mapped. Based on the determined information, the transmitting terminal transmits the first control information, the second control information, and the PSSCH (18-07).

Referring to FIG. 19 , the receiving terminal attempts to decode the first control information based on preset information ( 19-01). The receiving terminal determines whether to decode the second control information according to the bit field value of the first control information successfully decoded, and if decoding of the second control information is required, to which resource the second control information is mapped and performs decoding (19-03). Here, the reason for determining whether to decode the second control information is that, in a specific transmission type or transmission mode, decoding of the PSSCH may be possible only by decoding the first control information. Thereafter, the receiving terminal determines the PSSCH transmission resource and other scheduling information based on the bit field values of the decoded first control information (SCI 1) and the second control information (SCI 2) (19-05). The receiving terminal performs PSSCH decoding using the identified scheduling information and performs necessary subsequent operations (19-07).

As described above, after the terminal successfully decodes the first control information, it may not necessarily be necessary to decode the second control information. Successful decoding of the control information may indicate that CRC checking has been successful.

It is assumed that the number of subchannels in the resource pool is Nsubchannel. One subchannel may consist of one or more PRBs, and Nsubchannel may be a value set or preset in the resource pool, or a value calculated by a specific parameter. Here, data may be transmitted in PSSCH, and resource allocation for data transmission may indicate a resource region used for PSSCH mapping.

If initial transmission is _{performed in slot n 1} and retransmission for initial transmission is performed in slot n ₂ , control information transmitted in slot n ₁ may include resource allocation information for initial transmission and retransmission No. 1 have. This may be time domain resource information for slot n ₂ , or frequency domain information for _{slot n 1} and slot n _{2 .} If it is assumed that the number of subchannels in the frequency domain used for initial transmission and retransmission is the same, the information on the first subchannel to which the PSSCH mapping in the corresponding slot starts is determined from the mapping position of the corresponding control information transmitted in the same slot. In this case, the control information transmitted in the initial transmission needs to include the number of subchannels used for PSSCH mapping and information on the first subchannel to which the PSSCH for retransmission is mapped. In this case, in order to deliver frequency domain resource allocation information of the PSSCH of initial transmission and retransmission, a bit field having the following size (or a size smaller or larger than this within several bits) may be used in the control information.

The bitfield of this size may be for indicating the number of subchannels to which the PSSCH is mapped and the position of the start subchannel of the retransmission PSSCH,

may indicate the number of possible combinations of the number of subchannels to which the PSSCH is mapped and the starting subchannel position of the retransmission PSSCH. Using log with a base of 2 may be for calculating the number of bits to indicate possible cases of the number of cases.

Is

The smallest integer among larger integers may be indicated, and this may be used to indicate the size of a required bitfield as an integer.

If, as shown in FIG. 20, in order to indicate frequency resource information to which the PSSCH for the initial transmission and the third retransmission are mapped, at least one of the following methods is used to determine the size of the bit field for frequency resource allocation. you will be able to calculate

- Method 1: In order to transmit frequency domain resource allocation information of PSSCH of initial transmission and retransmission No. 3, a bit field of the following size (or a size smaller or larger than this within several bits) may be used for control information.

As an example, in FIG. 20, the number of cases of the starting subchannel position of the PSSCH transmitted _{in the slot n 3} and the slot n _{4 is}

Since it can be expressed as , the size of the bit field can be determined as in Method 1.

- Method 2: In order to transmit frequency domain resource allocation information of PSSCH of initial transmission and retransmission No. 3, a bit field having the following size (or a size smaller or larger than this within several bits) may be used for control information.

As an example, in FIG. 20, since it may be possible that the starting subchannel positions of the PSSCH transmitted _{in the slot n 3} and the slot n ₄ _{have N subchannel} branches, respectively, in this case, the size of the bit field may be determined as in method 2 . Method 2 may be a method of transmitting information on the start subchannel position of the PSSCH transmitted in _{slot n 3} and in slot n _{4 as independent bits.}

- Method 3: In order to transmit frequency domain resource allocation information of PSSCH of initial transmission and retransmission No. 3, a bit field having the following size (or a size smaller or larger than this within several bits) may be used for control information.

As an example, in FIG. 20, since the starting subchannel positions of the PSSCH transmitted _{in the slot n 3} and the slot n ₄ _{may each have N subchannel} branches, in this case, the size of the bit field may be determined as in method 3 . Method 3 may be a method of transmitting the start subchannel position of the PSSCH transmitted in _{slot n 3} and in slot n _{4 together with several bits.}

Hereinafter, the present disclosure describes embodiments for performing a method for transmitting and receiving sidelink data. More specifically, it provides a slot structure for sidelink transmission, and a method and apparatus for transmitting and receiving data in the slot structure.

[First embodiment]

A first embodiment of the present disclosure provides a structure of a slot for transmitting and receiving a sidelink control channel and data.

In a wireless communication system, it may be necessary for the terminal to amplify the signal strength in a process of receiving the signal. To this end, a received signal is passed through an amplifier to amplify the strength of the signal, and then signal processing is performed, and an amplifier capable of varying the degree of amplifying the signal may be used. For each amplifier, an input or output range having linearity between an input and an output may be defined. If the amplification is performed by increasing the amplification level too much, the output may be set to a range out of the linearity, and the received signal may be deformed, and such deformation may result in deterioration of the reception performance. Therefore, in order to guarantee performance, the degree of amplification may be set to operate in a section having linearity between the input and output of the amplifier. In addition, if the degree of amplification is set too low, the reception performance may not be secured because the reception signal may not be sufficiently amplified. Therefore, the degree of amplification can be continuously automatically adjusted to maximize amplification in the section with linearity between the input and output of the amplifier. This is called automatic gain control (AGC). The terminal can find an appropriate degree of amplification by performing AGC, and it takes some time to find the appropriate degree of amplification, and this required time is called AGC training time. The signal received during such AGC training time may not be used for the reception of actual control and data signals, and the AGC training time may be determined according to the setting of the initial value of the degree of amplification for performing AGC. In sidelink communication in which a terminal to which a signal is transmitted may continuously change, since the receiving terminal must continuously perform the AGC, an AGC training time may be required for every signal reception. As the AGC training time required for the receiving terminal is reduced, the received signal section that the terminal can use for signal processing increases, so the reception performance can be improved.

The transmitting terminal may transmit the preamble signal in one or more symbols before transmitting the sidelink control channel and data. The preamble signal may be used so that the receiving terminal can correctly perform automatic gain control (AGC) for adjusting the strength of the amplification when the receiving terminal amplifies the power of the received signal. A PSCCH including control information may be transmitted in early symbols of a slot, and a PSSCH scheduled by the control information of the PSCCH may be transmitted. A part of SCI, which is control information, may be mapped to the PSSCH and transmitted. In the physical channel structure in the sidelink slot, the preamble signal for performing AGC may be separately transmitted, but the sidelink channel and signal to be transmitted in the second symbol are copied and transmitted in the first symbol, and the receiver performs AGC using this It may also be possible to

The position of the symbol at which the DMRS is transmitted described in this embodiment may be applied by combining patterns of different positions according to the allocated length of the PSSCH. In the above, the allocated length of the PSSCH may be the number of symbols used for PSSCH transmission including DMRS excluding AGC symbols. In addition, in the method provided in this embodiment, a PSSCH may be mapped to a DMRS symbol according to availability of available resources. In addition, in the method provided in this embodiment, a part of control information may be mapped to a DMRS symbol according to whether a resource is available or a resource of a PSSCH. The DMRS pattern provided in this embodiment may be a physically absolute symbol position within a slot, but may also be a relative symbol position depending on an applied example. For example, the position of the DMRS symbol may be changed according to the positions of symbols used for sidelink in the slot. That is, when p is the index of the first symbol of the PSCCH, the position of the DMRS symbol provided in this embodiment may be given as a relative offset value from p.

21 is a diagram illustrating a DMRS of a sidelink control channel and data when the first three symbols are used for downlink in a slot according to an embodiment of the present disclosure.

This embodiment provides an example of maximally reusing the relative position of the downlink DMRS symbol, that is, the DMRS symbol of the PDSCH in the NR system. In addition, this embodiment provides an example of maximally reusing the relative positions of uplink DMRS symbols, ie, DMRS symbols of PUSCH, in the NR system. The DMRS symbol of the above-mentioned PUSCH may vary depending on the PUSCH type of the NR system. In the case of PUSCH type A, the position of the DMRS symbol is the same as the position of the DMRS symbol of the downlink PDSCH, and in the case of PUSCH type B The position of the DMRS symbol is different from the position of the DMRS symbol of the downlink PDSCH.

If the position within the slot of the DMRS of PUSCH type B defined in the NR system is regarded as the relative position from the first symbol of the PSCCH, which is a control channel transmitted in the slot of the sidelink, examples such as FIGS. 22A to 22D are possible. can

22A, 22B, 22C and 22D are diagrams each showing a pattern including one, two, three, and four DMRS symbols according to an embodiment of the present disclosure.

Each of the patterns shown in FIGS. 22A to 22D may be patterns used according to parameter values such as dmrs_number or dmrs-AdditionalPosition and the number of symbols used for PSSCH mapping. For example, dmrs-AdditionalPosition=pos2 (dmrs-AdditionalPosition may mean the number of additional symbols other than 1, for example, pos2 may mean the total number of 3 DMRS symbols. That is, posX is the total number of X +1 symbol), one of the DMRS patterns shown may be selected and used according to the number of PSSCH symbols from among the DMRS patterns shown in FIG. 22C.

In the present disclosure, the position of the first symbol of the PSCCH, which is a control channel transmitted in the slot of the sidelink, may mean the second symbol used as the sidelink in the slot.

In the present disclosure, a parameter value such as dmrs_number or dmrs-AdditionalPosition may be a value transmitted from control information (SCI) or first stage control information (1st stage SCI). Alternatively, a parameter value such as dmrs_number or dmrs-AdditionalPosition may be a value set in the resource pool, or may be a value indicated by SCI among values set in the resource pool. For example, a 2-bit indicator is transmitted in SCI, and the 2-bit indicator may indicate a value of dmrs-AdditionalPosition.

23A, 23B, and 23C are diagrams illustrating a modified example of a DMRS pattern according to an embodiment of the present disclosure. The patterns shown in FIGS. 22A to 22D may be further modified and supported in the sidelink. For example, the DMRS pattern of FIG. 22B including two symbol DMRSs in the sidelink may be modified and applied as shown in FIG. 23A. Similarly, FIG. 22c may be modified and used as a DMRS pattern including 3 symbol DMRS in the sidelink, and FIG. 22d may be modified and used as a DMRS pattern including 4 symbol DMRS in the sidelink. For example, the DMRS patterns of FIGS. 22C and 22D may be modified and used in FIGS. 23B and 23C , respectively.

According to an embodiment of the present disclosure, among the patterns provided according to the length of the PSSCH and the length of the PSCCH shown in FIGS. 22A to 22D and 23A to 23C , some or a combination of some may be used.

As for the position of the symbol at which the DMRS described in this embodiment is transmitted, different possible positions may be applied according to subcarrier spacing. For example, among the patterns provided according to the length of the PSSCH and the length of the PSCCH shown in FIGS. 22A to 22D and 23A , a part or a combination of parts may be used differently depending on the subcarrier spacing.

The position of the symbol at which the DMRS is transmitted described in this embodiment may be applied by combining patterns of different positions according to the allocated length of the PSSCH. In the above, the allocated length of the PSSCH may be the number of symbols used for PSSCH transmission including DMRS excluding AGC symbols.

In addition, in the method provided in this embodiment, a PSSCH may be mapped to a DMRS symbol according to availability of available resources.

In addition, in the method provided in this embodiment, a part of control information may be mapped to a DMRS symbol according to whether a resource is available or a resource of a PSSCH.

The DMRS pattern provided in this embodiment may be a physically absolute symbol position within a slot, but may also be a relative symbol position depending on an applied example. That is, the position of the DMRS symbol may be changed according to the position of the symbols used for sidelink in the slot. For example, when p is the index of the first symbol of the PSCCH, the position of the DMRS symbol provided in this embodiment may be given as a relative offset value from p. For example, FIG. 21 may be an embodiment in which a part of FIG. 23A is applied when the first three symbols in a slot are used for downlink.

[Example 1-1]

Embodiment 1-1 provides a method and apparatus for mapping a DMRS for decoding a PSSCH and also mapping a PSSCH in sidelink data transmission/reception.

24 is a diagram illustrating a mapping in a symbol to which a DMRS for decoding a PSSCH is mapped in sidelink data transmission/reception according to an embodiment of the present disclosure. Referring to FIG. 24 , mapping resource locations are different according to PSSCH DMRS Type 1 and Type 2 . One cell means one RE, and the number may be a layer number or an antenna port number. For example, in the mapping of type 1 in FIG. 24, DMRSs corresponding to

layers

2 and 3 or

antenna ports

2 and 3 are mapped to the 1, 3, 5, 7, 9, and 11th REs from the top, 2, DMRSs corresponding to

layers

0 and 1 or

antenna ports

0 and 1 may be mapped to the 4th, 6th, 8th, 10th, and 12th REs. Since only two layer transmissions can be supported in the sidelink, if DMRS is used according to a predetermined number, not all REs of one symbol are used for DMRS mapping.

If different transmitting terminals transmit positions of REs to which DMRSs are mapped differently, even if PSSCH transmission frequency resources of the two terminals overlap, the REs of DMRSs may not overlap, so channel estimation or channel sensing performance may be improved. For example, when terminal A and terminal B each transmit data using one layer, in the case of transmitting DMRS using REs corresponding to layer 0 in the type 1 DMRS mapping shown in FIG. 24, the terminal If A and UE B transmit PSSCH and/or DMRS in the same PRB, REs of DMRS transmitted by both UEs may overlap. Conversely, when UE A and UE B each transmit data using one layer, UE A uses the RE corresponding to layer 0 in the type 1 DMRS mapping shown in FIG. 24 to transmit PSSCH and/or DMRS , and UE B transmits PSSCH and/or DMRS using REs corresponding to layer 2, even if both UEs transmit PSSCH and DMRS in the same PRB, REs of DMRS transmitted by the two UEs do not overlap. can Accordingly, the channel estimation performance in this case may be improved. In this case, the operation may be different depending on how the CDM group is used. One CDM group in the above means, for example, in the case of type 1 in FIG. 24, REs marked 0/1 may be one CDM group, and REs marked 2/3 may be another CDM group. . In the case of Type 2 in FIG. 24 , REs marked 0/1 are one CDM group, REs marked 2/3 are another CDM group, and REs marked 4/5 are another CDM group. If two CDM groups are used and one port or two ports are transmitted, the PSSCH may be transmitted in an empty state without data (PSSCH) mapped to another CDM group. If one CDM group is used and one port or two ports are transmitted, data (PSSCH) may be mapped to another CDM group and the PSSCH may be transmitted.

As described above, when different UEs transmit PSSCH and/or DMRS, if DMRSs are transmitted in different CDM groups, DMRS REs may not overlap even if PSSCHs and DMRSs are transmitted in the same PRB. That is, when both terminal A and terminal B transmit one port and use different CDM groups, terminal B transmits DMRS in the 1st, 3rd, 5th, 7th, 9th, and 11th REs, and terminal A It may be a method of transmitting DMRS in the 2nd, 4th, 6th, 8th, 10th, and 12th REs. For example, a CDM group may be determined between transmitting and receiving terminals according to at least one of the following methods.

- Method 1: The CDM group may be determined according to the CRC ratio value of the PSCCH. That is, if the CRC bit value is an odd number when converted to a decimal number, PSSCH DMRS is transmitted from the first CDM group. have. That is, the CDM group may be determined according to the LSB or MSB value of the CRC bit. If the LSB (or MSB, or specific n-th bit value) value of the CRC bit is 0, PSSCH DMRS is transmitted in the first CDM group, and if the LSB (or MSB, or specific n-th bit value) value of the CRC bit is 1, two PSSCH DMRS may be transmitted in the th CDM group.

- Method 2: A CDM group may be determined according to the lowest (or highest) PRB index value through which the PSCCH is transmitted. That is, if the lowest (or highest) PRB index value through which the PSCCH is transmitted is odd, the PSSCH DMRS is transmitted in the first CDM group, and the lowest (or highest) PRB index value through which the PSCCH is transmitted is even. PSSCH DMRS may be transmitted in the th CDM group.

Whether the PSSCH is mapped and transmitted to REs to which DMRS is not mapped in the symbol in which the DMRS is transmitted may be determined according to the number of CDM groups. That is, in the case of DMRS type 1, when the number of CDM groups is 1, the PSSCH is mapped to the remaining CDM groups and transmitted. When the number of CDM groups is 2, the PSSCH is not mapped to the REs corresponding to the remaining CDM groups. . In case of DMRS type 2, if the number of CDM groups is 1, PSSCH is mapped to the remaining CDM groups and transmitted. If the number of CDM groups is 2 or 3, the REs corresponding to the remaining corresponding CDM groups are PSSCH is not mapped.

[Second embodiment]

The second embodiment provides a method and apparatus for mapping second control information (eg, two-step SCI) to a resource.

29 is a diagram illustrating a method of transmitting second control information in a PSSCH according to an embodiment of the present disclosure. The method may be referred to as a method in which the second control information is piggybacked to the PSSCH. The method is a method in which the second control information is encoded and mapped using a channel coding method different from the SL-SCH included in the PSSCH. The transmitting terminal transmits the PSCCH and the PSSCH to the receiving terminal, and in the PSCCH, the first control information may be mapped and delivered to the receiving terminal. The transmitting terminal maps and transmits the first control information using the PSCCH, and transmits the PSSCH according to the PSSCH scheduling information included in the first control information. The transmitting terminal maps the second control information to the resource region of the PSSCH.

29 is a diagram illustrating an example in which second control information is mapped to a PSSCH. 29( a ) is an example in which the second control information is mapped to the frontmost part of the slot so that the second control information can be received as quickly as possible. 29(b) is an example in which the second control information is mapped to the earliest part of the slot so that the second control information can be received as quickly as possible, and the last symbol to which the second control information is mapped is widely mapped in the frequency domain. This may be because the purpose of the drawings is to enable the receiving terminal to decode the second control information as quickly as possible. 29(c) is an example in which the second control information is mapped to the front part immediately after the DMRS of the PSSCH is mapped so that the second control information can be received as soon as possible after the DMRS of the PSSCH is received. In FIG. 29(d), the second control information is mapped to the front part as soon as possible after the DMRS of the PSSCH is mapped so that the second control information can be received as soon as possible after the DMRS of the PSSCH is received. In the last symbol to which the second control information is mapped, This is an example of widely spread mapping in the frequency domain. 29(e) is an example in which the DMRS of the PSSCH is mapped to the front part immediately after the DMRS is mapped so that the second control information can be received as soon as possible from the same symbol as the DMRS of the PSSCH. In (f) of FIG. 29, the DMRS of the PSSCH is mapped to the front part as soon as possible so that the second control information can be received as quickly as possible from the same symbol as the DMRS of the PSSCH. In the last symbol to which the second control information is mapped, This is an example of widely spread mapping in the frequency domain. In the drawings, the purpose of enabling the receiving terminal to decode the second control information as soon as possible after completing the channel estimation using the DMRS of the PSSCH and to use the sophisticated channel estimation information.

30 and 31 are diagrams illustrating different examples to which second control information is mapped according to an embodiment of the present disclosure. 30 is a diagram illustrating an example in which the first symbol of DMRS for PSSCH is located in the fourth symbol of the slot, and may be a diagram corresponding to (a), (b), (c), and (d) of FIG. 29, respectively. . 31A is a diagram illustrating an example of mapping second control information to all symbols to which PSSCH is mapped in a slot. 31( b ) is a diagram illustrating an example in which the second control information is mapped back and forth to the DMRS of the PSSCH, which secures good channel measurement performance by arranging the second control information near the DMRS to decode the second control information You will be able to increase your reliability.

When the receiving terminal decodes the PSCCH to obtain the first control information, information on the resource to which the PSSCH is mapped and other scheduling information can be obtained. The other scheduling information may include an MCS. Accordingly, when the receiving terminal obtains the first control information, it can determine the resource region and MCS information of the PSSCH, and decode the second control information mapped to the PSSCH.

When the second control information is mapped to the PSSCH, the number of bits in which the second control information is coded using channel coding

may be calculated as follows.

In the above, R is a coding rate of the PSSCH, Qm is a modulation order, and R and Qm may be obtained from MCS information included in the first control information for scheduling the PSSCH.

is a parameter for adjusting the number of coded bits of the second control information, and may be determined based on at least one of a resource pool setting, a PC5-RRC setting, or a bit field of the first control information. from above

is the number of bits of the second control information,

is the number of CRC bits added to the second control information before channel coding. from above

Is

It can be the smallest integer greater than or equal to.

When determining the amount of the mapped resource and the mapping resource of the second control information, or the number of bits in which the second control information is coded, the amount of the mapped resource and the mapping resource, or the number of bits, is the setting of the resource pool, or PC5- It may be determined based on the RRC configuration or the first control information. For example, similarly to the example provided in the second embodiment, when the second control information is mapped to the PSSCH, the number of bits or symbols in which the second control information is coded using channel coding

may be calculated as in Equation 2 below.

Equation 2 may be applied by being replaced with [Equation 3] as follows. from above

When the second control information is mapped, the RE (that is, the second control information is mapped If there is an RE) that does not exist, it is a variable determined so that the second control information is mapped to all remaining REs of the corresponding RB.

from above

In the above, Kr may be the size of the r-th codeblock of the TB included in the SL-SCH, that is, the PSSCH, and Kr may include the length of the CRC, but may be applied not to be included. In the above, C_{SC-SCL} may be the number of code blocks included in the TB included in the SL-SCH, that is, the PSSCH. from above

may be the SL-SCH, that is, the size of a TB included in the PSSCH, TBS. That is, in the above

SL-SCH, that is, the size of TB included in PSSCH, may be replaced with TBS.

36 is a diagram illustrating an example in which second control information is mapped to all remaining REs when there are REs remaining in an RB to which second control information is mapped according to an embodiment of the present disclosure.

In the above [Equation 2] and [Equation 3], when the second control information is mapped in units of RBs, if there are REs remaining in the RB to which the second control information is mapped, as in the example shown in FIG. 36, all remaining As shown in (b), the second control information is mapped to the remaining RE so that the second control information is mapped to the RE. 36 may be a diagram illustrating a last symbol to which the second control information is mapped when the second control information is mapped.

is a parameter for adjusting the number of coded bits of the second control information, and may be determined based on at least one of a resource pool setting, a PC5-RRC setting, or a bit field of the first control information. For example,

may be a value indicated by the first control information among the values set in the resource pool, and in the first control information

The size of the bit field to indicate may be determined according to the number of values set in the resource pool. That is, there are N values in the resource pool.

If it is set for , the size of the bit field is

etc. may be equal to a function of N. from above

is the number of bits of the second control information,

may be a parameter that determines the amount to which the second control information is mapped. from above

The value may be transmitted in the first control information, or may be a value preset in the resource pool.

For example, above

If the value is indicated in the first control information, the receiving terminal decodes the PSCCH to obtain the first control information, and

The value may be found, and the second control information may be decoded based on this. Thereafter, the receiving terminal may know the resource and scheduling parameter to which the PSSCH is mapped according to bitfield values included in the first control information and the second control information, and may perform decoding of the PSSCH based on the information. from above

may be the number of symbols allocated to the corresponding PSSCH, but may be determined in the following way.

- Method 1:

is the number of symbols that do not overlap with the PSCCH among symbols allocated to the corresponding PSSCH except for AGC symbols, and may optionally include DMRS symbols.

32 and 33 are diagrams illustrating an embodiment of a symbol allocated to a PSSCH according to an embodiment of the present disclosure. In the example of Figure 32

is the number of symbols from symbol 4 to symbol 12.

can be 9. In addition, in the example of FIG. 33

is the number of symbols from symbol 4 to symbol 6,

can be 3.

- Method 2:

is the number of symbols allocated to the PSSCH after the first symbol of the DMRS for the PSSCH and thereafter among the symbols allocated to the corresponding PSSCH except for the AGC symbol, and may optionally include DMRS symbols. That is, in the example of FIG. 32

is the number of symbols from symbol 4 to symbol 12.

can be 9. In the example of FIG. 33

is the number of symbols from symbol 1 to symbol 6,

can be 6.

- Method 3:

is the number of symbols that do not overlap the PSCCH among symbols allocated to the corresponding PSSCH except for AGC symbols, and DMRS symbols may be selectively excluded. That is, in the example of FIG. 32

is the number of symbols from symbol 4 to symbol 12, excluding

symbols

4 and 10.

can be 7. In the example of Figure 33

is the number of symbols excluding symbol 5 from symbol 4 to symbol 6,

can be 2.

in the above formula

is the number of REs to which the second control information can be mapped, and in the process of obtaining the number of REs, a region to which at least one of PSCCH, DMRS, PT-RS, etc. is mapped may be excluded (from the number of REs).

In the above, the values of the variables may be determined or determined as follows.

-

is the number of the 2 ^nd -stage SCI bits.
-

is the number of CRC bits for the 2 ^nd -stage SCI, which is 24 bits.
-

is indicated in the corresponding 1 ^st -stage SCI.
-

is the scheduled bandwidth of PSSCH transmission, expressed as a number of subcarriers.
-

is the number of subcarriers in OFDM symbol

that carries DMRS, in the PSSCH transmission.
-

is the number of subcarriers in OFDM symbol

that carries PT-RS, in the PSSCH transmission.
-

is the number of resource elements that can be used for transmission of the 2 ^nd -stage SCI in OFDM symbol

, for

and for

, in PSSCH transmission, where

, where sl-lengthSymbols is the number of sidelink symbols within the slot provided by higher layers as defined in [6, TS 38.214]. If higher layer parameter sl-PSFCH-Period = 2 or 4,

=3 if "PSFCH overhead indication" field of SCI format 1-A indicates "1", and

=0 otherwise. If higher layer parameter sl-PSFCH-Period = 0,

=0. If higher layer parameter sl-PSFCH-Period is 1,

=3.
-

-

is the number of vacant resource elements in the resource block to which the last coded symbol of the 2 ^nd -stage SCI belongs.
-

is the coding rate as indicated by "Modulation and coding scheme" field in SCI format 1-A.
-

is configured by higher layer parameter sl-Scaling .

In the above method, the second control information may be mapped from the first DMRS symbol of the corresponding slot.

34 is a diagram illustrating an embodiment in which second control information is mapped according to an embodiment of the present disclosure. It may be possible to map the second control information as shown in FIG. 34 .

35 is a diagram illustrating a case in which a resource for mapping second control information is insufficient according to an embodiment of the present disclosure. Specifically, according to Equation 2, FIG. 35

It is a diagram illustrating that resources for mapping the actual second control information may be insufficient when . That is, calculated in Equation 2 above

It may be a situation that occurs when is larger than the actual number of mappable symbols.

Accordingly, in this embodiment, the following method and apparatus are provided in order not to run out of resources for mapping as described above.

- Method 1: In a process in which the transmitting terminal transmits the PSCCH and the PSSCH, and at the same time maps and transmits the second control information, the transmitting terminal selects among the candidate values set as higher

by selecting

may be determined and the second control information may be transmitted. The transmitting terminal is more than the number of symbols to which the second control information can be mapped.

so as not to grow

You can only choose between. That is, the number of symbols to which the second control information can be mapped

to make it bigger

can be excluded from not being selected (that is, it can be excluded from the candidate value).

- Method 2: A terminal receiving the PSCCH, second control information, and PSSCH

, and the number of symbols to which the second control information can be mapped

In the smaller case, it may be a method of treating this case as an error. In this case, the receiving terminal may not attempt to decode the second control information. In this method, that is, the receiving terminal may omit decoding of control information and data information. In addition, in order to determine whether decoding is omitted, it may be determined based on the actual coding rate of the actual mapped data and control information. For example, if the actual coding rate is equal to or greater than a predetermined value, decoding may be omitted, and a value such as 0.95 or 0.9 may be used as the predetermined value.

- Method 3: The terminal selects from among the candidate values set as higher

When selecting , the terminal is more than the number of symbols to which the second control information can be mapped.

so as not to grow

can only be considered as set. base station or

In the process of setting the candidate value, the number of symbols to which the second control information can be mapped is greater than

so as not to grow

can only be set. That is, the base station or the

to make it smaller

may not be set.

- Method 4: Based on the number of resources (or number of symbols) available for the second control information

can be decided In particular, the number of bits of the second control information (

), the number of CRC bits (

), coding rate of PSSCH (

), modulation order (

),

a first value determined by at least some parameters of

and

Based on a second value determined based on , and a third value determined based on the number of resources (or number of symbols) available for the second control information,

can be decided For example, said

The value may be determined based on a minimum value of the first, second, and third values or a predefined rule. as a specific example

It may be a method of using [Equation 4] as follows in the process of calculating . This may be determined based on the number of resources available for the second control information.

from above

may be the number of symbols to which the second control information can be mapped or a value corresponding thereto. Alternatively, it may be the number of REs to which the PSSCH or the second control information can be mapped from the first DMRS symbol among resources allocated to the PSSCH, or a value corresponding thereto.

provided in the present disclosure

The calculation method may be used to calculate the number of resources to which the second control information is mapped. According to another embodiment provided in the present disclosure, in the process of calculating TBS,

The method of calculating

can be used to calculate values such as

[Third embodiment]

The third embodiment provides a method and apparatus for a terminal to transmit and receive control information or data in a sidelink. ^{In particular, for mapping to 2 nd} SCI in PSSCH in a two-layer transmission situation, a method and apparatus for mapping the same modulation symbol to two layers are provided.

First, the following scrambling operation is performed on the PSSCH.

- single codeword

For , block of bits

must be scrambled prior to modulation. here

and a codeword transmitted through a physical channel

means the number of bits in

- scrambled sequence

and a sequence like

Let's say we have (sequence

may use the sequence given in Section 5.2.1 of TS38.211 (Based on Release 16), one of the 5G NR standards.)

- Scrambling can be performed with the following pseudo code.

The scramble method is

Instead of applying different scrambling methods depending on the value,

The same scrambling method was applied regardless of the value.

single codeword

For , perform modulation such that the block of scrambled bits becomes a block of complex-valued modulation symbols as follows:

(here,

) In addition, actual modulation can be performed as described in Section 5.1 of TS38.211, one of the 5G NR standards, and has the following characteristics.

-

for each

about bit pairs

become QPSK symbols,

in case

,

in case

this can be (here

to be.)

-

In the case of , modulation is performed using one of QPSK, 16QAM, 64QAM, and 256QAM modulation schemes. (Here, the modulation order of the modulation method

are 2, 4, 6, 8, respectively,

to be.)

Layer mapping is the number of layers

can be performed as described in section 7.3.1.3 of TS38.211 for

can be expressed as In addition, the vector block

Precoding may be performed according to 6.3.1.5 of TS38.211 for

is equal to the identity matrix,

this is accomplished

Next, mapping to the virtual resource block may be performed as follows.

Block of complex-valued symbols for each antenna port used for PSSCH transmission in order to conform to the transmission power specified in TS38.213, one of the 5G NR standards

is the amplitude scaling factor

is multiplied by , and also a resource element in the virtual resource block allocated for transmission.

can be mapped to (here

is the first subcarrier in the lowest-numbered virtual resource block assigned for transmission.) However, the following criteria are satisfied:

- Complex-valued symbols are within the most resource allocated for transmission.

- Corresponding resource elements in the corresponding physical resource blocks are not used for transmission of the associated DM-RS, PT-RS, CSI-RS, or PSCCH.

A detailed mapping operation may be performed through the following two-step process.

- ^{Complex value symbols corresponding to bits for 2 nd} -stage SCI are indexed on allocated virtual resource blocks

in increasing order of first the index

) can be placed.

- Next, a process of mapping from virtual resource blocks to physical resource blocks may be performed according to a mapping method that does not apply interleaving (non-interleaved mapping). In this case, in VRB-to-PRB mapping, virtual resource block n may be mapped to physical resource block n.

More specifically, the mapping operation may be as follows.

- First, 2 ^nd -stage SCI (second control information) from the complex-valued symbol must be the index k 'on the high-cost VRB (virtual resource block) allocation, and the index corresponding to the bit of the

starts from the first PSSCH symbol transmitting the associated DM-RS (first, the complex-valued symbols corresponding to the bit for the 2 ^nd -stage SCI shall be in increasing order of first the index)

over the assigned virtual resource blocks and then the index

, starting a the first PSSCH symbol carrying an associated DM-RS)

- Second, 2 ^nd -stage SCI complex-valued symbol that does not correspond to a bit of the (second control information) will be high since the index k 's on the VRB (virtual resource block) allocation, and the index

is the position given by [6, TS 38.214]. The resource element used for the 2 ^nd -stage SCI in the first stage is not used for mapping in this stage (secondly, the complex-valued modulation symbols not corresponding to the 2 ^nd -stage SCI shall be in in increasing order of first the index

over the assigned virtual resource blocks, and then the index

with the starting position given by [6, TS 38.214]. Resource elements used for 2 ^nd -stage SCI in the first step shall not be used for mapping in this step.)

- In the above mapping operation, the resource element used for the PSSCH in the first OFDM symbol must be replicated in the OFDM symbol immediately preceding the first OFDM symbol in the mapping (The resource elements used for the PSSCH in the first OFDM symbol in the mapping operation) above shall be duplicated in the OFDM symbol immediately preceding the first OFDM symbol in the mapping.)

[Fourth embodiment]

The fourth embodiment provides a method and apparatus for considering the second control information in the process of calculating a transport block size (TBS).

The TBS calculation method in the sidelink may be performed in the following way. In the following process, the TBS may be determined based on the resource to which the PSSCH is allocated, the MCS, and control information.

from above

is the total number of REs allocated for PSSCH (total number of REs allocated for PSSCH)

) as a parameter to be considered when calculating, it means the number of coded modulation symbols used for the second control information.

Since the resource to which the second control information is mapped in the initial transmission and the retransmission for any one TB may vary depending on the presence and the resource of the PSSCH DMRS, CSI-RS, or PT-RS,

There may be a problem in that TBS is calculated differently by . To solve these problems, the

It may be necessary to calculate the method for calculating the TB in the same way in the initial transmission and retransmission of the TB. Therefore, using the following methods

It may be possible to calculate It may be possible to apply a combination of one or more of the following methods.

- Method B1:

It may be assumed that the DMRS of the PSSCH is transmitted in a specific symbol in the process of calculating . That is, it can be assumed that transmission is performed using a specific DMRS pattern and number of symbols. The above assumption may be different from the actual number of PSSCH DMRS symbols and symbol positions. For example, 3 symbols are used for PSSCH DMRS that is actually transmitted,

For calculation of , it can be assumed that PSSCH DMRS is transmitted in 2 symbols. As above, this

The number and pattern of PSSCH DMRS symbols assumed in the calculation may be set by higher signaling or one of the configured PSSCH DMRS patterns. For example, if the DMRS pattern {1,2,3} is set as upper signaling (ie, 1 symbol, 2 symbols, 3 symbols), using the smallest value 1

It may be possible to calculate

- Method B2:

In the process of calculating , it may be assumed that the CSI-RS for the sidelink is not transmitted.

- Method B3:

It can be assumed that the PT-RS for the sidelink is not transmitted in the process of calculating .

To calculate TBS from above

In the process of calculating

may be determined based on the number of resources (or the number of symbols) available for the second control information. In particular, the number of bits of the second control information (

), the number of CRC bits (

), coding rate of PSSCH (

), modulation order (

),

a first value determined by at least some parameters of

and

can be decided For example, said

The value may be determined based on a minimum value of the first, second, and third values or a predefined rule. As a specific example, as in Equation 4 above

It may be calculated based on or,

And it may be determined without considering the number of resources (or the number of symbols) available for the second control information. remind

may be assumed to be 0 or may be assumed to be an arbitrary value.

In the above description, the first to fourth embodiments of the present disclosure have been divided for convenience of description, but since each embodiment includes operations related to each other, it is also possible that at least two or more embodiments are combined. In addition, although the present disclosure has described a method and implementation of receiving control and data information in initial transmission and retransmission in the case of HARQ-ACK feedback, the methods and apparatuses proposed in the present disclosure do not have HARQ-ACK feedback. The same method or an embodiment thereof may be applied to the system.

In addition, although the present disclosure has described a method and an embodiment of receiving control and data information in consideration of initial transmission and retransmission for convenience, even in the case of applying repetition or repeated transmission for initial transmission instead of retransmission The same method or an embodiment thereof can be applied. Here, repeated transmission means additional transmission corresponding to the TB used for the initial transmission after the initial transmission.

A transmitter, a receiver, and a processor of a base station and a terminal capable of performing the above embodiments of the present disclosure are illustrated in FIGS. 25 (and 27) and 26 (and 28), respectively. In order to perform the operations described in the first to fourth embodiments, the receiving unit, processing unit, and transmitting unit of the base station and the terminal may operate according to each embodiment.

Referring to FIG. 25 , the terminal of the present disclosure may include a terminal receiving unit 25-00, a terminal transmitting unit 25-04, and a terminal processing unit 25-02. The terminal receiving unit 25-00 and the terminal may collectively refer to the transmitting unit 25-04 as a transceiver in an embodiment of the present disclosure. The transceiver may transmit/receive a signal to/from the base station. The signal may include control information and data. To this end, the transceiver may include an RF transmitter for up-converting and amplifying a frequency of a transmitted signal, and an RF receiver for low-noise amplifying and down-converting a received signal. In addition, the transceiver may receive a signal through a wireless channel, output it to the terminal processing unit 25-02, and transmit a signal output from the terminal processing unit 25-02 through a wireless channel. The terminal processing unit 25-02 may control a series of processes so that the terminal can operate according to the above-described embodiment of the present disclosure. For example, the terminal receiving unit 25-00 receives control information from the base station in downlink, and the terminal processing unit 25-02 determines the HARQ ID and the like according to the control information and prepares for transmission and reception accordingly. . Thereafter, the terminal transmitter 25-04 may transmit scheduled data to the base station.

Referring to FIG. 26 , the base station of the present disclosure may include a base station receiving unit 26-01, a base station transmitting unit 26-05, and a base station processing unit 26-03. The base station receiver 26-01 and the base station transmitter 26-05 may be collectively referred to as a transceiver in an embodiment of the present disclosure. The transceiver may transmit/receive a signal to/from the terminal. The signal may include control information and data. To this end, the transceiver may include an RF transmitter for up-converting and amplifying a frequency of a transmitted signal, and an RF receiver for low-noise amplifying and down-converting a received signal. In addition, the transceiver may receive a signal through a wireless channel, output it to the base station processing unit 26-03, and transmit a signal output from the base station processing unit 26-03 through a wireless channel. The base station processing unit 26-03 may control a series of processes so that the base station can operate according to the above-described embodiment of the present disclosure. For example, the base station processing unit 26-03 may transmit a downlink control signal to the terminal if necessary according to configuration information set by the base station processing unit 26-03. Thereafter, the base station transmitter 26-05 transmits related scheduling control information and data, and the base station receiver 26-01 receives feedback information from the terminal.

27 is a block diagram of a terminal according to an embodiment of the present disclosure.

Referring to FIG. 27 , the terminal may include a transceiver 27-05, a memory 27-10, and a processor 27-15. According to the communication method of the terminal described above, the transceiver 27-05, the processor 27-15, and the memory 27-10 of the terminal may operate. However, the components of the terminal are not limited to the above-described example. For example, the terminal may include more or fewer components than the aforementioned components. In addition, the transceiver 27-05, the processor 27-15, and the memory 27-10 may be implemented in the form of a single chip. In addition, the processors 27-15 may include one or more processors.

The transceiver 27-05 collectively refers to a receiver of a terminal and a transmitter of the terminal, and may transmit/receive a signal to and from a network entity, a base station, or another terminal. A signal transmitted and received with a network entity, a base station, or another terminal may include control information and data. To this end, the transceiver 27-05 may include an RF transmitter that up-converts and amplifies a frequency of a transmitted signal, and an RF receiver that low-noise amplifies and down-converts a received signal. However, this is only an embodiment of the transceiver 27-05, and components of the transceiver 27-05 are not limited to the RF transmitter and the RF receiver.

In addition, the transceiver 27-05 may receive a signal through a wireless channel, output it to the processor 27-15, and transmit a signal output from the processor 27-15 through a wireless channel.

The memory 27-10 may store programs and data necessary for the operation of the terminal. In addition, the memory 27-10 may store control information or data included in a signal obtained from the terminal. The memory 27 - 10 may be configured as a storage medium or a combination of storage media such as ROM, RAM, hard disk, CD-ROM, and DVD. Also, the memory 27-10 may not exist separately and may be included in the processor 27-15.

The processor 27-15 may control a series of processes so that the terminal can operate according to the above-described embodiment of the present disclosure. For example, the processor 27-15 may receive a control signal and a data signal through the transceiver 27-05, and process the received control signal and data signal. The processed control signal and data signal may be transmitted through the transceiver 27-05. In addition, the processor 27-15 may receive the DCI composed of two layers and control the components of the terminal to receive a plurality of PDSCHs at the same time. There may be a plurality of processors 27-15, and the processor 27-15 may execute a program stored in the memory 27-10 to perform a component control operation of the terminal.

Referring to FIG. 28 , the base 7 may include a transceiver 28-06, a memory 28-10, and a processor 28-15. According to the above-described communication method of the base station, the transceiver 28-06, the processor 28-15, and the memory 28-10 of the base station may operate. However, the components of the base station are not limited to the above-described example. For example, the base station may include more or fewer components than the above-described components. In addition, the transceiver 28-06, the processor 28-15, and the memory 28-10 may be implemented in the form of a single chip. In addition, processors 28-15 may include one or more processors.

The transceiver 28-06 collectively refers to a receiver of a base station and a transmitter of the base station, and may transmit/receive a signal to and from a terminal or a network entity. A signal transmitted and received with the terminal or network entity may include control information and data. To this end, the transceiver 28-06 may include an RF transmitter that up-converts and amplifies the frequency of a transmitted signal, and an RF receiver that low-noise amplifies and down-converts a received signal. However, this is only an embodiment of the transceiver 28-06, and components of the transceiver 28-06 are not limited to the RF transmitter and the RF receiver.

In addition, the transceiver 28-06 may receive a signal through a wireless channel, output it to the processor 28-15, and transmit a signal output from the processor 28-15 through a wireless channel.

The memory 28-10 may store programs and data necessary for the operation of the base station. In addition, the memory 28-10 may store control information or data included in a signal obtained from the base station. The memory 28-10 may be configured as a storage medium or a combination of storage media, such as ROM, RAM, hard disk, CD-ROM, and DVD. Also, the memory 28-10 does not exist separately and may be included in the processor 28-15.

The processor 28-15 may control a series of processes so that the base station can operate according to the above-described embodiment of the present disclosure. For example, the processor 28-15 may receive a control signal and a data signal through the transceiver 28-06, and process the received control signal and data signal. The processed control signal and data signal may be transmitted through the transceiver 28-06. In addition, the processor 28-15 may control each component of the base station to configure and transmit the DCI including allocation information for the PDSCH. The processor 28-15 may be plural, and the processor 28-15 may execute a program stored in the memory 28-10 to perform a component control operation of the base station.

On the other hand, the embodiments of the present disclosure disclosed in the present specification and drawings are only presented as specific examples to easily explain the technical content of the present disclosure and help the understanding of the present disclosure, and are not intended to limit the scope of the present disclosure. That is, it is apparent to those of ordinary skill in the art to which other modifications are possible based on the technical spirit of the present disclosure. In addition, each of the above embodiments may be operated in combination with each other as needed. In addition, the above embodiments may be implemented in other modifications based on the technical idea of the embodiment, such as LTE system, 5G system.

Methods according to the embodiments described in the claims or specifications of the present disclosure may be implemented in the form of hardware, software, or a combination of hardware and software.

When implemented in software, a computer-readable storage medium storing one or more programs (software modules) may be provided. One or more programs stored in a computer-readable storage medium may be configured to be executable by one or more processors in an electronic device (device configured for execution). One or more programs include instructions for causing an electronic device to execute methods according to embodiments described in a claim or specification of the present disclosure.

Such programs (software modules, software) include random access memory, non-volatile memory including flash memory, read only memory (ROM), electrically erasable programmable ROM (electrically erasable programmable read only memory, EEPROM), magnetic disc storage device, compact disc-ROM (CD-ROM), digital versatile discs (DVDs), or other It may be stored in an optical storage device or a magnetic cassette. Alternatively, it may be stored in a memory composed of a combination of some or all thereof. In addition, each configuration memory may be included in plurality.

In addition, the program is transmitted through a communication network consisting of a communication network such as the Internet, an intranet, a local area network (LAN), a wide area network (WAN), or a storage area network (SAN), or a combination thereof. It may be stored on an attachable storage device that can be accessed. Such a storage device may be connected to a device implementing an embodiment of the present disclosure through an external port. In addition, a separate storage device on the communication network may be connected to the device implementing the embodiment of the present disclosure.

In the specific embodiments of the present disclosure described above, components included in the disclosure are expressed in the singular or plural according to the specific embodiments presented. However, the singular or plural expression is appropriately selected for the context presented for convenience of description, and the present disclosure is not limited to the singular or plural component, and even if the component is expressed in plural, it is composed of the singular or singular. Even an expressed component may be composed of a plurality of components.

Meanwhile, although specific embodiments have been described in the detailed description of the present disclosure, various modifications are possible without departing from the scope of the present disclosure. Therefore, the scope of the present disclosure should not be limited to the described embodiments and should be defined by the claims described below as well as the claims and equivalents.

Claims

In the method of a first terminal in a communication system,

transmitting first sidelink control information (SCI) to a second terminal; and

based on the first SCI, transmitting a second SCI and sidelink data to the second terminal;

The number of coded modulation symbols for transmission of the second SCI is based on the first SCI.
According to claim 1,

The first SCI includes a hybrid automatic repeat request (HARQ) process number, information on redundancy version (RV), information on time domain resources of a physical sidelink shared channel (PSSCH), information on frequency domain resources of the PSSCH, and resources Information on reservation (resource reservation), information on modulation and coding scheme (MCS), information on demodulation pattern (DMRS) pattern, information indicating a beta offset value used to determine the number of the coded modulation symbols, or at least one of information indicating the second SCI,

The second SCI includes at least one of an HARQ process number, a new data indicator (NDI), information on RV, an HARQ feedback activation or deactivation indicator, an ID associated with the first terminal, or an ID associated with the second terminal A method characterized in that.
The method of claim 1,

The number of the coded modulation symbols is a value determined based on the first SCI and a resource element (RE) to which the second SCI can be mapped from the first symbol to which the DMRS is transmitted among resources of a physical sidelink shared channel (PSSCH). Method, characterized in that determined based on the number of.
According to claim 1,

A transport block size (TBS) associated with the sidelink data is based on the number of resource elements (REs) occupied by a physical sidelink control channel (PSCCH) and the number of coded modulation symbols for transmission of the second SCI. A method characterized in that it is determined.
In the method of a second terminal in a communication system,

Receiving first sidelink control information (SCI) from a first terminal; and

based on the first SCI, receiving a second SCI and sidelink data from the first terminal;

The number of coded modulation symbols for transmission of the second SCI is based on the first SCI.
6. The method of claim 5,

The first SCI includes a hybrid automatic repeat request (HARQ) process number, information on redundancy version (RV), information on time domain resources of a physical sidelink shared channel (PSSCH), information on frequency domain resources of the PSSCH, and resources Information on reservation (resource reservation), information on modulation and coding scheme (MCS), information on demodulation pattern (DMRS) pattern, information indicating a beta offset value used to determine the number of the coded modulation symbols, or at least one of information indicating the second SCI,

The second SCI includes at least one of an HARQ process number, a new data indicator (NDI), information on RV, an HARQ feedback activation or deactivation indicator, an ID associated with the first terminal, or an ID associated with the second terminal A method characterized in that.
6. The method of claim 5,

The number of the coded modulation symbols is a value determined based on the first SCI and a resource element (RE) to which the second SCI can be mapped from the first symbol to which the DMRS is transmitted among resources of a physical sidelink shared channel (PSSCH). is determined based on the number of

A transport block size (TBS) associated with the sidelink data is based on the number of resource elements (REs) occupied by a physical sidelink control channel (PSCCH) and the number of coded modulation symbols for transmission of the second SCI. A method characterized in that it is determined.
In the first terminal of the communication system,

transceiver; and

connected to the transceiver,

Transmitting first SCI (sidelink control information) to a second terminal through the transceiver,

a control unit configured to transmit a second SCI and sidelink data to the second terminal through the transceiver based on the first SCI;

The first terminal, characterized in that the number of coded modulation symbols (coded modulation symbols) for transmission of the second SCI is based on the first SCI.
9. The method of claim 8,

The first SCI includes a hybrid automatic repeat request (HARQ) process number, information on redundancy version (RV), information on time domain resources of a physical sidelink shared channel (PSSCH), information on frequency domain resources of the PSSCH, and resources Information on reservation (resource reservation), information on modulation and coding scheme (MCS), information on demodulation pattern (DMRS) pattern, information indicating a beta offset value used to determine the number of the coded modulation symbols, or at least one of information indicating the second SCI,

The second SCI includes at least one of an HARQ process number, a new data indicator (NDI), information on RV, an HARQ feedback activation or deactivation indicator, an ID associated with the first terminal, or an ID associated with the second terminal The first terminal, characterized in that.
9. The method of claim 8,

The number of the coded modulation symbols is a value determined based on the first SCI and a resource element (RE) to which the second SCI can be mapped from the first symbol to which the DMRS is transmitted among resources of a physical sidelink shared channel (PSSCH). The first terminal, characterized in that determined based on the number of.
9. The method of claim 8,

A transport block size (TBS) associated with the sidelink data is based on the number of resource elements (REs) occupied by a physical sidelink control channel (PSCCH) and the number of coded modulation symbols for transmission of the second SCI. The first terminal, characterized in that determined.
In the second terminal of the communication system,

transceiver; and

connected to the transceiver,

Receive first SCI (sidelink control information) from the first terminal through the transceiver,

a control unit configured to receive a second SCI and sidelink data from the first terminal through the transceiver based on the first SCI;

The second terminal, characterized in that the number of coded modulation symbols (coded modulation symbols) for transmission of the second SCI is based on the first SCI.
13. The method of claim 12,

The first SCI includes a hybrid automatic repeat request (HARQ) process number, information on redundancy version (RV), information on time domain resources of a physical sidelink shared channel (PSSCH), information on frequency domain resources of the PSSCH, and resources Information on reservation (resource reservation), information on modulation and coding scheme (MCS), information on demodulation pattern (DMRS) pattern, information indicating a beta offset value used to determine the number of the coded modulation symbols, or at least one of information indicating the second SCI,

The second SCI includes at least one of an HARQ process number, a new data indicator (NDI), information on RV, an HARQ feedback activation or deactivation indicator, an ID associated with the first terminal, or an ID associated with the second terminal The second terminal, characterized in that.
13. The method of claim 12,

The number of the coded modulation symbols is a value determined based on the first SCI and a resource element (RE) to which the second SCI can be mapped from the first symbol to which the DMRS is transmitted among resources of a physical sidelink shared channel (PSSCH). The second terminal, characterized in that determined based on the number of.
13. The method of claim 12,

The transport block size (TBS) associated with the sidelink data is based on the number of resource elements (REs) occupied by a physical sidlelink control channel (PSCCH) and the number of the coded modulation symbols for transmission of the second SCI. The second terminal, characterized in that determined.