Method and apparatus for partial retransmission in a wireless cellular communication system

Abstract

The disclosure relates to a communication method and system for aggregating a 5th-Generation (5G) communication system for supporting a high data rate beyond a 4th-Generation (4G) system and a technology for Internet of Things (IoT). The disclosure can be applied to intelligent services based on the 5G communication technology and the technology for IoT. A method for a base station to perform retransmission with respect to a code block that needs retransmission among transport blocks includes transmitting first information about a number of code block groups (CBGs) included in a transport block (TB) to a terminal, determining CBGs for the TB based on a number of code blocks (CBs) included in the TB and the first information, and transmitting the determined CBGs and control information including second information about transmission of the TB to the terminal.

Description

[0001] This application is a divisional application of a patent application with an application date of November 24, 2017, application number 201780072813.3, and invention name “Method and device for partial retransmission in a wireless cellular communication system”. Technical Field

[0002] The present disclosure relates generally to wireless communication systems, and more particularly, to methods and apparatus for performing retransmission of a code block requiring retransmission among a transport block if retransmission of an initially transmitted transport block is required. Background Art

[0003] In order to meet the needs of wireless data services that are on a growing trend after the commercialization of 4G communication systems, efforts have been made to develop improved 5G or pre-5G communication systems. For this reason, 5G or pre-5G communication systems are also referred to as super 4G network communication systems or post-LTE systems. 5G communication systems are considered to be implemented in higher frequency (millimeter wave) bands, such as 60GHz bands, to achieve higher data rates. In order to reduce the propagation loss of radio waves and increase the transmission distance, beamforming, massive multiple input multiple output (MIMO), full-dimensional MIMO (FD-MIMO), array antennas, analog beamforming, and massive antenna technology are discussed in 5G communication systems. In addition, in 5G communication systems, the development of system network improvements is being carried out based on advanced small cells, cloud radio access networks (RAN), ultra-dense networks, device-to-device (D2D) communications, wireless backhaul, mobile networks, cooperative communications, coordinated multipoint (CoMP), receiving-end interference elimination, etc. In 5G systems, hybrid FSK and QAM modulation (FQAM) and sliding window superposition coding (SWSC) have been developed as advanced coding modulation (ACM), and filter bank multi-carrier (FBMC), non-orthogonal multiple access (NOMA) and sparse code multiple access (SCMA) as advanced access technologies.

[0004] To achieve high data rates, the implementation of 5G communication systems in ultra-high frequency (millimeter wave) bands (e.g., similar to the 60 GHz band) has been considered. In order to reduce the path loss of radio waves and increase the transmission distance of radio waves in ultra-high frequency bands, technologies such as beamforming, massive MIMO, full-dimensional MIMO (FD-MIMO), array antennas, analog beamforming, and massive antennas have been discussed for use in 5G communication systems.

[0005] In addition, for system network improvements in 5G communication systems, technical developments have been made for evolved small cells, advanced small cells, cloud radio access networks (cloud RAN), ultra-dense networks, device-to-device communication (D2D), wireless backhaul, mobile networks, cooperative communications, coordinated multi-point (CoMP), and receive interference cancellation.

[0006] In addition, in 5G systems, hybrid FSK and QAM modulation (FQAM) and sliding window superposition coding (SWSC) corresponding to advanced coding modulation (ACM) systems, as well as filter bank multi-carrier (FBMC), non-orthogonal multiple access (NOMA) and sparse code multiple access (SCMA) corresponding to advanced connection technologies have been developed.

[0007] Meanwhile, the Internet, a human-centric network of connected devices where humans generate and consume information, has evolved into the Internet of Things (IoT), where distributed entities such as objects exchange and process information. The Internet of Everything (IoE), a combination of IoT technology and big data processing technology connected to cloud servers, has emerged.

[0008] With the technological elements required for IoT implementation, such as sensing technology, wired / wireless communications and network infrastructure, service interface technology, and security technology, research has recently begun on sensor networks for machine-to-machine connectivity, machine-to-machine (M2M) communication, and machine-type communication (MTC). This IoT environment can provide intelligent Internet of Things (IT) services that create new value for human life by collecting and analyzing data generated by connected objects. IoT can be applied to a variety of fields, including smart homes, smart buildings, smart cities, smart cars (or connected vehicles), smart grids, healthcare, smart instruments, and advanced medical services, by integrating and combining existing information technology (IT) with various industries.

[0009] Therefore, various attempts have been made to apply 5G communication systems to IoT networks. For example, sensor networks, machine-to-machine (M2M) communication, and MTC technologies have been implemented using beamforming, MIMO, and array antenna technologies corresponding to 5G communication technologies. As a big data processing technology, the application of cloud radio access networks (RAN) is an example of the convergence between 5G and IoT technologies. Summary of the Invention

[0010] Technical issues

[0011] In existing wireless communication systems, and specifically in existing Long Term Evolution (LTE) systems, data is transmitted in transport blocks (TBs). A TB is typically divided into several code blocks (CBs), and channel coding is performed on a CB-by-CB basis. However, if decoding fails in an initial transmission, even if decoding fails for only one CB, retransmission is performed on a TB-by-TB basis. In other words, conventionally, the entire TB must be retransmitted.

[0012] Technical Solution

[0013] Accordingly, the present disclosure has been made to address at least the problems and / or disadvantages described above and to provide at least the advantages described below.

[0014] According to one aspect of the present disclosure, a method is provided by a base station in a wireless communication system, the method including: sending first information related to the number of code block groups (CBGs) included in a transport block (TB) to a terminal; determining a CBG for the TB based on the number of code blocks (CBs) included in the TB and the first information; and sending the determined CBG and control information including second information related to transmission of the TB to the terminal.

[0015] Preferably, the method further includes: receiving first feedback information of the TB for transmission from the terminal based on the determined CBG, retransmitting at least one CBG included in the TB to the terminal based on the feedback information, and receiving second feedback information corresponding to the retransmission from the terminal, wherein the first feedback information includes confirmation (ACK) information corresponding to each determined CBG, and wherein the bit length of the second feedback information corresponds to the number of at least one CBG.

[0016] According to another aspect of the present disclosure, a method is provided by a terminal in a wireless communication system, the method including: receiving first information related to the number of code block groups (CBGs) included in a transport block (TB) from a base station; and receiving control information including second information related to transmission of the TB and a CBG for the TB from the base station, wherein the CBG for the TB is determined based on the number of code blocks (CBs) included in the TB and the first information.

[0017] Preferably, the method further includes: sending first feedback information for the TB including ACK information corresponding to each determined CBG to the base station, receiving at least one CBG included in the TB from the base station based on the first feedback information, and sending second feedback information corresponding to the reception of the at least one CBG, wherein the bit length of the second feedback information corresponds to the number of the at least one CBG.

[0018] According to another aspect of the present disclosure, a base station in a wireless communication system is provided, the base station including: a transceiver configured to send first information related to the number of code block groups (CBGs) included in a transport block (TB) to a terminal; and a controller configured to determine a CBG for a transport block (TB) based on the number of code blocks (CBs) included in the TB and the information, and to control the transceiver to send the determined CBG and control information including second information related to transmission of the TB to the terminal.

[0019] According to another aspect of the present disclosure, a terminal in a wireless communication system is provided, the terminal including: a transceiver configured to receive first information related to the number of code block groups (CBGs) included in a transport block (TB) from a base station; and a controller configured to control the transceiver to receive control information including second information related to transmission of the TB and a CBG for the TB from the base station, wherein the CBG for the TB is determined based on the number of code blocks (CBs) included in the TB and the first information.

[0020] Technical Effects

[0021] An aspect of the present disclosure is to provide a method for performing retransmission in units of CBs.

[0022] Another aspect of the present disclosure is to provide a method of performing retransmission in units of CBs, wherein a CB index for notifying an order of CBs is inserted into a CB to be operated.

[0023] Another aspect of the present disclosure is to provide a method and apparatus capable of effectively performing communication between a base station and a terminal (or terminal-to-terminal communication), wherein the terminal variously configures downlink or uplink frequency bandwidths in a radio frequency resource area used to perform downlink or uplink communication with the base station or the network, and receives downlink signals or sends uplink signals through different frequency bandwidths according to time or base station configuration or the type of signal received or sent by the terminal.

[0024] Another aspect of the present disclosure is to provide a method for performing retransmission on a per-CB or per-CB group basis when retransmission is required when transmitting one or two TBs, thereby enabling base stations and terminals to perform efficient transmission and reduce unnecessary data transmission. Specifically, partial retransmission can be used to retransmit only a portion of the initial transmission during retransmission, thereby saving resources required for retransmission.

[0025] Another aspect of the present disclosure is to efficiently perform communication between a base station and a terminal (or terminal-to-terminal communication) by configuring one or more frequency bandwidths or radio resource regions so that they have different sizes. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] The above and other aspects, features and advantages of certain embodiments of the present disclosure will become more apparent from the following detailed description taken in conjunction with the accompanying drawings, in which:

[0027] Figure 1A FIG2 illustrates a downlink time-frequency domain transmission structure of an LTE or LTE-Advanced (LTE-A) system;

[0028] Figure 1B The diagram shows the uplink time-frequency domain transmission structure of the LTE or LTE-A system;

[0029] Figure 1C Figure 1 illustrates data allocated in frequency-time resources for enhanced mobile broadband (eMBB), ultra-reliable and low-latency communication (URLLC), and massive machine type communication (mMTC) in a communication system;

[0030] Figure 1D Figure 2 illustrates data allocated in frequency-time resources for eMBB, URLLC, and mMTC in a communication system;

[0031] Figure 1E illustrates one transport block divided into several code blocks and including a cyclic redundancy check (CRC) added thereto according to an embodiment of the present disclosure;

[0032] Figure 1F FIG. 1 illustrates a transmission method using an outer code according to an embodiment of the present disclosure;

[0033] Figure 1G illustrates a communication system in which an outer code is used according to an embodiment of the present disclosure;

[0034] Figure 1H An example of partial retransmission according to an embodiment of the present disclosure is illustrated;

[0035] Figure 1I illustrates an example bit configuration of a CB group indicator according to an embodiment of the present disclosure;

[0036] Figure 1J illustrates an example bit configuration of a CB group new data indicator (NDI) according to an embodiment of the present disclosure;

[0037] Figure 1KA is a flowchart illustrating a method for a base station to configure a bit field of a CB group indicator according to an embodiment of the present disclosure;

[0038] Figure 1KB is a flowchart illustrating a method for a terminal to decode received data according to a bit field of a CB group indicator according to an embodiment of the present disclosure;

[0039] Figure 1KCis a flowchart illustrating a method for a base station to configure a bit field of a CB group NDI according to an embodiment of the present disclosure;

[0040] Figure 1KD is a flowchart illustrating a method for a terminal to decode received data according to a bit field of a CB group NDI according to an embodiment of the present disclosure;

[0041] Figure 1KE is a flowchart illustrating a method for a base station and a terminal according to an embodiment of the present disclosure;

[0042] Figure 1L illustrates mapping control information for transmission according to an embodiment of the present disclosure;

[0043] Figure 1MA is a flowchart illustrating a method for a base station to apply a channel code based on a control information type according to an embodiment of the present disclosure;

[0044] Figure 1MB is a flowchart illustrating a method for a terminal to perform channel code decoding based on a control information type according to an embodiment of the present disclosure;

[0045] Figure 1N FIGURE 1 illustrates a terminal according to an embodiment of the present disclosure;

[0046] Figure 1O FIGURE 1 illustrates a base station according to an embodiment of the present disclosure;

[0047] Figure 2A is a diagram illustrating a basic structure of a time-frequency domain as a radio resource region in which data or a control channel is transmitted in downlink in an LTE system or a similar system;

[0048] Figure 2B Figure 1 illustrates the services considered in 5G multiplexing through a system for transmission;

[0049] Figure 2C and Figure 2D illustrates a communication system to which the present disclosure is applied;

[0050] Figure 2E illustrates situations to be handled according to embodiments of the present disclosure; and

[0051] Figure 2F and Figure 2G The diagram illustrates a method proposed according to an embodiment of the present disclosure. DETAILED DESCRIPTION

[0052] <First embodiment>

[0053] In order to meet the demand for wireless data services that are on the rise after the commercialization of 4G communication systems, efforts have been made to develop improved 5G or pre-5G communication systems. For this reason, 5G or pre-5G communication systems are also referred to as super-4G network communication systems or post-LTE systems. In order to achieve high data rates, the implementation of 5G communication systems in ultra-high frequency (millimeter wave) bands (e.g., similar to the 60 GHz band) has been considered.

[0054] In order to reduce the path loss of radio waves in ultra-high frequency bands and increase the transmission distance of radio waves, technologies such as beamforming using array antennas, massive MIMO, full-dimensional MIMO (FD-MIMO), hybrid beamforming, and massive antennas have been discussed for 5G communication systems. In addition, for system network improvements in 5G communication systems, technical development has been made for evolved small cells, advanced small cells, cloud radio access networks (cloud RAN), ultra-dense networks, device-to-device communication (D2D), wireless backhaul, mobile networks, cooperative communication, coordinated multipoint (CoMP), and reception interference cancellation.

[0055] In addition, in 5G systems, hybrid FSK and QAM modulation (FQAM) and sliding window superposition coding (SWSC) corresponding to advanced coding modulation (ACM) systems, as well as filter bank multi-carrier (FBMC), non-orthogonal multiple access (NOMA) and sparse code multiple access (SCMA) corresponding to advanced connection technologies have been developed.

[0056] Meanwhile, the Internet, a human-centric network of connected devices where humans generate and consume information, has evolved into the Internet of Things (IoT), where distributed entities such as objects exchange and process data. The Internet of Everything (IoE), a combination of IoT technology and big data processing technology via connections to cloud servers, has emerged. As technological elements such as sensing technology, wired / wireless communication and network infrastructure, service interface technology, and security technology become necessary for IoT implementation, research has recently begun on sensor networks for machine-to-machine connections, machine-to-machine (M2M) communication, and machine-type communication (MTC).

[0057] This IoT environment can provide intelligent Internet technology (IT) services that create new value for human life by collecting and analyzing data generated by connected objects. IoT can be applied to a variety of fields, including smart homes, smart buildings, smart cities, smart cars or connected cars, smart grids, healthcare, smart instruments, and advanced medical services, by integrating and combining existing information technology (IT) with various industries.

[0058] Therefore, various attempts have been made to apply 5G communication systems to IoT networks. For example, sensor networks, machine-to-machine (M2M) communication, and MTC technologies have been implemented using beamforming, MIMO, and array antenna technologies corresponding to 5G communication technologies. As a big data processing technology, the application of cloud radio access networks (RAN) is an example of the convergence between 5G and IoT technologies.

[0059] On the other hand, in the new radio access technology (NR), which is the new 5G communication, various services are designed to be freely multiplexed in time and frequency resources. Therefore, waveforms / numerics and reference signals can be dynamically or freely allocated according to the needs of the corresponding services. In order to provide optimal services to terminals in wireless communication, it is important to provide optimized data transmission through the measurement of channel quality and interference, and therefore accurate channel state measurement is fundamental.

[0060] However, in the case of 5G channels, compared to 4G communications in which the channel and interference characteristics do not change significantly according to the frequency resources, the channel and interference characteristics change significantly according to the service, and therefore support for subsets of the frequency resource group (FRG) level for divided service measurements becomes necessary. On the other hand, in the NR system, the types of services supported can be divided into categories of enhanced mobile broadband (eMBB), massive machine type communication (mMTC), and ultra-reliable and low-latency communication (URLLC). eMBB can be a service aimed at high-speed transmission of large-capacity data, and mMTC can be a service aimed at minimizing terminal power and connecting multiple terminals. URLLC can be a service aimed at ultra-high reliability and low latency. Different requirements can be applied according to the type of service applied to the terminal.

[0061] In the communication system as described above, a plurality of services can be provided to users, and in order to provide such services to users, a method capable of providing respective services to match characteristics in the same time domain and an apparatus using the method are required.

[0062] Hereinafter, various embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. However, the present disclosure is not limited to the embodiments disclosed hereinafter but can be implemented in various forms.

[0063] The matters defined in the description, such as detailed construction and elements, are provided to assist those skilled in the art in a comprehensive understanding of the present disclosure, and the present disclosure will only be defined within the scope of the appended claims.

[0064] In explaining the embodiments, in order to more clearly describe the present disclosure without obscuring the present disclosure with unnecessary details, descriptions of technical contents that are well known in the field to which the present disclosure belongs and that are not directly related to the present disclosure will be omitted.

[0065] In the accompanying drawings, the size and relative size of some components may be exaggerated, omitted or briefly illustrated. In addition, the size of each component does not fully reflect its actual size. In addition, the same reference numerals may be used for the same or corresponding elements in the various figures.

[0066] Aspects and features of the present disclosure and methods for achieving the aspects and features will be apparent by reference to the embodiments described in detail with reference to the accompanying drawings. However, the present disclosure is not limited to the embodiments disclosed below but can be implemented in various forms. Things defined in the description, such as specific configurations and elements, are provided to help those skilled in the art fully understand the specific details of the present disclosure, and the present disclosure is defined only within the scope of the appended claims. Throughout the description of the present disclosure, the same reference numerals are used for the same elements in the various figures.

[0067] Each block of the flowchart and the combination of multiple blocks in the flowchart can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device instruct the device to implement the functions specified in one or more blocks of the flowchart. These computer program instructions can also be stored in a computer-usable or computer-readable memory, which can direct the computer or other programmable data processing device to operate in a particular manner so that the instructions stored in the computer-usable or computer-readable memory produce an article of manufacture, which includes the instruction means for implementing the functions specified in one or more blocks of the flowchart. The computer program instructions can also be loaded onto a computer or other programmable data processing device to cause a series of operating steps to be performed on the computer or other programmable device to produce a computer-implemented process, so that the instructions executed on the computer or other programmable device provide steps for implementing the functions specified in one or more blocks of the flowchart.

[0068] Each block of the flow chart can represent a module, segment or part of code comprising one or more executable instructions for implementing one or more specified logical functions. Alternatively, the functions represented in the block can occur in different orders. For example, depending on the functions involved, two blocks shown in succession can in fact be performed substantially simultaneously, or multiple blocks may sometimes be performed in reverse order.

[0069] Here, the term "unit" can refer to software and / or hardware components that perform certain tasks, such as field programmable gate arrays (FPGAs) or application-specific integrated circuits (ASICs). However, "units" are not limited to software or hardware. The term "unit" can be advantageously configured to be located on an addressable storage medium and configured to execute on one or more processors. Therefore, for example, a "unit" can include components, such as software components, object-oriented software components, class components, and task components, processes, functions, attributes, procedures, subroutines, segments of program code, drivers, firmware, microcode, circuits, data, databases, data structures, tables, arrays, and variables. The functions provided in components and "units" can be combined into fewer components and "units" or further divided into additional components and "units." Further, components and "units" can be implemented as one or more central processing units (CPUs) in an operating device or a secure multimedia card. A "unit" can include one or more processors.

[0070] Wireless communication systems have evolved from their initial voice-oriented service provisioning systems to broadband wireless communication systems that provide high-speed and high-quality packet data services based on communication standards such as 3GPP's High Speed ​​Packet Access (HSPA), Long Term Evolution (LTE) or Evolved Universal Terrestrial Radio Access (E-UTRA), LTE-Advanced (LTE-A), 3GPP2's High Rate Packet Data (HRPD), Ultra Mobile Broadband (UMB), and IEEE's 802.16e. Furthermore, 5G or New Radio (NR) communication standards have been developed for 5G wireless communication systems.

[0071] In the LTE system, which is a representative example of a broadband wireless communication system, the orthogonal frequency division multiplexing (OFDM) method is suitable for the downlink (DL), and the single-carrier frequency division multiple access (SC-FDMA) method is suitable for the uplink (UL). The uplink refers to a radio link through which a terminal (user equipment (UE) or mobile station (MS) transmits data or a control signal to a base station (BS or eNode B), and the downlink refers to a radio link through which a base station transmits data or a control signal to a terminal. In general, the multiple access method as described above separates data and control information from each user by allocating and operating time-frequency resources on which data or control information is carried for each user so that the resources do not overlap with each other, that is, so that orthogonality is achieved.

[0072] The LTE system uses the Hybrid Automatic Repeat Request (HARQ) method, in which the physical layer retransmits the corresponding data if a decoding failure occurs during initial transmission. The HARQ method allows the receiver to transmit information (a negative acknowledgement (NACK)) to notify the transmitter of the decoding failure if the receiver cannot accurately decode the data, allowing the transmitter to retransmit the corresponding data on the physical layer. The receiver combines the data retransmitted by the transmitter with previous data that it failed to decode to improve data reception performance. Alternatively, if the receiver has accurately decoded the data, it transmits information (an acknowledgment (ACK)) to notify the transmitter of the decoding success, allowing the transmitter to transmit new data.

[0073] Figure 1A Illustrated is a time-frequency domain that is a radio resource region from which data or a control channel is transmitted through downlink in the LTE system.

[0074] refer to Figure 1A , the horizontal axis represents the time domain, and the vertical axis represents the frequency domain. In the time domain, the minimum transmission unit is the Orthogonal Frequency Division Multiplexing (OFDM) symbol, and N symb OFDM symbols 1a-02 are included in one slot 1a-06, and two slots constitute one subframe 1a-05. The length of a slot is 0.5 milliseconds, and the length of a subframe is 1 millisecond. In addition, a radio frame 1a-14 is a time domain interval consisting of 10 subframes. The minimum transmission unit in the frequency domain is a subcarrier, and the transmission bandwidth of the entire system is a total of N BW subcarriers 1a-04.

[0075] In the time-frequency domain, the basic unit is a resource element (RE) 1a-12 which can be indicated as an OFDM symbol index and a subcarrier index.

[0076] Resource Block (RB) 1a-08 or Physical Resource Block (PRB) is defined as N in the time domain symb consecutive OFDM symbols 1a-02 and N in the frequency domain RB Therefore, RB 1a-08 consists of N symb ×N RB It consists of RE 1a-12.

[0077] In general, the minimum transmission unit of data is the RB unit mentioned above. In the LTE system, generally N symb =7, N RB =12, and N BW and N RB Proportional to the system transmission bandwidth. However, in another system other than the LTE system, a different value may be used.

[0078] The data rate increases in proportion to the number of RBs scheduled to the terminal. In the LTE system, six transmission bandwidths are defined and operated. In a frequency division duplex (FDD) system that divides and operates the downlink and uplink by frequency, the transmission bandwidth of the downlink and the transmission bandwidth of the uplink can be different from each other. The channel bandwidth indicates the radio frequency (RF) bandwidth corresponding to the system transmission bandwidth.

[0079] Table 1 below presents the corresponding relationship between the system transmission bandwidth and the channel bandwidth defined in the LTE system. For example, in an LTE system with a channel bandwidth of 10 MHz, the transmission bandwidth includes 50 RBs.

[0080] Table 1

[0081] <![CDATA[Channel bandwidth BW Channel [MHz]]]> 1.4 3 5 10 15 20 <![CDATA[Transmission Bandwidth Configuration N RB > 6 15 25 50 75 100

[0082] Downlink control information can be transmitted within the first N OFDM symbols in a subframe, for example, N = {1, 2, 3}. Therefore, the value N can be variably applied to each subframe based on the amount of control information to be transmitted in the current subframe. The transmitted control information includes a control channel transmission interval indicator indicating how many OFDM symbols are used to transmit control information, scheduling information about downlink data or uplink data, and a hybrid automatic repeat request (HARQ) acknowledgement / negative acknowledgement (ACK / NACK) signal.

[0083] In the LTE system, scheduling information about downlink data or uplink data is transmitted from the base station to the terminal through downlink control information (DCI). DCI can be defined according to various formats and can indicate whether the scheduling information is uplink (UL) data scheduling information (UL grant) or downlink (DL) data scheduling information (DL grant), whether the DCI is compact DCI with small-sized control information, whether spatial multiplexing using multiple antennas is applied, or whether the DCI is DCI for power control. For example, DCI format 1 for scheduling control information (DL grant) for downlink data may include at least one of the following control information.

[0084] - Resource Allocation Type 0 / 1 Flag: This flag indicates whether the resource allocation type is Type 0 or Type 1. Type 0 allocates resources in units of Resource Block Groups (RBGs) by applying a bitmap type. In LTE systems, the basic unit for scheduling is an RB, which is represented as time and frequency domain resources. An RBG is composed of multiple RBs, which are considered the basic unit for scheduling in Type 0. Type 1 allocates specific RBs within an RBG.

[0085] - Resource Block Allocation: This allocation indicates the RBs allocated for data transmission. The indicated resources are determined according to the system bandwidth and resource allocation method.

[0086] - Modulation and Coding Scheme (MCS): This scheme indicates a modulation method used for data transmission and the size of a transport block as data to be sent.

[0087] -HARQ process number: This number indicates the number of HARQ processes.

[0088] - New data indicator: This indicator indicates whether the HARQ transmission is an initial transmission or a retransmission.

[0089] - Redundancy version: This version indicates the redundancy version of HARQ.

[0090] - Transmit Power Control (TPC) command for Physical Uplink Control Channel (PUCCH): This command indicates a transmission power control command for PUCCH which is an uplink control channel.

[0091] The DCI may be transmitted through a physical downlink control channel (PDCCH) (or control information) or an enhanced PDCCH (EPDCCH) (or enhanced control information) which is a downlink physical control channel after being processed through channel coding and modulation.

[0092] In general, DCI is scrambled independently for each terminal using a specific radio network temporary identifier (RNTI) (or terminal identifier), CRC is added, channel coded, and then configured as a separate PDCCH to be transmitted. In the time domain, the PDCCH is mapped and transmitted for the control channel transmission interval. The mapping position of the PDCCH in the frequency domain is determined by the identifier (ID) of each terminal, and the PDCCH is transmitted across the transmission band of the entire system.

[0093] Downlink data may be transmitted on the Physical Downlink Shared Channel (PDSCH), which may be transmitted after the control channel transmission interval and determines scheduling information, such as a specific mapping location in the frequency domain or a modulation method, based on the DCI transmitted via the PDCCH.

[0094] The base station notifies the terminal of the modulation scheme and transport block size (TBS) applied to the PDSCH to be transmitted to the terminal through the MCS, which is included in the control information of the DCI. For example, the MCS may include 5 bits, more than 5 bits, or less than 5 bits. The TBS corresponds to the size of the TB before channel coding for error correction is applied to it, and is transmitted by the base station.

[0095] A TB may include a media access control (MAC) header, a MAC control element (CE), one or more MAC service data units (SDUs), and padding. In addition, a TB may indicate a data unit downloaded from the MAC layer to the physical layer, or a MAC protocol data unit (PDU).

[0096] The modulation methods supported in the LTE system are quadrature phase shift keying (QPSK), 16-quadrature amplitude modulation (16QAM), and 64QAM, and the modulation orders (Qm) correspond to 2, 4, and 6. That is, for QPSK modulation, 2 bits can be transmitted per symbol, for 16QAM modulation, 4 bits can be transmitted per symbol, and for 64QAM modulation, 6 bits can be transmitted per symbol. In addition, modulation methods of 256QAM or higher can be used depending on system modifications.

[0097] Figure 1B Illustrated is a time-frequency domain that is a radio resource region from which data or a control channel is transmitted through uplink in the LTE-A system.

[0098] refer to Figure 1B , the horizontal axis represents the time domain, and the vertical axis represents the frequency domain. In the time domain, the minimum transmission unit is the single carrier frequency division multiple access (SC-FDMA) symbol 1b-02, and N symb UL SC-FDMA symbols constitute a time slot 1b-06. In addition, two time slots constitute a subframe 1b-05. The minimum transmission unit in the frequency domain is a subcarrier, and the transmission bandwidth of the entire system 1b-04 is a total of N BW subcarriers. N BW Can have a value proportional to the system transmission band.

[0099] In the time-frequency domain, the basic unit of resources is the resource element (RE) 1b-12, and resources can be defined as SC-FDMA symbol index and subcarrier index. RB pair 1b-08 is defined as N in the time domain. symb UL consecutive SC-FDMA symbols and N in the frequency domain sc RB Therefore, one RB consists of N consecutive subcarriers. symb UL ×N sc RB RE.

[0100] In general, the minimum transmission unit of data or control information is an RB unit. The PUCCH is mapped to the frequency domain corresponding to one RB and is transmitted for one subframe.

[0101] In the LTE system, the timing relationship between the PDSCH, which is a physical channel for transmitting downlink data, or the PDCCH / EPDDCH including a semi-persistent scheduling (SPS) version, and the PUCCH, or the PUSCH, which is an uplink physical channel through which the corresponding HARQ ACK / NACK is transmitted, has been defined. For example, in an LTE system operating in FDD, the HARQ ACK / NACK corresponding to the PDSCH or the PDCCH / EPDCCH including an SPS version transmitted in the (n-4)th subframe is transmitted through the PUCCH or PUSCH in the nth subframe.

[0102] In the LTE system, downlink HARQ uses an asynchronous HARQ method in which data retransmission timing is not fixed. Specifically, if a terminal receives an HARQ NACK response relative to the initially transmitted data from the base station, the base station freely determines the transmission timing of the retransmitted data through scheduling operations. After decoding the received data for HARQ operations, the terminal buffers data determined to be erroneous and then combines it with the next retransmitted data.

[0103] If a PDSCH including downlink data sent from a base station in subframe n is received, the terminal sends uplink control information including HARQ ACK or NACK of the downlink data to the base station via PUCCH or PUSCH in subframe n+k. Here, k is defined differently according to the FDD or time division duplex (TDD) and subframe configuration of the LTE system. For example, in an FDD LTE system, k is fixed to 4. However, in a TDD LTE system, k can change according to the subframe configuration and the number of subframes.

[0104] In the LTE system, uplink HARQ adopts a synchronous HARQ method in which the data transmission time is fixed, in contrast to downlink HARQ. That is, the uplink / downlink timing relationship among the Physical Uplink Shared Channel (PUSCH), which is a physical channel for transmitting uplink data, the PDCCH, which is a preceding downlink control channel, and the Physical Hybrid Indicator Channel (PHICH), which is a physical channel through which downlink HARQ ACK / NACK corresponding to the PUSCH is transmitted, is fixed based on the following:

[0105] If a PDCCH including uplink scheduling control information sent from the base station in subframe n or a PHICH through which downlink HARQ ACK / NACK is transmitted is received, the terminal transmits uplink data corresponding to the control information via the PUSCH in subframe n+k. Here, k is defined differently depending on whether the LTE system is FDD or TDD and its configuration. For example, in an FDD LTE system, k is fixed to 4.

[0106] In a TDD LTE system, k can vary depending on the subframe configuration and the number of subframes. In an FDD LTE system, if the base station transmits an uplink scheduling grant or a downlink control signal and data to a terminal in subframe n, the terminal receives the uplink scheduling grant or downlink control signal and data in subframe n. Upon receiving the uplink scheduling grant in subframe n, the terminal transmits uplink data in subframe n+4. Upon receiving the downlink control signal and data in subframe n, the terminal transmits a HARQ ACK or NACK for the downlink data in subframe n+4. Therefore, the time it takes for the terminal to receive the uplink scheduling grant and transmit uplink data, or to receive downlink data and transmit a HARQ ACK or NACK, becomes 3 milliseconds, corresponding to three subframes.

[0107] - In addition, if the terminal receives a PHICH carrying a downlink HARQ ACK / NACK from the base station in subframe i, the PHICH corresponds to the PUSCH transmitted by the terminal in subframe ik. Here, k is defined differently depending on whether the LTE system is FDD or TDD and its configuration. For example, in an FDD LTE system, k is fixed to 4. However, in a TDD LTE system, k can change according to the subframe configuration and the number of subframes.

[0108] Figure 1C and Figure 1D The diagram illustrates data allocated in frequency-time resources for eMBB, URLLC, and mMTC in a communication system.

[0109] refer to Figure 1C and Figure 1D , the method used in each system to allocate frequency and time resources for information transmission will be described.

[0110] refer to Figure 1C , data for eMBB, URLLC, and mMTC are allocated in the entire system frequency band 1c-00. If URLLC data 1c-03, 1c-05, and 1c-07 are generated and their transmission becomes necessary while eMBB 1c-01 and mMTC 1c-09 are allocated and transmitted in a specific frequency band, URLLC data 1c-03, 1c-05, and 1c-07 can be transmitted by clearing the portion to which eMBB 1c-01 and mMTC 1c-09 have been allocated or by not transmitting eMBB 1c-01 and mMTC 1c-09.

[0111] In the above services, because URLLC needs to reduce latency, URLLC data 1c-03, 1c-05, and 1c-07 can be transmitted by allocating them to a portion of the resources already allocated to eMBB 1c-01. If URLLC is transmitted while being allocated to resources already allocated to eMBB, eMBB data may not be transmitted, and thus, eMBB data transmission performance may be reduced. In other words, in the above example, eMBB data transmission may fail due to URLLC allocation.

[0112] refer to Figure 1D , the entire system frequency band 1d-00 is divided into subbands 1d-02, 1d-04, and 1d-06 for transmitting services and data. Information related to the subband configuration can be predetermined and sent from the base station to the terminal through upper layer signaling. In addition, information related to subbands 1d-02, 1d-04, and 1d-06 can be optionally divided by the base station or network node, and services can be provided to the terminal without sending separate subband configuration information to the terminal. Figure 1D As shown, subband 1d-02 is used to send eMBB data, subband 1d-04 is used to send URLLC data, and subband 1d-06 is used to send mMTC data.

[0113] The length of the transmission time interval (TTI) used to send URLLC can be shorter than the length of the TTI used to send eMBB or mMTC. In addition, the response to the information about URLLC can be sent faster than eMBB or mMTC, and therefore, information can be sent or received with low latency.

[0114] Figure 1E The diagram illustrates a transport block divided into several code blocks and including a CRC according to an embodiment.

[0115] refer to Figure 1E In the uplink or downlink, a CRC 1e-03 may be added to the last portion or header of a TB 1e-01. The CRC 1e-03 may include 16 or 24 bits or a pre-fixed number of bits, or may include a variable number of bits depending on channel conditions. The CRC 1e-03 may be used to determine the success or failure of channel coding.

[0116] Blocks 1e-01 and 1e-03 to which the TB and CRC are added can be divided into several CBs 1e-07, 1e-09, 1e-11, and 1e-13 (1e-05). The maximum size of a CB can be predetermined, and in this case, the last code block 1e-13 can have a size larger or smaller than that of other CBs, or can have a length matching the length of other CBs by placing 0, a random value, or 1 therein.

[0117] CRCs 1e-17, 1e-19, 1e-21, and 1e-23 may be added to the divided code blocks (1e-15). The CRC may include 16 or 24 bits or a predetermined number of bits and may be used to determine the success / failure of channel coding. However, CRC 1e-03 added to the TB and CRCs 1e-17, 1e-19, 1e-21, and 1e-23 added to the CB may be omitted depending on the type of channel code to be applied to the CB.

[0118] For example, if a low-density parity check (LDPC) code other than a turbo code is applied to the CB, CRCs 1e-17, 1e-19, 1e-21, and 1e-23 to be inserted into the CB can be omitted. However, even if LDPC is applied, CRCs 1e-17, 1e-19, 1e-21, and 1e-23 can be added to the CB as is. Even if a polar code is used, the CRC can be added or omitted.

[0119] Figure 1F The diagram shows a transmission method using an external code, and Figure 1G The diagram shows a communication system using an external code.

[0120] refer to Figure 1F and Figure 1G , a method for transmitting a signal using an outer code will be described.

[0121] refer to Figure 1F , the transport block is divided into several code blocks, and the bits or symbols 1f-04 at the same position in each code block can be encoded with the second channel code to generate parity bits or symbols 1f-06 (1f-02). Thereafter, CRC can be added to each code block and the parity code blocks (1f-08 and 1f-10) generated by the second channel code encoding.

[0122] The addition of CRC may vary depending on the type of channel code. For example, if a turbo code is used as the first channel code, CRC 1f-08 and 1f-10 are added, but after that, each code block and parity code block may be encoded using the first channel code. The transport block is transmitted from the upper layer to the physical layer.

[0123] In the physical layer, the TB is considered as data. CRC is added to the TB. To generate the CRC, the TB data bits and the cycle generator polynomial can be used, and the cycle generator polynomial can be defined in various ways.

[0124] For example, if the cycle generator polynomial for a 24-bit CRC is g CRC24A (D)=D 24 +D 23 +D18 +D 17 +D 14 +D 11 +D 10 +D 7 +D 6 +D 5 +D 4 +D 3 +D+1, and L is L=24, then CRCp0,p1,p2,p3,…,p L-1 Determined by a0D A+23 +a1D A +22 +…+a A-1 D 24 +p0D 23 +p1D 22 +…+p 22 D 1 +p 23 Divide by the TB data a0, a1, a2, a3, ..., a A-1 g with remainder 0 CRC24A (D) and the value obtained.

[0125] In the above example, although the CRC length L=24, various lengths may be used, such as 12, 16, 32, 40, 48, and 64. CRC is added to the divided CB, and a cyclic generator polynomial different from that of the CRC of the TB may be used as the CRC of the CB.

[0126] In conventional LTE systems, during retransmissions due to an initial transmission failure, the initially transmitted TB is retransmitted. However, retransmissions may be performed in CBs or several CBs, rather than TBs. To achieve this, the terminal may send several bits of HARQ-ACK feedback per TB. Furthermore, during retransmissions, information is provided as scheduling control information sent from the base station, indicating which portion of the TB is being retransmitted.

[0127] refer to Figure 1G If an outer code is used, the data to be transmitted passes through the second channel coding encoder 1g-09. The channel code used for the second channel coding can be, for example, a Reed-Solomon code, a DCH code, a Raptor code, or a parity bit generating code. The bits or symbols that have passed through the second channel coding encoder 1g-09 pass through the first channel coding encoder 1g-11. The channel code used for the first channel coding can be a convolutional code, an LDPC code, a turbo code, or a polar code.

[0128] If a channel-coded symbol is received at the receiver, after passing through the channel 1g-13, the receiver side can continuously operate the first channel codec 1g-15 and the second channel codec 1g-17 based on the received signal. The first channel codec 1g-15 and the second channel codec 1g-17 can perform operations corresponding to the operations of the first channel codec 1g-11 and the second channel codec 1g-09.

[0129] However, if the outer code is not used, the second channel coder and the second channel coder / decoder are not used even though the first channel coder / encoder 1g-11 and the first channel coder / decoder 1g-05 are used in the transceiver. Even if the outer code is not used, the first channel coder / encoder 1g-11 and the first channel coder / decoder 1g-05 can be configured in the same manner as when the outer code is used.

[0130] Here, the eMBB service is referred to as the first type service, and the data used for the eMBB is referred to as the first type data. The first type service or the first type data is not limited to eMBB, but may correspond to a scenario where high-speed data transmission is required or broadband transmission is performed.

[0131] In addition, the URLLC service is referred to as the second type service, and the data used for the URLLC is referred to as the second type data. The second type service or the second type data is not limited to URLLC, but may correspond to a scenario where low latency or ultra-reliable transmission is required, or may correspond to another system where both low latency and ultra-reliability are required.

[0132] In addition, mMTC services are referred to as third-type services, and data used for mMTC is referred to as third-type data. The third-type service or third-type data is not limited to mMTC, but may correspond to scenarios where low speed, wide coverage, or low power is required.

[0133] Additionally, the first type of service may or may not include the third type of service.

[0134] To transmit the three services or data described above, different physical layer channel structures may be used for each type. For example, at least one of the TTI length, frequency resource allocation unit, control channel structure, and data mapping method may be different.

[0135] Although three services and three data have been described, there may be more kinds of services and corresponding data, and the present disclosure may be applicable thereto.

[0136] Although the following description of the methods and apparatuses is based on LTE or LTE-A systems and uses terminology from these systems, the present disclosure is also applicable to other wireless communication systems, for example, 5G mobile communication technology (5G or New Radio (NR)) developed after LTE-A may be included therein.

[0137] As described above, embodiments of the present disclosure provide methods for defining transmit / receive operations of a terminal and a base station for transmitting first to third types of services or data, and for operating terminals that receive different types of services or data schedules together in the same system. The first to third types of terminals receive the first to third types of services or data schedules. The first to third types of terminals may be the same terminal or different terminals.

[0138] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. When describing the present disclosure, if it is determined that it obscures the present disclosure with unnecessary details, the specific description of the relevant functions or configurations will be omitted. In addition, all terms used in the description are general terms that are widely used considering their functions in the present disclosure, but may differ depending on the intentions, customs, or new technologies of those skilled in the art to whom the present disclosure belongs. Therefore, they should be defined based on the content of the entire description of the present disclosure.

[0139] Here, the base station that performs resource allocation to the terminal can be an eNode B, a node B, a base station (BS), a radio access unit, a base station controller, or a node on a network. The terminal can include a user equipment (UE), a mobile station (MS), a cellular phone, a smart phone, a computer, or a multimedia system that can perform communication functions.

[0140] DL is a radio transmission path for a signal transmitted from a base station to a terminal, and UL is a radio transmission path for a signal transmitted from a terminal to a base station.

[0141] In addition, although LTE or LTE-A systems are exemplified below when explaining the embodiments of the present disclosure, the embodiments of the present disclosure can be applied to other communication systems with similar technical backgrounds or channel types. For example, 5G mobile communication technology (5G or New Radio (NR)) developed after LTE-A may be included therein. In addition, the embodiments of the present disclosure may also be applied to other communication systems through partial modifications thereof, as determined by those skilled in the art, without significantly departing from the scope of the present disclosure.

[0142] TTI can be a unit for sending control signals and data signals, or a unit for sending data signals. For example, in the downlink of an existing traditional LTE system, TTI becomes a subframe that is a time unit of 1 millisecond. However, in the uplink according to an embodiment of the present disclosure, TTI is a unit for sending control signals or data signals, or a unit for sending data signals. In the uplink of a traditional LTE system, TTI is a subframe that is a time unit of 1 millisecond in the same manner as in the downlink.

[0143] Unless otherwise specified, a shortened TTI terminal includes a terminal capable of transmitting control information, data, control information, and / or data in a TTI of 1 millisecond or less, and a normal TTI type terminal includes a terminal capable of transmitting control information, data, control information, and / or data in a TTI of 1 millisecond. In addition, in the present disclosure, shortened TTI, shorter TTI, short TTI, and sTTI have the same meaning and can be used interchangeably. In addition, in the present disclosure, normal TTI, subframe TTI, and traditional TTI have the same meaning and can be used interchangeably.

[0144] As described above, the 1 millisecond used as the basis for distinguishing between a shortened TTI and a normal TTI may differ depending on the system. That is, in a specific NR system, based on 0.2 milliseconds, if the TTI is shorter than 0.2 milliseconds, it may be a shortened TTI, and if the TTI is 0.2 milliseconds, it may be a normal TTI.

[0145] An important factor in the performance of wireless cellular communication systems is packet data delay. In LTE systems, signal transmission / reception is performed in subframes with a TTI of 1 millisecond. Therefore, terminals with a TTI shorter than 1 millisecond (i.e., short TTI UEs) can be supported.

[0146] However, in NR, which is a 5G mobile communication system, TTI can be shorter than 1 millisecond.

[0147] It is expected that short TTI terminals will be suitable for Voice over LTE (VoLTE) services and remote control services where latency is important.In addition, short TTI terminals are expected to enable mission-critical cellular-based Internet of Things (IoT).

[0148] In the present disclosure, shortened TTI data refers to data sent from PDSCH or PUSCH in units of shortened TTI, and normal TTI data refers to data sent from PDSCH or PUSCH in units of subframes. The control signal for shortened TTI refers to the control signal for shortened TTI mode operation, that is, sPDCCH, and the control signal for normal TTI refers to the control signal for normal TTI mode operation. For example, the control signal for normal TTI can be the physical control format indicator channel (PCFICH), PHICH, PDCCH, EPDCCH or PUCCH in a conventional LTE system.

[0149] Here, the terms "physical channel" and "signal" can be used interchangeably with "data" or "control signal". For example, although PDSCH is a physical channel through which normal TTI data is transmitted, PDSCH can be referred to as normal TTI data. In addition, although sPDSCH is a physical channel through which shortened TTI data is transmitted, sPDSCH can be referred to as shortened TTI data. Similarly, shortened TTI data transmitted in the downlink and uplink can be referred to as sPDSCH and sPUSCH.

[0150] Here, the uplink scheduling grant signal and the downlink data signal are referred to as the first signal, and the uplink data signal for the uplink scheduling grant and the HARQ ACK / NACK for the downlink data signal are referred to as the second signal. Among the signals sent by the base station to the terminal, the signal expecting a response from the terminal may be the first signal, and the response signal of the terminal corresponding to the first signal may be the second signal. In addition, the service category (or type) of the first signal and the second signal may belong to a category such as eMBB, mMTC, and URLLC.

[0151] The TTI length of the first signal refers to the length of time over which the first signal is transmitted, and the TTI length of the second signal refers to the length of time over which the second signal is transmitted. The transmission timing of the second signal may be information about when the terminal transmits the second signal and when the base station receives the second signal, and may be referred to as the second signal transmission / reception timing.

[0152] Unless a TDD system is specifically mentioned, it is generally assumed that the communication system involved is an FDD system. However, the method and apparatus according to the present disclosure can be applied to a TDD system with simple modifications thereof.

[0153] Here, upper-level (or upper layer) signaling is a method for transmitting a signal from a base station to a terminal using a downlink data channel of a physical layer or a method for transmitting a signal from a terminal to a base station using an uplink data channel of a physical layer, and may also be referred to as radio resource control (RRC) signaling or MAC CE.

[0154] In the following, indicates the smallest integer greater than X, and Indicates the largest integer less than X.

[0155] Figure 1H An example of partial retransmission according to an embodiment of the present disclosure is illustrated.

[0156] refer to Figure 1H The base station uses control signal 1h-01 to schedule eMBB data 1h-03 to terminal a. Subsequently, if eMBB data 1h-03 is transmitted, portion 1h-07 of the resources to which the eMBB data is mapped is used to transmit other data 1h-07 to terminal a or another terminal b. Subsequently, portion 1h-05 of the eMBB data that has already been transmitted or has not yet been transmitted to terminal a is retransmitted in the next TTI 1h-10. The unit for partial retransmission can be a CB or a CB group including one or more CBs.

[0157] The eMBB control signal 1h-01 transmits scheduling information for eMBB data 1h-03 to terminal a. If URLLC data is generated during the transmission of eMBB data 1h-03, the base station transmits the URLLC control signal and data to terminal b (1h-07). Transmission of the URLLC control signal and data is performed by mapping the URLLC control signal and data (1h-07) to the resources to be transmitted, without mapping a portion of the existing scheduled eMBB data 1h-03 to the resources.

[0158] Therefore, part of the eMBB data is not transmitted from the existing TTI 1h-05. As a result, the eMBB terminal may not be able to decode the eMBB data. To supplement this, part of the eMBB data not transmitted in TTI 1h-05 is transmitted in TTI 1h-10 (1h-13). Partial transmission is performed in TTI 1h-10 after the initial transmission and can be performed without receiving HARQ-ACK information for the initial transmission from the terminal. Through partial transmission, scheduling information can be transmitted from the control signal area 1h-09 of the next TTI.

[0159] The control signal region 1h-09 for the next TTI may include information (1h-11) regarding the symbol position at which the resource mapping of the eMBB or other data 1h-17 begins when the eMBB or other data 1h-17 is transmitted to another terminal. This information may be conveyed using partial bits of the DCI transmitted from the control signal region 1h-09. Using this information regarding the symbol position at which the resource mapping of the eMBB or other data 1h-17 begins, a specific symbol is used to perform partial transmission 1h-15 for the previous initial transmission. Figure 1H The eMBB control signal 1h-01 or 1h-09 may not be transmitted from the entire indicated area, but may be transmitted only from a portion of the area. In addition, the control signal 1h-01 or 1h-09 may also be transmitted from a portion of the frequency band different from the entire frequency band.

[0160] Although partial retransmission 1h-15 is performed in the next TTI because a portion of the eMBB is not transmitted for the transmission of URLLC data 1h-07, partial retransmission can be used in a manner such that the base station optionally retransmits a specific portion of the data, although it is not caused by URLLC data transmission. In addition, because a portion of the eMBB is not transmitted for the transmission of URLLC data 1h-07, partial retransmission 1h-05 is performed in the next TTI. However, partial retransmission 1h-15 can be distinguished from the initial transmission of the corresponding portion. That is, a terminal that has received partial retransmission 1h-15 in the next TTI 1h-10 does not perform HARQ decoding by combining it with the portion received in the previous TTI 1h-05, but can perform separate decoding using only partial retransmission 1h-15 in the next TTI 1h-10.

[0161] In addition, although retransmission is performed starting from the first symbol after the control signal at TTI 1h-10 after initial transmission, the position of retransmission can be variously changed to apply.

[0162] Although downlink transmission has been described as an example, retransmission is also applicable to uplink transmission. Figure 1H As indicated in (b) and (c), CB2 and CB3 among the 6 initially transmitted CBs are retransmitted.

[0163] [Example (1-1)]

[0164] According to the embodiments of the present disclosure, reference will be made to Figure 1H 、 Figure 1I and Figure 1J A method for configuring a piece of control information for transmitting scheduling information for partial retransmission of data is described. The scheduling information provided in this embodiment may be referred to as single-stage control information or single-segment control information.

[0165] Reference again Figure 1H , transmission control information 1h-01 and 1h-09 are used for scheduling the initially transmitted data 1h-03 and the partial retransmission 1h-15. The control information 1h-01 and 1h-09 may include bit fields having the same size. The control information 1h-01 and 1h-09 may include a bit field for partial retransmission. The bit field for partial retransmission may be a CB group indicator and a CB group NDI.

[0166] Figure 1I Illustrated is an example bit configuration of a CB group indicator according to an embodiment of the present disclosure.

[0167] refer to Figure 1I , the CB group indicator 1i-01 may indicate the CBs included in one TB of data currently scheduled for downlink data transmission. If scheduled for uplink transmission, the CB group indicator may indicate the CBs that the terminal should transmit in one TB.

[0168] For example, Figure 1I The diagram shows a CB group indicator 1i-01 including 4 bits 1i-10, 1i-11, 1i-12, and 1i-13. When mapping the CBS indicated by each bit, the method provided according to the following (1-3) embodiment can be applied. Simply put, for example, if one TB consists of 4 CBs, the information indicating one CB can be mapped to one bit sequentially from the front. For example, if the 4 bits 1i-10, 1i-11, 1i-12, and 1i-13 of the CB group indicator 1i-01 indicate 0110, the second and third CBs can be transmitted. If the 4 bits 1i-10, 1i-11, 1i-12, and 1i-13 of the CB group indicator 1i-01 indicate 0000, the base station and the terminal can determine that the corresponding transmission corresponds to the initial transmission.

[0169] Figure 1J Illustrated is an example bit configuration of a CB group NDI according to an embodiment of the present disclosure.

[0170] refer to Figure 1J , CB group NDI 1j-03 can indicate that decoding is performed using information of the initially transmitted CB or the currently transmitted CB by discarding information of the initially transmitted CB when decoding the currently received CB or CB group transmitted through downlink data. The CB group NDI may not be included in the control information for uplink scheduling.

[0171] For example, Figure 1JThe diagram shows a CB group NDI 1j-03 including bits 1j-20, 1j-21, 1j-22, and 1j-23. When mapping the CBs indicated by the respective bits, the method provided in accordance with the embodiment (1-3) can be applied. Simply put, for example, if one TB consists of four CBs, the information indicating one CB can be mapped sequentially to one bit from the front. For example, if the four bits 1j-20, 1j-21, 1j-22, and 1j-23 of the CB group NDI 1j-03 indicate 0110, decoding can be performed by not using or discarding the previously received second and third CB information when decoding the second and third CBs and using the currently received second and third CB parts.

[0172] When analyzing the CB group NDI, the CB group NDI can be connected to the CB group indicator as described above, because only part of the CB can be transmitted in the current retransmission, and therefore, the CB group NDI can be valid only with respect to the CB currently retransmitted. Therefore, when decoding a CB or CB group, if it is determined to discard the information initially transmitted, this determination can be made by multiplying the bits of the CB group NDI and the components of the CB group indicator. When four CBs are transmitted, for example, if the CB group NDI is 0101 and the CB group indicator is 0110, the terminal can determine that the second and third CBs are currently being transmitted based on the CB group indicator. When decoding the second CB based on the multiplication of the CB group NDI and the components of the CB group indicator by 0100, decoding can be performed by discarding the result of the initial transmission, and when decoding the third CB, decoding can be performed together with the result of the initial transmission.

[0173] Figure 1KA to Figure 1KD 2 is a flowchart illustrating operations of a base station and a terminal for configuring a CB group indicator and a CB group NDI. For convenience, an explanation will be made based on downlink data transmission, and the explanation can also be applied to uplink data transmission.

[0174] Figure 1KA is a flowchart illustrating a method for a base station to configure a bit field of a CB group indicator indicating whether to transmit a CB group when transmitting a TB.

[0175] refer to Figure 1KA , in step 1k1-02, the base station prepares for the transmission of the TB, and in step 1k1-04, determines whether the TB transmission is the initial transmission.

[0176] If the TB is initially transmitted at step 1k1-04, then at step 1k1-06, all CB group indicators are configured to 0. However, if the TB is not initially transmitted at step 1k1-04, then at step 1k1-08, the base station determines whether to transmit a specific CB group.

[0177] If the specific CB group is to be transmitted, then at step 1k1-10, the corresponding bit of the CB group indicator is configured to 1. However, if the specific CB group is not to be transmitted, then at step 1k1-12, the corresponding bit of the CB group indicator is configured to 0.

[0178] Figure 1KB is a flowchart illustrating a method for a terminal to decode a CB group by analyzing a bit field of a CB group indicator indicating whether the CB group is transmitted when receiving a TB according to an embodiment of the present disclosure.

[0179] refer to Figure 1KB , in step 1k2-02, the terminal prepares for receiving TBs, and in step 1k2-04, determines whether the CB group indicator is all 0. If the CB group indicator is all 0, then in step 1k2-06, the transmitted TB is identified as the initial transmission. If the CB group indicator is not all 0, then in step 1k2-08, the terminal determines whether a specific bit of the CB group indicator is 1. If the specific bit of the CB group indicator is 1, the terminal determines to transmit the corresponding CB group, and decodes the corresponding CB group in step 1k2-10. If the specific bit of the CB group indicator is 0, the terminal determines not to transmit the corresponding CB group, and does not decode the corresponding CB group in step 1k2-12.

[0180] Figure 1KC 1 is a flowchart illustrating a method for a base station to configure a bit field of a CB group NDI when transmitting a TB so that an initial transmission of a previously transmitted CB group is not used for decoding by a terminal according to an embodiment of the present disclosure.

[0181] refer to Figure 1KC , in step 1k3-02, the base station prepares for the transmission of the TB, and in step 1k3-04, determines whether to make the initial transmission of the specific CB group not be used for the terminal decoding. If in step 1k3-04, the base station determines that the initial transmission of the specific CB group is not used for the terminal decoding, then in order for the terminal to perform decoding using only the currently transmitted CB group without using the base station initial transmission of the specific CB group, in step 1k3-06, the corresponding bit of the CB group NDI is configured to 1. If in step 1k3-04, the base station determines not to make the initial transmission of the specific CB group not be used for the terminal decoding, that is, the terminal is to use the initial transmission of the specific CB group to perform HARQ combining and perform decoding of the currently transmitted CB group, then in step 1k3-08, the corresponding bit of the CB group NDI is configured to 0.

[0182] Figure 1KD is a flowchart illustrating a method for a terminal to determine whether to use an initial transmission of a previously transmitted CB group for terminal decoding by confirming an NDI bit field of a specific CB group according to an embodiment of the present disclosure.

[0183] refer to Figure 1KDIn step 1k4-02, the terminal prepares for reception of the TB, and in step 1k4-04, determines whether a specific bit of the CB group NDI is 1. If, in step 1k4-04, the specific bit of the CB group NDI is 1, then in step 1k4-06, the initial transmission of the corresponding CB group is not used for decoding the current CB group. However, if, in step 1k4-04, the specific bit of the CB group NDI is 0, then in step 1k4-08, HARQ combining is performed in order to use the initial transmission of the corresponding CB group for decoding the current CB group.

[0184] The sizes of the bit field of the CB group indicator and the NDI bit field of the CB group may be pre-configured from the base station, or determined values ​​may be used.

[0185] If the bit field of the CB group indicator and the NDI bit field of the CB group are included in the control information, the NDI information of the TB may be omitted from the control information.

[0186] (Example (1-1-1))

[0187] According to an embodiment of the present disclosure, a method is provided for performing CB group unit retransmission while reducing the number of bits in the control information when configuring a piece of control information for scheduling information for partial retransmission of transmitted data. Furthermore, CB group indicator value (CIV) information may be included in the control information for partial retransmission. For example, the CIV information is not included in the control information for initial transmission or full retransmission, but is included in the control information for partial retransmission. Furthermore, the control information may include a one-bit indicator for indicating whether the control information is for initial transmission, full retransmission, or partial retransmission.

[0188] In DCI for retransmissions, the resource allocation used for information bits can be reduced. For example, increasing the resource allocation unit value when performing partial retransmissions reduces the resource allocation used for information bits compared to during initial transmission. For example, in initial transmissions, resource allocation information is transmitted in one PRB, whereas in retransmissions, it is transmitted in four PRBs. Therefore, the number of bits of resource allocation information can be reduced, and as a result, can be used for the CB group indicator.

[0189] For resource allocation, RBG may be defined for resource allocation, and resource allocation may be performed in units of RBG.

[0190] Table 2

[0191] System bandwidth RBG size 1 RBG size 2 N_RB^DL P1 P2 ≤10 1 2 11-26 2 4 27-63 3 6 64-112 4 8 112-224 8 16 224-440 16 32

[0192] Table 2 is an example of defining the RBG size according to the number of PRBs included in the system bandwidth. In Table 2, P1 is an RBG value for configuring resource allocation information bits included in control information for initial transmission or complete retransmission, and P2 is an RBG value for configuring resource allocation information bits included in control information for partial retransmission.

[0193] For example, if there are 400 PRBs in the system frequency band, one RBG includes 16 PRBs in initial transmission, and if resource allocation is performed using a bitmap method, 25 bits of resource allocation information are required for initial transmission or complete retransmission. However, in partial retransmission, one RBG includes 32 PRBs, and 13 bits of resource allocation information are required.

[0194] Therefore, in partial retransmission, the number of resource allocation information bits can be reduced by 12 compared to initial transmission or full retransmission. These 12 bits can be used as a 6-bit CB group indicator and a 6-bit CB group NDI, where one TB is divided into six CB groups. In addition, 12 bits can be used to transmit 12-bit CIV information, where one TB is divided into seven CB groups. A 1-bit partial retransmission indicator can be used to indicate whether the control information is for initial transmission, full retransmission, or partial retransmission.

[0195] Figure 1KE is a diagram illustrating a method of a base station and a terminal according to an embodiment of the present disclosure.

[0196] refer to Figure 1KE The base station prepares downlink or uplink scheduling in step 1k5-02 and determines in step 1k5-04 whether the scheduling is for initial transmission or complete retransmission of TB units. If the scheduling is for initial transmission or complete retransmission, the base station configures resource allocation information by setting the partial retransmission indicator to 0 and selecting P1 as the RBG value in step 1k5-06, and includes the configured resource allocation information in the control information.

[0197] However, if the scheduling is for partial retransmission, the base station configures resource allocation information in step 1k5-08 by setting the partial retransmission indicator to 1 and selecting P2 as the RBG, and includes the CB group indicator and CB group NDI information in the control information. Alternatively, the CB group indicator and CB group NDI can be replaced by a CIV value as will be described below.

[0198] In step 1k5-12, the terminal decodes the received control information.

[0199] In step 1k5-14, the terminal determines whether the partial retransmission indicator specific bit is 0.

[0200] If the partial retransmission indicator is 0, the terminal determines in step 1k5-16 whether the scheduling is for initial transmission or full retransmission, and analyzes the resource allocation information by selecting the P1 value as the RBG. In step 1k5-18, transmission / reception is performed to follow the initial transmission or full retransmission.

[0201] However, if the partial retransmission indicator is 1 at step 1k5-14, the terminal determines in step 1k5-20 that the corresponding control information is for partial retransmission, analyzes the resource allocation information by selecting the P2 value as the RBG, and analyzes the CB group indicator and the CB group NDI value. Alternatively, the CB group indicator and the CB group NDI may be replaced by a CIV value as described below.

[0202] Information indicated by the partial retransmission indicator value may be different depending on a pre-agreed agreement.

[0203] In DCI for retransmission, the number of MCS and redundancy version (RV) bits to be applied can be reduced. For example, when performing partial retransmission, the MCS and RV are selected within a limited range compared to when performing initial transmission, and therefore, the number of MCS and RV bits can be reduced. For example, during initial transmission, all MCSs from QPSK to 256QAM can be selected, whereas during retransmission, only MCSs within a predetermined value of the MCS used during initial transmission can be selected. Therefore, the number of bits used for MCS and RV can be reduced, and therefore, may be used for the CB group indicator.

[0204] (Example (1-1-2))

[0205] According to an embodiment of the present disclosure, there is provided a method for inserting an indicator for distinguishing between initial transmission and partial retransmission, or an indicator for distinguishing between full retransmission and partial retransmission, into control information for transmitting scheduling information of partial retransmission of data.

[0206] For example, if one DCI bit at a specific position is 0, the terminal determines to perform full retransmission of one TB using the scheduling of the currently transmitted DCI, and analyzes the received DCI as DCI for full retransmission.

[0207] However, if one DCI bit at a specific position is 1, the terminal determines to perform retransmission in units of CB groups using the scheduling of the currently transmitted DCI, and analyzes the received DCI as DCI for partial retransmission.

[0208] The above information can be transmitted using a single bit. For example, if the corresponding indicator is 0, it indicates a complete retransmission, while if the corresponding indicator is 1, it indicates a partial retransmission.

[0209] This information can also be transmitted using a 2-bit NDI value. For example, if the corresponding indicator is 00, it indicates initial transmission, and if the corresponding indicator is 01, it indicates complete retransmission. However, if the corresponding indicator is 10, it indicates partial retransmission.

[0210] (Example (1-1-3))

[0211] According to an embodiment of the present disclosure, a method is provided for inserting an indicator for distinguishing between initial transmission and partial retransmission or an indicator for distinguishing between full retransmission and partial retransmission into control information, wherein a CB group indicator and a CB group NDI are not transmitted from a base station to a terminal.

[0212] The above information can be transmitted using a single bit. For example, if the corresponding indicator is 0, it indicates a complete retransmission, while if the corresponding indicator is 1, it indicates a partial retransmission.

[0213] This information can also be transmitted using a 2-bit NDI value. For example, if the corresponding indicator is 00, the terminal can determine that it indicates initial transmission, and if the corresponding indicator is 01, it indicates complete retransmission. However, if the corresponding indicator is 10, the terminal can determine that it indicates partial retransmission.

[0214] In the case of complete retransmission, all corresponding TBs are retransmitted, whereas in the case of partial retransmission, only the CB group determined as NACK may be retransmitted based on the HARQ-ACK information of the CB group transmitted from the terminal. The method for the terminal to transmit HARQ-ACK information of the CB group may be performed as in the embodiments (1-4), (1-5), and (1-5-1) of the present disclosure.

[0215] [Example (1-2)]

[0216] According to an embodiment of the present disclosure, a method is provided for configuring two pieces of control information for transmitting scheduling information for partial retransmission of data. The scheduling information provided in this embodiment may be referred to as two-level control information or two-segment control information.

[0217] Figure 1L FIGURE 1 illustrates mapping control information for transmission according to an embodiment of the present disclosure. In particular, Figure 1L The diagram illustrates downlink data transmission, control signals DCI 1 and DCI 2 being transmitted, and data mapped onto frequency-time resources.

[0218] refer to Figure 1LThe control signal DCI 1 11-03 may be mapped and transmitted in a region pre-agreed between the base station and the terminal or in a region configured by the base station. DCI 1 11-03 may include a carrier indicator field, resource block allocation, frequency hopping indicator, DCI format indicator, MCS value, RV value, NDI value, cyclic shift indicator to be used for DMRS, uplink index, SRS request indicator, resource allocation type indicator, and HARQ process number. DCI 2 11-05 may be transmitted in a portion of the allocated resource block region indicated by DCI 1 11-03.

[0219] DCI 2 11-05 may include a bit field for a CB group indicator and an NDI bit field for a CB group. The sizes of the bit field for the CB group indicator and the NDI bit field for the CB group may be calculated based on the control information included in DCI 1 11-03. For example, the TBS may be calculated based on the number of allocated resource blocks and the MCS value, and the number of CBs or CB groups may be known from the maximum length of the CBs that is predetermined or configured. Therefore, the number of CBs or the number of CB groups may be the size of the bit field for the CB group indicator and the NDI bit field for the CB group.

[0220] For example, if the number of CBs calculated according to DCI 1 and predetermined information is 4, the CB group indicator and the CB group NDI each consist of 4 bits. Therefore, the terminal can receive DCI 2 and find the CB group indicator and CB group NDI information.

[0221] Figure 1KA to Figure 1KD 2 is a flowchart illustrating operations of a base station and a terminal for configuring a CB group indicator and a CB group NDI. For convenience, an explanation will be made based on downlink data transmission, and the explanation can also be applied to uplink data transmission.

[0222] Figure 1KA 1. It is a flowchart illustrating a method for a base station to configure a bit field of a CB group indicator indicating whether a CB group is to be sent when sending a TB. When preparing to send a TB (1k1-02), the base station confirms whether the TB sending is an initial sending (1k1-04). If the TB is the initial sending, all CB group indicators are configured to 0 (1k1-06). If the TB is not the initial sending, it is confirmed whether a specific CB group is to be sent (1k1-08). If a CB group is to be sent, the corresponding bit of the CB group indicator is configured to 1 (1k1-10), whereas if the CB group is not to be sent, the corresponding bit of the CB group indicator is configured to 0 (1k1-12).

[0223] Figure 1KBIt is a flowchart illustrating a method for a terminal to decode a CB group by analyzing a bit field of a CB group indicator indicating whether the CB group is sent when receiving a TB. When preparing for reception of a TB (1k2-02), the terminal confirms whether the CB group indicator is all 0 (1k2-04). If the CB group indicator is all 0, the sent TB is considered to be an initial transmission (1k2-06). If the CB group indicator is not all 0, it is confirmed whether a specific bit of the CB group indicator is 1 (1k2-08). If the specific bit of the CB group indicator is 1, it is determined that the corresponding CB group is sent, and decoding of the corresponding CB group is performed (1k2-10). If the specific bit of the CB group indicator is 0, it is determined that the corresponding CB group is not sent, and decoding of the corresponding CB group is not performed (1k2-12).

[0224] Figure 1KC It is a flowchart illustrating a method for a base station to configure a bit field of a CB group NDI when transmitting a TB so that the initial transmission of a previously transmitted CB group is not used for terminal decoding. When preparing to transmit a TB (1k3-02), the base station determines whether to not use the initial transmission of a specific CB group for terminal decoding (1k3-04). In order for the terminal to perform decoding using only the currently transmitted CB group without using the initial transmission of a specific CB group, the corresponding bit of the CB group NDI is configured to 1 (1k3-06). If the terminal performs HARQ combining and decoding of the currently transmitted CB group using the initial transmission of a specific CB group, the corresponding bit of the CB group NDI is configured to 0 (1k3-08).

[0225] Figure 1KD This is a flowchart illustrating a method for a terminal to determine whether to use the initial transmission of a previously transmitted CB group for terminal decoding by confirming the NDI bit field of a specific CB group. When preparing for TB reception (1k4-02), the terminal confirms whether the specific bit of the CB group NDI is 1 (1k4-04). If the specific bit of the CB group NDI is 1, the initial transmission of the corresponding CB group is not used for decoding the current CB group (1k4-06). However, if the specific bit of the CB group NDI is 0, HARQ combining is performed to use the initial transmission of the corresponding CB group for decoding the current CB group (1k4-08).

[0226] (Example (1-2-1))

[0227] According to the (1-2-1)th embodiment, a method for selecting channel coding applied to DCI1 and DCI 2 in the (1-2)th embodiment will be described.

[0228] The base station configures the bit field of DCI 1 and applies a polar code. A CRC may be added before applying the polar code. Additionally, the base station configures the bit field of DCI 2 and applies a Reed-Muller (RM) code or a block code. The base station may apply different channel codes depending on the length of the bit field of DCI 2. If the bit field of DCI 2 indicates on, the channel code output bi may be calculated using Table 3 and Equation (1).

[0229] Table 3

[0230] i <![CDATA[M i,0 ]]> <![CDATA[M i,1 ]]> <![CDATA[M i,2 ]]> <![CDATA[M i,3 ]]> <![CDATA[M i,4 ]]> <![CDATA[M i,5 ]]> <![CDATA[M i,6 ]]> <![CDATA[M i,7 ]]> <![CDATA[M i,8 ]]> <![CDATA[M i,9 ]]> <![CDATA[M i,10 ]]> 0 1 1 0 0 0 0 0 0 0 0 1 1 1 1 1 0 0 0 0 0 0 1 1 2 1 0 0 1 0 0 1 0 1 1 1 3 1 0 1 1 0 0 0 0 1 0 1 4 1 1 1 1 0 0 0 1 0 0 1 5 1 1 0 0 1 0 1 1 1 0 1 6 1 0 1 0 1 0 1 0 1 1 1 7 1 0 0 1 1 0 0 1 1 0 1 8 1 1 0 1 1 0 0 1 0 1 1 9 1 0 1 1 1 0 1 0 0 1 1 10 1 0 1 0 0 1 1 1 0 1 1 11 1 1 1 0 0 1 1 0 1 0 1 12 1 0 0 1 0 1 0 1 1 1 1 13 1 1 0 1 0 1 0 1 0 1 1 14 1 0 0 0 1 1 0 1 0 0 1 15 1 1 0 0 1 1 1 1 0 1 1 16 1 1 1 0 1 1 1 0 0 1 0 17 1 0 0 1 1 1 0 0 1 0 0 18 1 1 0 1 1 1 1 1 0 0 0 19 1 0 0 0 0 1 1 0 0 0 0 20 1 0 1 0 0 0 1 0 0 0 1 21 1 1 0 1 0 0 0 0 0 1 1 22 1 0 0 0 1 0 0 1 1 0 1 23 1 1 1 0 1 0 0 0 1 1 1 24 1 1 1 1 1 0 1 1 1 1 0 25 1 1 0 0 0 1 1 1 0 0 1 26 1 0 1 1 0 1 0 0 1 1 0 27 1 1 1 1 0 1 0 1 1 1 0 28 1 0 1 0 1 1 1 0 1 0 0 29 1 0 1 1 1 1 1 1 1 0 0 30 1 1 1 1 1 1 1 1 1 1 1 31 1 0 0 0 0 0 0 0 0 0 0

[0231]

[0232] The terminal receives the control channel and, when decoding the control information, performs decoding by applying different channel codes according to DCI 1 and DCI 2. That is, to decode DCI 1, the terminal uses a decoder for polar codes, and to decode DCI 2, the terminal uses a decoder for block codes or RM codes.

[0233] Figure 1MA is a flowchart illustrating a method for a base station to apply a channel code based on a control information type according to an embodiment of the present disclosure.

[0234] refer to Figure 1MA , the base station prepares a control information bit field (1m1-02) and determines whether the format of the control information is DCI 1 (1m1-04). If the base station determines that the format is not DCI 1, the base station applies a block code or a RM code to a bit field consisting of a CB group indicator and a CP group NDI (1m1-08). If the base station determines that the format is DCI 1, the base station adds a CRC to a bit field consisting of a CIF, resource allocation, MCS, RV, and HARQ process number, and applies a polarization code to the bit field (1m1-06).

[0235] Figure 1MB is a flowchart illustrating a method for a terminal to perform channel code decoding based on a control information type according to an embodiment of the present disclosure.

[0236] refer to Figure 1MB , the base station prepares to decode the control information (1m2-02) and determines whether the format of the control information is DCI1 (1m2-04). If the terminal determines that the format is not DCI 1, the terminal performs decoding by using a decoder of a block code or RM code, and confirms the CB group indicator and CB group NDI from the bit field (1m2-08). If the terminal determines that the format is DCI 1, the terminal performs decoding by using a polar code, determines transmission success / failure through a CRC check, and confirms the control information from the bit field (1m2-06).

[0237] Although Figure 1MA and Figure 1MB The polar code is shown as being applied to DCI 1 and the RM code is shown as being applied to DCI 2, but they can be normalized using the same method for applying the first and second channel codes. Alternatively, the polar code can be used as the first channel code for DCI 1, and the repetition code can be used as the second channel code for DCI 2.

[0238] (Example (1-2-2))

[0239] According to an embodiment of the present disclosure, one of the bit field of the CB group indicator and the NDI bit field of the CB group may be omitted from the control information based on the configuration of the base station.

[0240] For example, when the CB group NDI is omitted and the CB group indicator is used. During partial retransmission, the base station can retransmit only a specific CB group and transmit information about the CB group being used for retransmission to the terminal through the CB group indicator. The terminal and the base station can previously determine whether to perform decoding with respect to the CB group received through partial retransmission after performing HARQ combining for initial transmission, or whether to perform decoding using only the data of the newly received CB group by discarding the data of the corresponding CB group received during initial transmission.

[0241] For example, the terminal and the base station may predetermine that when performing partial retransmission, while discarding the data of the corresponding CB group indicated by the CB group indicator received during the initial transmission, decoding is always performed using only the data of the newly received CB group. In addition, the base station may configure the terminal through upper-level signaling regarding whether to perform decoding with respect to the CB group received through partial retransmission after performing HARQ combining for the initial transmission, or whether to perform decoding using only the data of the newly received CB group by discarding the data of the corresponding CB group received during the initial transmission.

[0242] (Example (1-2-3))

[0243] According to an embodiment of the present disclosure, a method is provided in which a bit field of a CB group indicator and a bit field of an NDI of a CB group are included in a field to be analyzed simultaneously in control information based on the configuration of a base station. In particular, a description will be given of introducing a CB group indicator value (CIV), and transmitting the CB group indicator and CB group NDI information described above according to embodiment (1-1) or embodiment (1-2) through a single CIV value. As described above, if the CIV information is transmitted from a single control information, the NDI information of the TB can be omitted.

[0244] For example, the CIV value can be determined as follows.

[0245] Three scenarios are considered: 1) a CB group is not retransmitted, 2) even if retransmission is performed, the terminal performs decoding of the corresponding CB group using only the newly received part while discarding the data used for the initial transmission, or 3) the terminal performs decoding by performing HARQ combining with respect to the retransmitted part and the initial transmission part after retransmission is performed.

[0246] Therefore, assuming that a total of N CB groups are transmitted during initial transmission, the number of cases that the terminal should consider when performing retransmission may be 3^(N)-1 (or 3N-1), because when there are N CB groups, each group has three cases, and not all CB groups are retransmitted, the control signal according to retransmission will not be transmitted. Therefore, the number of cases to be considered by the terminal, 3N-1, can be expressed as a ternary number of N digits.

[0247] For example, if there are 4 CB groups, the CIV value can be expressed as 0120(3). In the above case, X(3) indicates that X is a ternary number.

[0248] In the above example, 0 in each digit indicates that the corresponding CB group has not been retransmitted, and 1 in each digit indicates that although the corresponding CB group has been retransmitted, decoding should be performed using only the newly received part while discarding the data used for the initial transmission. In addition, 2 in each digit may indicate that HARQ combining should be performed with respect to the retransmitted part and the initially transmitted part when the corresponding CB group has been retransmitted.

[0249] Therefore, 0120 (3) indicates that decoding is performed using only the data of the second retransmitted CB group while discarding the data of the initially transmitted second CB group, wherein the first and fourth CB groups are not retransmitted, but the second CB group is retransmitted, and the retransmission of the third CB group may be indicated, and decoding may be performed by performing HARQ combining relative to the retransmitted part and the initially transmitted part.

[0250] Therefore, the number of cases that the terminal should consider is 34-1=80 in total from 0001(3) to 2222(3). That is, the CIV value can be represented by a ternary number of 4 digits, and the CIV value determined as shown above can be converted into a binary number to be inserted into the bit field of the control information. That is, if there are 4 CB groups and 4 bits of the CB group indicator and 4 bits of the CB group NDI are required, a total of 8 bits are required. However, using the above CIV value, a total of 7 bits are required for 80 cases. As described above, the CIV value can be directly converted into a binary number, or the CIV-1 value can be converted into a binary number to be included in the control information.

[0251] If CIV=0120(3) is converted into a 7-digit binary number, it becomes CIV=0001111(2). Therefore, 0001111 can be included in the control information.

[0252] In addition, the CIV-1 value may be converted into a binary number, and 0001110 may be included in the control information.

[0253] If the control information is received, the terminal identifies the above CIV value and converts the CIV value into a ternary number to determine the transmission information for each CB group.

[0254] The above method is only an exemplary method for defining the CIV value, and the CIV value can be defined by other methods. For example, two CB groups can be defined as shown in Table 4 below.

[0255] Table 4

[0256] CIV First CB Group Second CB Group 0 Initial Send Initial Send 1 Initial Send Resend 2 Initial Send Do not send 3 Resend Initial Send 4 Resend Resend 5 Resend Do not send 6 Do not send Initial Send 7 Do not send Resend

[0257] Using Table 4, if there is data previously received by the terminal for the corresponding CB group, the initial transmission may indicate that decoding is performed using only the newly received portion while discarding the previously received portion, and the retransmission may indicate that decoding is performed for the corresponding CB group together with the previously received data. Not transmitting may indicate that the corresponding CB group is not currently being transmitted. Therefore, in Table 4, for CIV=1, the first CB group may indicate that if the terminal receives the first CB group, the corresponding CB group is decoded using only the newly received portion while discarding the previously received portion, and the second CB group may indicate that the corresponding CB group is decoded by performing HARQ combining together with the previously received portion. Table 4 can be modified in various ways and can be applied to define CIV information.

[0258] [Example (1-3)]

[0259] According to an embodiment of the present disclosure, a method for configuring a CB indicator and a CB NDI bit field included in control information is provided.

[0260] The number M of code block groups can be notified to the terminal by an upper layer signal from the base station, or information about the M value can be transmitted to the DCI. In addition, the number M can be automatically determined based on the number of code blocks included in the TBS, TB, or system frequency band. For example, the number M of code block groups can be determined by the TBS based on the TBS value of the scheduled data, as shown in Table 5 below.

[0261] Table 5

[0262] TBS value M TBS<61,440 1 61,440<TBS<122,880 2 122,880<TBS<184,320 3 184,320<TBS<245,760 4

[0263] Table 5 illustrates a scenario where the TBS value is less than 245,760, but is not limited thereto. The M value can be defined even with respect to a larger TBS value using a similar rule.

[0264] As another example, assuming that the unit of frequency resources is a resource block, the M value can be determined according to the system frequency band. In the LTE system, a resource block corresponds to 180 kHz, and although a resource block corresponds to 12 subcarriers, it can be determined differently in NR or 5G systems. For example, one resource block can be a frequency band corresponding to 375 kHz. Depending on the total number of resource blocks in the system frequency band, as shown in Table 6 below, the M value can be different.

[0265] Table 6

[0266] The total number of resource blocks in the system frequency band M ≤10 1 11-26 2 27-63 3 64-110 4

[0267] If the transmission of several code blocks fails after transmitting a TB, the transmitting end (e.g., base station) can perform retransmission only for the failed code blocks. When transmitting a code block during retransmission, code block index information can be included in the code block to be transmitted. Therefore, if data corresponding to the retransmission is received, the receiving end can confirm the code block index information and then perform decoding by combining it with the initial transmission when decoding the corresponding code block.

[0268] After the number M of CB groups is determined, the respective CBs are included in the groups in due order.

[0269] For example, if the total number of CBs is C, K+ and K- associated with a CB group can be calculated as shown in equation (2).

[0270]

[0271] K - =MK + (2)

[0272] From the front, the K+CB group includes CBs, and the remaining K-CB groups include A CB.

[0273] After configuring C CBs for M CB groups, a CB group indicator and a CB group NDI having an M-bit field may be generated respectively. The n-th bit of the CB group indicator indicates that the CB belongs to the n-th CB group, and the m-th bit of the CB group NDI indicates that the CB belongs to the m-th CB group. Therefore, the base station and the terminal may perform the above reference Figure 1KA 、 1KB , 1KC and 1KD.

[0274] For example, if C is 15 and M is 4, K+ becomes 3, and K- becomes 1. That is, 3 CB groups include CBs, and a CB group includes CBs. Therefore, CBs 1 to CB 4 belong to CB group 1, and CBs 5 to CB 8 belong to CB group 2. In addition, CBs 9 to CB 12 belong to CB group 3, and CBs 13 to CB 15 belong to CB group 4. Although CBs are continuously included in CB groups in the above description, they can be modified to be included in CB groups according to specific rules.

[0275] Although a method has been described in which the receiving end performs feedback of whether transmission of a code block has failed and the transmitting end performs partial retransmission of the code block, the two operations do not always need to be performed in combination and they may be used separately.

[0276] According to an embodiment of the present disclosure, initial transmission and retransmission may indicate initial transmission and retransmission in a HARQ operation.

[0277] [Example (1-4)]

[0278] Therefore, a method for a terminal to send HARQ-ACK feedback to a base station when a terminal to which partial retransmission has been configured receives downlink transmission will be described. In order to generate HARQ-ACK information in units of CB groups, the terminal configures one or more bits.

[0279] Similar to the method for determining M as described above, a bit field having the same size as the number of CB groups M is configured, the bits of the bit field can be used as information indicating whether the transmission of each CB group has been successful, and the bit field can be transmitted from the terminal to the base station for use as HARQ-ACK feedback information.

[0280] For example, if the number of CBs C is 15 and M is 4, K+ becomes 3 and K- becomes 1. That is, 3 CB groups include CBs, and a CB group includes CBs. Therefore, CBs 1 to 4 belong to CB Group 1, and CBs 5 to 8 belong to CB Group 2. Furthermore, CBs 9 to 12 belong to CB Group 3, and CBs 13 to 15 belong to CB Group 4. That is, the terminal sends M-bit HARQ-ACK feedback to the base station using the uplink control channel. If transmission for CB Group i is successful, the i-th bit in the M-bit HARQ-ACK feedback is set to 1, and if transmission for CB Group i fails, the i-th bit in the M-bit HARQ-ACK feedback is set to 0.

[0281] This method can also be applied to a terminal to which partial retransmission has been configured to send uplink data, and can be applied to a base station to send HARQ-ACK feedback to the terminal.

[0282] [Example (1-5)]

[0283] According to an embodiment of the present disclosure, a method is provided for a terminal to transmit HARQ-ACK in case that the terminal to which partial retransmission has been configured receives downlink data when transmission of a part of a CB group has failed and retransmission is performed during initial transmission.

[0284] When a terminal to which partial retransmission has been configured receives downlink data, HARQ-ACK feedback for initial transmission can be performed as described above. If transmission of some CB groups has failed during initial transmission, and partial retransmission is performed only for the CB groups for which transmission failed, the terminal can send only the HARQ-ACK bits for the CB groups used for transmission to the base station.

[0285] For example, if the number C of CBs transmitted during the initial transmission is 15 and M is 4, the terminal can perform HARQ-ACK transmission for the initial transmission as described above. For example, if the terminal sends feedback to the base station that the transmission of CB group 2 and CB group 3 has failed, the base station can include only CB group 2 and CB group 3 in the retransmission to be sent. Even if the terminal sends feedback to the base station that the transmission of CB group 2 and CB group 3 has failed, the base station can retransmit all CB groups based on the judgment of the base station. In this example, the base station includes only CB group 2 and CB group 3 in the retransmission. Therefore, during the retransmission, only CB group 2 and CB group 3 are included in the retransmission, and the CB group indicator can indicate 0110.

[0286] For HARQ-ACK feedback for partial retransmission, the terminal may configure a bit field whose size is different from the size of the bit field of the CB group indicator but is the same as the size corresponding to the number of CB groups to be partially retransmitted, and transmit the bit field to the base station as an uplink control signal. For example, if only CB group 2 and CB group 3 are included in the retransmission, a 2-bit HARQ-ACK bit field is prepared, in which information on whether the retransmitted CB group 2 has been successful is configured as the first bit, and information on whether the retransmitted CB group 3 has been successful is configured to be transmitted to the base station.

[0287] (Example (1-5-1))

[0288] According to an embodiment of the present disclosure, another method is provided for a terminal to transmit HARQ-ACK in case that a terminal to which partial retransmission has been configured receives downlink data when transmission of a part of a CB group has failed and retransmission is performed during initial transmission.

[0289] When a terminal to which partial retransmission has been configured receives downlink data, HARQ-ACK feedback for initial transmission can be performed as described above. If transmission of some CB groups has failed during initial transmission, and partial retransmission is performed only for the CB groups for which transmission failed, the terminal can reorganize the M transmitted CB groups and send HARQ-ACK bits having the same size as the size of the HARQ-ACK bits for initial transmission to the base station for the CB groups transmitted to the base station.

[0290] For example, if the number C of CBs transmitted during initial transmission is 15 and M is 4, the terminal may perform HARQ-ACK transmission for initial transmission as described above.

[0291] For example, if the terminal sends feedback to the base station that CB group 2 and CB group 3 have failed to transmit, the base station may include only CB group 2 and CB group 3 in the retransmission to be sent. Even if the terminal sends feedback to the base station that CB group 2 and CB group 3 have failed to transmit, the base station may retransmit all CB groups based on the base station's judgment. In this example, the base station includes only CB group 2 and CB group 3 in the retransmission. Therefore, during the retransmission, only CB group 2 and CB group 3 are included in the retransmission, and the CB group indicator may indicate 0110.

[0292] The HARQ-ACK feedback for partial retransmission includes a bit field having the same size as the bit field of the CB group indicator, and for this, the terminal can reorganize 4 CB groups. Because each of CB group 2 and CB group 3 includes 4 CBs, a total of 8 CBs are retransmitted. In order to organize 8 CBs into a new CB group, two CBs can be included in one CB group. Therefore, the terminal prepares a 4-bit HARQ-ACK, and whether the transmission of the first and second CBs among the 8 retransmitted CBs has been successfully configured to the first HARQ-ACK, and whether the transmission of the third and fourth CBs has been successfully configured to the second HARQ-ACK. Whether the transmission of the fifth and sixth CBs has been successfully configured to the third HARQ-ACK, and whether the transmission of the seventh and eighth CBs has been successfully configured to the fourth HARQ-ACK to be sent to the base station.

[0293] If retransmission for partial retransmission is needed again, the base station can perform retransmission per newly configured CB group.

[0294] [Example (1-6)]

[0295] The first to sixth embodiments relate to a reception method for a terminal using a HARQ process through initial transmission, entire TB retransmission, and entire CB retransmission during downlink transmission.

[0296] For each received TB and related HARQ operation information, the HARQ process may perform the following operations.

[0297] - If the NDI value is a value different from the previous value, for a process for broadcasting, for a process for transmitting system information, or data received for the first time, the received data is regarded as initial transmission.

[0298] - If the CB Group Indicator and CB Group NDI are disabled or not transmitted in another embodiment, the received data is considered as a whole TB retransmission.

[0299] - If in another embodiment the CB group indicators are all 0 or the CB group NDIs all indicate 0, the received data is considered to be a whole TB retransmission.

[0300] - The received data is considered as a CB group partial retransmission.

[0301] The terminal can perform the following operations.

[0302] - If the received data corresponds to an initial transmission, decoding of the received data is performed.

[0303] If the TB corresponding to the received data is not successfully decoded, in the case where the received data corresponds to a retransmission of the entire TB, the received data is combined with the corresponding TB data of the soft buffer and decoding of the combined data is performed. Data combining can be performed by combining log-likelihood ratio (LLR) values.

[0304] -If the TB corresponding to the received data is not successfully decoded, in the case where the received data corresponds to partial retransmission of a CB group, the portion corresponding to the CB group in which the CB group indicator and the CB group NDI both indicate 1 is combined with the corresponding portion stored in the existing soft buffer, and the portion corresponding to the CB group in which the CB group indicator indicates 1 but the CB group NDI indicates 0 is replaced by the newly received portion, while the corresponding portion stored in the existing soft buffer is discarded, and decoding of the combined or replaced data is performed.

[0305] If decoding of data performed on the corresponding TB has been successful, or previous decoding of the corresponding TB has been successful, the terminal performs the following operations.

[0306] - If the HARQ process is for broadcast, the decoded MAC PDU is delivered to upper layers.

[0307] - If the HARQ process is not used for broadcasting and data decoding for the corresponding TB has first succeeded, the decoded MAC PDU is delivered to the location for decomposition and demultiplexing.

[0308] -Generate ACK for the corresponding TB.

[0309] If data decoding performed on a corresponding TB is not successful, and previous decoding of the corresponding TB is not successful, the terminal performs the following operations.

[0310] - The data of the soft buffer for the corresponding TB is replaced by the data whose decoding has been performed by the terminal.

[0311] - Generate NACK for the corresponding TB.

[0312] If the HARQ process corresponds to a temporary C-RNTI value or a temporary terminal ID value, if contention resolution has not succeeded, if the HARQ process is a process for broadcast, or if a timer for controlling a timing advance (TA) value stops or expires, the MAC layer does not transmit the generated ACK or NACK to the physical layer. Instead, the generated ACK or NACK is transmitted from the MAC layer to the physical layer.

[0313] In order to implement the above-mentioned embodiments of the present disclosure, Figure 1N and Figure 1O The transmitter, receiver, and processor of a terminal or base station are illustrated in FIG. According to embodiments (1-1) to (1-6), a transmission / reception method for a base station or terminal is provided to determine and receive control information for partial retransmission, and for this, the receiver, processor, and transmitter of the base station or terminal should operate according to each embodiment.

[0314] Figure 1N FIGURE 1 illustrates a terminal according to an embodiment of the present disclosure. In particular, Figure 1N The terminal in can execute the above method.

[0315] refer to Figure 1N , the terminal includes a receiver 1n-00, a transmitter 1n-04 and a processor 1n-02.

[0316] Alternatively, the receiver 1n-00 and transmitter 1n-04 may be combined in a transceiver that transmits and receives signals to and from a base station. The signals may include control information and data. For example, the transceiver may include an RF transmitter that upconverts and amplifies the frequency of transmitted signals, and an RF receiver that low-noise amplifies received signals and downconverts the frequency of the amplified signals.

[0317] In addition, the transceiver can receive a signal through a radio channel, output the signal to the processor 1n-02, and transmit the signal output from the processor 1n-02 through the radio channel. The processor 1n-02 can control a series of processes so that the terminal can operate according to the above-mentioned embodiments of the present disclosure. For example, when receiving a data signal from the base station, the receiver 1n-00 can receive the CB group indicator, the CB group NDI, and the data, and the processor 1n-02 can perform data decoding based on the CB group indicator and the CB group NDI. Thereafter, the transmitter 1n-04 can send HARQ-ACK information following the CB group to the base station.

[0318] Figure 1O The figure shows a base station according to an embodiment of the present disclosure. Figure 1O The base station in can execute the above method.

[0319] refer to Figure 1O , the base station includes a receiver 1o-01, a transmitter 1o-05 and a processor 1o-03.

[0320] Alternatively, the receiver 10-01 and transmitter 10-05 are combined in a transceiver that transmits and receives signals to and from a terminal. As described above, the signals may include control information and data. For example, the transceiver may include an RF transmitter that upconverts and amplifies the frequency of transmitted signals, and an RF receiver that low-noise amplifies received signals and downconverts the frequency of the amplified signals.

[0321] In addition, the transceiver can receive signals through the radio channel, output signals to the processor 1o-03, and transmit signals output from the processor 1o-03 through the radio channel. The processor 1o-03 can control a series of processes so that the base station can operate according to the above-mentioned embodiments of the present disclosure.

[0322] For example, the processor 10-03 may operate to determine whether to insert the CB group indicator and the CB group NDI, and generate the CB group indicator, CB group NDI information, and corresponding data to be transmitted to the terminal. Thereafter, the transmitter 10-05 transmits control information including the CB group indicator and the CB group NDI, and the receiver 10-01 receives feedback information from each CB group for which the transmission has been successful.

[0323] In addition, the processor 10-03 can operate to generate a DCI including a CB group indicator and a CB group NDI information, or a higher-level signaling signal. The DCI or the higher-level signaling can indicate whether the code block index information is included in the scheduling signal.

[0324] <Second embodiment>

[0325] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the accompanying drawings.

[0326] When explaining the embodiments, descriptions of technical contents that are well known in the prior art to which the present disclosure belongs and that are not directly related to the present disclosure will be omitted. This is to convey the subject matter of the present disclosure more clearly by omitting unnecessary explanations without obscuring the subject matter of the present disclosure.

[0327] For the same reason, in the accompanying drawings, the size and relative size of some components may be exaggerated, omitted or briefly illustrated. In addition, the size of each component does not fully reflect its actual size. In the accompanying drawings, the same reference numerals are used for the same or corresponding elements in each figure.

[0328] Aspects and features of the present disclosure and methods for achieving the aspects and features will be apparent by reference to the embodiments described in detail with reference to the accompanying drawings. However, the present disclosure is not limited to the embodiments disclosed below but can be implemented in various forms. Things defined in the description, such as specific configurations and elements, are provided to help those skilled in the art fully understand the specific details of the present disclosure, and the present disclosure is defined only within the scope of the appended claims. Throughout the description of the present disclosure, the same reference numerals are used for the same elements in the various figures.

[0329] In this case, it will be understood that each block in the flowchart illustration, and combinations of blocks in the flowchart illustration, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device create means for implementing the functions specified in one or more blocks of the flowchart.

[0330] These computer program instructions may also be stored in a computer-usable or computer-readable memory that can direct a computer or other programmable data processing device to operate in a particular manner so that the instructions stored in the computer-usable or computer-readable memory produce an article of manufacture that includes instruction means for implementing the functions specified in one or more blocks of the flowchart. The computer program instructions may also be loaded onto a computer or other programmable data processing device so that a series of operational steps are executed on the computer or other programmable device to produce a computer-implemented process so that the instructions executed on the computer or other programmable device provide steps for implementing the functions specified in one or more blocks of the flowchart.

[0331] In addition, each block of the flowchart diagram can represent a module, segment or part of code that includes one or more executable instructions for implementing one or more specified logical functions. It should also be noted that in some alternative implementations, the functions marked in the blocks may not occur in order. For example, depending on the functions involved, two blocks shown in succession may in fact be executed substantially simultaneously, or multiple blocks may sometimes be executed in reverse order.

[0332] In this case, the term "unit" as used in the embodiments means, but is not limited to, software or hardware components that perform certain tasks, such as FPGAs or ASICs. However, "unit" is not intended to be limited to software or hardware. The term "unit" can be advantageously configured to be located on an addressable storage medium and configured to execute on one or more processors. Thus, for example, a "unit" can include components, such as software components, object-oriented software components, class components, and task components, processes, functions, attributes, procedures, subroutines, segments of program code, drivers, firmware, microcode, circuits, data, databases, data structures, tables, arrays, and variables. The functions provided for components and "units" can be combined into fewer components and "units", or further divided into additional components and "units". Further, components and "units" can be implemented as one or more CPUs in an operating device or a secure multimedia card. In addition, in an embodiment, a "unit" can include one or more processors.

[0333] Wireless communication systems have evolved from their initial voice-oriented service provisioning systems to broadband wireless communication systems that provide high-speed and high-quality packet data services based on communication standards such as 3GPP's High Speed ​​Packet Access (HSPA), Long Term Evolution (LTE) or Evolved Universal Terrestrial Radio Access (E-UTRA), LTE-Advanced (LTE-A), 3GPP2's High Rate Packet Data (HRPD), Ultra Mobile Broadband (UMB), and IEEE's 802.16e. Furthermore, 5G or New Radio (NR) communication standards have been developed for 5G wireless communication systems.

[0334] In the wireless communication system including 5G as described above, at least one service of enhanced mobile broadband (eMBB), massive machine type communication (mMTC) and ultra-reliable and low-latency communication (URLLC) may be provided to the terminal. Hereinafter, in all embodiments of the present disclosure, eMBB may be a service aimed at high-speed transmission of large-capacity data, mMTC may be a service aimed at minimizing terminal power and connecting multiple terminals, and URLLC may be a service aimed at ultra-reliability and low latency, but is not limited thereto. In addition, in all embodiments of the present disclosure, it is assumed that the URLLC service transmission time is shorter than the eMBB or mMTC service transmission time, but is not limited thereto. The three services described above may be important scenarios in an LTE system or a 5G / new radio beyond LTE or a next radio (NR) system.

[0335] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. When describing the present disclosure, if it is determined that it obscures the present disclosure with unnecessary details, the specific description of the relevant known functions or configurations will be omitted. In addition, all terms used in the description are general terms that are widely used in consideration of their functions in the present disclosure, but may differ depending on the intention or habit of the user or operator. Therefore, they should be defined based on the content of the entire description of the present disclosure. Hereinafter, a base station is a subject that performs resource allocation to a terminal, and may be at least one of an eNode B (or eNB), a gNode B (or gNB), a node B, a base station (BS), a radio connection unit, a base station controller, and a node on a network. A terminal may include a user equipment (UE), a mobile station (MS), a cellular phone, a smart phone, a computer, or a multimedia system capable of performing a communication function.

[0336] In the present disclosure, a downlink (DL) is a radio transmission path for a signal sent from a base station to a terminal, and an uplink (UL) refers to a radio transmission path for a signal sent from a terminal to a base station. In addition, the embodiments of the present disclosure to be described below may also be applied to other communication systems with similar technical backgrounds or channel types. In addition, the embodiments of the present disclosure may also be applied to other communication systems by partial modifications thereof within the scope of not significantly departing from the scope of the present disclosure at the discretion of those skilled in the art.

[0337] In the LTE system, which is a representative example of a broadband wireless communication system, an orthogonal frequency division multiplexing (OFDM) method is suitable for a downlink (DL), and a single-carrier frequency division multiple access (SC-FDMA) method is suitable for an uplink (UL). An uplink refers to a radio link through which a terminal (user equipment (UE) or a mobile station (MS)) transmits data or a control signal to a base station (BS or eNode B), and a downlink refers to a radio link through which a base station transmits data or a control signal to a terminal. In general, the multiple access method as described above can separate data and control information from each user by allocating and operating time-frequency resources on which data or control information is carried for each user, so that the resources do not overlap with each other, that is, so that orthogonality is achieved.

[0338] The LTE system uses the Hybrid Automatic Repeat Request (HARQ) method, in which the physical layer retransmits the corresponding data if a decoding failure occurs during initial transmission. The HARQ method allows the receiver to transmit information (a negative acknowledgement (NACK)) to notify the transmitter of the decoding failure if the receiver cannot accurately decode the data, allowing the transmitter to retransmit the corresponding data on the physical layer. The receiver combines the data retransmitted by the transmitter with previous data that it failed to decode to improve data reception performance. Alternatively, if the receiver has accurately decoded the data, it transmits information (an acknowledgment (ACK)) to notify the transmitter of the decoding success, allowing the transmitter to transmit new data.

[0339] Figure 2A 1 is a diagram illustrating a basic structure of a time-frequency domain as a radio resource region from which data or a control channel is transmitted through a downlink in an LTE system.

[0340] exist Figure 2A In the figure, the horizontal axis represents the time domain, and the vertical axis represents the frequency domain. In the time domain, the minimum transmission unit is the OFDM symbol, and the N symb OFDM symbols 2a-02 are combined to form a time slot 2a-06, and two time slots are combined to form a subframe 2a-05. The length of the time slot is 0.5 milliseconds, and the length of the subframe is 1 millisecond. In addition, the radio frame 2a-14 is a time domain interval consisting of 10 subframes. The minimum transmission unit in the frequency domain is a subcarrier, and the transmission bandwidth of the entire system is composed of a total of N BW It consists of subcarriers 2a-04.

[0341] In the time-frequency domain, the basic unit of resources is the resource element (RE) 2a-12, which can be indicated as an OFDM symbol index and a subcarrier index. A resource block (RB) 2a-08 or a physical resource block (PRB) is defined as N in the time domain. symbconsecutive OFDM symbols 2a-02 and N in the frequency domain RB Therefore, one RB 2a-08 consists of N consecutive subcarriers 2a-10. symb ×N RB In general, the minimum data transmission unit is the RB unit as described above. In the LTE system, generally N symb Yes N symb =7, N RB Yes N RB =12, and N BW and N RB Proportional to the system transmission bandwidth.

[0342] The data rate increases in proportion to the number of RBs scheduled to the terminal. In the LTE system, six transmission bandwidths are defined and operated. In the case of an FDD system that divides and operates the downlink and uplink by frequency, the transmission bandwidth of the downlink and the transmission bandwidth of the uplink may be different from each other. The channel bandwidth indicates the RF bandwidth corresponding to the system transmission bandwidth. Table 1A presents the correspondence between the system transmission bandwidth and the channel bandwidth defined in the LTE system. For example, in an LTE system with a channel bandwidth of 10 MHz, the transmission bandwidth consists of 50 RBs.

[0343] Table 7

[0344] <![CDATA[Channel bandwidth BW Channel [MHz]]]> 1.4 3 5 10 15 20 <![CDATA[Transmission Bandwidth Configuration N RB > 6 15 25 50 75 100

[0345] In the case of downlink control information, it is transmitted within the first N OFDM symbols of a subframe. In general, the number N is N = {1, 2, 3}. Therefore, the value N can be changed for each subframe depending on the amount of control information to be transmitted in the current subframe. The control information includes a control channel transmission interval indicator indicating how many OFDM symbols the control information is transmitted, scheduling information for downlink data or uplink data, and HARQ ACK / NACK signals.

[0346] In the LTE system, scheduling information about downlink data or uplink data is transmitted from the base station to the terminal through downlink control information (DCI). Uplink (UL) refers to the radio link through which the terminal sends data or control signals to the base station, and downlink (DL) refers to the radio link through which the base station sends data or control signals to the terminal.

[0347] DCI is defined according to various formats, and the determined DCI format is applied and operated according to whether the scheduling information is uplink data scheduling information (UL grant) or downlink data scheduling information (DL grant), whether the DCI is compact DCI with small-sized control information, whether spatial multiplexing using multiple antennas is applied, or whether the DCI is DCI for power control. For example, DCI format 1, which is scheduling control information (DL grant) for downlink data, may include at least one of the following control information.

[0348] - Resource Allocation Type 0 / 1 Flag: This flag indicates whether the resource allocation type is Type 0 or Type 1. Type 0 allocates resources in units of resource block groups (RBGs) by applying a bitmap. In LTE systems, the basic unit for scheduling is a resource block (RB), which is represented as time and frequency domain resources. An RBG is composed of multiple RBs, which are considered the basic unit for scheduling in Type 0. Type 1 allocates specific RBs within an RBG.

[0349] - Resource Block Allocation: This notifies the RBs allocated for data transmission. The indicated resources are determined according to the system bandwidth and resource allocation method.

[0350] - Modulation and Coding Scheme (MCS): This informs the modulation method used for data transmission and the size of the transport block as data to be sent.

[0351] -HARQ process number: This informs the number of HARQ processes.

[0352] - New Data Indicator: This informs whether the HARQ transmission is an initial transmission or a retransmission.

[0353] - Redundancy version: This informs the redundancy version of HARQ.

[0354] - Transmit Power Control (TPC) command for Physical Uplink Control Channel (PUCCH): This informs the transmission power control command for PUCCH which is an uplink control channel.

[0355] After being processed through channel coding and modulation, the DCI is transmitted through a Physical Downlink Control Channel (PDCCH) or an Enhanced PDCCH (EPDCCH) which is a downlink physical control channel.

[0356] In general, DCI is independently channel-coded for each terminal and then configured as a separate PDCCH to be transmitted. In the time domain, the PDCCH is mapped and transmitted for each control channel transmission interval. The mapping location of the PDCCH in the frequency domain is determined by the identifier (ID) of each terminal, and the PDCCH is distributed throughout the transmission band of the entire system.

[0357] Downlink data can be sent on the Physical Downlink Shared Channel (PDSCH), which is a physical channel for transmitting downlink data. The PDSCH can be transmitted after the control channel transmission interval and is notified of scheduling information such as a specific mapping position in the frequency domain or a modulation method by the DCI transmitted via the PDCCH.

[0358] The base station notifies the terminal of the modulation method and transport block size (TBS) applied to the PDSCH to be transmitted to the terminal through the 5-bit MCS among the control information constituting the DCI. The TBS corresponds to the size of the transport block (TB) to be transmitted by the base station before channel coding for error correction is applied.

[0359] The modulation methods supported in the LTE system are quadrature phase shift keying (QPSK), 16-quadrature amplitude modulation (16QAM), or 64QAM, and the modulation orders (Qm) correspond to 2, 4, and 6. That is, in the case of QPSK modulation, 2 bits can be transmitted per symbol, and in the case of 16QAM modulation, 4 bits can be transmitted per symbol. In addition, in the case of 64QAM modulation, 6 bits can be transmitted per symbol.

[0360] In 3GPP LTE Rel-10, bandwidth extension technology has been adopted to support higher data transmission rates compared to LTE Rel-8. Compared with LTE Rel-8 terminals that send data in one frequency band through frequency band extension, this technology, called bandwidth extension or carrier aggregation (CA), can increase the data transmission rate for the extended frequency band. The above-mentioned frequency band can be called component carrier (CC), and it is stipulated that LTE Rel-8 terminals have one component carrier with respect to downward and upward. In addition, the upward component carrier to which SIB-2 is connected to the constraint of the downward component carrier can be called a cell. The SIB-2 connection relationship between the downward component carrier and the upward component carrier is sent as a system signal or an upper-level signal. Terminals that support CA can receive downward data through multiple serving cells and can send upward data.

[0361] In Rel-10, if it is difficult for a base station to send a physical downlink control channel (PDCCH) in a specific serving cell to a specific terminal, it can configure a carrier indicator field (CIF) to notify another serving cell to send a PDCCH. The corresponding PDCCH indicates the physical downlink shared channel (PDSCH) or physical uplink shared channel (PUSCH) of the other serving cell. The CIF can be configured for terminals that support carrier aggregation.

[0362] The CIF is determined by adding 3 bits to the PDCCH information in a specific serving cell to indicate another serving cell, and is included only when cross-carrier scheduling is performed. If the CIF is not included, cross-carrier scheduling is not performed. If the CIF is included in downlink allocation (DL) information, the CIF indicates the serving cell to which the PDSCH scheduled by the DL allocation is to be transmitted, and if the CIF is included in uplink resource allocation information (UL grant), the CIF is defined to indicate the serving cell to which the PUSCH is to be transmitted.

[0363] As mentioned above, in LTE-10, carrier aggregation (CA) is defined as a bandwidth extension technology, and multiple service cells can be configured for the terminal. In addition, for data scheduling of the base station, the terminal sends channel information for multiple service cells to the base station periodically or aperiodically. The base station schedules data per carrier to send data, and the terminal sends A / N feedback for the data sent by each carrier. In LTE Rel-10, it is designed to send A / N feedback of a maximum of 21 bits, and if the transmission of A / N feedback and channel information overlaps with each other in one subframe, it is designed to send A / N feedback and discard the channel information. In LTE Rel-11, by multiplexing the channel information of one cell together with the A / N feedback, it is designed to send A / N feedback of a maximum of 22 bits and the channel information of one cell from the transmission resources of PUCCH format 3.

[0364] In LTE-13, assuming a maximum of 32 service cell configuration scenarios, and using not only licensed bands but also unlicensed bands, the number of service cells has been extended to a maximum of 32. In addition, considering that the number of licensed bands, such as LTE frequencies, is already limited, LTE services are provided in unlicensed bands, such as the 5GHz band, and this is called License Assisted Access (LAA). In LAA, the carrier aggregation technology in LTE is applied to support the LTE cell operating as a licensed band as a P cell, and the LAA cell operating as an unlicensed band as an S cell. Therefore, feedback generated by LTE in an LAA cell as an S cell should only be sent from the P cell, and in the LAA cell, downward subframes and upward subframes can be freely applied. Unless described separately in the description, LTE can be considered to include all LTE evolution technologies, such as LTE-A and LAA.

[0365] On the other hand, the new radio access technology (NR) as an ultra-LTE communication system, that is, the 5G wireless cellular communication system (referred to as "5G" in the description) needs to freely reflect the various needs of users and service providers, and thus can support services that meet various requirements.

[0366] Therefore, 5G can be defined as a network with a maximum terminal transmission speed of 20Gbps, a maximum terminal speed of 500km / h, a maximum delay time of 0.5ms, and 1,000,000 UE / km. 2 Among the requirements for terminal connection density, technologies that meet the requirements for various 5G-oriented service selections, such as enhanced mobile broadband (eMBB, hereinafter referred to as "eMBB" in this specification), massive machine type communication (mMTC, hereinafter referred to as "mMTC" in this specification), and ultra-reliable and low-latency communication (URLLC, hereinafter referred to as "URLLC" in this specification).

[0367] For example, to provide eMBB in 5G, from the perspective of a base station, it is necessary to provide a maximum terminal transmission speed of 20 Gbps via the downlink and a maximum terminal transmission speed of 10 Gbps via the uplink. At the same time, the average terminal transmission speed for body sensing should be increased. To meet the above requirements, there is a need for improved transmission / reception technologies, including more advanced multiple-input multiple-output (MIMO) transmission technologies.

[0368] Furthermore, to support application services such as the Internet of Things (IoT) in 5G, mMTC is being considered. To effectively provide IoT, mMTC requires large-scale terminal connection support, terminal coverage improvement, improved battery life, and terminal cost reduction. Because IoT is attached to several sensors and various machines to provide communication functions, it is necessary to support a large number of terminals (e.g., 1,000,000 UE / km) in a cell. 2 In addition, due to the nature of the service, there is a high probability that the terminal is located in a shadowed area, such as underground in a building or in an area not covered by a cell, so wider coverage than that provided by eMBB is required. There is a high probability that mMTC is configured for inexpensive terminals, and because it is difficult to frequently replace the terminal's battery, a very long battery life is required.

[0369] Finally, in the case of URLLC, which is cellular-based wireless communication for a specific purpose, it is a service for remote control of robots or machine devices, industrial automation, unmanned aerial vehicles, remote health care, and emergency alerts, and therefore needs to provide communication with low latency and ultra-reliability. For example, URLLC should meet a maximum delay time shorter than 0.5 milliseconds and also should meet a packet error rate equal to or lower than 10-5. Therefore, for URLLC, a transmission time interval shorter than the transmission time interval (TTI) of 5G services such as eMBB should be provided, and the design requires that wide resources should be allocated in the frequency band.

[0370] As described above, the services considered in the 5G wireless cellular communication system should be provided as a framework. That is, for efficient resource management and control, it is preferred that each service is not operated independently, but is controlled and transmitted as an integrated system.

[0371] Figure 2B Illustration of services considered in 5G to be transmitted and multiplexed through a system.

[0372] refer to Figure 2B , the frequency-time resource 2b-01 used by 5G includes the frequency axis 2b-02 and the time axis 2b-03. Figure 2B In this specification, eMBB 2b-05, mMTC 2b-06, and URLLC 2b-07 are operated by a 5G base station within a single framework. Furthermore, as a service that can be considered separately in 5G, an enhanced mobile broadcast / multicast service (eMBMS) 2b-08 for providing a cellular-based broadcast service is provided.

[0373] Services considered in 5G, such as eMBB 2b-05, mMTC 2b-06, URLLC 2b-07, and eMBMS 2b-08, can be multiplexed and transmitted via time division multiplexing (TDM) or frequency division multiplexing (FDM) within a system frequency bandwidth operated by 5G, and spatial division multiplexing may also be considered. For eMBB 2b-05, the maximum frequency bandwidth is transmitted at a specific time to provide increased data transmission speeds. Therefore, within the eMBB 2b-05 service, it is TDM-multiplexed with other services within the system transmission bandwidth 2b-01, and it is also TDM-multiplexed with other services within the system transmission bandwidth required by other services.

[0374] Compared to other services, mMTC 2b-06 requires increased transmission intervals to ensure wide coverage. This can be achieved by retransmitting the same packet within the transmission interval. To reduce terminal complexity and cost, the transmission bandwidth that can be received by the terminal is limited. To address this requirement, mMTC 2b-06 is FDM-multiplexed with other services within the 5G transmission system bandwidth 2b-01.

[0375] To meet the low latency requirements of the service, URLLC 2b-07 has a short TTI compared to other services. To meet ultra-reliability requirements, a low coding rate and wide bandwidth are required. Considering the requirements of URLLC 2b-07, URLLC 2b-07 is TDM-multiplexed with other services within the 5G transmission system bandwidth 2b-01.

[0376] To meet the needs of each service, each service as described above may have different transmission / reception technologies and transmission / reception parameters. For example, each service may have different numerology based on the service requirements. Here, numerology includes the cyclic prefix (CP) length, subcarrier spacing, OFDM symbol length, and time interval (TTI) in OFDM or Orthogonal Frequency Division Multiple Access (OFDMA)-based communication systems.

[0377] As an example of a service having different numerology, eMBMS 2b-08 can have a long CP length compared to other services. Because eMBMS 2b-08 sends a broadcast-based upper-level service, the same data can be sent in all cells. In this case, as seen from the terminal, if the signals received from multiple cells arrive within the CP length, the terminal can receive and decode all signals, and therefore, a single frequency network (SFN) diversity gain can be obtained. Even terminals located on the boundary can receive broadcast information without coverage limitations. However, if the CP length is relatively long compared to other services, waste due to CP overhead occurs. A long OFDM symbol length compared to other services is required, and therefore, a narrow subcarrier spacing compared to other services is required.

[0378] As another example of using different numerologies between services in 5G, for URLLC, due to the need for a short TTI, a shorter OFDM symbol length is required compared to other services, and a wider subcarrier spacing may be required.

[0379] As described above, in order to meet various requirements in 5G, the necessity of various services is described, and the needs of services considered illustratively are described.

[0380] Considering that the frequency range of 5G operation reaches several GHz to tens of GHz, and in the low-frequency several-GHz band, frequency division duplexing is preferred to TDD, and in the high-frequency tens-GHz band, TDD is considered more appropriate than FDD. However, in contrast to FDD, which seamlessly provides uplink / downlink transmission resources by arranging separate frequencies for uplink / downlink transmission, TDD should support both uplink / downlink transmission on a single frequency and provide only uplink resources or only downlink resources depending on the time.

[0381] If it is assumed that URLLC uplink transmission or downlink transmission is required in TDD, it becomes difficult to meet the low latency requirement required by URLLC due to the time delay until uplink or downlink resources appear. Therefore, for TDD, in order to meet the low latency requirement of URLLC, a method for dynamically changing the subframe up or down depending on whether URLLC data is up or down is required.

[0382] However, even for services and technologies beyond 5G Phase 2 or beyond 5G reused in 5G, 5G Phase 2 or beyond 5G technologies and services must be provided so that there are no backward compatibility issues when operating previous 5G technologies. This requirement is called forward compatibility, and technologies for satisfying forward compatibility should be considered when designing initial 5G.

[0383] In the initial LTE standardization phase, forward compatibility considerations were not prepared, and therefore, there may be limitations on providing new services within the LTE framework. For example, in enhanced machine type communication (eMTC) applied in LTE Release-13, communication becomes possible only in a frequency corresponding to 1.4 MHz, regardless of the system bandwidth provided by the serving cell, in order to reduce the cost of the terminal by reducing the complexity of the terminal. Therefore, since a terminal supporting eMTC cannot receive a PDCCH transmitted over the full frequency band of the existing system bandwidth, it cannot receive a signal during the time interval in which the PDCCH is transmitted.

[0384] Therefore, the 5G communication system should be designed so that services to be considered after the 5G system can coexist efficiently with the 5G communication system. In the 5G communication system, for future compatibility, resources can be freely allocated and transmitted so that services to be considered later can be freely transmitted in the time-frequency resource region supported by the 5G communication system. In order to support future compatibility in the 5G communication system, a method for freely allocating time-frequency resources is required.

[0385] Figure 2C and Figure 2D The communication system to which the present disclosure is applied is shown in FIG. The solution proposed in the present disclosure can be applied to Figure 2C system and Figure 2D of the system both.

[0386] refer to Figure 2C , the upper part illustrates a 5G cell 2c-02 operating in a standalone manner in one base station 2c-01. Terminal 2c-04 is a 5G-capable terminal with a 5G transmit / receive module. Terminal 2c-04 acquires synchronization through a synchronization signal transmitted from the 5G standalone cell 2c-01, receives system information, and then attempts random access to the 5G base station 2c-01. Terminal 2c-04, after completing the RRC connection with the 5G standalone base station 2c-11, additionally configures a 5G non-standalone cell 2c-15, and transmits and receives data through the 5G standalone base station 2c-11 or the 5G non-standalone base station 2c-12.

[0387] Assume that the duplex type of the 5G standalone base station 2c-11 or the 5G non-standalone base station 2c-12 is not restricted, and the 5G standalone base station 2c-11 and the 5G non-standalone base station 2c-12 are connected together via an ideal backhaul network or a non-ideal backhaul network. Therefore, when the ideal backhaul network 2c-13 is connected, fast X2 communication 2c-13 between the base stations becomes possible.

[0388] exist Figure 2C In the system shown in the lower part of the figure, the 5G cell can provide multiple service cells.

[0389] refer to Figure 2D The upper portion illustrates an LTE cell 2d-02 and a 5G cell 2d-03 coexisting in a base station 2d-01 in the network. Terminal 2d-04 may be an LTE-capable terminal having an LTE transmit / receive module, a 5G-capable terminal having a 5G transmit / receive module, or a terminal having both an LTE transmit / receive module and a 5G transmit / receive module.

[0390] Terminal 2d-04 acquires synchronization via a synchronization signal transmitted from LTE cell 2d-04 or 5G cell 2d-03, receives system information, and then transmits / receives data via base station 2d-01 and LTE cell 2d-02 or 5G cell 2d-03. The duplex type of LTE cell 2d-02 or 5G cell 2d-03 is not restricted. If the LTE cell is a P cell, uplink control transmission is performed via LTE cell 2d-02, and if the 5G cell is a P cell, uplink control transmission is performed via 5G cell 2d-03.

[0391] exist Figure 2D In the system shown in the upper part of the figure, LTE cells and 5G cells can be provided with multiple serving cells, and a total of 32 serving cells can be supported. It is assumed that in the network, base station 2d-01 is provided with both an LTE transmission / reception module (system) and a 5G transmission / reception module (system), and base station 2d-01 can manage and operate the LTE system and the 5G system in real time.

[0392] For example, when the LTE system and the 5G system operate at different times by dividing resources in time, the allocation of time resources of the LTE system and the 5G system can be dynamically selected. Terminal 2d-04 can know which resources are used to perform data reception from LTE cell 2d-02 and 5G cell 2d-03 by receiving a signal indicating the allocation of resources (time resources, frequency resources, antenna resources, or spatial resources) divided by the LTE cell and the 5G cell.

[0393] Figure 2DThe lower portion of the figure illustrates the installation of an LTE macro base station 2d-11 for wide coverage in the network and a 5G small base station 2d-12 for increased data throughput. The terminal 2d-14 can be an LTE-capable terminal having an LTE transmit / receive module, a 5G-capable terminal having a 5G transmit / receive module, or a terminal having both an LTE transmit / receive module and a 5G transmit / receive module.

[0394] Terminal 2d-14 acquires synchronization via a synchronization signal transmitted from LTE base station 2d-11 or 5G base station 2d-12, receives system information, and then transmits / receives data via LTE base station 2d-11 or 5G base station 2d-12. The duplex type of LTE macro base station 2d-11 or 5G small base station 2d-12 is not limited. If the LTE cell is a P cell, uplink control transmission is performed via LTE cell 2d-11, and if the 5G cell is a P cell, uplink control transmission is performed via 5G cell 2d-12.

[0395] Assume that LTE base station 2d-11 and 5G base station 2d-12 have an ideal backhaul network or a non-ideal backhaul network. Therefore, when an ideal backhaul network 2c-13 is connected, fast X2 communication 2c-13 between the base stations becomes possible. Even if only uplink transmission is performed with respect to LTE base station 2d-11, 5G base station 2d-12 can receive relevant control information from LTE base station 2d-11 in real time via X2 communication 2d-13.

[0396] exist Figure 2D In the system illustrated in the lower portion of FIG, , LTE cells and 5G cells can be provided with multiple serving cells, and a total of 32 serving cells can be supported. Base station 2d-11 or 2d-12 can manage and operate the LTE system and 5G system in real time. For example, when operating the LTE system and 5G system at different times by dividing resources in time, the allocation of time resources for the LTE system and 5G system can be dynamically selected, and a signal can be sent to another base station 2d-12 via X2.

[0397] Terminal 2d-14 can know what resources are used to perform data transmission / reception from LTE cell 2d-11 and 5G cell 2d-12 by receiving a signal indicating the allocation of resources (time resources, frequency resources, antenna resources or space resources) operated separately by the LTE cell and the 5G cell.

[0398] However, when the LTE base station 2d-11 and the 5G base station 2d-12 have a non-ideal backhaul network 2d-13, fast X2 communication 2d-13 between the base stations becomes impossible. Therefore, the base station 2d-11 or 2d-12 can semi-statically operate the LTE system and the 5G system.

[0399] For example, when the base station 2d-11 operates the LTE system and the 5G system at different times by dividing resources in time, the allocation of time resources of the LTE system and the 5G system is selected, and a signal is sent in advance to another base station 2d-12 to make it possible to distinguish resources between the LTE system and the 5G system. The terminal 2d-14 can know which resources are used to perform data transmission / reception from the LTE cell 2d-11 and the 5G cell 2d-12 by receiving a signal indicating the allocation of resources (time resources, frequency resources, antenna resources or spatial resources) dividedly operated by the LTE cell and the 5G cell from the LTE base station 2d-11 or the 5G base station 2d-12.

[0400] To explain the methods and devices proposed in the embodiments, the terms "physical channel" and "signal" may be used in the prior art LTE or LTE-A systems. However, the present disclosure may also be applied to wireless communication systems excluding LTE and LTE-A systems.

[0401] The embodiments of the present disclosure may be applied to FDD or TDD systems and may also be applied to new types of duplex modes (eg, LTE frame structure type 3).

[0402] Hereinafter, upper layer signaling or upper layer signal indicates a signal transmission method from a base station to a terminal using a downlink data channel of a physical layer, or a signal transmission method from a terminal to a base station using an uplink data channel of a physical layer, and refers to transmission between a base station and a terminal through at least one method of RRC signaling, Packet Data Convergence Protocol (PDCP) signaling, and MAC CE.

[0403] Figure 2E The following illustrates a situation to be handled according to an embodiment of the present disclosure.

[0404] refer to Figure 2E , a network, a base station or a cell may use a partial frequency bandwidth or a frequency resource area, for example, a frequency resource area equal to or smaller than the entire bandwidth 2e-00, such as 2e-02 and 2e-02, in a wireless resource area predefined for performing mobile communication with the terminal for the entire downlink or uplink frequency band 2e-00 to perform communication with the terminal.

[0405] For example, when a base station and a terminal that can communicate by adaptively changing the frequency bandwidth perform communication with each other, or when a base station and a terminal that can communicate by adaptively using at least one bandwidth perform communication with each other, the terminal can configure one or more frequency bands for communication from the base station. More specifically, the terminal can transmit the supportability (or UE performance) for the minimum or maximum frequency bandwidth that can be supported by the terminal itself, all supportable frequency resource areas, or some frequency resources in the frequency band 2e-00 to the base station via RRC signaling.

[0406] A base station that has received information about frequency bandwidths or UE capabilities that can be supported by a terminal can configure one or more different frequency bandwidths among the frequency bandwidths used to perform downlink or uplink transmissions to the terminal through RRC configuration information. The terminal can receive from the base station at least one frequency bandwidth (e.g., minimum frequency bandwidth) transmitted through a master information block (MIB) or a system information block (SIB) among the frequency bandwidths used to perform downlink or uplink transmissions with the base station. At least one frequency bandwidth (e.g., minimum frequency bandwidth) can also be predefined among the frequency bandwidths used to perform downlink or uplink transmissions to the base station relative to the carrier frequency used to perform communication, or the bandwidth of a synchronization signal received from the base station in a frequency band can be determined as at least one frequency bandwidth (e.g., minimum frequency bandwidth) among the frequency bandwidths used to perform downlink or uplink transmissions with the base station.

[0407] For ease of explanation, when performing communication between a base station and a terminal, the minimum frequency bandwidth that the base station has configured for the terminal among the used frequency bandwidths is referred to as the first frequency bandwidth, and a frequency bandwidth having a bandwidth wider than the first frequency bandwidth is referred to as the second frequency bandwidth. Although the explanation will be made assuming that two different frequency bandwidths are used, it is obvious that the technology proposed in the present disclosure is not limited thereto.

[0408] If the terminal has a minimum frequency region, the terminal can generally minimize the power consumption required for the terminal to perform signal processing, such as control signal reception and decoding and data signal reception and decoding. Therefore, when performing communication with a base station, compared to using a single frequency bandwidth (e.g., maximum frequency bandwidth) to transmit and receive signals at the terminal, it is preferable to minimize the power consumption of the terminal by minimizing the frequency bandwidth used to perform communication. However, if the frequency bandwidth is minimized, the data throughput becomes lower when using broadband to transmit or receive signals. Therefore, the frequency bandwidth can be adaptively changed in consideration of data throughput and power consumption.

[0409] In general, the terminal receives a control channel transmitted from the base station and receives a downlink signal based on the received control information. Information about the location or search space of the control channel transmitted by the base station can be predefined or can be configured for the terminal via an upper layer signal from the base station, a broadcast channel (e.g., PBCH), or a channel for transmitting system information (e.g., SIB).

[0410] When the base station sends downlink control information through a control channel, it can be predefined or configured from the base station to the terminal so that control information sent only to one terminal, control information sent publicly to at least one terminal or a group composed of terminals, and control information sent to all terminals performing communication with the base station are sent through different search spaces.

[0411] More specifically, the terminal can receive all or at least one of the time or frequency location information of the search space for control information and common control information (common control channel, cell-specific control channel or common control channel) sent by the base station to a group of terminals or specific terminals through MIB or SIB.

[0412] In order to perform communication with the base station, the terminal can receive all or at least one of time or frequency information of the search space used for the control channel (UE-specific control channel or UE-specific control channel) sent by the base station to the terminal through the MIB or SIB.

[0413] When configuring the search space position, at least one of the MIB, SIB, and RRC signal may include at least one of the time or frequency position information for the search space. The time or frequency position information for the search space may be predefined between the base station and the terminal, or the terminal may configure the search space by at least one value of a control channel element (CCE) index, a PRB index, and a subband index based on at least one of a frequency band with the smallest frequency bandwidth among the frequency bandwidth configured from the base station and the center frequency of the frequency band. In addition, the time or frequency position information for the search space may be predefined between the base station and the terminal, or the terminal may configure the search space by a positive / negative offset value based on at least one of a lowest CCE index, a lowest PRB index, and a lowest subband index of a frequency band with the smallest frequency bandwidth among the frequency bandwidth configured from the base station. In addition, the time or frequency position information for the search space may be predefined between the base station and the terminal, or the terminal may configure the search space by a positive / negative offset value based on the center frequency of a frequency band with the smallest frequency bandwidth among the frequency bandwidth configured from the base station.

[0414] When the search space position for the common control channel or the terminal's inherent control channel is configured through MIB, SIB or RRC signal, the terminal can receive information indicating a change (or increase) in the frequency bandwidth or frequency region from the base station, or the terminal that has determined that a change in the frequency band is required should reconfigure the common control channel in the changed frequency bandwidth or reconfigure the search space position for the terminal's inherent control channel.

[0415] Here, the search space location for the common control channel or the terminal-specific control channel signaled via the MIB, SIB, or RRC signal is referred to as the first search space, and the search space location for the common control channel or the terminal-specific control channel after the terminal frequency bandwidth is changed is referred to as the second search space. Alternatively, the search space for the first frequency bandwidth may be referred to as the first search space, and the search space for the second frequency bandwidth may be referred to as the second search space.

[0416] Figure 2F and Figure 2G The diagram illustrates a method proposed according to an embodiment of the present disclosure.

[0417] Method 1-1: If Figure 2F As shown, if the first frequency bandwidth is completely included in the second frequency band, the terminal can determine that the first search space and the second search space are at the same location. That is, the physical resource location from which the control channel is received is the same as the frequency location.

[0418] Method 1-2: If Figure 2F As shown, if the first frequency bandwidth is completely included in the second frequency band, the terminal can determine that the common control channel of the first search space and the common control channel of the second search space are in the same position. That is, the physical resource location from which the control channel is received is the same as the frequency location. The terminal can configure the terminal-specific control channel of the first search space and the terminal-specific control channel of the second search space differently from each other. For example, the search space for the terminal-specific control channel of the second search space can be configured by adding a positive / negative offset value to the first search space. The offset value can be predefined according to the change in frequency bandwidth, or the base station can send a signal for requesting a bandwidth change to the terminal.

[0419] Method 1-3: If at least a portion of the first frequency bandwidth is not included in the second frequency band, the terminal may determine that the first search space and the second search space are different locations.

[0420] The terminal may configure the second search space by, for example, at least one value of a CCE index transmitted via an MIB, SIB, or RRC signal. For example, the terminal may configure the second search space based on the center frequency of a frequency band in a second frequency bandwidth that has been configured for the terminal by the base station, by at least one value of a CCE index, a PRB index, or a subband index received via an MIB / SIB / RRC signal. A position corresponding to a CCE index, a PRB index, or a subband index received via an MIB / SIB / RRC signal based on at least one of the lowest CCE index, the lowest PRB index, and the lowest subband index of the second frequency bandwidth may be considered as the second search space, or the second search space may be configured by a received positive / negative offset value.

[0421] Method 2: If the base station configures a frequency bandwidth change for the terminal, the second search space information is included in the configuration information to be transmitted, and therefore, the terminal can determine the second search space location by receiving the configuration information. The configuration information may only include search space information (at least one of CCE index, PRB index, subband index, and offset) for UE-specific control channels within the second search space. The terminal can determine that the search space for common control channels in the second frequency band is the same as the first search space.

[0422] In the same manner as the change in the downlink frequency bandwidth, the uplink frequency bandwidth can also be changed. The terminal can transmit channel information including decoding success / failure (ACK / NACK) of the downlink data channel received from the base station via PUCCH transmission, and periodic or non-periodic channel information to the base station. The terminal can receive a plurality of PUCCH resources for performing PUCCH transmission configured from the base station via an RRC signal. The physical resources for PUCCH transmission can be configured from the base station via a downlink control channel. Therefore, if a change in the uplink frequency bandwidth is required, for example, when the frequency bandwidth or frequency is changed because the frequency band is wider than the first frequency band or when uplink transmission in another frequency band is required (for example, SRS transmission), it is also necessary to reconfigure the PUCCH transmission resources (second PUCCH resources) pre-configured by the upper layer signal.

[0423] Method 3-1: If Figure 2G As shown, if the first frequency bandwidth is completely included in the second frequency band, the terminal can determine that the first PUCCH resource and the second PUCCH resource are in the same position. That is, the physical resource position from which the PUCCH is transmitted is the same as the frequency position.

[0424] Method 3-2: If at least a portion of the first frequency bandwidth is not included in the frequency band, the terminal may determine the second PUCCH resource by applying a variable used during configuration of the first PUCCH resource to the second frequency band.

[0425] Method 4: The terminal may determine the second PUCCH resource by scaling and applying a variable used during configuration of the first PUCCH resource to the second frequency band according to a ratio of the first frequency bandwidth to the second frequency bandwidth.

[0426] For example, to configure a first PUCCH resource in a first frequency bandwidth, a configuration variable, such as a PUCCH resource list value, is configured as {0, 10, 30, 500}. If the second frequency bandwidth is twice the first frequency bandwidth, the second PUCCH resource can be configured as {0, 29, 60, 1000} obtained by scaling the variable used to configure the first PUCCH resource. If the maximum value of the variable used to configure the PUCCH transmission resource is fixed to N, the PUCCH resource value can be configured by additionally performing a modulo operation for scaling so that it is always equal to or less than N. For example, if the number N is N=549, the second PUCCH resource can be configured as {0, 20, 60, 451}.

[0427] Method 5: If the base station configures a frequency bandwidth change for the terminal, the second PUCCH resource information is included in the configuration information to be transmitted, and thus the terminal can receive the configuration information and can determine the second PUCCH resource information. The second PUCCH resource information included in the configuration information may include at least one of a scaling factor and an offset value for the first PUCCH resource information, and the terminal that has received the configuration information can configure the second PUCCH resource by applying the information to the first PUCCH resource.

[0428] On the other hand, the embodiments of the present disclosure have been presented to help those skilled in the art to gain a comprehensive understanding of the present disclosure, and do not limit the scope of the present disclosure. It is obvious to those skilled in the art in the field to which the present disclosure belongs that various modifications based on the technical concepts of the present disclosure are possible in addition to the embodiments disclosed herein. In addition, if necessary, the various embodiments can be combined with each other to operate. For example, the various parts of the various embodiments of the present disclosure can be combined with each other to be operated by a base station and a terminal. In addition, although the above embodiments are presented based on the NR system, they can be applied to other systems, such as FDD or TDD LTE systems, and other modifications based on the technical concepts of the embodiments can be specifically implemented.

[0429] Although preferred embodiments of the present disclosure have been described in the specification and drawings and specific terms have been used, this is merely a general meaning to help those skilled in the art gain a comprehensive understanding of the present disclosure and does not limit the scope of the present disclosure. It will be apparent to those skilled in the art that various modifications based on the technical concepts of the present disclosure in addition to the embodiments disclosed herein are possible.

[0430] On the other hand, the embodiments of the present disclosure have been presented to help ordinary technicians in this field to gain a comprehensive understanding of the present disclosure, and do not limit the scope of the present disclosure. It is obvious to ordinary technicians in the field to which the present disclosure belongs that various modifications based on the technical concepts of the present disclosure in addition to the embodiments disclosed here are possible. In addition, the various embodiments can be combined with each other to operate. For example, parts of embodiments 3-1 and 3-2 of the present disclosure or parts of embodiments 3-3 and 3-4 can be combined with each other to be operated by a base station and a terminal. In addition, although the above embodiments are presented based on an FDD LTE system, they can be applied to other systems, such as a TDD LTE system and a 5G or NR system, and other modifications based on the technical concepts of the embodiments can be specifically implemented.

[0431] As described above, in the present disclosure, the uplink scheduling grant signal and the downlink data signal are referred to as first signals, and the uplink data signal for the uplink scheduling grant and the HARQ ACK / NACK for the downlink data signal are referred to as second signals. However, the types of first and second signals described above are merely exemplary to facilitate explanation of the technical content of the present disclosure and to aid understanding of the present disclosure, but are not intended to limit the scope of the present disclosure. In other words, it is obvious to a person skilled in the art to which the present disclosure pertains that other first and second signals can be specifically implemented based on the technical concepts of the present disclosure.

[0432] While the present disclosure has been particularly shown and described with reference to certain embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the present disclosure as defined by the following claims and their equivalents.

Claims

1. A method performed by a terminal in a communication system, the method comprising: Receiving information about the number of code block groups CBG of a transport block TB from a base station via higher layer signaling, wherein the CBG includes one or more code blocks CB of the TB; identifying the number of the CBGs of the TB based on the information about the number of the CBGs; Receiving downlink control information (DCI) for scheduling downlink data transmission from a base station, wherein the DCI includes a new data indicator (NDI) and a CBG indicator; receiving data corresponding to the TB from a base station based on the DCI; determining, based on the NDI, whether the data corresponds to an initial transmission of the TB or a retransmission of the TB; decoding received data including the CBG in case the data corresponds to an initial transmission of the TB; and In a case where the data corresponds to a retransmission of the TB, received data including one or more of the CBGs is decoded based on the CBG indicator, wherein each bit of the CBG indicator indicates whether a corresponding CBG of the TB is present in the received data.

2. The method of claim 1, further comprising: identifying a hybrid automatic repeat request (HARQ)-ACK bit corresponding to the CBG or each of the one or more CBGs in the received data; as well as sending HARQ-ACK information including the HARQ-ACK bit to the base station, The number of bits of the HARQ-ACK information is equal to the number of CBGs.

3. The method according to claim 1, wherein The bit length of the CBG indicator for the TB is based on information about the number of the CBGs of the TB.

4. The method according to claim 1, wherein The DCI also includes an indicator indicating whether the one or more CBGs included in the received data and a previously received CBG are combinable.

5. The method according to claim 4, wherein: Decoding the received data including the one or more CBGs further comprises: If the indicator indicates that the one or more CBGs and the previously received CBG are combinable, combining the one or more CBGs with the previously received CBG; and Decode the combined CBG.

6. The method of claim 4, wherein: Decoding the received data including the one or more CBGs further comprises: If the indicator indicates that the one or more CBGs and the previously received CBG are not combinable, discarding the previously received CBG; and The one or more CBGs are decoded.

7. The method of claim 1, wherein: In case the received data corresponds to an initial transmission, the received data is decoded without regard to the CBG indicator.

8. A method performed by a base station in a communication system, the method comprising: Sending information about the number of code block groups CBG of a transport block TB to the terminal via higher layer signaling, wherein the CBG includes one or more code blocks CB of the TB; Sending downlink control information DCI for scheduling downlink data transmission to the terminal, wherein the DCI includes a new data indicator NDI and a CBG indicator; and Sending data corresponding to the TB to the terminal, Wherein, in a case where the NDI indicates that the data corresponds to an initial transmission of the TB, the data includes the CBG of the TB; and Wherein, in a case where the NDI indicates that the data corresponds to a retransmission of the TB, the data includes one or more CBGs in the CBGs, wherein each bit of the CBG indicator indicates whether a corresponding CBG of the TB is present in the data.

9. The method of claim 8, further comprising receiving HARQ-ACK information including a hybrid automatic repeat request HARQ-ACK bit from a terminal, the HARQ-ACK bit corresponding to the CBG of the data or each of the one or more CBGs, respectively. in, The number of bits of the HARQ-ACK information is equal to the number of CBGs.

10. The method of claim 8, wherein: The bit length of the CBG indicator for the TB is associated with information about the number of the CBGs of the TB.

11. The method of claim 8, wherein: The DCI includes an indicator indicating whether the one or more CBGs and a previously transmitted CBG are combinable.

12. A terminal in a communication system, the terminal comprising: transceiver; as well as The controller is configured as: receiving, via a transceiver, information about the number of code block groups CBG of a transport block TB from a base station via higher layer signaling, wherein the CBG includes one or more code blocks CB of the TB, identifying the number of the CBGs of the TB based on the information about the number of the CBGs, Receiving, via a transceiver, downlink control information (DCI) for scheduling downlink data transmission from a base station, wherein the DCI includes a new data indicator (NDI) and a CBG indicator, receiving, via a transceiver, data corresponding to the TB from a base station based on the DCI, determining whether the data corresponds to an initial transmission of the TB or a retransmission of the TB based on the NDI, decoding the received data including the CBG in case the data corresponds to an initial transmission of the TB, and In a case where the data corresponds to a retransmission of the TB, received data including one or more of the CBGs is decoded based on the CBG indicator, wherein each bit of the CBG indicator indicates whether a corresponding CBG of the TB is present in the received data.

13. The terminal according to claim 12, wherein: The controller is further configured to: identifying a hybrid automatic repeat request (HARQ)-ACK bit corresponding to the CBG or each of the one or more CBGs, respectively, in the received data; and sending, via the transceiver, HARQ-ACK information including the HARQ-ACK bits to a base station, The number of bits of the HARQ-ACK information is equal to the number of CBGs. The terminal according to claim 12 , wherein: The bit length of the CBG indicator for the TB is based on information about the number of the CBGs of the TB. The terminal according to claim 12 , wherein: The DCI also includes an indicator indicating whether the one or more CBGs included in the received data and a previously received CBG are combinable. The terminal according to claim 15 , wherein: The controller is further configured to: If the indicator indicates that the one or more CBGs and the previously received CBG are combinable, combining the one or more CBGs with the previously received CBG; as well as Decode the combined CBG. The terminal according to claim 15 , wherein: The controller is further configured to: If the indicator indicates that the one or more CBGs and the previously received CBG are not combinable, discarding the previously received CBG; as well as The one or more CBGs are decoded.

18. The terminal according to claim 12, wherein: In case the received data corresponds to an initial transmission, the received data is decoded without regard to the CBG indicator.

19. A base station in a communication system, the base station comprising: transceiver; as well as The controller is configured as: sending, via a transceiver, information about the number of code block groups CBG of a transport block TB to a terminal via higher layer signaling, wherein the CBG includes one or more code blocks CB of the TB, Sending, via the transceiver, downlink control information DCI for scheduling downlink data transmission to the terminal, wherein the DCI includes a new data indicator NDI and a CBG indicator, and Sending data corresponding to the TB to the terminal via the transceiver, Wherein, in a case where the NDI indicates that the data corresponds to an initial transmission of the TB, the data includes the CBG of the TB; and Wherein, in a case where the NDI indicates that the data corresponds to a retransmission of the TB, the data includes one or more CBGs in the CBGs, wherein each bit of the CBG indicator indicates whether a corresponding CBG of the TB is present in the data.

20. The base station according to claim 19, wherein: The controller is further configured to receive, from the terminal via the transceiver, HARQ-ACK information including hybrid automatic repeat request HARQ-ACK bits, the HARQ-ACK bits corresponding to the CBG of the data or each of the one or more CBGs, respectively. The number of bits of the HARQ-ACK information is equal to the number of CBGs.

21. The base station according to claim 19, wherein The bit length of the CBG indicator for the TB is associated with information about the number of the CBGs of the TB.

22. The base station according to claim 19, wherein The DCI includes an indicator indicating whether the one or more CBGs and a previously transmitted CBG are combinable.

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