Patent Application
20230164847
The disclosure relates to a communication system, and provides a method and an apparatus in which, when a terminal is capable of supporting both terrestrial network communication and satellite communication, the terminal operates differently depending on whether signal transmission or reception is performed in a situation of terrestrial communication or in a situation of satellite communication.
To meet the demand for wireless data traffic having increased since deployment of 4G communication systems, efforts have been made to develop an improved 5G or pre-5G communication system. Therefore, the 5G or pre-5G communication system is also called a “beyond 4G network” communication system or a “post LTE” system. The 5G communication system is considered to be implemented in ultrahigh frequency (mmWave) bands (e.g., 60 GHz bands) so as to accomplish higher data rates. To decrease propagation loss of the radio waves and increase the transmission distance in the ultrahigh frequency bands, beamforming, massive multiple-input multiple-output (massive MIMO), full dimensional MIMO (FD-MIMO), array antenna, analog beam forming, large scale antenna techniques are discussed in 5G communication systems. In addition, in 5G communication systems, development for system network improvement is under way based on advanced small cells, cloud radio access networks (cloud RANs), ultra-dense networks, device-to-device (D2D) communication, wireless backhaul, moving network, cooperative communication, coordinated multi-points (CoMP), reception-end interference cancellation and the like. In the 5G system, hybrid FSK and QAM modulation (FQAM) and sliding window superposition coding (SWSC) as an advanced coding modulation (ACM), and filter bank multi carrier (FBMC), non-orthogonal multiple access (NOMA), and sparse code multiple access (SCMA) as an advanced access technology have also been developed.
The Internet, which is a human centered connectivity network where humans generate and consume information, is now evolving to the Internet of things (IoT) where distributed entities, such as things, exchange and process information without human intervention. The Internet of everything (IoE), which is a combination of the IoT technology and the big data processing technology through connection with a cloud server, has emerged. As technology elements, such as “sensing technology”, “wired/wireless communication and network infrastructure”, “service interface technology”, and “security technology” have been demanded for IoT implementation, a sensor network, a machine-to-machine (M2M) communication, machine type communication (MTC), and so forth have been recently researched. Such an IoT environment may provide intelligent Internet technology (IT) services that create a new value to human life by collecting and analyzing data generated among connected things. IoT may be applied to a variety of fields including smart home, smart building, smart city, smart car or connected cars, smart grid, health care, smart appliances and advanced medical services through convergence and combination between existing information technology (IT) and various industrial applications.
In line with this, various attempts have been made to apply 5G communication systems to IoT networks. For example, technologies such as a sensor network, machine type communication (MTC), and machine-to-machine (M2M) communication may be implemented by beamforming, MIMO, and array antennas. Application of a cloud radio access network (cloud RAN) as the above-described big data processing technology may also be considered an example of convergence of the 5G technology with the IoT technology.
In the late 2010s and 2020s, as the cost of launching satellites is dramatically decreased, more companies have been trying to provide communication services through satellites. Accordingly, the satellite network has emerged as a next-generation network system for supplementing the existing terrestrial network. Although the satellite network does not provide a terrestrial network-level user experience, the satellite network can provide communication services in an area in which terrestrial networks are difficult to be built or in disaster situations. As described above, economic feasibility is secured through a recent sharp decrease in satellite launch costs. Some companies and 3GPP organizational partners are also promoting direct communication between smartphones and satellites.
The disclosure proposes a method and apparatus for efficiently providing satellite network communication to a terminal.
In order to solve the above problems, a method performed by a terminal in a communication system according to an embodiment of the disclosure includes: determining whether the terminal performs terrestrial network communication or satellite network communication; determining an antenna used for transmission or reception based on the determination; and performing communication using the antenna, wherein in case that the satellite network communication is determined to be performed, an antenna, which is included in the terminal and is close to a location of a satellite relating to the satellite network communication, is used to perform the communication.
In addition, a terminal in a communication system includes: a transceiver; and a controller configured to determine whether the terminal performs terrestrial network communication or satellite network communication, determine an antenna used for transmission or reception based on the determination, and control to perform communication using the antenna, wherein in case that the satellite network communication is determined to be performed, an antenna, which is included in the terminal and is close to a location of a satellite relating to the satellite network communication, is used to perform the communication.
According to the disclosure described above, a terminal can distinguish between terrestrial network communication and satellite communication, whereby efficient signal transmission or reception is possible.
New radio access technology (NR), which is new 5G communication, is designed to enable various services to be freely multiplexed in time and frequency resources. Accordingly, in the NR system, a waveform/numerology or the like, and/or a reference signal or the like may be dynamically or freely allocated according to needs of a corresponding service. In order to provide an optimal service to a terminal in wireless communication, it is required to perform data transmission optimized based on measurements of channel quality and interference. Accordingly, it is essential to accurately measure a channel state. The channel and interference characteristics are not dramatically changed depending on a frequency resource in a 4G communication system. However, unlike the 4G communication system, the channel and interference characteristics of which are not dramatically changed depending on a frequency resource, the channel and interference characteristics are dramatically changed depending on a service in a case of a 5G channel. Accordingly, subset support in a frequency resource group (FRG) dimension may be required in order to separately measure channel and interference characteristics. Meanwhile, the types of services supported in the NR system may be categorized into enhanced mobile broadband (eMBB), massive machine type communications (mMTC), and ultra-reliable and low-latency communications (URLLC). The eMBB may be a service targeting high-speed transmission of high-capacity data. The mMTC may be a service that targets minimizing power consumption by a terminal and access of multiple terminals. URLLC may be a service targeting high-reliability and low-latency. Different requirements may be applied depending on the type of service applied to a terminal.
As described above, a plurality of services may be provided to a user in a communication system, and in order to provide the plurality of services to a user, there is a desire for a method and apparatus for providing respective services in the same time interval according to the characteristics of the communication system.
Hereinafter, embodiments of the disclosure will be described in detail with reference to the accompanying drawings.
In describing the embodiments, descriptions related to technical contents well-known in the art and not associated directly with the disclosure will be omitted. Such an omission of unnecessary descriptions is intended to prevent obscuring of the main idea of the disclosure and more clearly transfer the main idea.
For the same reason, in the accompanying drawings, some elements may be exaggerated, omitted, or schematically illustrated. Further, the size of each element does not completely reflect the actual size. In the drawings, identical or corresponding elements are provided with identical reference numerals.
The advantages and features of the disclosure and ways to achieve them will be apparent by making reference to embodiments as described below in detail in conjunction with the accompanying drawings. However, the disclosure is not limited to the embodiments set forth below, but may be implemented in various different forms. The following embodiments are provided only to completely disclose the disclosure and inform those skilled in the art of the scope of the disclosure, and the disclosure is defined only by the scope of the appended claims. Throughout the specification, the same or like reference numerals designate the same or like elements.
Herein, it will be understood that each block of the flowchart illustrations, and combinations of blocks in the flowchart illustrations, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general purpose computer, special purpose computer, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions specified in the flowchart block or blocks. 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 apparatus to function in a particular manner, such that the instructions stored in the computer usable or computer-readable memory produce an article of manufacture including instruction means that implement the function specified in the flowchart block or blocks. The computer program instructions may also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer implemented process such that the instructions that execute on the computer or other programmable apparatus provide steps for implementing the functions specified in the flowchart block or blocks.
Further, each block of the flowchart illustrations may represent a module, segment, or portion of code, which includes one or more executable instructions for implementing the specified logical function(s). It should also be noted that in some alternative implementations, the functions noted in the blocks may occur out of the order. For example, two blocks shown in succession may in fact be executed substantially concurrently or the blocks may sometimes be executed in the reverse order, depending upon the functionality involved.
As used herein, the “unit” refers to a software element or a hardware element, such as a Field Programmable Gate Array (FPGA) or an Application Specific Integrated Circuit (ASIC), which performs a predetermined function. However, the “unit” does not always have a meaning limited to software or hardware. The “unit” may be constructed either to be stored in an addressable storage medium or to execute one or more processors. Therefore, the “unit” includes, for example, software elements, object-oriented software elements, class elements or task elements, processes, functions, properties, procedures, sub-routines, segments of a program code, drivers, firmware, micro-codes, circuits, data, database, data structures, tables, arrays, and parameters. The elements and functions provided by the “unit” may be either combined into a smaller number of elements, or a “unit”, or divided into a larger number of elements, or a “unit”. Moreover, the elements and “units” or may be implemented to reproduce one or more CPUs within a device or a security multimedia card. Further, the “unit” in the embodiments may include one or more processors.
A wireless communication system is advancing to a broadband wireless communication system for providing high-speed and high-quality packet data services using communication standards, such as high-speed packet access (HSPA) of 3GPP, LTE {long-term evolution or evolved universal terrestrial radio access (E-UTRA)}, LTE-Advanced (LTE-A), LTE-Pro, high-rate packet data (HRPD) of 3GPP2, ultra-mobile broadband (UMB), IEEE 802.16e, and the like, as well as typical voice-based services. Further, 5G or new radio (NR) communication standards as 5th-generation wireless communication systems are under discussion.
As a typical example of the broadband wireless communication system, an NR system employs an orthogonal frequency division multiplexing (OFDM) scheme in a downlink (DL) and an uplink (UL). In the disclosure, the downlink refers to a radio link via which a base station transmits a signal to a terminal, and the uplink refers to a radio link via which a terminal transmits a signal to a base station. More specifically, a cyclic-prefix OFDM (CP-OFDM) scheme is employed in the downlink, and two schemes, that is, CP-OFDM and discrete Fourier transform spreading OFDM (DFT-S-OFDM) scheme, are employed in the uplink. The uplink indicates a radio link through which a user equipment (UE) {or a mobile station (MS)} transmits data or control signals to a base station (or gNode B), and the downlink indicates a radio link through which the base station transmits data or control signals to the UE. The above multiple access scheme separates data or control information of respective users by allocating and operating time-frequency resources for transmitting the data or control information for each user so as to avoid overlapping each other, that is, so as to establish orthogonality.
The NR system employs a hybrid automatic repeat request (HARQ) scheme that retransmits corresponding data in a physical layer if decoding fails at the initial transmission. In the HARQ scheme, if a receiver fails to accurately decode data, the receiver transmits, to a transmitter, information (negative acknowledgement (NACK)) notifying of a decoding failure, so as to allow the transmitter to retransmit the corresponding data in a physical layer. The receiver combines data retransmitted by the transmitter with the previous data, for which decoding has failed, to increase a data reception performance. In addition, if the receiver accurately decodes data, the receiver transmits, to the transmitter, information (acknowledgement (ACK)) notifying of a decoding success, so as to allow the transmitter to transmit new data.
Referring to
A UE before radio resource control (RRC) connection may be configured with an initial bandwidth part (BWP) for initial access from a base station through a master information block (MIB). More specifically, the UE may receive configuration information about a search space and a control resource set (CORESET), in which a physical downlink control channel (PDCCH) for reception of system information required for initial access (which may correspond to remaining system information (RMSI) or system information block 1 (SIB 1)) may be transmitted, through the MIB in an initial access operation. The control resource set (CORESET) and search space, which are configured through the MIB, may be regarded as identity (ID) 0. The base station may notify the UE of configuration information, such as frequency allocation information, time allocation information, and numerology for the control resource set #0 through the MIB. In addition, the base station may notify the UE of configuration information regarding the monitoring periodicity and occasion for the control resource set #0, that is, configuration information regarding the search space #0, through the MIB. The UE may regard the frequency domain configured as the control resource set #0, obtained from the MIB, as an initial BWP for initial access. Here, the identifier (ID) of the initial BWP may be regarded as zero.
The MIB may include the following pieces of information.
MIB Field Descriptions
cellBarred
Value barred means that the cell is barred, as defined in TS 38.304 [20].
dmrs-TypeA-Position
Position of (first) DM-RS for downlink (see TS 38.211 [16], clause 7.4.1.1.2) and uplink (see TS 38.211 [16], clause 6.4.1.1.3).
intraFreqReselection
Controls cell selection/reselection to intra-frequency cells when the highest ranked cell is barred, or treated as barred by the UE, as specified in TS 38.304 [20].
pdcch-ConfigSIB1
Determines a common ControlResourceSet (CORESET), a common search space and necessary PDCCH parameters. If the field ssb-SubcarrierOffset indicates that SIB1 is absent, the field pdcch-ConfigSIB1 indicates the frequency positions where the UE may find SS/PBCH block with SIB1 or the frequency range where the network does not provide SS/PBCH block with SIB1 (see TS 38.213 [13], clause 13).
ssb-SubcarrierOffset
Corresponds to kSSB (see TS 38.213 [13]), which is the frequency domain offset between SSB and the overall resource block grid in number of subcarriers. (See TS 38.211 [16], clause 7.4.3.1).
The value range of this field may be extended by an additional most significant bit encoded within PBCH as specified in TS 38.213 [13].
This field may indicate that this cell does not provide SIB1 and that there is hence no CORESET #0 configured in MIB (see TS 38.213 [13], clause 13). In this case, the field pdcch-ConfigSIB1 may indicate the frequency positions where the UE may (not) find a SS/PBCH with a control resource set and search space for SIB1 (see TS 38.213 [13], clause 13).
subCarrierSpacingCommon
Subcarrier spacing for SIB1, Msg.2/4 for initial access, paging and broadcast SI-messages. If the UE acquires this MIB on an FR1 carrier frequency, the value scs15or60 corresponds to 15 kHz and the value scs30or120 corresponds to 30 kHz. If the UE acquires this MIB on an FR2 carrier frequency, the value scs15or60 corresponds to 60 kHz and the value scs30or120 corresponds to 120 kHz.
systemFrameNumber
The 6 most significant bits (MSB) of the 10-bit System Frame Number (SFN). The 4 LSB of the SFN are conveyed in the PBCH transport block as part of channel coding (i.e. outside the MIB encoding), as defined in clause 7.1 in TS 38.212 [17].
In a method of configuring the bandwidth part, the UEs before the RRC connection may receive configuration information about the initial bandwidth part through the master information block (MIB) in the initial access operation. More specifically, the UE may be configured with a control resource set for a downlink control channel through which downlink control information (DCI) for scheduling a SIB may be transmitted from a MIB of a physical broadcast channel (PBCH). The bandwidth of the control resource set configured through the MIB may be regarded as the initial bandwidth part. The UE may receive, through the configured initial bandwidth part, a physical downlink shared channel (PDSCH) through which the SIB is transmitted. The initial bandwidth part may be used for other system information (OSI), paging, and random access as well as the reception of the SIB.
When one or more bandwidth parts have been configured for a UE, a base station may indicate the UE to change the bandwidth part by using a bandwidth part indicator field in DCI.
In the NR system, in a case of a FDD system in which downlink and uplink are operated at separate frequencies, the downlink transmission bandwidth and the uplink transmission bandwidth may be different from each other. The channel bandwidth indicates an RF bandwidth corresponding to the system transmission bandwidth. Table 2 and Table 3 show part of a correspondence among a system transmission bandwidth, a subcarrier spacing, and a channel bandwidth defined in the NR system at a frequency bandwidth below 6 GHz and at a frequency bandwidth above 6 GHz, respectively. For example, in an NR system having a 100 MHz channel bandwidth at a 30 KHz subcarrier spacing, the transmission bandwidth is configured by 273 RBs. In the following, N/A may be a combination of a bandwidth and a subcarrier, which is not supported by the NR system.
In the NR system, the frequency range may be divided and defined as FR1 and FR2 as shown in Table 4.
In the above, the ranges of FR1 and FR2 may be differently changed and applied. For example, the frequency range of FR1 may be changed from 450 MHz to 6000 MHz and applied.
Next, a synchronization signal (SS)/physical broadcast channel block (PBCH) block in 5G will be described.
The SS/PBCH block may refer to a physical layer channel block including a primary SS (PSS), a secondary SS (SSS), and a PBCH. Specifically, the SS/PBCH block is as follows:
The UE may detect the PSS and the SSS in the initial access operation, and may decode the PBCH. The UE may obtain the MIB from the PBCH, and may be configured with the control resource set #0 (which may correspond to the control resource set having the CORESET index of 0) therefrom. The UE may monitor the control resource set #0 under an assumption that a demodulation reference signal (DMRS) transmitted in the selected SS/PBCH block and the control resource set #0 is quasi-co-located (QCLed). The UE may receive system information based on downlink control information transmitted from the control resource set #0. The UE may obtain, from the received system information, configuration information related to a random access channel (RACH) required for initial access. The UE may transmit a physical RACH (PRACH) to the base station by considering the selected SS/PBCH index, and the base station having received the PRACH may obtain information about an SS/PBCH block index selected by the UE. Through this process, the base station may know which block has been selected among the SS/PBCH blocks by the UE, and may know that the control resource set #0 associated therewith is monitored.
Next, downlink control information (DCI) in a 5G system will be described in detail.
In the 5G system, scheduling information about uplink data (or physical uplink shared channel (PUSCH) or downlink data (or physical downlink shared channel (PDSCH)) is transmitted from a base station to a UE through the DCI. The UE may monitor a fallback DCI format and a non-fallback DCI format with regard to the PUSCH or the PDSCH. The fallback DCI format may include a fixed field predefined between the base station and the UE, and the non-fallback DCI format may include a configurable field. In addition, there are various formats of DCI, and the DCI may indicate, according to each format, whether it is DCI for power control, DCI for notifying of a slot format indicator (SFI), and the like.
The DCI may be transmitted through a PDCCH which is a physical downlink control channel after channel coding and modulation is performed thereon. A cyclic redundancy check (CRC) may be attached to a DCI message payload, and the CRC may be scrambled by a radio network temporary identifier (RNTI) corresponding to the identity of the UE. Different RNTIs may be used according to the purpose of the DCI message, for example, a UE-specific data transmission, a power adjustment command, or a random access response. That is, the RNTI is not explicitly transmitted, but is included in a CRC calculation process and then transmitted. When receiving the DCI message transmitted through the PDCCH, the UE may check a CRC by using an assigned RNTI. When a CRC check result is correct, the UE may know that the corresponding message has been transmitted to the UE. The PDCCH is mapped and transmitted in a control resource set configured for the UE.
For example, DCI for scheduling a PDSCH for system information (SI) may be scrambled by an SI-RNTI. DCI for scheduling a PDSCH for a random access response (RAR) message may be scrambled by an RA-RNTI. DCI for scheduling a PDSCH for a paging message may be scrambled by a P-RNTI. DCI for notifying of a slot format indicator (SFI) may be scrambled by an SFI-RNTI. DCI for notifying of transmit power control (TPC) may be scrambled by a TPC-RNTI. DCI for scheduling UE-specific PDSCH or PUSCH may be scrambled by a cell RNTI (C-RNTI).
DCI format 0_0 may be used as a fallback DCI for scheduling a PUSCH. Here, a CRC may be scrambled by a C-RNTI. The DCI format 0_0 in which the CRC is scrambled by the C-RNTI may include, for example, pieces of information below.
DCI format 0_1 may be used as a non-fallback DCI for scheduling a PUSCH. Here, a CRC may be scrambled by a C-RNTI. The DCI format 0_1 in which the CRC is scrambled by the C-RNTI may include, for example, pieces of information below.
or ┌log2 (NSRS)┐bits
bits for non-codebook based PUSCH transmission;
DCI format 1_0 may be used as a fallback DCI for scheduling a PDSCH. Here, a CRC may be scrambled by a C-RNTI. The DCI format 1_0 in which the CRC is scrambled by the C-RNTI may include, for example, the following pieces of information below.
DCI format 1_1 may be used as a non-fallback DCI for scheduling a PDSCH. Here, a CRC may be scrambled by a C-RNTI. The DCI format 1_1 in which the CRC is scrambled by the C-RNTI may include, for example, pieces of information below.
Each piece of control information included in the DCI format 1_1 may be as follows.
Hereinafter, a method of allocating time domain resources for a data channel in a 5G communication system will be described.
A base station may configure, for a UE, a table for time-domain resource allocation information for a downlink data channel (PDSCH) and an uplink data channel (PUSCH) via higher layer signaling (e.g., RRC signaling). For PDSCH, a table including maxNrofDL-Allocations=16 entries at most may be configured, and for PUSCH, a table including maxNrofUL-Allocations=16 entries at most may be configured. The time-domain resource allocation information may include PDCCH-to-PDSCH slot timing (corresponding to a time interval in slot units between a timing at which a PDCCH is received and a timing at which a PDSCH scheduled by the received PDCCH is transmitted, and denoted by K0), PDCCH-to-PUSCH slot timing (corresponding to a time interval in slot units between a timing at which a PDCCH is received and a timing at which a PUSCH scheduled by the received PDCCH is transmitted, and denoted by K2), information on the position and length of a start symbol in which the PDSCH or PUSCH is scheduled within a slot, a mapping type of PDSCH or PUSCH, and the like. For example, information such as Table 9 or Table 10 below may be transmitted from the base station to the UE.
The base station may notify one of the entries in the above-described table representing the time-domain resource allocation information to the UE via L 1 signaling (e.g., DCI) (e.g., may be indicated by a “time-domain resource allocation” field in DCI). The UE may acquire time-domain resource allocation information for the PDSCH or PUSCH based on the DCI received from the base station.
In a case of data transmission through PDSCH or PUSCH, time-domain resource assignment may be transferred based on information about a slot in which a PDSCH or PUSCH is transmitted, a start symbol position S in the corresponding slot, and the number L of symbols to which the PDSCH or PUSCH is mapped. In the above, S may be a relative position from the start of a slot, L may be the number of consecutive symbols, and S and L may be determined based on a start and length indicator value (SLIV) defined as follows.
if (L−1)≤7 then SLIV=14·(L−1)+S
else SLIV=14·(14−L−1)+(14−1−S) Equation 1
In the NR system, a terminal may receive, through RRC configuration, the configuration in which an SLIV value, a PDSCH/PUSCH mapping type, and information on a slot in which a PDSCH/PUSCH is transmitted are included in one row (for example, the information may be configured in the form of Table). Thereafter, for the time-domain resource assignment of the DCI, by indicating an index value in the table configured as above, a base station may transmit, to a terminal, the SLIV value, the PDSCH or PUSCH mapping type, and information on the slot in which the PDSCH or PUSCH is transmitted.
In the NR system, the PUSCH mapping type is defined by type A and type B. With regard to the PUSCH mapping type A, the first symbol among DMRS symbols is located at the second or the third OFDM symbol in a slot. With regard to the PUSCH mapping type B, the first symbol among DMRS symbols is located at the first OFDM symbol in a time domain resource assigned via PUSCH transmission.
Hereinafter, a downlink control channel in a 5G communication system will be described in more detail with reference to the drawings.
The control resource set in the 5G system above may be configured for the UE by the base station via higher layer signaling (e.g., system information, MIB, RRC signaling). Configuration of the control resource set for the UE may be understood as providing information such as a control resource set identity, a frequency location of the control resource set, a symbol length of the control resource set, and the like. The higher layer signaling may include, for example, pieces of information of Table 11 below.
In Table 11, tci-StatesPDCCH (simply referred to as transmission configuration indication (TCI) state) configuration information may include information about one or multiple SS/PBCH block indices having a quasi-co-located (QCLed) relationship with a DMRS transmitted in the corresponding control resource set or a channel state information reference signal (CSI-RS) index.
The downlink data may be transmitted through a physical downlink shared channel (PDSCH) serving as a physical channel for downlink data transmission. The PDSCH may be transmitted after a control channel transmission interval, and scheduling information, such as a specific mapping position and modulation scheme in the frequency domain may be determined based on DCI transmitted through the PDCCH.
Through an MCS among control information configuring the DCI, a base station may notify a terminal of a modulation scheme applied to a PDSCH to be transmitted and the size (transport block size (TBS)) of data to be transmitted. In an embodiment, the MCS may be configured by 5 bits or more or fewer bits. The TBS corresponds to the size of data (transport block, TB) that the base station desires to transmit, before application of the channel coding for error correction to the data.
In the disclosure, a transport block (TB) may include a medium access control (MAC) header, a MAC control element (CE), one or more MAC service data units (SDUs), and padding bits. Alternatively, the TB may indicate the unit of data, which is delivered from a MAC layer to a physical layer, or a MAC protocol data unit (MAC PDU).
The modulation schemes supported by the NR system are quadrature phase shift keying (QPSK), 16 quadrature amplitude modulation (16 QAM), 64 QAM, and 256 QAM. Modulation orders (Qm) of the QPSK, 16 QAM, 64 QAM, and 256 QAM correspond to 2, 4, 6, and 8, respectively. That is, 2 bits per symbol in a case of QPSK modulation, 4 bits per symbol in a case of 16 QAM modulation, 6 bits per symbol in a case of 64 QAM modulation, and 8 bits per symbol in a case of 256 QAM modulation may be transmitted.
Referring to
In order to explain a method and apparatus proposed in the embodiment, the terms “physical channel” and “signal” in the NR system may be used. However, details of the disclosure may be applied to a wireless communication system other than the NR system.
Hereinafter, an embodiment of the disclosure will be described in detail with reference to the accompanying drawings. In the following description of the disclosure, a detailed description of known functions or configurations incorporated herein will be omitted when the same may make the subject matter of the disclosure rather unclear. The terms that will be used below are terms defined in consideration of the functions in the disclosure, and may differ according to users, intentions of the users, or customs. Therefore, the definitions of the terms should be made based on the contents throughout the specification.
Hereinafter, an embodiment of the disclosure is described using an NR system as an example, but an embodiment may be applied to other communication systems having a similar technical background or a similar channel form. In addition, embodiments of the disclosure may be modified without departing from the scope of the disclosure, and may be applied to other communication systems based on a determination by those skilled in the art.
In the disclosure, the terms “physical channel” and “signal” in a prior art may be used interchangeably with “data” or “control signal”. For example, a PDSCH is a physical channel through which data is transmitted, but in the disclosure, the PDSCH may be referred to as data.
Hereinafter, in the disclosure, higher layer signaling is a method for transmitting, by a base station, a signal to a terminal by using a downlink data channel of a physical layer or a method for transmitting, by a terminal, a signal to a base station by using an uplink data channel of a physical layer. The higher layer signaling may also be referred to as RRC signaling or MAC control element (CE).
Referring to
In addition, CRCs 517, 519, 521, and 523 may be added to the code blocks 507, 509, 511, and 513, respectively (indicated by reference numeral 515). The CRCs may include 16 bits, 24 bits, or a pre-fixed number of bits, and may be used to determine whether channel coding is successful.
The TB 501 and a cyclic generator polynomial may be used in order to generate the CRC 503, and the cyclic generator polynomial may be defined in various methods. For example, assuming that a cyclic generator polynomial for a 24-bit CRC is gCRC24A(D)=D24+D23+D18+D17+D14+D11+D10+D7+D6+D5+D4+D3+D+1 and L=24, a CRC p0, p1, p2, p3, . . . , pL-1 may be determined, with respect to TB data a0, a1, a2, a3, . . . , aA-1, to be a value obtained by dividing a0DA+23+a1DA+22+ . . . +aA−1D24+p0D23+p1D33+ . . . +p22D1+p23 by gCRC24A(D) with a remainder of 0. In the above example, the CRC length “L” is assumed to be 24 as an example, but the CRC length “L” may be determined to have different lengths, such as 12, 16, 24, 32, 30, 48, 64, and the like.
Through this process, the CRC is added to the TB, and then the TB having CRC added thereto may be divided into N CBs 507, 509, 511, and 513. CRCs 517, 519, 521, and 523 may be added to each of the divided CBs 507, 509, 511, and 513 (indicated by reference numeral 515). The CRCs added to the CBs may have a different length than that of the CRC added to the TB or may use a different cyclic generator polynomial. In addition, the CRC 503 added to the TB and the CRCs 517, 519, 521, and 523 added to the code blocks may be omitted depending on the type of a channel code to be applied to the code block. For example, if LDPC codes other than turbo codes are applied to code blocks, CRCs 517, 519, 521, and 523 to be inserted for each code block may be omitted.
However, even if the LDPC is applied, the CRCs 517, 519, 521, and 523 may be added to the code block as they are. In addition, CRC may be added or omitted even if a polar code is used.
As described above in
In the conventional LTE system, CRC for CB is added to the divided CB, data bits and the CRC of the CB are encoded with a channel code, and thus coded bits are determined and a number of bits, which have undergone predetermined rate matching to each of coded bits, may be determined.
The size of TB in the NR system may be calculated through the following operations.
Operation 1: N′RE, which is the number of REs assigned to PDSCH mapping in one PRB in the assigned resource, is calculated. N′RE may be calculated by NscRB·Nsymbsh−NDMRSPRB−NohPRB. Here, NscRB is 12, and Nsymbsh may represent the number of OFDM symbols allocated to the PDSCH. NDMRSPRB is the number of REs in one PRB occupied by DMRSs of the same CDM group. NohPRB is the number of REs occupied by the overhead in one PRB, which is configured via higher layer signaling, and may be configured to be one of 0, 6, 12, or 18. Thereafter, NRE, which is the total number of REs, allocated to the PDSCH may be calculated. NRE is calculated by min(156,N′RE)·nPRB, and nPRB denotes the number of PRBs allocated to a terminal.
Operation 2: Ninfo, which is the number of temporary information bits, may be calculated by NRE*R*Qm*v. Here, R is a code rate, Qm is a modulation order, and information of this value may be transferred using a predefined table and an MCS bit field of DCI. In addition, v is the number of assigned layers. In a case of Ninfo≤3824, TBS may be calculated through operation 3 below. Otherwise, TBS may be calculated through operation 4.
Operation 3: N′info may be calculated by the equation of
and n=max(3,└ log2(Ninfo)−6┘. TBS may be determined as a value, which is the closest to N′info among values equal to or greater than N′info in Table 12 below.
Operation 4: N′info may be calculated by the equation of
and n=└ log2(Ninfo−24)┘−5. TBS may be determined through a value of N′info and the following [pseudo-code 1]. In the following, C corresponds to the number of code blocks which one TB includes.
In the NR system, if one CB is input to an LDPC encoder, parity bits may be added to the CB and the CB added with the parity bits may be output. The amount of parity bits may differ according to an LDPC base graph. A method of transmitting all parity bits, generated by LDPC coding for a specific input, may be called full buffer rate matching (FBRM), and a method of limiting the number of parity bits that can be transmitted may be called limited buffer rate matching (LBRM). If resources are allocated for data transmission, the output of the LDPC encoder is made using a circular buffer, and bits of the buffer are repeatedly transmitted as many times as the number of the allocated resources is transmitted, and the length of the circular buffer may be denoted by Nab.
When the number of parity bits generated by LDPC coding is N, Ncb=N may be satisfied in the FBRM method. In the LBRM method, Ncb=min(N, Nref) may be satisfied, Nref is given by
and RLBRM may be determined to be ⅔. In order to calculate TBSLBRM, the method for obtaining the TBS described above is used. Here, the maximum modulation order and the maximum number of layers supported by a terminal in the corresponding cell are assumed. When it is configured to use an MCS table supporting 256QAM for at least one BWP in the corresponding cell, the maximum modulation order Qm is assumed to be “8”, and if not, the maximum modulation order Qm is assumed to be 6 (64QAM), the code rate is assumed to be 948/1024 that is the maximum code rate, NRE is assumed to satisfy 156·nPRB, and nPRB is assumed to satisfy nPRB,LBRM. Values of nPRB,LBRM may be given as in Table 13 below.
In the NR system, the maximum data rate supported by the terminal may be determined through Equation 2 below.
In Equation 2, J may denote the number of carriers grouped by carrier aggregation, Rmax=948/1024, vLayers(j) may denote the maximum number of layers, Qm(j) may denote a maximum modulation order, f(j) may denote a scaling index, and μ may denote a subcarrier spacing. The terminal may report f(j) as one value among 1, 0.8, 0.75, and 0.4, and μ may be given as shown in Table 14 below.
Further, Tsμ denotes an average OFDM symbol length, Tsμ may be calculated according to 10−3/14·2μ, and NPRRBW(j),μ may denote the maximum number of RBs in BW (j). OH(j) is an overhead value, and OH(j) may be given as 0.14 in the downlink of FR1 (a band equal to or less than 6 GHz) and given as 0.18 in the uplink thereof, and may be given as 0.08 in the downlink of FR2 (a band above 6 GHz) and given as 0.10 in the uplink thereof. Through Equation 2, the maximum data rate in the downlink in a cell having a 100 MHz frequency bandwidth at a 30 kHz subcarrier spacing may be calculated as shown in Table 15 below.
indicates data missing or illegible when filed
On the other hand, an actual data rate of a terminal, which may be measured in actual data transmission, may be a value obtained by dividing the amount of data by the data transmission time. This may be a value obtained by dividing a TBS in 1 TB transmission or a sum of TBSs in 2 TB transmission, by the TTI length. For example, as in the assumption shown in Table 15, the actual maximum data rate in a downlink in a cell having a 100 MHz frequency bandwidth at a 30 kHz subcarrier spacing may be determined as shown in Table 16 below according to the number of allocated PDSCH symbols.
RE
indicates data missing or illegible when filed
The maximum data rate supported by the terminal may be identified through Table 15, and the actual data rate according to the assigned TBS may be identified through Table 16. Here, the actual data rate may be greater than the maximum data rate depending on scheduling information.
In a wireless communication system, especially in an NR system, a data rate supportable by a terminal may be agreed between a base station and a terminal. The data rate may be calculated using the maximum frequency band, the maximum modulation order, and the maximum number of layers, which are supported by the terminal. However, the calculated data rate may be different from a value calculated based on a TBS and a transmission time interval (TTI) length used for actual data transmission.
Accordingly, a case, in which a terminal is assigned a TBS greater than a value corresponding to a data rate supported by the terminal itself, may occur. In order to prevent this case from occurring, there may be a restriction on schedulable TBSs according to the data rate supported by the terminal.
A PSS 601, an SSS 603, and the PBCH are mapped over 4 OFDM symbols, the PSS and the SSS are mapped to 12 RBs, and the PBCH is mapped to 20 RBs. A table in
Referring to
Since a terminal is generally located away from a base station, a signal transmitted by the terminal is received by the base station after a propagation delay. The propagation delay may be regarded as a value obtained by dividing a path through which radio waves are transmitted from the terminal to the base station by the speed of light, and may generally be regarded as a value obtained by dividing a distance from the terminal to the base station by the speed of light. In an embodiment, in a case of a terminal located 100 km away from the base station, a signal transmitted from the terminal is received by the base station after about 0.34 msec. On the other hand, a signal transmitted from the base station is also received by the terminal after about 0.34 msec. As described above, a timing at which a signal transmitted from the terminal arrives at the base station may differ according to the distance between the terminal and the base station. Therefore, when multiple terminals existing in different locations transmit signals at the same time, a timing at which signals arrive at the base station may all be different. In order to solve this problem and to allow signals transmitted from multiple terminals to arrive at the base station at the same time, a timing for transmission of the uplink signal may be different according to the position of each terminal. In 5G, NR, and LTE systems, this is called a timing advance (TA).
Hereinafter, a UE processing time according to a timing advance will be described in detail. When a base station transmits an uplink scheduling grant (UL grant) or a downlink control signal and data (DL grant and DL data) to a UE in slot n 802, the UE may receive the UL scheduling grant or the downlink control signal and data in slot n 804. In this case, the UE may receive the signal later by propagation delay (Tp) 810 than a timing at which the base station has transmitted the signal. In this embodiment, when the UE has received a first signal in slot n 804, the UE transmits a second signal corresponding thereto in slot (n+4) 806. Even when the UE transmits a signal to the base station, in order for the base station to receive the signal at a specific timing, the UE may transmit the HARQ ACK/NACK for uplink data or downlink data at the timing 806 which is earlier by a timing advance (TA) 812 than the slot (n+4) based on the received signal. Therefore, in this embodiment, a preparation time of the UE for transmitting uplink data after receiving the UL scheduling grant or for transferring the HARQ ACK or NACK after receiving the downlink data may correspond to a timing obtained by subtracting the TA from a timing corresponding to three slots (indicated by reference numeral 814).
In order to determine the above-described timing, the base station may calculate the absolute value of TA of the corresponding UE. The base station may calculate the absolute value of TA by adding or subtracting, to or from a TA value initially delivered to the initially accessed UE at the random access stage, a TA value variation subsequently transferred via higher layer signaling. In the disclosure, the absolute value of the TA may be a value obtained by subtracting a start time of the nth TTI received by the UE from a start time of the nth TTI transmitted by the UE.
Meanwhile, one of the important criteria for the performance of a cellular wireless communication system is packet data latency. To this end, in the LTE system, signal transmission and reception are performed in units of subframes having a TTI of 1 ms. In the LTE system operating as described above, a UE having a transmission time interval shorter than 1 ms (short-TTI UE) may be supported. On the other hand, in 5G or NR system, the transmission time interval may be shorter than 1 ms. The short-TTI UE is suitable for services such as voice over LTE (VoLTE) service and a remote control, in which latency is important. In addition, the short-TTI UE becomes a measure for realizing a mission-critical Internet of things (IoT) on a cellular basis.
In a 5G or NR system, when a PDSCH including downlink data is transmitted, the base station may indicate a value K1, which is a value corresponding to information about a timing at which the UE transmits HARQ-ACK information of the PDSCH, in DCI for scheduling the PDSCH. When the HARQ-ACK information includes a timing advance and is not indicated to be transmitted prior to a symbol L1, the UE may transmit the HARQ-ACK information to the base station. That is, the HARQ-ACK information may include a timing advance, and may be transmitted from the UE to the base station at the timing identical to or later than the symbol L1. When the HARQ-ACK information including a timing advance is indicated to be transmitted prior to the symbol L1, the HARQ-ACK information may not be valid HARQ-ACK information during HARQ-ACK transmission from the UE to the base station.
The symbol L1 may be the first symbol in which a cyclic prefix (CP) starts after Tproc,1 from the last timing of the PDSCH. Tproc,1 may be calculated according to Equation 3 below.
T
proc,1=((N1+d1,1+d1,2)(2048+144)·κ2−μ)·TC Equation 3
In Equation 3 above, N1, d1, 1, d1,2, κ, μ, and TC may be defined as follows.
In addition, in the 5G or NR system, when a base station transmits control information including a UL scheduling grant, the UE may indicate a value K2 corresponding to timing information for transmission of UL data or PUSCH.
When the PUSCH includes a timing advance and is not indicated to be transmitted prior to a symbol L2, the UE may transmit the PUSCH to the base station. That is, the PUSCH may include a timing advance, and may be transmitted from the UE to the base station at a timing identical to or later than the symbol L2. When the PUSCH includes a timing advance and is indicated to be transmitted prior to the symbol L2, the UE may ignore the UL scheduling grant control information from the base station.
The symbol L2 may be the first symbol in which a CP of the PUSCH symbol to be transmitted after Tproc,2 from the last timing of the PDCCH including a scheduling grant starts. Tproc,2 may be calculated according to Equation 4 below.
T
proc,1=((N2+d2,1)(2048+144)·κ2−μ)·TC Equation 4
In Equation 4 above, N2, d2,1, κ, μ, and TC may be defined as follows.
On the other hand, the 5G or NR system may configure a frequency band part (BWP) within one carrier so as to designate a specific terminal to perform transmission and reception in the configured BWP. This may be performed to reduce power consumption of the terminal. The base station may configure a plurality of BWPs, and may change an activated BWP using the control information. A timing that the terminal may use to change a BWP may be defined as shown in Table 19 below.
In Table 19, frequency range 1 may denote a frequency band of 6 GHz or less, and frequency range 2 may denote a frequency band of 6 GHz or greater. In the above-described embodiment, type 1 and type 2 may be determined according to UE capability. In the above-described embodiment, scenarios 1, 2, 3 and 4 are given as shown in Table 20 below.
In satellite communications (or non-terrestrial network), a Doppler shift occurs due to the continuous and rapid movement of the satellite, that is, a frequency offset of a transmission signal may occur.
On the other hand, in satellite communication, since a satellite is far from a user on the ground, a large latency occurs compared to the terrestrial network communication.
The disclosure provides a method and apparatus in which, when a UE is a terminal capable of supporting both terrestrial communication and satellite communication, the UE operates differently depending on whether a signal transmission/reception situation occurs in terrestrial communication or occurs in satellite communication. To this end, a method and an apparatus for allowing the UE to first distinguish between terrestrial network communication and satellite communication are also provided.
The first embodiment provides a method and apparatus in which a terminal determines whether signal transmission and reception is performed using terrestrial network communication or using satellite communication during the signal transmission and reception.
When a signal is received, the terminal may need to classify whether the corresponding signal is a signal transmitted from a satellite or a signal transmitted from a terrestrial base station. This may be needed for selecting a transmission antenna, a reception antenna, or a transmission/reception antenna, or may be needed for determining transmission power. For the above classification, the UE may use one of the following methods or a combination of one or more thereof. This method may be performed for distinguishing a transmission point in downlink. That is, the method may be performed for determining whether the transmission point corresponds to a terrestrial base station, whether the transmission point is for transmission to the terrestrial base station through a satellite, or whether the transmission point corresponds to a base station located on the satellite.
Using different sequences as described above may be a combination of one or more of the methods in which: different types of sequences are used (e.g., in a case of a terrestrial base station, M-sequence is used as a PSS sequence and a gold sequence is used as an SSS sequence. However, a terrestrial base station may transmit SS through a satellite, or a satellite base station may use one or more of ZC sequence, M-sequence, or gold sequence for PSS and/or SSS); although the same type of sequence is used, the sequence carries different pieces of information depending on the transmission point (that is, a sequence is generated based on different pieces of information); or SS is transmitted through different time and/or frequency resources depending on the transmission point.
When access is performed based on the PSS and/or SSS, the terminal may determine whether a signal transmitted/received according to the PSS and/or SSS uses terrestrial network communication or uses satellite communication.
For example, the propagation delay may be determined based on a difference between a reference time of a base station at which the base station transmits a signal and a reference time at which the terminal receives a signal from the base station. As an example, the base station may include, in the system information transmitted to terminals, global positioning system (GPS) reception time and/or location information of the base station itself (hereinafter, referred to as base station GPS time information, and GPS is only an example and this may be understood as information about time and location that the terminal and the base station can share. In addition, this may also be understood as information about time and/or location based on a specific system). In addition, the terminal may directly receive a separate GPS signal, and may configure its own reference time (terminal GPS time) by receiving the GPS signal.
Here, when a GPS system of the GPS time information, which is transmitted by the base station, and a terminal separately receive a GPS signal, the terminal may compare GPS time information (base station GPS time) transmitted by the base station and GPS time which is received and configured by the terminal itself (terminal GPS time), and may calculate a propagation delay from the satellite to the terminal or from the terminal to the satellite. In the disclosure, the GPS system is described as an example, but a global navigation satellite system (GNSS) other than GPS may be applied. In this case, the name or type of the GNSS system can be indicated by higher layer signaling. The base station may transmit information about the reference time to the terminal as system information or terminal-specific configuration information through higher layer signaling (ReferenceTimeInfo information element) as follows.
[ReferenceTimeInfo Field Descriptions]
If the referenceTimeInfo field is received in DLInformationTransfer message, the time field indicates the time at the ending boundary of the system frame indicated by referenceSFN. The UE considers this frame (indicated by referenceSFN) to be the frame which is nearest to the frame where the message is received (which can be either in the past or in the future).
If the referenceTimeInfo field is received in SIB9, the time field indicates the time at the SFN boundary at or immediately after the ending boundary of the SI-window in which SIB9 is transmitted.
If referenceTimeInfo field is received in SIB9, this field is excluded when determining changes in system information, i.e. changes of time should neither result in system information change notifications nor in a modification of valueTag in SIB 1.
That is, if the timeInfoType value is not configured or is not included, the time information may be a GPS-based time.
The second embodiment provides a method and apparatus for selecting a transmission antenna according to whether a transmission signal is uplink transmission in terrestrial network communication or uplink communication in satellite communication in a situation in which a terminal transmits a signal. Hereinafter, a method for select a transmission antenna by a terminal will be described, but this may also be applied to a method for selecting a reception antenna by a terminal.
On the other hand, in a case of satellite communication, since the satellite is located above the terminal, a method for performing transmission from an antenna located at the upper part of the terminal may experience less path loss or increase the antenna gain. Therefore, basically, by using a method for identifying whether satellite communication is being performed by the terminal provided in the first embodiment of the disclosure, in case that the satellite communication is identified being performed, when the terminal transmits a signal (by satellite), the first antenna 2400, which is an antenna at the upper part of the terminal, is used, and when the terminal transmits a signal using terrestrial network communication, the second antenna 2410, which is the lower part antenna of the terminal, may be used.
Meanwhile, a user may adjust the direction of a terminal in a random manner Therefore, when satellite communication is performed, an antenna used for transmission by the terminal may be an antenna at the upper part of the terminal, or may be an antenna which is close to the sky (or location of the satellite) by using a gyroscope sensor included in the terminal.
A gyroscope sensor refers to a sensor capable of detecting the current direction of the terminal by using the rotational moment of inertia, which is a kind of inertial force, and may refer to a sensor capable of detecting x, y, z-axis direction and/or x, y, and z-axis acceleration of the terminal regardless of the detection method.
The third embodiment provides a method in which when a terminal supporting satellite network communication is connected to a base station through a satellite, the terminal displays the connection to the base station through a satellite to a user.
When the terminal accesses the base station through a satellite, the terminal may notify that it has accessed the satellite network by displaying an icon related to the satellite on the screen (or display) of the terminal. The terminal accessing the satellite network may be identified as meaning that the corresponding base station accesses the terminal and then delivers information indicating that access to the satellite network is established to the terminal. Alternatively, the terminal may determine that it has accessed the satellite network by the method provided in the first embodiment or the like.
In addition, when the UE accesses the satellite network, information related to the satellite network may be provided to the user. The information may include, for example, information related to a fee to be paid by a user when making a call using voice and/or video or a fee to be paid by the user when transmitting data. The information may be displayed when uploading or downloading data, or may be displayed at the moment the user presses a call button or a call starts.
The fourth embodiment provides a method in which a terminal supporting terrestrial network communication and satellite network communication searches for a frequency in the process of finding a signal of a base station.
When the terminal supports a plurality of frequency bands, the terminal may select a frequency to be searched for first. Searching for a frequency in the above may be a process of finding a synchronization signal. In the frequency search process, the terminal may have information about a frequency band used for satellite network communication and a frequency band used for terrestrial network communication in advance. In this case, the terminal may first search for a frequency band used for terrestrial network communication. This is because, in general, the performance of terrestrial network communication can be better than that of satellite network communication.
As another example, the terminal may search for all frequency bands, and then may compare the strengths of signals transmitted by a satellite in a frequency band (e.g., the signal strength may be the strength of at least one synchronization signal or a reference signal transmitted by the satellite, and a signal to be to-be measured may be predetermined. This signal strength may be measured in units of dBm, and may be compared with a preconfigured or predetermined threshold value) so as to attempt access the base station first in a frequency band having a higher signal strength. Thereafter, when the attempted base station access is not successful, base station access in another frequency band may be attempted. When comparing the signal strengths, the terminal may compare the signal strength of a frequency band for satellite network communication with the sum of the signal strength of a frequency band for terrestrial communication and an offset value. In the above, a case in which the base station access is not successful may correspond to a case in which the terminal fails to receive a signal from the base station within a predetermined period of time in a random access procedure, or a case in which the terminal fails to receive a confirmation signal (e.g., msg 4) including the ID value of the terminal itself. For example, when the signal strength or signal-to-noise ratio of the frequency band for terrestrial network communication is “A”, and the signal strength or signal-to-noise ratio of the frequency band for satellite network communication is “B”, the terminal may directly compare A and B to select the frequency band of the terrestrial network or the satellite network and attempt access. However, as described above, when comparing “A+alpha” with “B” and “A+alpha” is greater than or equal to “B”, the terminal may attempt to access the base station in the terrestrial communication frequency band, and if “B” is larger than “A+alpha”, the terminal may attempt to access the base station in the frequency band for satellite network communication. This is because terrestrial network communication may generally have a small latency and may not have the Doppler effect compared to satellite network communication, stable communication can be expected, and thus it can be considered that the actual signal strength is greater.
The terminal attempts to access the base station in a selected band. For example, when the terminal selects a frequency band for terrestrial network communication according to the above-described method, the terminal acquires synchronization with the base station by receiving a synchronization signal or SSB, and then receives MIB and SIB to obtain configuration information, so as to perform a random access process. The terminal transmits the PRACH preamble to the base station using the terrestrial network, and receives the RAR from the base station. Thereafter, the terminal transmits Msg 3 based on a TA value and a UL grant, which are included in a received RAR, and receives Msg 4 from the base station.
For example, when the terminal selects a frequency band for satellite network communication, the terminal performs an operation similar to that when the terminal selects a frequency band for terrestrial network communication. In this case, after transmitting the PRACH preamble, the terminal may receive a configuration of the length of RAR window (this may be understood as a time at which the terminal attempts to detect DCI using RA-RNTI) having a value greater than 10 ms. This may be configured by system information, and the start timing of the RAR window may be a PDCCH region in which an RAR that appears first after PRACH preamble transmission can be transmitted.
Although the first to fourth embodiments of the disclosure have been separately described above for convenience of description, since each embodiment includes operations related to each other, it is also possible to combine at least two or more embodiments.
In order to perform the above embodiments of the disclosure, a transmitter, a receiver, and a processor of a terminal and a base station are shown in
Specifically,
The embodiments of the disclosure described and shown in the specification and the drawings are merely specific examples that have been presented to easily explain the technical contents of the disclosure and help understanding of the disclosure, and are not intended to limit the scope of the disclosure. That is, it will be apparent to those skilled in the art that other variants based on the technical idea of the disclosure may be implemented. Further, the above respective embodiments may be employed in combination, as necessary. Further, other variants of the above embodiments, based on the technical idea of the embodiments, may be implemented in LTE, 5G, and other systems.
| Number | Date | Country | Kind |
|---|---|---|---|
| 10-2020-0044281 | Apr 2020 | KR | national |
| 10-2020-0053825 | May 2020 | KR | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/KR2021/004549 | 4/12/2021 | WO |
