WO2020091554A1 - Method for transmitting and receiving downlink signal by terminal and base station in wireless communication system supporting unlicensed band, and devices supporting same - Google Patents

Method for transmitting and receiving downlink signal by terminal and base station in wireless communication system supporting unlicensed band, and devices supporting same Download PDF

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WO2020091554A1
WO2020091554A1 PCT/KR2019/014813 KR2019014813W WO2020091554A1 WO 2020091554 A1 WO2020091554 A1 WO 2020091554A1 KR 2019014813 W KR2019014813 W KR 2019014813W WO 2020091554 A1 WO2020091554 A1 WO 2020091554A1
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symbol
received
terminal
pdsch
base station
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PCT/KR2019/014813
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French (fr)
Korean (ko)
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김선욱
양석철
윤석현
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엘지전자 주식회사
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Priority to KR20190018217 priority
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    • HELECTRICITY
    • H04ELECTRIC COMMUNICATION TECHNIQUE
    • H04LTRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L5/00Arrangements affording multiple use of the transmission path
    • HELECTRICITY
    • H04ELECTRIC COMMUNICATION TECHNIQUE
    • H04WWIRELESS COMMUNICATION NETWORKS
    • H04W72/00Local resource management, e.g. wireless traffic scheduling or selection or allocation of wireless resources
    • H04W72/12Dynamic Wireless traffic scheduling ; Dynamically scheduled allocation on shared channel
    • HELECTRICITY
    • H04ELECTRIC COMMUNICATION TECHNIQUE
    • H04WWIRELESS COMMUNICATION NETWORKS
    • H04W74/00Wireless channel access, e.g. scheduled or random access
    • HELECTRICITY
    • H04ELECTRIC COMMUNICATION TECHNIQUE
    • H04WWIRELESS COMMUNICATION NETWORKS
    • H04W74/00Wireless channel access, e.g. scheduled or random access
    • H04W74/08Non-scheduled or contention based access, e.g. random access, ALOHA, CSMA [Carrier Sense Multiple Access]

Abstract

The present document discloses a method for transmitting and receiving a downlink signal by a terminal and a base station in a wireless communication system supporting an unlicensed band, and devices supporting same. As one specific example, disclosed in the present document are various operation examples in which the terminal and the base station transmit and receive a downlink signal on the basis of a time point when the base station starts to occupy the unlicensed band for physical downlink shared channel (PDSCH) transmission on the unlicensed band.

Description

Method for transmitting and receiving a downlink signal from a terminal and a base station in a wireless communication system supporting an unlicensed band, and devices supporting the same

The following description relates to a wireless communication system, and relates to a method for transmitting and receiving a downlink signal and a device supporting the downlink signal in a wireless communication system supporting an unlicensed band.

Wireless access systems have been widely deployed to provide various types of communication services such as voice and data. In general, a wireless access system is a multiple access system capable of supporting communication with multiple users by sharing available system resources (bandwidth, transmission power, etc.). Examples of the multiple access system include a code division multiple access (CDMA) system, a frequency division multiple access (FDMA) system, a time division multiple access (TDMA) system, an orthogonal frequency division multiple access (OFDMA) system, and a single carrier frequency (SC-FDMA). division multiple access) system.

In particular, as more communication devices require a larger communication capacity, an improved mobile broadband communication technology has been proposed compared to a conventional radio access technology (RAT). In addition, a communication system that considers services / UEs sensitive to reliability and latency as well as massive machine type communications (MTC) that provides various services anytime, anywhere by connecting multiple devices and objects has been proposed. Accordingly, advanced mobile broadband communication, massive MTC, and ultra-reliable and low latency communication (URLLC) have been introduced, and various technical configurations have been proposed for this.

The purpose of this document is to provide a method for transmitting and receiving a downlink signal between a terminal and a base station in a wireless communication system supporting an unlicensed band, and devices supporting the same.

The technical objectives to be achieved by the technical features described in this document are not limited to the above-mentioned matters, and other technical problems not mentioned have ordinary knowledge in the technical field related to the examples of this description to be described below. It can be considered by a ruler.

This document discloses a method for transmitting and receiving a downlink signal from a terminal and a base station in a wireless communication system supporting an unlicensed band, and devices supporting the same.

In this document, as an example, in a method for a user equipment to receive a downlink signal in a wireless communication system supporting an unlicensed band, scheduling information related to a physical downlink shared channel (PDSCH) is received from a base station. ; Determining a symbol position at which an actual PDSCH (actual PDSCH) is received from the base station through the unlicensed band within one slot determined based on the scheduling information; And (i) the demodulation reference signal through N symbols starting from the symbol position at which the actual PDSCH is received on the unlicensed band, based on the scheduling information and (ii) the symbol position at which the actual PDSCH is received. (demodulation reference signal; DMRS) and receiving a data signal, N is a natural number of 1 or more, discloses a method for receiving a downlink signal of a terminal in an unlicensed band.

In the present disclosure, the scheduling information may include start symbol information on which the PDSCH is scheduled, and symbol length information on the scheduled PDSCH.

In the present disclosure, the scheduling information may be received through a starting and length indicator value (SLIV) field in a physical downlink control channel (PDCCH).

In the present disclosure, the DMRS is included in (i) one or more DMRS candidate transmission symbols determined based on the scheduling information, and (ii) the N symbols starting from the symbol position at which the actual PDSCH is received. Can be received through M symbols. At this time, M may be a natural number less than or equal to N.

In the present disclosure, an N value may be determined based on the scheduling information. In this case, the DMRS may be received through M DMRS transmission symbols determined based on the N value among the N symbols starting from the symbol position where the actual PDSCH is received. At this time, M may be a natural number less than or equal to N.

In the above example, the N value may correspond to one of the following.

-Among the candidate transmission symbols for the preset PDSCH, a maximum candidate value less than or equal to the number of symbols from the symbol position to which the actual PDSCH is received in one slot to the boundary of the slot

-The symbol length value of the scheduled PDSCH indicated by the scheduling information

-The number of symbols from the symbol position to which the actual PDSCH is received in the one slot to the boundary of the slot

Alternatively, in the above example, according to the N value, the location of the M DMRS transmission symbols among the N symbols may be preset.

In the present disclosure, the UE, through the unlicensed band, determining a symbol position at which an actual PDSCH is received from the base station may include one or more of the following.

-Based on the signaling information received from the base station, the terminal determines the symbol position where the actual PDSCH is received

-Based on the symbol location where the scheduling information is received, the terminal determines the symbol location where the actual PDSCH is received

-The UE determines the symbol position at which the actual PDSCH is received, based on the symbol position at which the initial signal received from the base station is received.

In the above example, based on the symbol location at which the scheduling information is received, the terminal determining the symbol location at which the actual PDSCH is received may include one of the following.

-The UE determines the symbol position at which the actual PDSCH is received as the first symbol among the one or more symbols from which the scheduling information is received.

-The terminal determines the symbol position at which the actual PDSCH is received as the last symbol among the one or more symbols for which the scheduling information is received

For example, based on the fact that the actual PDSCH does not overlap on the frequency domain with the scheduling information, the terminal may determine a symbol position at which the actual PDSCH is received as the first symbol among the one or more symbols on which the scheduling information has been received. . Alternatively, based on the actual PDSCH overlapping on the scheduling information and the frequency domain, the UE may determine a symbol position at which the actual PDSCH is received as the last symbol among the one or more symbols on which the scheduling information is received.

As another example, based on that the first symbol index among the one or more symbols from which the scheduling information has been received exceeds a threshold value, the terminal determines the symbol position at which the actual PDSCH is received, the first of the one or more symbols from which the scheduling information is received. You can decide by symbol. Alternatively, based on the first symbol index of the one or more symbols from which the scheduling information was received is equal to or less than the threshold value, the terminal determines the symbol position at which the actual PDSCH is received, the last symbol of the one or more symbols from which the scheduling information is received. You can decide.

In this document, as another example, a terminal receiving a downlink signal in a wireless communication system supporting an unlicensed band, comprising: at least one transmitter; At least one receiver; At least one processor; And at least one memory operatively connected to the at least one processor and storing instructions that, when executed, cause the at least one processor to perform a specific operation, the specific operation being: from a base station. Receiving scheduling information related to a physical downlink shared channel (PDSCH); Determining a symbol position at which an actual PDSCH (actual PDSCH) is received from the base station through the unlicensed band within one slot determined based on the scheduling information; And (i) the demodulation reference signal through N symbols starting from the symbol position at which the actual PDSCH is received on the unlicensed band, based on the scheduling information and (ii) the symbol position at which the actual PDSCH is received. It includes receiving a (demodulation reference signal; DMRS) and a data signal, N is a natural number of 1 or more, initiates the terminal.

In the present disclosure, the terminal may communicate with at least one of a mobile terminal, a network, and an autonomous vehicle other than a vehicle including the terminal.

In this document, as another example, a base station transmitting a downlink signal in a wireless communication system supporting an unlicensed band, comprising: at least one transmitter; At least one receiver; At least one processor; And at least one memory operatively connected to the at least one processor and storing instructions that, when executed, cause the at least one processor to perform a specific operation, wherein the specific operation is: the unlicensed. Transmitting scheduling information related to a physical downlink shared channel (PDSCH) to a user equipment through a band; In one slot determined based on the scheduling information, an actual PDSCH (actual PDSCH) of some or all of the scheduled PDSCHs is transmitted based on a channel access procedure (CAP) for the unlicensed band. Determine N symbols, where N is a natural number greater than or equal to 1; And transmitting a demodulation reference signal (DMRS) and a data signal to the terminal through the N symbols on the unlicensed band.

The above-described aspects of the present description are only some of the embodiments disclosed in the present document, and various embodiments in which the technical features disclosed in the present document are reflected are detailed by those skilled in the art to be described below. It can be derived and understood based on description.

According to the examples disclosed in this document, there are the following effects.

More specifically, due to the nature of the unlicensed band, the base station may be difficult to transmit a downlink signal from (i) a time point pre-scheduled to the terminal or (ii) the time point the base station intended. For example, when the downlink signal is a PDSCH signal, the base station may transmit the PDSCH from (i) a pre-scheduled time to the terminal or (ii) a specific time after the base station's intended time. Accordingly, some symbols / frequency regions of the PDSCH may not be transmitted, or the PDSCH may be transmitted over a plurality of slots. In this case, according to the examples disclosed in this document, even if the base station cannot transmit the PDSCH signal from the expected time, the UE determines the symbol position at which the base station transmits the DMRS and the data signal through the PDSCH and has high reliability. The received signal can be acquired / detected.

The effects obtained from the examples disclosed in this document are not limited to the above-mentioned effects, and other effects not mentioned in the technical field to which the examples of the present description belong from various descriptions disclosed in this document below. Can be clearly drawn and understood by those with ordinary knowledge. That is, unintended effects of carrying out the examples disclosed in this document may also be derived by those skilled in the art from the examples disclosed in this document.

The accompanying drawings are provided to help understanding of the present description, and provide examples disclosed in this document together with a detailed description. However, the technical features of the examples disclosed in this document are not limited to specific drawings, and the features disclosed in each drawing may be combined with each other to constitute a new embodiment. Reference numerals in each drawing refer to structural elements.

1 is a view for explaining a physical channel and a signal transmission method using them.

2 and 3 are diagrams showing a radio frame structure based on the LTE system to which the examples of the present disclosure are applicable.

4 is a diagram showing a slot structure based on the LTE system to which the examples of the present disclosure are applicable.

5 is a diagram showing the structure of a downlink subframe based on the LTE system to which the examples of the present disclosure are applicable.

6 is a diagram showing the structure of an uplink subframe based on the LTE system to which the examples of the present disclosure are applicable.

7 is a diagram illustrating a structure of a radio frame based on an NR system to which the examples of the present disclosure are applicable.

8 is a diagram showing a slot structure based on the NR system to which the examples of the present disclosure are applicable.

9 is a diagram showing a self-contained slot structure applicable to the examples of the present description.

10 is a view showing one REG structure based on the NR system to which the examples of the present disclosure are applicable.

11 and 12 are views illustrating a typical connection scheme between a TXRU and an antenna element.

13 is a view briefly showing a hybrid beamforming structure in terms of a TXRU and a physical antenna applicable to the examples of the present description.

14 is a diagram briefly showing a beam sweeping operation for a synchronization signal and system information in a downlink (DL) transmission process according to examples of the present disclosure.

15 is a diagram briefly showing an SS / PBCH block applicable to the examples of the present description.

16 is a diagram briefly showing a configuration in which an SS / PBCH block applicable to the examples of the present description is transmitted.

17 is a diagram showing the RRC state and the RRC state transition (transition) of the terminal, and FIG. 18 shows the NR / NGC (NR / Next Gen Core) and E-UTRAN / EPC (Evolved) as well as the RRC state and RRC state switching of the terminal. -This is a diagram showing the mobility procedure supported between Universal Terrestrial Radio Access Network / Evolved Packet Core.

19 is a diagram illustrating a DRX cycle of a terminal applicable to the examples of the present description

20 shows an example of a wireless communication system supporting an unlicensed band applicable to the examples of the present description.

21 is a diagram for describing a CAP for unlicensed band transmission applicable to the examples of the present description.

22 is a diagram illustrating a partial TTI (partial TTI) or a partial subframe / slot applicable to the examples of the present description.

23 is a diagram illustrating a network initial access and subsequent communication processes applicable to various operation examples of the present disclosure.

24 and 25 are views simply showing an example of operation disclosed in this document.

26 to 33 are diagrams illustrating DMRS symbol positions according to various examples of the present disclosure.

34 is a flowchart simply illustrating an example of an operation of a terminal according to the present description.

35 is a flowchart briefly illustrating an example of an operation of a base station according to the present disclosure.

36 is a diagram briefly showing the operation of a terminal and a base station applicable to the present disclosure, FIG. 37 is a flowchart briefly showing the operation of a terminal applicable to the present disclosure, and FIG. 38 is a simple diagram showing the operation of a base station applicable to the present disclosure It is a flow chart.

39 illustrates a communication system applied to the examples of this disclosure.

40 illustrates a wireless device that can be applied to the examples of this disclosure.

41 shows another example of a wireless device applied to the examples of the present description.

42 illustrates a portable device applied to the examples of the present description.

43 illustrates a vehicle or autonomous vehicle applied to the examples of the present description.

The following embodiments combine components and features of the examples of the present disclosure in a predetermined form. Each component or feature can be considered to be optional unless stated otherwise. Each component or feature may be implemented in a form that is not combined with other components or features. In addition, some components and / or features may be combined to form examples of the present description. The order of the operations described in the examples of this description can be changed. Some configurations or features of one embodiment may be included in other embodiments, or may be replaced with corresponding configurations or features of other embodiments.

In the description of the drawings, procedures or steps that may obscure the subject matter of the examples of the present disclosure are not described, and procedures or steps that are understandable at the level of those skilled in the art are not described.

Throughout the specification, when a part "comprising or including" a certain component, it means that other components may be further included instead of excluding other components, unless otherwise specified. do. In addition, terms such as "... unit", "... group", and "module" described in the specification mean a unit that processes at least one function or operation, which is hardware or software or a combination of hardware and software. Can be implemented as In addition, "a (a or an)", "one (one)", "the (the)" and similar related terms in the context of describing the examples of the present description (especially in the context of the following claims) herein It may be used in a sense including both singular and plural unless otherwise indicated or clearly contradicted by context.

In the present specification, examples of the present description have been mainly described in relation to data transmission and reception between a base station and a mobile station. Here, the base station has a meaning as a terminal node of a network that directly communicates with a mobile station. Certain operations described in this document as being performed by a base station may be performed by an upper node of the base station in some cases.

That is, various operations performed for communication with a mobile station in a network consisting of a plurality of network nodes including a base station may be performed by a base station or other network nodes other than the base station. At this time, the 'base station' may be replaced by terms such as a fixed station, Node B, eNode B (eNB), gNode B (gNB), advanced base station (ABS), or access point. Can be.

In addition, in the examples of the present description, a terminal is a user equipment (UE), a mobile station (MS), a subscriber station (SS), a mobile subscriber station (MSS), It may be replaced with terms such as a mobile terminal or an advanced mobile station (AMS).

Further, the transmitting end refers to a fixed and / or mobile node that provides a data service or voice service, and the receiving end refers to a fixed and / or mobile node that receives a data service or voice service. Therefore, in the uplink, a mobile station can be a transmitting end and a base station can be a receiving end. Likewise, in the downlink, a mobile station can be a receiving end, and a base station can be a transmitting end.

The examples of the present description may be supported by standard documents disclosed in at least one of the wireless access systems IEEE 802.xx system, 3GPP (3rd Generation Partnership Project) system, 3GPP LTE system, 3GPP 5G NR system and 3GPP2 system, In particular, examples of this description are 3GPP TS 36.211, 3GPP TS 36.212, 3GPP TS 36.213, 3GPP TS 36.321, 3GPP TS 36.331, 3GPP TS 37.213, 3GPP TS 38.211, 3GPP TS 38.212, 3GPP TS 38.213, 3GPP TS 38.321 and 3GPP TS 38.331 It can be supported by documents. That is, obvious steps or parts not described in the examples of the present disclosure may be described with reference to the documents. Also, all terms disclosed in this document may be described by the standard document.

Hereinafter, preferred embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. DETAILED DESCRIPTION The detailed description set forth below, in conjunction with the accompanying drawings, is intended to describe exemplary embodiments applicable to the examples of the present description, and is not intended to represent the only embodiments in which the examples of the present description may be practiced.

In addition, specific terms used in the examples of the present description are provided to help understanding the examples of the present description, and the use of these specific terms is changed to other forms without departing from the technical spirit of the examples of the present description. Can be.

Hereinafter, a 3GPP NR system as well as a 3GPP LTE / LTE-A system will be described as an example of a radio access system in which the examples of the present disclosure can be used.

The following technologies include code division multiple access (CDMA), frequency division multiple access (FDMA), time division multiple access (TDMA), orthogonal frequency division multiple access (OFDMA), and single carrier frequency division multiple access (SC-FDMA). It can be applied to various wireless access systems.

CDMA may be implemented by radio technology such as Universal Terrestrial Radio Access (UTRA) or CDMA2000. TDMA may be implemented with wireless technologies such as Global System for Mobile communications (GSM) / General Packet Radio Service (GPRS) / Enhanced Data Rates for GSM Evolution (EDGE). OFDMA may be implemented with wireless technologies such as IEEE 802.11 (Wi-Fi), IEEE 802.16 (WiMAX), IEEE 802-20, and Evolved UTRA (E-UTRA).

UTRA is part of the Universal Mobile Telecommunications System (UMTS). 3GPP Long Term Evolution (LTE) is part of Evolved UMTS (E-UMTS) that uses E-UTRA, and adopts OFDMA in the downlink and SC-FDMA in the uplink. The LTE-A (Advanced) system is an improved 3GPP LTE system.

In order to clarify the description of the technical features of the examples of the present description, the examples of the present description mainly describe the 3GPP NR system as well as the 3GPP LTE / LTE-A system, but can be applied to the IEEE 802.16e / m system and the like.

1. 3GPP system general

1.1. Physical channels and general signal transmission

In a radio access system, a terminal receives information from a base station through downlink (DL) and transmits information to a base station through uplink (UL). The information transmitted and received by the base station and the terminal includes general data information and various control information, and various physical channels exist according to the type / use of the information they transmit and receive.

1 is a view for explaining a physical channel that can be used in the examples of the present description and a signal transmission method using them.

When the power is turned off again when the power is turned off, or the newly entered terminal performs an initial cell search operation such as synchronizing with the base station (S11). To this end, the terminal receives a primary synchronization channel (P-SCH: Primary Synchronization Channel) and a floating channel (S-SCH: Secondary Synchronization Channel) from the base station, synchronizes with the base station, and acquires information such as a cell ID.

Thereafter, the terminal may receive a physical broadcast channel (PBCH) signal from the base station to obtain intra-cell broadcast information.

On the other hand, the UE may check a downlink channel state by receiving a downlink reference signal (DL RS) in an initial cell search step.

After completing the initial cell search, the UE receives a physical downlink control channel (PDCCH) and a physical downlink control channel (PDSCH) according to the information on the physical downlink control channel, and thus more detailed system information. Can be obtained (S12).

Thereafter, the terminal may perform a random access procedure (Random Access Procedure) to complete the access to the base station (S13 ~ S16). To this end, the UE transmits a preamble through a physical random access channel (PRACH) (S13), and the RAR for the preamble through a physical downlink control channel and a corresponding physical downlink shared channel. Random Access Response) may be received (S14). The UE transmits a PUSCH (Physical Uplink Shared Channel) using scheduling information in the RAR (S15), and a collision resolution procedure such as reception of a physical downlink control channel signal and a corresponding physical downlink shared channel signal (Contention Resolution Procedure) ) Can be performed (S16).

After performing the above-described procedure, the UE receives the physical downlink control channel signal and / or the physical downlink shared channel signal (S17) and the physical uplink shared channel (PUSCH: Physical) as a general uplink / downlink signal transmission procedure. The Uplink Shared Channel (PUCCH) signal and / or the Physical Uplink Control Channel (PUCCH) signal may be transmitted (S18).

The control information transmitted by the terminal to the base station is collectively referred to as uplink control information (UCI). UCI includes HARQ-ACK / NACK (Hybrid Automatic Repeat and reQuest Acknowledgement / Negative-ACK), SR (Scheduling Request), CQI (Channel Quality Indication), PMI (Precoding Matrix Indication), RI (Rank Indication) information, etc. .

UCI is generally periodically transmitted through PUCCH, but can be transmitted through PUSCH when control information and data should be simultaneously transmitted. In addition, according to the request / instruction of the network, the UE may periodically transmit UCI through PUSCH.

1.2. Radio frame structure

2 and 3 are diagrams showing a radio frame structure based on the LTE system to which the examples of the present disclosure are applicable.

The LTE system supports Frame Type 1 for Frequency Division Duplex (FDD), Frame Type 2 for Time Division Duplex (TDD), and Frame Type 3 for Unlicensed Cell (UCell). In the LTE system, in addition to the primary cell (PCell), up to 31 secondary cells (SCells) may be aggregated. Unless otherwise specified, the operations described below can be applied independently for each cell.

In multi-cell merging, different frame structures can be used for different cells. Also, time resources (eg, subframes, slots, and subslots) in the frame structure may be collectively referred to as a time unit (TU).

FIG. 2 (a) shows a frame structure type 1. The type 1 frame structure can be applied to both a full duplex (Frequency Division Duplex) system and a half duplex (FDD) system.

The downlink radio frame is defined as 10 1ms subframes (Subframes, SFs). The subframe includes 14 or 12 symbols depending on the cyclic prefix (CP). When a normal CP is used, the subframe includes 14 symbols. When an extended CP is used, a subframe includes 12 symbols.

The symbol may mean an OFDM (A) symbol or an SC-FDM (A) symbol according to multiple access schemes. For example, the symbol may mean an OFDM (A) symbol in the downlink and an SC-FDM (A) symbol in the uplink. The OFDM (A) symbol is referred to as a CP-OFDM (A) (Cyclic Prefix-OFDM (A)) symbol, and the SC-FDM (A) symbol is DFT-s-OFDM (A) (Discrete Fourier Transform-spread-OFDM). (A)) may be referred to as a symbol.

One subframe may be defined as one or more slots as follows according to SCS (Subcarrier Spacing).

-When SCS = 7.5 kHz or 15 kHz, subframe #i is defined as two 0.5ms slots # 2i and # 2i + 1 (i = 0 to 9).

-When SCS = 1.25 kHz, subframe #i is defined as one 1ms slot # 2i.

-When SCS = 15 kHz, subframe #i may be defined as six subslots as illustrated in Table 1.

Table 1 illustrates a subslot configuration in one subframe (normally CP).

Figure PCTKR2019014813-appb-img-000001

2 (b) shows a frame structure type 2 (frame structure type 2). The type 2 frame structure is applied to the TDD system. The type 2 frame structure is composed of two half frames. The half frame includes 4 (or 5) general subframes and 1 (or 0) special subframes. The general subframe is used for uplink or downlink according to UL-DL configuration (Uplink-Downlink Configuration). The subframe consists of two slots.

Table 2 illustrates a subframe configuration in a radio frame according to the UL-DL configuration.

Figure PCTKR2019014813-appb-img-000002

Here, D represents a DL subframe, U represents a UL subframe, and S represents a special (special) subframe. The special subframe includes a downlink pilot time slot (DwPTS), a guard period (GP), and an uplink pilot time slot (UpPTS). DwPTS is used for initial cell search, synchronization, or channel estimation at the UE. UpPTS is used to match channel estimation at a base station and uplink transmission synchronization of a terminal. The guard period is a period for removing interference caused in the uplink due to the multipath delay of the downlink signal between the uplink and the downlink.

Table 3 illustrates the configuration of the special subframe.

Figure PCTKR2019014813-appb-img-000003

Here, X is set by higher layer signaling (eg, RRC (Radio Resource Control) signaling, etc.) or is given as 0.

3 is a diagram illustrating a frame structure type 3;

Frame structure type 3 may be applied to UCell operation. Although not limited to this, the frame structure type 3 can be applied only to the operation of a Licensed Assisted Access (LAA) SCell having a normal CP. The frame has a length of 10 ms, and is defined as 10 1 ms subframes. Subframe #i is defined as two consecutive slots # 2i and # 2i + 1. Each subframe in the frame may be used for downlink or uplink transmission, or may be empty. Downlink transmission occupies one or more consecutive subframes (occupy), and starts at any point in the subframe and ends at the subframe boundary or DwPTS of Table 3. Uplink transmission occupies one or more consecutive subframes.

4 is a diagram showing a slot structure based on the LTE system to which the examples of the present disclosure are applicable.

Referring to FIG. 4, one slot includes a plurality of OFDM symbols in a time domain and a plurality of resource blocks (RBs) in a frequency domain. The symbol also means a symbol period. The structure of the slot may be represented by a resource grid composed of N DL / UL RB × N RB sc subcarriers and N DL / UL symb symbols. Here, N DL RB indicates the number of RBs in the downlink slot, and N UL RB indicates the number of RBs in the UL slot. N DL RB and N UL RB depend on the DL bandwidth and the UL bandwidth, respectively. N DL symb represents the number of symbols in the DL slot, and N UL symb represents the number of symbols in the UL slot. N RB sc represents the number of subcarriers constituting RB. The number of symbols in the slot can be variously changed according to the SCS and CP lengths (see Table 1). For example, in the case of a normal CP, one slot includes 7 symbols, but in the case of an extended CP, one slot includes 6 symbols.

RB is defined as N DL / UL symb (e.g., 7) consecutive symbols in the time domain and N RB sc (e.g., 12) consecutive subcarriers in the frequency domain. Here, RB may mean a physical resource block (PRB) or a virtual resource block (VRB), and PRBs and VRBs may be mapped on a one-to-one basis. Two RBs, one for each of the two slots of the subframe, may be referred to as an RB pair. The two RBs constituting the RB pair may have the same RB number (or RB index). A resource composed of one symbol and one subcarrier is called a resource element (RE) or tone. Each RE in the resource grid can be uniquely defined by an index pair (k, l) in the slot. k is an index assigned from 0 to N DL / UL RB × N RB sc -1 in the frequency domain, and l is an index assigned from 0 to N DL / UL symb -1 in the time domain.

5 is a diagram showing the structure of a downlink subframe based on the LTE system to which the examples of the present disclosure are applicable.

Referring to FIG. 5, up to 3 (or 4) OFDM (A) symbols located in front of the first slot in a subframe correspond to a control region to which a downlink control channel is allocated. The remaining OFDM (A) symbol corresponds to a data region to which PDSCH is allocated, and the basic resource unit of the data region is RB. The downlink control channel includes a physical control format indicator channel (PCFICH), a physical downlink control channel (PDCCH), and a physical hybrid-arq indicator channel (PHICH).

The PCFICH is transmitted in the first OFDM symbol of the subframe, and carries information about the number of OFDM symbols (ie, the size of the control region) used for transmission of control channels in the subframe. PHICH is a response channel for uplink transmission, and carries a hybrid automatic repeat request (HARQ) acknowledgment (ACK) / negative-acknowledgement (NACK) signal. Control information transmitted through the PDCCH is referred to as downlink control information (DCI). The DCI includes uplink resource allocation information, downlink resource allocation information, or an uplink transmission (Tx) power control command for an arbitrary UE group.

6 is a diagram showing the structure of an uplink subframe based on the LTE system to which the examples of the present disclosure are applicable.

Referring to FIG. 6, one subframe 600 is composed of two 0.5ms slots 601. Each slot consists of a plurality of symbols 602, and one symbol corresponds to one SC-FDMA symbol. The RB 603 is a resource allocation unit corresponding to 12 subcarriers in the frequency domain and one slot in the time domain.

The structure of the uplink subframe is largely divided into a data area 604 and a control area 605. The data area refers to a communication resource used in transmitting data such as voice and packets transmitted from each terminal and includes a physical uplink shared channel (PUSCH). The control region refers to a communication resource used to transmit an uplink control signal, for example, a downlink channel quality report from each terminal, a reception ACK / NACK for a downlink signal, an uplink scheduling request, and the like, and a PUCCH (Physical Uplink). Control Channel).

SRS (Sounding Reference Signal) is transmitted through the SC-FDMA symbol located at the end on the time axis in one subframe.

7 is a diagram illustrating a structure of a radio frame based on an NR system to which the examples of the present disclosure are applicable.

The uplink and downlink transmission based on the NR system is based on a frame as shown in FIG. 7. One radio frame has a length of 10 ms, and is defined as two 5 ms half-frames (HFs). One half-frame is defined by 5 1ms subframes (Subframes, SFs). One subframe is divided into one or more slots, and the number of slots in the subframe depends on subcarrier spacing (SCS). Each slot includes 12 or 14 OFDM (A) symbols according to a cyclic prefix (CP). Normally, when CP is used, each slot contains 14 symbols. When an extended CP is used, each slot includes 12 symbols. Here, the symbol may include an OFDM symbol (or CP-OFDM symbol) and an SC-FDMA symbol (or DFT-s-OFDM symbol).

Table 4 shows the number of symbols per slot according to the SCS, the number of slots per frame, and the number of slots per subframe when the normal CP is used, and Table 5 shows the slot number according to the SCS when the extended CSP is used. It indicates the number of symbols, the number of slots per frame, and the number of slots per subframe.

Figure PCTKR2019014813-appb-img-000004

Figure PCTKR2019014813-appb-img-000005

In the above table, N slot symb indicates the number of symbols in the slot, N frame, μ slot indicates the number of slots in the frame, and N subframe, μ slot indicates the number of slots in the subframe .

In the NR system to which the examples of the present disclosure can be applied, OFDM (A) numerology (eg, SCS, CP length, etc.) may be set differently among a plurality of cells merged to one UE. Accordingly, a (absolute time) section of a time resource (eg, SF, slot, or TTI) composed of the same number of symbols (for convenience, collectively referred to as a time unit (TU)) may be set differently between merged cells.

NR supports multiple numerology (or subcarrier spacing (SCS)) to support various 5G services. For example, when the SCS is 15 kHz, it supports a wide area in traditional cellular bands, and when the SCS is 30 kHz / 60 kHz, it is dense-urban, lower latency. And a wider carrier bandwidth, and when the SCS is 60 kHz or higher, a bandwidth greater than 24.25 GHz is supported to overcome phase noise.

The NR frequency band is defined as a frequency range of two types (FR1, FR2). FR1, FR2 may be configured as shown in the table below. In addition, FR2 may mean millimeter wave (mmW).

Figure PCTKR2019014813-appb-img-000006

8 is a diagram showing a slot structure based on the NR system to which the examples of the present disclosure are applicable.

One slot includes a plurality of symbols in the time domain. For example, in the case of a normal CP, one slot includes 7 symbols, but in the case of an extended CP, one slot includes 6 symbols.

The carrier includes a plurality of subcarriers in the frequency domain. Resource block (RB) is defined as a plurality of (eg, 12) consecutive subcarriers in the frequency domain.

BWP (Bandwidth Part) is defined as a plurality of contiguous (P) RBs in the frequency domain, and may correspond to one numerology (eg, SCS, CP length, etc.).

The carrier may include up to N (eg, 5) BWPs. Data communication is performed through the activated BWP, and only one BWP can be activated for one terminal. Each element in the resource grid is referred to as a resource element (RE), and one complex symbol may be mapped.

9 is a diagram showing a self-contained slot structure based on the NR system to which the examples of the present disclosure are applicable.

In FIG. 9, a hatched area (eg, symbol index = 0) represents a downlink control area, and a black area (eg, symbol index = 13) represents an uplink control area. Other areas (eg, symbol index = 1 to 12) may be used for downlink data transmission or may be used for uplink data transmission.

According to this structure, the base station and the UE can sequentially perform DL transmission and UL transmission in one slot, and can transmit and receive DL data and transmit / receive UL ACK / NACK therein in one slot. As a result, this structure reduces the time it takes to retransmit data when a data transmission error occurs, thereby minimizing the delay of the final data transmission.

In this self-supporting slot structure, a type gap of a certain length of time is required for the base station and the UE to switch from the transmission mode to the reception mode or from the reception mode to the transmission mode. To this end, some OFDM symbols at a time point of switching from DL to UL in an independent slot structure may be set as a guard period (GP).

In the foregoing detailed description, the case where the independent slot structure includes both the DL control area and the UL control area has been described, but the control areas may be selectively included in the independent slot structure. In other words, the self-supporting slot structure applicable to the examples of the present disclosure may include a case in which both the DL control area and the UL control area are included as well as the case where both the DL control area and the UL control area are included as shown in FIG. 9.

In addition, the order of the regions constituting one slot may vary according to embodiments. For example, one slot may be configured in the order of DL control area / DL data area / UL control area / UL data area, or may be configured in the order of UL control area / UL data area / DL control area / DL data area.

The PDCCH may be transmitted in the DL control region, and the PDSCH may be transmitted in the DL data region. PUCCH may be transmitted in the UL control region, and PUSCH may be transmitted in the UL data region.

In PDCCH, downlink control information (DCI), for example, DL data scheduling information, UL data scheduling information, and the like may be transmitted. In the PUCCH, uplink control information (UCI), for example, ACK / NACK (Positive Acknowledgement / Negative Acknowledgement) information for DL data, CSI (Channel State Information) information, SR (Scheduling Request) may be transmitted.

PDSCH carries downlink data (eg, DL-shared channel transport block, DL-SCH TB), and modulation methods such as Quadrature Phase Shift Keying (QPSK), 16 Quadrature Amplitude Modulation (QAMK), 64 QAM, and 256 QAM are used. Applies. A codeword is generated by encoding TB. PDSCH can carry up to two codewords. For each codeword, scrambling and modulation mapping are performed, and modulation symbols generated from each codeword are mapped to one or more layers (Layer mapping). Each layer is mapped to a resource together with a DMRS (Demodulation Reference Signal) and is generated as an OFDM symbol signal and transmitted through a corresponding antenna port.

The PDCCH carries downlink control information (DCI) and a QPSK modulation method is applied. One PDCCH is composed of 1, 2, 4, 8, and 16 control channel elements (CCEs) according to an aggregation level (AL). One CCE is composed of six Resource Element Groups (REGs). One REG is defined by one OFDM symbol and one (P) RB.

10 is a view showing one REG structure based on the NR system to which the examples of the present disclosure are applicable.

In FIG. 10, D represents a resource element (RE) to which DCI is mapped, and R represents a RE to which DMRS is mapped. DMRS is mapped to the 1st, 5th, and 9th REs in the frequency domain direction within one symbol.

The PDCCH is transmitted through a control resource set (CORESET). CORESET is defined as a set of REGs with a given pneumonology (eg, SCS, CP length, etc.). Multiple OCRESETs for one UE may overlap in the time / frequency domain. CORESET may be set through system information (eg, MIB) or UE-specific higher layer (eg, Radio Resource Control, RRC, layer) signaling. Specifically, the number of RBs and the number of symbols (up to 3) constituting the CORESET may be set by higher layer signaling.

PUSCH carries uplink data (eg, UL-shared channel transport block, UL-SCH TB) and / or uplink control information (UCI), and CP-OFDM (Cyclic Prefix-Orthogonal Frequency Division Multiplexing) waveform Or, it is transmitted based on a DFT-s-OFDM (Discrete Fourier Transform-spread-Orthogonal Frequency Division Multiplexing) waveform. When the PUSCH is transmitted based on the DFT-s-OFDM waveform, the UE transmits the PUSCH by applying transform precoding. For example, if transform precoding is not possible (eg, transform precoding is disabled), the UE transmits a PUSCH based on the CP-OFDM waveform, and if transform precoding is possible (eg, transform precoding is enabled), the UE is CP-OFDM. PUSCH may be transmitted based on a waveform or a DFT-s-OFDM waveform. PUSCH transmission is dynamically scheduled by UL grant in DCI, or semi-static based on upper layer (eg, RRC) signaling (and / or Layer 1 (L1) signaling (eg, PDCCH)). Can be scheduled (configured grant). PUSCH transmission may be performed on a codebook basis or a non-codebook basis.

PUCCH carries uplink control information, HARQ-ACK and / or scheduling request (SR), and is divided into Short PUCCH and Long PUCCH according to the PUCCH transmission length. Table 7 illustrates PUCCH formats.

Figure PCTKR2019014813-appb-img-000007

PUCCH format 0 carries UCI up to 2 bits in size, and is mapped and transmitted based on a sequence. Specifically, the UE transmits one sequence among a plurality of sequences through PUCCH in PUCCH format 0 to transmit a specific UCI to the base station. The UE transmits a PUCCH in PUCCH format 0 in PUCCH resource for setting a corresponding SR only when transmitting a positive SR.

PUCCH format 1 carries UCI up to 2 bits in size, and modulation symbols are spread in an orthogonal cover code (OCC) in the time domain (set differently depending on whether frequency hopping is performed). DMRS is transmitted on a symbol in which a modulation symbol is not transmitted (ie, time division multiplexing (TDM)).

PUCCH format 2 carries UCI having a bit size larger than 2 bits, and modulation symbols are transmitted through DMRS and Frequency Division Multiplexing (FDM). DM-RS is located at symbol indices # 1, # 4, # 7, and # 10 in a given resource block at a density of 1/3. PN (Pseudo Noise) sequence is used for the DM_RS sequence. For 2 symbol PUCCH format 2, frequency hopping may be activated.

PUCCH format 3 does not allow terminal multiplexing in the same physical resource blocks, and carries a UCI having a bit size larger than 2 bits. In other words, PUCCH resources of PUCCH format 3 do not include orthogonal cover codes. The modulation symbol is transmitted by DMRS and Time Division Multiplexing (TDM).

PUCCH format 4 supports multiplexing up to 4 UEs in the same physical resource block, and carries a UCI having a bit size larger than 2 bits. In other words, PUCCH resource of PUCCH format 3 includes an orthogonal cover code. The modulation symbol is transmitted by DMRS and Time Division Multiplexing (TDM).

1.3. Analog beamforming

The millimeter wave (mmW) has a short wavelength, so multiple antenna elements can be installed in the same area. That is, since the wavelength is 1 cm in the 30 GHz band, a total of 100 antenna elements can be installed in a 2-dimension arrangement at 0.5 lambda (wavelength) intervals on a 5 * 5 cm panel. Accordingly, in millimeter wave (mmW), a plurality of antenna elements may be used to increase beamforming (BF) gain to increase coverage or increase throughput.

In this case, each antenna element may include a TXRU (Transceiver Unit) so that transmission power and phase can be adjusted for each antenna element. Through this, each antenna element can perform independent beamforming for each frequency resource.

However, in order to install the TXRU on all 100 antenna elements, there is a problem of ineffectiveness in terms of price. Therefore, a method of mapping a plurality of antenna elements to one TXRU and adjusting a beam direction with an analog phase shifter is considered. This analog beamforming method has a drawback that it is difficult to make frequency selective beamforming because only one beam direction can be generated in all bands.

As a solution to this, a hybrid beamforming (hybrid BF) having B TXRUs, which is a smaller number than Q antenna elements, may be considered as an intermediate form between digital beamforming and analog beamforming. In this case, although there are differences depending on the connection scheme of the B TXRU and Q antenna elements, the direction of beams that can be simultaneously transmitted may be limited to B or less.

11 and 12 are views illustrating a typical connection scheme between a TXRU and an antenna element. Here, the TXRU virtualization model represents the relationship between the output signal of the TXRU and the output signal of the antenna element.

FIG. 11 is a diagram illustrating how a TXRU is connected to a sub-array. 11, the antenna element is connected to only one TXRU.

On the other hand, Figure 12 is a diagram showing how the TXRU is connected to all antenna elements. In the case of Fig. 12, the antenna element is connected to all TXRUs. At this time, a separate adder is required as shown in FIG. 12 so that the antenna elements are connected to all TXRUs.

11 and 12, W represents a phase vector multiplied by an analog phase shifter. That is, W is a main parameter that determines the direction of analog beamforming. Here, the mapping between the CSI-RS antenna port and the TXRUs may be 1: 1 or 1: 1-to-many.

According to the configuration of FIG. 11, there is a disadvantage in that focusing of beamforming is difficult, but there is an advantage that the entire antenna configuration can be configured at a low cost.

According to the configuration of FIG. 12, there is an advantage in that focusing of beamforming is easy. However, since the TXRU is connected to all antenna elements, there is a disadvantage that the total cost increases.

When a plurality of antennas are used in an NR system to which the examples of the present disclosure are applicable, a hybrid beamforming technique combining digital beamforming and analog beamforming may be applied. At this time, analog beamforming (or radio frequency (RF) beamforming) refers to an operation of performing precoding (or combining) in an RF stage. In addition, in hybrid beamforming, baseband and RF stages perform precoding (or combining), respectively. This has the advantage of reducing the number of RF chains and D-A (Digital-to-Analog) (or A-D (Analog-to-Digital)) converters, while achieving near-digital beamforming performance.

For convenience of description, the hybrid beamforming structure may be represented by N transmit / receiver units (TXRU) and M physical antennas. In this case, digital beamforming for L data layers to be transmitted by the transmitting end may be represented by an N * L (N by L) matrix. Thereafter, the converted N digital signals are converted into analog signals through TXRU, and analog beamforming represented by an M * N (M by N) matrix is applied to the converted signals.

13 is a view briefly showing a hybrid beamforming structure in terms of a TXRU and a physical antenna applicable to the examples of the present description. In this case, the number of digital beams in FIG. 13 is L, and the number of analog beams is N.

Additionally, in the NR system to which the examples of the present disclosure can be applied, a method for supporting a more efficient beamforming to a terminal located in a specific area is considered by designing a base station to change analog beamforming in a symbol unit. Further, when defining a specific N TXRU and M RF antennas as one antenna panel as shown in FIG. 13, in the NR system according to the examples of the present disclosure, hybrid beamforming independent of each other may be applied. Even a method of introducing an antenna panel is being considered.

When the base station utilizes a plurality of analog beams as described above, the analog beams advantageous for signal reception may be different for each terminal. Accordingly, in the NR system to which the examples of the present disclosure are applicable, the base station transmits a signal by applying a different analog beam for each symbol in a specific subframe (SF) or slot (at least a synchronization signal, system information, paging, etc.) By doing so, a beam sweeping operation that allows all terminals to have a reception opportunity is considered.

14 is a diagram briefly showing a beam sweeping operation for a synchronization signal and system information in a downlink (DL) transmission process according to examples of the present disclosure.

In FIG. 14, a physical resource (or physical channel) in which system information of an NR system to which the examples of the present disclosure are applicable is transmitted in a broadcasting method is referred to as a physical broadcast channel (xPBCH). At this time, analog beams belonging to different antenna panels in one symbol may be simultaneously transmitted.

In addition, as illustrated in FIG. 14, in an NR system to which examples of the present disclosure are applicable, a reference signal transmitted by applying a single analog beam (corresponding to a specific antenna panel) as a configuration for measuring channels per analog beam (Reference signal, RS), the introduction of beam reference signals (Beam RS, BRS) is being discussed. The BRS may be defined for a plurality of antenna ports, and each antenna port of the BRS may correspond to a single analog beam. At this time, unlike the BRS, the synchronization signal or the xPBCH may be transmitted by applying all analog beams in the analog beam group so that any UE can receive it well.

1.4. Synchronization Signal Block (SSB or SS / PBCH block)

In the NR system to which the examples of the present disclosure are applicable, a primary synchronization signal (PSS), a secondary synchronization signal (SSS), and / or a physical broadcast channel (PSBCH) is one synchronization signal block (Synchronization Signal Block or Synchronization Signal PBCH block, hereinafter SS) block or SS / PBCH block). At this time, multiplexing of different signals within the one SS block may not be excluded. (Multiplexing other signals are not precluded within a 'SS block').

The SS / PBCH block may be transmitted in a band other than the center of the system band, and in particular, when the base station supports broadband operation, the base station may transmit multiple SS / PBCH blocks.

15 is a diagram briefly showing an SS / PBCH block applicable to the examples of the present description.

As shown in FIG. 15, the SS / PBCH block applicable to the examples of the present description may be composed of 20 RBs in 4 consecutive OFDM symbols. In addition, the SS / PBCH block is composed of PSS, SSS and PBCH, and the UE can perform cell search, system information acquisition, beam alignment for initial access, DL measurement, etc. based on the SS / PBCH block. .

PSS and SSS are each composed of 1 OFDM symbol and 127 subcarriers, and PBCH is composed of 3 OFDM symbols and 576 subcarriers. Polar coding and quadrature phase shift keying (QPSK) are applied to the PBCH. The PBCH is composed of a data RE and a DMRS (Demodulation Reference Signal) RE for each OFDM symbol. There are three DMRS REs for each RB, and three data REs exist between the DMRS REs. At this time, the location of the DMRS RE may be determined based on the cell ID (eg, a subcarrier index mapped based on the N cell ID mod 4 value may be determined).

In addition, the SS / PBCH block may be transmitted in a frequency band other than the center frequency of the frequency band used by the network.

To this end, in the NR system to which the examples of the present disclosure are applicable, a synchronization raster, which is a candidate frequency location for which a terminal should detect an SS / PBCH block, is defined. The synchronous raster can be distinguished from a channel raster.

The synchronous raster may indicate the frequency location of the SS / PBCH block that the UE can use to acquire system information when there is no explicit signaling for the SS / PBCH block location.

At this time, the synchronization raster may be determined based on GSCN (Global Synchronization Channel Number). The GSCN may be transmitted through RRC signaling (eg, Master Information Block (MIB), System Information Block (SIB), Remaining Minimum System Information (RMSI), Other System Information (OSI), etc.).

Such a synchronous raster is defined longer in the frequency axis than the channel raster in consideration of the complexity and detection speed of the initial synchronization and has fewer blind detections.

16 is a diagram briefly showing a configuration in which an SS / PBCH block applicable to the examples of the present description is transmitted.

In the NR system to which the examples of the present description are applicable, the base station may transmit the SS / PBCH block up to 64 times for 5 ms. At this time, multiple SS / PBCH blocks are transmitted with different transmission beams, and the terminal detects the SS / PBCH block by assuming that the SS / PBCH block is transmitted every 20 ms based on a specific one beam used for transmission. can do.

The maximum number of beams that a base station can use for SS / PBCH block transmission within a 5 ms time interval can be set as the frequency band is higher. For example, in a band below 3 GHz, the base station may transmit SS / PBCH blocks using up to four different beams in a 5 ms time interval, up to eight in a 3-6 GHz band, and up to 64 different beams in a band above 6 GHz.

1.5. Synchronization procedure

The terminal may perform synchronization by receiving the SS / PBCH block as described above from the base station. In this case, the synchronization procedure mainly includes a cell ID detection step and a timing detection step. Here, the cell ID detection step may include a PSS-based cell ID detection step and an SSS-based cell ID detection step (eg, detecting one physical layer cell ID of a total of 1008 physical layer cell IDs). In addition, the timing detection step may include a timing detection step based on PBCH DM-RS (Demodulation Reference Signal) and a timing detection step based on PBCH content (eg, MIB (Master Information Block)).

To this end, the UE may assume that PBCH, PSS, and SSS reception occasions exist on consecutive symbols. (That is, the UE may assume that the PBCH, PSS, and SSS constitute an SS / PBCH block, as described above). Subsequently, the UE may assume that the SSS, PBCH DM-RS, and PBCH data have the same Energy Per Resource Element (EPRE). In this case, the UE may assume that the ratio of the PSS EPRE to the SSS ERPE of the SS / PBCH block in the corresponding cell (ratio of PSS EPRE to SSS EPRE) is 0 dB or 3 dB. Or, if dedicated higher layer parameters (dedicated higher layer parameters) are not provided to the UE, SI-RNTI (System Information-Random Network Temporary Identifier), P-RNTI (Paging-Random Network Temporary Identifier), or RA-RNTI (Random Access-Random Network Temporary Identifier) is a terminal that monitors the PDCCH for DCI format 1_0 having cyclic scrambled CRC (Cyclic Redundancy Check) ratio of PDCCH DMRS EPRE to SSS EPRE (ratio of PDCCH DMRS EPRE to SSS EPRE) It can be assumed that this is within -8 dB to 8 dB.

First, the UE may acquire time synchronization and physical cell ID of the detected cell through PSS and SSS detection. More specifically, the terminal may acquire symbol timing for an SS block through PSS detection and detect a cell ID in a cell ID group. Subsequently, the UE detects a cell ID group through SSS detection.

In addition, the terminal may detect the time index (eg, slot boundary) of the SS block through DM-RS of the PBCH. Subsequently, the terminal may acquire half frame boundary information and system frame number (SFN) information through the MIB included in the PBCH.

At this time, the PBCH may indicate that the associated (or corresponding) RMSI PDCCH / PDSCH is transmitted in the same band or a different band from the SS / PBCH block. Accordingly, the UE can receive RMSI (eg, system information other than a master information block (MIB)) transmitted from a frequency band indicated by the PBCH or a frequency band where the PBCH is transmitted after decoding the PBCH. have.

In an SS / PBCH block in a half frame, first symbol indices for candidate SS / PBCH blocks may be determined according to subcarrier spacing of SS / PBCH blocks as follows. At this time, index # 0 corresponds to the first symbol of the first slot in the half frame.

(Case A: 15 kHz subcarrier spacing) The first symbols of candidate SS / PBCH blocks may have symbols of {2, 8} + 14 * n. For frequency bands below 3 GHz, n has a value of 0 or 1. For frequency bands above 3 GHz and below 6 GHz, n has a value of 0, 1, 2 or 3.

(Case B: 30 kHz subcarrier spacing) The first symbols of candidate SS / PBCH blocks may have {4, 8, 16, 32} + 28 * n symbols. For frequencies below 3 GHz, n has a value of 0. For frequency bands above 3 GHz and below 6 GHz, n has a value of 0 or 1.

(Case 30: 30 kHz subcarrier spacing) The first symbols of candidate SS / PBCH blocks may have {2, 8} + 14 * n symbols. For frequency bands below 3 GHz, n has a value of 0 or 1. For frequency bands above 3 GHz and below 6 GHz, n has a value of 0, 1, 2 or 3.

(Case D: 120 kHz subcarrier spacing) The first symbols of candidate SS / PBCH blocks may have {4, 8, 16, 20} + 28 * n symbols. For frequencies above 6 GHz, n has values of 0, 1, 2, 3, 5, 6, 7, 8, 19, 11, 12, 13, 15, 16, 17 or 18.

(Case E: 240 kHz subcarrier spacing) The first symbols of candidate SS / PBCH blocks may have symbols of {8, 12, 16, 20, 32, 36, 40, 44} + 56 * n. For frequencies above 6 GHz, n has values of 0, 1, 2, 3, 5, 6, 7 or 8.

In connection with the above operation, the terminal may acquire system information.

The MIB includes information / parameters for monitoring the PDCCH that schedules the PDSCH carrying System Information Block 1 (SIB1), and is transmitted to the terminal by the base station through the PBCH in the SS / PBCH block.

The UE may check whether a Control Resource Set (CORESET) for a Type0-PDCCH common search space exists based on the MIB. The Type0-PDCCH common search space is a type of PDCCH search space and is used to transmit a PDCCH for scheduling SI messages.

When a Type0-PDCCH common search space exists, the UE based on information in the MIB (eg, pdcch-ConfigSIB1) (i) a plurality of contiguous resource blocks and one or more contiguous (consecutive) constituting CORESET The symbols and (ii) PDCCH opportunity (eg, time domain location for PDCCH reception) may be determined.

When the Type0-PDCCH common search space does not exist, pdcch-ConfigSIB1 provides information on the frequency location where SSB / SIB1 exists and the frequency range where SSB / SIB1 does not exist.

SIB1 includes information related to availability and scheduling (eg, transmission period, SI-window size) of the remaining SIBs (hereinafter, SIBx, x is an integer greater than or equal to 2). For example, SIB1 may indicate whether SIBx is periodically broadcast or provided by an on-demand method (or by a terminal request). When SIBx is provided by an on-demand method, SIB1 may include information necessary for the UE to perform an SI request. SIB1 is transmitted through the PDSCH, PDCCH scheduling SIB1 is transmitted through the Type0-PDCCH common search space, and SIB1 is transmitted through the PDSCH indicated by the PDCCH.

1.6. Synchronization raster

Synchronization raster (Synchronization raster), if there is no explicit signaling for the SSB location, refers to the frequency location of the SSB that can be used by the terminal for obtaining system information. Global synchronization raster is defined for all frequencies. The frequency location of the SSB is defined by SS REF and the corresponding number GSCN (Global Synchronization Channel Number). The parameters that define SS REF and GSCN for all frequency ranges are:

Figure PCTKR2019014813-appb-img-000008

The mapping between the resource blocks of the synchronization raster and the corresponding SSB can be based on the following table. The mapping depends on the total number of resource blocks allocated in the channel and can be applied to both UL and DL.

Figure PCTKR2019014813-appb-img-000009

1.7. Antenna ports quasi co-location

A list of maximum M TCI (Transmission Configuration Indicator) state settings for one terminal may be set. The maximum M TCI state setting may be set by the upper layer parameter PDSCH-Config so that (the UE) can decode the PDSCH according to detection of the PDCCH including the DCI intended for the UE and a given serving cell. have. Here, the M value may be determined depending on the capability of the terminal.

Each TCI-state includes a parameter for setting a QCL (quasi co-location) relationship between one or two downlink reference signals and DMRS ports of the PDSCH. The QCL relationship is established based on the upper layer parameter qcl-Type1 for the first DL RS (downlink reference signal) and the upper layer parameter qcl-Type2 for the second DL RS (if set). For the case of two DL RSs, regardless of whether the reference signals are the same DL RS or a different DL RS, the QCL types should not be the same (shall not be the same). The QCL types correspond to each DL RS given by the upper layer parameter qcl-Type in the upper layer parameter QCL-Info , and the QCL types can have one of the following values.

-'QCL-TypeA': {Doppler shift, Doppler spread, average delay, delay spread}

-'QCL-TypeB': {Doppler shift, Doppler spread}

-'QCL-TypeC': {Doppler shift, average delay}

-'QCL-TypeD': {Spatial Rx parameter}

The terminal receives an activation command (activation command) used to map the maximum of 8 TCI states with a codepoint of a Transmission Configuration Indication (TCI) field in DCI. When the HARQ-ACK signal corresponding to the PDSCH including the activation command is transmitted in slot #n, the mapping between code points of the TCI fields in the TCIs states and the DCI is slot # (n + 3 * N subframe, μ slot + It can be applied from 1). Here, N subframe, μ slot is determined based on Table 4 or Table 5 described above. After the terminal receives the initial higher layer configuration of the TCI states (initial higher layer configuration) and before the terminal receives the activation command, the terminal has the DMRS port (s) of the PDSCH of the serving cell is' QCL-TypeA From the viewpoint, it is assumed that the SS / PBCH block and QCL determined in the initial access procedure are performed. Additionally, at the time, the UE may assume that the DMRS port (s) of the PDSCH of the serving cell is QCL with the SS / PBCH block determined in the initial access procedure from the perspective of 'QCL-TypeD'.

When the upper layer parameter tci-PresentInDCI is set to 'enabled' for CORESET scheduling PDSCH, the UE assumes that the TCI field exists in the PDCCH of DCI format 1_1 transmitted on the CORESET. For CORESET scheduling the PDSCH, the upper layer parameter tci-PresentInDCI is not set or the PDSCH is scheduled by DCI format 1_0, and the time offset between the reception time of the DL DCI and the reception time of the corresponding PDSCH is a threshold Threshold-Sched -Offset (the threshold is determined based on the reported UE capability ) or greater than or equal to, in order to determine the PDSCH antenna port QCL, the UE is a TCI state for the PDSCH or QCL assumption CORESET used for PDCCH transmission It is assumed that it is the same as the TCI state or QCL assumption applied to.

When the upper layer parameter tci-PresentInDCI is set to 'enabled' and the TCI field in DCI scheduling CC (component carrier) indicates the activated TCI states in the scheduled CC or DL BW (point to), the PDSCH When is scheduled by DCI format 1_1, the UE uses the TCI-State based on the TCI field included in the DCI in the detected PDCCH to determine the PDSCH antenna port QCL. If the time offset between the reception time of the DL DCI and the reception time of the corresponding PDSCH is greater than or equal to a threshold Threshold-Sched-Offset (the threshold is determined based on the reported UE capability), the UE performs the PDSCH of the serving cell. It is assumed that the DMRS port (s) are QCL with RS (s) in the TCI state for the QCL type parameter (s) given by the indicated TCI stated. When a single slot PDSCH is configured for the UE, the indicated TCI state should be based on the activated TCI states in the slot of the scheduled PDSCH. When CORESET associated with a search space set for cross-carrier scheduling is set to the terminal, the terminal assumes that the upper layer parameter tci-PresentInDC I is set to 'enabled' for the CORESET. When one or more TCI states set for the serving cell scheduled by the search area set include 'QCL-TypeD', the terminal is a time between the reception time of the detected PDCCH in the search area set and the reception time of the corresponding PDSCH. The offset is expected to be greater than or equal to the Threshold-Sched-Offset .

Higher layer parameters tci-PresentInDC I is for both cases set to 'enabled', or that in the RRC connected mode is not is the upper layer parameter tci-PresentInDC I set, if between reception of the PDSCH corresponding to the reception of the DL DCI time point offset If this threshold is less than Threshold-Sched-Offset , the terminal assumes the following. (i) The DMRS port (s) of the PDSCH of the serving cell has a QCL relationship to the RS (s) and QCL parameter (s) of the TCI state. (ii) At this time, the QCL parameter (s) is for PDCCH QCL indication of CORESET associated with the search area monitored with the lowest CORESET-ID in the last slot in one or more CORESETs in the activation BWP of the serving cell monitored by the terminal. For both the cases when higher layer parameter tci-PresentInDCI is set to 'enabled' and the higher layer parameter tci-PresentInDCI is not configured in RRC connected mode, if the offset between the reception of the DL DCI and the corresponding PDSCH is less than the threshold Threshold-Sched-Offset, the UE may assume that the DM-RS ports of PDSCH of a serving cell are quasi co-located with the RS (s) in the TCI state with respect to the QCL parameter (s) used for PDCCH quasi co-location indication of the CORESET associated with a monitored search space with the lowest CORESET-ID in the latest slot in which one or more CORESETs within the active BWP of the serving cell are monitored by the UE.)

In this case, when the 'QCL-TypeD' of the PDSCH DMRS is different from the 'QCL-TypeD' of the PDCCH DMRS overlapping on at least one symbol, the UE expects to prioritize the reception of the PDCCH associated with the corresponding CORESET. This operation can also be applied in the case of an intra band CA (if PDSCH and CORESET are in different CCs). If there is no TCI state including 'QCL-TypeD' among the set TCI states, the UE, regardless of the time offset between the reception time of the DL DCI and the reception time of the corresponding PDSCH, indicates the TCI indicated for the scheduled PDSCH. Obtain different QCL assumptions from state.

For periodic CSI-RS resources in the upper layer parameter NZP-CSI-RS-ResourceSet where the upper layer parameter trs-Info is set, the UE should assume that the TCI state indicates one of the following QCL type (s):

-'QCL-TypeC' for the SS / PBCH block, (when applicable) when (QCL-TypeD) is applicable, 'QCL-TypeD' for the same SS / PBCH block, or

-'QCL-TypeC' for SS / PBCH block and 'QCL for periodic CSI-RS resource in upper layer parameter NZP-CSI-RS-ResourceSet in which upper layer parameter repetition is set when (QCL-TypeD) is applicable -TypeD '

For the CSI-RS resource in the upper layer parameter NZP-CSI-RS-ResourceSet set without upper layer parameter trs-Info and upper layer parameter repetition , the terminal should assume that the TCI state indicates one of the following QCL type (s). :

-'QCL-TypeA' for CSI-RS resources in the upper layer parameter NZP-CSI-RS-ResourceSet where the upper layer parameter trs-Info is set, and when (QCL-TypeD) is applicable, for the same CSI-RS resource 'QCL-TypeD', or

-'QCL-TypeA' for the CSI-RS resource in the upper layer parameter NZP-CSI-RS-ResourceSet where the upper layer parameter trs-Info is set, and, for the SS / PBCH block if (QCL-TypeD) is applicable. QCL-TypeD ', or

-When 'QCL-TypeA' and (QCL-TypeD are applicable) for CSI-RS resource in the upper layer parameter NZP-CSI-RS-ResourceSet where the upper layer parameter trs-Info is set, the upper layer parameter repetition is set 'QCL-TypeD' for the periodic CSI-RS resource in the layer parameter NZP-CSI-RS-ResourceSet , or

-When 'QCL-TypeB' and 'QCL-TypeD' for CSI-RS resource in the upper layer parameter NZP-CSI-RS-ResourceSet where the upper layer parameter trs-Info is set is not applicable

For the CSI-RS resource in the upper layer parameter NZP-CSI-RS-ResourceSet where the upper layer parameter repetition is set, the terminal should assume that the TCI state indicates one of the following QCL type (s):

-'QCL-TypeA' for CSI-RS resources in the upper layer parameter NZP-CSI-RS-ResourceSet where the upper layer parameter trs-Info is set, and when (QCL-TypeD) is applicable, for the same CSI-RS resource 'QCL-TypeD', or,

-When 'QCL-TypeA' and (QCL-TypeD are applicable) for CSI-RS resource in the upper layer parameter NZP-CSI-RS-ResourceSet where the upper layer parameter trs-Info is set, the upper layer parameter repetition is set 'QCL-TypeD' for the CSI-RS resource in the layer parameter NZP-CSI-RS-ResourceSet , or

-'QCL-TypeC' for SS / PBCH block and 'QCL-TypeD' for the same SS / PBCH block if (QCL-TypeD) is applicable

For DMRS of the PDCCH, the UE should assume that the TCI state indicates one of the following QCL type (s):

-'QCL-TypeA' for CSI-RS resources in the upper layer parameter NZP-CSI-RS-ResourceSet where the upper layer parameter trs-Info is set, and when (QCL-TypeD) is applicable, for the same CSI-RS resource 'QCL-TypeD', or,

-When 'QCL-TypeA' and (QCL-TypeD are applicable) for CSI-RS resource in the upper layer parameter NZP-CSI-RS-ResourceSet where the upper layer parameter trs-Info is set, the upper layer parameter repetition is set 'QCL-TypeD' for the CSI-RS resource in the layer parameter NZP-CSI-RS-ResourceSet , or

-'QCL-TypeA' for CSI-RS resource in upper layer parameter NZP-CSI-RS-ResourceSet set without upper layer parameter trs-Info and upper layer parameter repetition , and, if (QCL-TypeD) is applicable, the same CSI -'QCL-TypeD 'for RS resource

For DMRS of PDSCH, the UE should assume that the TCI state indicates one of the following QCL type (s):

-'QCL-TypeA' for CSI-RS resources in the upper layer parameter NZP-CSI-RS-ResourceSet where the upper layer parameter trs-Info is set, and when (QCL-TypeD) is applicable, for the same CSI-RS resource 'QCL-TypeD', or,

-When 'QCL-TypeA' and (QCL-TypeD are applicable) for CSI-RS resource in the upper layer parameter NZP-CSI-RS-ResourceSet where the upper layer parameter trs-Info is set, the upper layer parameter repetition is set 'QCL-TypeD' for the CSI-RS resource in the layer parameter NZP-CSI-RS-ResourceSet , or

-'QCL-TypeA' for CSI-RS resource in upper layer parameter NZP-CSI-RS-ResourceSet set without upper layer parameter trs-Info and upper layer parameter repetition , and, if (QCL-TypeD) is applicable, the same CSI -'QCL-TypeD 'for RS resource

1.8. Bandwidth part (BWP)

In the NR system to which the examples of the present disclosure are applicable, up to 400 MHz frequency resources per component carrier (CC) may be allocated / supported. When a UE operating in such a wideband CC always operates with a radio frequency (RF) module for the entire CC turned on, battery consumption of the UE may increase.

Or, considering multiple usage examples operating in one broadband CC (e.g., eMBB (enhanced Mobile Broadband), URLLC, mMTC (massive Machine Type Communication), etc.), different numerology for each frequency band in the CC (eg : sub-carrier spacing) may be supported.

Alternatively, capability for a maximum bandwidth may be different for each UE.

In consideration of such a situation, the base station may instruct / configure the UE to operate only in some bandwidth, not the entire bandwidth of the broadband CC. Here, the corresponding partial bandwidth may be defined as a bandwidth part (BWP).

The BWP may consist of contiguous resource blocks (RBs) on the frequency axis, and one BWP may correspond to one pneumatic (eg, sub-carrier spacing, CP length, slot / mini-slot duration, etc.). have.

Meanwhile, the base station may set multiple BWPs in one CC set for the UE. For example, the base station may set a BWP that occupies a relatively small frequency region in a PDCCH monitoring slot, and schedule a PDSCH indicated by the PDCCH (or PDSCH scheduled by the PDCCH) on a larger BWP. Alternatively, the base station may set some UEs to other BWPs for load balancing when UEs are concentrated on a specific BWP. Alternatively, the base station may set some BWPs in the same slot by excluding some spectrums among the entire bandwidth in consideration of frequency domain inter-cell interference cancellation between neighboring cells.

The base station may set at least one DL / UL BWP to a UE associated with a wideband CC, and at least one DL / UL BWP among DL / UL BWP (s) set at a specific time (first layer signaling ( Example: DCI, etc.), MAC, RRC signaling, etc.) can be activated. At this time, the activated DL / UL BWP may be referred to as an active DL / UL BWP. The UE, such as before the initial access (initial access) process or the RRC connection is set (set up) may not receive the settings for the DL / UL BWP from the base station. DL / UL BWP assumed for this UE is defined as initial active DL / UL BWP.

1.9. CORESET (Control resource set)

One CORESET include N symb CORESET symbols (corresponding value having a value of 1, 2, 3) in the time domain and includes a CORESET N RB of RB in the frequency domain.

One control channel element (CCE) includes 6 resource element groups (REGs), and one REG is the same as one RB on one OFDM symbol. REGs in the CORESET are numbered in order according to the time-first manner. Specifically, the numbering starts from '0' for the first OFDM symbol in CORESET and the lowest-numbered RB.

A plurality of CORESETs may be set for one terminal. Each CORESET is related only to one CCE-to-REG mapping.

CCE-to-REG mapping for one CORESET may be interleaved or non-interleaved.

The setting information for CORESET can be set by the upper layer parameter ControlResourceSet IE.

In addition, setting information for CORESET 0 (eg, common CORESET) can be set by the upper layer parameter ControlResourceSetZero IE.

1.10. Downlink measurement

In order for the base station to support handover operation or inter-cell interference coordination of the terminal, the terminal needs to perform downlink measurement and report it to the base station. In the downlink measurement, there are various measurement methods and measurement values such as measurement for radio link monitoring (RLM), measurement for reporting channel state information (CSI), and measurement for radio resource management (RMM).

The RLM measurement may include, for example, downlink measurement used in the process of detecting a radio link failure (RLF) and finding a new radio link. The measurement for CSI reporting may include, for example, a measurement for the UE to measure and report the quality of a downlink channel, selecting / calculating an appropriate rank indicator, a precoding matrix indicator, and a channel quality indicator. The RRM measurement may include, for example, a measurement for determining whether the terminal is handed over.

RRM measurements include reference signal received power (RSRP), reference signal received quality (RSRQ), received signal strength indicator (RSSI), and signal to noise interference ratio (signal to noise) and interference ratio (SINR).

In the NR system to which the examples of the present disclosure are applicable, one or more of a synchronization signal (SS) or a channel state information reference signal (CSI-RS) is used as a reference signal for RRM measurement. Can be.

SS-RSRP is defined as the linear average of the powers of the resource elements carrying the SSS within the measured frequency bandwidth. The measurement time resource for SS-RSRP is limited within the SS / PBCH block measurement time configuration (SMTC) window section. If SS-RSRP is used for L1-RSRP set by the reporting setting, the measurement time resource limitation by the SMTC window section is not applied.

For SS-RSRP determination, CSI-RS may be utilized as well as SSS as well as PBCH DM-RS and, if indicated from a higher layer. SS-RSRP using PBCH DM-RS or CSI-RS is defined as a linear average of power of a resource element carrying a corresponding reference signal in consideration of power scaling of the reference signal. When SS-RSRP is not used for L1-RSRP, it is not applied that CSI-RS is additionally utilized for SS-RSRP determination.

SS-RSRP can be measured only by reference signals corresponding to an SS / PBCH block having the same SS / PBCH block index and the same physical layer cell identifier.

CSI-RSRP is defined as the linear average of the power of a resource element carrying CSI-RS. At this time, the CSI-RS set for RSRP measurement may be set in the measurement frequency bandwidth considered in the set CSI-RS occasions (CSI-RS occasions).

SS-RSRQ is defined as the value obtained by multiplying SS-RSRP by the number (N) of resource blocks in the NR carrier RSSI measurement bandwidth divided by 'NR carrier RSSI (NR carrier RSSI)' (that is, SS-RSRQ = N × SS-RSRP / (NR carrier RSSI) .Molecular (N × SS-RSRP) and denominator (NR carrier RSSI) are measured for the same set of resource blocks.

'NR carrier RSSI' is the OFDM of the measurement time resource in the measurement bandwidth, over N resource blocks, for received signals from all sources including co-channel serving and non-serving cells, adjacent channel interference, thermal noise, etc. Includes a linear average of the total received power measured by the terminal in symbols only. The measurement time resource for the NR carrier RSSI is limited within the SMTC window section. Additionally, when indicated by a higher layer, the NR carrier RSSI is measured from slots and symbols indicated by higher layer signaling.

CSI-RSRP is defined as a value obtained by multiplying CSI-RSRP by the number of resource blocks (N) in the CSI-RSSI measurement bandwidth by 'CSI-RSSI' (that is, CSI-RSRQ = N × CSI-RSRP / ( CSI RSSI) .Molecular (N × CSI-RSRP) and denominator (CSI-RSSI) are measured for the same set of resource blocks.

'CSI-RSSI' is the OFDM of the measurement time resource in the measurement bandwidth, over N resource blocks, for received signals from all sources including co-channel serving and non-serving cells, adjacent channel interference, thermal noise, etc. Includes a linear average of the total received power measured by the terminal in symbols only. The measurement time resource for the CSI-RSSI corresponds to OFDM symbols including set CSI-RS occasions.

SS-SINR is defined as a value obtained by dividing the linear average of the powers of the resource elements carrying the SSS within the same frequency bandwidth by the linear average of the noise and interference powers of the resource elements carrying the SSS. The measurement time resource for SS-SINR is limited within the SMTC window section. For the SS-SINR determination, PBCH DMRS may be used in addition to SSS.

CSI-SINR is defined as a value obtained by dividing a linear average of power of a resource element carrying CSI-RS within a same frequency bandwidth by a linear average of noise and interference power of a resource element carrying CSI-RS.

1.11. RRC state

17 is a diagram showing an RRC state and an RRC state transition of a terminal. The terminal has only one RRC state at a specific time.

18 is a diagram showing supported mobility procedures between RRC state and RRC state switching of a terminal, as well as between NR / NGC (NR / Next Gen Core) and E-UTRAN / EPC (Evolved-Universal Terrestrial Radio Access Network / Evolved Packet Core). to be.

The RRC state indicates whether the RRC layer of the terminal is logically connected to the layer of NG RAN (Radio Access Network). When an RRC connection is established (established), the UE may be in an RRC_CONNECTED state or an RRC_INACTIVE state. Or, if the RRC connection is not established, the terminal is in the RRC_IDLE state.

In the RRC_CONNECTED state or in the RRC_INACTIVE state, the terminal has an RRC connection, and accordingly, the NG RAN can recognize the presence of the UE in units of cells. On the other hand, in the RRC_IDLE state, the terminal cannot be recognized by the NG RAN, and the terminal is managed by the core network in a tracking area unit wider than the cell.

When the first user turns on the power of the terminal, the terminal finds an appropriate cell and maintains the RRC IDLE state in the cell. When it is only necessary to establish an RRC connection, the terminal in the RRC IDLE state establishes an RRC connection with the NG RAN through the RRC connection procedure, and switches to the RRC_CONNECTED state or RRC_INACTIVE state.

The RRC states of the terminal have the following characteristics.

(1) RRC_IDLE state

-The terminal may be configured for DRX (discontinuous reception) by the upper layer

-Mobility of the terminal is controlled based on the network settings

-The terminal monitors the paging channel

-The terminal performs neighbor cell measurement and cell (re) selection

-The terminal acquires system information

(2) RRC_INACITVE state

-The terminal may be set to DRX (discontinuous reception) by the upper layer or the RRC layer

-Mobility of the terminal is controlled based on the network settings

-The terminal stores the AS (Access Stratum) context

-The terminal monitors the paging channel

-The terminal performs neighbor cell measurement and cell (re) selection

-When moving out of the RAN-based notification area, the terminal performs an RAN-based notification area update

-The terminal acquires system information

(3) RRC_CONNECTED state

-The terminal stores the AS context

-The terminal transmits and receives unicast data

-In the lower layer, the terminal may be configured with a terminal-specific DRX

-For increased bandwidth, a terminal supporting CA (Carrier Aggregation) can use one or more SCell combined with SpCell (Special Cell)

-For increased bandwidth, a terminal supporting dual connectivity (DC) can use a secondary cell group (SCG) combined with a master cell group (MCG)

-The terminal monitors the paging channel

-When data is scheduled for the terminal, the terminal monitors the control channels associated with the shared data channel

-The terminal provides channel quality and feedback information

-The terminal performs neighbor cell measurement and cell (re) selection

-The terminal acquires system information

In particular, the UE in the RRC_IDLE state and the RRC_INACTIVE state may operate as follows.

Figure PCTKR2019014813-appb-img-000010

1.12. DRX (Discontinuous Reception)

A terminal according to an embodiment applicable to the examples of the present description may perform a DRX operation. The terminal in which DRX is set may lower power consumption by discontinuously receiving the DL signal. DRX may be performed in a Radio Resource Control (RRC) _IDLE state, an RRC_INACTIVE state, or an RRC_CONNECTED state. In RRC_IDLE state and RRC_INACTIVE state, DRX is used to discontinuously receive the paging signal. Hereinafter, DRX performed in the RRC_CONNECTED state will be described (RRC_CONNECTED DRX).

19 is a diagram illustrating a DRX cycle of a terminal applicable to the examples of the present description. The DRX cycle shown in FIG. 19 corresponds to the DRX cycle of the terminal in the RRC_CONNECTED state.

Referring to FIG. 19, the DRX cycle is composed of On Duration and Opportunity for DRX. The DRX cycle defines a time interval in which On Duration is periodically repeated. On Duration indicates a time period monitored by the UE to receive the PDCCH. When DRX is configured, the UE performs PDCCH monitoring during On Duration. When there is a successfully detected PDCCH during PDCCH monitoring, the terminal operates an inactivity timer and maintains an awake state. On the other hand, if there is no PDCCH successfully detected during PDCCH monitoring, the terminal enters a sleep state after the On Duration is over. Accordingly, when DRX is set, PDCCH monitoring / reception may be discontinuously performed in the time domain when the UE performs the procedures and / or methods described below. For example, when DRX is set, in the examples of the present description, the PDCCH reception opportunity (eg, a slot having a PDCCH search space) may be discontinuously set according to the DRX setting. On the other hand, if the DRX is not set, the PDCCH monitoring / reception may be continuously performed in the time domain when the UE performs the procedures and / or methods described below. For example, if DRX is not set, in the examples of the present description, the PDCCH reception opportunity (eg, a slot having a PDCCH search space) may be continuously set. Meanwhile, regardless of whether DRX is set, PDCCH monitoring may be limited in a time interval set as a measurement gap.

Table 11 shows a process of a terminal related to DRX (RRC_CONNECTED state). Referring to Table 11, DRX configuration information is received through higher layer (eg, RRC) signaling, and whether DRX ON / OFF is controlled by a DRX command of the MAC layer. When DRX is set, the UE may discontinuously perform PDCCH monitoring in performing the procedures and / or methods described / suggested in the examples of the present disclosure, as illustrated in FIG. 19.

Figure PCTKR2019014813-appb-img-000011

Here, MAC-CellGroupConfig includes configuration information necessary to set a medium access control (MAC) parameter for a cell group. MAC-CellGroupConfig may also include configuration information about DRX. For example, MAC-CellGroupConfig defines DRX and may include information as follows.

-Value of drx-OnDurationTimer: Defines the length of the start section of the DRX cycle

-Value of drx-InactivityTimer: Defines the length of time period in which the UE remains awake after the PDCCH opportunity where the PDCCH indicating the initial UL or DL data is detected.

-Value of drx-HARQ-RTT-TimerDL: Defines the length of the maximum time interval from DL initial transmission to DL retransmission.

-Value of drx-HARQ-RTT-TimerDL: After the grant for UL initial transmission is received, it defines the length of the maximum time interval from when the grant for UL retransmission is received.

-drx-LongCycleStartOffset: Define the length and start time of DRX cycle

-drx-ShortCycle (optional): Defines the length of time of the short DRX cycle

Here, if any one of drx-OnDurationTimer, drx-InactivityTimer, drx-HARQ-RTT-TimerDL, and drx-HARQ-RTT-TimerDL is in operation, the UE maintains the awake state and performs PDCCH monitoring at every PDCCH opportunity.

2. Unlicensed band system

20 shows an example of a wireless communication system supporting an unlicensed band applicable to the examples of the present description.

In the following description, a cell operating in a licensed band (hereinafter, L-band) is defined as an L-cell, and a carrier of the L-cell is defined as (DL / UL) LCC. In addition, a cell operating in an unlicensed band (hereinafter, U-band) is defined as a U-cell, and a carrier of the U-cell is defined as (DL / UL) UCC. The carrier / carrier-frequency of the cell may mean the operating frequency (eg, center frequency) of the cell. The cell / carrier (eg, CC) is collectively referred to as a cell.

When the terminal and the base station transmit and receive signals through carrier-coupled LCC and UCC as shown in FIG. 20 (a), LCC may be set to PCC (Primary CC) and UCC to SCC (Secondary CC).

As shown in FIG. 20 (b), the terminal and the base station may transmit and receive signals through one UCC or a plurality of carrier-coupled LCCs and UCCs. That is, the terminal and the base station can transmit and receive signals through only UCC (s) without LCC.

Hereinafter, the signal transmission / reception operation in the unlicensed band described in the examples of the present disclosure may be performed based on all the above-described deployment scenarios (unless otherwise stated).

2.1. Radio frame structure for unlicensed band

For operation in the unlicensed band, LTE frame structure type 3 (see FIG. 3) or NR frame structure (see FIG. 7) may be used. The configuration of OFDM symbols occupied for uplink / downlink signal transmission in a frame structure for an unlicensed band may be set by a base station. Here, the OFDM symbol may be replaced with an SC-FDM (A) symbol.

For downlink signal transmission through the unlicensed band, the base station may inform the UE of the configuration of OFDM symbols used in subframe #n or slot #n through signaling. In the following description, the subframe or slot may be replaced with a time unit (TU).

2.2. Downlink channel access procedure

The base station may perform the following downlink channel access procedure (CAP) for the unlicensed band to transmit a downlink signal in the unlicensed band. In the following description, assuming a case in which a P cell that is a licensed band and one or more S cells that are one or more unlicensed bands are basically set for a base station, the examples of the present disclosure are indicated by displaying the unlicensed bands as Licensed Assisted Access (LAA) S cells The downlink CAP operation applicable to the description will be described in detail. However, the downlink CAP operation may be equally applied even when only an unlicensed band is set for the base station.

2.2.1. Channel access procedure for transmission including PDSCH / PDCCH / EPDCCH (channel access procedure for transmission (s) including PDSCH / PDCCH / EPDCCH)

The base station senses whether the channel is in an idle state during the slot period of the delay duration T d , and after the counter N is 0 in step 4 below, the next unlicensed band cell (eg, LAA) A transmission including PDSCH / PDCCH / EPDCCH may be transmitted on a carrier where transmission is performed, such as an S cell or an NR-U cell. At this time, the counter N is adjusted by channel sensing for additional slot duration according to the following procedure:

1) Set N = N init . Here, N init is an arbitrary number of evenly distributed between p is from 0 CW (random number uniformly distributed between 0 and CW p). Then, it moves to Step 4.

2) If N> 0 and the base station chooses to decrement the counter, set N = N-1.

3) A channel for an additional slot section is sensed. At this time, when the additional slot section is idle, the process moves to step 4. If not, go to step 5.

4) If N = 0, the procedure is stopped. Otherwise, go to Step 2.

5) Add a delay interval T d in the busy (busy), sensing the channel until the slot is detected or the further delay of all slot interval T d are detected as idle.

6) If the corresponding channel is sensed as idle during all slot periods of the additional delay period T d , the process moves to step 4. If not, go to step 5.

The CAP for transmission including the PDSCH / PDCCH / EPDCCH of the base station described above can be summarized as follows.

21 is a diagram for describing a CAP for unlicensed band transmission applicable to the examples of the present description.

For downlink transmission, a transmission node (eg, a base station) may initiate a channel access process (CAP) to operate in an unlicensed band cell (eg, LAA S cell or NR-U cell, etc.) (S2110).

The base station may arbitrarily select the backoff counter N within the contention window CW according to step 1. At this time, the N value is set to the initial value N init (S2120). N init is selected as any value between 0 and CW p .

Subsequently, if the backoff counter value N is 0 according to step 4 (S2130; Y), the base station ends the CAP process (S2132). Subsequently, the base station may perform Tx burst transmission including PDSCH / PDCCH / EPDCCH (S2134). On the other hand, if the backoff counter value is not 0 (S2130; N), the base station decreases the backoff counter value by 1 according to step 2 (S2140).

Subsequently, the base station checks whether the channel of the unlicensed band cell (eg, LAA S cell or NR-U cell) is idle (S2150), and if the channel is idle (S2150; Y), the backoff counter value is 0. Check whether it is (S2130).

Conversely, if the channel is not idle in step S2150, that is, if the channel is busy (S2150; N), the base station according to step 5, a delay time longer than the slot time (eg, 9usec) (defer duration T d ; 25usec) While), it is checked whether the corresponding channel is idle (S2160). If the channel is idle in the delay period (S2170; Y), the base station can resume the CAP process again.

For example, if the backoff counter value N init is 10 and the backoff counter value is reduced to 5 and the channel is determined to be busy, the base station senses the channel for a delay period to determine whether it is idle. At this time, if the channel is idle during the delay period, the base station does not set the backoff counter value N init , but performs the CAP process again from the backoff counter value 5 (or 4 after decreasing the backoff counter value 1). Can be.

On the other hand, if the channel is busy during the delay period (S2170; N), the base station performs step S2160 again to check whether the channel is idle during the new delay period.

In the above procedure, if the base station after step 4 does not transmit the transmission including PDSCH / PDCCH / EPDCCH on the carrier where the unlicensed band cell (eg, LAA S cell or NR-U cell, etc.) transmission is performed, the base station If the condition is satisfied, a transmission including PDSCH / PDCCH / EPDCCH can be transmitted on the carrier:

If the base station is prepared to transmit PDSCH / PDCCH / EPDCCH and the corresponding channel is sensed as idle during at least the slot period T sl , and immediately before the transmission, the channel is established during all slot periods of the delay period T d immediately before the transmission. When sensing as children

Conversely, when the base station senses the channel after it is prepared to transmit, the channel is not sensed as idle during the slot period T sl , or any one of the delay period T d immediately before the intended transmission. If the channel is not sensed as idle during the period, the base station proceeds to step 1 after the channel is sensed as idle during the slot period of the delay period T d (proceed to step 1).

The delay period T d is composed of a period T f (= 16us) immediately following the m p consecutive slot periods. Here, each slot section T sl is 9us, and T f includes an idle slot section T sl at a starting point of T f .

If the base station senses the channel during the slot period T sl and the power detected by the base station for at least 4us in the slot period is less than the energy detection threshold X Thresh , the slot period T sl is considered as idle. Becomes (be considered to be idle). Otherwise, the slot section T sl is considered busy.

Figure PCTKR2019014813-appb-img-000012
Indicates a contention window. Here, CW p adjustment (CW p adjustment) is described in detail in 2.2.3 described later to section.

Figure PCTKR2019014813-appb-img-000013
And
Figure PCTKR2019014813-appb-img-000014
Is selected before step 1 of the above-described procedure (be chosen before step 1 of the procedure above).

Figure PCTKR2019014813-appb-img-000015
,
Figure PCTKR2019014813-appb-img-000016
And
Figure PCTKR2019014813-appb-img-000017
Is determined based on a channel access priority class related to transmission of the base station (see Table 12 below).

Figure PCTKR2019014813-appb-img-000018
2.2.4. It is adjusted according to the clause.

Figure PCTKR2019014813-appb-img-000019

In the above procedure, when N> 0, when the base station transmits discovery signal transmission that does not include PDSCH / PDCCH / EPDCCH, the base station decrements counter N during a slot period overlapping with the discovery signal transmission. Do not order.

The BS unlicensed band cells (such as: LAA S cell or a NR-U cells, and so on) for a period exceeding the T mcot, p of the table 12 on the carrier wave to be transmitted is performed (for a period exceeding T mcot, p), continuous It does not perform an explicit transmission.

For p = 3 and p = 4 in Table 12, if the absence of other technologies sharing the carrier can be guaranteed for a long period (e.g., by the level of regulation) (if the absence of any other technology sharing the carrier Can be guaranteed on a long term basis (eg, by level of regulation), T mcot, p is set to 10 ms. Otherwise, T mcot, p is set to 8 ms.

2.2.2. Channel access procedure for transmission including discovery signal transmission and not including PDSCH (discovery signal transmission (s) and not including PDSCH)

When the transmission period of the base station is 1 ms or less, the base station transmits an unlicensed band cell (for example, a LAA S cell or an NR-U cell) immediately after the corresponding channel is sensed as an idle for at least a sensing period T drs = 25 us. It is possible to transmit the transmission that includes discovery signal transmission and does not include PDSCH on the carrier. Here, T drs is composed of a section T f (= 16us) immediately following one slot section T sl = 9us. T f includes an idle slot section T sl at the starting point of T f . If the channel is sensed as idle during slot period T drs , the channel is considered idle during T drs (be considered to be idle).

2.2.3. Contention window adjustment procedure

When the base station performs transmission including the PDSCH associated with the channel access priority class p on the carrier, the base station performs 2.2.1. Maintain the contention window value CW p and adjust CW p using the following procedures before step 1 of the procedure detailed in the section (ie, prior to performing the CAP):

1> All priority classes

Figure PCTKR2019014813-appb-img-000020
for,
Figure PCTKR2019014813-appb-img-000021
Set to

2> If at least Z = 80% of HARQ-ACK values corresponding to PDSCH transmission (s) in a reference subframe k is determined as NACK, all priority classes

Figure PCTKR2019014813-appb-img-000022
Increases CW p for the next higher allowed value and remains in step 2 (remain in step 2). If not, go to Step 1.

In other words, when the probability that HARQ-ACK values corresponding to the PDSCH transmission (s) in the reference subframe k is determined to be NACK is at least 80%, the base station allows each set of CW values for each priority class, and then transmits the next value. Increase by rank. Alternatively, the base station maintains the CW values set for each priority class as initial values.

Here, reference subframe k is a starting subframe of the most recent transmission on the carrier made by the base station, where at least some HARQ-ACK feedback is expected to be available (Reference subframe k is the starting subframe of the most recent transmission on the carrier made by the eNB, for which at least some HARQ-ACK feedback is expected to be available).

The base stations are all priority classes

Figure PCTKR2019014813-appb-img-000023
Adjust the CW p value for for based on the reference subframe k given only once.

if

Figure PCTKR2019014813-appb-img-000024
In the case of, the next higher allowed value for the CW p adjustment is
Figure PCTKR2019014813-appb-img-000025
to be.

The probability (Z) that HARQ-ACK values corresponding to PDSCH transmission (s) in the reference subframe k are determined as NACK may be determined in consideration of the following items.

-HARQ-ACK values corresponding to PDSCH transmission (s) in subframe k and additionally subframe k + 1 when the transmission (s) of the base station for which HARQ-ACK feedback is available starts in the second slot of subframe k HARQ-ACK values corresponding to my PDSCH transmission (s) are also used

-If the HARQ-ACK values are the same unlicensed band cell allocated by (E) PDCCH transmitted from an unlicensed band cell (eg, LAA S cell or NR-U cell, etc.) (eg, LAA S cell or NR-U cell, etc.) ) On the PDSCH transmission (s),

   -If HARQ-ACK feedback for PDSCH transmission by the base station is not detected, or if the base station detects 'DTX', 'NACK / DTX' or other (any) status, it is counted as NACK (it is counted as NACK).

-If the HARQ-ACK values are assigned by (E) PDCCH transmitted from an unlicensed band cell (eg, LAA S cell or NR-U cell), other unlicensed band cell (eg, LAA S cell or NR-U cell, etc.) ) On the PDSCH transmission (s),

   -If HARQ-ACK feedback for PDSCH transmission by the base station is detected, the 'NACK / DTX' or other (any) state is counted as NACK and the 'DTX' state is ignored.

   -If HARQ-ACK feedback for PDSCH transmission by the base station is not detected,

      -When PUCCH format 1 with channel selection applied by the base station is expected to be used, the 'NACK / DTX' state corresponding to 'no transmission' is counted as NACK, The 'DTX' status corresponding to 'non-transmission' is ignored. Otherwise, HARQ-ACK for the PDSCH transmission is ignored.

-If PDSCH transmission has 2 codewords, the HARQ-ACK value of each codeword is considered individually.

-Bundled HARQ-ACK across M subframes (MQ) are considered M HARQ-ACK responses.

If the base station transmits a PDCCH / EPDDCH (PDCCH / EDPCCH with DCI format 0A / 0B / 4A / 4B) of DCI format 0A / 0B / 4A / 4B and does not include a PDSCH associated with channel access priority class p When transmitting on a channel starting from t 0 , the base station 2.2.1. Maintain the contention window size CW p and adjust CW p using the following procedures before step 1 of the procedure detailed in the section (ie, prior to performing the CAP):

1> All priority classes

Figure PCTKR2019014813-appb-img-000026
for,
Figure PCTKR2019014813-appb-img-000027
Set to

2> 10% of the UL transmission block scheduled by the base station from the UE using the type 2 channel access procedure (type 2 channel access procedure, detailed in Section 2.3.1.2.) During the time period t 0 and t 0 + T CO If less than is successfully received, all priority classes

Figure PCTKR2019014813-appb-img-000028
Increases CW p for the next higher allowed value and remains in step 2 (remain in step 2). If not, go to Step 1.

Here, T CO is 2.3.1. Is calculated according to the clause.

if

Figure PCTKR2019014813-appb-img-000029
The case to be used in K times in succession to produce the N init, the only use by K times in succession to produce the N init
Figure PCTKR2019014813-appb-img-000030
Only CW p for priority classes for p is reset to CW min, p. At this time, K is each priority class
Figure PCTKR2019014813-appb-img-000031
For {1, 2, ..., 8} is selected by the base station from the set of values.

2.2.4. Energy detection threshold adaptation procedure

The base station accessing the carrier where the unlicensed band cell (eg, LAA S cell or NR-U cell) transmission is performed sets the energy detection threshold (X Thresh ) to a maximum energy detection threshold X Thresh_max or less.

At this time, the maximum energy detection threshold X Thresh_max is determined as follows.

-If the absence of any other technology sharing the carrier can be guaranteed for a long period (e.g., by the level of regulation) (if the absence of any other technology sharing the carrier can be guaranteed on a long term basis (eg, by level of regulation)),

-

Figure PCTKR2019014813-appb-img-000032

-Here, X r is a maximum energy detection threshold (in dBm) defined in regulatory requirements when a rule is defined. If not,

Figure PCTKR2019014813-appb-img-000033

-If not,

-

Figure PCTKR2019014813-appb-img-000034

-Here, each variable is defined as follows.

Figure PCTKR2019014813-appb-img-000035

2.2.5. Channel access procedure for transmission (s) on multiple carriers

The base station may access multiple carriers on which unlicensed band cell (eg, LAA S cell or NR-U cell) transmission is performed through one of the following type A or type B procedures.

2.2.5.1. Type A multi-carrier access procedures

In accordance with the procedures disclosed in this section, the base station is configured for each carrier.

Figure PCTKR2019014813-appb-img-000036
Perform phase channel access. Here, C is a set of (intend to transmit) carrier to be transmitted by the base station,
Figure PCTKR2019014813-appb-img-000037
And q is the number of carriers to be transmitted by the base station.

2.2.1. The counter N of the clause (i.e. counter N considered in the CAP) is the carrier of each

Figure PCTKR2019014813-appb-img-000038
It is decided by each. In this case, the counter for each carrier is
Figure PCTKR2019014813-appb-img-000039
Is indicated. At this time,
Figure PCTKR2019014813-appb-img-000040
2.2.5.1.1. Or 2.2.5.1.2. It is maintained according to the clause.

2.2.5.1.1. Type A1

2.2.1. The counter N of the clause (i.e., the counter N considered in the CAP) is for each carrier.

Figure PCTKR2019014813-appb-img-000041
Is determined independently, and the counter for each carrier is
Figure PCTKR2019014813-appb-img-000042
Is indicated.

Base station is one carrier

Figure PCTKR2019014813-appb-img-000043
In case of cease phase transmission, if absence of other technology sharing the carrier can be guaranteed for a long period (e.g., by the level of regulation) (if the absence of any other technology sharing the carrier can be guaranteed on a long term basis (eg, by level of regulation)), each carrier c i (where c i differs from c j ,
Figure PCTKR2019014813-appb-img-000044
)for,
Figure PCTKR2019014813-appb-img-000045
After waiting for a section of or
Figure PCTKR2019014813-appb-img-000046
If the idle slot is detected after re-initializing, the base station
Figure PCTKR2019014813-appb-img-000047
The reduction can be resumed.

2.2.5.1.2. Type A2

Each carrier

Figure PCTKR2019014813-appb-img-000048
The star counter N is described above in 2.2.1. It can be determined according to the section, where each carrier counter
Figure PCTKR2019014813-appb-img-000049
Is indicated. here,
Figure PCTKR2019014813-appb-img-000050
Can mean a carrier having the largest CW p value. Each carrier
Figure PCTKR2019014813-appb-img-000051
for,
Figure PCTKR2019014813-appb-img-000052
Can be set to

Base station

Figure PCTKR2019014813-appb-img-000053
When issuing (cease) the transmission for any one carrier is determined, the base station is for all carriers
Figure PCTKR2019014813-appb-img-000054
To reinitialize.

2.2.5.2. Type B multi-carrier access procedure

carrier

Figure PCTKR2019014813-appb-img-000055
Can be selected as follows by the base station.

-The base station is multi-carrier

Figure PCTKR2019014813-appb-img-000056
Uniformly randomly from the C prior to transmission of each phase
Figure PCTKR2019014813-appb-img-000057
Select or

-The base station is at least once every 1 second

Figure PCTKR2019014813-appb-img-000058
Do not select.

Here, C is a set of (intend to transmit) carrier to be transmitted by the base station,

Figure PCTKR2019014813-appb-img-000059
And q is the number of carriers to be transmitted by the base station.

carrier

Figure PCTKR2019014813-appb-img-000060
For transmission on the base station, the base station is 2.2.5.2.1. Section or 2.2.5.2.2. Along with the modifications disclosed in Section 2.2.1. Carrier according to the procedure described in the section
Figure PCTKR2019014813-appb-img-000061
Channel connection.

Figure PCTKR2019014813-appb-img-000062
Of carriers
Figure PCTKR2019014813-appb-img-000063
For transmission on the

Each carrier

Figure PCTKR2019014813-appb-img-000064
For, the base station is a carrier
Figure PCTKR2019014813-appb-img-000065
At least immediately before the transmission on the (immediately) sensing interval (sensing interval)
Figure PCTKR2019014813-appb-img-000066
While carrier
Figure PCTKR2019014813-appb-img-000067
To sense. And, the base station is at least a sensing section
Figure PCTKR2019014813-appb-img-000068
While carrier
Figure PCTKR2019014813-appb-img-000069
Immediately after sensing that they are children (immediately after)
Figure PCTKR2019014813-appb-img-000070
You can perform the transmission on. Given interval
Figure PCTKR2019014813-appb-img-000071
My carrier
Figure PCTKR2019014813-appb-img-000072
When the channel is sanded to idle during all time periods during which phase idle sensing is performed, the carrier
Figure PCTKR2019014813-appb-img-000073
The
Figure PCTKR2019014813-appb-img-000074
For children can be considered.

The base station is a carrier

Figure PCTKR2019014813-appb-img-000075
(At this time,
Figure PCTKR2019014813-appb-img-000076
) For a period exceeding the T mcot, p of the table 12 on (for a period exceeding mcot T, p) it does not perform successive transmission. Where T mcot, p is the carrier
Figure PCTKR2019014813-appb-img-000077
It is determined using the channel access parameters used for.

2.2.5.2.1. Type B1

A single CW p value is maintained for carrier set C.

carrier

Figure PCTKR2019014813-appb-img-000078
To determine CW p for the phase channel access, the previous 2.2.3. Step 2 of the procedure described above in the section is modified as follows.

-All carriers

Figure PCTKR2019014813-appb-img-000079
At least of HARQ-ACK values corresponding to PDSCH transmission (s) in reference subframe k of
Figure PCTKR2019014813-appb-img-000080
Is determined to be NACK, all priority classes
Figure PCTKR2019014813-appb-img-000081
CW p for is increased to the next higher allowed value. If not, go to Step 1.

2.2.5.2.2. Type B2

2.2.3. Using the procedure described in the section, the CW p value is

Figure PCTKR2019014813-appb-img-000082
For independent maintenance. carrier
Figure PCTKR2019014813-appb-img-000083
To determine N init for, carrier
Figure PCTKR2019014813-appb-img-000084
The CW p value of is used. here,
Figure PCTKR2019014813-appb-img-000085
Is the carrier with the largest CW p of all carriers in set C.

2.3. Uplink channel access procedures

The UE and the base station scheduling the UL transmission for the UE perform the following procedure for access to a channel performing transmission (s) of an unlicensed band cell (eg, LAA S cell or NR-U cell). In the following description, it is basically assumed that a P cell that is a licensed band and a S cell that is one or more unlicensed bands are set for a terminal and a base station, and the unlicensed band is indicated as a LAA S cell and is applicable to the examples of the present description. The uplink CAP operation will be described in detail. However, the uplink CAP operation may be equally applied even when only an unlicensed band is set for the terminal and the base station.

2.3.1. Channel access procedure for uplink transmission (channel access procedure for uplink transmission (s))

The UE may access an unlicensed band cell (eg, LAA S cell or NR-U cell, etc.) on a carrier on which UL transmission (s) are performed according to a type 1 or type 2 UL channel access procedure. Type 1 channel access procedure is as follows 2.3.1.1. This is detailed in the section. For the type 2 channel access procedure, see 2.3.1.2. This is detailed in the section.

If the UL grant for scheduling PUSCH transmission indicates a type 1 channel access procedure, the UE performs a type 1 channel access to perform transmission including the PUSCH transmission, unless otherwise stated in this section.

If the UL grant for scheduling PUSCH transmission indicates a type 2 channel access procedure, the UE performs a type 2 channel access to perform transmission including the PUSCH transmission, unless otherwise specified in this section.

For SRS (Sounding Reference Signal) transmission that does not include PUSCH transmission, the UE performs a type 1 channel connection. UL channel access priority class p = 1 is used for SRS transmission without PUSCH.

Figure PCTKR2019014813-appb-img-000086

When the 'UL configuration for LAA' field sets 'UL offset' l and 'UL duration' d for subframe n,

If the end of UE transmission occurs within or before subframe n + l + d-1, the UE transmits subframe n + l + i (here,

Figure PCTKR2019014813-appb-img-000087
) A type 2 channel access procedure may be used for intra-transmission.

If the UE uses PDCCH DCI format 0B / 4B, a subframe set

Figure PCTKR2019014813-appb-img-000088
Scheduled to perform transmission including my PUSCH, and the UE is a subframe
Figure PCTKR2019014813-appb-img-000089
When the channel connection for my transmission is not possible, the UE subframes according to the channel connection type indicated in the DCI.
Figure PCTKR2019014813-appb-img-000090
Shall attempt to make a transmission. here,
Figure PCTKR2019014813-appb-img-000091
And w is the number of scheduling subframes indicated in the DCI.

If the UE uses one or more PDCCH DCI formats 0A / 0B / 4A / 4B, a set of subframes

Figure PCTKR2019014813-appb-img-000092
It is scheduled to perform transmission without gaps including PUSCH (transmission without gaps including PUSCH), and the subframe after the UE accesses to a carrier according to one of the type 1 or type 2 channel access procedure
Figure PCTKR2019014813-appb-img-000093
When performing my transmission, the UE is a subframe
Figure PCTKR2019014813-appb-img-000094
After that, transmission may continue (may continue transmission in subframe after
Figure PCTKR2019014813-appb-img-000095
). here,
Figure PCTKR2019014813-appb-img-000096
to be.

If the start of UE transmission in subframe n + 1 immediately follows the end of UE transmission in subframe n (immediately follow), the UE does not expect that different channel access types are indicated for transmission in the subframe.

If the UE uses one or more PDCCH DCI format 0A / 0B / 4A / 4B

Figure PCTKR2019014813-appb-img-000097
Scheduled to perform my transmission without gaps (transmission without gaps), if the UE is a subframe
Figure PCTKR2019014813-appb-img-000098
(here,
Figure PCTKR2019014813-appb-img-000099
) Stops transmission during or before, and if the corresponding channel is continuously sensed as idle by the UE after the UE stops transmission, the UE subframes
Figure PCTKR2019014813-appb-img-000100
After (here,
Figure PCTKR2019014813-appb-img-000101
) Transmission can be performed using a type 2 channel access procedure. If the channel is not continuously sensed as idle by the UE after the UE stops transmitting, the UE subframes
Figure PCTKR2019014813-appb-img-000102
After (here,
Figure PCTKR2019014813-appb-img-000103
) Subframe
Figure PCTKR2019014813-appb-img-000104
The transmission may be performed using the type 1 channel access procedure of the UL channel access priority class indicated in DCI corresponding to.

If the UE receives the UL grant and DCI instructs to start PUSCH transmission in subframe n using the type 1 channel access procedure, if the UE continues the type 1 channel access procedure before subframe n (the UE has an ongoing Type 1 channel access procedure before subframe n),

-If the UL channel access priority class value p 1 used for an ongoing type 1 channel access procedure is greater than or equal to the indicated UL channel access priority class value p 2 in the DCI, the UE responds to the UL grant Thus, PUSCH transmission may be performed by accessing a carrier using an ongoing type 1 channel access procedure.

-If the UL channel access priority class value p 1 used for the ongoing type 1 channel access procedure is smaller than the UL channel access priority class value p 2 indicated in the DCI, the UE proceeds with the channel access procedure in progress Terminate (terminate).

If the UE is scheduled to transmit on carrier set C in subframe n, if the UL grant scheduling PUSCH transmission on carrier set C indicates a type 1 channel access procedure, if the same for all carriers in carrier set C ' PUSCH starting position 'is indicated, and if the carrier frequencies of carrier set C are a subset of one of the preset carrier frequency sets,

-The UE is a carrier using a type 2 channel access procedure

Figure PCTKR2019014813-appb-img-000105
You can perform the transmission on.

-If carrier

Figure PCTKR2019014813-appb-img-000106
Phase (where,
Figure PCTKR2019014813-appb-img-000107
) Immediately before the UE transmission (immediately before) carrier
Figure PCTKR2019014813-appb-img-000108
When the type 2 channel access procedure is performed on the, and

-If the UE is a carrier using a type 1 channel access procedure

Figure PCTKR2019014813-appb-img-000109
(The UE has accessed carrier
Figure PCTKR2019014813-appb-img-000110
using Type 1 channel access procedure),

-Prior to performing a type 1 channel access procedure on any one carrier in carrier set C

Figure PCTKR2019014813-appb-img-000111
Is uniformly randomly selected from the carrier set C by the UE.

Base station 2.2.1. When performing a carrier transmission according to the channel access procedure disclosed in the section (the base station has transmitted on the carrier according to the channel access procedure described in clause 2.2.1), the base station transmits the PUSCH on the carrier in subframe n. A type 2 channel access procedure may be indicated in the DCI of the UL grant for scheduling the included transmission.

Or, the base station 2.2.1. When performing a carrier transmission according to the channel access procedure described in the section, the base station uses the 'UL Configuration for LAA' field to allow the UE to transmit a type 2 channel access procedure for transmission including PUSCH on a carrier in subframe n. It can indicate that it can be performed.

Alternatively, the sub-frame n = t 0 when occurring within the starting and ending time period to t 0 + T CO from the base station is a carrier

Figure PCTKR2019014813-appb-img-000112
In subframe n following transmission by the base station having a length, a transmission including a PUSCH on a corresponding carrier may be scheduled. here,
Figure PCTKR2019014813-appb-img-000113
And each variable can be defined as follows.

-t 0 : Time instant when the base station starts transmitting (time instant)

-T mcot, p : 2.2. Determined by base station according to clause

-T g : Total interval of all gap intervals greater than 25us occurring between DL transmission of the base station starting from t 0 and UL transmission scheduled by the base station and between any two UL transmissions scheduled by the base station

If UL transmissions are continuously scheduled, the base station schedules UL transmissions between consecutive subframes in t 0 and t 0 + T CO .

Figure PCTKR2019014813-appb-img-000114
For UL transmission on the carrier following transmission of the base station on the carrier in length, the UE may perform a type 2 channel access procedure for the UL transmission.

If the base station instructs the type 2 channel access procedure for the UE in DCI, the base station indicates the channel access priority class used to obtain the channel access in the DCI (If the base station indicates Type 2 channel access procedure for the UE in the DCI, the base station indicates the channel access priority class used to obtain access to the channel in the DCI).

2.3.1.1. Type 1 UL channel access procedure

After sensing that the channel is idle during the slot period of the delay period T d and the counter N becomes 0 in step 4, the UE may perform transmission using a type 1 channel access procedure. At this time, the counter N is adjusted by sensing a channel for the additional slot period (s) according to the following procedure.

1) Set N = N init . Here, N init is an arbitrary number of evenly distributed between p is from 0 CW (random number uniformly distributed between 0 and CW p). Then, it moves to Step 4.

2) If N> 0 and the UE chooses to decrement the counter, set N = N-1.

3) A channel for an additional slot section is sensed. Then, when the additional slot section is idle, the process moves to step 4. If not, go to step 5.

4) If N = 0, the procedure is stopped. Otherwise, go to Step 2.

5) Add a delay interval T d in the busy (busy), sensing the channel until the slot is detected or the further delay of all slot interval T d are detected as idle.

6) If the channel is sensed as idle during all slot periods of the additional delay period T d , the process moves to step 4. If not, go to step 5.

In summary, the above-described type 1 UL CAP of the UE can be summarized as follows.

For uplink transmission, a transmission node (eg, UE) may initiate a channel access process (CAP) to operate in an unlicensed band cell (eg, LAA S cell or NR-U cell) (S2110).

The UE may arbitrarily select the backoff counter N within the contention window (CW) according to step 1. At this time, the N value is set to the initial value N init (S2120). N init is selected as any value between 0 and CW p .

Subsequently, if the backoff counter value N is 0 according to step 4 (S2130; Y), the UE ends the CAP process (S2132). Subsequently, the UE may perform Tx burst transmission (S2134). On the other hand, if the backoff counter value is not 0 (S2130; N), the UE decreases the backoff counter value by 1 according to step 2 (S2140).

Subsequently, the UE checks whether the channel of the unlicensed band cell (eg, LAA S cell or NR-U cell) is idle (S2150), and if the channel is idle (S2150; Y), the backoff counter value is 0 Check whether it is (S2130).

On the contrary, if the channel is not idle in step S2150, that is, if the channel is busy (S2150; N), the UE according to step 5 has a longer delay time than the slot time (eg, 9usec) (defer duration T d ; 25usec) While), it is checked whether the corresponding channel is idle (S2160). If the channel is idle in the delay period (S2170; Y), the UE may resume the CAP process again.

For example, if the backoff counter value N init is 10 and the backoff counter value is reduced to 5 and the channel is determined to be busy, the UE senses whether the channel is idle by sensing the channel for a delay period. At this time, if the channel is idle during the delay period, the UE does not set the backoff counter value N init , but performs the CAP process again from the backoff counter value 5 (or 4 after decreasing the backoff counter value 1). Can be.

On the other hand, if the channel is busy during the delay period (S2170; N), the UE performs step S2160 again to check whether the channel is idle during the new delay period.

When the UE does not transmit the transmission including the PUSCH on the carrier on which the transmission (s) is performed after the step 4 of the above-described procedure in step 4 above, the unlicensed band cell (eg, LAA S cell or NR-U cell, etc.) is performed. The UE may transmit transmission including PUSCH on the carrier when the following conditions are satisfied.

-When the UE is ready to perform transmission including PUSCH and the corresponding channel in at least the slot interval T sl is sensed as idle, and

-When the channel is sensed as idle during all slot periods of the delay period T d immediately before transmission including the PUSCH (immediately before)

Conversely, if the channel is first sensed after the UE is ready to perform the transmission, the channel in the slot period T sl is not sensed as idle, or the delay period T d immediately before the intended transmission including PUSCH. If the corresponding channel is not sensed as idle during a slot period, the UE proceeds to step 1 after the corresponding channel is sensed as idle during slot periods of the delay period T d .

The delay period T d is composed of a period T f (= 16us) immediately following the m p consecutive slot periods. Here, each slot section T sl is 9us, and T f includes an idle slot section T sl at a starting point of T f .

If the UE senses a channel during the slot period T sl and the power measured by the UE for at least 4us within the slot period is less than the energy detection threshold XT hresh , the slot period T sl is considered to be idle (be considered to be idle ). Otherwise, the slot section T sl is considered busy.

Figure PCTKR2019014813-appb-img-000115
Indicates a contention window. Here, CW p adjustment (CW p adjustment) will be described in detail in 2.3.2 described later to section.

Figure PCTKR2019014813-appb-img-000116
And
Figure PCTKR2019014813-appb-img-000117
Is selected before step 1 of the above-described procedure (be chosen before step 1 of the procedure above).

Figure PCTKR2019014813-appb-img-000118
,
Figure PCTKR2019014813-appb-img-000119
And
Figure PCTKR2019014813-appb-img-000120
Is determined based on a channel access priority class signaled to the UE (see Table 13).

Figure PCTKR2019014813-appb-img-000121
2.3.3. It is adjusted according to the clause.

2.3.1.2. Type 2 UL channel access procedure

If the UE uses a type 2 channel access procedure for transmission including PUSCH, the UE has at least a sensing period

Figure PCTKR2019014813-appb-img-000122
In the meantime, immediately after sensing that the channel is idle (immediately after), transmission including the PUSCH may be transmitted. T short_ul is one slot interval
Figure PCTKR2019014813-appb-img-000123
Immediately following (immediately followed)
Figure PCTKR2019014813-appb-img-000124
It consists of. T f includes an idle slot section T sl at the starting point of the T f . If the phase is sensed as idle during the slot T short_ul , the channel is considered idle during the T short_ul .

2.3.2. Contention window adjustment procedure

If the UE performs transmission using a type 1 channel access procedure related to a channel access priority class p on a carrier, the UE performs 2.3.1.1. Maintain the contention window value CW p and adjust CW p using the following procedures before step 1 of the procedure detailed in the section (ie, prior to performing the CAP):

-When the NDI (New Data Indicator) value for at least one HARQ process associated with HARQ_ID_ref is toggled,

-All priority classes

Figure PCTKR2019014813-appb-img-000125
for,
Figure PCTKR2019014813-appb-img-000126
Set to

-If not, all priority classes

Figure PCTKR2019014813-appb-img-000127
Increase CW p for the next higher allowed value

Here, HARQ_ID_ref is the HARQ process ID of the UL-SCH in the reference subframe n ref . The reference subframe n ref is determined as follows.

-When the UE receives the UL grant in the subframe n g . Here, the subframe n w is the most recent subframe before the subframe n g -3 in which the UE transmits the UL-SCH using a type 1 channel access procedure.

-If the UE is a subframe

Figure PCTKR2019014813-appb-img-000128
In the case where transmission starts from subframe n 0 and includes a gapless UL-SCH, reference subframe n ref is subframe n 0 .

-If not, the reference subframe n ref is a subframe n w .

If the UE is a subframe set

Figure PCTKR2019014813-appb-img-000129
Within the PUSCH, the gapless transmission is scheduled to be transmitted using a type 1 channel access procedure, and if the UE cannot perform any transmission including the PUSCH in the subframe set, the UE Priority class
Figure PCTKR2019014813-appb-img-000130
To keep CW p value unchanged.

If the latest scheduling subframe for transmission is also a subframe

Figure PCTKR2019014813-appb-img-000131
If, the UE is all priority class
Figure PCTKR2019014813-appb-img-000132
The CW p value for the may use the recently scheduled Type 1 channel access procedure and maintain the same as the CW p value for transmission including PUSCH.

if

Figure PCTKR2019014813-appb-img-000133
In the case of, the next higher allowed value for the CW p adjustment is
Figure PCTKR2019014813-appb-img-000134
to be.

if

Figure PCTKR2019014813-appb-img-000135
The case to be used in K times in succession to produce the N init, the only use by K times in succession to produce the N init
Figure PCTKR2019014813-appb-img-000136
Only CW p for priority classes for p is reset to CW min, p. At this time, K is each priority class
Figure PCTKR2019014813-appb-img-000137
For {1, 2, ..., 8} is selected by the UE from the set of values.

2.3.3. Energy detection threshold adaptation procedure

The UE accessing the carrier where the unlicensed band cell (eg, LAA S cell or NR-U cell) transmission is performed sets the energy detection threshold (X Thresh ) to a maximum energy detection threshold X Thresh_max or less.

At this time, the maximum energy detection threshold X Thresh_max is determined as follows.

-If the UE is set with the upper layer parameter 'maxEnergyDetectionThreshold-r14',

-X Thresh_max is set equal to the value signaled by the upper layer parameter.

-If not,

-The UE is 2.3.3.1. X ' Thresh_max is determined according to the procedure described in the section.

   -If the UE is set with the upper layer parameter maxEnergyDetectionThresholdOffset-r14 ',

-X Thresh_max is set to X ' Thresh_max adjusted according to the offset value signaled by the upper layer parameter.

   -If not,

-The UE

Figure PCTKR2019014813-appb-img-000138
Set to

2.3.3.1. Default maximum energy detection threshold computation procedure

If the upper layer parameter 'ab senceOfAnyOtherTechnology-r14' indicates TRUE:

-

Figure PCTKR2019014813-appb-img-000139

-Here, X r is a maximum energy detection threshold (in dBm) defined in regulatory requirements when a rule is defined. If not,

Figure PCTKR2019014813-appb-img-000140

If not:

-

Figure PCTKR2019014813-appb-img-000141

-Here, each variable is defined as follows.

Figure PCTKR2019014813-appb-img-000142

2.4. Subframe / slot structure applicable to unlicensed band system

22 is a diagram illustrating a partial TTI (partial TTI) or a partial subframe / slot applicable to the examples of the present description.

In the Release-13 LAA system, a partial TTI defined as DwPTS is defined in order to make the most of MCOT in DL transmission burst transmission and support continuous transmission. The partial TTI (or partial subframe) refers to an interval in which a signal is transmitted only a length smaller than a conventional TTI (eg, 1 ms) in transmitting a PDSCH.

In the examples of the present description, for convenience of explanation, a starting partial TTI (starting partial TTI) or a starting partial subframe / slot refers to a form in which some symbols in the front frame are emptied, and an ending partial TTI (Ending Partial TTI) or ending partial The subframe / slot refers to a form in which some symbols behind the subframe are emptied. (On the other hand, an intact TTI is referred to as a normal TTI or full TTI.)

22 is a view showing various forms of the partial TTI described above. The first figure of FIG. 22 shows the ending partial TTI (or subframe / slot), and the second figure shows the starting partial TTI (or subframe / slot). In addition, the third diagram of FIG. 22 shows a partial TTI (or subframe / slot) in a form in which some of the front and rear symbols in the subframe / slot are emptied. Here, the time interval excluding signal transmission in the general TTI is called a transmission gap (TX gap).

However, although the description of FIG. 22 is based on the DL operation, the same may be applied to the UL operation. For example, a form in which PUCCH and / or PUSCH is transmitted may also be applied to a partial TTI structure illustrated in FIG. 22.

3. Example of operation of the terminal and the base station according to the examples of the present description

Hereinafter, an operation example of the terminal and the base station according to the examples of the present description will be described in more detail.

3.0. Network connection and communication process applicable to the examples in this description

The terminal may perform a network access process to perform various operation examples of the present disclosure. For example, the terminal may receive and store system information and configuration information necessary for performing various operation examples of the present disclosure while performing a connection to a network (eg, a base station). Configuration information necessary for the examples of the present description may be received through higher layer (eg, RRC layer; Medium Access Control, MAC, layer, etc.) signaling.

23 is a diagram illustrating a network initial access and subsequent communication processes applicable to various operation examples of the present disclosure. In the NR system, a physical channel and a reference signal can be transmitted using beam-forming. When beam-forming-based signal transmission is supported, a beam management process may be performed to align beams between a base station and a terminal. Further, the signal / channel proposed in various operation examples of the present disclosure may be transmitted / received using beam-forming. Beam alignment in a Radio Resource Control (RRC) IDLE mode may be performed based on a Synchronization Signal Block (SSB). On the other hand, beam alignment in RRC CONNECTED mode may be performed based on CSI-RS (in DL) and SRS (in UL). On the other hand, when beam-forming-based signal transmission is not supported, a beam-related operation may be omitted in the following description.

Referring to FIG. 23, a base station (eg, BS) may periodically transmit an SSB (S2302). Here, the SSB includes a Primary Synchronization Signal (PSS) / Secondary Synchronization Signal (SSS) / PBCH. The SSB can be transmitted using beam sweeping. Thereafter, the base station may transmit Remaining Minimum System Information (RMSI) and Other System Information (OSI) (S2304). The RMSI may include information (eg, PRACH configuration information) necessary for the UE to initially access the base station. Meanwhile, the terminal performs SSB detection and then identifies the best SSB. Thereafter, the terminal may transmit the RACH preamble (Message 1, Msg1) to the base station by using the PRACH resource linked / corresponding to the index (ie, beam) of the best SSB (S2306). The beam direction of the RACH preamble is associated with PRACH resources. Association between PRACH resources (and / or RACH preamble) and SSB (index) may be established through system information (eg, RMSI). Subsequently, as part of the RACH process, the base station transmits a random access response (RAR) (Msg2) in response to the RACH preamble (S2308), and the terminal uses Msg3 (eg, RRC Connection Request) using the UL grant in the RAR. Transmit (S2310), the base station may transmit a contention resolution (contention resolution) message (Msg4) (S2312). Msg4 may include RRC Connection Setup.

When an RRC connection is established between the base station and the UE through the RACH process, subsequent beam alignment may be performed based on SSB / CSI-RS (in DL) and SRS (in UL). For example, the terminal may receive SSB / CSI-RS (S2314). SSB / CSI-RS may be used by the UE to generate a beam / CSI report. Meanwhile, the base station may request the beam / CSI report to the terminal through DCI (S2316). In this case, the UE may generate a beam / CSI report based on the SSB / CSI-RS, and transmit the generated beam / CSI report to the base station through PUSCH / PUCCH (S2318). The beam / CSI report may include beam measurement results, information on a preferred beam, and the like. The base station and the terminal can switch the beam based on the beam / CSI report (S2320a, S2320b).

Thereafter, the terminal and the base station can perform various examples proposed in the present description. For example, the terminal and the base station process the information in the memory according to the examples of the present description based on the configuration information obtained in the network access process (eg, system information acquisition process, RRC connection process through RACH, etc.) The signal may be transmitted or the received wireless signal may be processed and stored in a memory. Here, the radio signal may include at least one of PDCCH, PDSCH, and RS (Reference Signal) for downlink, and at least one of PUCCH, PUSCH, and SRS for uplink.

In the following description, partial PDSCH (eg, PDSCH having a symbol length shorter than the PDSCH scheduled by the base station) is indicated as “pPDSCH”.

In the following description, TBS means Transport Block Size, and SLIV means “Starting and Length Indicator Value”. The SLIV field may correspond to an indication field for the number of symbols and the start symbol index in the slot of the PDSCH and / or PUSCH. The SLIV field may be transmitted through PDCCH (or DCI) scheduling the corresponding PDSCH and / or PUSCH.

In the following description, BWP means a bandwidth part. The BWP may be composed of continuous resource blocks (RBs) on the frequency axis. The BWP may correspond to one numerology (eg, sub-carrier spacing, CP (Cyclic Prefix) length, slot / mini-slot duration). Multiple BWPs in one carrier may be set. At this time, the maximum number of BWPs that can be set in one carrier may be separately set. However, the number of activated BWPs may be limited to some BWPs in the carrier (eg, 1 BWP).

In the following description, CORESET means a control resource set. CORESET may mean a time / frequency resource region in which PDCCH can be transmitted. The number of CORESETs in one BWP can be set or limited separately.

In the following description, SFI means a slot format indicator. SFI is an indicator indicating a symbol-level DL / UL direction in a specific slot (s), and the SFI may be transmitted through a group common PDCCH (DCI).

Based on the above technical matters, the terminal and the base station may operate as follows. After the base station succeeds in the channel access procedure (CAP) (or using the CAP), the DL transmission start time is (i) the middle of a slot other than the slot boundary (slot boundary), or (ii) the BS starts after the intended DL transmission start time. In the case of, the some symbols / frequency regions of the parasitic PDSCH may not be transmitted. At this time, a PDSCH in which some symbol / frequency domains are not transmitted is called a pPDSCH for convenience.

In this document, various operation examples applicable to the scheduling and transmission method and the reception method for the corresponding pPDSCH are described in detail.

In the following description, the CAP success time may mean a time point at which the base station starts transmitting a DL signal using the CAP. The end of the CAP may mean that the base station starts DL signal transmission using the CAP.

24 is a diagram briefly showing an example of the operation disclosed in this document.

As shown in FIG. 24, the base station can schedule the PDSCH of 14 symbols long on slot # N + 1 to the UE. However, when the actual CAP success time of the base station is a time after the eighth symbol (eg, symbol # 7) included in slot # N + 1, the base station, based on at least one of the following methods, slots A pPDSCH of 6 symbols in # N + 1 can be configured and transmitted to the terminal.

-Alt. 1: punctured 8 symbols of the PDSCH prepared in advance by the base station (or pre-scheduled to the UE) and transmits the pPDSCH composed of only the remaining 6 symbols to the UE

-Alt. 2: A pPDSCH composed of only the first 6 symbols of a PDSCH prepared in advance (or pre-scheduled to the UE) by the base station is transmitted to the UE. The remaining 8 symbols are not transmitted by puncturing.

-Alt. 3: Configure pPDSCH by performing rate matching according to the length of 6 symbols actually transmitted by the base station

In this case, in this document, a method of providing a starting symbol (or resource region) of a pPDSCH applicable to the examples to the terminal, a method of providing a PDSCH DM-RS transmission resource region to the terminal, and a method of scheduling the pPDSCH, etc. It will be described in detail. In the following description, unless otherwise stated, the methods proposed in this description are described in Alt. It can be applied to all of them.

25 is a diagram briefly showing another example of operation disclosed in this document.

As shown in FIG. 25, the base station may transmit a preconfigured PDSCH from a symbol after the end of the CAP regardless of slot boundaries (without puncturing / rate-matching of the preconfigured PDSCH). In other words, (i) a preconfigured (or scheduled to the UE) PDSCH has a length of 14 symbols, and (ii) based on the CAP of the base station, the signal transmission of the base station is from a symbol other than the first symbol in slot # N + 1. When starting, the base station may transmit the PDSCH of the 14 symbol length from the symbol after the end of the CAP (without considering slot boundaries). Correspondingly, the terminal can receive the PDSCH of the 14 symbol length from the base station (without consideration of slot boundaries).

In this case, in this document, a method of providing a starting symbol (or resource region) of a pPDSCH applicable to the examples to the terminal, a method of providing a PDSCH DM-RS transmission resource region to the terminal, and a method of scheduling the pPDSCH, etc. It will be described in detail. At this time, "preconfigured PDSCH" may be replaced with "pPDSCH" according to an operation example.

In this document, the PDCCH (or signal / channel, etc. that can inform information on the start symbol index of the pPDSCH) that basically schedules the pPDSCH is within the same slot example (eg partial slot) on an unlicensed band cell (aka Ucell). It is assumed to be transmitted. However, according to an embodiment, corresponding operation examples are transmitted on a PDCCH (or a signal / channel that can inform information on a pPDSCH start symbol index) on a carrier (eg, a licensed band or an unlicensed band) in which pPDSCH is not transmitted, or The PDCCH (or a signal / channel that can inform information about a pPDSCH start symbol index) is transmitted in a slot (s) that is later than a slot in which the pPDSCH is transmitted. In addition, SLIV information transmitted through the PDCCH can be set to indicate information set based on a start symbol and a number of symbols of a previously prepared PDSCH regardless of an actual pPDSCH start symbol index. Based on the SLIV information, the base station can calculate / instruct the TBS, and the terminal can also calculate the TBS value through the SLIV value in the PDCCH regardless of the actual starting time of the pPDSCH.

More specifically, the terminal may receive a PDCCH for scheduling pPDSCH and recognize a start symbol of pPDSCH. Subsequently, the terminal may receive the pPDSCH based on the recognized start symbol of the pPDSCH.

In addition, in response to the operation example of the terminal, the base station may transmit a PDCCH for scheduling the pPDSCH to the terminal, and implicitly / explicitly indicate / set the start symbol of the pPDSCH. Through this, the base station can support the UE to receive the pPDSCH based on the start symbol of the pPDSCH.

Accordingly, hereinafter, specific examples in which the UE recognizes the start symbol of the pPDSCH and / or specific examples in which the base station indicates the pPDSCH start symbol to the UE are described in detail.

3.1. pPDSCH start symbol signaling / recognition method

3.1.1. First pPDSCH start symbol signaling / recognition method

The UE receiving the pPDSCH may recognize the pPDSCH start symbol based on the PDCCH (or a separate PDCCH transmitted in the corresponding slot) scheduling the corresponding pPDSCH. In response to this, the base station may signal the pPDSCH start symbol to the UE through the PDCCH (or a separate PDCCH transmitted in the corresponding slot) for scheduling the pPDSCH. In this case, the separate PDCCH may include a PDCCH including information such as SFI and / or information about a channel occupancy time (COT) occupied by the base station, or may include a PDCCH defined separately.

Accordingly, in the following description, an example of a related operation is described based on a PDCCH for scheduling a pPDSCH, but the examples may be applied to the case of a separate PDCCH transmitted in a corresponding slot.

3.1.1.1. 1-1 pPDSCH start symbol signaling / recognition method

The base station may signal the start symbol position of the actual pPDSCH to the UE through a separate field included in the PDCCH. In other words, the base station may signal the starting point of the pPDSCH to the UE based on a separate field other than the SLIV field included in the PDCCH. In response to this, the terminal may recognize the start time of the actual pPDSCH based on the information signaled in a separate field other than the SLIV field.

The starting symbol position of the corresponding pPDSCH is (i) a method in which an absolute symbol index is signaled in the corresponding slot through the separate field, or (ii) a method in which an offset value from a starting symbol index indicated by SLIV is signaled. It can be determined on the basis of.

According to this method, the terminal acquires information on the starting symbol of the pPDSCH through explicit signaling, and has an advantage that the starting symbol of the pPDSCH can be more clearly known.

3.1.1.2. 1-2 pPDSCH start symbol signaling / recognition method

The base station may signal the start (or last next or specific) symbol index of the PDCCH (or CORESET) in the same slot for scheduling the pPDSCH to the UE as the start symbol index of the pPDSCH. Correspondingly, the UE may recognize the start (or last next or specific) symbol index of the PDCCH (or CORESET) for scheduling the pPDSCH as the start symbol index of the pPDSCH.

As a specific example, it is assumed in the example of FIG. 24 that the base station transmits a PDCCH for scheduling pPDSCH on slot # N + 1 to the UE. In other words, it is assumed in the example of FIG. 24 that the UE receives the PDCCH scheduling the pPDSCH on slot # N + 1, and decodes the PDCCH to obtain SLIV field information included in the PDCCH. In this case, when the starting symbol index indicated by the SLIV field is the first symbol (eg symbol # 0), the starting symbol index where the corresponding PDCCH is actually transmitted / received is the ninth symbol (eg symbol # 8), The base station can continuously transmit the pPDSCH from the ninth symbol (for example, symbol # 8). Correspondingly, the UE may recognize that (i) the PDSCH scheduled by the corresponding PDCCH is pPDSCH, and (ii) the starting symbol index of the pPDSCH is the ninth symbol (eg symbol # 8).

According to this method, there is an advantage that the base station does not need to configure the PDCCH differently according to the pPDSCH actual start symbol index.

To this end, the start symbol index of the pPDSCH may be set by upper layer signaling whether to recognize the start or end of the PDCCH (or CORESET) scheduling the pPDSCH (or in the same slot) or as a symbol index.

Alternatively, different rules may be applied to the starting symbol index of the pPDSCH according to the relationship between the resource region of the PDCCH (or CORESET) and the resource region of the scheduled pPDSCH.

For example, when the frequency resource region of the PDCCH (or CORESET) and the frequency resource region of the scheduled pPDSCH overlap, the start symbol index of the pPDSCH is the last next symbol index of the PDCCH (or CORESET) that schedules the pPDSCH (in the same slot) Can be As another example, when the frequency resource region of the PDCCH (or CORESET) and the frequency resource region of the scheduled pPDSCH do not overlap, the start symbol index of the pPDSCH (in the same slot) the start symbol index of the PDCCH (or CORESET) for scheduling the pPDSCH. Can be Alternatively, even if the frequency resource region of the PDCCH (or CORESET) and the frequency resource region of the scheduled pPDSCH overlap, the start symbol index of the pPDSCH is set to the start symbol index of the PDCCH (or CORESET) scheduling the pPDSCH (in the same slot) However, the pPDSCH of the region overlapping with the PDCCH (or CORESET) may not be transmitted and may be punctured (or rate-matched).

Alternatively, different rules may be applied to the starting symbol index of the pPDSCH according to the location of the resource region of the PDCCH (or CORESET).

For example, if the start symbol index of a PDCCH (or CORESET) scheduling a pPDSCH is X or less, the start symbol index of a pPDSCH is the last next symbol of a PDCCH (or CORESET) scheduling a pPDSCH (in the same slot) Can be determined / set by index. As another example, if the starting symbol index of the PDCCH (or CORESET) scheduling the pPDSCH is greater than X, the starting symbol index of the pPDSCH (in the same slot) is the starting symbol index of the PDCCH (or CORESET) scheduling the pPDSCH. Can be determined / set to.

In this description, PDCCH (or CORESET) means a PDCCH (or a corresponding CORESET) scheduling a corresponding pPDSCH, or all or some PDCCHs (or CORESETs) within a PDCCH monitoring occasion set in a corresponding slot. Can mean

3.1.1.3. 1-3 pPDSCH start symbol signaling / recognition method

The base station may signal the start symbol index of the pPDSCH to the UE based on the separate PDCCH information in the same slot as the pPDSCH. In response to this, the UE can recognize the start symbol index of the pPDSCH based on the separate PDCCH information in the same slot as the pPDSCH. For example, when the corresponding PDCCH can inform the SFI of the current slot, the symbol index indicated by the first DL (from the start or last symbol of the corresponding PDCCH or CORESET) of the corresponding SFI is the start symbol index of the pPDSCH. Signaling / recognition / determination.

3.1.2. Second pPDSCH start symbol signaling / recognition method

The base station transmitting the pPDSCH may signal the pPDSCH start symbol index to the UE based on the initial signal transmitted in the corresponding slot. In response to this, the UE receiving the pPDSCH may recognize the pPDSCH start symbol index based on the initial signal transmitted in the corresponding slot.

Characteristically, in a licensed band (or licensed carrier), at least periodicity of a signal / channel that needs to be periodically transmitted, such as a reference signal for measurement purposes, can be guaranteed. On the other hand, in the unlicensed band (or unlicensed carrier), if the signal transmitting entity does not occupy the unlicensed band (eg, LBT / CAP fails), the signal transmitting entity may not attempt to transmit a specific signal. Accordingly, a separate signal may be required to inform whether or not the actual signal is transmitted on the unlicensed band. In this document, such signals are referred to as initial signals. The initial signal may be transmitted in the first part of the TX burst on the unlicensed band, or may be transmitted in a specific unit time (eg, per slot boundary) within the TX burst.

The base station may signal the start (or last next or specific) symbol index of the initial signal in the slot for scheduling the pPDSCH to the UE as the start symbol index of the pPDSCH. Based on the initial signal, the UE may recognize the start (or last next or specific) symbol index of the initial signal (in the same slot) for scheduling the pPDSCH as the start symbol index of the pPDSCH. For example, in the example of FIG. 24, the base station may transmit pPDSCH from the ninth symbol on slot # N + 1 and transmit the initial signal from the ninth symbol to the UE. Through this method, the base station can signal the start symbol index of the corresponding pPDSCH to the terminal. As another example, in the example of FIG. 24, the UE receives the initial signal in the ninth symbol on slot # N + 1, performs buffering from the corresponding point, and then schedules the pPDSCH of slot # N + 1 on slot # N + 2. It is assumed that has been received. In this case, the UE may receive the pPDSCH while considering that the ninth symbol of slot # N + 1 is the start symbol index of the corresponding pPDSCH.

Based on the above-described various examples of the same, the UE can recognize the start symbol of the pPDSCH, and can receive the pPDSCH from the recognized start symbol index of the pPDSCH.

Independent of the above and various operation examples, the base station may signal the terminal of the last symbol of the pPDSCH. In response to this, the terminal can receive the pPDSCH up to the last symbol index of the recognized pPDSCH. At this time, the terminal can receive the pPDSCH by determining scheduling information based on the start / last symbol of the pPDSCH.

Hereinafter, various operation examples in which the base station indicates the pPDSCH last symbol to the terminal and / or various operation examples in which the terminal recognizes the pPDSCH last symbol will be described in detail.

3.2. pPDSCH last symbol signaling / recognition method

3.2.1. First pPDSCH last symbol signaling / recognition method

Assuming that the SLIV information on the PDCCH indicates the start symbol and the number of symbols of the PDSCH prepared in advance (or prescheduled) regardless of the start symbol index of the actual pPDSCH, the UE determines the pPDSCH last symbol index based on the SLIV information. Can be recognized.

At this time, a system constraint (eg, 2/4/7 symbols) may be applied to the number of transmission symbols of the pPDSCH. In this case, the last symbol position of the pPDSCH is (i) less than the number of symbols from the starting symbol index of the actual pPDSCH to the last symbol index (indicated by SLIV information) and (ii) the largest allowed pPDSCH transmission symbol due to system constraints. The last symbol position of the pPDSCH may be determined based on the number.

For example, the number of transmission symbols of pPDSCH is one of 2/4/7, and the PDSCH starting symbol index is 3 and the number of symbols is 7 (that is, the last symbol index of the corresponding PDSCH is 10) by SLIV information on the PDCCH. I assume. In this case, when the starting symbol index of the actual pPDSCH is 8, the number of symbols of the corresponding pPDSCH becomes 3, and thus 2 pPDSCH transmissions, which are the largest allowed number of transmission symbols among 3 or less, may be defined. At this time, the starting symbol index of pPDSCH (based on the starting symbol index of the pPDSCH) may be 8, the number of symbols may be 2, or the starting symbol index of pPDSCH (based on the ending symbol index of the pPDSCH) may be 9, and the number of symbols may be 2. .

Depending on the operation example, this restriction can be applied only when set to PDSCH mapping type B.

For reference, type A and type B may be defined as the PDSCH mapping type on the NR system.

First, in the case of type A, the symbol to which the DMRS for PDSCH is mapped is set to the third symbol (eg symbol # 2) or the fourth symbol (eg symbol # 3) in the slot regardless of the starting position and length of the PDSCH. Can be. In this case, the PDSCH may have 3 to 12 (or 14) symbol lengths.

On the other hand, in the case of type B, the location of the symbol to which the DMRS for PDSCH is mapped may be set as the first symbol of the assigned PDSCH. At this time, the PDSCH may have only a predetermined symbol length (eg, 2, 4, 7 symbol lengths, etc.). Or, even in this case, the PDSCH may have 3 to 12 (or 14) symbol lengths.

3.2.2. 2nd pPDSCH last symbol signaling / recognition method

In order to guarantee pPDSCH transmission as much as possible, the base station may transmit a corresponding pPDSCH (regardless of the slot boundary) by spanning the number of symbols on the SLIV from the starting symbol index of the pPDSCH. Correspondingly, when the UE recognizes the pPDSCH start symbol based on the various method (s) described above, the UE spans the corresponding pPDSCH (regardless of the slot boundary) by the number of symbols on the SLIV from the start symbol index. span) (eg, see FIG. 25).

Additionally, a rule that the last maximum symbol index of the pPDSCH according to the assumption is limited to a slot ending boundary or a specific symbol index may be applied. In this case, the specific symbol index may be set by higher layer signaling or L1 signaling (eg, DCI).

For example, based on the indication of the PDSCH whose L value is 7 and the S value is the fifth symbol (eg symbol # 4) by SLIV, even if the corresponding PDSCH is actually transmitted from the ninth symbol (eg symbol # 8), , The terminal can operate as follows. As a specific example, (i) the terminal may perform PDSCH reception for a period of 7 symbols from a corresponding start symbol based on a L value of 7, or (ii) a ninth symbol (eg: symbol # 8), the PDSCH can be received for a length of 6 symbols (that is, the last symbol index is the fourth symbol (eg symbol # 13)).

Correspondingly, despite the fact that the PDSCH having the L value of 7 and the S value of the fifth symbol (for example, symbol # 4) is indicated in SLIV transmitted through a specific PDCCH, the base station actually performs the PDSCH ninth due to the nature of the unlicensed band. When transmitting from a symbol (for example, symbol # 8), the base station transmits a PDSCH to the UE for 7 symbol periods from a corresponding start symbol based on (i) L value equal to 7, or (ii) end of a slot The PDSCH may be transmitted for a length of 6 symbols starting from the ninth symbol (eg symbol # 8) considering the boundary (ie, the last symbol index is the fourteenth symbol (eg symbol # 13)).

At this time, restrictions may be set on the number of transmission symbols of the pPDSCH. For example, the number of transmission symbols of the pPDSCH may be limited to only a few symbols such as 2, 4, and 7 symbols. Accordingly, the last symbol position (or number of symbols) of the actually transmitted pPDSCH is the number of symbols less than or equal to the number of symbols from the start symbol index of the actual pPDSCH to the last symbol index indicated by SLIV among the limited number of symbols. It can be determined based on.

For example, it is assumed that the number of transmission symbols of the pPDSCH is limited to 2, 4 or 7 symbol lengths, and the PDSCH starting symbol index is 3 and the number of symbols is indicated 7 by SLIV information on the PDCCH (ie, by the PDCCH). Assume that the last symbol index of the scheduled PDSCH is 10). In this case, if the actual pPDSCH starting symbol index is 8 (due to the nature of the unlicensed band), (i) the number of symbols of the pPDSCH is determined to be 6 symbols according to the aforementioned method (assuming that the symbol index in the slot is 0 to 13). ), (ii) The maximum number of allowed transmission symbols among 6 or less is 4, and finally, pPDSCH transmission with 4 symbol lengths may be defined / assumed / set.

In this case, the starting symbol index of pPDSCH (based on the starting symbol index of the pPDSCH) is set to 8, the number of symbols is set to 4, or the starting symbol index of pPDSCH (based on the ending boundary of the slot) is set to 10, and the number of symbols is set to 4 Can be.

Depending on the operation example, this restriction can be applied only when set to PDSCH mapping type B.

In addition, in the NR system to which the examples of the present disclosure are applicable, the location of a DMRS symbol to which an actual demodulation reference signal (DMRS) is transmitted may vary according to SLIV. Accordingly, in the examples of the present disclosure, a method in which the base station signals the location of the DMRS symbol to the terminal and / or a method in which the terminal recognizes the location of the DMRS symbol may be considered together. Hereinafter, various operation examples in which the base station signals the location of the DMRS symbol to the terminal and / or various operation examples in which the terminal recognizes the location of the DMRS symbol will be described in detail.

3.3. DMRS transmission symbol signaling / recognition method

3.3.1. First DMRS transmission symbol signaling / recognition method

As described above, in the NR system, the DMRS symbol position may be set differently according to SLIV. Assuming that the SLIV information on the PDCCH is indicated based on the number of start symbols and symbols of the PDSCH prepared in advance (or pre-scheduled) regardless of the actual pPDSCH start symbol index, (i) the terminal positions the DMRS symbol based on the corresponding SLIV information Recognizing, but (ii) based on the above-mentioned pPDSCH start symbol signaling / recognition method and / or pPDSCH last symbol signaling / recognition method, etc., based on recognizing a symbol period in which pPDSCH is transmitted, the terminal does not transmit pPDSCH. It can be assumed that DMRS is not transmitted at the location of the DMRS symbol in the symbol region.

For example, if the DMRS symbol position recognized by the UE based on SLIV information is the third and tenth symbols in the slot (ie, symbol # 2, symbol # 9), the pPDSCH is transmitted in the corresponding slot and the actual pPDSCH Based on the start symbol index being the ninth symbol (eg symbol # 8), the terminal does not transmit DMRS in the third symbol (eg symbol # 2) and DMRS in the tenth symbol (eg symol # 9). It can be recognized that it has been transmitted.

Correspondingly, in transmitting the pPDSCH from the ninth symbol (eg symbol # 8), the base station does not transmit DMRS in the third symbol (eg symbol # 2) and the tenth symbol (eg symol # 9). In the DMRS can be transmitted.

According to the operation example, there may not be any DMRS transmission symbol in the symbol region in which the actual pPDSCH is transmitted. In other words, the DMRS may not be transmitted on at least one or more symbols in a symbol region in which an actual pPDSCH is transmitted.

In this case, the UE cannot properly receive the corresponding pPDSCH. Accordingly, the terminal may receive a pPDSCH based on another DMRS transmission symbol recognition method (eg, a second / third DMRS transmission symbol recognition method, etc.) instead of the first DMRS transmission symbol recognition method described above. In other words, the base station may transmit the pPDSCH based on another DMRS transmission symbol signaling method (eg, second / third DMRS transmission symbol signaling method, etc.) instead of the first DMRS transmission symbol signaling method.

Alternatively, according to an operation example, the UE may receive a pPDSCH based on a DMRS transmission symbol recognition method other than the first DMRS transmission symbol recognition method (eg, a second / third DMRS transmission symbol recognition method, etc.). In response to this, the base station may transmit the pPDSCH to the UE based on a DMRS transmission symbol signaling method other than the first DMRS transmission symbol signaling method (eg, a second / third DMRS transmission symbol signaling method, etc.).

3.3.2. Second DMRS transmission symbol signaling / recognition method

When the UE recognizes the start symbol and / or the last symbol of the pPDSCH based on the above-described various pPDSCH start symbol recognition method and / or the pPDSCH last symbol recognition method, the terminal based on the recognized start / last symbol of the pPDSCH DMRS transmission symbols can be reinterpreted. Or, if the base station signals the start symbol and / or the last symbol of the pPDSCH to the terminal based on the various pPDSCH start symbol signaling methods and / or the pPDSCH last symbol signaling method described above, the terminal may transmit the pPDSCH based on the corresponding signaling. For the DMRS transmission symbol can be reinterpreted.

To this end, the DMRS symbol position (or DMRS symbol set) may be independently set according to the symbol length (L) value indicated by SLIV.

For example, it is assumed that there is a DMRS symbol set # 1 defined when L = 7 and a DMRS symbol set # 2 defined when L = 6. In this case, when the corresponding PDSCH is actually transmitted from the ninth symbol (for example, symbol # 8) for a PDSCH having an L value of 7 and an S value of 5 symbols on the SLIV, the UE considers the slot termination boundary and Example: starting from symbol # 8, pPDSCH can be received for a length of 6 symbols (ie, the UE receives the pPDSCH under the assumption that the last symbol index of the pPDSCH is the fourth symbol (eg symbol # 13)). . In this case, the terminal may determine the location of the DMRS symbol based on the DMRS symbol set # 2 rather than the DMRS symbol set # 1.

In other words, a SLIV field having an L value of 7 and an S value of 5 symbols is transmitted to the UE through the PDCCH transmitted by the base station, but the base station transmits the actual pPDSCH in the ninth symbol (for example, symbol # 8 due to the nature of the unlicensed band). When starting transmission from), the base station may transmit the pPDSCH to the UE only for a period of 6 symbols from the ninth symbol (for example, symbol # 8) in consideration of the slot termination boundary. In this case, the applied DMRS symbol position may be determined based on the DMRS symbol set # 2, not the DMRS symbol set # 1.

Depending on the operation example, this restriction can be applied only when set to PDSCH mapping type A.

3.3.3. Third DMRS transmission symbol recognition method

According to the above method, the DMRS symbol position for pPDSCH may be set / indicated by separate rules and / or signaling.

For example, when the UE recognizes the start symbol of the pPDSCH based on the above-described method for recognizing the start symbol of the pPDSCH, the UE may assume that the DMRS is transmitted after a certain symbol offset from the recognized start symbol index of the pPDSCH. . Correspondingly, when the base station signals the start symbol of the pPDSCH through the above-described start symbol signaling method of pPDSCH, the base station may transmit DMRS through a symbol after a certain symbol offset from the corresponding symbol index.

At this time, the offset value may be set differently depending on whether the set PDSCH mapping type is PDSCH mapping type A or type B. The offset value for each type may be set / instructed based on upper layer signaling or L1 signaling (eg, DCI).

Depending on the operation example, this restriction can be applied only when set to PDSCH mapping type B.

26 is a diagram illustrating a location of a DMRS symbol according to an example of the present disclosure.

As illustrated in FIG. 26, (i) a PDSCH prepared in advance (or scheduled) by a base station or (ii) a PDSCH scheduled through PDCCH may be allocated from symbol # 4 to symbol # 10 in a length of 7 symbols. At this time, the DMRS symbol may be indicated as an additional symbol. For example, the DMRS symbol position may be set to the first symbol (eg symbol # 4) and the fifth symbol (eg symbol # 8) of the corresponding PDSCH.

Accordingly, (i) the transmission time of the pPDSCH is delayed based on the CAP success time of the base station, or (ii) based on the above-described pPDSCH start symbol recognition method, the terminal sets the start symbol index of the pPDSCH to symbol # 8 It can be assumed.

27 and 28 are diagrams illustrating DMRS symbol positions according to another example of the present disclosure.

As shown in FIG. 27 or FIG. 28, based on the above-described second pPDSCH last symbol recognition method, the starting symbol index of the pPDSCH is 8, the last symbol index (based on the slot end boundary) is 13, and of the pPDSCH The length can be set / assumed to be 6 symbol lengths.

In this case, the DMRS transmission symbol position may be set / assumed to the DMRS set / indicated for a 6-symbol length pPDSCH and an additional DMRS position (eg, a second DMRS transmission symbol recognition method). Or, if the length of the pPDSCH is different from the length information in the PDCCH (for example, the L value indicated by the SLIV field), the DMRS transmission symbol is set only as the first symbol (without additional DM-RS) based on a predefined appointment. It may be (eg, a method of recognizing a third DMRS transmission symbol).

29 is a diagram showing the location of a DMRS symbol according to another example of the present disclosure.

As shown in FIG. 29, based on the above-mentioned third pPDSCH last symbol recognition method, the starting symbol index of the pPDSCH is 8, and considering the ending symbol index of the scheduled PDSCH, the last symbol index is 10, and of the pPDSCH The length can be set / assumed to be 3 symbol lengths.

In this case, the DMRS transmission symbol position may be set / assumed as a DMRS set / indicated for a 3 symbol length pPDSCH and an additional DMRS position (eg, a second DMRS transmission symbol recognition method). Or, if the length of the pPDSCH is different from the length information in the PDCCH (for example, the L value indicated by the SLIV field), the DMRS transmission symbol is set only as the first symbol (without additional DM-RS) based on a predefined appointment. It may be (eg, a method of recognizing a third DMRS transmission symbol).

30 is a diagram illustrating a location of a DMRS symbol according to another example of the present disclosure.

30, CORESET is set to symbol # 0 in a slot, and a PDCCH for scheduling a PDSCH in a corresponding slot may be transmitted through the CORESET. In this case, (i) the corresponding PDSCH prepared in advance (or pre-scheduled) by the base station, or (ii) PDSCH scheduled through the corresponding PDCCH may be allocated from symbol # 2 to symbol # 10 in 9 symbol length. At this time, the DMRS symbol may be indicated as an additional symbol. For example, the DMRS symbol position may be set to a fourth symbol (eg symbol # 3) and a tenth symbol (eg symbol # 9) in a slot.

Depending on the operation example, this restriction can be applied only when set to PDSCH mapping type A.

Accordingly, (i) the transmission time of the pPDSCH is delayed based on the CAP success time of the base station, or (ii) the start symbol index of the pPDSCH is set to symbol # 5 based on the above-described pPDSCH start symbol recognition method or the like (or PDCCH indicating SFI in symbol # 5 is transmitted / discovered), or (iii) based on the above-described pPDSCH start symbol recognition method, the UE may assume that the start symbol index of pPDSCH is set to symbol # 6.

31 to 33 are diagrams illustrating DMRS symbol positions according to another example of the present disclosure.

As shown in FIGS. 31 to 33, based on the method for recognizing the third pPDSCH last symbol, the starting symbol index of the pPDSCH is 6, the last symbol index of 10 (taking into account the ending symbol index of the scheduled PDSCH), and the pPDSCH The length of may be set / assumed to be 5 symbol lengths.

As a specific example, based on the method of recognizing the third DMRS transmission symbol as shown in FIG. 31, the UE considers the offset value for the DMRS symbol from the PDCCH (or CORESET) start (or last) symbol of FIG. 30 and DMRS at symbol # 8. It can recognize that is transmitted (or DMRS is received).

As another specific example, when the length of the pPDSCH is different from the length information in the PDCCH (for example, the L value indicated by the SLIV field) based on the method of recognizing the third DMRS transmission symbol as shown in FIG. 32, the UE may be previously defined. By appointment, it can be recognized that DMRS is transmitted (or DMRS is received) only in the first symbol (without additional DM-RS or considered mapping type B).

As another specific example, when the length of the pPDSCH is different from the length information in the PDCCH (for example, the L value indicated by the SLIV field) based on the method of recognizing the second DMRS transmission symbol as shown in FIG. 33, the UE is 5 symbols long It can be recognized that the DMRS is transmitted (or DMRS is received) in the DMRS set / indicated for (mapping type B) pPDSCH and additional DMRS locations.

34 is a flowchart simply illustrating an example of an operation of a terminal according to the present description.

The terminal according to the present description, (i) receives a PDCCH (or DCI) scheduling a pPDSCH, and (ii) various methods described above (eg, pPDSCH start symbol recognition method, pPDSCH last symbol recognition method, DM-RS transmission) Scheduling information for a pPDSCH based on a symbol recognition method, etc., and (iii) the pPDSCH (on an unlicensed band) using the determined scheduling information.

35 is a flowchart briefly illustrating an example of an operation of a base station according to the present disclosure.

The base station according to the present description configures / lives (i) PDSCH (s) on the assumption that DL transmission including PDSCH transmission can be started from the slot boundary, and (ii) DL transmission on an unlicensed band using CAP (eg: PDSH (s). At this time, if the CAP process of the base station succeeds in the middle of a specific slot (or when the base station starts DL transmission using a CAP from a specific symbol in a slot rather than a slot boundary), the base station determines the corresponding time point (that is, the CAP process is PPDSCH transmission can be started from the point of success). At this time, the base station may signal scheduling information for the pPDSCH to the UE based on the above-described pPDSCH start symbol signaling method, pPDSCH last symbol signaling method, and / or DM-RS transmission symbol signaling method.

36 is a diagram briefly showing the operation of a terminal and a base station applicable to the present disclosure, FIG. 37 is a flowchart briefly showing the operation of a terminal applicable to the present disclosure, and FIG. 38 is a simple diagram showing the operation of a base station applicable to the present disclosure It is a flow chart.

As described above, for the above-described operation, the terminal may perform an initial access (or random access) procedure to the base station. More specifically, the terminal may establish an (RRC) connection with the base station through the procedure of (i) RA preamble transmission, (ii) RAR message reception, etc. for the base station supporting unlicensed band. Subsequently, the terminal and the base station may perform the following operations.

Alternatively, the terminal may set the DRX mode by the base station, and perform the above-described operation based on the DRX mode. In response to this, the base station may set the DRX mode to the terminal and perform the following operations on the terminal set to the DRX mode.

First, the base station may perform a channel access procedure (CAP) for the unlicensed band for signal transmission on the unlicensed band (S3610, S3810). Based on the CAP (eg, when the base station occupies the unlicensed band, etc.), the base station may transmit scheduling information related to PDSCH to the terminal on the unlicensed band (S3620, S3820).

In response to this, the terminal may receive scheduling information related to a physical downlink shared channel (PDSCH) from the base station (S3620, S3710). At this time, the scheduling information may be received through the unlicensed band.

In the present disclosure, the scheduling information may include one or more of the following information.

-Start symbol information for which the PDSCH is scheduled

-Symbol length information of the scheduled PDSCH

In the present disclosure, the scheduling information may be received through a starting and length indicator value (SLIV) field in the PDCCH.

The UE may determine a symbol position in which an actual PDSCH (actual PDSCH) is received from the base station through the unlicensed band in one slot determined based on the scheduling information (S3630).

The terminal, based on (i) the scheduling information and (ii) the symbol position where the actual PDSCH is received, through the N symbols starting from the symbol position where the actual PDSCH is received on the unlicensed band from the base station A demodulation reference signal (DMRS) and a data signal may be received (S3650, S3730). Here, as N, one or more natural numbers may be applied.

Correspondingly, the base station, in one slot determined based on the scheduling information, actually or partially or entirely of the scheduled PDSCH based on a channel access procedure (CAP) for the unlicensed band N symbols to which PDSCH (actual PDSCH) is transmitted may be determined (S3640, S3830). Subsequently, the base station may transmit the DMRS and the data signal to the terminal through the N symbols on the unlicensed band (S3650, S3840).

In the present disclosure, the DMRS is included in (i) one or more DMRS candidate transmission symbols determined based on the scheduling information, and (ii) the N symbols starting from the symbol position at which the actual PDSCH is received. Can be received through M symbols. Here, as M, a natural number less than or equal to N may be applied.

Or, in the present disclosure, an N value may be determined based on the scheduling information. In this case, the DMRS may be received through M DMRS transmission symbols determined based on the N value among the N symbols starting from the symbol position where the actual PDSCH is received. Here, as M, a natural number less than or equal to N may be applied.

In this case, the N value may correspond to one of the following values.

-Among candidate transmission symbols for a preset PDSCH, a maximum candidate value less than or equal to the number of symbols from the symbol position to which the actual PDSCH is received in one slot to the boundary of the slot,

-The symbol length value of the scheduled PDSCH indicated by the scheduling information

-The number of symbols from the symbol position to which the actual PDSCH is received in the one slot to the boundary of the slot

Alternatively, in this case, according to the N value, the location of the M DMRS transmission symbols among the N symbols may be preset.

As another example, in the present disclosure, the terminal, through the unlicensed band, determining the symbol position at which the actual PDSCH is received from the base station may include one of the following.

-Based on the signaling information received from the base station, the terminal determines the symbol position where the actual PDSCH is received

-Based on the symbol location where the scheduling information is received, the terminal determines the symbol location where the actual PDSCH is received

-The UE determines the symbol position at which the actual PDSCH is received, based on the symbol position at which the initial signal received from the base station is received.

At this time, based on the symbol location where the scheduling information is received, the terminal determining the symbol location at which the actual PDSCH is received may include one of the following.

-The UE determines the symbol position at which the actual PDSCH is received as the first symbol among the one or more symbols from which the scheduling information is received.

-The terminal determines the symbol position at which the actual PDSCH is received as the last symbol among the one or more symbols for which the scheduling information is received

At this time, based on the fact that the actual PDSCH does not overlap on the frequency domain with the scheduling information, the terminal may determine the symbol position at which the actual PDSCH is received as the first symbol among the one or more symbols on which the scheduling information has been received. Alternatively, based on the actual PDSCH overlapping on the scheduling information and the frequency domain, the UE may determine a symbol position at which the actual PDSCH is received as the last symbol among the one or more symbols on which the scheduling information is received.

As another example, based on that the first symbol index among the one or more symbols from which the scheduling information has been received exceeds a threshold value, the terminal determines the symbol position at which the actual PDSCH is received, the first of the one or more symbols from which the scheduling information is received. You can decide by symbol. Alternatively, based on the first symbol index of the one or more symbols from which the scheduling information was received is equal to or less than the threshold value, the terminal determines the symbol position at which the actual PDSCH is received, the last symbol of the one or more symbols from which the scheduling information is received. You can decide.

Unlike the above-described operation example, the actual PDSCH may be transmitted and received on the next slot as well as one slot determined based on the scheduling information. As an example, as shown in FIG. 25, the actual PDSCH has the same symbol length as the PDSCH (pre-scheduled) from the time when the base station occupies the unlicensed band or starts transmission of the actual PDSCH and can be transmitted and received. have.

In this case, a symbol position in which DMRS is transmitted along with the actual PDSCH may be determined / set based on one of the following.

-A symbol position shifted by a predetermined symbol interval from a scheduled DMRS symbol position in the (pre-scheduled) PDSCH

-One or more newly defined symbol positions based on the actual symbol positions where the actual PDSCH is transmitted

It is obvious that the examples of the proposed method described above may also be included as one of implementation methods of the examples of the present description, and thus may be regarded as a kind of proposed methods. Further, the above-described proposed schemes may be implemented independently, but may also be implemented in a combination (or merge) form of some suggested schemes. Whether the application of the proposed methods is applied (or information on the rules of the proposed methods) can be defined so that the base station notifies the UE through a predefined signal (eg, physical layer signal or higher layer signal). have.

4. Example of a communication system to which the examples of this description apply

Without being limited thereto, various descriptions, functions, procedures, suggestions, methods and / or operational flowcharts of the examples of the present disclosure disclosed in this document may be used in various fields requiring wireless communication / connection (eg, 5G) between devices. Can be applied.

Hereinafter, with reference to the drawings will be illustrated in more detail. In the following drawings / description, the same reference numerals may exemplify the same or corresponding hardware blocks, software blocks, or functional blocks, unless otherwise indicated.

39 illustrates a communication system 1 applied to the examples of this disclosure.

Referring to FIG. 39, the communication system 1 applied to the examples of the present description includes a wireless device, a base station and a network. Here, the wireless device means a device that performs communication using a wireless access technology (eg, 5G NR (New RAT), Long Term Evolution (LTE)), and may be referred to as a communication / wireless / 5G device. Although not limited to this, the wireless device includes a robot 100a, a vehicle 100b-1, 100b-2, an XR (eXtended Reality) device 100c, a hand-held device 100d, and a home appliance 100e. ), Internet of Thing (IoT) devices 100f, and AI devices / servers 400. For example, the vehicle may include a vehicle equipped with a wireless communication function, an autonomous driving vehicle, a vehicle capable of performing inter-vehicle communication, and the like. Here, the vehicle may include a UAV (Unmanned Aerial Vehicle) (eg, a drone). XR devices include Augmented Reality (AR) / Virtual Reality (VR) / Mixed Reality (MR) devices, Head-Mounted Device (HMD), Head-Up Display (HUD) provided in vehicles, televisions, smartphones, It may be implemented in the form of a computer, wearable device, home appliance, digital signage, vehicle, robot, or the like. The mobile device may include a smart phone, a smart pad, a wearable device (eg, a smart watch, smart glasses), a computer (eg, a notebook, etc.). Household appliances may include a TV, a refrigerator, and a washing machine. IoT devices may include sensors, smart meters, and the like. For example, the base station and the network may also be implemented as wireless devices, and the specific wireless device 200a may operate as a base station / network node to other wireless devices.

The wireless devices 100a to 100f may be connected to the network 300 through the base station 200. AI (Artificial Intelligence) technology may be applied to the wireless devices 100a to 100f, and the wireless devices 100a to 100f may be connected to the AI server 400 through the network 300. The network 300 may be configured using a 3G network, a 4G (eg, LTE) network, or a 5G (eg, NR) network. The wireless devices 100a to 100f may communicate with each other through the base station 200 / network 300, but may directly communicate (e.g. sidelink communication) without going through the base station / network. For example, the vehicles 100b-1 and 100b-2 may communicate directly (e.g. Vehicle to Vehicle (V2V) / Vehicle to everything (V2X) communication). In addition, the IoT device (eg, sensor) may directly communicate with other IoT devices (eg, sensor) or other wireless devices 100a to 100f.

Wireless communication / connections 150a, 150b, and 150c may be achieved between the wireless devices 100a to 100f / base station 200 and the base station 200 / base station 200. Here, the wireless communication / connection is various wireless access such as uplink / downlink communication 150a and sidelink communication 150b (or D2D communication), base station communication 150c (eg relay, IAB (Integrated Access Backhaul)). It can be achieved through technology (eg, 5G NR). Through wireless communication / connections 150a, 150b, 150c, wireless devices and base stations / wireless devices, base stations and base stations can transmit / receive radio signals to each other. For example, wireless communication / connections 150a, 150b, 150c can transmit / receive signals over various physical channels To accomplish this, based on various proposals of the examples of this disclosure, transmission / reception of wireless signals. At least some of various configuration information setting processes, various signal processing processes (for example, channel encoding / decoding, modulation / demodulation, resource mapping / demapping, etc.), and resource allocation processes may be performed.

5. Examples of wireless devices to which the examples in this description apply

40 illustrates a wireless device that can be applied to the examples of this disclosure.

Referring to FIG. 40, the first wireless device 100 and the second wireless device 200 may transmit and receive wireless signals through various wireless access technologies (eg, LTE and NR). Here, {the first wireless device 100, the second wireless device 200} is {wireless device 100x, base station 200} and / or {wireless device 100x), wireless device 100x in FIG. 39 }.

The first wireless device 100 includes one or more processors 102 and one or more memories 104, and may further include one or more transceivers 106 and / or one or more antennas 108. The processor 102 controls the memory 104 and / or transceiver 106 and may be configured to implement the descriptions, functions, procedures, suggestions, methods and / or operational flowcharts disclosed herein. For example, the processor 102 may process information in the memory 104 to generate the first information / signal, and then transmit the wireless signal including the first information / signal through the transceiver 106. In addition, the processor 102 may receive the wireless signal including the second information / signal through the transceiver 106 and store the information obtained from the signal processing of the second information / signal in the memory 104. The memory 104 may be connected to the processor 102 and may store various information related to the operation of the processor 102. For example, the memory 104 is an instruction to perform some or all of the processes controlled by the processor 102, or to perform the descriptions, functions, procedures, suggestions, methods and / or operational flowcharts disclosed herein. You can store software code that includes Here, the processor 102 and the memory 104 may be part of a communication modem / circuit / chip designed to implement wireless communication technology (eg, LTE, NR). The transceiver 106 can be coupled to the processor 102 and can transmit and / or receive wireless signals through one or more antennas 108. The transceiver 106 may include a transmitter and / or receiver. The transceiver 106 may be mixed with a radio frequency (RF) unit. In the examples of the present description, the wireless device may mean a communication modem / circuit / chip.

The second wireless device 200 includes one or more processors 202, one or more memories 204, and may further include one or more transceivers 206 and / or one or more antennas 208. The processor 202 controls the memory 204 and / or transceiver 206 and may be configured to implement the descriptions, functions, procedures, suggestions, methods and / or operational flowcharts disclosed herein. For example, the processor 202 may process information in the memory 204 to generate third information / signal, and then transmit a wireless signal including the third information / signal through the transceiver 206. In addition, the processor 202 may receive the wireless signal including the fourth information / signal through the transceiver 206 and store the information obtained from the signal processing of the fourth information / signal in the memory 204. The memory 204 may be connected to the processor 202, and may store various information related to the operation of the processor 202. For example, the memory 204 is an instruction to perform some or all of the processes controlled by the processor 202, or to perform the descriptions, functions, procedures, suggestions, methods and / or operational flowcharts disclosed herein. You can store software code that includes Here, the processor 202 and the memory 204 may be part of a communication modem / circuit / chip designed to implement wireless communication technology (eg, LTE, NR). The transceiver 206 can be coupled to the processor 202 and can transmit and / or receive wireless signals through one or more antennas 208. Transceiver 206 may include a transmitter and / or receiver. Transceiver 206 may be mixed with an RF unit. In the examples of the present description, the wireless device may mean a communication modem / circuit / chip.

Hereinafter, hardware elements of the wireless devices 100 and 200 will be described in more detail. Without being limited to this, one or more protocol layers may be implemented by one or more processors 102 and 202. For example, one or more processors 102, 202 may implement one or more layers (eg, functional layers such as PHY, MAC, RLC, PDCP, RRC, SDAP). The one or more processors 102 and 202 may include one or more Protocol Data Units (PDUs) and / or one or more Service Data Units (SDUs) according to the descriptions, functions, procedures, suggestions, methods and / or operational flowcharts disclosed herein. Can be created. The one or more processors 102, 202 may generate messages, control information, data or information according to the descriptions, functions, procedures, suggestions, methods and / or operational flowcharts disclosed herein. The one or more processors 102, 202 generate signals (eg, baseband signals) including PDUs, SDUs, messages, control information, data or information according to the functions, procedures, suggestions and / or methods disclosed herein. , To one or more transceivers 106, 206. One or more processors 102, 202 may receive signals (eg, baseband signals) from one or more transceivers 106, 206, and descriptions, functions, procedures, suggestions, methods and / or operational flow diagrams disclosed herein Depending on the field, PDU, SDU, message, control information, data or information may be acquired.

One or more processors 102, 202 may be referred to as a controller, microcontroller, microprocessor, or microcomputer. The one or more processors 102, 202 can be implemented by hardware, firmware, software, or a combination thereof. For example, one or more Application Specific Integrated Circuits (ASICs), one or more Digital Signal Processors (DSPs), one or more Digital Signal Processing Devices (DSPDs), one or more Programmable Logic Devices (PLDs), or one or more Field Programmable Gate Arrays (FPGAs) May be included in one or more processors 102, 202. Descriptions, functions, procedures, suggestions, methods and / or operational flowcharts disclosed in this document may be implemented using firmware or software, and firmware or software may be implemented to include modules, procedures, functions, and the like. The descriptions, functions, procedures, suggestions, methods and / or operational flowcharts disclosed herein are either firmware or software set to perform or are stored in one or more processors 102, 202 or stored in one or more memories 104, 204. It can be driven by the above processors (102, 202). The descriptions, functions, procedures, suggestions, methods and / or operational flowcharts disclosed herein can be implemented using firmware or software in the form of code, instructions and / or instructions.

The one or more memories 104, 204 may be coupled to one or more processors 102, 202, and may store various types of data, signals, messages, information, programs, codes, instructions, and / or instructions. The one or more memories 104, 204 may be comprised of ROM, RAM, EPROM, flash memory, hard drives, registers, cache memory, computer readable storage media, and / or combinations thereof. The one or more memories 104, 204 may be located inside and / or outside of the one or more processors 102, 202. Also, the one or more memories 104 and 204 may be connected to the one or more processors 102 and 202 through various technologies such as a wired or wireless connection.

The one or more transceivers 106 and 206 may transmit user data, control information, radio signals / channels, and the like referred to in the methods and / or operational flowcharts of this document to one or more other devices. The one or more transceivers 106, 206 may receive user data, control information, radio signals / channels, and the like referred to in the descriptions, functions, procedures, suggestions, methods and / or operational flowcharts disclosed herein from one or more other devices. have. For example, one or more transceivers 106, 206 may be connected to one or more processors 102, 202, and may transmit and receive wireless signals. For example, one or more processors 102, 202 may control one or more transceivers 106, 206 to transmit user data, control information, or wireless signals to one or more other devices. In addition, one or more processors 102, 202 may control one or more transceivers 106, 206 to receive user data, control information, or wireless signals from one or more other devices. In addition, one or more transceivers 106, 206 may be coupled to one or more antennas 108, 208, and one or more transceivers 106, 206 may be described, functions described herein through one or more antennas 108, 208. , May be set to transmit and receive user data, control information, radio signals / channels, and the like referred to in procedures, proposals, methods, and / or operational flowcharts. In this document, the one or more antennas may be a plurality of physical antennas or a plurality of logical antennas (eg, antenna ports). The one or more transceivers 106 and 206 use the received radio signal / channel and the like in the RF band signal to process the received user data, control information, radio signal / channel, and the like using one or more processors 102 and 202. It can be converted to a baseband signal. The one or more transceivers 106 and 206 may convert user data, control information, and radio signals / channels processed using one or more processors 102 and 202 from a baseband signal to an RF band signal. To this end, the one or more transceivers 106, 206 may include (analog) oscillators and / or filters.

6. Examples of using wireless devices to which the examples in this description apply

41 shows another example of a wireless device applied to the examples of the present description. The wireless device may be implemented in various forms according to use-example / service (see FIG. 39).

Referring to FIG. 41, the wireless devices 100 and 200 correspond to the wireless devices 100 and 200 of FIG. 40, and various elements, components, units / units, and / or modules ). For example, the wireless devices 100 and 200 may include a communication unit 110, a control unit 120, a memory unit 130, and additional elements 140. The communication unit may include a communication circuit 112 and a transceiver (s) 114. For example, communication circuit 112 may include one or more processors 102,202 and / or one or more memories 104,204 of FIG. For example, the transceiver (s) 114 may include one or more transceivers 106,206 and / or one or more antennas 108,208 of FIG. 40. The control unit 120 is electrically connected to the communication unit 110, the memory unit 130, and the additional element 140, and controls various operations of the wireless device. For example, the controller 120 may control the electrical / mechanical operation of the wireless device based on the program / code / command / information stored in the memory unit 130. In addition, the control unit 120 transmits information stored in the memory unit 130 to the outside (eg, another communication device) through the wireless / wired interface through the communication unit 110 or externally (eg, through the communication unit 110). Information received through a wireless / wired interface from another communication device) may be stored in the memory unit 130.

The additional element 140 may be variously configured according to the type of wireless device. For example, the additional element 140 may include at least one of a power unit / battery, an input / output unit (I / O unit), a driving unit, and a computing unit. Although not limited to this, wireless devices include robots (FIGS. 39, 100A), vehicles (FIGS. 39, 100B-1, 100B-2), XR devices (FIGS. 39, 100C), portable devices (FIGS. 39, 100D), and household appliances. (Figs. 39, 100e), IoT devices (Figs. 39, 100f), digital broadcasting terminals, hologram devices, public safety devices, MTC devices, medical devices, fintech devices (or financial devices), security devices, climate / environment devices, It may be implemented in the form of an AI server / device (FIGS. 39, 400), a base station (FIGS. 39, 200), a network node, or the like. The wireless device may be movable or used in a fixed place depending on the use-example / service.

In FIG. 41, various elements, components, units / parts, and / or modules in the wireless devices 100 and 200 may be connected to each other through a wired interface, or at least some of them may be connected wirelessly through the communication unit 110. For example, in the wireless devices 100 and 200, the control unit 120 and the communication unit 110 are connected by wire, and the control unit 120 and the first unit (eg, 130 and 140) are connected through the communication unit 110. It can be connected wirelessly. Further, each element, component, unit / unit, and / or module in the wireless devices 100 and 200 may further include one or more elements. For example, the controller 120 may be composed of one or more processor sets. For example, the control unit 120 may include a set of communication control processor, application processor, electronic control unit (ECU), graphic processing processor, and memory control processor. In another example, the memory unit 130 includes random access memory (RAM), dynamic RAM (DRAM), read only memory (ROM), flash memory, volatile memory, and non-volatile memory (non- volatile memory) and / or combinations thereof.

Hereinafter, the implementation example of FIG. 41 will be described in more detail with reference to the drawings.

6.1. Examples of mobile devices to which the examples in this description apply

42 illustrates a portable device applied to the examples of the present description. The portable device may include a smart phone, a smart pad, a wearable device (eg, a smart watch, smart glasses), and a portable computer (eg, a notebook, etc.). The mobile device may be referred to as a mobile station (MS), a user terminal (UT), a mobile subscriber station (MSS), a subscriber station (SS), an advanced mobile station (AMS), or a wireless terminal (WT).

Referring to FIG. 42, the mobile device 100 includes an antenna unit 108, a communication unit 110, a control unit 120, a memory unit 130, a power supply unit 140a, an interface unit 140b, and an input / output unit 140c. ). The antenna unit 108 may be configured as part of the communication unit 110. Blocks 110 to 130 / 140a to 140c correspond to blocks 110 to 130/140 in FIG. 41, respectively.

The communication unit 110 may transmit and receive signals (eg, data, control signals, etc.) with other wireless devices and base stations. The controller 120 may perform various operations by controlling the components of the mobile device 100. The controller 120 may include an application processor (AP). The memory unit 130 may store data / parameters / programs / codes / commands necessary for driving the portable device 100. Also, the memory unit 130 may store input / output data / information. The power supply unit 140a supplies power to the portable device 100 and may include a wired / wireless charging circuit, a battery, and the like. The interface unit 140b may support the connection between the mobile device 100 and other external devices. The interface unit 140b may include various ports (eg, audio input / output ports, video input / output ports) for connection with external devices. The input / output unit 140c may receive or output image information / signal, audio information / signal, data, and / or information input from a user. The input / output unit 140c may include a camera, a microphone, a user input unit, a display unit 140d, a speaker, and / or a haptic module.

For example, in the case of data communication, the input / output unit 140c acquires information / signal (eg, touch, text, voice, image, video) input from the user, and the obtained information / signal is transmitted to the memory unit 130 Can be saved. The communication unit 110 may convert information / signals stored in the memory into wireless signals, and transmit the converted wireless signals directly to other wireless devices or to a base station. In addition, after receiving a radio signal from another wireless device or a base station, the communication unit 110 may restore the received radio signal to original information / signal. After the restored information / signal is stored in the memory unit 130, it can be output in various forms (eg, text, voice, image, video, heptic) through the input / output unit 140c.

6.2. Examples of vehicles or autonomous vehicles to which the examples in this description apply

43 illustrates a vehicle or autonomous vehicle applied to the examples of the present description. Vehicles or autonomous vehicles can be implemented as mobile robots, vehicles, trains, aerial vehicles (AVs), ships, and the like.

Referring to FIG. 43, the vehicle or autonomous vehicle 100 includes an antenna unit 108, a communication unit 110, a control unit 120, a driving unit 140a, a power supply unit 140b, a sensor unit 140c, and autonomous driving It may include a portion (140d). The antenna unit 108 may be configured as part of the communication unit 110. Blocks 110/130 / 140a through 140d correspond to blocks 110/130/140 in FIG. 42, respectively.

The communication unit 110 may transmit and receive signals (eg, data, control signals, etc.) with external devices such as other vehicles, base stations (e.g. base stations, road side units, etc.) and servers. The controller 120 may perform various operations by controlling elements of the vehicle or the autonomous vehicle 100. The controller 120 may include an electronic control unit (ECU). The driving unit 140a may cause the vehicle or the autonomous vehicle 100 to travel on the ground. The driving unit 140a may include an engine, a motor, a power train, wheels, brakes, and steering devices. The power supply unit 140b supplies power to the vehicle or the autonomous vehicle 100 and may include a wired / wireless charging circuit, a battery, and the like. The sensor unit 140c may obtain vehicle status, surrounding environment information, user information, and the like. The sensor unit 140c includes an inertial measurement unit (IMU) sensor, a collision sensor, a wheel sensor, a speed sensor, a tilt sensor, a weight sensor, a heading sensor, a position module, and a vehicle forward / Reverse sensor, battery sensor, fuel sensor, tire sensor, steering sensor, temperature sensor, humidity sensor, ultrasonic sensor, illumination sensor, pedal position sensor, and the like. The autonomous driving unit 140d maintains a driving lane, automatically adjusts speed, such as adaptive cruise control, and automatically moves along a predetermined route, and automatically sets a route when a destination is set. Technology, etc. can be implemented.

For example, the communication unit 110 may receive map data, traffic information data, and the like from an external server. The autonomous driving unit 140d may generate an autonomous driving route and a driving plan based on the acquired data. The control unit 120 may control the driving unit 140a so that the vehicle or the autonomous vehicle 100 moves along the autonomous driving path according to a driving plan (eg, speed / direction adjustment). During autonomous driving, the communication unit 110 may acquire the latest traffic information data non-periodically from an external server, and may acquire surrounding traffic information data from nearby vehicles. Also, during autonomous driving, the sensor unit 140c may acquire vehicle status and surrounding environment information. The autonomous driving unit 140d may update the autonomous driving route and driving plan based on newly acquired data / information. The communication unit 110 may transmit information regarding a vehicle location, an autonomous driving route, and a driving plan to an external server. The external server may predict traffic information data in advance using AI technology or the like based on the information collected from the vehicle or autonomous vehicles, and provide the predicted traffic information data to the vehicle or autonomous vehicles.

The examples in this description may be embodied in other specific forms without departing from the technical ideas and essential features disclosed in this document. Accordingly, the above detailed description should not be construed as limiting in all respects, but should be considered illustrative. The scope of the examples in this description should be determined by the rational interpretation of the appended claims, and all changes within the equivalent scope of the examples in this description are included in the scope of the examples in this description. In addition, in the claims, claims that do not have an explicit citation relationship may be combined to form an embodiment or may be included as new claims by amendment after filing.

The examples of the present description can be applied to various wireless access systems. As an example of various wireless access systems, there are 3GPP (3rd Generation Partnership Project) or 3GPP2 system. The examples of the present description can be applied not only to the various wireless access systems, but also to all technical fields to which the various wireless access systems are applied. Furthermore, the proposed method can also be applied to mmWave communication systems using ultra-high frequency bands. Furthermore, the proposed method can also be applied to a vehicle communication system or an autonomous driving system to which the above-described radio access system is applied.

Claims (14)

  1. In a method for a terminal to receive a downlink signal in a wireless communication system supporting an unlicensed band,
    Receiving scheduling information related to a physical downlink shared channel (PDSCH) from the base station;
    Determining a symbol position at which an actual PDSCH (actual PDSCH) is received from the base station through the unlicensed band within one slot determined based on the scheduling information; And
    Based on (i) the scheduling information and (ii) the symbol position at which the actual PDSCH is received, a demodulation reference signal through N symbols starting from a symbol position at which the actual PDSCH is received on the unlicensed band from the base station ( and receiving a demodulation reference signal (DMRS) and a data signal,
    N is a natural number of 1 or more, a method for receiving a downlink signal of a terminal in an unlicensed band.
  2. According to claim 1,
    The scheduling information,
    Start symbol information for which the PDSCH is scheduled, and
    A method for receiving a downlink signal of a terminal in an unlicensed band including symbol length information of the scheduled PDSCH.
  3. According to claim 2,
    The scheduling information,
    A method for receiving a downlink signal of a terminal in an unlicensed band, which is received through a starting and length indicator value (SLIV) field in a physical downlink control channel (PDCCH).
  4. According to claim 1,
    The DMRS,
    (i) among the one or more DMRS candidate transmission symbols determined based on the scheduling information, (ii) received through M symbols included in the N symbols starting from the symbol position where the actual PDSCH is received,
    M is a natural number less than or equal to N, a method for receiving a downlink signal of a terminal in an unlicensed band.
  5. According to claim 1,
    The N value is determined based on the scheduling information,
    The DMRS,
    Among the N symbols starting from the symbol position where the actual PDSCH is received, received through M DMRS transmission symbols determined based on the N value,
    M is a natural number less than or equal to N, a method for receiving a downlink signal of a terminal in an unlicensed band.
  6. The method of claim 5,
    The N value is,
    -Among candidate transmission symbols for a preset PDSCH, a maximum candidate value less than or equal to the number of symbols from the symbol position to which the actual PDSCH is received in one slot to the boundary of the slot,
    -The symbol length value of the scheduled PDSCH indicated by the scheduling information, or
    -The number of symbols from the symbol position where the actual PDSCH is received in the one slot to the boundary of the slot,
    A method of receiving a downlink signal of a terminal in an unlicensed band corresponding to one of the above.
  7. The method of claim 5,
    According to the N value, the location of the M DMRS transmission symbol among the N symbols is preset, the downlink signal reception method of the terminal in the unlicensed band.
  8. According to claim 1,
    The UE, through the unlicensed band, determines a symbol position where an actual PDSCH is received from the base station,
    -Based on the signaling information received from the base station, the terminal determines the symbol position where the actual PDSCH is received, or
    -Based on the symbol location where the scheduling information is received, the terminal determines the symbol location where the actual PDSCH is received, or
    -A method for receiving a downlink signal of a terminal in an unlicensed band, the method comprising determining, by the terminal, a symbol location at which the actual PDSCH is received, based on a symbol location at which an initial signal received from the base station is received. .
  9. The method of claim 8,
    Based on the symbol location where the scheduling information is received, the terminal determines the symbol location where the actual PDSCH is received,
    -The terminal determines the symbol position at which the actual PDSCH is received as the first symbol among one or more symbols from which the scheduling information is received, or
    -The terminal comprising: determining the symbol position at which the actual PDSCH is received as the last symbol among the one or more symbols for which the scheduling information is received, a method for receiving a downlink signal of a terminal in an unlicensed band.
  10. The method of claim 9,
    Based on the actual PDSCH is not overlapped on the frequency domain with the scheduling information, the terminal determines the symbol position at which the actual PDSCH is received as the first symbol among the one or more symbols on which the scheduling information has been received.
    Based on the actual PDSCH overlapping on the frequency domain with the scheduling information, the terminal determines the symbol position at which the actual PDSCH is received as the last symbol among the one or more symbols on which the scheduling information has been received. Downlink signal reception method.
  11. The method of claim 9,
    Based on the first symbol index of the one or more symbols from which the scheduling information is received exceeds a threshold value, the terminal determines the symbol position at which the actual PDSCH is received as the first symbol of the one or more symbols from which the scheduling information is received. and,
    Based on the first symbol index of the one or more symbols from which the scheduling information has been received is less than or equal to the threshold value, the terminal determines the symbol position at which the actual PDSCH is received as the last symbol among the one or more symbols from which the scheduling information is received. The method of receiving a downlink signal of a terminal in an unlicensed band.
  12. In a terminal receiving a downlink signal in a wireless communication system supporting an unlicensed band,
    At least one transmitter;
    At least one receiver;
    At least one processor; And
    And at least one memory operatively connected to the at least one processor and storing instructions that, when executed, cause the at least one processor to perform a particular operation,
    The specific action is:
    Receiving scheduling information related to a physical downlink shared channel (PDSCH) from a base station;
    Determining a symbol position at which an actual PDSCH (actual PDSCH) is received from the base station through the unlicensed band within one slot determined based on the scheduling information; And
    Based on (i) the scheduling information and (ii) the symbol position where the actual PDSCH is received, a demodulation reference signal through N symbols starting from the symbol position where the actual PDSCH is received on the unlicensed band from the base station ( and receiving a demodulation reference signal (DMRS) and a data signal,
    N is a natural number greater than or equal to 1, the terminal.
  13. The method of claim 12,
    The terminal communicates with at least one of a mobile terminal, a network, and an autonomous vehicle other than the vehicle in which the terminal is included.
  14. In the base station for transmitting a downlink signal in a wireless communication system supporting an unlicensed band,
    At least one transmitter;
    At least one receiver;
    At least one processor; And
    And at least one memory operatively connected to the at least one processor and storing instructions that, when executed, cause the at least one processor to perform a particular operation,
    The specific action is:
    Transmitting scheduling information related to a physical downlink shared channel (PDSCH) to the UE through the unlicensed band;
    In one slot determined based on the scheduling information, an actual PDSCH (actual PDSCH) of some or all of the scheduled PDSCHs is transmitted based on a channel access procedure (CAP) for the unlicensed band. Determine N symbols, where N is a natural number greater than or equal to 1; And
    And transmitting a demodulation reference signal (DMRS) and a data signal to the terminal through the N symbols on the unlicensed band.
PCT/KR2019/014813 2018-11-02 2019-11-04 Method for transmitting and receiving downlink signal by terminal and base station in wireless communication system supporting unlicensed band, and devices supporting same WO2020091554A1 (en)

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Citations (1)

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Publication number Priority date Publication date Assignee Title
KR20180004212A (en) * 2015-05-08 2018-01-10 삼성전자주식회사 Method and apparatus for partial sub-frame transmission and broadcast channel on an unlicensed spectrum

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KR20180004212A (en) * 2015-05-08 2018-01-10 삼성전자주식회사 Method and apparatus for partial sub-frame transmission and broadcast channel on an unlicensed spectrum

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