KR20190054978A - Method of operating beam for communication in wireless communication system and apparatus using same - Google Patents

Abstract

Disclosed is a base station of a wireless communication system, capable of efficiently transmitting data in the wireless communication system. According to the present invention, the base station of a wireless communication system comprises a communication module and a processor. The processor receives a radio resource control (RRC) signal from the base station of the wireless communication system through a communication module, acquires information about at least one transmission configuration indicator (TCI) state from the RRC signal, receives a physical downlink data channel including a media access control-control element (MAC-CE) from the base station of the wireless communication system through the communication module, and sets at least one beam parameter value for receiving a physical downlink control channel (PDCCH) in accordance with the TCI state indicated by the MAC-CE to receive the PDCCH.

Description

Field of the Invention [0001] The present invention relates to a method of operating a beam for communication in a wireless communication system,

The present invention relates to wireless communication systems. More particularly, the present invention relates to a beam operating method for communication in a wireless communication system and an apparatus using the same.

Since the commercialization of 4G (4th generation) communication systems, efforts are being made to develop new 5G (5th generation) communication systems to meet the increasing demand for wireless data traffic. The 5G communication system is called a beyond 4G network communication system, a post LTE system or a new radio (NR) system. In order to achieve a high data transmission rate, the 5G communication system includes a system operated using a very high frequency (mmWave) band of 6 GHz or more, and a communication system using a frequency band of 6 GHz or less in terms of ensuring coverage Are considered in the base station and the terminal.

The 3rd Generation Partnership Project (3GPP) NR system improves the spectral efficiency of the network, allowing operators to provide more data and voice services at a given bandwidth. Therefore, the 3GPP NR system is designed to meet the demand for high-speed data and media transmission in addition to high-capacity voice support. The advantage of an NR system is that it can have low throughput with high throughput, low latency, frequency division duplex (FDD) and time division duplex (TDD) support, improved end user experience and simple architecture on the same platform.

For more efficient data processing, the dynamic TDD of the NR system can use a method of varying the number of orthogonal frequency division multiplexing (OFDM) symbols that can be used for uplink and downlink according to the data traffic direction of users of the cell. For example, when the downlink traffic of the cell is higher than the uplink traffic, the base station can allocate a plurality of downlink OFDM symbols to the slot (or subframe). Information on the slot configuration should be sent to the terminals.

In the 5G communication system, beamforming, massive MIMO, full-dimensional MIMO, and FD-MIMO are used in order to mitigate the path loss of the radio wave in the very high frequency band and to increase the propagation distance of the radio wave. ), Array antennas, analog beam-forming, hybrid beamforming combining analogue beamforming and digital beamforming, and large scale antenna technology are being discussed. In order to improve the network of the system, the 5G communication system has developed an advanced small cell, an advanced small cell, a cloud radio access network (cloud RAN), an ultra-dense network, Device-to-device communication (D2D), vehicle to everything communication (V2X), wireless backhaul, non-terrestrial network communication (NTN) (CoMP), co-coordinated multi-points (CoMP), and interference cancellation, etc. have been developed. In addition, in the 5G system, advanced coding modulation (ACM) schemes such as hybrid FSK and QAM modulation and sliding window superposition coding (SWSC), advanced connection technology such as FBMC (filter bank multi-carrier) Non-orthogonal multiple access (NOMA), and sparse code multiple access (SCMA).

On the other hand, the Internet is evolving into an Internet of Things (IoT) network in which information is exchanged between distributed components such as objects in a human-centered connection network where humans generate and consume information. IoE (Internet of Everything) technology, which combines IoT technology with big data processing technology through connection with cloud servers, is also emerging. In order to realize IoT, technology elements such as sensing technology, wired / wireless communication and network infrastructure, service interface technology, and security technology are required. Recently, sensor network, machine to machine (M2M) And MTC (machine type communication) technologies are being studied. In the IoT environment, an intelligent IT (internet technology) service can be provided that collects and analyzes data generated from connected objects to create new value in human life. IoT is a field of smart home, smart building, smart city, smart car or connected car, smart grid, health care, smart home appliance, and advanced medical service through fusion of existing information technology . ≪ / RTI >

Accordingly, various attempts have been made to apply the 5G communication system to the IoT network. For example, technologies such as sensor network, machine to machine (M2M), and machine type communication (MTC) are implemented by techniques such as beamforming, MIMO, and array antennas, which are 5G communication technologies. The application of the cloud RAN as the big data processing technology described above is an example of the convergence of 5G technology and IoT technology. Generally, a mobile communication system has been developed to provide voice service while ensuring the user's activity.

However, the mobile communication system is gradually expanding not only the voice but also the data service, and now it has developed to the extent of providing high-speed data service. However, in a mobile communication system in which services are currently being provided, a more advanced mobile communication system is required due to a shortage of resources and a high-speed service demand of users.

It is an object of one embodiment of the present invention to provide a method and apparatus for operating a beam for efficient communication in a wireless communication system.

A terminal of a wireless communication system according to an embodiment of the present invention includes a communication module; And a processor for controlling the communication module. Wherein the processor is configured to receive a radio resource control (RRC) signal from the base station of the wireless communication system through the communication module, obtain information about at least one transmission configuration indicator (TCI) status from the RRC signal, A physical downlink data channel including a Media Access Control-Control Element (MAC-CE) from the base station of the system through the communication module, and for receiving at least a physical downlink control channel according to a TCI state indicated by the MAC- And sets a parameter value of any one of the beams to receive the physical downlink control channel.

The processor receives the physical downlink control channel response message according to a TCI state indicated by the MAC-CE based on a slot to which hybrid automatic repeat request (HARQ) -ACK feedback is transmitted for a physical downlink data channel including the MAC- And setting the parameter values of at least one of the beams for the physical downlink control channel.

After the first predetermined time elapses from the slot that transmitted the HARQ-ACK feedback for the physical downlink data channel including the MAC-CE, the processor controls the physical downlink control channel And set the parameter values of at least one of the beams for reception to receive the physical downlink control channel.

The first predetermined time may be at least one or more slot durations. The first predetermined time may be an integral multiple of the slot duration.

The HARQ-ACK feedback for the physical downlink data channel including the MAC-CE may indicate an ACK.

The processor calculates a parameter value of at least one beam for reception of the physical downlink control channel according to a TCI state indicated by the MAC-CE in the next slot of a slot in which the physical downlink data channel including the MAC-CE is received And receive the physical downlink control channel.

Wherein the processor is configured to receive a physical downlink control channel including downlink control information (DCI) from the base station through the communication module and to transmit at least a downlink control channel for physical downlink data channel reception according to a TCI state indicated by the DCI It is possible to receive physical downlink data channels by setting parameter values of any one of the beams.

Wherein the processor is configured to determine at least one parameter of at least one beam for reception of the physical downlink data channel according to a TCI state indicated by the DCI after a second predetermined time elapses from when the physical downlink control channel including the DCI is received And the physical downlink data channel can be received.

The second predetermined time may be at least one or more slot durations. The second predetermined time may be an integral multiple of the slot duration.

Wherein when the reception quality of at least one of the at least one beam for receiving the physical downlink control channel is lower than a predetermined reference reception quality, the processor transmits information about the beam whose reception quality is lower than the predetermined reference reception quality Lt; / RTI >

The processor may send to the base station hybrid automatic repeat request (HARQ) -ACK feedback and information about the beam whose reception quality is lower than the predetermined reference reception quality.

The processor may transmit the HARQ-ACK feedback, the scheduling request, and the information about the beam whose reception quality is lower than the predetermined reference reception quality to the base station.

A method of operating a terminal of a wireless communication system according to an embodiment of the present invention includes receiving a radio resource control (RRC) signal from a base station of the wireless communication system through the communication module; Obtaining information about at least one transmission configuration indicator (TCI) status from the RRC signal; Receiving a physical downlink data channel including a Media Access Control-Control Element (MAC-CE) from the base station of the wireless communication system through the communication module; And setting a parameter value of at least one beam for receiving a physical downlink control channel according to a TCI state indicated by the MAC-CE to receive a physical downlink control channel.

The step of receiving the physical downlink control channel includes: a TCI state indicated by the MAC-CE based on a slot to which hybrid automatic repeat request (HARQ) -ACK feedback is transmitted for the physical downlink data channel including the MAC- And setting the parameter value of at least one of the beams for the physical downlink control channel to receive the physical downlink control channel.

At least one of the parameters of the beam for reception of the physical downlink control channel according to a TCI state indicated by the MAC-CE based on a slot in which HARQ-ACK feedback for a physical downlink data channel including the MAC-CE is transmitted And receiving the physical downlink control channel by setting the MAC-CE value to the MAC-CE after a first predetermined time elapses from a slot transmitting HARQ-ACK feedback for the physical downlink data channel including the MAC- And setting the parameter value of at least one beam for receiving the physical downlink control channel according to the TCI state indicated by the physical downlink control channel.

The first predetermined time may be at least one or more slot durations. The first predetermined time may be an integral multiple of the slot duration.

The HARQ-ACK feedback for the physical downlink data channel including the MAC-CE may indicate an ACK.

In accordance with the TCI state indicated by the MAC-CE based on a slot in which the HARQ-ACK feedback for the physical downlink data channel including the MAC-CE is transmitted, at least one of the beams for reception of the physical downlink control channel Wherein the step of receiving the physical downlink control channel by setting a parameter value comprises the steps of: instructing the MAC-CE in at least one slot after a slot in which HARQ-ACK feedback for the physical downlink data channel including the MAC- And receiving the physical downlink control channel by setting a parameter value of at least one of the beams for receiving the physical downlink control channel according to the TCI state.

Wherein the step of receiving the physical downlink control channel comprises the steps of: receiving at least one physical downlink control channel for reception of the physical downlink control channel according to a TCI state indicated by the MAC-CE in a next slot of a slot that has received a physical downlink data channel including the MAC- It is possible to receive the physical downlink control channel by setting a parameter value of one beam.

The method includes receiving a physical downlink control channel including downlink control information (DCI) from the base station; And setting a parameter value of at least one beam for receiving a physical downlink data channel according to a TCI state indicated by the DCI to receive a physical downlink data channel.

Wherein the step of setting the parameter value of at least one beam for reception of the physical downlink data channel and receiving the physical downlink data channel according to the TCI state indicated by the DCI is performed at the time of receiving the physical downlink control channel including the DCI And setting the parameter value of at least one beam for reception of the physical downlink data channel according to a TCI state indicated by the DCI after a second predetermined time elapses from the physical downlink data channel to receive the physical downlink data channel .

The second predetermined time may be at least one or more slot durations. The second predetermined time may be an integral multiple of the slot duration.

The method includes transmitting information about a beam whose reception quality is lower than the predetermined reference reception quality when the reception quality of at least one of the beams for the physical downlink control channel reception is lower than a predetermined reference reception quality Step < / RTI >

Wherein the step of transmitting information on the beam having the reception quality lower than the predetermined reference reception quality includes transmitting information on the beam with the reception quality lower than the predetermined reference reception quality together with HARQ- . ≪ / RTI >

Wherein the step of transmitting the information on the beam with the reception quality lower than the predetermined reference reception quality comprises: transmitting to the base station a hybrid automatic repeat request (HARQ-ACK) feedback, a scheduling request, And transmitting information about the low beam together.

An embodiment of the present invention provides a method for efficiently transmitting data in a wireless communication system, a receiving method, and an apparatus using the same.

The effects obtained by the present invention are not limited to the above-mentioned effects, and other effects not mentioned can be clearly understood by those skilled in the art from the following description will be.

1 shows an example of a radio frame structure used in a wireless communication system.
2 shows an example of a downlink (DL) / uplink (UL) slot structure in a wireless communication system.
3 is a diagram for explaining a general signal transmission method using a physical channel and a corresponding physical channel used in a 3GPP system.
4 shows an SS / PBCH block for initial cell access in a 3GPP NR system.
5 shows a procedure for control information and control channel transmission in a 3GPP NR system.
6 is a diagram illustrating a CORESET (control resource set) in which a PDCCH (physical downlink control channel) in a 3GPP NR system can be transmitted.
7 is a diagram illustrating a method of setting a PDCCH search space in a 3GPP NR system.
8 is a conceptual diagram illustrating carrier aggregation.
9 is a diagram for explaining single carrier communication and multi-carrier communication.
10 is a diagram showing an example in which a cross carrier scheduling technique is applied.
11 is a block diagram showing the configuration of a terminal and a base station according to an embodiment of the present invention.
FIG. 12 shows a method of receiving a PDSCH by acquiring information on a QCL of a beam for receiving a PDSCH from a base station according to an embodiment of the present invention.
FIG. 13 shows a case where a terminal according to an embodiment of the present invention acquires information on a QCL of a beam for receiving a PDSCH from a base station, and maintains the QCL parameter setting as it is.
FIG. 14 shows that a UE according to an embodiment of the present invention sets a QCL parameter of a beam for receiving a physical downlink control channel according to information signaled by a base station.
FIG. 15 is a diagram illustrating a case where a plurality of TCI states are set in a specific CORESET in a base station according to an embodiment of the present invention, and a base station transmits a beam for receiving a physical downlink control channel It shows changing the setting.
FIG. 16 shows that the base station changes CORESET to change the beam configuration for physical downlink control channel reception according to an embodiment of the present invention.
17-18 illustrate non-sequence physical uplink control channels, beam failure information using a physical uplink data channel that does not use sequences, and failed beam measurement information transmission.

As used herein, terms used in the present invention are selected from general terms that are widely used in the present invention while taking into account the functions of the present invention. However, these terms may vary depending on the intention of a person skilled in the art, custom or the emergence of new technology. Also, in certain cases, there may be a term arbitrarily selected by the applicant, and in this case, the meaning thereof will be described in the description of the corresponding invention. Therefore, it is intended that the terminology used herein should be interpreted relative to the actual meaning of the term, rather than the nomenclature, and its content throughout the specification.

Throughout the specification, when a configuration is referred to as being "connected" to another configuration, it is not limited to the case where it is "directly connected," but also includes "electrically connected" do. Also, when an element is referred to as " including " a specific element, it is meant to include other elements, rather than excluding other elements, unless the context clearly dictates otherwise. In addition, the limitations of " above " or " below ", respectively, based on a specific threshold value may be appropriately replaced with "

The following description is to be understood as illustrative and non-limiting, such as code division multiple access (CDMA), frequency division multiple access (FDMA), time division multiple access (TDMA), orthogonal frequency division multiple access (OFDMA), single carrier frequency division multiple access And can be used in various wireless access systems. CDMA may be implemented in radio technology such as Universal Terrestrial Radio Access (UTRA) or CDMA2000. The TDMA may be implemented in a wireless technology such as Global System for Mobile communications (GSM) / General Packet Radio Service (GPRS) / Enhanced Data Rates for GSM Evolution (EDGE). OFDMA may be implemented in 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). 3rd Generation Partnership Project (3GPP) Long term evolution (LTE) is part of E-UMTS (Evolved UMTS) using E-UTRA and LTE-A (Advanced) is an evolved version of 3GPP LTE. 3GPP NR (New Radio) is a system that is designed separately from LTE / LTE-A. It is composed of Enhanced Mobile BroadBand (eMBB), Ultra-Reliable and Low Latency Communication (URLLC) ) Service. For the sake of clarity, the 3GPP NR is mainly described, but the technical idea of the present invention is not limited thereto.

Unless otherwise specified herein, a base station may include a next generation node B (gNB) as defined in 3GPP NR. Also, unless otherwise specified, the terminal may include a user equipment (UE). Hereinafter, in order to facilitate understanding of the explanation, each content is separately described as an embodiment, but each embodiment can be used in combination with each other. In the present disclosure, the configuration of the terminal may indicate the setting by the base station. Specifically, the base station can transmit a channel or a signal to the terminal and set a value of a parameter used in a terminal operation or a wireless communication system.

1 shows an example of a radio frame structure used in a wireless communication system.

Referring to FIG. 1, the radio frame (or radio frame) used in the 3GPP NR system may have a length of 10 ms (? _{F max} N _f / 100) * T _c ). In addition, the radio frame is composed of 10 equal sized subframes (SF). In this case, Δf _max = 480 × 10 ³ Hz, N _f = 4096, T _c = 1 / (Δf _ref * N _{f, ref} ), Δf _ref = 15 × 10 ³ Hz and N _{f and ref} = 2048. 10 subframes within one radio frame may be numbered from 0 to 9, respectively. Each subframe has a length of 1 ms and may be composed of one or a plurality of slots according to a subcarrier spacing. More specifically, the available subcarrier interval in the 3GPP NR system is 15 * 2 [ ^mu] kHz. μ is a subcarrier spacing configuration and may have a value of μ = 0 to 4. That is, 15 kHz, 30 kHz, 60 kHz, 120 kHz, or 240 kHz can be used at subcarrier intervals. A sub-frame of 1 ms in length may be composed of 2 ^占 slots. At this time, the length of each slot is 2- ^μ ms. 2 ^μ slots in one subframe can be numbered from 0 to 2 ^μ - 1, respectively. In addition, the slots in one radio frame can be numbered from 0 to 10 * 2 ^μ - 1, respectively. The time resource can be classified by at least one of a radio frame number (or a radio frame index), a subframe number (also referred to as a subframe index), and a slot number (or a slot index).

2 shows an example of a downlink (DL) / uplink (UL) slot structure in a wireless communication system. In particular, Figure 2 shows the structure of the resource grid of the 3GPP NR system.

There is one resource grid per antenna port. Referring to FIG. 2, a slot includes a plurality of orthogonal frequency division multiplexing (OFDM) symbols in a time domain and a plurality of resource blocks (RBs) in a frequency domain. An OFDM symbol also means one symbol period. Unless otherwise specified, an OFDM symbol may simply be referred to as a symbol. One RB includes 12 consecutive subcarriers in the frequency domain. Referring to FIG. 2, a signal transmitted in each slot can be represented as a resource grid consisting of N ^{size, μ} _{grid, x} * N ^RB _sc subcarriers and N ^slot _symb OFDM symbols have. Here, x = DL when the downlink resource lattice and x = UL when the uplink resource lattice. N ^{size, μ} _{grid, x} denotes the number of resource blocks (DL or UL) according to the subcarrier spacing factor μ, and N ^slot _symb denotes the number of OFDM symbols in the slot. N ^RB _sc is the number of subcarriers constituting one RB, and N ^RB _sc = 12. An OFDM symbol may be referred to as a cyclic prefix OFDM (CP-OFDM) symbol or a discrete Fourier transform spread OFDM (DFT-S-OFDM) symbol according to the multiple access scheme.

The number of OFDM symbols included in one slot may vary according to the length of a CP (cyclic prefix). For example, one slot may include 14 OFDM symbols in the case of a normal CP, but one slot may include 12 OFDM symbols in the case of an extended CP. In a specific embodiment, the extended CP may only be used at 60 kHz subcarrier spacing. Although FIG. 2 illustrates a case where one slot is composed of 14 OFDM symbols for convenience of description, embodiments of the present invention may be applied to slots having different numbers of OFDM symbols in a similar manner. Referring to FIG. 2, each OFDM symbol includes N ^{size, [mu]} _{grid, x} * N ^RB _sc subcarriers in the frequency domain. The type of subcarrier may be divided into a data subcarrier for data transmission, a reference signal subcarrier for transmission of a reference signal, and a guard band. The carrier frequency is also referred to as the center frequency (fc).

One RB may be defined by N ^RB _sc (e.g., twelve) consecutive subcarriers in the frequency domain. For reference, a resource composed of one OFDM symbol and one subcarrier may be referred to as a resource element (RE) or a tone. Therefore, one RB can be composed of N resource _symbols of N ^slots _symb * N ^RB _sc . Each resource element in the resource grid can be uniquely defined by an index pair (k, l) in one slot. k is an index assigned from 0 to N ^{size, μ} _{grid, x} * N ^RB _sc - 1 in the frequency domain, and l can be an index assigned from 0 to N ^slot _symb - 1 in the time domain.

In order for the terminal to receive a signal from the base station or to transmit a signal to the base station, the time / frequency synchronization of the terminal may be synchronized with the time / frequency synchronization of the base station. This is because the terminal and the terminal need to be synchronized so that the terminal can determine the time and frequency parameters necessary for demodulating the DL signal and transmitting the UL signal at the correct time.

Each symbol of a radio frame operating in a time division duplex (TDD) or an unpaired spectrum may be at least one of a DL symbol, an UL symbol, and a flexible symbol. It can be configured as any one. A radio frame operating as a downlink carrier in a frequency division duplex (FDD) or a paired spectrum may be composed of a downlink symbol or a flexible symbol, and a radio frame operating as an uplink carrier may be an uplink symbol or an uplink symbol. It can be composed of flexible symbols. The downlink transmission is possible in the downlink symbol but the uplink transmission is impossible and the uplink transmission is possible in the uplink symbol but the downlink transmission is impossible. Depending on the signal, the flexible symbol may be determined to be used in the downlink or in the uplink.

The information indicating the type of each symbol, that is, information indicating any one of the downlink symbol, the uplink symbol and the flexible symbol may be configured as a cell-specific or common RRC (Radio Resource Control) signal. have. In addition, the information on the type of each symbol may be additionally composed of UE-specific or dedicated RRC signals. I) the number of slots with only the downlink symbol from the beginning of the period of the cell specific slot configuration, iii) the number of slots with only the downlink symbol, The number of downlink symbols from the first symbol, iv) the number of slots having only the uplink symbol from the end of the period of the cell specific slot configuration, v) the number of uplink symbols from the last symbol of the slot immediately before the slot having only the uplink symbol It informs. Here, the symbol not constituted by any of the uplink symbol and the downlink symbol is a flexible symbol.

When information on a symbol type is composed of a UE-specific RRC signal, the base station can signal to the cell specific RRC signal whether the flexible symbol is a downlink symbol or an uplink symbol. At this time, the UE-specific RRC signal can not change the downlink symbol or the uplink symbol composed of the cell specific RRC signal to another symbol type. The UE-specific RRC signal may signal the number of downlink symbols among the N ^slot _symb symbols of the slot and the number of uplink symbols among the N ^slot _symb symbols of the corresponding slot for each slot. At this time, the downlink symbol of the slot can be configured continuously from the first symbol to the i'th symbol of the slot. Also, the uplink symbols of the slot may be consecutively configured from the jth symbol to the last symbol of the slot, where i < j. A symbol not constituted of either the uplink symbol or the downlink symbol in the slot is a flexible symbol.

The type of the symbol composed of the RRC signal as described above may be referred to as a semi-static DL / UL configuration. In the semi-static DL / UL configuration configured with the RRC signal, the flexible symbol includes a downlink symbol through a dynamic SFI (slot format information) transmitted on a physical downlink control channel (PDCCH) , Or a flexible symbol. At this time, the downlink symbol or the uplink symbol constituted by the RRC signal is not changed to another symbol type. Table 1 illustrates a dynamic SFI that the BS can instruct the UE.

In Table 1, D denotes a downlink symbol, U denotes an uplink symbol, and X denotes a flexible symbol. As shown in Table 1, up to two DL / UL switching within one slot may be allowed.

3 is a diagram for explaining a physical channel used in a 3GPP system (e.g., NR) and a general signal transmission method using the physical channel.

When the power of the terminal increases or the terminal enters a new cell, the terminal performs an initial cell search operation (S101). Specifically, the UE can synchronize with the BS in the initial cell search. To this end, the terminal may receive a primary synchronization signal (PSS) and a secondary synchronization signal (SSS) from a base station, synchronize with the base station, and obtain information such as a cell ID. Then, the terminal can receive the physical broadcast channel from the base station and obtain broadcast information in the cell.

After completion of the initial cell search, the UE receives a Physical Downlink Control Channel (PDCCH) and a physical downlink shared channel (PDSCH) according to the information on the PDCCH, More specific system information than one system information can be obtained (S102). Here, the system information received by the UE may be cell-common system information for a UE to operate correctly in a physical layer in a Radio Resource Control (RRC). At this time, the system information may be referred to as Remaining system information or System information block (SIB) 1.

If the terminal is initially connected to the base station or does not have radio resources for signal transmission (e.g., the terminal is in the RRC_IDLE mode), the terminal may perform a random access procedure with respect to the base station (steps S103 to S106). First, the UE transmits a preamble on a physical random access channel (PRACH) (S103), and receives a response message for a preamble on the PDCCH and the corresponding PDSCH from the base station (S104). When a random access response message valid to the UE is received, the UE transmits data including its own identifier and the like through a physical uplink shared channel (PUSCH) indicated by the uplink grant transmitted via the PDCCH To the base station (S105). Next, the UE waits for reception of the PDCCH as an indication of the base station for conflict resolution. When the UE has successfully received the PDCCH through its identifier (S106), the random access procedure is terminated. The UE can acquire the UE-specific system information necessary for the UE to operate properly during the random access procedure in the RRC layer and the physical layer. When the UE acquires the UE-specific system information from the RRC layer, the UE can enter the RRC-CONNECTED mode.

The RRC layer can be used for message generation and management for control between a UE and a Radio Access Network (RAN). More specifically, the Node B and the UE transmit the cell system information required for all UEs in the RRC layer, such as broadcasting, paging message delivery, mobility management and handover, It is possible to perform archival management including capacity management and basic management. Generally, since the update of the signal (hereinafter referred to as RRC signal) transmitted from the RRC layer is longer than the transmission time interval (TTI) in the physical layer, the RRC signal remains unchanged for a relatively long period .

After the procedure described above, the UE transmits PDCCH / PDSCH reception (S107) and physical uplink shared channel (PUSCH) / physical uplink control channel (PUCCH) as general uplink / downlink signal transmission procedures. (S108). In particular, the UE can receive downlink control information (DCI) through the PDCCH. The DCI may include control information such as resource allocation information for the UE. Also, the format of the DCI can be changed according to the purpose of use. The uplink control information (UCI) transmitted by the UE to the base station through the uplink includes a downlink / uplink ACK / NACK signal, a channel quality indicator (CQI), a precoding matrix index (PMI) ), And the like. Here, CQI, PMI, and RI may be included in CSI (channel state information). In the case of the 3GPP NR system, the UE can transmit control information such as HARQ-ACK and CSI described above via the PUSCH and / or PUCCH.

4 shows an SS / PBCH block for initial cell access in a 3GPP NR system.

The terminal can acquire time and frequency synchronization with a cell and perform an initial cell search process when the terminal is turned on or intends to connect to a new cell. The UE can detect the physical cell identity N ^cell _ID of the cell in the cell search process. To this end, the terminal may receive a synchronization signal, for example, a main synchronization signal (PSS) and a sub-synchronization signal (SSS) from a base station and synchronize with the base station. At this time, the terminal can acquire information such as a cell ID (identity).

Referring to FIG. 4 (a), a synchronization signal (SS) will be described more specifically. The synchronization signal can be divided into PSS and SSS. The PSS may be used to obtain time domain synchronization and / or frequency domain synchronization, such as OFDM symbol synchronization, slot synchronization. The SSS can be used to obtain frame synchronization, cell group ID. Referring to FIG. 4A and Table 2, the SS / PBCH block is composed of 20 RBs (= 240 subcarriers) continuous in the frequency axis, and may consist of 4 consecutive OFDM symbols on the time axis . In this case, the PSS in the SS / PBCH block is transmitted on the first OFDM symbol and the SSS on the 56th to 182nd subcarriers in the third OFDM symbol. Where the lowest subcarrier index of the SS / PBCH block is set to zero. In the first OFDM symbol to which the PSS is transmitted, the base station does not transmit a signal through the remaining subcarriers, i.e., 0 to 55 and 183 to 239th subcarriers. Also, the base station does not transmit a signal through the 48th to 55th and 183th to 191th subcarriers in the third OFDM symbol to which the SSS is transmitted. In the SS / PBCH block, the BS transmits a physical broadcast channel (PBCH) through the remaining RE except for the uplink signal.

The SS specifically identifies a total of 1008 unique physical layer cell IDs through a combination of the three PSSs and the SSS, and each physical layer cell ID has only one physical-layer cell- Thus, each group may be grouped into 336 physical-layer cell-identifier groups, including three unique identifiers. Therefore, the physical layer cell ID N ^cell _ID = 3N ⁽¹⁾ _ID + N ⁽²⁾ _ID includes an index N ⁽¹⁾ _ID in the range of 0 to 335 indicating a physical- - an index N ⁽²⁾ _ID of 0 to 2 indicating the physical-layer identifier in the identifier group. The terminal may detect the PSS and identify one of the three unique physical-layer identifiers. In addition, the terminal may detect the SSS and identify one of the 336 physical layer cell IDs associated with the physical-layer identifier. At this time, the sequence d _PSS (n) of the _PSS is as follows.

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Also, the sequence d _SSS (n) of the _SSS is as follows.

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로 주어진다.

.

A radio frame of 10 ms long can be divided into two half frames of 5 ms long. Referring to FIG. 4 (b), a slot through which an SS / PBCH block is transmitted in each half frame will be described. The slot through which the SS / PBCH block is transmitted may be any of cases A, B, C, D, In the case A, the subcarrier interval is 15 kHz, and the start point of the SS / PBCH block is {2, 8} + 14 * n-th symbol. At this time, n = 0, 1 at a carrier frequency of 3 GHz or less. Also, n = 0, 1, 2, and 3 at carrier frequencies below 6 GHz above 3 GHz. In the case B, the subcarrier interval is 30 kHz, and the starting point of the SS / PBCH block is {4, 8, 16, 20} + 28 * nth symbol. At this time, n = 0 at a carrier frequency of 3 GHz or less. Also, n = 0, 1 at carrier frequencies below 6 GHz above 3 GHz. In the case C, the subcarrier interval is 30 kHz, and the starting point of the SS / PBCH block is {2, 8} + 14 * nth symbol. At this time, n = 0, 1 at a carrier frequency of 3 GHz or less. Also, n = 0, 1, 2, and 3 at carrier frequencies below 6 GHz above 3 GHz. In the case D, the subcarrier interval is 120 kHz, and the starting point of the SS / PBCH block is {4, 8, 16, 20} + 28 * n-th symbol. In this case, n = 0, 1, 2, 3, 5, 6, 7, 8, 10, 11, 12, 13, 15, 16, 17, 18 can be obtained at a carrier frequency of 6 GHz or more. In the case E, the subcarrier interval is 240 kHz, and the start point of the SS / PBCH block is {8, 12, 16, 20, 32, 36, 40, 44} + 56 * nth symbol. At this time, n = 0, 1, 2, 3, 5, 6, 7, and 8 at a carrier frequency of 6 GHz or more.

5 shows a procedure for control information and control channel transmission in a 3GPP NR system. Referring to FIG. 5A, a base station can add a cyclic redundancy check (CRC) masked with a radio network temporary identifier (RNTI) to control information (e.g., downlink control information, DCI) (S202). The base station can scramble the CRC with an RNTI value determined according to the object / target of each control information. A common RNTI used by one or more UEs includes at least one of a system information RNTI (RNTI), a paging RNTI (P-RNTI), a random access RNTI (R-RNTI), and a transmit power control RNTI . In addition, the UE-specific RNTI may include at least one of a C-RNTI (cell temporary RNTI) and a CS-RNTI. The base station may perform rate matching on the amount of resource (s) used for PDCCH transmission after performing channel encoding (e.g., polar coding) (S204). Thereafter, the base station may multiplex the DCI (s) based on a control channel element (CCE) based PDCCH structure (S208). In addition, the base station may apply an additional process (S210) such as scrambling, modulation (e.g., QPSK), and interleaving to the multiplexed DCI (s) and then map the resource to be transmitted. The CCE is a basic resource unit for the PDCCH, and one CCE can be composed of a plurality of (e.g., six) resource element groups (REGs). One REG may be composed of plural (e.g., twelve) REs. The number of CCEs used for one PDCCH can be defined as an aggregation level. In the 3GPP NR system, an aggregation level of 1, 2, 4, 8 or 16 can be used. FIG. 5B is a diagram for multiplexing a CCE aggregation level and a PDCCH, and shows a type of CCE aggregation level used for one PDCCH and CCE (s) transmitted in the corresponding control domain.

6 is a diagram illustrating a CORESET (control resource set) in which a physical downlink control channel (PDCCH) in a 3GPP NR system can be transmitted.

CORESET is a time-frequency resource through which the PDCCH, which is a control signal for the UE, is transmitted. In addition, a search space to be described later may be mapped to one CORESET. Therefore, instead of monitoring all the frequency bands for PDCCH reception, the UE can decode the PDCCH mapped to the CORESET by monitoring the time-frequency domain designated by CORESET. The BS may configure one or more CORESETs for each cell to the MS. CORESET can consist of up to three consecutive symbols on the time axis. In addition, CORESET can be configured as a unit of six consecutive PRBs on the frequency axis. In the embodiment of FIG. 5, CORESET # 1 consists of consecutive PRBs, and CORESET # 2 and CORESET # 3 consist of discontinuous PRBs. CORESET can be located in any symbol in the slot. For example, in the embodiment of FIG. 5, CORESET # 1 starts at the first symbol of the slot, CORESET # 2 starts at the fifth symbol of the slot, and CORESET # 9 starts at the ninth symbol of the slot.

7 is a diagram illustrating a method of setting a PDCCH search space in a 3GPP NR system.

In order to transmit the PDCCH to the UE, at least one search space may exist in each CORESET. In the embodiment of the present invention, the search space is a set of all the time-frequency resources (hereinafter, PDCCH candidates) to which the PDCCH of the UE can be transmitted. The search space may include a common search space to which UEs of the 3GPP NR should commonly search, and a terminal-specific or UE-specific search space to which a specific UE must search. In the common search space, it is possible to monitor a PDCCH that is set so that all terminals in a cell belonging to the same base station search commonly. In addition, the UE-specific search space can be set for each UE to monitor the PDCCH allocated to each UE in different search space positions according to the UE. In the case of the UE-specific search space, the search space between the UEs may be partially overlapped due to the limited control region to which the PDCCH can be allocated. Monitoring the PDCCH includes blind decoding the PDCCH candidates in the search space. Successful blind decoding is expressed as (successfully) detected / received PDCCH, and when the blind decoding fails, PDCCH can be expressed as undetected / not received or not detected / received successfully.

For convenience of explanation, a PDCCH scrambled with a group common (GC) RNTI that one or more UEs already know to transmit downlink control information to one or more UEs is referred to as a group common (GC) PDCCH < / RTI > In addition, a PDCCH scrambled with a UE-specific RNTI already known by a specific UE to transmit uplink scheduling information or downlink scheduling information to one UE is referred to as a UE-specific PDCCH. The common PDCCH may be included in the common search space, and the UE-specific PDCCH may be included in the common search space or the UE-specific PDCCH.

The base station transmits resource allocation information (DL Grant) or UL-SCH (uplink-shared channel) related to resource allocation of a paging channel (PCH) and a downlink-shared channel (DL-SCH) (UL grant) related to a hybrid automatic repeat request to each terminal or terminal group. The base station can transmit the PCH transport block and the DL-SCH transport block through the PDSCH. The base station can transmit data excluding specific control information or specific service data through the PDSCH. In addition, the UE can receive data other than specific control information or specific service data through the PDSCH.

The base station can transmit information on which PDSCH data is transmitted to which terminal (one or a plurality of terminals), and how the PDSCH data is to be received and decoded by the corresponding terminal, in the PDCCH. For example, the DCI transmitted through a specific PDCCH is CRC masked with an RNTI of " A ", indicating that the DCI is allocated a PDSCH to a radio resource (e.g., a frequency position) Quot; (e.g., transport block size, modulation scheme, coding information, etc.). The UE monitors the PDCCH using its own RNTI information. In this case, if there is a UE that blind decodes the PDCCH using the " A " RNTI, the UE receives the PDCCH and receives PDSCH indicated by " B " and " C "

Table 3 shows an embodiment of a physical uplink control channel (PUCCH) used in a wireless communication system.

The PUCCH may be used to transmit the following uplink control information (UCI).

- SR (Scheduling Request): Information used for requesting uplink UL-SCH resources.

- HARQ-ACK: A response to the PDCCH (indicating DL SPS release) and / or a response to a downlink transport block (TB) on the PDSCH. The HARQ-ACK indicates whether information transmitted through the PDCCH or the PDSCH is received. The HARQ-ACK response includes positive ACK (simply ACK), negative ACK (NACK), DTX (Discontinuous Transmission) or NACK / DTX. Here, the term HARQ-ACK is used in combination with HARQ-ACK / NACK and ACK / NACK. In general, an ACK may be represented by a bit value of 1 and a NACK may be represented by a bit value of zero.

- CSI (Channel State Information): feedback information on the downlink channel. The UE generates a CSI-RS (Reference Signal) transmitted from the BS. Multiple Input Multiple Output (MIMO) -related feedback information includes RI (Rank Indicator) and PMI (Precoding Matrix Indicator). CSI can be divided into CSI part 1 and CSI part 2 according to the information indicated by CSI.

In the 3GPP NR system, five PUCCH formats can be used to support various service scenarios and various channel environments and frame structures.

PUCCH format 0 is a format capable of transmitting 1-bit or 2-bit HARQ-ACK information or SR. PUCCH format 0 can be transmitted via one or two OFDM symbols on the time axis and one PRB on the frequency axis. When PUCCH format 0 is transmitted in two OFDM symbols, the same sequence can be transmitted in two symbols with different RBs. In this case, the sequence may be a cyclic shift (CS) sequence from a base sequence used for PUCCH format 0. Accordingly, the UE can obtain a frequency diversity gain. Specifically, the UE can determine a cyclic shift (CS) value m _cs according to an M _bit bit UCI (M _bit = 1 or 2). Also, a base sequence having a length of 12 can be mapped to 12 REs of one OFDM symbol and one RB by cyclic-shifting a sequence based on a predetermined CS value m _cs . If the terminal is numbered using the number 12 of the cyclic shift as possible, the M _bit = 1, 1bit UCI 0 and 1, there is a difference in cyclic shift values can be mapped to the shift sequence, 6 of the two cyclic respectively. Further, when M _bit = 2, 2 _bits UCI 00, 01, 11, and 10 can be mapped to four cyclic-shifted sequences each having a difference in cyclic shift value of 3.

PUCCH format 1 can carry 1-bit or 2-bit HARQ-ACK information or SR. PUCCH format 1 can be transmitted over continuous OFDM symbols on the time axis and one PRB on the frequency axis. Here, the number of OFDM symbols occupied by the PUCCH format 1 may be one of 4 to 14. More specifically, UCI with M _bit = 1 can be modulated into BPSK. The terminal may be a modulation _bit M = 2 the UCI to the QPSK (quadrature phase shift keying). A signal is obtained by multiplying a modulated complex valued symbol d (0) by a sequence of length 12. At this time, the sequence may be a base sequence used for PUCCH format 0. The MS spreads the obtained signal to orthogonal cover code (OCC) on the even-numbered OFDM symbol to which the PUCCH format 1 is allocated. In PUCCH format 1, the maximum number of different terminals multiplexed in the same RB is determined according to the length of the OCC to be used. The odd-numbered OFDM symbols of the PUCCH format 1 may be mapped by spreading the demodulation reference signal (DMRS) to the OCC.

PUCCH format 2 can carry a UCI that exceeds 2 bits. PUCCH format 2 may be transmitted via one or two OFDM symbols on the time axis and one or more RBs on the frequency axis. When PUCCH format 2 is transmitted in two OFDM symbols, the same sequence can be transmitted on two different OFDM symbols to different RBs. Here, the sequence includes a plurality of modulated complex symbols d (0), ... , d (M _symbol- 1). Here, M _symbol can be M _bit / 2. Accordingly, the UE can obtain a frequency diversity gain. More specifically, the M _bit bit UCI (M _bit > 2) is bit-level scrambled and QPSK modulated to map to the RB (s) of one or two OFDM symbol (s). Wherein the number of RBs can be any one of 1 to 16.

PUCCH format 3 or PUCCH format 4 can carry a UCI that exceeds 2 bits. The PUCCH format 3 or the PUCCH format 4 can be transmitted over a continuous OFDM symbol on the time axis and one PRB on the frequency axis. The number of OFDM symbols occupied by PUCCH format 3 or PUCCH format 4 may be one of 4 to 14. Specifically, the UE can generate the complex symbols d (0) to d (M _symb -1) by modulating the M _bit bit UCI (M _bit > 2) with? / 2-BPSK . Here, M _symb = M _bit is used when? / 2-BPSK is used, and M _symb = M _bit / 2 is used when QPSK is used. The terminal may not apply block-by-unit spreading to PUCCH format 3. However, the terminal may use a PreDFT-OCC having a length of -12 so that the PUCCH format 4 may have two or four multiplexing capacities, so that one RB (i.e., 12 subcarriers) Can be applied. The terminal can transmit the spread signal by performing transmit precoding (or DFT-precoding) on the spread signal and mapping it to each RE.

At this time, the number of RBs occupied by the PUCCH format 2, the PUCCH format 3, or the PUCCH format 4 can be determined according to the length and the maximum code rate of the UCI transmitted by the terminal. When the UE uses PUCCH Format 2, the UE can transmit HARQ-ACK information and CSI information together via the PUCCH. If the number of RBs that can be transmitted by the UE is greater than the maximum number of RBs available in PUCCH Format 2, PUCCH Format 3, or PUCCH Format 4, the UE does not transmit some UCI information according to the priority of the UCI information, Only information can be transmitted.

PUCCH format 1, PUCCH format 3, or PUCCH format 4 may be configured via the RRC signal to indicate frequency hopping within the slot. When frequency hopping is configured, the index of the RB to be frequency hopped may consist of an RRC signal. When PUCCH format 1, PUCCH format 3, or PUCCH format 4 is transmitted over N OFDM symbols on the time axis, the first hop has floor (N / 2) OFDM symbols and the second hop has ceil N / 2) OFDM symbols.

PUCCH format 1, PUCCH format 3, or PUCCH format 4 may be configured to be repeatedly transmitted to a plurality of slots. At this time, the number K of slots through which the PUCCH is repeatedly transmitted can be configured by the RRC signal. The repeatedly transmitted PUCCHs must start at the same position in the OFDM symbol in each slot and have the same length. If any OFDM symbol of the OFDM symbol of a slot to which the UE should transmit a PUCCH is indicated as a DL symbol by the RRC signal, the UE can transmit the PUCCH to the next slot without transmitting the PUCCH in the corresponding slot.

On the other hand, in the 3GPP NR system, a UE can perform transmission / reception using a bandwidth smaller than or equal to the bandwidth of a carrier (or cell). For this purpose, the terminal can be configured with a bandwidth part (BWP) composed of a continuous bandwidth of a part of the carrier's bandwidth. A terminal operating in accordance with TDD or operating in an unpaired spectrum can be configured with up to four DL / UL BWP pairs in one carrier (or cell). In addition, the terminal can activate one DL / UL BWP pair. A terminal operating in accordance with FDD or operating in paired spectrum may be configured with up to four DL BWPs in the downlink carrier (or cell) and up to four UL BWPs in the uplink carrier (or cell) Can be configured. The terminal can activate one DL BWP and one UL BWP for each carrier (or cell). The terminal may or may not receive in time-frequency resources other than the activated BWP. An activated BWP can be referred to as an active BWP.

The base station can instruct the BWP activated through the downlink control information (DCI) among the BWPs configured by the UE. The BWP indicated via the DCI is activated and the other configured BWP (s) are deactivated. In a carrier (or cell) operating in TDD, a base station may include a bandwidth part indicator (BPI) indicating a BWP that is activated in the DCI that schedules the PDSCH or PUSCH to change the DL / UL BWP pair of the terminal. The terminal can receive the DCI scheduling the PDSCH or PUSCH and identify the DL / UL BWP pair that is activated based on the BPI. For a downlink carrier (or cell) operating as an FDD, the base station may include a BPI indicating the BWP to be activated in the DCI scheduling the PDSCH to change the DL BWP of the UE. For an uplink carrier (or cell) operating as an FDD, the base station may include a BPI indicating the BWP to be activated in the DCI that schedules the PUSCH to change the UL BWP of the terminal.

8 is a conceptual diagram illustrating carrier aggregation.

Carrier aggregation is a technique in which a radio communication system uses a frequency block or a (logical sense) cell composed of uplink resources (or component carriers) and / or downlink resources (or component carriers) Which is used as a single large logical frequency band. One component carrier may also be referred to as a PCell (Primary cell), a SCell (Secondary Cell), or a PScell (Primary SCell). However, for convenience of description, the term "component carrier" is used in the following description.

Referring to FIG. 8, in one example of a 3GPP NR system, the entire system band includes up to 16 component carriers, and each component carrier can have a bandwidth of up to 400 MHz. A component carrier may include one or more physically contiguous subcarriers. In FIG. 8, each of the component carriers is shown to have the same bandwidth, but this is merely an example, and each component carrier may have a different bandwidth. Also, although each component carrier is shown as being adjacent to each other in the frequency axis, this figure is shown in a logical concept, wherein each component carrier may be physically adjacent to or spaced from one another.

Different center frequencies may be used for each component carrier. Also, one central frequency common to physically adjacent component carriers may be used. Assuming that all the component carriers are physically contiguous in the embodiment of FIG. 8, the center frequency A may be used in all the component carriers. Further, assuming that each component carrier is not physically contiguous, the center frequency A and the center frequency B may be used in each of the component carriers.

When the entire system band is expanded by carrier aggregation, a frequency band used for communication with each terminal can be defined in units of a component carrier. Terminal A can use 100 MHz, which is the entire system band, and performs communication using all five component carriers. The terminals B ₁ to B ₅ can use only a bandwidth of 20 MHz and perform communication using one component carrier. Terminals C ₁ and C ₂ can use a 40 MHz bandwidth and each communicate using two component carriers. The two component carriers may be logically / physically adjacent or non-contiguous. In the embodiment of FIG. 8, the terminal C ₁ uses two non-adjacent component carriers, and the terminal C ₂ uses two adjacent component carriers.

9 is a diagram for explaining single carrier communication and multiple carrier communication. Particularly, FIG. 9A shows a subframe structure of a single carrier, and FIG. 9B shows a subframe structure of a multiple carrier.

Referring to FIG. 9A, a general wireless communication system can perform data transmission or reception through one DL band and a corresponding UL band in the FDD mode. In another specific embodiment, the wireless communication system divides a radio frame into an uplink time unit and a downlink time unit in a time domain in the TDD mode, and performs data transmission or reception through the uplink / downlink time unit . Referring to FIG. 9 (b), three 20 MHz component carriers (CCs) can be grouped into UL and DL, respectively, and a bandwidth of 60 MHz can be supported. Each CC may be adjacent or non-adjacent to one another in the frequency domain. FIG. 9 (b) shows a case where the bandwidth of the UL CC and the bandwidth of the DL CC are the same and symmetric, but the bandwidth of each CC can be determined independently. Asymmetric carrier aggregation in which the number of UL CCs is different from the number of DL CCs is also possible. The DL / UL CC allocated / configured to a specific UE through the RRC may be called a serving DL / UL CC of the specific UE.

The base station can activate some or all of the serving CCs of the terminal or deactivate some CCs to perform communication with the terminal. The base station can change the CC to be activated / deactivated, and change the number of CCs to be activated / deactivated. If a base station assigns a CC available for a UE to a cell-specific or a UE-specific, at least one of the CCs once allocated is not deactivated unless the CC allocation for the terminal is completely reconfigured or the terminal is handed over . One CC that is not inactivated by the UE is called a primary CC or a primary cell and a CC that can be freely activated / deactivated by the BS is referred to as a secondary CC (SCC) or a secondary cell ).

Meanwhile, the 3GPP NR uses the concept of a cell to manage radio resources. A cell is defined as a combination of a downlink resource and an uplink resource, that is, a combination of DL CC and UL CC. A cell may consist of DL resources alone, or a combination of DL resources and UL resources. If carrier aggregation is supported, the linkage between the carrier frequency of the DL resource (or DL CC) and the carrier frequency of the UL resource (or UL CC) may be indicated by system information. The carrier frequency means the center frequency of each cell or CC. The cell corresponding to the PCC is referred to as PCell, and the cell corresponding to the SCC is referred to as SCell. The carrier corresponding to the PCell in the downlink is DL PCC, and the carrier corresponding to the PCell in the uplink is UL PCC. Similarly, the carrier corresponding to SCell in the downlink is DL SCC, and the carrier corresponding to SCell in the uplink is UL SCC. Depending on the terminal capability, the serving cell (s) may consist of one PCell and zero or more SCell. For UEs that are in the RRC_CONNECTED state but no carrier aggregation is set or that do not support carrier aggregation, there is only one serving cell consisting of only PCell.

As mentioned above, the term cell used in carrier aggregation is distinguished from the term cell, which refers to a certain geographical area in which communication services are provided by one base station or one antenna group. That is, one component carrier may also be referred to as a scheduling cell, a scheduled cell, a PCell (Primary cell), a SCell (Secondary Cell), or a PScell (Primary SCell). However, in order to distinguish between a cell designating a certain geographical area and a cell for aggregation of carriers, in the present invention, a cell for collecting carriers is called a CC and a cell in a geographical area is called a cell.

10 is a diagram showing an example in which a cross carrier scheduling technique is applied. When cross-carrier scheduling is set, the control channel transmitted through the first CC may schedule the data channel transmitted through the first CC or the second CC using a carrier indicator field (CIF). The CIF is contained within the DCI. In other words, a scheduling cell is set up and the DL grant / UL grant transmitted in the PDCCH region of the scheduling cell schedules the PDSCH / PUSCH of the scheduled cell. That is, a search area for a plurality of component carriers exists in the PDCCH area of the scheduling cell. PCell is basically a scheduling cell, and a specific SCell can be designated as a scheduling cell by an upper layer.

In the embodiment of FIG. 10, it is assumed that three DL CCs are merged. Here, it is assumed that DL component carrier # 0 is DL PCC (or PCell), and DL component carrier # 1 and DL component carrier # 2 are DL SCC (or SCell). It is also assumed that the DL PCC is set to the PDCCH monitoring CC. If no cross-carrier scheduling is configured by UE-specific (or UE-group-specific or cell-specific) higher layer signaling, then the CIF is disabled and each DL CC is allowed to transmit its own PDSCH scheduling (non-cross-carrier scheduling, self-carrier scheduling). On the other hand, if cross-carrier scheduling is configured by terminal-specific (or terminal-group-specific or cell-specific) higher layer signaling, then CIF is enabled and a particular CC (e.g. DL PCC) A PDCCH for scheduling a PDSCH of a DL CC A as well as a PDCCH for scheduling a PDSCH of another CC may be transmitted (cross-carrier scheduling). On the other hand, PDCCH is not transmitted in other DL CCs. Accordingly, the UE monitors the PDCCH that does not include the CIF according to whether the UE is configured for cross carrier scheduling, receives the self-carrier-scheduled PDSCH, monitors the PDCCH including the CIF, and receives the cross-carrier scheduled PDSCH .

9 and 10 illustrate the subframe structure of the 3GPP LTE-A system, however, the same or similar configuration may be applied to the 3GPP NR system. However, in the 3GPP NR system, the subframes of FIGS. 9 and 10 may be replaced by slots.

11 is a block diagram showing the configuration of a terminal and a base station according to an embodiment of the present disclosure. In an embodiment of the present disclosure, a terminal may be implemented with various types of wireless communication devices or computing devices that are guaranteed to be portable and mobility. A UE may be referred to as a UE (User Equipment), an STA (Station), an MS (Mobile Subscriber), or the like. In addition, in the embodiment of the present disclosure, the base station controls and manages a cell (e.g., macro cell, femtocell, picocell, etc.) corresponding to a service area and transmits the signal, channel designation, channel monitoring, Function can be performed. The base station may be referred to as a next Generation NodeB (gNB) or an access point (AP) or the like.

As shown, a terminal 100 according to one embodiment of the present disclosure may include a processor 110, a communication module 120, a memory 130, a user interface 140, and a display unit 150 .

First, the processor 110 may execute various commands or programs, and may process data inside the terminal 100. [ In addition, the processor 110 can control the entire operation including each unit of the terminal 100, and can control data transmission / reception between the units. Here, the processor 110 may be configured to perform operations according to the embodiments described in this disclosure. For example, the processor 110 may receive the slot configuration information, determine the slot configuration based on the slot configuration information, and perform communication according to the determined slot configuration.

Next, the communication module 120 may be an integrated module that performs wireless communication using a wireless communication network and wireless LAN connection using a wireless LAN. To this end, the communication module 120 may include a plurality of network interface cards (NIC) such as cellular communication interface cards 121 and 122 and an unlicensed band communication interface card 123, either internally or externally . In the drawing, the communication module 120 is shown as an integrated integrated module, but each network interface card may be independently arranged according to the circuit configuration or use, unlike the drawing.

The cellular communication interface card 121 transmits and receives radio signals to and from a base station 200, an external device, and a server using a mobile communication network, and transmits a cellular communication service Can be provided. According to one embodiment, the cellular communication interface card 121 may include at least one NIC module that utilizes a frequency band of less than 6 GHz. At least one NIC module of the cellular communication interface card 121 is connected to at least one of the base station 200, the external device, and the server in accordance with a cellular communication standard or protocol of a frequency band of less than 6 GHz supported by the corresponding NIC module, Can be performed.

The cellular communication interface card 122 transmits and receives radio signals to and from a base station 200, an external device, and a server using a mobile communication network, and communicates with a cellular communication service Can be provided. According to one embodiment, the cellular communication interface card 122 may include at least one NIC module that utilizes a frequency band of 6 GHz or more. At least one NIC module of the cellular communication interface card 122 is capable of independently communicating cellular communication with at least one of the base station 200, the external device, and the server in accordance with a cellular communication standard or protocol of a frequency band of 6 GHz or more supported by the corresponding NIC module Can be performed.

The unlicensed band communication interface card 123 transmits and receives radio signals to and from the base station 200, the external device, and the server using the third frequency band, which is a license-exempt band, Provide communication service. The license-exempt band communication interface card 123 may include at least one NIC module that uses the license-exempt band. For example, a license-exempt band may be a band of 2.4 GHz or 5 GHz. At least one NIC module of the license-exempt band communication interface card 123 is connected to at least one of the base station 200, the external device, and the server, independently or in accordance with the license-exclusion band communication standard or protocol of the frequency band supported by the corresponding NIC module Wireless communication can be performed.

Next, the memory 130 stores a control program used in the terminal 100 and various data corresponding thereto. The control program may include a predetermined program required for the terminal 100 to perform wireless communication with at least one of the base station 200, the external device, and the server.

Next, the user interface 140 includes various types of input / output means provided in the terminal 100. That is, the user interface 140 can receive user input using various input means, and the processor 110 can control the terminal 100 based on the received user input. In addition, the user interface 140 may perform output based on instructions of the processor 110 using various output means.

Next, the display unit 150 outputs various images on the display screen. The display unit 150 may output various display objects such as a content executed by the processor 110 or a user interface based on a control command of the processor 110. [

In addition, the base station 200 according to one embodiment of the present disclosure may include a processor 210, a communication module 220, and a memory 230.

First, the processor 210 may execute various commands or programs and may process data within the base station 200. In addition, the processor 210 can control the entire operation including each unit of the base station 200, and can control data transmission / reception between the units. Here, processor 210 may be configured to perform operations according to the embodiments described in this disclosure. For example, the processor 210 may signal slot configuration information and perform communications according to the signaled slot configuration.

Next, the communication module 220 may be an integrated module that performs wireless communication using a wireless communication network and wireless LAN connection using a wireless LAN. To this end, the communication module 120 may include a plurality of network interface cards, such as the cellular communication interface cards 221 and 222 and the license-exclusion bandwidth communication interface card 223, either internally or externally. In the drawing, the communication module 220 is shown as an integrated integrated module, but each network interface card may be independently arranged according to the circuit configuration or use, unlike the drawing.

The cellular communication interface card 221 transmits and receives a radio signal to at least one of the terminal 100, the external device, and the server using the mobile communication network, and transmits the radio signal to the cellular Communication service can be provided. According to one embodiment, the cellular communication interface card 221 may include at least one NIC module that utilizes a frequency band of less than 6 GHz. At least one NIC module of the cellular communication interface card 221 is connected to at least one of the terminal 100, the external device, and the server in accordance with the cellular communication standard or protocol of the frequency band of less than 6 GHz supported by the corresponding NIC module, Can be performed.

The cellular communication interface card 222 transmits and receives radio signals to and from the terminal 100, the external device, and the server using the mobile communication network, and transmits the cellular communication service by the second frequency band Can be provided. According to one embodiment, the cellular communication interface card 222 may include at least one NIC module utilizing a frequency band of 6 GHz or more. At least one NIC module of the cellular communication interface card 222 can perform cellular communication with at least one of the terminal 100, the external device, and the server independently in accordance with the cellular communication standard or protocol of the frequency band of 6 GHz or more supported by the corresponding NIC module Can be performed.

The license-exempt band communication interface card 223 transmits and receives radio signals to and from the terminal 100, the external device, and the server using the third frequency band, which is a license-exempt band, Provide communication service. The license-exempt band communication interface card 223 may include at least one NIC module that uses the license-exempt band. For example, a license-exempt band may be a band of 2.4 GHz or 5 GHz. At least one NIC module of the license-exempted bandwidth communication interface card 223 is connected to at least one of the terminal 100, the external device, and the server, independently or in accordance with the license-exclusion band communication standard or protocol of the frequency band supported by the corresponding NIC module Wireless communication can be performed.

The terminal 100 and the base station 200 shown in FIG. 11 are block diagrams according to an embodiment of the present disclosure, in which blocks shown separately are logically distinguished from elements of a device. Thus, the elements of the device described above can be mounted as one chip or as a plurality of chips depending on the design of the device. In addition, a part of the configuration of the terminal 100, for example, the user interface 140, the display unit 150, and the like may be optionally provided in the terminal 100. [ In addition, the user interface 140, the display unit 150, and the like may be additionally provided to the base station 200 as needed.

FIG. 12 shows a method of receiving a PDSCH by acquiring information on a QCL of a beam for receiving a PDSCH from a base station according to an embodiment of the present invention.

The terminal can receive data from a plurality of transmission points (TP). In addition, the terminal can receive data transmitted from one TP through one or a plurality of beams. Data transmitted from each of the plurality of TPs or each of the plurality of beams may be transmitted through different channels. Accordingly, the UE can estimate the channel state for each of a plurality of channels. At this time, the terminal can treat one or a plurality of antennas using the same channel estimation value as one antenna port. At this time, the antenna port can be distinguished from the antenna, which is a physical concept in an abstract concept. Also, different reference signals may be used for each antenna port. The wireless communication apparatus can acquire information on the channel state corresponding to one of the antenna ports from the information on the channel state corresponding to the antenna port that is quasi-co-location (QCL) with the corresponding antenna port have.

At this time, the information on the channel state may be information on a large-scale property. More specifically, the information on the channel state includes information on at least one of a delay spread, a Doppler spread, a Doppler shift, an average gain, and an average delay . The UE calculates a power-delay profile, a delay spread, a Doppler spectrum and a Doppler spread estimation result for a radio channel corresponding to a specific antenna port based on a channel for a radio channel corresponding to another antenna port The same can be applied to the parameters used in the estimation. In addition, after the UE acquires time synchronization and frequency synchronization with respect to a specific antenna port, the UE acquires a signal used for acquiring time synchronization and frequency synchronization, a channel used for acquiring time synchronization and frequency synchronization, It can be assumed that the same sync and QCL information is applied to the port. Therefore, the UE can apply the same synchronization and QCL information to other antenna ports. Also, the UE can use an average value of RSRP measurements for each of the antenna ports that are QCLed as the average gain of the corresponding antenna port.

In addition, the UE can not infer information on a channel state corresponding to another antenna port that is not quasi-co-located from the information on the channel state corresponding to one of the antenna ports. In this case, the terminal can independently perform tracking for acquiring information on the channel state for each antenna port.

In order for the UE to receive the downlink control channel, the Node B may signal the UE with information about the QCL of the beam used for channel or signal reception. Specifically, the base station can set parameters to be used for signaling information on the QCL to the UE through radio resource control (RRC) setting and Media Access Control-Control Element (MAC-CE). For convenience of explanation, this is referred to as a QCL configuration. Through the RRC setting, the BS can configure at least one TCI state information to the UE. The terminal may configure one or more TCI status information through RRC setting from the base station. Each TCI state information may include a QCL setting relationship between the DM-RS port of the channel and one or more DL reference signals. When the BS configures one or more TCI status information by the RRC, the BS may signal the TCI status mapped to the QCL-related parameter to be used for the beam configuration for the physical downlink control channel reception through the MAC-CE. The UE sets a beam for receiving a physical downlink control channel as a QCL-related parameter mapped to a TCI state indicated by the MAC-CE, and can receive a physical downlink control channel through the set beam. The base station can also indicate information about the QCL used for the beam that receives the particular channel or signal. For ease of explanation, this is referred to as a QCL indication.

In order for the UE to receive the physical downlink data channel, the base station may signal the UE of information on the channel or the QCL of the beam used for signal reception. Specifically, the base station can set parameters to be used for signaling information on the QCL to the UE through the RRC setting and the MAC-CE. For convenience of explanation, this is referred to as a QCL configuration. Through the RRC setting, the base station can set at least one TCI state information to the UE, and each TCI state information can include a QCL setting relationship between the DM-RS port of the channel and one or more DL reference signals. When the base station configures one or more TCI state information to the UE in the RRC, the base station notifies the UE through the MAC-CE of a TCI state to be used for beam setting for physical downlink data channel reception and a physical downlink Signaling the mapping relationship between the values of the TCI field of the DCI being conveyed over the control channel. The terminal can set a beam for receiving the physical downlink data channel using the mapping relationship between the TCI state indicated through the MAC-CE and the QCL-related parameter from the base station to the terminal. The base station can indicate to the terminal through the DCI the TCI state corresponding to the QCL-related parameter to be applied to the beam used for receiving the physical downlink data channel of the terminal. Specifically, the base station can set the value of the TCI field of the DCI according to the mapping relationship between the TCI state signaled through the MAC-CE and the QCL-related parameter. The UE may apply the QCL-related parameters to the beam for receiving the physical downlink data channel according to the DCI field value. The base station can also indicate information about the QCL used for the beam that receives the particular channel or signal. For ease of explanation, this is referred to as a QCL indication.

In the embodiment of FIG. 12, the base station gNB signals the TSI state indicating the information on the QCL to be used for the PDSCH reception scheduled to the UE (UE) through the DCI of the PDCCH. The UE acquires information on the TCI state indicating the information on the QCL to be used for PDSCH reception scheduled for the UE. The UE receives the PDSCH from the base station gNB based on the information on the QCL to be used for the PDSCH reception. Specifically, the UE (UE) can set the QCL-related parameters based on the information on the QCL to be used for PDSCH reception. Efficient QCL setting, QCL indication, and beam changing method are required for efficient operation of the terminal. This will be described with reference to FIG. 13 through FIG.

The base station can perform QCL setting and QCL instruction for each CORESET so that the UE receives the physical downlink control channel. At this time, the UE can apply the same QCL setting when receiving a channel or a signal in all the search spaces in the CORESET. In addition, the base station can perform QCL setting and QCL indication for each search space. At this time, the UE can apply different QCL settings to each of the plurality of search spaces included in the same CORESET. The base station can perform QCL setting used for physical downlink data channel reception through a TCI (transmission configuration indicator) of the DCI of the physical downlink control channel. If two codewords (CW) are used for transmission of the physical downlink data channel, a DM-RS antenna port corresponding to each of the two CWs can be set. At this time, the base station can independently set QCL-related parameters for DM-RS antenna ports corresponding to different CWs. In a specific embodiment, the DM-RS antenna port corresponding to the first CW is QCL with NZP (nonzero power) CSI-RS corresponding to the first QCL parameter set, and the DM-RS antenna port corresponding to the second CW is the second It can be QCL with NZP CSI-RS corresponding to QCL parameter set. Also, when one codeword (CW) is used for transmission of the physical downlink data channel, the base station can set the same QCL-related parameters for every DM-RS antenna port corresponding to CW. In a specific embodiment, all DM-RS antenna ports corresponding to one CW can be QCLed with NZP CSI-RS corresponding to the first parameter set.

The base station may set at least one TCI state through RRC setting or RRC setting and MAC-CE. Specifically, the base station can set a list including at least one candidate TCI state to each terminal. At this time, QCL-related information can be mapped for each TCI state. The QCL-related information may include at least one of a type of a reference signal (RS), a transmission type of a reference signal, and a resource ID of a reference signal. The type of the reference signal may indicate at least one of an SS / PBCH block (Synchronization Signal / Physical Broadcast Channel Block) and a CSI-RS. Also, the transmission type of the reference signal may indicate at least one of periodic transmission, aperiodic transmission, and semi-persistent transmission. Also, one TCI state may be mapped to at least one reference signal set. Specifically, one TCI state may be mapped to one or two reference signal sets. Each reference signal set can represent a set of DM-RS antenna port groups and reference signals used for QCL setup. At this time, a plurality of DM-RS antenna ports using the same CW can be designated as one DM-RS antenna port group. Also, regardless of CW, the entire DM-RS antenna port can be designated as one DM-RS antenna port group. The reference signal set may include one or more reference signals. Specifically, the reference signal set may include at least one reference signal according to the QCL setting. For example, one set of reference signals may include a periodic CSI-RS, an aperiodic CSI-RS, and a semi-persistent CSI-RS. A plurality of reference signals included in one reference signal set may be QCL-connected to a DM-RS antenna port included in the DM-RS antenna port group corresponding to the reference signal set. Different reference signals included in one reference signal set may have different QCL-related parameters. Also, the base station may inidicate at least one TCI state that may be used for receiving the physical downlink data channel during at least one candidate TCI state through the DCI.

In a specific embodiment, each TCI state refers to one or two reference signal sets, and each of the reference signal sets may indicate a QCL relationship corresponding to one or two DM-RS port groups. At this time, the plurality of reference signals included in the reference signal set may be of different types. When the reference signal set includes a plurality of reference signals, each of the plurality of reference signals may have different QCL parameters. For example, the reference signal set may include a first reference signal and a second reference signal. In this case, the first reference signal corresponds to the first QCL parameter set, and the second reference signal corresponds to the second QCL parameter set. The reference signal set setting corresponding to each TCI set can be performed through a higher layer setting. Specifically, the reference signal set setting corresponding to each TCI set can be performed through RRC setting or RRC setting and MAC CE.

The QCL-related information mapped to the TCI state can indicate QCL-related information corresponding to the DM-RS used for reception of the physical downlink data channel. For convenience of description, a table indicating the mapping relationship between the TCI state and the QCL related information is referred to as a TCI state table. In a specific embodiment, the TCI state table can be determined according to the number of CWs used in the physical downlink data channel. In yet another specific embodiment, the same TCI state table may be used regardless of the number of CWs used in the physical downlink data channel.

In a specific embodiment, the TCI may be indicated by a 2-bit field. The TCI state table may be as shown in Table 4. Each of the first reference signal set RS set # 1 to the third reference signal set RS set # 3 includes SSB, cyclic CSI-RS, aperiodic CSI-RS, semi-persistent CSI- RS, SSB, and a reference signal other than CSI-RS. The number of reference signal sets used in the TCI state table may be one or more. As described above, the QCL state table can indicate the mapping relationship between the TCI state and the QCL-related parameters. At this time, the QCL-related parameter may include a resource identifier.

In Table 4, the value of the field indicating the TCI state is mapped to the same reference signal set in case of 01 _b and 11 _b . Even though the TCI status is mapped to the same reference signal set, the resource identifiers corresponding to the corresponding reference signal set may be different from each other. In a specific embodiment, the UE can receive the physical downlink data channel based on the TCI mapping table. For example, it is used and TCI mapping table shown in Table 4, the value of the field indicating the status of the TCI DL DCI may be a 01 _b. In addition, a specific beam is used for receiving a specific reference signal having a resource identifier corresponding to the second reference signal set. At this time, the UE can receive the physical downlink data channel scheduled to the DL DCI using the corresponding beam.

FIG. 13 shows a case where a terminal according to an embodiment of the present invention acquires information on a QCL of a beam for receiving a PDSCH from a base station, and maintains the QCL parameter setting as it is.

The base station can signal to the terminal that the QCL setting is the same as before using the value of the field indicating the TCI state. At this time, if the value of the field indicating the TCI state is a predetermined value, the UE can determine that the QCL setting for the UE is the same as before. At this time, the previous QCL setting may be the QCL state indicated through the TCI of the previously transmitted DCI. For example, when the field for indicating the state TCI field of 2 bits, the base station sets the value of the field indicating the state to the TCI 00 _b to QCL settings for the UE may signal the same as before. If the value of the field indicating the TCI state 00 _b, the UE may determine that QCL set for the terminal, the same as before.

13, the base station gNB sets the value of the field indicating the TCI state of the DCI of the PDSCH to a predetermined value, and transmits the value of the field indicating the TCI state of the DCI of the PDSCH to the UE (UE) using the QCL- Lt; RTI ID = 0.0 > PDSCH < / RTI > The UE determines that the value of the field indicating the TCI state of the DCI is a predetermined value. At this time, the UE receives the scheduled PDSCH to the UE without changing the QCL-related parameter setting.

If a TCI state table of Table 5 is applied, the base station can instruct the value of the field indicating the TCI state 00 _b using the QCL-related parameter previously set to the terminal to signal that it receives the scheduling PDSCH to the mobile station . Terminal when the value of the field indicating the status of the DCI TCI is 00 _b, the UE receives a scheduling PDSCH to the UE, without changing the QCL-related parameter settings.

As described above, two CWs can be used for physical downlink data channel reception. If two CWs are used, different DM-RS antenna port groups may be used for each CW. At this time, one TCI state can be mapped to two reference signal sets for setting QCL-related parameters corresponding to different DM-RS antenna port groups. Also, one TCI state can be mapped to one reference signal set. In Table 6, if the value of the field indicating the TCI state is 10 _b , the third reference signal set (RS set # 3) having the same DM-RS antenna port group is mapped. Also, the reference signals in the third reference signal set (RS set # 3) may have different resource identifiers.

In addition, as described above, the number of reference signal sets mapped to the TCI state can be changed according to the number of CWs used for physical downlink data channel reception. Table 7 shows an example in which the number of reference signal sets mapped to the TCI state varies depending on the number of CWs used for physical downlink data channel reception. If one CW is used for physical downlink data channel reception, the value of the field indicating the TCI state in Table 7 may be either _00b or _10b . If one CW is used for physical downlink data channel reception, the base station shall set the value of the field indicating TCI state to either _00b or _10b . If two CWs are used to receive the physical downlink data channel, the base station shall set the value of the field indicating the TCI state to either 00 _b or 10 _b .

The QCL-related information mapped to the TCI state can be updated. The base station can explicitly update the QCL-related information mapped to the TCI TCI state. In addition, the base station may update the QCL-related information mapped to the TCI TCI state implicitly.

When a terminal receives a physical downlink data channel scheduled by a DCI including a field indicating a TCI state, the terminal can apply a value of a QCL-related parameter indicated by a field value indicating the corresponding TCI state. In another embodiment, when a UE receives a DCI including a field indicating a TCI state, the UE may apply a value of a QCL-related parameter indicated by a field value indicating the TCI state when the scheduling offset has elapsed have. The scheduling offset may be a predetermined value. In yet another specific embodiment, the scheduling offset may be set by the base station. In these embodiments, the scheduling offset may be at least one slot duration. That is, the scheduling offset may be an integral multiple of the slot duration. Also, the scheduling offset may be determined according to the capacity of the UE.

In the embodiments described with reference to FIGS. 12 to 13, the point at which the UE changes the setting of the beam for physical downlink data channel reception may be a problem. The UE can receive a MAC-CE indicating a TCI state indicating a QCL-related parameter to be set by the UE. At this time, the UE receives the physical downlink control channel and can change the beam setting for receiving the physical downlink data channel according to the TCI state indicated by the received physical downlink control channel. In another embodiment of the present invention, the UE transmits the HARQ-ACK feedback for the physical downlink data channel including the MAC-CE indicating the TCI state indicating the QCL-related parameter to be set by the UE, The setting of the beam for reception can be changed. Specifically, after at least one subsequent slot of a slot that has transmitted HARQ-ACK feedback for a physical downlink data channel including a MAC-CE indicating a TCI state indicating a QCL-related parameter to be set by the UE, The setting of the beam for reception can be changed. In these embodiments, the HARQ-ACK feedback may be limited to the case of representing an ACK. Also, when a predetermined time has elapsed from a slot in which a UE transmits HARQ-ACK feedback for a physical downlink data channel including a MAC-CE indicating a TCI state indicating a QCL-related parameter to be set by the UE, The setting of the beam for receiving the data channel can be changed. At this time, the predetermined time may be a plurality of slots. In yet another specific embodiment, the predetermined time may be one slot. Also, the predetermined time may be less than the duration of the slot. For example, the predetermined time may be 1/2 slot. The predetermined time may be the duration of two OFDM symbols. Also, it may be four durations of a predetermined time OFDM symbol. Also, it may be seven durations of a predetermined time OFDM symbol.

In another specific embodiment, in a next cycle of a period of receiving a physical downlink control channel when a mobile station receives a physical downlink data channel including a MAC-CE indicating a TCI state indicating a QCL-related parameter to be set by the mobile station, The setting of the beam for receiving the physical downlink data channel can be changed. In another specific embodiment, after a predetermined time has elapsed from when the UE receives a physical downlink data channel including a MAC-CE indicating a TCI state indicating a QCL-related parameter to be set by the UE, The setting of the beam for reception can be changed. At this time, the predetermined time may be a plurality of slots. In yet another specific embodiment, the predetermined time may be one slot. In addition, the predetermined time may be 1/2 slot. The predetermined time may be the duration of two OFDM symbols. Also, it may be four durations of a predetermined time OFDM symbol. Also, it may be seven durations of a predetermined time OFDM symbol. In addition, the base station can independently set a time point at which the terminal changes the setting of the beam for each terminal. This is because the time spent for changing the beam setting may vary depending on the processing capability of the terminal. Specifically, the base station can set the time point at which the terminal changes the setting of the beam to any one of a plurality of time points using the RRC setting. At this time, the plurality of viewpoints may be the above-described viewpoints.

In addition, the TCI state can be used for QCL-related parameter signaling used for beam reporting. Specifically, the DCI that schedules uplink resources for beam reporting may include a field indicating a TCI state. The BS may signal the QCL-related parameters used in the reference signal measurement through the value of the field indicating the TCI status of the DCI that is scheduling the uplink resource for beam reporting. The UE can set the QCL-related parameters used in the reference signal measurement based on the value of the field indicating the TCI status of the DCI that schedules the uplink resource for beam reporting. Specifically, the UE can measure the reference signal according to the QCL-related parameter corresponding to the value of the field indicating the TCI status of the DCI. The terminal can transmit the reference signal measurement result to the base station. The base station can update the QCL-related parameters mapped to the TCI state based on the measurement result of the reference signal received from the terminal. Also, the base station can determine a QCL-related parameter value to be applied to a beam to be used for uplink transmission or downlink transmission, based on the measurement result of the reference signal received from the terminal.

In a specific embodiment, if the terminal has a preferred beam after the reference signal measurement and is preferred to the current beam, the terminal may signal the base station about the beam preferred by the terminal. The base station can update the QCL-related parameters mapped to the TCI state based on the information about the beam preferred by the terminal received from the terminal. The QCL-related parameter to which the TCI state indicated in the field indicating the TCI state is mapped in the DCI that schedules the uplink transmission resource may be updated by the operation of the base station. Also, the QCL-related parameter to which the TCI state indicated in the field indicating the TCI state of the DCI that schedules the physical data channel reception is mapped by the operation of the base station can be updated.

In this case, the field indicating the TCI state of the DCI may be the same as the field indicating the TCI state used for receiving the physical downlink data channel in the DCI scheduling the physical data channel reception. For convenience of description, a field indicating a TCI state in the DL DCI for indicating a QCL-related parameter used for receiving a physical downlink data channel is referred to as a DL TCI field, and a TCI state in the DCI for scheduling an UL transmission is indicated Field is referred to as a UL TCI field.

The base station can signal QCL-related parameters to the UE through RRC setting or MAC-CE without using the TCI state. Specifically, the base station can signal QCL-related parameters to the UE using RRC setting or RRC setting and resource setting or reporting setting information via MAC-CE.

In addition, the base station can signal to the terminal whether the terminal can arbitrarily determine the beam used for measuring the reference signal. For convenience of explanation, whether the terminal can arbitrarily determine a beam used for measuring the reference signal is referred to as beam change allowability information. Specifically, the BS may signal beam change allowance information to the UE through the DCI for beam reporting or reference signal triggering of the UE. In addition, the base station can signal beam change allowability information through upper layer signaling. Specifically, the base station can signal beam change allowability information through upper layer signaling for reporting setting. When the beam change allowability information indicates that the terminal can arbitrarily determine the beam used for the reference signal measurement, the terminal sets a QCL-related parameter to a value different from the value of the QCL-related parameter signaled by the base station, can do. When the beam change allowability information indicates that the UE can not arbitrarily determine the beam used for the reference signal measurement, the UE sets a QCL-related parameter with a value different from the value of the QCL-related parameter signaled by the base station, Can not be measured. In addition, when the beam change allowability information indicates that the terminal can not arbitrarily determine the beam used for the reference signal measurement, the terminal sets the QCL parameter according to the QCL parameter value of the beam used for the most recent physical downlink data channel reception To perform a reference signal measurement.

In addition, when the terminal can arbitrarily determine the beam used for measuring the reference signal, the base station can signal to the terminal whether the terminal changes the beam used for measuring the reference signal is explicitly signaled. For convenience of explanation, information indicating that a time point at which a beam used for measurement of a reference signal is explicitly signaled is referred to as explicit reception beam change information. The explicit receive beam modification information may be a one-bit field. In addition, the BS may signal explicit reception beam change information to the UE through the DCI for beam reporting of the UE or for triggering the reference signal. In addition, the base station can signal explicit reception beam change information through upper layer signaling. Specifically, the base station can signal explicit reception beam change information through upper layer signaling for reporting setting.

If the terminal implicitly changes the beam used for the reference signal measurement, the terminal may change the beam used to measure the reference signal at a particular point in time. The specific point in time may be a point in time with the base station. In another specific embodiment, the point-in-time may be the DCI reception point. In yet another specific embodiment, the point-in-time may be the physical downlink data channel reception point scheduled by the DCI. In another specific embodiment, the point-in-time may be the point in time at which the physical downlink data channel is transmitted after a certain offset from reporting the measurement result to the base station after the reference signal measurement.

If the terminal is not explicitly signaled when the beam used to measure the reference signal is to be changed, the terminal may change the beam used to measure the reference signal at a particular time. The specific point in time may be a point in time with the base station. In another specific embodiment, the point-in-time may be the DCI reception point. In yet another specific embodiment, the point-in-time may be the physical downlink data channel reception point scheduled by the DCI. In another specific embodiment, the point-in-time may be the point in time at which the physical downlink data channel is transmitted after a certain offset from reporting the measurement result to the base station after the reference signal measurement. If the terminal is explicitly signaled when the beam used to measure the reference signal is to be changed, the base station may indicate the point in time through the TCI of the DCI scheduling the reception of the physical downlink data channel of the terminal. When the UE receives the physical downlink data channel scheduled by the DCI, the UE can change the beam used for the reference signal measurement.

In such embodiments, the base station may signal information on QCL-related parameters that are mapped to the TCI state to the UE via RRC configuration or RRC configuration and MAC-CE. The base station can perform this upper layer signaling before or after the beam change.

The terminal may also use a metric or a threshold value when measuring the reference signal and determining the preferred beam. Here, the metric or threshold value may be predetermined. In yet another specific embodiment, the metric or threshold value may be set by the base station.

When the terminal reports the reference signal measurement result to the base station, the terminal can signal to the base station whether the beam used when the terminal measures the reference signal most recently used to receive the physical downlink data channel. At this time, the information may be a 1-bit field. In another specific embodiment, when the terminal reports the reference signal measurement result, the terminal informs the base station that the beam used in the measurement of the reference signal is a beam instructed by the DCI for scheduling the uplink resource for beam reporting Signaling. At this time, the information may be a 1-bit field. In these embodiments, the 1-bit information may be interpreted as at least one of information indicating whether a specific reception beam has been changed, information indicating whether a specific QCL-related parameter has been changed, and information indicating whether a specific reference reception beam has been changed.

FIG. 14 shows that a UE according to an embodiment of the present invention sets a QCL parameter of a beam for receiving a physical downlink control channel according to information signaled by a base station.

The BS can set the position of the CORESET time-frequency resource corresponding to the MS to the MS. Specifically, the base station can set the position of the CORESET time-frequency resource corresponding to the UE to the UE through the RRC setting. The UE can perform physical downlink control channel blind reception in the CORESET set in the UE. At this time, a physical downlink control channel for each of a plurality of terminals can be transmitted in one CORESET. When a base station changes a QCL-related parameter of a beam used to receive a physical downlink data channel, the base station can signal the changed QCL-related parameter to the UE using the QCL state set through upper layer signaling. At this time, the upper layer signaling may include RRC setting, or RRC setting and MAC-CE. The UE can set the QCL-related parameters of the beam used for the physical downlink control channel according to the QCL-related parameters signaled by the base station.

In the embodiment of FIG. 14, the base station gNB signals the UE to a QCL-related parameter to be used for PDCCH reception. Specifically, after the base station gNB sets a QCL-related parameter mapped to the TCI state to the UE, the base station gNB transmits a QCL-related parameter to be used for a specific CORESET to which a PDCCH to be used in receiving the PDCCH is transmitted Indicating the TCI state information corresponding to the TCI. The UE attempts to receive a PDCCH based on TCI status information corresponding to a QCL-related parameter to be used for PDCCH reception in a specific CORESET indicated by the base station gNB.

As described above, QCL-related parameters can be set for each CORESET. Also, the base station can set at least one TCI state information per CORESET to the UE through the RRC setting. Each TCI state information may include a QCL setup relationship between the DM-RS port of the physical downlink control channel and one or more DL reference signals. The base station can set QCL-related parameters for each CORESET using RRC setting or RRC setting and MAC-CE. At this time, the BS can signal to the UE the information related to the position of the CORESET and the QCL-related parameters matching the CORESET. The information related to the position of the CORESET may include at least one of a frequency position, an OFDM symbol position, a slot position, and a frame position. In addition, the information related to the location of the CORESET may include resource index information of the resource. At this time, the resource index information may include the position of a resource block (RB) in a frequency band. In addition, the information related to the location of the CORESET may include information related to the period in which the CORESET is transmitted. At this time, information related to the period in which CORESET is transmitted can be specified based on a specific time-frequency resource. If the BS has more than one TCI state information configured by the RRC, the BS can indicate one TCI state information among the one or more TCI state information to the UE through the MAC-CE. Accordingly, the UE can set a beam for the physical downlink control channel according to the QCL-related parameter mapped to the TCI state information indicated by the MAC-CE, and receive the physical downlink control channel using the set beam.

Table 8 shows the QCL-related parameters and PDCCH-related information set for each CORESET. The QCL-related parameters may include information that can be used in the beam configuration used for reception of the PDCCH transmitted in the corresponding CORESET. The QCL-related parameter may also include a reference index or a resource index that identifies the reference signal and information about the reference signal set. In addition, the base station may transmit at least one of information related to the search space corresponding to the CORESET, the aggregation level, the number of OFDM symbols transmitting the physical downlink control channel, and the resource mapping method, Can be set.

Each CORESET can be mapped to a beam used by the base station for transmission. The numbering for CORESET can be expressed in a time-frequency resource format. In addition, the numbering for CORESET may be expressed as an offset or period based on a particular time-frequency resource. Table 9 shows the beams used by the base stations mapped by each CORESET. In Table 9, the base station sets eight CORESETs, and the number of beams used by the base station is 64. At this time, 8 beams are mapped for each CORESET. CORESET can be mapped to a beam used for signal transmission such as periodically transmitted SSB. In addition, CORESET can be mapped to the entire set of beams that can be used in the physical downlink control channel transmission. The number of total beams to which CORESET is mapped and the beam shape may be unrestricted. The beam mapped to CORESET may be indicated by the beam index or the resource identifier of the SSB or CSI-RS.

The base station can set QCL-related parameters and CORESET location information mapped to CORESET using RRC setting or RRC setting and MAC-CE. The UE can monitor the physical downlink control channel in the CORESET based on the QCL-related parameter mapped to the CORESET set by the base station and the CORESET location-related information. Specifically, the UE can determine the location of the time-frequency resource to monitor the physical downlink control channel based on the CORESET location-related information. In addition, the UE can set the QCL parameters of the beam according to the QCL-related parameters mapped to the CORESET set by the base station, and attempt to receive the physical downlink control channel through the corresponding beam.

The UE may attempt to receive the physical downlink control channel in the CORESET initialized by the base station and attempt to receive the physical downlink control channel transmitted after the corresponding physical downlink control channel in the CORESET indicated by the DCI of the physical downlink control channel. In the embodiment of Table 8, four CORESETs are set to the terminal. At this time, the 2-bit field in the DCI of the PDCCH may indicate a CORESET to which the UE will attempt to receive the next PDCCH. The UE can attempt to receive the physical downlink control channel transmitted after the corresponding physical downlink control channel in the CORESET indicated by the DCI of the physical downlink control channel. The field indicating the CORESET to be received by the physical downlink control channel transmitted after the corresponding physical downlink control channel in the DCI of the physical downlink control channel may be a field having two or more bits.

The base station may update the information associated with the CORESET setting. Specifically, the base station can update the location information of the CORESET and the QCL-related parameters mapped to the CORESET using the RRC setting or the RRC setting and the MAC-CE. In addition, the base station may update the beam mapped to CORESET. In the embodiments of Tables 8 and 9, it is assumed that the base station attempts to change the beam mapped to the fifth CORESET (CORESET # 5). The fifth CORESET (CORESET # 5) is mapped from the 33rd beam (# 33) to the 40th beam (# 40). If the beam to be changed by the base station is the forty-first beam (# 41), the base station may set a sixth CORESET (CORESET # 6) mapped to the 41st beam (# 41) instead of the fifth CORESET have. When the BS to be changed is included in the CORESET set by the BS to the UE, the BS can indicate the CORESET including the beam to be changed instead of the CORESET previously instructed to the UE. The UE sets the QCL-related parameters of the beam to receive the physical downlink control channel according to the changed CORESET setting, and attempts to receive the physical downlink control channel.

When the base station sets CORESET to the UE, the BS can indicate a CORESET to be set to the UE through RRC setting or MAC-CE. At this time, the base station can use an index indicating CORESET. For example, in the case of 8 CORESETs as in the embodiment of Table 9, the base station can indicate a CORESET to be set to the UE using the 3-bit field of RRC setting or MAC-CE.

A concrete method of changing the beam setting used for receiving the physical downlink control channel will be described.

As described above, the base station can signal CORESET and QCL-related parameters via RRS configuration or MAC-CE. In addition, the BS can signal which CORESET among the CORESETs set to the UE through the DCI TCI. If the base station wishes to modify the beam or add the beam, the base station may signal on QCL-related parameters for the physical downlink data channel over the TCI of the DCI. At this time, when transmitting the physical downlink data channel, the BS not only notifies the UE through the MAC-CE of the CORESET-related information for the physical downlink control channel, the CORESET for physical downlink control channel beam change or the QCL- Lt; / RTI > can be signaled. At this time, when transmitting the physical downlink data channel, the UE can set or change the beam for physical downlink control channel reception based on the MAC-CE.

Also, the BS can signal changed CORESET-related information and modified QCL-related parameters to the UE through the RRC setting or the MAC-CE regardless of the point of time when the physical downlink data channel is transmitted. In addition, the base station can newly instruct the CORESET to be monitored by the UE through the DCI and change the beam-related setting used for receiving the physical downlink control channel. The base station can use the method of changing the CORESET through the MAC-CE and the method of changing the CORESET through the DCI. In addition, the base station can signal which of two methods the terminal uses through the RRC setting. In the case where the setting related to the beam used for receiving the physical downlink control channel is changed as described above, the terminal transmits the beam used for physical downlink control channel reception when a certain offset has elapsed after receiving the information indicating that the setting related to the beam is changed You can change related settings. In addition, when the setting related to the beam used for receiving the physical downlink control channel is changed, the UE receives the information indicating that the setting related to the beam is changed, and then, when receiving the physical downlink control channel in the CORESET, You can change the settings associated with the beam being used.

In another specific embodiment, the base station may indicate the QCL-related parameters of the beam used for physical downlink control channel reception using the TCI state indicated by the DCI of the physical downlink data channel described above. At this time, the UE can set the QCL-related parameters of the beam used for the physical downlink control channel according to the QCL-related parameter mapped to the TCI state indicated by the DCI of the physical downlink data channel. The UE can receive the physical downlink control channel using the corresponding beam. When four CORESETs are set as in the embodiment of Table 8, CORESET can be put into a 2-bit TCI state. If N CORESETs are mapped to one TCI state, the base station can indicate N CORESETs with CORNES mapped to the TCI state via 2N bits. When such an embodiment is applied, the base station may not need to set it independently for CORESET. In addition, the base station may not need to separately operate QCL-related parameters mapped to CORESET.

Embodiments for changing the beam setting used for reception of the physical downlink control channel as described above can be used together. In addition, the BS may signal to the MS which method to use through upper layer signaling. At this time, the upper layer signaling may include the RRC setting.

In the above-described embodiments, a method for changing a beam-related setting used by a terminal for receiving a physical downlink control channel / physical downlink data channel has been described. A method for changing the physical uplink data channel, physical uplink control channel and SRS is needed. This will be described.

The base station can change the setting of the beam used for the uplink transmission through the QCL indication. Specifically, the base station can change the setting of the beam used for the uplink transmission using the TCI of the UL DCI. At this time, the UE can apply the QCL-related parameters indicated through the TCI of the UL DCI only to the physical uplink control channel transmission (hereinafter referred to as the first scheme). In another specific embodiment, the UE can apply the QCL-related parameters indicated by the TCI of the UL DCI only to the physical uplink data channel transmission (hereinafter referred to as the second scheme). In another specific embodiment, the UE can apply the QCL-related parameters indicated by the TCI of the UL DCI to the physical uplink control channel transmission and the physical uplink data channel transmission (hereinafter referred to as the third scheme). In another specific embodiment, the UE can apply the QCL-related parameters indicated through the TCI of the UL DCI to the uplink channel transmission scheduled through the corresponding DCI (hereinafter, the fourth scheme). In another specific embodiment, the UE can apply the QCL-related parameters indicated by the TCI of the UL DCI to the SRS transmission (hereinafter, the fifth scheme). In another specific embodiment, the UE can apply the QCL-related parameters indicated through the TCI of the UL DCI to the physical uplink control channel transmission, the physical uplink data channel transmission, and the SRS transmission (hereinafter referred to as the sixth scheme). In another specific embodiment, the UE can apply QCL-related parameters indicated through the TCI of the UL DCI to uplink channel transmission scheduled through the corresponding DCI and uplink channel transmission triggered through the corresponding DCI (hereinafter referred to as the seventh mode ).

The mapping relationship between the QCL state for uplink transmission and the QCL-related parameters may be set to be the same as the mapping relationship between the QCL state for downlink transmission and the QCL-related parameters. In this embodiment, the base station does not need to set the mapping relationship between the QCL state for uplink transmission and the QCL-related parameters separately from the mapping relationship between the QCL state for downlink transmission and the QCL-related parameters. At this time, the base station can signal beam configuration information for uplink transmission as well as beam configuration for downlink transmission using the mapping relationship between QCL state and QCL related parameters for downlink transmission. In another specific embodiment, the mapping relationship between the QCL state and the QCL-related parameters for the uplink transmission may be set independently of the mapping relationship between the QCL state and the QCL-related parameters for downlink transmission. In this embodiment, the base station needs to set the mapping relationship between the QCL state for uplink transmission and the QCL-related parameters separately from the mapping relationship between the QCL state for downlink transmission and the QCL-related parameters.

When the first scheme, the second scheme, and the third scheme are applied at the same time, the base station can indicate to the terminal which of the three schemes is used through the uplink DCI. Specifically, the field indicating which of the three methods is used may be a 2-bit field. At this time, when the value of the field is equal to 00 _b, the MS may use for uplink Physical the QCL-related parameter that maps to the TCI state indicating the corresponding DCI control channel transmission. Further, when the value of the field is 01 _b, the terminal may use the QCL-related parameter that maps to the TCI state indicating the corresponding DCI a physical uplink data channel transmission. Also, if the value of the corresponding field is _10b , the UE can use the QCL-related parameter mapped to the TCI state indicated by the corresponding DCI for physical uplink control channel transmission and physical uplink data channel transmission. If the value of the field is 11 _b , it can indicate the default operating mode. If yet another particular embodiment, the value of the field 11 _b, the UE can use the uplink transmission channel transmitted to the DCI the upstream transmission of the scheduling DCI the QCL-related parameter that maps to the TCI state indicative.

When the first to sixth schemes are applied at the same time, the base station can indicate which of the six schemes is used to the terminal through the uplink DCI. Specifically, the field indicating which of the six schemes is used may be a 3-bit field. At this time, when the value of the field 000 in _b, the MS may use for uplink Physical the QCL-related parameter that maps to the TCI state indicating the corresponding DCI control channel transmission. Also, if the value of the corresponding field is 001 _b , the UE can use the QCL-related parameter mapped to the TCI state indicated by the corresponding DCI in the physical uplink data channel transmission. Further, when the value of the field is equal to 010 _b, the UE can use for the uplink physical DCI the QCL-related parameter that maps to the TCI status indicating control channel transmission, and a physical uplink data channel transmission. If the value of the corresponding field is 011 _b , it can indicate the default operating mode. In another specific embodiment, if the value of the field is equal to 011 _b, the UE can use the uplink transmission channel transmitted to the DCI the upstream transmission of the scheduling DCI the QCL-related parameter that maps to the TCI state indicative. If the value of the corresponding field is 100 _b , the UE can use the QCL-related parameter mapped to the TCI state indicated by the corresponding DCI in SRS transmission. If the value of the corresponding field is 100 _b , the UE can use the QCL-related parameter mapped to the TCI state indicated by the corresponding DCI for physical uplink control channel transmission, physical uplink data channel transmission, and SRS transmission. Further, when the value of the field 110 in _b, the UE can use the uplink transmission channel transmitted to the uplink transmission is DCI DCI scheduling or triggering the QCL-related parameter that maps to the TCI state indicative.

Also, the base station can signal to the UE that the QCL-related parameters for uplink transmission are not changed by using a predetermined TCI status value as in the above-described TCI status value for downlink transmission.

When the UE fails to receive the physical downlink control channel of all serving cells, the UE can declare a beam failure to the base station. At this time, the base station can transmit information on a new candidate beam to the terminal. The terminal may identify the new candidate beam and send a beam failure recovery request to the base station. The terminal may receive a response to the beam failure recovery request from the base station. In this operation, the UE can perform the beam failure only when it fails to receive the physical downlink control channel of all the serving cells. If the terminal fails to receive some of the serving physical downlink control channels, the terminal can not request a configuration change on the beam. Therefore, when the reception of a part of the downlink physical downlink control channels fails, there is a problem that the communication efficiency must be neglected even if the communication efficiency deteriorates. There is a need for a method for solving the case of failing to receive the physical downlink control channel of some serving cell. This will be described with reference to FIG. 15 to FIG.

As described above, the candidate set of the downlink transmission reference signal can be set through the RRC setting. In addition, a downlink transmission reference signal which is a reference of the QCL can be set through the RRC setting for each TCI state. Also, the MAC-CE may be used to select 2 ^N TCI states for QCL indication for reception of the physical downlink data channel among a plurality of TCI states. At this time, the selected TCI state can be reused for CORESET. The TCI state can be set per CORESET. Specifically, a plurality of TCI states can be set in one CORESET. At this time, the base station can use MAC-CE to indicate which TCI state is used for reception of the physical downlink control channel transmitted through the corresponding CORESET. In addition, one TCI state can be set for one CORESET. At this time, MAC-CE signaling indicating which TCI state is to be used for physical downlink control channel reception transmitted via CORESET is not required.

FIG. 15 is a diagram illustrating a case where a plurality of TCI states are set in a specific CORESET in a base station according to an embodiment of the present invention, and a base station transmits a beam for receiving a physical downlink control channel It shows changing the setting.

A method is described in which a plurality of TCI states are set in a specific CORESET and a base station changes a beam setting for receiving a physical downlink control channel of a terminal with QCL-related parameters corresponding to any one of the plurality of TCI states. The base station may use the MAC-CE to indicate the TCI state indicating the QCL-related parameters to be set by the terminal during a plurality of TCI states. The UE can change the setting of the beam for receiving the physical downlink control channel according to the QCL-related parameter mapped to the TCI state indicated by the MAC-CE. When the BS determines that the MS can receive the physical downlink control channel with the currently used beam, the BS can transmit the physical downlink control channel to the beam currently used by the MS.

In another specific embodiment, when the BS determines that the UE can not receive the physical downlink control channel with the beam currently being used, the BS determines whether the UE can receive the physical downlink control channel in the CORESET set in the UE, The downlink control channel can be transmitted. In addition, when the BS determines that the UE can not receive the physical downlink control channel with the beam currently being used, the BS determines the CORESET at the earliest point among the CORESETs that the UE can receive the physical downlink control channel, Lt; RTI ID = 0.0 > downlink < / RTI > When the BS determines that the UE can not receive the physical downlink control channel with the beam currently being used, the base station uses the MAC-CE to transmit the physical downlink data channel scheduled by the physical downlink control channel, It can indicate the TCI state mapped to the QCL-related parameter to be used by the UE among the CORESET to receive the channel and the TCI state corresponding to the corresponding CORESET.

A method in which a plurality of TCI states are set in a specific CORESET and a base station changes a beam setting for receiving a physical downlink control channel in a terminal with a QCL-related parameter that does not correspond to any TCI state among a plurality of TCI states will be described. The base station can transmit information on the QCL-related parameters or beam direction information to be changed by the base station to the terminal using the MAC-CE. As described above, when the Node B determines that the UE can receive the physical downlink control channel with the beam currently being used, the Node B may transmit the physical downlink data control channel scheduled by the DCI of the physical downlink control channel transmitted to the UE Information on the QCL-related parameters or beam indication information can be transmitted using MAC-CE. When the BS determines that the MS can not receive the physical downlink control channel using the currently used beam, the BS may transmit the physical downlink control channel in the CORESET in which the UE can receive the physical downlink control channel among the CORESets set to the UE have. In addition, when the BS determines that the UE can not receive the physical downlink control channel with the beam currently being used, the BS determines the CORESET at the earliest point among the CORESETs that the UE can receive the physical downlink control channel, Lt; RTI ID = 0.0 > downlink < / RTI >

In the embodiment of FIG. 15, the base station gNB determines that the UE (UE) can receive the PDCCH in the CORESET set to the UE (UE). The base station gNB transmits the PDCCH through a CORESET set to the UE. At this time, when the gNB transmits the PDSCH scheduled by the DCI of the PDCCH, it can transmit information on the TCI state change using the MAC-CE. The UE receives the MAC-CE and changes the setting of the beam for PDCCH reception according to the QCL-related parameter indicated by the changed TCI state. At this time, the base station gNB may transmit the first PDCCH of FIG. 15 through a different CORESET than the CORESET that is intended to change the TCI state according to the operation and determination of the base station gNB. In addition, the MAC-CE can indicate which CORESET is to be changed from the CORESET set to the UE.

FIG. 16 shows that the base station changes CORESET to change the beam configuration for physical downlink control channel reception according to an embodiment of the present invention.

The BS may change the setting of the beam for receiving the physical downlink control channel by changing the CORESET set to the UE. The base station can change the beam configuration for receiving the physical downlink control channel of the UE to the TCI state mapped to the CORESET instead of the CORESET currently set to the UE. At this time, if the BS determines that the MS can receive the physical downlink control channel, the BS uses the MAC-CE at the transmission time point of the physical downlink data channel scheduled by the DCI of the physical downlink control channel, Can be transmitted. When a plurality of TCI states are set in the corresponding CORESET, the base station can indicate one of a plurality of TCI states in the QCL-related parameter to be set by the UE. The information related to the CORESET may include time and frequency location information for the newly established CORESET based on the information on the CORESET previously transmitted in the RRC setting or MAC-CE. In addition, the information associated with the CORESET may include information regarding QCL-related parameters mapped to the corresponding CORESET. Specifically, the information on the QCL-related parameters may include information on the TCI state. In addition, the information related to the CORESET may include time and frequency location information for the newly established CORESET irrespective of the information about the CORESET previously transmitted in the RRC setting or the MAC-CE. At this time, the information related to the CORESET may include the TCI state set in the corresponding CORESET.

If the BS determines that the UE can not receive the physical downlink control channel with the beam currently being used, the BS determines whether the physical downlink control channel is received from the CORESET, which is the earliest CORESET among the CORESETs, The downlink control channel can be transmitted. When the BS determines that the UE can not receive the physical downlink control channel using the beam currently being used, the base station transmits the physical downlink data channel scheduled by the physical downlink control channel, using MAC-CE, Can be transmitted.

In a specific embodiment, the location of the CORESET to which CORESET change information is transmitted may be changed by the operation of the base station. This is because the goal is to communicate CORESET change information through another CORESET. Also, the above-described embodiments can be applied to the case of changing the setting of a plurality of beams for receiving a physical downlink control channel. In addition, the MAC-CE may contain all the information needed to set the CORESET or TCI state.

In the embodiment of FIG. 16, the base station gNB transmits a PDCCH in CORESET set to the UE. The base station gNB transmits the MAC-CE to the PDSCH scheduled by the DCI of the PDCCH. At this time, the base station gNB may transmit the information for resetting or changing the CORESET using the corresponding MAC-CE. The terminal UE receives the MAC-CE. Thereafter, the UE does not attempt to receive PDCCH in a specific CORESET but attempts to receive PDCCH within the CORESET that is reset based on the changed information. The information that resets or changes the CORESET may include information about the TCI state mapped to that CORESET. In addition, the information to reset or change CORESET may include other information for PDCCH reception. At this time, the base station gNB may transmit the first PDCCH of FIG. 16 according to the operation and determination of the base station gNB through a different CORESET than the CORESET for changing the TCI state. In addition, the MAC-CE can indicate which CORESET is to be changed from the CORESET set to the UE.

In the embodiments described with reference to FIGS. 15 to 16, it may be a problem that the UE changes the setting of the beam for receiving the physical downlink control channel. The UE can change the setting of the beam for the physical downlink control channel reception in the next slot of the slot that has received the physical downlink data channel including the MAC-CE indicating the TCI status indicating the QCL-related parameter to be set by the UE . In another specific embodiment, the UE transmits a HARQ-ACK feedback for a physical downlink data channel including a MAC-CE indicating a TCI state indicating a QCL-related parameter to be set by the UE, The setting of the beam for reception can be changed. Specifically, in the next slot of a slot in which a UE transmits HARQ-ACK feedback for a physical downlink data channel including a MAC-CE indicating a TCI state indicating a QCL-related parameter to be set by the UE, Can be changed. In addition, the HARQ-ACK feedback may be limited to the case of indicating ACK. Also, when a predetermined time has elapsed from a slot in which a UE transmits HARQ-ACK feedback for a physical downlink data channel including a MAC-CE indicating a TCI state indicating a QCL-related parameter to be set by the UE, The setting of the beam for receiving the control channel can be changed. At this time, the predetermined time may be a plurality of slots. In yet another specific embodiment, the predetermined time may be one slot. Also, the predetermined time may be less than the duration of the slot. For example, the predetermined time may be 1/2 slot. The predetermined time may be the duration of two OFDM symbols. Also, it may be four durations of a predetermined time OFDM symbol. Also, it may be seven durations of a predetermined time OFDM symbol.

In another specific embodiment, in a next cycle of a period of receiving a physical downlink control channel when a mobile station receives a physical downlink data channel including a MAC-CE indicating a TCI state indicating a QCL-related parameter to be set by the mobile station, It is possible to change the setting of the beam for receiving the physical downlink control channel. In another specific embodiment, after a predetermined time has elapsed since the UE received a physical downlink data channel including a MAC-CE indicating a TCI state indicating a QCL-related parameter to be set by the UE, The setting of the beam for reception can be changed. At this time, the predetermined time may be a plurality of slots. In yet another specific embodiment, the predetermined time may be one slot. In addition, the predetermined time may be 1/2 slot. The predetermined time may be the duration of two OFDM symbols. Also, it may be four durations of a predetermined time OFDM symbol. Also, it may be seven durations of a predetermined time OFDM symbol. In addition, the base station can independently set a time point at which the terminal changes the setting of the beam for each terminal. This is because the time spent for changing the beam setting may vary depending on the processing capability of the terminal. Specifically, the base station can set the time point at which the corresponding terminal changes the beam to any one of a plurality of time points using the RRC setting. At this time, the plurality of viewpoints may be the above-described viewpoints.

A method of updating the TCI status and CORESET information corresponding to the physical downlink control channel will be described. Table 10 shows examples of resource information and TCI status information corresponding to CORESET.

In Table 10, the TCI state corresponding to CORESET is changed. In Table 10, the TCI state mapped to the first CORESET (CORESET # 1) is changed from the first TCI state (TCI state # 1) to the second TCI state (TCI state # 2). In addition, the TCI state mapped to the second CORESET (CORESET # 2) is changed from the third TCI state (TCI state # 3) to the fourth TCI state (TCI state # 4). Also, the TCI state mapped to the third CORESET (CORESET # 3) is changed from the fifth TCI state (TCI state # 5) to the sixth TCI state (TCI state # 6). In addition, the TCI state mapped to the fourth CORESET (CORESET # 4) is changed from the seventh TCI state (TCI state # 7) to the eighth TCI state (TCI state # 8).

If the base station changes the TCI state mapped to CORESET to the currently set CORESET, the base station can indicate the TCI state to be newly mapped to CORESET using MAC-CE. For example, if the base station changes the TCI state mapped to the second CORESET (CORESET # 2), the base station may transmit the physical downlink control channel using the fourth TCI state (TCI state # 4). The base station may transmit the scheduled physical downlink data channel to the physical downlink control channel, and may include the MAC-CE in the physical downlink data channel. At this time, the MAC-CE indicates the third TCI state (TCI state # 3). If two TCI states are set in the CORESET, the base station can use the 1-bit field of the MAC-CE to indicate the TCI state mapped to CORESET. When three or more TCI states are set in the CORESET, the base station can indicate a TCI state mapped to CORESET using more than 2 bits of the MAC-CE field. When the UE receives the physical downlink data channel including the MAC-CE, the UE can determine the TCI state indicated by the MAC-CE. The UE can set a beam for physical control channel reception according to the TCI state indicated by the MAC-CE and attempt to receive the physical control channel within the corresponding CORESET.

As described above, the base station can change the TCI state mapped to the CORESET using information signaled from a CORESET other than the CORESET. Specifically, when transmitting the physical data channel scheduled by the physical downlink control channel transmitted in the first CORESET, the BS may change the TCI state mapped to the second CORESET using the MAC-CE of the physical data channel. At this time, the MAC-CE may include a field indicating a first CORESET and a field indicating a TCI state mapped to the first CORESET. Since the first CORESET (CORESET # 1) to the fourth CORESET (CORESET # 4) are set in the embodiment of Table 10, the MAC-CE sets the 2-bit field indicating the first CORESET and the TCI state mapped to the first CORESET Bit field that indicates the number of bits to be transmitted. The number of bits of the field indicating the first CORESET and the number of bits indicating the TCI state mapped to the first CORESET may be increased according to the number of CORESETs and the number of TCI states set for each CORESET in the specific embodiment. When a UE receives a physical downlink data channel including a MAC-CE, the UE can determine a CORESET indicated by the MAC-CE and a TCI state mapped to the corresponding CORESET. The UE can set a beam for physical control channel reception according to the TCI state indicated by the MAC-CE, and attempt to receive the physical control channel from the CORESET indicated by the MAC-CE.

As described above, when the TCI state mapped to the CORESET is changed, the base station can signal information on the TCI state mapped to the CORESET to the UE using the MAC-CE. When a UE receives a MAC-CE signaling information on a TCI state mapped to a CORESET, the BS and the UE can apply the TCI state, which is mapped to the corresponding CORESET, to the changed TCI state. If a new TCI state is added, the MAC-CE may not include information indicating the TCI state to be changed. Also, if the TCI state mapped to CORESET is changed to another TCI state set in the CORESET, the MAC-CE may not include information indicating the CORESET to be changed.

As described above, the base station can replace the CORESET set in the UE with the new CORESET information. When a new CORESET is added, the MAC-CE may not include information indicating the CORESET to be changed. When a new CORESET is added, the MAC-CE may include information on the location information and the TCI state for the new CORESET. It is possible to use the information about the new CORESET as signaling information by using the instruction information for the CORESET not activated among the previously set CORESET as the new CORESET information.

The above-described embodiments can also be applied to the case of receiving a physical downlink control channel using a plurality of beams.

The UE can transmit the beam failure information to the BS even when some of the beams set to the UE for the physical downlink control channel reception fails. At this time, the beam failure may indicate a case where the reception quality of the beam is lower than a predetermined reference quality. A method in which a UE transmits beam failure information in a sequence-based physical uplink control channel transmission will be described.

The UE can transmit only the beam failure information. In the sequence-based physical uplink control channel transmission of the UE, the UE can use 1 bit or 2 bits. Also, if the beam reception quality is lower than the predetermined reference reception quality, the terminal can transmit information about the beam. Table 11 shows an example of transmitting the beam failure information in the sequence-based physical uplink control channel transmission in the UE. For convenience of explanation, the case where the beam fails is indicated as on and marked off.

The UE can multiplex and transmit HARQ-ACK feedback information and information indicating whether the beam fails or not. The HARQ-ACK feedback is divided into ACK and NACK, and when the beam fails, the HARQ-ACK feedback is divided into failures. Therefore, the sequence transmitted by the UE can be divided into four sequences. Since the UE can transmit the NACK due to the failure of decoding the physical downlink data channel, the UE needs to distinguish the beam failure and the NACK and transmit the sequence.

In another specific embodiment, if the HARQ-ACK feedback is a NACK and the beam fails, the terminal may not transmit any information to the base station. Therefore, the sequence transmitted by the terminal can be distinguished by a total of three sequences as shown in Table 12. [

Table 13 to Table 14 show an embodiment in which 2-bit HARQ-ACK feedback and beam failure information are multiplexed.

When 2-bit ACK / NACK is multiplexed with the failure information in the fifth sequence of Table 13 (Sequence # 5), it may not be distinguished whether 2 bits indicate ACK / NAC. Specifically, when the 2-bit ACK / NACK is multiplexed with the failure information, the fifth sequence (Sequence # 5) indicates that the beam fails and both bits of HARQ-ACK feedback indicate NACK, And the bit indicates NACK. When the UE transmits a fifth sequence (sequence # 5) together with a second sequence (sequence # 2) or a third sequence (sequence # 3), the BS transmits the reception result indicated by the HARQ- . Table 14 shows an embodiment in which seven sequences are used when a 2-bit ACK / NACK is multiplexed with the failure information.

The base station may multiplex the ACK / NACK and the scheduling request (SR) together with the beam failure information. At this time, the number of sequences can be defined by a possible combination of ACK / NACK, SR, and beam failure information. In a specific embodiment, the SR may indicate that scheduling is not requested, and the UE may not transmit the physical musical control channel if the beam failure information indicates that the beam does not fail and the HARQ-ACK feedback indicates a NACK. Also, the UE may joint-code and transmit beam failure information and SR. At this time, either beam failure information or SR may have a higher priority. If the SR has a higher priority than the beam failure information, the ON and OFF of the combined information of the beam failure information and the SR may indicate whether scheduling is requested or not. Also, if the beam failure information has a higher priority than the SR, the ON and OFF of the combined information of the beam failure information and the SR may indicate whether the beam failed or not. In such embodiments, the base station may set which of the SR and beam failure information has higher priority via at least one of RRC setting, MAC-CE and DCI. Information indicating whether SR or beam failure information has a higher priority may be a 1-bit field. Specifically, the base station can set which of the SR and beam failure information has a higher priority using the DCI that schedules the physical downlink data channel corresponding to the HARQ-ACK feedback transmission. When the base station sets which of SR and beam failure information has higher priority via RRC setting or MAC-CE, the base station sets priority to HARQ-ACK feedback and multiplexing that occur after RRC setting or MAC-CE reception Ranking can be applied.

Non-sequence physical uplink control channels, non-sequence physical uplink data channels, and failed beam measurement information transmission are described with reference to FIGS. 17 through 18. FIG.

The UE may transmit the beam failure information and the failed beam measurement information using a physical uplink control channel that does not use a sequence or a physical uplink data channel that does not use a sequence. In a specific embodiment, the BS may set the type and content of the beam failure information to be multiplexed on the physical uplink control channel or the physical uplink data channel. In addition, the BS can flexibly change the type and content of the beam failure information to be multiplexed by the MS on the physical uplink control channel or the physical uplink data channel. At this time, the base station can set the terminal not to multiplex the beam failure information to the physical uplink control channel or the physical uplink data channel. The base station can flexibly change the type and content of the beam failure information to be multiplexed by the UE to the physical uplink control channel or the physical uplink data channel using at least one of RRC setting, MAC-CE and DCI. In another specific embodiment, the type and content of the beam failure information to be multiplexed by the UE to the physical uplink control channel or the physical uplink data channel may be fixed. When the UE piggybacks an ACK or a NACK with a physical uplink data channel, the UE may transmit beam failure information and failed beam measurement information together with the corresponding physical uplink data channel.

In the embodiment of FIG. 17, the UE receives the PDCCH including the uplink DCI from the BS. At this time, the UE can determine that the beam used for PDCCH reception has failed. Also, the terminal receives the reference signal DL RS to the base station. At this time, the UE can perform the failed beam measurement. The UE may transmit ACK or NACK, beam failure information, and information indicating the failed beam.

In another specific embodiment, the UE may multiplex beam-information reporting or CSI reporting on a physical uplink control channel or a physical uplink data channel and transmit it to the base station. In a specific embodiment, the BS may set the type and content of the beam failure information to be multiplexed on the physical uplink control channel or the physical uplink data channel. In addition, the BS can flexibly change the type and content of the beam failure information to be multiplexed by the MS on the physical uplink control channel or the physical uplink data channel. At this time, the base station can set the terminal not to multiplex the beam failure information to the physical uplink control channel or the physical uplink data channel. The base station can flexibly change the type and content of the beam failure information to be multiplexed by the UE to the physical uplink control channel or the physical uplink data channel using at least one of RRC setting, MAC-CE and DCI. In another specific embodiment, the type and content of the beam failure information to be multiplexed by the UE to the physical uplink control channel or the physical uplink data channel may be fixed.

When the terminal piggybacks beam information reporting or CSI reporting with a physical uplink data channel, the terminal may also transmit beam failure information and information about failed beam measurements along with the physical uplink data channel.

In the embodiment of FIG. 18, the UE receives the PDCCH including the uplink DCI from the BS. At this time, the UE can determine that the beam used for PDCCH reception has failed. Also, the terminal receives the reference signal DL RS to the base station. At this time, the UE can perform the failed beam measurement. The UE may transmit ACK or NACK, beam failure information, and information indicating the failed beam.

In the above-described embodiments, the physical downlink data channel may include a PDSCH. The physical uplink data channel may also include a PUSCH. In addition, the physical downlink control channel may include a PDCCH. Also, the physical uplink control channel may comprise a PUCCH. In addition, other kinds of data channels and control channels may be applied in the embodiment described with the PUSCH, PDCCH, PUCCH, and PDCCH as an example.

While the method and system of the present invention have been described with reference to particular embodiments, some or all of their components or operations may be implemented using a computing system having a general purpose hardware architecture.

It will be understood by those skilled in the art that the foregoing description of the present invention is for illustrative purposes only and that those of ordinary skill in the art can readily understand that various changes and modifications may be made without departing from the spirit or essential characteristics of the present invention. will be. It is therefore to be understood that the above-described embodiments are illustrative in all aspects and not restrictive. For example, each component described as a single entity may be distributed and implemented, and components described as being distributed may also be implemented in a combined form.

The scope of the present invention is defined by the appended claims rather than the detailed description and all changes or modifications derived from the meaning and scope of the claims and their equivalents are to be construed as being included within the scope of the present invention do.

Claims (20)

In a terminal of a wireless communication system,
Communication module; And
And a processor for controlling the communication module,
The processor
Receiving a radio resource control (RRC) signal from a base station of the wireless communication system through the communication module, obtaining information about at least one transmission configuration indicator (TCI) status from the RRC signal, A physical downlink data channel including a Media Access Control-Control Element (MAC-CE) from the base station through the communication module, And setting a parameter value of the beam to receive the physical downlink control channel
Wireless communication terminal .. The method of claim 1,
The processor
(TTI) indicated by the MAC-CE based on a slot to which HARQ (hybrid automatic repeat request) -ACK feedback for a physical downlink data channel including the MAC-CE is transmitted. And setting a parameter value of one of the beams to receive the physical downlink control channel
Wireless communication terminal. 3. The method of claim 2,
The processor
After a first predetermined time elapses from a slot to which HARQ-ACK feedback for a physical downlink data channel including the MAC-CE has been transmitted, for a physical downlink control channel reception according to a TCI state indicated by the MAC- And setting a parameter value of at least one of the beams to receive the physical downlink control channel
Wireless communication terminal. 4. The method of claim 3,
Wherein the first predetermined time is at least one slot duration
Wireless communication terminal. 3. The method of claim 2,
The HARQ-ACK feedback for the physical downlink data channel including the MAC-CE indicates an ACK
The wireless communication terminal 3. The method of claim 2,
The processor
Setting a parameter value of at least one beam for reception of the physical downlink control channel according to a TCI state indicated by the MAC-CE in a next slot of a slot in which a physical downlink data channel including the MAC-CE is received, Receiving a physical downlink control channel
Wireless communication terminal. The method of claim 1,
The processor
A physical downlink control channel including downlink control information (DCI) from the base station through the communication module; and at least one physical downlink control channel for receiving physical downlink data channels according to a TCI state indicated by the DCI And sets the parameter value of the beam to receive the physical downlink data channel
Wireless communication terminal. 8. The method of claim 7,
The processor
Setting a parameter value of at least one beam for reception of the physical downlink data channel according to a TCI state indicated by the DCI after a second predetermined time elapses from when the physical downlink control channel including the DCI is received To receive the physical downlink data channel
Wireless communication terminal. 9. The method of claim 8,
Wherein the second predetermined time is at least one slot duration
Wireless communication terminal. The method of claim 1,
The processor
When the reception quality of at least one of the beams for the physical downlink control channel reception is lower than a predetermined reference reception quality, the base station transmits information about the beam whose reception quality is lower than the predetermined reference reception quality
Wireless communication terminal. 11. The method of claim 10,
The processor
The base station transmits hybrid automatic repeat request (HARQ) -ACK feedback and information about the beam whose reception quality is lower than the predetermined reference reception quality
Wireless communication terminal. 12. The method of claim 11,
The processor
And transmits the HARQ-ACK feedback, the scheduling request and the information on the beam having the reception quality lower than the predetermined reference reception quality together to the base station
Wireless communication terminal. In a method of operating a terminal of a wireless communication system
Receiving a radio resource control (RRC) signal from a base station of the wireless communication system through the communication module;
Obtaining information about at least one transmission configuration indicator (TCI) status from the RRC signal;
Receiving a physical downlink data channel including a Media Access Control-Control Element (MAC-CE) from the base station of the wireless communication system through the communication module; And
And setting a parameter value of at least one beam for receiving a physical downlink control channel according to a TCI state indicated by the MAC-CE to receive a physical downlink control channel
How it works. The method of claim 13,
The step of receiving the physical downlink control channel
In accordance with a TCI state indicated by the MAC-CE based on a slot transmitting HARQ (hybrid automatic repeat request) -ACK feedback for the physical downlink data channel including the MAC-CE, And setting the parameter values of at least one of the beams to receive the physical downlink control channel
How it works. The method of claim 14,
At least one of the parameters of the beam for reception of the physical downlink control channel according to a TCI state indicated by the MAC-CE based on a slot in which HARQ-ACK feedback for a physical downlink data channel including the MAC-CE is transmitted And the step of receiving the physical downlink control channel by setting a value
After the first predetermined time elapses from the slot in which the HARQ-ACK feedback for the physical downlink data channel including the MAC-CE is transmitted, the physical downlink control channel reception is performed according to the TCI state indicated by the MAC- And setting the parameter values of at least one of the beams for receiving the physical downlink control channel
How it works. 16. The method of claim 15,
Wherein the first predetermined time is at least one slot duration
How it works. The method of claim 14,
The HARQ-ACK feedback for the physical downlink data channel including the MAC-CE indicates an ACK
How it works. The method of claim 13,
The operating method
Receiving a physical downlink control channel including downlink control information (DCI) from the base station; And
And setting a parameter value of at least one beam for receiving a physical downlink data channel according to a TCI state indicated by the DCI to receive a physical downlink data channel
How it works. The method of claim 18,
The step of receiving the physical downlink data channel by setting a parameter value of at least one beam for physical downlink data channel reception according to the TCI state indicated by the DCI
Setting a parameter value of at least one beam for reception of the physical downlink data channel according to a TCI state indicated by the DCI after a second predetermined time elapses from when the physical downlink control channel including the DCI is received And receiving the physical downlink data channel
How it works. 20. The method of claim 19,
Wherein the second predetermined time is at least one slot duration
How it works.

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