KR20200130050A - Method and apparatus for beam management in wireless communication systems - Google Patents

Abstract

The present disclosure relates to a communication technique for fusing a 5^th generation (5G) communication system with an Internet of things (IoT) technology to support a higher data transmission rate than that of a 4^th generation (4G) system and a system thereof. The present disclosure can be applied to an intelligent service (for example, smart home, smart building, smart city, smart car or connected car, healthcare, digital education, retail business, security and safety related services, etc.) based on a 5G communication technology and an IoT-related technology. According to the present disclosure, disclosed are a method and apparatus for changing a beam or managing a beam. A control signal processing method in a wireless communication system comprises the steps of: receiving a first control signal transmitted from a base station; processing the first control signal received; and transmitting a second control signal generated based on the processing to the base station.

Description

Method and apparatus for beam management in wireless communication system {METHOD AND APPARATUS FOR BEAM MANAGEMENT IN WIRELESS COMMUNICATION SYSTEMS}

The present disclosure relates to a wireless communication system, and more specifically, to a method and apparatus for managing or changing a beam in a wireless communication system.

Efforts are being made to develop an improved 5G communication system or a pre-5G communication system in order to meet the increasing demand for wireless data traffic after the commercialization of 4G communication systems. For this reason, a 5G communication system or a pre-5G communication system is called a Beyond 4G Network communication system or an LTE system and a Post LTE system. The 5G communication system defined by 3GPP is called the New Radio (NR) system.

In order to achieve a high data rate, the 5G communication system is being considered for implementation in the ultra-high frequency (mmWave) band (eg, such as the 60 Giga (60 GHz) band). In order to mitigate the path loss of radio waves in the ultra-high frequency band and increase the transmission distance of radio waves, in 5G communication systems, beamforming, massive MIMO, and Full Dimensional MIMO (FD-MIMO) ), array antenna, analog beam-forming, and large scale antenna techniques were discussed and applied to NR systems.

In addition, in order to improve the network of the system, in 5G communication system, advanced small cell, advanced small cell, cloud radio access network (cloud RAN), ultra-dense network , Device to Device communication (D2D), wireless backhaul, moving network, cooperative communication, CoMP (Coordinated Multi-Points), and interference cancellation And other technologies are being developed.

In addition, in 5G systems, advanced coding modulation (ACM) schemes such as Hybrid FSK and QAM Modulation (FQAM) and SWSC (Sliding Window Superposition Coding), advanced access technologies such as Filter Bank Multi Carrier (FBMC), NOMA (non-orthogonal multiple access), and sparse code multiple access (SCMA) have been developed.

On the other hand, the Internet is evolving from a human-centered network in which humans generate and consume information, to an Internet of Things (IoT) network that exchanges and processes information between distributed components such as objects. Internet of Everything (IoE) technology, which combines IoT technology with big data processing technology through connection with cloud servers, is also emerging. In order to implement IoT, technology elements such as sensing technology, wired/wireless communication and network infrastructure, service interface technology, and security technology are required, and recently, a sensor network for connection between objects, machine to machine , M2M), and MTC (Machine Type Communication) technologies are being studied. In the IoT environment, intelligent IT (Internet Technology) services that create new value in human life by collecting and analyzing data generated from connected objects can be provided. IoT is the field of smart home, smart building, smart city, smart car or connected car, smart grid, healthcare, smart home appliance, advanced medical service, etc. through the convergence and combination of existing IT (Information Technology) technology and various industries. Can be applied to.

Accordingly, various attempts have been made to apply a 5G communication system to an IoT network. For example, 5G communication such as a sensor network, machine to machine (M2M), and machine type communication (MTC) is being implemented by techniques such as beamforming, MIMO, and array antenna. As the big data processing technology described above, a cloud radio access network (cloud RAN) is applied as an example of the convergence of 5G technology and IoT technology.

Meanwhile, various studies on beam-based communication in 5G communication systems are being conducted, and thus an improved beam change or beam management scheme is required.

The present invention relates to a reception beam changing method in a next-generation mobile communication system using a beam, and particularly proposes an effective reception beam changing method in a low frequency band that does not require a long time to change a reception beam.

The present invention for solving the above problem is a control signal processing method in a wireless communication system, the method comprising: receiving a first control signal transmitted from a base station; Processing the received first control signal; And transmitting a second control signal generated based on the processing to the base station.

In the present invention, in performing a reception beam change in a next-generation mobile communication system, it is possible to perform effective reception beam change in a low frequency band, particularly in consideration of different beam change time required for each frequency band.

1A is a diagram showing a structure of an LTE system referred to for description of the present invention.
1B is a diagram showing a radio protocol structure in an LTE system referred to for description of the present invention.
1C is a diagram showing the structure of a next-generation mobile communication system to which the present invention is applied.
1D is a diagram showing a radio protocol structure of a next generation mobile communication system to which the present invention can be applied.
1E is a diagram showing the structure of another next-generation mobile communication system to which the present invention can be applied.
1F is an exemplary diagram of a frame structure used in an NR system to which the present invention is applied.
FIG. 1G is a diagram illustrating an overall procedure for indicating a beam of a downlink signal transmitted to a Physical Downlink Shared Channel (PDSCH) in the NR system referred to in the present invention.
1H is a diagram showing a procedure for determining a method of changing a reception beam of a frequency range (FR) 2 band according to conditions in an NR system applied to the present invention.
1I is a diagram illustrating a procedure for determining a method of changing a reception beam of an FR1 band according to conditions in an NR system according to an embodiment of the present invention.
1I is a block diagram showing the internal structure of a terminal to which the present invention is applied.
1J is a block diagram showing the configuration of an NR base station according to the present invention.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. In this case, it should be noted that in the accompanying drawings, the same components are indicated by the same reference numerals as possible. In addition, detailed descriptions of known functions and configurations that may obscure the subject matter of the present invention will be omitted.

In describing the embodiments herein, descriptions of technical contents that are well known in the technical field to which the present invention pertains and are not directly related to the present invention will be omitted. This is to more clearly convey the gist of the present invention by omitting unnecessary description.

For the same reason, some components in the accompanying drawings are exaggerated, omitted, or schematically illustrated. In addition, the size of each component does not fully reflect the actual size. The same reference numerals are assigned to the same or corresponding components in each drawing.

Advantages and features of the present invention, and a method of achieving them will become apparent with reference to the embodiments described below in detail together with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, but may be implemented in a variety of different forms, only the present embodiments are intended to complete the disclosure of the present invention, and the general knowledge in the technical field to which the present invention pertains. It is provided to completely inform the scope of the invention to the possessor, and the invention is only defined by the scope of the claims. The same reference numerals refer to the same components throughout the specification.

At this time, it will be appreciated that each block of the flowchart diagrams and combinations of the flowchart diagrams may be executed by computer program instructions. Since these computer program instructions can be mounted on the processor of a general purpose computer, special purpose computer or other programmable data processing equipment, the instructions executed by the processor of the computer or other programmable data processing equipment are described in the flowchart block(s). It creates a means to perform functions. These computer program instructions can also be stored in computer-usable or computer-readable memory that can be directed to a computer or other programmable data processing equipment to implement a function in a particular way, so that the computer-usable or computer-readable memory It is also possible to produce an article of manufacture containing instruction means for performing the functions described in the flowchart block(s). Computer program instructions can also be mounted on a computer or other programmable data processing equipment, so that a series of operating steps are performed on a computer or other programmable data processing equipment to create a computer-executable process to create a computer or other programmable data processing equipment. It is also possible for instructions to perform processing equipment to provide steps for executing the functions described in the flowchart block(s).

In addition, each block may represent a module, segment, or part of code that contains one or more executable instructions for executing the specified logical function(s). In addition, it should be noted that in some alternative execution examples, functions mentioned in blocks may occur out of order. For example, two blocks shown in succession may in fact be executed substantially simultaneously, or the blocks may sometimes be executed in reverse order depending on the corresponding function.

In this case, the term'~ unit' used in the present embodiment means software or hardware components such as FPGA or ASIC, and'~ unit' performs certain roles. However,'~ part' is not limited to software or hardware. The'~ unit' may be configured to be in an addressable storage medium, or may be configured to reproduce one or more processors. Thus, as an example,'~ unit' refers to components such as software components, object-oriented software components, class components and task components, processes, functions, properties, and procedures. , Subroutines, segments of program code, drivers, firmware, microcode, circuitry, data, database, data structures, tables, arrays, and variables. The components and functions provided in the'~ units' may be combined into a smaller number of elements and'~ units', or may be further divided into additional elements and'~ units'. In addition, components and'~ units' may be implemented to play one or more CPUs in a device or a security multimedia card.

A term for identifying an access node used in the following description, a term for network entities, a term for messages, a term for an interface between network objects, a term for various identification information And the like are illustrated for convenience of description. Therefore, the present invention is not limited to the terms described below, and other terms referring to objects having an equivalent technical meaning may be used.

For convenience of description below, the present invention uses terms and names defined in the 3GPP 3rd Generation Partnership Project Long Term Evolution (LTE) standard. However, the present invention is not limited by the terms and names, and can be applied equally to systems conforming to other standards.

1A is a diagram showing a structure of an LTE system referred to for description of the present invention.

Referring to Figure 1a, as shown, the radio access network of the LTE system is a next-generation base station (Evolved Node B, hereinafter eNB, Node B or base station) (1a-05, 1a-10, 1a-15, 1a-20) and It consists of a Mobility Management Entity (MME, 1a-25) and a Serving-Gateway (S-GW, 1a-30). User equipment (hereinafter referred to as UE or terminal) 1a-35 accesses an external network through eNBs 1a-05 to 1a-20 and S-GW 1a-30.

In FIG. 1A, the eNBs 1a-05 to 1a-20 correspond to the existing Node B of the UMTS system. The eNB is connected to the UEs 1a-35 through a radio channel and performs a more complex role than the existing Node B. In the LTE system, all user traffic including real-time services such as VoIP (Voice over IP) through the Internet protocol are serviced through a shared channel, so status information such as buffer status, available transmission power status, and channel status of UEs A device that collects and performs scheduling is required, and the eNB (1a-05~1a-20) is in charge of this. One eNB typically controls multiple cells. For example, in order to implement a transmission rate of 100 Mbps, the LTE system uses, for example, an orthogonal frequency division multiplexing (OFDM) in a 20 MHz bandwidth as a radio access technology. In addition, an adaptive modulation and coding method (hereinafter referred to as AMC) that determines a modulation scheme and a channel coding rate according to the channel state of the terminal is applied. The S-GW 1a-30 is a device that provides a data bearer, and creates or removes a data bearer under the control of the MME 1a-25. The MME is a device responsible for various control functions as well as mobility management functions for a terminal, and is connected to a plurality of base stations.

1B is a diagram showing a radio protocol structure in an LTE system referred to for description of the present invention.

Referring to Figure 1b, the radio protocol of the LTE system is PDCP (Packet Data Convergence Protocol 1b-05, 1b-40), RLC (Radio Link Control 1b-10, 1b-35), MAC (Medium Access Control 1b-15, 1b-30). PDCP (1b-05, 1b-40) is in charge of operations such as IP header compression/restore. The main functions of PDCP are summarized as follows.

- Header compression and decompression (ROHC only)

- Transfer of user data

- In-sequence delivery of upper layer PDUs at PDCP re-establishment procedure for RLC AM

- Order reordering function (For split bearers in DC (only support for RLC AM): PDCP PDU routing for transmission and PDCP PDU reordering for reception)

- Duplicate detection of lower layer SDUs at PDCP re-establishment procedure for RLC AM

- Retransmission of PDCP SDUs at handover and, for split bearers in DC, of PDCP PDUs at PDCP data-recovery procedure, for RLC AM

- Ciphering and deciphering

- Timer-based SDU discard in uplink.

Radio Link Control (hereinafter referred to as RLC) (1b-10, 1b-35) performs ARQ operation by reconfiguring a PDCP packet data unit (PDU) to an appropriate size. The main functions of RLC are summarized as follows.

- Data transfer function (Transfer of upper layer PDUs)

- ARQ function (Error Correction through ARQ (only for AM data transfer))

- Concatenation, segmentation and reassembly of RLC SDUs (only for UM and AM data transfer)

- Re-segmentation of RLC data PDUs (only for AM data transfer)

- Reordering of RLC data PDUs (only for UM and AM data transfer)

- Duplicate detection (only for UM and AM data transfer)

- Error detection function (Protocol error detection (only for AM data transfer))

- RLC SDU discard function (RLC SDU discard (only for UM and AM data transfer))

- RLC re-establishment

The MACs 1b-15 and 1b-30 are connected to several RLC layer devices configured in one terminal, and perform an operation of multiplexing RLC PDUs to MAC PDUs and demultiplexing RLC PDUs from MAC PDUs. The main functions of MAC are summarized as follows.

- Mapping between logical channels and transport channels

- Multiplexing/demultiplexing of MAC SDUs belonging to one or different logical channels into/from transport blocks (TB) delivered to/from the physical layer on transport channels

- Scheduling information reporting

- HARQ function (Error correction through HARQ)

- Priority handling between logical channels of one UE

- Priority handling between UEs by means of dynamic scheduling

- MBMS service identification

- Transport format selection

- Padding function

The physical layer (1b-20, 1b-25) channel-codes and modulates upper layer data, converts it into OFDM symbols, and transmits it to the radio channel, or demodulates OFDM symbols received through the radio channel and decodes the channel and delivers it to the upper layer. Do the action. In addition, the physical layer also uses HARQ (Hybrid ARQ) for additional error correction, and the receiving end transmits whether or not a packet transmitted by the transmitting end is received in 1 bit. This is called HARQ ACK/NACK information. Downlink HARQ ACK/NACK information for uplink transmission is transmitted through a PHICH (Physical Hybrid-ARQ Indicator Channel) physical channel, and uplink HARQ ACK/NACK information for downlink transmission is PUCCH (Physical Uplink Control Channel) or It may be transmitted through a PUSCH (Physical Uplink Shared Channel) physical channel.

Meanwhile, the PHY layer may be composed of one or a plurality of frequencies/carriers, and a technology for simultaneously setting and using a plurality of frequencies is referred to as a carrier aggregation technology (carrier aggregation, hereinafter referred to as CA). CA technology refers to the use of only one carrier for communication between a terminal (or user equipment, UE) and a base station (E-UTRAN NodeB, eNB), and a subcarrier using an additional primary carrier and one or a plurality of subcarriers The amount of transmission can be dramatically increased by the number of. Meanwhile, in LTE, a cell in a base station using a primary carrier is called a PCell (Primary Cell), and a subcarrier is called a SCell (Secondary Cell).

Although not shown in this figure, there is an RRC (Radio Resource Control, hereinafter referred to as RRC) layer, respectively, above the PDCP layer of the terminal and the base station, and the RRC layer transmits access and measurement-related configuration control messages for radio resource control. You can give and take.

1C is a diagram showing the structure of a next-generation mobile communication system to which the present invention is applied.

Referring to FIG. 1C, as shown, a radio access network of a next-generation mobile communication system includes a next-generation base station (New Radio Node B, NR NB, 1c-10) and a New Radio Core Network (NR CN, or NG CN: Next Generation). Core Network, 1c-05). The user terminal (New Radio User Equipment, hereinafter referred to as NR UE or terminal, 1c-15) accesses the external network through the NR NB 1c-10 and NR CN 1c-05.

In Figure 1c, the NR NB (1c-10) corresponds to the eNB (Evolved Node B) of the existing LTE system. The NR NB is connected to the NR UE 1c-15 through a radio channel, and can provide a service superior to that of the existing Node B. In the next-generation mobile communication system, all user traffic is serviced through a shared channel, so a device that collects and schedules status information such as buffer status, available transmission power status, and channel status of UEs is required. (1c-10) is in charge. One NR NB typically controls multiple cells. In order to implement ultra-high-speed data transmission compared to the existing LTE, it may have more than the existing maximum bandwidth, and a beamforming technology may be additionally grafted by using Orthogonal Frequency Division Multiplexing (OFDM) as a wireless access technology. . In addition, an adaptive modulation and coding method (hereinafter referred to as AMC) that determines a modulation scheme and a channel coding rate according to the channel state of the terminal is applied. The NR CN (1c-05) performs functions such as mobility support, bearer setup, and QoS setup. The NR CN is a device in charge of various control functions as well as a mobility management function for a terminal, and is connected to a plurality of base stations. In addition, the next-generation mobile communication system can be linked with the existing LTE system, and the NR CN is connected to the MME 1c-25 through a network interface. The MME is connected to an existing base station, the eNB (1c-30).

1D is a diagram showing a radio protocol structure of a next-generation mobile communication system to which the present invention can be applied.

Referring to Figure 1d, the radio protocol of the next-generation mobile communication system is NR SDAP (Service Data Adaptation Protocol) (1d-01, 1d-45), NR PDCP (1d-05, 1d-40), respectively in the terminal and the NR base station, It consists of NR RLC (1d-10, 1d-35) and NR MAC (1d-15, 1d-30).

The main functions of the NR SDAP (1d-01, 1d-45) may include some of the following functions.

- Transfer of user plane data

- QoS flow and data bearer mapping function for uplink and downlink (mapping between a QoS flow and a DRB for both DL and UL)

- QoS flow ID marking function for uplink and downlink (marking QoS flow ID in both DL and UL packets)

- A function of mapping a relective QoS flow to a data bearer for uplink SDAP PDUs (reflective QoS flow to DRB mapping for the UL SDAP PDUs).

For the SDAP layer device, the UE may be configured with an RRC message to set whether to use the header of the SDAP layer device or the function of the SDAP layer device for each PDCP layer device, bearer or logical channel, and the SDAP header. If is set, the UE uses the NAS QoS reflective configuration 1-bit indicator (NAS reflective QoS) in the SDAP header and the AS QoS reflective configuration 1-bit indicator (AS reflective QoS) to map the QoS flow and data bearer of the uplink and downlink. Can be instructed to update or reset. The SDAP header may include QoS flow ID information indicating QoS. The QoS information may be used as data processing priority, scheduling information, etc. to support smooth service.

The main functions of NR PDCP (1d-05, 1d-40) may include some of the following functions.

- Header compression and decompression (ROHC only)

- Transfer of user data

- In-sequence delivery of upper layer PDUs

- Out-of-sequence delivery of upper layer PDUs

- PDCP PDU reordering for reception

- Duplicate detection of lower layer SDUs

- Retransmission of PDCP SDUs

- Ciphering and deciphering

- Timer-based SDU discard in uplink.

In the above, the reordering function of the NR PDCP device refers to a function of rearranging the PDCP PDUs received from the lower layer in order based on the PDCP sequence number (SN), and the function of delivering data to the upper layer in the rearranged order. It may include, or may include a function of immediately delivering without considering the order, may include a function of recording lost PDCP PDUs by rearranging the order, and reporting the status of lost PDCP PDUs It may include a function of performing the transmission side, and may include a function of requesting retransmission of lost PDCP PDUs.

The main functions of the NR RLC (1d-10, 1d-35) may include some of the following functions.

- Data transfer function (Transfer of upper layer PDUs)

- In-sequence delivery of upper layer PDUs

- Out-of-sequence delivery of upper layer PDUs

- ARQ function (Error Correction through ARQ)

- Concatenation, segmentation and reassembly of RLC SDUs

- Re-segmentation of RLC data PDUs

- Reordering of RLC data PDUs

- Duplicate detection

- Protocol error detection

- RLC SDU discard function (RLC SDU discard)

- RLC re-establishment

In the above, the in-sequence delivery function of the NR RLC device refers to the function of delivering RLC SDUs received from the lower layer to the upper layer in order, and originally, one RLC SDU is divided into several RLC SDUs and received. If so, it may include a function of reassembling and delivering it, and may include a function of rearranging the received RLC PDUs based on RLC sequence number (SN) or PDCP sequence number (SN), and rearranging the order It may include a function of recording lost RLC PDUs, may include a function of reporting a status of lost RLC PDUs to a transmitting side, and a function of requesting retransmission of lost RLC PDUs. If there is a lost RLC SDU, it may include a function of transferring only RLC SDUs before the lost RLC SDU to a higher layer in order, or if a predetermined timer expires even if there is a lost RLC SDU, the timer It may include a function of delivering all RLC SDUs received before the start of the system in order to the upper layer, or if a predetermined timer expires even if there is a lost RLC SDU, all RLC SDUs received so far are sequentially transferred to the upper layer. It may include the ability to deliver. In addition, RLC PDUs may be processed in the order in which they are received (regardless of the order of serial number and sequence number, in the order of arrival) and delivered to the PDCP device regardless of the order (Out-of sequence delivery). Segments stored in a buffer or to be received in the future may be received, reconstructed into one complete RLC PDU, processed, and delivered to the PDCP device. The NR RLC layer may not include a concatenation function, and the function may be performed by the NR MAC layer or may be replaced with a multiplexing function of the NR MAC layer.

In the above, the out-of-sequence delivery function of the NR RLC device refers to a function of directly delivering RLC SDUs received from the lower layer to the upper layer regardless of the order, and originally, one RLC SDU is When it is divided into SDUs and received, it may include a function of reassembling and transmitting them, and includes a function of storing the RLC SN or PDCP SN of the received RLC PDUs, sorting the order, and recording the lost RLC PDUs. I can.

The NR MACs 1d-15 and 1d-30 may be connected to several NR RLC layer devices configured in one terminal, and the main functions of the NR MAC may include some of the following functions.

- Mapping between logical channels and transport channels

- Multiplexing and demultiplexing function (Multiplexing/demultiplexing of MAC SDUs)

- Scheduling information reporting

- HARQ function (Error correction through HARQ)

- Priority handling between logical channels of one UE

- Priority handling between UEs by means of dynamic scheduling

- MBMS service identification

- Transport format selection

- Padding function

The NR PHY layer (1d-20, 1d-25) channel-codes and modulates upper layer data, converts it into OFDM symbols, and transmits it to the radio channel, or demodulates and channel-decodes OFDM symbols received through the radio channel to the upper layer. You can perform the transfer operation.

1E is a diagram showing the structure of another next-generation mobile communication system to which the present invention can be applied.

Referring to FIG. 1E, a cell serviced by a beam-based NR gNB (1e-05) has several Transmission Reception Points (TRPs, 1e-10, 1e-15, 1e-20, 1e-25, 1e-30). , 1e-35, 1e-40). TRP (1e-10 to 1e-40) represents a block in which some functions of transmitting and receiving physical signals in an existing NR base station (eNB) are separated, and is composed of a plurality of antennas. The NR gNB 1e-05 may be expressed as a central unit (CU) and a TRP may be expressed as a distributed unit (DU). The functions of the NR gNB 1e-05 and TRP may be configured by separating each layer from the PDCP/RLC/MAC/PHY layer such as 1e-45. That is, the TRP can perform the function of the corresponding layer with only the PHY layer (1e-15, 1e-25), and the TRP can perform the functions of the corresponding layers with only the PHY layer and the MAC layer (1e- 10, 1e-35, 1e-40), the TRP can perform functions of the corresponding layers with only the PHY layer, the MAC layer, and the RLC layer (1e-20, 1e-30). In particular, the TRP (1e-10 to 1e-40) can use a beamforming technology that transmits and receives data by generating narrow beams in various directions using a plurality of transmit and receive antennas. The user terminal 1e-50 connects to the NR gNB 1e-05 and the external network through the TRPs 1e-10 to 1e-40. The NR gNB (1e-05) collects and schedules status information such as buffer status, available transmission power status, and channel status of the terminals to service users, and the terminal and the core network (CN), especially It supports connection between AMF/SMF(1e-50).

1F is an exemplary diagram of a frame structure used in an NR system to which the present invention is applied.

The NR system aims at a higher transmission rate than LTE, and considers a scenario operating at high frequencies to secure a wide frequency bandwidth. In particular, a scenario in which data having a high data rate is transmitted to a terminal by generating a directional beam at a high frequency can be considered.

Accordingly, the NR base station, or the transmission reception point (TRP, 1f-01), is the terminal in the cell (1f-71) (1f-73) (1f-75) (1f-77) (1f-79 When communicating with ), a scenario of communicating using different beams can be considered. That is, in this exemplary drawing, terminal 1 (1f-71) communicates using beam #1 (1f-51), and terminal 2 (1f-73) communicates using beam #5 (1f-55), Terminals 3, 4, 5 (1f-75) (1f-77) (1f-79) assume a scenario in which they communicate through beam #7 (1f-57).

In order to measure which beam the UE communicates with the TRP, an overhead subframe (hereinafter referred to as osf, 1f-03) through which a common overhead signal is transmitted exists in time. The osf may include a Primary Synchronization Signal (PSS) for obtaining timing of an Orthogonal Frequency Division Multiplexing (OFDM) symbol, a Secondary Synchronization Signal (SSS) for detecting a cell ID, and the like. In addition, a PBCH (Physical Broadcast Channel) containing system information, MIB (Master Information Block), or information essential for the terminal to access the system (for example, the bandwidth of the downlink beam, the system frame number, etc.) is transmitted. I can. In addition, in the osf, the base station transmits a reference signal using different beams for each symbol (or over several symbols). A beam index value for distinguishing each beam may be derived from the reference signal. In this exemplary drawing, it is assumed that there are 12 beams from #1 (1f-51) to #12 (1f-62) transmitted by the base station, and different beams are swept for each symbol in the osf. It is assumed that it is transmitted. That is, each beam is transmitted for each symbol within osf (e.g., beam #1 (1f-51) transmission in the first symbol (1f-31)), and the terminal measures the osf, It is possible to measure whether the signal from the beam is strongest.

In this exemplary drawing, a scenario in which the corresponding osf is repeated every 25 subframes is assumed, and the remaining 24 subframes are data subframes (data subframes dsf, 1f-05) in which general data is transmitted/received. Accordingly, according to the scheduling of the base station, the terminals 3, 4, 5 (1f-75,) (1f-77) and (1f-79) communicate using beam #7 in common (1f-11), and the It is assumed that terminal 1 (1f-71) communicates using beam #1 (1f-13), and terminal 2 (1f-73) communicates using beam #5 (1f-15). In this exemplary drawing, transmission beams #1 (1f-51) to #12 (1f-62) of the base station are mainly schematically illustrated, but the reception beam of the terminal for receiving the transmission beam of the base station (e.g., the terminal 1 (1f-81), (1f-83), (1f-85), (1f-87)) of (1f-71) may be additionally considered. In this exemplary drawing, the terminal 1 has four beams (1f-81), (1f-83), (1f-85), and (1f-87), and determines which beam has the best reception performance. To perform beam sweeping. In this case, when multiple beams cannot be used at the same time, one reception beam for each osf may be used to receive as many osf as the number of reception beams to find an optimal transmission beam of the base station and a reception beam of the terminal.

The terminal has a procedure (terminal capability report, UE capability report) for reporting the capability supported by the terminal to the corresponding base station while connected to the serving base station. The base station transmits a UE capability inquiry message requesting capability report to the UE in the connected state (RRC CONNECTED MODE). In the message, the base station may include a UE capability request by RAT type. The request for each RAT type may include requested frequency band information. In addition, the UE capability request message may request a plurality of RAT types in one RRC message container, or may include a UE capability request message including a request for each RAT type multiple times to the UE. That is, the UE capability inquiry is repeated a plurality of times, and the UE may configure a corresponding UE capability information message and report a plurality of reports. In the next-generation mobile communication system, it is possible to request terminal capability for MR-DC including NR, LTE, and EN-DC. For reference, the UE capability Inquiry message is generally sent at an early stage after the UE connects, but it can be requested under any conditions when the base station needs it.

In the above step, the terminal receiving the UE capability report request from the base station configures the terminal capability according to the RAT type and band information requested from the base station. Below is a summary of how the UE configures the UE capability in the NR system.

One. If the UE receives a list of LTE and/or NR bands as a UE capability request from the base station, the UE configures a band combination (BC) for EN-DC and NR stand alone (SA). That is, a BC candidate list for EN-DC and NR SA is constructed based on the bands requested by the base station as FreqBandList. In addition, the priorities of the bands have priorities in the order described in FreqBandList.

2. If the “eutra-nr-only” flag or the “eutra” flag is set, NR SA BCs are completely removed from the candidate list of the configured BC. This may occur only when the LTE base station (eNB) requests “eutra” capability.

3. Thereafter, the UE removes fallback BCs from the BC candidate list configured in the above step. Here, fallback BC corresponds to a case in which a band corresponding to at least one SCell is removed from a super set BC, and can be omitted because the super set BC can already cover the fallback BC. This step also applies to MR-DC, that is, to LTE bands. BCs remaining after this stage are the final “list of candidate BCs”.

4. The terminal selects BCs to be reported by selecting BCs suitable for the requested RAT type from the final "candidate BC list". In this step, the terminal constructs a supportedBandCombinationList in a predetermined order. That is, the UE configures the BC and UE capabilities to be reported in accordance with the order of the preset rat-Type. (nr -> eutra-nr -> eutra). In addition, featureSetCombination for the configured supportedBandCombinationList is configured, and a list of “candidate feature set combinations” is formed from the candidate BC list from which the list for fallback BC (including the capability of the same or lower level) has been removed. The “candidate feature set combination” includes both a feature set combination for NR and EUTRA-NR BC, and can be obtained from a feature set combination of UE-NR-Capabilities and UE-MRDC-Capabilities containers.

5. In addition, if the requested rat Type is eutra-nr and has an effect, featureSetCombinations are included in both containers, UE-MRDC-Capabilities and UE-NR-Capabilities. However, the NR feature set includes only UE-NR-Capabilities.

After the terminal capability is configured, the terminal transmits a UE capability information message including the terminal capability to the base station. The base station then performs appropriate scheduling and transmission/reception management for the corresponding terminal based on the terminal capability received from the terminal.

In NR, the 450 MHz-6000 MHz band is divided into frequency range 1 (FR1) and the 24250 MHz-52600 MHz band is divided into frequency range 2 (FR2). In NR, operation bands such as Table 1 (NR operating bands in FR1) to Table 2 (NR operating bands in FR2) are supported for the FR1 and FR2 bands. The values in Tables 1 and 2 are determined according to regional policies and regulations and can be changed according to future circumstances. In addition, in the case of carrier aggregation (CA) to dual connectivity (DC), possible NR operation band pairs may be determined similarly to Table 1 or Table 2.

[Table 1]

[Table 2]

Next, downlink control information (DCI) in the 5G system will be described in detail.

In the 5G system, scheduling information for uplink data (or physical uplink data channel (Physical Uplink Shared Channel, PUSCH)) or downlink data (or physical downlink data channel (Physical Downlink Shared Channel, PDSCH)) is provided through DCI. It is transmitted from the base station to the terminal. The UE may monitor a DCI format for fallback and a DCI format for non-fallback for PUSCH or PDSCH. The countermeasure DCI format may be composed of a fixed field selected between the base station and the terminal, and the non-preparation DCI format may include a configurable field.

The DCI may be transmitted through a physical downlink control channel (PDCCH) through a channel coding and modulation process. A Cyclic Redundancy Check (CRC) is attached to the DCI message payload, and the CRC is scrambling with a Radio Network Temporary Identifier (RNTI) corresponding to the identity of the terminal. Different RNTIs are used according to the purpose of the DCI message, for example, UE-specific data transmission, power control command, or random access response. That is, the RNTI is not explicitly transmitted, but is included in the CRC calculation process and transmitted. Upon receiving the DCI message transmitted on the PDCCH, the UE checks the CRC using the allocated RNTI, and if the CRC check result is correct, the UE can know that the message has been transmitted to the UE.

For example, DCI scheduling a PDSCH for system information (SI) may be scrambled with SI-RNTI. The DCI scheduling the PDSCH for a Random Access Response (RAR) message may be scrambled with RA-RNTI. The DCI scheduling the PDSCH for the paging message can be scrambled with P-RNTI. The DCI notifying the SFI (Slot Format Indicator) may be scrambled with SFI-RNTI. DCI notifying TPC (Transmit Power Control) can be scrambled with TPC-RNTI. The DCI for scheduling a UE-specific PDSCH or PUSCH may be scrambled with a Cell RNTI (C-RNTI).

DCI format 0_0 may be used as a countermeasure DCI for scheduling PUSCH, and in this case, CRC may be scrambled with C-RNTI. DCI format 0_0 in which CRC is scrambled with C-RNTI may include, for example, the following information.

[Table 3]

DCI format 0_1 may be used as a non-preparative DCI for scheduling PUSCH, and in this case, CRC may be scrambled with C-RNTI. DCI format 0_1 in which CRC is scrambled by C-RNTI may include, for example, the following information.

[Table 4]

DCI format 1_0 may be used as a countermeasure DCI for scheduling the PDSCH, and in this case, the CRC may be scrambled with C-RNTI. DCI format 1_0 in which CRC is scrambled with C-RNTI may include, for example, the following information.

[Table 5]

DCI format 1_1 may be used as a non-preparative DCI for scheduling the PDSCH, and in this case, the CRC may be scrambled with C-RNTI. DCI format 1_1 in which CRC is scrambled with C-RNTI may include, for example, the following information.

[Table 6]

1G is a diagram illustrating an entire procedure for indicating a beam of a downlink signal transmitted to a PDSCH in the NR system referred to in the present invention.

In the NR system, it is designed to perform data transmission/reception between a terminal and a base station using a directional beam. As a characteristic of data communication through a directional beam, there is a point that it is possible to support a high data rate through a wide bandwidth and resources due to the use of high frequency, and on the other hand, there may be a limitation that a direction must be set well. In the NR system, basically, the terminal measures a synchronization signal through the SS/PBCH block in the initial access stage, and data transmission/reception may be performed through the beam direction in which the synchronization signal is detected. Thereafter, the base station sets up to 64 downlink beams used for transmission through the PDCCH to the UE as RRC messages, and among them, one of the actually used beams is indicated through the MAC CE. In addition, the base station also includes an operation of setting and indicating a downlink beam used for transmission through the PDSCH. In certain conditions, a downlink beam used for transmission through a PDCCH may be used instead of a downlink beam used for transmission through a PDSCH. The above condition is a case where the processing time for switching from the downlink beam for the PDCCH to the downlink beam for the PDSCH is shorter than the requested processing time.

The direction (1g-06 to 1g-10) of the beam through which the CSI-RS resource 1g-15 is transmitted may be set for the base station to which the terminal 1g-20 is connected and the TRP 1g-05. The beam configuration can be applied to a beam in which all transmission resources transmitted from the PDSCH are transmitted, and the procedure is as follows.

One. Step 1g-25: Set the TCI state in PDSCH-Config for each BWP of the serving cell through RRC configuration (Up to 128 beams can be configured in Rel-15)

2. Step 1g-30: With respect to the TCI state, which is the beam through which the PDSCH set in the RRC message is transmitted, a beam candidate group to be activated to the terminal is indicated to the MAC CE (in Rel-15, up to 8 beams, that is, TCI state can be activated). The purpose of the MAC CE can be understood as a process of selecting candidate beams that can be dinamicly indicated by DCI during TCI state set by RRC, reducing the TCI state that the UE must manage, and reducing the number of bits indicated by the DCI. I can.

3. Step 1g-35: Instructing a specific beam from among the candidate beams indicated by the MAC CE through an indicator of DCI (in Rel-15, it consists of 3 bits)

The maximum number of TCI states that the base station can set for each component carrier (CC) to the terminal in step 1g-25, and in 1g-30, the base station activates the terminal for each CC and each bandwidth part (BWP). The maximum number of TCI states that may be allowed may be respectively limited by the terminal capability reporting parameters maxNumberConfiguredTCIstatesPerCC and maxNumberActiveTCI-PerBWP of Table 7. In particular, maxNumberActiveTCI-PerBWP is a parameter that limits the number of QCL type-D activated for PDSCH and CORESET in the BWP, and is applied to both FR1 and FR2 bands (FR1-FR2 DIFF column is mapped to No in Table 3) It should be noted that

[Table 7]

Table 8 shows the upper layer signaling structure of TCI state and quasi co-location (QCL) information. Referring to Table 8, one TCI state includes at most two QCL types (qcl-Type1, qcl-Type2), and one QCL type is set to one of type A, type B, type C, and type D QCL-Info Is connected with At this time, the types of large scale parameter values that the target RS can refer from the reference RS according to the QCL type are as follows.

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

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

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

'QCL-TypeD': {Spatial Rx parameter} (that is, reception beam related information)

In Table 8, QCL-Info connected to qcl-Type1 can be set to one of QCL-TypeA, QCL-TypeB, and QCL-TypeC. If qcl-Type2 is set, QCL-Info connected thereto is set as QCL-TypeD.

[Table 8]

Table 9 shows the UE capability reporting parameters for QCL-typeD “PDSCH beam switching (or timeDurationForQCL, UE capa 2-2)” and “Max number of downlink RS resources used for QCL type-D in the active TCI states and active spatial relation. This is a table showing the characteristics of “info (or UE capa 2-62)”. Referring to Table 9, the UE reports the time interval required to change the reception beam from a minimum of 7 symbols to a maximum of 28 symbols based on a 60 kHz subcarrier interval (SCS) to the base station through timeDurationForQCL or based on a 120 kHz subcarrier interval (SCS). From a minimum of 14 symbols to a maximum of 28 symbols, it is possible to report the time interval required for the reception beam change. The 60kHz and 120kHz SCS are values that can be set only in FR2, and according to Table 9, it can be seen that timeDurationForQCL is also available only in FR2. In addition, the UE can inform the base station of how many downlink reference signals can be used as a reference RS for QCL type-D of the activated TCI state through “UE capa 2-62”. For example, if the value of “UE capa 2-62” is 1, this means that there is only one reference RS of QCL type-D in the activated TCI state, and dynamic change to the QCL-type D, that is, the reception beam. It can be interpreted as meaning that it cannot. On the other hand, if the value of “UE capa 2-62” is 2 or more, this means that there are two or more reference RSs of QCL type-D in the activated TCI state, and dynamic change to the QCL-type D, that is, the reception beam can be performed. It can be interpreted as meaning.

[Table 9]

1H is a diagram showing a procedure for determining a method of changing a reception beam of an FR2 band according to conditions in an NR system applied to the present invention. 1H, the UE additionally determines the type of the DCI format of the PDCCH if it is'enabled' according to whether the upper layer parameter tci-PresentinDCI for the CORESET scheduling PDSCH is set (1h-00) (1h- 05). If tci-PresentinDCI is not set, it is determined whether the time gap (scheduling offset) between the DL DCI and the PDSCH is greater than or equal to the timeDurationForQCL reported by the UE capability report regardless of the DCI format (1h-15). In step 1h-05, if DCI format 1_1 is received, the UE assumes that the TCI field exists in the corresponding DCI (1h-10), and the time gap (scheduling offset) between the DL DCI and the PDSCH is reported as the UE capability report timeDurationForQCL Determine whether it is greater than or equal to (1h-20). In step 1h-05, if DCI format 1_0 is received, the terminal proceeds to step 1h-15. If the interval between DCI and PDSCH in steps 1h-15 to 1h-20 is less than timeDurationForQCL, the UE is the QCL parameter used for CORESET associated with the monitored search spate having the lowest CORESET ID in the DMRS port of the PDSCH and the most recent slot. Apply (1h-30). On the other hand, if the interval between DCI and PDSCH in step 1h-15 is greater than or equal to timeDurationForQCL, the UE applies the QCL assumption such as CORESET used to transmit the corresponding PDCCH to the corresponding PDSCH DMRS port (1h-35). If the interval between DCI and PDSCH in step 1h-20 is greater than or equal to timeDurationForQCL, the UE applies the QCL assumption indicated by the TCI field in the corresponding PDCCH (DCI) to the corresponding PDSCH DMRS port (1h-25). On the other hand, if the UE does not include a QCL-typeD among the TCI states set “for all BWPs”, the UE always follows the indicated TCI state regardless of the interval between the DCI and the PDSCH allocated by the DCI. QCL assumptions can be obtained (1h-40).

According to the present invention, the condition "for all BWPs" in steps 1h-40 may be replaced with other conditions depending on the situation. For example, in step 1h-40, the condition “for all BWPs” is defined as “for all BWPs set in FR1” or “for all BWPs set in one serving cell” by adding more detailed restrictions between DCI and PDSCH. Regardless of the interval, it is possible to increase the number of uses of the method according to the indicated TCI state.

On the other hand, as described above, timeDurationForQCL is a value that can be set only in FR2, and when the terminal receives QCL-typeD in FR1, there is no available timeDurationForQCL value, so that the determination criterion of the terminal in steps 1h-15 or 1h-20 becomes ambiguous. That is, when the UE is configured with QCL-typeD in FR1, it is not classified as one of the final QCL assumption methods 1h-25, 1h-30, 1h-35, and 1h-40 of FIG. 1H.

In the present invention, in order to solve the ambiguity that occurs when the terminal receives QCL-typeD in FR1, methods of assuming QCL of the terminal and the base station in the above case are provided.

<First embodiment: timeDurationForQCL determination method for FR1>

In the first embodiment, a method for determining timeDurationForQCL in FR1 is provided so that the UE does not have ambiguity in the determination of steps 1h-15 to 1h-20 based on this.

As described above, the base station may set the QCL type D to the second QCL type in the TCI state to inform the UE of the channel to which the corresponding TCI state is applied or a reception beam direction to be applied when receiving a signal. Meanwhile, the reception beam may include both an analog beam-based reception beam based on hardware and a digital beam (or precoding) based reception beam based on digital signal processing. Since the UE capability report for timeDurationForQCL in FR2 focuses on the analog beam-based reception beam change, consider the speed of the analog beam change procedure and have a minimum value of 7 symbols and 14 symbols, that is, half slots at 60 kHz and 12 kHz SCS. do. On the other hand, in the case of FR1, QCL type D assumes a reception beam that considers both an analog beam and a digital beam, and if the terminal uses a digital beam-based reception beam without an analog beam, such as using an omni-directional antenna, the beam change rate Is fast, and post-processing for different reception beams is possible through buffering, so a half-slot time gap may not be necessary as in FR2.

Considering the different situations in FR1 and FR2, it is possible to use three specific methods to determine timeDurationForQCL in FR1 as follows.

* Method 1: The first method is to define a fixed value timeDurationForQCL for FR1. That is, in the case of FR1, timeDurationForQCL is not a value determined by the UE capability report, but a specific value such as X∈{0, 2, or 4} OFDM symbol, etc., and applied to steps 1h-15 to 1h-20. It is possible. At this time, the value of X may be determined as one value in the physical layer standard or may be indicated by higher layer signaling such as RRC.

* Method 2: The second method is to extend the UE capability report for timeDurationForQCL to FR1. That is, timeDurationForQCL may additionally include at least one or more values for 15 kHz and 30 kHz SCS in addition to values for conventional 60 kHz and 12 kHz SCS. Alternatively, it is possible to newly define timeDurationForQCL2 and promise to apply values or values included in the corresponding UE capability report in the case of 15 kHz and 30 kHz SCS.

그리고

의 값들을 각각 적용하는 것이 가능하다. 상기 수식은 본 방법을 적용하기 위한 일례로 ceilling function을 flooring function으로 대체하는 등 다양한 응용이 가능하나 설명의 요지를 흐리지 않기 위하여 생략한다. 또 다른 예시로 종래 timeDurationForQCL이 포함하는 두 가지 값 들을 모두 사용하여 15kHz 및 30kHz SCS를 위한 값들로 각각 환산하는 것이 가능하다. 예를 들어 60kHz SCS를 위한 X1과 120kHz SCS를 위한 X2 를 X1은 15kHz SCS를 위한 값으로 환산하고, X2는 30kHz SCS를 위한 값으로 환산한다. 구체적인 환산 방법은 위와 유사하므로 생략하도록 한다.* Method 3: The third method is a method of extending the conventional timeDurationForQCL report value for FR2 for FR1. As an example, by selecting one of two values included in the conventional timeDurationForQCL (for example, selecting only X1 of X1 for 60kHz SCS and X2 for 120kHz SCS), the value can be converted into values for 15kHz and 30kHz SCS. have. At this time, the length of OFDM symbol and slot is inversely proportional to the SCS value. For example, if X1 = 7 is reported, the base station and the terminal are at 15 kHz and 30 kHz.

And

It is possible to apply each of the values of. The above formula is an example for applying this method, and various applications such as replacing the ceilling function with a flooring function are possible, but are omitted in order not to obscure the subject matter of the description. As another example, it is possible to convert into values for 15 kHz and 30 kHz SCS using both values included in the conventional timeDurationForQCL. For example, X1 for 60kHz SCS and X2 for 120kHz SCS are converted to values for X1 for 15kHz SCS, and X2 for values for 30kHz SCS. The specific conversion method is similar to the above, so it will be omitted.

<Second embodiment: How to allow QCL-typeD change regardless of timeDurationForQCL in FR1>

In the second embodiment, a method for allowing QCL-typeD change regardless of timeDurationForQCL in FR1 is provided, and based on this, the UE performs the determination of the assumptions 1h-25, 1h-30, 1h-35 to 1h-40. So there is no ambiguity.

As described above, the base station may set the QCL type D to the second QCL type in the TCI state to inform the UE of the channel to which the corresponding TCI state is applied or a reception beam direction to be applied when receiving a signal. Meanwhile, the reception beam may include both an analog beam-based reception beam based on hardware and a digital beam (or precoding) based reception beam based on digital signal processing. Since the UE capability report for timeDurationForQCL in FR2 focuses on the analog beam-based reception beam change, consider the speed of the analog beam change procedure and have a minimum value of 7 symbols and 14 symbols, that is, half slots at 60 kHz and 12 kHz SCS. do. On the other hand, in the case of FR1, QCL type D assumes a reception beam that considers both an analog beam and a digital beam, and if the terminal uses a digital beam-based reception beam without an analog beam, such as using an omni-directional antenna, the beam change rate Is fast, and post-processing for different reception beams is possible through buffering, so a half-slot time gap may not be necessary as in FR2.

Considering the different situations in FR1 and FR2, it is possible to use two specific methods as follows to determine the QCL-typeD assumption in FR1.

* Method 1: The first method is a method of determining the QCL assumption according to the indicated TCI state regardless of the time gap between the DCI and the PDSCH when the SCS of the BWP through which the PDSCH and PDCCH are transmitted is 15 kHz or 30 kHz.

* Method 2: The second method is a method of introducing a new upper layer parameter indicating omission/ignorance of steps 1h-15 to 1h-20. For example, when the upper layer parameter is set, the UE uses DCI format 1_1 regardless of the time gap between DCI and PDSCH, and uses the QCL assumption according to the indicated TCI state when tci-PresentinDCI is set, and DCI format 1_1 but tci- If PresentinDCI is not set or DCI format 1_0, it can be promised to apply the QCL assumption by referring to the TCI state for the CORESET to which the DCI assigned the corresponding PDSCH is transmitted.

<Third Example: How to Disallow QCL-typeD Setting in FR1>

In the third embodiment, by disallowing the setting of QCL-typeD in FR1 or not allowing dynamic change to QCL-typeD in FR1, in the case of FR1, it is always converged to steps 1h-40 to eliminate ambiguity in terminal operation. That's the way.

For example, if the UE does not include QCL-typeD among the TCI states set “for BWP using 15 kHz SCS or 30 kHz SCS (that is, for FR1 BWPs)”, the UE shall have DCI within the corresponding serving cell. The QCL assumption can be obtained according to the always indicated TCI state irrespective of the interval between the and the PDSCH allocated by the DCI.

The condition “for a BWP using 15 kHz SCS or 30 kHz SCS” can be replaced with other conditions depending on the situation. For example, various applications such as “for all BWPs set in FR1” or “one serving cell” are possible.

As another example, the UE is “for BWP using 15 kHz SCS or 30 kHz SCS (that is, for FR1 BWPs)” TCI that is always indicated regardless of the interval between the DCI in the corresponding serving cell and the PDSCH allocated by the DCI QCL assumptions can be obtained depending on the state.

As another example, the UE may not expect that the TCI states set for the BWP using 15kHz SCS or 30kHz SCS (that is, for FR1 BWPs) include QCL-typeD.

<Fourth embodiment: QCL assumption method when tci-PresentinDCI is not set in FR1>

In the fourth embodiment, a QCL assumption method is provided when the upper layer parameter tci-PresentinDCI is not set in FR1, that is, when the TCI field in DCI does not exist.

As described above, FR1 omits comparing the time interval between DCI and PDSCH in steps 1h-15 when tci-PresentinDCI is not set in steps 1h-00, based on the easier QCL-typeD change compared to FR2 (i.e. Regardless of the scheduling offset between the DCI and the PDSCH), it can be promised to apply the QCL assumption of the CORESET to which the DCI is transmitted to the PDSCH DMRS (1h-35).

Solutions for UEs configured with QCL-TypeD at FR1

Option 1: Assume the scheduling offset threshold in FR1 as well as FR2

Option 1-1: Define a fixed value of timing gap between the reception of DL DCI and the corresponding PDSCH to determine UE assumption on TCI states

Option 1-2: Define timeDurationForQCL for FR1 (e.g. UE can report one among {4, 7, or 14})

Option 1-3: Reuse (and transform) timeDurationForQCL for FR2

…

Option 2: Define a new method to ignore the scheduling offset threshold in FR1

Option 2-1: For the BWP with SCS of 15 or 30kHz, the UE shall obtain the other QCL assumptions from the indicated TCI states for its scheduled PDSCH irrespective of the time offset between the reception of the DL DCI and the corresponding PDSCH (Need to Revise default behavior)

Option 2-2: Introduce a new higher layer parameter that explicitly inform to ignore the scheduling offset threshold in the BWP

…

Option 3: Clarify that QCL-TypeD is not configured for FR1

Terminal: If QCL-TypeD is not set and tci-PresentDCI is disabled, the CORESET QCL assumption is followed.

<Fifth Embodiment: Method 1 of applying aperiodic CSI-RS QCL>

Tables 10 to 11 are tables showing the characteristics of the UE capability reporting parameter "A-CSI-RS beam switching timing (or beamSwitchTiming, UE capa 2-28)" for beam change of aperiodic CSI-RS. Referring to Table 10, the terminal provides the base station through beamSwitchTiming, the minimum time interval required for changing a reception beam corresponding to one symbol length of {14, 28, 48, 224, 336} for 60 kHz and 120 kHz subcarrier intervals (SCS). Each can be reported. The 60kHz and 120kHz SCS are values that can be set only in FR2, and according to Tables 10 to 11, it can be seen that beamSwitchTiming is also available only in FR2.

[Table 10]

[Table 11]

Table 12 shows the QCL assumptions of the base station and the terminal for the aperiodic CSI-RS according to the “interval between the triggering DCI of a certain aperiodic CSI-RS and the transmission/reception timing of the aperiodic CSI-RS (aperiodic CSI-RS triggering offset)” It is a table showing the method. At this time, in Table 12, the aperiodic CSI-RS does not have the upper layer parameter trs-Info set (that is, it is not the CSI-RS set to CSI-RS for tracking (TRS, time/frequency tracking RS)), and the upper layer parameter If repetition is not set (that is, not CSI-RS for L1-RSRP or CSI-RS set to CSI-RS for beam management), that is, CSI-RS for CSI acquisition (ie, CSI-RS for CQI calculation) ), but it is possible to expand to CSI-RS for other purposes such as CSI-RS for tracking or CSI-RS for L1-RSRP in the future. Referring to Table 12, the UE is instructed to configure a QCL including QCL type and QCL RS source information for each aperiodic CSI-RS resource in the CSI-RS resource set associated with each CSI triggering state. At this time, the QCL configuration may include a list of TCI states.

Let the aperiodic CSI-RS triggering offset be defined as the interval between the last symbol of the PDCCH including the triggering DCI and the first symbol of the aperiodic CSI-RS indicated by the corresponding triggering DCI. If the aperiodic CSI-RS triggering offset is less than the beamSwitchTiming value reported by the UE, the UE performs one of the following two operations according to conditions. If another downlink signal indicating a certain TCI state exists in the same symbol as the aperiodic CSI-RS, the UE applies the QCL assumption of the another downlink signal when receiving the aperiodic CSI-RS. Here, the other downlink signal is a PDSCH having a scheduling offset greater than a timeDurationForQCL value, or another aperiodic CSI-RS having an aperiodic CSI-RS triggering offset greater than a beamSwitchTiming value, or a periodic CSI-RS, or a semi-persistent CSI-RS. It can be one of. If not (i.e., if another downlink signal indicating a certain TCI state is not present in the same symbol as the aperiodic CSI-RS), the terminal is monitored in the most recent slot in the corresponding cell (serving cell) The QCL assumption used for CORESET with the lowest CORESET ID among the search spaces is applied when receiving the aperiodic CSI-RS.

If the aperiodic CSI-RS triggering offset is greater than or equal to the beamSwitchTiming value reported by the UE, the UE may apply the QCL assumption in the TCI state indicated for the corresponding aperiodic CSI-RS resource.

[Table 12]

Meanwhile, as previously described, beamSwitchTiming is a value that can be set only in FR2, and when the terminal receives QCL-typeD in FR1, there is no available beamSwitchTiming value, so that the determination criterion of the terminal according to Table 12 is ambiguous. That is, when the UE is configured with QCL-typeD in FR1, it is not classified as one of the UE operations according to Table 12.

In the present invention, in order to solve the ambiguity that occurs when the terminal receives QCL-typeD in FR1, methods of assuming QCL of the terminal and the base station in the above case are provided.

<Sixth embodiment: beamSwitchTiming determination method for FR1>

In the first embodiment, a beamSwitchTiming determination method in FR1 is provided so that there is no ambiguity in the UE performing the determination according to Table 12 based on this.

As described above, the base station may set the QCL type D to the second QCL type in the TCI state to inform the UE of the channel to which the corresponding TCI state is applied or a reception beam direction to be applied when receiving a signal. Meanwhile, the reception beam may include both an analog beam-based reception beam based on hardware and a digital beam (or precoding) based reception beam based on digital signal processing. Since the UE capability report for beamSwitchTiming in FR2 focuses on changing the reception beam based on the analog beam, it has a minimum value of 14 symbols, that is, one slot at 60kHz or 12kHz SCS in consideration of the speed of the analog beam change procedure. On the other hand, in the case of FR1, QCL type D assumes a reception beam that considers both an analog beam and a digital beam, and if the terminal uses a digital beam-based reception beam without an analog beam, such as using an omni-directional antenna, the beam change rate Is fast, and post-processing for different reception beams is possible through buffering, so a half-slot time gap may not be necessary as in FR2.

Considering different situations in FR1 and FR2, it is possible to use three specific methods for determining beamSwitchTiming in FR1 as follows.

* Method 1: The first method is to define a fixed value of beamSwitchTiming for FR1. That is, in the case of FR1, the beamSwitchTiming is not a value determined by the UE capability report, but a specific value such as X∈{0, 2, or 4} OFDM symbol, etc., can be determined and applied to Table 12. At this time, the value of X may be determined as one value in the physical layer standard or may be indicated by higher layer signaling such as RRC.

* Method 2: The second method is to extend the UE capability report for beamSwitchTiming to FR1. That is, beamSwitchTiming may additionally include at least one or more values for 15 kHz and 30 kHz SCS in addition to values for conventional 60 kHz and 12 kHz SCS. Alternatively, by newly defining beamSwitchTiming2, it is possible to promise to apply values or values included in the corresponding terminal capability report in the case of 15 kHz and 30 kHz SCS.

그리고

의 값들을 각각 적용하는 것이 가능하다. 상기 수식은 본 방법을 적용하기 위한 일례로 ceilling function을 flooring function으로 대체하는 등 다양한 응용이 가능하나 설명의 요지를 흐리지 않기 위하여 생략한다. 또 다른 예시로 종래 beamSwitchTiming이 포함하는 두 가지 값 들을 모두 사용하여 15kHz 및 30kHz SCS를 위한 값들로 각각 환산하는 것이 가능하다. 예를 들어 60kHz SCS를 위한 X1과 120kHz SCS를 위한 X2 를 X1은 15kHz SCS를 위한 값으로 환산하고, X2는 30kHz SCS를 위한 값으로 환산한다. 구체적인 환산 방법은 위와 유사하므로 생략하도록 한다.* Method 3: The third method is a method of extending the beamSwitchTiming report value for the conventional FR2 for FR1. For example, by selecting one of two values included in the conventional beamSwitchTiming (for example, selecting only X1 of X1 for 60kHz SCS and X2 for 120kHz SCS), the value can be converted into values for 15kHz and 30kHz SCS. have. In this case, a characteristic in which the length of the OFDM symbol and the slot is inversely proportional to the SCS value may be used. For example, if X1 = 14 is reported, the base station and the terminal are at 15 kHz and 30 kHz.

And

It is possible to apply each of the values of. The above formula is an example for applying this method, and various applications such as replacing the ceilling function with a flooring function are possible, but are omitted in order not to obscure the subject matter of the description. As another example, it is possible to convert into values for 15 kHz and 30 kHz SCS using both values included in the conventional beamSwitchTiming. For example, X1 for 60kHz SCS and X2 for 120kHz SCS are converted to values for X1 for 15kHz SCS, and X2 for values for 30kHz SCS. The specific conversion method is similar to the above, so it will be omitted.

<Seventh embodiment: How to allow QCL-typeD change regardless of beamSwitchTiming in FR1>

In the seventh embodiment, a method for allowing QCL-typeD change regardless of beamSwitchTiming in FR1 is provided so that there is no ambiguity in the UE performing the determination according to Table 12 based on this.

As described above, the base station may set the QCL type D to the second QCL type in the TCI state to inform the UE of the channel to which the corresponding TCI state is applied or a reception beam direction to be applied when receiving a signal. Meanwhile, the reception beam may include both an analog beam-based reception beam based on hardware and a digital beam (or precoding) based reception beam based on digital signal processing. Since the UE capability report for beamSwitchTiming in FR2 focuses on changing the reception beam based on the analog beam, consider the speed of the analog beam changing procedure and have a minimum value of 7 symbols and 14 symbols, that is, half slots at 60 kHz and 12 kHz SCS. do. On the other hand, in the case of FR1, QCL type D assumes a reception beam that considers both an analog beam and a digital beam, and if the terminal uses a digital beam-based reception beam without an analog beam, such as using an omni-directional antenna, the beam change rate Is fast, and post-processing for different reception beams is possible through buffering, so a half-slot time gap may not be necessary as in FR2.

Considering the different situations in FR1 and FR2, it is possible to use two specific methods as follows to determine the QCL-typeD assumption in FR1.

* Method 1: The first method is a method of determining the QCL assumption according to the indicated TCI state regardless of the aperiodic CSI-RS triggering offset when the SCS of the BWP through which the PDSCH and PDCCH are transmitted is 15 kHz or 30 kHz.

* Method 2: The second method is to introduce a new upper layer parameter that informs the omission/ignorance of the judgment process in Table 12. For example, when the upper layer parameter is set, the UE uses the QCL assumption according to the TCI state indicated by the triggering DCI regardless of the aperiodic CSI-RS triggering offset, and if the higher layer parameter is not set, the most recent slot It can be promised to apply the QCL assumption by referring to the TCI state for the CORESET that has the lowest CORESET-ID among the CORESETs related to the search space monitored in.

In this embodiment, if another downlink signal indicating a certain TCI state exists in the same symbol as the aperiodic CSI-RS, the UE applies the QCL assumption of the another downlink signal when receiving the aperiodic CSI-RS can do. Here, the other downlink signal may be one of a PDSCH having a scheduling offset larger than a timeDurationForQCL value, a periodic CSI-RS, or a semi-persistent CSI-RS.

In the present embodiment, a specific criterion when different aperiodic CSI-RSs that assume different QCL-TypeDs overlap with a state in which a new higher layer parameter indicating omission/ignorance of the determination process in Table 12 is set to'ON', For example, the QCL-TypeD assumption applied to the CSI-RS having the lowest/highest resource ID can be used to receive the corresponding OFDM symbol. Through this, it is possible to guarantee that one reception beam assumption can be used in one OFDM symbol.

In the present embodiment, a new higher layer parameter indicating omission/ignorance of the determination process of Table 12 may be restricted to be applicable only to FR1.

<Eighth Example: How to Disallow QCL-typeD Setting in FR1>

In the third embodiment, by disallowing the setting of QCL-typeD in FR1 or not allowing dynamic change to QCL-typeD in FR1, in the case of FR1, it is always converged to steps 1h-40 to eliminate ambiguity in terminal operation. That's the way.

For example, if the UE does not include QCL-typeD among the TCI states set “for BWP using 15 kHz SCS or 30 kHz SCS (that is, for FR1 BWPs)”, the UE shall have DCI within the corresponding serving cell. Regardless of the interval between the and the aperiodic CSI-RS allocated by the DCI, the QCL assumption can be obtained according to the always indicated TCI state.

The condition “for a BWP using 15 kHz SCS or 30 kHz SCS” can be replaced with other conditions depending on the situation. For example, various applications such as “for all BWPs set in FR1” or “one serving cell” are possible.

As another example, the UE is always "for BWP using 15kHz SCS or 30kHz SCS (ie, for FR1 BWPs)" regardless of the interval between the DCI in the serving cell and the aperiodic CSI-RS allocated by the DCI. QCL assumption can be obtained according to the indicated TCI state.

As another example, the UE may not expect that the TCI states set for the BWP using 15kHz SCS or 30kHz SCS (that is, for FR1 BWPs) include QCL-typeD.

1I is a block diagram showing the internal structure of a terminal to which the present invention is applied.

Referring to the drawing, the terminal includes a radio frequency (RF) processing unit 1i-10, a baseband processing unit 1i-20, a storage unit 1i-30, and a control unit 1i-40. .

The RF processing unit 1i-10 performs a function of transmitting and receiving a signal through a wireless channel such as band conversion and amplification of a signal. That is, the RF processing unit 1i-10 up-converts the baseband signal provided from the baseband processing unit 1i-20 to an RF band signal, and then transmits it through an antenna, and an RF band signal received through the antenna. Is down-converted to a baseband signal. For example, the RF processing unit 1i-10 may include a transmission filter, a reception filter, an amplifier, a mixer, an oscillator, a digital to analog convertor (DAC), an analog to digital convertor (ADC), and the like. I can. In the drawing, only one antenna is shown, but the terminal may include a plurality of antennas. In addition, the RF processing unit 1i-10 may include a plurality of RF chains. Furthermore, the RF processing unit 1i-10 may perform beamforming. For the beamforming, the RF processing unit 1i-10 may adjust a phase and a magnitude of each of signals transmitted/received through a plurality of antennas or antenna elements. In addition, the RF processing unit may perform MIMO, and may receive multiple layers when performing the MIMO operation.

The baseband processing unit 1i-20 performs a function of converting between a baseband signal and a bit stream according to the physical layer standard of the system. For example, when transmitting data, the baseband processing unit 1i-20 generates complex symbols by encoding and modulating a transmission bit stream. In addition, when receiving data, the baseband processing unit 1i-20 restores a received bit stream through demodulation and decoding of the baseband signal provided from the RF processing unit 1i-10. For example, in the case of the OFDM (orthogonal frequency division multiplexing) scheme, when transmitting data, the baseband processing unit 1i-20 generates complex symbols by encoding and modulating a transmission bit stream, and subcarriers of the complex symbols After mapping to, OFDM symbols are constructed through an inverse fast Fourier transform (IFFT) operation and a cyclic prefix (CP) insertion. In addition, when receiving data, the baseband processing unit 1i-20 divides the baseband signal provided from the RF processing unit 1i-10 in units of OFDM symbols, and applies a fast Fourier transform (FFT) operation to subcarriers. After reconstructing the mapped signals, the received bit stream is restored through demodulation and decoding.

The baseband processing unit 1i-20 and the RF processing unit 1i-10 transmit and receive signals as described above. Accordingly, the baseband processing unit 1i-20 and the RF processing unit 1i-10 may be referred to as a transmission unit, a reception unit, a transmission/reception unit, or a communication unit. Furthermore, at least one of the baseband processing unit 1i-20 and the RF processing unit 1i-10 may include a plurality of communication modules to support a plurality of different wireless access technologies. In addition, at least one of the baseband processing unit 1i-20 and the RF processing unit 1i-10 may include different communication modules to process signals of different frequency bands. For example, the different wireless access technologies may include a wireless LAN (eg, IEEE 802.11), a cellular network (eg, LTE), and the like. In addition, the different frequency bands may include a super high frequency (SHF) (eg, 2.NRHz, NRhz) band, and a millimeter wave (eg, 60GHz) band.

The storage unit 1i-30 stores data such as a basic program, an application program, and setting information for the operation of the terminal. Particularly, the storage unit 1i-30 may store information related to a second access node that performs wireless communication using a second wireless access technology. In addition, the storage unit 1i-30 provides stored data according to the request of the control unit 1i-40.

The control unit 1i-40 controls overall operations of the terminal. For example, the control unit 1i-40 transmits and receives signals through the baseband processing unit 1i-20 and the RF processing unit 1i-10. In addition, the control unit 1i-40 writes and reads data in the storage unit 1i-40. To this end, the control unit 1i-40 may include at least one processor. For example, the control unit 1i-40 may include a communication processor (CP) that controls communication and an application processor (AP) that controls an upper layer such as an application program.

1J is a block diagram showing the configuration of an NR base station according to the present invention.

As shown in the figure, the base station includes an RF processing unit (1j-10), a baseband processing unit (1j-20), a backhaul communication unit (1j-30), a storage unit (1j-40), and a control unit (1j-50). It consists of including.

The RF processing unit 1j-10 performs a function of transmitting and receiving a signal through a wireless channel such as band conversion and amplification of a signal. That is, the RF processing unit 1j-10 up-converts the baseband signal provided from the baseband processing unit 1j-20 to an RF band signal and then transmits it through an antenna, and the RF band signal received through the antenna Is down-converted to a baseband signal. For example, the RF processing unit 1j-10 may include a transmission filter, a reception filter, an amplifier, a mixer, an oscillator, a DAC, an ADC, and the like. In the drawing, only one antenna is shown, but the first access node may include a plurality of antennas. In addition, the RF processing unit 1j-10 may include a plurality of RF chains. Furthermore, the RF processing unit 1j-10 may perform beamforming. For the beamforming, the RF processing unit 1j-10 may adjust a phase and a magnitude of each of signals transmitted and received through a plurality of antennas or antenna elements. The RF processor may perform a downlink MIMO operation by transmitting one or more layers.

The baseband processing unit 1j-20 performs a function of converting between a baseband signal and a bit stream according to the physical layer standard of the first wireless access technology. For example, when transmitting data, the baseband processing unit 1j-20 generates complex symbols by encoding and modulating a transmission bit stream. In addition, when receiving data, the baseband processing unit 1j-20 restores a received bit stream through demodulation and decoding of the baseband signal provided from the RF processing unit 1j-10. For example, in the case of the OFDM scheme, when transmitting data, the baseband processing unit 1j-20 generates complex symbols by encoding and modulating a transmission bit stream, mapping the complex symbols to subcarriers, and then IFFT OFDM symbols are configured through calculation and CP insertion. In addition, when receiving data, the baseband processing unit 1j-20 divides the baseband signal provided from the RF processing unit 1j-10 in units of OFDM symbols, and reconstructs signals mapped to subcarriers through FFT operation. After that, the received bit stream is restored through demodulation and decoding. The baseband processing unit 1j-20 and the RF processing unit 1j-10 transmit and receive signals as described above. Accordingly, the baseband processing unit 1j-20 and the RF processing unit 1j-10 may be referred to as a transmission unit, a reception unit, a transmission/reception unit, a communication unit, or a wireless communication unit.

The backhaul communication unit 1j-30 provides an interface for performing communication with other nodes in the network. That is, the backhaul communication unit 1j-30 converts a bit stream transmitted from the main station to another node, for example, an auxiliary base station, a core network, etc., into a physical signal, and converts the physical signal received from the other node into a bit. Convert to heat

The storage unit 1j-40 stores data such as a basic program, an application program, and setting information for the operation of the main station. In particular, the storage unit 1j-40 may store information on bearers allocated to the connected terminal, measurement results reported from the connected terminal, and the like. In addition, the storage unit 1j-40 may store information that is a criterion for determining whether to provide multiple connections to the terminal or stop. In addition, the storage unit 1j-40 provides stored data according to the request of the control unit 1j-50.

The controller 1j-50 controls overall operations of the main station. For example, the control unit 1j-50 transmits and receives signals through the baseband processing unit 1j-20 and the RF processing unit 1j-10 or through the backhaul communication unit 1j-30. Also, the control unit 1j-50 writes and reads data in the storage unit 1j-40. To this end, the control unit 1j-50 may include at least one processor.

Although the above embodiments were individually prepared for convenience of description, they are not independent/exclusive when applied in practice, and several embodiments may be configured together. For example, it may be promised that the base station and the terminal apply one of the second embodiments to DCI format 1_1 in FR1, and follow the fourth embodiment in a fallback mode. Other combinations are possible, but omitted in order not to obscure the subject matter of the description.

The embodiments disclosed in the present specification and drawings are merely provided specific examples for easy explanation and understanding of the present invention, and are not intended to limit the scope of the present invention. Therefore, the scope of the present invention should be construed that all changes or modified forms derived based on the technical idea of the present disclosure other than the embodiments disclosed herein are included in the scope of the present invention.

Claims (1)

In the control signal processing method in a wireless communication system,
Receiving a first control signal transmitted from a base station;
Processing the received first control signal; And
And transmitting a second control signal generated based on the processing to the base station.

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