KR20200050518A - Method and apparatus of resource configuration in V2X sidelink - Google Patents

Abstract

The present invention provides a method for setting a resource region to be transmitted/received by each terminal in an environment supporting terminal-to-terminal communication in addition to base station-terminal communication in a 3rd generation partnership project (3GPP) new radio (NR) system. According to an embodiment of the present invention, provided is a method for setting a sidelink transmission resource in a next generation wireless network, in which a base station instructs a set of resource pools (RPs).

Description

V2X transmission resource setting method and apparatus {Method and apparatus of resource configuration in V2X sidelink}

The present invention provides a method for setting a resource region to be transmitted / received by each terminal in an environment supporting terminal-to-terminal communication in addition to a base station-terminal in a 3GPP NR system. In particular, based on a predefined resource pool for each terminal, a method for setting a terminal transmission resource region capable of providing signal search complexity and resource setting convenience of all terminals is provided by limiting a resource pool to be used by an actual individual terminal.

One embodiment provides a method of setting a sidelink transmission resource in a next generation wireless network, wherein the base station indicates a set of RPs to perform sidelink transmission and reception to the terminal.

1 is a diagram briefly showing a structure of an NR wireless communication system to which the present embodiment can be applied.
2 is a diagram for explaining a frame structure in an NR system to which the present embodiment can be applied.
3 is a diagram for describing a resource grid supported by a radio access technology to which the present embodiment can be applied.
4 is a diagram for describing a bandwidth part supported by a radio access technology to which the present embodiment can be applied.
5 exemplarily shows a synchronization signal block in a radio access technology to which the present embodiment can be applied.
6 is a diagram for explaining a random access procedure in a radio access technology to which the present embodiment can be applied.
7 is a view for explaining CORESET.
8 is a diagram showing the configuration of a base station according to another embodiment.
9 is a view showing the configuration of a user terminal according to another embodiment.

Hereinafter, some embodiments of the present technology will be described in detail with reference to exemplary drawings. In adding reference numerals to the components of each drawing, the same components may have the same reference numerals as possible even though they are displayed on different drawings. In addition, in describing the technical idea, when it is determined that the detailed description of the related known configuration or function may obscure the subject matter of the technical idea, the detailed description may be omitted.

In addition, in describing components of the present embodiments, terms such as first, second, A, B, (a), and (b) may be used. These terms are only for distinguishing the component from other components, and the essence, order, order, or number of the component is not limited by the term. When a component is described as being "connected", "coupled" or "connected" to another component, the component may be directly connected to or connected to the other component, but different components between each component It will be understood that the "intervenes" may be, or each component may be "connected", "coupled" or "connected" through other components.

In addition, the terms and technical names used in the present specification are for describing specific embodiments, and the technical idea is not limited to the terms. The terms described below may be interpreted as meanings generally understood by those having ordinary knowledge in the technical field to which this technical idea belongs, unless otherwise defined. When the term is an incorrect technical term that does not accurately represent the technical idea, it should be understood as being replaced by a technical term that can be correctly understood by those skilled in the art. In addition, the general terms used in this specification should be interpreted as defined in the dictionary or in context before and after, and should not be interpreted as an excessively reduced meaning.

The wireless communication system in the present specification means a system for providing various communication services such as voice and data packets using radio resources, and may include a terminal, a base station, and a core network.

The embodiments disclosed below can be applied to a wireless communication system using various wireless access technologies. For example, the present embodiments are code division multiple access (CDMA), frequency division multiple access (FDMA), timedivision multiple access (TDMA), orthogonal frequency division multiple access (OFDMA), and single-electron frequency division multiple access (SC-FDMA). It can be applied to various wireless access technologies such as. CDMA may be implemented with a radio technology such as universal terrestrial radio access (UTRA) or CDMA2000. TDMA may be implemented with radio technologies such as global system for mobile communications (GSM) / general packet radio service (GPRS) / enhanced data rates for GSM evolution (EDGE). OFDMA may be implemented with wireless technologies such as the Institute of Electrical and Electronics Engineers (IEEE) 802.11 (Wi-Fi), IEEE 802.16 (WiMAX), IEEE 802-20, and Evolved UTRA (E-UTRA). IEEE 802.16m is an evolution of IEEE 802.16e, and provides backward compatibility with a system based on IEEE 802.16e. UTRA is part of a universal mobile telecommunications system (UMTS). 3rd generation partnership project (3GPP) long term evolution (LTE) is part of evolved UMTS (E-UMTS) using evolved-UMTS terrestrial radio access (E-UTRA), adopts OFDMA in the downlink and SC- in the uplink. Adopt FDMA. As described above, the present embodiments may be applied to a currently disclosed or commercialized wireless access technology, or may be applied to a wireless access technology currently being developed or to be developed in the future.

Meanwhile, the terminal in the present specification is a comprehensive concept that refers to a device including a wireless communication module that performs communication with a base station in a wireless communication system. UEs in WCDMA, LTE, HSPA, and IMT-2020 (5G or New Radio) (User Equipment), of course, should be interpreted as a concept including all of MS (Mobile Station), User Terminal (UT), Subscriber Station (SS), and wireless device in GSM. In addition, the terminal may be a user portable device such as a smart phone depending on the type of use, and in the V2X communication system, it may mean a vehicle, a device including a wireless communication module in the vehicle, or the like. In addition, in the case of a machine type communication system, it may mean an MTC terminal or an M2M terminal equipped with a communication module so that the machine type communication is performed.

The base station or cell herein refers to an end that communicates with a terminal in terms of a network, Node-B (Node-B), evolved Node-B (eNB), gNode-B (gNB), Low Power Node (LPN), Sector, Site, Various types of antennas, Base Transceiver System (BTS), Access Point, Point (e.g., Send Point, Receive Point, Send / Receive Point), Relay Node (Relay Node) ), Mega cell, macro cell, micro cell, pico cell, femto cell, remote radio head (RRH), radio unit (RU), and small cell (small cell).

Since the various cells listed above have a base station that controls each cell, the base station can be interpreted in two ways. 1) a device that provides a mega cell, a macro cell, a micro cell, a pico cell, a femto cell, and a small cell in relation to the wireless area, or 2) the wireless area itself. In 1), all devices that provide a predetermined wireless area are controlled by the same entity or interact to configure the wireless area in a collaborative manner. Points, transmission / reception points, transmission points, reception points, and the like, according to a configuration method of a wireless area, are examples of a base station. In 2), the radio area itself, which receives or transmits a signal from the perspective of the user terminal or the neighboring base station, may be directed to the base station.

In this specification, a cell is a component carrier having a coverage of a signal transmitted from a transmission / reception point or a signal transmitted from a transmission / reception point, or a transmission / reception point itself. Can be.

Uplink (Uplink, UL, or uplink) means a method of transmitting and receiving data to the base station by the terminal, downlink (Downlink, DL, or downlink) means a method of transmitting and receiving data to the terminal by the base station A downlink may refer to a communication or communication path from multiple transmission / reception points to a terminal, and an uplink may refer to a communication or communication path from a terminal to multiple transmission / reception points. At this time, in the downlink, the transmitter may be a part of multiple transmission / reception points, and the receiver may be a part of the terminal. In addition, in the uplink, the transmitter may be a part of the terminal, and the receiver may be a part of the multiple transmission / reception points.

In the uplink and downlink, control information is transmitted and received through control channels such as a physical downlink control channel (PDCCH), a physical uplink control channel (PUCCH), and a physical downlink shared channel (PDSCH), a physical uplink shared channel (PUSCH), and the like. The same data channel is configured to transmit and receive data. Hereinafter, a situation in which signals are transmitted and received through channels such as PUCCH, PUSCH, PDCCH, and PDSCH is also referred to as 'transmit and receive PUCCH, PUSCH, PDCCH and PDSCH'. do.

In order to clarify the description, hereinafter, the technical idea is mainly focused on the 3GPP LTE / LTE-A / NR (New RAT) communication system, but the technical features are not limited thereto.

3GPP has been conducting research on 5G (5th-Generation) communication technology to meet the requirements of ITU-R's next-generation wireless access technology after research on 4G (4th-Generation) communication technology. Specifically, 3GPP is conducting research on new NR communication technology that is separate from LTE-A pro and 4G communication technology, which have improved LTE-Advanced technology to meet the requirements of ITU-R with 5G communication technology. LTE-A pro and NR are both expected to be submitted in 5G communication technology, but hereinafter, for convenience of explanation, the present embodiments will be described with reference to NR.

The operating scenario in NR defined various operation scenarios by adding considerations for satellites, automobiles, and new verticals in the existing 4G LTE scenarios.In terms of service, it has an eMBB (Enhanced Mobile Broadband) scenario, high terminal density, but wide It is deployed in the range and supports the Massive Machine Communication (mmmTC) scenario, which requires low data rate and asynchronous connection, and the Ultra Reliability and Low Latency (URLLC) scenario, which requires high responsiveness and reliability and supports high-speed mobility. .

To satisfy this scenario, NR discloses a wireless communication system to which a new waveform and frame structure technology, low latency technology, ultra-high-bandwidth (mmWave) support technology, and forward compatibility technology are applied. In particular, the NR system proposes various technical changes in terms of flexibility in order to provide forward compatibility. The main technical features will be described below with reference to the drawings.

<NR system general>

1 is a diagram briefly showing the structure of an NR system to which the present embodiment can be applied.

Referring to FIG. 1, the NR system is divided into 5GC (5G Core Network) and NR-RAN parts, and NG-RAN is controlled for a user plane (SDAP / PDCP / RLC / MAC / PHY) and user equipment (UE). It consists of gNB and ng-eNBs that provide a plane (RRC) protocol termination. The gNB interconnects or the gNB and ng-eNB are interconnected via an Xn interface. gNB and ng-eNB are each connected to 5GC through an NG interface. The 5GC may include an Access and Mobility Management Function (AMF), which is responsible for a control plane such as a terminal access and mobility control function, and a User Plane Function (UPF), which is a control function for user data. The NR includes support for frequencies below 6 GHz (FR1, Frequency Range 1) and frequencies above 6 GHz (FR2, Frequency Range 2).

gNB means a base station providing NR user plane and control plane protocol termination to the terminal, and ng-eNB means a base station providing E-UTRA user plane and control plane protocol termination to the terminal. The base station described in this specification should be understood as a meaning encompassing gNB and ng-eNB, and may be used in a sense to refer to a gNB or ng-eNB as necessary.

<NR wave form, pneumatics and frame structure>

In NR, a CP-OFDM waveform using a cyclic prefix is used for downlink transmission, and CP-OFDM or DFT-s-OFDM is used for uplink transmission. OFDM technology is easy to combine with multiple input multiple output (MIMO), and has the advantage of being able to use a low-complexity receiver with high frequency efficiency.

On the other hand, in the NR, since the demands for data rate, delay rate, and coverage for each of the three scenarios described above are different from each other, it is necessary to efficiently satisfy the requirements for each scenario through a frequency band constituting an arbitrary NR system. . To this end, a technique for efficiently multiplexing a plurality of different numerology-based radio resources has been proposed.

값이 2의 지수 값으로 사용되어 지수적으로 변경된다.Specifically, the NR transmission numerology is determined based on sub-carrier spacing (CP) and cyclic prefix (CP), and is based on 15khz as shown in Table 1 below.

The value is used as an exponent value of 2 and is changed exponentially.

Subcarrier spacing Cyclic prefix Supported for data Supported for synch 0 15 Normal Yes Yes One 30 Normal Yes Yes 2 60 Normal, Extended Yes No 3 120 Normal Yes Yes 4 240 Normal No Yes

As shown in Table 1 above, the NR numerology can be divided into 5 types according to the subcarrier spacing. This is different from that in which the subcarrier spacing of LTE, which is one of 4G communication technologies, is fixed at 15khz. Specifically, the subcarrier interval used for data transmission in NR is 15, 30, 60, and 120 khz, and the subcarrier interval used for synchronization signal transmission is 15, 30, 12, and 240 khz. In addition, the extended CP applies only to the 60khz subcarrier spacing. On the other hand, the frame structure (frame structure) in the NR is defined as a frame having a length of 10ms composed of 10 subframes (subframe) having the same length of 1ms. One frame can be divided into 5 ms half frames, and each half frame includes 5 subframes. In the case of a 15khz subcarrier interval, one subframe is composed of one slot, and each slot is composed of 14 OFDM symbols.

2 is a diagram for explaining a frame structure in an NR system to which the present embodiment can be applied.

Referring to FIG. 2, the slot is fixedly composed of 14 OFDM symbols in the case of a normal CP, but the length of the slot may vary depending on the subcarrier interval. For example, in the case of a numerology having a 15 khz subcarrier spacing, the slot is 1 ms long and is configured to have the same length as the subframe. On the contrary, in the case of a neuromerlage having a 30 khz subcarrier spacing, a slot is composed of 14 OFDM symbols, but two slots may be included in one subframe with a length of 0.5 ms. That is, the subframe and the frame are defined with a fixed time length, and the slot is defined by the number of symbols, so that the time length may vary according to the subcarrier interval.

Meanwhile, the NR defines a basic unit of scheduling as a slot, and also introduces a mini-slot (or sub-slot or non-slot based schedule) to reduce transmission delay in a radio section. If a wide subcarrier interval is used, the length of one slot is inversely shortened, and thus transmission delay in a wireless section can be reduced. The mini-slot (or sub-slot) is for efficient support for the URLLC scenario and can be scheduled in units of 2, 4, and 7 symbols.

Also, unlike LTE, uplink and downlink resource allocation is defined as a symbol level within one slot. In order to reduce HARQ delay, a slot structure capable of directly transmitting HARQ ACK / NACK in a transmission slot has been defined, and this slot structure is referred to as a self-contained structure.

NR is designed to support a total of 256 slot formats, of which 62 slot formats are used in Rel-15. In addition, a common frame structure constituting an FDD or TDD frame is supported through a combination of various slots. For example, a slot structure in which all symbols of a slot are set to downlink, a slot structure in which all symbols are set to uplink, and a slot structure in which downlink symbols and uplink symbols are combined are supported. In addition, NR supports that data transmissions are scheduled to be distributed in one or more slots. Accordingly, the base station can inform the terminal whether the slot is a downlink slot, an uplink slot, or a flexible slot using a slot format indicator (SFI). The base station may indicate the slot format by indicating the index of a table configured through RRC signaling using SFI, and dynamically indicate through DCI (Downlink Control Information) or statically or quasi-statically through RRC. It might be.

<NR Physical Resources>

With regard to physical resources in NR, antenna ports, resource grids, resource elements, resource blocks, and bandwidth parts are considered. Can be.

The antenna port is defined such that a channel carrying a symbol on the antenna port can be inferred from a channel carrying another symbol on the same antenna port. If the large-scale property of a channel carrying a symbol on one antenna port can be inferred from a channel carrying a symbol on another antenna port, the two antenna ports are QC / QCL (quasi co-located or quasi co-location). Here, a wide range of characteristics include one or more of delay spread, doppler spread, frequency shift, average received power, and received timing.

3 is a diagram for describing a resource grid supported by a radio access technology to which the present embodiment can be applied.

Referring to FIG. 3, a resource grid may exist according to each neuromerging because the NR supports a plurality of neuromerging on the same carrier. In addition, the resource grid may exist according to the antenna port, subcarrier spacing, and transmission direction.

A resource block is composed of 12 subcarriers and is defined only on the frequency domain. In addition, the resource element (resource element) is composed of one OFDM symbol and one subcarrier. Therefore, as shown in FIG. 3, the size of one resource block may vary according to the subcarrier interval. In addition, in NR, "Point A" serving as a common reference point for the resource block grid, a common resource block, and a virtual resource block are defined.

4 is a diagram for describing a bandwidth part supported by a radio access technology to which the present embodiment can be applied.

Unlike LTE, where the carrier bandwidth is fixed at 20Mhz in NR, the maximum carrier bandwidth is set from 50Mhz to 400Mhz for each subcarrier interval. Therefore, it is not assumed that all terminals use all of these carrier bandwidths. Accordingly, in NR, as shown in FIG. 4, a terminal can be used by designating a bandwidth part within a carrier bandwidth. In addition, the bandwidth part is associated with one neurology and is composed of a subset of consecutive common resource blocks, and can be dynamically activated with time. A maximum of 4 bandwidth parts are configured in the uplink and downlink, respectively, and data is transmitted and received using the bandwidth part activated at a given time.

In the case of a paired spectrum, the uplink and downlink bandwidth parts are independently set, and in the case of an unpaired spectrum, unnecessary frequency re-tunning is prevented between downlink and uplink operation. In order to achieve this, the bandwidth part of the downlink and uplink is set in pairs so that the center frequency can be shared.

<NR initial connection>

In NR, a terminal accesses a base station and performs a cell search and random access procedure to perform communication.

Cell search is a procedure in which a terminal synchronizes with a cell of a corresponding base station, acquires a physical layer cell ID, and acquires system information using a synchronization signal block (SSB) transmitted by the base station.

5 exemplarily shows a synchronization signal block in a radio access technology to which the present embodiment can be applied.

Referring to FIG. 5, the SSB is composed of a primary synchronization signal (PSS) and a secondary synchronization signal (SSS) and three OFDM symbols occupying one symbol and 127 subcarriers, respectively, and a PBCH spanning 240 subcarriers.

The UE receives the SSB by monitoring the SSB in the time and frequency domain.

SSB can be transmitted up to 64 times in 5 ms. Multiple SSBs are transmitted in different transmission beams within a 5 ms time period, and the UE performs detection by assuming that SSBs are transmitted every 20 ms periods based on a specific one beam used for transmission. The number of beams that can be used for SSB transmission within 5 ms time may increase as the frequency band increases. For example, up to 4 SSB beams can be transmitted at 3 GHz or less, and up to 8 SSBs can be transmitted using up to 8 different beams in the frequency band from 3 to 6 GHz and up to 64 in the frequency band above 6 GHz.

Two SSBs are included in one slot, and the starting symbol and the number of repetitions in the slot are determined according to the subcarrier interval.

On the other hand, SSB is not transmitted at the center frequency of the carrier bandwidth, unlike the SS of the conventional LTE. That is, the SSB may be transmitted out of the center of the system band, and when supporting broadband operation, a plurality of SSBs may be transmitted on the frequency domain. Accordingly, the terminal monitors the SSB using a synchronization raster, which is a candidate frequency location for monitoring the SSB. The carrier raster and the synchronization raster, which are the center frequency location information of the channel for initial access, are newly defined in the NR, and the synchronization raster has a wider frequency interval than the carrier raster, and thus supports fast SSB search of the UE. Can be.

The terminal may acquire MIB through the PBCH of the SSB. The MIB (Master Information Block) includes minimum information for the terminal to receive the remaining system information (RMSI, Remaining Minimum System Information) broadcast by the network. In addition, PBCH is information on the location of the first DM-RS symbol on the time domain, information for the UE to monitor SIB1 (for example, SIB1 neuromerging information, information related to SIB1 CORESET, search space information, PDCCH Related parameter information, etc.), offset information between the common resource block and the SSB (the position of the absolute SSB in the carrier is transmitted through SIB1), and the like. Here, the SIB1 pneumatic information is equally applied to messages 2 and 4 of the random access procedure for accessing the base station after the terminal completes the cell search procedure.

The aforementioned RMSI means System Information Block 1 (SIB1), and SIB1 is broadcast periodically (ex, 160 ms) in a cell. SIB1 includes information necessary for the UE to perform the initial random access procedure, and is periodically transmitted through the PDSCH. In order to receive SIB1, the UE must receive pneumatic information used for SIB1 transmission and control resource set (CORESET) information used for scheduling of SIB1 through the PBCH. The UE checks scheduling information for SIB1 using SI-RNTI in CORESET, and acquires SIB1 on the PDSCH according to the scheduling information. SIBs other than SIB1 may be periodically transmitted or may be transmitted according to a terminal request.

6 is a diagram for explaining a random access procedure in a radio access technology to which the present embodiment can be applied.

Referring to FIG. 6, when cell search is completed, the UE transmits a random access preamble for random access to the base station. The random access preamble is transmitted through PRACH. Specifically, the random access preamble is transmitted to the base station through PRACH composed of continuous radio resources in a specific slot that is periodically repeated. In general, a contention-based random access procedure is performed when the UE initially accesses a cell, and a non-competition-based random access procedure is performed when random access is performed for beam failure recovery (BFR).

The terminal receives a random access response to the transmitted random access preamble. The random access response may include a random access preamble identifier (ID), UL grant (uplink radio resource), temporary C-RNTI (Temporary Cell-Radio Network Temporary Identifier) and TAC (Time Alignment Command). Since one random access response may include random access response information for one or more terminals, a random access preamble identifier may be included to inform which terminal the included UL Grant, temporary C-RNTI, and TAC are valid. The random access preamble identifier may be an identifier for the random access preamble received by the base station. The TAC may be included as information for the UE to adjust uplink synchronization. The random access response may be indicated by a random access identifier on the PDCCH, that is, a Random Access-Radio Network Temporary Identifier (RA-RNTI).

Upon receiving a valid random access response, the terminal processes the information included in the random access response, and performs scheduled transmission to the base station. For example, the UE applies TAC and stores a temporary C-RNTI. In addition, by using UL Grant, data stored in the buffer of the terminal or newly generated data is transmitted to the base station. In this case, information capable of identifying the terminal should be included.

Finally, the terminal receives a downlink message for contention resolution.

<NR CORESET>

The downlink control channel in the NR is transmitted in a control resource set (CORESET) having a length of 1 to 3 symbols, and transmits up / down scheduling information, slot format index (SFI), and transmit power control (TPC) information. .

Thus, in order to secure the flexibility of the system, NR introduced the concept of CORESET. CORESET (Control Resource Set) means a time-frequency resource for a downlink control signal. The UE may decode the control channel candidate using one or more search spaces in the CORESET time-frequency resource. QCL (Quasi CoLocation) assumptions for each CORESET were established, and this is used to inform the characteristics of the analog beam direction in addition to delay spread, Doppler spread, Doppler shift, and average delay, which are characteristics assumed by the conventional QCL.

7 is a view for explaining CORESET.

Referring to FIG. 7, CORESET may exist in various forms within a carrier bandwidth within one slot, and CORESET may consist of up to 3 OFDM symbols in a time domain. In addition, CORESET is defined as a multiple of 6 resource blocks from the frequency domain to the carrier bandwidth.

The first CORESET is indicated through the MIB as part of the initial bandwidth part configuration to receive additional configuration information and system information from the network. After establishing a connection with the base station, the terminal may receive and configure one or more CORESET information through RRC signaling.

In this specification, frequency, frame, subframe, resource, resource block, region, band, subband, control channel, data channel, synchronization signal, various reference signals, various signals, various messages related to NR (New Radio) Can be interpreted as meaning used in the past or present or various meanings used in the future.

In the conventional 3GPP LTE, a sidelink transmission / reception method for supporting V2X communication, which is a concept of fusion of D2D between terminals and V2V, which is an inter-vehicle communication and V2I, which is a vehicle-to-base station communication, is additional feature It is standardized as. In more distinction, D2D is a service scenario that assumes communication between existing terminals in a mutually equal relationship, and V2V is an extended terminal-to-terminal communication service scenario that assumes a wireless communication environment between general pedestrians and vehicle terminals with different characteristics. In order to successfully utilize radio resources with or without the assistance of a base station, various technologies have been standardized in initial access and resource allocation.

Meanwhile, in NR, studies are underway for standardizing V2X related to sidelink support and changed service requirements, and the following four new service scenarios are assumed.

· Vehicles Platooning enables the vehicles to dynamically form a platoon traveling together. All the vehicles in the platoon obtain information from the leading vehicle to manage this platoon. These information allow the vehicles to drive closer than normal in a coordinated manner, going to the same direction and traveling together.

Extended Sensors enables the exchange of raw or processed data gathered through local sensors or live video images among vehicles, road site units, devices of pedestrian and V2X application servers. The vehicles can increase the perception of their environemnt beyond of what their own sensors can detect and have a more broad and holistic view of the local situation. High data rate is one of the key characteristics.

Advanced Driving enables semi-automated or full-automated driving. Each vehicle and / or RSU shares its own perception data obtained from its local sensors with vehicles in proximity and that allows vehicles to synchronize and coordinate their trajectories or manoeuvres. Each vehicle shares its driving intention with vehicles in proximity too.

· Remote Driving enables a remote driver or a V2X application to operate a remote vehicle for those passengers who cannot drive by themselves or remote vehicles located in dangerous environments. For a case where variation is limited and routes are predictable, such as public transportation, driving based on cloud computing can be used. High reliability and low latency are the main requirements.

On the other hand, NR V2X has been tentatively agreed to support the transmission method of Mode 1 where the base station manages communication resources between terminals and Mode 2 that manages communication resources through communication between terminals. Branch transmission types were agreed at RAN1 # 94 meeting, and each is expressed as Mode 2- (a) to Mode 2- (d) or Mode 2a to Mode 2d.

a) UE autonomously selects sidelink resource for transmission

b) UE assists sidelink resource selection for other UE (s)

c) UE is configured with NR configured grant (type-1 like) for sidelink transmission

d) UE schedules sidelink transmissions of other UEs

Particularly, 2a, in which the UE selects a resource by itself, and 2b, which can assist in selecting a resource of another UE by transmitting channel configuration assistant information, have been discussed as a transmission mode different from the existing LTE V2X.

Meanwhile, the existing NR introduced the concept of BWP (BandWidth Part) defined for each user in order to perform efficient broadband communication. Through this, each user can limit and use a frequency resource region to be used for transmission / reception in the entire carrier band. However, it has not been decided whether to set BWP for the sidelink channel.

In the existing LTE V2X, a radio resource area that can be transmitted by each user is defined as a resource pool (RP), and is transmitted as SIB to each user performing V2X communication. Rel. At 14, up to 16 RPs can be set, and the following information is included as part of the setting value when setting.

1. Frequency offset and band to be the RP position on the frequency

2. Time offset and period to be the RP position on the time axis

The DL / UL BWP of the UE basically narrows the RF frequency range to the range supported by the user by allowing the UE to transmit / receive signals only within the corresponding band, and reduces the number of BD executions to support user terminals with various performances while supporting the amount of data. It is a technology to enable users to reduce transmission / reception power by supporting flexible configuration. However, in a side link, especially in a Mode 2 based transmission environment in which the base station is not directly involved in setting transmission / reception resources, as described above, the transmitting user randomly selects a specific area among the resource pools provided by the cell and transmits the result. Since the user can arbitrarily adjust the transmission band according to his / her situation at the time, the BWP for transmission has no meaning, and upon reception, virtually all users can receive it for reception. There is a problem of using the entire band. In order to solve the issue, the need to introduce BWP has been discussed, but there are issues such as complexity of configuration and reconfiguration, and a method of improving the configuration form of an existing resource pool is also discussed.

In the present invention, in the NR-V2X sidelink system, an additional configuration method related to a resource pool is provided for a user to manage a transmission band and set resources suitable for their transmission situation. In particular, it provides a setting method for limiting the transmission / reception bands by limiting the transmission / reception resource pools that can be used by individual users so that sidelink communication can be performed only in a part of the set resource pools.

The present invention provides (1) a base station-based resource pool limit setting method , (2) a user-based resource pool limit setting method , (3) a resource pool setting value delivery method , and (4) a resource pool setting change request method . . Before describing the operation of the invention, some terms used in the present invention are defined. The terms used to describe the present invention may be used later, other terms having the same meaning may be used, to explain the role of the actual object and not to limit the scope of the technology.

● Tx RP: RP that the UE performs transmission.

● Rx RP: RP that the UE performs reception.

● RP pair: A pair of Tx RP and Rx RP that can transmit and receive each other. Pointing to the same RP from a cell perspective, more than one user involved.

Here, the above two RPs are not necessarily set differently from one user's point of view, and in this case, terms used technically may not be defined differently from each other.

(1) Base station-based resource pool limit setting method : This method is a method in which a base station instructs a user in advance of a set of RPs for a user to perform sidelink transmission and reception in a environment in which a resource pool is set for a user. This designates a set of RPs that can be used for actual transmission or reception in a situation where the user knows the entire RP information, and is generally interpreted as a subset of the entire RP set. Here, the entire RP means the entire RP delivered to the user, and does not mean all the RPs actually generated by the base station, and the base station may transmit only some of the RPs managed by the base station during initial setup. Specifically, the following methods may be applied.

① Limit setting method through RRC message: This method is a method of designating Tx / Rx RP that a user can use for transmission / reception among all Tx / Rx RP preset in the form of RRC. As a specific indication method, IDs or index values of RPs to be used for actual transmission may be delivered to a list, or when the total number of resource pools is N, an RP to be activated or limited in the form of a bitmap of length N may be indicated. .

This instruction can be defined separately at the time of initial setup and at the time of reconfiguration. When setting the RP one by one in the form of ID designation at the time of resetting, a message that means adding to the existing list and deleting from the existing list can be defined. . In particular, a method of redefining the RP of the corresponding index may be applied by assigning an index to the RP to be activated, and when a subsequent change is necessary.

② How to designate the use of RP: When the user sets the RP to perform the actual transmission through method ①, the use of the RP can be set at the same time or after the setting is performed. For example, the RP obtained for use can be set / indicated for use among actual unicast / groupcast / broadcast. In particular, in the case of unicast / groupcast, the source ID or destination ID may be additionally set / directed. It might be. It is also possible to change the RP already set for use to another use through the corresponding instruction. Indicating the purpose and ID of a specific RP may be performed before the setting of the method ① is applied after the initial setting of the RP is completed.

Below are specific examples.

1. Initially, five Tx RPs of TRP1, TRP2, TRP3, TRP4, and TRP5 are set for the UE, and five Rx RPs of RRP1, RRP2, RRP3, RRP4, and RRP5 are set. (Existing technology)

2. The base station instructs the UE to use only TRP1, TRP3, RRP2, and RRP4 for actual sidelink transmission / reception. Thereafter, the UE cannot transmit by selecting TRP2, 4, or 5. (Method (1) -①)

3. The base station instructs TRP1 to use UE2 for unicast transmission and RRP4 to UE3,4,5 group for groupcast reception. At this time, TRP1 uses UE2 as a destination ID, RRP4 uses UE 3,4, 5 Indicate the group ID of the group. (Method (1) -②)

4. The base station instructs the increased traffic to use a relatively wide TRP4 instead of a narrow TRP3 as a Tx RP to be actually used. At this time, the RP corresponding to the Tx RP index 2 set as the existing TRP3 is indicated as a method of setting the TRP4. (Method (1) -①)

5. The base station instructs RRP4 to be used for changing the broadcast reception purpose. (Method (1) -②)

(2) User-based resource pool limit setting method : This method is a method in which a user defines a set of RPs for himself / herself to transmit and receive in an environment where resource pool-related settings are made to the user. Like methods (1) -②, the use of RP can also be set. Basically, it is similar to base station based setup, but the following methods can be additionally applied in detail to perform user based setup.

① How the base station limits the number of RPs that a user can use for transmission in advance: The more RPs the user can actually transmit among the set RPs, the more advantageous it is in securing channel availability. However, the reception complexity of other users in the cell increases accordingly. Accordingly, when the UE directly configures whether to use each RP, the base station can set the UE to not use too many RPs in advance by limiting the number of resource pools that each UE can set. This may be set to set an absolute value, that is, a certain number of RPs as an active RP, or may be limited to a maximum / minimum value. In addition, this restriction may be valid only for Tx RP, may be valid only for Rx RP, may be valid for both, or may be separately set for each Tx RP / Rx RP.

② Method of transmitting the set value to the base station: Even if the UE sets it by itself, the base station needs to know the set value in order to transmit information to other users or perform optimized resource setting, etc. You may need a way to pass on. Specifically, a corresponding setting value may be transmitted to a base station through a UE RRC message through a Ux channel, or a base station may receive a setting value broadcasting to another user.

The following is a specific embodiment when performing UE-based configuration in the same situation as in method (1).

1. Initially, five Tx RPs of TRP1, TRP2, TRP3, TRP4, and TRP5 are set for the UE, and five Rx RPs of RRP1, RRP2, RRP3, RRP4, and RRP5 are set. (Existing technology)

2. The base station sets the maximum value of Tx RP to be used for actual transmission to 2 and the minimum value of Rx RP to 2 to instruct the UE. (Method (2) -①)

3. The UE sets only TRP1, TRP3, RRP2, and RRP4 to be used for actual sidelink transmission / reception and transmits it to the base station as RRC. Thereafter, the UE does not transmit by selecting TRP2, 4 or 5. (Method (2)-②))

4.The UE sets TRP1 to be used for unicast transmission to UE2 and RRP4 to be used for groupcast reception to groups UE3,4,5, where UE2 is the destination ID for TRP1 and UE 3,4 for RRP4. Set group ID of 5 groups and transmit related information to the base station through RRC. (Method (2)-②))

5. The UE judges itself according to its traffic volume and sets TRP4 as the Tx RP to be actually used instead of TRP3, and transmits it to the base station through RRC. (Method (2)-②))

6. The UE changes RRP4 to use for broadcast reception and sets it to use, and transmits it to the base station through RRC. (Method (2)-②))

(3) Delivery method of resource pool setting value : This method is a method of delivering the set or set RP limit value to another user to another user. This may be transmitted through an RRC message directly by a base station that has actually performed configuration or received a configuration value from the UE, or may be transmitted through a higher layer message broadcast by the corresponding UE. In particular, it may be transmitted in the form of auxiliary information for setting transmission resources of other users that can be used in Mode 2b. The transmission may be transmitted whenever the setting is changed, or may be transmitted at regular intervals, or both. Specifically, the following methods may be applied.

① Delivery in broadcast form: When delivered in the corresponding manner, the delivery value may include specific information about the setting information. For example, the index of the set RPs, the destination ID in the case of Tx RP, and the source ID in the case of Rx RP may be set, and additionally, information related to priority and frequency of use may be included in the form of auxiliary information.

② Delivered in the form specified to the target UE: When a certain RP is activated and the Destination ID / source ID is set, the information may be delivered only to the UE that needs to receive the information. For example, when RP1 is set as a RP for unicast transmission to UE1, and RP2 is set for broadcast transmission of UE1, and a total of two active RPs are set, UE2 is called RP1 and RP2 as UE1's transmission RP. It can be delivered, and only RP2 can be transmitted to other UEs as the transmission RP of UE1. Alternatively, RP1 can be used but delivered to an RP that does not need to be attempted. This may be in the form of specifying the destination ID of RP1, or in the form of distinguishing only the RP used for transmission that it should receive from the RP that is not received in the form of a boolean value.

(4) Resource pool setting change request method : This method activates the RP when some of the two or more UEs that need to communicate with each other do not set the RP suitable for communication as their Tx / Rx RP. This is how to change the resource pool settings so that you can do it. In other words, if none of the values set by two users that need to perform communication is set as Tx RP on one side and Rx RP on the other side, that is, the Tx / Rx RP pair that matches each other Since it is impossible to communicate between two users when it does not exist, at least one user must change the setting value, and a method of determining which user will change his setting value for mutual communication is included.

① How to determine the user to change the setting value: When each user judges individually and resets the RP to be activated by himself, the situation where the RP matched by one side can be inconsistent again can be repeated. To solve this problem, two users Among them, priority should be given to deciding which users should be changed first. This may be divided into a method of sequentially setting priorities between UEs and a method of setting according to the situation. First, based on the UE ID or the group ID and RNTI involved, it may be determined in a prior order, or may be determined in a different parameter order given in advance for each user. This parameter may be newly defined for the corresponding order, or a newly defined parameter for another purpose, for example, a value given in the order of participation in the network may be used.

As a method according to the situation, the Tx RP can be changed first, or, conversely, the Rx RP can be changed first, and a user with a large number of set RPs can change it first, or a user with a small number can change it first. Since there may be more than one user having the same parameter for various reasons, the above-described parameters may be applied in combination. For example, users having the same number of RPs set to each other may have priority determined in the order of ID.

Actually, one side may have data to send or receive, but the other side may not yet confirm the existence of the user, or they may not know the necessity of link establishment because they do not have data to send or receive. The above method can be applied when more than one continuous mismatch occurs.

In addition, if you want to configure more Tx / Rx RP pairs, a method of directly sending an RRC message to a target user through an already activated pair may also be applied.

② How to request a change in the setting value: In an environment in which the base station determines whether to activate the RP or not, the UE may send a request for changing the setting value to the base station so that the UE can perform mutual communication. This request message may be sent in the form of an ID or an index of an RP that wants to be activated, or an ID of a target UE that wants to communicate. Here, in order to prevent a case where both UEs request a change, and as a result, reset RPs become inconsistent again, a priority determination method between UEs provided in methods (4) -① may be applied. Alternatively, when both requests are changed, the base station may make a decision at random. For example, if a method of requesting an RP to be used is applied, one UE maintains the requested RP first when resetting the active RP of the other UE. can do.

③ Unicast / Groupcast setting method: The above methods are useful for setting broadcast RP, but the following procedure can be introduced when configuring the unicast or groupcast link for the first time in the environment where the UE sets RP by itself. . First, the UE that wants to transmit arbitrarily sets the Tx RP including the Destination ID, and then transmits the corresponding configuration information through the method (3) as its own RP configuration information. Upon receiving the corresponding configuration information, the receiving UE sets the corresponding RP to Rx RP for unicast reception, sets the Source ID to the corresponding UE, and then transmits its configuration information through the method (3). If the corresponding Rx RP of the receiving UE is not set even after a certain period of time due to a reception error or collision due to multiple requests, the RP may be changed and retried.

Under the assumption that there is a broadcast RP pair between transmitting and receiving UEs, the sender can directly request an Rx RP to be used for unicast / groupcast reception among Rx RPs set by the receiving UE, and the receiving UE similarly responds to this. You can send it by broadcast.

The methods (1), (2), and (3) provided in the present invention and each sub-method may be applied independently of each other in combination. In addition, the method described in the present invention has been described based on the use of CommResourePool for performing data transmission, but the idea of the present invention can be applied to DiscResourcePool for performing transmission for other purposes, for example, for performing discovery transmission.

Through the method provided by the present invention, a resource pool setting capable of efficiently performing transmission band management for each user in a V2X sidelink communication environment can be performed, thereby reducing power consumption of each UE and efficiently using band resources. I can manage it.

8 is a diagram showing the configuration of a base station 1000 according to another embodiment.

Referring to FIG. 8, the base station 1000 according to another embodiment includes a control unit 1010, a transmission unit 1020, and a reception unit 1030.

The control unit 1010 controls the overall operation of the base station 1000 according to a method of setting a sidelink transmission resource in a next-generation wireless network required to perform the present invention.

The transmitting unit 1020 and the receiving unit 1030 are used to transmit and receive signals, messages, and data necessary to perform the present invention described above.

9 is a view showing the configuration of a user terminal 1100 according to another embodiment.

Referring to FIG. 9, the user terminal 1100 according to another embodiment includes a reception unit 1110, a control unit 1120, and a transmission unit 1130.

The reception unit 1110 receives downlink control information, data, and messages from a base station through a corresponding channel.

In addition, the control unit 1120 controls the overall operation of the user terminal 1100 according to a method of setting a sidelink transmission resource in a next-generation wireless network required to perform the present invention.

The transmitter 1130 transmits uplink control information, data, and a message to the base station through a corresponding channel.

The above-described embodiments can be supported by standard documents disclosed in at least one of the wireless access systems IEEE 802, 3GPP and 3GPP2. That is, steps, components, and parts that are not described in order to clearly reveal the technical idea among the embodiments may be supported by the above-described standard documents. In addition, all terms disclosed in this specification may be described by standard documents disclosed above.

The above-described embodiments may be implemented through various means. For example, the embodiments can be implemented by hardware, firmware, software, or a combination thereof.

For implementation by hardware, the method according to the embodiments includes one or more Application Specific Integrated Circuits (ASICs), Digital Signal Processors (DSPs), Digital Signal Processing Devices (DSPDs), Programmable Logic Devices (PLDs), FPGAs (Field Programmable Gate Arrays), processors, controllers, microcontrollers, microprocessors, and the like.

In the case of implementation by firmware or software, the method according to the embodiments may be implemented in the form of an apparatus, procedure, or function that performs the functions or operations described above. The software code can be stored in a memory unit and driven by a processor. The memory unit is located inside or outside the processor, and can exchange data with the processor by various known means.

In addition, the terms "system", "processor", "controller", "component", "module", "interface", "model" and "unit" described above generally refer to computer-related entity hardware, hardware and software. It can mean a combination, software or running software. For example, the above-described components may be, but are not limited to, a processor driven process, a processor, a controller, a control processor, an object, an execution thread, a program, and / or a computer. For example, both an application running on a controller or processor and a controller or processor can be a component. One or more components can be in a process and / or thread of execution, and the components can be located on one system or deployed to more than one system.

The above description and the accompanying drawings are merely illustrative of the technical idea of the present invention, and those of ordinary skill in the art may combine, separate, and replace configurations without departing from the essential characteristics of the present technology. Various modifications and variations such as changes will be possible. Therefore, the embodiments disclosed in the present specification are not intended to limit the technical spirit, but to explain, and the scope of the technical spirit is not limited by these embodiments. The scope of protection of the technical spirit should be interpreted by the claims, and all technical spirits within the scope equivalent thereto should be interpreted as being included in the scope of the present specification.

Claims (1)

In the method of setting the sidelink transmission resources in the next generation wireless network,
A method in which a base station indicates a set of RPs to perform sidelink transmission and reception to a terminal

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