KR20200017737A - Apparatus and method for transmitting and receiving a sidelink synchronization signal in a new radio - Google Patents

Abstract

Proposed is a method for transmitting and receiving a sidelink, that is an NR sidelink, wherein the sidelink is a wireless link between terminals for providing a V2X service in a next generation / 5G radio access network (NR). Especially, proposed is a method for transmitting and receiving an NR sidelink transmission and reception signal.

Description

Method and apparatus for transmitting and receiving sidelink synchronization signal in next generation wireless network {APPARATUS AND METHOD FOR TRANSMITTING AND RECEIVING A SIDELINK SYNCHRONIZATION SIGNAL IN A NEW RADIO}

Embodiments of the present invention relate to a signal transmission / reception method for providing a V2X service in a next generation / 5G wireless access network (hereinafter referred to as “NR [New Radio]”).

In one aspect, embodiments of the present invention, in a method for transmitting and receiving a radio link between terminals in a next generation wireless access network, transmitting a synchronization signal for side link synchronization at the sidelink synchronization source node, sidelink synchronization A terminal belonging to coverage of a source node provides a method comprising setting an initial sidelink bandwidth part for receiving a transmitted synchronization signal.

1 illustrates an example of symbol level alignment among different SCSs.
2 is a diagram illustrating a conceptual example of a bandwidth part.
3 is a diagram illustrating a configuration of a base station according to another embodiment.
4 is a diagram illustrating a configuration of a user terminal according to another embodiment.

Hereinafter, some embodiments of the present invention will be described in detail through exemplary drawings. In adding reference numerals to the components of each drawing, it should be noted that the same reference numerals are used to refer to the same components as much as possible, even if displayed on different drawings. In addition, in describing the present invention, if it is determined that the detailed description of the related well-known configuration or function may obscure the gist of the present invention, the detailed description thereof will be omitted.

In the present specification, the wireless communication system refers to a system for providing various communication services such as voice and packet data. The wireless communication system includes a user equipment (UE) and a base station (BS).

A user terminal is a comprehensive concept of a terminal in a wireless communication, and includes a user equipment (UE) in WCDMA, LTE, HSPA, and IMT-2020 (5G or New Radio), as well as a mobile station (MS) and a UT in GSM. It should be interpreted as a concept that includes a user terminal, a subscriber station (SS), and a wireless device.

A base station or cell generally refers to a station for communicating with a user terminal, and includes a Node-B, an evolved Node-B, an eNB, a gNode-B, and a Low Power Node. ), Sector, site, various types of antenna, base transceiver system (BTS), access point, access point (for example, transmission point, reception point, transmission / reception point), relay node ( It is meant to encompass various coverage areas such as relay nodes, mega cells, macro cells, micro cells, pico cells, femto cells, remote radio heads (RRHs), radio units (RUs), and small cells.

Since the various cells listed above have a base station for controlling each cell, the base station may be interpreted in two meanings. 1) the device providing the mega cell, the macro cell, the micro cell, the pico cell, the femto cell, the small cell in relation to the radio area, or 2) the radio area itself. In 1) all devices that provide a given wireless area are controlled by the same entity or interact with each other to cooperatively configure the wireless area to the base station. According to the configuration of the wireless area, a point, a transmission point, a transmission point, a reception point, and the like become one embodiment of a base station. In 2), the base station may indicate the radio area itself that receives or transmits a signal from a viewpoint of a user terminal or a neighboring base station.

In the present specification, a cell refers to a component carrier having coverage of a signal transmitted from a transmission / reception point or a signal transmitted from a transmission point or a transmission / reception point, and the transmission / reception point itself. Can be.

In the present specification, the user terminal and the base station are used in a comprehensive sense as two entities (uplink or downlink) transmitting and receiving subjects used to implement the technology or technical idea described in the present invention, and are not limited by the terms or words specifically referred to. Do not.

Here, the uplink (Uplink, UL, or uplink) refers to a method for transmitting and receiving data to the base station by the user terminal, the downlink (Downlink, DL, or downlink) means to transmit and receive data to the user terminal by the base station It means the way.

The uplink transmission and the downlink transmission may use a time division duplex (TDD) scheme that is transmitted using different times, and a frequency division duplex (FDD) scheme, a TDD scheme and a FDD scheme, which are transmitted using different frequencies. Mixed mode may be used.

In addition, in a wireless communication system, uplink and downlink are configured based on one carrier or a pair of carriers to configure a standard.

The uplink and the downlink transmit control information through a control channel such as a physical downlink control channel (PDCCH), a physical uplink control channel (PUCCH), a physical downlink shared channel (PDSCH), a physical uplink shared channel (PUSCH), and the like. It is composed of the same data channel to transmit data.

Downlink (downlink) may mean a communication or communication path from the multiple transmission and reception points to the terminal, uplink (uplink) may mean a communication or communication path from the terminal to the multiple transmission and reception points. In this case, in the downlink, the transmitter may be part of multiple transmission / reception points, and the receiver may be part of the terminal. In addition, in uplink, a transmitter may be part of a terminal, and a receiver may be part of multiple transmission / reception points.

Hereinafter, a situation in which a signal is transmitted and received through a channel such as a PUCCH, a PUSCH, a PDCCH, and a PDSCH may be described in the form of 'sending and receiving a PUCCH, a PUSCH, a PDCCH, and a PDSCH.'

Meanwhile, high layer signaling described below includes RRC signaling for transmitting RRC information including an RRC parameter.

The base station performs downlink transmission to the terminals. The base station transmits downlink control information such as scheduling required for reception of a downlink data channel, which is a main physical channel for unicast transmission, and a physical downlink for transmitting scheduling grant information for transmission on an uplink data channel. The control channel can be transmitted. Hereinafter, the transmission and reception of signals through each channel will be described in the form of transmission and reception of the corresponding channel.

There is no limitation on the multiple access scheme applied in the wireless communication system. Time Division Multiple Access (TDMA), Frequency Division Multiple Access (FDMA), Code Division Multiple Access (CDMA), Orthogonal Frequency Division Multiple Access (OFDMA), Non-Orthogonal Multiple Access (NOMA), OFDM-TDMA, OFDM-FDMA, Various multiple access techniques such as OFDM-CDMA can be used. Here, the NOMA includes a sparse code multiple access (SCMA) and a low density spreading (LDS).

One embodiment of the present invention is for asynchronous radio communication evolving to LTE / LTE-Advanced, IMT-2020 via GSM, WCDMA, HSPA, and synchronous radio communication evolving to CDMA, CDMA-2000 and UMB. Can be applied.

In the present specification, a MTC terminal may mean a terminal supporting low cost (or low complexity) or a terminal supporting coverage enhancement. Alternatively, in the present specification, the MTC terminal may mean a terminal defined in a specific category for supporting low cost (or low complexity) and / or coverage enhancement.

In other words, in the present specification, the MTC terminal may mean a newly defined 3GPP Release-13 low cost (or low complexity) UE category / type for performing LTE-based MTC related operations. Alternatively, in the present specification, the MTC terminal supports an enhanced coverage compared to the existing LTE coverage, or UE category / type defined in the existing 3GPP Release-12 or lower, or newly defined Release-13 low cost (or supporting low power consumption). low complexity) can mean UE category / type. Or, it may mean a further Enhanced MTC terminal defined in Release-14.

In the present specification, a NB-IoT (NarrowBand Internet of Things) terminal refers to a terminal that supports radio access for cellular IoT. The objectives of the NB-IoT technology include improved indoor coverage, support for large scale low speed terminals, low sensitivity, low cost terminal cost, low power consumption, and optimized network architecture.

As a typical usage scenario in New Radio (NR), which is recently discussed in 3GPP, enhanced Mobile BroadBand (eMBB), Massive Machine Type Communication (MMTC), and Ultra Reliable and Low Latency Communication (URLLC) are being raised.

In this specification, frequencies, frames, subframes, resources, resource blocks, regions, bands, subbands, control channels, data channels, synchronization signals, various reference signals, various signals, and various messages related to NR (New Radio). May be interpreted as meaning used in the past or present, or various meanings used in the future.

Meanwhile, the following description will be given for the technical idea based on two nodes of the terminal and the base station, but this is only for convenience of understanding, and the same technical idea may be applied between the terminal and the terminal. For example, the base station described below has been described and described by way of example to disclose a single node for communicating with the terminal, it may be replaced with other terminals or infrastructure devices for communicating with the terminal as needed.

That is, the present technical concept may be applied to not only communication between the terminal and the base station, but also device to device, side link communication, and vehicle communication (V2X). In particular, the present invention may be applied to the terminal-to-terminal communication in the next-generation radio access technology, and the terms such as a signal and a channel of the present specification may be variously modified and applied according to the type of communication between terminals.

For example, the terms PSS and SSS may be changed and applied to a primary D2D synchronization signal (PSSS) and a secondary D2D synchronization signal (SSSS) in terminal-to-device communication, respectively. In addition, the channel for transmitting broadcast information such as the above-described PBCH is changed to PSBCH, the channel for transmitting data in sidelinks such as PUSCH and PDSCH is converted into PSSCH, and the channel for transmitting control information such as PDCCH and PUCCH is changed to PSCCH. Can be applied. On the other hand, in the terminal-to-terminal communication, a discovery signal is required, which is transmitted and received through the PSDCH. However, it is not limited to these terms.

Hereinafter, the technical concept will be described as an example of communication between the terminal and the base station, but the base station node may be replaced with another terminal as necessary, and thus the technical concept may be applied.

NR (New Radio)

The NR, which was recently implemented in 3GPP, has been designed to meet various QoS requirements required for each detailed and detailed usage scenario as well as improved data rate compared to LTE. Specifically, eMBB (enhancement Mobile BroadBand), mMTC (massive MTC) and URLLC (Ultra Reliable and Low Latency Communications) are defined as typical usage scenarios of NR, and a flexible frame compared to LTE as a method for satisfying each usage scenario requirements. Structure design is required. Since each usage scenario has different requirements for data rates, latency, reliability, coverage, etc., it is a method for efficiently satisfying requirements for each usage scenario through a frequency band constituting an arbitrary NR system. For example, it is designed to efficiently multiplex radio resource units based on subcarrier spacing, subframe, TTI, etc.).

As one method for this, a method of multiplexing and supporting scheduling units in a time domain based on TDM, FDM, or TDM / FDM through one or a plurality of NR component carriers for numerology having different subcarrier spacing values In constructing, discussions were made on how to support more than one time unit. In this regard, in NR, a subframe is defined as a kind of time domain structure, and as a reference numerology for defining the subframe duration, 14 OFDM symbols of 15 kHz sub-carrier spacing (SCS) based normal CP overhead, which is the same as LTE, are used. We decided to define a single subframe duration consisting of. Accordingly, in NR, the subframe has a time duration of 1 ms. However, unlike LTE, a subframe of NR is an absolute reference time duration, and slots and mini-slots may be defined as time units based on actual uplink / downlink data scheduling. In this case, the number of OFDM symbols and the y value of the corresponding slot are determined to have a value of y = 14 regardless of the SCS value in the case of normal CP.

Accordingly, any slot consists of 14 symbols, and depending on the transmission direction of the slot, all symbols are used for DL transmission, all symbols are used for UL transmission, or DL portion + (gap) + It can be used in the form of a UL portion.

In addition, in any numerology (or SCS), a mini-slot consisting of fewer symbols than the slot is defined, and a short time-domain scheduling interval for transmitting / receiving uplink / downlink data is set or slot aggregation based on this. A long time-domain scheduling interval for transmitting and receiving uplink / downlink data may be configured. In particular, in case of transmission / reception of latency critical data such as URLLC, it is difficult to satisfy latency requirement when scheduling is performed by slot unit based on 1ms (14 symbols) defined in numerology-based frame structure with small SCS value such as 15kHz. For this purpose, a mini-slot consisting of fewer OFDM symbols than the corresponding slot can be defined to define scheduling for latency critical data such as the corresponding URLLC.

Alternatively, as described above, by supporting multiplexing numerology having different SCS values in one NR carrier by TDM and / or FDM method, based on slot (or mini-slot) length defined for each numerology Scheduling data according to latency requirements is also being considered. For example, as shown in FIG. 1, when the SCS is 60 kHz, since the symbol length is reduced to about 1/4 compared to the SCS 15 kHz, when the slot is configured with 14 OFDM symbols, the slot length based on the 15 kHz is On the other hand, the slot length based on 60kHz is reduced to about 0.25ms.

As described above, in NR, a method of satisfying each requirement of URLLC and eMBB by defining different SCS or different TTI length is being discussed.

Wider bandwidth operations

In the case of the existing LTE system, it supports scalable bandwidth operation for any LTC CC (Component Carrier). That is, according to the frequency deployment scenario, any LTE operator may configure a bandwidth of at least 1.4 MHz and up to 20 MHz in configuring one LTE CC, and a normal LTE terminal may have a bandwidth of 20 MHz for one LTE CC. Supports transmit and receive capability.

However, in the case of NR, the design is made to support NR terminals having different transmit / receive bandwidth capabilities through one wideband NR CC. Accordingly, bandwidths segmented for arbitrary NR CCs as shown in FIG. By configuring one or more bandwidth part (s) consisting of, it is required to support flexible wider bandwidth operation through different bandwidth part configuration and activation for each terminal.

In more detail, in NR, one or more bandwidth parts may be configured through one serving cell configured from a terminal perspective, and the corresponding UE activates one DL bandwidth part and one UL bandwidth part in the corresponding serving cell and uplink / downlink data. It is defined to be used for sending and receiving. In addition, when a plurality of serving cells are configured in the corresponding UE, that is, even for a UE to which CA is applied, one DL bandwidth part and / or UL bandwidth part is activated for each serving cell to use up / down radio resources of the corresponding serving cell. It is defined to be used for link data transmission and reception.

Specifically, the initial bandwidth part for the initial access procedure of the terminal in any serving cell is defined, one or more UE-specific bandwidth part (s) is configured through dedicated RRC signaling for each terminal, and fallback for each terminal A default bandwidth part for operation can be defined.

However, depending on the capability and configuration of the bandwidth part (s) of the terminal in any serving cell can be defined to activate and use a plurality of DL and / or UL bandwidth parts at the same time, in NR rel-15 any terminal in any terminal It is defined to activate only one DL bandwidth part and UL bandwidth part at a time.

Specific BWP configuration and activation methods defined in NR shall be attached through TS 38.213 of appendix [1].

LTE sidelink

In the existing LTE system, a wireless channel and a wireless protocol design for direct link between terminals, that is, sidelink transmission and reception, have been made to provide direct communication between terminals and V2X (especially V2V) services. In this regard, PSSS / SSSS, which is a synchronization signal for synchronization between a wireless sidelink transmitter and a receiver, and a PSBCH (Physical Sidelink Broadcasting Channel) for transmitting and receiving sidelink MIB (Master Information Block) related thereto are defined, and a PSDCH for transmitting and receiving discovery information is also defined. A physical sidelink discovery channel (PSC), a sidelink control channel (PSCCH) for transmitting and receiving sidelink control information (SCI), and a physical sidelink shared channel (PSSCH) for transmitting and receiving sidelink data have been designed.

With regard to specific sidelink radio signals and radio channel transmission / reception methods defined in LTE, the contents of the TS 36.211 document of the appendix [2] and the TS 36.213 document of the appendix [3] are appended.

The present invention proposes a synchronization signal transmission / reception method for NR sidelink.

Point 1: initial sidelink BWP  Justice

Sidelink synch. Transmit PSSS / SSSS and PSBCH for sidelink synchronization from the source node and corresponding sidelink synch. UEs belonging to the coverage of the source node may define an initial sidelink BWP for receiving the transmitted PSSS / SSSS and PSBCH.

Scheme 1: Base Station Configuration

As a method of defining an initial sidelink BWP for an arbitrary terminal, the initial sidelink BWP may be configured by a base station / network and transmitted to the terminal through cell-specific or UE-specific higher layer signaling. The initial sidelink BWP configuration information may include information such as frequency resource information, time interval resource information, SCS and CP values.

In this case, at most one initial sidelink BWP configuration may be made for any UE in any serving cell.

Alternatively, up to N initial sidelink BWP configurations may be configured for any UE in any serving cell, and may be defined to transmit and receive PSSS / SSSS and PSBCH through one of the initial sidelink BWPs in a specific sidelink slot. have. In this case, the corresponding N initial sidelink BWPs may be indicated to the UE through an L1 control signaling or MAC CE signaling in which an initial sidelink BWP in which PSSS / SSSS and PSBCH transmission and reception are performed in an arbitrary sidelink slot.

Option 2: DL / UL of UE BWP  Setting-based

As a method for implicitly configuring the initial sidelink BWP, an initial sidelink BWP for an arbitrary terminal may be determined by an initial active UL BWP or an initial active DL BWP configured for the corresponding terminal. For example, initial sidelink BWP may be defined to be equal to initial active UL BWP or initial active DL BWP.

As another method of implicitly configuring the initial sidelink BWP, an initial sidelink BWP for an arbitrary terminal may be determined by a first active UL BWP or a first active DL BWP configured for the corresponding terminal. For example, initial sidelink BWP may be defined to be equal to first active UL BWP or first active DL BWP.

As another method of implicitly configuring the initial sidelink BWP, an initial sidelink BWP for an arbitrary terminal may be determined by a default DL BWP configured for the corresponding terminal. For example, the initial sidelink BWP may be defined to be the same as the default DL BWP.

As another method of implicitly configuring the initial sidelink BWP, it may be determined by an active UL BWP or an active DL BWP of an arbitrary terminal.

However, different implicit configuration methods may be applied to the implicit configuration method according to the frame structure, duplexing method (ie, TDD or FDD) of the cell to which the UE belongs, or the serving cell in which the sidelink configuration is performed is a primary cell. Different implicit configuration methods can be applied depending on whether they are secondary cells or not. In addition, different implicit configuration methods may be applied depending on whether the corresponding sidelink is configured through an uplink radio resource or a downlink radio resource.

Scheme 3: based on system bandwidth or frequency range of serving cell

The initial sidelink BWP may be determined by the bandwidth and the center frequency of the component carrier constituting the serving cell in which the sidelink configuration for any terminal is made.

Alternatively, the initial sidelink BWP may be configured by frequency range and frequency band in which sidelink is configured.

For example, the initial sidelink BWP may determine the frequency location, bandwidth, SCS, CP value, etc. of the initial sidelink BWP according to the bandwidth or the center frequency of the component carrier constituting the serving cell, the frequency range of the center frequency, and the like.

Point 2: mission critical sidelink BWP  Justice

Mission critical sidelink BWP can be defined for mission critical data transmission and reception via sidelink. The mission critical sidelink BWP may be defined as a BWP that is always activated for sidelink transmission and reception from any terminal. As a method for this, all sidelink BWPs configured for a certain UE may be defined to include a corresponding mission critical BWP. Alternatively, it can be defined to switch to the mission critical BWP at regular intervals in the time period.

As a method of configuring a mission critical BWP, the corresponding mission critical BWP may be set by a base station / network and transmitted to a terminal through cell-specific or UE-specific higher layer signaling. Or synch. It may be set by the source node and transmitted through PSBCH or PSDCH.

As another method of configuring a mission critical BWP, the mission critical BWP may be configured implicitly. For example, when an initial sidelink BWP for transmission and reception for the PSSS / SSSS and PSBCH is defined, the corresponding initial sidelink BWP may be defined as a mission critical BWP. Alternatively, the mission critical BWP may be configured by the bandwidth and the center frequency of the component carrier constituting the serving cell in which the sidelink configuration is performed, or the frequency range and frequency band in which the sidelink is configured.

In addition, if an initial sidelink BWP or mission critical BWP is defined, the initial sidelink BWP or mission critical BWP is configured through one or more of the methods described in point 1 and point 2 above or as a combination of one or more methods. All cases may be included within the scope of the present invention.

For example, a method of configuring an initial sidelink BWP for transmitting PSSS / SSSS and PSBCH in an arbitrary terminal and a method of configuring an initial sidelink BWP for receiving PSSS / SSSS and PSBCH in an arbitrary terminal may be different from each other. . Alternatively, different initial sidelink BWP configuration methods or mission critical sidelink BWP configuration methods may be applied according to sidelink transmission mode, discovery type, or coverage scenario (ie, in-coverage terminal or out-of-coverage terminal) of the terminal.

3 is a diagram illustrating a configuration of a base station 1000 according to another embodiment.

Referring to FIG. 3, the base station 1000 according to another embodiment includes a controller 1010, a transmitter 1020, and a receiver 1030.

The control unit 1010 controls the overall operation of the base station 1000 according to the transmission and reception of the synchronization signal for the side-link synchronization in order to transmit and receive the radio link between terminals in the next generation wireless access network according to the present invention described above.

The transmitter 1020 and the receiver 1030 are used to transmit and receive signals, messages, and data necessary for carrying out the present invention.

4 is a diagram illustrating a configuration of a user terminal 1100 according to another embodiment.

Referring to FIG. 4, the user terminal 1100 according to another embodiment includes a receiver 1110, a controller 1120, and a transmitter 1130.

The receiver 1110 receives downlink control information, data, and a message 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 the transmission and reception of the synchronization signal for synchronizing the sidelink in order to transmit and receive the radio link between terminals in the next generation wireless access network according to the present invention described above.

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

In addition, terms such as "system", "processor", "controller", "component", "module", "interface", "model", "unit" generally refer to computer-related entity hardware, a combination of hardware and software, It may mean software or running software. For example, the foregoing components may be, but are not limited to, a process driven by a processor, 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 components. One or more components can be within a process and / or thread of execution and a component can be located on one system or deployed on more than one system.

The standard contents or standard documents mentioned in the above embodiments are omitted to simplify the description of the specification and form a part of the present specification. Accordingly, the addition of the contents of the above standard and part of the standard documents to the specification or the description in the claims should be interpreted as falling within the scope of the present invention.

The above description is merely illustrative of the technical idea of the present invention, and those skilled in the art to which the present invention pertains may make various modifications and changes without departing from the essential characteristics of the present invention. Therefore, the embodiments disclosed in the present invention are not intended to limit the technical spirit of the present invention but to describe the present invention, and the scope of the technical idea of the present invention is not limited by these embodiments. The protection scope of the present invention should be interpreted by the following claims, and all technical ideas within the scope equivalent thereto should be construed as being included in the scope of the present invention.

Claims (1)

In the method for transmitting and receiving a radio link between terminals in a next generation wireless access network,
Transmitting a synchronization signal for synchronizing sidelink synchronization at the sidelink synchronization source node; And
And setting, by the terminal belonging to the coverage of the sidelink synchronization source node, an initial sidelink bandwidth part for receiving the transmitted synchronization signal.

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