WO2018056696A1

WO2018056696A1 - Method for transmitting/receiving data in wireless communication system and device therefor

Info

Publication number: WO2018056696A1
Application number: PCT/KR2017/010328
Authority: WO
Inventors: 신석민; 고현수; 김기준
Original assignee: 엘지전자(주)
Priority date: 2016-09-20
Filing date: 2017-09-20
Publication date: 2018-03-29

Abstract

Disclosed are a method for transmitting/receiving data in a wireless communication system and a device therefor. Specifically, the method comprises the steps of: receiving, from a base station, a synchronization signal at a first frequency region by means of a detection attempt according to a preset first frequency interval; identifying a second frequency region for receiving a downlink channel by using a specific value associated with a center frequency and a frequency offset of the first frequency region; and receiving, from the base station, the downlink channel at the identified second frequency region, wherein the specific value is a value, among at least one value configured on the basis of the difference between the first frequency interval and a second frequency interval, that is indicated by the base station, wherein the first frequency interval may be configured so as to be greater than the second frequency interval.

Description

Method for transmitting and receiving data in a wireless communication system and apparatus therefor

The present invention relates to a wireless communication system, and more particularly, to a method for transmitting and receiving data by a terminal and an apparatus supporting the same.

Mobile communication systems have been developed to provide voice services while ensuring user activity. However, the mobile communication system has expanded not only voice but also data service, and the explosive increase in traffic causes shortage of resources and users require faster services. Therefore, a more advanced mobile communication system is required. .

The requirements of the next generation of mobile communication systems will be able to accommodate the explosive data traffic, dramatically increase the data rate per user, greatly increase the number of connected devices, very low end-to-end latency, and high energy efficiency. It should be possible. Dual connectivity, Massive Multiple Input Multiple Output (MIMO), In-band Full Duplex, Non-Orthogonal Multiple Access (NOMA), Super Various technologies such as wideband support and device networking have been studied.

The present specification proposes a method in which a terminal detects a synchronization signal and transmits and receives data in a wireless communication system.

More specifically, in a wireless communication system, a terminal detects a synchronization signal in units of frequency raster and identifies a frequency band used for data transmission and reception using preset frequency offset information and information indicated by a base station. Suggest.

In addition, the present specification, based on the relationship between the frequency raster unit and the channel raster unit, even if the terminal detects the synchronization signal in frequency raster unit, a method for setting information for identifying the frequency region of the cell of the base station set in the channel raster unit Suggest.

In addition, the present specification proposes various methods for transmitting the information set as described above to the terminal by the base station.

The technical problems to be achieved in the present invention are not limited to the technical problems mentioned above, and other technical problems not mentioned above will be clearly understood by those skilled in the art from the following description. Could be.

In a method of transmitting and receiving data by a terminal in a wireless communication system according to an exemplary embodiment of the present invention, the method may attempt detection according to a preset first frequency interval, thereby detecting a first frequency region ( a downlink channel using a process of receiving a synchronization signal from a base station in a frequency region and using a specific value related to a center frequency and a frequency offset of the first frequency domain identifying a second frequency domain to receive a channel), and receiving the downlink channel from the base station in the identified second frequency domain, wherein the specific value comprises: the first frequency interval; A value indicated by the base station among one or more values set based on a difference between two frequency intervals, wherein the first frequency interval is The set to be larger than the second frequency interval.

In the method according to an embodiment of the present disclosure, the first frequency region is one of a plurality of frequency regions set in units of the first frequency interval, and the second frequency region is the second frequency interval. It may be one of a plurality of frequency domains set in units.

In the method according to an embodiment of the present invention, the second frequency domain is located in a frequency domain separated by a product of the specific value and the third frequency interval based on the first frequency domain. The third frequency interval may be set based on a bandwidth of the resource block and the second frequency interval.

In addition, in the method according to an embodiment of the present invention, the bandwidth of the resource block is set according to a subcarrier spacing applied to the synchronization signal, and the method may include setting information indicating the subcarrier spacing ( The method may further include receiving configuration information from the base station.

Further, in the method according to an embodiment of the present disclosure, the third frequency interval may be set to a least common multiple of the bandwidth of the resource block and the second frequency interval.

In addition, in the method according to an embodiment of the present disclosure, a difference value between the center frequency of the first frequency domain and the center frequency of the second frequency domain may be set as a multiple of the least common multiple.

In addition, in the method according to an embodiment of the present disclosure, when the first frequency interval is set k times larger than the second frequency interval, the number of one or more values may be set to be smaller than or equal to k. .

The method may further include receiving configuration information indicating the one or more values from the base station, wherein the specific value may be indicated through a sequence for generating the synchronization signal. have.

In addition, in the method according to an embodiment of the present invention, the specific value may be indicated through a cyclic shift index of the sequence.

In the method according to an embodiment of the present invention, the first frequency interval may be a frequency raster unit, and the second frequency interval may be a channel raster unit.

In addition, in a terminal for transmitting and receiving data in a wireless communication system according to an embodiment of the present invention, the terminal includes a transceiver for transmitting and receiving a wireless signal, and a processor functionally connected to the transceiver. Here, the processor attempts detection according to a preset first frequency interval, receives a synchronization signal from a base station in a first frequency domain, and receives a synchronization signal of the first frequency domain. Identifying a second frequency region to receive a downlink channel using specific values associated with a center frequency and a frequency offset, and from the base station in the identified second frequency region Control to receive the downlink channel, wherein the specific value is a value indicated by the base station among one or more values set based on a difference between the first frequency interval and a second frequency interval, and the first frequency interval is It is set larger than the second frequency interval.

Further, in the terminal according to an embodiment of the present invention, the first frequency region is one of a plurality of frequency regions set in units of the first frequency interval, and the second frequency region is the second frequency interval. It may be one of a plurality of frequency domains set in units.

In the terminal according to an embodiment of the present invention, the second frequency domain is located in a region separated by a product of the specific value and the third frequency interval on the basis of the first frequency domain on the frequency domain. The three frequency interval may be set based on the bandwidth of the resource block and the second frequency interval.

According to an embodiment of the present invention, in a NR (New RAT) system supporting a wide system bandwidth, the terminal is synchronized in a frequency raster unit that is set larger than the channel raster unit. Detection of the signal can be performed. Accordingly, overhead and time required for detecting the synchronization signal of the terminal can be reduced.

In addition, according to an embodiment of the present invention, even if the frequency band at which the base station transmits a synchronization signal and the frequency band in which the actual cell is formed (that is, the frequency domain used for data transmission and reception) are different, the terminal is indicated by the base station. Using the information, it is possible to efficiently perform synchronization signal detection and data transmission and reception in each band.

In addition, according to an embodiment of the present invention, since the base station can form a cell in the desired frequency region irrespective of the frequency region in which the synchronization signal of the terminal is performed, it is possible to efficiently use the system band (that is, the frequency band) It works.

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

BRIEF DESCRIPTION OF THE DRAWINGS The accompanying drawings, which are included as part of the detailed description in order to provide a thorough understanding of the present invention, provide embodiments of the present invention and together with the description, describe the technical features of the present invention.

Figure 1 shows an example of the overall system structure of the NR to which the method proposed in this specification can be applied.

2 illustrates a relationship between an uplink frame and a downlink frame in a wireless communication system to which the method proposed in the present specification may be applied.

3 illustrates an example of a resource grid supported by a wireless communication system to which the method proposed in the present specification can be applied.

4 shows examples of an antenna port and a neuralology-specific resource grid to which the method proposed in this specification can be applied.

5 shows an example of a self-contained subframe structure to which the method proposed in this specification can be applied.

FIG. 6 shows examples of synchronization signal transmission based on a relationship between a channel raster value and a frequency raster value to which the method proposed in this specification can be applied.

7 shows an operation flowchart of a terminal for transmitting and receiving data to which the method proposed in the present specification can be applied.

8 illustrates a block diagram of a wireless communication device to which the methods proposed herein may be applied.

9 is a block diagram illustrating a communication device according to one embodiment of the present invention.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. The detailed description, which will be given below with reference to the accompanying drawings, is intended to explain exemplary embodiments of the present invention and is not intended to represent the only embodiments in which the present invention may be practiced. The following detailed description includes specific details in order to provide a thorough understanding of the present invention. However, one of ordinary skill in the art appreciates that the present invention may be practiced without these specific details.

In some instances, well-known structures and devices may be omitted or shown in block diagram form centering on the core functions of the structures and devices in order to avoid obscuring the concepts of the present invention.

In this specification, a base station has a meaning as a terminal node of a network that directly communicates with a terminal. The specific operation described as performed by the base station in this document may be performed by an upper node of the base station in some cases. That is, it is obvious that various operations performed for communication with a terminal in a network composed of a plurality of network nodes including a base station may be performed by the base station or other network nodes other than the base station. The term 'base station (BS)' refers to a fixed station, a Node B, an evolved-NodeB (eNB), a base transceiver system (BTS), an access point (AP), and a general NB (gNB). Can be replaced by In addition, a 'terminal' may be fixed or mobile, and may include a user equipment (UE), a mobile station (MS), a user terminal (UT), a mobile subscriber station (MSS), a subscriber station (SS), and an AMS ( Advanced Mobile Station (WT), Wireless Terminal (WT), Machine-Type Communication (MTC) Device, Machine-to-Machine (M2M) Device, Device-to-Device (D2D) Device, etc.

Hereinafter, downlink (DL) means communication from a base station to a terminal, and uplink (UL) means communication from a terminal to a base station. In downlink, a transmitter may be part of a base station, and a receiver may be part of a terminal. In uplink, a transmitter may be part of a terminal and a receiver may be part of a base station.

Specific terms used in the following description are provided to help the understanding of the present invention, and the use of such specific terms may be changed to other forms without departing from the technical spirit of the present invention.

The following techniques are code division multiple access (CDMA), frequency division multiple access (FDMA), time division multiple access (TDMA), orthogonal frequency division multiple access (OFDMA), single carrier frequency division multiple access (SC-FDMA), and NOMA It can be used in various radio access systems such as non-orthogonal multiple access. CDMA may be implemented by a radio technology such as universal terrestrial radio access (UTRA) or CDMA2000. TDMA may be implemented with wireless technologies such as global system for mobile communications (GSM) / general packet radio service (GPRS) / enhanced data rates for GSM evolution (EDGE). OFDMA may be implemented in a wireless technology such as IEEE 802.11 (Wi-Fi), IEEE 802.16 (WiMAX), IEEE 802-20, evolved UTRA (E-UTRA). UTRA is part of a universal mobile telecommunications system (UMTS). 3rd generation partnership project (3GPP) long term evolution (LTE) is a part of evolved UMTS (E-UMTS) using E-UTRA, and employs OFDMA in downlink and SC-FDMA in uplink. LTE-A (advanced) is the evolution of 3GPP LTE.

Embodiments of the present invention may be supported by standard documents disclosed in at least one of IEEE 802, 3GPP, and 3GPP2, which are wireless access systems. That is, steps or parts which are not described to clearly reveal the technical spirit of the present invention among the embodiments of the present invention may be supported by the above documents. In addition, all terms disclosed in the present document can be described by the above standard document.

For clarity, the following description focuses on 3GPP LTE / LTE-A / NR (New RAT), but the technical features of the present invention are not limited thereto.

As the spread of smart phones and IoT (Internet of Things) terminals is rapidly spreading, the amount of information exchanged through a communication network is increasing. As a result, next-generation wireless access technologies can provide faster service to more users than traditional communication systems (or traditional radio access technologies) (e.g., enhanced mobile broadband communication). )) Needs to be considered.

To this end, a design of a communication system considering a machine type communication (MTC) that provides a service by connecting a plurality of devices and objects has been discussed. In addition, a design of a communication system (eg, Ultra-Reliable and Low Latency Communication (URLLC)) that considers a service and / or terminal sensitive to communication reliability and / or latency is also considered. Is being discussed.

In the following specification, for convenience of description, the next generation radio access technology is referred to as NR (New RAT), and the radio communication system to which the NR is applied is referred to as an NR system.

용어 정의Term Definition

eLTE eNB: An eLTE eNB is an evolution of an eNB that supports connectivity to EPC and NGC.

gNB: Node that supports NR as well as connection with NGC.

New RAN: A radio access network that supports NR or E-UTRA or interacts with NGC.

Network slice: A network slice defined by the operator to provide an optimized solution for specific market scenarios that require specific requirements with end-to-end coverage.

Network function: A network function is a logical node within a network infrastructure with well-defined external interfaces and well-defined functional behavior.

NG-C: Control plane interface used for the NG2 reference point between the new RAN and NGC.

NG-U: User plane interface used for the NG3 reference point between the new RAN and NGC.

Non-standalone NR: A deployment configuration where a gNB requires an LTE eNB as an anchor for control plane connection to EPC or an eLTE eNB as an anchor for control plane connection to NGC.

Non-Standalone E-UTRA: Deployment configuration in which the eLTE eNB requires gNB as an anchor for control plane connection to NGC.

User plane gateway: The endpoint of the NG-U interface.

시스템 일반System general

1 is a view showing an example of the overall system structure of the NR to which the method proposed in this specification can be applied.

Referring to Figure 1, the NG-RAN consists of gNBs that provide control plane (RRC) protocol termination for the NG-RA user plane (new AS sublayer / PDCP / RLC / MAC / PHY) and UE (User Equipment). do.

The gNBs are interconnected via an Xn interface.

The gNB is also connected to the NGC via an NG interface.

More specifically, the gNB is connected to an Access and Mobility Management Function (AMF) through an N2 interface and to a User Plane Function (UPF) through an N3 interface.

NR(New Rat) 뉴머롤로지(Numerology) 및 프레임(frame) 구조NR (New Rat) Numerology and Frame Structure

Multiple numerologies can be supported in an NR system. Here, the numerology may be defined by subcarrier spacing and cyclic prefix overhead. In this case, the plurality of subcarrier intervals may be represented by an integer N (or,

Can be derived by scaling. Further, even if it is assumed that very low subcarrier spacing is not used at very high carrier frequencies, the used numerology may be selected independently of the frequency band.

In addition, in the NR system, various frame structures according to a number of numerologies may be supported.

Hereinafter, an Orthogonal Frequency Division Multiplexing (OFDM) neurology and frame structure that can be considered in an NR system will be described.

Multiple OFDM numerologies supported in the NR system may be defined as shown in Table 1.

With regard to the frame structure in the NR system, the size of the various fields in the time domain

Is expressed as a multiple of the time unit. From here,

ego,

to be. Downlink and uplink transmissions

It consists of a radio frame having a section of (radio frame). Here, each radio frame is

It consists of 10 subframes having a section of. In this case, there may be a set of frames for uplink and a set of frames for downlink.

As shown in FIG. 2, the transmission of an uplink frame number i from a user equipment (UE) is greater than the start of the corresponding downlink frame at the corresponding UE.

You must start before.

Numerology

For slots, slots within a subframe

Numbered in increasing order of within a radio frame

They are numbered in increasing order of. One slot is

Consists of consecutive OFDM symbols of,

Is determined according to the numerology and slot configuration used. Slot in subframe

Start of OFDM symbol in the same subframe

Is aligned with the beginning of time.

Not all terminals can transmit and receive at the same time, which means that not all OFDM symbols of a downlink slot or an uplink slot can be used.

Table 2 shows numerology

Shows the number of OFDM symbols per slot for a normal CP in Table 3,

This indicates the number of OFDM symbols per slot for the extended CP in.

NR 물리 자원(NR Physical Resource)NR Physical Resource

In relation to physical resources in the NR system, an antenna port, a resource grid, a resource element, a resource block, a carrier part, etc. Can be considered.

Hereinafter, the physical resources that may be considered in the NR system will be described in detail.

First, with respect to the antenna port, the antenna port is defined so that the channel on which the symbol on the antenna port is carried can be inferred from the channel on which another symbol on the same antenna port is carried. If the large-scale property of a channel carrying a symbol on one antenna port can be deduced from the channel carrying the symbol on another antenna port, then the two antenna ports are quasi co-located or QC / QCL. quasi co-location relationship. Here, the wide range characteristics include one or more of delay spread, Doppler spread, frequency shift, average received power, and received timing.

3 shows an example of a resource grid supported by a wireless communication system to which the method proposed in the present specification can be applied.

Referring to Figure 3, the resource grid is in the frequency domain

By way of example, one subframe includes 14 x 2 ^u OFDM symbols, but is not limited thereto.

In an NR system, the transmitted signal is

One or more resource grids composed of subcarriers, and

Is described by the OFDM symbols of. From here,

to be. remind

Denotes the maximum transmission bandwidth, which may vary between uplink and downlink as well as numerologies.

In this case, as shown in Figure 4, the numerology

And one resource grid for each antenna port p.

Numerology

And each element of the resource grid for antenna port p is referred to as a resource element and is an index pair

Uniquely identified by From here,

Is the index on the frequency domain, Refers to the position of a symbol within a subframe. Index pair when referring to a resource element in a slot

This is used. From here,

to be.

Numerology

Resource elements for antenna and antenna port p

Is a complex value

Corresponds to If there is no risk of confusion, or if no specific antenna port or numerology is specified, the indices p and

Can be dropped, so the complex value is

or

This can be

In addition, the physical resource block (physical resource block) is in the frequency domain

It is defined as consecutive subcarriers. On the frequency domain, the physical resource blocks can be zero

Numbered until. At this time, a physical resource block number on the frequency domain

And resource elements

The relationship between is given by Equation 1.

In addition, with respect to a carrier part, the terminal may be configured to receive or transmit using only a subset of the resource grid. At this time, the set of resource blocks set to be received or transmitted by the UE is from 0 on the frequency domain.

Numbered until.

Self-contained 서브프레임 구조Self-contained subframe structure

The TDD (Time Division Duplexing) structure considered in the NR system is a structure that processes both uplink (UL) and downlink (DL) in one subframe. This is to minimize latency of data transmission in the TDD system, and the structure is referred to as a self-contained subframe structure.

5 shows an example of a self-contained subframe structure to which the method proposed in this specification can be applied. 5 is merely for convenience of description and does not limit the scope of the present invention.

Referring to FIG. 5, as in legacy LTE, it is assumed that one subframe includes 14 orthogonal frequency division multiplexing (OFDM) symbols.

In FIG. 5, an area 502 means a downlink control region, and an area 504 means an uplink control region. Also, regions other than regions 502 and 504 (that is, regions without a separate indication) may be used for transmission of downlink data or uplink data.

That is, uplink control information and downlink control information are transmitted in one self-contained subframe. On the other hand, in the case of data, uplink data or downlink data is transmitted in one self-contained subframe.

When using the structure shown in FIG. 5, within one self-contained subframe, downlink transmission and uplink transmission may proceed sequentially, and transmission of downlink data and reception of uplink ACK / NACK may be performed. .

As a result, when an error in data transmission occurs, the time required for retransmission of data can be reduced. In this way, delays associated with data delivery can be minimized.

In the self-contained subframe structure as shown in FIG. 5, a base station (eNodeB, eNB, gNB) and / or a terminal (user equipment (UE)) switches from a transmission mode to a reception mode. A time gap is required for the process or the process of switching from the reception mode to the transmission mode. In relation to the time gap, when uplink transmission is performed after downlink transmission in the self-contained subframe, some OFDM symbol (s) may be set to a guard period (GP).

아날로그 빔포밍(analog beamforming)Analog beamforming

In a millimeter wave (mmWave, mmW) communication system, as the wavelength of a signal is shortened, multiple (or multiple) antennas may be installed in the same area. For example, in the 30CHz band, the wavelength is about 1cm, and when the antennas are installed at 0.5 lambda intervals on a panel of 5cm x 5cm according to the 2-dimension arrangement, a total of 100 Antenna elements may be installed.

Accordingly, in the mmW communication system, a method of increasing coverage or increasing throughput may be considered by increasing beamforming (BF) gain using a plurality of antenna elements.

At this time, when a TXRU (Transceiver Unit) is installed to enable transmission power and phase adjustment for each antenna element, independent beamforming is possible for each frequency resource.

However, the method of installing TXRU in all antenna elements (eg, 100 antenna elements) may be ineffective in terms of price. Accordingly, a method of mapping a plurality of antenna elements to one TXRU and controlling the direction of the beam by using an analog phase shifter may be considered.

Since the analog beamforming method as described above can generate only one beam direction in all bands, a problem arises in that the frequency selective beam operation cannot be performed.

Accordingly, hybrid beamforming with B TXRUs, which is less than Q antenna elements, may be considered as an intermediate form between digital beamforming and analog beamforming. In this case, although there is a difference depending on the connection scheme of the B TXRU and Q antenna elements, the direction of the beam capable of transmitting signals at the same time may be limited to B or less.

In the present specification, a description of a synchronization signal to be used for an initial access procedure in a new system (ie, an NR system) is described.

The physical signal and / or physical channel used in the system may be a x-PSS (Primary Synchronization signal), x-SSS (with x-) added to distinguish from a legacy LTE system. It may be referred to (or defined) as Secondary Synchronization Signal (x-PBCH), Physical Broadcast Channel (x-PBCH), Physical Downlink Control Channel (xPDCCH) / Enhanced PDCCH (x-EPDCCH), Physical Downlink Shared Channel (x-PDSCH), or the like. Here, 'x' may mean 'NR'. Synchronization signal (SS) considered in the present specification refers to signals used by a terminal to perform synchronization, such as x-PSS, x-SSS, and / or x-PBCH.

In addition, in the NR system, a scheme of transmitting a synchronization signal using an analog beamforming method may be considered. In this case, the base station may transmit the synchronization signal through a beam direction set differently for each symbol at a time point of transmitting the preset synchronization signal (ie, a synchronization subframe). In this case, the terminal may acquire synchronization with respect to time-frequency based on the synchronization signal transmitted in the beam direction most suitable (or suitable) for the terminal.

In addition, the NR system supports usage scenarios (ie, services) with different service requirements. For example, the NR system supports services such as Enhanced Mobile Broadband (eMBB), Ultra-Reliable and Low Latency Communication (URLLC), and Massive Machine Type Communication (mMTC).

However, key performance indicators (KPIs) required by each of the services are different, and accordingly, subcarrier spacing, subframe length, CP length, etc. for each service are different. The numerology needs to be set differently. In addition, as described above, as one NR system supports a plurality of services configured with different numerologies, there may be a case where different numerologies are multiplexed.

In general, a terminal may be configured to detect a synchronization signal at a constant frequency interval in an initial access procedure. For example, in the existing LTE system (that is, legacy LTE system), the terminal may attempt to detect the synchronization signal by changing the frequency for each channel raster (for example, 100kHz).

However, the NR system, unlike the existing LTE system, can support (or use) a wider range of system bandwidth and support higher carrier frequencies. Therefore, the UE attempts to detect a synchronization signal for each existing channel raster (eg, 100 kHz) may be inefficient in terms of synchronization overhead.

In order to reduce this synchronization overhead, in a NR system, a method of defining a frequency raster having a larger interval than a channel raster (for example, 100 kHz) as a basic unit is considered. In this case, the terminal of the NR system may be configured to attempt to detect a synchronization signal in units of the frequency raster. That is, in the NR system, a frequency raster unit for the synchronization signal may be additionally used.

For example, when the frequency raster of the NR system is set to 1 MHz, the terminal may attempt to detect a synchronization signal at 0, 1 MHz, 2 MHz, 3 MHz, and N MHz (where N is an integer). Through this, the number of attempts to detect the synchronization signal performed by the terminal can be reduced to one tenth (that is, 1/10) than that of the conventional LTE system.

In the present specification, when a frequency raster is used in an NR system, a method of detecting a synchronization signal according to the frequency raster unit will be described with respect to an initial access procedure. Specifically, a description will be given of establishing a relationship between the frequency raster and the channel raster and a method (eg, timing of transmitting corresponding information) for transmitting information about the relationship to the terminal.

As mentioned above, in the NR system, the use of multiple neurology and detection of a synchronization signal based on the frequency raster may be considered. In this case, the terminal may detect the synchronization signal by moving the frequency domain for each frequency raster for initial access. In this case, the base station selects the neuronology of the synchronization signal may be classified into two types according to whether the terminal knows information on the neurology of the synchronization signal.

First, a method in which a base station transmits a synchronization signal may be considered in a state in which it is assumed that the terminal knows the numerology to be applied to the synchronization signal in advance. For example, the base station may be configured to transmit a synchronization signal using the same numerology for all frequency rasters. In this case, the terminal may detect a sync signal for each frequency raster (that is, attempt to detect a sync signal for each frequency raster) using a single (ie, one) neuralology.

In another example, a predetermined frequency band range is set in advance, and the base station may be configured to transmit a synchronization signal using a numerology corresponding to the frequency band according to a specific rule. That is, it is assumed that different numerologies are set for each frequency band. In this case, the terminal selects an initial frequency raster and detects a synchronization signal using a numerology corresponding to the frequency band.

In the case of the first method described above, since the UE knows (in advance) the numerology of the corresponding synchronization signal, the acquisition time for the synchronization signal can be reduced.

On the contrary, secondly, the UE does not know the neuralology to be applied to the synchronization signal in advance, and a method of detecting the synchronization signal through blind decoding on possible numerology candidates may also be considered. have. Here, a possible neuronal candidate means a neuronal candidate that can be applied to a synchronization signal. In this case, the UE needs to perform blind decoding on possible neuronal candidates for every frequency raster. For example, if the subcarrier spacing can be set to 15 kHz and 60 kHz, the terminal performs blind decoding for the first sync signal with the subcarrier spacing set to 15 KHz and the second sync signal with 60 kHz for every frequency raster. Can be done.

In the case of the second method described above, the base station can freely arrange the frequency bands (ie, in an easy-to-use manner) and transmit a synchronization signal using the desired numerology in the frequency band. Through this, there is an advantage in that the frequency band can be efficiently used (or operated) within the system bandwidth.

Hereinafter, when frequency raster based synchronization signal detection is considered in an NR system, a detailed description of the relationship between frequency raster and channel raster will be described. In addition, the contents of the timing at which the base station transmits information on the relationship to the terminal for data transmission and reception with the terminal will also be described below.

For example, the detection of the synchronization signal is performed in units of frequency rasters, but the reception of downlink channels and / or signals (eg, PBCH, PDCCH, PDSCH, etc.) after the synchronization signal may be performed in units of channel rasters. In this case, the terminal may move (ie, change frequency) to a frequency domain (or frequency band) in which the downlink channel and / or signal is transmitted using the information on the relationship.

As mentioned above, in an NR system, the frequency raster may be set at a larger fundamental interval than the channel raster. Therefore, depending on whether the value of the channel raster is located above the frequency raster grid (i.e., the specific frequency region set according to the frequency raster), the relationship between the channel raster and the frequency raster can be divided into two types as follows. Can be.

First, the value of the channel raster may be located above (or on) the frequency raster grid. In other words, the channel raster grid may overlap the frequency raster grid. Here, the channel raster grid may mean a specific frequency region set in channel raster units, and the frequency raster grid may mean a specific frequency region set in frequency raster units.

For example, if the channel raster grid is set to 100 kHz and the frequency raster grid is set to 1 MHz (that is, the channel raster is set in 100 kHz and the frequency raster is set in 1 MHz), the channel raster value is 1 MHz. Each unit can be located in the frequency raster grid. For another example, if the channel raster grid is set to 100 kHz and the frequency raster grid is set to 10 MHz, the channel raster value may be located in the frequency raster grid every 10 MHz units.

Secondly, the value of the channel raster may not be located on the frequency raster grid. For example, if the channel raster grid is set to 100 kHz and the frequency raster grid is set to 1 MHz, the channel raster value is not located in the frequency raster grid except in units of 1 MHz. As another example, if the channel raster grid is set to 100 kHz and the frequency raster grid is set to 10 MHz, the channel raster value is not located in the frequency raster grid except in units of 10 MHz.

At this time, the base station is configured to transmit a synchronization signal on the frequency raster grid (ie, in the frequency raster unit), and thus, the terminal detects the synchronization signal based on the frequency raster grid (ie, in the frequency raster unit). It can be set to. In this case, the frequency domain in which the base station transmits the synchronization signal and the frequency domain in which the actual cell is formed (that is, the frequency domain corresponding to the actual channel raster of the base station) may be set differently. Accordingly, the base station needs to transmit information on a frequency offset between the frequency raster and the actual channel raster and / or information on the numerology used in the carrier.

Here, the actual channel raster may mean a channel raster corresponding to a frequency domain in which the base station transmits a downlink channel and / or a signal after the synchronization signal. That is, the base station needs to transmit information about the offset between the frequency domain used for transmission of the synchronization signal and the frequency domain used for transmitting and receiving actual data to the terminal.

Hereinafter, the details of the frequency offset and a method of transmitting a synchronization signal by the base station and detecting the transmitted synchronization signal by the terminal will be described in detail.

The carrier frequency (i.e., center frequency is represented by F _c , the channel raster grid unit is represented by r _c , and the frequency raster grid unit is represented by r _f .

The number of subcarriers per resource block is represented by

Therefore, the bandwidth of 1 RB is

*

It can be expressed as. Assuming that the synchronization signal is transmitted through the even number of RBs, the center frequency of all of the even number of RBs to which the synchronization signal is transmitted may be set to a value of one of the RB boundaries.

In this case, the minimum frequency unit for the center frequency of all the even numbered RBs to which the synchronization signal is transmitted is located (or present) on the channel raster grid unit (ie, r _c )

*

Is the least common multiple of and r _c . The least common multiple is

It can be expressed as. From here,

May mean a minimum frequency interval for overlapping the center frequency of all of the even-numbered RBs and the channel raster unit.

On the other hand, as described above, the channel raster value may or may not be located on the frequency raster grid. That is, the channel raster value may or may not overlap the frequency raster value. Here, the channel raster value means one of the values apart from the center frequency (i.e., F _c ) by r _c , and the frequency raster value represents one of the values apart from the center frequency (ie, F _c ) by r _f units. Can mean.

Therefore, when the base station transmits a carrier on a specific channel raster, the base station transmits the synchronization signal at a frequency position where no additional raster offset is generated even if the terminal detects the synchronization signal for each frequency raster grid. Can be set. Here, the additional raster offset may be a difference between a center frequency value set for transmitting a sync signal (eg, PSS) at the base station and a center frequency value set for detecting (or receiving) a sync signal (eg, PSS) at the terminal. Can mean.

In this case, the frequency position at which the additional raster offset is not generated may mean a frequency raster grid (that is, set in accordance with a specific rule) (ie, a frequency domain in units of frequency rasters). That is, even when the base station transmits and receives data in the frequency domain corresponding to the specific channel raster, the base station considers the synchronization signal detection operation of the terminal performed in the frequency raster unit, and transmits the synchronization signal to the specific frequency region in the frequency raster unit. Can be sent from. However, the base station needs to transmit information on the relationship between the specific frequency region in which the synchronization signal is transmitted and the frequency region in which (real) data is transmitted and received to the terminal.

Specifically, when the channel raster value is represented by a, and the frequency raster value is represented by b, the base station determines a certain frequency from the corresponding channel raster according to the difference between the channel raster value and the frequency raster value (ie, d = a-b). The sync signal may be transmitted at a position separated by (ie, a preset frequency interval). As such, as the base station transmits the synchronization signal at a certain frequency away from the channel raster (which transmits the carrier), even if the terminal attempts to detect the synchronization signal at a frequency raster grid interval (that is, in units of frequency rasters), an additional raster offset This may not occur.

At this time, the terminal identifies (or determines, determines) the channel raster on which the carrier is transmitted using the information on the predetermined frequency and the frequency domain where the synchronization signal is detected (that is, the position on the frequency domain corresponding to the specific frequency raster). )can do. Here, the constant frequency for setting so that the additional raster offset does not occur even if the terminal detects the synchronization signal in frequency raster unit may be set using Equation 2.

In Equation 2, x mod y means a modular operation, and means the remainder of x divided by y. In addition, the d means the difference between the channel raster value and the frequency raster value,

Denotes a minimum common multiple of a bandwidth of 1 RB and a channel raster value, and r _f may denote a frequency raster unit.

Also, k may be one of integers satisfying Equation 2. That is, k is the sum of the difference between the channel raster value and the frequency raster value and the product of the least common multiple and the k (i.e., d +

* k) may mean an integer for setting to be a multiple of the frequency raster. Here, setting a positive integer k having the smallest absolute value satisfying equation (2) according to each condition means that the synchronization signal is spaced apart from the carrier frequency (ie, the center frequency) by a minimum distance in the positive direction. This may mean setting up a transmission from a place.

Also, although the value of k has been described herein as being a positive integer (including zero), the value of k may be set to a negative integer (including zero). That is, the synchronization signal may be set to be transmitted in a positive direction away from the carrier frequency or may be set to be transmitted in a negative direction away from the carrier frequency. In this case, in order to cover the entire frequency band, the direction in which the synchronization signal is transmitted may be set in advance in one of a positive direction and a negative direction. Alternatively, the k value may be set to include both a positive integer and a negative integer. In this case, the synchronization signal may be transmitted in the positive direction for some of the difference values between the channel raster value and the frequency raster value, and in the negative direction for the others.

Hereinafter, an example in which specific numbers are substituted for the above-described frequency offset will be described.

Specifically, the carrier frequency (ie, center frequency) (ie, F _c ) is set to 4 GHz, the channel raster grid unit (ie, r _c ) is set to 100 kHz, and the frequency raster grid The unit (ie, r _f ) may be set to 1 MHz. Also, subcarrier spacing (i.e.,

) Is set to 15 kHz, and the number of subcarriers per RB (i.e.

) Is set to 12, so that a bandwidth of 1 RB (that is,

*

) Is 180 kHz.

In addition, it is assumed that the base station transmits a synchronization signal through six RBs. At this time, the minimum frequency unit for the center frequency of the even number of RBs to which the synchronization signal is transmitted is located (or present) on the channel raster grid unit (that is, r _c )

*

And the least common multiple of r _c ,

) Is 900 kHz.

In that example (i.e.

= 15 kHz,

= 12, r _c = 100 kHz, rf = 1 MHz) and candidates of positive integer k can be represented as shown in Table 4 based on Equation 2 above. Here, candidates of positive integer k may refer to candidates of value k for transmitting the synchronization signal at a predetermined distance away from the center frequency in the positive direction.

In Table 4, the underlined values mean the value added to the channel raster value (that is, the frequency domain in which the base station forms a cell to transmit and receive data) for each case. That is, the base station may transmit a synchronization signal in the frequency domain in which the underlined values are added to the channel raster value for each case. In this case, the terminal may identify (or determine) a frequency domain supported by the base station by using information on the frequency domain in which the synchronization signal is detected (that is, received) and the k value indicated by the base station. Here, the frequency domain supported by the base station may include a frequency domain set in units of channel rasters.

Through this method, even when the base station forms a cell in units of channel rasters, the base station transmits a synchronization signal in a frequency domain set in units of frequency rasters, and the terminal performs synchronization signal detection in units of frequency rasters. Can be.

For example, if the channel raster value (ie a) is 4001.1 MHz (ie 4 GHz + 1100 kHz) and the frequency raster value (ie b) is 4001 MHz (ie 4 GHz + 1 MHz), then the difference value between the two (ie d = a-b) is 100 kHz (i.e. 4001.1 MHz-4001 MHz = 0.1 MHz). In this case, when the least common multiple value, the difference value, and the frequency raster grid unit value (that is, the frequency raster unit) are substituted into Equation 2 to calculate the smallest positive integer k, k becomes 1. That is, the smallest positive integer k that satisfies (100 (kHz) + 900 (kHz) * k) mod 1000 (kHz) = 0 is 1.

Therefore, when the channel raster value is 4001.1 MHz as shown in the above example, the base station may be configured to transmit a synchronization signal centered on 4002 MHz obtained by adding 900 kHz to the corresponding channel raster value. In this case, the terminal may receive the synchronization signal without additional raster offset even if the terminal detects the synchronization signal in frequency raster units.

On the other hand, as mentioned above, k may be set to a negative integer (including 0). In this case, for example

= 15 kHz,

= 12, r _c = 100 kHz, rf = 1 MHz), candidates of negative integer k can be represented as shown in Table 5 based on Equation 2 above. Here, the candidates of negative integer k may refer to candidates of k value for transmitting the synchronization signal at a predetermined distance away from the center frequency in the negative direction.

Unlike Table 4, in Table 5, the underlined values mean a value that is subtracted from the channel raster value (that is, the frequency domain in which the base station forms a cell to transmit and receive actual data) for each case. That is, for each case, the base station may transmit a synchronization signal in a frequency domain corresponding to a frequency where the underlined values are subtracted from the channel raster value. Even in this case, the terminal may identify the frequency domain supported by the base station by using the frequency domain where the synchronization signal is detected and the k value indicated by the base station.

When the base station transmits a synchronization signal by applying a specific k corresponding to Table 4 or Table 5, examples of a frequency domain in which the synchronization signal is transmitted may be expressed as shown in FIG. 6.

FIG. 6 shows examples of synchronization signal transmission based on a relationship between a channel raster value and a frequency raster value to which the method proposed in this specification can be applied. 6 is merely for convenience of description and does not limit the scope of the present invention.

Referring to FIG. 6, it is assumed that a bandwidth of 1 RB is 180 kHz, a channel raster grid unit (ie, channel raster unit) is 100 kHZ, and a frequency raster grid unit (ie, frequency raster unit) is 1 MHz. In this case, the base station transmits a synchronization signal through six RBs, forms a cell in a frequency domain (that is, 100 kHz) set in units of channel rasters, and transmits and receives data. In addition, the terminal attempts to detect a synchronization signal according to a frequency raster unit (ie, in units of 1 MHz).

FIG. 6A illustrates a frequency range of a synchronization signal to which a positive integer k (ie, k is 1) is applied when the difference value (ie, d) is 100 kHz as shown in Table 4 above. In this case, the positive integer k may mean a positive integer k having the smallest absolute value including 0 satisfying the condition of Equation 2 when the difference value is 100 kHz. In this case, the channel raster value (i.e., the frequency domain in which the base station forms the cell) is 100 kHz, and the center frequency of the frequency domain in which the synchronization signal is transmitted is 1000 kHz (i.e., 100 kHz + 900 * 1).

Accordingly, the terminal can detect the synchronization signal transmitted by the base station at 6 RBs centered on 1000 kHz without additional raster offset. In addition, the terminal uses the center frequency (ie, 1000 kHz) of the frequency domain where the synchronization signal is detected and the k value (ie, k is 1) indicated by the base station, and the channel raster value (ie, 100 kHz) for the base station. Can be identified (or determined).

In contrast, FIG. 6B illustrates a frequency range of a synchronization signal to which a negative integer k (that is, k is -9) is applied when the difference value (that is, d) is 100 kHz as shown in Table 5 above. . In this case, the negative integer k may mean a negative integer k having the smallest absolute value including 0 satisfying the condition of Equation 2 when the difference value is 100 kHz. In this case, the channel raster value (i.e., the frequency domain in which the base station forms the cell) is 100 kHz, and the center frequency of the frequency domain in which the synchronization signal is transmitted is -8000 kHz (i.e., 100 kHz + 900 * (-9)).

Accordingly, the terminal can detect the synchronization signal transmitted by the base station at 6 RBs centered on -8000 kHz without additional raster offset. Further, the terminal uses the center frequency (ie, -8000 kHz) of the frequency domain where the synchronization signal is detected and the k value indicated by the base station (that is, k is -9) to the channel raster value for the base station (ie, 100 kHz).

In addition, according to the above examples, the terminal that has completed synchronization through the frequency raster grid needs to receive specific information from the base station to know the actual channel raster value. That is, when the terminal attempts to detect in frequency raster units and receives a synchronization signal, the terminal needs to determine information (ie, the frequency domain set in the channel raster units) actually supported by the base station. information indicating the value of k). If 10 k value candidates exist as in the above-described example, the corresponding information may consist of 4 bits.

At this time, in the above example, the subcarrier spacing (

) Only changes from 15 kHz to 30 kHz (or 60 kHz) (that is, the least common multiple (

) Changes from 900 kHz to 1800 kHz (or 7200 kHz), the number of k value candidates is changed from 10 to 5. In this case, the information necessary (or required) to know the actual channel raster value may consist of 3 bits. Further, the number of candidates of the k value is not only subcarrier interval but also the number of subcarriers per RB (

), The channel raster grid unit r _c , the frequency raster grid unit r _f , and the like.

That is, if the variable parameter values as described above are fixed (each one value), a positive integer k that includes zero, which is set according to the difference value (ie, d) between the channel raster and the frequency raster. (I.e., the positive integer k with the lowest absolute value) (or the negative integer k with 0) is the number of elements of the information. In other words, the number of elements of the information necessary for the terminal to know the actual channel raster value of the base station is equal to the number of integers k satisfying Equation 2 above.

In this case, when the frequency raster grid is T times wider than the channel raster grid (that is, the frequency raster unit is T times larger than the channel raster unit), the number of k may be at most T. Here, k is a positive integer k (or negative integer k) having the smallest absolute value satisfying Equation (2). In this case, the information (that is, information required for the terminal to know the actual channel raster value) is

It may consist of bits. From here,

Is the ceiling (or ceiling) function and represents the smallest integer that is equal to or greater than X.

Further, in various embodiments of the present disclosure, the terminal detecting the synchronization signal in frequency raster units may need information for identifying (or determining) a frequency domain (eg, a frequency domain set in channel raster units) actually supported by the base station. Can be received using various methods.

The time point (or signal and / or channel) at which the base station transmits the information to the terminal may be variously considered. In this case, the information may include information related to a frequency offset (eg, the k value described above), information on a numerology (eg, subcarrier spacing), and the like. In this case, the information related to the frequency offset and / or the information about the numerology may be information set for each sub-band. Hereinafter, examples of methods for transmitting the information to the terminal by the base station will be described in detail. Hereinafter, the information is referred to as channel raster related information.

For example, the base station may transmit channel raster related information to the terminal through a synchronization signal (eg, x-PSS and / or x-SSS). That is, the base station may transmit the information to the terminal using a synchronization signal used for synchronization and cell selection.

In this case, the terminal may move to the position on the frequency domain corresponding to the (real) channel raster of the subband to be serviced using the received channel raster related information. Thereafter, the terminal may set the numerology using the received channel raster related information and perform decoding of a broadcast channel (eg, x-PBCH).

At this time, the area where the synchronization signal is transmitted may be used for transmission and reception of data set to the same numerology as the synchronization signal when the synchronization signal is not transmitted. In other words, the frequency domain in which the synchronization signal is transmitted may be used for the synchronization signal transmission in the synchronization signal transmission period, and may be used for the data transmission set to the same numerology as the synchronization signal when the synchronization signal transmission period is not.

Thereafter, the terminal may decode a system information block (SIB) (eg, x-SIB included in the x-PDSCH) to obtain system information. Through this, the terminal may proceed (or perform) a random access procedure for the base station.

In this case, the channel raster related information may be transmitted (or indicated) through a sequence for generating a synchronization signal (eg, an m-sequence, a Zadoff-Chu sequence). For example, the base station transmits the configuration information about the k candidate values described above to the terminal, and uses a specific k using a cyclic shift index or a root index of a sequence constituting a synchronization signal. You can indicate the value.

A method of transmitting channel raster related information using a synchronization signal has an advantage in that the terminal may change the channel raster only once (that is, change the frequency only once).

For another example, the base station may transmit the channel raster related information to the terminal through a master information block (MIB) included in the broadcast channel (eg, x-MIB included in the x-PBCH). In this case, however, since the UE is synchronized with the frequency raster grid (that is, in units of frequency raster), the terminal cannot accurately know the value of the channel raster through which the broadcast channel is transmitted.

Therefore, in this case, a method of setting a default band (ie, a default frequency domain) including an area in which a synchronization signal is transmitted and setting the broadcast channel to be transmitted in the corresponding default band may be considered. At this time, the base station transmits the frequency offset information for the default band to the terminal through a synchronization signal (for example, x-PSS and / or x-SSS), the terminal moves to the default band using the information, and then broadcast The cast channel can be decoded. At this time, it is assumed that the default band including the synchronization signal uses the same numerology. In other words, it is assumed that only one (i.e., single) neuronology is used within the default band, regardless of the particular neuronology value.

The terminal may decode the broadcast channel and move to a channel raster (ie, a position in a frequency domain corresponding to the channel raster) corresponding to a subband desired to be serviced. Thereafter, the terminal appropriately sets the numerology using channel raster related information received through the broadcast channel, and performs decoding of a system information block (SIB) (eg, x-SIB included in the x-PDSCH). System information can be obtained. In this way, the terminal may perform a random access procedure for the base station.

A method of transmitting channel raster related information using a broadcast channel has an advantage that an acquisition time for a synchronization signal is not delayed.

For another example, the base station may transmit the channel raster related information to the terminal through a system information block (SIB) (eg, x-SIB included in the x-PDSCH). However, since the terminal performs synchronization through the frequency raster grid, the terminal cannot accurately know the value of the channel raster through which the system information block is transmitted.

Therefore, in this case, a method of setting a default band including an area in which a synchronization signal is transmitted and setting a broadcast channel (eg, x-PBCH) and the system information block to be transmitted in the default band may be considered. . At this time, the base station transmits the frequency offset information for the default band to the terminal through a synchronization signal (for example, x-PSS and / or x-SSS), the terminal moves to the default band using the information, and then It is possible to decode the broadcast channel and the system information block. At this time, it is assumed that the default band including the synchronization signal uses the same numerology.

The terminal may decode the system information block and move to a channel raster (ie, a position in a frequency domain corresponding to the channel raster) corresponding to a subband desired to be serviced. Thereafter, the terminal may appropriately set the numerology using the channel raster related information received through the system information block and perform a random access procedure for the corresponding base station.

The method for transmitting the channel raster related information using the system information block has an advantage that the acquisition time for the synchronization signal is not delayed, and the system information block can be freely set with a space for transmitting the information.

In addition, the base station preferentially transmits only the frequency offset information for the default band through the synchronization signal, the terminal may be configured to complete the decoding of the broadcast channel and the system information block and performing the random access procedure through the default band. In this case, after completing the random access procedure, the terminal may be configured to receive information related to the neurology for each subband used in the entire system. Thereafter, the terminal may be configured to transmit / receive data by performing the use of numerology and frequency shifting applied to a subband corresponding to a service desired to be received.

Furthermore, in addition to the above descriptions, in various embodiments of the present disclosure, when information on a neighbor cell list for inter-frequency handover is reported, the following cases may be provided. Can be considered.

First, a case where a default numerology of a camp-on cell (ie, a cell in which a terminal is camped on) and a default numerology of all cells including an adjacent cell are always set to be the same. Can be considered. Details of the case are as follows.

When the base station informs the neighbor cell list for inter-frequency handover, the base station is the center of the band in which the synchronization signal of the neighbor cell set based on the channel raster grid (that is, set in the channel raster unit) is transmitted. It may be set to inform the terminal of the information about the frequency (center frequency). In this case, the base station may be configured to transmit a synchronization signal by shifting the frequency by a predetermined interval so that no additional raster offset (ie, additional frequency offset) is generated even in the case of neighboring cells. . In this case, the terminal may be configured to receive a synchronization signal of an adjacent cell using a default neuralology, and receive a frequency offset value between the frequency raster and the channel raster through the received synchronization signal.

Thereafter, the terminal may be configured to transition to the carrier frequency of the corresponding cell and complete the decoding of the broadcast channel and the system information block and the execution of the random access procedure. In this case, after completing the random access procedure, the terminal may be configured to receive information related to the neurology for each subband used in the entire system. Thereafter, the terminal may be configured to transmit and receive data by performing use of frequency and frequency shifting of the neuralology applied to the subband corresponding to the service that the user wants to receive.

Alternatively, a case may be considered in which the default neurology of the camp-on cell and the cell where the default neurology of neighboring cells are not the same as the same cell coexist. Details of the contents are as follows.

When the base station informs the neighbor cell list for inter-frequency handover, the base station informs information about the center frequency of the band in which the synchronization signal of the neighboring cell set based on the channel raster grid and the default value used by the corresponding cell. It may be set to inform the information about the numerology. In this case, the base station may be configured to transmit a synchronization signal by shifting the frequency by a predetermined interval so that no additional raster offset (ie, additional frequency offset) is generated even in the case of neighboring cells. . In this case, the terminal may be configured to receive a synchronization signal of an adjacent cell by using a default neuralology corresponding to each cell, and receive a frequency offset value between the frequency raster and the channel raster through the received synchronization signal.

7 shows an operation flowchart of a terminal for transmitting and receiving data to which the method proposed in the present specification can be applied. 7 is merely for convenience of description and does not limit the scope of the invention.

Referring to FIG. 7, the terminal attempts to detect a synchronization signal in frequency raster units (ie, the first frequency interval), and the base station forms a cell in channel raster units (ie, the second frequency interval) to generate data. It is assumed a case of transmitting and receiving. In addition, the frequency raster unit (for example, 1 MHz) is set larger than the channel raster unit (for example, 100 kHz).

In step S705, the terminal attempts detection (ie, detection of a synchronization signal) according to a preset first frequency interval and receives a synchronization signal from a base station in a first frequency domain. Here, the first frequency region may be one of a plurality of frequency regions set in units of a first frequency interval (that is, set in units of frequency rasters). The terminal attempts to detect the synchronization signal in frequency raster units and receives the synchronization signal as described above.

Thereafter, in step S710, the terminal identifies a second frequency region to receive a downlink channel using a specific value related to the center frequency and the frequency offset of the first frequency region. Here, the specific value related to the frequency offset may mean channel raster related information (eg, an integer k value) described above. Also, the second frequency domain may be one of a plurality of frequency domains set in units of second frequency intervals (ie, set in channel raster units).

In this case, the specific value is a value indicated by the base station among one or more values (eg, k values shown in Table 4 or Table 5) set based on the difference between the first frequency interval and the second frequency interval. The operation of the terminal identifying the second frequency region is the same as the operation of the terminal identifying the actual channel raster value (that is, the frequency region in which the base station forms the actual cell).

Thereafter, in step S715, the terminal receives a downlink channel from the base station in the identified second frequency domain. Here, the downlink channel may mean a broadcast channel (eg, PBCH), a downlink channel (eg, PDSCH) including a system information block, and the like. That is, the terminal may move to the identified second frequency domain in the first frequency domain where the synchronization signal is received and receive the downlink channel. The operation of receiving the downlink channel in the second frequency domain by the terminal is the same as the operation of receiving the downlink channel and / or a signal from the base station by moving to the frequency domain corresponding to the actual channel raster value described above.

In this case, the second frequency domain may be located in a region separated by the product of the specific value and the third frequency interval with respect to the first frequency region on the frequency domain. Here, the third frequency interval may be set based on the bandwidth of the resource block and the second frequency interval. At this time, the bandwidth of the resource block is set according to the subcarrier interval applied to the synchronization signal, the terminal may receive the configuration information indicating the subcarrier interval from the base station. In this case, the third frequency interval is the least common multiple of the bandwidth of the resource block and the second frequency interval (eg, included in Equation 2 described above).

It can be set to). Further, the difference value between the center frequency of the second frequency domain and the center frequency of the second frequency domain may be set to a multiple of the least common multiple (ie, an integer multiple).

Also, the terminal may receive configuration information (eg, channel raster information described above) indicating one or more values set based on a difference between the first frequency interval and the second frequency interval. In this case, the specific value may be indicated through a sequence for generating the synchronization signal. Specifically, the specific value may be indicated through the cyclic shift index of the sequence.

본 발명이 적용될 수 있는 장치 일반General apparatus to which the present invention can be applied

Referring to FIG. 8, the wireless communication system includes a base station 810 and a plurality of terminals 820 located in an area of the base station 810.

The base station 810 includes a processor 811, a memory 812, and a radio frequency unit 813. The processor 811 implements the functions, processes, and / or methods proposed in FIGS. 1 to 7. Layers of the air interface protocol may be implemented by the processor 811. The memory 812 is connected to the processor 811 and stores various information for driving the processor 811. The RF unit 813 is connected to the processor 811 to transmit and / or receive a radio signal.

The terminal 820 includes a processor 821, a memory 822, and an RF unit 823.

The processor 821 implements the functions, processes, and / or methods proposed in FIGS. 1 to 7. Layers of the air interface protocol may be implemented by the processor 821. The memory 822 is connected to the processor 821 and stores various information for driving the processor 821. The RF unit 823 is connected to the processor 821 and transmits and / or receives a radio signal.

The

memories

812 and 822 may be inside or outside the

processors

811 and 821, and may be connected to the

processors

811 and 821 by various well-known means.

As an example, in order to transmit and receive downlink data (DL data) in a wireless communication system supporting a low latency service, the terminal is a radio frequency (RF) unit for transmitting and receiving a radio signal, and a functional unit with the RF unit. It may include a processor connected to.

Also, the base station 810 and / or the terminal 820 may have a single antenna or multiple antennas.

In particular, FIG. 9 illustrates the terminal of FIG. 8 in more detail.

9, a terminal includes a processor (or a digital signal processor (DSP) 910, an RF module (or RF unit) 935, and a power management module 905). ), Antenna 940, battery 955, display 915, keypad 920, memory 930, SIM card Subscriber Identification Module card) 925 (this configuration is optional), speaker 945 and microphone 950. The terminal may also include a single antenna or multiple antennas. Can be.

The processor 910 implements the functions, processes, and / or methods proposed in FIGS. 1 to 7. The layer of the air interface protocol may be implemented by the processor 910.

The memory 930 is connected to the processor 910 and stores information related to the operation of the processor 910. The memory 930 may be inside or outside the processor 910 and may be connected to the processor 910 by various well-known means.

The user enters command information, such as a telephone number, for example by pressing (or touching) a button on keypad 920 or by voice activation using microphone 950. The processor 910 receives the command information, processes the telephone number, and performs a proper function. Operational data may be extracted from the SIM card 925 or the memory 930. In addition, the processor 910 may display command information or driving information on the display 915 for the user to recognize and for convenience.

The RF module 935 is connected to the processor 910 to transmit and / or receive an RF signal. The processor 910 passes the command information to the RF module 935 to transmit, for example, a radio signal constituting voice communication data to initiate communication. The RF module 935 is composed of a receiver and a transmitter for receiving and transmitting a radio signal. Antenna 940 functions to transmit and receive wireless signals. Upon receiving the wireless signal, the RF module 935 may forward the signal and convert the signal to baseband for processing by the processor 910. The processed signal may be converted into audible or readable information output through the speaker 945.

The embodiments described above are the components and features of the present invention are combined in a predetermined form. Each component or feature is to be considered optional unless stated otherwise. Each component or feature may be embodied in a form that is not combined with other components or features. In addition, it is also possible to configure the embodiments of the present invention by combining some components and / or features. The order of the operations described in the embodiments of the present invention may be changed. Some components or features of one embodiment may be included in another embodiment, or may be replaced with corresponding components or features of another embodiment. It is obvious that the embodiments can be combined to form a new claim by combining claims which are not expressly cited in the claims or by post-application correction.

Embodiments according to the present invention may be implemented by various means, for example, hardware, firmware, software, or a combination thereof. In the case of a hardware implementation, an embodiment of the present invention may include one or more application specific integrated circuits (ASICs), digital signal processors (DSPs), digital signal processing devices (DSPDs), programmable logic devices (PLDs), and FPGAs ( field programmable gate arrays), processors, controllers, microcontrollers, microprocessors, and the like.

In the case of implementation by firmware or software, an embodiment of the present invention may be implemented in the form of a module, procedure, function, etc. that performs the functions or operations described above. The software code may be stored in memory and driven by the processor. The memory may be located inside or outside the processor, and may exchange data with the processor by various known means.

It will be apparent to those skilled in the art that the present invention may be embodied in other specific forms without departing from the essential features of the present invention. Accordingly, the above detailed description should not be construed as limiting in all aspects and should be considered as illustrative. The scope of the invention should be determined by reasonable interpretation of the appended claims, and all changes within the equivalent scope of the invention are included in the scope of the invention.

In the wireless communication system of the present invention, a method for transmitting and receiving data by the terminal has been described with reference to an example applied to a 3GPP LTE / LTE-A system and a 5G system (New RAT system), but can be applied to various wireless communication systems. Do.

Claims

In the method of transmitting and receiving data in a wireless communication system,

Attempting detection according to a preset first frequency interval, receiving a synchronization signal from a base station in a first frequency region, and

Identifying a second frequency domain to receive a downlink channel using a specific value associated with a center frequency and a frequency offset of the first frequency domain;

Receiving the downlink channel from the base station in the identified second frequency domain,

The specific value is a value indicated by the base station among one or more values set based on a difference between the first frequency interval and a second frequency interval,

And wherein the first frequency interval is set greater than the second frequency interval.
The method of claim 1,

The first frequency domain is one of a plurality of frequency domains set in units of the first frequency interval,

The second frequency domain is one of a plurality of frequency domains set in units of the second frequency interval.
The method of claim 2,

The second frequency domain is located in an area separated by a product of the specific value and a third frequency interval with respect to the first frequency domain in a frequency domain.

The third frequency interval is set based on a bandwidth of the resource block and the second frequency interval.
The method of claim 3, wherein

The bandwidth of the resource block is set according to a subcarrier spacing applied to the synchronization signal,

And receiving configuration information indicating the subcarrier interval from the base station.
The method of claim 4, wherein

And wherein the third frequency interval is set to a least common multiple of the bandwidth of the resource block and the second frequency interval.
The method of claim 5,

And a difference value between the center frequency of the first frequency domain and the center frequency of the second frequency domain is set to a multiple of the least common multiple.
The method of claim 3, wherein

And if the first frequency interval is set k times greater than the second frequency interval, the number of one or more values is set to be less than or equal to k.
The method of claim 3, wherein

Receiving setting information indicating the one or more values from the base station;

The specific value is indicated through a sequence of generating the synchronization signal.
The method of claim 8,

The specific value is indicated via a cyclic shift index of the sequence.
The method of claim 3, wherein

The first frequency interval is a frequency raster unit,

And wherein said second frequency interval is a channel raster unit.
In the terminal for transmitting and receiving data in a wireless communication system,

A transceiver for transmitting and receiving a wireless signal,

A processor that is functionally connected to the transceiver;

The processor,

Attempt detection according to a preset first frequency interval, receive a synchronization signal from a base station in a first frequency domain,

Identifying a second frequency region to receive a downlink channel using a specific value associated with a center frequency and a frequency offset of the first frequency region,

Control to receive the downlink channel from the base station in the identified second frequency domain,

The specific value is a value indicated by the base station among one or more values set based on a difference between the first frequency interval and a second frequency interval,

The first frequency interval is set larger than the second frequency interval.
The method of claim 11,

The first frequency domain is one of a plurality of frequency domains set in units of the first frequency interval,

The second frequency domain is one of a plurality of frequency domains set in units of the second frequency interval.
The method of claim 12,

The second frequency domain is located in an area separated by a product of the specific value and the third frequency interval with respect to the first frequency domain on the frequency domain.

The third frequency interval is set based on a bandwidth of a resource block and the second frequency interval.