KR20180011419A - Apparatus and method of frame structure design for NR(New Radio) - Google Patents

Abstract

The present invention proposes a method for configuring a frame structure for NR. Specially, the present invention proposes a downlink synchronization signal transmitting method for synchronizing a terminal for supporting transmission and reception operations based on different numerologies (e.g. subcarrier spacing, subframe, TTI etc.) through one NR frequency band to satisfy different requirements according to a usage scenario or deployment scenario of the terminal, and a method for configuring a frame structure for supporting the same.

Description

TECHNICAL FIELD [0001] The present invention relates to a frame structure design method and apparatus for a next generation radio access network,

The present embodiments relate to a frame structure for a next generation / 5G radio access network (hereinafter referred to as "NR [New Radio]") in which discussion has been started in 3GPP.

According to an embodiment of the present invention, there is provided a method of designing a frame structure for a next-generation radio access network, the method comprising the steps of: forming a downlink synchronization signal independent of each numerology type and transmitting the downlink synchronization signal; Determining a priority of a numerology type for receiving a signal, and searching for a downlink synchronization signal according to a priority of a determined numerology type.

FIG. 1 is a diagram illustrating a TDM based multiplexing between numerical specific synchronization signal transmission (when L = 1, 2, and 3).
FIG. 2 is a diagram illustrating FDM-based multiplexing between numerical data and specific synchronization signal transmission (when L = 1, 2, and 3).
3 is a diagram illustrating a configuration of a base station according to another embodiment of the present invention.
4 is a diagram illustrating a configuration of a user terminal according to another embodiment of the present invention.

Hereinafter, some embodiments of the present invention will be described in detail with reference to exemplary drawings. It should be noted that, in adding reference numerals to the constituent elements of the drawings, the same constituent elements are denoted by the same reference symbols as possible even if they are shown in different drawings. In the following description of the present invention, a detailed description of known functions and configurations incorporated herein will be omitted when it may make the subject matter of the present invention rather unclear.

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

In other words, the MTC terminal in this specification may mean a newly defined 3GPP Release-13 low cost (or low complexity) UE category / type for performing LTE-based MTC-related operations. Alternatively, the MTC terminal may support enhanced coverage over the existing LTE coverage or a UE category / type defined in the existing 3GPP Release-12 or lower that supports low power consumption, or a newly defined Release-13 low cost low complexity UE category / type.

The wireless communication system in the present invention is widely deployed to provide various communication services such as voice, packet data and the like. A wireless communication system includes a user equipment (UE) and a base station (BS, or eNB). The user terminal in this specification is a comprehensive concept of a terminal in wireless communication. It is a comprehensive concept which means a mobile station (MS), a user terminal (UT), an SS (User Equipment) (Subscriber Station), a wireless device, and the like.

A base station or a cell generally refers to a station that communicates with a user terminal and includes a Node-B, an evolved Node-B (eNB), a sector, a Site, a BTS A base transceiver system, an access point, a relay node, a remote radio head (RRH), a radio unit (RU), and a small cell.

That is, the base station or the cell in this specification is interpreted as a comprehensive meaning indicating a partial region or function covered by BSC (Base Station Controller) in CDMA, NodeB in WCDMA, eNB in LTE or sector (site) And covers various coverage areas such as megacell, macrocell, microcell, picocell, femtocell and relay node, RRH, RU, and small cell communication range.

Since the various cells listed above exist in the base station controlling each cell, the base station can be interpreted into two meanings. i) the device itself providing a megacell, macrocell, microcell, picocell, femtocell, small cell in relation to the wireless region, or ii) indicating the wireless region itself. i indicate to the base station all devices that are controlled by the same entity or that interact to configure the wireless region as a collaboration. An eNB, an RRH, an antenna, an RU, an LPN, a point, a transmission / reception point, a transmission point, a reception point, and the like are exemplary embodiments of a base station according to a configuration method of a radio area. ii) may indicate to the base station the wireless region itself that is to receive or transmit signals from the perspective of the user terminal or from a neighboring base station.

Therefore, a base station is collectively referred to as a base station, collectively referred to as a megacell, macrocell, microcell, picocell, femtocell, small cell, RRH, antenna, RU, low power node do.

Herein, the user terminal and the base station are used in a broad sense as the two transmitting and receiving subjects used to implement the technical or technical idea described in this specification, and are not limited by a specific term or word. The user terminal and the base station are used in a broad sense as two (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 a specific term or word. Here, an uplink (UL, or uplink) means a method of transmitting / receiving data to / from a base station by a user terminal, and a downlink (DL or downlink) .

There are no restrictions on multiple access schemes applied to wireless communication systems. Various multiple access schemes such as Code Division Multiple Access (CDMA), Time Division Multiple Access (TDMA), Frequency Division Multiple Access (FDMA), Orthogonal Frequency Division Multiple Access (OFDMA), OFDM-FDMA, OFDM- Can be used. An embodiment of the present invention can be applied to asynchronous wireless communication that evolves into LTE and LTE-advanced via GSM, WCDMA, and HSPA, and synchronous wireless communication that evolves into CDMA, CDMA-2000, and UMB. The present invention should not be construed as limited to or limited to a specific wireless communication field and should be construed as including all technical fields to which the idea of the present invention can be applied.

A TDD (Time Division Duplex) scheme in which uplink and downlink transmissions are transmitted using different time periods, or an FDD (Frequency Division Duplex) scheme in which they are transmitted using different frequencies can be used.

In systems such as LTE and LTE-advanced, a standard is constructed by configuring uplink and downlink based on a single carrier or carrier pair. The uplink and the downlink are divided into a Physical Downlink Control Channel (PDCCH), a Physical Control Format Indicator CHannel (PCFICH), a Physical Hybrid ARQ Indicator CHannel, a Physical Uplink Control CHannel (PUCCH), an Enhanced Physical Downlink Control Channel (EPDCCH) Transmits control information through the same control channel, and is configured with data channels such as PDSCH (Physical Downlink Shared CHannel) and PUSCH (Physical Uplink Shared CHannel), and transmits data.

On the other hand, control information can also be transmitted using EPDCCH (enhanced PDCCH or extended PDCCH).

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

The wireless communication system to which the embodiments are applied may be a coordinated multi-point transmission / reception system (CoMP system) or a coordinated multi-point transmission / reception system in which two or more transmission / reception points cooperatively transmit signals. antenna transmission system, or a cooperative multi-cell communication system. A CoMP system may include at least two multipoint transmit and receive points and terminals.

The multi-point transmission / reception point includes a base station or a macro cell (hereinafter referred to as 'eNB'), and at least one mobile station having a high transmission power or a low transmission power in a macro cell area, Lt; / RTI >

Hereinafter, a downlink refers to a communication or communication path from a multipoint transmission / reception point to a terminal, and an uplink refers to a communication or communication path from a terminal to a multiple transmission / reception point. In the downlink, a transmitter may be a part of a multipoint transmission / reception point, and a receiver may be a part of a terminal. In the uplink, the transmitter may be a part of the terminal, and the receiver may be a part of multiple transmission / reception points.

Hereinafter, a situation in which a signal is transmitted / received through a channel such as PUCCH, PUSCH, PDCCH, EPDCCH, and PDSCH is expressed as 'PUCCH, PUSCH, PDCCH, EPDCCH and PDSCH are transmitted and received'.

In the following description, an indication that a PDCCH is transmitted or received or a signal is transmitted or received via a PDCCH may be used to mean transmitting or receiving an EPDCCH or transmitting or receiving a signal through an EPDCCH.

That is, the physical downlink control channel described below may mean a PDCCH, an EPDCCH, or a PDCCH and an EPDCCH.

Also, for convenience of description, the PDCCH, which is an embodiment of the present invention, may be applied to the PDCCH, and the PDCCH may be applied to the portion described with the EPDCCH.

Meanwhile, the High Layer Signaling described below includes RRC signaling for transmitting RRC information including RRC parameters.

The eNB performs downlink transmission to the UEs. The eNB includes a physical downlink shared channel (PDSCH) as a main physical channel for unicast transmission, downlink control information such as scheduling required for reception of PDSCH, and uplink data channel A physical downlink control channel (PDCCH) for transmitting scheduling grant information for transmission in a Physical Uplink Shared Channel (PUSCH). Hereinafter, the transmission / reception of a signal through each channel will be described in a form in which the corresponding channel is transmitted / received.

NR (New Radio)

3GPP recently approved the study item "Study on New Radio Access Technology" for research on next generation / 5G radio access technology, and based on this, RAN WG1 has frame structure, channel coding and modulation , waveform & multiple access scheme and so on.

NR is required to be designed so as to satisfy not only an improved data transmission rate as compared with LTE, but also various requirements required for granular and specific usage scenarios. In particular, enhancement mobile broadband (eMBB), massive MTC (MMTC) and URLLC (Ultra Reliable and Low Latency Communications) have been proposed as typical usage scenarios of NR. As a method to satisfy the requirements of each usage scenario, structure design is required.

In particular, there is a need for a different resource allocation structure for each usage scenario. As a way to support this, there is a need for multiplexing between different numerologies through one NR frequency band. That is, in order to efficiently support NR terminals operating under different resource allocation units based on different subcarrier spacing and different transmission time interval (TTI) structures for each usage scenario or deployment scenario over one NR frequency band frame structure and thus the physical signal / channels.

In the present invention, a method of constructing a frame structure for NR is proposed. As described above, in order to satisfy different requirements according to a usage scenario or a deployment scenario of a terminal, transmission and reception operations based on different numerologies (eg, subcarrier spacing, subframe, TTI etc.) are supported through one NR frequency band A method for transmitting a downlink synchronization signal for synchronizing a terminal and a method for constructing a frame structure for supporting the same are proposed.

As described above, eMBB, mMTC, and URLLC are considered as typical usage scenarios of NR that are being discussed in 3GPP.

Since each usage scenario has different requirements for data rates, latency, coverage, etc., it is necessary to use different numerology (eg subcarrier) to efficiently satisfy the requirements of each usage scenario through frequency bands constituting an NR system there is a need for a method of effectively multiplexing a radio resource unit based on a space, a subframe, a TTI, etc.

For example, in the same way as the conventional LTE, a 1-ms subframe (or TTI) structure based on a 15-kHz subcarrier spacing, a 0.5-ms subframe (or TTI) structure based on a subcarrier spacing of 30 kHz, and a 0.25- There is a need to support the structure over one NR frequency band.

The present invention proposes a method for efficiently supporting a plurality of numerologies having different subcarrier spacing and thus a subframe (or TTI) length over one NR frequency band.

For the description of the present invention, a numerology type consisting of a set of subcarrier spacing and subframe (or TTI) lengths is referred to as N1, N2, N3, ... .

For example, N1 is a numerology type with a 1ms subframe (or TTI) length structure based on a 15kHz subcarrier spacing. N2 is another numerology type with a 0.5ms subframe (or TTI) structure based on subcarrier spacing at 30kHz. , And N3 can be defined as a third numerology type with a 60 kHz based 0.25 ms subframe (or TTI) structure.

However, the concept of the present invention can be applied regardless of the number of numerology types defined for NR, and specific values of subcarrier spacing and subframe (or TTI) lengths constituting each numerology type.

Point 1: Numerology specific synchronization

An NR base station / transmission / reception point constituting an arbitrary NR cell through an arbitrary NR frequency band can be defined to individually transmit a downlink synchronization signal for each numerology type supported by the corresponding cell.

That is, when M number of numerology types Nk ~ N (k + M-1) having different subcarrier spacing or different subframe (or TTI) lengths are supported at an arbitrary NR cell / base station / transmission / reception point, / Base station / transmission / reception point constitute an independent downlink synchronization signal for each numerology type, and each of the terminals defines to synchronize downlink synchronization based on one or more of the numerology type synchronization signals .

Specifically, according to the center frequency of the NR frequency band in which a usage scenario or an arbitrary NR cell is configured for each NR terminal (or the terminal performs the NR cell search), priority for each numerology type for receiving the downlink synchronization signal is Can be determined.

That is, a numerical type having the highest priority for receiving a cell search and a downlink synchronization signal for each UE, that is, a UE-specific primary numerology type and a secondary numerology type (s), may be defined.

Accordingly, the UE performs the downlink synchronization signal search based on the primary numerology type having the highest priority. If the downlink synchronization based on the primary numerology type is unsuccessful, the UE sequentially selects the secondary numerology type (s) The downlink synchronization signal search and the cell search can be performed.

In this case, an arbitrary NR cell not only transmits a downlink synchronization signal separately for each numerology type supported by the corresponding cell, but also transmits a physical channel (for example, a physical channel such as a PBCH for transmitting an MIB of an LTE system) The other system configuration related system information transmitted through the main system information transmitted or the downlink data channel (or downlink common channel, i.e., downlink physical channel such as the PDSCH of the LTE system) It can be transmitted separately.

Or a plurality of numerology types are supported in an arbitrary NR cell, and a separate downlink synchronization signal is transmitted for each numerology type, and a cell-specific primary numerology type and a secondary numerology type for the numerology types supported in the corresponding cell, type (s), the downlink physical channel for transmitting the main system information for terminal synchronization, or other system information related to cell configuration may be defined to be transmitted based on the primary numerology type.

In this case, the primary numerology type is arbitrarily determined by the center frequency of the NR frequency band in which the corresponding NR cell is configured, or arbitrarily by the base station / transmitting / receiving point constituting the corresponding cell, and the numerology type is represented by primary numerology type to the UE.

When a cell-specific primary numerology type is defined as described above, an arbitrary UE can synchronize downlink synchronization based on a primary numerology type, receive system information, a specific secondary numerology type is set, and a synchronization signal for the corresponding secondary numerology type is received for each terminal, so that downlink synchronization for the secondary numerology type can be performed.

However, in this case, information on the secondary numerology type (s) supported by the corresponding cell through the system information in which the corresponding base station / transmission / reception point is transmitted based on the primary numerology type, and information on the secondary resource type Information (i.e., time / frequency allocation information for each secondary numerology type) or downlink synchronization signal transmission resource allocation information (time / frequency allocation information) for each secondary numerology type.

Point 2: multiplexing among numerology specific synchronization signal

1. TDM based multiplexing

As shown in FIG. 1, the downlink synchronization signal transmission resources of each numerology type supported by an arbitrary NR cell can be defined to multiplex based on TDM.

In other words, if M number of numerology types Nk ~ N (k + M-1) having different subcarrier spacing or different subframe (or TTI) lengths are supported at an arbitrary NR cell / base station / transmission / reception point, the downlink synchronization signal can be defined to be transmitted based on a certain period, PL (L = k, k + 1, ..., k + M-1) for each numerology type.

In this case, the downlink synchronization signal transmission period of each numerology type, PL, may have the same fixed value regardless of the numerology type, or may have a separate value for each numerology type.

2. FDM based multiplexing

As shown in FIG. 2, it is possible to define downlink synchronization signal transmission resources for each numerology type supported by an arbitrary NR cell to be multiplexed based on FDM.

That is, when M number of numerology types Nk ~ N (k + M-1) having different subcarrier spacing or different subframe (or TTI) lengths are supported at an arbitrary NR cell / base station / transmission / reception point, P, the downlink synchronization signal transmission for each numerology type is performed through different frequency regions of the same subframe (or corresponding time interval).

In this case, the position in the frequency axis where the synchronization signal is transmitted for each numerology type in the subframe (or the corresponding time interval) in which the downlink synchronization signal transmission is performed depends on the center frequency of the frequency band in which the NR cell is configured, And numerology type.

3 is a diagram illustrating a configuration of a base station according to another embodiment of the present invention.

3, a base station 1000 according to another embodiment includes a control unit 1010, a transmission unit 1020, and a reception unit 1030.

The controller 1010 controls the overall operation of the base station, which is required to form an independent downlink according to the numerology type and transmit the numerology type to the UE according to the present invention described above.

The transmitting unit 1020 and the receiving unit 1030 are used to transmit and receive signals, messages, and data necessary for carrying out the present invention to and from the terminal.

4 is a diagram illustrating a configuration of a user terminal according to another embodiment of the present invention.

4, a user terminal 1100 according to another embodiment includes a receiving unit 1110, a control unit 1120, and a transmitting unit 1130.

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

In addition, the controller 1120 determines the priorities of the numerology types according to the center frequency of the NR frequency band and controls the overall operation of the terminals required to search the downlink according to the priorities of the numerology types.

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

The standard content or standard documents referred to in the above-mentioned embodiments constitute a part of this specification, for the sake of simplicity of description of the specification. Therefore, it is to be understood that the content of the above standard content and some of the standard documents is added to or contained in the scope of the present invention, as falling within the scope of the present invention.

The foregoing description is merely illustrative of the technical idea of the present invention, and various changes and modifications may be made by those skilled in the art without departing from the essential characteristics of the present invention. Therefore, the embodiments disclosed in the present invention are intended to illustrate rather than limit the scope of the present invention, and the scope of the technical idea of the present invention is not limited by these embodiments. The scope of protection of the present invention should be construed according to the following claims, and all technical ideas within the scope of equivalents should be construed as falling within the scope of the present invention.

Claims (1)

A frame structure design method for a next generation radio access network,
A step in which a downlink synchronization signal independent of each numerology type is constructed and transmitted;
Determining priority of a numerology type for receiving the downlink synchronization signal according to a center frequency of an NR frequency band for each terminal; And
And searching for the downlink synchronization signal according to a priority of the determined numerology type.

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