KR20180091320A - Method and apparatus for frame boundary timing acquisition for nr communication system - Google Patents

Abstract

The present disclosure relates to a method and an apparatus for acquiring a frame boundary timing in a new radio (NR) system. According to an embodiment of the present disclosure, a method for a terminal to acquire a frame boundary timing in a wireless communication system comprises the steps of: detecting a synchronization signal block transmitted from a base station; determining a time domain index in which the synchronization signal block is included based on at least one of a predetermined position on a time domain or a predetermined position on a frequency domain of a synchronization signal in the synchronization signal block; and determining a frame boundary timing based on the determined time domain index.

Description

[0001] METHOD AND APPARATUS FOR FRAME BOUNDARY TIMING ACQUISITION FOR NR COMMUNICATION SYSTEM [0002]

This disclosure relates to wireless communication systems, and more particularly, to a method and apparatus for frame boundary timing acquisition in an NR (New Radio) system.

The International Telecommunication Union (ITU) has been developing IMT (International Mobile Telecommunication) frameworks and standards, and is currently under discussion for 5G (5G) communication through a program called "IMT for 2020 and beyond" .

In order to meet the requirements of "IMT for 2020 and beyond", the 3rd Generation Partnership Project (3GPP) NR (New Radio) system is designed to support a variety of neuromancers in consideration of various scenarios, service requirements, and to support numerology. However, the method of configuring the synchronization signals in the NR system, the intra-slot multiplexing of the synchronization signals, and the method of indicating the frame timing (or frame boundary) to be provided to the terminal in the synchronization procedure have been specifically described none.

SUMMARY OF THE INVENTION The present invention provides a method and apparatus for a terminal to obtain frame boundary timing in an NR system.

SUMMARY OF THE INVENTION It is a technical object of the present disclosure to provide a method and apparatus for a terminal performing an initial cell access to obtain frame boundary timing based on an SS block structure.

The technical objects to be achieved by the present disclosure are not limited to the above-mentioned technical subjects, and other technical subjects which are not mentioned are to be clearly understood from the following description to those skilled in the art It will be possible.

A method for a terminal to obtain frame boundary timing in a wireless communication system according to an aspect of the present disclosure includes detecting a synchronization signal block transmitted from a base station; Determining a time domain index to which the synchronization signal block belongs based on at least one of a predetermined position on the time domain or a predetermined position on the frequency domain of the synchronization signal in the synchronization signal block; And determining frame boundary timing based on the determined time domain index.

The features briefly summarized above for this disclosure are only exemplary aspects of the detailed description of the disclosure which follow, and are not intended to limit the scope of the disclosure.

According to the present disclosure, a method and apparatus may be provided for a terminal in a NR system to obtain frame boundary timing.

According to the present disclosure, a method and apparatus can be provided for a terminal performing initial cell access to obtain frame boundary timing based on an SS block structure.

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

1 is a diagram for explaining an exemplary configuration of an SS block, an SS burst, and an SS burst set to which the present disclosure can be applied.
Figure 2 is an exemplary illustration of beam transmission within an SS burst in which the present disclosure may be applied.
3 illustrates an SS block transmission structure according to the present disclosure.
4 is a diagram for explaining a frame boundary timing acquisition method based on a slot structure according to the present disclosure.
5 is a diagram illustrating examples of a default slot structure in accordance with the present disclosure;
6 and 7 are views for explaining a frame boundary timing detection scheme based on NR-SSS physical resource location according to the present disclosure.
8 is a diagram illustrating a configuration of a wireless device according to the present disclosure;

Hereinafter, embodiments of the present disclosure will be described in detail with reference to the accompanying drawings, which will be easily understood by those skilled in the art. However, the present disclosure may be embodied in many different forms and is not limited to the embodiments described herein.

In the following description of the embodiments 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 disclosure rather unclear. Parts not related to the description of the present disclosure in the drawings are omitted, and like parts are denoted by similar reference numerals.

In the present disclosure, when an element is referred to as being "connected", "coupled", or "connected" to another element, it is understood that not only a direct connection relationship but also an indirect connection relationship May also be included. Also, when an element is referred to as " comprising "or" having "another element, it is meant to include not only excluding another element but also another element .

In the present disclosure, the terms first, second, etc. are used only for the purpose of distinguishing one element from another, and do not limit the order or importance of elements, etc. unless specifically stated otherwise. Thus, within the scope of this disclosure, a first component in one embodiment may be referred to as a second component in another embodiment, and similarly a second component in one embodiment may be referred to as a first component .

In the present disclosure, the components that are distinguished from each other are intended to clearly illustrate each feature and do not necessarily mean that components are separate. That is, a plurality of components may be integrated into one hardware or software unit, or a single component may be distributed into a plurality of hardware or software units. Thus, unless otherwise noted, such integrated or distributed embodiments are also included within the scope of this disclosure.

In the present disclosure, the components described in the various embodiments are not necessarily essential components, and some may be optional components. Thus, embodiments consisting of a subset of the components described in one embodiment are also included within the scope of the present disclosure. Also, embodiments that include other elements in addition to the elements described in the various embodiments are also included in the scope of the present disclosure.

The present disclosure is directed to a wireless communication network, wherein operations performed in a wireless communication network may be performed in a process of controlling a network and transmitting or receiving signals in a system (e.g., a base station) And may be performed in a process of transmitting or receiving a signal from a terminal coupled to a wireless network.

It will be appreciated that various operations performed for communication with a terminal in a network consisting of a plurality of network nodes including a base station may be performed by a base station or other network nodes other than the base station. A 'base station (BS)' may be replaced by terms such as a fixed station, a Node B, an eNodeB (eNB), a gNodeB (gNB), an access point (AP) In addition, 'terminal' may be replaced with terms such as User Equipment (UE), Mobile Station (MS), Mobile Subscriber Station (MSS), Subscriber Station (SS) .

In this disclosure, transmitting or receiving a channel implies transmitting or receiving information or signals over the channel. For example, transmitting a control channel means transmitting control information or signals through a control channel. Similarly, transmitting a data channel means transmitting data information or signals over the data channel.

In the following description, the term NR system is used for the purpose of distinguishing a system to which various examples of this disclosure apply from an existing system, but the scope of the present disclosure is not limited by these terms. Further, while the term NR system herein is used as an example of a wireless communication system capable of supporting various subcarrier spacing (SCS), the term itself is limited to a wireless communication system supporting a plurality of SCSs no.

First, the numerology considered in the NR system will be explained.

NR neurorrosion can refer to a number of fundamental factors or factors that create a resource grid on the time-frequency domain for the design of an NR system. For example, the subcarrier spacing corresponds to 15 kHz (or 7.5 kHz in the case of a MBSFN (Multicast-Broadcast Single-Frequency Network)), as an example of a download of the 3GPP LTE / LTE-A system. It should be noted that the term " cyclic prefix " refers not only to subcarrier spacing but also to CP (Cyclic Prefix) lengths (determined based on subcarrier spacing) ), The number of orthogonal frequency division multiplexing (OFDM) symbols in a predetermined time interval, the duration of one OFDM symbol, and the like. That is, different memories can be distinguished from each other by having different values in at least one of the subcarrier spacing, the CP length, the TTI length, the number of OFDM symbols within a predetermined time interval, or the duration of one OFDM symbol.

To meet the requirements of "IMT for 2020 and beyond", the current 3GPP NR system considers multiple neighbors in consideration of various scenarios, various service requirements, and compatibility with potential new systems. More specifically, as a ringer of existing wireless communication systems, it is difficult to support higher frequency bands, faster moving speeds, lower delays, etc. required by "IMT for 2020 and beyond " It is necessary to define.

For example, the NR system may support applications such as Enhanced Mobile Broadband (eMBB), Massive Machine Type Communications (mMTC) / Ultra Machine Type Communications (uMTC), and URLLC (Ultra-Reliable and Low Latency Communications). In particular, the requirements for the user plane latency for the URLLC or eMBB service are 0.5ms in the uplink and 4ms in both the uplink and downlink, which is a requirement for 3GPP Long Term Evolution (LTE) and LTE-Advanced Lt; RTI ID = 0.0 > 10ms < / RTI >

In order to satisfy various scenarios and various requirements in one NR system, it is required to support various types of neurology. In particular, it is required to support a plurality of SCSs, as opposed to supporting one subcarrier spacing (SCS) in an existing LTE / LTE-A system.

To solve the problem of not being able to use a wide bandwidth in a frequency range or carrier such as the existing 700 MHz or 2 GHz, a new newsletter for an NR system including supporting a plurality of SCS, Or a wireless communication system operating in a frequency range or carrier such as 40 GHz, but the scope of the present disclosure is not so limited.

In order to newly define such an NR system, it is preferable to define a synchronization scheme having a meaning as a first step for the mobile communication terminal to access the network. However, a method of configuring a synchronization signal to support synchronization, a method of mapping a synchronization signal on a time-frequency resource and transmitting the synchronization signal, a method of receiving a synchronization signal mapped on a time-frequency resource, It is not.

Hereinafter, a description will be given of examples of the present disclosure of a method for configuring synchronization signals in an NR system, intra-slot multiplexing of synchronization signals, and a method for indicating frame timing (or frame boundary) do.

1 is a diagram for explaining an exemplary configuration of an SS block, an SS burst, and an SS burst set to which the present disclosure can be applied.

At least the PSS / SSS and / or PBCH may be transmitted within one SS block. In addition, other signals may be transmitted together in the SS block. For example, a Measurement Reference Signal (MRS) that can be used for channel quality measurement for beamforming transmission, a Temporary Synchronization Signal (TSS) for indicating a time domain index (e.g., SS block index, etc.) Can be multiplexed and transmitted within the SS block.

In one SS block, an NR-SS signal and a broadcast channel are allocated to physical resources through Frequency Division Multiplexing (FDM), Time Division Multiplexing (TDM), or a combination thereof, To the terminal.

A beam transmission based SS block may be transmitted by using one or more different beams among the SS blocks in at least the SS burst set period. In particular, a beam-transmission-based SS block transmission may be used to compensate for channel attenuation occurring in a high frequency band (e.g., 6 GHz or more (over 6 GHz)). Alternatively, in a frequency band other than the high frequency band (e.g., below 6 GHz), all SS blocks can be transmitted in a single beam form.

One or more SS blocks may constitute one SS burst. SS blocks constituting one SS burst can be allocated consecutively or discontinuously in time or frequency domain.

One or more SS bursts may constitute one SS burst set. From the terminal point of view, periodic NR-SS reception can be expected at every SS burst set periodicity.

During at least initial cell access for a particular frequency band, the terminal may assume a default SS burst transmission period value. In the RRC connected mode or the RRC idle mode, the UE may receive updated information regarding the SS burst set transmission period from the base station.

As shown in FIG. 1, one SS block may include at least NR-PSS / NR-SSS and potentially NR-PBCH.

One SS block can be transmitted with one or more beams applied. Here, the number of nominal beams M is defined, of which the number P of actual beams can be determined.

One SS burst may consist of one or more SS blocks. Here, the number (N) of nominal SS blocks constituting one SS burst is defined, and the number (T) of actual SS blocks can be determined.

One SS burst set may consist of one or more SS bursts.

Also, all SS blocks may not always transmit synchronization signals and broadcast channels (e.g., NR-PBCH, NR-SIB (System Information Block)). For example, some SS blocks may be actually used and some SS blocks may be unused depending on the cell configuration such as TRP (Total Radiated Power). A specific SS block may transmit only a synchronization signal and not a broadcast channel, or a certain SS block may transmit a broadcast channel and may not transmit a synchronization signal.

Hereinafter, a method of indicating a synchronization signal, SS structure, and timing information for the NR system will be described.

In the NR system, a synchronization signal, a random access signal, and a broadcast channel (e.g., a broadcast signal) are generated in order to overcome a bad channel environment in which path loss, phase noise, frequency offset, (NR-PBCH, NR-SIB (System Information Block)), and the like.

In order to support multiple beam transmissions, the beam width, the number of beams, etc. may be determined, which may include the environment of the cell with the TRP (e.g., target coverage area, ISD Distance), a carrier frequency band, and the like). Therefore, it is required to define the maximum number of beams to be transmitted on the maximum physical resources (eg SS block / SS burst / SS burst set) to provide implementation flexibility.

Figure 2 is an exemplary illustration of beam transmission within an SS burst in which the present disclosure may be applied.

2 (a) shows an example in which one beam is applied to one SS block and a general analog beamforming method is applied. In this case, the number of applicable beams may be limited depending on the number of RF chains in general.

FIG. 2 (b) shows an example in which two beams are applied to one SS block and a general digital beamforming method or a hybrid beamforming method is applied. In this example, beam sweeping is possible to cover the target coverage area within a shorter time. Therefore, it is possible to consume fewer SS block resources than the example of FIG. 2 (a) and to improve the network resource consumption efficiency.

As shown in Figure 1, the NR system may require one or more beam transmissions to be applied to the same SS block. Therefore, SS block transmission with different beam patterns through beam sweeping for each SS block can be transmitted to satisfy the target coverage area.

Here, the transmission for satisfying the target coverage area may be such that each of the one or more beam transmissions is transmitted based on the beam width and / or the azimuth intended by the base station, Quot; means to cover a given target area as a whole of the transmission.

As shown in Table 1 below, in a system in which beamforming is not applied to the synchronization signal, the symbol timing is obtained by receiving the PSS, and the CP type, the frame structure, and the subframe index information are obtained by blind decoding the SSS , And finally obtain the frame timing and the subframe index and the symbol index within the frame. The frame index can be finally provided to the UE through the PBCH.

Referring to FIG. 1, in the NR system, a method of acquiring a frame / symbol timing by periodically transmitting a synchronization signal on a predetermined physical resource can not be applied as it is. However, a synchronization signal supporting one or more beam transmission A method by which a terminal can obtain frame / symbol timing is not yet defined. Thus, this disclosure redefines the way in which a terminal acquires frame / symbol timing (e.g., index) in an NR system where one or more beam transmissions are allowed.

Hereinafter, an SS structure and a frame timing indicating scheme according to the present disclosure will be described.

3 illustrates an SS block transmission structure according to the present disclosure.

Assume that N is the number of OFDM symbols per SS block (# OFDM symbol per SS block). I can be determined according to a multiplexing method between a synchronization signal such as NR-PSS / SSS, NR-TSS, NR-PBCH, MRS, and a broadcast channel. For example, the N value may be 1, 2, or 4.

Assume M is the number of beams per SS block (# of beam per SS block). The value of M may refer to the maximum number of beams applied to one SS block, and the number of beams and the beam width may be set by the base station. Therefore, the base station may transmit a beam by the number of all possible beams in one SS block, or may transmit the SS through a certain number of beams.

Assume that the number of SS blocks per SS burst (# of SS block per SS burst) is I. The number of SS blocks that can be configured for each SS burst may always have a fixed I value or an I value may be set according to the fixed SS burst duration T and the number of OFDM symbols N constituting one SS block It may be changed.

The value of the SS burst duration is assumed to be T, and the unit thereof may be ms. The value of T may be determined according to one or more of the subcarrier spacing (SCS), the number of OFDM symbols constituting one SS block (I), and the number of fixed SS blocks (N) constituting one SS burst have. For example, the T value may have a value of 1 ms, 2 ms, 4 ms, ..., and so on.

The SS burst periodicity may be assumed to be J, and the unit thereof may be ms. The SS burst has a fixed period and its value can be determined according to the requirements for the synchronization time. For example, the value of J may be 5 ms, but is not limited to that value, and a different J value may be set for each SCS depending on the value of SCS, other SS transport structures, and so on.

The number of SS bursts per SS burst set (# of SS burst per SS burst set) is assumed to be K. The K value may be set to a fixed value or may be set by the base station through higher layer signaling or the like.

In addition, an SS burst set periodicity can be defined. From the point of view of the terminal, if it is succeeded to detect one SS block for at least initial cell access, it can be assumed that the period in which the same beam pattern as the beam pattern in the detected SS block is transmitted is SS burst set periodicity.

Hereinafter, examples of the present disclosure for providing the UE with the above information (i.e., configuration information related to the synchronization signal) through the NR synchronization signal and broadcast channels based on the SS block transmission structure according to the above assumption will be described do.

If the number of OFDM symbols constituting one SS block is plural (for example, N = 2, 3 or 4), NR-SS and NR-PBCH can be multiplexed through TDM or a combination of FDM and TDM.

It is assumed that a subframe has a 1 ms time interval. That is, although the SCS is different, the subframe can be defined as a fixed predetermined time period.

One slot may be set differently according to the SCS, for example, as shown in Table 2 below. In Table 2 below, one slot is composed of 7 symbols when SCS is 15 kHz, but one slot may be composed of 7 or 14 symbols in the case of SCS of the other values.

The number of slots that can achieve one subframe (1 ms) may vary depending on the SCS value. Referring to Table 2, when the SCS is 15 kHz, the number of symbols of one slot is 7 and the number of slots per subframe is 2. If the number of symbols of one slot is 7 when the SCS is 30 kHz, the number of slots per subframe may be 4. If the number of symbols of one slot is 7 when the SCS is 60 kHz, the number of slots per subframe may be 8.

Accordingly, if at least one SS burst time interval is determined to be a predetermined length, the number of SS blocks can be defined accordingly. Here, the SS burst time interval may be defined in units of slots, subframes, or time units (e.g., in units of ms).

For example, in 15KHz subcarrier spacing (SCS), the SS burst period can be defined as 1ms (subframe). If one SS block is composed of N (for example, N = 2, 3 or 4) OFDM symbols, a fixed number of SS blocks may be configured for each SS burst. Or, according to the number of OFDM symbols constituting one SS block, the SS burst interval may be larger or smaller than 1 ms according to the SCS value.

The number of SS blocks in the SS burst interval may be determined based on the time interval length of the SS block (e.g., 2, 3, or 4 symbols).

As the terminal receives an arbitrary SS block, the terminal can know the boundary of at least OFDM symbol timing according to the structure including the number of OFDM symbols per predetermined SS block. However, even if the SS receives the SS block, the SS may not know information about which SS block index corresponds to which symbol index, and which symbol index corresponds to the corresponding symbol timing, You may also not know about the information. Also, since information on how many beams are applied to one SS block is also required to perform procedures such as initial synchronization, RRM measurement, random access, etc., when one or more beams are applied to an SS transmission, resource index information may also be needed.

Hereinafter, the terminal will be described in various examples of this disclosure for at least initial cell access, frame boundary timing acquisition of the terminal, and frame boundary timing indication of the base station .

Examples of the present disclosure include measures to determine frame boundary timing based on the synchronization signal detected by the terminal. For example, the terminal may compare the position in the time domain in which the synchronization signal was detected and the predetermined time domain position for the synchronization signal (e.g., comparison with the default slot structure) And determine a frame boundary accordingly. Further, for example, the terminal may compare the position in the frequency domain where the synchronization signal is detected and the predetermined frequency domain position with respect to the synchronization signal (for example, comparison with a predetermined frequency offset combination) To determine the temporal domain index to which it belongs, and thus to determine the frame boundary.

The terminal must perform an initial cell access procedure including synchronization and acquisition of system information in order to access the NR system. As described above, the NR system transmits a synchronization signal and broadcast channels to a mobile station in order to provide synchronization and system information under the structure of SS block / SS burst / SS burst set. During such a process, the terminal can obtain frame boundary timing information.

The UE can monitor at least NR-SS / PBCH signals in the SS block for initial cell access based on at least a default subcarrier spacing value.

Here, the default subcarrier spacing may correspond to a numerology value that the terminal assumes for at least the initial cell access purpose for each frequency band. Through this value, the UE can presume a time domain resource structure (for example, OFDM symbol length, slot structure, sub-frame structure, radio frame structure, etc.) for NR-SS reception in the SS block at least. As an example for the default subcarrier spacing, at least one of 15 kHz, 30 kHz, or 60 kHz may be used as the default subcarrier spacing value in the below 6 GHz frequency band range, and in the over 6 GHz (or 6 to 52.6 GHz) 120 kHz, or 240 kHz may be used as the default subcarrier spacing value.

It is assumed that one set of time base positions of SS blocks that can be transmitted in the SS burst set is defined for each frequency band. This may be predetermined in advance or may additionally be determined by the setting of the base station. At least for the initial cell access purpose, the time axis positions of the transmittable SS blocks are predetermined, and the base station can determine whether to transmit the actual SS block within the transmittable SS block time. Or it may be predetermined so that all SS blocks are always used for actual SS block transmission.

The terminal may monitor SS blocks for initial cell access based at least on the value of the default SS burst set periodicity. If the terminal has succeeded in detecting and synchronizing at least the NR-SS with one SS block, the terminal can expect and expect that the same form of NR-SS reception will be possible after the default synchronization signal burst set period.

4 is a diagram for explaining a frame boundary timing acquisition method based on a slot structure according to the present disclosure.

In the example of FIG. 4, SS frame index and SS burst index are shown, and a frame boundary timing acquisition method based on a slot structure for an initial cell access terminal is shown.

The UE performing at least the initial cell access knows the information about the frequency band, the associated default subcarrier spacing, the default SS burst set period value, and the positions in the time domain of the SS block available in the corresponding frequency band, can do.

Referring to FIG. 4, the UE assumes a 15kHz default subcarrier spacing value for initial cell access, for example, in a frequency band corresponding to below 6GHz. Also, it is assumed that the SS has a default synchronization signal burst set period value of 10ms, two SS bursts in one SS burst set, and two SS blocks in one SS burst. In this way, the SS blocks in one SS burst set are formed as one set, and at least one of NR-SS / PBCH / NR-TSS (Ternary SS) / MRS (Measurement RS) Whether or not to do this depends on the setting of the base station. In the present invention, the terminals performing the initial cell access assume the number of SS blocks fixed in one SS burst set and its period per frequency band / range.

The UE must monitor the SS blocks during a certain window period because at least during the initial cell access, the UE can not know at what instant the SS blocks are to be transmitted. Once at least 420 the NR-SS in one SS block has been successfully detected during the monitoring, it may be expected that the same SS block will be received at least after SS burst set periodicity (410). It is possible to combine signals received at least among the SS blocks through the assumption for reception of the SS block of the terminal, and the quality of the received signals can be improved through such an operation.

In the following description, the terminal detects the SS block, which means that the terminal succeeds in receiving signals and channels to be transmitted in the SS block.

As shown in FIG. 4, if the terminal detects at least one SS block, it may derive one or more time index values of SS block index, OFDM symbol index, slot index, or radio frame number. For example, the terminal may derive the time index values through one or more combinations of the NR-SS signal NR-TSS signal, the NR-PBCH channel. Based on the derived time index value (for example, SS block index, etc.), the UE can know which SS block belongs to which slot in the NR frame.

4, if the UE succeeds in detecting an SS block corresponding to the SS block index # 1 405 in one SS burst set 406, Lt; / RTI > Since it is predetermined in advance how many OFDM symbols constitute one SS block (for example, two, three, or four OFDM symbols can constitute one SS block (404, 405, 424 or 425) , It is possible to derive how many SS blocks can be transmitted in one slot 401.

On the other hand, not only the terminals attempting to access only the initial cell but also all the terminals already camping on the cell or camping on the cell exist in the cell. Therefore, in the same slot 401, a resource area 403 for transmitting uplink control information as well as a resource area 402 for transmitting downlink control information is multiplexed with SS blocks 404 and 405 .

The problem of estimating the frame boundary through the SS block detection is that at least the downlink control information transmission region 402 can be changed dynamically for each slot. In addition, the uplink control information transmission area 403 can be dynamically changed per slot according to the amount of uplink control information transmission. Therefore, it is difficult for the base station to provide information on the uplink or downlink control information area mentioned above during initial cell access. Thus, in the present disclosure, a terminal may use a "default slot structure" in which an SS block is transmitted to derive at least frame boundary timing.

5 is a diagram illustrating examples of a default slot structure in accordance with the present disclosure;

One slot through which the SS block is transmitted may be determined as described above. Next, the UE can assume a fixed number of downlink / uplink control areas (based on the number of OFDM symbols) in the slot, and the value of the slot can be any value smaller than the number of OFDM symbols constituting the slot .

The UE can determine that the SS block is located in the remaining OFDM symbol regions except for the fixed downlink / uplink control region in one slot to which the SS block is transmitted (if any).

The applicable default slot structure can be configured as in the example of FIG. However, the scope of the present disclosure is not limited thereto, and includes any slot structure satisfying such a structure.

For example, as shown in FIG. 5, the number of SS blocks and their positions can be fixed in one slot, and the rest of the OFDM symbols have various channels and signals (downlink control channel, downlink data channel, A link control channel, an uplink data channel, an MRS, a sounding reference signal (SRS), and the like) may be allocated and transmitted at predetermined positions. The transmission of these various channels and signals may be established by the base station or may be determined by a predetermined method in an SS block transmission slot.

In the example of the slot 4401 in FIG. 5, three SS blocks 4402, 4403 and 4404 fixed in one slot are located, and the positions of the PSS / SSS / PBCH allocated to each SS block are shown in FIG. 5 . ≪ / RTI >

Here, instead of the NR-PBCH, an MRS may be transmitted for channel measurement purposes, for terminals other than the initial cell access terminals (e.g., neighbor cell terminals, RRC connected / idle terminals, etc.). This is because the NR-PBCH does not need to be transmitted every SS block. This SS block can be referred to as a channel measurement SS block (SS block # 1 (4403) in FIG. 5).

Of course, the initial cell access terminals may also detect the SS block, but receive the NR-PBCH from another SS block because there is no NR-PBCH channel for cell access. In addition, resources can be set and scheduled for the MRS and the downlink control channel / data channel transmission (4405) using the remaining OFDM symbols except for the OFDM symbol to which the SS blocks are allocated according to the setting of the additional base station.

In the example of the slot 4501 of FIG. 5, three SS blocks 4502, 4503 and 4504 fixed to one slot are located, and the positions of the PSS / SSS / PBCH allocated to each SS block are shown in FIG. 5 . ≪ / RTI > Here, SS block # 0 is a channel measurement SS block.

5, two fixed SS blocks 4604 and 4605 are located in one slot, and the positions of the PSS / SSS / PBCH allocated to each SS block are as shown in the example of FIG. 5 Can be predetermined.

5, two fixed SS blocks 4704 and 4705 are located in one slot, and the positions of the PSS / SSS / PBCH allocated to each SS block are as shown in the example of FIG. 5 Can be predetermined.

Also, according to the present disclosure, it is not considered in the terminal how the signals such as the NR-SS / NR-PBCH in one SS block are actually multiplexed, and the terminal determines the frame boundary timing based on a predetermined multiplexing method Can be estimated.

For example, an SS block structure such as SS block # 0 (404) and SS block # 1 (405) in FIG. 4 may be assumed, but not limited thereto. At least NR-SS and NR- TDM. ≪ / RTI > Other RSs (e.g., MRS, NR-TRS, etc.) may also be multiplexed in various ways with the signals in the SS block.

The default slot structure may assume different slot structures for at least the initial cell access, depending on one or more of the frequency band / range, default subcarrier spacing, minimum NR-SS bandwidths.

In the default slot structure, the base station may indicate the downlink control region / uplink control region to the terminal for another purpose including initial cell access. For example, the base station transmits the group common PDCCH to the UE, so that at least the UEs connected to the cell and the camping-on UEs can notify the UEs of the downlink / uplink control region in an area excluding the positions of the fixed SS blocks And can also provide information about the downlink / uplink control region to the UEs as to whether the UE can use for channel measurement or data transmission. In this case, the terminal must conform to the slot structure based on the value indicated by the base station.

4, if the UE detects the SS block # 1 405 in one slot 401 composed of 14 OFDM symbols, for example, the downlink control region 402 includes four OFDM symbols, SS block # 0 404 assumes a default slot structure having four OFDM symbols and the uplink control region 403 has two OFDM symbols. Therefore, the mobile station can derive the frame boundary based on the predetermined downlink control region and the location of the SS block based on the timing acquired through the PSS / SSS reception in the SS block # 1 (407).

The SS transmission bandwidth is generally less than the system bandwidth. Therefore, the downlink control region and the uplink control region corresponding to the SS transmission bandwidth of the initial cell access terminal are allocated to the uplink control region and the downlink control region based on the default subcarrier spacing (15 kHz in the example of FIG. 4) We should assume the symbol interval.

The downlink control region and the uplink control region set by the actual base station may be equal to or smaller than the size of the control region assumed by the UE performing initial cell access, The frame boundary can be easily estimated by assuming that the downlink control region and the uplink control region always have a fixed interval.

The method proposed by the present invention is not limited to the above examples. For example, the default subcarrier spacing value for initial cell access may be one of 30, 60, 120, 240 kHz instead of 15 kHz. Also, the number of OFDM symbols constituting one slot may be seven instead of fourteen. Also, the number of OFDM symbols constituting one SS block may be 2 or 3 instead of 4. Also, the possible number of SS blocks in a slot can be one of 3, 4, 5, 6, or 7 instead of 2. Also, the size of the DL control region assumed by the UE attempting at least the initial cell access may be different values within one slot instead of four OFDM symbols according to the length of the slot SS block and the default subcarrier spacing values have. Likewise, at least the uplink control region in one slot assumed by the UE performing initial cell access. Also, although the above example has been described based on the SS block index, the proposed scheme can be applied based on the SS burst index. For example, based on the SS burst index not the SS block index in the SS burst set, the position in the frame of the SS burst including the detected SS block is grasped, and the proposed slot structure predetermined for the initial cell access terminal Based on the assumption, the terminal can derive the frame boundary.

As a further example of this disclosure, the terminal may derive frame boundary timing based on the NR-SSS sequence or an allocation location on the physical resources of the NR-SSS.

6 and 7 are views for explaining a frame boundary timing detection scheme based on NR-SSS physical resource location according to the present disclosure.

Instead of utilizing SS burst index or SS block index information, the UE monitors the frequency offset combination between a predetermined SSS1 (for example, m0) and SSS2 (for example, m1) in the frequency domain . The UE performs monitoring based on the frequency axis position of each SS block of the predetermined SSS1 / SSS2 sequence and derives the SS burst index value based on the SS block index value derived in this manner. Since the derived SS burst index value is determined for each SS burst set and the corresponding frame boundary is predetermined in advance, the UE can estimate the frame boundary with the derived SS burst index value .

The SS according to this example may not need the SS burst index information. Instead, the terminal monitors the change combination of the frequency allocation positions between the predetermined SSS1 and SSS2 on the frequency domain. There is no additional complexity here. Because the terminal performs blind monitoring for each SS block interval in order to know the SS block index value, the SS block index value and the frame timing information can be acquired at the same time according to the monitoring result.

If a different SSS sequence is assigned in the frequency resources above or below the PSS at the frame boundary, the UE can recognize the frame timing.

8 is a diagram illustrating a configuration of a wireless device according to the present disclosure;

8 shows a base station apparatus 800 for transmitting a synchronization signal and a terminal apparatus 850 for receiving a synchronization signal.

The base station apparatus 800 may include a processor 810, an antenna unit 820, a transceiver 830, and a memory 840.

The processor 810 performs baseband related signal processing and may include an upper layer processing unit 811 and a physical layer processing unit 812. [ The upper layer processing unit 811 can process the operations of the MAC layer, the RRC layer, or higher layers. The physical layer processing unit 812 can process the operation of the PHY layer (e.g., downlink transmission signal processing, uplink reception signal processing). In addition to performing baseband related signal processing, the processor 810 may also control operation of the entire base station apparatus 800. [

The antenna unit 820 may include one or more physical antennas, and may support MIMO transmission / reception when the antenna includes a plurality of antennas. The transceiver 830 may include an RF transmitter and an RF receiver. The memory 840 may store computationally processed information of the processor 810, software related to the operation of the base station device 800, an operating system, applications, and the like, and may include components such as buffers.

The processor 810 of the base station device 800 may be configured to implement base station operation in the embodiments described herein.

For example, the upper layer processing unit 811 in the processor 810 generates setting information necessary for SS block, MRS, and downlink / uplink control information transmission, and transmits the setting information to the terminal To the device 850.

The physical layer processing unit 812 in the processor 810 of the base station apparatus may include an SS block transmitting unit 813, a control information transmitting unit 814, and a reference signal transmitting unit 815.

For example, the SS block transmitter 813 transmits a default SCS for each frequency band range (e.g., below 6GHz, over 6GHz, etc.), a default SS burst set periodicity, time position of SS blocks, default slot structure, and so on. The control information transmitting unit 814 may transmit control information to the UE in the control area defined in the same slot as the SS block (e.g., according to the default slot structure). The reference signal transmitter 815 may also transmit a reference signal (e.g., MRS, etc.) at a particular location (e.g., in accordance with the default slot structure) defined in the same slot as the SS block.

The terminal 850 may include a processor 860, an antenna unit 870, a transceiver 880, and a memory 890.

The processor 860 performs baseband-related signal processing, and may include an upper layer processing unit 861 and a physical layer processing unit 862. [ The upper layer processing unit 861 may process an operation of a MAC (Medium Access Control) layer, an RRC (Radio Resource Control) layer, or higher layers. The physical layer processing unit 862 can process the operation of the physical (PHY) layer (e.g., uplink transmission signal processing, downlink reception signal processing). In addition to performing baseband-related signal processing, the processor 860 may also control operation of the entire terminal device 850. [

The antenna unit 870 may include one or more physical antennas, and may support multiple input multiple output (MIMO) transmission / reception when the antenna includes a plurality of antennas. The transceiver 880 may include a radio frequency (RF) transmitter and an RF receiver. The memory 890 may store information processed by the processor 860, software related to the operation of the terminal device 850, an operating system, applications, and the like, and may include components such as buffers.

The processor 860 of the terminal device 850 may be configured to implement terminal operations in the embodiments described herein.

For example, the upper layer processing unit 861 in the processor 860 receives the SS block, the MRS, the setup information required for the downlink / uplink control information transmission from the base station through the upper layer signaling, The physical layer processing unit 862 can provide information necessary for performing SS block detection or the like.

The physical layer processing unit 862 in the processor 860 of the terminal device may include an SS block receiving unit 813, a control information receiving unit 864, and a reference signal receiving unit 865. [

For example, the SS block receiving unit 863 receives a default SCS, a default SS burst set periodicity, and a time of SS blocks for each frequency band range (for example, below 6GHz, over 6GHz, etc.) Location, default slot structure, and so on. The control information receiving unit 864 may attempt to detect the control information in the control area defined in the same slot as the SS block (e.g., according to the default slot structure). Also, the reference signal receiver 865 may receive a reference signal (e.g., MRS, etc.) at a specific location defined in the same slot as the SS block (e.g., according to the default slot structure). Based on this, the physical layer processing unit 862 can determine the frame boundary timing and notify it to the upper layer processing unit 861.

Although the exemplary methods of this disclosure are represented by a series of acts for clarity of explanation, they are not intended to limit the order in which the steps are performed, and if necessary, each step may be performed simultaneously or in a different order. In order to implement the method according to the present disclosure, the illustrative steps may additionally include other steps, include the remaining steps except for some steps, or may include additional steps other than some steps.

The various embodiments of the disclosure are not intended to be all-inclusive and are intended to illustrate representative aspects of the disclosure, and the features described in the various embodiments may be applied independently or in a combination of two or more.

In addition, various embodiments of the present disclosure may be implemented by hardware, firmware, software, or a combination thereof. In the case of hardware implementation, one or more application specific integrated circuits (ASICs), digital signal processors (DSPs), digital signal processing devices (DSPDs), programmable logic devices (PLDs), field programmable gate arrays A general processor, a controller, a microcontroller, a microprocessor, and the like.

The scope of the present disclosure is to be accorded the broadest interpretation as understanding of the principles of the invention, as well as software or machine-executable instructions (e.g., operating system, applications, firmware, Instructions, and the like are stored and are non-transitory computer-readable medium executable on the device or computer.

Claims (1)

A method for a terminal to acquire frame boundary timing in a wireless communication system,
Detecting a synchronization signal block transmitted from the base station;
Determining a time domain index to which the synchronization signal block belongs based on at least one of a predetermined position on the time domain or a predetermined position on the frequency domain of the synchronization signal in the synchronization signal block; And
And determining a frame boundary timing based on the determined time domain index.

Images