KR102489799B1 - Method and apparatus for transmission and reception of reference signal for broadcast channel in nr communication system - Google Patents

Abstract

The present disclosure relates to a method and apparatus for transmitting and receiving a reference signal for a broadcast channel in a new radio (NR) system. A method for transmitting a reference signal for demodulation of a physical broadcast channel (PBCH) in a wireless communication system according to an embodiment of the present disclosure includes a sequence generation length determined based on a maximum configurable bandwidth for one bandwidth portion, and generating the reference signal based on an initialization time point determined based on at least one of a radio frame index, a slot index, a symbol index, a synchronization signal (SS) burst set index, and an SS block index; mapping the generated reference signal to a location of a resource element (RE) determined based on at least one of a frequency domain shift value and a time domain shift value; and transmitting the mapped reference signal and the PBCH to a terminal.

Description

Method and apparatus for transmitting and receiving reference signals for broadcast channels for NR systems

The present disclosure relates to a wireless communication system, and more specifically, to a method and apparatus for transmitting and receiving a reference signal for a broadcast channel in a New Radio (NR) system.

The International Telecommunication Union (ITU) is developing IMT (International Mobile Telecommunication) frameworks and standards, and recently, discussions for 5G communication are underway through a program called "IMT for 2020 and beyond" .

In order to meet the requirements presented by "IMT for 2020 and beyond", the 3GPP (3rd Generation Partnership Project) NR (New Radio) system considers various scenarios, service requirements, potential system compatibility, etc. (numerology) is being discussed in the direction of support. However, a method for transmitting and receiving a reference signal for a broadcast channel in the NR system has not yet been specifically determined.

A technical problem of the present disclosure is to provide a method and apparatus for transmitting and receiving a reference signal for a physical broadcast channel in an NR system.

An additional technical problem of the present disclosure is to provide a method and apparatus for transmitting and receiving a demodulation reference signal for demodulation of a physical broadcast channel.

An additional technical problem of the present disclosure is to provide a method and apparatus for constructing a reference signal that improves interference avoidance performance of a physical broadcast channel.

The technical problems to be achieved in the present disclosure are not limited to the technical problems mentioned above, and other technical problems not mentioned will be clearly understood by those skilled in the art from the description below. You will be able to.

According to one aspect of the present disclosure, a method for transmitting a reference signal for demodulation of a physical broadcast channel (PBCH) in a wireless communication system includes a sequence generation length determined based on a maximum configurable bandwidth for one bandwidth portion, and generating the reference signal based on an initialization time point determined based on at least one of a radio frame index, a slot index, a symbol index, a synchronization signal (SS) burst set index, and an SS block index; mapping the generated reference signal to a location of a resource element (RE) determined based on at least one of a frequency domain shift value and a time domain shift value; and transmitting the mapped reference signal and the PBCH to a terminal.

The features briefly summarized above with respect to the disclosure are merely exemplary aspects of the detailed description of the disclosure that follows, and do not limit the scope of the disclosure.

According to the present disclosure, a method and apparatus for transmitting and receiving a reference signal for a physical broadcast channel in an NR system may be provided.

According to the present disclosure, a method and apparatus for transmitting and receiving a demodulation reference signal for demodulation of a physical broadcast channel may be provided.

According to the present disclosure, a method and apparatus for constructing a reference signal that enhances interference avoidance performance of a physical broadcast channel can be provided.

Effects obtainable in the present disclosure are not limited to the effects mentioned above, and other effects not mentioned may 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, SS burst, and SS burst set to which the present disclosure may be applied.
2 to 5 are diagrams for explaining an SS burst structure to which the present disclosure can be applied.
6 is a diagram illustrating an example of resource allocation in an SS block to which the present disclosure may be applied.
7 is a diagram for explaining a bandwidth of an NR system to which the present disclosure is applied.
8 and 9 are diagrams illustrating examples of locations of DMRS REs per PRB for NR-PBCH in an SS block according to the present disclosure.
10 is a diagram illustrating examples of DMRS frequency domain shift according to the present disclosure.
11 is a diagram illustrating examples of DMRS time domain shift according to the present disclosure.
12 is a diagram illustrating a DMRS transmission/reception method for NR-PBCH according to the present disclosure.
13 is a diagram showing configurations of a base station device and a terminal device according to the present disclosure.
14 is a diagram for explaining pseudo random sequence generation according to the present disclosure.
15 and 16 are diagrams illustrating examples of PBCH reference signal sequence allocation according to the present disclosure.

Hereinafter, with reference to the accompanying drawings, embodiments of the present disclosure will be described in detail so that those skilled in the art can easily carry out the present disclosure. However, the present disclosure may be implemented in many different forms and is not limited to the embodiments described herein.

In describing the embodiments of the present disclosure, if it is determined that a detailed description of a known configuration or function may obscure the gist of the present disclosure, a detailed description thereof will be omitted. And, in the drawings, parts irrelevant to the description of the present disclosure are omitted, and similar reference numerals are attached to similar parts.

In the present disclosure, when a component is said to be "connected", "coupled" or "connected" to another component, this is not only a direct connection relationship, but also an indirect connection relationship between which another component exists. may also be included. In addition, when a component "includes" or "has" another component, this means that it may further include another component without excluding other components unless otherwise stated. .

In the present disclosure, terms such as first and second are used only for the purpose of distinguishing one element from another, and do not limit the order or importance of elements unless otherwise specified. Accordingly, within the scope of the present 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 another embodiment. can also be called

In the present disclosure, components that are distinguished from each other are intended to clearly explain each characteristic, and do not necessarily mean that the components are separated. That is, a plurality of components may be integrated to form a single hardware or software unit, or a single component may be distributed to form a plurality of hardware or software units. Accordingly, even such integrated or distributed embodiments are included in the scope of the present disclosure, even if not mentioned separately.

In the present disclosure, components described in various embodiments do not necessarily mean essential components, and some may be optional components. Therefore, an embodiment composed of a subset of components described in one embodiment is also included in the scope of the present disclosure. In addition, embodiments including other components in addition to the components described in various embodiments are also included in the scope of the present disclosure.

The present disclosure describes a wireless communication network, and operations performed in the wireless communication network are performed in the process of controlling the network and transmitting or receiving signals in a system (for example, a base station) that manages the wireless communication network, or It may be performed in a process of transmitting or receiving a signal from a terminal coupled to a wireless network.

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. 'Base Station (BS)' may be replaced by terms such as fixed station, Node B, eNodeB (eNB), gNodeB (gNB), and access point (AP). In addition, 'terminal' will be replaced with terms such as User Equipment (UE), Mobile Station (MS), Mobile Subscriber Station (MSS), Subscriber Station (SS), and non-AP STA. can

In the present disclosure, transmitting or receiving a channel means transmitting or receiving information or a signal through a corresponding channel. For example, transmitting a control channel means transmitting control information or a signal through the control channel. Similarly, transmitting a data channel means transmitting data information or a signal through 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 the present disclosure are applied from existing systems, but the scope of the present disclosure is not limited by this term. In addition, the term NR system in this specification is used as an example of a wireless communication system capable of supporting various subcarrier spacing (SCS), but the term NR system itself is not limited to a wireless communication system supporting a plurality of SCS not.

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

NR numerology may mean a numerical value of a basic element or factor generating a resource grid in the time-frequency domain for designing an NR system. For example, as an example of the numerology of the 3GPP LTE/LTE-A system, the subcarrier spacing corresponds to 15 kHz (or 7.5 kHz in the case of a Multicast-Broadcast Single-Frequency Network (MBSFN)) and a normal CP or an extended CP. . However, the term numerology does not limitly mean only subcarrier spacing, and the length of CP (Cyclic Prefix), which is related to (or determined based on subcarrier spacing), Transmit Time Interval (TTI) ) length, the number of Orthogonal Frequency Division Multiplexing (OFDM) symbols within a predetermined time interval, and the duration of one OFDM symbol. That is, different numerologies may be distinguished from each other by having different values in one or more of subcarrier spacing, CP length, TTI length, number of OFDM symbols within a predetermined time interval, or duration of one OFDM symbol.

In order to meet the requirements presented by "IMT for 2020 and beyond", the current 3GPP NR system considers multiple numerologies in consideration of various scenarios, various service requirements, and compatibility with potential new systems. More specifically, since it is difficult to support a higher frequency band, faster movement speed, lower delay, etc. required by "IMT for 2020 and beyond" with the numerology of the existing wireless communication system, a new numerology 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 ultra-reliable and low latency communications (URLLC). In particular, the requirement for user plane latency for URLLC or eMBB service is 0.5 ms in uplink and 4 ms in both uplink and downlink, which is consistent with 3GPP Long Term Evolution (LTE) and LTE-Advanced (LTE-A) systems. It requires significant latency reduction compared to the 10 ms latency requirement of .

In order to satisfy such various scenarios and various requirements in one NR system, it is required to support various numerologies. In particular, unlike supporting one subcarrier spacing (SCS) in the existing LTE/LTE-A system, it is required to support a plurality of SCSs.

A new numerology for NR systems, which includes supporting multiple SCSs, solves the problem of not being able to use a wide bandwidth in a carrier or frequency range such as 700 MHz or 2 GHz, 6 GHz It may be determined assuming a wireless communication system operating in a frequency range or carrier such as 40 GHz or higher, but the scope of the present disclosure is not limited thereto.

In order to newly define such an NR system, the terminal obtains basic minimum system information of the network through the NR-Physical Broadcast CHannel (NR-PBCH) and identifies a cell identifier. It is required to do first. However, a processing method for NR-PBCH transmission, that is, a channel coding chain structure for minimum system information transmitted through NR-PBCH, resource allocation, transmission method, etc. has not been specifically defined yet. .

Hereinafter, various examples of the present disclosure related to transmission and reception of NR-PBCH in an NR system will be described.

Hereinafter, a structure of an NR-Synchronization Signal (NR-SS) related to NR-PBCH transmission will be first described.

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

The NR-SS may include a primary SS (NR-PSS) and a secondary SS (NR-SSS), and may further include a ternary SS (NR-TSS) if supported. NR-TSS may be applied to indicate at least an index of an SS block. 1 shows an NR-PSS/SSS/TSS transmission structure.

In FIG. 1, the physical resource location of NR-PSS/SSS/TSS transmitted for each SS block does not indicate an actual physical location, but at least NR-PSS/SSS and PBCH transmission can be performed within one SS block. is to show Multiplexing for other signals and channels such as NR-PSS/SSS and NR-PBCH allocated to actual physical resources can be applied in various ways.

The SS block will be described.

At least NR-PSS/SSS is included in one SS block and transmitted. That is, the UE assumes that at least NR-PSS/SSS transmission is performed within the SS block. However, whether or not signals such as actual NR-PSS/SSS/PBCH are transmitted in possible SS blocks depends on the base station's decision. Depending on the NR-PBCH transmission period and method, at least NR-PSS/SSS/PBCH transmission may always exist in one SS block, or NR-PSS/SSS/PBCH may not exist. Alternatively, in a specific SS block, NR-PBCH transmission may be skipped and at least NR-PSS/SSS transmission may be performed. Alternatively, if NR-PBCH transmission is performed independently of NR-SS transmission and NR-SS and NR-PBCH are not always transmitted together in an SS block, NR-PBCH is transmitted using a specific SS block or fixed SS blocks can be transmitted

Additionally, other signals may be transmitted together in the SS block. For example, a measurement reference signal (MRS) that can be used by an RRC IDLE or RRC connected mode terminal to measure channel quality for beamforming transmission, or at least a time domain index including an SS block index TSS, etc. for indicating the NR-PSS/SSS/PBCHs may be multiplexed and transmitted within one SS block together with the NR-PSS/SSS/PBCHs.

In one SS block, the synchronization signal (NR-SS) and the broadcast channel (NR-PBCH) are transmitted to physical resources through frequency division multiplexing (FDM), time division multiplexing (TDM), or a combination of FDM and TDM. It can be allocated and transmitted to the terminal by the base station.

At least one or a plurality of different beams are applied between the SS blocks within the periodicity of the SS burst set, so that the SS block based on beam transmission or omni-directional beam transmission can be transmitted In particular, multi-beam transmission-based SS block transmission is required to compensate for channel attenuation occurring in a high frequency band (eg, 6 GHz or higher). However, in other frequency bands (eg, less than 6 GHz), it may be transmitted once or repeatedly between all or some SS blocks in the form of a single beam or omni-directional beam transmission. However, omni-directional beam transmission is applied to one or a plurality of SS blocks so that signals and channels such as NR-SS/PBCH can be transmitted, or multiple The decision on what to base beam transmission on is purely up to the base station implementation. Therefore, how many SS blocks / SS bursts are actually used within the SS burst set periodicity depends on each base station according to the beam width, frequency range, channel environment, target beam coverage of a transmission reception point (TRP) cell, etc. can be determined and used independently.

Next, an SS burst will be described.

2 to 5 are diagrams for explaining SS block physical allocation within an SS burst structure or slot to which the present disclosure can be applied.

One or a plurality of SS blocks constitute one SS burst. If an SS burst does not need to be defined within the SS burst set periodicity, it can be simply viewed as an allocation on physical resources of contiguous SS blocks.

As shown in FIGS. 2 to 5, SS blocks constituting one SS burst may be continuously allocated or discontinuously allocated in the time or frequency domain. Also, the SS burst unit may not be necessary depending on the SS burst set design method. In such a case, contiguous or discontinuous SS blocks are defined in the SS burst set.

Next, the SS burst set will be described.

One SS burst set may be configured based on one or a plurality of SS blocks or one or a plurality of SS bursts.

From the terminal point of view, periodic NR-SS reception to which the same beam type is applied is expected for each SS burst set periodicity.

During at least initial cell access for each specific frequency band, the UE assumes a default SS burst transmission period value for each frequency range (eg, subcarrier spacing).

At least an RRC connected, RRC idle (RRC IDLE) or RRC inactive terminal can receive updated information about the SS burst set transmission period from the base station. The information provided in this way will be used for later channel measurement (e.g. RRM measurement).

Next, the SS burst set composition will be described.

Examples of how SS blocks are allocated to physical resources based on the SS block/SS burst/SS burst set structure can be shown as shown in FIGS. 2 to 5.

In the example of FIG. 2, an SS burst is composed of consecutive SS blocks within one slot. A gap may exist between SS bursts for each slot, and the gap may be mainly used for transmitting and receiving downlink (DL) / uplink (UL) control information, blank symbols, etc. there is. In addition, the range of the gap may consist of at least 1 to 3 OFDM symbols, but is not limited thereto.

In the example of FIG. 3, an SS burst may be composed of consecutive SS blocks, and SS blocks may be allocated and transmitted between a plurality of slots. The example of FIG. 2 is a structure in which one SS block cannot be allocated across slots, and the example in FIG. 3 is a structure in which one SS block can be allocated across slots.

In the example of FIG. 4, each SS block is transmitted in a fixed position and time interval with three discontinuous OFDM symbols. The first 2 OFDM symbols and the last 2 OFDM symbols in each slot are not used for SS block transmission and can be allocated as a gap as in the example of FIG. 2 .

In the example of FIG. 5 , one or a plurality of SS blocks may be transmitted within an SS block transmission window. Each SS block can be allocated only within one slot, similar to the example of FIG. 2 .

6 is a diagram illustrating an example of resource allocation in an SS block to which the present disclosure may be applied.

Basically, NR-PSS/SSS can be used to indicate time/frequency synchronization and Cell ID for initial cell access, and NR-TSS can indicate a time index (eg, SS block index), and NR-PSS/SSS It can be multiplexed and transmitted together with /PBCH within one SS block.

For example, in FIG. 6(a), one SS block includes three OFDM symbols and SS BW, and NR-TSS, NR-PSS, and NR-TSS are mapped to the first OFDM symbol by FDM method, NR-SSS is mapped to the second OFDM symbol, and NR-PBCH is mapped to the third OFDM symbol. The example of FIG. 6(b) is an example of changing the temporal order of signals/channels mapped to OFDM symbols in the example of FIG. 6(a).

Hereinafter, NR-SS default parameters will be described.

From the terminal point of view, it is necessary to define numerology and related parameters assumed in a specific frequency range (eg, less than 6 GHz), at least for the purpose of initial access. For example, assuming that the default subcarrier spacing assumed by the terminal for initial access in less than 6 GHz is 30 kHz and the NR-SS / PBCH transmission bandwidth (transmission BW) is 10 MHz, the terminal receives the signals can do. By doing this, the terminal can minimize delay, complexity, and power consumption for initial access.

At least for the purpose of initial access, the base station and the terminal may define a parameter set related to the default subcarrier spacing and NR-SS transmission BW as follows.

- Parameter set#W related to 15kHz subcarrier spacing and NR-SS transmission BW not greater than 5MHz

- Parameter set#X related to 30kHz subcarrier spacing and NR-SS transmission BW not greater than 10MHz

- Parameter set#Y related to 120kHz subcarrier spacing and NR-SS transmission BW not greater than 40MHz

- Parameter set #Z related to 240kHz subcarrier spacing and NR-SS transmission BW not greater than 80MHz

The default subcarrier spacing is independent of the subcarrier spacing for data transmission. Therefore, the default subcarrier spacing for signals and channels such as NR-SS/PBCH for at least initial access and the subcarrier spacing for data transmission (eg, Physical Downlink Shared Channel (PDSCH)) may be different.

For each frequency band range, the UE may assume a different default SS burst set periodicity value. Otherwise, the default SS burst set periodicity value may always have a fixed value (e.g. 20 ms) regardless of the frequency band range. Therefore, information such as default subcarrier spacing, frequency band range, SS burst set periodicity, and the number of SS blocks (# of SS block within a SS burst set periodicity) in the SS burst set periodicity may be included in the parameter set.

Also, the maximum number of SS blocks in an SS burst set may be defined as L. Different L values may be given for each frequency band range. Since L is the maximum number of SS blocks that can exist in the system, the number of SS blocks actually transmitted (used) by the base station may be less than or equal to L. From the point of view of the terminal performing initial access, the number of SS blocks used for the actual transmission and the location on time/frequency are not known. Therefore, blind decoding is performed at all possible positions to determine whether NR-SS and NR-PBCH transmission is performed and decoding is performed. Meanwhile, a terminal in RRC CONNECTED/IDLE mode may receive information about the location of an SS block actually transmitted from a base station for the purpose of channel measurement. Through this, the terminal can measure a more reliable channel measurement value and report it to the base station.

The maximum value of the number L of SS blocks in the SS burst set may be set differently according to the frequency range. For example, for a frequency range up to 3 GHz, the value of L may be 1, 2, or 4. For the frequency range from 3 GHz to 6 GHz, the value of L can be 4 or 8. For the frequency range from 6 GHz to 52.6 GHz, the L value may be 64.

In addition, a single set of possible SS block time locations per frequency band may be defined. Specifically, the time positions of possible SS blocks within the SS burst set periodicity are defined as one set for each frequency band, and the positions of possible SS blocks are predefined based on the L value, which is the maximum number of SS blocks. In this way, the number and time positions of SS blocks used for transmission of actual NR-SS and NR-PBCH within the set of time positions of each predefined SS block for each frequency range depend on the selection of the base station as described above. It depends.

Hereinafter, NR-PBCH will be described.

Information (ie, content) included in the NR-PBCH may be referred to as an NR-Master Information Block (MIB). Some of the minimum system information (minimum SI) that the terminal must know for initial access of the NR system is configured as MIB. The corresponding MIB is then broadcast to terminals through the NR-PBCH channel. Since the current NR system considers at least multi-beam transmission and multiple numerologies, a larger MIB size than the MIB size defined in the LTE system is expected.

Information that can be included in the MIB for the current NR system is as follows.

- At least part of the system frame number (SFN). Part of the system frame number may be provided in the MIB and the rest may be obtained by the UE through NR-PBCH blind detection, or all of the system frame number may be provided through the MIB. For example, in the NR system, the system frame number or the hyper system frame number is explicitly indicated using 7, 10, or 17 bits in the MIB, and the remaining 3 bits of information are implicitly transmitted by the PBCH transmission method. The system frame number can be obtained.

- CRC (Cyclic Redundancy Check). The CRC in the MIB information field can be defined with a size of 16 bits or 24 bits. In the case of using a 24-bit CRC, the possibility of generating a false alarm can be lowered through the CRC check, so that the NR-PBC can be detected more reliably.

- PDSCH configuration information to receive RMSI for receiving remaining information (Remaining Minimum SI, RMSI) of minimum system information (minimum SI). For example, it is a control search area (PDCCH configuration information) of a physical downlink control channel (PDCCH) for scheduling a PDSCH channel carrying the RMSI information. Here, information on the PDCCH control search region included in the MIB corresponds to PDCCH configuration information for receiving the corresponding PDCCH when a PDSCH transmitting an RMSI is scheduled through the PDCCH.

- SS block index. When SS block index information is not provided through other signals (eg, NR-SSS, NR-TSS), SS block index may be explicitly provided through NR-PBCH.

- Value Tag. Information for notifying in advance through the MIB that the contents of the RMSI are changed. Accordingly, unnecessary time delay and operation can be avoided when the terminal acquires the new system information (SI).

- Scrambling of DMRS and data for PDSCH of data and demodulation reference signal (DeModulation Reference Siganl, DMRS) for PDSCH. In the case of transmitting RMSI information through the PDSCH in a single frequency network method, scrambling can be performed using a specific identifier (eg, group cell identifier) to support a single frequency network operation. can be provided through

- Configuration information for initial uplink transmission. Corresponds to configuration information for random access channel transmission.

- Other additional information.

The size of all NR-MIB information bits including the information as in the above examples may have a value between about 40 bits and 100 bits.

Next, NR-PBCH transmission BW will be described.

Similar to the default parameter set for the NR-SS, a parameter set related to NR-PBCH transmission may also be determined according to the default SCS and the NR-PBCH maximum transmission BW. At least for the purpose of initial access, the base station and the terminal may define a parameter set related to default subcarrier spacing and NR-PBCH transmission BW as in the example below. The NR-PBCH transmission bandwidth can be determined based on the default subcarrier spacing value assumed for each frequency range and the NR-PBCH transmission bandwidth (i.e. 288 Resource Element (RE)).

- Parameter set#W related to 15kHz subcarrier spacing and NR-PBCH transmission BW (e.g. 15kHz * 288) not greater than 5MHz

- Parameter set#X related to 30kHz subcarrier spacing and NR-PBCH transmission BW (e.g. 30kHz * 288) not greater than 10MHz

- Parameter set#Y related to 120kHz subcarrier spacing and NR-PBCH transmission BW (e.g. 120kHz * 288) not greater than 40MHz

- Parameter set #Z related to 240kHz subcarrier spacing and NR-PBCH transmission BW (e.g. 240kHz * 288) not greater than 80MHz

In the NR-PBCH numerology, at least for initial access, the UE assumes that the NR-SS and NR-PBCH have the same numerology. However, for other purposes (eg, channel measurement, etc.), the numerology (eg, SCS) value for NR-SS and NR-PBCH may be set differently from the default subcarrier spacing value according to the setting of the base station. .

In multiplexing of NR-SS (NR-PSS / NR-SSS) / NR-PBCH in the SS block, NR-PSS and NR-SSS in both single beam and multi beam scenarios Multiplexing with TDM. Also, in both single beam and multi beam scenarios, NR-SS and NR-PBCH are multiplexed by TDM. That is, within one SS block, NR-PSS, NR-SSS, and NR-PBCH are all multiplexed by TDM. Therefore, they are allocated and transmitted on different OFDM symbols.

As the NR-PBCH transmission method, a single antenna port-based transmission or a space frequency block coding (SFBC) transmission method may be applied, and the number of antenna ports to be defined for PBCH transmission may be determined according to each transmission method. In the NR system, since the UE can always perform PBCH decoding based on the assumption of a fixed number of antenna ports, the reception complexity of the UE is reduced.

For a reference signal for demodulation of NR-PBCH, NR-SSS or DMRS may be considered. The NR-SSS is located in an OFDM symbol right next to the NR-PBCH in the same SS block and is used for decoding with the assumption of the same antenna port as that of the PBCH. In this case, since an additional reference signal for the NR-PBCH is not required, the overhead of the reference signal may not increase. On the other hand, when a demodulation reference signal (DMRS) is used for NR-PBCH demodulation, DMRS can apply more flexible resource mapping on an OFDM symbol through which NR-PBCH is transmitted, thereby providing more improved link performance.

Hereinafter, examples of the present disclosure for RS configuration and transmission and reception schemes for the NR-PBCH will be described. Specifically, a demodulation reference signal (DMRS) used for demodulation of NR-PBCH will be described.

A receiver of the NR-PBCH may estimate a channel using DMRS transmitted together with the NR-PBCH, and demodulate the NR-PBCH based on the estimated channel. In the present disclosure, a method for generating a DMRS sequence for NR-PBCH and mapping physical resources is described.

In the present disclosure, it is assumed that the DMRS is designed based on a gold-sequence based on quadrature phase shift keying (QPSK).

A structure in the frequency and time domains in which the NR-PBCH is transmitted may consist of at least 24 PRBs (i.e. 288 REs) and 2 OFDM symbols in an SS block. (One PRB assumes a configuration of 12 REs per OFDM symbol in the frequency domain). If the number of DMRS resource elements (REs) per PRB and per OFDM symbol is one of 2, 4, or 6, the number of REs allocated for DMRS per OFDM symbol in the real frequency domain is among the total 288 REs. It can be one of 48(=2*24), 96(=4*24), or 144(=6*24). However, it is not limited to the number of DMRS resource elements, and 3 or 5 may also be considered in consideration of PBCH decoding performance requirements and RS overhead. For ease of description, the present invention will be described below on the assumption that 2 or 4 DMRS REs are allocated to each RB for each OFDM symbol.

A structure in the frequency and time domains in which other NR-PBCHs are transmitted may be configured to be allocated on at least 20 PRBs (i.e. 240 REs) and 3 OFDM symbols within an SS block. Referring to FIG. 15, in the first OFDM symbol in the SS block, PSS is allocated on 127 RE (i.e. subcarrier) of the center frequency to which the SS block is allocated, PBCH on 240 RE in the second symbol, and SSS in the third symbol. PBCHs may be allocated to both sides of the center and the PBCH may be allocated to the last OFDM symbol. Here, the bandwidth of the SS block to which the PBCH is allocated corresponds to 20 PRBs, and the PSS transmission bandwidth transmitted in the first OFDM symbol corresponds to about 12 PRBs, and the PSS sequence is allocated and transmitted on 127 REs. Similarly, SSS transmission is allocated with the same bandwidth as PSS and transmitted on 127 REs. Except for REs to which PSS is transmitted within the SS block bandwidth (20 PRB) on the OFDM symbol in which the PSS is transmitted, the remaining REs are not used for SS block transmission. Therefore, if the frequency axis position of PSS/SSS/PBCH is indicated by the subcarrier index of the SS block bandwidth, as shown in FIG. 15, PSS (first OFDM symbol and subcarrier indexes 56 to 182), SSS (third OFDM symbol and subcarrier indexes 56 to 182) and PBCH (second/fourth OFDM symbol and subcarrier indexes 0 to 239) and PBCH (third OFDM symbol and subcarrier indexes 0 to 47, 192 to 239). As a result, the PBCH can be transmitted using the last 3 OFDM symbol intervals within one SS block composed of 4 OFDM symbols in the time domain. As mentioned above, each PRB on the 3 OFDM symbols in which the PBCH is transmitted is allocated and transmitted on 3 OFDM symbols at a uniform 4 RE interval with 3 RS overheads among 12 REs in the same DMRS. .

7 is a diagram for explaining a bandwidth of an NR system to which the present disclosure is applied.

In generating a DMRS sequence for NR-PBCH, it is necessary to consider the maximum system bandwidth (Max BW) value. This can be expressed as the maximum system bandwidth N ^max,DMRS _RB . Since the maximum system bandwidth is a bandwidth assumed for DMRS sequence generation, it may be different from the system bandwidth for one component carrier.

In the NR system, one or a plurality of bandwidth parts (BW parts) may exist within the system bandwidth of one component carrier (CC). Each BW part may be composed of one group consisting of consecutive PRBs. Each BW part may potentially include transmission of the SS block according to the configuration of the base station, but there may be a BW part that does not include transmission of the SS block. Accordingly, as shown in FIG. 7 , potentially at least one NR-PBCH may be transmitted by the base station through one or more BW parts within the system bandwidth of one CC.

Settings for one BW part may include at least the following elements.

- Center frequency: For example, the center location of the BW part in the frequency domain

- Numerology: For example, subcarrier spacing, CP length, frequency range, etc.

- Bandwidth: For example, the number of PRBs (24, 48, 96, ...)

- SS block (ie, NR-PSS / SSS / PBCH) existence: presence / absence (presence / absence)

As described above, one BW part is composed of consecutive PRBs within the system bandwidth of one CC.

Possible BW values for one BW part may be determined in advance as described above. The BW value of one BW part may be determined as a set of possible values that are greater than at least 20 or 24 PRBs (ie, 204 or 288 REs) and smaller than the system bandwidth. Among them, the largest BW value can be defined as the maximum possible BW (ie, N ^{max, DMRS} _RB ) within one BW part setting. N ^max,DMRS _RB may be defined for DMRS sequence generation. In addition, the BW that can be set within one BW part may be set to be equal to or smaller than the UE Max BW capability of the corresponding UE. Therefore, bandwidth settings for different BW parts for each terminal may be instructed by the base station according to the maximum bandwidth capability of each terminal.

In addition, the "maximum possible number of BW parts" that can exist within one system bandwidth may be predetermined.

The number of BW parts configured for the UE may be determined according to the number of BW parts configured. Information on the number of BW parts configured for the UE may be provided and configured to the UE through higher layer signaling (eg, RRC signaling) by the base station. For example, the possible number of BW part settings may be set as 1, 2, 4, 8, ....

Each of the BW part settings may be independently determined. Each BW part setting may be determined within a range of possible values. Each BW part configuration may be provided to the terminal through higher layer signaling by the base station. Depending on how many independent BW part configurations are provided to the UE, at least one or more BW part configurations may be provided to the UE. The maximum possible number of BW part settings may be determined in advance as described above.

In the above example, higher layer signaling for BW part configuration may be UE dedicated RRC signaling.

Each BW part may be set to have a different bandwidth. The bandwidth of each BW part may be set according to UE capabilities.

For example, in the example of FIG. 7 , two BW parts are set for UE1, and BW parts #1 and #2 for UE1 may be set to have different BWs. Each BW part includes SS block.

Two BW parts are set for UE2, and BW parts #1 and #2 for UE2 may be set to have the same BW.

Three BW parts are set for UE2, and BW parts #1, #2, and #3 for UE3 may be set to have the same BW. In particular, in the example of FIG. 7, the BW of each BW part for UE3 is 24 PRBs equal to the bandwidth of the SS block.

One BW part is set for UE4, and it can be set to have the same BW as the UE operating bandwidth (ie, system bandwidth).

That is, if the SS block can exist in the BW part, the bandwidth of the BW part can be at least equal to or greater than the SS block bandwidth. Otherwise, the bandwidth for the BW part may be smaller than the SS block bandwidth. Accordingly, the bandwidth of the BW part configured for each terminal may be determined based on at least the maximum bandwidth capability of the terminal and the SS block bandwidth.

As shown in the example of FIG. 7 , a BW part may be set for each UE independently according to the UE max BW capability within the System BW of one CC. Therefore, the BW for generating the NR-PBCH DMRS sequence considered in the present disclosure should consider the environment operating on different bandwidths for each UE. In addition, the above-described bandwidth configuration has been described with the example of a terminal in an RRC Connected state, but terminals not connected to RRC (eg, RRC idle or RRC inactive) also have NR - It shall support receiving PBCH DMRS. Accordingly, in the present disclosure, a method for generating a DMRS sequence considering various bandwidth allocation cases as described above will be described.

Equation 1 below shows DMRS sequence generation. Equation 1 corresponds to an example of generating a DMRS using a QPSK-based gold sequence.

As shown in Equation 1, the DMRS sequence is generated with a length of n*N ^max,DMRS _RB , and some or all of the generated sequence may be mapped to the NR-PBCH DMRS RE.

In Equation 1, the n value may be determined as one of the examples below.

- Number of DMRS REs per PRB (ie, meaning that a sequence is generated for each OFDM symbol)

- Number of DMRS REs per PRB * 2 OFDM symbols (that is, a sequence is generated for each SS block)

- Number of DMRS REs per PRB * 2 OFDM symbol * Number of SS blocks per Slot(s) (that is, a sequence is generated per Slot(s))

- Number of DMRS REs per PRB * 2 OFDM symbol * Number of SS blocks per SS burst set unit (L) (That is, it means that a sequence is generated per SS burst set unit)

- Number of DMRS REs per PRB * 2 OFDM symbol * Number of SS blocks per Slot(s) * Number of slots per 80ms (ie, a sequence is generated every 80ms)

In addition, the maximum number of BWs or PRBs (ie, N ^{max, DMRS} _RB ) to be assumed for generation of an NR-PBCH DMRS sequence in the frequency domain in one OFDM symbol is by one of the examples of Equations 2 to 4 below can be determined

In Equation 2, K _max,BWpart means the maximum number of the BW parts that can exist in the system BW of one CC from the point of view of the NR base station, and N ^max,SSblock _RB is the maximum bandwidth of the SS block (eg, 24 PRBs).

The value of K _max,BWpart , which is the maximum possible number of BW parts from the viewpoint of the NR base station, may be different from the setting of the maximum number of BW parts from the viewpoint of the terminal. That is, from the viewpoint of the NR base station, the maximum possible K _max,BWpart in the system BW in one CC may be equal to or greater than the maximum number of BW parts that can be configured or configured for the UE. K _max,BWpart may be predetermined as a value known to the base station and the terminal in advance.

In Equation 3, N ^max,BWpart _PRB means the maximum possible BW within one BW part setting, that is, the maximum number of PRBs.

As in the example of Equation 2, DMRS generation based on the maximum number of BW parts (K _{max, BWpart} ) and the maximum BW of one BW part (N ^{max, BWpart} _PRB ) that can exist in one system BW from the viewpoint of the NR base station For Max. BW can be determined.

In Equation 4, the number of PRBs for sequence generation may be determined equal to 20 or 24 PRBs to which NR-PBCHs are allocated. In this case, regardless of the PRB that forms the BW part within the system bandwidth, max. BW can be determined.

The definition of the maximum bandwidth in the frequency domain for generating the proposed NR-PBCH DMRS sequence is the existence of a bandwidth part (BP) that can exist within one system bandwidth (e.g. BP maximum bandwidth, maximum number of BPs, etc.) and existence within each BP A maximum bandwidth value for DMRS generation is determined in advance in consideration of a possible PBCH (SS block) so that the terminal is used for PBCH decoding before being connected to the system.

Hereinafter, an initialization time and generation method of c(i), which is a pseudo-random sequence used for generating a DMRS sequence for NR-PBCH, will be described.

In the following example, it is assumed that the terminal determines the time index based on the signal received through the SS block in relation to the initialization time of the pseudo-random sequence for generating the DMRS sequence. For example, it is assumed that the terminal can obtain SS block index information through blind search using NR-TSS and obtains OFDM symbol index, slot index, radio frame boundary information, etc. based on this.

In addition, it is assumed that the terminal can detect SS block index or half frame timing (e.g. 5 ms time window timing within one 10 ms radio frame) according to the proposed method through blind decoding of the DMRS sequence.

The half-frame timing mentioned here indicates whether a 5 ms time window within a radio frame corresponding to a 10 ms period corresponds to the front 5 ms or the back 5 ms using 1-bit information. Half-frame timing information can be delivered through PBCH DMRS, but DMRS with SS block index information (2 bits, L = 4) in the frequency band range (frequency range below 3 GHz) with L = 4, which is the maximum number of SS blocks. It can be used as a sequence initialization value to instruct terminals. The above-mentioned time information shows that the SS block and half frame timing information can be obtained and utilized using only DMRS without PBCH decoding for channel measurement of potential target cells mainly during handover. This operation helps to minimize the complexity and power consumption of the UE by preventing the UE from performing PBCH decoding when measuring channels for multiple cells, especially during handover.

In addition, in the following examples, it is considered that scrambling sequences of different units are generated according to DMRS TTI units (ie, DMRS estimation units).

Example 1

This embodiment relates to a method of initializing and generating a scrambling sequence every 80 ms.

Example 1-1

According to this embodiment, one or more of a radio frame index, a slot index, and an OFDM symbol index may be used as input values for initializing a DMRS sequence.

The radio frame index may have a value of one of 0 to 7 within 80ms unit.

The slot index may mean a slot index per radio frame. For example, assuming a subcarrier spacing (SCS) of 240 KHz, it may have a value of 0 to 319. In all embodiments below, it is assumed that the range of the slot index per radio frame varies according to the subcarrier spacing value. This is because the slot index value defined per radio frame varies according to subcarrier spacing. In the above example, when 240 kHz subcarrier spacing is assumed, it is 0 to 319, but when 15 kHz subcarrier spacing is assumed, one of 0 to 19 may be used as the slot index value.

OFDM symbol index may mean an OFDM symbol index per slot. For example, it may have a value of 0 to 13.

Example 1-2

According to this embodiment, one or more of an SS burst set index, an SS block index, and an OFDM symbol index may be used as input values for initializing a DMRS sequence.

The SS burst set index may have a value of 0 to 3 within a unit of 80 ms.

The SS block index may mean an SS block index per SS burst set. Depending on the frequency range, the SS block index may have a different value and may have a value of 0 to L-1. Here, L means the maximum number of SS blocks in the SS burst set as described above.

The OFDM symbol index may mean an OFDM symbol index per SS block. For example, it can have a value of 0 or 1. Alternatively, it may have a value of 0 to 3. or one of 0 to 13.

Example 2

This embodiment relates to a method of initializing and generating a scrambling sequence for each slot(s). If scrambling sequence initialization and generation for DMRS sequence generation is performed for each of a plurality of slots, initialization and generation for DMRS sequence generation are performed based on a time unit (20 ms) corresponding to the plurality of slots.

Example 2-1

According to this embodiment, one or more of a slot(s) index and an OFDM symbol index may be used as input values for initializing a DMRS sequence.

The slot(s) index may mean a slot index per radio frame. For example, assuming a subcarrier spacing (SCS) of 240 KHz, it may have a value of 0 to 319. As described above, it is assumed that the range of the slot index per radio frame varies according to the subcarrier spacing value.

OFDM symbol index may mean an OFDM symbol index per slot. For example, it may have a value of 0 to 13.

Example 2-2

According to this embodiment, one or more of a slot(s) index, an SS block index, and an OFDM symbol index may be used as input values for initializing a DMRS sequence.

The slot(s) index may mean a slot index per radio frame. For example, assuming a subcarrier spacing (SCS) of 240 KHz, it may have a value of 0 to 319.

The SS block index may mean an SS block index per slot (s).

The OFDM symbol index may mean an OFDM symbol index per SS block. For example, it can have a value of 0 or 1. Alternatively, it may have a value of 0 to 3. or one of 0 to 13.

Example 3

This embodiment relates to a method of initializing and generating a scrambling sequence for each one or a plurality of SS blocks. That is, PBCH DMRS sequence generation is performed for each SS block or for each SS block, and SS block index and half frame timing index information are used in addition to the above-mentioned cell ID as initialization values for each DMRS sequence generation. If scrambling sequence initialization and generation for DMRS sequence generation is performed for each of a plurality of SS blocks, the plurality of SS blocks may be assumed to be SS bursts. Initialization and generation for DMRS sequence generation are performed based on a time unit (20 ms) corresponding to the plurality of SS blocks.

Example 3-1

According to this embodiment, one or more of a slot(s) index, an SS block index, and an OFDM symbol index may be used as input values for initializing a DMRS sequence.

The slot(s) index may mean a slot index per radio frame. For example, assuming a subcarrier spacing (SCS) of 240 KHz, it may have a value of 0 to 319. As described above, it is assumed that the range of the slot index per radio frame varies according to the subcarrier spacing value.

The SS block index may mean an SS block index per slot (s).

The OFDM symbol index may mean an OFDM symbol index per SS block. For example, it can have a value of 0 or 1. Alternatively, it may have a value of 0 to 3. or one of 0 to 13.

Example 3-2

According to this embodiment, one or more of an SS block index, an OFDM symbol index, and half frame timing information may be used in addition to a cell ID as input values for initializing a DMRS sequence.

The SS block index may mean an SS block index per radio frame. For example, assuming a subcarrier spacing (SCS) of 240 KHz, it may have a value of 0 to 319. As described above, it is assumed that the range of the slot index per radio frame varies according to the subcarrier spacing value.

Alternatively, the SS block index may mean an SS block index per SS burst set. Depending on the frequency range, the SS block index may have a different value and may have a value of 0 to L-1. Here, L means the maximum number of SS blocks in the SS burst set as described above.

The OFDM symbol index may mean an OFDM symbol index per SS block. For example, it can have a value of 0 or 1. Alternatively, it may have a value of 0 to 3. or one of 0 to 13.

Example 4

This embodiment relates to a method of initializing and generating a scrambling sequence for each one or a plurality of SS burst sets. If scrambling sequence initialization and generation for DMRS sequence generation is performed for each of a plurality of SS burst sets, initialization and generation for DMRS sequence generation are performed based on the plurality of SS burst set time units (20 ms).

Example 4-1

According to this embodiment, one or more of a radio frame index, a slot(s) index, an SS block index, and an OFDM symbol index may be used as input values for initializing a DMRS sequence.

The radio frame index may have a value corresponding to a radio frame index 0 or 1 existing within a time corresponding to a 20 ms SS burst set period.

The slot(s) index may mean a slot index per radio frame. For example, assuming a subcarrier spacing (SCS) of 240 KHz, it may have a value of 0 to 319. As described above, it is assumed that the range of the slot index per radio frame varies according to the subcarrier spacing value.

The SS block index may mean an SS block index per slot (s).

The OFDM symbol index may mean an OFDM symbol index per SS block. For example, it can have a value of 0 or 1. Alternatively, it may have a value of 0 to 3. or one of 0 to 13.

Example 4-2

According to this embodiment, one or more of an SS block index and an OFDM symbol index may be used as input values for initializing a DMRS sequence.

The SS block index may mean an SS block index per radio frame. For example, assuming a subcarrier spacing (SCS) of 240 KHz, it may have a value of 0 to 319. As described above, it is assumed that the range of the slot index per radio frame varies according to the subcarrier spacing value.

Alternatively, the SS block index may mean an SS block index per SS burst set. Depending on the frequency range, the SS block index may have a different value and may have a value of 0 to L-1. Here, L means the maximum number of SS blocks in the SS burst set as described above.

The OFDM symbol index may mean an OFDM symbol index per SS block. For example, it can have a value of 0 or 1. Alternatively, it may have a value of 0 to 3. or one of 0 to 13.

In addition to the input value for DMRS sequence initialization as described above, one or more of identifier information, CP length information, or SS block frequency location index information (ie, Bandwidth Part index information: BP index that can exist in one component carrier) You may use more. The identifier information may include a cell identifier (cell ID), a terminal identifier (UE ID), a virtual identifier (Virtual ID), and the like. The CP length may mean a normal CP or an extended CP, and when the value of information indicating the CP length is 0, it corresponds to the normal CP, and when the value is 1, it may correspond to the extended CP. The SS block frequency location index information may correspond to an index of a frequency location of an SS block within a system bandwidth of one CC or a BP index value.

In the above examples, it is assumed that the terminal acquires a time domain index (eg, SS block index) based on a signal included in the SS block. NR-PBCH DMRS may be received. In this case, the terminal may further use one or more of identifier information, CP length information, or SS block frequency location index (BP index) information. The identifier information may correspond to a cell identifier (cell ID) obtained from NR-PSS/SSS. The CP length may mean a normal CP or an extended CP, and an assumption of a CP length predetermined between the base station and the terminal may be applied before decoding the NR-PBCH. SS block frequency location index information may correspond to an index value for a frequency location of an SS block within a system bandwidth of one CC.

Equations 5 and 6 below show examples of C _init , which is an initialization value of a pseudo-random sequence.

As in Equations 5 and 6, initialization of the pseudo-random sequence may be performed based on the NR cell ID or the initialization values of the NR cell ID and CP length.

According to the scrambling generation unit as described above, the value n in Equation 1 may be determined as one of the examples below.

- Number of DMRS REs per PRB (ie, meaning that a sequence is generated for each OFDM symbol)

- Number of DMRS REs per PRB * 2 OFDM symbols (that is, a sequence is generated for each SS block)

- Number of DMRS REs per PRB * 2 OFDM symbol * Number of SS blocks per Slot(s) (that is, a sequence is generated per Slot(s))

- Number of DMRS REs per PRB * 2 OFDM symbol * Number of SS blocks per SS burst set unit (L) (That is, it means that a sequence is generated per SS burst set unit)

- Number of DMRS REs per PRB * 2 OFDM symbol * Number of SS blocks per Slot(s) * Number of slots per 80ms (ie, a sequence is generated every 80ms)

Hereinafter, a method of mapping DMRS to REs will be described.

8 and 9 are diagrams illustrating examples of locations of DMRS REs per PRB for NR-PBCH in an SS block according to the present disclosure.

Within one PRB, 2, 4 or 6 REs may be uniformly allocated for DMRS in the frequency domain. The position of the OFDM symbol to which the NR-PBCH and DMRS are allocated within the SS block is not limited to the examples of FIGS. 8 and 9, and the NR-PBCH and DMRS may be allocated to OFDM symbols at other positions.

According to the present disclosure, one or more of a frequency domain shift or a time domain shift may be applied to the DMRS RE.

Since the NR-PBCH DMRS is transmitted at a fixed frequency location, intercell interference may occur between DMRSs of neighboring cells or transmission/reception points (TRPs). Unlike PDSCH or PUSCH (Physical Uplink Shared Channel), frequency selective scheduling and freedom for controlling MCS cannot be provided for NR-PBCH transmission, so a method for avoiding interference between neighboring cell DMRSs is required.

First, the frequency domain shift will be described.

10 is a diagram illustrating examples of DMRS frequency domain shift according to the present disclosure.

For the DMRS for NR-PBCH, a shift in the frequency axis may be applied based on a predetermined ID and/or BP index and/or SS block/SS burst/SS burst set index value. Hereinafter, an example in which only a predetermined ID value is applied is described, but the shift may be applied based on a predetermined ID value and an SS block index without being limited thereto. The frequency domain shift may be applied according to the example of FIG. 10 (a) or FIG. 10 (b).

V_dmrs_shift represents the degree (or magnitude) of shift in the frequency domain and can be expressed in units of REs. For example, the V_dmrs_shift value can be obtained through a mod operation between at least an ID value and the number of shiftable REs between DMRS REs. The ID value may be one of various ID values such as Cell ID, UE ID, or Virtual ID.

In the example of FIG. 10(a), all NR-PBCH OFDM symbols transmitted by DMRS are shifted in the same direction based on one same V_dmrs_shift value.

In the example of FIG. 10 (b), each OFDM symbol for NR-PBCH is based on a plurality of different V_dmrs_shift values in independent directions (eg, V_dmrs_shift for NR-PBCH / DMRS OFDM symbol #0 Value #0 is applied, and value V_dmrs_shift#1 is applied to NR-PBCH/DMRS OFDM symbol #1).

If the DMRS TTI unit (or DMRS sequence generation unit) is a slot/SS block and 4 REs are set as REs for DMRS transmission in one PRB on one NR-PBCH/DMRS OFDM symbol, V_dmrs_shift#0 and the value of V_dmrs_shift#1 may be determined according to Equation 7 below.

For example, the possible combinations of values V_dmrs_shift#0 and V_dmrs_shift#1 are (0, 0), (1, 0), (2, 0), (0, 1), (1, 1), (2, 1 ), (0, 2), (1, 2), (2, 2).

If the DMRS TTI unit (or DMRS sequence generation unit) is a slot/SS block and two REs are set as REs for DMRS transmission in one PRB on one NR-PBCH/DMRS OFDM symbol, V_dmrs_shift#0 and the value of V_dmrs_shift#1 may be determined according to Equation 8 below.

Next, the time domain shift will be described.

11 is a diagram illustrating examples of DMRS time domain shift according to the present disclosure.

For DMRS for NR-PBCH, frequency axis based on a predetermined ID (eg, cell ID, UE ID, virtual ID) and / or BP index and / or SS block / SS burst / SS burst set index value shift can be applied. Hereinafter, an example in which only a predetermined ID value is applied is described, but the shift may be applied based on a predetermined ID value and an SS block index without being limited thereto. The time domain shift may be applied according to the example of FIG. 11 (a) or FIG. 11 (b).

H_dmrs_shift represents the degree (or size) of shift in the time domain and can be expressed in units of OFDM symbols. If it is assumed that one or two SS blocks are located in one slot, H_dmrs_shift can be performed in units of OFDM symbols. Since the UE can acquire the OFDM symbol boundary and Cell ID through NR-PSS/SSS blind monitoring, the time position of the SS block in the actual slot can be estimated through the Cell ID value.

In the time domain, the location of the SS block within a slot can be moved only within a slot or within a partial time domain (eg, 7 OFDM symbols) within a slot based on at least an ID value. As shown in the example of FIG. 11 below, if two SS blocks exist in one slot and each SS block moves in the time domain by dividing half of the slot, the movement is determined by Equation 9 below based on the ID value Shift can be performed in the time domain according to the value of H_dmrs_shift. Accordingly, the DMRS location in the time domain can be changed based on at least the ID value. Examples other than Equation 9 are of course applicable.

In Equation 9, H_dmrs_shift_SSblock#0 is a time domain shift value applied to SS block index #0 within one slot, and H_dmrs_shift_SSblock#1 is a time domain shift value applied to SS block index #1 within one slot. .

According to the present disclosure, both a frequency domain shift and a time domain shift may be applied to a DMRS RE for NR-PBCH. Therefore, even if NR-PBCH DMRSs transmitted from different cells or TRPs are transmitted on the same subcarrier according to the same V_shift value, interference avoidance performance can be maximized because they are transmitted on different OFDM symbols according to different H_shift values. Accordingly, the demodulation performance of the NR-PBCH can be greatly improved.

12 is a diagram illustrating a DMRS transmission/reception method for NR-PBCH according to the present disclosure.

In step S1210, the base station may determine the DMRS sequence generation length based on the maximum BW (ie, N ^{max, DMRS} _RB ) that can be set for one BW part. Specifically, the value of N ^max,DMRS _RB in Equation 1 is based on one or more of K _max,BWpart , N ^max,SSblock _RB , or N ^max,BWpart _PRB according to one of Equations 2 to 4. can be determined

In addition, the DMRS sequence generation length may be determined based on n and N ^max,DMRS _RB in Equation 1 above. For example, a sequence may be generated and initialized for each OFDM symbol, for each SS block, for each slot, for each SS burst set, and for each 80 ms. Accordingly, the lengths of sequences generated based on one same initial value may be determined differently. can

In step S1220, the base station may determine a DMRS sequence initialization and generation time point. An input value for DMRS sequence initialization may be determined based on one or more of a radio frame index, a slot index, an OFDM symbol index, an SS burst set index, or an SS block index. If the SS block index information is not obtained and the terminal cannot obtain the time index information in advance, the DMRS sequence is generated based on at least one of a predetermined ID (e.g. Cell ID), CP length, and BP index information. carry out

In step S1230, the base station may determine an RE to which the generated DMRS sequence is mapped. Here, the DMRS mapping RE may be determined by applying one or more of a frequency domain shift and a time domain shift based on at least a predetermined ID.

In step S1240, the base station may map the DMRS sequence to the determined RE.

In step S1250, the base station may transmit a DMRS for demodulation of the NR-PBCH to the terminal together with the NR-PBCH.

In step S1260, the UE can receive the DMRS based on previously known information about the DMRS sequence generation length, initialization time, mapping RE location, etc. (ie, the same information as the information used by the base station for DMRS sequence generation and RE mapping), , a channel can be estimated based on the received DMRS. Also, the UE may perform NR-PBCH demodulation based on the estimated channel.

13 is a diagram showing configurations of a base station device and a terminal device according to the present disclosure.

The base station device 1300 may include a processor 1310, an antenna unit 1320, a transceiver 1330, and a memory 1340.

The processor 1310 performs baseband-related signal processing and may include an upper layer processing unit 1311 and a physical layer processing unit 1315. The upper layer processing unit 1311 may process operations of a Medium Access Control (MAC) layer, a Radio Resource Control (RRC) layer, or higher layers. The physical layer processing unit 1315 may process physical (PHY) layer operations (eg, uplink reception signal processing and downlink transmission signal processing). In addition to performing baseband-related signal processing, the processor 1310 may control overall operations of the base station device 1300 .

The antenna unit 1320 may include one or more physical antennas, and may support multiple input multiple output (MIMO) transmission and reception when including a plurality of antennas. The transceiver 1330 may include a radio frequency (RF) transmitter and an RF receiver. The memory 1340 may store information processed by the processor 1310, software related to the operation of the base station device 1300, an operating system, an application, and the like, and may include components such as a buffer.

The processor 1310 of the base station device 1300 may be configured to implement the base station operation in the embodiments described in the present invention.

The higher layer processing unit 1311 of the processor 1310 may generate control information included in MIB transmitted through the NR-PBCH and transmit it to the physical layer processing unit 1312 through the BCH.

The physical layer processor 1312 of the processor 1310 may include a DMRS sequence generator 1314, a DMRS sequence RE mapping unit 1316, and an NR-PBCH and DMRS transmission symbol generator 1318.

The DMRS sequence generation unit 1314 may determine the DMRS sequence generation length based on the maximum BW (ie, N ^{max, DMRS} _RB ) that can be set for one BW part. Specifically, the value of N ^max,DMRS _RB in Equation 1 is based on one or more of K _max,BWpart , N ^max,SSblock _RB , or N ^max,BWpart _PRB according to one of Equations 2 to 4. can be determined

In addition, the DMRS sequence generation unit 1314 may determine the DMRS sequence generation length based on n and N ^max,DMRS _RB in Equation 1 above. For example, a sequence may be generated for each OFDM symbol, each SS block, each slot, and each 80 ms, and accordingly, the generated sequence may have different lengths based on one same initial value.

In addition, the DMRS sequence generation unit 1314 may determine a DMRS sequence initialization time point. An input value for DMRS sequence initialization may be determined based on one or more of a radio frame index, a slot index, an OFDM symbol index, an SS burst set index, or an SS block index.

The DMRS sequence RE mapping unit 1316 may determine an RE to which the generated DMRS sequence is mapped. Here, the DMRS mapping RE may be determined by applying one or more of a frequency domain shift and a time domain shift based on a predetermined ID. The DMRS sequence RE mapping unit 1316 may map the DMRS sequence to the determined RE.

The NR-PBCH and DMRS transmission symbol generation unit 1318 may generate a symbol (eg, OFDM symbol) to be transmitted after completing RE mapping of the NR-PBCH and DMRS. Accordingly, the generated transmission symbol may be transmitted to the terminal device 1350 through the transceiver 1330 .

The terminal device 1350 may include a processor 1360, an antenna unit 1370, a transceiver 1380, and a memory 1390.

The processor 1360 performs baseband-related signal processing and may include an upper layer processing unit 1361 and a physical layer processing unit 1365. The upper layer processing unit 1361 may process operations of a MAC layer, an RRC layer, or higher layers. The physical layer processing unit 1365 may process PHY layer operations (eg, downlink reception signal processing and uplink transmission signal processing). In addition to performing baseband-related signal processing, the processor 1360 may also control overall operations of the terminal device 1350 .

The antenna unit 1370 may include one or more physical antennas, and may support MIMO transmission and reception when including a plurality of antennas. The transceiver 1380 may include an RF transmitter and an RF receiver. The memory 1390 may store information processed by the processor 1360, software related to the operation of the terminal device 1350, an operating system, an application, and the like, and may include components such as a buffer.

The processor 1360 of the terminal device 1350 may be configured to implement the operation of the terminal in the embodiments described in the present invention.

The physical layer processing unit 1362 of the processor 1360 may include a DMRS receiving unit 1364, a channel estimation unit 1366, and an NR-PBCH demodulation unit 1368.

The DMRS receiving unit 1364 receives the DMRS based on previously known information about the DMRS sequence generation length, initialization time, mapping RE location, etc. (that is, the same information as the information used by the base station for DMRS sequence generation and RE mapping). can

The channel estimator 1366 may estimate a channel based on the received DMRS.

The NR-PBCH demodulator 1368 may perform NR-PBCH demodulation based on the estimated channel.

Matters described in the examples of the present invention may be equally applied to the operations of the base station device 1300 and the terminal device 1350, and redundant descriptions are omitted.

Further examples of the present disclosure for a PBCH DMRS sequence are described below.

The following examples may be combined with the examples described with reference to FIGS. 1 to 13 described above or may be applied as separate examples.

[Example A: Gold sequence order 31 (Gold sequence order N=31)]

A pseudo-random (PN) sequence can be used as a reference signal sequence for generating a reference signal. A sequence based on a Gold Sequence generated by a bit-to-bit modular 2 operation of two m-sequences, each generated based on a 31st-order primitive polynomial, is used. At this time, since the 31st order primitive polynomial can be implemented as a Linear Feedback Shift Register (LFSR) whose length (or size) is 31, pseudo-random based on the Gold Sequence The sequence can be viewed as a two-stage configuration of a Linear Feedback Shift Register (LFSR) having a size of 31.

In Equation 10, c(n) is a pseudo-random sequence based on a Gold Sequence having a length of M _PN , and n = 0, 1, ..., M _PN -1. Also, x1(n) represents the first m-sequence and x2(n) represents the second m-sequence. Nc is considered in order to utilize the generated sequence as a sequence starting from a sequence index generated as many as Nc or more without affecting the initialization value. This is an arbitrary value given to take a more random value, and may be Nc = 1600, but is not limited thereto. Also, hereinafter, "mod A" means a modular A operation, which corresponds to an operation that divides by A and takes the remainder.

PN sequence generation can be defined using the Gold sequence order N. The order of the Gold sequence may be determined in consideration of how many system parameters are required in the NR system as initialization bits or the computational complexity of the system. If, for example, based on the Gold sequence of order 31, two Polynomial ^1st : x31 + x3 + 1, ^2nd : x31 +x3 + x2 + 1 + 1 and the following equation can be used. To generate a PN sequence, the initial value (Cinit) is a combination of Cell ID or Cell ID and other time information (SS block index 2 or 3 bits, OFDM symbol index 1 or 4 bits, 5 ms timing, etc.) as discussed above. Can be configured. there is. Then, it is finally mapped to PBCH DMRS RE and transmitted using BPSK or QPSK modulation.

As an example, a PN sequence with degree N=31 can be generated based on two polynomials as follows. A PN sequence based on a Gold sequence having a different order may be generated based on a different polynomial using the Cinit values suggested below.

으로 결정된다. 아래 제안된 Cinit 값은 상기 2^nd polynomial의 초기값으로

와 같은 방식으로 초기값을 결정한다.N _c =1600, and 1 ^st polynomial is initialized to x ₁ (0)=1, x ₁ (n)=0, n=1, 2, ..., 30. ^2nd polynomial is

is determined by The Cinit value suggested below is the initial value of the 2 ^nd polynomial.

The initial value is determined in the same way as

[Example B: Gold sequence order N>31 (Gold sequence order N>31)]

As mentioned above, a method of generating a PN sequence based on a gold sequence having a different order may be considered. This is the range of slot indexes increased in the current NR system (240 subcarrier spacing: 160 (8 bits), 480 subcarrier spacing: 320 (9 bits)), OFDM symbol index (14, 4 bits), cell ID (10 bits) and number of codewords (1 bit ) and considering the number of RNTIs (16 bits), etc., at least a 36-bit initial value may be required. Therefore, the Gold sequence of order 31 above may not be able to satisfy it.

Unlike the Gold sequence order 31, a Gold sequence-based PN sequence having a Gold sequence order longer than 31 may be generated. Likewise, each of the two m-sequences is generated based on the two primitive polynomials. Here, the degree of the first primitive polynomial and the second primitive polynomial is N (n>31), and the coefficients a _i , b _j (i{N-1, N -2, ..., 1 , 0}, the value of j{N-1, N-2, ..., 1, 0} is 0 or 1.

The first primitive polynomial can be any irreducible primitive polynomial of degree N.

The second primitive polynomial is x ₁ ((q n) mod 2, which is a sequence sampled by q when the m-sequence generated based on the first primitive polynomial is x ₁ (n). ^N -1) as a primitive polynomial with m-sequence. Therefore, when the m-sequence generated based on the second primitive polynomial is x ₂ (n), x ₂ (n) = x ₁ ((q·n)mod 2 ^N -1). Here, q is derived as in Equation 12. So q is always odd.

Here, the k value can be obtained through Equation 12 according to the relation between the polynomial order (N) and the k value. Therefore, one or a plurality of k values may exist according to the N value. gcd(N,k) means the greatest common divisor operation between N and k.

Gold sequence orders that do not meet the above conditions are excluded from the table below. That is, a Gold sequence order that is a multiple of 4 (N mod 4=0) is not considered for generating a Gold sequence.

Hereinafter, an example of a method of generating a Gold sequence having a value greater than the Gold sequence order 31 will be described. In the case of Gold sequence order 45 (N = 45, N odd), the first primitive polynomial for the first m-sequence below can be selected through Table 1 below.

Table 1 below shows examples of primitive polynomials when N>31.

Order of Gold sequence (N) Primitive ^Polynomial for 1st m-sequence (x1) 33 33 6 4 1 0 34 34 7 6 5 2 1 0 35 35 2 0 37 37 5 4 3 2 1 0 38 38 6 5 1 0 39 39 4 0 41 41 3 0 42 42 5 4 3 2 1 0 43 43 6 4 3 0 45 45 4 3 1 0 46 46 8 5 3 2 1 0 47 47 5 0 49 49 6 5 4 0 50 50 4 3 2 0 51 51 6 3 1 0 53 53 6 2 1 0 54 54 6 5 4 3 2 0 55 55 6 2 1 0 57 57 5 3 2 0 58 58 6 5 1 0 59 59 6 5 4 3 1 0 61 61 5 2 1 0 62 62 6 5 3 0 63 1 0

과 같은 의미이다. For example, for N=45, the first primitive polynomial can be expressed as x45 + x4 + x3 + x1 + 1, which is

has the same meaning as

The next ^2nd m-sequence is, as already mentioned, every qth sample of the ^1st m-sequence generated according to the first original polynomial x ₂ (n) = x ₁ ((q n)mod 2 ^N - 1) is created by collecting The method of generating a sequence by collecting every qth sample usually generates the same sequence as the method of generating the second m-sequence by defining a second original polynomial for generating a 2 ^nd m-sequence. The conditions for a 1 ^st m-sequence and a 2 ^nd m-sequence to be a preferred pair are as follows.

- A polynomial order (N) is an N value that is not a multiple of 4 and is an odd number or N mod 4=2.

- where q and gcd(N,k) can be derived according to Equation 12. So q is always odd.

Here, the k value can be obtained through the above method according to the relationship between the Gold sequence polynomial order (N) and the k value. Therefore, one or a plurality of k values may exist according to the N value. gcd(N,k) means the greatest common divisor operation between N and k.

The result of applying the Cinit value to the 2 ^nd m-sequence thus generated is the same as the result of performing cyclic shift of the sequence. Therefore, a cyclic shift is possible as much as the length of the Gold sequence (2 ^N -1, where N is a polynomial order). That is, a sequence can be generated based on a cyclic shifted value with an arbitrary value between 1 and 2 ^N -1, and the random value corresponds to a specific Cinit value, respectively. For example, if a sequence is created by defining a specific value (eg Cell ID) as a Cinit value as in the method proposed below, it can be regarded as the same as a sequence generated by cyclic shifting as much as the Cell ID value.

As a result, when the Gold sequence order N=45, a PN sequence based on the Gold sequence can be generated as shown in Equation 13.

N _c =1600, and 1 ^st polynomial is initialized to x ₁ (0)=1, x ₁ (n)=0, n=1, 2, ..., 30. q is 3 (n is an odd number), so every third sample of the x1 sequence (1 ^st m-sequence) can be composed of a sequence of x2 (2 ^nd m-sequence). In order to generate the final x2 sequence (2 ^nd m-sequence), as shown in Equation 13, the x2 sequence is cyclically shifted based on the cyclic shift (T ⁱ ) value corresponding to the Cinit value, and the x2 sequence (2 ^nd sequence) is finally create with

으로 결정된다. 아래 제안된 Cinit 값은 상기 2^nd polynomial의 초기값으로

와 같은 방식으로 초기값을 결정한다.As a different expression method, of course, the second original polynomial for generating the 2 ^nd sequence can be defined in the same way as described above for N=31, and the final 2 ^nd sequence can be generated based on the Cinit value suggested below. In that case, in the same way as for N=31, the 2 ^nd sequence is

is determined by The Cinit value suggested below is the initial value of the 2 ^nd polynomial.

The initial value is determined in the same way as

[Example C: Gold-like sequence order N=36]

As mentioned above, it is possible to generate a PN sequence based on a Gold-like sequence whose order is longer than 31. For example, a PN sequence is generated as shown in Equation 14 with two proposed polynomials based on a Gold-like sequence of degree 36.

으로 결정된다. 아래 제안된 Cinit 값은 상기 2^nd polynomial 의 초기값으로

와 같은 방식으로 초기값을 결정한다.N _c =1600, and 1 ^st polynomial is initialized to x ₁ (0)=1, x ₁ (n)=0, n=1, 2, ..., 35. ^2nd polynomial is

is determined by The Cinit value suggested below is the initial value of the 2 ^nd polynomial.

The initial value is determined in the same way as

[Definition of Cinit needed to create a gold (gold-like) sequence]:

1. PBCH DMRS sequence is initialized for each SS block

When a PN sequence (pseudo-random sequence) is generated based on one of the proposed gold sequences, Cinit values include at least N ^cell _ID and n _ssblock as suggested above, and examples such as Equation 15 below It can be configured through one of the values.

At the beginning of each SS block in the SS burst set, it should be initialized using one of the Cinit values.

That is, generation of PBCH reference signals in SS blocks is performed for each SS block, and reference signals corresponding to two OFDM symbols are generated and mapped.

If information on the SS block transmission period (5 ms) needs to be transmitted through the PBCH DMRS sequence in addition to the above information, N SS block _{5 ms} can be considered to determine the ^Cinit value as shown in Equation 16 below.

At the beginning of each SS block in the SS burst set, it must be initialized using one of the Cinit values.

2. PBCH DMRS sequence is initialized for each OFDM symbol in SS block

When a PN sequence (pseudo-random sequence) is generated based on one of the proposed gold sequences, Cinit values include at least N ^cell _ID and n _ssblock as suggested above, and examples such as Equation 17 below It can be configured through one of the values.

It should be initialized with the Cinit value at the beginning of an OFDM symbol in each SS block in an SS burst set.

If information on the SS block transmission period (5 ms) must also be delivered through the PBCH DMRS sequence, a Cinit value can be defined as shown in Equation 18.

It should be initialized with the Cinit value at the beginning of an OFDM symbol in each SS block in an SS burst set.

Each parameter considered in the PBCH DMRS sequence initialization is as follows.

- n _ssblock : SS block index transmitted through PBCH DMRS, and has a range of 0 to 3 (2 bits) or 0 to 7 (3 bits). When n _ssblock corresponds to 3 bits, if L=4 (the maximum number of SS blocks), the lower 2 bits (eg 000, 001, 010, 011) among 3 bits are used, and if L=8, 3 bits (eg000 , 001, 010, 011, 100, 101, 110, 111) are used to transmit the SS block index. When L = 64, 6-bit information is indicated to the terminal by combining the n _ssblock and MIB SS block index fields (eg 3(n _ssblock DMRS) + 3(MIB) = 6 bits). If n _ssblock corresponds to 2 bits, it indicates the SS block index corresponding to 2 bits among the maximum number of SS blocks regardless of the L value. If L = 8 or L = 64, the base station can deliver the SS block index corresponding to L = 8 and L = 64 to the terminal through a combination with the SS block index field (3 or 4 bits) in the PBCH MIB. In the present invention, for ease of explanation, n _ssblock is assumed to be 3 bits, but is not limited thereto, and 2 bits or other numbers of bits are also applicable to the proposed method.

Table 2 below shows an example of an SS block index indication according to an L value in the case of a 3-bit SS block index through DMRS.

Table 3 below shows an example of an SS block index indication according to an L value in the case of a 2-bit SS block index through DMRS.

- N ^cell _ID : NR cell ID value in the range of 0 to 1007 (10 bits).

- N ^SSblock _5ms : SS block transmission period (5ms) has information on timing (0 to 1) range

- l ': OFDM symbol index for PBCH DMRS transmission in SS block has a range of 0 to 1 or 0 to 13.

: L=4 인 경우, n_ssblock(즉, SS block 인덱스의 2개의 LSB bits)와 하나의 라디오 프레임 내의 하프 프레임 타이밍

이 함께 고려된 인덱스 이거나, 만약 L=8 또는 64인 경우에는 n_ssblock(즉, SS block 인덱스의 3개의 LSB bits)만이 고려된 인덱스이다.

: When L = 4, half frame timing within n _ssblock (ie, 2 LSB bits of SS block index) and one radio frame

is an index considered together, or if L = 8 or 64, only n _ssblocks (ie, 3 LSB bits of the SS block index) are considered indexes.

[PN sequence based on Kasami sequence]:

The pseudo-random sequence proposed in the present invention is based on a Kasami sequence and is a sequence generated by bit-to-bit modular 2 operation of three m-sequences. In this case, the first m-sequence is generated based on the first primitive polynomial, the second m-sequence is generated based on the second primitive polynomial, A 3 m-sequence is generated based on the third primitive polynomial. Here, the degree of the first primitive polynomial and the second primitive polynomial is M, and the degree of the third primitive polynomial is M/2. Therefore, M is an even number. If this is expressed as a mathematical expression, it is equal to Equation 19. Here, the coefficients a _i , b _j , c _k (i{M-1, M-2, ..., 1, 0}, j{M-1, M-2, . .., 1, 0}, k{M/2-1, M/2-2, ..., 1, 0} ) is 0 or 1.

The first primitive polynomial can be any irreducible primitive polynomial of degree M.

The _{second primitive polynomial is x 1 (} (f ₁ · _n ) mod 2 ^M -1) as a primitive polynomial with m-sequence. Therefore, when the m-sequence generated based on the second primitive polynomial is x ₂ (n), x ₂ (n) = x ₁ ((f ₁ n)mod 2 ^M -1).

The _{third primitive polynomial is x 1 ( (f 2 ·} n) mod 2 ^M -1) as a primitive polynomial with m-sequence. Therefore, when the m-sequence generated based on the third primitive polynomial is x ₃ (n), x ₃ (n) = x ₁ ((f ₂ n)mod 2 ^M -1).

where n{0, 1, ..., 2 ^M -2). In this case, the sampling value f ₁ =1+2 ^(M+2)/2 may be the value, and the sampling value f ₂ =1+2 ^M/2 may be the value.

Also, "mod A" means a modular A operation, which corresponds to an operation that divides by A and takes the remainder.

At this time, as shown in FIG. 14, the first m-sequence based on the first primitive polynomial of M degree may be implemented as an LFSR having a length (or size) of M. In addition, a second m-sequence based on a second primitive polynomial of degree M may be implemented as an LFSR having a length (or size) of M. In addition, a third m-sequence based on a third primitive polynomial of order M/2 may be implemented as an LFSR having a length (or size) of M/2. A final sequence is generated by performing a modulo 2 operation bit by bit on three m-sequences generated through these three LFSRs.

Therefore, this can be implemented with two LFSRs each having a length (length, or size) of M and one LFSR having a length (or size) of M/2, that is, a total of three LFSRs. It can.

When expressed as an equation in the above generation method, it is equal to Equation 20. c(n) is a pseudo-random sequence proposed in the present invention having a length of M _PN , and n = 0, 1, ..., M _PN -1. In addition, x ₁ (n) represents the first m-sequence, x ₂ (n) represents the second m-sequence, and x ₃ (n) represents the third m-sequence indicates N _c is an arbitrary value given to take a more random value by generating a generated sequence to a certain extent without affecting the initialization value, and may be N _c =1600, but is not limited thereto, and any other value may be used. Coefficients a _i , b _j , c _k (i{M-1, M-2, ..., 1, 0}, j{M-1, M-2, .. ., 1, 0}, k{M/2-1, M/2-2, ..., 1, 0}) is 0 or 1.

At this time, the initial value of the first LFSR for generating the first m-sequence x ₁ (n) and the second for generating the second m-sequence x ₂ (n) The initial value of the LFSR and the initial value of the third LFSR for generating the third m-sequence x ₃ (n) may be given as in Equation 21, and eventually of the first LFSR The initialization value uses a fixed initialization value, and the initialization value of the second LFSR and the initialization value of the third LFSR follow the c _{init_1} value and the c _{init_2} value based on the system parameter, respectively.

As shown in Equation 21, up to M bits in the initialization value c _{init_1} of the second LFSR and up to M / 2 bits in the initialization value c _{init_2} of the third LFSR, different pseudo-random depending on the system parameters of a total of 3M / 2 bits You can create sequences.

Hereinafter, a specific example when M=30 will be given for the pseudo-random sequence generation method proposed in the present invention described through FIG. 14 and Equations 19 to 21. M = 30 is a larger value among even-numbered M values that satisfy 32-bit operation.

The pseudo-random sequence proposed in the present invention is a sequence generated by bit-to-bit modular 2 operation of three m-sequences. In this case, the first m-sequence is generated based on the first primitive polynomial, the second m-sequence is generated based on the second primitive polynomial, A 3 m-sequence is generated based on the third primitive polynomial. Here, the degree of the first primitive polynomial and the second primitive polynomial is 30, and the degree of the third primitive polynomial is 15. If this is expressed as a mathematical expression, it is equal to Equation 22.

The first primitive polynomial can be any irreducible primitive polynomial of degree 15.

The _{second primitive polynomial is x 1 (} (f ₁ · _n ) mod 2 ³⁰ -1) as a primitive polynomial with m-sequence. Therefore, when x ₂ (n) is an m-sequence generated based on the second primitive polynomial, x ₂ (n) = x ₁ ((f ₁ n)mod 2 ³⁰ -1).

The _{third primitive polynomial is x 1 ( (f 2 ·} n) mod 2 ³⁰ -1) as a primitive polynomial with m-sequence. Therefore, when x ₃ (n) is an m-sequence generated based on the third primitive polynomial, x ₃ (n) = x ₁ ((f ₂ n)mod 2 ³⁰ -1).

where n{0, 1, ..., 2 ³⁰ -2). In this case, the sampling value f1 = 1 + 2 ¹⁶ may be, and the sampling value f ₂ = 1 + 2 ¹⁵ may be.

Also, "mod A" means a modular A operation, which corresponds to an operation that divides by A and takes the remainder.

In this case, the first m-sequence based on the first primitive polynomial of degree 30 may be implemented as an LFSR having a length (or size) of 30. In addition, a second m-sequence based on a second primitive polynomial of degree 30 may be implemented as an LFSR having a length (or size) of 30. In addition, a third m-sequence based on a third primitive polynomial of degree 15 may be implemented as an LFSR having a length (or size) of 15. A final sequence is generated by performing a modulo 2 operation bit by bit on three m-sequences generated through these three LFSRs.

Therefore, this can be implemented with two LFSRs each having a length (length, or size) of 30 and one LFSR having a length (length, or size) of 15, that is, a total of three LFSRs. will be.

Expressed as an equation in the above generation method, it is equal to Equation 23. c(n) is a pseudo-random sequence proposed in the present invention having a length of M _PN , and n = 0, 1, ..., M _PN -1. In addition, x ₁ (n) represents the first m-sequence, x ₂ (n) represents the second m-sequence, and x ₃ (n) represents the third m-sequence indicates N _c is an arbitrary value given to take a more random value by generating a generated sequence to a certain extent without affecting the initialization value, and may be N _c =1600, but is not limited thereto, and any other value may be used.

At this time, the initial value of the first LFSR for generating the first m-sequence x ₁ (n) and the second for generating the second m-sequence x ₂ (n) The initial value of the LFSR and the initial value of the third LFSR for generating the third m-sequence x ₃ (n) may be given as in Equation 24, and eventually of the first LFSR The initialization value uses a fixed initialization value, and the initialization value of the second LFSR and the initialization value of the third LFSR follow the c _{init_1} value and the c _{init_2} value based on the system parameter, respectively.

As shown in Equation 24, different pseudo-random sequences can be generated according to a system parameter of up to 30 bits in the initialization value c _{init_1} of the second LFSR and up to 15 bits in the initialization value c _{init_2} of the third LFSR, totaling 45 bits. there will be a number

[Cinit definition needed to create Kasami sequence]:

1. PBCH DMRS sequence is initialized for each SS block

The proposed pseudo-random sequence (PN sequence) based on the Kasami sequence can be defined based on the following Cinit values and their combinations. Any combination of values suggested below can be used for each of Cinit_1 and Cinit_2 within the range that does not exceed order N (Cinit_1) and order N/2 (Cinit_2).

Table 4 below shows an example of a method of configuring Cinit_1 and Cinit_2 for generating a Kasami sequence.

Embodiment A configuration examples:

Embodiment B-1 configuration example:

Embodiment B-2 configuration example:

Embodiment C-1 configuration example:

Embodiment C-2 configuration example:

At the beginning of each SS block in the SS burst set, a PN sequence should be initialized with one value of Cinit_1 and one value of Cinit_2.

If information on the SS block transmission period (5 ms) needs to be additionally delivered through the PBCH DMRS sequence, N SS block _{5 ms} can be added to ^Cinit_1 or Cinit_2 as follows and used as an initial value for generating a PN sequence.

Examples of possible combinations for Cinit_1 (order N) are shown in Table 5 below.

Examples of possible combinations for Cinit_2 (order N/2) are shown in Table 6 below.

All other system parameters are the same as already mentioned.

- N ^SSblock _5ms : SS block transmission period (5ms) has information on timing (0 to 1) range.

2. PBCH DMRS sequence is initialized for each SS block and OFDM symbol

Each of the initialization values Cinit_1 and Cinit_2 for generating a PN sequence (pseudo-random sequence) may be defined based on a combination of N ^cell _ID , n _ssblock , and l '. Table 7 below is an excerpt of some of the various combinations, and in the present invention, the combinations are not limited to the following embodiments, and the N ^cell _ID , n _ssblock , and l 'are one of all combinations in Cinit_1 and Cinit_2, respectively. Assume that the PN sequence can be initialized using the combination.

Table 7 below shows an example of a method of configuring Cinit_1 and Cinit_2 for generating a Kasami sequence.

Examples in the case of l: 1-bit assumption, n _ssblock : 3-bit assumption, and N ^cell _ID : 10-bit assumption will be described below.

Embodiment A-1 configuration example:

Embodiment A-2 configuration example:

Embodiment B-1 configuration example:

Embodiment B-2 configuration example:

Embodiment C-1 configuration example:

Embodiment C-2 configuration example:

Embodiment D-1 configuration example:

Embodiment D-2 configuration example:

At the beginning of each OFDM symbol in each SS block in the SS burst set, it should be initialized with the values of Cinit_1 and Cinit_2.

If information on the SS block transmission period (5 ms) needs to be additionally delivered through the PBCH DMRS sequence, as shown in Equation 25 below, N ^SSblock _{5 ms} is added to the Cinit_1 or Cinit_2 as an initial value for generating a PN sequence can also be utilized.

All other parameters are the same as already mentioned.

- l ': OFDM symbol index for PBCH DMRS transmission in SS block has a range of 0 to 1 or 0 to 13.

A DMRS sequence is generated using one of the initialization values for generating the two PN sequences and the QPSK modulation scheme as shown in Equation 1. Of course, the BPSK modulation scheme can also be used.

As shown in FIG. 15, 3 DMRS REs in all PRBs within the PBCH transmission bandwidth are used to allocate the proposed PBCH DMRS sequence for each symbol. V_dmrs_shift = ID mod 4 in the frequency axis based on different cell IDs, virtual cell IDs, or UE IDs according to the above-described equations.

In FIG. 16, the PBCH reference signal is transmitted for the purpose of indicating the proposed SS block index only in the transmission bandwidth in which NR-SS is transmitted, and the reference signal generated based on only the Cell ID is transmitted in other PBCH bandwidths. V_dmrs_shift = ID mod 4 in the frequency axis based on different cell IDs, virtual cell IDs, or UE IDs according to the above-described equations.

Exemplary methods of this disclosure are presented as a series of operations for clarity of explanation, but this is not intended to limit the order in which steps are performed, and each step may be performed concurrently or in a different order, if desired. In order to implement the method according to the present disclosure, other steps may be included in addition to the exemplified steps, other steps may be included except for some steps, or additional other steps may be included except for some steps.

Various embodiments of the present disclosure are intended to explain representative aspects of the present disclosure, rather than listing all possible combinations, and matters described in various embodiments may be applied independently or in combination of two or more.

In addition, various embodiments of the present disclosure may be implemented by hardware, firmware, software, or a combination thereof. For 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 (FPGAs), It may be implemented by a processor (general processor), controller, microcontroller, microprocessor, or the like.

The scope of the present disclosure is software or machine-executable instructions (eg, operating systems, applications, firmware, programs, etc.) that cause operations according to methods of various embodiments to be executed on a device or computer, and such software or It includes a non-transitory computer-readable medium in which instructions and the like are stored and executable on a device or computer.

Claims (18)

In the method of transmitting a signal,
Determining an initialization value for a reference signal associated with a physical broadcast channel (PBCH);
generating a reference signal associated with the PBCH based on the initialization value;
Mapping the generated reference signal to one or more resource elements (REs); and
Transmitting the mapped reference signal and the PBCH to a terminal, wherein the resource elements (REs) are included in an SS block corresponding to a synchronization signal (Synchronization Signal, SS) block index,
The SS block corresponding to the SS block index includes at least four orthogonal frequency division multiplexing (OFDM) symbols,
Among the at least four OFDM symbols, a first OFDM symbol includes a Primary Synchronization Signal (PSS), a second OFDM symbol includes a part of the PBCH, and a third OFDM symbol includes a Secondary Synchronization Signal (PSS). Signal, SSS),
The second OFDM symbol is located between the first OFDM symbol and the third OFDM symbol,
The third OFDM symbol is located between the second OFDM symbol and a fourth OFDM symbol included in the at least four OFDM symbols,
The remaining PBCH parts except for the part of the PBCH are mapped to the second OFDM symbol and the fourth OFDM symbol,
A demodulation reference signal (DMRS) associated with the PBCH is mapped to the second, third, and fourth OFDM symbols.
According to claim 1,
The initialization value is
A method for transmitting a reference signal, which is determined based on at least one of a cell identifier, the SS block index, and a half-frame timing index.
According to claim 2,
The mapping step is
Characterized in that, based on at least one value of a shift value in the frequency domain or a shift value in the time domain, the generated reference signal is mapped to one or more resource elements, a method for transmitting a reference signal,
According to claim 3,
The half frame timing index,
A method for transmitting a reference signal corresponding to a 1-bit value indicating a first half frame of a radio frame or a second half frame of the radio frame.
delete According to claim 2,
The cell identifier is a method for transmitting a reference signal, characterized in that related to the identifier of the base station associated with the terminal.
delete delete According to claim 2,
Initializing a scrambling sequence for each SS block and generating a reference signal associated with the PBCH based on the initialized scrambling sequence.
In the device for transmitting a signal,
Determines an initialization value for a reference signal related to a physical broadcast channel (PBCH), generates the reference signal related to the PBCH based on the initialization value, and converts the generated reference signal to one or more resource elements Processors that map to (Resource Elements, REs); and
Including a transmitter for transmitting the PBCH and the mapped reference signal to a terminal,
The resource elements (REs) are included in the SS block corresponding to the synchronization signal (Synchronization Signal, SS) block index,
The SS block corresponding to the SS block index includes at least four orthogonal frequency division multiplexing (OFDM) symbols,
Among the at least four OFDM symbols, a first OFDM symbol includes a Primary Synchronization Signal (PSS), a second OFDM symbol includes a part of the PBCH, and a third OFDM symbol includes a Secondary Synchronization Signal (PSS). Signal, SSS),
The second OFDM symbol is located between the first OFDM symbol and the third OFDM symbol,
The third OFDM symbol is located between the second OFDM symbol and a fourth OFDM symbol included in the at least four OFDM symbols,
The remaining PBCH parts except for the part of the PBCH are mapped to the second OFDM symbol and the fourth OFDM symbol,
A demodulation reference signal (DMRS) associated with the PBCH is mapped to the second, third, and fourth OFDM symbols.
According to claim 10,
The initialization value is determined based on at least one of a cell identifier, the SS block index, and a half-frame timing index.
According to claim 11,
the processor,
An apparatus for transmitting a reference signal, characterized in that mapping the generated reference signal to one or more resource elements based on one or more values of a frequency domain shift value or a time domain shift value.
According to claim 12,
The half frame timing index is
An apparatus for transmitting a reference signal corresponding to a 1-bit value indicating a first half frame of a radio frame or a second half frame of the radio frame.
delete According to claim 11,
The cell identifier is related to an identifier of a base station associated with the terminal.
delete delete According to claim 11,
the processor,
An apparatus for transmitting a reference signal that initializes a scrambling sequence for each SS block and generates a reference signal associated with a PBCH based on the initialized scrambling sequence.

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