KR20210050977A - Frequency resource measuring method and apparatus performing the same - Google Patents

Abstract

Disclosed are a frequency resource measuring method and a device performing the same. According to an embodiment of the present invention, the frequency resource measuring method comprises the steps of: receiving a synchronization signal/physical broadcast channel block (SS/PBCH) transmitted from a base station; setting an energy detection (ED) threshold based on the SS/PBCH; and determining whether to use a resource block based on the ED threshold. Therefore, the present invention can provide a technique for measuring a frequency resource being used by a terminal with high accuracy.

Description

Frequency resource measurement method and device that performs it {FREQUENCY RESOURCE MEASURING METHOD AND APPARATUS PERFORMING THE SAME}

The following embodiments relate to a method of measuring a frequency resource and an apparatus for performing the same.

Since the commercialization of the 4G (4th generation) communication system, efforts have been made to develop a new 5G (5th generation) communication system to meet the increasing demand for wireless data traffic. The 5G communication system is called a beyond 4G network communication system, a post LTE system, or a new radio (NR) system. In order to achieve a high data rate, the 5G communication system includes a system operated using an ultra-high frequency (mmWave) band of 6 GHz or higher, and a communication system operated using a frequency band of 6 GHz or lower in terms of securing coverage. Including the implementation in the base station and the terminal is being considered.

The 3rd Generation Partnership Project (3GPP) NR system improves the spectrum efficiency of the network, enabling carriers to provide more data and voice services in a given bandwidth. Therefore, the 3GPP NR system is designed to meet the demand for high-speed data and media transmission in addition to supporting large-capacity voice. The advantage of the NR system is that it can have low operating costs with high throughput, low latency, frequency division duplex (FDD) and time division duplex (TDD) support, improved end-user environment and simple architecture on the same platform.

For more efficient data processing, the dynamic TDD of the NR system may use a method of varying the number of orthogonal frequency division multiplexing (OFDM) symbols that can be used for uplink and downlink according to the data traffic direction of users of the cell. For example, when the downlink traffic of the cell is more than the uplink traffic, the base station may allocate a plurality of downlink OFDM symbols to a slot (or subframe). Information on the slot configuration should be transmitted to the terminals.

Various attempts are being made to apply the 5G communication system to the IoT network. For example, technologies such as sensor network, machine to machine (M2M), and machine type communication (MTC) are implemented by techniques such as beamforming, MIMO, and array antenna, which are 5G communication technologies. As the big data processing technology described above, the cloud radio access network (cloud RAN) is also an example of the convergence of 5G technology and IoT technology. In general, mobile communication systems have been developed to provide voice services while ensuring user activity.

However, mobile communication systems are gradually expanding their range to not only voice but also data services, and have developed to the extent that they can provide high-speed data services. However, in a mobile communication system in which a service is currently provided, a more advanced mobile communication system is required due to a shortage of resources and a demand for a high-speed service from users.

In addition, in the context of providing services using multi-band multi-band frequency aggregation technology through 5G communication systems and providing commercial services that combine mobile communication IoT services with various industries, mobile data traffic is continuously increasing. In order to forecast and establish a future frequency allocation plan, a method of measuring the amount of frequency used in a specific frequency band in which the 5G communication system is being serviced is required.

The embodiments may provide a technique for measuring a frequency resource being used by a terminal with high accuracy using energy detection (ED) in a wireless communication system.

A frequency resource measurement method according to an embodiment includes receiving a synchronization signal/physical broadcast channel block (SS/PBCH) transmitted from a base station, and an energy detection (ED) threshold based on the SS/PBCH block. And determining whether to use a resource block based on the ED threshold.

The SS/PBCH block may include at least one of a primary synchronization signal (PSS), a secondary synchronization signal (SSS), a physical broadcast channel (PBCH), and a physical broadcast channel-demodulation reference signal (PBCH-DMRS).

The setting may include determining a reference power based on the SS/PBCH block and setting an ED threshold based on the reference power.

The determining may include measuring a reception power level for at least one of the signals included in the SS/PBCH block, and a resource block occupied by the SS/PBCH block based on the power level. It may include the step of determining the reference power for the bandwidth (bandwidth) in the carrier (carrier) to be measured.

The receiving may include receiving the same SS/PBCH block index among the indexes of the SS/PBCH block.

The SS/PBCH block may be an SS/PBCH block periodically transmitted with different indexes.

The determining of the reference power may include determining the reference power by calculating an average of the measured power based on the SS/PBCH block.

The setting of the ED threshold based on the reference power may include a power level measured by receiving a physical downlink control channel (PDCCH) or a demodulation reference signal (DM-RS) of a PDCCH and a PDCCH distributed based on the reference power. It may include the step of setting the ED threshold based on.

The setting of the ED threshold based on the reference power includes measuring a channel and a power level in a channel bandwidth in which a wideband DM-RS is configured, and a reception power level and a resource block of the PDCCH based on the measurement result. It may include measuring fluctuations with respect to the power level, and setting an ED threshold value of the resource block based on the fluctuation and the reference power.

The apparatus for measuring frequency resources according to an embodiment includes a memory including instructions and a processor for executing the instructions, and when the instructions are executed by the processor, the processor comprises: SS/PBCH transmitted from the base station. Receive a synchronization signal/physical broadcast channel block, set an energy detection (ED) threshold based on the SS/PBCH block, and determine whether to use a resource block based on the ED threshold. Judge.

The SS/PBCH block may include at least one of a primary synchronization signal (PSS), a secondary synchronization signal (SSS), a physical broadcast channel (PBCH), and a physical broadcast channel-demodulation reference signal (PBCH-DMRS).

The processor may determine a reference power based on the SS/PBCH block and set an ED threshold based on the reference power.

The processor measures a reception power level for at least one of the signals included in the SS/PBCH block, and to measure based on a resource block occupied by the SS/PBCH block based on the power level. The reference power for a bandwidth in a carrier may be determined.

The processor may receive the same SS/PBCH block index among the indexes of the SS/PBCH block.

The SS/PBCH block may be an SS/PBCH block periodically transmitted with different indexes.

The processor may determine the reference power by calculating an average of the power measured based on the SS/PBCH block.

The processor may receive a physical downlink control channel (PDCCH) distributed based on the reference power or a demodulation reference signal (DM-RS) of a PDCCH and a PDCCH and set the ED threshold based on a measured power level. .

The processor measures a channel and a power level in a channel bandwidth in which a wideband DM-RS is configured, and measures a fluctuation of a reception power level of a PDCCH and a power level between resource blocks based on a measurement result, and the ED threshold values of the resource blocks may be set based on the variation and the reference power.

1 shows an example of a radio frame structure used in a wireless communication system.
2 shows an example of a structure of a resource grid of a 3GPP NR system.
3 is a diagram illustrating an example of a physical channel used in a 3GPP system and a general signal transmission method using the physical channel.
4A and 4B show an example of an SS/PBCH block for initial cell access in a 3GPP NR system.
5A is a flowchart illustrating an example of a procedure for transmission of control information and a control channel in a 3GPP NR system, and FIG. 5B is a diagram illustrating an example of transmission of control information and a control channel in a 3GPP NR system.
6 shows an example of a CORESET in which a PDCCH can be transmitted in a 3GPP NR system.
7 is a diagram illustrating an example of a method of setting a PDCCH search space in a 3GPP NR system.
8 is a diagram for describing an example of carrier aggregation.
9A is a diagram illustrating an example of a subframe structure of a single carrier, and FIG. 9B is a diagram illustrating an example of a subframe structure of a multicarrier.
10 is a diagram illustrating an example of a method to which a cross-carrier scheduling technique is applied.
11 is a schematic block diagram of a wireless communication system in which an apparatus for measuring a frequency resource according to an embodiment is implemented.
12 is a schematic block diagram of the apparatus for measuring a frequency resource shown in FIG. 11.
13 is a diagram illustrating a method of measuring a frequency resource by an apparatus for measuring a frequency resource according to an embodiment.
14 is a detailed block diagram of the wireless communication system shown in FIG. 11.

Hereinafter, embodiments will be described in detail with reference to the accompanying drawings. However, since various changes may be made to the embodiments, the scope of the patent application is not limited or limited by these embodiments. It is to be understood that all changes, equivalents, or substitutes to the embodiments are included in the scope of the rights.

The terms used in the examples are used for illustrative purposes only and should not be construed as limiting. Singular expressions include plural expressions unless the context clearly indicates otherwise. In the present specification, terms such as "comprise" or "have" are intended to designate the presence of features, numbers, steps, actions, components, parts, or combinations thereof described in the specification, but one or more other features. It is to be understood that the presence or addition of elements or numbers, steps, actions, components, parts, or combinations thereof does not preclude in advance. In addition, the limitations of "greater than" or "less than" based on a specific threshold value may be appropriately replaced with "greater than" or "less than", respectively, according to embodiments.

Terms such as first or second may be used to describe various elements, but the elements should not be limited by terms. The terms are only for the purpose of distinguishing one component from other components, for example, without departing from the scope of rights according to the concept of the embodiment, the first component may be named as the second component, and similarly The second component may also be referred to as a first component.

Unless otherwise defined, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art to which the embodiment belongs. Terms as defined in a commonly used dictionary should be interpreted as having a meaning consistent with the meaning in the context of the related technology, and should not be interpreted as an ideal or excessively formal meaning unless explicitly defined in the present application. Does not.

In addition, in the description with reference to the accompanying drawings, the same reference numerals are assigned to the same components regardless of the reference numerals, and redundant descriptions thereof will be omitted. In describing the embodiments, when it is determined that a detailed description of related known technologies may unnecessarily obscure the subject matter of the embodiments, the detailed description thereof will be omitted.

The terms used in the present specification have been selected as currently widely used general terms as possible while considering functions in the present invention, but this may vary according to the intention, custom, or the emergence of new technologies of technicians in the field. In addition, in certain cases, there are terms arbitrarily selected by the applicant, and in this case, the meaning will be described in the description of the corresponding invention. Therefore, terms used in the present specification should be interpreted based on the actual meaning of the term and the entire contents of the present specification, not a simple name of the term.

The following embodiments include code division multiple access (CDMA), frequency division multiple access (FDMA), time division multiple access (TDMA), orthogonal frequency division multiple access (OFDMA), single carrier frequency division multiple access (SC-FDMA), and the like. The same can be applied to various wireless access systems. CDMA may be implemented with a radio technology such as Universal Terrestrial Radio Access (UTRA) or CDMA2000. TDMA may be implemented with a radio technology such as Global System for Mobile communications (GSM)/General Packet Radio Service (GPRS)/Enhanced Data Rates for GSM Evolution (EDGE). OFDMA may be implemented with a wireless technology such as IEEE 802.11 (Wi-Fi), IEEE 802.16 (WiMAX), IEEE 802-20, and Evolved UTRA (E-UTRA). UTRA may be a part of Universal Mobile Telecommunications System (UMTS). 3rd Generation Partnership Project (3GPP) long term evolution (LTE) is a part of Evolved UMTS (E-UMTS) using E-UTRA, and Advanced (LTE-A) may be an evolved version of 3GPP LTE. 3GPP NR (New Radio) is a system designed separately from LTE/LTE-A, and the requirements of IMT-2020 are eMBB (enhanced mobile broadband), URLLC (Ultra-Reliable and Low Latency Communication), and mMTC (massive machine type communication). ) It may be a system for supporting services. Hereinafter, for clear explanation, the description is based on 3GPP NR, but the technical idea of the present invention is not limited thereto.

Unless otherwise specified in the specification, a base station may include a next generation node B (gNB) defined in 3GPP NR. In addition, unless otherwise specified, the terminal may include user equipment (UE). Hereinafter, for better understanding, each content is separately divided into embodiments and described, but each of the embodiments may be used in combination with each other. Hereinafter, the configuration of the terminal may mean configuration by the base station. Specifically, the base station may transmit a channel or signal to the terminal to set an operation of the terminal or a parameter value used in a wireless communication system.

1 shows an example of a radio frame structure used in a wireless communication system.

Referring to FIG. 1, a radio frame (or radio frame) used in a 3GPP NR system may have a length _{of 10 ms (Δf max} N _f /100)T _{c ).} In addition, the radio frame may consist of 10 subframes (SF) of equal size. Here, Δf _max =480×103Hz, N _f =4096, T _c =1/(Δf _ref N _f,ref ), Δfref=15×103Hz, and N _f,ref =2048.

Each of the 10 subframes in one radio frame may be numbered from 0 to 9. Each subframe has a length of 1 ms, and may be composed of one or a plurality of slots according to subcarrier spacing.

Specifically, the subcarrier spacing that can be used in the 3GPP NR system is 15×2 ^μ kHz. Here, μ is a subcarrier spacing configuration, and μ may have a value of 0 to 4. That is, the subcarrier interval may be 15 kHz, 30 kHz, 60 kHz, 120 kHz, or 240 kHz.

A subframe of 1 ms length may consist ^{of 2 μ slots.} At this time, the length of each slot may be ^{2 -μ ms.} Each of the 2 ^μ slots in one subframe may be assigned a number from 0 to 2 ^{μ -1.}

Each of the slots in one radio frame may be assigned a number ^{from 0 to 10 × 2 μ -1.} The time resource may be classified by at least one of a radio frame number (or radio frame index), a subframe number (or subframe index), and a slot number (or slot index).

2 shows an example of a structure of a resource grid of a 3GPP NR system

In a wireless communication system, a downlink (DL) and/or uplink (UL) slot may include a resource grid having a structure as shown in FIG. 2.

In a wireless communication system, there may be one resource grid per antenna port.

The slot may include a plurality of orthogonal frequency division multiplexing (OFDM) symbols in the time domain, and may include a plurality of resource blocks (RBs) in the frequency domain. The OFDM symbol may mean one symbol period. Unless otherwise specified, an OFDM symbol may be referred to as a symbol. One resource block may include 12 consecutive subcarriers in the frequency domain.

개의 서브캐리어(subcarrier)와

개의 OFDM 심볼로 구성되는 자원격자로 표현될 수 있다. 여기서, 하향링크 자원 격자일 때, x=DL이고, 상향링크 자원 격자일 때, x=UL일 수 있다.

은 서브캐리어 간격 구성 인자 μ에 따른 자원 블록의 개수를 나타내고 x(DL 또는 UL)는

은 슬롯 내의 OFDM 심볼의 개수를 나타낼 수 있다.

는 하나의 자원 블록을 구성하는 서브캐리어의 개수로,

=12일 수 있다.The signal transmitted from each slot is

Subcarriers and

It can be represented by a resource grid consisting of four OFDM symbols. Here, in the case of a downlink resource grid, x=DL, and in the case of an uplink resource grid, x=UL.

Represents the number of resource blocks according to the subcarrier interval configuration factor μ, and x (DL or UL) is

May represent the number of OFDM symbols in the slot.

Is the number of subcarriers constituting one resource block,

May be =12.

The OFDM symbol may be referred to as a cyclic prefix OFDM (CP-OFDM) symbol or a discrete Fourier transform spread OFDM (DFT-S-OFDM) symbol according to a multiple access scheme.

The number of OFDM symbols included in one slot may vary according to the length of a cyclic prefix (CP). For example, in the case of a normal CP, one slot may include 14 OFDM symbols, and in the case of an extended CP, one slot may include 12 OFDM symbols. In a specific embodiment, the extended CP may be used only in a 60 kHz subcarrier interval.

In FIG. 2, for convenience of explanation, one slot is configured of 14 OFDM symbols, but embodiments of the present invention may be applied in the same manner to slots having different numbers of OFDM symbols.

개의 서브캐리어를 포함할 수 있다. 서브캐리어는 데이터 전송을 위한 데이터 서브캐리어, 참조 신호(reference signal)의 전송을 위한 참조 신호 서브캐리어, 및/또는 가드 밴드(guard band)를 포함할 수 있다. 캐리어 주파수는 중심 주파수(center frequency(f_c))라고 지칭될 수도 있다.Each OFDM symbol is in the frequency domain

It may include three subcarriers. The subcarrier may include a data subcarrier for data transmission, a reference signal subcarrier for transmission of a reference signal, and/or a guard band. The carrier frequency may also be referred to as a center frequency (f _{c ).}

개(예를 들어, 12개)의 연속하는 서브캐리어에 의해 정의될 수 있다. 하나의 OFDM 심볼과 하나의 서브캐리어로 구성된 자원을 자원 요소(resource element(RE)) 혹은 톤(tone)이라고 지칭할 수 있다. 따라서, 하나의 자원 블록은

개의 자원 요소로 구성될 수 있다.One resource block in the frequency domain

It can be defined by a number of (eg, 12) consecutive subcarriers. A resource composed of one OFDM symbol and one subcarrier may be referred to as a resource element (RE) or a tone. Thus, one resource block is

It can be composed of four resource elements.

까지 부여되는 인덱스이며, l은 시간 도메인에서 0부터

까지 부여되는 인덱스일 수 있다.Each resource element in the resource grid may be uniquely defined by an index pair (k, l) in one slot. k is from 0 in the frequency domain

Is an index given to, and l is from 0 in the time domain.

It can be an index that is given up to.

In order for the terminal to receive a signal from the base station or transmit a signal to the base station, the time/frequency synchronization of the terminal may be matched with the time/frequency synchronization of the base station. When the base station and the terminal are synchronized, time and frequency parameters required for the terminal to perform demodulation of the DL signal and transmission of the UL signal at an accurate time can be determined.

Each symbol of a radio frame operating in time division duplex (TDD) or unpaired spectrum is at least one of a downlink symbol, an uplink symbol, or a flexible symbol. It can be composed of either one.

A radio frame operating as a downlink carrier in a frequency division duplex (FDD) or paired spectrum may be composed of a downlink symbol and/or a flexible symbol, and a radio frame operating as an uplink carrier is an uplink It may be composed of a symbol and/or a flexible symbol.

Downlink transmission is possible in a downlink symbol, but uplink transmission is impossible. In an uplink symbol, uplink transmission is possible, but downlink transmission may not be possible. The flexible symbol may be used for downlink or uplink depending on a signal.

Information on the type of each symbol (for example, information on whether to indicate any one of a downlink symbol, an uplink symbol, and a flexible symbol) is a cell-specific (cell-specific or common) RRC (radio resource control) signal.

In addition, information on the type of each symbol may additionally be configured as a UE-specific or dedicated RRC signal.

The base station uses the cell-specific RRC signal: i) the period of the cell-specific slot configuration, ii) the number of slots having only downlink symbols from the beginning of the period of the cell-specific slot configuration, iii) the slot immediately following the slot having only the downlink symbols The number of downlink symbols from the first symbol, iv) the number of slots with only uplink symbols from the end of the period of the cell-specific slot configuration, v) the number of uplink symbols from the last symbol of the slot immediately preceding the slot with only uplink symbols. Can provide. Here, a symbol not composed of either an uplink symbol or a downlink symbol may be a flexible symbol.

When the information on the symbol type is composed of a UE-specific RRC signal, the base station may signal whether the flexible symbol is a downlink symbol or an uplink symbol with a cell-specific RRC signal. In this case, the UE-specific RRC signal cannot change a downlink symbol or an uplink symbol composed of a cell-specific RRC signal to another symbol type.

개의 심볼 중 하향링크 심볼의 수 및/또는 상향링크 심볼의 수를 시그널링할 수 있다. 이때, 슬롯의 하향링크 심볼은 슬롯의 첫 심볼부터 i번째 심볼까지 연속적으로 구성될 수 있다. 또한, 슬롯의 상향링크 심볼은 슬롯의 j번째 심볼부터 마지막 심볼까지 연속적으로 구성될 수 있다(여기서, i<j). 슬롯에서 상향링크 심볼과 하향링크 심볼 어느 것으로도 구성되지 않은 심볼은 플랙서블 심볼일 수 있다.The UE-specific RRC signal is for each slot.

The number of downlink symbols and/or the number of uplink symbols among the symbols may be signaled. In this case, the downlink symbol of the slot may be continuously configured from the first symbol to the i-th symbol of the slot. In addition, the uplink symbol of the slot may be continuously configured from the j-th symbol to the last symbol of the slot (here, i<j). A symbol not composed of either an uplink symbol or a downlink symbol in a slot may be a flexible symbol.

Information on the type of a symbol composed of an RRC signal as described above may be referred to as a semi-static DL/UL configuration. In a semi-static DL/UL configuration composed of an RRC signal, a flexible symbol is a downlink symbol and an uplink symbol through dynamic slot format information (SFI) transmitted through a physical downlink control channel (PDCCH). , And/or may be indicated by a flexible symbol. At this time, the downlink symbol or uplink symbol composed of the RRC signal is not changed to another symbol type. An example of the dynamic SFI that the base station can indicate to the terminal may be shown in Table 1.

In Table 1, D represents a downlink symbol, U represents an uplink symbol, and X represents a flexible symbol. DL/UL switching can be allowed up to two times in one slot.

3 is a diagram illustrating an example of a physical channel used in a 3GPP system and a general signal transmission method using the physical channel.

The 3GPP system may be, for example, an NR system.

When the power of the terminal increases or the terminal newly enters the cell, the terminal may perform an initial cell search operation (S101). Specifically, the terminal can synchronize with the base station in initial cell search. To this end, the terminal may receive a primary synchronization signal (PSS) and a secondary synchronization signal (SSS) from the base station to synchronize with the base station and obtain information such as a cell ID. Thereafter, the terminal may receive the physical broadcast channel from the base station to obtain broadcast information in the cell.

After completing the initial cell search, the UE acquires through initial cell search by receiving a physical downlink control channel (PDCCH) and a physical downlink shared channel (PDSCH) according to the information carried on the PDCCH. It is possible to obtain more specific system information than one system information (S102). Here, the system information received by the UE is cell-common system information for the UE to properly operate in the physical layer of the RRC, and Remaining system information or System information block (SIB) ) May be referred to.

When the terminal accesses the base station for the first time or there is no radio resource for signal transmission (eg, when the terminal is in the RRC_IDLE mode), the terminal may perform a random access process with the base station (S103 to S106).

The UE may transmit a preamble through a physical random access channel (PRACH) (S103) and receive a response message to the preamble through a PDCCH and a corresponding PDSCH from the base station (S104).

When the terminal receives a valid random access response message, the terminal transmits data including its own identifier, etc. through a physical uplink shared channel (PUSCH) indicated by an uplink grant transmitted from the base station through the PDCCH. It can be transmitted to the base station (S105).

Next, the terminal waits for the reception of the PDCCH as an indication of the base station for collision resolution, and when the terminal successfully receives the PDCCH through its identifier (S106), the random access process may be terminated.

During the random access process, the UE may acquire UE-specific system information necessary for the UE to properly operate at the physical layer in the RRC layer. When the terminal obtains terminal-specific system information from the RRC layer, the terminal may enter an RRC connection mode (RRC_CONNECTED mode).

The RRC layer may be used for message generation and management for control between a terminal and a radio access network (RAN). For example, in the RRC layer, the base station and the terminal broadcast the cell system information necessary for all terminals in the cell, manage the delivery of paging messages, manage mobility and handover, and report the measurement of the terminal and control it. , Storage management including terminal capability management and/or security management (eg, key management) may be performed.

In general, since the update of the signal (hereinafter, referred to as RRC signal) transmitted from the RRC layer is longer than the transmission time interval (TTI) in the physical layer, the RRC signal can be maintained unchanged for a long period. .

After the above-described procedures (S101 to S106), the UE receives PDCCH/PDSCH (S107) and physical uplink shared channel (PUSCH)/physical uplink control channel as a general uplink/downlink signal transmission procedure. Uplink control channel (PUCCH)) may be transmitted (S108).

The UE may receive downlink control information (DCI) through the PDCCH. DCI may include control information such as resource allocation information for the terminal.

The format of DCI may vary depending on the purpose of use. Uplink control information (UCI) transmitted by the UE to the base station through the uplink includes a downlink/uplink ACK/NACK signal, a channel quality indicator (CQI), a precoding matrix index (PMI), and a rank (RI). indicator) and the like. Here, CQI, PMI, and RI may be included in channel state information (CSI).

In the case of a 3GPP NR system, the UE may transmit control information such as HARQ-ACK and CSI described above through PUSCH and/or PUCCH.

4A and 4B show an example of an SS/PBCH block for initial cell access in a 3GPP NR system.

When the terminal is powered on or newly accesses a cell, the terminal may acquire time and frequency synchronization with the cell and perform an initial cell search process. The UE may detect the ^cell's _{physical cell identity (N cell ID} ) during the cell search process.

The terminal may receive a synchronization signal from the base station and synchronize with the base station. In this case, the terminal may obtain information such as a cell identifier (identity (ID)).

The synchronization signal SS may be divided into a main synchronization signal PSS and a sub synchronization signal SSS.

PSS may be used to obtain time domain synchronization and/or frequency domain synchronization such as OFDM symbol synchronization and slot synchronization. SSS can be used to obtain frame synchronization and cell group ID.

4A and 2, the SS/PBCH block is composed of 20 RBs (for example, 240 subcarriers) consecutive in the frequency axis, and may be composed of 4 OFDM symbols consecutive in the time axis. .

In this case, in the SS/PBCH block, the PSS may be transmitted through the first OFDM symbol, and the SSS may be transmitted through the 56th to 182th subcarriers in the third OFDM symbol. Here, the lowest subcarrier index of the SS/PBCH block may be assigned from 0.

The base station may not transmit a signal through the remaining subcarriers, that is, 0 to 55 and 183 to 239 th subcarriers in the first OFDM symbol in which the PSS is transmitted. In addition, the base station may not transmit a signal through the 48th to 55th and 183th to 191th subcarriers in the third OFDM symbol in which the SSS is transmitted.

The base station may transmit a physical broadcast channel (PBCH) through the remaining REs except for the above signal in the SS/PBCH block.

SS is a total of 1008 unique physical layer cell identifiers through a combination of three PSSs and SSSs, so that each physical layer cell identifier is part of only one physical-layer cell-identifier group, so that each group is three unique. It may be grouped into 336 physical-layer cell-identifier groups including one identifier.

Therefore, the physical layer cell ID N ^cell _ID = 3N ⁽¹⁾ _ID + N ⁽²⁾ _ID ^{is an index N (1)} _ID in the range from 0 to 335 representing a physical-layer cell-identifier group and the physical-layer cell -It can be uniquely defined by ^{the index N (2)} _ID from 0 to 2 indicating the physical-layer identifier in the identifier group.

The UE can detect the PSS and identify one of the three unique physical-layer identifiers. In addition, the terminal may detect the SSS and identify one of 336 physical layer cell IDs associated with the physical-layer identifier.

In this case, the sequence d _PSS (n) of the PSS can be expressed as in Equation 1.

이고,

일 수 있다.here,

ego,

Can be

In addition, the sequence d _SSS (n) of the SSS can be expressed as in Equation 2.

이고,

일 수 있다.here,

ego,

Can be

A 10ms long radio frame can be divided into two 5ms long half frames. 4B shows a slot in which an SS/PBCH block is transmitted in a half frame.

The slot in which the SS/PBCH block is transmitted may be any one of Cases A, B, C, D, and E.

In Case A, the subcarrier interval is 15 kHz, and the start time of the SS/PBCH block may be {2, 8} + 14n-th symbol. At this time, it may be n=0, 1 at a carrier frequency of 3 GHz or less. In addition, it may be n = 0, 1, 2, 3 at a carrier frequency of more than 3 GHz and less than 6 GHz.

In Case B, the subcarrier interval is 30 kHz, and the start time of the SS/PBCH block may be {4, 8, 16, 20} + 28n-th symbol. In this case, n may be 0 at a carrier frequency of 3 GHz or less. In addition, it may be n = 0, 1 at a carrier frequency of more than 3 GHz and less than 6 GHz.

In Case C, the subcarrier interval is 30 kHz, and the start time of the SS/PBCH block may be {2, 8} + 14n-th symbol. At this time, it may be n=0, 1 at a carrier frequency of 3 GHz or less. In addition, it may be n = 0, 1, 2, 3 at a carrier frequency of more than 3 GHz and less than 6 GHz.

In Case D, the subcarrier interval is 120 kHz, and the start time of the SS/PBCH block may be {4, 8, 16, 20} + 28n-th symbol. In this case, n=0, 1, 2, 3, 5, 6, 7, 8, 10, 11, 12, 13, 15, 16, 17, 18 at a carrier frequency of 6 GHz or higher.

In Case E, the subcarrier interval is 240 kHz, and the start time of the SS/PBCH block may be {8, 12, 16, 20, 32, 36, 40, 44} + 56n-th symbol. In this case, n=0, 1, 2, 3, 5, 6, 7, 8 at a carrier frequency of 6 GHz or higher.

5A is a flowchart illustrating an example of a procedure for transmission of control information and a control channel in a 3GPP NR system, and FIG. 5B is a diagram illustrating an example of transmission of control information and a control channel in a 3GPP NR system.

The base station may add a cyclic redundancy check (CRC) masked (eg, XOR operation) with a radio network temporary identifier (RNTI) to control information (eg, DCI) (S902). The base station may scramble the CRC with an RNTI value determined according to the purpose/target of each control information.

The common RNTI used by one or more terminals is at least one of system information RNTI (SI-RNTI), paging RNTI (P-RNTI), random access RNTI (RA-RNTI), and transmit power control RNTI (TPC-RNTI). Can include. In addition, the terminal-specific RNTI may include at least one of a cell temporary RNTI (C-RNTI) and a CS-RNTI.

After performing channel encoding (eg, polar coding) (S204), the base station may perform rate-matching according to the amount of resources used for PDCCH transmission (S906).

The base station may multiplex DCI based on a PDCCH structure based on a control channel element (CCE) (S208). In addition, the base station may apply an additional process (S210) such as scrambling, modulation (eg, QPSK), and interleaving to the multiplexed DCI, and then map it to a resource to be transmitted.

CCE is a basic resource unit for the PDCCH, and one CCE may be composed of a plurality of (eg, 6) resource element groups (REGs). One REG may consist of a plurality (eg, 12) of REs.

The number of CCEs used for one PDCCH may be defined as an aggregation level. Aggregation levels of 1, 2, 4, 8 or 16 can be used in the 3GPP NR system.

5B is a diagram for multiplexing of a CCE aggregation level and a PDCCH, and shows the types of CCE aggregation levels used for one PDCCH and CCE(s) transmitted in a control region according thereto.

6 shows an example of a CORESET in which a PDCCH can be transmitted in a 3GPP NR system.

CORESET (control resource set) may be a time-frequency resource in which the PDCCH, which is a control signal for the terminal, is transmitted. A search space to be described later may be mapped to one CORESET. Accordingly, the UE may decode the PDCCH mapped to the CORESET by monitoring the time-frequency region designated as CORESET instead of monitoring all frequency bands for PDCCH reception.

The base station may configure one or a plurality of CORESET for each cell to the terminal. CORESET can consist of up to 3 consecutive symbols on the time axis. In addition, CORESET may be configured in units of six consecutive physical resource blocks (PRBs) on the frequency axis.

CORESET#1 is composed of continuous PRBs, and CORESET#2 and CORESET#3 are composed of discontinuous PRBs. CORESET can be placed on any symbol in the slot. For example, CORESET#1 may start at the first symbol of the slot, CORESET#2 may start at the 5th symbol of the slot, and CORESET#9 may start at the 9th symbol of the slot.

7 is a diagram illustrating an example of a method of setting a PDCCH search space in a 3GPP NR system.

At least one search space may exist in each CORESET in order to transmit the PDCCH to the UE. The search space is a set of all time-frequency resources (hereinafter, PDCCH candidates) to which the PDCCH of the UE can be transmitted.

The search space may include a common search space to be searched for by a UE of 3GPP NR and a terminal-specific search space to be searched for by a specific UE (Terminal-specific search space or UE-specific search space). .

In the common search space, it is possible to monitor the PDCCH, which is configured so that all terminals in a cell belonging to the same base station search in common. In addition, the terminal-specific search space may be set for each terminal so that the PDCCH allocated to each terminal can be monitored at different search space positions according to the terminal.

The UE-specific search space may be allocated because the search space between UEs partially overlaps due to a limited control region to which the PDCCH can be allocated. Monitoring the PDCCH may include blind decoding PDCCH candidates in the search space.

When blind decoding is successful, the PDCCH is (successfully) detected/received, and when blind decoding is failed, the PDCCH is not detected/received, or successfully detected/received.

For convenience of description below, a PDCCH scrambled with a group common (GC) RNTI already known by one or more terminals in order to transmit downlink control information to one or more terminals is referred to as a group common PDCCH or a common PDCCH. .

In addition, in order to transmit uplink scheduling information or downlink scheduling information to one specific terminal, a PDCCH scrambled with a terminal-specific RNTI already known by a specific terminal is referred to as a terminal-specific PDCCH.

The common PDCCH may be included in the common discovery space, and the UE-specific PDCCH may be included in the common discovery space and/or the UE-specific PDCCH.

The base station allocates information related to resource allocation of a paging channel (PCH) and a downlink-shared channel (DL-SCH), which are transmission channels, through the PDCCH (eg, DL Grant) or resource allocation of an uplink-shared channel (UL-SCH). And information (eg, UL grant) related to hybrid automatic repeat request (HARQ) may be notified to each terminal or terminal group.

The base station may transmit the PCH transport block and the DL-SCH transport block through the PDSCH. The base station may transmit specific control information or data excluding specific service data through the PDSCH. In addition, the terminal may receive data excluding specific control information or specific service data through the PDSCH.

The base station may transmit information on which terminal (one or more terminals) the PDSCH data is transmitted to and how the corresponding terminal should receive and decode the PDSCH data in the PDCCH.

For example, DCI transmitted through a specific PDCCH is CRC masked with an RNTI of "A", and the DCI indicates that a PDSCH is allocated to a radio resource (eg, a frequency location) of "B", Assuming that "C" indicates transmission format information (eg, transport block size, modulation method, coding information, etc.), the UE monitors the PDCCH using RNTI information it has. In this case, if there is a UE that blindly decodes the PDCCH using the “A” RNTI, the UE may receive the PDCCH and receive the PDSCH indicated by “B” and “C” through the received PDCCH information. have.

Table 3 shows an example of a PUCCH used in a wireless communication system.

PUCCH can be used to transmit uplink control information (UCI). Uplink control information may include SR (Scheduling Request), HARQ-ACK, and/or CSI (Channel State Information).

SR (Scheduling Request) may be information used to request an uplink UL-SCH resource.

HARQ-ACK may be a response to a PDCCH (indicating DL SPS release) and/or a response to a downlink transport block (TB) on the PDSCH. HARQ-ACK may indicate whether the reception of information transmitted through the PDCCH or PDSCH is successful. The HARQ-ACK response may include positive ACK (hereinafter, ACK), negative ACK (hereinafter, NACK), discontinuous transmission (DTX), and/or NACK/DTX. HARQ-ACK may be referred to interchangeably as HARQ-ACK/NACK and/or ACK/NACK. ACK may be expressed as a bit value of 1 and NACK may be expressed as a bit value of 0.

Channel State Information (CSI) may be feedback information on a downlink channel. The terminal can be generated based on the CSI-RS (Reference Signal) transmitted by the base station. Feedback information related to multiple input multiple output (MIMO) may include a rank indicator (RI) and a precoding matrix indicator (PMI). CSI may be divided into CSI Part 1 and CSI Part 2 according to information indicated by CSI.

In the 3GPP NR system, five PUCCH formats may be used to support various service scenarios, various channel environments, and frame structures.

PUCCH format 0 may be a format capable of carrying 1-bit or 2-bit HARQ-ACK information or SR.

PUCCH format 0 may be transmitted through one or two OFDM symbols on the time axis and one PRB on the frequency axis. When PUCCH format 0 is transmitted in two OFDM symbols, the same sequence may be transmitted in different RBs in the two symbols. In this case, the sequence may be a sequence that is cyclic shifted (CS) from a base sequence used in PUCCH format 0. Through this, the terminal can obtain a frequency diversity gain.

Specifically, the UE may determine a cyclic shift (CS) value m _{cs according to the M bit bit UCI (1 or 2).} In addition, a sequence obtained by cyclic shifting a base sequence of length 12 based on a predetermined CS value m _cs may be mapped to 1 OFDM symbol and 12 REs of 1 RB and transmitted.

When the number of cyclic shifts available to the UE is 12 and M _bit = 1, 1 bit UCI 0 and 1 may be mapped to two cyclic shifted sequences having a difference of 6 cyclic shift values, respectively. In addition, when M _bit = 2, 2 bits UCI 00, 01, 11, and 10 may be mapped to four cyclic shifted sequences in which the difference between the cyclic shift values is 3, respectively.

PUCCH format 1 may carry 1-bit or 2-bit HARQ-ACK information or SR. PUCCH format 1 may be transmitted through consecutive OFDM symbols on the time axis and one PRB on the frequency axis. Here, the number of OFDM symbols occupied by PUCCH format 1 may be one of 4 to 14.

Specifically, UCI with M _bit = 1 can be modulated with BPSK. The UE may _{modulate the UCI of M bit} = 2 with quadrature phase shift keying (QPSK). A signal is obtained by multiplying the modulated complex valued symbol d(0) by a sequence of length 12. In this case, the sequence may be a base sequence used for PUCCH format 0. The terminal transmits the obtained signal by spreading the obtained signal on the even-numbered OFDM symbol to which the PUCCH format 1 is allocated using a time axis orthogonal cover code (OCC). In PUCCH format 1, the maximum number of different terminals multiplexed with the same RB is determined according to the length of the OCC used. The odd-numbered OFDM symbols of PUCCH format 1 may be mapped by spreading a demodulation reference signal (DMRS) to OCC.

PUCCH format 2 can carry UCI in excess of 2 bits. PUCCH format 2 may be transmitted through one or two OFDM symbols on the time axis and one or more RBs on the frequency axis. When PUCCH format 2 is transmitted in two OFDM symbols, the same sequence may be transmitted in different RBs through two OFDM symbols. Here, the sequence is a plurality of modulated complex symbols d(0), ... , d (M _symbol -1). Here, the M _symbol may be M _bit /2. Through this, the terminal can obtain a frequency diversity gain.

Specifically, the M _bit bit UCI (M _bit >2) is bit-level scrambled, QPSK modulated, and mapped to RB(s) of one or two OFDM symbol(s). Here, the number of RBs may be one of 1 to 16.

PUCCH format 3 or PUCCH format 4 can carry UCI in excess of 2 bits. PUCCH format 3 or PUCCH format 4 may be transmitted through consecutive OFDM symbols on the time axis and one PRB on the frequency axis. The number of OFDM symbols occupied by PUCCH format 3 or PUCCH format 4 may be one of 4 to 14.

Specifically, the UE may generate _{complex symbols d(0) to d (M symbol} -1) _{by modulating Mbit bit UCI (M bit} >2) with π/2-BPSK (Binary Phase Shift Keying) or QPSK. Here, if π/2-BPSK is used, M _symbol =M _bit , and if QPSK is used, M _symbol =M _bit /2. The UE may not apply block-by-block spreading to PUCCH format 3. However, the UE uses a length-12 PreDFT-OCC so that PUCCH format 4 can have two or four multiplexing capacities, spreading per RB (i.e., 12 subcarriers) on a block-by-block basis. Can be applied. The UE may transmit precoding (or DFT-precoding) the spread signal and map it to each RE, thereby transmitting the spread signal.

In this case, the number of RBs occupied by PUCCH format 2, PUCCH format 3, or PUCCH format 4 may be determined according to the length and maximum code rate of UCI transmitted by the UE. When the UE uses PUCCH format 2, the UE may transmit HARQ-ACK information and CSI information together through PUCCH.

When the number of RBs that the UE can transmit is greater than the maximum number of available RBs in PUCCH format 2, PUCCH format 3, or PUCCH format 4, the UE does not transmit some UCI information according to the priority of UCI information and the remaining UCI information Can only be transmitted.

PUCCH format 1, PUCCH format 3, or PUCCH format 4 may be configured through an RRC signal to indicate frequency hopping within a slot. When frequency hopping is configured, the index of the RB to be frequency hopping may be configured as an RRC signal. When PUCCH format 1, PUCCH format 3, or PUCCH format 4 is transmitted over N OFDM symbols on the time axis, the first hop has floor (N/2) OFDM symbols and the second hop is ceil ( It may have N/2) OFDM symbols.

PUCCH format 1, PUCCH format 3, or PUCCH format 4 may be configured to be repeatedly transmitted in a plurality of slots. In this case, the number K of slots through which PUCCH is repeatedly transmitted may be configured by an RRC signal.

PUCCHs that are repeatedly transmitted start from OFDM symbols at the same position in each slot and must have the same length. If any one of the OFDM symbols of the slot in which the UE should transmit the PUCCH is indicated as a DL symbol by the RRC signal, the UE can transmit the PUCCH by delaying it to the next slot without transmitting in the corresponding slot.

Meanwhile, in the 3GPP NR system, the UE may perform transmission/reception using a bandwidth less than or equal to the bandwidth of the carrier (or cell). To this end, the terminal may be configured with a bandwidth part (BWP) consisting of a portion of the bandwidth of the carrier.

A terminal operating according to TDD or operating in an unpaired spectrum can receive up to four DL/UL BWP pairs for one carrier (or cell). In addition, the terminal may activate one DL/UL BWP pair. A terminal operating according to FDD or operating in a paired spectrum can receive up to 4 DL BWPs on a downlink carrier (or cell) and up to 4 UL BWPs on an uplink carrier (or cell). Can be configured.

The UE may activate one DL BWP and UL BWP for each carrier (or cell). The terminal may not receive or transmit in time-frequency resources other than the activated BWP. The activated BWP may be referred to as an active BWP.

The base station may indicate an activated BWP among the BWPs configured by the terminal through downlink control information (DCI). The BWP indicated through DCI is activated, and other configured BWP(s) are deactivated.

In a carrier (or cell) operating in TDD, the base station may include a bandwidth part indicator (BPI) indicating the BWP activated in the DCI scheduling the PDSCH or PUSCH to change the DL/UL BWP pair of the terminal.

The UE may receive a DCI scheduling a PDSCH or a PUSCH and may identify a DL/UL BWP pair activated based on the BPI. In the case of a downlink carrier (or cell) operating in FDD, the base station may include a BPI indicating the activated BWP to the DCI scheduling the PDSCH to change the DL BWP of the terminal.

In the case of an uplink carrier (or cell) operating in FDD, the base station may include a BPI indicating a BWP activated in DCI scheduling a PUSCH in order to change the UL BWP of the terminal.

8 is a diagram for explaining carrier aggregation.

Carrier aggregation is a frequency block or (logical meaning) in which the UE is configured with uplink resources (or component carriers) and/or downlink resources (or component carriers) in order for the wireless communication system to use a wider frequency band. ) It refers to a method of using multiple cells as one large logical frequency band.

One component carrier (CC) may also be referred to as a primary cell (PCell), a secondary cell (SCell), or a primary SCell (PScell). However, hereinafter, for convenience of description, the term “component carrier” will be used.

FIG. 8 shows an example of a 3GPP NR system in which the entire system band includes a maximum of 16 component carriers, and each component carrier has a bandwidth of a maximum of 400 MHz. A component carrier may include one or more physically contiguous subcarriers.

In FIG. 8, it is shown that each component carrier has the same bandwidth, but each component carrier may have a different bandwidth. In addition, although FIG. 8 shows that each component carrier is adjacent to each other on the frequency axis as a logical concept, each component carrier may be physically adjacent to each other or may be separated from each other.

Different center frequencies may be used in each component carrier. In addition, one center frequency common to component carriers that are physically adjacent may be used.

Assuming that all component carriers are physically adjacent, the center frequency A can be used in all component carriers. In addition, assuming that the respective component carriers are not physically adjacent, the center frequency A and the center frequency B may be used in each of the component carriers.

When the entire system band is extended by carrier aggregation, a frequency band used for communication with each terminal may be defined in a component carrier unit.

Terminal A can use the entire system band of 100 MHz and can perform communication using all five component carriers. Terminals B1 to B5 can use only 20 MHz bandwidth and can perform communication using one component carrier. Terminals C1 and C2 may use a 40 MHz bandwidth and may perform communication using two component carriers, respectively.

The two component carriers may or may not be logically/physically contiguous. In FIG. 8, a case in which terminal C1 uses two non-adjacent component carriers and terminal C2 uses two adjacent component carriers is illustrated.

9A is a diagram illustrating an example of a subframe structure of a single carrier, and FIG. 9B is a diagram illustrating an example of a subframe structure of a multicarrier.

A typical wireless communication system (eg, FDD mode) may perform data transmission or reception through one DL band and one UL band corresponding thereto. As another example, a wireless communication system (e.g., TDD mode) divides a radio frame into an uplink time unit and a downlink time unit in a time domain, and data transmission or reception can be performed through an uplink/downlink time unit. have.

Referring to FIG. 9B, three 20MHz component carriers (CC) are gathered in each of the UL and the DL, so that a bandwidth of 60MHz may be supported. Each of the CCs may or may not be adjacent to each other in the frequency domain.

In FIG. 9B, a case in which both the bandwidth of the UL CC and the bandwidth of the DL CC are the same and is symmetric is illustrated, but the bandwidth of each CC may be independently determined. In addition, asymmetric carriers having different numbers of UL CCs and DL CCs may be aggregated. A DL/UL CC allocated/configured to a specific terminal through RRC may be referred to as a serving DL/UL CC of a specific terminal.

The base station may perform communication with the terminal by activating some or all of the serving CCs of the terminal or deactivating some of the CCs. The base station may change the activated/deactivated CC, and may change the number of activated/deactivated CCs.

When the base station allocates a cell-specific or terminal-specific CC available to the terminal, at least one of the allocated CCs is not deactivated once the CC allocation for the terminal is completely reconfigured or the terminal does not handover. May not.

One CC that is not deactivated to the terminal is called a primary CC (PCC) or a PCell (primary cell), and a CC that the base station can freely activate/deactivate is a secondary CC (SCC)) or SCell ( secondary cell).

Meanwhile, 3GPP NR uses the concept of a cell to manage radio resources. A cell is defined as a combination of a downlink resource and an uplink resource, that is, a combination of a DL CC and a UL CC.

A cell may be configured with a DL resource alone or a combination of a DL resource and a UL resource. When carrier aggregation is supported, a linkage between a carrier frequency of a DL resource (or DL CC) and a carrier frequency of a UL resource (or UL CC) may be indicated by system information.

The carrier frequency may mean the center frequency of each cell or CC. A cell corresponding to the PCC may be referred to as a PCell, and a cell corresponding to the SCC may be referred to as an SCell. The carrier corresponding to the PCell in the downlink is DL PCC, and the carrier corresponding to the PCell in the uplink is UL PCC.

Similarly, a carrier corresponding to an SCell in downlink is a DL SCC, and a carrier corresponding to an SCell in uplink is a UL SCC. Depending on the terminal capability, the serving cell(s) may consist of one PCell and zero or more SCells.

In the case of a UE that is in the RRC_CONNECTED state but does not support carrier aggregation or does not support carrier aggregation, only one serving cell composed of PCells may exist.

As mentioned above, the term cell used in carrier aggregation may be distinguished from the term cell indicating a certain geographic area in which communication service is provided by one base station or one antenna group. That is, one component carrier may also be referred to as a scheduling cell, a scheduled cell, a primary cell (PCell), a secondary cell (SCell), or a primary SCell (PScell).

However, in order to distinguish between a cell indicating a certain geographic area and a cell of carrier aggregation, in the present invention, the cell of the carrier aggregation may be referred to as a CC, and the cell of the geographic area may be referred to as a cell.

10 is a diagram illustrating an example of a method to which a cross-carrier scheduling technique is applied.

When cross-carrier scheduling is configured, the control channel transmitted through the first CC may schedule a data channel transmitted through the first CC or the second CC using a carrier indicator field (CIF).

CIF can be included in DCI. For example, a scheduling cell is configured, and a DL grant/UL grant transmitted in a PDCCH region of a scheduling cell may schedule a PDSCH/PUSCH of a scheduled cell. That is, a search region for a plurality of component carriers may exist in the PDCCH region of the scheduling cell. The PCell is basically a scheduling cell, and a specific SCell may be designated as a scheduling cell by an upper layer.

In FIG. 10, it is assumed that three DL CCs are merged. Here, DL component carrier #0 is assumed to be a DL PCC (or PCell), and DL component carrier #1 and DL component carrier #2 are assumed to be DL SCC (or SCell). In addition, it is assumed that the DL PCC is set as the PDCCH monitoring CC.

If crosscarrier scheduling is not configured by UE-specific (or UE-group-specific or cell-specific) higher layer signaling, CIF is disabled, and each DL CC has its own without CIF according to the NR PDCCH rule. Only the PDCCH scheduling the PDSCH can be transmitted (non-cross-carrier scheduling, self-carrier scheduling).

On the other hand, when cross-carrier scheduling is configured by terminal-specific (or terminal-group-specific or cell-specific) higher layer signaling, CIF is enabled, and a specific CC (e.g., DL PCC) uses CIF. By using the PDCCH for scheduling the PDSCH of DL CC A, as well as the PDCCH for scheduling the PDSCH of another CC can be transmitted (cross-carrier scheduling).

On the other hand, PDCCH may not be transmitted in other DL CCs. Therefore, the UE monitors the PDCCH that does not include CIF and receives the self-carrier-scheduled PDSCH according to whether the UE is configured with cross-carrier scheduling, or monitors the PDCCH including the CIF to receive the cross-carrier-scheduled PDSCH. I can.

Meanwhile, FIGS. 9A to 10 illustrate a subframe structure of a 3GPP LTE-A system, but the same or similar configuration may be applied to a 3GPP NR system. However, in the 3GPP NR system, the subframes of FIGS. 9A to 10 may be replaced with slots.

FIG. 11 is a schematic block diagram of a wireless communication system in which the apparatus for measuring frequency resources according to an embodiment is implemented, and FIG. 12 is a schematic block diagram of the apparatus for measuring frequency resources shown in FIG. 11.

The wireless communication system 10 may include a terminal 100 and a base station 200.

The terminal 100 may be implemented as various types of wireless communication devices or computing devices that guarantee portability and mobility. The terminal may be referred to as a user equipment (UE), a station (STA), a mobile subscriber (MS), or the like.

The base station 200 controls and manages a cell (eg, a macro cell, a femto cell and/or a pico cell, etc.) corresponding to a service area, and transmits a signal, assigns a channel, monitors a channel, self-diagnosis, and/or relays. It can perform functions such as. The base station may be referred to as a Next Generation NodeB (gNB) or an Access Point (AP).

The terminal 100 may include a frequency resource measuring device 300.

The frequency resource measuring apparatus 300 may measure a frequency resource being used by the terminal 100 in a wireless communication system. For example, the frequency resource measuring apparatus 300 may measure the frequency resource being used by the terminal 100 by using energy detection (ED).

In addition, the frequency resource measuring apparatus 300 may increase the accuracy of measurement through the ED, and may set an ED threshold for performing the ED.

The frequency resource measuring apparatus 300 may include a memory 400 and a processor 500.

The memory 400 may store instructions (or programs) executable by the processor 500. For example, the instructions may include instructions for executing an operation of the processor 500 and/or an operation of each component of the processor 500.

The processor 500 may process data stored in the memory 400. The processor 500 may execute computer-readable code (eg, software) stored in the memory 400 and instructions induced by the processor 500.

The processor 500 may be a data processing device implemented in hardware having a circuit having a physical structure for executing desired operations. For example, desired operations may include code or instructions included in a program.

For example, a data processing device implemented in hardware is a microprocessor, a central processing unit, a processor core, a multi-core processor, and a multiprocessor. , Application-Specific Integrated Circuit (ASIC), Field Programmable Gate Array (FPGA).

The processor 500 may be implemented separately from the terminal 100, but may be implemented with an existing processor 110 included in the terminal 100. Also, the memory 400 may be implemented as the existing memory 130 included in the terminal 100.

FIG. 13 is a diagram for describing a frequency resource measurement operation of the frequency resource measurement apparatus shown in FIG. 11.

The frequency resource measurement apparatus 300 detects energy in CORESET set as one or more symbols and frequency resources on the channel bandwidth set by the base station 200 set to the terminal 100 by the base station 200 set on one carrier (energy detection (ED)). ) To measure the frequency resource in use.

The frequency resource measurement apparatus 300 may perform energy detection (ED) on a CORESET set as one or more symbols and frequency resources on a channel bandwidth set by the base station 200 to the terminal 100. The frequency resource measurement apparatus 300 is a resource for data traffic transmitted in downlink on the channel bandwidth set by the base station 200 to the terminal 100 by the base station 200 set in one carrier through energy detection (ED). It is possible to determine whether to use a block (RB) or a resource block group (RB group).

In the case of self-carrier scheduling and the CORESET bandwidth set to all bands on one carrier, the frequency resource measurement apparatus 300 is distributed on the frequency band and the received power of the PDCCH is transmitted. Based on the ED threshold value may be set.

The frequency resource measuring apparatus 300 performs energy detection on a resource block and/or a resource block group in a frequency domain for data traffic transmitted in downlink based on an ED threshold value, and thus a resource block and/or a resource block group. You can determine whether or not to use.

The frequency resource measuring apparatus 300 may improve measurement performance for setting an ED threshold. For example, the frequency resource measuring apparatus 300 may accurately measure an element for setting an ED threshold.

The apparatus 300 for measuring frequency resources may receive an SS/PBCH block transmitted from the base station 200 and set a power level received from the SS/PBCH block as an ED threshold.

The SS/PBCH block may include a primary synchronization signal (PSS), a secondary synchronization signal (SSS), a physical broadcast channel (PBCH), and a physical broadcast channel-demodulation reference signal (PBCH-DMRS).

The frequency resource measuring apparatus 300 may measure a reception power level for at least one signal among PSS, SSS, PBCH, and PBCH-DMRS.

The frequency resource measuring apparatus 300 refers to a reference power for a channel bandwidth of a carrier to be measured based on 20 resource blocks (20-RBs) occupied by the SS/PBCH block based on the received power level. power) can be determined.

The frequency resource measurement apparatus 300 determines the received power when the terminal 100 receives the same SS/PBCH block index among SS/PBCH block indexes transmitted from the base station 200 in order to determine an accurate reference power. The reference power can be determined through the average of.

In addition, the frequency resource measurement apparatus 300 includes the same SS/PBCH block transmitted at different times by the terminal 100 among SS/PBCH block indexes periodically transmitted every 20 ms from the base station 200 to determine the reference power. When receiving the index, the reference power may be determined through the average of the received power.

The configuration of CORESET#0 for receiving RMSI-PDSCH (remaining minimum system information-physical downlink shared channel) in the wireless communication system 10 is PDCCH-Config-SIB1 included in PBCH contents when SS/PBCH is received. It can be obtained through 8bits information (see Table 4).

The PDCCH-Config-SIB1 information may include bandwidth, duration, starting timing, and frequency location information occupied by CORESET #0. Therefore, at the time/frequency location occupied by CORESET#0, the frequency resource measurement device 300 monitors the Type-0 PDCCH that is scrambled and transmitted with the SI-RNTI allocated for transmission of system information, so that the RMSI-PDSCH is The allocated information may be obtained through the corresponding Type-0 PDCCH and the RMSI-PDSCH may be received.

If the time/frequency location occupied by CORESET#0 is called an initial bandwidth part (BWP), the base station 200 can set up to 4 BWPs for each terminal 100 to be used to transmit the PDSCH independently of the initial BWP. have. The base station 200 may set one of up to four BWPs as an active BWP.

If the base station 200 does not set up to four BWPs other than the initial BWP, the initial BWP may be set as the active BWP. For example, in order to simplify the wireless communication system 10, the base station 200 may set the initial BWP as an active BWP so that the base station 200 may transmit the PDSCH to the terminal 100 through the active BWP. The terminal 100 may receive the PDSCH transmitted from the base station 200 in the active BWP.

The frequency resource measuring apparatus 300 may measure a power level based on a PDCCH that is scrambled with SI-RNTI and transmitted.

When the base station 200 uses the initial BWP as an active BWP set to the terminal 100, the frequency resource measuring apparatus 300 may receive the PDCCH distributed over the entire frequency domain of the initial BWP. At this time, the PDCCH may be scrambled with SI-RNTI transmitted from the initial BWP and transmitted.

The frequency resource measuring apparatus 300 may measure a fluctuation of a reception power level of a PDCCH and a frequency resource, that is, a resource block or a power level between resource blocks.

The frequency resource measuring apparatus 300 receives the PDCCH distributed based on the received reference power of the received SS/PBCH block and calculates a variation in the measured reception power level to determine a power level that may be different between the resource blocks. Can be measured.

The frequency resource measuring apparatus 300 may set an ED threshold value for each resource block and/or resource block group when energy is detected based on a power level.

The frequency resource measurement apparatus 300 may determine whether a resource block and/or a resource block group is being used or not, based on the ED threshold, and measure the use information of frequencies used in one or more carriers. have.

The frequency resource measuring apparatus 300 may measure the power level based on the PDCCH DM-RS used for the PDCCH transmitted by being scrambled with SI-RNTI.

When the base station 200 uses the initial BWP as an active BWP set to the terminal 100, the frequency resource measuring apparatus 300 is scrambled with the SI-RNTI transmitted from the initial BWP, and the entire frequency domain of the initial BWP transmitted. It is possible to receive a PDCCH distributed to and a demodulation reference signal (DM-RS) of the PDCCH.

The frequency resource measurement apparatus 300 may measure a change in a received power level of a PDCCH and a DM-RS of the PDCCH and a power level between frequency resources (eg, a resource block and/or a resource block group).

The frequency resource measurement apparatus 300 receives the PDCCH and the DM-RS of the PDCCH distributed based on the reception reference power of the received SS/PBCH block, calculates a variation in the measured reception power level, and calculates the difference between the resource blocks. You can measure power levels that can vary.

The frequency resource measuring apparatus 300 may determine whether the corresponding resource block and/or resource block group is being used by setting an ED threshold value for each resource block and/or resource block group when energy is detected based on the power level. have. The frequency resource measuring apparatus 300 may measure usage information of frequencies used in one or more carriers.

The frequency resource measuring apparatus 300 may measure the power level based on the wideband DM-RS transmitted to CORESET#0.

In the case of LTE, a signal is transmitted after being allocated to the entire channel bandwidth used in a cell specific reference signal (CRS) system. In the case of the NR system, a CRS does not exist and a UE specific DM-RS is used as a reference signal used for demodulation of a PDCCH and a PDSCH during downlink transmission.

Similar to the LTE CRS, the NR system does not have a reference signal allocated to the full bandwidth, so the coverage of the PDCCH, which is a downlink control channel transmitted in the NR system, will be deteriorated than the coverage of the PDCCH, which is an LTE downlink control channel. I can.

Therefore, in the NR system, the terminal 100 may configure and set a wideband DM-RS in order to prevent the coverage of the PDCCH from deteriorating than that of LTE. The terminal 100 may prevent the coverage of the PDCCH from deteriorating by receiving a wideband DM-RS in a wider bandwidth transmitted from the base station 200 and using it for decoding of the PDCCH.

When the wideband DM-RS is configured in the terminal 100, the frequency resource measuring apparatus 300 may perform channel measurement and power level measurement through the wideband DM-RS. The frequency resource measurement apparatus 300 includes a reception power level and a frequency resource of the PDCCH through channel measurement and power level measurement in a channel bandwidth in which a wideband DM-RS is configured (for example, between resource blocks and/or resource block groups). You can measure fluctuations in the power level.

The frequency resource measurement apparatus 300 may set an ED threshold value for each resource block and/or resource block group when energy is detected based on the reference power measured based on the SS/PBCH block.

The frequency resource measuring apparatus 300 determines whether the corresponding resource block and/or resource block group is being used or not based on the ED threshold value for each resource block and/or resource block group, and You can measure the usage information of the frequency used in.

14 is a detailed block diagram of the wireless communication system shown in FIG. 11.

The terminal 100 may include a processor 110, a communication module 120, a memory 130, a user interface 140, and a display 150.

The processor 110 and the memory 130 may be the processor 500 and the memory 400 shown in FIG. 12, respectively. For example, the frequency resource measuring apparatus 300 may be implemented with the processor 110 and the memory 130.

The processor 110 may execute various commands or programs and process data inside the terminal 100. In addition, the processor 110 may control the entire operation including each unit of the terminal 100 and control data transmission/reception between the units. Here, the processor 110 may be configured to perform all functions of the terminal 100. For example, the processor 110 may receive slot configuration information, determine a slot configuration based on this, and perform communication according to the determined slot configuration.

The communication module 120 may be an integrated module that performs wireless communication using a wireless communication network and wireless LAN access using a wireless LAN. The communication module 120 may include a first communication module 121, a second communication module 122, and a third communication module 123.

For example, the first communication module 121 and the second communication module may be a cellular communication interface card, and the third communication module 123 may be an unlicensed band communication interface card. That is, the communication module 120 may include a plurality of network interface cards (NICs) including the cellular communication interface cards 121 and 122 and the unlicensed band communication interface card 123 in an internal or external form. have.

In FIG. 14, the communication module 120 is shown as an integrated integrated module, but the first communication module to the third communication module 121 to 123 (for example, each network interface card) may be independently arranged according to the circuit configuration or use. I can.

The cellular communication interface card 121 transmits and receives a radio signal with at least one of the base station 200, an external device, and a server using a mobile communication network, and provides a cellular communication service according to a first frequency band based on a command of the processor 110. Can provide.

The cellular communication interface card 121 may include at least one NIC module using a frequency band of less than 6 GHz. At least one NIC module of the cellular communication interface card 121 independently communicates with at least one of the base station 200, an external device, and a server according to a cellular communication standard or protocol of a frequency band of less than 6 GHz supported by the corresponding NIC module. You can do it.

The cellular communication interface card 122 transmits and receives a radio signal with at least one of the base station 200, an external device (not shown), and a server (not shown) using a mobile communication network, and based on a command of the processor 110 It is possible to provide a cellular communication service based on the second frequency band.

The cellular communication interface card 122 may include at least one NIC module using a frequency band of 6 GHz or higher. At least one NIC module of the cellular communication interface card 122 independently performs cellular communication with at least one of the base station 200, an external device, and a server according to a cellular communication standard or protocol of a frequency band of 6 GHz or higher supported by the corresponding NIC module. You can do it.

The unlicensed band communication interface card 123 transmits and receives a radio signal with at least one of the base station 200, an external device, and a server using a third frequency band that is an unlicensed band, Can provide communication service.

The unlicensed band communication interface card 123 may include at least one NIC module using the unlicensed band. For example, the unlicensed band may be a 2.4 GHz or 5 GHz band.

At least one NIC module of the unlicensed band communication interface card 123 is independently or dependently connected to at least one of the base station 200, an external device, and a server according to the unlicensed band communication standard or protocol of the frequency band supported by the corresponding NIC module. Wireless communication can be performed.

The memory 130 may store a control program used in the terminal 100 and various data corresponding thereto. Such a control program may include a predetermined program necessary for the terminal 100 to perform wireless communication with at least one of the base station 200, an external device, and a server.

The user interface 140 may include various types of input/output means provided in the terminal 100. For example, the user interface 140 may receive a user's input using various input means, and the processor 110 may control the terminal 100 based on the received user input. In addition, the user interface 140 may perform output based on a command of the processor 110 using various output means.

The display 150 may output various images on the display screen. The display 150 may output various display objects such as content executed by the processor 110 or a user interface based on a control command of the processor 110.

The base station 200 may include a processor 210, a communication module 220, and a memory 230.

The processor 210 may execute various commands or programs and process data inside the base station 200. In addition, the processor 210 may control the entire operation including each unit of the base station 200 and control data transmission/reception between the units.

The processor 210 may be configured to perform a function of the base station 200. For example, the processor 210 may signal slot configuration information and perform communication according to the signaled slot configuration.

The communication module 220 may be an integrated module that performs wireless communication using a wireless communication network and wireless LAN access using a wireless LAN. The communication module 220 may include a first communication module 221, a second communication module 222, and a third communication module 223.

For example, the first communication module 221 and the second communication module may be a cellular communication interface card, and the third communication module 223 may be an unlicensed band communication interface card. That is, the communication module 220 may include a plurality of network interface cards including the cellular communication interface cards 221 and 222 and the unlicensed band communication interface card 223 in an internal or external form.

In FIG. 14, the communication module 220 is shown as an integrated integrated module, but the first to third communication modules 221 to 223 (for example, each network interface card) may be independently arranged according to the circuit configuration or use. I can.

The cellular communication interface card 221 transmits and receives a wireless signal with at least one of the terminal 100, an external device (not shown), and a server (not shown) using a mobile communication network, and based on a command of the processor 210 It is possible to provide a cellular communication service based on the first frequency band.

The cellular communication interface card 221 may include at least one NIC module using a frequency band of less than 6 GHz. At least one NIC module of the cellular communication interface card 221 independently includes a terminal 100, an external device (not shown), and a server ( Cellular communication may be performed with at least one of (not shown).

The cellular communication interface card 222 transmits and receives a wireless signal with at least one of the terminal 100, an external device (not shown), and a server (not shown) using a mobile communication network, and based on a command of the processor 210 It is possible to provide a cellular communication service based on the second frequency band.

The cellular communication interface card 222 may include at least one NIC module using a frequency band of 6 GHz or higher. At least one NIC module of the cellular communication interface card 222 is independently a terminal 100, an external device (not shown), and a server (not shown) according to a cellular communication standard or protocol of a frequency band of 6 GHz or higher supported by the corresponding NIC module. City) can perform cellular communication with at least one of.

The unlicensed band communication interface card 223 transmits and receives a wireless signal with at least one of the terminal 100, an external device (not shown), and a server (not shown) using a third frequency band that is an unlicensed band, and the processor 210 ) On the basis of the command, it is possible to provide a communication service of the unlicensed band.

The unlicensed band communication interface card 223 may include at least one NIC module using the unlicensed band. For example, the unlicensed band may be a 2.4 GHz or 5 GHz band.

At least one NIC module of the unlicensed band communication interface card 223 is independently or dependent on the unlicensed band communication standard or protocol of the frequency band supported by the corresponding NIC module, the terminal 100, an external device (not shown), and It is possible to perform wireless communication with at least one of the servers (not shown).

As a block diagram showing an example of the terminal 100 and the base station 200 shown in FIG. 14, the separated blocks are shown by logically distinguishing elements of the device. Accordingly, the elements of the above-described device may be mounted as one chip or as a plurality of chips according to the design of the device. In addition, some components of the terminal 100, for example, the user interface 140 and the display 150 may be selectively provided in the terminal 100. In addition, the user interface 140 and the display 150 may be additionally provided in the base station 200 as necessary.

The method according to the embodiment may be implemented in the form of program instructions that can be executed through various computer means and recorded in a computer-readable medium. The computer-readable medium may include program instructions, data files, data structures, etc. alone or in combination. The program instructions recorded on the medium may be specially designed and configured for the embodiment, or may be known and usable to those skilled in computer software. Examples of computer-readable recording media include magnetic media such as hard disks, floppy disks, and magnetic tapes, optical media such as CD-ROMs and DVDs, and magnetic media such as floptical disks. -A hardware device specially configured to store and execute program instructions such as magneto-optical media, and ROM, RAM, flash memory, and the like. Examples of program instructions include not only machine language codes such as those produced by a compiler, but also high-level language codes that can be executed by a computer using an interpreter or the like. The hardware device described above may be configured to operate as one or more software modules to perform the operation of the embodiment, and vice versa.

The software may include a computer program, code, instructions, or a combination of one or more of these, configuring the processing unit to operate as desired or processed independently or collectively. You can command the device. Software and/or data may be interpreted by a processing device or, to provide instructions or data to a processing device, of any type of machine, component, physical device, virtual equipment, computer storage medium or device. , Or may be permanently or temporarily embodyed in a transmitted signal wave. The software may be distributed over networked computer systems and stored or executed in a distributed manner. Software and data may be stored on one or more computer-readable recording media.

As described above, although the embodiments have been described by the limited drawings, a person of ordinary skill in the art can apply various technical modifications and variations based on the above. For example, the described techniques are performed in a different order from the described method, and/or components such as systems, structures, devices, circuits, etc. described are combined or combined in a form different from the described method, or other components Alternatively, even if substituted or substituted by an equivalent, an appropriate result can be achieved.

Therefore, other implementations, other embodiments, and claims and equivalents fall within the scope of the following claims.

Claims (18)

Receiving a synchronization signal/physical broadcast channel block (SS/PBCH) transmitted from a base station;
Setting an energy detection (ED) threshold based on the SS/PBCH block; And
Determining whether to use a resource block based on the ED threshold
Frequency resource measurement method comprising a.
The method of claim 1,
The SS/PBCH block,
A method for measuring frequency resources including at least one of a primary synchronization signal (PSS), a secondary synchronization signal (SSS), a physical broadcast channel (PBCH), and a physical broadcast channel-demodulation reference signal (PBCH-DMRS).
The method of claim 1,
The setting step,
Determining a reference power based on the SS/PBCH block; And
Setting an ED threshold based on the reference power
Frequency resource measurement method including
The method of claim 3,
The determining step,
Measuring a reception power level for at least one of the signals included in the SS/PBCH block; And
Determining the reference power for a bandwidth in a carrier to be measured based on a resource block occupied by the SS/PBCH block based on the power level
Frequency resource measurement method comprising a.
The method of claim 1,
The receiving step,
Receiving the same SS/PBCH block index among the indexes of the SS/PBCH block
Frequency resource measurement method comprising a.
The method of claim 5,
The SS/PBCH block is an SS/PBCH block periodically transmitted with different indices.
The method of claim 3,
The step of determining the reference power,
Determining the reference power by calculating an average of the measured power based on the SS/PBCH block
Frequency resource measurement method comprising a.
The method of claim 3,
Setting an ED threshold value based on the reference power,
Receiving a physical downlink control channel (PDCCH) distributed based on the reference power or a demodulation reference signal (DM-RS) of the PDCCH and the PDCCH, and setting the ED threshold based on the measured power level
Frequency resource measurement method comprising a.
The method of claim 3,
Setting an ED threshold value based on the reference power,
Measuring a channel and a power level in a channel bandwidth in which a wideband DM-RS is configured; And
Measuring a fluctuation of a received power level of a PDCCH and a power level between resource blocks based on the measurement result;
Setting an ED threshold value of the resource block based on the variation and the reference power
Frequency resource measurement method comprising a.
A memory containing instructions; And
A processor for executing the instructions
Including,
When the instructions are executed by the processor, the processor,
Receives a synchronization signal/physical broadcast channel block (SS/PBCH) transmitted from the base station, sets an energy detection (ED) threshold based on the SS/PBCH block, and sets a resource block based on the ED threshold ( resource block)
Frequency resource measurement device.
The method of claim 10,
The SS/PBCH block,
Including at least one of a primary synchronization signal (PSS), a secondary synchronization signal (SSS), a physical broadcast channel (PBCH), and a physical broadcast channel-demodulation reference signal (PBCH-DMRS)
Frequency resource measurement device.
The method of claim 10,
The processor,
Determining a reference power based on the SS/PBCH block and setting an ED threshold based on the reference power
Frequency resource measurement device.
The method of claim 12,
The processor,
A carrier to be measured based on a resource block occupied by the SS/PBCH block based on the power level and measured a reception power level for at least one of the signals included in the SS/PBCH block To determine the reference power for the bandwidth at
Frequency resource measurement device.
The method of claim 10,
The processor,
Frequency resource measuring apparatus for receiving the same SS/PBCH block index among the indexes of the SS/PBCH block.
The method of claim 14,
The SS/PBCH block is an SS/PBCH block periodically transmitted with different indices.
The method of claim 12,
The processor,
Determining the reference power by calculating an average of the measured power based on the SS/PBCH block
Frequency resource measurement device.
The method of claim 12,
The processor,
Receiving a physical downlink control channel (PDCCH) distributed based on the reference power or a demodulation reference signal (DM-RS) of a PDCCH and a PDCCH, and setting the ED threshold based on the measured power level
Frequency resource measurement device.
The method of claim 12,
The processor,
Measure the channel and power level in the channel bandwidth in which the wideband DM-RS is configured, measure the fluctuation of the received power level of the PDCCH and the power level between resource blocks based on the measurement result, and the fluctuation and the reference Setting the ED threshold of the resource blocks based on power
Frequency resource measurement device.

Images