Methods and apparatus for transmitting and receiving signals in a wireless communication system

Abstract

A method and apparatus for transmitting and receiving signals in a wireless communication system are disclosed. More specifically, a method for transmitting signals by means of applying analog beams that vary / independently for each symbol cell is disclosed, as well as an apparatus supporting the method, characterized in that the transmission of signals is based on the successful location of a channel access procedure (e.g., Listen-After-Speak (LBT)) for signal transmission in an unlicensed frequency band by means of applying analog beams that vary / independently for each symbol cell.

Description

[0001] This application is a divisional application of patent application No. 201780048786.6 (PCT / KR2017 / 008323), filed with the Chinese Patent Office on February 2, 2019, with an international application date of August 2, 2017, entitled "Method for transmitting and receiving signals in a wireless communication system supporting an unlicensed frequency band and an apparatus supporting the method". Technical Field

[0002] This disclosure relates to wireless communication systems, and more specifically, to methods for transmitting and receiving signals between a terminal and a base station in a wireless communication system supporting unlicensed frequency bands, and to apparatus for supporting such methods.

[0003] Specifically, this disclosure relates to a method for transmitting signals by applying different / independent analog beams to each symbol based on the location of a channel access procedure (e.g., Listen-Before-Speak (LBT)) for successfully performing signal transmission in an unlicensed frequency band, and an apparatus supporting the method. Background Technology

[0004] Wireless access systems have been widely deployed to provide various types of communication services, such as voice or data. Typically, wireless access systems are multiple access systems, which support communication for multiple users by sharing available system resources (bandwidth, transmit power, etc.) among themselves. Examples of multiple access systems include Code Division Multiple Access (CDMA), Frequency Division Multiple Access (FDMA), Time Division Multiple Access (TDMA), Orthogonal Frequency Division Multiple Access (OFDMA), and Single Carrier Frequency Division Multiple Access (SC-FDMA).

[0005] The need for mobile broadband communications, which significantly improves upon existing radio access technologies (RATs), has increased due to the high communication capacity required by many communication devices. Furthermore, large-scale machine-type communications (MTC) capable of providing various services anytime and anywhere by interconnecting multiple devices or objects has been considered in next-generation communication systems. In addition, communication system designs capable of supporting services / UEs sensitive to reliability and latency have been discussed.

[0006] As mentioned above, the introduction of next-generation RATs, considering enhanced mobile broadband communications, massive MTC, ultra-reliable and low-latency communications (URLLC), etc., has been discussed. Summary of the Invention

[0007] Technical issues

[0008] The purpose of this invention is to provide a method and apparatus for transmitting and receiving signals between a terminal and a base station when a newly proposed wireless communication system supports unlicensed frequency bands.

[0009] More specifically, the object of the present invention is to provide a signal transmission and reception method and apparatus thereof that take into account the characteristics of unlicensed frequency bands in which signal transmission and reception are performed in a contention-based manner and the characteristics of new wireless communication systems in which independent analog beams can be applied to each symbol.

[0010] Those skilled in the art will understand that the purposes achievable by this disclosure are not limited to those specifically described above, and that the above and other purposes achievable by this disclosure will become clearer from the following detailed description.

[0011] Technical solution

[0012] This invention proposes a method and apparatus for transmitting signals from a first communication node to a second communication node in a wireless communication system that supports unlicensed frequency bands.

[0013] In one aspect of the invention, a method is provided for transmitting a signal from a first communication node to a second communication node in a wireless communication system supporting an unlicensed frequency band. The method may include: performing a channel access procedure for signal transmission in the unlicensed frequency band; and transmitting the signal to the second communication node in the unlicensed frequency band by applying an independent analog beam to each symbol for a predetermined number of symbol periods starting from the symbol for which the channel access procedure was successful.

[0014] In another aspect of the invention, a communication node is provided for transmitting signals to different communication nodes in a wireless communication system supporting an unlicensed frequency band. The communication node may include: a transmitter; and a processor connected to the transmitter, the processor being configured to: perform a channel access procedure for signal transmission in the unlicensed frequency band; and transmit the signal to the different communication nodes in the unlicensed frequency band by applying an independent analog beam to each symbol for a predetermined number of symbol periods starting from the symbol where the channel access procedure was successful. Hereinafter, for ease of description, the communication node will be referred to as a first communication node, and the different communication nodes will be referred to as a second communication node.

[0015] In this invention, the channel access process may include listen-before-say (LBT) for checking whether another signal is being transmitted in the unlicensed frequency band by channel sensing on the unlicensed frequency band.

[0016] Furthermore, the analog beams applied to each symbol during a predetermined number of symbol periods starting from the symbol that has successfully entered the channel access process can be analog beams determined sequentially from the first analog beam index in a predetermined analog beam index order to be applied when the first communication node transmits the signal.

[0017] Alternatively, the analog beams applied to each symbol during a predetermined number of symbol periods starting from the symbol in which the channel access procedure was successful can be from the analog beams corresponding to the symbols in which the channel access procedure was successful, in a predetermined analog beam index order to be applied when the first communication node transmits the signal.

[0018] In this case, the predetermined number of symbol periods can be equal to or less than the symbol area required for signal transmission.

[0019] If the symbol region required for signal transmission is greater than the symbol length from the successful completion of the channel access procedure until the time period allocated to the first communication node for signal transmission, then a predetermined number of symbol periods may be equal to the symbol length from the successful completion of the channel access procedure until the time period allocated to the first communication node for signal transmission.

[0020] Alternatively, if the symbol area required for signal transmission is less than the symbol length from the successful completion of the channel access procedure until the time period allocated to the first communication node for signal transmission, a predetermined number of symbol periods may be equal to the symbol length of the symbol area required for signal transmission.

[0021] In this invention, the first communication node can be a new RAT (NR) base station or a terminal. Additionally, the second communication node can be a terminal or an NR base station.

[0022] In addition, the signal may include a synchronization signal and a signal or random access preamble for radio resource management (RRM) measurements.

[0023] Specifically, when the signal includes a synchronization signal and a signal for RRM measurement, the first communication node can send information about the symbol indicating a successful channel access process to the second communication node.

[0024] It should be understood that the foregoing general description and the following detailed description of this disclosure are exemplary and explanatory, and are intended to provide further explanation of the claimed disclosure.

[0025] Beneficial effects

[0026] It is evident from the above description that the embodiments of the present invention have the following effects.

[0027] According to the present invention, a terminal or base station is able to transmit signals by applying an independent analog beam to each symbol during a predetermined number of symbol periods after successfully performing a channel access procedure in an unlicensed frequency band.

[0028] In addition, this signaling method can be applied when the NR base station sends a discovery reference signal (DRS) or when the UE sends a random access preamble.

[0029] Those skilled in the art will understand that the effects achievable through this disclosure are not limited to those specifically described above, and that other advantages of this disclosure will become more apparent from the following detailed description taken in conjunction with the accompanying drawings. Attached Figure Description

[0030] The accompanying drawings are included to provide a further understanding of the invention, and together with the detailed description, they provide embodiments of the invention. However, the technical features of the invention are not limited to the specific drawings. The features disclosed in each drawing are combined with each other to configure new embodiments. The reference numerals in each drawing correspond to structural elements.

[0031] Figure 1 It is a diagram illustrating the physical channel and the signal transmission method using the physical channel;

[0032] Figure 2 This is a diagram illustrating an exemplary radio frame structure;

[0033] Figure 3 This is a diagram of an exemplary resource grid illustrating the duration of a downlink slot;

[0034] Figure 4 This is a diagram illustrating an exemplary structure of an uplink subframe;

[0035] Figure 5 This is a diagram illustrating an exemplary structure of a downlink subframe;

[0036] Figure 6 This is a diagram illustrating an exemplary carrier aggregation (CA) environment supported in a Long Term Evolution-Unlicensed (LTE-U) system;

[0037] Figure 7 This is a diagram illustrating an exemplary frame-based device (FBE) operation as one of the Listen-Before-Speak (LBT) operations;

[0038] Figure 8 This is a block diagram illustrating the FBE operation;

[0039] Figure 9 This is a diagram illustrating an exemplary load-based device (LBE) operation as one of the LBT operations;

[0040] Figure 10 This diagram illustrates a method for transmitting a Discovery Reference Signal (DRS) supported in a Licensed Assisted Access (LAA) system.

[0041] Figure 11 This is a diagram illustrating the Channel Access Procedure (CAP) and Contention Window Adjustment (CWA).

[0042] Figure 12This is a diagram illustrating a portion of the transmission time interval (TTI) or a portion of the subframe applicable to the present invention;

[0043] Figure 13 This is a diagram illustrating a self-contained subframe structure applicable to the present invention;

[0044] Figure 14 and 15 This is a diagram illustrating a representative method for connecting a TXRU to an antenna element;

[0045] Figure 16 The diagram illustrates the configuration by which the gNB transmits signals when operating with a subcarrier spacing of approximately 15 kHz, either by configuring a shorter TTI than the normal TTI or by increasing the carrier spacing.

[0046] Figure 17 The diagram illustrates a configuration where the bandwidth of the signal transmitted by the base station or terminal varies due to changes in the subcarrier spacing.

[0047] Figure 18 The diagram illustrates the configuration of the transmittable subband set in each bandwidth and the transmission of signals in each subband set, based on the LBT results.

[0048] Figure 19 The illustration shows the index of the analog beam used for NR-DRS transmission of each symbol in a subframe according to the present invention;

[0049] Figure 20 The figure illustrates an NR-DRS transmission method according to an embodiment of the present invention;

[0050] Figure 21 The figure illustrates an NR-DRS transmission method according to another embodiment of the present invention;

[0051] Figure 22 The figure illustrates an NR-DRS transmission method according to yet another embodiment of the present invention;

[0052] Figure 23 The figure illustrates a random access preamble transmission method according to an embodiment of the present invention; and

[0053] Figure 24 The diagram illustrates the configuration of the user equipment and base station for implementing the proposed embodiment. Detailed Implementation

[0054] The embodiments of this disclosure described below are combinations of elements and features of this disclosure in a specific form. Unless otherwise stated, elements or features are to be considered selective. Each element or feature may be practiced without combination with other elements or features. Furthermore, embodiments of this disclosure may be constructed by combining portions of elements and / or features. The order of operations described in the embodiments of this disclosure may be rearranged. Some structures or elements of any embodiment may be included in another embodiment and may be replaced by corresponding structures or features of another embodiment.

[0055] In the description of the accompanying drawings, detailed descriptions of known processes or steps of this disclosure will be avoided so as not to obscure the subject matter of this disclosure. Furthermore, processes or steps that are understandable to those skilled in the art will not be described.

[0056] Throughout the specification, when a part “comprises” or “includes” a component, this means that other components are not excluded, and may be further included unless otherwise stated. The terms “unit,” “-or / or,” and “module” described in the specification indicate a unit for performing at least one function or operation, which may be implemented by hardware, software, or a combination thereof. Additionally, the terms “a / an,” “an,” “the,” etc., may include both singular and plural representations in the context of this disclosure (more specifically, in the context of the appended claims), unless otherwise indicated in the specification or unless the context clearly states otherwise.

[0057] In the embodiments of this disclosure, the data transmission and reception relationship between a base station (BS) and a user equipment (UE) is primarily described. A BS refers to a terminal node of the network that communicates directly with the UE. Specific operations described as being performed by the BS can be performed by the upstream node of the BS.

[0058] That is, it is obvious that in a network consisting of multiple network nodes including the BS, various operations for communicating with the UE can be performed by the BS or network nodes other than the BS. The term "BS" can be replaced by fixed station, Node B, evolved Node B (eNode B or eNB), Advanced Base Station (ABS), access point, etc.

[0059] In embodiments of this disclosure, the term "terminal" can be replaced by UE, mobile station (MS), subscriber station (SS), mobile subscriber station (MSS), mobile terminal, advanced mobile station (AMS), etc.

[0060] The transmitting end is a fixed and / or mobile node that provides data or voice services, and the receiving end is a fixed and / or mobile node that receives data or voice services. Therefore, on the uplink (UL), the UE can act as the transmitting end and the BS can act as the receiving end. Similarly, on the downlink (DL), the UE can act as the receiving end and the BS can act as the transmitting end.

[0061] The embodiments of this disclosure can be supported by standard specifications disclosed for at least one radio access system, including IEEE 802.xx systems, 3GPP systems, 3GPP Long Term Evolution (LTE) systems, and 3GPP2 systems. Specifically, the embodiments of this disclosure can be supported by standard specifications 3GPP TS 36.211, 3GPP TS 36.212, 3GPP TS 36.213, 3GPP TS 36.321, and 3GPP TS 36.331. That is, steps or portions of the technical concept not described in the embodiments of this disclosure to clearly reveal the technical concept of this disclosure can be explained by the aforementioned standard specifications. All terms used in the embodiments of this disclosure can be explained by the standard specifications.

[0062] Embodiments of the present disclosure will now be described in detail with reference to the accompanying drawings. The detailed description given below with reference to the drawings is intended to explain exemplary embodiments of the present disclosure and not merely to illustrate embodiments that can be implemented according to the present disclosure.

[0063] The following detailed description includes specific terminology in order to provide a thorough understanding of this disclosure. However, it will be apparent to those skilled in the art that certain terms may be substituted with other terms without departing from the technical spirit and scope of this disclosure.

[0064] For example, the term TxOP can be used interchangeably with the Transmit Period or Reserved Resource Period (RRP) for the same purpose. Furthermore, the Listen-Before-Speak (LBT) procedure can be performed for the same purpose as the Carrier Sense procedure, CCA (Clear Channel Assessment), and CAP (Channel Access Procedure) used to determine whether the channel state is idle or busy.

[0065] The following text explains the 3GPP LTE / LTE-A system, which is an example of a radio access system.

[0066] The embodiments disclosed herein can be applied to various wireless access systems, such as 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), etc.

[0067] CDMA can be implemented as radio technologies such as Universal Terrestrial Radio Access (UTRA) or CDMA2000. TDMA can be implemented as radio technologies such as Global System for Mobile Communications (GSM) / General Packet Radio Service (GPRS) / GSM Evolution Enhanced Data Rate (EDGE). OFDMA can be implemented as radio technologies such as IEEE 802.11 (Wi-Fi), IEEE 802.16 (WiMAX), EEE 802.20, Evolved UTRA (E-UTRA), etc.

[0068] UTRA is part of the Universal Mobile Telecommunications System (UMTS). 3GPP LTE is part of the evolved UMTS (E-UMTS) using E-UTRA, employing OFDMA for DL ​​and SC-FDMA for UL. LTE Advanced (LTE-A) is an evolution of 3GPP LTE. Although embodiments of this disclosure are described in the context of 3GPP LTE / LTE-A systems to illustrate the technical features of this disclosure, this disclosure is also applicable to IEEE 802.16e / m systems, etc.

[0069] 1.3GPP LTE / LTE-A systems

[0070] 1.1. Physical channel and the signal transmission and reception methods using it

[0071] In a radio access system, the UE receives information from the eNB on the DL and transmits information to the eNB on the UL. The information transmitted and received between the UE and eNB includes general data information and various types of control information. Depending on the type / purpose of the information transmitted and received between the eNB and UE, there are many physical channels.

[0072] Figure 1 A physical channel and a general signal transmission method using the physical channel are shown, which can be used in embodiments of this disclosure.

[0073] When the UE is powered on or enters a new cell, the UE performs an initial cell search (S11). The initial cell search involves obtaining synchronization with the eNB. Specifically, the UE synchronizes its timing with the eNB and obtains information such as the cell identifier (ID) by receiving the primary synchronization channel (P-SCH) and secondary synchronization channel (S-SCH) from the eNB.

[0074] Then, the UE can obtain information broadcast in the cell by receiving the Physical Broadcast Channel (PBCH) from the eNB.

[0075] During the initial cell search, the UE can monitor the DL channel status by receiving the downlink reference signal (DL RS).

[0076] After the initial cell search, the UE can obtain more detailed system information by receiving the Physical Downlink Control Channel (PDCCH) and receiving the Physical Downlink Shared Channel (PDSCH) based on the information in the PDCCH (S12).

[0077] To establish a connection with the eNB, the UE can perform a random access procedure with the eNB (S13 to S16). During the random access procedure, the UE can transmit a preamble on the Physical Random Access Channel (PRACH) (S13) and receive the PDCCH and the PDSCH associated with the PDCCH (S14). In the case of contention-based random access, the UE can additionally perform a contention resolution procedure, including transmitting an additional PRACH (S15) and receiving the PDCCH signal and the corresponding PDSCH signal (S16).

[0078] After the above process, the UE can receive PDCCH and / or PDSCH from the eNB (S17), and send the Physical Uplink Shared Channel (PUSCH) and / or Physical Uplink Control Channel (PUCCH) to the eNB during the general UL / DL signal transmission process (S18).

[0079] The control information sent by the UE to the eNB is usually called uplink control information (UCI). UCI includes hybrid automatic repeat and request-acknowledge / negative-acknowledge (HARQ-ACK / NACK), scheduling request (SR), channel quality indicator (CQI), precoding matrix index (PMI), rank indicator (RI), etc.

[0080] In LTE systems, UCIs are typically transmitted periodically on the PUCCH. However, if control information and service data should be transmitted simultaneously, they can be transmitted on the PUSCH. Additionally, UCIs can be transmitted intermittently on the PUSCH once a request / command is received from the network.

[0081] 1.2. Resource Structure

[0082] Figure 2 An exemplary radio frame structure is shown for use in embodiments of this disclosure.

[0083] Figure 2 (a) shows frame structure type 1. Frame structure type 1 is applicable to full frequency division duplex (FDD) systems and half-FDD systems.

[0084] A radio frame is 10 ms long (Tf = 307200 Ts) and consists of 20 time slots of equal size, indexed from 0 to 19. Each time slot is 0.5 ms long (Tslot = 15360 Ts). A subframe consists of two consecutive time slots. The i-th subframe consists of the 2nd and (2i+1)th time slots. That is, a radio frame consists of 10 subframes. The time required to transmit a subframe is defined as the Transmission Time Interval (TTI). Ts is the sampling time given as Ts = 1 / (15kHz × 2048) = 3.2552 × 10⁻⁸ (approximately 33 ns). A time slot consists of multiple resource blocks (RBs) in the frequency domain and multiple orthogonal frequency division multiplexing (OFDM) symbols or SC-FDMA symbols in the time domain.

[0085] A time slot comprises multiple OFDM symbols in the time domain. Since OFDMA is used for deep learning in 3GPP LTE systems, one OFDM symbol represents one symbol period. An OFDM symbol can also be called an SC-FDMA symbol or a symbol period. An RB is a resource allocation unit that comprises multiple consecutive subcarriers within a time slot.

[0086] In a full FDD system, each of the 10 subframes can be used simultaneously for DL ​​(Deep Transmission) and UL (Ultra-Low Transmission) transmissions during a 10ms duration. DL and UL transmissions are distinguished by frequency. On the other hand, a UE cannot perform simultaneous transmission and reception in a semi-FDD system.

[0087] The radio frame structure described above is purely exemplary. Therefore, the number of subframes in a radio frame, the number of time slots in a subframe, and the number of OFDM symbols in a time slot can be changed.

[0088] Figure 2 (b) shows frame structure type 2. Frame structure type 2 is applied to time division duplex (TDD) systems. A radio frame is 10 ms long (Tf = 307200 Ts) and consists of two half-frames, each 5 ms long (Tf = 153600 Ts). Each half-frame consists of five subframes, each 1 ms long (Tf = 30720 Ts). The i-th subframe consists of the 2nd and (2i+1)th time slots, each with a length of 0.5 ms (Tslot = 15360 Ts). Ts is the sampling time given as Ts = 1 / (15kHz × 2048) = 3.2552 × 10⁻⁸ (approximately 33 ns).

[0089] Type 2 frames include special subframes with three fields: Downlink Pilot Time Slot (DwPTS), Guard Period (GP), and Uplink Pilot Time Slot (UpPTS). DwPTS is used for initial cell search, synchronization, or channel estimation at the UE, while UpPTS is used for channel estimation and UL transmission synchronization with the UE at the eNB. GP is used to eliminate UL interference between UL and DL caused by multipath delay of the DL signal.

[0090] Table 1 below lists the special subframe configurations (DwPTS / GP / UpPTS length).

[0091] [Table 1]

[0092]

[0093] Figure 3 The illustration shows an exemplary structure of a DL resource grid for the duration of a DL slot, which can be used in embodiments of this disclosure.

[0094] refer to Figure 3 A DL time slot includes multiple OFDM symbols in the time domain. One DL time slot includes 7 OFDM symbols in the time domain, and the RB includes 12 subcarriers in the frequency domain, but this disclosure is not limited thereto.

[0095] Each element of the resource grid is called a resource element (RE). An RB consists of 12x7 REs. The number of RBs in a DL slot (NDL) depends on the DL transmit bandwidth. The structure of an uplink slot can be the same as that of a downlink slot.

[0096] Figure 4 The structure of a UL subframe that can be used in embodiments of this disclosure is shown.

[0097] refer to Figure 4 In the frequency domain, a UL subframe can be divided into a control area and a data area. The PUCCH carrying the UCI is allocated to the control area, and the PUSCH carrying user data is allocated to the data area. To maintain single-carrier attributes, the UE does not transmit the PUCCH and PUSCH simultaneously. A pair of RBs in the subframe is allocated to the UE's PUCCH. The RBs in the RB pair occupy different subcarriers in the two time slots. Therefore, it is said that the RB pair hops frequencies at the time slot boundaries.

[0098] Figure 5 The structure of a DL subframe that can be used in embodiments of this disclosure is shown.

[0099] refer to Figure 5Up to three OFDM symbols in a DL subframe, starting with OFDM symbol 0, are used as the control area for the allocated control channels, and the remaining OFDM symbols in the DL subframe are used as the data area for the allocated PDSCH. The DL control channels defined for the 3GPP LTE system include the Physical Control Format Indicator Channel (PCFICH), PDCCH, and Physical Hybrid ARQ Indicator Channel (PHICH).

[0100] The PCFICH is transmitted in the first OFDM symbol of the subframe, carrying information about the number of OFDM symbols used to transmit the control channel in the subframe (i.e., the size of the control area). The PHICH is the response channel for UL transmission, transmitting HARQACK / NACK signals. The control information carried on the PDCCH is called Downlink Control Information (DCI). The DCI transmits UL resource allocation information, DL resource allocation information, or UL transmit (Tx) power control commands to the UE group.

[0101] 1.3. CSI Feedback

[0102] In 3GPP LTE or LTE-A systems, User Equipment (UE) is defined to report Channel State Information (CSI) to the Base Station (BS or eNB). In this paper, CSI refers to information indicating the quality of the radio channel (or link) formed between the UE and the antenna port.

[0103] For example, CSI may include rank indicator (RI), precoding matrix indicator (PMI), and channel quality indicator (CQI).

[0104] Here, RI represents the rank information for the corresponding channel, which means the number of streams received by the UE using the same time and frequency resources. This value depends on the long-term fading of the channel. Subsequently, RI can typically be fed back to the BS by the UE at longer intervals than PMI or EQI.

[0105] PMI is a value that reflects the characteristics of the channel space and is based on metrics such as SINR that indicate the precoding index preferred by the UE.

[0106] CQI is a value indicating the strength of the channel and typically refers to the receive SINR that can be obtained when the BS uses PMI.

[0107] In 3GPP LTE or LTE-A systems, the base station can configure multiple CSI procedures for the UE and receive CSI reports from the UE for each procedure. Here, the CSI procedures are configured with CSI-RS for specifying the signal quality from the base station and CSI Interference Measurement (CSI-IM) resources for interference measurement.

[0108] 1.4. RRM Measurement

[0109] LTE systems support Radio Resource Management (RRM) operations, including power control, scheduling, cell search, cell reselection, handover, radio link or connection monitoring, and connection establishment / re-establishment. In this context, the serving cell can request the UE to send RRM measurement information, containing measurements used to perform RRM operations. As a representative example, in an LTE system, the UE can measure cell search information, Reference Signal Received Power (RSRP), Reference Signal Received Quality (RSRQ), etc., for each cell, and then report the measured information. Specifically, in an LTE system, the UE receives a 'measConfig' for RRM measurements from the serving cell via higher-layer signals, and then measures the RSRP or RSRQ based on the information in the 'measConfig'.

[0110] In LTE systems, RSRP, RSRQ, and RSSI have been defined as follows.

[0111] RSRP is defined as the linear average of the power contribution (in [W]) of resource elements carrying a cell-specific reference signal within the considered measurement frequency bandwidth. For example, cell-specific reference signal R0 would be used for RSRP determination. If the UE can reliably detect that R1 is available, it can use R1 in addition to R0 to determine RSRP.

[0112] The reference point for RSRP will be the UE's antenna connector.

[0113] If receiver diversity is being used by the UE, the reported value should not be lower than the corresponding RSRP of any of the diversity branches.

[0114] RSRQ is defined as the ratio N × RSRP / (E-UTRA carrier RSSI), where N is the number of RBs in the E-UTRA carrier RSSI measurement bandwidth. Measurements in the numerator and denominator should be performed on the same set of resource blocks.

[0115] E-UTRA carrier RSSI is a linear average of the total received power (in [W]) observed only in OFDM symbols containing the reference symbol for antenna port 0, across N resource blocks from all sources, including serving and non-serving cells, adjacent channel interference, thermal noise, etc. If higher-layer signaling indicates a specific subframe for performing RSRQ measurements, then RSSI is measured on all OFDM symbols in the indicated subframe.

[0116] The reference point for RSRQ should be the UE's antenna connector.

[0117] If receiver diversity is being used by the UE, the reported value should not be lower than the corresponding RSRQ of any of the diversity branches.

[0118] RSSI is defined as the received broadband power, including noise and thermal noise generated within the receiver within the bandwidth defined by the receiver pulse shaping filter.

[0119] The reference point for the measurement results should be the UE's antenna connector.

[0120] If receiver diversity is being used by the UE, the reported value should not be lower than the corresponding UTRA carrier RSSI of any of the individual receive antenna branches.

[0121] Based on the above definitions, in the case of intra-frequency measurement, a UE operating in an LTE system can measure RSRP with the bandwidth indicated by the Allowed Measurement Bandwidth Related Information Element (IE) sent in System Information Block Type 3 (SIB3). Meanwhile, in the case of inter-frequency measurement, the UE can measure RSRP with the bandwidth corresponding to one of the 6, 15, 25, 50, 75, or 100 Resource Blocks (RBs) indicated by the IE associated with the allowed measurement bandwidth sent in SIB5. Alternatively, if no IE is present, the UE can measure RSRP across the entire downlink (DL) system frequency bandwidth by default.

[0122] Upon receiving information about the allowed measurement bandwidth, the UE can treat the corresponding value as the maximum measurement bandwidth and then freely measure the RSRP value within that range. However, if the serving cell sends an IE defined as WB-RSRQ to the UE and sets the allowed measurement bandwidth to be equal to or greater than 50 RBs, the UE should calculate the RSRP value for the entire allowed measurement bandwidth. Simultaneously, when RSSI is calculated, the UE measures the RSSI using the frequency band of the UE receiver according to the definition of RSSI bandwidth.

[0123] 2. LTE-U system

[0124] 2.1 LTE-U System Configuration

[0125] The following describes a method for transmitting and receiving data in a CA environment of LTE-A bands corresponding to licensed and unlicensed bands. In embodiments of this disclosure, LTE-U system refers to an LTE system that supports such CA states as licensed and unlicensed bands. WiFi or Bluetooth (BT) bands can be used as unlicensed bands. An LTE-A system operating on an unlicensed band is referred to as LAA (Licensed Assisted Access), and LAA can correspond to a scheme that uses a combination of licensed and unlicensed bands to perform data transmission / reception in the unlicensed band.

[0126] Figure 6 The diagram illustrates an example of a CA environment supported in an LTE-U system.

[0127] For ease of description, it is assumed that the UE is configured to perform wireless communication in each of the licensed and unlicensed frequency bands using two CCs. The method described below can be applied to cases where three or more CCs are configured for the UE.

[0128] In the embodiments of this disclosure, it is assumed that the carrier of the licensed frequency band can be the primary CC (PCC or PCell), and the carrier of the unlicensed frequency band can be the secondary CC (SCC or SCell). However, the embodiments of this disclosure can be applied to situations where multiple licensed and multiple unlicensed frequency bands are used in the carrier aggregation method. Moreover, the methods proposed in this disclosure can be applied to even 3GPP LTE systems and other systems.

[0129] exist Figure 6 In this context, an eNB supports both licensed and unlicensed frequency bands. That is, the UE can transmit and receive control information and data via the PCC (licensed band) and also via the SCC (unlicensed band). However, Figure 6 The states shown are merely examples, and the embodiments of this disclosure can be applied to CA environments where even one UE accesses multiple eNBs.

[0130] For example, a UE can configure a macro eNB (M-eNB) and PCell, and can also configure a small eNB (S-eNB) and SCell. In this case, the macro eNB and small eNB can connect to each other via the backhaul network.

[0131] In embodiments of this disclosure, unlicensed frequency bands can be operated in a contention-based random access method. In this case, the eNB supporting the unlicensed frequency band can perform a carrier sense (CS) procedure before data transmission and reception. The CS procedure determines whether the corresponding frequency band is reserved by another entity.

[0132] For example, the eNB in ​​the SCell checks whether the current channel is busy or idle. If it determines that the corresponding frequency band is idle, the eNB can send a scheduling grant to the UE to allocate resources via the (E)PDCCH of the PCell in cross-carrier scheduling mode and via the PDCCH of the SCell in self-scheduling mode, and can attempt to send and receive data.

[0133] At this point, the eNB can configure a TxOP consisting of N consecutive subframes. In this case, the value of N and the use of the N subframes can be previously notified to the UE from the eNB via PCell, or via the physical control channel or physical data channel through higher-layer signaling.

[0134] 2.2 Carrier Sense (CS) Process

[0135] In embodiments of this disclosure, the CS process may be referred to as an Idle Channel Assessment (CCA) process. During the CCA process, whether a channel is busy or idle can be determined based on a predetermined CCA threshold or a CCA threshold configured via higher-layer signaling. For example, if energy above the CCA threshold is detected in an unlicensed frequency band SCell, it can be determined whether the channel is busy or idle. If the channel is determined to be idle, the eNB can begin signal transmission in the SCell. This process may be referred to as LBT.

[0136] Figure 7 This is a view illustrating an exemplary frame-based device (FBE) operation as one of the LBT operations.

[0137] The European Telecommunications Standards Institute (ETSI) defines two LBT operations (EN 301 893 V1.7.1): Frame-Based Equipment (FBE) and Load-Based Equipment (LBE). In FBE, a fixed frame consists of a channel occupancy time (e.g., 1 ms to 10 ms) and an idle period. The channel occupancy time is the period during which a communication node that has completed channel access can continue transmitting. The idle period is at least 5% of the channel occupancy time, and CCA is defined as the operation for monitoring the channel during a CCA time slot (at least 20 μs) at the end of the idle period.

[0138] The communication node performs CCA periodically on a fixed frame basis. If the channel is not occupied, the communication node transmits data during the channel-occupied time. Conversely, if the channel is occupied, the communication node postpones transmission and waits until the next CCA time slot.

[0139] Figure 8 This is a block diagram illustrating the FBE operation.

[0140] refer to Figure 8 The communication node (i.e., eNB) managing the SCell performs CCA during the CCA time slot [S810]. If the channel is idle [S820], the communication node performs data transmission (Tx) [S830]. If the channel is busy, the communication node waits for a period of time calculated by subtracting the CCA time slot from the fixed frame period, and then resumes CCA [S840].

[0141] The communication node transmits data during the channel occupancy period [S850]. Upon completion of data transmission, the communication node waits for a time period calculated by subtracting the CCA time slot from the idle period [S860], and then resumes CCA [S810]. If the channel is idle but the communication node does not transmit data, the communication node waits for a time period calculated by subtracting the CCA time slot from the fixed frame period [S840], and then resumes CCA [S810].

[0142] Figure 9 This is a view illustrating an exemplary LBE operation as one of the LBT operations.

[0143] refer to Figure 9 (a) In LBE, the communication node first sets q (q∈{4,5,...,32}) and then performs CCA during the CCA time slot.

[0144] Figure 9 (b) is a block diagram illustrating the LBE operation. (Refer to...) Figure 9 (b) Describe the LBE operation.

[0145] The communication node can perform CCA during the CCA time slot [S910]. If the channel is not occupied in the first CCA time slot [S920], the communication node can transmit data by guaranteeing a time period of up to (13 / 32)q ms [S930].

[0146] Conversely, if the channel is occupied in the first CCA time slot, the communication node arbitrarily (i.e., randomly) selects N (N∈{1,2,…,q}) and stores the selected N value as an initial count. The communication node then listens for the channel status on a CCA time slot basis. Each time the channel is not occupied in a particular CCA time slot, the communication node decrements the count by 1. If the count is 0, the communication node can transmit data by guaranteeing a time period of up to (13 / 32)q ms [S940].

[0147] Discontinuous transmission in 2.3DL

[0148] When discontinuous transmission is performed on an unlicensed carrier with a finite maximum transmission period, the discontinuous transmission may affect several functions necessary for the operation of the LTE system. These functions can be supported by one or more signals transmitted at the beginning of a discontinuous LAA DL transmission. Functions supported by signals include AGC configuration, channel reservation, and similar features.

[0149] When a signal is sent by an LAA node, the channel reservation is significant for sending signals via the channel. It is reserved to send signals to other nodes after the channel access is successfully executed via LBT operation.

[0150] The functionality supported by one or more signals necessary for performing LAA operations, including discontinuous DL transmissions, includes functions for detecting LAA DL transmissions sent by the UE and functions for frequency and time synchronization. In this context, the requirement for functionality does not imply the exclusion of other available functions. Functionality can be supported by other methods.

[0151] 2.3.1 Time and frequency synchronization

[0152] The design objective recommended by the LAA system is to support the UE in obtaining time and frequency synchronization via discovery signals used to measure RRM (Radio Resource Management) and each reference signal, or a combination thereof, included in the reference signals in the DL transmission burst. Discovery signals used to measure RRM transmitted from the serving cell can be used to obtain coarse time or frequency synchronization.

[0153] 2.3.2DL Transmission Timing

[0154] When DL LAA is designed, it can follow the CA timing relationship between serving cells composed of CAs, which is defined in LTE-A systems (Rel-12 or earlier) for subframe boundary adjustment. However, this does not mean that the base station only starts DL transmission at the subframe boundary. Although all OFDM symbols are unavailable in the subframe, the LAA system can support PDSCH transmission based on the results of LBT operations. In this case, it is necessary to support the transmission of control information necessary for performing PDSCH transmission.

[0155] 2.4 Measurement and Reporting of RRM

[0156] The LTE-A system can transmit a discovery signal at the starting point to support RRM functions, including those for cell detection. In this case, the discovery signal can be referred to as the Discovery Reference Signal (DRS). To support RRM functions for LAA, the discovery signal and its transmission / reception functions in the LTE-A system can be applied in a modified manner.

[0157] 2.4.1. Detection of Reference Signal (DRS)

[0158] The DRS of the LTE-A system is designed to support the enabling / disabling of small cells. In this case, disabling a small cell corresponds to a state where most functions are turned off except for the periodic transmission of DRS. DRS is transmitted at DRS transmission intervals of 40, 80, or 160 ms. The DMTC (Discovery Measurement Timing Configuration) corresponds to the time period during which DRS can be expected to be received by the UE. DRS transmission can occur at any time during the DMTC. The UE can expect DRS to be transmitted continuously from the cell assigned to the UE using the corresponding intervals.

[0159] If DRS (Digital Submission Response) is used in an LTE-A system, it may introduce new constraints. For example, while DRS transmission, such as very short control transmissions without LBT (Low-Level Bit Transmission), is permissible in some areas, short control transmissions without LBT are not allowed in others. Therefore, DRS transmission in an LAA system can become the target of LBT.

[0160] When a DRS is transmitted, if the LBT is applied to a DRS similar to that transmitted in an LTE-A system, the DRS may not be transmitted via a periodic scheme. In particular, the two schemes described below can be considered for transmitting DRS in an LAA system.

[0161] As a first option, DRS is sent at a fixed location in the DMTC configured only based on the conditions of LBT.

[0162] As a second option, DRS transmission is permitted at one or more different time locations in the DMTC configured based on the conditions of LBT.

[0163] As a different aspect of the second scheme, the number of time positions can be limited to one time position in a subframe. If it is more advantageous, DRS transmissions that can be performed both outside the configured DMTC and within the DMTC are permitted.

[0164] Figure 10 This is a diagram used to explain the DRS transmission method supported by the LAA system.

[0165] refer to Figure 10 , Figure 10 The upper part shows the aforementioned first scheme for sending DRS and Figure 10 The lower part illustrates the aforementioned second scheme for transmitting DRS. Specifically, in the first scheme, the UE is able to receive DRS only at a determined location within the DMTC cycle. Conversely, in the second scheme, the UE is able to receive DRS at a random location within the DMTC cycle.

[0166] In LTE-A systems, when a UE performs RRM measurements based on DRS transmission, it can perform a single RRM measurement based on multiple DRS timings. However, in LAA systems using DRS, ensuring that DRS is transmitted at a specific location is difficult due to LBT constraints. Even if the DRS is not actually transmitted from the base station, the quality of the RRM measurement results reported by the UE may degrade if the UE assumes the presence of the DRS. Therefore, when designing LAA DRS, it is necessary to allow the existence of DRS to be detected in a single DRS timing. By doing so, it may be possible for the UE to combine the presence of the DRS with RRM measurement results performed only on the successfully detected DRS timing.

[0167] Signals including DRS do not guarantee that DRS transmissions are temporally adjacent. Specifically, if there is no data transmission in a subframe accompanying a DRS, there may be OFDM signals in which no physical signals are transmitted. When operating in unlicensed frequency bands, other nodes can listen for idle channels during the quiet period between DRS transmissions. To avoid the aforementioned problems, it is preferable that transmission bursts including DRS signals are configured by adjacent OFDM symbols in which several signals are transmitted.

[0168] 2.5 Channel Access Procedure and Contention Window Adjustment Procedure

[0169] The aforementioned channel access procedure and contention window adjustment procedure are explained below from the perspective of the transmitting node.

[0170] Figure 11 This is a flowchart used to explain CAP and CWA.

[0171] In order for an LTE transmitting node (e.g., a base station) to operate in one or more LAA SCells corresponding to an unlicensed frequency band cell used for DL ​​transmission, it may initiate a Channel Access Procedure (CAP) [S1110].

[0172] The base station can randomly select a backoff counter N from the contention window (CW). In this case, N is configured with an initial value Ninit [S1120]. Ninit changes from 0 to the CW. p The value is randomly selected from the middle.

[0173] Subsequently, if the backoff counter value (N) corresponds to 0 [S1122], the base station terminates CAP and performs a Tx burst transmission including PSCH [S1124]. Conversely, if the backoff value is not 0, the base station decrements the backoff counter value by 1 [S1130].

[0174] The base station checks whether the channel of (one or more) LAA SCells is in an idle state [S1140]. If the channel is in an idle state, the base station checks whether the backoff value corresponds to 0 [S1150]. While decrementing the backoff counter value by 1, the base station repeatedly checks whether the channel is in an idle state until the backoff value becomes 0.

[0175] In step S1140, if the channel is not idle, i.e., if the channel is busy, the base station checks whether the channel is idle for a delay duration (more than 15 uses) longer than the time slot duration (e.g., 9 uses). If the channel is idle during the delay duration, the base station can resume CAP [S1144]. For example, when the backoff counter value Ninit corresponds to 10, if the channel state is determined to be busy after the backoff counter value is reduced to 5, the base station listens to the channel during the delay duration and determines whether the channel is idle. In this case, if the channel is idle during the delay duration, the base station again performs CAP from the backoff counter value 5 (or by reducing the value by 1 from the backoff counter value 4) instead of configuring the backoff counter value Ninit. Conversely, if the channel is busy during the delay duration, the base station again performs step S1142 to check whether the channel is idle during the new delay duration.

[0176] Return to reference Figure 11 The base station checks whether the backoff counter value (N) has become 0 [S1150]. If the backoff counter value (N) becomes 0, the base station terminates CAP and may be able to send a Tx burst including PDSCH.

[0177] The base station can receive HARQ-ACK information from the UE in response to a Tx burst [S1170]. The base station can adjust the CWS (contention window size) based on the HARQ-ACK information received from the UE [S1180].

[0178] In step S1180, as a method for adjusting CWS, the base station can adjust CWS based on the HARQ-ACK information on the first subframe of the most recently transmitted Tx burst (i.e., the starting subframe of the Tx burst).

[0179] In this scenario, the base station can set the initial CW to each priority level before CWP is executed. Subsequently, if the probability that the HARQ-ACK value corresponding to the PDSCH transmitted in the reference subframe is determined to be NACK is equal to or greater than 80%, the base station will increase the CW value of each priority level to the next higher priority level.

[0180] In step S1160, the PDSCH can be allocated using either a self-carrier scheduling scheme or a cross-carrier scheduling scheme. If the PDSCH is allocated using a self-carrier scheduling scheme, the base station calculates the DTX, NACK / DTX, or ANY states in the HARQ-ACK information fed back by the UE as NACK. If the PDSCH is allocated using a cross-carrier scheduling scheme, the base station calculates the NACK / DTX and ANY states as NACK and does not calculate the DTX state in the HARQ-ACK information fed back by the UE as NACK.

[0181] If bundling is performed on M (M>=2) number of subframes and the bundled HARQ-ACK information is received, the base station can treat the bundled HARQ-ACK information as a response to M number of HARQ-ACK messages. In this case, it is preferable that the reference subframe is included in the M number of bundled subframes.

[0182] 2.6. Channel Access Priority Level

[0183] [Table 2]

[0184]

[0185] As shown in Table 2, a total of four channel access priority levels are defined in the version 13 LAA system. Furthermore, the lengths of the delay period, CWS, MCOT (Maximum Channel Occupancy Time), etc., are defined according to each of the channel access priority levels. Therefore, when an eNB transmits downlink signals via an unlicensed frequency band, the eNB performs random backoff using the LBT parameters determined according to the channel access priority level and may then be able to access the channel only for a finite maximum transmission time after the random backoff is complete.

[0186] For example, in channel access priority levels 1 / 2 / 3 / 4, the maximum channel occupancy time (MCOT) is determined by 2 / 3 / 8 / 8 ms. In environments where no other RATs such as Wi-Fi exist (e.g., by adjusting the level), the maximum channel occupancy time (MCOT) is determined by 2 / 3 / 10 / 10 ms.

[0187] As shown in Table 2, the set of CWS that can be configured according to the level is defined. One difference from Wi-Fi systems is that different backoff counter values ​​are not defined according to the channel access priority level and LBT is performed using a single backoff counter value (this is called single-engine LBT).

[0188] For example, when an eNB intends to access a channel via LBT operation of level 3, since CWmin (=15) is configured as the initial CWS, the eNB performs random backoff by randomly selecting an integer ranging from 0 to 15. If the backoff counter value becomes 0, the eNB starts a DL Tx and randomly selects a new backoff counter for the next Tx burst after the DL Tx burst is completed. In this case, if an event for increasing CWS is triggered, the eNB increases the size of CWS to 31, corresponding to the next size, randomly selecting an integer ranging from 0 to 31, and performs random backoff.

[0189] In this scenario, when the CWS of level 3 increases, the CWS of all levels also increase. Specifically, if the CWS of level 3 becomes 31, then the CWS of levels 1 / 2 / 4 become 7 / 15 / 31. If an event used to decrease the CWS is triggered, the CWS value of all levels is initialized by CWmin regardless of the CWS value at the time of triggering.

[0190] 2.7. Subframe Structure Applicable to LAA Systems

[0191] Figure 12 This is an illustration of a portion of the TTI or a portion of the subframes applicable to the present invention.

[0192] In the version 13LAA system, MCOT is utilized as much as possible when DL Tx bursts are transmitted. To support continuous transmission, a partial TTI, defined as DwPTS, is introduced. A partial TTI (or partial subframe) corresponds to a segment in which the signal is transmitted for a length that is as short as possible compared to the old TTI (e.g., 1 ms) when PDSCH is transmitted.

[0193] In this invention, for clarity, the start portion of a TTI or start portion of a subframe corresponds to a form where a portion of the symbol positioned at the beginning of the subframe is cleared. The end portion of a TTI or end portion of a subframe corresponds to a form where a portion of the symbol positioned at the end of the subframe is cleared. (Conversely, a complete TTI is referred to as a normal TTI or a full TTI.)

[0194] Figure 12 The diagram illustrates the various types of TTIs mentioned above. Figure 12 The first attached figure shows the end portion of the TTI (or subframe) and the second attached figure shows the beginning portion of the TTI (or subframe). Figure 12 The third accompanying figure illustrates a portion of the TTI (or subframe) where symbols are cleared at the beginning and end of the subframe. In this case, the time segment during which signal transmission is excluded from the normal TTI is called the transmission gap (TX gap).

[0195] Although Figure 12 The invention is explained based on DL (Low-Low) operations, but the invention is also equally applicable to UL (Low-Low) operations. For example, Figure 12 The TTI structure shown can also be used to send PUCCH or PUSCH.

[0196] 3. New Radio Access Technology System

[0197] With an increasing number of communication devices demanding greater communication capacity, there is a need for enhanced mobile broadband communications on top of existing radio access technologies (RATs). Furthermore, large-scale machine-type communications (MTC) capable of providing various services anytime, anywhere by connecting multiple devices and objects is also being considered. Communication system designs for services / UEs sensitive to reliability and latency are also under discussion.

[0198] Therefore, the introduction of new radio access technologies considering enhanced mobile broadband communications, massive MTC, and ultra-reliable low-latency communications (URLLC) is being discussed. In this invention, for simplicity, this technology will be referred to as New RAT or NR (New Radio).

[0199] 2.1. Self-contained subframe structure

[0200] Figure 13 This is a diagram illustrating a self-contained subframe structure applicable to the present invention.

[0201] In the NR system applicable to this invention, the following is proposed: Figure 13 The self-contained subframe structure shown is intended to minimize data transmission latency in TDD systems.

[0202] exist Figure 13 In the diagram, shaded areas (e.g., symbol index = 0) represent downlink control areas, and black areas (e.g., symbol index = 13) represent uplink control areas. Other areas (e.g., symbol indices = 1 to 12) can be used for either downlink or uplink data transmission.

[0203] In this structure, DL and UL transmissions can be performed sequentially within a single subframe. Furthermore, DL data can be transmitted and received within a single subframe, and the UL ACK / NACK used for it can be transmitted and received within the same subframe. As a result, this structure reduces the time spent retransmitting data in case of transmission errors, thereby minimizing the latency of the final data transmission.

[0204] In this self-contained subframe structure, a time slot of a certain length is required to allow the base station and UE to switch from transmit mode to receive mode or vice versa. For this purpose, some OFDM symbols in the self-contained subframe structure during the switch from DL to UL can be designated as guard periods (GP).

[0205] Although the case of a self-contained subframe structure including both DL control regions and UL control regions has been described above, control regions can be selectively included in a self-contained subframe structure. In other words, the self-contained subframe structure according to the present invention can include not only the case containing both DL control regions and UL control regions, but also the case containing only one of the DL control regions or UL control regions, such as... Figure 13 As shown in the image.

[0206] For simplicity, the frame structure configured above is referred to as a subframe, but this configuration can also be called a frame or a time slot. For example, in an NR system, a unit consisting of multiple symbols can be called a time slot. In the following description, subframes or frames can be replaced with the time slots described above.

[0207] 2.2. OFDM Parameter Set (Numerology)

[0208] NR systems use OFDM transmission schemes or similar transmission schemes. Here, NR systems can typically have OFDM parameter sets as shown in Table 3.

[0209] [Table 3]

[0210] parameter value Subcarrier spacing (Δf) 75kHz OFDM symbol length 13.33us Cyclic prefix (CP) length 1.04us / 0.94us System BW 100MHz Number of available subcarriers 1200 Subframe length 0.2ms Number of OFDM symbols per subframe 14 symbols

[0211] Alternatively, the NR system may use an OFDM transmission scheme or a similar transmission scheme, and may use an OFDM parameter set selected from several OFDM parameter sets shown in Table 4. Specifically, as disclosed in Table 4, the NR system may take the 15 kHz subcarrier spacing used in the LTE system as a basis, and use OFDM parameter sets with subcarrier spacings of 30, 60, and 120 kHz as multiples of the 15 kHz subcarrier spacing.

[0212] In this context, the cyclic prefix, system bandwidth (BW), and number of available subcarriers disclosed in Table 4 are merely examples applicable to the NR system according to the present invention, and their values ​​may depend on the implementation method. Typically, for a subcarrier spacing of 60 kHz, the system bandwidth can be set to 100 MHz. In this case, the number of available subcarriers can be greater than 1500 and less than 1666. Furthermore, the subframe length and the number of OFDM symbols per subframe disclosed in Table 3 are merely examples applicable to the NR system according to the present invention, and their values ​​may depend on the implementation method.

[0213] [Table 3]

[0214]

[0215] 3.3. Simulated Beamforming

[0216] In millimeter-wave (mmW) systems, due to the short wavelength, multiple antenna elements can be mounted in the same area. That is, considering a wavelength of 1 cm in the 30 GHz band, a total of 100 antenna elements can be mounted in a 5x5 cm panel with a spacing of 0.5λ (wavelength) in a 2D array. Therefore, in mmW systems, coverage or throughput can be improved by increasing beamforming (BF) gain through the use of multiple antenna elements.

[0217] In this configuration, each antenna element can include a transceiver unit (TXRU) that enables adjustment of the transmit power and phase of each antenna element. By doing so, each antenna element can perform independent beamforming based on frequency resources.

[0218] However, mounting the TXRU across all approximately 100 antenna elements is cost-inefficient. Therefore, a method has been considered that uses analog phase shifters to map multiple antenna elements to a single TXRU and adjust the beam direction. However, this method is disadvantageous because frequency-selective beamforming is impossible, as only one beam direction is generated across the entire frequency band.

[0219] To address this issue, a hybrid BF with B TXRUs (Turn-Tube Units) and fewer than Q antenna elements can be considered as an intermediate form between digital and analog BF. In the case of a hybrid BF, the number of beam directions that can be transmitted simultaneously is limited to B or fewer, depending on how the B TXRUs and Q antenna elements are connected.

[0220] Figure 14 and Figure 15 This is a diagram illustrating a representative connection method for connecting the TXRU to the antenna element. Here, the TXRU virtualization model represents the relationship between the TXRU output signal and the antenna element output signal.

[0221] Figure 14 A method for connecting TXRUs to a subarray is shown. Figure 14 In this configuration, an antenna element is connected to a TXRU.

[0222] at the same time, Figure 15 A method for connecting all TXRUs to all antenna elements is shown. Figure 15In this configuration, all antenna elements are connected to all TXRUs. In this case, separate additional units are needed to connect all antenna elements to, for example... Figure 15 All TXRUs shown in the image.

[0223] exist Figure 14 and Figure 15 In this context, W indicates the phase vector weighted by the analog phase shifter. That is, W is the primary parameter determining the direction of the analog beamforming. In this case, the mapping relationship between the CSI-RS antenna port and the TXRU can be 1:1 or one-to-many.

[0224] Figure 14 The disadvantage of the configuration shown is that achieving beamforming focusing is difficult, but it has the advantage that all antennas can be configured at low cost.

[0225] on the contrary, Figure 15 The configuration shown is advantageous because beamforming focusing can be easily achieved. However, it has the disadvantage of high cost because all antenna elements are connected to the TXRU.

[0226] 4. Proposed Implementation Examples

[0227] The aforementioned NR system has considered using frequency bands above 6 GHz as well as frequency bands below 6 GHz. Furthermore, the NR system has also considered using both unlicensed and licensed frequency bands. Therefore, this invention proposes an operation method for an NR system operating in an unlicensed frequency band (and more specifically, in the 5 GHz unlicensed frequency band).

[0228] In the 5GHz unlicensed frequency band, LTE-A Pro and LAA ( / eLAA) systems, as well as IEEE 802.11a / n / ac ( / ax) systems, have already been deployed. Therefore, if an NR system to which this invention can be applied is configured to operate in the corresponding frequency band, the NR system should be designed not only by considering fair and efficient coexistence with other systems, but also by considering coexistence with the NR systems of other network operators.

[0229] Meanwhile, the legacy LTE version 13LAA system has configured its channel grid and bandwidth with consideration for coexistence with Wi-Fi systems. Specifically, the center frequency has been allowed a maximum variation of 200kHz based on a predefined 20MHz-based Wi-Fi channel, and the bandwidth has been equally set to 20MHz. Furthermore, Talk-After-Listen (LBT) operation (or channel access operation) has been configured to be performed based on 20MHz. Moreover, the LAA system has applied the same subcarrier spacing of 15kHz as the LTE system.

[0230] If the 5GHz band operation is defined for an NR system to which the present invention can be applied, taking into account the above considerations, then the 20MHz-based LBT method and a 15kHz subcarrier spacing can be applied to the NR system. Alternatively, an NR system to which the present invention can be applied can consider introducing a subcarrier spacing higher than 15kHz. This reduces the symbol / subframe time length and thus minimizes the actual transmission time of reserved signals that only occupy the channel. Furthermore, when a subcarrier spacing higher than 15kHz is introduced, a band higher than 20MHz can also be considered.

[0231] Therefore, this invention proposes a method for transmitting DL / UL channels / signals when both a subcarrier spacing above 15 kHz and a frequency band above 20 MHz are introduced into an NR system operating in the 5 GHz unlicensed frequency band.

[0232] Discovery Signals (DRS) have been introduced to measure deactivated small cells in legacy LTE(-A) systems without additional traffic. DRS can be configured to be transmitted periodically every tens of milliseconds (ms). Therefore, the eNB can periodically configure the UE's Discovery Measurement Timing (DMTC) on a 6ms basis, and the UE can receive the DRS within the corresponding DMTC window and then use the received DRS for coarse synchronization, cell detection, RRM measurements, etc. In this case, RRM measurements can include a Reference Received Power (RSRP) measurement as the signal strength from the desired cell and a Reference Received Quality (RSRQ) measurement as the ratio of the signal strength from the desired cell to interference, noise, etc.

[0233] DRS can include signals such as primary synchronization signal (PSS), secondary synchronization signal (SSS), cell-specific reference signal (CRS), etc., and if configured, DRS can further include channel state information reference signal (CSI-RS).

[0234] An NR system to which this invention can be applied should be able to support serving cell measurements and (intra-frequency or inter-frequency) neighboring cell measurements to handle handovers caused by UE mobility. For this purpose, similar to the DRS of an LTE system, a signal can be defined for the NR system for cell search and RRM measurements. Hereinafter, this signal is referred to as the NR-DRS, which is distinct from the DRS of an LTE system.

[0235] NR-DRS can include all or some of the following signals: PSS, SSS, beamforming RS (BRS), beamfining RS (BRRS), and CSI-RS. Additionally, the gNB can be configured with a time window in which NR-DRS measurements will be performed. In the following text, this time window is referred to as NR-DMTC, which is distinct from the DMTC of the LTE system. NR-DMTC can be configured with a period of tens (or hundreds) milliseconds.

[0236] In an NR system to which this invention can be applied, multiple antennas (specifically, in the millimeter-wave band) can be used to transmit NR-DRS via beamforming. In other words, the transmitter can use an analog beam to transmit a portion of the signal covering the entire cell in each time unit and use multiple time units to perform omnidirectional beam scanning of the analog beam to cover the entire cell.

[0237] Meanwhile, in legacy LTE systems, the UE can transmit a Physical Random Access Channel (PRACH) to achieve uplink synchronization during initial access or in RRC_CONNECTED / RRC_IDLE mode. Similarly, in NR systems to which this invention can be applied, the UE can transmit a random access preamble for the same purpose. Specifically, the random access preamble can be transmitted or received via beamforming (specifically, in millimeter-wave mode).

[0238] Therefore, this invention proposes a method for efficiently transmitting NR-DRS and random access preamble in unlicensed frequency bands based on random access.

[0239] Although a subframe (SF) is considered in this document as an example of a time unit with a predetermined length, the corresponding configuration can also be replaced by at least one time slot, transmission time interval (TTI), or symbol of the NR system.

[0240] 4.1. DL / UL Channel / Signal Transmission Method

[0241] The DL / UL channel / signal transmission method proposed in this invention can be classified based on the following two methods.

[0242] Method 1: Set the system bandwidth to 20MHz, regardless of the subcarrier spacing.

[0243] Method 2: The system bandwidth can be higher than 20MHz.

[0244] The following text will describe the specific operations for each of the two methods in detail.

[0245] 4.1.1. Method 1 (Set the system bandwidth to 20MHz, regardless of subcarrier spacing)

[0246] According to this method, the system bandwidth can be set to 20MHz, regardless of the subcarrier spacing. However, the subcarrier spacing can only be increased in the first (or some) time units (e.g., SF) of the transmitted pulse to minimize the transmission time of the reserved signal that only occupies the channel. Specifically, if a base station or terminal is operating in an NR system to which this invention can be applied and is unable to initiate data transmission at the start of a subframe boundary due to an LBT failure, the base station or terminal can attempt to transmit a signal with a transmission time interval (TTI) shorter than the subframe duration before attempting data transmission in the next subframe. Alternatively, if a base station or terminal is operating with a subcarrier spacing of f0 (e.g., 15kHz) and is unable to initiate data transmission at the start of a subframe boundary due to an LBT failure, the base station or terminal can transmit signals in shorter subframes by applying a subcarrier spacing greater than f0 (e.g., 30 or 60kHz).

[0247] Figure 16 The illustration shows a configuration in which an NR-based base station (i.e., a next-generation node B (gNB)) transmits signals by configuring a shorter TTI than the typical TTI or by increasing the subcarrier spacing while operating with a subcarrier spacing of approximately 15 kHz.

[0248] In this specification, the base station operating in the NR system is referred to as a gNB, which is distinct from the eNB. It is an example of an LTE base station, but in some embodiments, the gNB can be replaced by an eNB.

[0249] like Figure 16 As shown, when operating with a subcarrier spacing of approximately 15 kHz, the gNB can configure a TTI (e.g., 2 or 4 symbols) shorter than the duration of a time unit (e.g., a subframe or time slot) at the start of the transmission pulse (i.e., 1 ms or 0.5 ms) to minimize the transmission time used only for signals occupying the channel, and then transmit the DL signal. Alternatively, when operating with a subcarrier spacing of approximately 15 kHz, the gNB can change the subcarrier spacing to 60 kHz and then use subframes shorter than 1 ms (e.g., 0.25 ms) to transmit the DL signal until the next 15 kHz subframe boundary (i.e., SF#N2).

[0250] This signal transmission method can be applied similarly to the start and end points of a transmission pulse. Specifically, when the intention is to apply the signal transmission method to the end point of a transmission pulse, the application of the signal transmission method can be indicated by a previous subframe.

[0251] In addition, the signal transmission method can be applied not only to DL transmission, but also to UL transmission in the same way. Furthermore, in the case of UL transmission, the DCI can indicate to the UE whether to apply the corresponding method.

[0252] However, as an exception, it may not be necessary to change the parameter set, such as the subcarrier spacing reserved for the transmission of some of the signals below in a subframe. Therefore, the above signaling method may not be applicable to subframes in which some of the signals below will be transmitted.

[0253] - Synchronization signals (e.g., PSS, SSS, etc.)

[0254] - Beamforming-related signals (e.g., beamforming reference signals, beam thinning reference signals, etc.)

[0255] -RRM measurement-related signals (e.g., beamforming reference signals)

[0256] -CSI measurement-related signals (e.g., CSI-RS)

[0257] Alternatively, if the above signal transmission method is applied to a subframe that reserves the transmission of some of the signals mentioned above, rules can be established to discard some of the signals mentioned above that are to be transmitted in the corresponding subframe. For example, the above signal transmission method may not be applied to subframes that include PSS / SSS configured to be transmitted at a period of 5ms. Alternatively, if the corresponding method is applied, PSS / SSS may not be transmitted in the subframe.

[0258] In LTE systems, updates to the contention window size (CWS) for DL / UL transmission are defined based on the HARQ-ACK information corresponding to the reference subframe. Furthermore, because... Figure 12 If some subframes can be applied to DL / UL, then reference subframes for some subframes can also be considered.

[0259] In this case, if a short TTI (sTTI) or a subframe with a large subcarrier spacing is transmitted at the beginning of the transmission pulse as proposed in this invention, the definition of the reference subframe can be changed.

[0260] For example, when sending sTTI,

[0261] 1> Only the first STTI can be defined as the reference subframe.

[0262] 2> All sTTIs in the corresponding subframe can be defined as reference subframes.

[0263] 3> The next subframe and all STTIs in the corresponding subframe can be defined as the reference subframe, or

[0264] 4> The next subframe can be defined as a reference subframe other than the subframe that includes sTTI.

[0265] In the following text, reference will be made to Figure 16 Description example. When as Figure 16 The diagram shows how to transmit and receive signals in subframes with a large subcarrier spacing.

[0266] A> Only SF#2 can be defined as the reference subframe.

[0267] B> All SF#2 / 3 / 4 within the duration of SF#N1 can be defined as reference subframes.

[0268] C> SF#N2 and SF#2 / 3 / 4 during the duration of SF#N1 can be defined as reference subframes, or

[0269] In addition to SF#2 / 3 / 4 within the duration of SF#N1, SF#N2 corresponding to the next subframe can also be defined as the reference subframe.

[0270] 4.1.2. Method 2 (Allows system bandwidth higher than 20MHz)

[0271] 4.1.2.1 First Method

[0272] Figure 17 The diagram illustrates a configuration where the bandwidth of the signal transmitted by a base station or terminal changes as the subcarrier spacing changes.

[0273] When Figure 17 As shown, introducing a 60kHz subcarrier spacing reduces the length of a time unit (e.g., a subframe) by 1 / 4 compared to a 15kHz subcarrier spacing. Additionally, the system bandwidth can be set to 80MHz, which is four times larger than a 15kHz subcarrier spacing.

[0274] In this scenario, the base station or terminal can perform LBT on each 20MHz subband and transmit data only from the subbands where LBT was successful. For ease of description, assume a subband is 20MHz and a constituent carrier (CC) has a bandwidth of 80MHz. However, generally, a subband can refer to the bandwidth where the base station and terminal can independently perform LBT, and the bandwidth of a CC can be configured differently depending on the subcarrier spacing and system characteristics.

[0275] 4.1.2.1.1. Method for configuring the control channel

[0276] Since the data / signal transmission of each subband is essentially determined based on the LBT results at the base station or terminal, the control channel can be configured to prevent it from overlapping with multiple subbands. In other words, when transmitting an NR-PDCCH (i.e., a DL control channel carrying DL / UL scheduling information in the NR system) on resources of multiple subcarriers in an NR system to which this invention can be applied, there may be a limitation that all subcarriers and resources constituting an NR-PDCCH should belong to the same subband.

[0277] Additionally, if a search space and number of BD rounds are configured for each subframe in which each UE should perform blind detection (BD) on the NR-PDCCH, then the search space and number of BD rounds will be different for each subband.

[0278] For example, similar to legacy LTE systems, the number of BD candidates for the NR-PDCCH can be configured for each aggregation level (AL). Therefore, the number of BD candidates for the NR-PDCCH can essentially be set to perform BD 6 / 6 / 2 / 2 times respectively when the AL is 1 / 2 / 4 / 8. In this case, BD can be configured to perform 2 / 2 / 0 / 0 times for each AL in subband #1, 1 / 1 / 1 / 1 times for each AL in subband #2, 2 / 2 / 0 / 0 times for each AL in subband #3, and 1 / 1 / 1 / 1 times for each AL in subband #4.

[0279] As another example, when AL is 1 / 2 / 4 / 8, BD can be configured to perform 6 / 6 / 2 / 2 times for each subband (or 4 / 4 / 1 / 1 times, which are reduced equally).

[0280] 4.1.2.1.2. Method for transmitting data channels corresponding to NR-PDCCH

[0281] As described in Section 4.1.2.1, when establishing a constraint that all resources constituting an NR-PDCCH should be included in the same subband by considering the LBT results resulting from the characteristics of the unlicensed frequency band, there may be a constraint that the data channel corresponding to the NR-PDCCH should be included in the same subband. In this case, because the HARQ-ACK for each subband is transmitted separately, the CWS value for each subband can be updated, and LBT can be performed separately.

[0282] Alternatively, if, as described in Section 4.1.2.1, despite the restriction that all resources constituting an NR-PDCCH should be included in the same subband, regardless of whether the subband actually transmitting the NR-PDCCH can transmit the corresponding data channel in any subband, the base station and terminal may have difficulty updating the CWS value for each subband.

[0283] In this scenario, it might be necessary for all subbands to have a common CWS value, rather than distinct CWS values. Specifically, the base station and terminal can update the CWS value based on the HARQ-ACK of the active subband, perform LBT by extracting (or selecting) a random backoff value for each subband based on the common CWS value, and then attempt transmission in the specific subband. In this way, the base station and terminal can initialize all backoff counter values.

[0284] Generally, a gNB can perform a series of processes on the DL data to be transmitted in SF#n, such as transport block (TB) generation, encoding, scrambling, interleaving, and resource element (RE) mapping at least in SF#n-1. However, if the actual transmitted subband changes according to the results of LBT performed immediately before the boundary of SF#n, the gNB may have difficulty performing DL data transmission based on the transmitted subband.

[0285] To address the above issues, a method of performing RE mapping in advance can be considered by dividing the same TB on a sub-band basis. For example, in the case of frequency-domain-first RE mapping, the base station or terminal can first perform RE mapping for all symbols in a specific sub-band across all frequencies, and then continue performing RE mapping in other sub-bands. In this case, if the base station or terminal is configured to transmit signals in a specific sub-band based on the LBT results, the base station or terminal can only transmit signals in sub-bands that would have been impossible in previously configured subframes by truncating the transmission.

[0286] 4.1.2.1.3. RSSI Measurement Method

[0287] In LTE Release 13LAA systems, UEs have been configured to perform RSSI measurements separately for carrier selection in unlicensed bands and report average RSSI values ​​and channel occupancy (i.e., the percentage of samples with RSSI values ​​above a threshold). For this purpose, an RSSI Measurement Timing Configuration (RMTC) has been introduced for the corresponding measurements, and the RMTC is set to perform DRS transmission independently of the Discovery Signal (DRS) Measurement Timing Configuration (MTC).

[0288] For the same or similar reasons, RMTC and RSSI measurements can be incorporated into NR to which this invention can be applied.

[0289] However, in NR systems to which this invention can be applied, the RMTC can perform and report RSSI measurements (e.g., average RSSI values ​​and / or channel occupancy) differently or independently for each subband. This is because interference from Wi-Fi and LAA systems can be measured differently in each subband.

[0290] 4.1.2.1.4. UL Resource Allocation Method

[0291] In the LTE Release 14e LAA system, a new method has been introduced to perform UL transmission for UEs in unlicensed frequency bands. For this purpose, an RB-interleaved PUSCH transmission method has been applied by considering adjustments related to occupied bandwidth and power spectral density.

[0292] RB-interleaved PUSCH transmission refers to the allocation of PUSCH resources on an interleaved basis. For example, a 100-RB system (i.e., a system bandwidth of 20 MHz) can consist of 10 interleavings, each consisting of 10 RBs. Alternatively, a 50-RB ​​system (i.e., a system bandwidth of 10 MHz) can consist of 5 interleavings, each consisting of 10 RBs. In this case, the RBs constituting each interleaving can be evenly distributed with 10 RB intervals. For RB-interleaved PUSCH transmission, PUSCH resources can essentially be allocated to the UE on an interleaved basis. Specifically, PUSCH resources can be allocated to the UE on a 10-RB, 20-RB, or 30-RB basis.

[0293] Similarly, UL resources in unlicensed frequency bands can be scheduled to at least one UE in an NR system to which this invention can be applied. In this case, if the NR base station can share its occupied channel occupancy with its associated UE, the NR base station can only restrict the UE to perform UL transmission in the subband where the NR base station has successfully performed LBT.

[0294] To this end, the NR base station can notify the UE of subbands that allow UL channel transmission in addition to RB-interleaved PUSCH transmission. For example, if the NR base station intends to share the DL channel occupancy protected by subbands #1 / 2 / 3 of SF#7 / 8 / 9 / 10 with different UEs, the NR base station can send a message to the UE indicating that UL transmission (e.g., PUSCH, PUCCH, PRACH, etc.) should be attempted in subbands #1 / 2 / 3 instead of the entire system bandwidth. This message can be sent by a UE-specific DCI or a cell-shared (or UE group-specific) DCI.

[0295] 4.1.2.1.5. Method for configuring resources for NR-PRACH (the physical channel carrying a preamble in the NR system)

[0296] As described in Section 4.1.2.1.1, since the transmission of each subband can be determined based on the LBT result, a PRACH transmission resource can be configured so that it does not overlap with multiple subbands.

[0297] 4.1.2.1.6. Method for configuring SRS transmit bandwidth

[0298] In LTE Release 14e LAA systems, SRS can only be transmitted in the last symbol of a specific SF, as in legacy LTE systems. Specifically, only wideband SRS transmission is permitted. For example, in a 100-RB system, SRS can be distributed across the central 96 RBs. In this case, the number of combs used can be either 2 or 4, depending on the configuration.

[0299] As described in Section 4.1.2.1.4, when an NR base station is able to share its occupied channel occupancy with its associated UE, the base station can only restrict the UE to perform UL transmission in the subband where the base station has successfully performed LBT. In other words, SRS transmission can only be performed in a limited manner in the subband where the base station has successfully performed LBT, or in some subbands other than wideband. Therefore, additional signaling regarding SRS bandwidth may be required. This information can be transmitted by a UE-specific DCI or a cell-shared (or UE group-specific) DCI.

[0300] 4.1.2.2. Second Method

[0301] When the homomorphically transmittable subband changes according to the LBT result described in the first method, the complexity of the TB configuration method at the gNB / UE, the PDCCH BD at the UE, etc., may increase. Considering this increased complexity, the gNB / UE can only be configured to attempt DL / UL transmission across the entire system bandwidth if the LBT is successful across the entire system bandwidth. Otherwise, the gNB / UE can be configured to attempt DL / UL transmission. Alternatively, when the LBT fails, the gNB / UE can only be configured to attempt DL / UL transmission within a specific set of subbands.

[0302] Figure 18 The diagram illustrates a configuration where a set of transmittable subbands is configured in each bandwidth, and signals are transmitted in each subband set based on the LBT results. Although Figure 18 Only the DL case is shown, but Figure 18 The configuration shown can be applied to UL applications.

[0303] Specifically, such as Figure 18As shown, the transmittable subband sets can be configured with bandwidths of 20MHz, 40MHz, and 80MHz respectively. Next, the base station can only attempt DL transmission within the allowable subband set selected based on the LBT results.

[0304] 4.1.2.2.1. Signals / channels that can be transmitted only in the 20MHz main and subband.

[0305] According to the present invention, it is only possible to transmit some or all of the following signals / channels in the 20MHz main and subband.

[0306] - Synchronization signals (e.g., PSS, SSS, etc.)

[0307] - Beamforming-related signals (e.g., beamforming reference signals, beam thinning reference signals, etc.)

[0308] -RRM measurement-related signals (e.g., beamforming reference signals)

[0309] - Broadcast information (e.g., PBCH, system information, paging, random access response, transmit pulse length, channel occupancy time, main 20MHz subband information, etc.)

[0310] - Random Access Preamble

[0311] - Scheduling request

[0312] 4.1.2.3. Methods for configuring subband sets

[0313] The set of subbands that are allowed to transmit signals can be configured via L1 or higher-level signaling (e.g., RRC signaling). In this case, gNBs provided by the same operator can be configured with the same primary 20MHz subband. Additionally, the DL subband set may differ from the UL subband set.

[0314] 4.1.2.4.TB Configuration Method

[0315] According to the present invention, a method for configuring a TB for DL / UL transmission can be determined as follows. First, the gNB / UE can configure a TB individually in each transmittable subband set, perform LBT, and attempt DL / UL transmission by selecting one of the configured TBs in each subband set where the LBT is successful.

[0316] 4.2 NR-DRS Transmission Method

[0317] As described above, NR-DRS can be transmitted over multiple time units via beamforming or beam scanning.

[0318] Figure 19The illustration shows the incident point of the analog beam for NR-DRS transmission for each symbol in a subframe according to the present invention.

[0319] Reference Figure 19 The left image ( Figure 19 (a)) The gNB can perform NR-DRS transmission by forming different beams in each symbol of a subframe consisting of 14 symbols. In this case, the PSS / SSS / BRS (PBCH) constituting the NR-DRS can be transmitted distributed across the symbols.

[0320] Alternatively, refer to Figure 19 The right image ( Figure 19 (b) The gNB can perform NR-DRS transmission on multiple symbols using the same beam. In this case, NR-DRS including PSS / SSS can be transmitted in the first symbol of two symbols configured with the same beam, and NR-DRS including BRS ( / PBCH) can be transmitted in the second symbol. Alternatively, the same sequence can be duplicated and transmitted in multiple symbols. Furthermore, for transmission, different SFs and different parameter sets can be applied (e.g., the symbol length can be increased by applying smaller subcarrier spacing).

[0321] In addition to the SF transmitting DRS on licensed or unlicensed carriers (via L1 signaling or higher-layer signaling), this NR-DRS configuration method (or whether the measurement should be performed using only one sample (one-time measurement) or by accumulating multiple time samples) can also be indicated by a specific SF. For example, the NR-DRS transmitted in a particular symbol may include information about the cell / transmit and receive point (TRP) / beam ID and / or symbol / SF / SF group index.

[0322] In the following text, for ease of description, it will be as follows: Figure 19 The SF that transmits NR-DRS is called the DRS SF. Additionally, the symbol area used to transmit NR-DRS is called the DRS timing.

[0323] Figure 19 The example shown is an NR-DRS transmitted on all symbols of the DRS SF. However, in another example, the NR-DRS can be configured not to be transmitted on some symbols of the DRS SF (e.g., the first two or the last two symbols), even if the DRS timing consists of 14 symbols.

[0324] 4.2.1. First NR-DRS Transmission Method

[0325] DRS SFs can be configured with predetermined periods. This section describes in detail the NR-DRS transmission method when the number of DRS SF candidates that can be transmitted in each time period is 1.

[0326] (1) If the gNB fails to perform LBT before sending the DRS SF (i.e., if the channel is busy), the gNB may not perform the transmission in the corresponding DRS SF.

[0327] (2) Even if the gNB fails to transmit the DRS SF in terms of LBT, the gNB can still perform LBT. Afterwards, the gNB can attempt to transmit from the time (or symbol) of successful LBT to the next SF boundary.

[0328] Figure 20 The illustration shows an NR-DRS transmission method according to an embodiment of the present invention.

[0329] like Figure 20 As shown, if the gNB fails to perform LBT before the start of a symbol but succeeds immediately after symbol #2, the gNB can perform NR-DRS transmission from symbol #2 to symbol #13. In this case, as... Figure 20 The left image ( Figure 20 As shown in (a)), the NR-DRS in symbol #0 can be sent in symbol #2. Alternatively, as Figure 20 As shown in the right figure (as in 20(b)), NR-DRS transmission can be performed after the NR-DRS in the truncated symbol #0 / 1.

[0330] If the NR-DRS contains information about symbols, SFs, and / or SF group indexes, it may require, for example... Figure 20 The right image ( Figure 20 (b) shows that transmission is performed by truncating the NR-DRS. This is because if the NR-DRS transmission is as follows... Figure 20 The left image ( Figure 20 If the operation is performed as shown in (a)), the UE can observe that the beam direction of the NR-DRS changes according to the transmission start time of the gNB.

[0331] In addition, such as Figure 19 The right image ( Figure 19 As shown in (b), when NR-DRS is transmitted on multiple symbols in the same direction, if the gNB cannot transmit NR-DRS in some symbols according to the LBT result, the gNB can discard the entire NR-DRS transmission in the corresponding beam direction. In other words, if the gNB fails to perform LBT before symbol #8 (i.e., beam #4) but succeeds in LBT before symbol #9 (i.e., beam #4), the gNB may not perform NR-DRS transmission in symbol #9.

[0332] 4.2.2. Second NR-DRS Transmission Method

[0333] Section 4.2.1 has described the NR-DRS transmission method when the number of DRS SF candidates that can be transmitted in each time period is 1. However, the number of DRS SF candidates that can be transmitted in each time period can be set to 2 or more to increase the NR-DRS transmission probability. Therefore, this section will describe the NR-DRS transmission method when there are multiple DRS SF candidates.

[0334] (1) Similar to (1) of the first NR-DRS transmission method described above, if the gNB fails to perform LBT before transmitting the DRS SF (i.e., if the channel is busy), the gNB may not perform transmission in the corresponding DRS SF, but will perform LBT again before transmitting the next DRS SF.

[0335] (2) Similar to (2) of the first NR-DRS transmission method described above, even if the gNB fails to perform LBT during the transmission of the DRS SF, the gNB can continue to perform LBT. Afterwards, the gNB can attempt to transmit from the time (or symbol) of successful LBT to the next SF boundary.

[0336] (3) Since the maximum area that can be transmitted for NR-DRS can be larger than the DRS timeout, the gNB can be allowed to continuously transmit from the symbol where the LBT was successful until the DRS timeout ends. In other words, the gNB can continuously transmit NR-DRS from the symbol where the LBT was successful until the DRS timeout ends.

[0337] Figure 21 The illustration shows an NR-DRS transmission method according to another embodiment of the present invention.

[0338] If gBN succeeds in LBT before symbol #2, then gNB can proceed as follows: Figure 21 The left image ( Figure 21 (a)) shows that beams #0 through #13 are used to perform NR-DRS transmission starting from symbol #2. Alternatively, if the gNB successfully performs LBT before symbol #2, the gNB can use beams #2 through #13 to perform NR-DRS transmission starting from symbol #2 of the first SF, and then continue NR-DRS transmission in symbols #0 and #1 using beams #0 and #1 respectively.

[0339] In this case, if the NR-DRS contains information about symbols, SFs, and / or SF group indexes, it may be necessary to... Figure 21 The right image ( Figure 21 (b) shows the NR-DRS sent after the cyclic rotation.

[0340] In addition, such as Figure 19 The right image ( Figure 19 As shown in (b), when NR-DRS is transmitted on multiple symbols in the same direction, if the gNB is unable to transmit NR-DRS in some symbols according to the LBT result, the gNB may discard the entire NR-DRS transmission in the corresponding beam direction.

[0341] (4) When NR-DRS transmission is performed as described in Figure (3), multiplexing of the DL / UL channels on the two SFs is not required. In other words, multiplexing with another DL / UL channel is not allowed in an SF that includes NR-DRS.

[0342] In order to use resources more effectively, such as Figure 22 As shown, NR-DRS transmission can be allowed until the next SF boundary or a predetermined symbol area.

[0343] Figure 22 The illustration shows an NR-DRS transmission method according to a further embodiment of the present invention.

[0344] like Figure 22 As shown, NR-DRS can be transmitted on more than 14 symbols. In this case, as... Figure 22 The top image ( Figure 22 As shown in (a)), NR-DRS can be transmitted from the LBT's successful symbols in the beam directions of beams #0 to #13. Alternatively, as Figure 22 base map ( Figure 22 As shown in (b), NR-DRS can be transmitted from the incident point of the beam corresponding to the symbol of LBT success in a predetermined order of beam direction.

[0345] (5) When the number of DRS SF candidates is 2 or more, different NR-DRS transmission methods can be applied based on the location of the SF in which the gNB successfully performs LBT. For example, if the gNB successfully performs LBT in the last SF among the DRS SF candidates, the gNB can use method (1) or (2) to perform NR-DRS transmission. On the other hand, if the gNB successfully performs LBT in any SF among the DRS SF candidates other than the last SF, the gNB can use method (3) or (4) to perform NR-DRS transmission.

[0346] If the gNB is configured to use method (1) for NR-DRS transmission because LBT was successfully performed in the last SF among the DRS SF candidates but failed to be performed at the start boundary of the last SF, then the gNB may no longer perform LBT for NR-DRS transmission in the corresponding time period.

[0347] In the first and second NR-DRS transmission methods described above, the UE may need information about the symbol of the DRS SF that the gNB actually begins NR-DRS transmission. For example, the UE may need the above information to search for the optimal beam or perform RRM measurements.

[0348] Next, the gNB can send information indicating the NR-DRS start symbol of the most recent DRS SF in a SF other than the DRS SF on a licensed or unlicensed carrier (via L1 signaling or higher layer signaling).

[0349] Conversely, the UE can report information about the symbol / SF (e.g., cell detection, RRM measurement, optimal beam information, etc.) of the measurement performed by the UE based on the NR-DRS report, which is sent separately from / together with the measurement results.

[0350] 4.3. Random Access Preamble Sending Method

[0351] Section 4.2 has described a method for NR-DRS transmission based on the gNB's successful transmission of NR-DRS by forming a simulated beam. For this purpose, the gNB can be configured to transmit the SF (Self-Programming Streaming Preamble) at predetermined intervals. Additionally, the gNB can form a simulated beam as a receiver and attempt to receive the SF transmitted from a UE present in the cell coverage area by performing receive beam scanning in an omnidirectional manner across multiple time units.

[0352] If the gNB can form a simulated beam in different directions on each symbol, the UE can essentially transmit a random access preamble consisting of a single symbol to the gNB. When transmitting the random access preamble, the UE is unaware of when the gNB's receive beam is optimized to receive the random access preamble. Therefore, the UE can even transmit a random access preamble consisting of a single symbol over multiple symbols, rather than transmitting it within a single symbol.

[0353] In this case, the preamble sequence transmitted by the UE can be configured as follows:

[0354] (1) The sequence can be configured regardless of the index of the symbol / SF that the UE attempts to transmit; or

[0355] (2) The sequence can be configured differently based on the index of the symbol / SF that the UE attempts to send.

[0356] More broadly, when a UE transmits a preamble by forming the same beam, it can transmit the preamble across multiple symbols. For example, the same sequence can be copied and transmitted across multiple symbols. Furthermore, for transmission, different subcarrier spacings and different parameter sets can be applied (e.g., the symbol length can be increased by applying smaller subcarrier spacings).

[0357] 4.3.1. First Random Access Preamble Transmission Method

[0358] When a preamble transmission SF is configured with a predetermined period, the UE can be configured to transmit the preamble if LBT is successfully performed before the boundary of the corresponding SF (or the first symbol reserved for preamble transmission). Otherwise, the UE can be configured to discard the preamble transmission in the corresponding SF.

[0359] Alternatively, even if the UE fails to perform LBT before the boundary of the corresponding SF (or the first symbol reserved for preamble transmission), the UE can continue performing LBT and then transmit the preamble starting from the first symbol where the UE successfully performed LBT. For example, when preamble transmission is reserved for four symbols starting from symbol #0, if the UE fails to perform LBT before symbol #0 / 1 but then successfully performs LBT immediately after symbol #2, the UE can perform preamble transmission from symbol #2 to symbol #X. In this case, X can be set to 3 or 5.

[0360] Additionally, when the sequence of preambles is configured differently based on the index of the symbol / SF to be sent, a preamble can be sent after truncating the preamble(s) to be sent in symbol #0 / 1.

[0361] 4.3.2. Second Random Access Preamble Transmission Method

[0362] When multiple preamble transmission SFs are configured with a predetermined period, the UE can transmit the preamble from the time when the UE successfully performs LBT to the next SF. For example, when preamble transmission is reserved from symbol #0 to symbol #14, if the UE fails to perform LBT before the start of symbol #0 / 1 but then successfully performs LBT immediately after symbol #2, the UE can perform preamble transmission from symbol #2 to the next SF for symbol #2.

[0363] Additionally, when the sequence of preambles is configured differently based on the index of the symbol / SF to be sent, a preamble can be sent after truncating the preamble(s) to be sent in symbol #0 / 1.

[0364] Furthermore, although multiple preamble transmission SFs are configured with predetermined periods, the first random access preamble transmission method can be applied to each of the SFs. Alternatively, the first random access preamble transmission method can only be applied if the UE successfully performs LBT in the last of the multiple SFs.

[0365] 4.3.3. Third Random Access Preamble Transmission Method

[0366] Because NR-DRS is transmitted in DL, transmission can be assumed to be performed by the same node. However, because the random access preamble is transmitted in UL, transmission can be attempted by different UEs. For example, if UE1 and UE2 perform LBT to transmit the preamble in the same SF, UE1 may start transmitting first due to different channel states, while UE2 may determine that the channel is busy and therefore may not attempt to transmit the preamble. Therefore, methods for supporting multiplexing of preamble transmission among multiple UEs will be described in detail in this section.

[0367] 4.3.3.1. First Multiplexing Method

[0368] A specific time period (e.g., before the start of the preamble transmission SF configured with a predetermined period) is set as the common sensing period. Afterward, the UE can only perform preamble transmission (without additional LBT) in any symbol of the preamble transmission SF if it successfully performs LBT within the corresponding time period.

[0369] 4.3.3.2. Second Multiplexing Method

[0370] For sensing purposes, a time period can be configured between the preamble SF transmissions.

[0371] Figure 23 The illustration shows a random access preamble transmission method according to an embodiment of the present invention.

[0372] like Figure 23 As shown, preamble transmission is only permitted in even-numbered symbols, while LBT can be performed in odd-numbered symbols. Alternatively, frequency resources can be allocated to odd-numbered symbols for sensing purposes. In this case, the corresponding frequency resources should be used for preamble transmission, and the UE should be able to perform CCA based on the amount of energy detected in the corresponding frequency resources.

[0373] If you plan to Figure 23 If a UE that sends a preamble in symbols #1 / 3 / 5 performs LBT identification in symbol #0 of the first SF, but successfully performs LBT in symbol #2 / 4, then the UE can send a preamble in symbol #3 / 5 of the first SF and try LBT in symbol #1 of the next SF to send the preamble.

[0374] 4.3.3.3. Third Multiplexing Method

[0375] Especially in unlicensed frequency bands, preambles can be transmitted via FDM other than TDM using a 1-symbol structure. In other words, a gNB can receive preambles in all directions without performing receive beamforming.

[0376] 4.3.3.4. Fourth Multiplexing Method

[0377] If the gNB occupies the channel before the preamble transmission (SF) and notifies the UE that intends to perform the preamble transmission of the occupied channel, the UE can attempt to perform the preamble transmission without performing the LBT.

[0378] For example, suppose the preamble transmission SF is SF#n+k (e.g., k=4) and the gNB successfully performs LBT before SF#n. The gNB then notifies the UE of the successful LBT via L1 signaling in SF#n. Upon receiving the L1 signaling, the UE can attempt preamble transmission without performing LBT in SF#n+k (e.g., k=4). In this case, the gNB may need to configure the preamble transmission SF intermittently based on the actual time the gNB successfully performs LBT, rather than configuring it at predetermined intervals.

[0379] In all of the above methods for transmitting the random access preamble, the SF that transmits the random access preamble (hereinafter referred to as RACH SF) may be related to the NR-DRS SF.

[0380] For example, the SF following k SFs from the first (or last) SF in the NR-DRS SF candidate can be set as the first (or last) SF in the RACH SF candidate.

[0381] Furthermore, the index of the preamble symbol / SF / beam to be transmitted in the RACH SF can be determined by the index of the symbol / SF / beam of the signal to be transmitted in the NR-DRS SF. If the SF / symbol at the start of NR-DRS transmission changes according to the LBT result of the gNB, then the position of the SF / symbol at the start of the RACH SF and the index of the preamble symbol / SF / beam to be transmitted in the RACH SF also change according to the SF / symbol at the start of NR-DRS transmission.

[0382] Conversely, the location of the NR-NRS SF and the signals transmitted within it can be determined based on the RACH SF. For example, the SF that appears immediately following the end of the DRS timing in the NR-DRS SF can be set as the RACH SF.

[0383] In summary, the present invention discloses various configurations including the following signal transmission methods.

[0384] First, the present invention discloses a method for transmitting a signal to a second communication node through a first communication node in a wireless communication system that supports unlicensed frequency bands.

[0385] The first communication node can perform a channel access procedure to transmit signals in an unlicensed frequency band. Here, the channel access procedure may include a listen-before-speak (LBT) procedure for checking whether another signal is being transmitted in the unlicensed frequency band by channel sensing on the unlicensed frequency band.

[0386] Subsequently, the first communication node can transmit signals to the second communication node within a predetermined number of symbol periods of the symbols from which the channel access process was successfully completed, by applying independent analog beams to each symbol in the unlicensed frequency band.

[0387] In this case, the analog beams applied to each symbol within a predetermined number of symbol periods from symbols that have successfully entered the channel access process can be analog beams determined sequentially from the first analog beam index in a predetermined order of analog beam indexes to be applied when the first communication node transmits the signal.

[0388] Alternatively, the analog beams applied to each symbol within a predetermined number of symbol periods from symbols from which the channel access process was successful can be analog beams determined sequentially and rotatably from the analog beam indices corresponding to the symbols from which the channel access process was successful, according to a predetermined analog beam index order to be applied when the first communication node transmits the signal.

[0389] Here, the predetermined number of symbol periods can be equal to or less than the symbol area required for signal transmission.

[0390] For example, if the symbol area required for signal transmission is greater than the symbol length from the successful symbol of the channel access process to the time period allocated to the first communication node for the signal transmission, a predetermined number of symbol periods can be set to be equal to the symbol length from the successful symbol of the channel access process to the time period allocated to the first communication node for the signal transmission.

[0391] As another example, if the symbol area required for signal transmission is less than the symbol length from the successful completion of the channel access procedure to the time period allocated to the first communication node for the signal transmission, a predetermined number of symbol periods can be set to be equal to the symbol length of the symbol area required for signal transmission.

[0392] In this invention, the first communication node can be a new RAT (NR) base station or a terminal. Additionally, the second communication node can be a terminal or an NR base station.

[0393] In this invention, the signals transmitted by the first communication node may include synchronization signals and signals for radio resource management (RRM) measurements or random access preambles.

[0394] Specifically, when the signal includes a synchronization signal and a signal for RRM measurement, the first communication node can send information about the symbol indicating a successful channel access process to the second communication node.

[0395] Since each example of the proposed method can be considered as a method of implementing the present invention, it is obvious that each example can be considered as the proposed method. Furthermore, the proposed method can be implemented not only independently but also by combining (or merging) some of the proposed methods. Moreover, rules can be defined such that information about whether the proposed method is applied (or information about the rules associated with the proposed method) should be sent from the base station to the terminal via predefined signals (e.g., physical layer signals, higher layer signals, etc.).

[0396] 5. Equipment Configuration

[0397] Figure 24 This is a diagram illustrating the configuration of the UE and BS that can be implemented by the embodiments proposed in this invention. Figure 24 The embodiments shown illustrate the operation of the UE and base station to implement methods for transmitting and receiving signals.

[0398] UE 1 can act as a transmitter on UL and a receiver on DL. Base station (eNB or next-generation node B (gNB)) 100 can act as a receiver on UL and a transmitter on DL.

[0399] In other words, each of the UE and the base station may include a transmitter (Tx) 10 or 110 and a receiver (Rx) 20 or 120 for controlling the transmission and reception of information, data and / or messages; and an antenna 30 or 130 for transmitting and receiving information, data and / or messages.

[0400] Each of the UE and the base station may also include a processor 40 or 140 for implementing the foregoing embodiments of the present disclosure, and a memory 50 or 150 for temporarily or permanently storing the operations of the processor 40 or 140.

[0401] In this invention, each of the NR base station 100 and the UE 1 can operate as a first or a second communication node. For example, when the NR base station 100 operates as a first communication node, the UE 1 can operate as a second communication node. Conversely, when the UE 1 operates as a first communication node, the NR base station 100 can operate as a second communication node.

[0402] In this scenario, the first communication node can use a processor to execute a channel access procedure for signal transmission in an unlicensed frequency band, and transmit the signal to the second communication node in the unlicensed frequency band by applying an independent analog beam to each symbol from which the channel access procedure is successfully completed for a predetermined number of symbol periods.

[0403] The Tx and Rx of the UE and the base station can perform functions for data transmission, high-speed packet channel coding, OFDM packet scheduling, TDD packet scheduling and / or channelized packet modulation / demodulation. Figure 24 Each of the UE and base station may also include a low-power radio frequency (RF) / intermediate frequency (IF) module.

[0404] Meanwhile, the UE can be any of the following: Personal Digital Assistant (PDA), cellular phone, Personal Communication Service (PCS) phone, Global System for Mobile Communications (GSM) phone, Wideband Code Division Multiple Access (WCDMA) phone, Mobile Broadband System (MBS) phone, handheld PC, laptop PC, smartphone, multi-mode multi-frequency (MM-MB) terminal, etc.

[0405] A smartphone is a terminal that combines the advantages of both a mobile phone and a PDA. It integrates the functions of a PDA, such as fax sending and receiving, internet connectivity, and data communication, into a mobile phone. MB-MM terminals refer to terminals that have multiple built-in modem chips and can operate in either mobile internet systems or other mobile communication systems (such as CDMA 2000, WCDMA, etc.).

[0406] Embodiments of this disclosure can be implemented by various means, such as hardware, firmware, software, or combinations thereof.

[0407] In a hardware configuration, the method according to an exemplary embodiment of the present disclosure can be implemented by 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), processors, controllers, microcontrollers, microprocessors, etc.

[0408] In firmware or software configuration, the methods according to embodiments of this disclosure can be implemented in the form of modules, processes, functions, etc., that perform the above-described functions or operations. Software code can be stored in memory 50 or 150 and executed by processor 40 or 140. The memory is located internally or externally to the processor and can send data to and receive data from the processor by various known means.

[0409] It will be appreciated by those skilled in the art that this disclosure may be practiced in other specific ways besides those set forth herein without departing from the spirit and essential characteristics of this disclosure. The above embodiments are therefore to be construed as illustrative rather than restrictive in all respects. The scope of this disclosure should be determined by the appended claims and their legal equivalents, not by the description, and all changes falling within the meaning and equivalence of the appended claims are intended to be included therein. It will be apparent to those skilled in the art that claims not explicitly recited in each other in the appended claims may be presented in combination as embodiments of this disclosure or included as new claims by subsequent amendments after the filing of this application.

[0410] Industrial applicability

[0411] This disclosure applies to a variety of radio access systems, including 3GPP systems and / or 3GPP2 systems. Beyond these radio access systems, embodiments of this disclosure are applicable to all technical fields where radio access systems find their application. Furthermore, the proposed method can also be applied to mmWave communication using UHF bands.

Claims

1. A method for using a user equipment (UE) in a wireless communication system supporting unlicensed frequency bands, the method comprising: Receive downlink control information (DCI) from base station (BS), which includes resource allocation information for transmission of the Physical Uplink Shared Channel (PUSCH) based on interleaved resource blocks (RBs). The resource allocation information includes information about interleaving and one or more subbands, wherein the one or more subbands are configured within the bandwidth used for the carrier; and The PUSCH is sent to the BS based on the information about the interleaving and the one or more subbands included in the DCI.

2. The method according to claim 1, in, Each of the interleavings comprises 10 RBs evenly distributed at intervals of 10 RBs within the bandwidth.

3. The method according to claim 1, in, Resources for the PUSCH transmission in the frequency domain are allocated in an interleaved manner.

4. The method according to claim 1, in, The resources used for the PUSCH transmission in the frequency domain are determined based on the intersection of the interleaving and the one or more subbands indicated by the resource allocation information.

5. The method according to claim 1, in, The bandwidth is divided into multiple sub-bands in the frequency domain, and a channel access procedure is performed independently for each of the one or more sub-bands.

6. The method of claim 1, further comprising: Receive information from the BS for configuring PUSCH transmission based on the interleaved RBs.

7. A user equipment (UE) for use in a wireless communication system supporting unlicensed frequency bands, the UE comprising: At least one processor; and At least one computer memory, operatively coupled to the at least one processor and configured to, when executed, cause the at least one processor to perform operations including: Receive downlink control information (DCI) from base station (BS), which includes resource allocation information for transmission of the Physical Uplink Shared Channel (PUSCH) based on interleaved resource blocks (RBs). The resource allocation information includes information about interleaving and one or more subbands, wherein the one or more subbands are configured within the bandwidth used for the carrier; and The PUSCH is sent to the BS based on the information about the interleaving and the one or more subbands included in the DCI.

8. The UE according to claim 7, in, Each of the interleavings comprises 10 RBs evenly distributed at intervals of 10 RBs within the bandwidth.

9. The UE according to claim 7, in, Resources for the PUSCH transmission in the frequency domain are allocated in an interleaved manner.

10. The UE according to claim 7, in, The resources used for the PUSCH transmission in the frequency domain are determined based on the intersection of the interleaving and the one or more subbands indicated by the resource allocation information.

11. The UE according to claim 7, in, The bandwidth is divided into multiple sub-bands in the frequency domain, and a channel access procedure is performed independently for each of the one or more sub-bands.

12. The UE according to claim 7, in, The operation further includes receiving information from the BS for configuring PUSCH transmissions based on the interleaved RBs.

13. A method for using a base station (BS) in a wireless communication system supporting unlicensed frequency bands, the method comprising: Perform channel access procedures for multiple sub-bands included in the bandwidth; Based on the results of the channel access procedure, downlink control information (DCI) is sent to the user equipment (UE). The downlink control information (DCI) includes resource allocation information for the UE's Physical Uplink Shared Channel (PUSCH) transmission based on interleaved resource blocks (RBs). The resource allocation information includes information about the interleaving and one or more subbands among the plurality of subbands, wherein the one or more subbands are configured within the bandwidth used for the carrier, and Wherein, the one or more sub-bands are sub-bands where the channel access process was successful; and The PUSCH is received from the UE based on information about the interleaving and the one or more subbands included in the DCI.

14. A base station (BS) for use in a wireless communication system supporting unlicensed frequency bands, the BS comprising: At least one processor; and At least one computer memory, operatively coupled to the at least one processor and configured to, when executed, cause the at least one processor to perform operations including: Perform channel access procedures for multiple sub-bands included in the bandwidth; Based on the results of the channel access procedure, downlink control information (DCI) is sent to the user equipment (UE). The downlink control information (DCI) includes resource allocation information for the UE's Physical Uplink Shared Channel (PUSCH) transmission based on interleaved resource blocks (RBs). The resource allocation information includes information about the interleaving and one or more subbands among the plurality of subbands, wherein the one or more subbands are configured within the bandwidth used for the carrier, and Wherein, the one or more sub-bands are sub-bands where the channel access process was successful; and The PUSCH is received from the UE based on information about the interleaving and the one or more subbands included in the DCI.

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