Signal transmission and reception method for unlicensed band communication and apparatus therefor

Abstract

The present disclosure designs a signal transmission and reception method for unlicensed band communication and an apparatus therefor. A method for transmitting a signal by a terminal operating in an unlicensed band comprises the steps of: receiving configuration information on a carrier from a base station; receiving configuration information for configuring N (wherein N is an integer) guard bands for certain frequency regions of the carrier; signals are transmitted to a base station using a first frequency region belonging to a bandwidth portion of a carrier, wherein the first frequency region may be a region of the frequency region of the bandwidth portion that does not include N guard bands.

Description

[0001] This application is a divisional application of the Chinese invention patent application with application number 202080014598.3, filed on February 6, 2020, which entered the Chinese national phase on August 13, 2021, and invention name “Signal sending and receiving method and device for unlicensed band communication”. Technical Field

[0002] The present invention relates to a method for sending or receiving a signal in a communication system and a device thereof, and more particularly, to a method for sending or receiving a signal through a wide frequency band in a mobile communication system supporting unlicensed band communication and a device therefor. Background Art

[0003] A communication system (hereinafter referred to as a New Radio (NR) communication system) using a higher frequency band (e.g., a frequency band of 6 GHz or higher) than the frequency band of Long Term Evolution (LTE) (or LTE-A) (e.g., a frequency band below 6 GHz) is being considered for handling the soaring wireless data. The NR communication system can support not only frequency bands below 6 GHz but also frequency bands of 6 GHz or higher, and can support various communication services and scenarios compared to the LTE communication system. For example, the usage scenarios of the NR communication system may include enhanced mobile broadband (eMBB), ultra-reliable low latency communication (URLLC), massive machine type communication (mMTC), etc.

[0004] On the other hand, as a solution to the increased demand for data, communications using unlicensed bands have attracted attention. Currently, communication technologies using unlicensed bands include unlicensed LTE (LTE-U), licensed assisted access (LAA), MultiFire, etc. In addition to existing functions, the NR communication system can also support an independent mode that operates independently only in the unlicensed band. However, the initial access process in the unlicensed band, the signal transmission process, the channel access scheme suitable for the flexible frame structure, the broadband carrier operation, etc. have not been clearly defined. Therefore, it is necessary to clearly define the operations of the base station and the terminal for the above-mentioned technical elements. Summary of the invention

[0005]

Technical issues

[0006] An object of the present invention to solve the above-mentioned problems is to provide a method for configuring a listen-before-talk (LBT) subband in a communication system operating in an unlicensed band and transmitting or receiving a signal by using the LBT subband.

[0007] An object of the present invention to solve the above-mentioned problems is to provide a method for transmitting or receiving a signal by using a guard band of an LBT sub-band in a communication system operating in an unlicensed band.

[0008] An object of the present invention to solve the above-mentioned problems is to provide a method for mapping a data channel to resource elements (REs) by considering an LBT subband and a guard band in a communication system operating in an unlicensed band.

[0009] An object of the present invention to solve the above-mentioned problem is to provide a method for configuring a discovery reference signal (DRS) resource, a method for transmitting a DRS, and a method for measuring a DRS in a communication system operating in an unlicensed band.

[0010]

Technical solution

[0011] An exemplary embodiment of the present invention to achieve this purpose, as a method for sending signals performed by a terminal operating in an unlicensed band, may include receiving configuration information of a carrier from a base station; receiving configuration information for configuring a portion of a frequency region of the carrier as N guard bands, where N is a natural number; and sending a signal to the base station using a first frequency region belonging to a bandwidth portion of the carrier, wherein the first frequency region is a region of the frequency region of the bandwidth portion that does not include the N guard bands.

[0012] The frequency region of a carrier may be composed of one or more consecutive resource blocks (RBs), each guard band is composed of zero or more consecutive RBs in the RBs constituting the carrier, and the configuration information for configuring the N guard bands includes relevant information of the start RB and the end RB of each guard band.

[0013] The frequency region of the carrier may be divided into (N+1) subbands based on the N guard bands, and each subband may be composed of one or more consecutive RBs.

[0014] The starting RB of the first subband among the (N+1) subbands may be the starting RB of the carrier, and the ending RB of the first subband may be an RB whose index is one lower than the index of the starting RB of the first guard band; the starting RB of the nth subband among the (N+1) subbands (n=2, ..., N) may be an RB whose index is one higher than the index of the ending RB of the (n-1)th guard band, and the ending RB of the nth subband may be an RB whose index is one lower than the index of the starting RB of the nth guard band; and the starting RB of the (N+1)th subband among the (N+1) subbands may be an RB whose index is one higher than the index of the ending RB of the Nth guard band, and the ending RB of the (N+1)th subband is the ending RB of the carrier.

[0015] The bandwidth portion may include at least a portion of the (N+1) sub-bands.

[0016] Configuration information for configuring the N guard bands may be received through radio resource control (RRC) signaling.

[0017] The signal may include an uplink data channel, and the uplink data channel may be mapped to the first frequency region in a staggered structure.

[0018] The bandwidth portion can be obtained during the initial access process of the terminal or configured from the base station.

[0019] The method may also include receiving indication information from the base station indicating activation of at least part of the N protection bands; and starting from the time point indicated by the indication information, sending a signal to the base station using a second frequency region of at least part of the activated protection band among the N protection bands included in the frequency region of the bandwidth part.

[0020] The indication information may be received from the base station through at least one of RRC signaling, downlink control information (DCI), and medium access control (MAC) control element (CE).

[0021] Another exemplary embodiment of the present invention for achieving this purpose, as a method for receiving signals performed by a base station operating in an unlicensed band, may include: sending configuration information of a carrier to a terminal; sending configuration information for configuring a portion of a frequency region of the carrier as N guard bands, where N is a natural number; receiving a signal from the terminal using a first frequency region belonging to a bandwidth portion of the carrier, wherein the first frequency region is a region in the frequency region of the bandwidth portion that does not include the N guard bands.

[0022] The frequency region of the carrier may consist of one or more consecutive resource blocks (RBs), each guard band may consist of zero or more consecutive RBs among the RBs constituting the carrier, and the configuration information for configuring the N guard bands may include information related to the start RB and end RB of each guard band.

[0023] The frequency region of the carrier may be divided into (N+1) subbands based on the N guard bands, and each subband may be composed of one or more consecutive RBs.

[0024] The starting RB of the first subband among the (N+1) subbands may be the starting RB of the carrier, and the ending RB of the first subband may be an RB whose index is one lower than the index of the starting RB of the first guard band; the starting RB of the nth subband (n=2, ..., N) among the (N+1) subbands may be an RB whose index is one higher than the index of the ending RB of the (n-1)th guard band, and the ending RB of the nth subband may be an RB whose index is one lower than the index of the starting RB of the nth guard band; and the starting RB of the (N+1)th subband among the (N+1) subbands may be an RB whose index is one higher than the index of the ending RB of the Nth guard band, and the ending RB of the (N+1)th subband may be the ending RB of the carrier.

[0025] The bandwidth portion may include at least a portion of the (N+1) sub-bands.

[0026] Configuration information for configuring the N guard bands may be transmitted through radio resource control (RRC) signaling.

[0027] The signal may include an uplink data channel, and the uplink data channel may be mapped to the first frequency region in a staggered structure.

[0028] The bandwidth portion may be acquired by the terminal during the initial access process of the terminal, or may be configured to the terminal by the base station.

[0029] The method may also include sending indication information from the terminal to indicate activation of at least part of the N guard bands; and starting from the time point indicated by the indication information, receiving a signal from the terminal using a second frequency region, wherein the second frequency region includes at least part of the activated guard bands among the N guard bands in the frequency region of the bandwidth part.

[0030] The indication information may be transmitted to the terminal through at least one of RRC signaling, downlink control information (DCI), and medium access control (MAC) control element (CE).

[0031]

Beneficial Effects

[0032] According to the exemplary embodiments of the present invention as described above, a method for configuring an LBT subband in a communication system (e.g., an NR-U system) operating in an unlicensed band may be defined. In addition, a guard band corresponding to the LBT subband may be used for signal transmission, thereby improving resource efficiency. In addition, a method for configuring resources for DRS, a method for transmitting DRS, and a method for measuring DRS may be defined for a communication system operating in an unlicensed band. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 is a conceptual diagram illustrating a configuration of an LBT sub-band according to an exemplary embodiment of the present invention.

[0034] Figure 2 is a conceptual diagram illustrating a configuration of an LBT sub-band according to other exemplary embodiments of the present invention.

[0035] Figure 3 is a conceptual diagram illustrating configuration of an LBT subband and a carrier in an unlicensed band according to an exemplary embodiment of the present invention.

[0036] Figure 4 is a conceptual diagram illustrating configuration of an LBT subband and a carrier in an unlicensed band according to other exemplary embodiments of the present invention.

[0037] Figure 5is a conceptual diagram illustrating an exemplary embodiment of a method of activating a guard band in a bandwidth portion consisting of a plurality of LBT sub-bands.

[0038] Figure 6 is a conceptual diagram illustrating another exemplary embodiment of a method of activating a guard band in a bandwidth portion consisting of a plurality of LBT sub-bands.

[0039] Figure 7 is a conceptual diagram illustrating still another exemplary embodiment of a method of activating a guard band in a bandwidth portion consisting of a plurality of LBT sub-bands.

[0040] Figure 8 is a conceptual diagram illustrating a configuration of an LBT sub-band according to still another exemplary embodiment of the present invention.

[0041] Fig. 9 is a conceptual diagram for describing an exemplary embodiment of a data channel remapping method taking into account an LBT sub-band and a guard band.

[0042] Fig.10 is a conceptual diagram for describing an exemplary embodiment of configuring DRS resources in the time domain.

[0043] Fig.11 is a conceptual diagram for describing a first exemplary embodiment of a DRS resource configuration in the frequency domain and / or time domain.

[0044] Fig.12 is a conceptual diagram for describing a second exemplary embodiment of a DRS resource configuration in the frequency domain and / or time domain.

[0045] Fig.13 is a conceptual diagram for describing a third exemplary embodiment of a DRS resource configuration in the frequency domain and / or time domain.

[0046] Fig.14 is a conceptual diagram for describing a fourth exemplary embodiment of DRS resource configuration in the frequency domain and / or time domain.

[0047] Fig.15 is a conceptual diagram for describing an exemplary embodiment of a DRS transmission method in the frequency domain and / or time domain.

[0048] Fig.16 is a conceptual diagram illustrating another exemplary embodiment of DRS transmission in the frequency domain and / or time domain.

[0049] Fig.17 is a conceptual diagram illustrating yet another exemplary embodiment of DRS transmission in the frequency domain and / or time domain.

[0050] Fig.18 is a conceptual diagram illustrating an exemplary embodiment of a DRS transmission method in a wideband carrier.

[0051] Fig.19 is a conceptual diagram illustrating another exemplary embodiment of a DRS transmission method in a wideband carrier.

[0052] Fig. 20 is a conceptual diagram for describing an exemplary embodiment of a configuration of an SS / PBCH block actually transmitted in an unlicensed band.

[0053] Fig.21 is a conceptual diagram for describing other exemplary embodiments of a configuration of an SS / PBCH block actually transmitted in an unlicensed band.

[0054] Fig. 22 is a block diagram illustrating a communication node according to an exemplary embodiment of the present invention.

[0055] [Invention method]

[0056] Although the present invention is susceptible to various modifications and alternative forms, specific embodiments are shown and described in detail by way of example in the drawings. However, it should be understood that this description is not intended to limit the present invention to specific embodiments, but on the contrary, the present invention covers all modifications, equivalents and substitutes that fall within the spirit and scope of the present invention.

[0057] Although the terms "first", "second", etc. may be used herein with reference to various elements, these elements should not be construed as being limited by these terms. These terms are only used to distinguish one element from another element. For example, without departing from the scope of the present invention, a first element may be referred to as a second element, and a second element may be referred to as a first element. The term "and / or" includes any and all combinations of one or more of the related listed items.

[0058] It will be understood that when an element is referred to as being "connected" or "coupled" to another element, it may be directly connected or coupled to the other element, or there may be intermediate elements. Conversely, when an element is referred to as being "directly connected" or "directly coupled" to another element, there are no intermediate elements.

[0059] The terms used herein are only used for the purpose of describing specific embodiments and are not intended to limit the embodiments of the present invention. As used herein, the singular forms "a", "an" and "the" are also intended to include the plural forms, unless the context clearly indicates otherwise. It will be further understood that when the terms "comprise", "comprising", "including" and / or "comprising" are used herein, it indicates the presence of the features, integers, steps, operations, elements, parts and / or combinations thereof, but does not exclude the presence or addition of one or more other features, integers, steps, operations, elements, parts and / or combinations thereof.

[0060] Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the invention belongs. It will be further understood that, unless expressly defined as such herein, terms defined in commonly used dictionaries should be interpreted as having a meaning consistent with their meaning in the context of the relevant art and will not be interpreted in an idealized or overly formal sense.

[0061] Hereinafter, preferred exemplary embodiments of the present invention will be described in more detail with reference to the accompanying drawings. In order to facilitate general understanding when describing the present invention, the same components in the drawings are represented by the same reference numerals, and their repeated description is omitted.

[0062] A wireless communication system to which an exemplary embodiment of the present invention is applied will be described. A wireless communication system to which an exemplary embodiment of the present invention is applied is not limited to the contents described below, and the exemplary embodiment of the present invention can be applied to various wireless communication systems.

[0063] The present invention relates to a method for sending or receiving a signal in a communication system supporting an unlicensed band, and more specifically, to a method and apparatus for channel access and signal transmission using a wide frequency band of an unlicensed band. For ease of description, an NR communication system will be used as an example to describe a communication system to which an exemplary embodiment of the present invention is applied, but the spirit or exemplary embodiments of the present invention can be applied to various communication systems without being limited thereto. In addition, the present invention is used for communication in an unlicensed band, but the spirit or exemplary embodiments of the present invention can be easily applied to communication in a licensed band and various applications.

[0064] The NR communication system can support a wider system bandwidth (e.g., carrier bandwidth) than the system bandwidth provided by the LTE communication system in order to effectively use the wide frequency band. For example, the maximum system bandwidth supported by the LTE communication system may be 20 MHz. On the other hand, the NR communication system can support a carrier bandwidth of up to 100 MHz in a frequency band of 6 GHz or below, and a carrier bandwidth of up to 400 MHz in a frequency band of 6 GHz or above.

[0065] In order to meet various technical requirements, the numerology applied to physical signals and channels in NR communication systems may be different. In a communication system that applies OFDM waveform technology based on cyclic prefix (CP), the numerology may include subcarrier spacing and CP length (or CP type). Table 1 below may be a first exemplary embodiment of a numerology configuration for CP-based OFDM. The subcarrier spacing may have a multiplication relationship of a second power, and the CP length may be scaled in the same proportion as the OFDM symbol length. Depending on the frequency band in which the communication system operates, some numerologies of Table 1 may be supported. When the subcarrier spacing is 60kHz, extended CP may be additionally supported.

[0066]

Table 1

[0067]

[0068] In the following description, a frame structure in a communication system (e.g., an NR communication system) will be described. In the time domain, the building blocks may be subframes, time slots, and / or micro-time slots. A subframe may be used as a transmission unit, and the length of a subframe may have a fixed value (e.g., 1 ms) regardless of the subcarrier spacing. The time slot may include 14 consecutive OFDM symbols. The length of a time slot may be variable, different from the length of a subframe, and may be inversely proportional to the subcarrier spacing. A time slot may be used as a scheduling unit, and may also be used as a configuration unit for scheduling and hybrid automatic repeat request (HARQ) timing design.

[0069] The base station can use part of the time slot or the entire time slot to schedule the data channel (for example, the physical downlink shared channel (PDSCH), the physical uplink shared channel (PUSCH), or the physical sidelink shared channel (PSSCH)). Alternatively, the base station can use multiple time slots to schedule the data channel. A mini-time slot can be used as a transmission unit, and the length of the mini-time slot can be set to be shorter than the length of the time slot. A time slot with a length shorter than that of a traditional time slot may be referred to as a "mini-time slot" in a communication system. The physical downlink control channel (PDCCH) that monitors the duration and / or period of the data channel can be configured to be shorter than a traditional time slot, thereby supporting transmission based on mini-time slots.

[0070] A microslot may refer to a scheduling or transmission unit that is shorter than a slot. Scheduling based on microslots can be used for partial slot transmission in unlicensed bands or NR and LTE coexistence bands, URLLC transmission, multi-user scheduling based on analog beamforming, etc. NR can support microslot-based transmission by configuring a physical downlink control channel (PDCCH) monitoring period and a data channel duration that is shorter than a traditional slot.

[0071] In the frequency domain, the building block may be a physical resource block (PRB). One PRB may include 12 consecutive subcarriers, regardless of the subcarrier spacing. Therefore, the bandwidth occupied by one PRB may be proportional to the numerology subcarrier spacing. PRB may be used as a frequency domain resource allocation unit for a control channel and / or a data channel. The minimum resource allocation unit for a downlink control channel may be a control channel element (CCE). One CCE may include one or more PRBs. The minimum resource allocation (e.g., bitmap-based resource allocation) unit for a data channel may be a resource block group (RBG). One RBG may include one or more PRBs.

[0072] A time slot (e.g., a time slot format) may consist of a combination of one or more of a downlink duration, a flexible duration, or an unknown duration (hereinafter collectively referred to as a "flexible duration") and an uplink duration. Each of the downlink duration, the flexible duration, and the uplink duration may include one or more consecutive symbols. The flexible duration may be between the downlink duration and the uplink duration, between the first downlink duration and the second downlink duration, or between the first uplink duration and the second uplink duration. When the flexible duration is inserted between the downlink duration and the uplink duration, the flexible duration may be used as a guard period. A time slot may include multiple flexible durations. Alternatively, a time slot may not include a flexible duration. The terminal may semi-statically or periodically perform predefined operations or operations configured by the base station (e.g., PDCCH monitoring operations, synchronization signal / physical broadcast channel (SS / PBCH) block reception and measurement operations, channel state information reference signal (CSI-RS) reception and measurement operations, downlink semi-persistent scheduling (SPS) PDSCH reception operations, sounding reference signal (SRS) transmission operations, physical random access channel (PRACH) transmission operations, periodically configured PUCCH transmission operations, PUSCH transmission operations according to the configured authorization, etc.) within the corresponding flexible duration until the corresponding flexible duration is covered as the downlink duration or the uplink duration. Alternatively, the terminal may not perform any operations within the corresponding flexible duration until the corresponding flexible duration is covered as the downlink duration or the uplink duration.

[0073] The slot format can be semi-statically configured by higher layer signaling (e.g., radio resource control (RRC) signaling). Information indicating the semi-static slot format may be included in the system information, and the semi-static slot format may be configured in a cell-specific manner. For example, the cell-specific slot format may be configured by the RRC parameter "TDD-UL-DL-ConfigCommon". In addition, the slot format may be additionally configured for each terminal by UE-specific higher layer signaling (e.g., RRC signaling). For example, the UE-specific slot format may be configured by the RRC parameter "TDD-UL-DL-ConfigDedicated". The flexible duration of the slot format configured in a cell-specific manner may be overwritten by UE-specific higher layer signaling as a downlink duration or an uplink duration. In addition, the slot format may be dynamically indicated by a slot format indicator (SFI) included in the downlink control information (DCI).

[0074] The terminal can perform most of the downlink and uplink operations in the bandwidth part. The bandwidth part can be defined as a set of consecutive PRBs in the frequency domain. In a bandwidth part, only one numerology can be used to transmit a control channel or a data channel. A terminal performing an initial access procedure can obtain the configuration information of the initial bandwidth part from the base station through system information. A terminal operating in the RRC connected state can obtain the configuration information of the bandwidth part from the base station through UE-specific higher layer signaling.

[0075] The configuration information of the bandwidth part may include numerology applied to the bandwidth part (e.g., subcarrier spacing and CP length). In addition, the configuration information of the bandwidth part may also include information indicating the position of the starting PRB of the bandwidth part and information indicating the number of PRBs constituting the bandwidth part. At least one of the bandwidth parts configured for the terminal may be activated. For example, within one carrier, an uplink bandwidth part and a downlink bandwidth part may be activated respectively. In a communication system based on time division duplex (TDD), a pair of an uplink bandwidth part and a downlink bandwidth part may be activated. If multiple bandwidth parts are configured for the terminal within one carrier, the active bandwidth part of the terminal may be switched.

[0076] In the present disclosure, the statement that a certain frequency band (e.g., a carrier, a bandwidth portion, a listen-before-talk (LBT) subband, a guard band, etc.) is activated may mean that the specific frequency band is changed to a state in which a base station or a terminal can use the corresponding frequency band to send or receive a signal. In addition, the statement that a certain frequency band is activated may mean that the certain frequency band is switched to a state in which a radio frequency (RF) filter (e.g., a bandpass filter) of a transceiver includes the frequency band to operate.

[0077] The minimum resource unit constituting the PDCCH may be a resource element group (REG). A REG may consist of one PRB (e.g., 12 subcarriers) in the frequency domain and one OFDM symbol in the time domain. Therefore, one REG may include 12 resource elements (REs). In an OFDM-based communication system, an RE may be the minimum physical resource unit consisting of one subcarrier and one OFDM symbol. A demodulation reference signal (DMRS) for demodulating the PDCCH may be mapped to 3 of the 12 REs constituting the REG, and control information (e.g., modulated DCI) may be mapped to the remaining 9 REs.

[0078] A PDCCH candidate may consist of one CCE or aggregated CCEs. A CCE may consist of multiple REGs. In an exemplary embodiment, the CCE aggregation level may be referred to as L, and the number of REGs constituting one CCE may be referred to as K. A communication system (e.g., an NR communication system) may support "K=6, L=1, 2, 4, 8, or 16". The higher the CCE aggregation level, the more physical resources available for PDCCH transmission. In this case, the reception performance of the PDCCH may be improved by using a low code rate for PDCCH transmission.

[0079] A control resource set (CORESET) may be a resource region for a terminal to blindly decode a PDCCH. A CORESET may consist of multiple REGs. A CORESET may consist of one or more PRBs in the frequency domain and one or more symbols (e.g., OFDM symbols) in the time domain. The symbols constituting a CORESET may be continuous in the time domain. The PRBs constituting a single CORESET may be continuous or discontinuous in the frequency region. A DCI (e.g., a PDCCH) may be transmitted in a CORESET or a search space logically associated with the CORESET. A cell and a terminal may be configured with multiple CORESETs, which may overlap with each other.

[0080] The CORESET can be configured to the terminal through PBCH (for example, system information transmitted through PBCH). The ID of the CORESET configured by PBCH can be 0. That is, the CORESET configured by PBCH can be called CORESET#0. A terminal operating in an RRC idle state can perform a monitoring operation in CORESET#0 to receive the first PDCCH during the initial access process. Not only terminals operating in the RRC idle state but also terminals operating in the RRC connected state can perform monitoring operations in CORESET#0. In addition to the system information transmitted through PBCH, the CORESET can also be configured to the terminal by other system information (for example, system information block type 1 (SIB1)). For example, in order to receive a random access response (or Msg2) during a random access process, the terminal can receive SIB1 containing the configuration information of the CORESET. In addition, the CORESET can be configured to the terminal through UE-specific higher layer signaling (for example, RRC signaling).

[0081] In each downlink bandwidth part, one or more CORESETs can be configured for the terminal. Here, configuring a CORESET in a bandwidth part means that the CORESET is logically associated with the bandwidth part, and the terminal monitors the corresponding CORESET in the bandwidth part. The initial downlink active bandwidth part may include CORESET#0 and may be associated with CORESET#0. CORESET#0 having a quasi-co-location (QCL) relationship with the SS / PBCH block can be configured for terminals in the primary cell (PCell), secondary cell (SCell) and primary and secondary cell (PSCell). In the secondary cell (SCell), CORESET#0 may not be configured for the terminal.

[0082] The PDCCH candidates constituting the search space may be composed of CCEs selected by a predefined hash function within the timing of the search space or CORESET. The search space may be defined and configured for each CCE aggregation level. In this case, a set of search spaces for all CCE aggregation levels may be referred to as a "search space set". In an embodiment, "search space" may mean a "search space set", and "search space set" may mean a "search space".

[0083] A search space set can be logically associated with a single CORESET. A CORESET can be logically associated with one or more search space sets. The common search space set configured through PBCH can be used to monitor the DCI of the PDSCH that schedules the transmission of SIB1. The ID of the common search space set configured through PBCH can be set to 0, that is, the common search space set configured through PBCH can be defined as a PDCCH common search space set of type 0 or search space set #0. Search space set #0 can be logically associated with CORESET #0.

[0084] Search space sets can be classified into common search space sets and UE-specific search space sets. Common DCI can be transmitted in the common search space set, and UE-specific DCI can be transmitted in the UE-specific search space set. Taking into account the freedom of scheduling and / or fallback transmission, UE-specific DCI can also be transmitted in the common search space set. For example, common DCI may include resource allocation information of PDSCH for transmitting system information, paging, power control commands, slot format indicator (SFI), preemption indicator, etc. UE-specific DCI may include PDSCH resource allocation information, PUSCH resource allocation information, etc. Multiple DCI formats can be defined according to the payload and size of DCI, the type of radio network temporary identifier (RNTI), etc.

[0085] In an exemplary embodiment, a common search space may be referred to as a “CSS” and a common search space set may be referred to as a “CSS set.” In addition, in an exemplary embodiment, a UE-specific search space may be referred to as a “USS” and a UE-specific search space set may be referred to as a “USS set.”

[0086] The exemplary embodiments of the present disclosure may be applied to various communication scenarios using unlicensed bands. For example, with the assistance of the main cell in the licensed band, the cell in the unlicensed band may be configured as a secondary cell, and the carrier of the secondary cell may be aggregated with other carriers. Alternatively, the cell in the unlicensed band (e.g., the secondary cell) and the cell in the licensed band (e.g., the main cell) may support dual-connection operation. Therefore, the transmission capacity may be increased. Alternatively, the cell in the unlicensed band may independently perform the function of the main cell. Alternatively, the downlink carrier of the licensed band may be combined with the uplink carrier of the unlicensed band, and the combined carrier may function as a cell. On the other hand, the uplink carrier of the licensed band may be combined with the downlink carrier of the unlicensed band, and the combined carrier may function as a cell. In addition, the exemplary embodiments of the present disclosure may be applied to other communication systems (e.g., communication systems supporting licensed bands) and communication systems supporting unlicensed bands.

[0087] In unlicensed band communications, a contention-based channel access scheme can be used to meet spectrum regulation conditions and coexist with existing communication nodes (e.g., Wi-Fi stations). For example, a communication node that wishes to access a channel in an unlicensed band can identify the channel occupancy state by performing an idle channel assessment (CCA) operation. A transmitting node (e.g., a communication node performing a transmission operation) can determine whether a channel is busy or idle based on a predefined (or preconfigured) CCA threshold. When the channel state is idle, the transmitting node can transmit a channel and / or a signal in the corresponding channel. The above operation may be referred to as a "listen before talk (LBT) operation". Depending on whether an LBT operation is performed and how the LBT operation is applied, the LBT operation can be divided into four categories. The first category may be a scheme in which the transmitting node does not perform an LBT operation. That is, when the first category is used, the transmitting node can send a signal without performing a channel listening operation. The second category may be a scheme in which the transmitting node performs an LBT operation without a random backoff operation. The third category may be a scheme in which the transmitting node uses a fixed-size contention window (CW) to perform an LBT operation based on a random backoff value. The fourth category may be a scheme in which the sending node uses a contention window of a variable size to perform an LBT operation based on a random backoff value.

[0088] The LBT operation may be performed in units of a specific frequency bundle. The frequency bundle may be referred to as an "LBT subband". Here, the LBT operation may include the above-mentioned CCA operation, and may also include data transmission through the CCA operation as appropriate. The bandwidth of the LBT subband may vary according to spectrum regulations, frequency bands, communication systems, operators, manufacturers, and the like. For example, in a frequency band where Wi-Fi sites coexist, the bandwidth of the LBT subband may be 20 MHz or approximately 20 MHz. That is, a communication node may perform a channel sensing operation and / or a data transmission operation according to the channel sensing operation in units of 20 MHz or approximately 20 MHz. For example, the LBT subband may be a set of continuous RBs corresponding to approximately 20 MHz. In this case, the bandwidth of the set of continuous RBs may not exceed 20 MHz. In the following description, the statement that the LBT subband is XL MHz may indicate that the bandwidth of the LBT subband is XL MHz or approximately XL MHz. Unless otherwise specified, XL may be assumed to be 20. In this specification, in some cases, an RB may represent a physical resource block (PRB) constituting a bandwidth portion. Alternatively, RB may represent a common RB (CRB) or a virtual RB (VRB). Specifically, when RB is used in the sense of an RB constituting a carrier, RB may represent a CRB constituting a carrier. In an NR communication system, CRB may refer to an RB on a common RB grid configured for a terminal based on "point A".

[0089] Taking into account the above-mentioned LBT operation, the bandwidth portion of the carrier and / or the bandwidth portion configured for the terminal can be configured as a multiple of XL. For example, the carrier and / or the bandwidth portion can be configured as 20, 40, 60, 80 MHz, etc. In the following description, the statement that the bandwidth portion of the carrier and / or the bandwidth portion is X MHz can indicate that the bandwidth and / or the bandwidth portion of the carrier is X MHz or approximately X MHz. For example, the carrier and / or the bandwidth portion may include a set of continuous RBs corresponding to approximately X MHz. The carrier and / or the bandwidth portion in the NR communication system may be defined as a set of CRBs in a common RB grid. The bandwidth portion may be configured within one carrier. Alternatively, the bandwidth portion may be configured in the form of a frequency region including multiple carriers. In the latter case, the bandwidth portion may be logically associated with multiple carriers.

[0090] In unlicensed band communications, a sending node may occupy a channel for a period of time when an LBT operation is successful. In this case, the channel occupation time or channel occupation interval may be referred to as "channel occupation time (COT)". The statement that the LBT operation of the sending node is successful may indicate that the sending node has obtained the COT. The sending node may use a portion of the COT initiated by the sending node or the entire COT to send signals and / or channels. In addition, the COT initiated by the sending node may be shared with the receiving node. The receiving node that shares the COT can not only receive signals but also send signals. As a result, the sending node that initiates the COT can not only send signals but also receive signals within the corresponding COT. In this specification, a "sending node" may refer to a node that starts or initiates a COT, i.e., an initiating node, and a "receiving node" may refer to a node that sends and receives signals within the corresponding COT without starting or initiating the corresponding COT.

[0091] LBT subband configuration

[0092] A bandwidth portion may consist of one or more LBT sub-bands (or "sub-bands" for convenience).

[0093] Figure 1 is a conceptual diagram illustrating a configuration of an LBT sub-band according to an exemplary embodiment of the present invention.

[0094] Figure 1 Case (a) shows a first exemplary embodiment of a bandwidth portion configuration including a plurality of sub-bands, Figure 1 Case (b) shows a second exemplary embodiment of a bandwidth portion configuration including a plurality of sub-bands, and Figure 1 Case (c) shows a third exemplary embodiment of a bandwidth portion configuration including a plurality of sub-bands.

[0095] refer to Figure 1 In cases (a) to (c), a bandwidth portion may be composed of four LBT subbands, and each LBT subband may have a bandwidth of 20 MHz. That is, XL = 20. Since the transmitting node, i.e., the base station or the terminal, performs CCA on the LBT subband before transmitting the signal, the communication node may occupy the channel corresponding to part of the bandwidth portion or the entire bandwidth portion, and use it for signal transmission according to the channel sensing result.

[0096] For example, refer to Figure 1 In case (a), the sending node can successfully perform LBT operations in all LBT subbands of the bandwidth part at a certain point in time and use the entire frequency band of the bandwidth part to send signals. Figure 1In case (b), the sending node can successfully perform LBT operation on some LBT subbands of the bandwidth, namely the first, third, and fourth subbands at a certain point in time, and send signals on the corresponding subbands. Figure 1 In case (c), the transmitting node can successfully perform an LBT operation on some LBT subbands of the bandwidth part, namely, the first, second, and third subbands at a certain point in time, and transmit a signal on the corresponding subband. In the following description, a successful LBT operation of a communication node may mean that a channel is determined to be in an idle state as a result of performing CCA. On the other hand, a failed LBT operation of a communication node may mean that a channel is determined to be occupied by another node as a result of performing CCA.

[0097] In the unlicensed band, one or more LBT subbands can be activated for the terminal. The LBT subbands can belong to the same carrier or the same bandwidth part, or to different carriers or different bandwidth parts. One or more carriers can be activated for the terminal, one or more bandwidth parts can be activated in each activated carrier, and each activated bandwidth part belonging to the unlicensed band can be composed of one or more LBT subbands. Alternatively, each activated carrier can be composed of one or more LBT subbands. In the following description, the case where one carrier or one active bandwidth part is composed of one or more LBT subbands will be mainly considered. However, the proposed method is not limited to this, and can be easily applied to the case where multiple LBT subbands belong to multiple carriers or multiple active bandwidth parts.

[0098] On the other hand, a guard band may be inserted between LBT subbands constituting a carrier or bandwidth portion. This may be referred to as an "intra-carrier (intra-carrier) guard band" to distinguish it from an inter-carrier guard band. A transmitting node may ensure normal channel sensing operation in an unoccupied LBT subband by transmitting a signal in a frequency region that does not include a guard band in an occupied LBT subband. For example, referring to Figure 1 In case (b), in order to ensure the normal channel sensing operation in the second sub-band, a guard band may be inserted in the first and third sub-bands, and the transmitting node may not transmit a signal in the guard band, thereby minimizing the interference caused to the second sub-band. Figure 1 In case (c), in order to ensure normal channel sensing operation in the fourth subband, a guard band may be inserted into the third subband, and the transmitting node may not transmit a signal in the guard band, thereby minimizing interference to the fourth subband.

[0099] Figure 2 is a conceptual diagram illustrating a configuration of an LBT sub-band according to other exemplary embodiments of the present invention.

[0100] Figure 2Case (a) shows a fourth exemplary embodiment of a configuration of a bandwidth portion including a plurality of sub-bands, and Figure 2 Case (b) shows a fifth exemplary embodiment of a configuration of a bandwidth portion including a plurality of sub-bands.

[0101] refer to Figure 2 In cases (a) and (b), the bandwidth portion can consist of four LBT sub-bands. Figure 2 In an exemplary embodiment of case (a), the bandwidth portion may not include a guard band between sub-bands, and Figure 2 In an exemplary embodiment of case (b), the bandwidth portion may include a guard band between sub-bands.

[0102] In the above exemplary embodiments, each subband may be composed of some RBs in the RBs constituting a bandwidth part or a carrier. In the following description, the expression "a subband constitutes a bandwidth part or consists of PRBs constituting a bandwidth part" may be interpreted as having the same meaning as "a subband constitutes a carrier or consists of CRBs constituting a carrier". In the following description, the number of RBs constituting a bandwidth part or a carrier is represented by NB, and the number of LBT subbands constituting a bandwidth part or a carrier is represented by K. In this case, when the number of RBs constituting the kth subband is NS(k) (k=1,2,...,K), NS(k) may be a natural number less than or equal to NB. In an exemplary embodiment, NS(k) may have the same value for all k. Alternatively, in another exemplary embodiment, NS(k) may have independent values ​​with respect to k. The RBs constituting each subband may be continuous in the frequency domain.

[0103] When an LBT subband or subband is composed of RBs by the above method, the term "LBT subband" or "subband" can be replaced with more general terms such as "RB set", "PRB set", "CRB set", etc.

[0104] The upper limit of NS(k) may be predefined in the technical specification. In one example, the upper limit of NS(k) may be the number of RBs corresponding to (or less than) the bandwidth of a channel in consideration of the guard band, which is a unit for performing LBT operations. In another example, the maximum value of the subband bandwidth is defined, and the subband bandwidth may be limited so that the subband bandwidth determined by NS(k) does not exceed (or is less than) the maximum value of the defined subband bandwidth. Similarly, the lower limit of NS(k) may be predefined in the technical specification. In one example, the lower limit of NS(k) may also be the number of RBs corresponding to (or less than) the bandwidth of a channel in consideration of the guard band, which is a unit for performing LBT operations. In another example, the minimum value of the subband bandwidth is defined, and the subband bandwidth may be limited so that the subband bandwidth determined by NS(k) is not less than (or greater than) the minimum value of the defined subband bandwidth. The maximum and / or minimum value of the subband bandwidth does not necessarily have to be an integer multiple of the bandwidth of an RB, and may be any positive number. Alternatively, NS(k) may be predefined in the technical specification. That is, the bandwidth of each subband can be composed of a fixed number of RBs. This may correspond to the case where the upper and lower limits of NS(k) are the same. Alternatively, the base station may configure the bandwidth portion or carrier, subband, guard band, etc., so that each subband in the bandwidth portion or carrier is included in the frequency range of each predefined channel (excluding the guard band). The above-mentioned values, upper and / or lower limits of NS(k) and the maximum and / or minimum values ​​of the subband bandwidth may be defined differently for each numerology (e.g., subcarrier spacing). In addition, these values ​​may be defined differently for each frequency band.

[0105] Similarly, each guard band may be composed of some RBs in the RBs constituting the bandwidth part or carrier. When the number of LBT subbands constituting the bandwidth part or carrier is K, the number of guard bands may be (K-1). In this case, when the number of RBs constituting the g-th guard band is NG(g) (g=1, 2, ..., K-1), NG(g) may be an integer greater than or equal to 0 and less than or equal to NB. In an exemplary embodiment, NG(g) may have the same value for all g. Alternatively, in another exemplary embodiment, NG(g) may have values ​​that are independent of each other with respect to g. The RBs constituting each guard band may be continuous in the frequency domain.

[0106] The upper limit of NG(g) may be predefined in the technical specification. Alternatively, the maximum value of the guard band bandwidth is defined, and the bandwidth of the guard band may be limited so that the bandwidth of the guard band determined by NG(g) does not exceed (or is less than) the defined maximum value of the guard band bandwidth. Alternatively, the lower limit of NG(g) may be predefined in the technical specification. Alternatively, the minimum value of the guard band bandwidth is defined, and the bandwidth of the guard band may be limited so that the bandwidth of the guard band determined by NG(g) is not less than (or greater than) the defined minimum value of the guard band bandwidth. The maximum and / or minimum value of the guard band bandwidth may be expressed in terms of the number of RBs. Alternatively, the maximum and / or minimum value of the bandwidth of the guard band does not necessarily have to be an integer multiple of the bandwidth of an RB, but may be an arbitrary positive number. Alternatively, NG(g) may be predefined in the technical specification. That is, the bandwidth of each guard band may consist of a fixed number of RBs. This may correspond to the case where the upper and lower limits of NG(g) are the same. The predefined NG(g) value may be used as the default value for the guard band bandwidth. That is, when the terminal does not receive information about the size of the guard band from the base station, the terminal can use the predefined NG(g) value to construct the guard band. Alternatively, the base station can configure the bandwidth part or carrier, subband, guard band, etc., so that each guard band in the bandwidth part or carrier includes the frequency range of each guard band predefined between adjacent channels. The above-mentioned value, upper limit value and / or lower limit value of NG(g) and the maximum value and / or minimum value of the bandwidth of the guard band can be defined differently for each numerology (e.g., subcarrier spacing). In addition, these values ​​can be defined differently for each frequency band.

[0107] In the above exemplary embodiments, the union of the RBs constituting the LBT subband and the guard band may be the same as the set of RBs constituting the carrier. That is, all RBs of a carrier or bandwidth portion may belong to at least one LBT subband or guard band. At the same time or separately, the set of RBs constituting each LBT subband and guard band may be a disjoint set (that is, their intersection may be an empty set). That is, a certain RB in a carrier or bandwidth portion may belong to only one LBT subband or only one guard band. That is, the starting RB of the first subband may be the starting RB of the carrier, and the ending RB of the first subband may be an RB whose index is one lower than the index of the starting RB of the first guard band. The starting RB of the kth subband (k=2,…,K-1) may be an RB whose index is one higher than the index of the ending RB of the (k-1)th guard band, and the ending RB of the kth subband may be an RB whose index is one lower than the index of the starting RB of the kth guard band. The start RB of the K-th subband may be an RB having an index one higher than the index of the end RB of the (K-1)-th guard band, and the end RB of the K-th subband may be the end RB of the carrier.

[0108] Alternatively, the LBT subband and the guard band may have an intersection with each other. That is, a certain RB may belong to multiple LBT subbands. Alternatively, a certain RB may belong to both the LBT subband and the guard band.

[0109] As described above, part or all of the information about the composition of the subbands in the bandwidth part or carrier (i.e., the number of LBT subbands constituting the bandwidth part or carrier, the set of RBs constituting each LBT subband, and the set of RBs constituting each guard band) can be predefined for each "channel" to which the frequency band and bandwidth part are allocated. For example, in the case where the subcarrier spacing is 30kHz and 15kHz, it can be defined that the bandwidth occupied by an LBT subband with a bandwidth of 20MHz in a certain frequency band corresponds to 51 and 106 consecutive PRBs, respectively, and can be shared in advance between the base station and the terminal. That is, for all k in the frequency band, NS(k)=51 and NS(k)=106.

[0110] Alternatively, the base station may send some or all of the information about the configuration of the subband in the bandwidth part or carrier to the terminal. In the above example, the frequency position of each LBT subband (e.g., the starting RB index of the LBT subband) may be predefined for each channel or signaled to the terminal from the base station. For another example, information about the number of LBT subbands constituting the bandwidth part or carrier, information about the set of RBs constituting each LBT subband, and / or information about the set of RBs constituting each guard band may be signaled to the terminal from the base station. In some cases, information about the set of RBs constituting each LBT subband and information about the set of RBs constituting each guard band may be interchangeable. In this case, one of the two pieces of information may be signaled to the terminal. Information about the set of RBs constituting the LBT subband or guard band may be represented by the starting RB index and the ending RB index constituting the LBT subband or guard band. Alternatively, information about the RB set may be represented by the starting RB index and the number of RBs.

[0111] In the following description, unless otherwise specified, "signaling" may refer to physical layer signaling (e.g., downlink control information (DCI)), MAC signaling (e.g., MAC control element (CE)), RRC signaling (e.g., master information block (MIB), system information block (SIB), cell-specific RRC signaling, terminal-specific RRC signaling, etc.), etc. "Signaling" may refer to a combination of two or more of physical layer signaling, MAC signaling, and RRC signaling. In addition, in the following description, unless otherwise specified, "signaling (or configuration)" may refer to signaling (or configuration) through an explicit scheme and signaling (or configuration) through an implicit scheme. For example, configuration information about a subband in a bandwidth part or a carrier may be configured to the terminal through RRC signaling, or may be configured together with bandwidth part configuration information or carrier configuration information. Information about the subband configuration in a bandwidth part or a carrier may be configured differently for each bandwidth part or each carrier. The values ​​of NB, NS(k) and / or NG(g) may be different for each bandwidth part or carrier, or for each subcarrier spacing applied to a bandwidth part or carrier. Information about the composition of the LBT subband may only apply to the bandwidth part of the terminal specific configuration. For the uplink and / or downlink initial active bandwidth part, K=1.

[0112] The initial active bandwidth part may be notified to the terminal by the base station through the transmission of the SS / PBCH block. For example, the terminal may successfully detect the SS / PBCH block and obtain the downlink initial active bandwidth part from the frequency position of the SS / PBCH block. When there are multiple bandwidths and / or frequency positions that the downlink initial active bandwidth part may have, at least a portion of the information about the frequency position of the downlink initial active bandwidth part may be included in the control information (e.g., MIB) transmitted through the PBCH. For example, the base station may signal the frequency region of CORESET#0 (i.e., CORESET with ID=0) to the terminal through the PBCH, and the terminal may regard the frequency region of CORESET#0 as the downlink initial active bandwidth part. In this case, the number of PRBs constituting the downlink initial active bandwidth part may be a multiple of 6. Alternatively, the base station may explicitly signal the frequency region of the downlink initial active bandwidth part to the terminal through the PBCH. In this case, the bandwidth of the downlink initial active bandwidth part may be less than the bandwidth of the above-mentioned one LBT subband. Alternatively, the downlink initial active bandwidth part may have a bandwidth corresponding to the bandwidth of the above-mentioned one LBT subband. The initial active bandwidth portion may also consist of consecutive PRBs in the frequency domain.

[0113] On the other hand, the initial active bandwidth part can be configured to the terminal in two stages. For example, as described above, the base station can signal the frequency region of CORESET#0 to the terminal through PBCH, and the terminal can regard the frequency region of CORESET#0 as the downlink initial active bandwidth part (hereinafter referred to as the "first downlink initial active bandwidth part"). Alternatively, the base station can explicitly signal the frequency region of the first downlink initial active bandwidth part to the terminal through PBCH. In addition, the terminal can be configured with a downlink initial active bandwidth part (hereinafter, "the second downlink initial active bandwidth part") through system information (e.g., SIB1). For example, the second downlink initial active bandwidth part can be configured to have a bandwidth corresponding to the bandwidth of one LBT subband mentioned above. In this case, the terminal can regard the second downlink initial active bandwidth part as valid, and can limit the configuration of PBCH to only represent the frequency region of CORESET#0.

[0114] When an unlicensed band carrier is configured for a terminal as a secondary cell (SCell), the initial active bandwidth portion of the unlicensed band carrier may be configured from the base station to the terminal. For example, the base station may signal the terminal through a primary cell (PCell) or a primary secondary cell (PSCell) to notify the terminal of information about the initial active bandwidth portion of the unlicensed band carrier. The signaling may be RRC signaling.

[0115] The initial active bandwidth part may be composed of multiple LBT sub-bands. As described above, when the initial active bandwidth part is configured for the terminal in two stages, the initial active bandwidth part configured in the second stage (for example, the second downlink initial active bandwidth part) may be composed of one or more LBT sub-bands. In addition, the initial active bandwidth part configured to the terminal as an unlicensed band carrier of a secondary cell may be composed of one or more LBT sub-bands. The method in which multiple LBT sub-bands constitute the initial active bandwidth part may follow the above method. In this case, the base station may configure the terminal with configuration information about the subbands and / or protection bands of the initial active bandwidth part. This information may be configured to the terminal together with the configuration information of the initial active bandwidth part (for example, through system information or SIB1, or through RRC signaling). The initial active bandwidth part may include a downlink initial active bandwidth part and an uplink initial active bandwidth part.

[0116] Hereinafter, a method of applying configuration of an LBT subband and / or a guard band to a bandwidth portion configured in a carrier when the LBT subband and / or the guard band are configured in the carrier will be described.

[0117] Figure 3 is a conceptual diagram illustrating a configuration of a carrier and an LBT subband in an unlicensed band according to an exemplary embodiment of the present invention.

[0118] Figure 3 Case (a) shows a first exemplary embodiment of the configuration of a carrier and an LBT subband in an unlicensed band, Figure 3 Case (b) shows a first exemplary embodiment of a method of applying an LBT subband configured in a carrier to a bandwidth part, and Figure 3 Case (c) shows a second exemplary embodiment of a method of applying an LBT subband configured in a carrier to a bandwidth part.

[0119] refer to Figure 3 In case (a), the carrier can be configured within a channel bandwidth of 40 MHz. The carrier may be composed of continuous RBs and may be configured in an area of ​​the 40 MHz channel that is not included in the inter-carrier guard band defined at the two frequency ends. In this case, in order to meet the requirements of occupied channel bandwidth (OCB), a minimum bandwidth value (in Hz) or a minimum number of RBs for the carrier may be defined. The minimum bandwidth value or the minimum number of RBs for the carrier may be defined for each frequency band, each country or region, each channel bandwidth size and / or each subcarrier spacing. The carrier may also include an intra-carrier guard band. An intra-carrier guard band may be defined as having an integer number of CRBs on a CRB grid, and according to this exemplary embodiment, two CRBs may constitute a guard band. The size and / or frequency position of the guard band may be predefined and shared between the base station and the terminal.

[0120] The carrier may also include two LBT subbands and one guard band. These may be configured from the base station to the terminal in the manner described above. The sizes of the first subband and the second subband may be the same or different. The guard band may be configured as three consecutive RBs and may include two predefined CRBs. Typically, the guard band (e.g., three RBs) configured by the base station for the terminal may include a predefined guard band (e.g., two CRBs). Alternatively, when the guard band size is not 0 (e.g., including one or more RBs), the guard band configured by the base station for the terminal may include a predefined guard band.

[0121] refer to Figure 3 In cases (b) and (c), the bandwidth portion can be configured in the carrier. Figure 3 In case (b), the first bandwidth part may consist of a portion of the RBs constituting the carrier, and may include the first and second subbands and at least a portion of the guard band. The first and second subbands of the first bandwidth part may consist of RBs respectively configured as the first and second subbands in the relevant carrier. In addition, the guard band of the first bandwidth part may consist of RBs (i.e., three RBs) configured as the guard band in the relevant carrier. Figure 3In case (c), the second bandwidth part may be composed of a portion of the RBs constituting the carrier and may include at least a portion of the second subband. The second subband of the second bandwidth part may be composed of RBs configured as the second subband in the relevant carrier. The second subband may be considered to be a subband or a first subband having a first index (e.g., index 0) within the second bandwidth part. Alternatively, when the bandwidth part includes only one subband, it may be considered that no subband is configured in the corresponding bandwidth part. In this way, LBT subbands and / or guard bands may be configured in the carrier and applied to the bandwidth part configured in the carrier so as to be considered for signal transmission in the bandwidth part. According to this exemplary embodiment, each guard band in the bandwidth part may exist only between two subbands. That is, the start PRB and the end PRB of the bandwidth part may not be configured as guard bands.

[0122] In the above method, the initial active bandwidth part may include only one LBT subband. That is, the initial active bandwidth part may be composed of RBs belonging to the same LBT subband in the carrier associated with the initial active bandwidth part. In addition, the initial active bandwidth part may not include a carrier guard band. The base station may appropriately configure the LBT subband and / or guard band in the carrier to meet the above conditions. For example, Figure 3 The second bandwidth portion of case (c) may be Figure 3 The initial active bandwidth part of the carrier in case (a), where the initial active bandwidth part may refer to the downlink and / or uplink initial active bandwidth part, or may refer to the first and / or second downlink initial active bandwidth part.

[0123] Also in the unlicensed band, the frequency ranges of the downlink and uplink bandwidth parts may be configured differently. In this case, the above method may be applied to the downlink bandwidth part and the uplink bandwidth part, respectively. For example, Figure 3 The first bandwidth portion of case (b) may be a downlink bandwidth portion, Figure 3 The second bandwidth portion of case (c) may be an uplink bandwidth portion.

[0124] Also in the unlicensed band, it may not be necessary to configure the LBT subband in some cases. For example, when the bandwidth of the carrier or bandwidth portion is small (for example, 20 MHz or less in the 5 GHz band), the configuration of the LBT subband may be unnecessary. Alternatively, in a band where heterogeneous radio access technology (RAT) terminals (such as Wi-Fi terminals) do not coexist, operations based on the LBT subband may be unnecessary. With this in mind, methods for configuring LBT subbands and / or guard bands can be selectively applied depending on the situation.

[0125] The base station can dynamically indicate the terminal of the LBT subbands available for transmission in the LBT subbands configured in the carrier or bandwidth part. The available LBT subbands can be determined by the result of the LBT operation performed by the base station. For example, the base station can select some or all of the LBT subbands belonging to the channel occupied by the LBT operation as available LBT subbands, and indicate the selected subbands to the terminal. Information about the available LBT subbands can be transmitted by physical layer signaling. For example, it can be transmitted on the PDCCH contained in the DCI. The PDCCH can be a group common PDCCH, and the terminal can monitor and receive it in a CSS set (e.g., a type 3 PDCCH CSS set). Information about the available LBT subbands can be represented by a bitmap. Each bit of the bitmap can indicate the availability of each LBT subband, and the LBT subbands participating in the dynamic availability indication can be configured to the terminal through higher layer signaling (e.g., RRC signaling). For example, when four LBT subbands are configured in the carrier or bandwidth part, the base station can configure these three LBT subbands to the terminal through RRC signaling, and dynamically indicate the 3-bit bitmap corresponding thereto to inform whether each subband is available or unavailable. A bitmap may correspond to an LBT subband of one or more carriers. When the terminal indicates that a certain LBT subband is available through the above method, assuming that the LBT subband is available within a predefined or agreed time period with the base station, the terminal may perform PDCCH monitoring, signal transmission, etc. (for example, until the COT to which the received DCI belongs or the end of the transmission burst).

[0126] On the other hand, the LBT subband and the guard band may overlap in the frequency domain. That is, a portion of the RBs constituting the LBT subband may be configured as a guard band (or guard RB).

[0127] Figure 4 is a conceptual diagram illustrating configuration of a carrier and an LBT subband in an unlicensed band according to other exemplary embodiments of the present invention.

[0128] refer to Figure 4 , two LBT subbands can be configured in a carrier or bandwidth part. The first subband and the second subband can be configured to be adjacent to each other, and the union of the RBs constituting the first subband and the second subband can be the same as the set of RBs constituting the carrier or the bandwidth part. That is, each RB in the carrier or the bandwidth part can belong to at least one subband. In addition, the sets of RBs constituting the first subband and the second subband, respectively, can be disjoint sets. That is, each RB in the carrier or the bandwidth part can belong to at most one subband. When the above two conditions are met at the same time, the frequency range (i.e., size and position) of each LBT subband can be represented only by the boundary position between the LBT subbands (e.g., the last RB index of the first subband or the first RB index of the second subband), which can be notified to the terminal from the base station by signal.

[0129] In addition, refer to Figure 4 , the last RB of the first subband and the first two RBs of the second subband can be configured as intra-carrier guard bands. The frequency ranges of the guard band and the LBT subband can be configured independently. Alternatively, the RBs constituting the guard band can be configured for the terminal, and the terminal can find out which LBT subband each guard RB belongs to through a predetermined rule. For example, assuming that the number of guard RBs constituting the guard band is G (G is a natural number), then the G guard RBs can belong to adjacent lower (or higher) frequency subbands. Applying the above rules to Figure 4 In an exemplary embodiment of , three guard RBs may belong to the first (or second) subband. For another example, the first ceil(G / 2) (or floor(G / 2)) guard RBs may belong to a lower frequency adjacent subband, and the last floor(G / 2) (or ceil(G / 2)) guard RBs may belong to a higher frequency adjacent subband. Applying the above rule to Figure 4 In an exemplary embodiment, the first two (or one) RBs of the three protection RBs may belong to the first subband, and the last (or two) RBs of the three protection RBs may belong to the second subband. Alternatively, the terminal may know which LBT subband each protection RB belongs to through configuration from the base station. The index of the protection RB may be configured to the terminal in the form of an RB offset relative to a specific RB index (e.g., a specific RB indicating a subband boundary corresponding to the protection RB).

[0130] When the above method is applied, the terminal or base station can use the remaining RBs except the protection RBs to transmit signals in each LBT sub-band during the time period when the protection band is deactivated. On the other hand, the terminal or base station can use RBs including one or more protection RBs to transmit signals in each LBT sub-band during the period when the protection band is activated. That is, the first RB set may be composed of RBs that do not include protection RBs, and the second RB set may be composed of RBs including protection RBs. In addition, according to the above method, regardless of whether the protection band is activated, the frequency range of each LBT sub-band may be unchanged (for example, until reconfigured by RRC signaling). The activation and deactivation of the protection band will be described later.

[0131] Signal transmission method within the guard band

[0132] In a bandwidth portion, when all LBT operations of LBT subbands adjacent to a certain guard band are successful and the corresponding LBT subband is occupied by the transmitting node and / or the receiving node (and used for transmission), the guard band can be used for signal transmission. Similarly, the guard band can be activated in this case.

[0133] For example, refer to Figure 2In case (b), when the base station successfully performs LBT operation on the first and second subbands and occupies the first and second subbands at the same time, the base station and / or the terminal can not only use the first and second subbands to transmit signals, but also use the first guard band. On the other hand, when the base station fails to perform LBT operation in any one of the first subband and the second subband, the first guard band may not be used for signal transmission. Similarly, in this case, the first guard band may be deactivated. This method may be referred to as "method 001". Through method 001, whether to allow signal transmission in the guard band can be dynamically changed according to the result of the LBT operation. In this case, "whether the LBT subband adjacent to a certain guard band is occupied and / or whether the signal is transmitted through the guard band" can be signaled from the base station to the terminal, or from the terminal to the base station. For example, the base station can explicitly or implicitly indicate to the terminal the subband set occupied by the base station and used for downlink transmission through PDCCH, group common PDCCH, DM-RS, etc. The terminal can identify whether the LBT subband adjacent to the guard band is occupied through signaling, and determine whether to transmit the signal in the guard band according to the above conditions.

[0134] Alternatively, a signal may be sent from the base station to the terminal as to whether a guard band is used. This method may be referred to as "Method 002". For example, a signal may be sent from the base station to the terminal as to whether the resource allocation of a data channel (e.g., PDSCH or PUSCH) includes a guard band. For example, the above information may be included in a DCI (e.g., a DCI including scheduling information for the PDSCH or PUSCH) and may be dynamically indicated to the terminal. In this case, the guard band whose use is indicated may be part or all of the guard bands constituting the bandwidth portion. For example, it may be indicated only from the base station to the terminal as to whether a guard band between subbands occupied by the base station is used. Similarly, information about a set of subbands occupied by the base station may be sent from the base station to the terminal as a signal.

[0135] As described above, there may be two types of sets consisting of PRBs constituting the bandwidth part. The first PRB set is a set consisting of all PRBs constituting the bandwidth part. According to the above method, the cardinality of the first PRB set may be NB. The second PRB set may be a set consisting of PRBs constituting the bandwidth part that do not include PRBs belonging to the above-mentioned protection band. According to the above method, the cardinality of the second PRB set may be (NB-NG(1)-NG(2)-...-NG(K-1)). Here, NB can be regarded as the number of PRBs constituting the bandwidth part (not the number of RBs constituting the carrier), K can be regarded as the number of LBT subbands constituting the bandwidth part (not the carrier), and NG(g) can be regarded as the number of PRBs constituting the g-th protection band in the bandwidth part (not the number of RBs constituting the g-th protection band in the carrier).

[0136] In this case, the first PRB set or the second PRB set can be used for the transmission of various signals and channels transmitted by the node. In one example, the first PRB set can be used for the transmission of data channels (e.g., PDSCH, PUSCH). That is, the data channel can be allocated to part or all of the PRBs constituting the first PRB set, and part or all of the PRBs may include PRBs constituting the guard band. When the first PRB set is used for the transmission of a signal or channel, as described above, the PRBs constituting the guard band can be used for transmission only when certain conditions are met. In another example, the frequency resource region of CORESET can be allocated in the PRBs constituting the second PRB set. That is, the remaining PRBs except the PRBs constituting the guard band can be used for the transmission of PDCCH. In another example, the first PRB set can be used for the transmission of synchronization signals, reference signals, etc., for the measurement of channel state information (CSI), radio resource management (RRM), radio link monitoring (RLM), beam quality, etc. The synchronization signal may include a primary synchronization signal (PSS), a secondary synchronization signal (SSS), etc., and the reference signal may include a channel state information reference signal (CSI-RS), a sounding reference signal (SRS), etc.

[0137] On the other hand, in method 001 or method 002, when the LBT operations of the LBT subbands adjacent to a certain guard band are all successful and the corresponding LBT subbands are occupied by the transmitting node and / or the receiving node (and used for transmission), the guard band can be activated for the entire duration of the time period (e.g., COT or downlink transmission burst period) in which the adjacent LBT subband is occupied. On the other hand, in this case, the guard band can be partially activated (or partially deactivated) in a partial time period (e.g., COT or downlink transmission burst period) in which the adjacent LBT subband is occupied. The latter exemplary embodiment will refer to Figure 5 Give a description.

[0138] Figure 5 is a conceptual diagram illustrating an exemplary embodiment of a method of activating a guard band in a bandwidth portion consisting of a plurality of LBT sub-bands.

[0139] refer to Figure 5 , a bandwidth portion may be composed of three LBT sub-bands, namely, the first, second and third sub-bands. In addition, guard bands may be provided between adjacent LBT sub-bands. The first guard band may be provided between the first sub-band and the second sub-band, and the second guard band may be provided between the second sub-band and the third sub-band. In this exemplary embodiment, Figure 5 The bandwidth portion shown may be a downlink bandwidth portion or an uplink bandwidth portion. In the former case, the sending node or the node initiating the COT may be a base station, while in the latter case, the sending node or the node initiating the COT may be a terminal. Figure 5 , the base station or the terminal can successfully perform the LBT operation in the first subband and the second subband before the time point t1, and transmit the downlink or uplink transmission burst in the first subband and the second subband from the time point t1.

[0140] According to the guard band activation condition of method 001 or the signaling of method 002, the first guard band can be activated and used for signal transmission in the transmission burst period or the COT corresponding thereto. In addition, the second guard band can be deactivated and not used for signal transmission. In addition, according to the above method, the first guard band can be partially activated in a part of the COT. Figure 5 , the first guard band may be deactivated from time point t1 to time point t2, and may be activated from time point t2. The first guard band may also be activated until the COT or the end of the transmission burst. That is, a guard band that may be deactivated at the end of the COT or the transmission burst. In this case, each of the time points t1 and t2 may represent a start time point of a specific symbol or a boundary between specific symbols.

[0141] Therefore, a certain physical signal and / or channel may be transmitted in a resource area within a COT or a transmission burst in resource areas A, B, C, D, E, and F. For example, a terminal may expect to allocate a data channel (e.g., PDSCH, PUSCH, DM-RS for its decoding) within a resource area. In addition, reference signals (e.g., CSI-RS, SRS, etc.), control channels (e.g., CORESET, PUCCH resources, etc.), reserved resources, etc. may be configured and transmitted in a resource area. Alternatively, reference signals, control channels, etc. may be transmitted in the remaining resource areas other than resource areas C and D, i.e., in the resource areas where resource areas A, B, E, and F are combined. This may correspond to the second PRB set in the frequency domain described above. Assuming that PDSCH or PUSCH is not transmitted in the reserved resources, the terminal may rate match PDSCH or PUSCH around the reserved resources.

[0142] The time point at which the guard band is activated within the COT, that is, the time point t2, can be notified to the terminal by a signal from the base station, or can be notified to the base station by a signal from the terminal. For example, when the COT is a COT initiated by the base station, the base station can explicitly or implicitly signal the time point t2 to the terminal through PDCCH, group common PDCCH, DM-RS, etc. A group of downlink signals for transmitting information about the time point t2 can be used as an initial signal for downlink transmission burst detection of the terminal. When the group of downlink signals for transmitting information about the time point t2 includes a group common PDCCH, the group common PDCCH may include time slot format information, COT related information, and a subband set occupied in the COT in addition to information about the time point t2. In the case of NR, the group common PDCCH may correspond to DCI format 2_0 or a new DCI format to which DCI format 2_0 is modified. The base station may notify the terminal of the time point t2 at least at the beginning of the COT or a downlink transmission burst (e.g., part or all of the first A symbol of the COT).

[0143] Alternatively, the time point t2 can be semi-statically configured from the base station to the terminal. For example, the time point t2 can be configured to the terminal through RRC signaling (e.g., system information, cell-specific RRC signaling, or terminal-specific RRC signaling). Alternatively, the time point t2 can be pre-defined in the technical specification. The time point t2 can be defined using a time offset (e.g., B symbols, C time slots, etc.) relative to a reference time point (e.g., the start time point of the COT or the transmission burst, i.e., the time point t1), or can be configured or indicated from the base station to the terminal or from the terminal to the base station. The C time slots may include partial time slots. For example, depending on the position of the time point t1, the first time slot of the C time slots starting from the time point t1 may be a full time slot or a partial time slot. That is, the time point t2 can be defined, configured, or indicated as the start time point of the (C+1)th time slot among the time slots constituting the COT or the transmission burst. According to an exemplary embodiment, C=1. That is, the time point t2 can be the start time point of the second time slot among the time slots constituting the COT or the transmission burst. Applying this to Figure 5 According to the first exemplary embodiment, the time point t2 may be a start time point of the time slot (n+1).

[0144] The minimum time offset that a terminal can support can be defined as the capability of the terminal. Alternatively, factors that cause the time offset (e.g., digital / analog transmission bandwidth adjustment time, digital / analog filtering change time, etc.) can be defined as the capability of the terminal. In this case, the base station can appropriately configure the time point at which the guard band is activated based on the capability information of the terminal. Multiple terminals can have different capabilities regarding time offset, and capability information can be transmitted from the terminal to the base station. For example, capability information can be defined as an RRC message. In addition, the time offset may be different for each digital numerology (e.g., subcarrier spacing), or may be different for each frequency band. Two or more of the above methods can be used together.

[0145] The time point t2 may be defined or configured for each LBT category for channel acquisition. For example, when a COT or a transmission burst is initiated by the first category of LBT operation, the base station and the terminal may know in advance a set of LBT subbands occupied by the COT or the transmission burst, and may activate the guard band at a time point earlier than that in the case of the second to fourth categories of LBT operation. For example, the guard band may be activated from the start time point of the COT or the transmission burst. Applying this to Figure 5 According to the first exemplary embodiment, the time point t2 and the time point t1 may coincide with each other.

[0146] Based on the time point at which the guard band is activated within the COT or the transmission burst, the previous duration may be referred to as "D1" and the subsequent duration may be referred to as "D2". For example, D1 may be the duration from time point t1 to time point t2. For example, the second PRB set may be used for signal transmission in D1, and the first PRB set may be used for signal transmission in D2. In this case, one data channel (e.g., PDSCH or PUSCH) allocated to the terminal may belong to only one of D1 and D2.

[0147] Figure 6 is a conceptual diagram illustrating another exemplary embodiment of a method of activating a guard band in a bandwidth portion consisting of a plurality of LBT sub-bands.

[0148] In addition to the activation time of the first guard band, Figure 6 An exemplary embodiment of Figure 5 That is, reference Figure 6, the activation time point of the first protection band, that is, time point t2, can be the starting time point of time slot (n+1). In addition, D1 can be the duration from time point t1 to time point t2, and D2 can be the duration from time point t2 to the end time point of COT, that is, the entire duration of time slot (n+1). As described above, the data channels, that is, the first, second and third PDSCHs, can be allocated to the resource area where A, B, D, E and F are combined. In this case, by the above method, each PDSCH can belong to only one of D1 and D2. That is, the first and second PDSCHs can belong only to D1, and the third PDSCH can belong only to D2. The terminal may not expect any data channel to be allocated to belong to both D1 and D2. Alternatively, the terminal may regard the above situation (that is, the situation where the data channel is allocated to belong to both D1 and D2) as an error, and may not send or receive the allocated data channel.

[0149] The terminal may assume that the first PRB set or the second PRB set is used for resource allocation of data channels in D1 and D2. For example, the terminal may assume that PDSCH or PUSCH is allocated in the second PRB set in D1, so that the frequency domain resource allocation information can be interpreted based on this assumption. In addition, the terminal may assume that PDSCH or PUSCH is allocated in the first PRB set in D2, so that the frequency domain resource allocation information can be interpreted based on this assumption. For example, the terminal may interpret the frequency domain resource allocation field of the DCI based on the PRB index in the first or second PRB set.

[0150] The above method can be applied in the case of scheduling by dynamic grant and in the case of configuration grant or semi-persistent scheduling. Alternatively, the above method can be applied to data channels (e.g., PDSCH, PUSCH) scheduled by dynamic grant or DCI. The CRC applied to the dynamic grant or DCI may be scrambled by C-RNTI, MCS-C-RNTI, second C-RNTI, etc. In addition, the CRC applied to the dynamic grant or DCI may be scrambled by CS-RNTI. The latter case may correspond to the initial transmission and retransmission of PDSCH configured by type 2 grant or by semi-persistent scheduling. On the other hand, unlike dynamic scheduling, since the resource allocation by configuration grant or semi-persistent scheduling is semi-statically repeated periodically, it may be difficult to ensure that a data channel always belongs to only one of D1 and D2. Therefore, the data channel allocated by configuration grant or semi-persistent scheduling may belong to both D1 and D2. In this case, the terminal may not send or receive the data channel. In addition, the terminal may not send or expect to receive a hybrid automatic repeat request confirmation (HARQ-ACK) corresponding to the data channel.

[0151] Alternatively, when the resource region of the data channel belongs to both D1 and D2, the data channel can be transmitted. In this case, when the DM-RS used to decode the data channel is mapped to the symbol belonging to D1, the DM-RS may not be mapped to the guard band. That is, the DM-RS may be mapped only within the second PRB set. Therefore, channel assessment of the guard band may be difficult to pass through the DM-RS. To solve this problem, when the data channel is transmitted through the resource region belonging to both D1 and D2, the DM-RS may be mapped to the symbol belonging to D2. For example, when type 2 mapping is used for PDSCH or PUSCH, the DM-RS used for its decoding may be mapped to the earliest symbol in the symbol belonging to D2. In this case, when CORESET is configured in the earliest one or more symbols in D2, the DM-RS used for decoding PDSCH can be mapped to one or more symbols after the symbol to which CORESET is mapped. As another method of enabling channel assessment of the guard band, an additional DM-RS can be sent for decoding the data channel. For example, the DM-RS mapped to the beginning of the data channel may be mapped only to the second PRB set in D1, while the additional DM-RS may be mapped to the first PRB set including the guard band in D2.

[0152] When a data channel is repeatedly transmitted or when time slot aggregation is applied, multiple transmission instances constituting the repeated transmission of the data channel may be allocated to different durations. For example, when a PDSCH is transmitted twice, the first PDSCH instance may belong to D1, and the second PDSCH instance may belong to D2. In this case, the frequency domain resource allocation of the first instance may be equally applied to other instances except the first instance. That is, when the first instance is placed in D1, the remaining instances may not be allocated to the guard band. To solve this problem, the data channel may be allocated in the first PRB set even in D1. That is, the nominal resource allocation of the data channel may include the protection PRB regardless of the duration; and when the data channel is allocated in a resource region including the protection PRB in D1, the terminal may send or receive the data channel in the region not including the protection PRB. The terminal may puncture the data channel for the protection PRB, and may not map the data channel to the protection PRB. Alternatively, the terminal may rate match the data channel around the protection PRB.

[0153] According to the above method, the PRB set that can be used for resource allocation of the data channel can be changed dynamically. For example, the second PRB set can be used at the beginning of the COT or the transmission burst, and the first PRB set can be used after a specific time point. Alternatively, the PRB set that is valid for resource allocation of the data channel can be dynamically indicated to the terminal. For example, information about the available PRB set can be included in the DCI for scheduling the data channel, and the frequency domain resource allocation of the data channel can be performed for the available PRB set indicated by the DCI. For example, the information of the frequency domain resource allocation field of the PDSCH or PUSCH can be interpreted based on the PRB index of the available PRB set indicated by the same DCI. The base station can indicate the first PRB set or the second PRB set as an available PRB set. The DCI field used for this can be composed of 1 bit. Alternatively, at least a portion of the DCI field defined for other purposes can be used to send information about the available PRB set to the terminal.

[0154] In the above method, in addition to the first and second PRB sets, another PRB set may be indicated as an available PRB set. Each PRB set may include one or more LBT subbands and zero or more guard bands. Each PRB set may be configured to the terminal by higher layer signaling (e.g., RRC signaling). In this case, the size of the DCI field for indicating the available PRB set may be determined by the number of (candidate) PRB sets configured by higher layer signaling.

[0155] On the other hand, when frequency hopping between time slots or between transmission instances is applied to the data channel, at least a portion of the remaining instances may be mapped to a frequency region including a guard band. Alternatively, the terminal may expect that all transmission instances constituting repeated transmissions of the data channel are always scheduled to belong to only one of D1 and D2.

[0156] In addition to data channels, the above-mentioned method can also be applied to other physical signals and channels. For example, for each transmission of a signal and channel (eg, aperiodic CSI-RS, aperiodic SRS, etc.) dynamically indicated to a terminal, only one of D1 and D2 may be used.

[0157] On the other hand, a method of dynamically changing the frequency range of the LBT sub-band according to whether the guard band is activated may be considered.

[0158] Figure 7 is a conceptual diagram illustrating still another exemplary embodiment of a method of activating a guard band in a bandwidth portion composed of a plurality of LBT sub-bands.

[0159] refer to Figure 7, two LBT subbands can be configured in a carrier or bandwidth portion. In addition, a guard band can be configured in a carrier or bandwidth portion. The guard band can be activated at a certain point in time and can be used for signal transmission. In this case, the frequency range of the LBT subband can be changed based on the point in time when the guard band is activated or deactivated. That is, the range of the LBT subbands of D1 and D2 can be different. For example, Figure 7 As shown, the LBT subband in D1 may have a range that does not include a guard band or a guard PRB. On the other hand, the range of the LBT subband in D2 may include a guard band or a guard PRB. The ranges of the LBT subbands of D1 and D2 may be configured separately. Alternatively, the range of the LBT subband in one duration may be configured, and the range of the LBT subband in another duration may be derived therefrom. The duration and LBT subband in which each guard PRB is included may be determined by a predetermined rule or by a configuration from a base station.

[0160] According to the LBT subband configuration method proposed in the present invention, the base station can appropriately configure the LBT subband and / or the guard band between the LBT subbands according to the situation. For example, the base station can configure the subband and / or the guard band so that each subband constituting the bandwidth portion corresponds to each channel of the corresponding frequency band. For example, in the 5GHz unlicensed band, each channel can be channelized so that it has a 20MHz bandwidth. In this case, the base station can configure the bandwidth portion for the terminal so that each subband in the bandwidth portion belongs to each 20MHz channel. For another example, the base station can configure the guard band between the subbands in the bandwidth portion and control the interference between the subbands. On the other hand, the base station may not configure the guard band for the terminal (for example, the number of PRBs of the guard band is set to 0), and the base station and / or the terminal can control the interference between the subbands by appropriately applying the waveform generation scheme, the modulation scheme, etc.

[0161] On the other hand, in the above exemplary embodiments, the statement that the data channel is not mapped to the guard band (e.g., guard PRB) within the carrier may mean that the data channel is rate matched around the guard band (e.g., guard PRB) within the carrier. That is, in some cases, the operation of mapping the data channel to a resource region that does not include specific resources (e.g., PRB) may be equivalent to the operation of rate matching the data channel around the resource region that does not include specific resources (e.g., PRB). Some cases may include the case where the data channel is PUSCH. Specifically, when PUSCH is mapped and transmitted on one or more interlaces in one or more LBT subbands, according to the proposed method, the terminal may transmit PUSCH in a PRB that does not include the guard PRB among the PRBs constituting the interlace. This may mean that the terminal transmits PUSCH by matching the PUSCH rate around the guard PRB. In this case, the resource allocation information of PUSCH may include one or more LBT subbands or their indices and one or more LBT subbands or their indices, which may be configured or indicated from the base station to the terminal.

[0162] In addition, in the above exemplary embodiments, the intra-carrier guard band may refer to reserved resources. For example, when the intra-carrier guard band consists of one or more PRBs, the base station may configure the PRBs as reserved resources to the terminal. The terminal may send PUSCH by rate matching the PUSCH around the reserved resources (when the resource area of ​​the PUSCH includes reserved resources configured by the base station), and the base station may receive PUSCH on the premise that the PUSCH is rate matched by avoiding the reserved resources. That is, the terminal may transmit PUSCH by mapping PUSCH to a resource area of ​​PUSCH other than the reserved resources. Therefore, the reserved resources may mean a resource area where the transmission of PUSCH (or PDSCH) is unavailable. The terminal may transmit PUSCH in a resource area other than the protection PRB by configuring the protection PRB as a reserved resource of the base station and mapping PUSCH (or PDSCH) around the reserved resources and performing rate matching.

[0163] The reserved resources can generally be configured as a combination of one or more PRBs in the frequency domain and / or one or more symbols (or one or more time slots) in the time domain. When the frequency domain information is configured to be omitted, the reserved resources may include all PRBs in the frequency domain (e.g., all PRBs in the bandwidth part). When the time domain information is configured to be omitted, the reserved resources may include all symbols in the time domain. When it is necessary to configure the carrier guard band of the unlicensed band as a reserved resource, only the frequency domain information may be configured, that is, information indicating the PRB set corresponding to the guard band may be configured.

[0164] The terminal can semi-statically configure the reserved resources and can always or semi-statically rate match the PUSCH (or PDSCH) around the reserved resources. A higher layer signaling process (e.g., RRC signaling) can be used for this purpose. For example, the protection PRB in the carrier of the unlicensed band can be configured as a semi-static reserved resource. In this case, the base station and the terminal can not transmit the data channel in the protection PRB in any time interval within the COT. This may lead to a reduction in spectrum efficiency.

[0165] On the other hand, the base station can dynamically instruct the terminal whether to rate match the data channel around the configured reserved resources. A physical layer signaling process (e.g., DCI signaling) can be used for this purpose. Specifically, one or more reserved resource groups can be configured, and the terminal can be instructed whether to rate match each group by scheduling the field value of the DCI. A reserved resource group may include one or more reserved resource configurations. In the case of PUSCH through dynamic authorization, the above method can be used to indicate whether the terminal is rate matching PUSCH around reserved resources (e.g., protection PRBs). In this case, the base station can allocate PUSCH to a resource area that does not include protection PRBs by instructing the terminal to rate match PUSCH around the protection PRBs in D1, and allocate PUSCH to a resource area that includes protection PRBs by instructing the terminal not to rate match PUSCH around the protection PRBs in D2.

[0166] On the other hand, when PUSCH is a configuration grant, the terminal may not receive an uplink grant corresponding to PUSCH. The scheduling information of PUSCH can be configured by RRC signaling or indicated by a previously transmitted DCI. In this case, it may be difficult to indicate the above operations in D1 and D2 by the rate matching field of DCI. That is, it may be difficult for the terminal to dynamically indicate by the base station whether to map PUSCH by including reserved resources (e.g., protection PRBs).

[0167] In the proposed method, the time domain resource region of the reserved resources can be defined or configured based on a specific time point within the COT or a transmission burst (e.g., a downlink or uplink transmission burst). For example, the time domain resource region of the reserved resources can be determined as a predetermined time interval from the starting time point of the COT or the transmission burst. The predetermined time interval can be composed of one or more symbols or one or more time slots. In the latter case, the first time slot can be a partial time slot. For example, the predetermined time interval can be the interval from the starting time point of the COT or the transmission burst to the Xth occurring time slot boundary (X is a natural number). The predetermined time interval can be pre-defined in the technical specification or configured by the base station to the terminal. For example, X=1, X=2, etc. can be defined in the technical specification, or the value of X can be configured for the terminal. The predetermined time interval can correspond to D1. In this case, the reserved resources can be configured by semi-static signaling.

[0168] According to the above method, the protection PRB within the carrier can be configured as the frequency resource of the reserved resource, and the time resource of the reserved resource can be defined or configured as a certain time starting from the COT or the starting time point of the transmission burst. The reserved resources can be considered as semi-static reserved resources. That is, the terminal can always or semi-statically rate match the PUSCH (or PDSCH) around the reserved resources and transmit the PUSCH (or PDSCH). Even so, since the reserved resources only exist until a certain time point (e.g., D1) within the COT or the transmission burst, it is possible for the terminal to map the data channel to the protection PRB thereafter (e.g., D2).

[0169] In another proposed method, the terminal may determine whether to rate match the PUSCH around the reserved resources, and transmit information about whether the terminal matches the PUSCH around the reserved resources together with the corresponding PUSCH to the base station. The PUSCH may be a PUSCH authorized by configuration. Information about whether to perform rate matching may be piggybacked and transmitted on the PUSCH as uplink control information (UCI). For convenience, the UCI may be referred to as a configuration grant (CG)-UCI. Specifically, the CG-UCI may be mapped to a portion of the resource region or the entire resource region of the PUSCH for transmission, and channel coding may be applied separately from the PUSCH. The CG-UCI may be mapped to one or more symbols other than the symbol to which the DM-RS for PUSCH decoding is mapped. The reserved resources may be semi-statically configured by the base station (e.g., by RRC signaling). Information about whether the terminal matches the PUSCH around the reserved resources may be represented by 1 bit. On the other hand, a reserved resource group may be configured for the terminal, and the base station may be indicated to whether the terminal performs rate matching in units of the reserved resource group. For example, when two reserved resource groups are configured for the terminal, information on whether the terminal matches the PUSCH rate around each reserved resource group can be represented by 1 bit respectively, and 2 bits in total, and sent to the base station.

[0170] According to the above method, the intra-carrier protection PRB can be semi-statically configured as a reserved resource, and the terminal can dynamically transmit information about whether to rate match the PUSCH around the reserved resources together with the PUSCH to the base station. For example, the terminal can perform PUSCH rate matching around the intra-carrier protection PRB in D1, and send the information about rate matching together with the PUSCH to the base station. In addition, the terminal may not rate match the PUSCH around the intra-carrier protection PRB in D2 (that is, the PUSCH can be mapped to an area including the protection PRB), and send the information together with the PUSCH to the base station. The base station can receive information about whether to perform rate matching (such as UCI), identify the resource area to which the PUSCH is mapped through this information, and perform a PUSCH reception operation based on the identified resource area.

[0171] In another proposed method, when PUSCH is allocated to consecutive LBT subbands, the terminal may assume that there is no guard band or guard PRB between adjacent LBT subbands. That is, the terminal may use all PRBs belonging to the LBT subband for PUSCH transmission. In this case, there is no frequency gap between LBT subbands and the LBT subbands may be adjacent to each other.

[0172] Remapping of data channels

[0173] According to the above method, a guard band can be defined or configured between two adjacent LBT sub-bands of a bandwidth portion. At the same time, a method of defining or configuring two guard bands between two adjacent LBT sub-bands to effectively remap data channels (e.g., PDSCH, PUSCH, PSSCH, etc.) can be considered.

[0174] Figure 8 is a conceptual diagram illustrating a configuration of an LBT sub-band according to still another exemplary embodiment of the present invention.

[0175] refer to Figure 8 , a bandwidth portion may consist of four sub-bands, and two guard bands may be inserted between each two adjacent sub-bands. Each of the two guard bands may correspond to one of the two adjacent sub-bands. For example, guard bands corresponding to the respective sub-bands (e.g., lower guard band and upper guard band) may exist at both ends of the bandwidth of each sub-band. In special cases, guard bands may not be inserted at both ends of the bandwidth portion. For example, Figure 8 In an exemplary embodiment of the present invention, the lower guard band of the first sub-band and the upper guard band of the fourth sub-band may not be defined or configured.

[0176] Similarly, each guard band may be composed of some of the PRBs constituting the bandwidth portion. According to the above method, when the number of LBT subbands constituting the bandwidth portion is K, the number of guard bands may be (2×K-2). The guard bands may be configured to have sizes independent of each other. Alternatively, some or all of the guard bands may be configured to be of the same size, i.e., the same number of PRBs. The size of some guard bands may be zero. The number of PRBs constituting each guard band may be signaled to the terminal by the above method. The sizes of two adjacent guard bands and their signaling may be associated with each other.

[0177] In addition, even in Figure 8 In an exemplary embodiment of the present invention, the guard band can be used for signal transmission by the above method. In addition, the above guard band activation and deactivation methods can also be applied equally. For example, a pair of adjacent guard bands can be activated or deactivated at the same time by the above described conditions or signaling.

[0178] On the other hand, a data channel can be allocated to multiple LBT subbands within a bandwidth portion. In this case, when the LBT operation of the transmitting node fails in some subbands, the data channel may be punctured in the subbands where the LBT operation fails and transmitted only in the remaining subbands where the LBT operation succeeds. Code block group (CBG)-based transmission can be used for such subband-based puncturing robust transmission. A CBG can be composed of one or more code blocks (CBs), and the data channel can include one or more CBGs. The receiving node can receive the data channel and perform a CRC check on each CBG, and feedback HARQ-ACK to the transmitting node based on the CBG. The transmitting node can receive the HARQ-ACK for each CBG and improve the transmission efficiency by retransmitting only the CBG that the receiving node failed to receive.

[0179] Considering the uncertainty of the above-mentioned LBT operation, it may be advantageous to map each CBG to as few LBT subbands as possible. To this end, the signals (e.g., modulated symbol sequences) constituting the data channel (e.g., PDSCH or PUSCH) can be mapped sequentially in units of LBT subbands. That is, the symbol sequence of PDSCH or PUSCH can be first mapped to the RE of the first LBT subband in the scheduling resource area, then mapped to the RE of the second LBT subband, and finally mapped to the RE of the last LBT subband. Within a subband, the subcarrier index in the frequency domain can be remapped in ascending order first, and then the symbol index in the time domain can be remapped in ascending order. In addition, when a data channel has multiple transmission layers, the data channel can be remapped in the order of transmission layer domain, frequency domain, and time domain within a subband, with priority given to the transmission layer domain. When the data channel includes multiple CBs, the symbol sequences constituting the multiple CBs can be mapped in sequence according to the mapping rules. Whether the mapping rule is applied can be notified to the terminal by a signal from the base station (e.g., through RRC signaling). Separate signaling procedures may be used for uplink transmissions (eg, PUSCH) and downlink transmissions (eg, PDSCH).

[0180] On the other hand, when the bandwidth portion includes a guard band, the data channel may be remapped to a resource region including the guard band, in which case the LBT subband and the guard band may be considered in the remapping of the data channel. As a method for processing mapping to the guard band, each guard band may be considered to belong to any subband, and the remapping of the data channel may be performed in the above-mentioned mapping order. This method may be referred to as "method 010".

[0181] Fig. 9 is a conceptual diagram for describing an exemplary embodiment of a data channel remapping method taking into account an LBT sub-band and a guard band.

[0182] Fig. 9 Case (a) shows a first exemplary embodiment of data channel remapping considering LBT sub-band and guard band, Fig. 9 Case (b) shows a second exemplary embodiment of data channel remapping considering LBT sub-band and guard band, and Fig. 9 Case (c) shows a third exemplary embodiment of data channel remapping considering LBT sub-band and guard band.

[0183] refer to Fig. 9 In cases (a) to (c), a bandwidth portion may include two LBT sub-bands and may include one or more guard bands. In this exemplary embodiment, the number of transmission layers of the data channel is not considered. That is, it is assumed that the number of transmission layers is one layer.

[0184] refer to Fig. 9 In case (a), there may be two guard bands between subbands. The first guard band may be an upper guard band of the first subband, and the second guard band may be a lower guard band of the second subband. In this case, according to method 010, each guard band may be considered to belong to any one subband, and remapping (RE mapping) of the data channel (e.g., PDSCH or PUSCH) may be performed. For example, the upper guard band of the first subband may be considered to belong to the first subband, and the lower guard band of the second subband may be considered to belong to the second subband. Under the above assumptions, the data channel may be remapped to the frequency domain, time domain, LBT subband domain, and transport layer domain in a predetermined order. Reference Fig. 9 In case (a), the data channel may be remapped in the order of frequency first and time second in the first subband including the upper guard band of the first subband, and then the data channel may be remapped in the order of frequency first and time second in the second subband including the lower guard band of the second subband. As described above, the symbol sequence may be mapped to the subcarriers in ascending order in the frequency domain. However, in the figure, this is represented in units of PRBs.

[0185] refer to Fig. 9 In case (b), there may be guard bands at both ends of the bandwidth of each bandwidth part. The first and second guard bands may be the lower guard band and the upper guard band of the first subband, respectively, and the third and fourth guard bands may be the lower guard band and the upper guard band of the second subband, respectively. Also in this case, according to method 010, each guard band may be considered to belong to any one subband, and remapping of the data channel may be performed. For example, the lower guard band and the upper guard band of the first subband may be considered to belong to the first subband, while the lower guard band and the upper guard band of the second subband may be considered to belong to the second subband. Under the above assumptions, the data channel may be remapped to the frequency domain, the time domain, the LBT subband domain, and the transport layer domain in a predetermined order.

[0186] refer to Fig. 9 In case (c), there may be a guard band between subbands. Also in this case, according to method 010, the guard band may be considered to belong to any subband, and remapping of the data channel may be performed. For example, the guard band may be considered to belong to the first subband. Under the above assumptions, the data channel may be remapped to the frequency domain, time domain, LBT subband domain, and transport layer domain in a predetermined order. Fig. 9 In case (c), the data channel may be first remapped in the first subband including the guard band in the order of frequency first and time second, and then remapped in the second subband in the order of frequency first and time second.

[0187] On the other hand, in the unlicensed band, a PUSCH or PUCCH resource allocation scheme based on interleaving can be considered. One interleaving can be composed of equally spaced PRBs. For example, one interleaving can be composed of every tenth PRB. Assuming that the bandwidth part consists of 50 PRBs, 10 interleavings (e.g., interleavings 0 to 9) can be defined in the bandwidth part, and each interleaving can be composed of 5 PRBs. PUSCH or PUCCH can be allocated to one or more LBT subbands within a bandwidth part. For example, PUSCH can be allocated to interleaving 0 of a specific LBT subband of the bandwidth part. In this case, interleaving 0 can be defined as some PRBs with equal intervals among all PRBs constituting the LBT subband. In addition, PUSCH or PUCCH can be allocated to multiple interleavings. Information (e.g., a set of indices) about the interleaving and LBT subbands to which PUSCH or PUCCH is allocated can be configured or indicated to the terminal.

[0188] In addition to the remapping of the data channel, method 010 can also be applied to transmission in units of LBT subbands. For example, according to method 010, the guard band can be considered to be included in the LBT subband, and an interlace can be defined for the LBT subband including the guard band. That is, an interlace can be defined as a number of PRBs with equal intervals among all PRBs constituting one or more LBT subbands and one or more guard bands included therein. When a PUSCH or PUCCH is assigned to an interlace including a guard band, the PUSCH or PUCCH including the guard band can be transmitted when the guard band is activated.

[0189] DRS candidate resource configuration

[0190] In the NR system, the base station can transmit multiple SS / PBCH blocks to support multi-beam based initial access of the terminal. Multiple SS / PBCH blocks can be transmitted in one SS / PBCH block transmission period, and the same beam or different beams can be applied to them. In one SS / PBCH block transmission period, the number of SS / PBCH block candidates that can be transmitted and the time resource location of each candidate can be pre-defined in the technical specifications for each frequency band, and the base station can actually transmit part or all of one or more SS / PBCH block candidates. The SS / PBCH block can include at least DM-RS, PBCH, SSS and PSS for decoding PBCH.

[0191] On the other hand, in the unlicensed band, due to the failure of the LBT operation of the base station (or terminal), the SS / PBCH block may not be transmitted in certain time intervals. Therefore, in the unlicensed band, it may be helpful to increase the number of candidate resources that can transmit SS / PBCH blocks. Hereinafter, a method of defining or configuring multiple discovery reference signal (DRS) resources in the time domain and frequency region and using them to transmit DRS will be described. In an exemplary embodiment, DRS can be configured, transmitted and measured in the time domain (e.g., within a DRS cycle, within a DRS transmission window) and the frequency domain (e.g., within a carrier, within a bandwidth part, within an LBT subband) even in a singular number. In the following exemplary embodiments, for ease of description, a method of configuring, transmitting and measuring "multiple" DRS will be described, but "multiple" DRS (e.g., multiple SS / PBCH blocks) can also be interpreted as "at least one" or "one or more" DRS (e.g., "at least one" or "one or more" SS / PBCH blocks).

[0192] In the following description, DRS may refer to a group of signals and channels used for RRM measurement and reporting, cell selection, cell search, initial access, etc. of a terminal, and may include at least SS / PBCH blocks. In addition, in addition to SS / PBCH blocks, DRS may also include CORESET (or PDCCH search space), PDSCH, CSI-RS, etc. For example, DRS may include resources of CORESET#0 and PDCCH search space set #0 or a PDCCH type 0 CSS set associated with CORESET#0, and DCI (e.g., DCI for scheduling a PDSCH including SIB1) may be transmitted through PDCCH candidates of the search space set in the resources.

[0193] In one DRS transmission cycle, multiple DRS candidates may be defined or configured. Each DRS candidate may correspond to each SS / PBCH block candidate. That is, each DRS candidate may include at least one SS / PBCH block candidate, and also include CORESET (or PDCCH search space), PDCCH, PDSCH, CSI-RS, etc. associated with the SS / PBCH block candidate. The CORESET (or PDCCH search space), PDCCH, PDSCH, CSI-RS, etc. constituting the DRS candidate may be mapped around the resource area to which the SS / PBCH block candidate associated with it is mapped. For example, the signals and channels constituting the DRS candidate, or their resource areas, may be mapped to the same time slot as the SS / PBCH block candidate associated with it. In addition, the signals and channels constituting the DRS candidate, or their resource areas, may be mapped to the same subband or another subband as the SS / PBCH block candidate associated with it. The base station may actually transmit some or all of one or more DRS candidates. Hereinafter, the expression that a base station transmits or measures a DRS or a DRS candidate may mean that the base station transmits or measures a signal and / or a channel (eg, a SS / PBCH block or a SS / PBCH block candidate) constituting the DRS or the DRS candidate.

[0194] Fig.10 is a conceptual diagram for describing an exemplary embodiment of configuring DRS resources in the time domain.

[0195] refer to Fig.10 , a DRS transmission window can consist of 10 time slots, each of which can include two DRS candidate resources (or two SS / PBCH block candidate resources). 20 DRS candidates (or 20 SS / PBCH block candidates) can be arranged in one DRS transmission window. Fig.10 In the figure, for convenience, only the SS / PBCH block is shown in the components of the DRS. In this case, the subcarrier spacing can be 30kHz, the length of one time slot can be 0.5ms, and the length of the DRS transmission window can be 5ms (i.e., the length of half a radio frame). If a subcarrier spacing of 15kHz is used, a DRS transmission window can be composed of 5 time slots, each time slot can include two DRS candidate resources (or two SS / PBCH block candidate resources), and 10 DRS candidates (or 10 SS / PBCH block candidates) can be arranged in one DRS transmission window. The DRS transmission window may appear periodically in the time domain. For example, the period of the DRS transmission window may be 20ms or 40ms. In addition, the period of the DRS transmission window may be configured from the base station to the terminal. In some cases, the DRS transmission window may be used in the same or similar sense as the SS / PBCH block burst set. In addition, hereinafter, for convenience, the periodicity of the DRS transmission window may be referred to as "DRS periodicity".

[0196] The base station may actually send some or all DRS candidates according to the beam operation scheme and LBT results. For example, when the base station occupies the channel through the second type of LBT operation, the base station may send DRS at a predetermined time interval, for example, up to 5% of the DRS transmission window period. In addition, the time interval shall not exceed 1ms. In this case, according to Fig.10 In an exemplary embodiment, a base station may transmit up to four DRSs in one downlink transmission burst or COT.

[0197] On the other hand, multiple DRS candidates can be defined or configured in the frequency domain. When a bandwidth part or carrier (hereinafter collectively referred to as a "bandwidth part") consists of multiple LBT sub-bands, multiple DRSs can be transmitted at different frequency positions within a bandwidth part. For example, multiple DRS candidates within a bandwidth part can be defined or configured in different LBT sub-bands (or sub-bands corresponding to LBT sub-bands). The base station can actually transmit part or all of the multiple DRS candidates in multiple LBT sub-bands. The method may be referred to as "method 100".

[0198] Fig.11 is a conceptual diagram for describing a first exemplary embodiment of a DRS resource configuration in the frequency domain and / or time domain.

[0199] refer to Fig.11 , one bandwidth part may be composed of four LBT subbands. In this case, according to method 100, a DRS candidate or a resource region (eg, a DRS transmission window) including a DRS candidate may be defined or configured for each LBT subband. Fig.11 , a DRS transmission window can be defined or configured for each subband, and the time position of the DRS transmission window can be the same for all subbands. This method may be referred to as "method 110". Specifically, method 110 can be used as a default operating method for a terminal to perform initial access or when the terminal is in an RRC idle state. In the following description, when considering multiple DRSs in the frequency domain, the DRS transmission window can be used as a concept that includes both time and frequency resources. In addition, unless otherwise specified, a bandwidth portion may refer to a downlink bandwidth portion.

[0200] In method 110, the same time position of the DRS transmission window may mean that the length, periodicity, start time point or boundary of the DRS transmission window are the same. Fig.11, for all LBT subbands in the bandwidth part, the length, periodicity and starting time point of the DRS transmission window can be the same. For example, all DRS transmission windows can have a length of 5 ms and a periodicity of 40 ms. In this case, the common time resource configuration information can be transmitted only once per bandwidth part, rather than being repeatedly sent to the terminal for each subband.

[0201] Fig.12 is a conceptual diagram for describing a second exemplary embodiment of DRS resource configuration in the frequency domain and / or time domain, and Fig.13 is a conceptual diagram for describing a third exemplary embodiment of a DRS resource configuration in the frequency domain and / or time domain.

[0202] refer to Fig.12 and 13 , as Fig.11 In an exemplary embodiment, a bandwidth portion may include four LBT subbands, and a resource region (e.g., a DRS transmission window) or a DRS candidate including a DRS candidate may be defined or configured for each subband. According to this exemplary embodiment, the time position of the DRS transmission window may be different for each subband. As described above, a method in which the time position of the DRS transmission window may be different for each subband may be referred to as "method 120".

[0203] In this exemplary embodiment, the lengths of the DRS transmission windows of each subband may be the same. For example, the lengths of all DRS transmission windows may be 5 ms. Alternatively, the lengths of the DRS transmission windows of each subband may be different. Fig.12 In an exemplary embodiment of the present invention, the periodicity of the DRS transmission window of each subband may be the same. However, for each subband, the starting time point of each periodicity of the DRS transmission window may be different. On the other hand, referring to Fig.13 In an exemplary embodiment, the periodicity of the DRS transmission windows of each subband and the start time point of each periodicity may be the same. That is, the common periodicity and period may be applied to multiple DRS transmission windows. In this case, the time position of each DRS transmission window may be different within the same period, and the time position may be defined as a time offset value or configured to the terminal. Fig.13 In an exemplary embodiment of the present invention, the time offsets of the DRS transmission windows of the first to fourth subbands may be represented by T1, T2, T3, and T4, respectively. For example, the common periodicity may be 40 ms, and the time offsets T1, T2, T3, and T4 may be 0 ms, 5 ms, 10 ms, and 15 ms, respectively. On the other hand, even if method 120 is applied, the time positions of some or all DRS transmission windows may be the same. For example, the time offsets T1, T2, T3, and T4 may all have the same value. This may correspond to Fig.11That is, in some cases, the method for configuring DRS resources by method 110 may also be implemented by method 120. In addition, in the above exemplary embodiments, according to the starting time point of the DRS transmission window, the DRS transmission windows may overlap at least partially in time.

[0204] According to the above exemplary embodiment, at least one DRS transmission window may be configured for each LBT subband constituting a bandwidth portion. On the other hand, according to another exemplary embodiment of the present invention, a DRS transmission window may be configured for each of some LBT subbands constituting a bandwidth portion.

[0205] In the above method, multiple DRS candidates may be arranged in the time domain within each DRS transmission window. In this case, the configuration of the time domain DRS resources (or DRS candidate resources) within the DRS transmission window may be equally applied to all corresponding LBT subbands. Fig.10 The DRS resource configuration of the first exemplary embodiment can be equally applied to Figure 11 to Figure 13 In the exemplary embodiment of FIG.

[0206] Fig.14 is a conceptual diagram for describing a fourth exemplary embodiment of configuring DRS resources in the frequency domain and / or time domain.

[0207] according to Fig.14 In an exemplary embodiment, multiple DRS transmission windows may be configured in multiple LBT subbands constituting a bandwidth portion, and each DRS transmission window may include multiple DRS candidates in the time domain. Fig.14 In cases (a) and (b), one bandwidth part may include two DRS transmission windows in the frequency domain, and each DRS transmission window may include 10 DRS candidates (or 10 SS / PBCH block candidates). Therefore, in this case, a maximum of 20 DRS candidates may be configured in one DRS cycle in the bandwidth part. Fig.14 In an exemplary embodiment of case (a), the DRS transmission window of the first subband and the DRS transmission window of the second subband may be aligned in the time domain. Fig.14 In an exemplary embodiment of case (b), the time positions of the DRS transmission window of the first subband and the DRS transmission window of the second subband may be different from each other.

[0208] In the above method, the base station may signal the terminal about the location of the plurality of DRS resources in the frequency domain and / or time domain. For example, in the above exemplary embodiment, the base station may signal the terminal about the length and / or time location of the DRS transmission window for each subband. For example, in Fig.13In an exemplary embodiment, the common periodicity of the DRS transmission window and the time offset of the DRS transmission window of each subband within the period can be notified to the terminal by a signal from the base station. In addition, the frequency position of the DRS resource of each subband can be notified to the terminal by a signal from the base station. The frequency position of the DRS resource can be signaled to the terminal as the frequency position information of the specific signal and / or channel (e.g., SS / PBCH block) constituting the DRS. For example, the terminal can obtain the frequency position information of the SS / PBCH block of each LBT subband through signaling from the base station, and the frequency position information can indicate the CRB or PRB to which the SS / PBCH block is mapped. For example, the signaling can be cell-specific RRC signaling (e.g., SIB, SIB1, etc.). Alternatively, the signaling can be terminal-specific (UE-specific) RRC signaling.

[0209] The location information of multiple DRS resources can not only help terminals in RRC connected mode, but also help terminals in RRC idle mode or RRC inactive mode to receive DRS. Information about the DRS resources of the terminal may be included in the DRS and transmitted. For example, the information may be transmitted through PBCH or MIB. Alternatively, the information may be implicitly or explicitly transmitted through another signal constituting the SS / PBCH block (e.g., PSS, SSS, and DM-RS for decoding PBCH). Alternatively, the information may be transmitted to the terminal via PDSCH included in system information (e.g., SIB1). In this case, considering the signaling overhead, only partial information about the location of the DRS resources may be transmitted. For example, information about the number or set of LBT subbands in which DRS can be transmitted may be transmitted through the above-mentioned signaling process. In this case, the terminal, in particular a terminal in RRC idle mode or a terminal in RRC inactive mode, may assume that the location of the DRS time resources (e.g., DRS transmission window) is as shown in Figure 8 As in the exemplary embodiment of , it is the same in multiple LBT sub-bands.

[0210] Some DRS resource location information may be predefined in the technical specifications. For example, the default value of the DRS periodicity may be predefined in the technical specifications. In addition, the terminal may obtain the DRS resource location information of at least some subbands by receiving the SS / PBCH block (e.g., during the initial access process). For example, the terminal may obtain the position of half a radio frame including the DRS by receiving the PBCH DM-RS and / or PBCH in any of the multiple subbands constituting the bandwidth portion. In this case, for example, in the case of method 110, when the relative distance between the DRS resources of each subband in the time domain is predetermined, the terminal may determine the time resource position (e.g., DRS transmission window) of the DRS of other subbands based on the time resource position (e.g., the position of the DRS transmission window) obtained by the above method. In addition, the terminal may receive the DRS resource position of at least some LBT subbands by RRC signaling (e.g., cell-specific or terminal-specific RRC signaling). For example, for method 120, the base station may configure the DRS transmission window for the terminal independently for each subband by RRC signaling. This information may be included in the bandwidth portion configuration information, or transmitted to the terminal together with the bandwidth portion configuration information.

[0211] In the above method, multiple DRSs corresponding to different LBT subbands may include CORESET#0 and / or search spaces (e.g., search space set #0) associated therewith and the configuration of CORESET#0 (e.g., resource configuration, PDCCH monitoring operation configuration, etc.), and the search space associated therewith (e.g., search space set #0) may be the same or common for multiple subbands. For another example, the terminal assumes that the configuration of the SS / PBCH block actually transmitted among the SS / PBCH block candidates (i.e., the index of the SS / PBCH block, the time resource position of the SS / PBCH block within the DRS transmission window, etc.) may be the same or common for multiple subbands. The terminal may be notified by a signal from the base station which SS / PBCH block (or which DRS) is actually sent among multiple SS / PBCH block candidates (or multiple DRS candidates). Generally, the terminal may assume that the PDSCH is not transmitted in the resource region of the corresponding SS / PBCH block (or the corresponding DRS). That is, the terminal may receive the PDSCH by rate matching the PDSCH around the corresponding resource region.

[0212] Alternatively, the configuration of the pattern of the actually transmitted SS / PBCH blocks or their indices (i.e., the PDSCH rate matching pattern of the SS / PBCH blocks) may be independent for each subband. This may provide the base station with greater flexibility in the use of physical resources.

[0213] DRS transmission

[0214] After configuring multiple DRS resources or DRS candidate resources in the frequency domain and / or time domain in a bandwidth part by the above method, the base station can send multiple DRSs at multiple frequency positions and / or multiple time positions in a DRS cycle in a bandwidth part. In addition, the terminal can receive multiple DRSs at multiple frequency positions and / or multiple time positions in a DRS cycle in a bandwidth part. For example, the base station and the terminal can send and receive DRSs in multiple LBT subbands within a DRS transmission window periodicity (e.g., 40ms) in a bandwidth part.

[0215] DRS can be transmitted in multiple LBT subbands within a reference periodicity. For example, multiple DRS transmission windows can be configured in multiple LBT subbands by the above method. The base station can transmit DRS to the terminal within a reference periodicity by using the DRS resources of one or more DRS transmission windows in the multiple DRS transmission windows. In this case, the base station can select any DRS candidate from all DRS candidates within the reference periodicity, and actually transmit the selected DRS candidate to the terminal. Alternatively, the base station can select any DRS candidate from the DRS candidates (such as SS / PBCH block candidates) configured to the terminal during actual transmission, and transmit the selected DRS candidate to the terminal. This method may be referred to as "method 130".

[0216] Alternatively, a rule may restrict the DRS candidates that the base station can select and actually transmit. For example, the base station may transmit at most one DRS (e.g., at most one SS / PBCH block) to the terminal at one point in time (e.g., certain symbols). The terminal may not expect to transmit multiple DRSs with different frequency positions at one point in time (e.g., certain symbols) in a bandwidth portion. When multiple DRSs are detected at multiple frequency positions at one point in time, the terminal may select one of the detected multiple DRSs and receive the DRS. This method may be referred to as "method 131". When method 131 is used, a DRS may be selected arbitrarily by the terminal or according to a priority configuration or predetermined rules from the base station. These restrictions may be applied when the DRS transmission windows of the respective subbands and the DRS candidates they include at least partially overlap in the time domain.

[0217] Alternatively, the base station may simultaneously send multiple DRSs (e.g., multiple SS / PBCH blocks) in multiple LBT subbands and / or multiple DRS transmission windows. That is, the terminal may expect to simultaneously receive multiple DRSs (e.g., multiple SS / PBCH blocks) in multiple LBT subbands and / or multiple DRS transmission windows. This method may be referred to as "method 132". Information about multiple LBT subbands and / or multiple DRS transmission windows may be signaled from the base station to the terminal.

[0218] Fig.15is a conceptual diagram for describing an exemplary embodiment of a DRS transmission method in the frequency domain and / or time domain.

[0219] Fig.15 Case (a) shows a first exemplary embodiment of DRS transmission in the frequency domain and / or time domain, Fig.15 Case (b) shows a second exemplary embodiment of DRS transmission in the frequency domain and / or time domain, and Fig.15 Case (c) shows a third exemplary embodiment of DRS transmission in the frequency domain and / or time domain.

[0220] refer to Fig.15 In cases (a) and (c), DRS can be transmitted in multiple LBT subbands within a reference periodicity in a bandwidth part. Fig.15 According to the first exemplary embodiment of case (a), the base station can successfully perform the third or fourth type LBT operation in the first and second LBT sub-bands, and can transmit the DRS for a relatively long time. Fig.15 A second exemplary embodiment of case (b) and Fig.15 In the third exemplary embodiment of case (c), the base station can successfully perform the second type of LBT operation in the first and second LBT subbands, and can transmit the DRS in a relatively short time. For convenience, only the SS / PBCH block is shown as an example of the signal and channel constituting the DRS.

[0221] refer to Fig.15 In case (a), the base station may send DRS at multiple frequency locations at one time point. This may be implemented by method 130. Fig.15 In case (b), the base station can transmit the DRS at a single frequency position at a time point. This can be achieved by method 131. Fig.15 In case (c), the base station may transmit DRS at multiple frequency locations at one time point. This may be achieved by method 132.

[0222] Fig.15 The exemplary embodiment of case (b) can help to transmit a larger number of DRS in the time domain under the same frequency regulation conditions. For example, as described above, the time that the channel is occupied by the DRS based on the second type of LBT is limited to 5% or less of the total time, and the maximum duration of each DRS burst can be 1ms. In this case, assuming that the DRS periodicity is 20ms and the downlink bandwidth portion is configured with a subcarrier spacing of 15kHz, the base station can transmit at most two DRS or SS / PBCH blocks through one subband in one DRS period. On the other hand, according to Fig.15In an exemplary embodiment of case (b), the base station may perform LBT operations twice within one DRS transmission window, thereby using two subbands, transmitting two DRS or SS / PBCH blocks per subband within one DRS periodicity, and transmitting a total of four DRS or SS / PBCH blocks. In this case, a frequency regulation condition may be applied to each subband and the frequency regulation condition may be satisfied.

[0223] Alternatively, frequency regulation conditions may be applied to each bandwidth portion. Fig.15 In the second exemplary embodiment of case (b), according to the above assumption, since a total of four DRSs are transmitted in one bandwidth portion at a time of 2 ms within a DRS cycle of 20 ms, this can be determined as a violation of frequency regulation. In this case, only one of the two DRS bursts may be transmitted so that the total duration of the DRS bursts within one cycle does not exceed 1 ms, i.e., 5% of 20 ms.

[0224] Alternatively, the DRS may be transmitted in up to S LBT subbands within a reference periodicity. For example, by configuring multiple DRS transmission windows in multiple LBT subbands using the above method, the base station may transmit the DRS to the terminal by using DRS resources of up to S DRS transmission windows among the multiple DRS transmission windows within a reference periodicity. According to the method, the S available DRS transmission windows may jump periodically, i.e., jump between LBT subbands. This method may be referred to as "method 132". According to an exemplary embodiment of method 132, S=1. Method 132 may be used in combination with the above-described method 130 and / or method 131.

[0225] For example, even if LBT succeeds on more than S subbands, the base station may transmit DRS only on up to S subbands in the subbands where LBT succeeds. The S subbands in which DRS is transmitted can be arbitrarily selected by the base station, i.e., based on the implementation of the base station. In this case, since the terminal does not know in which subband the DRS is sent, the terminal can attempt to receive DRS in multiple subbands. That is, the terminal can blindly detect DRS in multiple subbands. At the same time or in other ways, the terminal can be configured with transmission priorities between subbands constituting a bandwidth portion, and DRS can be transmitted in S subbands according to the priority in the subband where the LBT operation is successful (e.g., with the highest priority). The transmission priority can be defined or configured to be substantially limited to DRS transmission. Alternatively, the transmission priority can be used for transmissions other than DRS. For example, the priority can be notified to the terminal by a signal from the base station. For another example, the priority can be determined based on the index of the LBT subband. For example, a DRS of a lower index LBT subband can have a higher priority than a DRS of a higher index LBT subband.

[0226] According to the above method, there are multiple DRS transmission windows in the frequency domain of a bandwidth part, and S available DRS transmission windows can jump between them. Depending on the result of the LBT operation, the jump can be applied periodically and / or timely. In this case, multiple DRS transmission windows can be configured independently for each frequency. For example, the DRS transmission window in the first LBT subband can be configured as a first DRS transmission window according to a DRS configuration parameter set for the first LBT subband; and the DRS transmission window in the second LBT subband can be configured as a second DRS transmission window according to a DRS configuration parameter set for the second LBT subband. In this case, jumping of available DRS transmission windows can be applied between multiple DRS configurations. Alternatively, multiple DRS transmission windows can be configured by a DRS configuration parameter set defined for each bandwidth part.

[0227] Fig.16 is a conceptual diagram illustrating another exemplary embodiment of DRS transmission in the frequency domain and / or time domain.

[0228] refer to Fig.16 , a DRS configuration for a bandwidth portion may include all DRS transmission windows in the bandwidth portion, and the DRS transmission windows may be arranged in one or more LBT subbands. In this case, similar to Fig.13 In an exemplary embodiment, a common DRS transmission window periodicity may be applied to DRS transmissions of a base station and a terminal. The common DRS transmission window periodicity may be signaled from the base station to the terminal.

[0229] Fig.17 is a conceptual diagram illustrating yet another exemplary embodiment of DRS transmission in the frequency domain and / or time domain.

[0230] refer to Fig.17 , one bandwidth part can be composed of four LBT subbands. A DRS transmission window can be configured in each LBT subband, and the DRS transmission window can be periodically arranged in each LBT subband. In addition, a common DRS transmission window periodicity (e.g., 40ms) can be used for all LBT subbands by the above method. In this case, according to method 132, the base station can transmit DRS in at most one LBT subband within each DRS transmission window period. Fig.17, the base station may transmit DRS in the DRS transmission window of the first subband of the nth period, transmit DRS in the DRS transmission window of the third subband of the (n+1)th period, and transmit DRS in the DRS transmission window of the second subband of the (n+2)th period. That is, the DRS transmission window in which DRS is transmitted may jump periodically and / or timely between multiple LBT subbands. The base station may dynamically determine the frequency hopping pattern of the DRS transmission window based on the result of the LBT operation of the base station. In this case, the terminal may monitor or detect DRS (e.g., SS / PBCH blocks) for multiple DRS transmission windows in the frequency domain. Alternatively, the base station may determine the frequency hopping pattern of the DRS transmission window by considering the frequency hopping pattern, transmission priority, etc. previously defined or configured from the base station to the terminal. For example, the terminal may be configured with the transmission priority (or detection priority) of the frequency region for multiple DRS transmission windows by the base station, and the terminal may determine the monitoring or detection order for multiple DRS transmission windows based on the transmission priority. In this case, depending on whether the LBT operation is successful, DRS may or may not be actually transmitted in the DRS transmission window determined by the pattern. In addition, Fig.17 Unlike the exemplary embodiments of the present invention, the DRS or DRS transmission window can only jump in a part of the subbands constituting the bandwidth part. For example, in the remaining subbands, the DRS can be transmitted in all DRS transmission windows in which the LBT operation is successful for the terminal making initial access.

[0231] In the above method, the reference periodicity may be the periodicity of the DRS transmission window of a specific LBT subband. Fig.13 When a common DRS transmission window periodicity is used as shown in the exemplary embodiment of the present invention, the reference periodicity can be based on the common DRS transmission window periodicity. Alternatively, the reference periodicity can be a separate periodicity that is different from the period of the DRS transmission window. This can be signaled from the base station to the terminal.

[0232] As described above, when DRS is transmitted in multiple LBT subbands within a bandwidth part, the terminal may regard multiple DRS as cell-defining DRS. Alternatively, when SS / PBCH blocks are transmitted in multiple LBT subbands within a bandwidth part as described above, the terminal may regard multiple SS / PBCH blocks as cell-defining SS / PBCH blocks. For example, the terminal may perform receiving operations such as RRM measurement, RLM measurement, beam quality measurement, time-frequency synchronization tracking, etc. by using multiple DRS or multiple SS / PBCH blocks transmitted in multiple subbands. In this case, the terminal may assume that a quasi-co-location (QCL) relationship is established between SS / PBCH blocks with the same index. When SS / PBCH blocks received at multiple frequency positions have the same index or have a QCL relationship with each other, the terminal can receive the SS / PBCH blocks by combining them. Thereby, the reception performance of the SS / PBCH blocks can be improved.

[0233] In this specification, the statement that a QCL is established between signals or channels may mean that the terminal may assume that the signal and the channel have the same radio channel characteristics in terms of delay spread, Doppler spread, Doppler shift, average gain, average delay, spatial Rx parameters, receive beam characteristics, etc. In the case of NR, the QCL may include QCL-type A, QCL-type B, QCL-type C, and QCL-type D. The index of the SS / PBCH block may be an index for identifying the resource region to which the SS / PBCH block is mapped. Alternatively, the index of the SS / PBCH block may be an index for identifying the beam or QCL of the SS / PBCH block. The index for identifying the beam or QCL of the SS / PBCH block may be derived from the index for identifying the resource region of the SS / PBCH block. The QCL relationship between certain signals and / or channels may be pre-defined in the technical specification, or may be explicitly or implicitly signaled to the terminal from the base station. For example, the transmission configuration information (TCI) status information configured from the base station to the terminal may include information about the QCL relationship and the signal and / or channel to which the QCL is applied.

[0234] On the other hand, the DRS may be transmitted only in L subbands occupied by the LBT operation among the K LBT subbands constituting the bandwidth part (here, L is a natural number equal to or less than K). Alternatively, the DRS may be transmitted only in M ​​subbands that are continuous in the frequency domain among the subbands occupied by the successful LBT operation among the K LBT subbands constituting the bandwidth part (here, M is a natural number equal to or less than K). The LBT operation may be an LBT operation based on random backoff (e.g., the third or fourth type of LBT). The LBT operation may also be an LBT operation without random backoff (e.g., the second type of LBT). In this case, the number of LBT subbands in which the DRS can be transmitted within a COT may be further limited. This method may be referred to as method 140. For example, the base station may transmit the DRS in up to N subbands within a COT. N may be a natural number equal to or less than L or a natural number equal to or less than M. N may be predefined in the technical specification. In addition, N may be notified to the terminal by a signal from the base station. According to an exemplary embodiment, N=1. In the following description, it is assumed that N=1. Similarly or alternatively, the terminal may assume that DRS is transmitted in up to N subbands within a COT. When the terminal successfully receives DRS in N subbands, the terminal may not attempt DRS detection in the remaining subbands. In this case, the terminal may assume that DRS is not transmitted in the remaining subbands.

[0235] Fig.18 is a conceptual diagram illustrating an exemplary embodiment of a DRS transmission method in a wideband carrier.

[0236] Fig.18 Case (a) shows a first exemplary embodiment of DRS transmission in a broadband carrier, and Fig.18 Case (b) shows a second exemplary embodiment of DRS transmission in a wideband carrier.

[0237] refer to Fig.18 In cases (a) and (b), K = 3. The base station can also successfully perform two LBT operations within a certain DRS transmission window, transmitting DRS bursts in the second and fifth time slots.

[0238] refer to Fig.18 In cases (a) and (b), the first DRS burst may be transmitted in the first subband and the second subband (L=2 or M=2). In this case, according to method 140, the base station may transmit the DRS only in one of the subbands in which the first DRS burst is transmitted, that is, transmit the DRS in the first subband. When the terminal does not know at which time point in which subband the first DRS burst is sent (for example, in the case of transmission based on the second type of LBT), the terminal may attempt to detect the DRS in each subband. In order to reduce the complexity of DRS detection of the terminal, the DRS transmission priority between subbands may be determined. The priority may be configured from the base station to the terminal. Alternatively, the priority may be predefined by a technical specification. For example, a subband with a lower index may have a higher priority. In this case, the terminal may attempt to detect the DRS in order of high subband priority, and if the DRS is detected in one subband (or generally N subbands), the DRS detection may be omitted in the remaining subbands.

[0239] When multiple DRS bursts (and / or downlink transmission bursts) are transmitted in the same DRS transmission window or the same DRS periodicity, these DRSs may be transmitted in the same subband in the multiple DRS bursts. Fig.18 In case (a), the DRS may be transmitted in the first and second DRS bursts in the same subband, i.e., the first subband. Alternatively, in the above case, it may be allowed to transmit the DRS in multiple DRS bursts in different subbands. For example, referring to Fig.18 In case (b), the DRS may be transmitted in different subbands, ie, the first and second subbands in the first and second DRS bursts.

[0240] Method 140 and the method applied to the above exemplary embodiments may be applied to be limited to some signals or channels constituting the DRS. For example, the above method may be applied to be limited to SS / PBCH blocks. For example, through method 140, SS / PBCH blocks may be transmitted in up to N subbands among L or M occupied subbands. For another example, according to method 140, PDCCH, PDSCH, etc. may be transmitted in up to N subbands among L or M occupied subbands. For example, the PDCCH may be a PDCCH for scheduling a PDSCH including SIB1, a PDCCH whose CRC is scrambled by SI-RNTI, etc. For example, the PDSCH may be a PDSCH including SIB1.

[0241] On the other hand, some signals constituting DRS may be transmitted in subbands other than N subbands. For example, some signals may include PDSCH, CSI-RS, etc. PDSCH may be a PDSCH including SIB1. Alternatively, PDSCH may also be a PDSCH including SIBs other than SIB1 or including paging messages. In addition, some signals may include PDCCH. Back Fig.18 In case (a), within the first DRS burst, the base station may transmit some signals constituting DRS only in the first subband (e.g., SS / PBCH blocks, PDCCHs belonging to PDCCH search space set #0 or type 0 PDCCH CSS set, PDSCH, etc.), but transmit some other signals constituting DRS in some or all of the first and second subbands (e.g., PDSCH, CSI-RS, etc.). In this case, information about the subbands in which PDSCH is scheduled or can be scheduled (and resource allocation information therein) may be sent to the terminal on the PDCCH that schedules PDSCH (e.g., PDCCH sent in PDCCH search space set #0, PDCCH of CRC scrambled by SI-RNTI, etc.). Alternatively, information about the subbands in which PDSCH is scheduled or can be scheduled may be transmitted to the terminal via SS / PBCH blocks (e.g., MIB included in PBCH). The subbands in which PDSCH is scheduled or can be scheduled may be some or all of the subbands occupied by the corresponding DRS burst.

[0242] Fig.19 is a conceptual diagram illustrating another exemplary embodiment of a DRS transmission method in a wideband carrier.

[0243] refer to Fig.19, the base station can successfully perform LBT operation and transmit DRS bursts in two frequency-contiguous subbands. For example, the LBT operation may be a second-class LBT operation, and the duration of the DRS burst may be 1 ms or less. For another example, the LBT operation may be a random backoff-based LBT (e.g., a fourth or third-class LBT operation). In this case, according to this exemplary embodiment, some signals constituting DRS, namely SS / PBCH blocks, PDCCH (e.g., PDCCH transmitted through PDCCH search space set #0, type 0 PDCCH CSS set, etc.) and PDSCH (e.g., PDSCH including SIB1) may be transmitted in the first subband. In addition, some other signals constituting DRS, namely PDSCH (e.g., another SIB other than SIB1, i.e., PDSCH including other system information (OSI) and PDSCH including paging messages) may be transmitted in the second subband. In addition, some other signals that do not constitute DRS, namely PDSCH (for example, PDSCH including unicast data, PDSCH of CRC scrambled by C-RNTI, MCS-C-RNTI, CS-RNTI, etc. scheduled by DCI) can be transmitted in the second subband. In this case, the PDSCH transmitted in the second subband can be scheduled by the PDCCH of the first subband. The terminal can rate match the PDSCH received through the second subband with respect to the SS / PBCH block candidates configured as the SS / PBCH blocks actually transmitted in the second subband. In addition, some other signals constituting DRS, namely CSI-RS, can be transmitted in the first subband and the second subband. In this exemplary embodiment, the first subband and the second subband can be summarized as a subband for transmitting DRS (or SS / PBCH blocks) and a subband for not transmitting DRS (or SS / PBCH blocks), respectively.

[0244] exist Fig.19In an exemplary embodiment of , when the first and second subbands are occupied by the second type of LBT operation, if the frequency regulation condition is applied independently to each subband, the subband in which the specific signal constituting the DRS is not transmitted may be interpreted as a violation of the regulation. For example, if the SS / PBCH block is not transmitted in the second subband, but only the paging message or OSI is transmitted, this may be interpreted as a violation of the frequency regulation. To address this issue, when the second type of LBT operation (simultaneously) occupies multiple LBT subbands, the SS / PBCH block may be transmitted in each subband. In this case, some subbands may also include a PDSCH containing SIB1 and a PDCCH corresponding thereto, while another subband may also include a PDSCH containing paging or OSI and a PDCCH corresponding thereto. That is, SIB1 may be transmitted only in some subbands. In addition, in addition to the SS / PBCH block for each subband, different signals and channels may also be transmitted. Alternatively, a new second type of LBT scheme for multiple channels or multiple subbands may be defined, and the frequency regulation condition may be applied on a bandwidth portion basis. In this case, the subband applied to Fig.19 The method of the exemplary embodiment may be effective.

[0245] DRS Measurement

[0246] On the other hand, the terminal can perform DRS-based measurements. For example, the terminal can receive part or all of the signals and channels that constitute the DRS, and use them to measure RRM, RLM, CSI, beam quality, etc. To this end, the base station can configure a time window for DRS-based measurements for the terminal (hereinafter referred to as the "DRS measurement window"). For example, the DRS measurement window may refer to a time window configured by the SS / PBCH block measurement timing configuration (SMTC) (or DRS measurement timing configuration (DMTC)). The terminal can perform DRS-based RRM measurements (for example, RRM measurements using SSS and / or PBCH DM-RS) at least within the SMTC window, and can report the results to the base station. For another example, the DRS measurement window may refer to a window for measuring the RLM of the terminal. The terminal can perform DRS-based RLM at least within the RLM measurement window, determine the synchronization state or the asynchronous state of the corresponding radio link, and report it to a higher layer.

[0247] In this case, the terminal can be configured with multiple DRS measurement windows in the frequency domain. When a bandwidth part consists of multiple LBT sub-bands, the terminal can be configured with multiple DRS measurement windows at different frequency positions in a bandwidth part. For example, multiple DRS measurement windows in a bandwidth part can be configured in different LBT sub-bands (or sub-bands corresponding to LBT sub-bands). The method for configuring multiple DRS measurement windows may be the same or similar to the above-mentioned method for configuring the DRS transmission window. For example, the method for configuring the length or duration, period and time offset of the DRS measurement window for the terminal may be the same or similar to the above-mentioned method for configuring the length or duration, period and time offset of the DRS transmission window for the terminal. In addition, the terminal may assume that the DRS measurement window and the DRS transmission window are the same in at least some sub-bands. This assumption may be valid (as a default configuration) until the terminal is configured with a DRS measurement window in the corresponding sub-band by the base station.

[0248] Although the above content of the present invention has been described as an example of configuring and / or transmitting a DRS in the frequency domain within an LBT sub-band, the method or exemplary embodiment is not limited thereto, but can also be easily extended to the case where multiple DRSs are configured and / or transmitted in the frequency domain within an LBT sub-band or within a bandwidth portion where the LBT sub-band is not configured. For example, multiple DRS transmission windows or multiple DRS measurement windows can be configured at different frequency positions within an LBT sub-band. Multiple DRS transmission windows or multiple DRS measurement windows can be configured not to overlap with each other in the frequency domain. In this case, the above method can be applied identically or similarly to the configuration of the DRS transmission window or the DRS measurement window, the transmission of the DRS, etc. In addition, the above method can be applied only to some sub-bands that constitute the bandwidth portion.

[0249] PDSCH rate matching

[0250] As described above, the base station may configure the SS / PBCH block actually transmitted from among multiple SS / PBCH block candidates to the terminal. Multiple SS / PBCH block candidates may be SS / PBCH block candidates constituting DRS opportunities, DRS transmission windows, SS / PBCH block burst sets, and the like. The SS / PBCH block actually transmitted may be configured to the terminal via RRC signaling (e.g., RRC parameter 'ssb-PositionsInBurst'). In this case, the RRC signaling may be cell-specific (e.g., as contained in SIB1) or terminal-specific (e.g., as contained in the RRC parameter 'ServingCellConfigCommon'). The terminal may receive the PDSCH by rate matching the PDSCH around the resource area of ​​the SS / PBCH block configured as the SS / PBCH block actually transmitted. In this case, the base station may not actually transmit the SS / PBCH block configured as the SS / PBCH block actually transmitted to the terminal. However, the terminal may rate match the PDSCH around the resources of the SS / PBCH block, regardless of whether it is actually transmitted.

[0251] On the other hand, in unlicensed band communication, DRS can be transmitted based on multiple LBT categories. For example, the base station can perform the second type of LBT operation, acquire a channel, and transmit DRS. Alternatively, the base station can perform the third or fourth type of LBT operation, acquire a channel, and transmit DRS. In this case, the configuration of the SS / PBCH block actually transmitted in the two cases may be different. This will be described below with reference to the accompanying drawings.

[0252] Fig. 20 is a conceptual diagram for describing an exemplary embodiment of a configuration of an SS / PBCH block actually transmitted in an unlicensed band.

[0253] Fig. 20 Case (a) shows a first exemplary embodiment of a configuration of an SS / PBCH block for actual transmission in the unlicensed band, Fig. 20 Case (b) shows a first exemplary embodiment of SS / PBCH block transmission according to LBT, and Fig. 20 Case (c) shows a second exemplary embodiment of SS / PBCH block transmission according to LBT.

[0254] First, refer to Fig. 20In cases (b) and (c), the base station may perform a random backoff-based LBT operation (e.g., a fourth type of LBT operation), acquire a channel, and transmit a downlink transmission burst. In this case, if the interval of the downlink transmission burst, i.e., the COT, includes a DRS transmission window, the base station may transmit a DRS or SS / PBCH block within the COT. The base station may also transmit other downlink signals such as PDCCH, PDSCH, CSI-RS, etc., together with the DRS or SS / PBCH block within the COT.

[0255] In general, a COT initiated by an LBT operation based on random backoff may have a longer duration than a COT initiated by an LBT operation without random backoff. Fig. 20 In the exemplary embodiments of cases (b) and (c), multiple DRS candidates or multiple SS / PBCH block candidates may be included in one COT. Fig. 20 In case (b), the COT may include 18 SS / PBCH block candidates, namely SS / PBCH block candidates with indexes 0 to 17. Fig. 20 In case (c), the COT may include 12 SS / PBCH block candidates, namely, SS / PBCH block candidates with indexes 8 to 19.

[0256] In this case, the base station may actually transmit only some of the SS / PBCH block candidates included in the COT. For example, in the case of a serving unit or system where a single beam is used to transmit SS / PBCH blocks, it may be sufficient to actually transmit one or a few SS / PBCH blocks. Fig. 20 In case (b), the base station may actually transmit only some of the 18 SS / PBCH block candidates belonging to the COT, namely, the SS / PBCH blocks with indices 0, 8, and 16. Fig. 20 In case (c), the base station may actually transmit only some of the 12 SS / PBCH block candidates belonging to the COT, namely, the SS / PBCH blocks with indices 8 and 16.

[0257] In this case, in order to enable the terminal to match the PDSCH rate to the SS / PBCH blocks that the base station actually transmits or can actually transmit, that is, the SS / PBCH blocks with indices 0, 8, and 16, the SS / PBCH blocks that are actually transmitted can be notified to the terminal by signaling. Fig. 20 In case (a), the base station can configure the SS / PBCH blocks with indices 0, 8 and 16 among the total 20 SS / PBCH block candidates constituting the DRS transmission window for the terminal as the SS / PBCH blocks actually transmitted according to the above method.

[0258] Fig.21is a conceptual diagram for describing other exemplary embodiments of configurations of SS / PBCH blocks actually transmitted in an unlicensed band.

[0259] Fig.21 Case (a) shows a second exemplary embodiment of a configuration of an SS / PBCH block for actual transmission in the unlicensed band, Fig.21 Case (b) shows a third exemplary embodiment of the configuration of SS / PBCH blocks for actual transmission in the unlicensed band, and Fig.21 Case (c) shows a fourth exemplary embodiment of the configuration of SS / PBCH blocks for actual transmission in the unlicensed band.

[0260] First, refer to Fig.21 In cases (b) and (c), the base station may perform an LBT operation (e.g., a second type of LBT operation) without random backoff, acquire a channel, and transmit a downlink transmission burst or a DRS burst. In this case, as described above, the maximum duration of a DRS burst may be limited (e.g., 1 ms), and thus, one DRS burst may include several DRS candidates or several SS / PBCH block candidates. For example, referring to Fig.21 In case (b), the DRS burst may include four SS / PBCH block candidates, namely, SS / PBCH block candidates with indices 4 to 7, refer to Fig.21 In case (c), four SS / PBCH block candidates, namely, SS / PBCH block candidates with indexes 13 to 16, may be included in the DRS burst.

[0261] In this case, the base station may actually transmit part or all of the SS / PBCH block candidates contained in the COT. Fig.21 In cases (b) and (c), regardless of the start time point of the DRS burst, the base station may actually transmit only two SS / PBCH blocks with even-numbered indices among the four SS / PBCH blocks included in the DRS burst. In this case, in order to enable the terminal to rate-match the PDSCH with the SS / PBCH blocks with even-numbered indices actually transmitted by the base station, regardless of the start time point of the DRS burst, such as Fig.21 In an exemplary embodiment of case (a), all SS / PBCH blocks having even-numbered indexes in the DRS transmission window may be configured to the terminal as SS / PBCH blocks actually transmitted.

[0262] According to the above method, part or all of the SS / PBCH blocks constituting the DRS transmission window can be configured to the terminal as the SS / PBCH blocks actually transmitted. This can always be applied in the same way regardless of the category of the LBT operation performed for the DRS transmission. The method may be referred to as "method 150". Alternatively, when DRS transmission is performed through the second type of LBT operation, part or all of the SS / PBCH blocks constituting the DRS burst can be configured to the terminal as the SS / PBCH blocks actually transmitted. However, this method may not work when the terminal does not know the starting time point of the DRS burst. On the other hand, according to method 150, since the terminal knows the absolute position of the SS / PBCH block actually transmitted within the DRS transmission window, the terminal can correctly rate match the PDSCH on the corresponding resource even when the terminal does not know the starting time point of the DRS burst.

[0263] On the other hand, when comparing Fig. 20 An exemplary embodiment of the case (a) and Fig.21 In the exemplary embodiment of case (a), for the case where LBT based on random backoff is performed for DRS transmission and the case where LBT operation without random backoff is performed for DRS transmission, the SS / PBCH block candidate set configured to the terminal as the SS / PBCH block actually transmitted may be different. Fig. 20 Case (a) and Fig.21 Case (a), in the latter case, it may be helpful to configure a large number of SS / PBCH block candidates as SS / PBCH blocks for actual transmission. In the proposed method, for the case where LBT based on random backoff (e.g., the fourth or third type of LBT operation) is performed for DRS transmission and the case where LBT operation without random backoff (e.g., the second type of LBT operation) is performed for DRS transmission, the base station may configure the set of SS / PBCH blocks for actual transmission, i.e., the PDSCH rate matching mode for the SS / PBCH blocks, differently. This method may be referred to as "method 151". The sets of SS / PBCH blocks for actual transmission configured for the former and latter cases will be represented as S1 and S2, respectively.

[0264] The SS / PBCH block candidates (e.g., S1 and / or S2) configured as the SS / PBCH blocks actually transmitted can be signaled to the terminal via a bitmap. For example, the size of the bitmap can be equal to the number of SS / PBCH block candidates constituting the DRS transmission burst, and each bit can correspond to each SS / PBCH block candidate sequentially. Alternatively, the size of the bitmap can be smaller than the number of SS / PBCH block candidates constituting the DRS transmission burst to reduce signaling overhead. For example, each bit of the bitmap can correspond sequentially to each group of SS / PBCH block candidates with the same beam index. The beam index of the SS / PBCH block is just a convenient term, and can actually be an index indicating the QCL or TCI state of the SS / PBCH block. SS / PBCH blocks with the same beam index can QCL with each other, or the same TCI state information can be applied. That is, the terminal can assume that SS / PBCH blocks with the same beam index or SSS, PBCH DM-RS, etc. constituting the SS / PBCH block are QCL with each other. The QCL relationship between SS / PBCH blocks can be signaled to the terminal from the base station. For example, the terminal may assume that SS / PBCH blocks with the same PBCH DM-RS sequence are QCLed within the same DRS transmission window and / or between DRS transmission windows of different periods. In this case, for example, when 8 DM-RS sequences are used to indicate the index of the SS / PBCH block and / or the index of the beam, the length of the bitmap may be 8 bits. On the other hand, only some of the bits constituting the bitmap may be used to configure the SS / PBCH block actually transmitted. For example, only Y bits of the bits constituting a bitmap of length X may be used to configure the SS / PBCH block actually transmitted. Y bits may correspond to Y SS / PBCH block indices and / or beam indices. For example, X may be 8, and Y may be 1, 2, 4, or 8. The remaining unused (XY) bits may be transmitted as predefined values ​​(e.g., "0").

[0265] It can be seen from the above exemplary embodiments that, compared with DRS transmission through the fourth or third type LBT operation, more SS / PBCH candidate blocks can be configured as SS / PBCH blocks actually transmitted for DRS transmission through the second type LBT operation. In this case, an inclusion relationship can be established between S1 and S2. For example, S1 can be a subset of S2.

[0266] For method 151, the terminal can distinguish between DRS transmission through the second type of LBT operation and DRS transmission through the fourth (or third) type of LBT operation by receiving a downlink signal. For example, when the terminal receives a downlink initial signal and / or information about the structure and duration of the COT, the terminal can regard the downlink transmission burst or DRS burst received from the time point of reception as a transmission according to the fourth (or third) type of LBT operation. In addition, if the terminal successfully detects or receives DRS, such as an SS / PBCH block, without receiving a downlink initial signal and / or information about the structure and duration of the COT (outside the COT), the terminal can regard the downlink transmission burst or DRS burst containing the DRS, such as the SS / PBCH block, as a transmission according to the second type of LBT operation. Through this method, the terminal can distinguish LBT categories and receive PDSCH by applying the PDSCH rate matching mode corresponding to each LBT category.

[0267] The downlink initial signal can be used for downlink transmission burst detection of the terminal. The downlink initial signal can be placed at the beginning of the downlink transmission burst. By successfully detecting the downlink initial signal, the terminal can detect the downlink transmission burst and perform a receiving operation such as PDCCH monitoring. Various downlink signals and channels can be used as the downlink initial signal. For example, a DM-RS for demodulating PDCCH can be used as a downlink initial signal. Alternatively, a broadband DM-RS of CORESET can be used as a downlink initial signal. In this case, the broadband DM-RS may not be used to demodulate PDCCH. Alternatively, the DM-RS of the group common PDCCH can be used as a downlink initial signal. Alternatively, the DM-RS of the group common PDCCH and the control information contained in the group common PDCCH can be used as a downlink initial signal. Alternatively, the broadband DM-RS of the group common PDCCH and the control information contained in the group common PDCCH can be used as a downlink initial signal. In this case, when the group common DCI is successfully received (for example, when the cyclic redundancy check (CRC) is successful), the terminal can detect the downlink transmission burst. Alternatively, CSI-RS can be used as a downlink initial signal.

[0268] Configuration of the device according to the invention

[0269] Fig. 22 is a block diagram illustrating a communication node according to an exemplary embodiment of the present invention.

[0270] Fig. 22 The communication node shown may be a terminal or a base station, as an apparatus for performing a method according to an exemplary embodiment of the present invention.

[0271] refer to Fig. 22 , the communication node 2200 may include a transceiver 2230 connected to a network to perform communication, a memory 2220, and at least one processor 2210. In addition, the communication node 2200 may also include an input interface device 2240, an output interface device 2250, a storage device 2260, etc. The components included in the communication node 2200 may be connected through a bus 2270 to communicate with each other.

[0272] However, each component included in the communication node 2200 may be connected to the processor 2210 through a separate interface or a separate bus instead of the common bus 2270. For example, the processor 2210 may be connected to at least one of the memory 2220, the transceiver 2230, the input interface device 2240, the output interface device 2250, and the storage device 2260 through a dedicated interface.

[0273] The processor 2210 may execute at least one instruction stored in at least one of the memory 2220 and the storage device 2260. The processor 2210 may refer to a central processing unit (CPU), a graphics processing unit (GPU), or a dedicated processor on which a method according to an exemplary embodiment of the present invention is executed. Each of the memory 2220 and the storage device 2260 may be configured as at least one of a volatile storage medium and a non-volatile storage medium. For example, the memory 2220 may be configured with at least one of a read-only memory (ROM) and a random access memory (RAM).

[0274] The exemplary embodiments of the present disclosure may be implemented as program instructions that can be executed by various computers and recorded on computer-readable media. The computer-readable medium may include program instructions, data files, data structures, or a combination thereof. The program instructions recorded on the computer-readable medium may be specifically designed and configured for the present disclosure, or may be known and available to those skilled in the art of computer software.

[0275] Examples of computer readable media may include hardware devices such as ROM, RAM, flash memory, etc., which are specifically configured to store and execute program instructions. Examples of program instructions include machine codes generated by a compiler, for example, and high-level language codes executed by a computer using an interpreter. The above exemplary hardware devices may be configured to operate as at least one software module to perform embodiments of the present disclosure, and vice versa.

[0276] Although the embodiments of the present disclosure and its advantages have been described in detail, it should be understood that various changes, substitutions, and alterations can be made herein without departing from the scope of the disclosure.

Claims

1. A terminal method, comprising: receiving first configuration information of a carrier from a base station; identifying some of the resource blocks RB constituting the carrier as guard bands; receiving second configuration information from the base station, and determining a first time period and a second time period based on the second configuration information; as well as performing communication with the base station based on a first RB group in the first time period and a second RB group in the second time period, The first RB group includes RBs among the RBs constituting the carrier except for the RBs constituting the protection band, the second RB group includes RBs among the RBs constituting the carrier including the RBs constituting the protection band, and the communication with the base station includes the sending of data channels.

2. The method according to claim 1, wherein: In the first time period, the first RB group includes a first sub-band and a second sub-band, and the guard band is located between the first sub-band and the second sub-band.

3. The method according to claim 2, wherein: The RBs constituting the guard band are determined based on third configuration information explicitly received from the base station, or based on frequency positions of the first subband and the second subband.

4. The method according to claim 1, wherein: The second RB group coincides with an activated BWP in the carrier.

5. The method according to claim 1, wherein: The second configuration information includes a time offset relative to a reference time, the time offset indicating a time of transition from the second period to the first period, and the second configuration information is received from the base station through a radio resource control (RRC) message.

6. The method according to claim 1, wherein: The data channel is allocated only in one of the first time period and the second time period.

7. The method according to claim 1, wherein: When the data channel is allocated in both the first time period and the second time period, the terminal skips transmission of the data channel.

8. The method according to claim 1, wherein: The data channel is allocated in the first time period, the data channel is mapped to a physical resource block PRB constituting the first RB group, and the PRB is indicated to the terminal based on an index designated within the first RB group.

9. The method according to claim 1, wherein: The data channel is allocated in the second period, the data channel is mapped to PRBs constituting the second RB group, and the PRBs are indicated to the terminal based on an index designated within the second RB group.

10. The method according to claim 1, wherein: When the data channel is allocated in the first period and the data channel is nominally allocated to PRBs constituting the second RB group, the terminal receives the data channel in RBs other than the RBs constituting the guard band.

11. The method according to claim 10, wherein: The data channels are velocity matched around the RBs constituting the guard band, or are punctured relative to the RBs constituting the guard band.

12. The method according to claim 1, wherein: The data channel is repeatedly transmitted, and a first data channel instance and a second data channel instance constituting the repeated transmission of the data channel are transmitted in the first time period and the second time period respectively, and a frequency resource region to which the first data channel instance is mapped is equal to a frequency resource region to which the second data channel instance is mapped.

13. The method according to claim 1, wherein: The data channel is repeatedly transmitted, a first data channel instance and a second data channel instance constituting the repeated transmission of the data channel are both received in one of the first time period and the second time period, and a frequency resource region to which the first data channel instance is mapped is equal to a frequency resource region to which the second data channel instance is mapped.

14. The method according to claim 1, wherein: The data channel is a physical uplink shared channel PUSCH, and the transmission of the data channel is indicated to the terminal through dynamic scheduling or semi-persistent scheduling.

15. A method of a base station, comprising: Sending first configuration information of a carrier to a terminal; Sending second configuration information of a carrier to the terminal, where the second configuration information allows the terminal to determine a first time period and a second time period; as well as performing communication with the terminal based on a first RB group in the first time period and a second RB group in the second time period, The first RB group includes RBs among the RBs constituting the carrier except for the RBs constituting the protection band, the second RB group includes RBs among the RBs constituting the carrier including the RBs constituting the protection band, and the communication with the base station includes reception of a data channel.

16. The method according to claim 15, wherein: In the first time period, the first RB group includes a first sub-band and a second sub-band, and the guard band is located between the first sub-band and the second sub-band.

17. The method according to claim 15, wherein: The data channel is allocated only in one of the first time period and the second time period.

18. The method according to claim 15, wherein: The data channel is repeatedly sent, a first data channel instance and a second data channel instance constituting repeated reception of the data channel are received in the first time period and the second time period respectively, and a frequency resource region to which the first data channel instance is mapped is equal to a frequency resource region to which the second data channel instance is mapped.

19. The method according to claim 15, wherein: The data channel is repeatedly received, a first data channel instance and a second data channel instance constituting the repeated reception of the data channel are both received in one of the first time period and the second time period, and a frequency resource region to which the first data channel instance is mapped is equal to a frequency resource region to which the second data channel instance is mapped.

20. A terminal comprising at least one processor, wherein: The at least one processor causes the terminal to execute: receiving first configuration information of a carrier from a base station; identifying some of the resource blocks RB constituting the carrier as guard bands; receiving second configuration information from the base station, and determining a first time period and a second time period based on the second configuration information; as well as performing communication with the base station based on a first RB group in the first time period and a second RB group in the second time period, The first RB group includes RBs among the RBs constituting the carrier except for the RBs constituting the protection band, the second RB group includes RBs among the RBs constituting the carrier including the RBs constituting the protection band, and the communication with the base station includes the sending of data channels.

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