Method and user equipment for a user equipment

Abstract

This application relates to methods for user equipment and user equipment. The present invention proposes a method for adjusting the contention window size of a base station / terminal. The method is characterized by transmitting data to the terminal / base station via a frequency band in a bandwidth portion of the terminal, said bandwidth portion being a portion of a carrier bandwidth configured for the terminal; receiving feedback information about the data from the terminal / base station; adjusting the contention window size of the base station / terminal based on the feedback information, said contention window size being within a range of a counter value for CAP used as an operation for the base station / terminal to determine channel occupancy, said bandwidth portion overlapping with multiple CAP bandwidths; and adjusting the contention window size for at least one of said multiple CAP bandwidths if the frequency band in which data is transmitted overlaps with said multiple CAP bandwidths.

Description

[0001] This application is a divisional application of the original invention patent application No. 201980009098.8 (International Application No.: PCT / KR2019 / 001711, Application Date: February 12, 2019, Invention Title: Method for Adjusting the Size of a Competition Window in a Wireless Communication System and Communication Apparatus Using the Method). Technical Field

[0002] This disclosure relates to wireless communication, and more specifically, to a method for adjusting the size of a contention window in a wireless communication system and a communication apparatus using the method. Background Technology

[0003] As more and more communication devices require greater communication capabilities, there is a need for improved mobile broadband communications using existing radio access technologies. Furthermore, massive machine-type communication (MTC) that provides various services by connecting numerous devices and objects is one of the main issues to be considered in next-generation communications. Additionally, communication system designs considering reliability / latency-sensitive services / UEs are being discussed. The introduction of next-generation radio access technologies considering enhanced mobile broadband (eMBB), massive machine-type communication (mMTC), and ultra-reliable low-latency communication (URLLC) is discussed. For convenience, this new technology may be referred to in this disclosure as a new radio access technology (new RAT or NR).

[0004] In cellular communication systems such as LTE / NR systems, unlicensed frequency bands that are the same as those used in traditional WiFi systems at 2.4 GHz or those that are the same as those used in the newly emerging 5 GHz and 60 GHz bands are considered to be used for service offloading.

[0005] Since it is essentially assumed that wireless transmission / reception is achieved in a contention-based manner among the respective communication nodes in the unlicensed frequency band, channel sensing needs to be performed before the respective communication node transmits a signal to confirm that no signal transmission has occurred among other communication nodes. For convenience, this operation is called pre-talk listening (LBT) or the channel access procedure, and specifically, the operation of confirming whether another communication node is transmitting a signal is defined as carrier sensing (CS). When it is determined that another communication node is not transmitting a signal, it is defined as constituting a confirmed idle channel assessment (CCA).

[0006] The eNB or UE in an LTE system must also perform LBT to transmit signals in the unlicensed frequency band (for convenience, referred to as the U band). Regarding communication technologies using the unlicensed frequency band, NR needs to consider the bandwidth portion that depends on the UE's bandwidth capabilities when discussing beamforming technologies using multiple antennas and communication technologies using the new unlicensed frequency band. Summary of the Invention

[0007] Technical issues

[0008] This disclosure provides a method for adjusting the size of a contention window in a wireless communication system and a communication apparatus using the method.

[0009] Technical solution

[0010] In one aspect, a method is provided for adjusting the contention window size of a user equipment (UE) in a wireless communication system. The method includes the steps of: transmitting data to a base station (BS) via a frequency band in a bandwidth portion of the UE, wherein the bandwidth portion is a portion of a carrier bandwidth configured for the UE; receiving feedback information from the BS regarding the data; and adjusting the contention window size of the UE based on the feedback information, wherein the contention window size is a range of counter values ​​used in a channel access procedure (CAP) as an operation for the UE to determine channel occupancy, wherein the bandwidth portion overlaps with a plurality of CAP bandwidths that serve as the bandwidth for the UE to perform the channel access procedure, and wherein, based on the overlap of the frequency band transmitting data with the plurality of CAP bandwidths, the UE adjusts the contention window size for at least one of the plurality of CAP bandwidths based on the feedback information.

[0011] The UE can adjust the contention window size only for the CAP bandwidth of the resource with the largest proportion of allocated data among the multiple CAP bandwidths.

[0012] The UE can adjust the contention window size for each of the plurality of CAP bandwidths that overlap data.

[0013] The UE can perform a channel access procedure for the bandwidth portion, and when the UE fails in the CAP operation for a specific duration or at least a specific count, the UE can switch to a different bandwidth portion.

[0014] The different bandwidth portions can be pre-configured bandwidth portions, bandwidth portions before switching, or initial / default bandwidth portions.

[0015] When the bandwidth portion is switched, the contention window size can be adjusted to the minimum value for all priority categories.

[0016] When the bandwidth portion is switched, the contention window size can be adjusted to the value used in the bandwidth portion before the switch.

[0017] When the bandwidth portion is switched, the contention window size can be adjusted to the value contained in the downlink control information (DCI) that reports the bandwidth portion switching command.

[0018] When the bandwidth portion is switched, the contention window size can be adjusted to a value one level lower than the value before the switch, which is allowed for all priority categories.

[0019] When the bandwidth portion is switched, the contention window size can be adjusted to the value previously used in the corresponding bandwidth portion.

[0020] The feedback information may include uplink grants associated with the Hybrid Automatic Repeat Request (HARQ) processing identifier (ID) used for sending data. If the New Data Indicator (NDI) of the feedback information is switched, the contention window size may be adjusted to the minimum value for all priority categories. If the NDI of the feedback information is not switched, the contention window size may be adjusted to a value one level higher than all priority categories. The contention window size to be adjusted may be the contention window size for the CAP bandwidth of the resource with the largest proportion of allocated data among the plurality of CAP bandwidths.

[0021] When the counter value is initially set, the counter value can be set to any value that is greater than or equal to 0 and less than or equal to the competition window size.

[0022] The counter value can be adjusted by sensing the channel during the channel access process.

[0023] On the other hand, a method is provided for adjusting the contention window size of a base station (BS) in a wireless communication system. The method includes the steps of: transmitting data to a user equipment (UE) via a frequency band in a bandwidth portion of the UE, wherein the bandwidth portion is a portion of a carrier bandwidth configured for the UE; receiving feedback information from the UE regarding the data; and adjusting the contention window size of the BS based on the feedback information, wherein the contention window size is a range of counter values ​​used in a channel access procedure (CAP) as an operation for the BS to determine channel occupancy, wherein the bandwidth portion of the UE overlaps with a plurality of CAP bandwidths that constitute the bandwidth for the BS to perform the channel access procedure, and wherein, based on the overlap between the frequency band transmitting the data and the plurality of CAP bandwidths, the BS adjusts the contention window size for at least one of the plurality of CAP bandwidths based on the feedback information.

[0024] The BS can adjust the contention window size only for the CAP bandwidth of the resource with the largest proportion of allocated data among the multiple CAP bandwidths.

[0025] The BS can adjust the contention window size for each of the plurality of CAP bandwidths that overlap data.

[0026] In another aspect, a user equipment (UE) is provided, comprising: a transceiver that transmits and receives radio signals; and a processor operatively coupled to the transceiver, wherein the processor is configured to: transmit data to a base station (BS) via a frequency band in a bandwidth portion of the UE, wherein the bandwidth portion is a portion of a carrier bandwidth configured for the UE; receive feedback information from the BS regarding the data; and adjust a contention window size of the UE based on the feedback information, wherein the contention window size is a range of counter values ​​used in a channel access procedure (CAP) as an operation for the UE to determine channel occupancy, wherein the bandwidth portion overlaps with a plurality of CAP bandwidths as the bandwidth for the UE to perform the channel access procedure, and wherein, based on the overlap of the frequency band for transmitting data with the plurality of CAP bandwidths, the UE adjusts the contention window size for at least one of the plurality of CAP bandwidths based on the feedback information.

[0027] Beneficial effects

[0028] According to this disclosure, a method for performing pre-talk listening (LBT) based on the transmission of each bandwidth portion and beam introduced in the NR system, a method for adjusting the contention window size, and a method for performing LBT taking into account the time gap between the successful timing of LBT and the actual transmission timing are proposed to enable more efficient communication using unlicensed frequency bands in the NR system. Attached Figure Description

[0029] Figure 1 A wireless communication system to which this disclosure can be applied is shown.

[0030] Figure 2 This is a diagram illustrating the wireless protocol architecture used in the user plane.

[0031] Figure 3 This is a diagram illustrating the wireless protocol architecture used for the control plane.

[0032] Figure 4 An example of a system architecture for a next-generation radio access network (NG-RAN) using NR is presented.

[0033] Figure 5 This illustrates the functional division between NG-RAN and 5GC.

[0034] Figure 6 An example of a frame structure that can be applied in NR is shown.

[0035] Figure 7 An example of CORESET is shown.

[0036] Figure 8 This is a diagram illustrating the differences between the control area of ​​the relevant technology and the CORESET in NR.

[0037] Figure 9 An example of a frame structure for a new radio access technology is shown.

[0038] Figure 10 This is an abstract schematic diagram illustrating hybrid beamforming from the perspective of the TXRU and the physical antenna.

[0039] Figure 11 The beam scanning operation used for synchronizing signals and system information during downlink (DL) transmission is illustrated.

[0040] Figure 12 The LBT performed for each beam is illustrated schematically.

[0041] Figure 13 The diagram illustrates PDSCH scheduling in the case where the BWP configured for the UE is greater than the LBT bandwidth.

[0042] Figure 14 This is a flowchart of a method for adjusting the competition window size of a BS according to an embodiment of the present disclosure.

[0043] Figure 15 This is a flowchart of a method for adjusting the contention window size of a UE according to another embodiment of this disclosure.

[0044] Figure 16 Used to describe CWS adjustments based on NACK, measured in units of CBG.

[0045] Figure 17 This is an example used to illustrate CWS adjustments based on NACK, expressed in units of CBG.

[0046] Figure 18 An example used to describe the application of [Proposed Method #17].

[0047] Figure 19 This is a block diagram illustrating the components of the transmitting device 1810 and the receiving device 1820 that implement the present disclosure.

[0048] Figure 20 An example of the signal processing module structure in the transmitting device 1810 is shown.

[0049] Figure 21 Another example of the signal processing module structure in the transmitting device 1810 is shown.

[0050] Figure 22 An example of a wireless communication device according to an implementation example of this disclosure is shown. Detailed Implementation

[0051] Figure 1 A wireless communication system to which this disclosure can be applied is shown. This wireless communication system may be referred to as an evolved UMTS terrestrial radio access network (E-UTRAN) or a long-term evolution (LTE) / LTE-A system.

[0052] E-UTRAN includes at least one base station (BS) 20 that provides a control plane and a user plane to user equipment (UE) 10. UE 10 can be fixed or mobile and can be referred to by other terms such as mobile station (MS), user terminal (UT), subscriber station (SS), mobile terminal (MT), radio device, etc. BS 20 is typically a fixed station that communicates with UE 10 and can be referred to by other terms such as evolved Node B (eNB), base transceiver system (BTS), access point, etc.

[0053] The BS20 interconnects via the X2 interface. The BS20 also connects to the Evolved Packet Core (EPC) 30 via the S1 interface, and more specifically, to the Mobility Management Entity (MME) via the S1-MME and to the Serving Gateway (S-GW) via the S1-U.

[0054] EPC 30 includes an MME, S-GW, and a Packet Data Network Gateway (P-GW). The MME contains UE access information or UE capability information, which is typically used for UE mobility management. The S-GW is a gateway that terminates at the E-UTRAN. The P-GW is a gateway that terminates at the PDN.

[0055] The radio interface protocol between the UE and the network can be divided into three layers based on the well-known Open Systems Interconnection (OSI) model in communication systems: Layer 1 (L1), Layer 2 (L2), and Layer 3 (L3). Among these, the Physical (PHY) layer (Layer 1) provides information transmission services using physical channels, while the Radio Resource Control (RRC) layer (Layer 3) controls radio resources between the UE and the network. For this purpose, the RRC layer exchanges RRC messages between the UE and the BS.

[0056] Figure 2 This is a diagram illustrating the wireless protocol architecture used in the user plane. Figure 3 This is a diagram illustrating the wireless protocol architecture used for the control plane. The user plane is the protocol stack used for user data transmission. The control plane is the protocol stack used for control signal transmission.

[0057] Reference Figure 2 and Figure 3The PHY layer provides information transmission services to the upper layers via physical channels. The PHY layer connects to the Media Access Control (MAC) layer, which is the upper layer, via transport channels. Data is transmitted between the MAC layer and the PHY layer via transport channels. Transport channels are classified according to how data is transmitted through the radio interface and their characteristics.

[0058] Data moves between different PHY layers (i.e., the transmitter's PHY layer and the receiver's PHY layer) via physical channels. These physical channels can be modulated according to an orthogonal frequency division multiplexing (OFDM) scheme and use time and frequency as radio resources.

[0059] The functions of the MAC layer include mapping between logical channels and transport channels, as well as multiplexing and demultiplexing transport blocks provided through physical channels on the transport channels of MAC Service Data Units (SDUs) belonging to logical channels. The MAC layer provides services to the Radio Link Control (RLC) layer through logical channels.

[0060] The RLC layer's functions include the concatenation, segmentation, and reassembly of RLC SDUs. To ensure the various types of Quality of Service (QoS) required for radio bearers (RBs), the RLC layer provides three operating modes: Transparent Mode (TM), Unacknowledged Mode (UM), and Acknowledged Mode (AM). AM RLC provides error correction via Automatic Repeat Request (ARQ).

[0061] The RRC layer is defined only on the control plane. The RRC layer is associated with the configuration, reconfiguration, and release of radio bearers, and is responsible for the control of logical channels, transport channels, and PHY channels. RB represents the logical path provided by Layer 1 (PHY layer) and Layer 2 (MAC layer, RLC layer, and PDCP layer) for transmitting data between the UE and the network.

[0062] The Packet Data Convergence Protocol (PDCP) layer on the user plane performs functions including the transmission of user data and header compression and encryption. The PDCP layer on the user plane also performs functions related to the transmission of control plane data and encryption / integrity protection.

[0063] RB configuration refers to the process of defining the characteristics of the radio protocol layer and channel to provide specific services and configuring various detailed parameters and operating methods. RBs can be divided into two types: Signaling RB (SRB) and Data RB (DRB). SRBs are used as channels for transmitting RRC messages on the control plane, while DRBs are used as channels for transmitting user data on the user plane.

[0064] If an RRC connection is established between the UE's RRC layer and the E-UTRAN's RRC layer, the UE is in an RRC connected state. Otherwise, the UE is in an RRC idle state.

[0065] Downlink transport channels used for transmitting data from the network to the UE include a broadcast channel (BCH) for transmitting system information and a shared downlink channel (SCH) for transmitting user service or control messages. Service or control messages for downlink multicast or broadcast services can be transmitted via the downlink SCH, or via a separate downlink multicast channel (MCH). Furthermore, uplink transport channels used for transmitting data from the UE to the network include a random access channel (RACH) for transmitting initial control messages and a shared uplink channel (SCH) for transmitting user service or control messages.

[0066] The logical channels located above the transport channel and mapped to the transport channel include the Broadcast Control Channel (BCCH), Paging Control Channel (PCCH), Common Control Channel (CCCH), Multicast Control Channel (MCCH), and Multicast Service Channel (MTCH).

[0067] A physical channel comprises multiple OFDM symbols in the time domain and multiple subcarriers in the frequency domain. A subframe comprises multiple OFDM symbols in the time domain. A Resource Allocation Unit (RB) is a unit of resource allocation that includes multiple OFDM symbols and multiple subcarriers. Additionally, each subframe may allocate specific subcarriers of a specific OFDM symbol (e.g., the first OFDM symbol) to the Physical Downlink Control Channel (PDCCH), i.e., the L1 / L2 control channel. The Transmission Time Interval (TTI) is the unit of time for subframe transmission.

[0068] The following text will describe the new radio access technology (New RAT, NR).

[0069] With an increasing number of communication devices demanding greater communication capabilities, there is a need for improved mobile broadband communications compared to existing radio access technologies (RATs). Furthermore, massive machine-type communications (MTC) that provides various services by connecting numerous devices and objects is one of the main issues to be considered in next-generation communications. Additionally, communication system designs considering stability / latency-sensitive services / UEs are being discussed. The introduction of next-generation radio access technologies, taking into account enhanced mobile broadband communications (eMBB), massive machine-type communications (mMTC), and ultra-reliable low-latency communications (URLLC), is discussed, and for convenience, this new technology may be referred to in this disclosure as a new radio access technology (new RAT or NR).

[0070] Figure 4 An example of a system architecture using NR next-generation radio access network (NG-RAN) is given.

[0071] Reference Figure 4 NG-RAN may include gNBs and / or eNBs that provide user plane and control plane protocol termination to terminals. Figure 4 This example only includes the gNB. The gNB and eNB are connected via the Xn interface. The gNB and eNB are connected to the 5G core network (5GC) via the NG interface. More specifically, the gNB and eNB are connected to the Access and Mobility Management Function (AMF) via the NG-C interface and to the User Plane Function (UPF) via the NG-U interface.

[0072] Figure 5 Example of functional division between NG-RAN and 5GC.

[0073] The gNB can provide functions such as inter-cell radio resource management (inter-cell RRM), radio bearer management (RB control), connection mobility control, radio access control, measurement configuration and specification, and dynamic resource allocation. The AMF can provide functions such as NAS security and idle-state mobility processing. The UPF can provide functions such as mobility anchoring and PDU processing. The SMF can provide functions such as UE IP address assignment and PDU session control.

[0074] Figure 6 An example of a frame structure that can be applied in NR is shown.

[0075] Reference Figure 6 A frame can consist of 10 milliseconds (ms) and include 10 subframes, each consisting of 1 ms.

[0076] Depending on the subcarrier spacing, one or more time slots can be included in a subframe.

[0077] Table 1 below illustrates the subcarrier spacing configuration μ.

[0078] [Table 1]

[0079]

[0080] Table 2 below illustrates the number of time slots (N) in a frame configured with subcarrier spacing μ. frame,μ slot ), the number of time slots in the subframe (N) subframe,μ slo ), the number of symbols in the time slot (N) slot symb )wait.

[0081] [Table 2]

[0082]

[0083] exist Figure 6 In the example, μ = 0, 1, 2 is shown.

[0084] The Physical Downlink Control Channel (PDCCH) may include one or more Control Channel Elements (CCEs), as illustrated in Table 3 below.

[0085] [Table 3]

[0086] Aggregation level Number of CCEs 1 1 2 2 4 4 8 8 16 16

[0087] That is, the PDCCH can be transmitted through resources including 1, 2, 4, 8, or 16 CCEs. Here, a CCE includes six Resource Element Groups (REGs), and a REG includes a resource block in the frequency domain and an orthogonal frequency division multiplexing (OFDM) symbol in the time domain.

[0088] Furthermore, in future wireless communication systems, a new unit called the Control Resource Set (CORESET) can be introduced. Terminals can receive PDCCHs within the CORESET.

[0089] Figure 7 An example of CORESET is shown.

[0090] Reference Figure 7 CORESET includes N in the frequency domain. CORESET RB N in the resource block and time domain CORESET symb ∈{1,2,3} symbols. N can be provided by the base station via higher-layer signaling. CORESET RB and N CORESET symb .like Figure 7 As illustrated, a CORESET may include multiple CCEs (or REGs).

[0091] The UE can attempt to detect PDCCH in units of 1, 2, 4, 8, or 16 CCEs in the CORESET. One or more CCEs that can attempt to detect PDCCH in this CORESET can be referred to as PDCCH candidates.

[0092] Multiple CORESETs can be configured for the terminal.

[0093] Figure 8 This is a diagram illustrating the differences between the control area of ​​the relevant technology and the CORESET in NR.

[0094] Reference Figure 8The control area 800 of an existing wireless communication system (e.g., LTE / LTE-A) is configured across the entire system frequency band used by the base station (BS). All terminals, except for a few that only support narrowband (e.g., eMTC / NB-IoT terminals), must be able to receive wireless signals across the entire system frequency band of the BS in order to correctly receive / decode control information sent by the BS.

[0095] On the other hand, in NR, the aforementioned CORESET is introduced. CORESETs 801, 802, and 803 are radio resources used to transmit control information received by the terminal, and can utilize only a portion rather than the entire system bandwidth. The BS can allocate CORESETs to each UE and can transmit control information through the allocated CORESETs. For example, in... Figure 8 In this configuration, the first CORESET 801 can be assigned to UE 1, the second CORESET 802 can be assigned to UE 2, and the third CORESET 803 can be assigned to UE 3. In NR, the terminal can receive control information from the BS without having to receive the entire system frequency band.

[0096] CORESET can include UE-specific CORESET for sending UE-specific control information and public CORESET for sending common control information for all UEs.

[0097] Furthermore, depending on the application, NR may require high reliability. In such cases, the target block error rate (BLER) of downlink control information (DCI) transmitted via a downlink control channel (e.g., physical downlink control channel (PDCCH)) can be significantly reduced compared to conventional techniques. As an example of a method to meet the requirement of high reliability, the content included in the DCI can be reduced and / or the amount of resources used for DCI transmission can be increased. Here, resources may include at least one of resources in the time domain, resources in the frequency domain, resources in the code domain, and resources in the spatial domain.

[0098] The following technologies / features can be applied in NR.

[0099] <Self-contained subframe structure>

[0100] Figure 9 An example of a frame structure for a new radio access technology is shown.

[0101] In NR, such as Figure 9 As shown, the structure in which the control channel and data channel are time-division multiplexed within a TTI can be regarded as a frame structure in order to minimize latency.

[0102] exist Figure 9In the diagram, the shaded area represents the downlink control area, and the black area represents the uplink control area. The remaining area can be used for either downlink (DL) data transmission or uplink (UL) data transmission. This structure is characterized by performing DL and UL transmissions sequentially within a subframe, allowing DL data to be sent and ULACK / NACK to be received within the same subframe. Therefore, the time required from a data transmission error to data retransmission is reduced, thereby minimizing the latency of the final data transmission.

[0103] In this data and TDM control subframe structure, there may be time gaps required for base stations and terminals to switch from transmit mode to receive mode or from receive mode to transmit mode. Therefore, some OFDM symbols during the DL to UL handover can be set as guard periods (GP) in the self-contained subframe structure.

[0104] <Simulated Beamforming #1>

[0105] In millimeter-wave (mmW) radiation, the wavelength is shortened, allowing a large number of antenna elements to be installed in the same area. That is, a wavelength of 1 cm at 30 GHz means that a total of 100 antenna elements can be installed in a two-dimensional array in a 5×5 cm panel with a spacing of 0.5λ (wavelength). Therefore, in mmW, a large number of antenna elements can be used to increase beamforming (BF) gain, thereby increasing coverage or improving throughput.

[0106] In this scenario, if transceiver units (TXRUs) are provided to adjust the transmit power and phase of each antenna element, independent beamforming can be performed for each frequency resource. However, installing TXRUs for all approximately 100 antenna elements is cost-inefficient. Therefore, a method using analog phase shifters to map a large number of antenna elements to a single TXRU and control the beam direction is considered. This analog beamforming can only form a beam direction across all frequency bands, thus failing to provide frequency-selective beamforming.

[0107] Hybrid beamforming (BF) with B TXRUs (less than Q antenna elements) can be considered an intermediate form between digital BF and analog BF. In this case, the number of beam directions that can be transmitted simultaneously is limited to B, although this number depends on the method of connecting the B TXRUs and Q antenna elements.

[0108] <Simulated Beamforming #2>

[0109] When multiple antennas are used in NR (Radio Frequency Identification), hybrid beamforming emerges as a combination of digital and analog beamforming. Here, in analog beamforming (or RF beamforming), precoding (or combination) is performed at the RF end, thus achieving performance similar to digital beamforming while reducing the number of RF chains and D / A (or A / D) converters. For ease of description, the hybrid beamforming structure can be represented by N TXRUs and M physical antennas. Then, the digital beamforming of the L data layers to be transmitted at the transmitter can be represented by an N×L matrix. The converted N digital signals are converted into analog signals via TXRUs and then analog beamforming, represented by an M×N matrix, is applied.

[0110] Figure 10 This is an abstract schematic diagram illustrating hybrid beamforming from the perspective of the TXRU and the physical antenna.

[0111] exist Figure 10 In this system, the number of digital beams is L, and the number of analog beams is N. Furthermore, in NR systems, by designing the base station to change analog beamforming on a symbolic basis, more efficient beamforming for terminals located in specific areas is considered. Additionally, when N TXRUs and M RF antennas are limited to... Figure 7 When considering one antenna panel, consider introducing multiple antenna panels suitable for independent hybrid beamforming in the NR system.

[0112] When a base station uses multiple analog beams as described above, the analog beams suitable for receiving signals can be different for different terminals. Therefore, it is advisable to consider a beam scanning operation in which the base station applies multiple analog beams to at least the synchronization signal, system information and paging per symbol in a specific subframe (SF), so that all terminals can have a chance to receive signals.

[0113] Figure 11 The beam scanning operation used for synchronizing signals and system information during downlink (DL) generation is illustrated.

[0114] exist Figure 11 In NR systems, the physical resources (or physical channels) that transmit system information via broadcast are called physical broadcast channels (xPBCH). Here, analog beams belonging to different antenna panels can be transmitted simultaneously within a single symbol, and the following is being discussed: Figure 8The example illustrates the introduction of a beam reference signal (BRS) as a reference signal (RS) for applying a single analog beam (corresponding to a specific antenna panel) to measure the channel of each analog beam. The BRS can be defined for multiple antenna ports, and each antenna port of the BRS can correspond to a single analog beam. Here, all analog beams in the analog beam group are applied to a synchronization signal or xPBCH, and then the synchronization signal or xPBCH is transmitted so that any terminal can continuously receive the synchronization signal or xPBCH.

[0115] <Bandwidth Component (BWP)>

[0116] NR systems can support up to 400 MHz for each component carrier (CC). If a UE operating within this wideband CC is always RF-powered for the entire CC, battery consumption will increase. Alternatively, considering multiple use cases operating within a wideband CC (e.g., eMBB, URLLC, mMTC, etc.), different sets of parameters (e.g., subcarrier spacing (SCS)) can be supported for different frequency bands within the CC. Alternatively, each UE can have different capabilities for the maximum bandwidth. In this regard, the BS can instruct the UE to perform operation only within a portion of the bandwidth, rather than the entire bandwidth of the wideband CC. For convenience, a portion of the bandwidth is defined as a bandwidth portion (BWP). A BWP can consist of contiguous resource blocks (RBs) on the frequency axis and can correspond to a set of parameters (e.g., SCS, cyclic prefix (CP) length, slot / slot duration, etc.).

[0117] Furthermore, the BS can configure multiple BWPs within a single CC configured for a UE. For example, a BWP occupying a relatively small frequency domain can be configured in the PDCCH monitoring slot, and the PDSCH indicated in the PDCCH can be scheduled on a BWP wider than that BWP. Alternatively, when UEs are concentrated at a specific BWP, another BWP can be configured for some of the UEs for load balancing. Alternatively, considering the cancellation of inter-cell frequency domain interference between adjacent cells, the BWPs on both sides can be configured in the same time slot by excluding some of the center spectrum from the entire bandwidth. That is, the BS can configure at least one DL / UL BWP for a UE associated with a wideband CC. At least one DL / UL BWP configured at a specific time can be activated (via L1 signaling, MAC CE, or RRC signaling, etc.). A handover to another configured DL / UL BWP can be indicated (via L1 signaling, MAC CE, or RRC signaling, etc.). The handover to the predetermined DL / UL BWP can occur when the timer value expires according to the timer. In this case, the activated DL / UL BWP is defined as a valid DL / UL BWP. During initial access or before establishing an RRC connection, the UE may not receive configuration for the DL / UL BWP. In this case, the DL / UL BWP assumed by the UE is defined as the initially valid DL / UL BWP.

[0118] The channel access procedure based on Licensed Assisted Access (LAA) will be described below.

[0119] First, the downlink channel access process will be described.

[0120] The eNB operating the LAA Scell ​​should perform the channel access procedure described in this section to access the channel on which the LAA Scell ​​is being transmitted.

[0121] The channel access procedure for transmitting PDSCH / PDCCH / EPDCCH will be described below.

[0122] During the delay duration T d After the channel is first sensed to be idle during the additional time slot duration and after counter N reaches 0 in step 4, the eNB can transmit PDSCH / PDCCH / EPDCCH on the carrier performing LAA Scell ​​transmission. The counter N is adjusted by sensing the channel during the additional time slot duration according to the following steps:

[0123] 1) Set N = N init , where N init It is uniformly distributed between 0 and CW pA random number between [the given numbers] is generated, and then proceed to step 4;

[0124] 2) If N > 0 and eNB selects a decrementing counter, then set N = N - 1;

[0125] 3) Sensing the channel during the additional time slot duration, and if the additional time slot duration is idle, proceed to step 4; otherwise, proceed to step 5;

[0126] 4) If N = 0, stop; otherwise, go to step 2;

[0127] 5) Sensing the channel until either during the additional delay duration T d A busy time slot is detected, or an additional delay duration T is detected. d Until all time slots are idle;

[0128] 6) If the additional delay duration T d If the channel is detected to be idle during all time slot durations, proceed to step 4; otherwise, proceed to step 5.

[0129] If the eNB has not yet transmitted PDSCH / PDCCH / EPDCCH on the carrier on which LAA Scell ​​transmission is performed after step 4 of the above process, and if the eNB is ready to transmit PDSCH / PDCCH / EPDCCH for at least the time slot duration T... sl If the channel is sensed to be idle and if the delay duration T immediately preceding the transmission is... d If the channel has been sensed to be idle for the entire duration of the time slots, the eNB may transmit on that carrier, including PDSCH / PDCCH / EPDCCH. If the eNB first senses the channel after being ready to transmit, during the time slot duration T... sl The channel has not yet been detected as idle, or if the delay duration T immediately preceding the expected transmission... d If the channel is not idle during any time slot duration, then the eNB will detect the channel as not idle during the delay duration T. d After sensing that the channel is idle during the time slot duration, proceed to step 1.

[0130] Delay duration T d Including the duration T immediately following each time slot sl =9us of m p Duration T following a consecutive time slot duration f =16us, and T f Including T f Initial idle time slot duration T sl .

[0131] If the eNB senses the channel during the time slot duration, then the time slot duration T is considered to be... sl The device is idle, and the power detected by the eNB is less than the energy detection threshold X for at least 4 µs within the duration of the time slot. Thresh Otherwise, the time slot duration T sl They are considered busy.

[0132] CW min,p ≤CW p ≤CW max,p It's a competitive window. CW p The adjustment is described during the competition window adjustment process.

[0133] Select CW before step 1 in the above process. min,p and CW max,p .

[0134] m p CW min,p and CW max,p Based on the channel access priority category associated with eNB transmission, as shown in Table 4.

[0135] If the eNB sends a discovery signal that does not include PDSCH / PDCCH / EPDCCH when N>0 in the above process, then the eNB should not decrement N during the duration of the time slot overlapping with the discovery signal transmission.

[0136] Beyond the T given in Table 4 mcot,p During the specified period, the eNB should not transmit continuously on the carrier on which LAA Scell ​​transmission is performed.

[0137] For p=3 and p=4, if it can be guaranteed for a long period that no other carrier-sharing technology exists (e.g., at the specified level), T mcot,p =10ms, otherwise, T mcot,p =8ms.

[0138] Table 4 is a table of channel access priority categories.

[0139] [Table 4]

[0140]

[0141] The following describes the channel access procedure that includes the transmission of a discovery signal but not the transmission of a PDSCH.

[0142] At least the sensing interval T drs=If the channel is detected to be idle within 25µs and the transmission duration is less than 1ms, the eNB may immediately transmit a discovery signal, but not a PDSCH, on the carrier on which LAA Scell ​​transmission is performed. T drs Including the duration T immediately following a time slot sl =Duration T after 9us f =16us, and T f Including T f Initial idle time slot duration T sl If the time slot duration T drs If the internal sensor detects that the channel is idle, then the channel is in T drs The space inside is considered to be free.

[0143] The competition window adjustment process will be described below.

[0144] If the eNB transmits a PDSCH on the carrier that includes a channel access priority class p, the eNB maintains the contention window value CW. p Adjust CW before using the following steps for step 1 of the above-mentioned process for these sends. p :

[0145] 1) For each priority category p∈{1,2,3,4}, set CW p =CW min,p ;

[0146] 2) If at least Z = 80% of the HARQ-ACK values ​​corresponding to the PDSCH transmission in reference subframe k are determined to be NACK, then in step 2, the CW will be applied to each priority category p ∈ {1, 2, 3, 4} p Increase to the next higher allowable value and hold; otherwise, go to step 1.

[0147] The reference subframe k is the starting subframe of the most recent transmission made by the eNB on the carrier, and at least some HARQ-ACK feedback is expected to be available for that transmission.

[0148] The eNB should only base its CW on the given reference subframe k for each priority class p∈{1,2,3,4}. p The value is adjusted once.

[0149] If CW p =CW max,p This is used to adjust CW p The next higher allowed value is CW. max,p .

[0150] To determine Z,

[0151] - If the eNB transmission for which HARQ-ACK feedback is available begins in the second time slot of subframe k, then in addition to the HARQ-ACK value corresponding to the PDSCH transmission in subframe k+1, the HARQ-ACK value corresponding to the PDSCH transmission in subframe k+1 is also used.

[0152] -If the HARQ-ACK value corresponds to a PDSCH transmission on the same LAASCell assigned by the (E)PDCCH transmitted on the LAASCell,

[0153] --If the eNB does not detect a HARQ-ACK response sent for the PDSCH, or if the eNB detects a "DTX", "NACK / DTX", or "any" state, it is counted as NACK.

[0154] --If the HARQ-ACK value corresponds to a PDSCH transmission on LAASCell assigned by an (E)PDCCH transmitted on another serving cell,

[0155] --If the eNB detects a HARQ-ACK response sent for the PDSCH, it will count the "NACK / DTX" or "any" status as NACK and ignore the "DTX" status.

[0156] --If the eNB does not detect HARQ-ACK feedback sent for PDSCH,

[0157] ---If the UE is expected to use PUCCH format 1b with channel selection, the "NACK / DTX" state corresponding to "No Transmission" is counted as NACK, while the "DTX" state corresponding to "No Transmission" is ignored. Otherwise, HARQ-ACK for PDSCH transmission is ignored.

[0158] - If the PDSCH transmission has two codewords, the HARQ-ACK value for each codeword is considered separately.

[0159] - A bundled HARQ-ACK across M subframes is considered as M HARQ-ACK responses.

[0160] If the eNB transmits PDCCH / EPDCCH in DCI format with 0A / 0B / 4A / 4B on the channel starting from time t0, but does not transmit PDSCH associated with channel access priority class p, then the eNB maintains the contention window value CW. p And adjust CW before using the following steps for step 1 of the process described in subsection 15.1.1 for these transmissions. p :

[0161] 1) For each priority category p∈{1,2,3,4}, set CW p =CW min,p ;

[0162] 2) If at t0 and t0+T CO If less than 10% of the UL transport blocks scheduled by the eNB using the Type 2 channel access procedure have been successfully received during the time interval, then in step 2, the CW will be applied to each priority class p∈{1,2,3,4}. p Increase to the next higher allowable value and hold; otherwise, go to step 1.

[0163] If in order to generate N init And continuous use of CW p =CW max,p K times, then only for generating N init And continuous use of CW p =CW max,p The priority category p of K times will CW p Reset to CW min,p For each priority category p∈{1,2,3,4}, eNB selects K from the set of values ​​{1,2,…,8}.

[0164] The energy detection threshold adaptation process will be described below.

[0165] eNBs accessing the carrier transmitted by LAA Scell ​​should set the energy detection threshold (X) Thresh Set to less than or equal to the maximum energy detection threshold X Thresh_max .

[0166] Determine X as follows Thresh_max :

[0167] If it can be guaranteed over a long period that no other carrier-sharing technology exists (e.g., at the specified level), then:

[0168]

[0169] ---wherein, when X r This is the maximum energy detection threshold (in dBm) defined by regulatory requirements when these requirements are defined; otherwise, X r =T max +10dB.

[0170] -otherwise,

[0171]

[0172] -in:

[0173] --For transmissions including PDSCH, T A =10dB;

[0174] --For transmissions that include discovery signal transmissions but not PDSCH transmissions, T A =5dB;

[0175] --P H =23dBm

[0176] --P TX This is the maximum eNB output power (unit: dBm) set for the carrier.

[0177] ---eNB uses the maximum transmit power set by a single carrier, regardless of whether single-carrier or multi-carrier transmission is used.

[0178] --T max (dBm)=10·log10(3.16228·10 -8 (mW / MHz)·BWMHz(MHz))

[0179] --BWMHz is the single-carrier bandwidth (unit: MHz).

[0180] The channel access procedure for transmission on multiple carriers will be described below.

[0181] The eNB can execute multiple carriers transmitted by the LAA Scell ​​based on an access process that will be described subsequently as either Type A or Type B.

[0182] The following section will describe the Type A multicarrier access process.

[0183] The eNB should, in accordance with the channel access procedures mentioned above for the transmission of PDSCH / PDCCH / EPDCCH, process each carrier c i Channel access is performed on C, where C is the set of carriers that the eNB intends to transmit on it, and i = 0, 1, ..., q-1, and q is the number of carriers that the eNB intends to transmit on it.

[0184] For each carrier c i Determine the counter N described above in the channel access process for transmitting PDSCH / PDCCH / EPDCCH, and represent it as follows: Maintain based on type A1 or type A2

[0185] The following text will describe type A1.

[0186] For each carrier c iIndependently determine the counter N as described above in the channel access process for transmitting PDSCH / PDCCH / EPDCCH, and express it as...

[0187] If it cannot be guaranteed in the long term that no other carrier-sharing technology will exist (e.g., at the specified level), then when the eNB stops on any carrier c j When transmitting on ∈C, for each carrier c i ≠c j The eNB can either wait for a duration of 4 T. sl Then either reinitialize The decrementing process restarts when an idle time slot is detected.

[0188] The following text will describe type A2.

[0189] For example, regarding carrier c j The counter N is determined in the channel access process described above for transmitting PDSCH / PDCCH / EPDCCH, and is denoted as follows: Among them, c j It has the largest CW p The value of the carrier. For each carrier c i , When the eNB stops at its determination When transmitting on any of the carriers, the eNB should reinitialize for all carriers.

[0190] The following section will describe the Type B multicarrier access process.

[0191] The eNB selects carrier c as follows: j ∈C:

[0192] -eNB uses multiple carrier c i Before each transmission is performed on C, c is uniformly and randomly selected from C. j Choose C i ∈C, or

[0193] -eNB selects c j The frequency does not exceed once per second.

[0194] Where C is the set of carriers that the eNB intends to transmit on it, i = 0, 1, ... q-1, and q is the number of carriers that the eNB intends to transmit on it.

[0195] In order to use carrier c j Send it online.

[0196] -eNB should, in accordance with the channel access procedures mentioned above for the transmission of PDSCH / PDCCH / EPDCCH, on carrier c j The channel access was performed, and modifications were made for either type B1 or type B2.

[0197] In order to use carrier c i ≠c j (c i Send on ∈C),

[0198] -For each carrier c i The eNB should immediately follow the carrier c j At least the sensing interval T before transmission mc =Sense carrier c within 25µs i And the eNB can be immediately followed by at least the sensing interval T mc Internal sensing c i After idle, on carrier c i Transmit on carrier c. If the channel is sensed to be idle throughout the entire duration, then carrier c... i Considered to be targeting T mc It is idle, throughout all time durations, at a given interval T. mc On carrier c j Perform this idle sensing.

[0199] Beyond the T given in Table 4 mcot,p During the specified time period, the eNB should not be on carrier c. i ≠c j (c i ∈C) are transmitted continuously, where, using the carrier c j The channel access parameters used to determine T mcot,p The value of .

[0200] The following text will describe type B1.

[0201] For a set of carriers C, maintain a single CW p value.

[0202] To determine the carrier c j CW access via channel on p Modify step 2 of the competition window adjustment process mentioned above as follows:

[0203] If with all carriers c i If at least Z = 80% of the PDSCH transmissions in reference subframe k ∈ C correspond to a HARQ-ACK value that is determined to be NACK, then CW will be performed for each priority class p ∈ {1,2,3,4}. p Increase to the next higher allowed value; otherwise, go to step 1.

[0204] The following text will describe type B2.

[0205] Using the contention window adjustment process mentioned above, for each carrier c i ∈C independently maintains CW p value.

[0206] To determine the carrier c j N init Using carrier c j1 CW of ∈C p Value, where c j1 It is the carrier with the largest CW among all carriers in set C. p The carrier wave.

[0207] The UL channel access process will be described below.

[0208] The UE and the eNB that schedules the UL transmission for the UE shall perform the following procedures described for the UE to access the channel on which LAA Scell ​​transmission is performed.

[0209] The channel access procedure for uplink transmission will be described below.

[0210] The UE can perform LAA ScellUL transmitted carriers on one of the access procedures during the Type 1 or Type 2 UL channel access process.

[0211] If the UL authorization indication for the PUSCH transmission is scheduled to be a Type 1 channel access procedure, the UE shall use the Type 1 channel access procedure to transmit the transmission including the PUSCH transmission, unless otherwise stated below.

[0212] If the UL authorization indication for the PUSCH transmission is scheduled to be a Type 2 channel access procedure, the UE shall use the Type 2 channel access procedure to transmit the transmission including the PUSCH transmission, unless otherwise stated below.

[0213] The UE should use a Type 1 channel access procedure to transmit SRS without PUSCH transmission. UL channel access priority category p=1 is used for SRS transmission without PUSCH.

[0214] Table 5 lists the channel access priority categories for the uplink.

[0215] [Table 5]

[0216]

[0217] If the "UL Configuration for LAA" field is configured with "UL Offset" l and "UL Duration" d for subframe n, then

[0218] If the end of UE transmission occurs in or before subframe n+l+d-1, the UE can use channel access type 2 to transmit in subframe n+l+i, where i = 0, 1, ..., d-1, regardless of the channel access type signaled in the UL grant for these subframes.

[0219] If the UE is scheduled to use PDCCH DCI format 0B / 4B in subframe set n0, n1, ..., n w-1 The transmission includes the transmission of PUSCH, and if the UE cannot transmit in subframe n k If the UE accesses the channel used for transmission in subframe n, then the UE should attempt to access the channel according to the channel access type indicated in the DCI. k+1 The transmission takes place in the form of a subframe, where k∈{0,1,…w-2} and w is the number of scheduled subframes indicated in the DCI.

[0220] If the UE is scheduled to use one or more PDCCH DCI formats 0A / 0B / 4A / 4B in the subframe set n0,n1,…,n w-1 The transmission includes gapless PUSCH transmission, and the UE, after one access carrier during the access process according to Type 1 or Type 2 UL channel, in subframe n k If the transmission is performed in n, then the UE can... k Then continue sending in subframes, where k∈{0,1,…w-1}.

[0221] If UE transmission ends in subframe n and begins immediately in subframe n+1, it is not expected that the UE will be indicated with different channel access types for transmission in these subframes.

[0222] If the UE is scheduled to use one or more PDCCH DCI formats 0A / 0B / 4A / 4B in subframes n0, n1, ..., n w-1 It is transmitted without gaps, and if the UE is in subframe n k1 If transmission was stopped during or before this period (k1∈{0,1,…w-2}), and if the UE senses that the channel has been idle since the UE stopped transmission, the UE can use the Type 2 channel access procedure in subsequent subframe n. k2 The UE transmits (k2∈{1,…w-1}). If the UE senses that the channel is not always idle after it stops transmitting, the UE can use a channel with subframe n. k2 The corresponding UL channel access priority category type 1 channel access procedure indicated in the DCI is used in subsequent subframe n. k2 Send in, k2∈{1,…w-1}.

[0223] If the UE receives a UL grant and the DCI indicates the start of PUSCH transmission in subframe n using a Type 1 channel access procedure, and if the UE has an ongoing Type 1 channel access procedure prior to subframe n.

[0224] - If the UL channel access priority category value p1 used for the ongoing Type 1 channel access procedure is equal to or greater than the UL channel access priority category value p2 indicated in the DCI, the UE can respond to the UL grant transmission PUSCH by using the access carrier of the ongoing Type 1 channel access procedure.

[0225] - If the UL channel access priority category value p1 used for an ongoing Type 1 channel access procedure is less than the UL channel access priority category value p2 indicated in the DCI, the UE should terminate the ongoing channel access procedure.

[0226] If the UE is scheduled to transmit on a set C of carriers in subframe n, and if the PUSCH transmission on the set C of scheduled carriers indicates a Type 1 channel access procedure, and if all carriers in the set C of carriers indicate the same "PUSCH start position", and if the carrier frequencies of the set C of carriers are a subset of a predefined set of carrier frequencies,

[0227] - The UE can use the Type 2 channel access procedure to access the carrier c. i Send on ∈C.

[0228] -If immediately following carrier c j Before UE transmission on carrier c ∈C(i≠j) i The Type 2 channel access procedure was executed, and

[0229] -If the UE uses a Type 1 channel access procedure to access carrier c j ,

[0230] - Wherein, before performing a Type 1 channel access procedure on any carrier in the set of carriers C, the UE uniformly and randomly selects carrier c from the set of carriers C. j .

[0231] When the eNB has already transmitted on the carrier according to the channel access procedure mentioned above for transmitting PDSCH / PDCCH / EPDCCH, the eNB may indicate a Type 2 channel access procedure in the UL-authorized DCI that schedules the transmission of PUSCH on the carrier in subframe n. Alternatively, when the eNB has already performed transmission on the carrier according to the channel access procedure mentioned above for transmitting PDSCH / PDCCH / EPDCCH, the eNB may use the "UL Configuration for LAA" field to indicate that the UE may perform a Type 2 channel access procedure for transmitting PUSCH on the carrier in subframe n, or if it starts from t0 and is within t0+T CO If subframe n occurs within the end of the time interval, the eNB can schedule transmissions, including PUSCH, on the carrier within subframe n. These transmissions are initiated by the eNB within a time interval of duration T. short_ul After transmission on this carrier at a frequency of 25µs, where T CO =T mcot,p +T g ,in,

[0232] -t0 indicates the time when the eNB has started sending.

[0233] -T mcot,p The value is determined by the eNB as described in the downlink channel access procedure.

[0234] -T g It is the total duration of all gaps with a duration longer than 25µs that occur between the eNB's DL transmission and the eNB-scheduled UL transmission, as well as between any two UL transmissions scheduled by the eNB starting from t0.

[0235] If t0 and t0+T can be scheduled continuously CO If UL transmissions occur between consecutive frames, the eNB should schedule them in consecutive frames.

[0236] In order to perform a duration T on the eNB short_ul =After transmitting on the carrier within 25us, UL transmission is performed on the same carrier. The UE can use the Type 2 channel access procedure to perform UL transmission.

[0237] If the eNB indicates a Type 2 channel access procedure for the UE in the DCI, then the eNB indicates the channel access priority category for obtaining access to the channel in the DCI.

[0238] The following section describes the Type 1 UL channel access procedure.

[0239] UE can be delayed for duration T dAfter the channel is first sensed to be idle during the time slot duration and after counter N reaches zero in step 4, transmission is performed using a Type 1 channel access procedure. The counter N is adjusted by sensing the channel during the additional time slot duration according to the following steps:

[0240] 1) Set N = N init , where N init It is uniformly distributed between 0 and CW p A random number between these values ​​is generated, then proceed to step 4;

[0241] 2) If N > 0 and the UE selects a decrementing counter, then set N = N - 1;

[0242] 3) Sensing the channel during the additional time slot duration, and if the additional time slot duration is idle, proceed to step 4; otherwise, proceed to step 5;

[0243] 4) If N = 0, stop; otherwise, go to step 2;

[0244] 5) Sensing the channel until either during the additional delay duration T d A busy time slot or an additional delay duration T is detected within the time slot. d Until all time slots are idle;

[0245] 6) If the additional delay duration T d If the channel is detected to be idle for all time slot durations, proceed to step 4; otherwise, proceed to step 5.

[0246] If the UE has not yet transmitted a PUSCH-included message on the carrier on which it performs LAA Scell ​​transmission after step 4 of the above process, and if at least during the time slot duration T when the UE is ready to transmit a PUSCH-included message... sl If the channel is detected to be idle, and if the delay duration T immediately preceding the transmission including PUSCH is... d If the channel is sensed to be idle during all time slot durations, the UE can transmit on the carrier, including the PUSCH. If the UE first senses the channel after being ready to transmit, during time slot duration T... sl The channel has not yet been detected as idle, or if the delay duration T immediately preceding the expected transmission including PUSCH is not detected. d If the channel is not sensed to be idle during any time slot duration, then the UE will remain idle for the delay duration T. d After sensing that the channel is idle during the time slot duration, proceed to step 1.

[0247] Delay duration T d Including the duration T immediately following each time slotsl =9us of m p Duration T following a consecutive time slot duration f =16us, and T f Including T f Initial idle time slot duration T sl .

[0248] If the UE senses the channel during the time slot duration, then the time slot duration T is considered to be... sl Idle, and the power detected by the UE is less than the energy detection threshold X for at least 4µs within the duration of this time slot. Thresh Otherwise, the time slot duration T sl They are considered busy.

[0249] CW p (CW min,p ≤CW p ≤CW max,p () is the competition window. The following describes the competition window adjustment process, specifically the CW. p Applications.

[0250] Select CW before step 1 in the above process. min,p and CW max,p .

[0251] m p CW min,p and CW max,p Based on the channel access priority category for signaling to the UE as shown in Table 5.

[0252] X will be described in the energy detection threshold adaptation process described below. Thresh Applications.

[0253] The following section will describe the Type 2 UL channel access procedure.

[0254] If a UL UE uses a Type 2 UL channel access procedure to transmit PUSCH, the UE can do so within at least the sensing interval T. short_ul = Once the channel is detected to be idle within 25µs, a transmission including PUSCH is immediately sent. T short_ul Including the duration T immediately following a time slot sl =Duration T after 9us f =16us, and T f Including T f Initial idle time slot duration T sl If in T short_ul If the channel is sensed to be idle during the duration of time slot T, then the channel is considered to be for T. short_ul It is available.

[0255] The competition window adjustment process will be described below.

[0256] If the UE transmits on a carrier using a Type 1 channel access procedure associated with channel access priority category p, the UE maintains the contention window value CW. p And adjust the CW for these transmissions before step 1 of the type 1 uplink channel access procedure mentioned above using the following process. p :

[0257] - If the NDI value for at least one HARQ process associated with HARQ_ID_ref is switched,

[0258] --For each priority category p∈{1,2,3,4}, set CW p =CW min,p ;

[0259] Otherwise, CW will be applied to each priority category p∈{1,2,3,4} p Increase to the next higher allowable value.

[0260] HARQ_ID_ref is the reference subframe n ref The HARQ processing ID of UL-SCH in the data. The reference subframe n is determined as follows. ref :

[0261] -If the UE is in subframe n g If a UL authorization is received in subframe n, then subframe n w It is the subframe n in which the UE has sent UL-SCH during the Type 1 channel access procedure. g The nearest subframe before -3.

[0262] -If the UE starts with subframe n0 and is in subframes n0, n1, ..., n w If the transmission includes gapless transmission of UL-SCH, then refer to subframe n. ref It is subframe n0,

[0263] --Otherwise, refer to subframe n ref It is a subframe n w .

[0264] If the UE is scheduled to use a type 1 channel access procedure in the subframe set n0, n1, ..., n w-1 The transmission includes a PUSCH transmission without gaps, and if the UE is unable to transmit any transmission including a PUSCH in the set of subframes, the UE can maintain CW for each priority class p∈{1,2,3,4}. p The value remains unchanged.

[0265] If the reference subframe used for the final scheduled transmission is also n ref Then the UE can maintain the CW for each priority category p∈{1,2,3,4} p The value is the same as the value sent in the final schedule of the PUSCH using the Type 1 channel access procedure.

[0266] If CW p =CW max,p This is used to adjust CW p The next higher allowed value is CW. max,p .

[0267] If in order to generate N init And continuous use of CW p =CW max,p K times, then only for generating N init And continuous use of CW p =CW max,p The priority category p of K times, CW p Reset to CW min,p For each priority category p∈{1,2,3,4}, the UE selects K from the set of values ​​{1,2,…,8}.

[0268] The energy detection threshold adaptation process will be described below.

[0269] UEs accessing the carrier transmitted by LAA Scell ​​on it should set the power detection threshold (X) Thresh Set to less than or equal to the maximum energy detection threshold X Thresh_max .

[0270] Determine X as follows Thresh_max :

[0271] - If the UE is configured with a higher layer parameter "maxEnergyDetectionThreshold-r14"

[0272] --X Thresh_max It is set to the value that is signaled via higher-level parameters;

[0273] -otherwise,

[0274] --The UE should determine X' according to the default maximum energy detection threshold calculation process, which will be described later. Thresh_max .

[0275] --If the UE is configured with the higher-level parameter "energyDetectionThresholdOffset-r14"

[0276] ---Adjust X' based on the offset value signaled via higher-level parameters. Thresh_max To set X Thresh_max ;

[0277] -otherwise,

[0278] ---UE should set X Thresh_max =X' Thresh_max .

[0279] The following section describes the process for calculating the default maximum energy detection threshold.

[0280] If the higher-level parameter "absenceOfAnyOtherTechnology-r14" indicates TRUE:

[0281] - in,

[0282] --When these requirements are defined, X r It is the maximum energy detection threshold (in dBm) defined by regulatory requirements; otherwise, X r =T max +10dB.

[0283] otherwise,

[0284] -

[0285] in,

[0286] -T A =10dB;

[0287] -P H =23dBm;

[0288] -P TX Set to P CMAX_H,c The value;

[0289] -T max (dBm)=10·log10(3.16228·10 -8 (mW / MHz)·BWMHz(MHz));

[0290] --BWMHz is the single-carrier bandwidth (unit: MHz).

[0291] The disclosure will be described below.

[0292] This disclosure proposes a multi-beam pre-talk listening method and a contention window size adjustment scheme when a transmitting node performs a channel access procedure in a wireless communication system including a base station (BS) and a user equipment (UE) in an unlicensed frequency band.

[0293] With the growing demand for higher communication capacity in many communication devices, the efficient use of limited frequency bands in next-generation wireless communication systems is becoming increasingly important. In cellular communication systems such as LTE / NR systems, unlicensed frequency bands that are the same as those used in traditional WiFi systems at 2.4 GHz or those that are the newly emerging 5 GHz and 60 GHz bands are considered to be used for service offloading.

[0294] Since it is essentially assumed that wireless transmission / reception is achieved in a contention-based manner among the respective communication nodes in the unlicensed frequency band, channel sensing needs to be performed before the respective communication node transmits a signal to confirm that no signal transmission has occurred among other communication nodes. For convenience, this operation is called pre-talk listening (LBT), and specifically, the operation of confirming whether another communication node is transmitting a signal is defined as carrier sensing (CS). When it is determined that another communication node is not transmitting a signal, it is defined as achieving a confirmed idle channel assessment (CCA).

[0295] In LTE systems, the eNB or UE must also perform LBT (Low-License Bit Transmission) to transmit signals in the unlicensed frequency band (for convenience, referred to as the U-band). Additionally, when the eNB or UE in an LTE / NR system transmits signals, another communication node, such as WiFi, must perform CCA (Corrective Caution) to prevent interference. For example, in the WiFi standard (801.11ac), the CCA threshold is defined as -62dBm for non-WiFi signals and -82dBm for WiFi signals. This means that, for example, when a signal other than WiFi is received at a power greater than or equal to -62dBm, the STA (Stationary Access Point) or AP (Access Point) will not transmit signals to prevent interference.

[0296] Furthermore, similar to using multiple antenna elements in millimeter-wave (mmW) NR to increase beamforming (BF) gain and thus increase coverage or throughput, multi-beam operation can also be utilized in the NR U-band. However, for NR systems operating in unlicensed bands (e.g., 5 GHz, 37 GHz, 60 GHz) and coexisting with another system (e.g., 802.11ac / ax / ad / ay, etc.), multi-beam LBT operation should be performed before the transmitting node performs transmission. The LBT method can differ when the channel is occupied by LBT operation and transmission is performed through the occupied channel, when transmission is performed simultaneously with beam scanning of multiple analog beams, and when transmission is performed by fixing the beam as a single analog beam.

[0297] Additionally, when reporting at least a certain percentage of NACKs for data transmitted by multiple UEs that successfully performed LBT in a specific time slot, CWS adjustments may also be required in the NR U band, similar to the case of increasing the Contention Window Size (CWS). NR is a system in which UEs with various bandwidth capabilities coexist. UEs capable of transmitting / receiving across the entire carrier bandwidth and UEs supporting only a portion of the carrier bandwidth can coexist. A subset consisting of a contiguous portion of a Physical Resource Block (PRB) within the carrier bandwidth is called a Bandwidth Part (BWP). Up to four BWPs can be configured for a UE via higher-layer signals. The UE only performs transmission / receive using the valid BWPs among the configured BWPs at specific timings and does not anticipate receiving PDSCH, PDCCH, CSI-RS, TRS, etc., in areas other than the valid BWPs. Thus, since this is an environment where UEs with different bandwidth capabilities coexist, it is necessary to appropriately calculate the NACK for PDSCH scheduled for multiple BS LBT BWPs in an overlapping / overlapping manner in a time slot by taking into account the UE's BWP and the BS's LBT bandwidth, thereby adjusting the CWS when at least a certain ratio of NACKs occurs.

[0298] For example, considering a scenario where the BS's LBT bandwidth 1 and LBT bandwidth 2 are consecutively set to 20MHz on the frequency axis, and UE A has a 40MHz bandwidth capability that completely overlaps with the BS's LBT bandwidth, a PDSCH spanning both BS LBT bandwidths can be scheduled in a single time slot via the UE's BWP. In this case, when the scheduled PDSCH fails to decode and therefore reports a NACK to the BS, the BS should determine which of LBT bandwidth 1 and LBT bandwidth 2 should be considered when adjusting the CWS for the NACK.

[0299] Therefore, this disclosure proposes an LBT method for the case where transmission is performed simultaneously by scanning several analog beams while the channel is occupied after LBT is performed and the occupied channel is used for transmission, and an LBT method for the case where transmission is performed simultaneously while fixed to a single analog beam. Furthermore, this disclosure proposes a method for adjusting the CWS for each LBT bandwidth when UEs with different BWP capabilities coexist and PDSCH is scheduled by overlapping multiple LBT bandwidths with the BS.

[0300] In the following, in this disclosure, the Physical Broadcast Channel (PBCH) refers to a physical channel that transmits basic system information such as system bands and SFN (System Frame Number) (hereinafter, MIB (Master Information Block)). RMSI (Residual Minimal System Information) refers to system information required for any random access procedure other than the MIB. OSI (Other System Information) refers to remaining system information other than the MIB and RMSI. Furthermore, SS (Synchronization Signal) refers to a synchronization signal, DM-RS (Demodulation Reference Signal) refers to a reference signal used for data demodulation, and a time slot refers to a basic time unit consisting of multiple OFDM symbols.

[0301] First, the multi-beam LBT will be described in more detail below.

[0302] In the NR U band, beamforming technology utilizing multiple antennas in the NR system is also considered as an essential component. In unlicensed bands, to ensure fair coexistence with pre-existing Wi-Fi devices in the corresponding band before data transmission by transmitting nodes (before media access is performed), pre-talk listening (LBT) should be performed. To transmit signals while performing beam scanning in the NR U band, the following multi-beam LBT method can be considered.

[0303] First, in the method of performing LBT on the signal to be transmitted by performing beam scanning after performing wide-beam LBT such as SS block, the transmitting node can operate by selecting one of the following three methods. The UE can operate when notifying the BS of one of these three methods.

[0304] (1) A method of transmitting while performing an omnidirectional LBT and simultaneously scanning the beam.

[0305] Method (1) is a method that performs omnidirectional LBT in addition to the specific direction even if transmission in a specific beam direction is introduced in NR.

[0306] (2) A method of performing transmission by scanning the beam only in the beam direction where LBT is successful after performing LBT once in all directions, or by scanning all beams only when LBT is successful in all directions, and not attempting to transmit even when LBT fails in one beam direction.

[0307] Regarding method (2), for example, one could consider the case where the entire direction is divided into four different beam directions (e.g., beam direction 1, beam direction 2, beam direction 3, and beam direction 4) and LBT is performed for each of the different beam directions. In this paper, when method (2) is applied, if LBT is successfully performed only for beam direction 1 and beam direction 3, the transmitting node can perform transmission only for beam direction 1 and beam direction 3. Alternatively, since LBT fails for some beam directions, transmission cannot be performed in all beam directions.

[0308] (3) A method of performing directional LBT in all directions except the beam direction in which transmission is not actually performed and attempting to transmit by performing beam scanning in the beam direction in which LBT is successful.

[0309] For example, in the case mentioned above in method (2), it is possible to consider the case where the transmitting node does not actually perform transmission based on beam direction 4. In this case, the transmitting node can perform LBT only for beam directions 1, 2, and 3. In this document, when LBT is successfully performed only for beam directions 1 and 3 as described above, the transmitting node can perform transmission only for beam directions 1 and 3.

[0310] The method proposed in this disclosure will be described below with respect to multi-beam LBT.

[0311] [Proposed Method #1] The duration of the LBT (CCA) slot required for the execution of LBT in Method (1) is set to be longer than the duration of LBT in a specific direction in Method (2) so that the total time required in LBT is similar.

[0312] For example, if T is the LBT (CCA) slot duration required to perform LBT in a particular direction, and the total number of beams that will undergo LBT is 4, so that performing LBT for each beam takes a total of 4T time, then when performing LBT in one omnidirectional direction, the LBT slot duration can be a larger value than the LBT time T required for each beam (e.g., 4T).

[0313] [Proposed Method #1] The relationship between omnidirectional LBT and directional LBT is considered as follows: the product of the time required to perform directional LBT for each direction and the total number of directions for omnidirectional splitting is set to be close to or equal to the time required to perform omnidirectional LBT.

[0314] Furthermore, in the case of method (2), since transmission is performed only in the direction of the beam in which the directional LBT is successful, the index of the beam to be transmitted may have to be dynamically indicated to the receiving node.

[0315] [Proposed Method #2] An SRS resource, such as a beam management SRS, containing information about the beam direction of a successful LBT, is transmitted in the uplink to inform the receiving node of the beam direction in which the LBT was actually successfully performed.

[0316] That is, according to [Proposed Method #2], the transmitting node can report information about the beam direction of a successful LBT to the receiving node, making it easier for the receiving node to identify the beam direction of a successful LBT, thereby performing the receiving operation related to that beam direction more smoothly.

[0317] However, in this paper, the beam direction can be replaced by the resource area to be transmitted, and SRS resource means the time-frequency resource on which the BS indicates SRS transmission.

[0318] For example, suppose there are three beam directions #1, #2, and #3 on which LBT should be performed from the perspective of the transmitting node. Sequence A and / or frequency resource 1 can be transmitted when LBT is successfully performed in all beam directions; sequence B and / or frequency resource 2 can be transmitted when LBT is successfully performed in beam directions #1 and #2, or beam directions #2 and #3, or beam directions #1 and #3; and sequence C and / or frequency resource 3 can be transmitted when LBT is successfully performed in only one of these three directions. Of course, the sequences can be configured differently for all cases obtained from the LBT results. Therefore, when the corresponding SRS resource is transmitted in the beam direction where LBT was successfully performed based on the directional LBT results, the receiving node can learn about the beam direction on which LBT was actually successfully performed.

[0319] Additionally, when a BS instructs repeated transmissions in the same beam direction, it needs to inform the BS of the specific resource on which transmission actually begins. For example, suppose the BS instructs three repeated transmissions in a specific beam direction, and the corresponding transmission attempt order is represented by a first order, a second order, and a third order. In this case, if the BS has information on the order in which the corresponding signals were transmitted together when LBT was successfully performed for the corresponding direction, it can know the order in which the LBT was successful among the three repeated transmissions.

[0320] [Proposed Method #3] Information about the beam direction in which LBT was successfully performed as a result of LBT is included together and the receiving node is informed via PUCCH (PDCCH) or PUSCH (PDSCH) while transmitting a signal in the beam direction in which LBT was successfully performed as a result of directional LBT.

[0321] In other words, similar to the [Proposed Method #2] mentioned above, information about the beam direction of a successful LBT is transmitted via PUCCH / PUSCH / PDCCH / PDSCH.

[0322] Furthermore, in method (2), a beam in a specific direction that failed to perform LBT can be generated while performing directional LBT. In this case, the following method can be regarded as a detailed operation of multi-beam LBT.

[0323] [Proposed Method #4] When LBT in a specific direction cannot be performed, the next direction's LBT is performed with a delay corresponding to the time required to send a signal in the corresponding direction (after all LBTs are completed), or all transmissions in all directions are discarded.

[0324] Figure 12 The LBT performed for each beam is illustrated schematically. In this paper, Figure 12 An example is shown in the case where there are three beams (i.e., beam A, beam B, and beam C). Figure 12 Figure (a) shows the transmission process for each beam after LBT is performed normally for each beam when LBT is successfully performed for all beams, and Figure 12 (b) shows the transmission process when LBT fails for beam A.

[0325] For example, when directional LBT is performed sequentially in three directions, the transmission process following the normal LBT is as follows: Figure 12 As shown in (a), directional LBT is performed sequentially from beam A to beam C, and transmission is then performed for each beam in the same order. However, if LBT fails for beam A, since it is known that no signal transmission is performed in the direction of beam A after LBT has been completed in all directions, LBT can be performed with a delay corresponding to the time required to transmit a signal when LBT is successful in the direction of beam A, instead of immediately performing LBT for the next beam (i.e., beam B). Figure 12 As shown in (b) of the document.

[0326] In this paper, for example, when a specific node fails to perform LBT for beam A but successfully performs LBT for beams B and C, if... Figure 12 As shown in (a), after performing LBT on all beams, the transmission delay of the beam for which LBT will be successfully performed during the transmission time duration for beam A (i.e., if as shown in (a)). Figure 12If, as shown in (a), no transmission is performed for beam A during the transmission time duration for beam A, then another node can successfully perform LBT and thus be able to transmit a signal during that time duration. Therefore, even if a particular node successfully performs LBT for beams B and C and thus transmits its signal, interference may occur due to the signal transmission of another node.

[0327] To solve this problem, consider the following methods: when... Figure 12 In (b) shown, when LBT fails for beam A, a gap corresponding to the transmission time duration for beam A is configured before performing LBT for beams B and C, such that LBT operations for beams B and C are performed after this gap. That is, in this method, when LBT fails for beam A, LBT operations for beams B and C are delayed until the transmission time duration.

[0328] In addition, in this article, Figure 12 In case (b), when the LBT fails in the direction of beam A, the specific node that has performed the LBT during the duration of the signal transmission delay may not perform any operation.

[0329] In addition, in this paper, when an LBT failure occurs in a specific direction in an intermediate direction other than the first or last direction of the LBT for all directions, the following two options can be considered.

[0330] - Option 1: When the LBT sequence is determined for each direction while LBT is being performed sequentially and LBT fails in a particular direction, the LBT is temporarily delayed for the time required to send the remaining beams when LBT succeeds, and the signal is sent only in the direction where LBT succeeds.

[0331] - Option 2: Even if LBT fails for the intermediate direction, LBT is still performed in the subsequent directions, and signals can be sent only for the directions where LBTs have been consecutively successful. For example, if LBT fails only for direction #3 out of a total of 6 directions, the sending node can selectively send signals on the preceding directions #1 and #2 or the subsequent directions #4, #5 and #6 where LBTs have been consecutively successful, depending on the pre-configuration or protocol.

[0332] [Proposed Method #5] A method in which beams used to perform directional LBT are grouped so that the methods mentioned above can be applied within corresponding groups.

[0333] For example, if there are six beams #1 to #6 for performing directional LBT, the beams can be paired so that every two beams are set as a group. In this paper, [Proposed Method #4] can be applied to groups of beams instead of individual beams to perform directional LBT. For a failed group of beams, the next LBT can be performed on the group of beams by temporarily delaying the transmission time. Signals can be transmitted only in the direction of the group of beams where the LBT was successful.

[0334] According to [Proposed Method #5], each of the beam directions mentioned above in [Proposed Method #1] to [Proposed Method #4] can be applied as a beam group.

[0335] Next, when signals such as DL data are transmitted in a narrow beam after narrow beam LBT is performed, a random backoff-based LBT execution process is required in the LBT processing for each beam.

[0336] [Proposed Method #6] is based on the LBT method with individual random backoff for each beam direction.

[0337] In this method, a backoff counter can be set independently for each beam direction. When a transmitting node changes the beam direction used for LBT execution to a specific beam direction A midway through LBT execution based on random backoff, the existing backoff counter for beam direction A can be temporarily maintained, and LBT can be executed in the other beam direction. When returning to beam direction A to execute LBT, the maintained counter value can be increased to a predetermined or agreed-upon specific value. In this case, a penalty can be added. The penalty can start from the same value as the counter value that began to decrease or was maintained, and can additionally begin decreasing the counter only during idle states within a specific time period.

[0338] [Proposed Method #6] proposes a method to configure individual beam-by-beam random backoff counters for each beam direction by considering beam-by-beam operations introduced in the existing LBT scheme based on random backoff counters, and to configure and change the beam-by-beam random backoff counters when performing beam-by-beam LBT operations.

[0339] [Proposed Method #7] Similar to SS blocks / RMSI / OSCI / paging, even for broadcast data transmitted simultaneously with beam scanning after wide-beam LBT, LBT is performed based on random backoff.

[0340] Regarding [Proposed Method #7], the LBT scheme shown in Table 6 below can be applied in a COT initiation performed by gNB. The methods disclosed in Table 6 below are merely examples, and various methods different from those in Table 6 may be considered.

[0341] [Table 6]

[0342]

[0343] -Note: Applicability of LBT schemes other than initial / random access, mobility, paging, transmission of reference-only signals and transmission of PDCCH only (e.g., RACH message 4), handover commands, GC-PDCCH, or other LBT schemes except for Category 4 control messages related to short message paging transmitted separately or multiplexed with DRS.

[0344] Furthermore, existing wide-beam LBT methods involve performing an LBT omnidirectionally or in a specific direction once, followed by transmission in the corresponding direction if the LBT is successful. The proposed method, however, involves performing the LBT based on random backoff, such as DL data, during the LBT execution. However, to allow the signal transmitted via beam scanning to complete contention faster than DL data, the CWS can be set to be smaller than that of the narrow-beam LBT, or the LBT slot duration can be set shorter, or the CCA threshold can be increased, thus reducing the time required before performing medium access (MA).

[0345] Furthermore, the proposed method is also applicable to uplinks such as SRS. The method applicable to beam-managed SRS can be considered a representative example.

[0346] In other words, existing LBT methods include Type 1, which is an LBT method based on a random backoff counter, and Type 2, which is an LBT method executed without a random backoff counter. In Type 1, the transmit signal is transmitted by including a PDSCH in the transmit signal, while in Type 2, the transmit signal is transmitted without including a PDSCH. That is, Type 2 is used when transmitting non-unicast data. Furthermore, Type 1 can also be referred to as Category 4 (or cat.4) LBT, and Type 2 can also be referred to as Category 2 (or cat.2) LBT.

[0347] In this paper, even when sending non-unicast data, [Proposed Method #7] considers using the LBT method based on a random backoff counter instead of the Type 2 method. Furthermore, in [Proposed Method #7], whether to apply the LBT method based on a random backoff counter can vary depending on the type or configuration of the non-unicast data.

[0348] [Proposed Method #8] A method of performing LBT by scaling the CCA threshold or the energy value measured for CCA according to the ratio of the specific beam in which the transmission is intended to be performed when transmission is performed only in a specific beam direction.

[0349] First, when performing omnidirectional LBT, if the measured energy value is P, the existing method performs transmission by comparing the measured energy value P with the CCA threshold T and by considering that the channel is idle only when P < T. However, if as a result of scaling the measured energy value P by a ratio R of the beams to be transmitted in all directions (where R is a rational number satisfying 0 < R ≤ 1), P × R < T, then the method may determine that the channel is idle, or if as a result of scaling the CCA threshold, P < T / R, then the method may determine that the channel is idle.

[0350] When comparing the measured power / energy value with the threshold by considering fairness with omnidirectional LBT in the case of introducing directional LBT, scaling based on the ratio of the beams is considered in the method.

[0351] Hereinafter, the method of adjusting the CWS for each BWP will be described in more detail.

[0352] Existing LAA includes a CWS adjustment method. In this method, the bandwidth capability of the UE is up to 20 MHz, which is the same as the LBT bandwidth of the BS. For example, when the BS intends to transmit downlink (DL) data through 5 consecutive time slots after successful LBT, the PDSCH for 10 UEs is scheduled in the first time slot of the DL burst. At least 8 NACKs are reported from the UEs, so that when the NACK ratio is greater than or equal to 80%, LBT is performed again by increasing the CWS.

[0353] However, in NR, a UE capable of performing transmission / reception using the entire carrier bandwidth (up to about 400 MHz) according to the bandwidth capability of the UE can coexist with a UE capable of performing transmission / reception only through a subset of the bandwidth smaller than the carrier bandwidth (e.g., BWP).

[0354] Figure 13 Schematically shows the PDSCH scheduling in the case where the BWP configured for the UE is larger than the LBT bandwidth.

[0355] Figure 13 Schematically shows the LBT bandwidth (BW) 1 and 2 of the gNB and the BWP of the UE. Here, for example, the two LBT BWs 1 and 2 can overlap with one BWP of the UE. Here, each of the LBT BW 1 and LBT BW 2 can be 20 MHz. Additionally, here, the BWP of the UE can be 40 MHz.

[0356] In this case, Figure 13 Schematically shows the case where PDSCH 1 and PDSCH 2 are allocated. Here, as Figure 13As shown, we can consider the case where PDSCH 1 is allocated across LBT BW 1 and LBT BW 2 and PDSCH 2 is allocated only to LBT BW 2.

[0357] like Figure 13 As shown, a UE having a BW corresponding to the value obtained by adding the LBT BW 1 and LBT BW 2 of the gNB as the BWP can be configured to completely overlap with the two LBT BWs of the gNB, and PDSCH can be scheduled across these two gNB LBT BWs. In this case, the NACK ratio can be calculated as a criterion for CWS adjustment for the LBT BW 1 and LBT BW 2 of the gNB using the following proposed method.

[0358] [Proposed Method #9] A method to adjust the CWS of LBT BW based on the UE's BWP.

[0359] In this method, for LBT BWs in the gNB that overlap with the UE's BWP, all PDSCHs scheduled for the UE's BWP are considered based on the NACK ratio to adjust the CWS. For example, when... Figure 13 As shown, when the UE's BWP overlaps with the gNB's LBT BW 1 and LBT BW 2, all PDSCHs scheduled for the UE's BWP (i.e., both PDSCH 1 and PDSCH 2) are considered for the NACK count of LBT BW 1 and LBT BW 2, so as to help increase CWS when it is greater than or equal to a certain NACK ratio.

[0360] [Proposed Method #10] A method for adjusting the CWS of LBT BW based on PDSCH scheduling resources.

[0361] In this method, when the resource scheduled using PDSCH belongs to a specific gNB LBT BW, the NACK of PDSCH is considered when adjusting the CWS of the corresponding LBT BW. For example, in Figure 13 In this case, since PDSCH 2 belongs only to the LBT BW of the gNB, the CWS adjustment for LBT BW 2 can only consider the NACK of PDSCH 2. In the case of PDSCH 1, since the scheduled resources belong to both LBT BW 1 and LBT BW 2, if the decoding result of PDSCH 1 is NACK, it can be considered for use in both LBT BWs, and therefore for CWS adjustment. Alternatively, the CWS adjustment can only be considered for the LBT BW with a larger proportion of PDSCH 1 resources among these two LBT BWs.

[0362] Specifically, for example, in Figure 13In the case of PDSCH 1, all resources scheduled for PDSCH 1 can be allocated to LBT BW 1 at a ratio of 40% and to LBT BW 2 at a ratio of 60%. In this case, according to [Proposed Method #10], if the decoding result of PDSCH 1 is NACK, the decoding result of CWS adjustment for each BW can be considered by taking into account the 40:60 ratio of the resources allocated to LBT BW 1 and LBT BW 2, or the decoding result of CW adjustment for LBT BW 2 with the higher allocated resource ratio can be considered only.

[0363] [Proposed Method #11] A method similar to PUSCH that adjusts the CWS of the UE LBT BW during uplink data transmission.

[0364] This method involves when the UE passes through the Figure 13 In the case where the UE's DL BW is changed to UL BW, the PDSCH is changed to PUSCH, and the gNB's LBT BW 1 and LBT BW 2 are changed to the UE's LBT BW 1 and LBT BW 2, and LBT is successfully transmitted to send a UL burst in each LBT BW, how to apply the PUSCH transmission result to adjust the CWS of each of the UE's LBT BW 1 and LBT BW 2? That is, the method mentioned above can also be applied equivalently to the uplink.

[0365] Specifically, as a method, there is a method that adjusts the CWS by taking into account the PUSCH transmission result (i.e., NACK) for each of LBT BW 1 and LBT BW 2 when the UE's UL BW overlaps with the UE's LBT BW.

[0366] As an alternative approach, as in [Proposed Method #10], the CWS is adjusted based on the PUSCH scheduling resources for the UE, by considering the transmission results of the LBT BW when scheduling the corresponding PUSCH transmission resources in a specific LBT BW. Similarly, the CWS adjustment can consider the PUSCH transmission results when scheduling PUSCH transmission resources for both LBT BWs across the UE, or it can only consider the PUSCH transmission results when scheduling PUSCH transmission resources for the LBT BW with a larger proportion of PUSCH resources for the CWS adjustment.

[0367] [Proposed Method #12] A method for setting CWS and / or fallback counter values ​​when BWP is switched.

[0368] The gNB can activate at least one of the configured DL / UL BWPs at a specific time for the UE (via L1 signaling, MAC CE, or RRC signaling, etc.). Alternatively, it can instruct a handover to another configured DL / UL BWP (via L1 signaling, MAC CE, or RRC signaling, etc.), or it can implement a handover to a determined DL / UL BWP when a timer-based timer value expires. Thus, when a DL / UL BWP is switched, the maximum CWS and / or backoff counter values ​​applied to the BWP before or after the handover can be reset or maintained.

[0369] Specifically, when switching the BWP via timer or signaling as described above, the UE's CWS and backoff counter values ​​can be adjusted according to the following options.

[0370] - Option 1: Reset to the minimum CWS value for all priority categories

[0371] In this paper, the priority category can be the channel access priority category in Tables 4 and 5. Specifically, taking the channel access priority category in Table 4 as an example, if the channel access priority category is 3, then the CWS of the BWP used for handover can be reset to 15, which is the minimum value among {15, 31, 63}.

[0372] Option 2: Keep the CWS used in the previous BWP

[0373] Option 3: Use the new CWS indicated by downlink control information (DCI).

[0374] That is, Option 3 is for the following method: when instructing the BWP to switch via DCI, the CWS for the switched BWP is also indicated.

[0375] Option 4: Change to CWS from the previous step

[0376] Option 5: Use the CWS value previously used in the corresponding BWP.

[0377] In this paper, taking the channel access priority category in Table 4 as an example as described above, if the channel access priority category is 3 for specific data and the CWS size for the BWP before handover is 31, according to option 4, if the channel access priority category is 3, then the CWS for the BWP after handover is 15, which is the CWS from the previous step. Alternatively, according to option 5, if the channel access priority category is 3, then 31 is used directly.

[0378] [Proposed Method #13] When an LBT failure occurs more persistently in a BWP than a specific time in the DL / UL LBT, the DL / UL LBT switches to another BWP, and the CWS and backoff counter values ​​are adjusted as in [Proposed Method #12].

[0379] When LBT failures occur more frequently in the DL or UL LBT within the BWP currently camped by the UE than a specific time or a specific count (in this document, the specific time or count can be based on a timer value or a pre-configured value), the DL / UL LBT can be performed in the corresponding BWP by switching to a pre-agreed and / or configured specific BWP. In this document, the pre-agreed and / or configured BWP can be the BWP before the handover or the initial / default BWP. Thus, when the UE performs a handover of the BWP, the CWS value can be adjusted as in [Proposed Method #12].

[0380] Specifically, if the gNB instructs the UE to perform a BWP handover and transmit an uplink PUSCH at the new BWP, but the UE fails to perform an LBT at the new BWP and therefore cannot transmit a PUSCH, it may be unclear from the gNB's perspective whether the UE is unable to correctly receive the BWP handover instruction or is unable to transmit due to an LBT failure. Furthermore, the BWP / resource transmitted by the UE may not be aligned with the BWP / resource expected by the gNB. In this case, similar to the above description, the UE can switch to a pre-agreed or configured specific BWP and adjust the CWS value as in [Proposed Method #12]. In this document, the pre-agreed and / or configured BWP can be the BWP before the handover or the initial / default BWP. By configuring such a rule or method, when the UE switches to a pre-agreed or configured BWP, the gNB can unambiguously identify whether the UE has not yet successfully performed an LBT or has not yet received a BWP handover instruction.

[0381] Figure 14 This is a flowchart of a method for adjusting the contention window size of a BS according to an embodiment of this disclosure. In this document, the BS may include the eNB or gNB mentioned above.

[0382] Reference Figure 14 The BS transmits data to the UE through the frequency band in the bandwidth portion of the UE (S1410). In this document, the bandwidth portion may be a part of the carrier bandwidth configured for the UE.

[0383] Subsequently, the BS receives feedback information about the data from the UE (S1420).

[0384] Subsequently, the BS adjusts its contention window size based on the feedback information (S1430). In this paper, the contention window size can be within the range of counter values ​​used in the Channel Access Procedure (CAP), which is the operation by which the BS determines channel occupancy.

[0385] In this article, the bandwidth portion can overlap with the bandwidth of multiple CAP operations performed by the BS. Detailed examples can be found in... Figure 13 The location shown is the same. Furthermore, although... Figure 13 Only one example is shown where two CAP bandwidths of the BS overlap with a portion of the UE's bandwidth; however, it is also possible for one CAP bandwidth of the BS to overlap with a portion of the UE's bandwidth. Alternatively, the CAP bandwidth of the BS can have the same size as the bandwidth portion. Alternatively, three or more CAP bandwidths of the BS can overlap with a portion of the UE's bandwidth.

[0386] Furthermore, in this paper, when the frequency band in which data is transmitted overlaps with multiple CAP bandwidths, the BS can adjust the contention window size for at least one of the multiple CAP bandwidths based on feedback information. Specifically, as in [Proposed Method #9], the contention window size can be adjusted for all of the multiple overlapping CAP bandwidths. Alternatively, the contention window size can be adjusted only for the CAP bandwidth that allocates / includes relatively more resources for data.

[0387] Figure 15 This is a flowchart of a method for adjusting the contention window size of a UE according to another embodiment of this disclosure.

[0388] Reference Figure 15 The UE transmits data to the BS (S1510) through the frequency band in the bandwidth portion of the UE. In this document, the bandwidth portion may be a part of the carrier bandwidth configured for the UE.

[0389] Subsequently, the UE receives feedback information about the data from the BS (S1520).

[0390] Subsequently, the UE adjusts its contention window size based on the feedback information (S1530). In this paper, the contention window size can be within the range of counter values ​​used in the Channel Access Procedure (CAP), which is the operation by which the BS determines channel occupancy.

[0391] In this paper, the bandwidth portion may overlap with the bandwidth of multiple CAP operations performed by the UE. A detailed example can be found in the detailed example described in [Proposed Method #11]. Furthermore, although... Figure 13[Proposed Method #11] only shows an example where two CAP bandwidths of the UE overlap with a portion of the UE's bandwidth, but it is also possible for one CAP bandwidth of the UE to overlap with a portion of the UE's bandwidth. Alternatively, the CAP bandwidth of the UE may have the same size as the bandwidth portion. Alternatively, three or more CAP bandwidths of the UE may overlap with a portion of the UE's bandwidth.

[0392] In addition, in this paper, when the frequency band in which data is transmitted overlaps with multiple CAP bandwidths, the UE can adjust the contention window size for at least one of the multiple CAP bandwidths based on feedback information.

[0393] also, Figure 14 and Figure 15 This involves adjusting the contention window size for both the BS and UE. Although each of the proposed methods [Proposed Method #9] through [Proposed Method #13] is written from either the UE's or BS's perspective, the proposed methods can be applied to both the BS and UE. Furthermore, Figure 14 and Figure 15 The CAP and CAP bandwidth described herein can have the same meaning as pre-talk listening (LBT) and LBT bandwidth, respectively.

[0394] The following section describes in more detail the method of performing LBT by taking into account the gap between the successful timing of LBT and the actual transmission timing.

[0395] Because of the introduction of the concept of Bandwidth Part (BWP) in NR, the bandwidth of the BWP configured for a BS or UE in an unlicensed band can be at least 20MHz. In this case, LBT should succeed, and the bandwidth in which LBT is performed can be a multiple of 20MHz, i.e., 20MHz × N (where N is a natural number).

[0396] In this paper, when LBT is successfully performed only on a portion of the total bandwidth, the transmitting node can delay transmission until LBT is successful across the entire bandwidth, or it can perform transmission using only the portion of the bandwidth for which LBT was successfully performed. The RF chain can be modified during the process of changing the transmission bandwidth at the transmitting node, or additional operations may be required to meet requirements such as in-band / out-of-band transmission and / or frequency domain spectral masking based on the actual transmission bandwidth.

[0397] [Proposed Method #14] When LBT is successfully performed on a portion of the total bandwidth and thus the transmission bandwidth is changed to the bandwidth in which LBT was successfully performed, if there is a time gap between the successful timing of LBT and the actual transmission start timing, then a short LBT is performed again on the bandwidth in which LBT was successfully performed immediately before transmission, and transmission is performed when the channel is idle.

[0398] However, a short LBT refers to an LBT that allows a transmission attempt to be made after determining that the channel is idle following an LBT performed during a specific time period (e.g., 25µs). Additionally, in the proposed method, LBTs can be performed in multiples of 20MHz (i.e., 20MHz × N, where N is a natural number).

[0399] However, the proposed method may only apply to cases where the time required for the transmitting node to change its transmission bandwidth is greater than or equal to a specific time. Specifically, the time required to change the transmission bandwidth can vary depending on the capabilities of the UE or gNB. Furthermore, the time required to change can vary based on the relationship between the total bandwidth and the transmission bandwidth (e.g., when the difference between the total bandwidth and the transmission bandwidth is greater than or equal to a threshold).

[0400] As mentioned above, in the process of changing the transmission bandwidth to the size of the bandwidth in which LBT is successfully performed, requirements such as changes in the operating bandwidth of the RF chain can create a time gap between the actual transmission timing and the successful LBT timing. In this paper, when channel sensing cannot be performed due to changes in RF bandwidth, when transmission is performed after the corresponding time, the channel may suddenly become busy due to another nearby node. Therefore, a short LBT can only be performed again to start transmission once it is confirmed that the channel is idle.

[0401] For example, when the BW of the BWP is 80MHz, if the four LBT BWs in ascending order of frequency, in units of 20MHz, are BW#1, BW#2, BW#3, and BW#4, then there may be cases where LBTs in units of 20MHz are successfully performed for BW#1 and BW#2, but not for BW#4.

[0402] In this scenario, the transmitting node can reconfigure its transmission bandwidth to 40MHz and perform short LBTs again in 20MHz increments for BW#1 and BW#2 before starting transmission with the reconfigured bandwidth. Transmission can begin upon confirmation that the channel is idle.

[0403] Specifically, for example, in the process of a specific node changing its transmission bandwidth, if another node successfully performs a short-term bandwidth test (LBT) and therefore performs transmission during the time gap that may occur between the successful LBT timing and the actual transmission start timing of the specific node, the specific node may not be able to perform transmission even if the LBT is successful. Therefore, the specific node performs a short LBT again to ensure the accuracy of whether the specific node performed transmission based on the result of the short LBT.

[0404] Specifically, when the size of a portion of the entire bandwidth where LBT was successfully performed (denoted as BW#X for convenience) is greater than 20MHz, which is the unit of LBT, if the result obtained by performing a short LBT indicates that LBT was successfully performed only for a portion of the bandwidth BW#X, BW#Y (where BW#X > BW#Y), the transmission bandwidth can be adjusted again using the portion of bandwidth (i.e., BW#Y) in a tiered manner, and transmission can begin after performing the short LBT. Alternatively, if the LBT result for BW#Y indicates that the channel is busy, the CWS used in the first LBT of the previous BW#X can be updated (or reused) relative to the bandwidth where the first LBT was successfully performed (i.e., BW#X), and Category 4 LBT can be performed again from the beginning. More generally, if it is determined that even the portion of the entire bandwidth where LBT was successfully performed, BW#X, is busy after the short LBT, operations can be performed to perform Category 4 LBT again. In this case, the bandwidth where LBT was performed can be the entire bandwidth, or it can be a transmission node implementation issue. In this case, LBT can be performed by updating (or reusing) CWS when performing the first LBT.

[0405] For example, following the example above, if a short LBT in 20MHz increments is performed again for BW#1 and BW#2, but the LBT is successful for BW#1 and fails for BW#2, the transmit bandwidth can be reconfigured for BW#1, and transmission can begin once the channel is confirmed to be idle after the short LBT was performed. Alternatively, if the short LBT result indicates that the channel is busy even for either BW#1 or BW#2, Category 4 LBT can be restarted by updating (or reusing) the existing CWS across the entire 80MHz bandwidth.

[0406] Furthermore, the proposed method can be applied when time gaps are needed even midway through an actual transmission. An exemplary implementation requiring gaps even midway through transmission could be a method of performing LBT by applying the proposed method during the time gap, which occurs when the broadband RF bandwidth is kept constant for an initial specific duration (e.g., X symbols or 1 time slot), the RF is changed to a sub-band RF band after the corresponding duration (while preparing for signal processing involved in RF changes), and the remaining transmissions are subsequently performed. In this document, if the time gap is within a specific time period, it can be excluded from the application of the proposed method.

[0407] [Proposed Method #15] When the LBT bandwidth is defined as the basic frequency axis resource unit for BS-adjusted CWS, a CWS adjustment method based on HARQ-ACK corresponding to the PDSCH that overlaps with one or more LBT bandwidths (in this case, HARQ-ACK may refer to HARQ-ACK of CBG units configured to be retransmitted in units of code block groups (CBGs)).

[0408] That is, unlike the existing CWS adjustment based on the NACK ratio on a per-transmit-block basis, the introduction of retransmission on a per-CBG basis in NR necessitates the consideration of CWS adjustment based on the NACK ratio on a per-CBG basis.

[0409] Figure 16 Used to describe CWS adjustments based on NACK, measured in units of CBG.

[0410] Reference Figure 16 The diagram illustrates LBT BW 1 and LBT BW 2 of the gNB, with PDSCH 1 scheduled across both LBT BW1 and LBT BW 2, and PDSCH 2 scheduled only for LBT BW 2. In this case, the CWS adjustment method for PDSCH 1 may be problematic.

[0411] Specifically, a CWS adjustment method based on NACK, using CBG as the unit, can be considered. Alternatively, in Figure 16 In the case of PDSCH1, similar to CBG 1 to CBG 6, the NACK of all CBGs in a transport block can be regarded as a NACK, and CWS adjustment based on it can be considered.

[0412] In this paper, when a specific CBG in the scheduled PDSCH overlaps with multiple LBT bandwidths, the following options can be considered.

[0413] Option 1: Using CBG HARQ-ACK feedback results in CWS adjustments across multiple LBT bandwidths

[0414] Specifically, refer to Figure 16 For example, in CBG 1 through CBG 6 of PDSCH 1, CBG 1 and CBG 4 are included in LBT BW 1, and CBG 3 and CBG 6 are included in LBT BW 2, while CBG 2 and CBG 5 span LBT BW 1 and LBT BW 2. In this document, according to option 1, NACK for each of CBG 2 and CBG 5 can be used in the CWS adjustment for both LBT BW 1 and LBT BW 2.

[0415] - Option 2: HARQ-ACK feedback results are used only for CWS adjustment of LBT bandwidth with a large proportion of downlink resources scheduled for CBG (in the case of the same proportion, it can be used only for CWS adjustment of a specific LBT BW indicated by a pre-agreed method or higher-layer signal (e.g., RRC signaling) or dynamic control signal (e.g., DCI).

[0416] Specifically, for example, refer to Figure 16 The following scenario is possible: resources for CBG 2 and CBG 5 are allocated to LBT BW 1 at a ratio of 40% and to LBT BW 2 at a ratio of 60%, respectively. In this case, according to Option 2, NACK for CBG 2 and CBG 5 can only be used in the CWS adjustment for LBT BW 2, which is allocated resources at the higher ratio.

[0417] That is, such as Figure 16 As shown, when the BS is configured with BWPs such as LBT BW 1 and LBT BW 2 for performing LBT in 20MHz units and the bandwidth of the UE's BWP includes the two LBT BWs of the BS, the case where the BS can schedule PDSCHs that overlap with multiple LBT BWs can be considered.

[0418] In this article, if as Figure 16 The PDSCH shown is configured for (re)transmission in units of CBGs, so PDSCH1 and PDSCH2 can include 6 CBGs and 2 CBGs, respectively. If each CBG scheduled for the first time slot of the DL burst (hereinafter, refer to the DL resource) exists only within one LBT BW of the BS, then the HARQ-ACK feedback for the corresponding CBG can be applied only to the CWS adjustment of the LBT BW including the CBG. That is, since the HARQ-ACK for CBG 1 and CBG 4 constituting PDSCH 1 is used for the CWS adjustment of LBT BW 1, and CBG 3 and CBG 6 of PDSCH 1 and CBG 1 and CBG 2 of PDSCH 2 are included in LBT BW 2, the HARQ-ACK for the corresponding CBG can be used only for the CWS adjustment of its LBT BW. However, since CBG 2 and CBG 5 constituting PDSCH are scheduled by overlapping with LBT BW1 and LBT BW 2 of BS, CWS adjustment can be performed as in the proposed methods (1) or (2).

[0419] [Proposed Method #16] When the basic frequency axis resource unit of the UE adjusts the CWS is defined as an LBT BW, the CWS adjustment method is based on the decoding result of the PUSCH that overlaps with one or more LBT BWs (in this case, the decoding result can be assumed by the CBG retransmission schedule or new data schedule of the PUSCH (re)transmitted by the CBG unit configured therein).

[0420] In this paper, when a specific CBG in the scheduled PUSCH overlaps with multiple LBT bandwidths, the following options can be considered.

[0421] Option 1: Using CBG decoding results in CWS adjustment of multiple overlapping LBT bandwidths

[0422] Option 2: Using CBG decoding results in some CWS adjustments based on LBT bandwidth.

[0423] In addition, the reference LBT bandwidth can be configured or indicated by the BS's dynamic control signals (e.g., DCI) or higher-layer signals (e.g., RRC signaling), or the reference LBT bandwidth can be used for CWS adjustment of the LBT bandwidth with a large proportion of uplink (UL) resources scheduled for the CBG to be transmitted.

[0424] However, the methods mentioned above are applicable under the following premise: when the BS fails to receive a specific CBG, a retransmission of the CBG is always indicated in the next retransmission schedule. This principle can be applied to the CBG index with time advance for all time slots or to the first time slot of a UL burst considered by the BS.

[0425] Figure 17 This is an example used to illustrate CWS adjustments based on NACK, expressed in units of CBG.

[0426] For example, such as Figure 17 As shown, when PUSCH 1, configured to be retransmitted in units of CBG, is scheduled in the first time slot of an uplink (UL) burst and configured as a reference UL resource (orange), new data can be scheduled by sending a UL grant to the UE after 3ms or 4ms, depending on the decoding result of PUSCH 1 by the BS, or the retransmission of some or all of the CBGs constituting PUSCH 1 can be indicated.

[0427] exist Figure 17 Since PUSCH 1 is scheduled by overlapping with LBT BW 1 and LBT BW 2 of the UE, the CWS of each LBT BW can be adjusted according to the decoding result of PUSCH 1 as in [Proposed Method #16].

[0428] If a retransmission schedule for some or all CBGs of PUSCH 1 is indicated by a UL authorization (e.g., Block Group Transmission Information (CBGTI)), it can be assumed that the CBG for the corresponding retransmission schedule is NACK, and the UE can perform CBW adjustment for the LBT BW scheduled for the corresponding CBG. Regarding CWS adjustment for each LBT BW of the UE, if, as in [Proposed Method #4], only the CBG indicating retransmission is scheduled for a specific LBT BW, CWS adjustment can be applied only to the LBT bandwidth. If a CBG overlaps with two LBT BWs, it can be used for CWS adjustment of both LBT BWs, or it can be used only for CWS adjustment of the LBT BW with the larger proportion of UL resources.

[0429] Furthermore, PUSCH 1 can be successfully decoded when new data is scheduled instead of being retransmitted via UL authorization indication. Therefore, ACK can be assumed, and CWS for each LBT BW can be initialized.

[0430] [Proposed Method #17] A method for hierarchically adjusting and managing individual CWS for each LBT unit BW (e.g., multiples of 20 MHz) performing LBT.

[0431] Compared to LTE systems, NR supports wider bandwidth operation. Therefore, a wide bandwidth (>20MHz) can be divided into multiple sub-bands in 20MHz units, enabling LBT (Local Band Breakdown) and CWS (Channel Window System) adjustment / management in each sub-band. Alternatively, when performing multi-carrier channel access as in LAA (Local Access Area), LBT can be performed and CWS can be managed in 20MHz units by selecting specific representative carriers.

[0432] Figure 18 An example used to describe the application of [Proposed Method #17].

[0433] When both sub-band LBT (e.g., 20MHz) and wideband LBT (>20MHz) are supported and can be used through semi-static or dynamic switching of two LBT types in an NR unlicensed band, such as Figure 18 As shown, it may be effective to hierarchically adjust and manage individual CWS for each LBT unit bandwidth (e.g., multiples of 20 MHz).

[0434] For example, when configuring Figure 18When there are six BWPs (BWP 0 to BWP 5), BWP 3 includes BWP 0 and BWP 1, BWP 4 includes BWP 1 and BWP 2, and BWP 5 includes the remainder. In this case, the results obtained by performing sub-band LBT in 20MHz increments (e.g., the results obtained by performing LBT on BWP 0) can be considered for CWS adjustment of the corresponding BWP, and the results can also be considered for CWS adjustment of BWPs that include the corresponding BWP (e.g., BWP 3 and BWP 5 that include BWP 0). Therefore, when the CWS in BWP 0 is updated to a higher level value, the CWS of BWP 3 and BWP 5 are also updated to a higher level value.

[0435] Additionally, when performing broadband LBT in BWP 3 or BWP 5, LBT can be performed using the previously updated CWS. When broadband LBT succeeds and the CWS of BWP 3 is thus initialized, the CWS of BWP 0 and / or BWP 1 may be initialized together or not, depending on the configuration.

[0436] Furthermore, this disclosure is not limited to direct communication between UEs, but also applies to uplink or downlink. In such cases, BS or relay nodes, etc., can use the proposed method.

[0437] Examples of the proposed schemes mentioned above can be included as one of the implementation methods of this disclosure, and therefore can be clearly regarded as one of the proposed methods. Furthermore, although the schemes mentioned above can be implemented independently, they can also be implemented by combining (or merging) some proposed schemes. Rules can be defined such that information regarding whether a proposed method is applied (or information regarding the rules governing the proposed method) is reported by the BS to the UE via predefined signals (e.g., physical layer signals or higher layer signals) or by the transmitting UE to the receiving UE.

[0438] Figure 19 This is a block diagram illustrating the components of the transmitting device 1810 and the receiving device 1820 that perform the present disclosure. In this document, each of the transmitting and receiving devices can be a BS or a UE.

[0439] The transmitting device 1810 and the receiving device 1820 may each include: transceivers 1812 and 1822, which are capable of transmitting or receiving radio signals carrying information and / or data, signals, and messages; memories 1813 and 1823, which store various types of information related to communication in a wireless communication system; and processors 1811 and 1821, which are connected to components such as transceivers 1812 and 1822 and memories 1813 and 1823 and are configured to control memories 1813 and 1823 and / or transceivers 1812 and 1822, causing the corresponding devices to perform at least one of the embodiments mentioned above in this disclosure. In this document, the transmitter / receiver may be referred to as a transceiver.

[0440] Memory 1813 and 1823 can store programs for processing and control by processor 1811 and 1821, and temporarily store input / output information. Memory 1813 and 1823 can be used as buffers.

[0441] Processors 1811 and 1821 generally control the overall operation of various modules in the transmitting and receiving devices. Specifically, processors 1811 and 1821 can execute various control functions for carrying out this disclosure. Processors 1811 and 1821 may also be referred to as controllers, microcontrollers, microprocessors, microcomputers, etc. Processors 1811 and 1821 can be implemented by hardware, firmware, software, or a combination thereof. When this disclosure is implemented using hardware, ASICs (Application-Specific Integrated Circuits), DSPs (Digital Signal Processors), DSPDs (Digital Signal Processing Devices), PLDs (Programmable Logic Devices), FPGAs (Field-Programmable Gate Arrays), etc., configured to execute this disclosure can be included in processors 1811 and 1821. Furthermore, when this disclosure is implemented using firmware or software, the firmware or software can be configured to include modules, programs, functions, etc., that perform the functions or operations of this disclosure, and the firmware or software configured to execute this disclosure can be included in processors 1811 and 1821 or stored in memories 1813 and 1823 and executed by processors 1811 and 1821.

[0442] The processor 1811 of the transmitting device 1810 can perform predetermined encoding and modulation on the signal and / or data to be transmitted to the outside, and then send the encoded and modulated signal or data to the transceiver 1812. For example, the processor 1811 can generate codewords by performing demultiplexing, channel coding, scrambling, and modulation on the data string to be transmitted. The codewords may include information equivalent to a transport block (TB) as a data block provided by the MAC layer. A transport block (TB) can be encoded into a codeword. Each codeword can be sent to the receiving device through one or more layers. For up-conversion, the transceiver 1812 may include an oscillator. The transceiver 1812 may include one or more transmit antennas.

[0443] The signal processing procedure of the receiving device 1820 can be the reverse of that of the transmitting device 1810. The transceiver 1822 of the receiving device 1820 can receive radio signals transmitted from the transmitting device 1810 under the control of the processor 1821. The transceiver 1822 may include one or more receiving antennas. The transceiver 1822 can recover each signal received through the receiving antennas into a baseband signal by performing down-conversion. The transceiver 1822 may include an oscillator for down-conversion. The processor 1821 can recover the data intended to be transmitted by the transmitting device 1810 by performing decoding and demodulation on the radio signals received through the receiving antennas.

[0444] Transceivers 1812 and 1822 may include one or more antennas. According to one embodiment, under the control of processors 1811 and 1821, the antennas can be used to transmit signals processed by transceivers 1812 and 1822 to the outside or to receive external radio signals and transmit those radio signals to transceivers 1812 and 1822. The antennas may also be referred to as antenna ports. Each antenna may correspond to a single physical antenna, or may be constructed from a combination of two or more physical antennas. Signals transmitted from each antenna cannot be deconstructed by receiving device 1820. A reference signal (RS) transmitted in association with the antenna defines the angle of the antenna from receiving device 1820 and enables receiving device 1820 to perform channel estimation on the antenna, regardless of whether the channel is a single radio channel from a physical antenna or a composite channel from multiple physical antenna elements including the antenna. That is, the antenna is defined such that the channel carrying symbols on the antenna can be derived from channels carrying other symbols on the same antenna. A transceiver that supports multiple-input multiple-output (MIMO) functionality for transmitting / receiving data using multiple antennas can be connected to two or more antennas.

[0445] Figure 20 An example of the structure of a signal processing module in a transmitting device 1810 is shown. In this document, it can be composed of, for example... Figure 20The processors of BS / UE, such as the 1811 and 1821, perform signal processing.

[0446] Reference Figure 20 The transmitting device 1810 in the UE or BS may include a scrambler 301, a modulator 302, a layer mapper 303, an antenna port mapper 304, a resource block mapper 305, and a signal generator 306.

[0447] The transmitting device 1810 can transmit one or more codewords. The encoded bits in each codeword are scrambled by the scrambler 301 and transmitted over the physical channel. The codeword can also be referred to as a data string and can be equivalent to a transport block as a data block provided by the MAC layer.

[0448] The modulator 302 modulates the scrambled bits into complex-valued modulation symbols. The modulator 302 can modulate the scrambled bits according to a modulation scheme and arrange them into complex-valued symbols representing their positions on the signal constellation. The modulation scheme is unrestricted, and m-phase-shift keying (m-PSK) or m-quadrature amplitude modulation (m-QAM) can be used to modulate the encoded data. The modulator can also be called a modulation mapper.

[0449] Complex-valued modulation symbols can be mapped to one or more transmission layers by layer mapper 303. Complex-valued modulation symbols on a layer can be mapped by antenna port mapper 304 for transmission at the antenna port.

[0450] Resource block mapper 305 can map complex-valued modulation symbols for corresponding antenna ports to suitable resource elements in virtual resource blocks allocated for transmission. The resource block mapper can map virtual resource blocks to physical resource blocks according to a suitable mapping scheme. Resource block mapper 305 can allocate complex-valued modulation symbols for corresponding antenna ports to suitable subcarriers and multiplex them according to the user.

[0451] Signal generator 306 can modulate complex-valued modulation symbols (i.e., antenna-specific symbols) for a corresponding antenna port according to a specific modulation scheme (e.g., orthogonal frequency division multiplexing (OFDM)) to generate complex-valued time-domain OFDM symbol signals. The signal generator can perform an inverse fast Fourier transform (IFFT) on the antenna-specific symbols, and a cyclic prefix (CP) can be inserted into the time-domain symbol to which the IFFT has been performed. The OFDM symbols undergo digital-to-analog conversion, up-conversion, etc., and are transmitted to a receiving device through the corresponding transmitting antenna. The signal generator may include an IFFT module, a CP insertion device, a digital-to-analog converter (DAC), an up-converter, etc.

[0452] Figure 21Another example of the signal processing module structure in the transmitting device 1810 is shown. In this document, it can be composed of, for example... Figure 19 The processors of the UE / BS, such as the 1811 and 1821, perform signal processing.

[0453] Reference Figure 21 The transmitting device 1810 in the UE or BS may include a scrambler 401, a modulator 402, a layer mapper 403, a precoder 404, a resource block mapper 405, and a signal generator 406.

[0454] For a codeword, the transmitting device 1810 can scramble the encoded bits in the codeword using the scrambler 401, and then transmit the scrambled bits through the physical channel.

[0455] The modulator 402 modulates the scrambled bits into complex-valued modulation symbols. The modulator can modulate the scrambled bits according to a predetermined modulation scheme and arrange the scrambled bits into complex-valued symbols representing their positions on the signal constellation. The modulation scheme is unrestricted, and the encoded data can be modulated using π / 2-binary phase shift keying (π / 2-BPSK), m-phase shift keying (m-PSK), or m-quadrature amplitude modulation (m-QAM).

[0456] Complex-valued modulation symbols can be mapped to one or more transport layers by layer mapper 403.

[0457] Complex-valued modulation symbols on a layer can be pre-coded by pre-encoder 404 for transmission through antenna ports. In this paper, the pre-encoder can perform precoding after transform precoding of the complex-valued modulation symbols. Alternatively, the pre-encoder can perform precoding without transform precoding. Pre-encoder 404 can process complex-valued modulation symbols according to MIMO using multiple transmit antennas to output antenna-specific symbols and distribute these symbols to the corresponding resource block mapper 405. The output z of pre-encoder 404 can be obtained by multiplying the output y of layer mapper 403 by an N×M precoding matrix W. In this paper, N is the number of antenna ports, and M is the number of layers.

[0458] Resource block mapper 405 maps complex-valued modulation symbols for the corresponding antenna port to appropriate resource elements in the virtual resource block allocated for transmission.

[0459] Resource block mapper 405 can assign complex-valued modulation symbols to appropriate subcarriers and multiplex them according to the user.

[0460] Signal generator 406 can modulate complex-valued modulation symbols according to a specific modulation scheme (e.g., OFDM) to generate complex-valued time-domain OFDM symbol signals. Signal generator 406 can perform an inverse fast Fourier transform (IFFT) on antenna-specific symbols, and a cyclic prefix (CP) can be inserted into the time-domain symbol to which the IFFT has been performed. The OFDM symbol undergoes digital-to-analog conversion, up-conversion, etc., and is transmitted to a receiving device through a corresponding transmitting antenna. Signal generator 406 may include an IFFT module, a CP insertion device, a digital-to-analog converter (DAC), an up-converter, etc.

[0461] The signal processing of the receiving device 1820 can be the reverse of that of the transmitting device. Specifically, the processor 1821 of the transmitting device 10 decodes and modulates the radio signals received from the outside through the antenna port of the transceiver 1822. The receiving device 1820 may include multiple receiving antennas, and the signals received through the receiving antennas are recovered into baseband signals, and then recovered into data strings intended to be transmitted by the transmitting device 10 through multiplexing and MIMO demodulation. The receiving device 1820 may include: a signal recovery device for recovering the received signals into baseband signals; a multiplexer for combining and multiplexing the received signals; and a channel demodulator for demodulating the multiplexed signal string into corresponding codewords. The signal recovery device, multiplexer, and channel demodulator may be configured as integrated modules or independent modules to perform their functions. More specifically, the signal recovery device may include: an analog-to-digital converter (ADC) for converting an analog signal into a digital signal; a CP remover for removing CP from the digital signal; an FFT module for applying a Fast Fourier Transform (FFT) to the CP-removed signal to output frequency domain symbols; and a resource element demapper / equalizer for recovering the frequency domain symbols into antenna-specific symbols. The antenna-specific symbols are then recovered to the transport layer via a multiplexer, and the transport layer recovers the symbols into codewords intended to be transmitted by the transmitting device via a channel demodulator.

[0462] Figure 22 An example of a wireless communication device according to an implementation example of this disclosure is shown.

[0463] Reference Figure 22The wireless communication device (e.g., UE) may include at least one of the following: a processor 2310 such as a digital signal processor (DSP) or microprocessor; a transceiver 2335; a power management module 2305; an antenna 2340; a battery 2355; a display 2315; a keyboard 2320; a global positioning system (GPS) chip 2360; a sensor 2365; a memory 2330; a subscriber identification module (SIM) card 2325; a speaker 2345; and a microphone 2350. Multiple antennas and multiple processors may be provided.

[0464] The processor 2310 can implement the functions, processes and methods described in this specification. Figure 21 The processor 2310 can be Figure 19 The processors 1811 and 1821.

[0465] The memory 2330 is connected to the processor 2310 and stores information related to the operation of the processor. The memory can be located inside or outside the processor and can be connected to the processor via various technologies such as wired and wireless connections. Figure 21 The memory 2330 can be Figure 19 The memory modules 1813 and 1823.

[0466] Users can use various technologies, such as pressing buttons on keypad 2320 and activating sound using microphone 2350, to input various types of information, such as phone numbers. Processor 2310 can receive user information, process user information, and perform appropriate functions, such as making a call using the entered phone number. In some scenarios, data can be retrieved from SIM card 2325 or memory 2330 to perform appropriate functions. In some scenarios, processor 2310 can display various types of information and data on display 2315 for user convenience.

[0467] Transceiver 2335 is connected to processor 2310 and transmits / receives radio signals such as radio frequency (RF) signals. The processor can control the transceiver to initiate communication or transmit radio signals containing various types of information or data, including audio communication data. The transceiver includes a transmitter and a receiver for transmitting and receiving radio signals. Antenna 2340 facilitates the transmission and reception of radio signals. In some implementation examples, when the transceiver receives a radio signal, it can forward the signal and convert it into a baseband frequency for processing by the processor. The processed signal can be processed using various techniques, such as converting it into audible or readable information, so that it is output through speaker 2345. Figure 21 The transceiver can be Figure 19 The transceivers are 1812 and 1822.

[0468] Although not in Figure 22 As shown, the UE can additionally include various components such as a camera and a Universal Serial Bus (USB) port. For example, the camera can be connected to the processor 2310.

[0469] Figure 22 This is merely one example of how a UE can be implemented, and such examples are not limited to this. A UE may not necessarily include... Figure 22 All components. That is, some components (e.g., keyboard 2320, GSP chip 2360, sensor 2365, and SIM card) may not be required components, and in this case, they may not be included in the UE.

Claims

1. A method for a user equipment (UE) in a wireless communication system, the method being performed by the UE and comprising the following steps: Receive the Physical Downlink Shared Channel (PDSCH) from the base station (BS); and Send a HARQ-ACK response to the BS corresponding to the PDSCH. The HARQ-ACK feedback is used to adjust the contention window of the BS, and Specifically, based on the overlap of the PDSCH with multiple frequency resource sets and the channel access procedure performed by the BS on the multiple frequency resource sets, the HARQ-ACK feedback is used for the contention window adjustment process for each of the multiple frequency resource sets.

2. The method according to claim 1, wherein, The channel access procedure is performed for the unlicensed frequency band.

3. The method according to claim 1, wherein, Each of the plurality of frequency resource sets completely or partially overlaps with the frequency resource set on which the PDSCH is received.

4. The method according to claim 1, wherein, The PDSCH is received in units of code block groups (CBGs), and The HARQ-ACK feedback is sent in units of CBG.

5. The method according to claim 1, wherein, The contention window is a counter value used to determine channel occupancy during channel access.

6. The method according to claim 5, wherein, The counter value is initially configured to be greater than or equal to 0 and less than or equal to the size of the competition window.

7. The method according to claim 1, wherein, The PDSCH is received on multiple time-domain resources.

8. The method according to claim 7, wherein, The HARQ-ACK feedback is sent based on each of the plurality of time-domain resources.

9. The method according to claim 1, wherein, Each of the multiple frequency resource sets has the same size as the others.

10. The method according to claim 9, wherein, The size is 20 MHz.

11. The method according to claim 1, wherein, The base station is a gNodeB or a gNB.

12. A user equipment (UE), the UE comprising: A transceiver that transmits and receives radio signals; as well as A processor, operatively coupled to the transceiver, wherein the processor is configured to: Receive the Physical Downlink Shared Channel (PDSCH) from the base station (BS); and Send a HARQ-ACK response to the BS corresponding to the PDSCH. The HARQ-ACK feedback is used to adjust the contention window of the BS, and Specifically, based on the overlap of the PDSCH with multiple frequency resource sets and the channel access procedure performed by the BS on the multiple frequency resource sets, the HARQ-ACK feedback is used for the contention window adjustment process for each of the multiple frequency resource sets.

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