Method for performing communication in wireless communication system, and device therefor

Abstract

Disclosed are a method for performing communication in a wireless communication system and a device therefor according to various embodiments. Disclosed are a method and a device therefor, the method comprising: receiving, from a base station, configuration information including information on an OAM beam sequence and a time interval for a plurality of OAM beams associated with an OAM beam-based operation; determining a specific OAM beam among the plurality of OAM beams on the basis of an SSB received from the base station; and transmitting or receiving a signal in a time resource corresponding to the specific OAM beam among time resources TDMed according to the OAM beam sequence within the time interval.

Description

Method for performing communication in a wireless communication system and device therefor

[0001] The present invention relates to a method for a terminal to perform communication based on an OAM (Orbital Angular Momentum) beam in a wireless communication system and a device therefor.

[0002] Wireless communication systems are multiple access systems that support communication with multiple users by sharing available system resources (e.g., bandwidth, transmission power, etc.). Examples of multiple access systems include code division multiple access (CDMA), frequency division multiple access (FDMA), time division multiple access (TDMA), orthogonal frequency division multiple access (OFDMA), single carrier frequency division multiple access (SC-FDMA), and multi-carrier frequency division multiple access (MC-FDMA).

[0003] As more and more communication devices demand greater communication capacity, the need for improved mobile broadband communication compared to existing radio access technology (RAT) is emerging. Furthermore, massive Machine Type Communications (MTC), which connects numerous devices and objects to provide various services anytime, anywhere, is also a key issue to be considered in next-generation communication. Furthermore, communication system design that considers reliability and latency-sensitive services / terminals is being discussed. The introduction of next-generation radio access technologies that take into account enhanced mobile broadband communication, massive MTC, and URLLC (Ultra-Reliable and Low Latency Communication) is being discussed. For convenience, these technologies are referred to as new RAT or NR in the present invention.

[0004] The technical challenge to be achieved is to provide a method for performing signal transmission and reception operations more accurately and efficiently.

[0005] The technical challenges are not limited to the technical challenges mentioned above, and other technical challenges not mentioned will be clearly understood by those skilled in the art to which the present invention pertains from the description below.

[0006] A method by a UE (User equipment) according to one aspect may include the steps of: receiving configuration information including information on an Orbital Angular Momentum (OAM) beam sequence and a time interval for a plurality of OAM beams related to an OAM beam-based operation from a base station; determining a specific OAM beam from among the plurality of OAM beams based on a Synchronization Signal Block (SSB) received from the base station; and transmitting or receiving a signal in a time resource corresponding to the specific OAM beam from among time resources that are time division multiplexed (TDM) according to the OAM beam sequence within the time interval.

[0007] Alternatively, the OAM beam sequence is characterized in that it is set based on the proximity of the geographic area in which each of the plurality of OAM beams is received with an intensity greater than a specific threshold in the first geographic area, the orbital information of the satellite associated with the base station, and the distribution of UEs in the first geographic area.

[0008] Alternatively, the above setting information is characterized in that it is set to be cell and TAC (Tracking Area Code) specific.

[0009] Alternatively, the setting information is characterized in that capability information indicating support of the OAM beam-based operation is received.

[0010] Alternatively, the capability information is characterized in that it is reported based on the UE supporting the capability to estimate the elevation angle with respect to the base station based on satellite information related to the base station and the capability to receive OAM beams.

[0011] Alternatively, the OAM beam sequence is characterized in that it is updated based on the distribution and density of UEs in a first geographic area corresponding to a specific Tracking Area Code (TAC).

[0012] Alternatively, the UE is characterized in that it does not report on channel state information (CSI) during the time period in which the OAM-based operation is performed.

[0013] Alternatively, the time interval is set based on an epoch time associated with the base station, and the length of the time interval is set to be equal to the length of a valid time interval of the epoch time associated with the base station.

[0014] Alternatively, the above setting information is characterized in that it is activated or deactivated through RRC (Radio Resource Control) signaling or MAC-CE (Medium Access Control-Control Element).

[0015] Alternatively, the base station is characterized as being a Non-terrestrial Network (NTN).

[0016] A non-transitory computer-readable storage medium having recorded thereon instructions for performing the above-described method by a UE according to another aspect may be provided.

[0017] According to another aspect, a UE performing the above-described method may be provided.

[0018] According to another aspect, a processing device may be provided for controlling a UE performing the above-described method.

[0019] In another aspect, a method by a base station in a wireless communication system may include the steps of transmitting configuration information including information on an Orbital Angular Momentum (OAM) beam sequence and a time interval for a plurality of OAM beams related to an OAM beam-based operation; and receiving or transmitting a signal using a corresponding OAM beam in each of time resources that are time division multiplexed (TDM) according to the OAM beam sequence within the time interval.

[0020] According to another aspect, a base station performing the above-described method may be provided.

[0021] Various embodiments can perform signal transmission and reception operations more accurately and efficiently using OAM beams.

[0022] The effects that can be obtained in various embodiments are not limited to the effects mentioned above, and other effects not mentioned will be clearly understood by those skilled in the art to which the present invention pertains from the description below.

[0023] The drawings attached to this specification are intended to provide an understanding of the present invention, illustrate various embodiments of the present invention, and together with the description of the specification serve to explain the principles of the present invention.

[0024] Figure 1 shows the structure of an LTE system.

[0025] Figure 2 shows the structure of the NR system.

[0026] Figure 3 shows the structure of a radio frame of NR.

[0027] Figure 4 shows the slot structure of an NR frame.

[0028] FIG. 5 is a diagram for explaining physical channels that can be used in various embodiments and a signal transmission method using the same.

[0029] Figure 6 shows an example of a CSI-related procedure.

[0030] FIG. 7 illustrates a communication structure that can be provided in a 6G system according to one embodiment of the present disclosure.

[0031] Figure 8 illustrates examples of wireless sensing modes supported by ISAC.

[0032] Figure 9 is a diagram for explaining a non-terrestrial network (NTN).

[0033] Figure 10 is a diagram illustrating a non-terrestrial network (NTN) overview and scenario.

[0034] Figures 11 to 13 are drawings for explaining a multiplexing method using OAM or OAM beams.

[0035] Figure 14 is a diagram for explaining multi-OAM mode operation.

[0036] Figures 15 to 21 are drawings for explaining a method of performing communication using an OAM beam in NTN.

[0037] FIGS. 22 to 25 are drawings for explaining a method of setting an OAM beam sequence for OAM open loop operation.

[0038] Figure 26 is a diagram for explaining a method in which a terminal supporting OAM-based communication performs OAM-based communication.

[0039] Figure 27 is a diagram for explaining a method in which a base station supporting OAM-based communication performs OAM-based communication with a terminal.

[0040] Figure 28 illustrates a communication system applied to the present invention.

[0041] Figure 29 illustrates a wireless device applicable to the present invention.

[0042] Fig. 30 shows another example of a wireless device applied to the present invention.

[0043] A wireless communication system is a multiple access system that supports communication with multiple users by sharing available system resources (e.g., bandwidth, transmission power, etc.). Examples of multiple access systems include code division multiple access (CDMA), frequency division multiple access (FDMA), time division multiple access (TDMA), orthogonal frequency division multiple access (OFDMA), single carrier frequency division multiple access (SC-FDMA), and multi-carrier frequency division multiple access (MC-FDMA).

[0044] Sidelink refers to a communication method that establishes a direct link between user equipment (UE), allowing voice or data to be exchanged directly between terminals without going through a base station (BS). Sidelink is being considered as a solution to address the burden on base stations due to rapidly increasing data traffic.

[0045] V2X (vehicle-to-everything) refers to a communication technology that exchanges information with other vehicles, pedestrians, and infrastructure-based objects through wired / wireless communication. V2X can be divided into four types: V2V (vehicle-to-vehicle), V2I (vehicle-to-infrastructure), V2N (vehicle-to-network), and V2P (vehicle-to-pedestrian). V2X communication can be provided through the PC5 interface and / or Uu interface.

[0046] Meanwhile, as more and more communication devices demand greater communication capacity, the need for improved mobile broadband communication compared to existing radio access technology (RAT) is emerging. Accordingly, communication systems that consider services or terminals sensitive to reliability and latency are being discussed. Next-generation wireless access technologies that consider improved mobile broadband communication, massive MTC, and URLLC (Ultra-Reliable and Low Latency Communication) can be called new radio access technology (RAT) or new radio (NR). NR can also support V2X (vehicle-to-everything) communication.

[0047] The following technologies can be used in various wireless communication systems, such as CDMA (code division multiple access), FDMA (frequency division multiple access), TDMA (time division multiple access), OFDMA (orthogonal frequency division multiple access), and SC-FDMA (single carrier frequency division multiple access). CDMA can be implemented with wireless technologies such as UTRA (universal terrestrial radio access) or CDMA2000. TDMA can be implemented with wireless technologies such as GSM (global system for mobile communications) / GPRS (general packet radio service) / EDGE (enhanced data rates for GSM evolution). OFDMA can be implemented with wireless technologies such as IEEE (Institute of Electrical and Electronics Engineers) 802.11 (Wi-Fi), IEEE 802.16 (WiMAX), IEEE 802-20, and E-UTRA (evolved UTRA). IEEE 802.16m is an evolution of IEEE 802.16e, providing backward compatibility with systems based on IEEE 802.16e. UTRA is part of UMTS (universal mobile telecommunications system). 3GPP (3rd generation partnership project) LTE (long term evolution) is a part of E-UMTS (evolved UMTS) that uses E-UTRA (evolved-UMTS terrestrial radio access), employing OFDMA in the downlink and SC-FDMA in the uplink.LTE-A (advanced) is an evolution of 3GPP LTE.

[0048] 5G NR, the successor to LTE-A, is a new clean-slate mobile communications system featuring high performance, low latency, and high availability. 5G NR can utilize all available spectrum resources, from low-frequency bands below 1 GHz, mid-frequency bands between 1 GHz and 10 GHz, and high-frequency (millimeter wave) bands above 24 GHz.

[0049] For clarity, the description will focus on LTE-A or 5G NR, but the technical ideas of the embodiment(s) are not limited thereto.

[0050] Figure 1 illustrates the architecture of an applicable LTE system. This may be referred to as an Evolved-UMTS Terrestrial Radio Access Network (E-UTRAN) or a Long Term Evolution (LTE) / LTE-A system.

[0051] Referring to FIG. 1, the E-UTRAN includes a base station (20; BS) that provides a control plane and a user plane to a terminal (10). The terminal (10) may be fixed or mobile, and may be referred to by other terms such as a mobile station (MS), a user terminal (UT), a subscriber station (SS), a mobile terminal (MT), a wireless device, etc. The base station (20) refers to a fixed station that communicates with the terminal (10), and may be referred to by other terms such as an evolved-NodeB (eNB), a base transceiver system (BTS), an access point, etc.

[0052] Base stations (20) can be connected to each other via the X2 interface. The base station (20) is connected to an EPC (Evolved Packet Core, 30) via the S1 interface, more specifically, to an MME (Mobility Management Entity) via the S1-MME, and to an S-GW (Serving Gateway) via the S1-U.

[0053] The EPC (30) consists of an MME, an S-GW, and a P-GW (Packet Data Network-Gateway). The MME holds information about terminal access and capabilities, and this information is primarily used for terminal mobility management. The S-GW is a gateway with the E-UTRAN as its endpoint, and the P-GW is a gateway with the PDN as its endpoint.

[0054] The layers of the radio interface protocol between the terminal and the network can be divided into L1 (Layer 1), L2 (Layer 2), and L3 (Layer 3) based on the three lower layers of the Open System Interconnection (OSI) standard model, which is widely known in communication systems. Among these, the physical layer belonging to Layer 1 provides an information transfer service using a physical channel, and the RRC (Radio Resource Control) layer located in Layer 3 controls radio resources between the terminal and the network. To this end, the RRC layer exchanges RRC messages between the terminal and the base station.

[0055] Figure 2 shows the structure of the NR system.

[0056] Referring to FIG. 2, the NG-RAN may include a gNB and / or an eNB that provides user plane and control plane protocol termination to the UE. FIG. 7 illustrates a case where only a gNB is included. The gNB and eNB are connected to each other via an Xn interface. The gNB and eNB are connected to the 5th generation core network (5G Core Network: 5GC) via the NG interface. More specifically, they 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.

[0057] Figure 3 shows the structure of a radio frame of NR.

[0058] Referring to FIG. 3, radio frames can be used for uplink and downlink transmission in NR. A radio frame has a length of 10 ms and can be defined as two 5 ms half-frames (Half-Frames, HF). A half-frame can include five 1 ms sub-frames (Subframes, SF). A sub-frame can be divided into one or more slots, and the number of slots within a sub-frame can be determined by the Subcarrier Spacing (SCS). Each slot can include 12 or 14 OFDM (A) symbols depending on the cyclic prefix (CP).

[0059] When normal CP is used, each slot can contain 14 symbols. When extended CP is used, each slot can contain 12 symbols. Here, the symbols can include OFDM symbols (or CP-OFDM symbols), SC-FDMA (Single Carrier - FDMA) symbols (or DFT-s-OFDM (Discrete Fourier Transform-spread-OFDM) symbols).

[0060] Table 1 below shows the number of symbols per slot ((N)) depending on the SCS setting (u) when normal CP is used. slot symb ), number of slots per frame ((N frame,u slot ) and the number of slots per subframe ((N subframe,u slot ) is an example.

[0061] SCS (15*2 u )N slot symb N frame,u slot N subframe,u slot 15KHz (u=0)1410130KHz (u=1)1420260KHz (u=2)14404120KHz (u=3)14808240KHz (u=4)1416016

[0062] Table 2 illustrates the number of symbols per slot, the number of slots per frame, and the number of slots per subframe according to SCS when extended CP is used.

[0063] SCS (15*2 u )N slot symb N frame,u slot N subframe,u slot 60KHz (u=2)12404

[0064] In an NR system, OFDM(A) numerologies (e.g., SCS, CP length, etc.) can be configured differently across multiple cells that are merged into a single terminal. Accordingly, the (absolute time) interval of a time resource (e.g., subframe, slot, or TTI) (conveniently referred to as a TU (Time Unit)) consisting of the same number of symbols can be configured differently across the merged cells. In NR, multiple numerologies or SCSs can be supported to support various 5G services. For example, when the SCS is 15 kHz, a wide area in traditional cellular bands can be supported, and when the SCS is 30 kHz / 60 kHz, dense-urban, lower latency, and wider carrier bandwidth can be supported. When the SCS is 60 kHz or higher, bandwidths greater than 24.25 GHz may be supported to overcome phase noise.

[0065] The NR frequency band can be defined by two types of frequency ranges. The two types of frequency ranges can be FR1 and FR2. The numerical values ​​of the frequency ranges can be changed, and for example, the two types of frequency ranges can be as shown in Table 3 below. Among the frequency ranges used in the NR system, FR1 can mean the "sub 6 GHz range", and FR2 can mean the "above 6 GHz range" and can be called millimeter wave (mmW).

[0066] Frequency Range designationCorresponding frequency rangeSubcarrier Spacing (SCS)FR1450MHz - 6000MHz15, 30, 60kHzFR224250MHz - 52600MHz60, 120, 240kHz

[0067] As described above, the numerical value of the frequency range of the NR system can be changed. For example, FR1 may include a band from 410 MHz to 7125 MHz, as shown in Table 4 below. That is, FR1 may include a frequency band above 6 GHz (or 5850, 5900, 5925 MHz, etc.). For example, the frequency band above 6 GHz (or 5850, 5900, 5925 MHz, etc.) included within FR1 may include an unlicensed band. The unlicensed band may be used for various purposes, such as for vehicular communications (e.g., autonomous driving).

[0068] Frequency Range designationCorresponding frequency rangeSubcarrier Spacing (SCS)FR1410MHz - 7125MHz15, 30, 60kHzFR224250MHz - 52600MHz60, 120, 240kHz

[0069] Figure 4 shows the slot structure of an NR frame.

[0070] Referring to Figure 4, a slot includes multiple symbols in the time domain. For example, in the case of a normal CP, one slot may include 14 symbols, but in the case of an extended CP, one slot may include 12 symbols. Alternatively, in the case of a normal CP, one slot may include 7 symbols, but in the case of an extended CP, one slot may include 6 symbols.

[0071] A carrier includes multiple subcarriers in the frequency domain. An RB (Resource Block) can be defined as multiple (e.g., 12) consecutive subcarriers in the frequency domain. A BWP (Bandwidth Part) can be defined as multiple consecutive (P)RBs ((Physical) Resource Blocks) in the frequency domain, and can correspond to one numerology (e.g., SCS, CP length, etc.). A carrier can include up to N (e.g., 5) BWPs. Data communication can be performed through activated BWPs. Each element can be referred to as a Resource Element (RE) in the resource grid, and one complex symbol can be mapped to it.

[0072] Meanwhile, the wireless interface between terminals or between terminals and a network may be composed of an L1 layer, an L2 layer, and an L3 layer. In various embodiments of the present disclosure, the L1 layer may refer to a physical layer. Furthermore, for example, the L2 layer may refer to at least one of a MAC layer, an RLC layer, a PDCP layer, and an SDAP layer. Furthermore, for example, the L3 layer may refer to an RRC layer.

[0073] Bandwidth part (BWP)

[0074] The NR system can support up to 400 MHz per component carrier (CC). If a terminal operating in such a wideband CC always operates with the RF on for the entire CC, the terminal battery consumption may increase. Alternatively, when considering multiple use cases (e.g., eMBB, URLLC, MMTC, V2X, etc.) operating within a wideband CC, different numerologies (e.g., sub-carrier spacing) may be supported for each frequency band within the CC. Alternatively, each terminal may have different capabilities for maximum bandwidth. Considering this, the base station can instruct the terminal to operate only in a portion of the bandwidth rather than the entire bandwidth of the wideband CC, and this portion of bandwidth is conveniently defined as a bandwidth part (BWP). A BWP can be composed of consecutive resource blocks (RBs) on the frequency axis and can correspond to a single numerology (e.g., sub-carrier spacing, CP length, slot / mini-slot duration).

[0075] Meanwhile, the base station can set multiple BWPs even within a single CC configured for the UE. For example, in the PDCCH monitoring slot, a BWP occupying a relatively small frequency range can be set, and the PDSCH indicated by the PDCCH can be scheduled on a larger BWP. Alternatively, if UEs are concentrated in a specific BWP, some UEs can be set to a different BWP for load balancing. Alternatively, considering frequency domain inter-cell interference cancellation between neighboring cells, a portion of the spectrum in the middle of the total bandwidth can be excluded, and both BWPs can be set within the same slot. That is, the base station can configure at least one DL / UL BWP for a terminal associated with a wideband CC, and can activate at least one DL / UL BWP among the configured DL / UL BWP(s) at a specific point in time (by L1 signaling or MAC CE or RRC signaling, etc.), and switching to another configured DL / UL BWP can be indicated (by L1 signaling or MAC CE or RRC signaling, etc.), or switching to a predetermined DL / UL BWP when the timer value expires based on a timer. At this time, the activated DL / UL BWP is defined as the active DL / UL BWP. However, the terminal may not receive the configuration for the DL / UL BWP in situations such as when the terminal is in the initial access process or before the RRC connection is set up. In such situations, the DL / UL BWP assumed by the terminal is defined as the initial active DL / UL BWP.

[0076] FIG. 5 is a diagram for explaining physical channels that can be used in various embodiments and a signal transmission method using the same.

[0077] Referring to FIG. 5, a terminal that is powered on again after being powered off or that has newly entered a cell performs an initial cell search operation, such as synchronizing with the base station, in step S11. To this end, the terminal receives a Synchronization Signal Block (SSB) from the base station. The SSB includes a Primary Synchronization Signal (PSS), a Secondary Synchronization Signal (SSS), and a Physical Broadcast Channel (PBCH). Based on the PSS / SSS, the terminal synchronizes with the base station and obtains information such as a cell ID (cell identity). In addition, the terminal can obtain broadcast information within the cell based on the PBCH. Meanwhile, the terminal can check the downlink channel status by receiving a Downlink Reference Signal (DL RS) during the initial cell search phase.

[0078] A terminal that has completed initial cell search can obtain more specific system information by receiving a physical downlink control channel (PDCCH) and a physical downlink shared channel (PDSCH) based on physical downlink control channel information (S12).

[0079] Thereafter, the terminal may perform a random access procedure to complete connection to the base station (S13 to S16). To this end, the terminal may transmit a preamble through a physical random access channel (PRACH) (S13) and receive a random access response (RAR) for the preamble through a physical downlink control channel and a corresponding physical downlink shared channel (S14). The terminal may transmit a physical uplink shared channel (PUSCH) using scheduling information in the RAR (S15) and perform a contention resolution procedure such as receiving a physical downlink control channel signal and a corresponding physical downlink shared channel signal (S16).

[0080] Meanwhile, in addition to the random access process performed in 4 steps as above (4-step RACH, type-1 random access procedure), when the random access process is performed in 2 steps (2-step RACH, type-2 random access procedure), S13 / S15 may be performed as one operation in which the terminal performs transmission (e.g., transmission operation of message A including PRACH preamble and / or PUSCH), and S14 / S16 may be performed as one operation in which the base station performs transmission (e.g., transmission operation of message B including RAR and / or collision resolution information).

[0081] A terminal that has performed the procedure described above can then perform general uplink / downlink signal transmission procedures, such as receiving a physical downlink control channel signal and / or a physical downlink shared channel signal (S17) and transmitting a physical uplink shared channel (PUSCH: Physical Uplink Shared Channel) signal and / or a physical uplink control channel (PUCCH: Physical Uplink Control Channel) signal (S18).

[0082] Control information transmitted from a terminal to a base station is collectively referred to as uplink control information (UCI). UCI includes information such as HARQ-ACK / NACK (Hybrid Automatic Repeat and reQuest Acknowledgement / Negative-ACK), SR (Scheduling Request), CQI (Channel Quality Indication), PMI (Precoding Matrix Indication), and RI (Rank Indication).

[0083] UCI is typically transmitted periodically over the PUCCH, but can also be transmitted over the PUSCH when control information and data must be transmitted simultaneously. Furthermore, terminals can transmit UCI aperiodically over the PUSCH at the request / instruction of the network.

[0084] CSI-related actions

[0085] Figure 6 shows an example of a CSI-related procedure.

[0086] The terminal receives configuration information related to CSI from the base station via RRC signaling (610). The configuration information related to CSI may include at least one of CSI-IM (interference management) resource-related information, CSI measurement configuration-related information, CSI resource configuration-related information, CSI-RS resource-related information, or CSI report configuration-related information.

[0087] - CSI-IM resources can be configured for interference measurement (IM) of the terminal. In the time domain, the CSI-IM resource set can be configured periodically, semi-persistently, or aperiodicly. The CSI-IM resources can be configured as Zero Power (ZP)-CSI-RS for the terminal. The ZP-CSI-RS can be configured separately from the Non-Zero Power (NZP)-CSI-RS.

[0088] - The UE may assume that the CSI-RS resource(s) for channel measurement configured for one CSI reporting and the CSI-IM / NZP CSI-RS resource(s) for interference measurement (when NZP CSI-RS resource(s) are used for interference measurement) are in a QCL relationship with respect to 'QCL-TypeD' per resource.

[0089] - The CSI resource configuration may include at least one of a CSI-IM resource for interference measurement, an NZP CSI-RS resource for interference measurement, and an NZP CSI-RS resource for channel measurement. The CMR (channel measurement resource) may be an NZP CSI-RS for CSI acquisition, and the IMR (Interference measurement resource) may be an NZP CSI-RS for CSI-IM and IM.

[0090] - CSI-RS can be configured for one or more terminals. Different CSI-RS configurations may be provided for each terminal, or the same CSI-RS configuration may be provided to multiple terminals. CSI-RS can support up to 32 antenna ports. CSI-RS corresponding to N (N is 1 or greater) antenna ports can be mapped to N RE locations within a time-frequency unit corresponding to one slot and one RB. When N is 2 or greater, N-port CSI-RS can be multiplexed using CDM, FDM, and / or TDM schemes. CSI-RS can be mapped to REs other than REs to which CORESET, DMRS, and SSB are mapped. In the frequency domain, CSI-RS can be configured for the entire bandwidth, a portion of the bandwidth (BWP), or a portion of the bandwidth. CSI-RS may be transmitted in each RB within the bandwidth for which CSI-RS is configured (i.e., density = 1), or in every second RB (e.g., even or odd RB) (i.e., density = 1 / 2). When CSI-RS is used as a Tracking Reference Signal (TRS), a single-port CSI-RS may be mapped on three subcarriers in each resource block (i.e., density = 3). One or more CSI-RS resource sets may be configured for a UE in the time domain. Each CSI-RS resource set may include one or more CSI-RS configurations. Each CSI-RS resource set may be configured periodically, semi-persistently, or aperiodicly.

[0091] - The CSI report configuration may include configurations for feedback type, measurement resources, report type, etc. The NZP-CSI-RS resource set may be used for the CSI report configuration of the corresponding terminal. The NZP-CSI-RS resource set may be associated with CSI-RS or SSB. In addition, multiple periodic NZP-CSI-RS resource sets may be configured as TRS resource sets. (i) The feedback type may include a Channel Quality Indicator (CQI), a Precoding Matrix Indicator (PMI), a CSI-RS Resource Indicator (CRI), an SSB Resource block Indicator (SSBRI), a Layer Indicator (LI), a Rank Indicator (RI), a Layer 1-Reference Signal Received Strength (RSRP), etc. (ii) Measurement resources may include configurations for downlink signals and / or downlink resources on which the terminal performs measurements to determine feedback information. The measurement resources may be configured as ZP and / or NZP CSI-RS resource sets associated with CSI reporting configurations. The NZP CSI-RS resource set may include a CSI-RS set or an SSB set. For example, L1-RSRP may be measured for a CSI-RS set or an SSB set. (iii) Reporting types may include configurations for a time point at which the terminal performs reporting and an uplink channel, etc. The reporting time point may be configured as periodic, semi-persistent, or aperiodic. Periodic CSI reporting may be transmitted on PUCCH. Semi-persistent CSI reporting may be transmitted on PUCCH or PUSCH based on a MAC CE indicating activation / deactivation. Aperiodic CSI reporting may be indicated by DCI signaling.For example, the CSI request field of an uplink grant may indicate one of several report trigger sizes. Aperiodic CSI reports may be transmitted on the PUSCH.

[0092] The terminal measures CSI based on configuration information related to CSI. CSI measurement may include a procedure of receiving a CSI-RS (620) and computing the received CSI-RS to acquire CSI (630).

[0093] The UE can transmit a CSI report to the base station (760). For the CSI report, the time and frequency resources that the UE can use are controlled by the base station. The CSI (channel state information) can include at least one of a channel quality indicator (CQI), a precoding matrix indicator (PMI), a CSI-RS resource indicator (CRI), an SS / PBCH block resource indicator (SSBRI), a layer indicator (LI), a rank indicator (RI), L1-RSRP, and / or L-SINR.

[0094] The time domain behavior of CSI reporting supports periodic, semi-persistent, and aperiodic. i) Periodic CSI reporting is performed on short PUCCH and long PUCCH. The periodicity and slot offset of periodic CSI reporting can be configured by RRC, and refer to the CSI-ReportConfig IE. ii) SP (semi-periodic) CSI reporting is performed on short PUCCH, long PUCCH, or PUSCH. In case of SP CSI on short / long PUCCH, the periodicity and slot offset are configured by RRC, and CSI reporting is activated / deactivated by separate MAC CE / DCI. In case of SP CSI on PUSCH, the periodicity of SP CSI reporting is configured by RRC, but the slot offset is not configured by RRC, and SP CSI reporting is activated / deactivated by DCI (format 0_1). For SP CSI reporting on PUSCH, a separate RNTI (SP-CSI C-RNTI) is used. The initial CSI reporting timing follows the PUSCH time domain allocation value indicated in the DCI, and subsequent CSI reporting timings follow the cycle set by RRC. DCI format 0_1 ​​includes a CSI request field and can activate / deactivate a specific configured SP-CSI trigger state. SP CSI reporting has the same or similar activation / deactivation mechanism as the data transmission mechanism on the SPS PUSCH.iii) Aperiodic CSI reporting is performed on PUSCH and is triggered by DCI. In this case, information related to the triggering of aperiodic CSI reporting can be transmitted / indicated / configured via MAC-CE. For AP CSI with AP CSI-RS, the AP CSI-RS timing is configured by RRC, and the timing for AP CSI reporting is dynamically controlled by DCI.

[0095] CSI codebooks defined in the NR standard (e.g., PMI codebooks) can be broadly divided into Type I and Type II codebooks. Type I codebooks are primarily targeted at SU (Single User)-MIMO, which supports both high-order and low-order signals. Type II codebooks can primarily support MI-MIMO, which supports up to two layers. Compared to Type I, Type II codebooks can provide more accurate CSI, but may increase signaling overhead. Meanwhile, Enhanced Type II codebooks were introduced to address the CSI overhead shortcomings of existing Type II codebooks. Enhanced Type II codebooks were introduced by reducing the codebook payload by considering frequency-axis correlation.

[0096] CSI reporting via PUSCH can be configured as Part 1 and Part 2. Part 1 has a fixed payload size and is used to identify the number of information bits in Part 2. Part 1 is transmitted in its entirety before Part 2.

[0097] - For Type I CSI feedback, Part 1 contains the RI (if reported), the CRI (if reported), and the CQI of the first code word. Part 2 contains the PMI, and when RI > 4, Part 2 contains the CQI.

[0098] - For Type II CSI feedback, Part 1 contains the RI (if reported), CQI, and an indication of the number of non-zero WB amplitude coefficients per layer of Type II CSI. Part 2 contains the PMI of Type II CSI.

[0099] - For Enhanced Type II CSI feedback, Part 1 contains the RI (if reported), CQI, and the total number of non-zero WB amplitude coefficients for all layers of Enhanced Type II CSI. Part 2 contains the PMI of Enhanced Type II CSI.

[0100] If CSI reporting on PUSCH includes two parts and the CSI payload to be reported is less than the payload size provided by the PUSCH resources allocated for CSI reporting, the UE may omit part of Part 2 CSI.

[0101] Meanwhile, semi-persistent CSI reporting performed in PUCCH format 3 or 4 supports Type II CSI feedback, but only Part 1 of Type II CSI feedback.

[0102] QCL (quasi-co location)

[0103] Two antenna ports are quasi-co-located if the channel properties of one antenna port can be inferred from the channel properties of the other antenna port. The channel properties may include one or more of Delay spread, Doppler spread, Frequency / Doppler shift, Average received power, Received Timing / average delay, and Spatial RX parameters.

[0104] A terminal can configure a list of multiple TCI-State configurations via the upper layer parameter PDSCH-Config. Each TCI-State is associated with one or two DL reference signals and a QCL configuration parameter between the DM-RS port of the PDSCH. The QCL can include qcl-Type1 for the first DL RS and qcl-Type2 for the second DL RS. The QCL type can correspond to one of the following:

[0105] - 'QCL-TypeA': {Doppler shift, Doppler spread, average delay, delay spread}

[0106] - 'QCL-TypeB': {Doppler shift, Doppler spread}

[0107] - 'QCL-TypeC': {Doppler shift, average delay}

[0108] - 'QCL-TypeD': {Spatial Rx parameter}

[0109] Beam Management (BM)

[0110] The BM process is a process for acquiring and maintaining a set of BS (or transmission and reception point (TRP)) and / or UE beams that can be used for downlink (DL) and uplink (UL) transmission / reception, and may include the following processes and terms.

[0111] - Beam measurement: An operation in which a BS or UE measures the characteristics of a received beamforming signal.

[0112] - Beam determination: An operation in which a BS or UE selects its own transmit beam (Tx beam) / receive beam (Rx beam).

[0113] - Beam sweeping: An operation of covering a spatial domain using transmit and / or receive beams over a predetermined time interval in a predetermined manner.

[0114] - Beam report: An operation in which a UE reports information about a beamformed signal based on beam measurement.

[0115] The BM process can be divided into (1) a DL BM process using SSB or CSI-RS, and (2) a UL BM process using SRS (sounding reference signal). In addition, each BM process can include Tx beam sweeping to determine a Tx beam and Rx beam sweeping to determine an Rx beam.

[0116] At this time, the DL BM process may include (1) transmission of beamformed DL RSs (e.g., CSI-RS or SSB) by the BS and (2) beam reporting by the UE.

[0117] Here, the beam report may include preferred DL RS ID(s) and corresponding reference signal received power (RSRP). The DL RS ID may be an SSB Resource Indicator (SSBRI) or a CSI-RS Resource Indicator (CRI).

[0118] FIG. 7 illustrates a communication structure that can be provided in a 6G system according to an embodiment of the present disclosure. The embodiment of FIG. 7 can be combined with various embodiments of the present disclosure.

[0119] New network characteristics in 6G may include:

[0120] - Satellite integrated network

[0121] - Connected Intelligence: Unlike previous generations of wireless communication systems, 6G is revolutionary, upgrading the wireless evolution from "connected objects" to "connected intelligence." AI can be applied at every stage of the communication process (or at every signal processing step, as described below).

[0122] - Seamless integration of wireless information and energy transfer

[0123] - Ubiquitous super 3D connectivity: Access to networks and core network functions of drones and very low Earth orbit satellites will create super 3D connectivity in 6G ubiquitous.

[0124] Some general requirements for the new network characteristics of 6G, such as the above, may be as follows:

[0125] - small cell networks

[0126] - Ultra-dense heterogeneous network

[0127] - High-capacity backhaul

[0128] - Radar technology integrated with mobile technology: High-precision localization (or location-based services) through communications is a key feature of 6G wireless communication systems. Therefore, radar systems will be integrated with 6G networks.

[0129] - Softwarization and virtualization

[0130] Below, the core implementation technologies of the 6G system are described.

[0131] - Artificial Intelligence: Incorporating AI into communications can streamline and improve real-time data transmission. AI can use numerous analytics to determine how complex target tasks should be performed. This means AI can increase efficiency and reduce processing delays. Time-consuming tasks such as handovers, network selection, and resource scheduling can be performed instantly using AI. AI can also play a crucial role in machine-to-machine (M2M), machine-to-human, and human-to-machine communications. Furthermore, AI can facilitate rapid communication in brain-computer interfaces (BCIs). AI-based communication systems can be supported by metamaterials, intelligent structures, intelligent networks, intelligent devices, intelligent cognitive radios, self-sustaining wireless networks, and machine learning.

[0132] - THz communication (terahertz communication): Data rates can be increased by increasing the bandwidth. This can be achieved by utilizing sub-THz communication with a wide bandwidth and applying advanced massive MIMO technology. THz waves, also known as sub-millimeter waves, typically refer to the frequency range between 0.1 THz and 10 THz with corresponding wavelengths ranging from 0.03 mm to 3 mm. The 100 GHz to 300 GHz band (Sub-THz band) is considered a major portion of the THz band for cellular communications. Adding the Sub-THz band to the mmWave band will increase the capacity of 6G cellular communications. Among the defined THz bands, 300 GHz to 3 THz lies in the far infrared (IR) frequency band. While part of the optical band, the 300 GHz to 3 THz band lies at the boundary of the optical band, immediately following the RF band. Therefore, this 300 GHz to 3 THz band exhibits similarities to RF. Figure 7 illustrates the electromagnetic spectrum according to one embodiment of the present disclosure. The embodiment of FIG. 7 can be combined with various embodiments of the present disclosure. Key characteristics of THz communications include (i) a widely available bandwidth to support very high data rates, and (ii) high path loss at high frequencies (highly directional antennas are essential). The narrow beamwidth generated by the highly directional antenna reduces interference. The small wavelength of THz signals allows for a much larger number of antenna elements to be integrated into devices and base stations operating in this band. This enables the use of advanced adaptive array technologies to overcome range limitations.

[0133] - Large-scale MIMO technology

[0134] - Hologram beamforming (HBF)

[0135] - Optical wireless technology

[0136] - Free-space optical transmission backhaul network (FSO backhaul network)

[0137] - Quantum communication

[0138] - Cell-free communication

[0139] - Integration of wireless information and power transmission

[0140] - Integration of wireless communication and sensing

[0141] - Integrated access and backhaul network

[0142] - Big data analysis

[0143] - Reconfigurable intelligent surface

[0144] - metaverse

[0145] - Blockchain

[0146] Unmanned aerial vehicles (UAVs): UAVs, or drones, will be a key element in 6G wireless communications. In most cases, high-speed data wireless connectivity can be provided using UAV technology. Base stations (BSs) can be installed on UAVs to provide cellular connectivity. UAVs may offer specific capabilities not found in fixed BS infrastructure, such as easy deployment, robust line-of-sight links, and controlled mobility. During emergencies such as natural disasters, deploying terrestrial communications infrastructure is not economically feasible and sometimes cannot provide services in volatile environments. UAVs can easily handle these situations. UAVs will become a new paradigm in wireless communications. This technology facilitates three fundamental requirements for wireless networks: enhanced mobile broadband (eMBB), URLLC, and mMTC. UAVs can also support various purposes, such as enhancing network connectivity, fire detection, disaster emergency services, security and surveillance, pollution monitoring, parking monitoring, and accident monitoring. Therefore, UAV technology is recognized as one of the most important technologies for 6G communications.

[0147] - Autonomous driving (self-driving): V2X (vehicle to everything), a key element in building autonomous driving infrastructure, can be a technology that allows cars to communicate and share with various elements on the road for autonomous driving, such as vehicle-to-vehicle (V2V) and vehicle-to-infrastructure (V2I) wireless communication. Fast transmission speeds and low-latency technologies are essential to maximize autonomous driving performance and ensure high safety. Furthermore, in the future, autonomous driving will go beyond simply providing warnings or guidance messages to drivers and may require active intervention in vehicle operation and direct control of the vehicle in dangerous situations. To this end, the amount of information that needs to be transmitted and received may become enormous, so 6G is expected to maximize autonomous driving with faster transmission speeds and lower latency than 5G.

[0148] - Non-terrestrial networks (NTN): NTN can refer to a network or network segment that uses radio frequency (RF) resources mounted on a satellite (or unmanned aerial system (UAS) platform). A satellite (or UAS platform) can create a service link with a UE. A satellite (or UAS platform) can be connected to a gateway via a feeder link. A satellite can be connected to a data network via a gateway. A beam footprint can refer to an area where a signal transmitted by a satellite can be received. Referring to FIG. 9, a satellite (or UAS platform) can create a service link with a UE. A satellite (or UAS platform) connected to a UE can be connected to another satellite (or UAS platform) via inter-satellite links (ISL). Another satellite (or UAS platform) can be connected to a gateway via a feeder link. Satellites can connect to data networks through other satellites and gateways based on regenerative payloads. If there is no ISL between a satellite and another satellite, a feeder link between the satellite and the gateway may be required. NTN can be implemented based on various scenarios. For example, a satellite (or UAS platform) can implement transparent or regenerative (with onboard processing) payloads. For example, a satellite (or UAS platform) can generate multiple beams across a designated service area based on the satellite's (or UAS platform's) field of view. For example, the satellite's (or UAS platform's) field of view may vary depending on the onboard antenna diagram and minimum elevation angle.For example, a transparent payload may include radio frequency filtering, frequency conversion, and amplification. Therefore, the waveform signal repeated by the payload may not be altered. For example, a regenerative payload may include radio frequency filtering, frequency conversion and amplification, demodulation / decoding, switching and / or routing, and coding / modulation. For example, a regenerative payload may be substantially equivalent to equipping a satellite (or UAS platform) with all or part of the base station functions.

[0149] - Integrated Sensing and Communication (ISAC): Wireless sensing is a technology that uses radio frequencies to determine the instantaneous linear velocity, angle, distance (range), etc. of an object, thereby obtaining information about the characteristics of the environment and / or objects within the environment. Because radio frequency sensing does not require a device to connect to the object through a network, it can provide a service for object positioning without a device. The ability to obtain range, velocity, and angle information from radio frequency signals can enable a wide range of new capabilities, such as various object detection, object recognition (e.g., vehicles, humans, animals, UAVs), and high-precision localization, tracking, and activity recognition. Wireless sensing services can provide information to a variety of industries (e.g., drones, smart homes, V2X, factories, railways, public safety, etc.), enabling applications such as intruder detection, assisted vehicle steering and navigation, trajectory tracking, collision avoidance, traffic management, and health and traffic management. In some cases, wireless sensing can utilize non-3GPP type sensors (e.g., radar, cameras) to further support 3GPP-based sensing. For example, the operation of wireless sensing services, i.e., sensing operations, may depend on the transmission, reflection, and scattering of wireless sensing signals. Therefore, wireless sensing offers an opportunity to enhance existing communication systems from a communication network to a wireless communication and sensing network.

[0150] ISAC

[0151] Figure 8 illustrates examples of wireless sensing modes supported by ISAC.

[0152] Referring to Figure 8, when considering the transmission and reception operations and the nodes participating in them in the 3GPP standard, the sensing mode can be broadly classified as follows.

[0153] (a) BS mono-static sensing mode: BS that transmits radio waves receives the reflected signal.

[0154] (b) BS-to-BS bi-static sensing mode: A BS receives the reflected signal of a radio wave transmitted by another BS.

[0155] (c) BS-to-UE bi-static sensing mode: UE receives the signal reflected from the radio wave transmitted by BS.

[0156] (d) BS mono-static sensing mode: UE that transmits radio wave receives reflected signal

[0157] (e) UE-to-UE bi-static sensing mode: A UE receives the reflected signal of a radio wave transmitted by a specific transmitting UE.

[0158] (f) UE-to-BS bi-static sensing mode: BS receives the reflected signal of the radio wave transmitted by the transmitting UE.

[0159] However, in addition to the six use cases mentioned above, a sensing mode that includes multiple transmitting / receiving nodes can be referred to using the term multi-static sensing mode.

[0160] Wireless sensing via ISAC / JCAS is being considered for various scenarios. Generally, wireless sensing is intended to obtain information about a target without (or regardless of) a communication module. The scenarios considered can be broadly categorized into three categories.

[0161] (1) Object detection and tracking: A scenario for sensing target objects or people or tracking location information. Representative scenarios that can be considered include intruder detection in indoor / outdoor situations, location tracking of UAVs or AGVs, and autonomous driving support.

[0162] (2) Environment monitoring: A scenario for the purpose of collecting information about the environment around the transmitting / receiving node. Representative scenarios that can be considered include rainfall information observation and flood sensing scenarios.

[0163] (3) Motion monitoring: A scenario for sensing the motion of a target, such as a scenario for distinguishing human motion or gestures.

[0164] The performance metrics and levels required for each of the above scenarios vary and may differ from one another. To design an ISAC / JCAS suitable for the service quality required for each scenario, various key performance requirements must be considered. TS 22.137 of the 3GPP standard defines the following key performance requirements for each service scenario: positioning estimation accuracy, velocity estimation accuracy, confidence level, sensing resolution, missed detection probability, false alarm probability, sensing service maximum delay, and refreshing rate. The required levels for each key performance requirement may vary depending on the service scenario.

[0165] Radio frequency sensing capabilities can provide device-less object localization services because they do not require devices connected to the object via a network. The ability to obtain range, velocity, and angle information from radio frequency signals can enable a wide range of new capabilities, such as diverse object sensing, object recognition (e.g., vehicles, humans, animals, UAVs), and high-precision localization, tracking, and activity recognition. Wireless sensing services can provide information to a variety of industries (e.g., unmanned aerial vehicles, smart homes, V2X, factories, railways, public safety, etc.), enabling applications such as intruder detection, assisted vehicle steering and navigation, trajectory tracking, collision avoidance, traffic management, and health and traffic management. In some cases, wireless sensing can utilize non-3GPP type sensors (e.g., radar, cameras) to further support 3GPP-based sensing. For example, the operation of a wireless sensing service, i.e., the sensing operation, may rely on the transmission, reflection, and scattering of wireless sensing signals. Therefore, wireless sensing can provide an opportunity to enhance existing communication systems from communication networks to wireless communication and sensing networks.

[0166] Non-Terrestrial Networks reference

[0167] Figure 9 is a diagram for explaining non-terrestrial networks (NTN, hereinafter referred to as NTN).

[0168] Non-terrestrial networks (NTNs) are wireless networks built using satellites (e.g., geostationary orbit (GEO) / low earth orbit (LEO) satellites). NTN networks can provide expanded coverage and highly reliable network services. For example, NTNs can be configured independently or combined with conventional terrestrial networks to form a wireless communication system. For example, NTN networks can be comprised of: i) links between satellites and UEs; ii) links between satellites; and iii) links between satellites and gateways.

[0169] The following terms may be used to describe the configuration of a wireless communication system using satellites.

[0170] - Satellite: A space payload carrying a communications transmitter, usually a bent pipe payload or a regenerative payload, placed in low Earth orbit (LEO) at an altitude of 500 to 2000 km, medium Earth orbit (MEO) at an altitude of 8000 to 20000 km, or geostationary Earth orbit (GEO) at an altitude of 35,786 km.

[0171] - Satellite network: A network or network segment that uses space launch vehicles to carry transmission equipment relay nodes or base stations.

[0172] - Satellite RAT: A RAT defined to support at least one satellite.

[0173] - Terrestrial: Located on the surface of the Earth.

[0174] - Terrestrial network: A network or segment of a network located on the surface of the Earth.

[0175] The use cases that can be provided by a communication system utilizing satellite connectivity can be divided into three categories. The “Service Continuity” category can be used to provide network connectivity in geographic areas where 5G services are not accessible via the wireless coverage of terrestrial networks. For example, satellite connectivity can be used for UEs associated with pedestrian users, or for UEs on moving terrestrial ground platforms (e.g., cars, coaches, trucks, trains), aerial platforms (e.g., commercial or private jets), or maritime platforms (e.g., sea vessels). The “Service Ubiquity” category can be used for IoT / public safety-related emergency networks / home access when terrestrial networks are unavailable (e.g., due to disasters, destruction, economic reasons, etc.). The “Service Scalability” category encompasses services that leverage the extensive coverage of satellite networks.

[0176] For example, a 5G satellite access network can be connected to a 5G Core Network. In this case, the satellite can be a bent pipe satellite or a regenerative satellite. The NR radio protocols can be used between the UE and the satellite. Additionally, the F1 interface can be used between the satellite and the gNB.

[0177] As mentioned above, non-terrestrial networks (NTNs) refer to wireless networks built using devices that are not fixed on the ground, such as satellites. Satellite networks are a prime example. NTNs can enable expanded coverage and highly reliable network services. For example, NTNs can be configured independently or combined with existing terrestrial networks to form a wireless communication system.

[0178] The use cases that can be provided by a communication system using NTN can be divided into three categories. The “Service Continuity” category can be used to provide network connectivity in geographic areas where 5G services are not accessible via the wireless coverage of terrestrial networks. For example, satellite connectivity can be used for UEs associated with pedestrian users, or for UEs on moving terrestrial platforms (e.g., cars, coaches, trucks, trains), aerial platforms (e.g., commercial or private jets), or maritime platforms (e.g., sea vessels). The “Service Ubiquity” category can be used for IoT / public safety-related emergency networks / home access when terrestrial networks are unavailable (e.g., due to disasters, destruction, economic reasons, etc.). The “Service Scalability” category encompasses services that leverage the extensive coverage of satellite networks.

[0179] Referring to FIG. 9, the NTN may be configured to include one or more satellites (410), one or more NTN gateways (420) capable of communicating with the satellites, and one or more UEs ( / BSs) (430) capable of receiving mobile satellite services from the satellites. For the convenience of explanation, the NTN will be described with reference to an example including a satellite, but the scope of the present invention is not limited thereto. Accordingly, the NTN may be configured to include not only the satellites, but also aerial vehicles (Unmanned Aircraft Systems (UAS) encompassing tethered UAS (TUA), Lighter than Air UAS (LTA), Heavier than Air UAS (HTA), all operating in altitudes typically between 8 and 50 km including High Altitude Platforms (HAPs), etc.).

[0180] Satellite (410) is a space-borne vehicle equipped with a bent pipe payload or regenerative payload telecommunication transmitter and can be located in LEO (low Earth orbit), MEO (medium Earth orbit), or GEO (geostationary Earth orbit). NTN gateway (420) is an earth station or gateway located on the surface of the earth and provides sufficient RF power / sensitivity to access the satellite. NTN gateway corresponds to a TNL (transport network layer) node.

[0181] In an NTN network, there may be i) links between a satellite and a UE, ii) links between satellites, and iii) links between a satellite and an NTN gateway. A service link refers to a wireless link between a satellite and a UE. If multiple satellites exist, ISLs (Inter-satellite links) may exist between satellites. A feeder link refers to a wireless link between an NTN gateway and a satellite (or UAS platform). The gateway can be connected to a data network and transmit and receive data with the satellite via the feeder link. The UE can transmit and receive data with the satellite via the service link.

[0182] NTN operation scenarios can consider two scenarios, one based on transparent payload and one based on regenerative payload. Figure 9 (a) illustrates an example of a scenario based on transparent payload. In a scenario based on transparent payload, the signal repeated by the payload is not changed. Satellites (410) repeat the NR-Uu radio interface from the feeder link to the service link (or vice versa), and the satellite radio interface (SRI) on the feeder link is NR-Uu. The NTN gateway (420) supports all functions required to forward the signals of the NR-Uu interface. In addition, different transparent satellites can be connected to the same gNB on the ground. Figure 9 (b) illustrates an example of a scenario based on regenerative payload. In a scenario based on regenerative payload, the satellite (410) can perform some or all of the functions of a conventional base station (e.g., gNB), such as frequency conversion / demodulation / decoding / modulation, etc. The service link between the UE and the satellite uses the NR-Uu radio interface, and the feeder link between the NTN gateway and the satellite uses the satellite radio interface (SRI). The SRI corresponds to the transport link between the NTN gateway and the satellite.

[0183] The UE (430) may be connected to the 5GCN simultaneously via an NTN-based NG-RAN and a conventional cellular NG-RAN. Alternatively, the UE may be connected to the 5GCN simultaneously via two or more NTNs (e.g., LEO NTN+GEO NTN, etc.).

[0184] Figure 10 is a diagram illustrating a non-terrestrial network (NTN) overview and scenario.

[0185] NTN refers to a network or network segment that utilizes RF resources from satellites (or UAS platforms). Typical scenarios for NTN networks providing access to user equipment may include an NTN scenario based on transparent payloads, as illustrated in Figure 10 (a), and an NTN scenario based on regenerative payloads, as illustrated in Figure 10 (b).

[0186] NTNs are typically characterized by the following elements:

[0187] -One or more sat-gateways connecting the non-terrestrial network to the public data network.

[0188] -GEO satellites are served by one or more satellite gateways deployed across the satellite target coverage (e.g., regional or continental coverage) (or, it can be assumed that a UE in a cell is served by only one sat-gateway).

[0189] Non-GEO satellites can be served continuously from one or multiple satellite gateways at a time. This system ensures continuity of service and feeder links between continuous-service satellite gateways for sufficient time to allow for mobility anchoring and handovers.

[0190] - Feeder link or wireless link between satellite-gateway and satellite (or UAS platform)

[0191] - Service link or wireless link between user equipment and satellite (or UAS platform)

[0192] A satellite (or UAS platform) capable of implementing transparent or regenerative (with onboard processing) payloads. Here, the satellite (or UAS platform) can generate multiple beams within a service area typically bounded by its field of view. The beam footprints are typically elliptical. The field of view of the satellite (or UAS platform) can vary depending on the onboard antenna diagram and minimum elevation angle.

[0193] - Transparent payload: radio frequency filtering, frequency conversion, and amplification (wherein the repetitive waveform signal may not be altered by the payload).

[0194] - Regenerative payload: Radio frequency filtering, frequency conversion and amplification, as well as demodulation / decoding, switching and / or routing, coding / modulation (this may be essentially equivalent to having all or part of the base station functions (e.g. gNB) on the satellite (or UAS platform).

[0195] - Optional inter-satellite links (ISL) for satellite constellations. This may require regenerative payloads on the satellites. Alternatively, ISL can operate at RF frequencies or in wideband (optical bands).

[0196] -Terminals can be serviced by satellites (or UAS platforms) within the target service area.

[0197] Table 5 below defines several types of satellites (or UAS platforms).

[0198] PlatformsAltitude rangeOrbitTypical beam footprint sizeLow-Earth Orbit (LEO) satellite300 - 1500 kmCircular around the earth100 - 1000 kmMedium-Earth Orbit (MEO) satellite7000 - 25000 km100 - 1000 kmGeostationary Earth Orbit (GEO) satellite35 786 kmnotional station keeping position fixed in terms of elevation / azimuth with respect to a given earth point200 - 3500 kmUAS platform (including HAPS)8 - 50 km (20 km for HAPS)5 - 200 kmHigh Elliptical Orbit (HEO) satellite400 - 50000 kmElliptical around the earth200 - 3500 km

[0199] In general, GEO satellites and UAS can be used to provide continental, regional, or local services. LEO and MEO constellations can be used to provide services in both the Northern and Southern Hemispheres. Alternatively, LEO and MEO constellations can provide global coverage, including polar regions. This may require appropriate orbital inclination, sufficient beam generation, and inter-satellite links. Meanwhile, HEO satellite systems may not be considered for NTN.

[0200] We can consider an NTN providing access to terminals in the six reference scenarios described below.

[0201] - Circular orbit and nominal station maintenance platform.

[0202] - Highest RTD constraint

[0203] - Highest Doppler constraint

[0204] - A transparent and a regenerative payload

[0205] - One ISL case and one non-ISL case. For inter-satellite links, a regenerative payload may be required.

[0206] - Fixed or steerable beams resulting respectively in moving or fixed beam foot print on the ground.

[0207] The six reference scenarios described above can be defined as in Table 6 below, and parameters for each scenario can be defined as in Table 7.

[0208] Transparent satelliteRegenerative satelliteGEO based non-terrestrial access networkScenario AScenario BLEO based non-terrestrial access network:steerable beamsScenario C1Scenario D1LEO based non-terrestrial access network:the beams move with the satelliteScenario C2Scenario D2

[0209] ScenariosGEO based non-terrestrial access network (Scenario A and B)LEO based non-terrestrial access network (Scenario C & D)Orbit typenotional station keeping position fixed in terms of elevation / azimuth with respect to a given earth pointcircular orbiting around the earthAltitude35,786 km600 km1,200 kmSpectrum (service link)<6 GHz (e.g. 2 GHz)>6 GHz (e.g. DL 20 GHz, UL 30 GHz)Max channel bandwidth capability (service link)30 MHz for band < 6 GHz1 GHz for band > 6 GHzPayloadScenario A : Transparent (including radio frequency function only)Scenario B: regenerative (including all or part of RAN functions)Scenario C: Transparent (including radio frequency function only)Scenario D: Regenerative (including all or part of RAN functions)Inter-Satellite linkNoScenario C: NoScenario D: Yes / No (Both cases are possible.)Earth-fixed beamsYesScenario C1: Yes (steerable beams), see note 1Scenario C2: No (the beams move with the satellite)Scenario D 1: Yes (steerable beams), see note 1Scenario D 2: No (the beams move with the satellite)Max beam foot print size (edge to edge) regardless of the elevation angle3500 km (Note 5)1000 kmMin Elevation angle for both sat-gateway and user equipment10° for service link and 10° for feeder link10° for service link and 10° for feeder linkMax distance between satellite and user equipment at min elevation angle40,581 km1,932 km (600 km altitude)3,131 km (1,200 km altitude)Max Round Trip Delay (propagation delay only)Scenario A: 541.46 ms (service and feeder links)Scenario B: 270.73 ms (service link only)Scenario C: (transparent payload: service and feeder links)- 25.77 ms (600km)- 41.77 ms (1200km)Scenario D: (regenerative payload: service link only)- 12.89 ms (600km)- 20.89 ms (1200km)Max differential delay within a cell (Note 6)10.3 ms3.12 ms and 3.18 ms for respectively 600km and 1200kmMax Doppler shift (earth fixed user equipment)0.93 ppm24 ppm (600km)21ppm(1200km)Max Doppler shift variation (earth fixed user equipment)0.000 045 ppm / s0.27ppm / s (600km)0.13ppm / s(1200km)User equipment motion on the earth1200 km / h (eg aircraft)500 km / h (eg high speed train)Possibly 1200 km / h (eg aircraft)User equipment antenna typesOmnidirectional antenna (linear polarisation), assuming 0 dBiDirective antenna (up to 60 cm equivalent aperture diameter in circular polarisation)User equipment Tx powerOmnidirectional antenna: UE power class 3 with up to 200 mWDirective antenna: up to 20 WUser equipment Noise figureOmnidirectional antenna: 7 dBDirective antenna: 1.2 dBService link3GPP defined New RadioFeeder link3GPP or non-3GPP defined Radio interface3GPP or non-3GPP defined Radio interface.

[0210] - NOTE 1: Each satellite can use beamforming technology to steer its beam toward a fixed point on Earth. This can be applied for a period corresponding to the satellite's visibility time.

[0211] - NOTE 2: The maximum delay variation within a beam (earth fixed user equipment) can be calculated based on the minimum elevation angle for both the gateway and the terminal.

[0212] - NOTE 3: The maximum differential delay within the beam can be calculated based on the maximum beam foot print diameter at nadir.

[0213] - NOTE 4: The speed of light used in delay calculations is 299792458 m / s.

[0214] - NOTE 5: Maximum beam footprint size for GEO can be based on modern GEO high throughput systems assuming spot beams at the edge of coverage (low elevation).

[0215] - NOTE 6: The maximum differential delay at the cell level can be calculated by considering the beam-level delay for the largest beam size. However, it cannot be ruled out that a cell may contain more than one beam when the beam size is small or medium. However, the cumulative differential delay of all beams within the cell does not exceed the maximum differential delay at the cell level in the above tables.

[0216] The NTN study results can be applied not only to GEO scenarios but also to all NGSO scenarios with circular orbits above 600 km in altitude.

[0217] Ephemeris data and Epoch time related to NTN

[0218] In relation to NTN, ephemeris data may be provided. Ephemeris data may include information about the satellite's orbital trajectory. Orbital parameters in the orbital information may include semi-major axis, eccentricity, inclination, right ascension of the ascending node, argument of periapsis, and mean anomaly at a reference point in time. The first five parameters can determine the orbital plane, and the remaining two parameters can be used to determine the precise satellite position at a time.

[0219] For example, orbital data may include information about the following parameters:

[0220] - Orbital plane parameters: Square root of semi major axis(semi-major axis, Eccentricity, Inclination angle at reference time(inclination), Longitude of ascending node of orbit plane(right ascension of the ascending node), Argument of perigee(argument of periapsis)

[0221] - Satellite level parameters: Mean anomaly at reference time (true anomaly and a reference point in time), Ephemeris reference time (the epoch)

[0222] Such orbital data can be provided in terms of epoch time.

[0223] Here, epoch time refers to the reference time at which a specific event occurs in a system involving a satellite or high-speed vehicle. It is generally considered the "initial reference time," and time synchronization can be achieved based on the epoch time. For example, the epoch time can be used as a reference point for synchronization between a satellite (or NTN) and a UE, for calculating satellite orbital information, or for data transmission.

[0224] Meanwhile, the serving satellite orbit and common TA related parameters may be signaled in the same SIB message and may have the same epoch time. If explicitly provided via the SIB, the epoch time of the assistance information (i.e., the serving satellite orbit and common TA parameters) may be the start time of the DL subframe indicated by the subframe number signaled together with the SFM and the assistance information. If not explicitly indicated in the SIB, the epoch time of the assistance information may be implicitly determined as the end of the SI window during the transmission of the NTN-specific SIB. Alternatively, if provided via dedicated signaling, the epoch time of the assistance information may be the start time of the DL subframe indicated by the SFN and the subframe number. For the serving cell, if the epoch time is explicitly indicated by the SFN and the subframe number, the UE may consider this frame as the current SFN or the next upcoming SFN following the frame in which the message indicating the epoch time was received. For neighboring cells, if the epoch time is explicitly indicated by the SFN and subframe number, the UE may consider this frame as the closest frame to the frame in which the message indicating the epoch time was received.

[0225] OAM (Orbital Angular Momentum)

[0226] Figures 11 to 13 are drawings for explaining a multiplexing method using OAM or OAM beams.

[0227] OAM (Orbital Angular Momentum) can be a method that can replace the existing H / V (Horizontal / Vertical) Polarization multiplexing of up to 2. For example, OAM has the advantage of being able to utilize N multiplexing depending on the antenna array application, thereby increasing communication capacity. For example, among the beams using OAM (or, OAM beams), beams that can sufficiently satisfy orthogonality can be transmitted simultaneously to maximize the multiplexing gain, and the receiver can receive according to the corresponding OAM beam or OAM state.

[0228] Wireless OAM technology can achieve high transmission rates in line-of-sight (LoS) channels by mode-division multiplexing and transmitting multiple signals using modes with different helical phase fronts. Wireless OAM technology, which began its research in the field of optical communications, has recently attracted significant attention in the field of wireless communications. In 1992, researchers at Leiden University in the Netherlands discovered that the OAM of electromagnetic waves is related to the helical transverse phase structure, which changes depending on the degree of twisting of the phase front. Furthermore, as illustrated in Figure 11 (a), in 2011, Lund University in Sweden demonstrated that a Uniform Circular Array (UCA) antenna can be used to transmit a beam with the same characteristics as an OAM signal. Therefore, by transmitting OAM multimodes using a UCA antenna, the capacity of the channel can be increased.

[0229] Specifically, Orbital Angular Momentum (OAM) can be effectively utilized to maximize data transmission capacity in the communications field and overcome the limitations of existing technologies by leveraging the unique physical properties of light. The use of OAM in communications primarily focuses on utilizing the spiral topology of light as an information medium, which can dramatically expand bandwidth when combined with existing data transmission methods such as frequency, time, and space. For example, OAM communication technology can utilize the spiral topology of light. Specifically, OAM beams have different topological charges, which can act as independent data channels. For example, each OAM mode with a topological charge of m=+2, m=+1, m=0, m=-1, and m=-2 can operate independently without interfering with each other. Meanwhile, the topological charges can also be defined as OAM modes or OAM states. Therefore, OAM communication technology can simultaneously transmit multiple data streams in the same frequency and time band through OAM beams according to the topological charges. Multiplexing according to this number of turns can be defined as mode multiplexing.

[0230] More specifically, as a principle of OAM multiplexing, each OAM mode has a different phase distribution, making them orthogonal to one another. This orthogonality allows multiple signals to be transmitted without duplication on a single physical channel. Combined with existing frequency division multiplexing (FDM) and time division multiplexing (TDM), this can maximize communication channel capacity.

[0231] Referring to FIG. 11 (b) and FIG. 12, a wireless OAM signal is generated so that its phase changes linearly from 0 to 2πm in a clockwise direction along an arc on a plane perpendicular to the direction of propagation of electromagnetic waves, and at this time, the OAM beam or OAM signal can have mode m based on the winding number. In this way, since different mode signals in a wireless OAM system have phases that change at different speeds in space, by utilizing the orthogonality of this phase, even when multiple mode signals are superimposed and transmitted using the same space, the desired signal can be completely separated at the receiving end.

[0232] This wireless OAM technology may have some differences from the existing LoS-MIMO technology. In the existing MIMO technology, in order to form N independent channels between the transmitting and receiving antennas, there may be overhead due to the SVD-MIMO (Singular Value Decomposition-Multiple Input Multiple Output) method (the channel estimated by the receiving side must be fed back to the transmitting side). In contrast, the wireless OAM method can form N independent channels without this channel feedback (or even without channel information). Meanwhile, the biggest problem with the wireless OAM technology is that since the higher-order modes except for mode 0 are transmitted with a phase that varies from 0 to 2πm in space, the signal amplitude has a null on the axis of propagation of the electromagnetic wave, so the intensity of the higher-order mode signal is received relatively lower than that of mode 0 at a receiver far from the transmitter.

[0233] Specifically, electromagnetic radiation fundamentally carries both energy and momentum. Momentum is a physical quantity that describes the motion of particles caused by radio waves, causing them to move both linearly and angularly.

[0234] Referring to Fig. 12 (a), the linear momentum of a basically nonrelativistic, spinless, classical particle ( ) has angular momentum, which is a radiation point (x i ) angular momentum (J) from the reference point mesh ) can be defined as in the following mathematical expression 1.

[0235]

[0236] Additionally, the total angular momentum can be expressed as in Equation 2.

[0237]

[0238] Here, J EM SAM (spin angular momentum; S) is as shown in the following mathematical formula 3. EM and OAM (orbital angular momentum; L EM ) is the sum of.

[0239]

[0240] The total angular momentum is always the same under the same field conditions due to the law of conservation of energy. OAM can be a factor affected by the spatial distribution of the field. The OAM shape can be changed by changing the spatial structure in linear momentum. For example, as illustrated in Fig. 12 (b), OAM can have turns, OAM modes, or OAM shapes of m=+2, m=+1, m=0, m=-1, and m=-2.

[0241] Specifically, the shape of the OAM beam can vary depending on the OAM mode (turning number). For example, referring to Fig. 12 (b), a representative example of OAM can be a helical mode. Helical modes of an electromagnetic field can have a wavefront that has a helical shape with respect to the center (e.g., m=+2, m=+1, m=-1, and m=-2, not m=0). Such helical modes have already been utilized in the existing laser field and are defined as LG (Laguerre-Gaussian) modes, which are representative examples.

[0242] Referring to Fig. 13, it can have various orthogonal beams and energy field distributions according to OAM state / mode (or OAM winding number) (here, the antenna related to OAM can be composed of an inner circle 8 array and an outer circle 16 array). The OAM state / mode is based on the beam direction (z). It has OAM components, can be affected by the vertical phase of (H = field energy, w = frequency). In Fig. 13, an equally spaced circular antenna array (with strong right-hand circular polarization) was used to study the applicability of OAM. Therefore, (This factor is estimated by the receiver side or provided by the transmitter side for the transmission / reception distance x0 and E and H field or Poynting vector values) and if the reception energy M is measurable, then conversely, the OAM state / mode It becomes possible to estimate the specific OAM state / mode. Wow, actually An example of comparison may be as shown in Table 8 below.

[0243] lsj= l+s = 0-1-1-1.019-0.0191-10-0.0220.9782-110.9711.9713-121.812.81

[0244] Basically, the total number of OAM states / modes that can be generated N is equal to the number of antennas / 2 on the ring perpendicular to the beam direction (e.g., in the case of a 1-Tier Ring Array such as in Fig. 11 (a)), and the number of estimable OAM states / modes can have a relationship as shown in the following mathematical expression 4.

[0245]

[0246] OAM Array

[0247] Figure 14 is a diagram for explaining multi-OAM mode operation.

[0248] In relation to the operation of the multi-OAM mode (or, OAM multi-beam operation), the antenna array may be composed of a plurality of UCAs (5 UCAs) as illustrated in FIG. 14. In this case, each UCA antenna array may perform transmission through an independent OAM mode / state based on the following mathematical expression 5. Here, L may be the number of the OAM mode. The OAM mode in the structure of such an antenna array may generally have a cone-shaped beam pattern. That is, each UCA may form OAM beams in a cone-shaped shape with orthogonality. Meanwhile, the shape of the OAM beam may have various shapes, not just the cone-shaped.

[0249]

[0250] In this way, OAM communication can roughly predict the spatial distribution of OAM beams on the ground according to the OAM mode / state (m). In this case, geographical areas where reception performance is optimized for each OAM mode or each OAM beam can be distinguished. This is because the energy distribution and phase structure of the signal can be determined according to the mode / state / turning number of the OAM beam. For example, in relation to the above-described NTN, the spatial distribution of the electromagnetic field according to the phase turning number of the OAM beam can be predicted through physical models and simulations. Specifically, based on the orbit and geographical location of the satellite, and the angle that the OAM beam forms with the ground surface, the geographical area where the signal strength is the highest (or above a certain threshold) can be predicted according to each mode / state / turning number (m). At this time, the areas where the energy distribution is concentrated can differ for each OAM mode depending on the turning number of the OAM beam.

[0251] Below, a method of utilizing the OAM communication method for NTN communication is described in detail, taking into account that the concentration areas of energy distribution according to the number of turns of the OAM beam or the OAM mode can be distinguished from each other.

[0252] OAM, NTN, and Mobility UE Relationships

[0253] Figures 15 to 21 are drawings for explaining a method of performing communication using an OAM beam in NTN.

[0254] Referring to FIG. 15, from an MU-MIMO perspective, an environment may arise in which additional multiplexing and diversity gain can be obtained through OAM operation from a single UE perspective after an existing beamforming operation (e.g., hybrid beamforming).

[0255] For example, as illustrated in Fig. 16, various satellites such as LEO, GEO, MEO, HAPS (High Attitude Platform Station), and ATG (Air to Ground) can exist in NTN. In this case, in the case of HAPS or LEO orbiting in low orbit, OAM operation that can obtain multiplexing and diversity gain through OAM can be applied under the assumption of an Earth moving cell. In particular, when considering transmission restrictions due to TA (Excessive Time Advance), the OAM method can be considered as a method for simplifying the beam operation method. For example, a method of utilizing an OAM beam in NTN communication can be considered as a transmission technique that can simply obtain CSI while inheriting the existing numerology such as NR.

[0256] In particular, as described above, in the case of OAM beams, there is a tendency for a horizontally omnidirectional radiation pattern regardless of the directions of the mobile terminal and the satellite. In the case of NTN communication, this tendency of the radiation pattern can be helpful in improving signal performance in NTN communication. Due to the LoS communication characteristics between the NTN primary satellite and the terminal, the NTN primary satellite (and / or the terminal) may have sufficient ability to relatively accurately estimate / produce terminal position and velocity information through the satellite's ephemeris information and GNSS, etc. Therefore, the utilization of the OAM beam may be high in the case of the NTN communication system.

[0257] Taking this into consideration, the following describes in detail the open loop OAM (or MIMO) operation and the method for setting it to support the OAM transmission method when there is a satellite, terminal and / or gateway capable of OAM transmission (or transmission of OAM beams).

[0258] Among the satellites used for NTN, those moving in low-latitude, fast-moving orbits, such as LEO, and mobile UEs may require significant beam operation operations through beam measurements and feedback from a Legacy MIMO beam perspective. From a traditional NR beam management perspective, the measurement resources and overhead can be as follows.

[0259] - Resources for beam measurement: SSB, CSI-RS, TRS, SRS, RACH

[0260] - Overheads for beam reporting: CSI reporting by PUCCH and PUSCH

[0261] The trigger means for handover as shown in Table 9 below can also be considered as a beam trigger method for beam management (e.g., Measurement-based beam management, Location-based beam management, Time / Timer-based beam management, Time advanced information based beam management, Elevation angles of source and target based beam management).

[0262] Triggering SchemesAdvantagesDisadvantagesMeasurement-based - less specification impact (i.e. similar to terrestrial networks); - supported by Rel-16 Mobility Enhanced WI; - relies on UE estimation and established channel estimation techniques; - based on received power and cell quality. - requires a list of neighbor cells, which can be difficult given the fast-moving nature of LEO satellites and inconsistent or variable cell coverage. - small RSRP / RSRQ variations in areas of cell overlap and propagation delay can make measurement-based triggering (e.g. A3 events) unreliable. - can be difficult to direct a UE to perform a handover to a specific country.Location-based - useful when cell boundaries are distributed / undefined. - can activate mandatory HO based on UE location. - precise triggers such as UE location can be known with some accuracy. - satellite ephemeris and deterministic satellite motion can be used to predict / pre-configure trigger conditions. - useful to overcome the problem of small RSRP / RSRQ variations in areas of cell overlap. - UE can initiate HO Fewer measurements may need to be performed for this purpose. - Since the timing advance is derived based on the distance between the UE and the satellite, directly configuring the distance as a trigger condition may help reduce complexity and power consumption on the UE side when calculating the timing advance. - The UE may trigger HO to an unavailable cell (e.g., if the NTN cell is out of range, inconsistent, under varying channel conditions, or if the network sets an incorrect trigger condition). - Some UEs may not have positioning capabilities. - The UE needs to continuously track the satellite trajectories, and the network needs up-to-date UE position information, which may incur high overhead.Time / Timer based - can be useful to maintain service continuity when UE loses ground coverage; - Mandatory HO can be activated based on timing; - Network can configure different timing lengths to mitigate possible RACH congestion; - Works with satellite ephemeris and can exploit deterministic movement of satellites; - UE may need to perform less measurements for HO purposes; - UE may trigger HO to an unavailable cell (e.g., if NTN cell is out or inconsistent, channel conditions vary, or network sets wrong trigger conditions). - Depending on the accuracy of ephemeris data and mobility of the UE, this may not be a correct trigger, resulting in early / late HO for example. - Maintaining multiple timers for every UE may result in high overhead. TA value based - Timing advance based triggering is suitable for the problem that when a UE sends a RACH preamble, it needs to compensate time in advance to ensure that the target cell receives the preamble correctly. - Also, RSRP / RSRQ between overlapping cells. Timing advance-based triggering can provide higher accuracy for triggering points because the difference in values ​​is small. - Requires a GNSS-capable UE. Support for this is not part of Rel-16 and must be explicitly added. Elevation angles for source and target cell-based triggering - Beneficial for irregularly shaped handover areas - The UE must estimate the elevation angle based on the UE position and satellite astronomical data.

[0263] Measurement-based beam management can refer to a beam management method based on measurement in existing communication systems such as NR / LTE, and can be the most precise beam management method. However, as illustrated in Fig. 17 (a), if the existing NR beam measurement and reporting method is directly applied to the frameworks for beam management between the UE and the satellite of the serving link in the NTN beam topology, rapid measurement and reporting may be required due to rapid movement between the Earth moving cell and the moving UE. Such rapid measurement and reporting may require a lot of overhead in the NTN system.

[0264] For NTN, orbital (or ephemeris) information, indicating the orbit of each satellite, can be transmitted as the basis. If beam management is performed based on such orbital information, beam updates can be performed without significant overhead. Furthermore, UE location information relative to the serving link satellite can be obtained using terminal location information, such as GNSS. If a beam management method based on such relative positional relationships is defined as location-based beam management, the following issues must be considered.

[0265] - The UE may trigger beam switching to an unavailable cell (e.g., if the NTN cell is out of range or inconsistent, under varying channel conditions, or if the network sets incorrect trigger conditions).

[0266] - Some UEs may not have positioning capabilities.

[0267] - The UE must continuously track the satellite trajectory, and the network requires up-to-date UE location information, which may result in high overhead.

[0268] To offset the problems of the above location-based beam management method, if beam management is performed based on time / timer, overhead can be reduced compared to location-based beam management, but the following problems may occur.

[0269] - The UE may trigger beam sweeping on an unavailable cell (e.g., if the NTN cell is out of service or inconsistent, channel conditions vary, or the network sets incorrect trigger conditions).

[0270] - Depending on the accuracy and mobility of the UE's orbital (or ephemeris) data, this may not be an accurate trigger, leading to, for example, early / late beam switching.

[0271] - Maintaining multiple timers for every UE can result in high overhead.

[0272] TA information may already implicitly include satellite and UE location information. In an RRC connection state, the gNB and UE can perform beam management operations using the TA information and time offset values.

[0273] Specifically, for the beam topology of Fig. 17 (b), the need for precise information on the movement direction of a terminal within a moving Earth cell, such as LEO, to find a beam for an RRC connection, whether measurement-based or location-based, can be reduced. For example, when considering the following scenarios, a beam sequence (e.g., sequential sweeping of a target beam) can be predefined.

[0274] Referring to Figs. 18 (a) and (b), the area where the OAM beam is radiated on the ground surface may differ depending on the winding number (m). In other words, based on a cone-shaped OAM beam, a geographical area where the optimal OAM beam is detected may be distinguished for each OAM mode / state. For example, due to the tendency of the horizontally omnidirectional radiation pattern of the OAM beam (e.g., the tendency to emit the same energy in all directions in the horizontal plane due to the helical structure and phase repeatability of the OAM beam), the OAM beam may be uniformly radiated in the horizontal direction (or in the direction parallel to the ground surface). In this case, the OAM beam may be radiated in the shape of a circle or a circular ring on the ground surface. For example, as illustrated in FIG. 18 (a) and / or FIG. 18 (b), an OAM beam with m = 0 may have its energy focused in a predetermined circular region, an OAM beam with m = 1 may have its energy focused in a circular ring region surrounding the predetermined circular region, and an OAM beam with m = 2 may have its energy focused in a circular ring region surrounding the circular ring of the OAM beam with m = 1. For example, as the value of m increases, the energy of the OAM beam may be focused in a circular ring region that is further from the central circular region in a specific geographic area.

[0275] Based on these characteristics, a sequence of OAM beams can be defined in relation to the movement of the UE. Specifically, a scenario in which a different beam sequence is consistently generated from the initial beam depending on the movement of the UE may be as illustrated in FIG. 18.

[0276] NTN scenario A or B can be defined as a mobile terminal and an earth fixed cell scenario. Referring to Fig. 18 (a), a terminal can move through a satellite central beam (OAM state = 0) (e.g., defined as scenario A-1 or B-1). In this case, the optimal beam sequence according to the OAM beam width according to each OAM state can be as shown in Fig. 18 (a). Here, the OAM beam (Ω) for a moving UE j ) for the optimal reception time is N. j can be defined as, in this case, as shown in Fig. 18 (a), the OAM beam sequence is Ω j -> Ω j-1 -> ... ->Ω0->...-> Ω j can be. In this case, the time sequence corresponding to the target OAM beam is N j -> N j-1 -> ... -> N0->...-> N j It could be.

[0277] Referring to Fig. 18 (b), the UE does not penetrate the geographical area corresponding to OAM state 0 and Ω j-α can move across (scenario A-2 or B-2). In this case, the OAM beam sequence is Ω j -> Ω j-1 -> ... ->Ω j-α ->...-> Ω j can be. Also, the time sequence corresponding to the target OAM beam is N j -> N j-1 -> ... -> N j-α ->...-> N j It can be. Here, intuitively, N j-α >= N j It can be seen that Ω is j-α In Ω j-α-1We will not consider scenarios that slightly overlap. The biggest advantage of this transmission operation is that the gNB can identify the beam topology (OAM sequence) of each RRC-connected terminal after the OAM-based communication operation is triggered and the time T has elapsed. At this time, the gNB can identify the optimal OAM beam for each terminal and implicitly indicate the OAM beam setting related to the optimal OAM beam through the PDSCH resource allocation of each terminal. In this case, there may be no need for a reference signal for additional OAM beam measurement within the frame structure for data transmission for each RRC-connected terminal. In other words, additional CSI feedback may not be required either.

[0278] Meanwhile, the greatest advantage of having a circular (or cone) OAM beam shape may be that it can easily acquire information about terminals connected at the boundary of a tracking area code (TAC) by utilizing the outermost OAM beam. In this case, a handover operation can be performed for UEs capable of receiving the outermost OAM beam.

[0279] Specifically, referring to FIG. 19, at a specific time T, the outermost OAM beam may be transmitted from the TAC (e.g., Cell ID K, TAC D) of the corresponding gNB or cell. At this time, it can be identified that the terminals capable of receiving the outermost OAM beam are UE1, UE5, and UE7. In this case, UE1, UE5, and UE7 can inform the base station that they are located at the outermost part of the cell by feeding back the received CSI. Therefore, the feedback information for the CSI for both Transparent and Regenerate payloads can be utilized for a handover operation with an adjacent cell. In particular, when only specific corresponding terminals perform the handover operation, the overhead of the handover on the cell or base station side can be significantly reduced. For example, the UE can perform a trigger procedure for the handover procedure when an OAM beam corresponding to the outermost part is received.

[0280] In order to perform communication based on the existing system in NTN for existing Earth-moving cells (e.g., LEO) and mobile terminals, position tracking between satellites and terminals may be essential. Therefore, the above-described solution may increase the cost of the communication system. For example, referring to FIG. 20, an OAM transmitting and receiving terminal may be configured so that the OAM cone is oriented toward the satellite at a predetermined cone angle (θc). Furthermore, signal performance improvement can be achieved through the tendency of the horizontally omnidirectional radiation pattern of the OAM beam, regardless of the orientation of the mobile terminal and satellite. In such OAM-based terminal transmission and reception communication, satellite tracking may not be required. In this case, the cost and complexity of the NTN communication system can be significantly reduced. For example, the terminal only needs to be positioned so that the predetermined cone angle is oriented toward the satellite.

[0281] Referring to FIG. 21, an OAM beam relationship can be defined based on the orbit (or ephemeris) information of the satellite and the position / velocity information of the terminal. Specifically, the base station can estimate / produce the position / orbit of the satellite and the position / movement velocity information of the terminals. In this case, the base station can estimate the 2D distance between the satellite (or gNB) and the terminal based on the cone-shaped OAM beam, and can determine / decide which OAM beam (or which OAM mode / state) is optimal for each terminal based on the estimated 2D distance. In addition, the base station can estimate the degree of 2D displacement between the satellite and the terminal after a specific time T, and can also estimate which OAM beam is optimal for each terminal after time T. For example, as described above, due to the tendency of the OAM beam's horizontally omnidirectional radiation pattern, the base station can determine which OAM beam is optimal based on the distance the UE is from a particular center (e.g., the location of a satellite projected onto the Earth's surface).

[0282] Below, a method for setting up beams or resources for NTN communication based on the characteristics of the OAM beam described above is described in detail.

[0283] Hereinafter, a base station can be defined as a station or transceiver that is the subject of the network's control, data, and synchronization protocol. In the case of NTN's Transparent Payload, the base station / gNB can be a ground gateway, and in the case of Regenerated Payload, a satellite can be a gNB. In addition, even if a specific beam pattern is not specified in the OAM beam shape below, the shape of the OAM beam basically means a cone-shaped shape / pattern, but it does not exclude OAM beam shapes / patterns other than the cone-shaped shape / pattern. In addition, in the following, for the convenience of explanation, the description is based on a frequency band where the channel itself has a rank of 1, but it is obvious that the following suggestions can also be applied to a frequency band where the channel has a rank of 2 or higher.

[0284] Open loop MIMO operation capable of OAM operation in NTN communication environment

[0285] FIGS. 22 to 25 are drawings for explaining a method of setting an OAM beam sequence for OAM open loop operation.

[0286] (1) Proposal 1: Setting UE capabilities linked to OAM open loop operation

[0287] When performing a transmission operation of a signal based on an OAM beam of a gNB (or, a satellite in an NTN), the OAM open loop may mean that data transmitted using the OAM beam of the gNB (e.g., transmission of an OAM beam for a specific OAM mode / state) can be received by the terminal (reception of an OAM beam for a specific OAM mode / state). In this case, the gNB / base station can allocate a transmission section for an optimal OAM beam for a specific terminal (e.g., showing a UE-specific tendency) without any CSI feedback in the RRC connection state.

[0288] For this purpose, an Enable A bit for OAM open-loop operation may be set in the upper layer. At this time, the number of M layers may be specified in relation to resource allocation through the upper layer configuration. Alternatively, it may be signaled as activated / deactivated via MAC-CE. Enabling the OAM open-loop operation may mean that the base station has the ability to acquire precise orbit (or ephemeris) data (or astronomical data), and / or the ability to precisely calculate / judge the location / mobility information (e.g., speed, direction of movement, etc.) of the terminal within the cell and TAC. In addition, the update of the location and movement information between the gNB and the terminal for a specific period of time may be performed within a valid time period (validity duration) based on the epoch time. This means that the base station and the terminal may have the ability to estimate the elevation angle between the gNB and the terminal during a specific time interval from a specific transmission timing.

[0289] Here, the transmission timing (Tα) for such a specific OAM open loop operation can be set through at least one of a symbol number, a subframe number, a slot number, a frame number, and a SFN (System Frame Number). Alternatively, the OAM open loop operation can be activated / deactivated through MAC-CE. The time period (e.g., the activation time period) of the OAM open loop operation can be indicated / set as the number of N symbols, the number of N subframes, or the number of N frames through a higher layer, RRC signaling, or MAC-CE. If there is no setting for the timing and duration of the OAM open loop operation, the time period or active time period of the OAM open loop operation can be until the OAM open loop operation (or OAM-based operation) is disabled through separate signaling in an RRC connection state.

[0290] For example, an enabler 1 bit for OAM open loop operation for the gNB and an enabler 1 bit for UE OAM open loop operation may be configured. In this case, the gNB may mean that both the gNB and the UE can determine / predict gNB and UE location / mobility information when the enabler 1 bit for OAM open loop operation for the gNB and the enabler 1 bit for UE OAM open loop operation are 11. Alternatively, it may mean that the gNB and the UE can determine / calculate the elevation angle between the gNB and the UE. At this time, if the time interval of the OAM open loop operation is set to 4, the OAM open loop operation can be valid for 4 SFN, and after 4 SFN has elapsed, the instruction / setting of the enabler for the OAM open loop operation can be requested again or the OAM open loop operation can be disabled.

[0291] (2) Proposal 2: Setting of OAM beam sequence linked to OAM open loop operation

[0292] A set of OAM beam sequences associated with OAM open loop operation can be configured cell-specifically (or cell ID-specifically) and / or TAC-specifically. For example, a set of OAM beam sequences, as shown in Table 11 below, can be pre-configured or pre-defined for specific cell IDs and TAC IDs.

[0293] For example, referring to FIG. 22 (a), an OAM beam can be divided into regions corresponding to Ω0, Ω1, Ω2, Ω3, Ω4, and Ω5, respectively, in a specific geographical area according to an OAM mode / state. For example, as described above, due to the tendency of the horizontally omnidirectional radiation pattern of the OAM beam, a geographical area where energy is concentrated can be divided for each OAM beam (and / or OAM beam mode / state), as illustrated in FIG. 22 (a).

[0294] Specifically, the OAM beam sequence setting may be linked to the setting of the OAM open loop operation, and may be a setting for the OAM beam sequence, which is a sequence of OAM beams to be sequentially used in an RRC connection state, and / or a setting for time resources that are time division multiplexed (TDM) according to the OAM beam sequence. For example, the gNB may determine / predict an OAM beam sequence for an OAM beam to be used for each time section based on the orbit of the satellite and the position / movement speed of the UEs, and may transmit / transmit setting information for the TDMed time resources in a TAC-specific (or cell ID and TAC ID-specific) manner according to the determined / predicted OAM beam sequence.

[0295] For example, the OAM beam sequence configuration may include at least one of the following information:

[0296] a. Number of orthogonal OAM beams (N OAM )

[0297] b. OAM beam sequence (or OAM beam sequence set): refers to a sequential OAM beam set.

[0298] - For example, an OAM beam sequence can be indicated by a specific OAM index as shown in Table 10 below. Here, Ω1 to Ω5 can be orthogonal OAM mode / state-specific OAM beams.

[0299] OAM beam sequenceΩ0Ω1Ω2Ω3Ω4Ω500123451501234245012333450124234501512345060,31,42,5---7---2,31,40,5

[0300] - For example, an OAM beam sequence set / table such as Table 10 may be set or predefined by a higher layer signal. In this case, the OAM sequence setting is N OAM =6 and OAM beam sequence=7 are indicated / triggered, the OAM beam sequence (or OAM mode sequence) may be Ω5->Ω4->Ω3->Ω3->Ω4->Ω5 (e.g., an integer defined for each OAM beam sequence is the order of the OAM beam). For example, referring to FIG. 22 (a), the beam sequence for UE1 in cell K, TAC D may be indicated / set as 7 as the OAM beam sequence based on the position and movement direction of the UE1 (e.g., the OAM beam sequence may be indicated UE-specifically).

[0301] c. OAM sequence operation time interval (T OAM ): defined as the number of symbols, slots, subframes, or frames. Or, the valid time interval associated with the update of the epoch time and T OAM These may correspond to each other.

[0302] - For example, T OAMcan be 30 radio frames. In this case, an equal time interval can be allocated for each OAM beam, and the time interval for each OAM beam can be 5 radio frames. For example, if the OAM beam sequence setting is N OAM =6, OAM beam sequence = 7, T OAM = In case of 30 frames, the TDM frame structure according to the OAM beam sequence may be as shown in Fig. 22 (b).

[0303] For example, referring to Fig. 22 (a) and (b), the NTN scenario A-2 or B-2 for OAM beam sequence operation is set up. As shown in Fig. 22 (a), the distribution of terminals of the gNB may mainly move in the direction of Ω5->Ω4->Ω3->Ω3->Ω4->Ω5. In this case, the gNB may set the OAM beam sequence setting for the UEs for the OAM beam sequence = 7, as shown in Fig. 22 (b). In this case, the UEs may set the time resource (T) according to each OAM beam based on the SSB or synchronization signal of each OAM beam. OAM,m ) can transmit and receive signals based on the OAM beam. For example, the UE can specify / identify which OAM transmission / reception beam is currently optimal based on whether the optimal SSB is detected in a time interval within a time interval consisting of 30 frames. In addition, the UE can specify / identify the time resource (T ) corresponding to the optimal OAM beam. OAM,m ) can implicitly know the time resources scheduled for itself. For example, UE1 may trigger OAM open-loop operation at Tα. In this case, UE1 determines that the optimal OAM beam at its current location is Ω5 (e.g., because the optimal SSB is detected in the time interval corresponding to Ω5), and schedules a time resource from Tα. During the time, the optimal OAM beam tends to be Ω5. For example, UE1 can change the optimal OAM beam in the form of Ω5->Ω4->Ω3->Ω3->Ω4->Ω5 during the OAM beam sequence period, and can obtain resource allocation opportunities for all time resources for the OAM beam sequence.

[0304] In other words, the base station can determine an optimal OAM beam sequence for a given geographic area based on the mainly distributed geographic area and movement direction of the UEs, and allocate TDM time resources to the UEs based on the determined OAM beam sequence.

[0305] (3) Proposal 3: Setting the transmission timing of the OAM beam sequence linked to the OAM open loop operation.

[0306] For transmission operation of an OAM beam sequence (or, OAM open-loop operation), the gNB must be able to predict the distribution of terminals when the OAM sequence operation starts within the TAC and the distribution of terminals until the OAM beam sequence ends. The transmission time of the OAM beam sequence can be set to the terminal in a cell-specific and / or TAC-specific manner as SFN, frame, subframe, symbol, and / or slot information. Specifically, the transmission time of the OAM sequence can be set through at least one of the following methods.

[0307] - Periodic Scheduling: SFN, frame, subframe, symbol and / or slot related to the transmission time of OAM beam sequence can be specified / configured through upper layer signaling (e.g., RRC signaling).

[0308] - Based on the update point of the epoch time: The start point of transmission of the OAM beam sequence for RRC connected terminals or the start point of data scheduling can be indicated / set based on the update point of the epoch time.

[0309] - The start time (Tα) of the OAM open loop operation and the transmission time of the OAM beam sequence can be set to coincide.

[0310] - In the event trigger format, it can be triggered (e.g., triggered for an update of an OAM beam sequence) by predicting the density of terminals within a specific TAC and the density distribution of terminals during an OAM beam sequence period. In this case, a trigger related to the start of transmission of an OAM beam sequence configuration can be cell and / or TAC-specific and indicated via DCI.

[0311] Referring to Figures 23 (a) and 23 (b), the first T OAM (=0) at the second T OAM (T (OAM,0)+ T_ (OAM,1) ) may change the distribution / density of UEs. For example, as shown in Figs. 24 (b) and (c), the distribution of UEs by area corresponding to the OAM mode may change from Fig. 24 (b) to Fig. 24 (c). In this case, a QAM beam sequence such as Fig. 24 (a) may be set (e.g., the first T OAM The reference time topology can be changed to a time topology such as Fig. 24 (a). Specifically, the first T OAM When the OAM beam sequence operation is defined as the reference time at which the OAM beam sequence operation is triggered, the resource allocation location of the Low Priority UE in the OAM sequence operation is T as an example. OAM,2 PUSCH for low priority UEs can be transmitted in the area. The UE priority criteria for the time interval of the OAM sequence open loop can be assumed to be an implementation issue.

[0312] The above OAM beam sequence operation / setting can be determined / set according to the topology and movement of UEs in the TAC within the cell in the form of an event trigger. At this time, in the case of a terminal with a low priority for resource allocation, a resource region corresponding to a specific OAM beam may or may not be allocated within the time interval of the OAM beam sequence. Whether or not a resource corresponding to a specific OAM beam is allocated to a terminal with a low priority for resource allocation can be implicitly determined through an SSB detection method within the time interval of the OAM beam sequence or through satellite orbital information and terminal location information.

[0313] For example, referring to FIG. 25, the base station can calculate the two-dimensional (2D) distance and 2D displacement between the satellite's position and the terminal's position / mobility information projected onto the ground based on the satellite's orbital information and the terminal's position / mobility information. Through this, the base station can calculate / predict the distribution / density of UEs that can be RRC-connected by geographical area corresponding to the OAM mode or OAM beam. In this case, the base station can determine the optimal OAM beam sequence based on the distribution / density of UEs that can be RRC-connected by geographical area corresponding to the calculated OAM mode or OAM beam, and provide the UEs with the OAM beam sequence setting for the OAM beam sequence through DCI or trigger the OAM open-loop operation.

[0314] (4) Proposal 4: OAM multi-beam sequence operation setting

[0315] OAM multi-beam sequences are specific to T OAM,mThis may mean that two or more OAM beams can be transmitted during the section. Accordingly, an OAM multi-beam sequence setting may be added, or a setting in which two or more OAM beam sequences are triggered simultaneously may also be possible. Specifically, an OAM multi-beam sequence set may be predefined as in Table 11 (an example of a case in which simultaneous transmission of H = 2 OAM beams is possible during an OAM beam sequence section). The base station may instruct / provide the OAM multi-beam sequence to the UEs through RRC or MAC-CE based on the predefined OAM multi-beam sequence set.

[0316] multi-beam sequenceΩ0, Ω1Ω1, Ω2Ω2, Ω3Ω3, Ω4Ω4, Ω5Ω0, Ω500123451501234245012333450124234501512345060,31,42,5---7---2,31,40,5

[0317] Meanwhile, information about the OAM multi-beam sequence setting set is T OAM,m It may include different OAM multi-beam sequences depending on the number of simultaneously transmitted OAM beams within T OAM,m When the number of simultaneous transmission OAM beams within the base station is set to H, the base station selects a set of OAM multi-beam sequences preset to H, and the triggered / set OAM multi-beam sequence within the selected set of OAM multi-beam sequences can be set / indicated via RRC or MAC-CE.

[0318] Alternatively, when an OAM beam sequence set is configured as in Table 10, two or more OAM beam sequences in the OAM beam sequence set may be triggered simultaneously to configure an OAM multi-beam sequence. For example, the base station may indicate OAM multi-beam sequences 1 and 2 through RRC or MAC-CE based on the OAM beam sequence set for Table 10. In this case, the following OAM multi-beam sequences may be configured within the time interval of the OAM beam sequence.

[0319] Ω 1, Ω2-> Ω 2, Ω3-> Ω 3, Ω4-> Ω 4, Ω5-> Ω 0, Ω5-> Ω 0, Ω1

[0320] Figure 26 is a diagram for explaining a method in which a terminal supporting OAM-based communication performs OAM-based communication.

[0321] Here, the terminal may be a terminal supporting OAM-based communication (or OAM beam sequence operation, OAM open-loop operation) as described above. In addition, the base station may transmit a signal through a satellite supporting NTN and OAM-based communication, or may be a satellite supporting NTN and OAM-based communication. For example, as described above, the terminal may support the ability to estimate an elevation angle with respect to the base station based on satellite orbital information related to the base station and the ability to transmit or receive an OAM beam. In addition, the base station may also be a base station having the ability to estimate / calculate a positional relationship between the base station (or satellite) and the terminal based on satellite orbital information related to the base station and position / mobility information of the terminal and the ability to transmit or receive an OAM beam. In the following, for convenience of explanation, it is assumed that the base station is a satellite performing NTN operation.

[0322] Specifically, the base station can perform communication with the terminal using a plurality of OAM beams having a plurality of OAM modes / states / turning numbers defined in FIGS. 11 to 13, 14 to 21, etc. As described above, the plurality of OAM beams may be beams in which areas where energy is concentrated are distinguished from each other in a given geographical area. For example, referring to FIGS. 18 (a) and (b), an area radiated on the ground surface may differ depending on the OAM mode (turning number) / OAM state. In other words, when based on a cone shape OAM beam, a geographical area in which an optimal OAM beam is detected can be distinguished for each OAM mode / state. More specifically, due to the tendency of the horizontally omnidirectional radiation pattern of the OAM beam (e.g., the tendency to emit the same energy in all directions in the horizontal plane due to the helical structure and phase repeatability of the OAM beam), the OAM beam can be uniformly radiated in the horizontal direction (or, in the direction parallel to the ground surface). In this case, the OAM beam may be radiated in the form of a circle or a circular ring on the surface of the Earth. As illustrated in FIG. 18 (a) and / or FIG. 18 (b), the OAM beam with m = 0 may have its energy concentrated in a predetermined circular area, the OAM beam with m = 1 may have its energy concentrated in a circular ring area surrounding the predetermined circular area, and the OAM beam with m = 2 may have its energy concentrated in a circular ring area surrounding the circular ring of the OAM beam with m = 1. For example, as the value of m increases, the energy of the OAM beam may be concentrated in a circular ring area further from the central circular area in a specific geographical area.

[0323] In this way, a base station can predict / determine the optimal reception area for each OAM mode / OAM state in a specific geographical area. For example, as shown in FIG. 18, FIG. 21, and FIG. 22, the base station can predict / determine the ring area for each OAM mode based on the circular area (or the position of the satellite projected on the Earth's surface) where the OAM beam of OAM mode 0 (m=0) reaches the Earth's surface with a reception intensity higher than a specific threshold. Alternatively, the base station can calculate / determine the 2D distance range (i.e., the range where energy is concentrated) for each OAM mode based on the center of the circular area where the OAM beam of OAM mode 0 (m=0) reaches the Earth's surface with a reception intensity higher than a specific threshold. Based on this, the base station can set / determine the OAM beam sequence associated with a given geographical area as described above.

[0324] Specifically, referring to FIG. 26, the terminal may receive configuration information related to an OAM (Orbital Angular Momentum) beam-based operation (or, OAM open-loop operation) from the base station (S261). The configuration information may include information on an OAM beam sequence for a plurality of OAM beams and a time interval (a time interval during which an OAM beam-based operation is performed) as described above. For example, the configuration information may include information on an OAM beam sequence configuration as described with reference to FIGS. 22 to 25. In addition, in relation to the OAM sequence configuration, information on an OAM sequence set may be preset as shown in Table 10 or Table 11 through RRC signaling, and the OAM sequence configuration may include information on an index for a specific OAM sequence among the OAM sequence set.

[0325] Meanwhile, as described above, the configuration information may be transmitted to the terminal based on a report of capability information regarding whether the terminal supports OAM beam-based operation. In other words, if the base station can support / activate OAM beam-based operation and the terminal reports the capability information, the base station may activate OAM beam-based communication operation with the terminal and transmit the configuration information to the terminal. Alternatively, the configuration information may be configured to be cell- and TAC (Tracking Area Code)-specific. For example, the configuration information may be applied to terminals that communicate with a base station for which a specific cell ID and a specific TAC ID are configured.

[0326] Alternatively, the OAM beam sequence may be set based on the distribution of terminals, movement paths, and orbital information of satellites as described in Proposal 2. For example, the OAM beam sequence may be set based on the proximity of a geographic area in which each of the plurality of OAM beams is received with an intensity greater than a specific threshold in a first geographic area determined based on a specific TAC and / or cell ID, orbital information of a satellite associated with the base station, and the distribution of terminals in the first geographic area. For example, as described in FIG. 22, the base station may predict which areas among a plurality of areas corresponding to the plurality of OAM beams the terminals sequentially pass through through the distribution and movement paths of the terminals in the first geographic area (which may change depending on the movement of the satellite), and may determine / set an OAM beam sequence corresponding to the areas through which the terminals sequentially pass through among the plurality of areas. For example, based on the distribution and movement path of the terminal as in Fig. 22 (a), the base station can set an OAM beam sequence of Ω5->Ω4->Ω3->Ω3->Ω4->Ω5 to the terminal.

[0327] Alternatively, the OAM beam sequence described above may be updated based on changes in the distribution, density, and / or movement path of UEs in a first geographic area corresponding to a specific Tracking Area Code (TAC). For example, the OAM beam sequence may be updated using a method similar to that described in Proposal 3.

[0328] Alternatively, the time interval may be set based on the epoch time associated with the base station as described in Proposals 2 and 3. Alternatively, the length of the time interval may be set equal to the length of the valid time interval of the epoch time associated with the base station.

[0329] Alternatively, as described in the above-described proposal 1, the OAM beam-based operation or the configuration information may be activated or deactivated via RRC (Radio Resource Control) signaling or MAC-CE (Medium Access Control-Control Element). For example, the base station may indicate activation / deactivation of the OAM beam-based operation or application of the configuration information via RRC or MAC-CE.

[0330] Next, the terminal can determine a specific OAM beam among the plurality of OAM beams based on the SSB (Synchronization Signal Block) received from the base station (S263). For example, as described with reference to FIG. 22 (b), the time resource information includes information on time resources TDMed for each OAM beam / OAM mode, and an SSB can be transmitted in a corresponding time resource for each OAM beam / OAM mode. In this case, the terminal can confirm / specify a time resource in which an optimal SSB is received among the time resources based on the configuration information, and determine what the optimal OAM beam is at its location based on the OAM beam sequence and the specified time resource. In this case, the terminal can detect an optimal OAM beam for itself through monitoring the SSB, continuously determine / change an OAM beam for communication with the base station, and determine a time resource allocated to itself in response to the optimal OAM beam changed based on the OAM beam sequence.

[0331] Next, the terminal can receive or transmit a signal to or from the base station using the specific OAM beam in the time resources corresponding to or allocated to the specific OAM beam among the time resources based on the configuration information (S265). For example, the terminal can determine the time resource corresponding to the specific OAM beam among the time resources (i.e., time resources TDM'd according to the OAM beam sequence) within the time interval based on the OAM beam sequence included in the configuration information, and can receive a signal transmitted from the base station or transmit a signal to the base station using the specific OAM beam within the time resource. Meanwhile, as described in FIG. 22 or the like, the length of the TDM'd time resource for each OAM beam sequentially indicated in the OAM beam sequence within the time interval may be the same. For example, according to the configuration information, the length of the time interval may be 30 frames, and the number of OAM beams sequentially indicated in the OAM beam sequence may be 6. In this case, the length of the OAM beam or the time resource for each OAM state may be the same as 5 frames. Alternatively, the length of the TDMed time resource for each OAM beam sequentially indicated in the OAM beam sequence within the above time interval may be different from each other. For example, the OAM beam sequence configuration information may explicitly indicate the length of the time resource for each OAM beam sequentially indicated by the OAM beam sequence.

[0332] Meanwhile, as described above, OAM beam-based operation based on OAM beam sequence can be defined as OAM open-loop operation. For example, the terminal can omit reporting of CSI based on CSI-RS within the time interval. This is because the terminal can know optimal beam information for each time resource through OAM beam sequence without setting the optimal beam through CSI reporting.

[0333] Figure 27 is a diagram for explaining a method in which a base station supporting OAM-based communication performs OAM-based communication with a terminal.

[0334] The base station can perform communication with the terminal using a plurality of OAM beams having a plurality of OAM modes (winding numbers) / OAM states defined in FIGS. 11 to 13, 14 to 21, etc. For example, the base station can predict / determine the optimal reception area for each OAM mode / OAM state for a specific geographical area. As in FIGS. 18, 21, and 22, the base station can predict / determine the ring area for each OAM mode based on the circular area where the OAM beam of OAM mode 0 (m=0) reaches the ground surface with a reception intensity higher than a specific threshold. Alternatively, the base station can calculate / determine the 2D distance range (i.e., the range where energy is concentrated) for each OAM mode based on the center of the circular area where the OAM beam of OAM mode 0 (m=0) reaches the ground surface with a reception intensity higher than a specific threshold. Based on this, the base station can set / determine the OAM beam sequence associated with a predetermined geographical area as described above.

[0335] Specifically, referring to FIG. 27, the base station can transmit configuration information related to Orbital Angular Momentum (OAM) beam-based operation (or, OAM open-loop operation) (S271). For example, the configuration information can include information on an OAM beam sequence configuration as described with reference to FIGS. 22 to 25 and a time interval to which the OAM beam sequence configuration is applied. Alternatively, the configuration information can include information on time resources TDMed according to the OAM beam sequence for the time interval. In relation to the OAM sequence configuration, information on an OAM sequence set can be preset as shown in Table 10 or Table 11 through RRC signaling, and the OAM sequence configuration can include information on an index for a specific OAM sequence among the OAM sequence set.

[0336] For example, the base station can determine the OAM beam sequence to be applied to the first geographic area (meaning, the first geographic area may be continuously changed when the base station is not a geostationary satellite) related to the specific TAC based on the distribution of terminals, movement paths, and orbital information of satellites as described in Proposal 2. First, the base station can determine / predict the area where energy is concentrated for each OAM beam / OAM mode in the first geographic area. For example, the base station can determine areas in the first geographic area where each of the plurality of OAM beams is received with an intensity higher than a specific threshold. For example, as described above, the base station can determine the range of the area where the energy of each OAM beam is concentrated based on a specific reference point (the center point of OAM mode 0). Next, the base station can determine the OAM beam sequence based on information about the distribution and / or movement paths of terminals in the first geographic area and satellite orbital information. For example, as described in FIG. 22, the base station can predict which of a plurality of areas corresponding to a plurality of OAM beams the terminals sequentially pass through through the distribution and movement paths of the terminals for the first geographic area, and can determine / set an OAM beam sequence based on the order of the areas the terminals sequentially pass through. For example, based on the distribution and movement paths of the terminals as in FIG. 22 (a), the base station can determine the OAM beam sequence for the first geographic area as Ω5->Ω4->Ω3->Ω3->Ω4->Ω5.

[0337] Alternatively, the OAM beam-based operation may be performed based on a report of capability information of the terminal. Specifically, when the terminal reports the capability information, the base station may perform an operation of the OAM beam-based operation with the terminal. Meanwhile, the configuration information may be configured to be cell- and TAC (Tracking Area Code)-specific. For example, the configuration information may be applied to terminals that communicate with a base station for which a specific cell ID and a specific TAC ID are configured. Alternatively, as described in the above-described proposal 1, the base station may indicate whether to activate or deactivate the OAM beam-based operation or the configuration information through RRC (Radio Resource Control) signaling or MAC-CE (Medium Access Control-Control Element).

[0338] Alternatively, the OAM beam sequence described above may be updated based on changes in the distribution, density, and / or movement path of UEs in the first geographic area corresponding to a specific Tracking Area Code (TAC). For example, the OAM beam sequence for the first geographic area may be updated in a manner similar to the above-described proposal 3.

[0339] Alternatively, the time interval may be set based on the epoch time associated with the base station as described in Proposals 2 and 3. Alternatively, the length of the time interval may be set equal to the length of the valid time interval of the epoch time associated with the base station.

[0340] Next, the base station can transmit or receive signals for terminals using the corresponding OAM beam in each of the TDM-ed time resources according to the OAM beam sequence (S273). For example, the base station can predict the optimal OAM beam and the corresponding time resource for each terminal based on satellite orbit information and the location information / mobility information of each terminal. In this case, the base station can transmit a signal (PDSCH) for the terminal in the predicted optimal OAM beam and the corresponding time resource for each terminal, or schedule the PDSCH for the predicted optimal OMA beam and the corresponding time resource for each terminal through PDCCH / DCI. For example, the base station can predict terminals located in a geographical area corresponding to a specific OAM beam / mode mapped to a specific time resource. In this case, the base station can transmit a downlink signal (PDSCH / PDCCH) for at least one of the predicted terminals using the specific OAM beam in the specific time resource. Alternatively, the base station may allocate / schedule resources for transmission of an uplink signal (PUSCH / PUCCH) to at least one of the predicted terminals within the specific time resource.

[0341] Meanwhile, as described above, OAM beam-based operation based on the OAM beam sequence can be defined as OAM open-loop operation. For example, the base station can skip / omit transmission of a signal for CSI-RS within the time interval.

[0342] In this way, the proposed invention can omit feedback of CSI reports through the OAM beam sequence, so that effective communication can be performed even in an NTN communication environment where RTT and propagation delay are considerably large and the movement status of satellites and terminals changes significantly. Alternatively, the proposed invention can effectively guarantee communication between a UE and a base station through an optimal beam direction even in the absence of CSI reports on channel status through the OAM beam sequence. Alternatively, the proposed invention can effectively allocate / specify time resources for communication through an optimal QAM beam corresponding to changes in the positions of the UE and NTN through TDM of a time interval according to the OAM beam sequence.

[0343] Examples of communication systems to which the invention applies

[0344] Although not limited thereto, the various descriptions, functions, procedures, proposals, methods and / or operational flowcharts of the present invention disclosed in this document may be applied to various fields requiring wireless communication / connection (e.g., 5G) between devices.

[0345] Hereinafter, more specific examples will be provided with reference to the drawings. In the drawings / descriptions below, the same drawing reference numerals may represent identical or corresponding hardware blocks, software blocks, or functional blocks, unless otherwise described.

[0346] Figure 28 illustrates a communication system applied to the present invention.

[0347] Referring to FIG. 28, a communication system (1) applied to the present invention includes a wireless device, a base station, and a network. Here, the wireless device refers to a device that performs communication using a wireless access technology (e.g., 5G NR (New RAT), LTE (Long Term Evolution)) and may be referred to as a communication / wireless / 5G device. Although not limited thereto, the wireless device may include a robot (100a), a vehicle (100b-1, 100b-2), an XR (eXtended Reality) device (100c), a hand-held device (100d), a home appliance (100e), an IoT (Internet of Things) device (100f), and an AI device / server (400). For example, the vehicle may include a vehicle equipped with a wireless communication function, an autonomous vehicle, a vehicle capable of performing vehicle-to-vehicle communication, etc. Here, the vehicle may include an Unmanned Aerial Vehicle (UAV) (e.g., a drone). XR devices include AR (Augmented Reality) / VR (Virtual Reality) / MR (Mixed Reality) devices, and can be implemented in the form of HMD (Head-Mounted Device), HUD (Head-Up Display) installed in a vehicle, television, smartphone, computer, wearable device, home appliance, digital signage, vehicle, robot, etc. Mobile devices can include smartphone, smart pad, wearable device (e.g., smart watch, smart glass), computer (e.g., laptop, etc.), etc. Home appliances can include TV, refrigerator, washing machine, etc. IoT devices can include sensors, smart meters, etc. For example, base stations and networks can also be implemented as wireless devices, and a specific wireless device (200a) can act as a base station / network node to other wireless devices.

[0348] Wireless devices (100a to 100f) can be connected to a network (300) via a base station (200). Artificial Intelligence (AI) technology can be applied to the wireless devices (100a to 100f), and the wireless devices (100a to 100f) can be connected to an AI server (400) via the network (300). The network (300) can be configured using a 3G network, a 4G (e.g., LTE) network, a 5G (e.g., NR) network, etc. The wireless devices (100a to 100f) can communicate with each other via the base station (200) / network (300), but can also communicate directly (e.g., sidelink communication) without going through the base station / network. For example, vehicles (100b-1, 100b-2) can communicate directly (e.g., V2V (Vehicle to Vehicle) / V2X (Vehicle to Everything) communication). In addition, IoT devices (e.g., sensors) can communicate directly with other IoT devices (e.g., sensors) or other wireless devices (100a to 100f).

[0349] Wireless communication / connection (150a, 150b, 150c) can be established between wireless devices (100a~100f) / base stations (200), and base stations (200) / base stations (200). Here, wireless communication / connection can be achieved through various wireless access technologies (e.g., 5G NR) such as uplink / downlink communication (150a), sidelink communication (150b) (or, D2D communication), and communication between base stations (150c) (e.g., relay, IAB (Integrated Access Backhaul). Through wireless communication / connection (150a, 150b, 150c), wireless devices and base stations / wireless devices, and base stations and base stations can transmit / receive wireless signals to each other. For example, wireless communication / connection (150a, 150b, 150c) can transmit / receive signals through various physical channels. To this end, at least some of various configuration information setting processes for transmitting / receiving wireless signals, various signal processing processes (e.g., channel encoding / decoding, modulation / demodulation, resource mapping / demapping, etc.), and resource allocation processes can be performed based on various proposals of the present invention.

[0350] Examples of wireless devices to which the present invention is applied

[0351] Figure 29 illustrates a wireless device applicable to the present invention.

[0352] Referring to FIG. 29, the first wireless device (100) and the second wireless device (200) can transmit and receive wireless signals through various wireless access technologies (e.g., LTE, NR). Here, {the first wireless device (100), the second wireless device (200)} can correspond to {the wireless device (100x), the base station (200)} and / or {the wireless device (100x), the wireless device (100x)} of FIG. 28.

[0353] A first wireless device (100) includes one or more processors (102) and one or more memories (104), and may further include one or more transceivers (106) and / or one or more antennas (108). The processor (102) controls the memories (104) and / or the transceivers (106), and may be configured to implement the descriptions, functions, procedures, proposals, methods, and / or operational flowcharts disclosed in this document. For example, the processor (102) may process information in the memory (104) to generate first information / signal, and then transmit a wireless signal including the first information / signal via the transceiver (106). In addition, the processor (102) may receive a wireless signal including second information / signal via the transceiver (106), and then store information obtained from signal processing of the second information / signal in the memory (104). The memory (104) may be connected to the processor (102) and may store various information related to the operation of the processor (102). For example, the memory (104) may perform some or all of the processes controlled by the processor (102), or may store software code including commands for performing the descriptions, functions, procedures, proposals, methods, and / or operation flowcharts disclosed in this document. Here, the processor (102) and the memory (104) may be part of a communication modem / circuit / chipset designed to implement wireless communication technology (e.g., LTE, NR). The transceiver (106) may be connected to the processor (102) and may transmit and / or receive wireless signals via one or more antennas (108). The transceiver (106) may include a transmitter and / or a receiver. The transceiver (106) may be used interchangeably with an RF (Radio Frequency) unit. In the present invention, a wireless device may also mean a communication modem / circuit / chipset.

[0354] According to one example, the first wireless device (100) or terminal may include a processor (102) and a memory (104) connected to the RF transceiver. The memory (104) may include at least one program capable of performing operations related to the embodiments described in FIGS. 14 to 27.

[0355] Specifically, the processor (102) controls the RF transceiver (106) to receive configuration information including information on an OAM beam sequence and a time interval for a plurality of OAM beams related to an OAM (Orbital Angular Momentum) beam-based operation from a base station, determine a specific OAM beam among the plurality of OAM beams based on a SSB (Synchronization Signal Block) received from the base station, and transmit or receive a signal in a time resource corresponding to the specific OAM beam among time resources that are time division multiplexed (TDM) according to the OAM beam sequence within the time interval.

[0356] Alternatively, a processing device including a processor (102) and a memory (104) may be configured. In this case, the processing device may include at least one processor; and at least one memory connected to the at least one processor and storing instructions, wherein the instructions, based on being executed by the at least one processor, cause the terminal (100) to: receive from a base station configuration information including information on an OAM (Orbital Angular Momentum) beam sequence and a time interval for a plurality of OAM beams related to an OAM beam-based operation, determine a specific OAM beam among the plurality of OAM beams based on an SSB (Synchronization Signal Block) received from the base station, and transmit or receive a signal in a time resource corresponding to the specific OAM beam among time resources that are time division multiplexed (TDM) according to the OAM beam sequence within the time interval.

[0357] Alternatively, a non-transitory computer-readable storage medium having recorded thereon instructions for performing the proposed methods described with reference to FIGS. 9 to 12 may be configured.

[0358] The second wireless device (200) includes one or more processors (202), one or more memories (204), and may further include one or more transceivers (206) and / or one or more antennas (208). The processor (202) controls the memories (204) and / or the transceivers (206), and may be configured to implement the descriptions, functions, procedures, proposals, methods, and / or operational flowcharts disclosed in this document. For example, the processor (202) may process information in the memory (204) to generate third information / signals, and then transmit a wireless signal including the third information / signals via the transceivers (206). Furthermore, the processor (202) may receive a wireless signal including fourth information / signals via the transceivers (206), and then store information obtained from signal processing of the fourth information / signals in the memory (204). The memory (204) may be connected to the processor (202) and may store various information related to the operation of the processor (202). For example, the memory (204) may perform some or all of the processes controlled by the processor (202), or may store software code including commands for performing the descriptions, functions, procedures, proposals, methods, and / or operation flowcharts disclosed in this document. Here, the processor (202) and the memory (204) may be part of a communication modem / circuit / chip designed to implement wireless communication technology (e.g., LTE, NR). The transceiver (206) may be connected to the processor (202) and may transmit and / or receive wireless signals via one or more antennas (208). The transceiver (206) may include a transmitter and / or a receiver. The transceiver (206) may be used interchangeably with an RF unit. In the present invention, a wireless device may also mean a communication modem / circuit / chip.

[0359] According to one example, the second wireless device (200) or base station may include a processor (202) and a memory (204) connected to the RF transceiver. The memory (204) may include at least one program capable of performing operations related to the embodiments described in FIGS. 14 to 27.

[0360] Specifically, the processor (202) controls the transceiver (206) or the RF transceiver to transmit configuration information including information on an OAM beam sequence and a time interval for a plurality of OAM beams related to an OAM (Orbital Angular Momentum) beam-based operation, and can receive or transmit a signal using a corresponding OAM beam in each of time division multiplexed (TDM) time resources according to the OAM beam sequence within the time interval.

[0361] Hereinafter, the hardware elements of the wireless device (100, 200) will be described in more detail. Although not limited thereto, one or more protocol layers may be implemented by one or more processors (102, 202). For example, one or more processors (102, 202) may implement one or more layers (e.g., functional layers such as PHY, MAC, RLC, PDCP, RRC, SDAP). One or more processors (102, 202) may generate one or more Protocol Data Units (PDUs) and / or one or more Service Data Units (SDUs) according to the descriptions, functions, procedures, proposals, methods, and / or operation flowcharts disclosed in this document. One or more processors (102, 202) may generate messages, control information, data, or information according to the descriptions, functions, procedures, proposals, methods, and / or operation flowcharts disclosed in this document. One or more processors (102, 202) can generate signals (e.g., baseband signals) including PDUs, SDUs, messages, control information, data or information according to the functions, procedures, proposals and / or methods disclosed herein, and provide the signals to one or more transceivers (106, 206). One or more processors (102, 202) can receive signals (e.g., baseband signals) from one or more transceivers (106, 206) and obtain PDUs, SDUs, messages, control information, data or information according to the descriptions, functions, procedures, proposals, methods and / or operational flowcharts disclosed herein.

[0362] One or more processors (102, 202) may be referred to as a controller, a microcontroller, a microprocessor, or a microcomputer. One or more processors (102, 202) may be implemented by hardware, firmware, software, or a combination thereof. For example, one or more Application Specific Integrated Circuits (ASICs), one or more Digital Signal Processors (DSPs), one or more Digital Signal Processing Devices (DSPDs), one or more Programmable Logic Devices (PLDs), or one or more Field Programmable Gate Arrays (FPGAs) may be included in one or more processors (102, 202). The descriptions, functions, procedures, proposals, methods, and / or operational flowcharts disclosed in this document may be implemented using firmware or software, and the firmware or software may be implemented to include modules, procedures, functions, etc. The descriptions, functions, procedures, suggestions, methods and / or operation flowcharts disclosed in this document may be implemented using firmware or software configured to perform one or more processors (102, 202) or stored in one or more memories (104, 204) and executed by one or more processors (102, 202). The descriptions, functions, procedures, suggestions, methods and / or operation flowcharts disclosed in this document may be implemented using firmware or software in the form of codes, instructions and / or sets of instructions.

[0363] One or more memories (104, 204) may be coupled to one or more processors (102, 202) and may store various forms of data, signals, messages, information, programs, codes, instructions, and / or commands. The one or more memories (104, 204) may be configured as ROM, RAM, EPROM, flash memory, hard drives, registers, cache memory, computer-readable storage media, and / or combinations thereof. The one or more memories (104, 204) may be located internally and / or externally to the one or more processors (102, 202). Additionally, the one or more memories (104, 204) may be coupled to the one or more processors (102, 202) via various technologies, such as wired or wireless connections.

[0364] One or more transceivers (106, 206) can transmit user data, control information, wireless signals / channels, etc., as mentioned in the methods and / or flowcharts of this document, to one or more other devices. One or more transceivers (106, 206) can receive user data, control information, wireless signals / channels, etc., as mentioned in the descriptions, functions, procedures, proposals, methods and / or flowcharts of this document, from one or more other devices. For example, one or more transceivers (106, 206) can be connected to one or more processors (102, 202) and can transmit and receive wireless signals. For example, one or more processors (102, 202) can control one or more transceivers (106, 206) to transmit user data, control information, or wireless signals to one or more other devices. Additionally, one or more processors (102, 202) may control one or more transceivers (106, 206) to receive user data, control information, or wireless signals from one or more other devices. Additionally, one or more transceivers (106, 206) may be coupled to one or more antennas (108, 208), and one or more transceivers (106, 206) may be configured to transmit and receive user data, control information, wireless signals / channels, or the like, as referred to in the descriptions, functions, procedures, proposals, methods, and / or operational flowcharts disclosed herein, via one or more antennas (108, 208). In this document, one or more antennas may be multiple physical antennas or multiple logical antennas (e.g., antenna ports). One or more transceivers (106, 206) can convert received user data, control information, wireless signals / channels, etc. from RF band signals to baseband signals in order to process the received user data, control information, wireless signals / channels, etc. using one or more processors (102, 202).One or more transceivers (106, 206) may convert user data, control information, wireless signals / channels, etc. processed by one or more processors (102, 202) from baseband signals to RF band signals. For this purpose, one or more transceivers (106, 206) may include an (analog) oscillator and / or filter.

[0365] Examples of wireless devices to which the present invention is applied

[0366] Figure 30 illustrates another example of a wireless device applicable to the present invention. The wireless device may be implemented in various forms depending on the use case / service.

[0367] Referring to FIG. 30, the wireless device (100, 200) corresponds to the wireless device (100, 200) of FIG. 29 and may be composed of various elements, components, units / units, and / or modules. For example, the wireless device (100, 200) may include a communication unit (110), a control unit (120), a memory unit (130), and additional elements (140). The communication unit may include a communication circuit (112) and a transceiver(s) (114). For example, the communication circuit (112) may include one or more processors (102, 202) and / or one or more memories (104, 204) of FIG. 30. For example, the transceiver(s) (114) may include one or more transceivers (106, 206) and / or one or more antennas (108, 208) of FIG. 29. The control unit (120) is electrically connected to the communication unit (110), the memory unit (130), and the additional elements (140) and controls the overall operation of the wireless device. For example, the control unit (120) may control the electrical / mechanical operation of the wireless device based on the program / code / command / information stored in the memory unit (130). In addition, the control unit (120) may transmit information stored in the memory unit (130) to an external device (e.g., another communication device) via a wireless / wired interface through the communication unit (110), or store information received from an external device (e.g., another communication device) via a wireless / wired interface in the memory unit (130).

[0368] The additional element (140) may be configured in various ways depending on the type of the wireless device. For example, the additional element (140) may include at least one of a power unit / battery, an input / output unit (I / O unit), a driving unit, and a computing unit. Although not limited thereto, the wireless device may be implemented in the form of a robot (Fig. 28, 100a), a vehicle (Fig. 28, 100b-1, 100b-2), an XR device (Fig. 28, 100c), a portable device (Fig. 28, 100d), a home appliance (Fig. 28, 100e), an IoT device (Fig. 28, 100f), a digital broadcasting terminal, a hologram device, a public safety device, an MTC device, a medical device, a fintech device (or a financial device), a security device, a climate / environmental device, an AI server / device (Fig. 28, 400), a base station (Fig. 28, 200), a network node, etc. Wireless devices may be mobile or stationary depending on the use / service.

[0369] In FIG. 30, various elements, components, units / parts, and / or modules within the wireless device (100, 200) may be entirely interconnected via a wired interface, or at least some may be wirelessly connected via a communication unit (110). For example, within the wireless device (100, 200), the control unit (120) and the communication unit (110) may be wired, and the control unit (120) and a first unit (e.g., 130, 140) may be wirelessly connected via the communication unit (110). In addition, each element, component, unit / part, and / or module within the wireless device (100, 200) may further include one or more elements. For example, the control unit (120) may be composed of a set of one or more processors. For example, the control unit (120) may be composed of a set of a communication control processor, an application processor, an electronic control unit (ECU), a graphics processing processor, a memory control processor, etc. As another example, the memory unit (130) may be composed of RAM (Random Access Memory), DRAM (Dynamic RAM), ROM (Read Only Memory), flash memory, volatile memory, non-volatile memory, and / or a combination thereof.

[0370] Here, the wireless communication technology implemented in the wireless device (XXX, YYY) of the present specification may include not only LTE, NR, and 6G, but also Narrowband Internet of Things for low-power communication. At this time, for example, NB-IoT technology may be an example of LPWAN (Low Power Wide Area Network) technology, and may be implemented with standards such as LTE Cat NB1 and / or LTE Cat NB2, and is not limited to the above-described names. Additionally or alternatively, the wireless communication technology implemented in the wireless device (XXX, YYY) of the present specification may perform communication based on LTE-M technology. At this time, for example, LTE-M technology may be an example of LPWAN technology, and may be called by various names such as eMTC (enhanced Machine Type Communication). For example, LTE-M technology can be implemented by at least one of various standards such as 1) LTE CAT 0, 2) LTE Cat M1, 3) LTE Cat M2, 4) LTE non-BL (non-Bandwidth Limited), 5) LTE-MTC, 6) LTE Machine Type Communication, and / or 7) LTE M, and is not limited to the above-described names. Additionally or alternatively, the wireless communication technology implemented in the wireless device (XXX, YYY) of the present specification can include at least one of ZigBee, Bluetooth, and Low Power Wide Area Network (LPWAN) considering low-power communication, and is not limited to the above-described names. For example, ZigBee technology can create PAN (personal area networks) related to small / low-power digital communication based on various standards such as IEEE 802.15.4, and can be called by various names.

[0371] The embodiments described above are combinations of components and features of the present invention in a predetermined form. Each component or feature should be considered optional unless explicitly stated otherwise. Each component or feature may be implemented without being combined with other components or features. Furthermore, it is also possible to form an embodiment of the present invention by combining some components and / or features. The order of operations described in the embodiments of the present invention may be changed. Some components or features of one embodiment may be included in another embodiment or may be replaced with corresponding components or features of another embodiment. It is self-evident that claims that do not have an explicit citation relationship in the patent claims may be combined to form an embodiment or may be incorporated as a new claim through a post-application amendment.

[0372] In this document, embodiments of the present invention have been described primarily focusing on the signal transmission and reception relationship between a terminal and a base station. This transmission and reception relationship is equally / similarly extended to signal transmission and reception between a terminal and a relay or a base station and a relay. Certain operations described as being performed by a base station in this document may, in some cases, be performed by its upper node. That is, it is obvious that various operations performed for communication with a terminal in a network composed of multiple network nodes including a base station may be performed by the base station or other network nodes other than the base station. The base station may be replaced by terms such as fixed station, Node B, eNode B (eNB), and access point. In addition, the terminal may be replaced by terms such as UE (User Equipment), MS (Mobile Station), MSS (Mobile Subscriber Station).

[0373] Embodiments of the present invention may be implemented by various means, for example, hardware, firmware, software, or a combination thereof. In the case of hardware implementation, an embodiment of the present invention may be implemented by one or more application specific integrated circuits (ASICs), digital signal processors (DSPs), digital signal processing devices (DSPDs), programmable logic devices (PLDs), field programmable gate arrays (FPGAs), processors, controllers, microcontrollers, microprocessors, etc.

[0374] When implemented via firmware or software, an embodiment of the present invention may be implemented in the form of modules, procedures, functions, etc. that perform the functions or operations described above. The software code may be stored in a memory unit and executed by a processor. The memory unit may be located within or outside the processor and may exchange data with the processor via various known means.

[0375] It will be apparent to those skilled in the art that the present invention can be embodied in other specific forms without departing from the scope of the invention. Therefore, the above detailed description should not be construed as limiting in any respect, but rather as illustrative. The scope of the present invention should be determined by a reasonable interpretation of the appended claims, and all modifications within the scope of equivalents of the present invention are intended to be included within the scope of the present invention.

[0376] The embodiments of the present invention as described above can be applied to various mobile communication systems.

Claims

1. In the method by UE (User equipment), A step of receiving configuration information including information on an OAM beam sequence and time interval for a plurality of OAM beams related to an OAM (Orbital Angular Momentum) beam-based operation from a base station; A step of determining a specific OAM beam among the plurality of OAM beams based on an SSB (Synchronization Signal Block) received from the base station; and A method comprising a step of transmitting or receiving a signal in a time resource corresponding to the specific OAM beam among time resources that are time division multiplexed (TDM) according to the OAM beam sequence within the time interval.

2. In paragraph 1, A method characterized in that the OAM beam sequence is set based on the proximity of a geographic area in which each of the plurality of OAM beams is received with an intensity greater than a specific threshold in a first geographic area, orbital information of a satellite associated with the base station, and distribution of UEs in the first geographic area.

3. In paragraph 1, A method characterized in that the above setting information is set to be cell and TAC (Tracking Area Code) specific.

4. In paragraph 1, A method characterized in that the above setting information is received in which capability information indicating support of the OAM beam-based operation is reported.

5. In paragraph 4 A method characterized in that the above capability information is reported based on the UE's ability to estimate an elevation angle with respect to the base station based on satellite orbit information related to the base station and its ability to receive OAM beams.

6. In paragraph 1, A method, characterized in that the OAM beam sequence is updated based on the distribution and density of UEs in a first geographic area corresponding to a specific Tracking Area Code (TAC).

7. In paragraph 1, A method characterized in that the UE does not report on CSI (channel state information) during the time period in which the OAM-based operation is performed.

8. In paragraph 1, The above time interval is set based on the epoch time associated with the base station, A method, characterized in that the length of the above time interval is set to be equal to the length of the valid time interval of the epoch time associated with the base station.

9. In paragraph 1, A method characterized in that the above setting information is activated or deactivated through RRC (Radio Resource Control) signaling or MAC-CE (Medium Access Control-Control Element).

10. In paragraph 1, A method, characterized in that the base station is a non-terrestrial network (NTN).

11. A non-transitory computer-readable storage medium recording commands for performing the method described in paragraph 1.

12. In UE (User equipment), RF (Radio Frequency) transmitter and receiver; and A processor connected to the RF transceiver, The processor controls the RF transceiver to receive configuration information including information on an OAM beam sequence and a time interval for a plurality of OAM beams related to an OAM (Orbital Angular Momentum) beam-based operation from a base station, determines a specific OAM beam among the plurality of OAM beams based on an SSB (Synchronization Signal Block) received from the base station, and transmits or receives a signal in a time resource corresponding to the specific OAM beam among time resources that are time division multiplexed (TDM) according to the OAM beam sequence within the time interval.

13. In a processing device that controls UE (User equipment), at least one processor; and At least one memory connected to said at least one processor and storing instructions, said instructions being executed by said at least one processor, wherein said UE: A processing device that receives configuration information including information on an OAM beam sequence and time interval for a plurality of OAM beams related to an OAM (Orbital Angular Momentum) beam-based operation from a base station, determines a specific OAM beam from among the plurality of OAM beams based on an SSB (Synchronization Signal Block) received from the base station, and transmits or receives a signal in a time resource corresponding to the specific OAM beam from among time resources that are time division multiplexed (TDM) according to the OAM beam sequence within the time interval.

14. In the method by the base station, A step of transmitting configuration information including information on an OAM beam sequence and time interval for a plurality of OAM beams related to an OAM (Orbital Angular Momentum) beam-based operation; and A method comprising a step of receiving or transmitting a signal using a corresponding OAM beam in each of time resources that are time division multiplexed (TDM) according to the OAM beam sequence within the time interval. 15.RF(Radio Frequency) transmitter and receiver; and A processor connected to the RF transceiver, A base station, wherein the processor controls the RF transceiver to transmit configuration information including information on an OAM beam sequence and a time interval for a plurality of OAM beams related to an OAM (Orbital Angular Momentum) beam-based operation, and receives or transmits a signal using a corresponding OAM beam in each of time resources that are time division multiplexed (TDM) according to the OAM beam sequence within the time interval.

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