Timing and frequency adjustment in non-terrestrial networks

Abstract

Apparatuses, methods, and systems are disclosed for timing and frequency adjustment in non-terrestrial networks. One apparatus (1200) includes a processor (1205) that determines (1405) a first frequency from one of a first reference signal received from a mobile wireless communication network and a configuration message received from the mobile wireless communication network. The processor (1205) determines (1410) a second frequency from a second reference signal received from the mobile wireless communication network. The processor (1205) calculates (1415) a second timing advance value based on a first timing advance value, the first determined frequency, and the second determined frequency, the first timing advance value received as part of a control message. The apparatus (1200) includes a transceiver (1225) that transmits (1420) an uplink signal to the mobile wireless communication network using the second timing advance value.

Description

[0001] Cross-reference of related applications

[0002] This application claims the benefit of U.S. Provisional Patent Application No. 63 / 078,797, filed September 15, 2020, by Majid Ghanbarinejad et al., entitled “TIMING AND FREQUENCYADJUSTMENTS IN NON-TERRESTRIAL NETWORKS,” which is incorporated herein by reference. Technical Field

[0003] The subject matter disclosed in this article generally relates to wireless communication, and more specifically, to timing and frequency adjustments in non-terrestrial networks. Background Technology

[0004] Non-terrestrial networks include components involving non-terrestrial flying objects. Therefore, signal timing and frequency adjustments may be required for efficient and effective communication. Summary of the Invention

[0005] Disclosed procedures for timing and frequency adjustment in non-terrestrial networks. These procedures may be implemented by devices, systems, methods, or computer program products.

[0006] In one embodiment, a device includes: a processor that determines a first frequency from one of a first reference signal received from a mobile wireless communication network and a configuration message received from the mobile wireless communication network. In one embodiment, the processor determines a second frequency from a second reference signal received from the mobile wireless communication network. In one embodiment, the processor calculates a second timing advance value based on a first timing advance value, the first determined frequency, and the second determined frequency, the first timing advance value being received as part of a control message. In one embodiment, the device includes: a transceiver that transmits an uplink signal to the mobile wireless communication network using the second timing advance value.

[0007] In one embodiment, another device includes: a transceiver that transmits one of a first reference signal and a configuration message to a user equipment (“UE”) device; transmits a second reference signal to the UE device; transmits a control message including a first timing advance value to the UE device; and receives an uplink signal transmitted using the second timing advance value from the UE device, the second timing advance value being determined based on: a first frequency determined from the first reference signal and the configuration message; a second frequency determined from the second reference signal; and the first timing advance value. Attached Figure Description

[0008] A more specific description of the embodiments briefly described above will be presented by referring to the specific embodiments illustrated in the accompanying drawings. While understanding that these illustrations depict only some embodiments and therefore should not be considered limiting, the embodiments will be described and explained in a more specific and detailed manner using the accompanying drawings, in which:

[0009] Figure 1A This is a schematic block diagram illustrating one embodiment of a wireless communication system for timing and frequency adjustment in a non-terrestrial network according to one or more embodiments of the present disclosure.

[0010] Figure 1B This is a schematic block diagram illustrating one embodiment of another wireless communication system for timing and frequency adjustment in a non-terrestrial network according to one or more embodiments of the present disclosure;

[0011] Figure 2 A diagram illustrating the accuracy of UE timing advance adjustments;

[0012] Figure 3 A diagram illustrating a table of timing error limits according to one or more embodiments of the present disclosure;

[0013] Figure 4 Depicting N according to one or more embodiments of this disclosure TA offset A graph of the table of values;

[0014] Figure 5 A diagram illustrating the TA component in an NTN according to one or more embodiments of the present disclosure (for simplicity, the TA offset N is not plotted). TA offset );

[0015] Figure 6A A diagram illustrating one embodiment of a scenario of an NTN based on a regenerable payload according to one or more embodiments of the present disclosure;

[0016] Figure 6B A diagram illustrating one embodiment of an NTN architecture based on a regenerable payload according to one or more embodiments of the present disclosure;

[0017] Figure 6C A diagram illustrating one embodiment of a user plane based on a regenerative payload NTN according to one or more embodiments of the present disclosure;

[0018] Figure 6D A diagram illustrating one embodiment of a control plane for an NTN based on a regenerative payload according to one or more embodiments of the present disclosure;

[0019] Figure 7AA diagram illustrating one embodiment of a scenario of NTN based on a transparent payload according to one or more embodiments of the present disclosure;

[0020] Figure 7B A diagram illustrating one embodiment of an NTN architecture based on a transparent payload according to one or more embodiments of the present disclosure;

[0021] Figure 7C A diagram illustrating one embodiment of a user plane based on a transparent payload NTN according to one or more embodiments of the present disclosure;

[0022] Figure 7D A diagram illustrating one embodiment of a control plane for an NTN based on a transparent payload according to one or more embodiments of the present disclosure;

[0023] Figure 8 A diagram illustrating one embodiment of a unified method for timing adjustment at NT-TRP and UE according to one or more embodiments of the present disclosure;

[0024] Figure 9 A diagram illustrating one embodiment of an NTN having a non-zero relative velocity between the NT-TRP and the UE, according to one or more embodiments of the present disclosure;

[0025] Figure 10 A diagram illustrating an example embodiment of updating TA values ​​based on time, according to one or more embodiments of the present disclosure;

[0026] Figure 11 A diagram illustrating an example embodiment of updating TA values ​​based on Doppler according to one or more embodiments of the present disclosure;

[0027] Figure 12 This is a block diagram illustrating an embodiment of a user equipment device that can be used for timing and frequency adjustment in non-terrestrial networks;

[0028] Figure 13 This is a block diagram illustrating an embodiment of network equipment that can be used for timing and frequency adjustment in non-terrestrial networks;

[0029] Figure 14 This is a block diagram illustrating an embodiment of a first method for timing and frequency adjustment in non-terrestrial networks; and

[0030] Figure 15 This is a block diagram illustrating an embodiment of a second method for timing and frequency adjustment in non-terrestrial networks. Detailed Implementation

[0031] As those skilled in the art will understand, aspects of the embodiments may be embodied as systems, devices, methods, or program products. Therefore, embodiments may take the form of entirely hardware embodiments, entirely software embodiments (including firmware, resident software, microcode, etc.), or embodiments combining software and hardware aspects.

[0032] For example, the disclosed embodiments can be implemented as hardware circuitry that includes custom-designed very large-scale integration (“VLSI”) circuitry or gate arrays, off-the-shelf semiconductors (e.g., logic chips, transistors, or other discrete components). The disclosed embodiments can also be implemented in programmable hardware devices (e.g., field-programmable gate arrays, programmable array logic, programmable logic devices, etc.). As another example, the disclosed embodiments may include one or more physical or logical blocks of executable code, which may, for example, be organized as objects, processes, or functions.

[0033] Furthermore, embodiments may take the form of a program product embodied in one or more computer-readable storage devices storing machine-readable code, computer-readable code, and / or program code (hereinafter referred to as code). The storage device may be tangible, non-transitory, and / or non-transferable. The storage device may not embody signals. In one embodiment, the storage device employs only signals for accessing the code.

[0034] Any combination of one or more computer-readable media may be used. The computer-readable media may be a computer-readable storage medium. The computer-readable storage medium may be a storage device for storing code. The storage device may be (e.g., but not limited to) an electronic, magnetic, optical, electromagnetic, infrared, holographic, micromechanical, or semiconductor system, device, or apparatus, or any suitable combination thereof.

[0035] More specific examples of storage devices (a non-exhaustive list) will include the following: electrical connections having one or more wires, portable computer disks, hard disks, random access memory (“RAM”), read-only memory (“ROM”), erasable programmable read-only memory (“EPROM” or flash memory), portable optical disc read-only memory (“CD-ROM”), optical storage devices, magnetic storage devices, or any suitable combination of the foregoing. In the context of this document, computer-readable storage media can be any tangible medium that can contain or store programs for use by or in connection with an instruction execution system, device, or apparatus.

[0036] The code used to implement the operations of the embodiments can be of any number of lines and can be written in any combination of one or more programming languages, including object-oriented programming languages ​​(such as Python, Ruby, Java, Smalltalk, C++, etc.), and conventional procedural programming languages ​​(such as the "C" programming language, etc.) and / or machine languages ​​(such as assembly language). The code can be entirely on the user's computer, partially on the user's computer, as a standalone software package, partially on the user's computer and partially on a remote computer, or entirely on a remote computer or server. In the latter case, the remote computer can be connected to the user's computer via any type of network (including local area network ("LAN"), wireless LAN ("WLAN"), or wide area network ("WAN"), or can be connected to an external computer (e.g., via the Internet through an Internet service provider ("ISP").

[0037] Furthermore, the features, structures, or characteristics described in the embodiments can be combined in any suitable manner. In the following description, numerous specific details (e.g., examples of programming, software modules, user selection, network transactions, database queries, database structures, hardware modules, hardware circuits, hardware chips, etc.) are provided to provide a thorough understanding of the embodiments. However, those skilled in the art will recognize that the embodiments can be practiced without one or more of these specific details or using other methods, components, materials, etc. In other instances, well-known structures, materials, or operations have not been shown or described in detail to avoid obscuring aspects of the embodiments.

[0038] Throughout this specification, references to "an embodiment," "an embodiment," or similar language mean that a particular feature, structure, or characteristic described in connection with an embodiment is included in at least one embodiment. Therefore, the phrases "in an embodiment," "in one embodiment," and similar language throughout this specification may (but not necessarily) refer to the same embodiment, but rather to "one or more, but not all, embodiments," unless explicitly stated otherwise. The terms "comprising," "including," "having," and variations thereof mean "comprising but not limited to," unless explicitly stated otherwise. An enumerated list of items does not imply that any or all items are mutually exclusive unless explicitly stated otherwise. The terms "a," "an," and "described" also mean "one or more," unless explicitly stated otherwise.

[0039] As used herein, a list containing the conjunction “and / or” includes any single item in the list or a combination of items in the list. For example, a list of A, B and / or C includes only A, only B, only C, a combination of A and B, a combination of B and C, a combination of A and C, or a combination of A, B and C. As used herein, a list using the term “one or more of…” includes any single item in the list or a combination of items in the list. For example, one or more of A, B and C includes only A, only B, only C, a combination of A and B, a combination of B and C, a combination of A and C, or a combination of A, B and C. As used herein, a list using the term “one of…” includes one and only one of any single item in the list. For example, “one of A, B and C” includes only A, only B, or only C, excluding combinations of A, B and C. As used herein, “selected as a member of the group consisting of A, B and C” includes one and only one of A, B, or C, excluding combinations of A, B and C. As used in this article, “selecting members of a group consisting of A, B, and C and their combinations” includes only A, only B, only C, combinations of A and B, combinations of B and C, combinations of A and C, or combinations of A, B, and C.

[0040] The following description refers to schematic flowcharts and / or schematic block diagrams of methods, apparatus, systems, and program products according to embodiments. It should be understood that each block of the schematic flowcharts and / or schematic block diagrams, and combinations of blocks in the schematic flowcharts and / or schematic block diagrams, can be implemented by code. This code can be provided to a processor of a general-purpose computer, special-purpose computer, or other programmable data processing apparatus to produce machinery, such that instructions executable by the processor of the computer or other programmable data processing apparatus create components for implementing the functions / actions specified in the flowcharts and / or block diagrams.

[0041] The code may also be stored in a storage device, which may instruct a computer, other programmable data processing equipment or other devices to function in a particular manner, such that the instructions stored in the storage device produce an article of writing containing instructions that implement the functions / actions specified in the flowchart and / or block diagram.

[0042] The code may also be loaded onto a computer, other programmable data processing apparatus or other device to cause a series of operational steps to be performed on the computer, other programmable apparatus or other device to produce a computer-implemented process, such that the code executing on the computer or other programmable device provides a process for implementing the functions / actions specified in the flowchart and / or block diagram.

[0043] The flowcharts and / or block diagrams in the figures illustrate the architecture, functionality, and operation of possible implementations of the device, system, method, and program products according to various embodiments. In this regard, each block in the flowcharts and / or block diagrams may represent a module, segment, or portion of code containing one or more executable instructions for implementing one or more specified logical functions.

[0044] It should also be noted that in some alternative implementations, the functions mentioned in the boxes may not appear in the order shown in the figures. For example, in fact, depending on the functionality involved, two boxes shown consecutively may be performed substantially simultaneously, or the boxes may sometimes be performed in reverse order. Other steps and methods that are functionally, logically, or effectively equivalent to one or more boxes or portions thereof in the illustrated figures are conceivable.

[0045] While various arrow and line types may be used in flowcharts and / or block diagrams, they are not intended to limit the scope of the corresponding embodiments. In fact, some arrows or other connecting symbols may be used only to indicate the logical flow of the depicted embodiment. For example, an arrow may indicate a wait or monitoring period of unspecified duration between enumeration steps in a depicted embodiment. It should also be noted that each block in a block diagram and / or flowchart, and combinations of blocks in block diagrams and / or flowcharts, may be implemented by a dedicated hardware-based system or a combination of dedicated hardware and code that performs the specified function or action.

[0046] In each figure, the description of an element may refer to an element in a previous figure. In all figures, the same numbers refer to the same elements, including alternative embodiments of the same elements.

[0047] Generally, this disclosure describes systems, methods, and apparatuses for timing and frequency adjustment in non-terrestrial networks. In some embodiments, computer code embedded in a computer-readable medium may be used to perform the methods. In some embodiments, the apparatus or system may include a computer-readable medium containing computer-readable code that, when executed by a processor, causes the apparatus or system to perform at least a portion of the solutions described below.

[0048] This disclosure proposes a unified framework for adjusting timing advance in non-terrestrial networks. The proposed method covers various scenarios, including systems with regenerative and transparent payloads, with or without equipment to signal position and velocity. Specifically, a method for adjusting and updating timing advance based on Doppler measurements of a reference signal is proposed and detailed.

[0049] In one embodiment, the subject matter disclosed herein describes a solution for timing advance (“TA”) and frequency adjustment in a non-terrestrial network (“NTN”). The unattended or satellite-borne communication entity providing the service link to the UE is referred to as a non-terrestrial transmit-receive point (“NT-TRP”). ​​It should be noted that the functionality and protocol stack implemented in the NT-TRP may differ in different scenarios, such as in systems based on transparent payloads to regenerated payloads. Communication from the UE to the NT-TRP may be referred to as an uplink, and communication from the NT-TRP to the UE may be referred to as a downlink.

[0050] Figure 1A A wireless communication system 100 supporting random access procedures in a non-terrestrial network is depicted according to embodiments of the present disclosure. In one embodiment, the wireless communication system 100 includes at least one remote unit 105, a radio access network (“RAN”) 120 (e.g., NG-RAN), and a mobile core network 140. The RAN 120 and the mobile core network 140 form a mobile communication network. The RAN 120 may consist of a base station unit 110, with the remote unit 105 communicating with the base station unit 110 using a wireless communication link 115. Even Figure 1A The system depicts a specific number of remote units 105, base station units 110, wireless communication links 115, RAN 120, satellites 130, non-terrestrial network gateways 125 (e.g., satellite ground / earth devices), and mobile core networks 140. However, those skilled in the art will recognize that the wireless communication system 100 may include any number of remote units 105, base station units 110, wireless communication links 115, RAN 120, satellites 130, non-terrestrial network gateways 125 (e.g., satellite ground / earth devices), and mobile core networks 140.

[0051] In one implementation, RAN 120 is compatible with the 5G system specified in the 3GPP specification. In another implementation, RAN 120 is compatible with the LTE system specified in the 3GPP specification. However, more generally, the wireless communication system 100 may implement another open or proprietary communication network, such as WiMAX and other networks. This disclosure is not intended to limit implementation to any particular wireless communication system architecture or protocol.

[0052] In one embodiment, remote unit 105 may include a computing device, such as a desktop computer, laptop computer, personal digital assistant (“PDA”), tablet computer, smartphone, smart TV (e.g., a TV connected to the Internet), smart appliance (e.g., an appliance connected to the Internet), set-top box, game console, security system (including security cameras), in-vehicle computer, network device (e.g., router, switch, modem), etc. In some embodiments, remote unit 105 includes a wearable device, such as a smartwatch, fitness tracker, optical head-mounted display, etc. Furthermore, remote unit 105 may be referred to as UE, subscriber unit, mobile device, mobile station, user, terminal, mobile terminal, fixed terminal, subscriber station, user terminal, wireless transmit / receive unit (“WTRU”), apparatus, or other terms used in this technology.

[0053] Remote unit 105 can communicate directly with base station unit 110 in RAN 120 via uplink (“UL”) and downlink (“DL”) communication signals. In some embodiments, remote unit 105 communicates in a non-terrestrial network via UL and DL communication signals between remote unit 105 and satellite 130. Satellite 130 can communicate with RAN 120 via NTN gateway 125 using UL and DL communication signals between satellite 130 and NTN gateway 125. NTN gateway 125 can communicate directly with base station unit 110 in RAN 120 via UL and DL communication signals. Furthermore, UL and DL communication signals can be carried via wireless communication link 115. Here, RAN 120 is an intermediate network providing remote unit 105 with access to mobile core network 140.

[0054] In some embodiments, remote unit 105 communicates with application server 151 via a network connection to mobile core network 140. For example, application 107 in remote unit 105 (e.g., a web browser, media client, telephone / VoIP application) can trigger remote unit 105 to establish a PDU session (or other data connection) with mobile core network 140 via RAN 120. Mobile core network 140 then uses the PDU session to relay services between remote unit 105 and application server 151 in packet data network 150. Note that remote unit 105 may establish one or more PDU sessions (or other data connections) with mobile core network 140. Thus, remote unit 105 may simultaneously have at least one PDU session for communicating with packet data network 150 and at least one PDU session for communicating with another data network (not shown).

[0055] Base station unit 110 may be distributed across a geographical area. In some embodiments, base station unit 110 may also be referred to as an access terminal, access point, base station, Node-B, eNB, gNB, Home Node-B, relay node, RAN node, or any other term used in this art. Base station unit 110 typically comprises a portion of a radio access network (“RAN”) (e.g., RAN 120) communicatively coupled to one or more controllers corresponding to one or more base station units 110. These and other elements of the radio access network are not described but are generally well known to those skilled in the art. Base station unit 110 is connected to mobile core network 140 via RAN 120.

[0056] Base station unit 110 can serve several remote units 105 within a service area (e.g., a cell or cell sector) via wireless communication link 115. Base station unit 110 can communicate directly with one or more of the remote units 105 via communication signals. Typically, base station unit 110 transmits DL communication signals to serve the remote units 105 in the time, frequency, and / or spatial domains. Furthermore, DL communication signals can be carried via wireless communication link 115. Wireless communication link 115 can be any suitable carrier in licensed or unlicensed radio spectrum. Wireless communication link 115 facilitates communication between one or more of the remote units 105 and / or one or more of the base station unit 110. Note that during NR-U operation, base station unit 110 communicates with remote units 105 via unlicensed radio spectrum.

[0057] In one embodiment, the mobile core network 140 is a 5G core (“5GC”) or an evolved packet core (“EPC”) that may be coupled to a packet data network 150, such as the Internet, private data networks, and other data networks. The remote unit 105 may have a subscription or other account to the mobile core network 140. Each mobile core network 140 belongs to a single Public Land Mobile Network (“PLMN”). This disclosure is not intended to limit implementation to any particular wireless communication system architecture or protocol.

[0058] The mobile core network 140 includes several network functions (“NFs”). As depicted, the mobile core network 140 includes multiple user plane functions (“UPFs”) 141. The mobile core network 140 also includes multiple control plane functions, including (but not limited to) access and mobility management functions (“AMFs”) 143, session management functions (“SMFs”) 145, policy control functions (“PCFs”) 147, and unified data management functions (“UDMs”) 149 serving RAN 120.

[0059] In various embodiments, the mobile core network 140 supports different types of mobile data connections and different types of network slices, wherein each mobile data connection utilizes a specific network slice. Here, a "network slice" refers to a portion of the mobile core network 140 optimized for a specific type of service or communication service. Network examples may be identified by S-NSSAI, while a set of network slices authorized for use by the remote unit 105 is identified by NSSAI. In some embodiments, various network slices may contain individual examples of network functions, such as SMF 145 and UPF 141. In some embodiments, different network slices may share some common network functions, such as AMF 143. For ease of illustration, Figure 1A Different network slices are not shown, but their support is assumed.

[0060] although Figure 1A While a specific number and type of network functions are depicted, those skilled in the art will recognize that the mobile core network 140 may contain any number and type of network functions. Furthermore, in the case where the mobile core network 140 is an EPC, the depicted network functions can be replaced by appropriate EPC entities (e.g., MME, S-GW, P-GW, HSS, etc.). In some embodiments, the mobile core network 140 may include an AAA server.

[0061] Although Figure 1A This description depicts components of a 5G RAN and 5G core network, but the described embodiments are applicable to other types of communication networks and RATs, including IEEE 802.11 variants, GSM, GPRS, UMTS, LTE variants, CDMA2000, Bluetooth, ZigBee, Sigfoxx, etc. For example, in an LTE variant involving EPC, the AMF may be mapped to the MME, the SMF to the control plane portion of the PGW and / or to the MME, the UPF to the SGW and the user plane portion of the PGW, and the UDM / UDR to the HSS, etc.

[0062] In the following description, the term "gNB" is used for a base station, but it can be replaced by any other radio access node (e.g., RAN node, eNB, BS, gNB, AP, NR, etc.). Furthermore, the operation is primarily described in the context of 5G NR. However, the proposed solution / method is equally applicable to other mobile communication systems that support timing and frequency adjustments in non-terrestrial networks.

[0063] Figure 1B Another wireless communication system 175 supporting random access procedures in non-terrestrial networks is depicted according to embodiments of the present disclosure. In one embodiment, Figure 1B Generally similar to Figure 1A The non-terrestrial network 100 is depicted in the image. Figure 1BIn this embodiment, remote unit 105 communicates directly with base station unit 110 in RAN 120 via uplink (“UL”) and downlink (“DL”) communication signals on wireless communication link 115. In a non-terrestrial network embodiment, RAN 120 may communicate with mobile core network 140 via NTN gateway 125, which may be directly connected to RAN 120 communicating with satellite 130. In other embodiments, satellite 130 communicates with another NTN gateway 125 directly connected to mobile core network 140.

[0064] In one embodiment, some or all of the base station functionality can be performed on satellite 130 or other NT-TRPs. This embodiment, which may be referred to as "regenerative payload," is a primary use case for the Doppler-based method described below.

[0065] In some embodiments, the timing relationships and uplink timing requirements of the NTN are enhanced to account for long propagation delays and mobile cells within the NTN. For example, an idle or onboard NT-TRP provides connectivity between a user equipment (“UE”) via a “serving link” and a network via a “feeder link” through a gateway. Propagation delays in the serving link are typically much greater than those in access links in terrestrial cellular systems. Furthermore, in addition to the case of NT-TRPs on geostationary satellites, cells are potentially mobile, possibly at high speeds in the case of low Earth orbit (“LEO”) satellites, requiring continuous adjustments to the uplink timing relative to the downlink. Moreover, the variations in different beams are different because each beam is at a different angle to the ground station (UE), resulting in different ephemeris projections. In one embodiment, these all require enhancements to the specification of uplink timing adjustments, and further enhancements may allow the system to optimize timing adjustments by predicting NT-TRP movement and future ephemeris.

[0066] Regarding transmission timing adjustment, the n-TimingAdvanceOffset of the serving cell can provide the UE with the timing advance offset value N of the serving cell. TA,offset If the n-TimingAdvanceOffset of the serving cell is not provided to the UE, then the UE determines the default value N for the timing advance offset of the serving cell. TA,offset .

[0067] If the UE is configured to use two UL carriers for a serving cell, then the same timing offset value N TA,offset Applicable to two carriers.

[0068] After receiving a timing advance command for a timing advance group (“TAG”), the UE bases its decision on a value N that the UE expects to be the same for all serving cells in the TAG. TA,offsetFurthermore, the uplink timing of the Physical Uplink Shared Channel (“PUSCH”) / Sound Reference Signal (“SRS”) / Physical Uplink Control Channel (“PUCCH”) transmission on all serving cells in the TAG is adjusted based on the received timing advance command, wherein the uplink timing for PUSCH / SRS / PUCCH transmission is the same for all serving cells in the TAG.

[0069] For frequency bands with synchronous continuous EN-DC within a frequency band combination that has an inapplicable maximum transmission timing difference requirement, such as as described in Note 1 of Table 7.5.3-1 in TS 38.133, if the UE indicates ul-TimingAlignmentEUTRA-NR as "required" and the uplink transmission timing based on timing adjustment indications from the TAGs of the MCG and SCG is determined by the UE to be different, then the UE adjusts the transmission timing of PUSCH / SRS / PUCCH transmissions on all serving cell portions of the frequency band with synchronous continuous EN-DC based on the timing adjustment indications from the TAGs of the serving cells in the MCG within the frequency band. When PUSCH / SRS / PUCCH overlaps (or even partially overlaps) with a random access preamble transmitted in another CG in time, it is not expected that the UE will transmit PUSCH / SRS / PUCCH in one CG.

[0070] Regarding 2 μ • 15kHz SCS, used for the timing advance command of TAG, indicates that the uplink timing is 16.64T relative to the current uplink timing of TAG. c / 2 μ The change in multiples.

[0071] In the case of random access response, the timing advance command T of TAG A Through T A The index value = 0, 1, 2, ..., 3846 indicates N. TA Values, of which have 2 μ The amount of time alignment for the TAG of the 15kHz SCS is N. TA =T A ·16·64 / 2 μ In one instance, N TA It can be defined in TS 38.211 and relates to the SCS transmitted from the UE on the first uplink after receiving the random access response.

[0072] In other cases, the timing advance command T used for TAG A Indicates the current N TA Value N TA_old By index value T A=0,1,2,...,63 to the new N TA Value N TA_new The adjustments, including those for 2 μ ·15kHz SCS, N TA_new =N TA_old +(T A -31)·16·64 / 2 μ .

[0073] If a UE has multiple valid UL bandwidth portions (“BWPs”) in the same TAG, encompassing the UL BWPs in two UL carriers of the serving cell, then the timing advance command value is the maximum SCS relative to the multiple valid UL BWPs. The applicable N for UL BWPs with lower SCS... TA_new The value can be rounded to align with the timing advance granularity of the UL BWP with a lower SCS, while meeting the timing advance accuracy requirements.

[0074] According to positive or negative values, N TA The adjustment of the value indicates whether the uplink transmission timing used for TAG will be advanced or delayed by the corresponding amount.

[0075] For timing advance commands received on uplink time slot n, and for transmissions other than PUSCHs authorized by the Random Access Response (“RAR”) UL or PUCCHs with HARQ-ACK information in response to a successful RAR, the corresponding adjustments to the uplink transmission timing are applied starting from the beginning of uplink time slot n+k+1. N T,1 It is the duration in msec of N1 symbols corresponding to the Physical Downlink Shared Channel (“PDSCH”) processing time of UE Processing Capability 1 when additional PDSCH DM-RS is configured, where N... T,2 It is the duration in msec of N2 symbols corresponding to the PDSCH preparation time of UE processing capability 1, where N... TA,max It is the maximum timing advance value in msec that can be provided by the 12-bit TA command field. It is the number of time slots per subframe, and T sf This is the subframe duration of 1 ms. N1 and N2 are determined by the minimum SCS among all configured UL BWPs for all uplink carriers and all configured DL BWPs for the corresponding downlink carriers in the TAG. For μ = 0, the UE assumes N 1,0 =14. Time slot n and It is determined relative to the minimum SCS among all configured ULBWPs of all uplink carriers in the TAG. N TA,maxIt is determined by the minimum SCS among all configured UL BWPs relative to all uplink carriers in the TAG and all configured initial UL BWPs provided by the initialUplinkBWP. Assume T TA =0, uplink time slot n is the last time slot in the uplink time slots that overlaps with the time slot received by PDSCH, where PDSCH provides timing advance commands and T TA It is predefined, for example, as in TS 38.211.

[0076] If the UE changes the effective UL BWP between the time the timing advance command is received and the time the corresponding adjustment is applied to the uplink transmission timing, the UE determines the timing advance command value based on the SCS of the new effective UL BWP. If the UE changes the effective UL BWP after the adjustment is applied to the uplink transmission timing, the UE assumes the same absolute timing advance command value before and after the effective UL BWP change.

[0077] If a downlink timing change is received without a timing advance command and is not compensated or only partially compensated through uplink timing adjustment, then the UE will therefore change N. TA .

[0078] If two adjacent time slots overlap due to a TA command, the duration of the latter time slot is reduced relative to the former time slot.

[0079] Regarding timing advance adjustments, in EN-DC, NR-DC, NE-DC, and NR SA operating modes, timing advance from the gNB to the UE is initiated using a MAC message that implicitly includes timing advance adjustments (e.g., as defined in Clause 5.2 of TS 38.321). In one embodiment, the UE adjusts its uplink transmission timing at time slot n+k+1 in response to a timing advance command received in time slot n, where the value of k is predefined, for example, as in Clause 4.2 of TS 38.213. The same requirement also applies when the UE is unable to transmit configured uplink transmissions due to channel evaluation procedures.

[0080] Regarding the accuracy of timing advance adjustment, compared with the timing of previous uplink transmissions, the UE should, for example... Figure 2 Table 200 shows that the UE timing advance adjustment accuracy requirement is better or the same relative accuracy to adjust the timing of its transmission to the timing advance value of the signal notification.

[0081] Regarding UE transmission timing, in one embodiment, the UE should have the ability to follow the frame timing changes of a reference cell in a connected state. In one embodiment, uplink frame transmission occurs (N) before the first detected path (in terms of time) of receiving the corresponding downlink frame from the reference cell. TA +N TA offset )×T c In one embodiment, for a serving cell in the PTAG, the UE should use SpCell as a reference cell to derive the UE transmission timing for the cell in the PTAG. In one embodiment, for a serving cell in the STAG, the UE should use any of the activated SCells as a reference cell to derive the UE transmission timing for the cell in the STAG. In one embodiment, the UE initial transmission timing accuracy, progressive timing adjustment requirements, and one-time timing adjustment requirements are defined in the following requirements:

[0082] • In one embodiment, the initial transmission timing error of the UE should be less than or equal to ±T e The timing error limit value T e exist Figure 3 As specified in Table 300. This requirement applies when it is the first transmission in a DRX cycle of PUCCH, PUSCH, and SRS, or when it is a Physical Random Access Channel (“PRACH”) transmission.

[0083] • In one embodiment, the UE should satisfy the initial transmission Te requirement, provided that at least one SSB is available at the UE during the last 160ms. In one embodiment, the reference point for the UE's initial transmission timing control requirement should be the downlink timing of the reference cell minus (N TA +N TA offset )×T c In one embodiment, downlink timing is defined as the time (in terms of time) at which the first detected path is received from the reference cell for the corresponding downlink frame. N of PRACH TA It is defined as 0.

[0084] • In one embodiment, the other channels (N) TA +N TA offset )×T c (with T) c (in units) represents the difference between the UE transmission timing and the downlink timing immediately following the advance of the application's final timing. In one embodiment, N for other channels TA No change until the next timing advance is received. In one embodiment, N TA offset The value depends on the duplex mode and frequency range (FR) of the cell where uplink transmission occurs. TA offset exist Figure 4 Defined in Table 400.

[0085] • In one embodiment, when it is not the first transmission in a DRX cycle or there is no DRX cycle, and when it is a transmission of PUCCH, PUSCH and SRS transmissions, the UE should be able to change the transmission timing based on the downlink frames received by the reference cell, except when applying timing advance.

[0086] Regarding uplink timing advance / RACH procedures, the following aspects are generally applicable:

[0087] • DL synchronization via SSB

[0088] Random access via PRACH

[0089] • UL timing advance and frequency synchronization maintenance

[0090] In one embodiment, the evaluation and analysis take into account the characteristics of satellite communication systems, such as potentially large cell coverage and high Doppler. The impact of typical implementations in existing satellite systems is also considered, such as partial frequency pre-compensation for DL ​​and timing post-compensation at the satellite network side. Based on the corresponding results, solutions, conclusions, and some observations are presented below.

[0091] In one embodiment, a performance evaluation of DL synchronization performance is performed regarding DL synchronization via SSB. It has been observed that, for initial DL synchronization, robust performance can be provided by the SSB design in version 15, specifically in the cases of GEO and LEO with common frequency shifts relative to the point beam center at the network side, for example, the presence of beam-specific pre-compensation.

[0092] However, for LEO without pre-compensation for frequency offset, additional complexity may be required at the UE receiver to achieve robust DL initial synchronization performance based on SSB version 15. Further enhancements to the SSB may not be necessary.

[0093] In one embodiment, regarding random access, it has been observed that, assuming pre-compensation for timing and frequency offsets of UL transmissions at the UE side (e.g., if the UE has the necessary level of accuracy to know the UE's geographic location), the existing version 15 PRACH format and preamble sequence can be reused.

[0094] However, in one embodiment, if timing and frequency offset pre-compensation is not performed on the UE side for UL transmission, then the following options can be used to support enhanced PRACH format and / or preamble sequence:

[0095] Option-1: A single Zadoff-Chu sequence based on a larger SCS and a higher number of repeats. Further use of CP and NCS may be determined in normative work.

[0096] Option-2: A solution based on multiple Zadoff-Chu sequences with different roots.

[0097] Option-3: Gold / m sequence as a preamble sequence with additional processes (such as modulation and transform precoding).

[0098] Option-4: A single Zadoff-Chu sequence with a combination of scrambled sequences.

[0099] Regarding the maintenance of UL timing advance and frequency synchronization, taking into account the large cell coverage, long round-trip time (“RTT”) and high Doppler, in one embodiment, enhancements are considered to ensure the performance of timing and frequency synchronization for UL transmission.

[0100] For timing advance (TA) during initial access and subsequent TA maintenance, in one embodiment, the following solution uses... Figure 5 Identify the terms by referring to the definitions provided in the document:

[0101] Option 1: Obtain the TA autonomously at the UE, where the UE's known location and satellite ephemeris are:

[0102] In this way, the required TA value for UL transmissions including PRACH can be calculated by the UE. Corresponding adjustments can be made using UE-specific differential TA or full TA (composed of UE-specific differential TA and common TA).

[0103] Full TA compensation at the UE side enables alignment of the UL timing within the UE and the timing of both the DL and UL frames at the network side. However, in the case of satellites with transparent payloads, further discussion on how to handle the effects introduced by the feeder link will be addressed in the normative work. If the effects introduced by the feeder link are not compensated for by the UE in the corresponding compensation, then additional network management of the timing offset between the DL and UL frames may be required.

[0104] Regarding UE-specific differential timing only, in one embodiment, an additional indication on a single reference point should be signaled to the UE per beam / cell to achieve UL timing alignment among UEs within the coverage area of ​​the same beam / cell. Timing offset between DL and UL frame timings at the network side should also be managed by the network, regardless of the satellite payload type.

[0105] Focusing on the accuracy of the self-calculated TA value at the UE side, in one embodiment, additional TA signaling from the network to the UE is refined for TA, for example during initial access and / or TA maintenance, which can be determined in the normative work.

[0106] Option 2: Timing advance adjustment based on network indications:

[0107] In one embodiment, the common TA refers to the common component of the propagation delay shared by all UEs within the coverage area of ​​the same satellite beam / cell, which is broadcast by the network per satellite beam / cell. In one embodiment, the calculation of this common TA is performed by the network assuming at least one single reference point per satellite beam / cell.

[0108] In one embodiment, the UE-specific differential TA from the network is also required as an indication of the version 15 TA mechanism. To accommodate greater NTN coverage, in one embodiment, an extension of the value range of the TA indication in the RAR is explicitly or implicitly identified. In one embodiment, whether negative TA values ​​are supported in the corresponding indication will be determined during the specification phase.

[0109] Furthermore, in one embodiment, indication of the timing drift rate from the network to the UE is also supported to enable TA adjustment at the UE side. To calculate the common TA for either of the two options described above, in one embodiment, a single reference point for each beam is considered as the baseline.

[0110] For UL frequency compensation, in one embodiment, at least for LEO systems, the following solutions are identified, taking into account beam-specific post-compensation for common frequency offset at the network side:

[0111] Option-1: Both the estimation and pre-compensation of the UE-specific frequency offset are performed at the UE side. This value can be obtained using the DL reference signal, UE location, and satellite ephemeris.

[0112] Option-2: The required frequency offset for UL frequency compensation, at least in LEO systems, is indicated by the network to the UE. This value can be obtained at the network side if a UL signal (e.g., a preamble) is detected.

[0113] In one embodiment, if frequency offset compensation is performed by the network in the uplink and / or downlink respectively, then it is also supported for the network to indicate the compensated frequency offset value. However, in one embodiment, the indication of the Doppler drift rate is unnecessary.

[0114] In one embodiment, a solution is proposed for timing advance (TA) adjustments in the NTN. In one embodiment, the unattended or satellite-borne communication entity providing the service link to the UE is referred to as the non-terrestrial transmit-receive point (NT-TRP). It should be noted that the functionality and protocol stack implemented in the NT-TRP may differ in different scenarios, such as in systems based on transparent payloads to regenerated payloads. In one embodiment, communication from the UE to the NT-TRP is referred to as the uplink, and communication from the NT-TRP to the UE is referred to as the downlink.

[0115] Figure 6A This describes an embodiment of an NTN system based on regenerative payload. Figure 6B Describe the corresponding architecture of the NTN system based on regenerative payload, and Figure 6C and 6D This section describes the corresponding user plane and control plane of an NTN system based on regenerative payloads.

[0116] Figure 7A This describes an embodiment of an NTN system based on transparent payload. Figure 7B Describe the corresponding architecture of the NTN system based on regenerative payload, and Figure 7C and 7D This section describes the corresponding user plane and control plane of an NTN system based on regenerative payloads.

[0117] In a transparent payload scenario, in one embodiment, an unloaded or satellite transceiver relays communication between the UE and the gateway without handling the payload. Therefore, in one embodiment, TA signaling is generated by the gNB connected to the gateway, and the propagation delay of the feeder link should be taken into account.

[0118] In addition, in one embodiment, the scenario can be divided based on whether the NT-TRP's ephemeris (position and velocity information) is available and whether the UE is equipped with a Global Navigation Satellite System (“GNSS”) receiver (e.g., a Global Positioning System (“GPS”) receiver).

[0119] In one embodiment, a first method is proposed for a scenario with a regenerable payload and ephemeris / GNSS information:

[0120] 1. NT-TRP transmits SS / PBCH blocks

[0121] 2. NT-TRP broadcasts ephemeris information G in SIB. NW

[0122] 3. The UE obtains its own location information G from GNSS. UE

[0123] 4. UE based on G NWand G UE Calculate TA1

[0124] 5. The UE transmits the RACH preamble when applying TA1.

[0125] 6. NT-TRP transmission of RAR files containing TA2

[0126] 7. UE transmits UL when applying TA1+TA2

[0127] 8. NT-TRP transmits TA commands containing TA3.

[0128] 9. The UE then applies TA3 immediately following TA1+TA2.

[0129] The above method includes actions for both the NT-TRP and the UE. In one embodiment, during the communication step of this method (and other methods in this disclosure), the UE can receive a signal when the NT-TRP transmits a signal, and vice versa.

[0130] Further details regarding the above method are provided below. The terms satellite and NT-TRP are used interchangeably in this disclosure. However, it should be noted that the scope of the method is not limited to satellite systems, and similar methods can be applied to other types of non-terrestrial communication entities.

[0131] In step 1, in one embodiment, the NT-TRP transmits one or more SS / PBCH blocks. In one embodiment, the UE can receive SS / PBCH blocks and perform synchronization, obtain system information, etc.

[0132] In step 2, in one embodiment, the NT-TRP broadcasts satellite ephemeris information (GNW) in a System Information Block (“SIB”), for example. In one embodiment, the satellite ephemeris information (GNW) includes the satellite’s 3D position and velocity. Alternatively, the ephemeris may contain only 3D position information and not velocity information.

[0133] In one embodiment, an alternative example of transmitting satellite position and / or velocity is by NT-TRP or satellite transmission timestamps. An example of a timestamp is the parameter ReferenceTimeInfo-r16 as specified in NR Release 16. To allow for a uniform framework, in one embodiment, it is assumed that the GNW includes timestamps to implement this alternative. However, depending on the specification or implementation, the configuration or parameter including timestamps may differ from the configuration or parameter including satellite ephemeris. In any case, in one embodiment, the symbol GNW is used to identify a configuration or parameter that may include position, velocity, timestamps, or any other information from which ephemeris and / or timestamps associated with NT-TRP, service links, etc., may be obtained, or at least all of these.

[0134] In step 3, in one embodiment, the UE may obtain its own location information GUE, for example, via GNSS. In one embodiment, an alternative example of obtaining location information is obtaining a reference time. Similar to the explanation of GNW above, in one embodiment, the symbol GUE is used to indicate any or at least one or all of location, velocity, reference time, or any other information about the location, velocity, or reference time associated with the UE that can be obtained therefrom.

[0135] In step 4, in one embodiment, the UE calculates a timing advance value TA1 based on the locations (e.g., 3D coordinates) of the TRP and LTRP, and the locations (e.g., 3D coordinates) of the UE and LUE. For example, if the GNW and GUE respectively include the NT-TRP ephemeris / location, PTRP (e.g., 3D coordinates), and UE location, PUE (e.g., 3D coordinates), TA1 can be calculated by calculating the propagation delay associated with the distance |PUE-PTRP| between the NT-TRP and the UE. Alternatively, in one embodiment, if the GNW and GUE respectively include the time, timestamp, or reference time associated with the TRP and TTRP, and the UE time or reference time TUE associated with the reception time of the signal transmitted at the TTRP, then TA1 can be calculated by calculating the time difference |TUE-TTRP|.

[0136] In one embodiment, the UE may additionally calculate the change in TA value over time, which may be referred to as the TA drift rate. In one embodiment, the TA drift rate may be calculated using different methods. If the UE obtains the satellite's rate VTRP and / or its own velocity VUE, then in one embodiment, the UE may calculate the TA drift rate associated with the relative velocity |VUE-VTRP|. In the special case where the UE is not moving (e.g., the UE receiver antenna is a very small aperture terminal (“VSAT”) antenna), the UE cannot obtain its own velocity information, or additionally, the UE velocity is very small compared to the NT-TRP velocity, and it may be assumed that VUE is calculated as zero for the TA drift rate.

[0137] Alternatively, in one embodiment, if the satellite ephemeris includes the satellite's 3D position but not velocity information, the UE can obtain the TA drift rate by calculating the difference within a series of position values ​​associated with the NT-TRP. As another alternative, in one embodiment, if the UE obtains updated timestamp information from the NT-TRP and / or updated reference time information from the UE GNSS, the TA drift rate can be calculated based on consecutive values ​​of the NT-TRP timestamp and the UE reference time. As yet another alternative, in one embodiment, the UE obtains the TA drift rate via separate signaling.

[0138] Furthermore, in one embodiment, a method for updating the TA value based on Doppler measurements is proposed in the next section.

[0139] In one embodiment, step 4 can be implemented through an implementation scheme and / or configuration. This will be explained under the unified configuration section below.

[0140] In step 5, in one embodiment, the UE transmits the RACH preamble on the PRACH when applying the calculated TA1. In one embodiment, the UE obtains the PRACH information from system information, and the PRACH transmission may be associated with the synchronization signal (“SS”) / physical broadcast channel (“PBCH”) (or periodic CSI-RS) received in step 1.

[0141] In step 6, in one embodiment, once the NT-TRP receives the RACH preamble, it transmits a RAR message. The RAR message may contain information about a new timing advance value (e.g., timing advance adjustment) TA2.

[0142] In step 7, in one embodiment, the UE applies TA2 to transmit an uplink message, such as Msg3. In step 8, which can be performed frequently, in one embodiment, the NT-TRP transmits a TA command including a new timing advance value (TA3). Different options may be possible for this step. In embodiment 1, TA3 does not include the TA drift rate or does not take TA drift into account. In embodiment 2, TA3 includes the TA drift rate or takes TA drift into account.

[0143] In step 9, in one embodiment, after receiving the TA command, the UE calculates the new timing advance value as follows:

[0144] • For Example 1: TAnew := TAold+TA3+TAdrift, where TAdrift is obtained in step 8.

[0145] • For Example 2: TAnew: = TAold + TA3.

[0146] In some instances, if a downlink timing change is received without a timing advance command and is not compensated or only partially compensated by uplink timing adjustments, the UE will therefore change the timing advance value. Further details regarding the unified approach are provided below.

[0147] In one embodiment, a method is proposed for a scenario with a regenerable payload but no ephemeris / GNSS information:

[0148] 1. NT-TRP transmits SS / PBCH blocks

[0149] 2. NT-TRP broadcasts TA in SIB ref

[0150] 3. UE in application TA1:=TA ref Transmit RACH preamble

[0151] 4. NT-TRP transmission of RAR files containing TA2

[0152] 5. UE transmits UL when applying TA1+TA2

[0153] 6. NT-TRP transmits TA commands containing TA3.

[0154] 7. The UE then applies TA3 immediately following TA1+TA2.

[0155] In step 1, in one embodiment, the NT-TRP transmits one or more SS / PBCH blocks. The UE can receive the SS / PBCH blocks and perform synchronization, obtain system information, etc.

[0156] In step 2, in one embodiment, the NT-TRP broadcasts a reference timing advance TAref, for example, in the System Information Block (“SIB”). The reference TA may take into account variations in TA caused by propagation delays from satellite to ground and delays in applying the reference TA.

[0157] In step 3, in one embodiment, the UE transmits a RACH preamble on the PRACH when the application timing advance TA1:=TAref. In one embodiment, the UE obtains the PRACH information from system information, and the PRACH transmission may be associated with the SS / PBCH (or periodic CSI-RS) received in step 1.

[0158] In one embodiment, once the NT-TRP receives the RACH preamble, it transmits a RAR message in step 4. The RAR message may contain information about a new timing advance value (e.g., timing advance adjustment) TA2. The value of TA2 can vary significantly for different UEs because the delay calculated for propagation from satellite to ground corresponds to a reference point on the ground, while UEs are expected to be spatially dispersed.

[0159] In step 5, in one embodiment, the UE applies TA2 to transmit uplink messages, such as Msg3. In step 6, which is frequently performed, in one embodiment, the NT-TRP transmits a TA command including a new timing advance value (TA3). Different options are possible for this step. In some embodiments (Embodiment 1), TA3 does not include the TA drift rate or does not take TA drift into account. In embodiment 1a, the NT-TRP transmits control messages, such as MAC CE messages containing only the TAdrift value. In embodiment 1b, the NT-TRP transmits control messages, such as MAC CE messages containing a TAdrift value that varies according to the Doppler shift. The Doppler shift may be associated with one or more SS / PBCH blocks. In other embodiments (Embodiment 2), TA3 includes the TA drift rate or takes TA drift into account.

[0160] In step 7, in one embodiment, after receiving the TA command, the UE calculates the new timing advance value as follows:

[0161] • For Example 1: TAnew := TAold+TA3+TAdrift, where TAdrift is obtained in step 6.

[0162] • For Example 2: TAnew: = TAold + TA3.

[0163] In some instances, if a downlink timing change is received without a timing advance command and is not compensated or only partially compensated by uplink timing adjustments, the UE will therefore change the timing advance value. Further details regarding the unified approach are discussed below.

[0164] In one embodiment, a method is discussed for a scenario with a transparent payload and ephemeris / GNSS information.

[0165] 1. NT-TRP transmits SS / PBCH blocks

[0166] 2. NT-TRP broadcasts the ephemeris G of NT-TRP (and GW) in the SIB. NW

[0167] 3. The UE obtains its own location information G from GNSS. UE

[0168] 4. UE based on G NW and G UE Calculate TA1

[0169] 5. The UE transmits the RACH preamble when applying TA1.

[0170] 6. NT-TRP transmission of RAR files containing TA2

[0171] 7. UE transmits UL when applying TA1+TA2

[0172] 8. NT-TRP transmits TA commands containing TA3.

[0173] 9. The UE then applies TA3 immediately following TA1+TA2.

[0174] In step 1, in one embodiment, the NT-TRP transmits one or more SS / PBCH blocks. The UE can receive the SS / PBCH blocks and perform synchronization, obtain system information, etc.

[0175] In step 2, in one embodiment, the NT-TRP broadcasts satellite ephemeris information (GNW) in a System Information Block (“SIB”), for example. In one embodiment, the satellite ephemeris information (GNW) includes the satellite’s 3D position and velocity. Alternatively, in one embodiment, the ephemeris information may contain only 3D position information and not velocity information. In this scenario, in one embodiment, since the message originates from a gateway (“GW”), the GNW may contain additional information associated with the feeder link. For example, the additional information may include information about the gateway’s location or the propagation delay between the gateway and the satellite. Note that in one embodiment, the ground-based gNB may obtain the satellite ephemeris or feeder link propagation delay via a separate satellite radio interface (“SRI”) that may not be NR-based.

[0176] In one embodiment, an alternative example of transmitting satellite and / or gateway position and / or velocity is via NT-TRP or satellite transmission timestamps. An example of a timestamp is the parameter ReferenceTimeInfo-r16 as specified in NR Release 16. To allow for a uniform framework, in one embodiment, it is assumed that the GNW includes timestamps to implement this alternative. However, in one embodiment, the configuration or parameters including timestamps may differ from those including satellite and / or gateway ephemeris information, depending on the specification or implementation. In any case, in one embodiment, the symbol GNW is used to identify a configuration or parameter that may include position, velocity, timestamps, or any other information through which ephemeris and / or timestamps associated with the NT-TRP, gateway (“GW”), feeder link, serving link, inter-satellite link, and / or the like.

[0177] In step 3, in one embodiment, the UE may obtain its own location information GUE, for example, via GNSS. In one embodiment, an alternative example of obtaining location information is obtaining a reference time. Similar to the explanation of GNW above, in one embodiment, the symbol GUE is used to indicate any or at least one or all of location, velocity, reference time, or any other information about the location, velocity, or reference time associated with the UE that can be obtained therefrom.

[0178] In step 4, in one embodiment, the UE calculates a timing advance value TA1 based on the GNW and GUE. For example, if the GNW includes the NT-TRP ephemeris PTRP and the GW location PGW, and if the LTRP includes the UE location PUE, then TA1 can be calculated by adding the propagation delay associated with the distance between the gateway and the NT-TRP to the distance between the NT-TRP and the UE, |PTRP-PGW|+|PUE-PTRP|. Note that in the case of multi-hop satellite networks, in one embodiment, it may also be necessary to add the propagation delay associated with the inter-satellite link (“ISL”).

[0179] Alternatively, if timing information is available, propagation delay can be calculated using timing information in one embodiment. For example, if the GNW includes a timestamp TGW associated with the gateway, and if the GUE includes a UE reference time TUE associated with the reception time of a signal transmitted at the TGW, then TA1 can be calculated by calculating the time difference |TUE-TGW|. As another example, the UE can calculate the total propagation delay as the sum of several items (e.g., serving link delay, feeder link delay, and possibly inter-satellite link delay). Each of these items can be calculated as a time difference |T2-T1| or a propagation delay |P2-P1| / c based on information provided by the network ephemeris and the UE GNSS. In this example, each of T1, T2, P1, and P2 can be associated with the UE, the gateway, the serving satellite or the intermediate satellite in the NT-TRP, a multi-hop system, etc., and c denotes the speed of light.

[0180] In one embodiment, the UE may additionally calculate the change in TA value over time, which may be referred to as the TA drift rate. The TA drift rate can be calculated using different methods. In one embodiment, if the UE obtains velocity information, such as its own velocity VUE and the velocity of the serving satellite VTRP, the gateway velocity VGW, the velocity of intermediate satellites in a multi-hop system, and / or the like, then the UE may calculate the TA drift rate associated with the relative velocities |VUE-VTRP|, |VUE-VGW|, etc. In the special case where the UE and / or gateway are not mobile (e.g., the UE receiver antenna is a very small aperture terminal (“VSAT”) antenna), the UE / GW does not obtain / report its velocity information, or additionally, the UE / GW velocity is very small compared to the NT-TRP velocity; in one embodiment, VUE and / or VGW may be assumed to be zero for the TA drift rate calculation.

[0181] Alternatively, in one embodiment, if the satellite ephemeris includes the satellite's 3D position but not velocity information, the UE can obtain the TA drift rate by calculating the difference within a series of position values ​​associated with the NT-TRP. As another alternative, in one embodiment, if the UE can obtain updated timestamp information from the NT-TRP and / or updated reference time information from the UE GNSS, the TA drift rate can be calculated based on consecutive values ​​of the NT-TRP timestamp and the UE reference time. As yet another alternative, in one embodiment, the UE can obtain the TA drift rate via separate signaling.

[0182] In step 5, in one embodiment, the UE transmits the RACH preamble on the PRACH when applying the calculated TA1. In one embodiment, the UE obtains the PRACH information from system information, and the PRACH transmission may be associated with the SS / PBCH (or periodic CSI-RS) received in step 1.

[0183] In step 6, in one embodiment, once the NT-TRP receives the RACH preamble, it transmits a RAR message. The RAR message may contain information about a new timing advance value (e.g., timing advance adjustment) TA2.

[0184] In step 7, in one embodiment, the UE applies TA2 to transmit an uplink message, such as Msg3. In step 8, which is frequently performed, in one embodiment, the NT-TRP transmits a TA command including a new timing advance value (TA3). Different options are possible for this step. In some embodiments (Embodiment 1), TA3 does not include the TA drift rate or does not take TA drift into account. In other embodiments (Embodiment 2), TA3 includes the TA drift rate or takes TA drift into account.

[0185] Next, in step 9, after receiving the TA command, the UE calculates the new timing advance value as follows:

[0186] • For Example 1: TAnew := TAold+TA3+TAdrift, where TAdrift is obtained in step 8.

[0187] • For Example 2: TAnew: = TAold + TA3.

[0188] In some instances, if a downlink timing change is received without a timing advance command and is not compensated or is only partially compensated by uplink timing adjustment, then the UE will change the timing advance value accordingly.

[0189] In another embodiment, a method is disclosed for a scenario with a transparent payload and no ephemeris / GNSS information:

[0190] 1. NT-TRP transmits SS / PBCH blocks

[0191] 2. NT-TRP broadcasts TA in SIB ref

[0192] 3. UE in application TA1:=TA ref Transmit RACH preamble

[0193] 4. NT-TRP transmission of RAR files containing TA2

[0194] 5. UE transmits UL when applying TA1+TA2

[0195] 6. NT-TRP transmits TA commands containing TA3.

[0196] 7. The UE then applies TA3 immediately following TA1+TA2.

[0197] In step 1, in one embodiment, the NT-TRP transmits one or more SS / PBCH blocks. The UE can receive the SS / PBCH blocks and perform synchronization, obtain system information, etc.

[0198] In step 2, in one embodiment, the NT-TRP broadcasts a reference timing advance TAref, for example, in the System Information Block (“SIB”). The reference TA may take into account TA variations caused by propagation delays from the gateway to the satellite and then to the ground, as well as delays in applying the reference TA.

[0199] In step 3, in one embodiment, the UE transmits a RACH preamble on the PRACH when the application timing advance TA1:=TAref. The UE obtains the PRACH information from the system information, and the PRACH transmission can be associated with the SS / PBCH (or periodic CSI-RS) received in step 1.

[0200] In one embodiment, once the NT-TRP receives the RACH preamble, it transmits a RAR message in step 4. The RAR message may contain information about a new timing advance value (e.g., timing advance adjustment) TA2. The value of A2 can vary significantly for different UEs because the delay calculated for propagation from satellite to ground corresponds to a reference point on the ground, while UEs are expected to be spatially dispersed.

[0201] In step 5, in one embodiment, the UE applies TA2 to transmit uplink messages, such as Msg3. In step 6, which is frequently performed, in one embodiment, the NT-TRP transmits a TA command including a new timing advance value (TA3). Different options are possible for this step. In some embodiments (Embodiment 1), TA3 does not include the TA drift rate or does not take TA drift into account. In embodiment 1a, the NT-TRP transmits control messages, such as MAC CE messages containing only the TAdrift value. In embodiment 1b, the NT-TRP transmits control messages, such as MAC CE messages containing a TAdrift value that varies according to the Doppler shift. The Doppler shift may be associated with one or more SS / PBCH blocks. In other embodiments (Embodiment 2), TA3 includes the TA drift rate or takes TA drift into account.

[0202] In step 7, in one embodiment, after receiving the TA command, the UE calculates the new timing advance value as follows:

[0203] • For Example 1: TAnew := TAold+TA3+TAdrift, where TAdrift is obtained in step 6.

[0204] • For Example 2: TAnew: = TAold + TA3.

[0205] In some instances, if a downlink timing change is received without a timing advance command and is not compensated or is only partially compensated by uplink timing adjustment, then the UE will change the timing advance value accordingly.

[0206] The aforementioned methods differ in steps and details depending on the availability of position / velocity information and whether the system is based on a regenerated payload or a transparent payload.

[0207] In addition to the above embodiments, other situations may need to be considered for standardization when other types of relays (e.g., smart repeaters) are used as NT-TRPs, when multiple NT-TRPs are connected via inter-satellite links (“ISL”), when the UE is non-terrestrial, and / or similar situations.

[0208] In one embodiment, it is expected that the NTN features in the NR will cover all the scenarios described above, as well as any other scenarios that may or may not currently be considered. Therefore, a flexible and unified framework for the system and methods can be expected, especially in the early stages of standardization.

[0209] Figure 8 A flowchart is presented showing a unified approach to timing adjustments in NTN.

[0210] Regarding the method for NT-TRP 800, in step 1 805, NT-TRP transmits one or more SS / PBCH blocks. NT-TRP may or may not apply Doppler pre-compensation for transmitting the SS / PBCH blocks. As used herein, Doppler pre-compensation may refer to the purpose of fully or partially compensating for radio frequency shifts in the transmitter (in this case, NT-TRP) caused by mobility, such as those perceived by the receiver (here, the UE). In cases where NT-TRP applies Doppler pre-compensation to SS / PBCH block transmission (e.g., beam-specific pre-compensation for common frequency shifts), in one embodiment, the frequency shift purpose is to compensate for Doppler frequency shifts perceived at / with respect to a reference point typically on the ground (e.g., the point beam center). Therefore, the SS / PBCH blocks may still be shifted due to Doppler shifts perceived by UEs in other geographic areas.

[0211] In step 2 810, in one embodiment, the NT-TRP broadcasts additional information, for example, in one or more System Information Blocks (“SIBs”). The broadcast information may include information based on the legacy terrestrial network, such as information configured for the Random Access Channel (“RACH”), such as the RACH preamble, RACH timing, and / or the like. Furthermore, the broadcast information may include additional information specific to the NTN, such as the following:

[0212] Information about NTN:

[0213] i. The type of vehicle on which the NT-TRP is deployed, such as a GEO satellite, LEO satellite, UAV, balloon, etc. Alternatively, the altitude angle from the nadir and / or the absolute value of the vehicle's velocity can be used.

[0214] ii. Architecture / protocol information, such as whether the service link is provided by regenerable payload NT-TRP, transparent payload NT-TRP, smart repeaters, etc. In the case of regenerable payload NT-TRP, CU-DU segmentation information can also be provided.

[0215] iii. Topological information, such as multi-hop information.

[0216] • The location on which NT-TRP satellites / UAVs are deployed.

[0217] • The speed of NT-TRP satellites / UAVs deployed on it.

[0218] • The location of a reference point (usually on the ground).

[0219] • Connect the NT-TRP to the gateway location of the core network.

[0220] • The location of one or more intermediate satellites / UAVs connected via inter-satellite links (ISL) in a multi-hop NTN.

[0221] • The speed of one or more intermediate satellites / UAVs connected via inter-satellite links (ISL) in a multi-hop NTN.

[0222] • Propagation delay of the service link, such as the propagation delay from satellite / UAV to a reference point (usually on the ground).

[0223] i. The drift rate of the aforementioned propagation delay, which varies with time.

[0224] ii. The drift rate of the aforementioned propagation delay, which varies according to the Doppler frequency shift. The Doppler frequency shift can be associated with the SS / PBCH block and can be indicated by an index to the SS / PBCH block.

[0225] • Propagation delay of the feeder link, for example, the propagation delay from the gateway to the satellite / UAV.

[0226] i. The drift rate of the aforementioned propagation delay, which varies with time.

[0227] ii. The drift rate of the aforementioned propagation delay, which varies according to the Doppler frequency shift. The Doppler frequency shift can be associated with the SS / PBCH block and can be indicated by an index to the SS / PBCH block.

[0228] • Propagation delay of inter-satellite links (ISL) in multi-hop NTN.

[0229] i. The drift rate of the aforementioned propagation delay, which varies with time.

[0230] ii. The drift rate of the aforementioned propagation delay, which varies according to the Doppler frequency shift. The Doppler frequency shift can be associated with the SS / PBCH block and can be indicated by an index to the SS / PBCH block.

[0231] • Information on Doppler pre-compensation. This information may indicate: whether Doppler pre-compensation is applied when transmitting SS / PBCH blocks; the amount of Doppler pre-compensation in frequency or parts per million (ppm) or as a multiple of the SS / PBCH block subcarrier spacing; etc.

[0232] In step 3, 815, in one embodiment, NT-TRP monitors the initial access channel, such as the Physical Random Access Channel (“PRACH”). In one embodiment, NT-TRP takes propagation delay into account when scheduling and monitoring resources used for initial access. After receiving the initial access message (e.g., the Random Access Channel (RACH) preamble), in one embodiment, NT-TRP may calculate a timing advance value TA2. This value may be positive, 0, or negative.

[0233] In step 4, 820, in one embodiment, the NT-TRP transmits a response to the initial access message, such as a random access response (“RAR”). The RAR may include a timing advance adjustment value TA2.

[0234] In step 5, 825, in one embodiment, NT-TRP calculates a new timing advance adjustment value TA3 to be added to the current timing advance value. The TA3 value can be positive, 0, or negative.

[0235] In step 6 830, in one embodiment, the NT-TRP transmits a control message, such as a MACCE message including the value of TA3. Steps 5 825 and 6 830 can be executed consecutively in a loop.

[0236] Regarding the method for UE 850 corresponding to the method for NT-TRP 800, in step 1 855, the UE receives one or more SS / PBCH blocks. The SS / PBCH blocks may be received with or without Doppler pre-compensation. It should be noted that even when the SS / PBCH blocks are received with Doppler pre-compensation, the frequency perceived by the UE may still be shifted from the target frequency of the SS / PBCH blocks.

[0237] In step 2 860, in one embodiment, the UE receives additional information, for example, in one or more System Information Blocks (“SIBs”). The UE may obtain the SIB information from previously received SS / PBCH blocks. The broadcast information may include information based on the legacy terrestrial network, such as information on the timing of the Random Access Channel (“RACH”). Furthermore, the broadcast information may include additional NTN-specific information, as mentioned above in step 2 810 of the NT-TRP method 800.

[0238] In step 3 865, in one embodiment, the UE transmits an initial access message (e.g., a random access channel (“RACH”) preamble) on an initial access channel (e.g., a physical random access channel (“PRACH”)).

[0239] In step 4,870, in one embodiment, the UE receives a response to an initial access message, such as a random access response (“RAR”). The RAR may include a timing advance value TA2, which the UE adds to the current timing advance value to transmit the next uplink signal. This TA2 value may be positive, 0, or negative.

[0240] In step 5 875, in one embodiment, the UE transmits uplink signals when applying the current value of the timing advance.

[0241] In step 6 880, in one embodiment, the UE receives a control message, such as a MAC CE message including the value of TA3. The value of TA3 can be positive, 0, or negative. In one embodiment, the UE adds the value of TA3 to the current timing advance value for transmitting the next uplink signal. Steps 5 875 and 6 880 can be executed consecutively in a loop.

[0242] Figure 9 This relates to an embodiment for obtaining the TA drift rate from the Doppler frequency shift. In one embodiment, the NT-TRP 902 may be on a LEO satellite 904 traveling at a speed V 906 (e.g., greater than 7 km / s). Depending on the component V'908 of V projected onto the line of sight between the NT-TRP 902 and the UE 910, the downlink signal from the NT-TRP 902 may have its frequency shifted by, for example, 21 to 24 ppm when received by the UE 910. The UE 910 may frequently measure a reference signal (e.g., an SS / PBCH block) from the NT-TRP 902 to obtain the instantaneous value of the Doppler frequency shift. Since V'908 varies even when V906 is constant, frequent measurements may be necessary to keep the Doppler frequency shift up-to-date.

[0243] Based on the following calculations, UE 910 can use the Doppler frequency shift value to update the timing advance value. Let f D Indicates the instantaneous frequency of the signal, where frequency f c The frequency shift is due to the relative velocity V'. The change ΔTA in timing advance (“TA”) over a time interval Δt can be obtained as follows.

[0244]

[0245]

[0246]

[0247]

[0248] In the above equation, l is the instantaneous distance between NT-TRP 902 and UE 910, and T... p It is the instantaneous propagation delay, and c is the speed of light. Therefore, if the (target) frequency f... c If the carrier frequency is known and the period starting from the last TA is relatively small, then the change in TA can be calculated.

[0249] In practice, the combination of TA commands, explicit indications of TA drift, and the above calculations based on Doppler frequency shift can be used by the UE to update the TA.

[0250] To implement this method, the non-pre-compensated reference signal (e.g., the SS / PBCH block) should be configured for f D Measurement. For beam-based methods where different reference signals may have different spatial quasi-co-locations (QCLs), the reference signals should be spatially quasi-co-located (via QCL), for example, by using any other signal indicating QCL type D for obtaining timing information from the NT-TRP 902.

[0251] The NT-TRP 902 can apply Doppler pre-compensation to other downlink signals. Therefore, the NT-TRP 902 can specify one or more reference signals (e.g., SS / PBCH blocks) for UE 910 to perform Doppler measurements. Indications for reference signals not being Doppler pre-compensated or specified for Doppler measurements can be explicitly or implicitly passed to UE 910. Explicit indications can be passed from network configuration. Implicit indications may be provided due to the lack of Doppler pre-compensation configuration parameters associated with the reference signal. In either case, UE 910 can use the reference signal to perform Doppler measurements.

[0252] An alternative to the above method is to correlate the Doppler pre-compensation value with the reference signal as follows. Consider the Doppler pre-compensation f at UE910. p Applied to the target frequency f c The scenario is the reference signal. Then, when the UE 910 performs a Doppler measurement on the reference signal, it obtains the Doppler frequency shift version f of the Doppler pre-compensated frequency. D '=f D -f p , where f D This refers to the frequency received without applying pre-compensation. Note that f... D 'Should be close to f' c However, it depends on the beamwidth of the satellite signal on the ground, f p The resolution, etc., the two values ​​can be different. In this method, f pThe value can be broadcast or transmitted to UE910. Once UE910 receives this value, it can calculate f. D =f D '+f p And if UE 910 knows f c Then, the above equation can be used to update the value of TA.

[0253] In one embodiment associated with "tracking area management" in the NG-RAN architecture, two types of NTN cells are defined—NTN cells that are fixed to the ground and NTN cells that are mobile to the ground. When an NTN cell is mobile to the ground, the NT-TRP 902 can fix the beam on its antenna and apply fixed Doppler precompensation to the signal in a semi-static manner. In this case, the value of the Doppler precompensation f p It can be broadcast or transmitted via a semi-static configuration. However, when the NTN cell should be fixed to the ground, such as the NT-TRP 902 deployed on a mobile LEO satellite, the beam may need to be switched over time. Due to the changing angle with respect to the ground, fixed Doppler pre-compensation may not work.

[0254] In this case, the instantaneous Doppler pre-compensation value f p This should be relayed to the ground. For this purpose, lower-level signaling (such as MAC CE messages) can be used to relay f p Value. Alternatively, f p The value can be passed along with the expiration timer value. As another alternative example, f p The value can be associated with QCL type D or another parameter associated with the reference signal. In cases where the Doppler pre-compensation value of the reference signal expires or is otherwise unavailable, the UE 910 can stop adjusting TA based on the Doppler measurement.

[0255] In one embodiment, the aforementioned method, particularly the unified method covering different scenarios such as regenerative payloads, transparent payloads, and access to ephemeris and / or GNSS, requires a unified configuration for operation. This configuration is typically a semi-static configuration of the Radio Resource Control (“RRC”) entity and lower-level signaling (e.g., MAC CE messages and DCI messages). The following table illustrates the values ​​used for the unified configuration:

[0256]

[0257] Table 1: Configuration for TA Adjustment

[0258] Reference signal Select {SSBRI, CRI, etc.} Report quality Doppler shift scope granularity

[0259] Table 2: Configuration for Doppler Measurement and Reporting

[0260]

[0261] Table 3: Configurations for Doppler precompensation

[0262] exist Figure 10 In one embodiment shown, another approach to uplink TA adjustment is to minimize the workload on the UE side. In this approach, UE behavior is largely controlled by the NT-TRP. The NT-TRP provides the UE with TA values ​​by transmitting control messages (e.g., MAC CE messages) to the UE. Where the TA value is contained within a control message, the method is similar to TA signaling in legacy systems, except that a wider range of TA values ​​may be required, thus necessitating new control messages.

[0263] Alternatively, the TA value can be provided by transmitting the common TA value for the entire beam / cell and the differential TA value for the UE served by the beam / cell. In this case, the UE obtains the complete TA value by adding the common TA value and the differential TA value.

[0264] To compensate for the change in TA from time T1 when the control message is transmitted by the NT-TRP until time T2 when the value is applied by the UE, the NT-TRP may need to perform calculations to predict the required TA value at T2 and indicate the TA value in the control message transmitted by the NT-TRP at T1. This process can be performed at the NT-TRP and is transparent to the UE.

[0265] In this method, the frequency of transmitting control messages providing updated TA values ​​(e.g., full, differential, common, or a combination thereof) can depend on the relative speed between the NT-TRP and the UE. Therefore, a disadvantage of this method is that control messages containing updated TA values ​​may need to be frequent, thus imposing significant signaling overhead on the downlink.

[0266] To reduce the frequency of TA signaling from NT-TRP to the UE, a method can be defined for the UE to adjust the TA value between receiving control messages that explicitly indicate a new TA value. In this method, the relationship between the TA value and other parameters available to the UE can be provided.

[0267] In an embodiment, a control message (e.g., a MAC CE message) provides parameters for updating the TA value based on time. The function can be linear, for example, based on the TA. t =TA0+at, where:

[0268] ·TA t It is the TA value updated at time t starting from the time slot where the TA value takes effect, where t is a time parameter in the form of the number of time slots, the number of frames, the parameter configuration (numerology) based on the current effective downlink bandwidth (e.g., subcarrier spacing), or reference parameter configuration, etc.

[0269] TA0 is the TA value that is signaled by the control message to be applied in the first time slot when the control message takes effect (i.e., when t=0); and

[0270] The value of 'a' is signaled by a control message.

[0271] Control messages may contain an expiration date for the applicability of the equation. Alternatively or additionally, the equation for updating the TA value at the UE may expire upon receiving a new control message providing a new TA0 and / or a value.

[0272] The calculation of these parameters can be left to the NT-TRP to perform based on beam angle, velocity, elevation angle, etc., in a manner that is completely or partially transparent to the UE.

[0273] In a more general case, the parameters of the nonlinear equation (e.g., a quadratic function of the time parameter t) can be provided by the control message so that the UE can update the TA value before receiving the next control message from the NT-TRP.

[0274] The flowchart of the example implementation is in Figure 11 Described in the text.

[0275] In step 1 1002, the UE receives a control message including an initial timing advance value (TA0) and a timing advance drift rate value (a) that varies over time. The control message containing these values ​​may be a MAC CE message. The time unit may be a time slot, a frame, a parameter configuration based on the current effective downlink bandwidth portion (e.g., subcarrier spacing), a reference parameter configuration, or any other unit determined by specifications, configurations, control signaling, etc.

[0276] In step 2 1004, the UE initializes the time parameter with a value. The value can be 0, an offset from the time of receiving the control message in step 1, a value determined by the control message in step 1 1002, and / or the like.

[0277] In step 3 1006, the UE calculates the timing advance value (“TA”) based on the parameters in the control message. If the initial value of the time parameter in step 2 1004 is a non-zero value t_0, then the UE can set TA←TA0+a.(t-t_0).

[0278] In step 4 1008, the UE may apply the TA value according to the specification. For example, the UE may begin transmitting uplink signals according to the TA value before receiving the corresponding downlink signal. Alternatively, the UE may further shift the uplink transmission frequency by an offset, such as by specifying it for NTN or by signaling it via configuration or control messages.

[0279] In step 5 1010, the UE determines whether it has received a new control message including the TA drift rate parameter value. If it has, the UE applies the value from the new control message for the next uplink transmission (the method returns to step 11002). Otherwise, the UE continues to use the current value (the method continues to step 6 1012).

[0280] In another embodiment, a control message (e.g., a MAC CE message) may indicate an equation for updating the TA value based on Doppler parameters, which can be obtained by the UE by measuring a reference signal. For example, consider the case where the UE receives an SS / PBCH block as a reference signal for an indicated quasi-co-location (“QCL”) source. Then, by performing measurements on the SS / PBCH block, the UE can update the TA value based on the latest measured Doppler frequency shift with respect to the reference frequency.

[0281] exist Figure 11 In some of the examples shown, if the downlink timing change received without a timing advance command is not compensated or is only partially compensated through uplink timing adjustment, then the UE will change the timing advance value accordingly.

[0282] In step 1102, the UE receives a control message including an initial timing advance value (TA0), a timing advance drift rate value (a) that varies according to the frequency, and a reference frequency (f0). The control message may be a MAC CE message. The frequency unit may be determined by specifications, configuration, control signaling, etc.

[0283] In step 2 1104, the UE performs a measurement on the reference signal and obtains the frequency f associated with the reference signal. The UE may obtain information about the reference signal resources prior to step 2 1104, either according to specifications, through configuration, or through control signaling.

[0284] In step 3 1106, the UE calculates the timing advance value (“TA”) based on the parameters in the control message.

[0285] In step 4 1108, the UE may apply the TA value according to the specification. For example, the UE may begin transmitting uplink signals according to the TA value before receiving the corresponding downlink signal. Alternatively, the UE may further shift the uplink transmission frequency by an offset, such as by specifying it for the NTN or by signaling it via configuration or control messages.

[0286] In step 5 1110, the UE determines whether it has received a new control message including the TA drift rate parameter value. If it has, the UE applies the value from the new control message for the next uplink transmission (returning to step 11102). Otherwise, the UE continues to use the current value (returning to step 2 1104).

[0287] Similar to previous embodiments, the calculation of parameters can be left to the NT-TRP to perform based on beam angle, velocity, elevation angle, etc., in a manner that is completely or partially transparent to the UE.

[0288] The reference frequency value f0 can be notified via a control message or by signaling via configuration. Alternatively, the reference frequency value f0 can be set to the frequency obtained from the latest measurement by the SS / PBCH block when the control message becomes valid.

[0289] In the above method, instead of the SS / PBCH block, a reference signal (e.g., CSI-RS) can be used to measure Doppler parameters.

[0290] In cases where NT-TRP performs Doppler precompensation, the above method may not work properly. However, if Doppler precompensation is applied to a common reference point, the method may still be applicable.

[0291] In another instance, if NT-TRP applies Doppler precompensation to some communications (e.g., downlink shared channels), then the Doppler-based approach is applicable, but some reference signals (e.g., SS / PBCH blocks) are not Doppler precompensated.

[0292] The above method can be extended to cases where NT-TRP indicates TA based on ephemeris and other parameters. In some embodiments, a combination of parameters such as time, Doppler, and ephemeris can be used to indicate the rate of change of TA.

[0293] The UE behavior in the above situations can be determined through configuration and / or standard specifications. Whether and how to configure the UE depends on the UE capabilities that can be passed to the NT-TRP or gateway after connecting to the network.

[0294] The method in this disclosure is applicable to the entire cell provided by NT-TRP. Alternatively, TA signaling can be beam-specific. The reason for beam-specific signaling is that propagation delay can vary significantly with respect to the accuracy of the cell phase determined by the UE's RAN4.

[0295] It is expected that the UE at the center of the serving beam will indicate the QCL with respect to the spatial Rx parameters to a reference signal one at a time. However, at the beam boundaries, it may be beneficial to provide timing adjustment signaling for more than one beam. In this approach, TA commands and signaling can provide indications to the SSB index or CRI.

[0296] In one embodiment, similar to the method used for regenerating payloads, from the UE's perspective of an NTN based on a transparent payload, one approach is to minimize UE-side procedures and explicitly transmit a message including the TA value to each UE. This message may include a common TA and UE-specific differential TAs, as interpreted for a regenerated payload scenario. Furthermore, the TA value (specifically, the full TA or the common TA) may include the propagation delay of the feeder link, which is generally common across all UEs. However, in one embodiment, this method imposes significant signaling overhead on transmitting the updated TA value to the UE.

[0297] In embodiments that address this problem, the NT-TRP may broadcast a common TA value or location (and possibly speed) information associated with the NT-TRP and / or the gateway (“GW”) to provide the UE with a common TA value or a full TA value. Furthermore, the NT-TRP may communicate the TA drift rate to the UE using one of the methods proposed in this disclosure. Subsequently, another signaling from the NT-TRP / gNB at the UE and / or locally calculated may provide a differential TA value that can be added to the common TA value (also referred to as a reference TA value).

[0298] To extend the proposed method to cases with transparent payloads when ephemeris / GNSS is unavailable, the full or common TA may include feeder link delay. Alternatively, the feeder link delay and / or feeder link delay drift rate should be broadcast to the UE.

[0299] In several embodiments of this disclosure, a communication entity (e.g., a gNB, gateway (“GW”), NT-TRP, or UE) may transmit messages including values ​​of parameters (e.g., timing advance (TA), common TA, reference TA, full TA, differential TA, TA drift rate, etc.). It is important to note that this expression is simplified. In practice, parameter values ​​are digitized and sometimes compressed for the transmission of digital messages. A TA value (e.g., the example mentioned above) can be described as TA = N TA .T c .X+Y, where N TA It is an integer value that typically has a fixed bit width, T c The values ​​of X and Y are determined by standards, and are defined by standard specifications and / or configuration or signaling. Therefore, in one embodiment, it is expected that these values ​​will be correctly understood by the transmitter and receiver, and thus, the receiver can clearly calculate the parameter values ​​after receiving a message. Furthermore, each value may be transmitted in more than one parameter (potentially in more than one message).

[0300] In one embodiment, the above principle applies to other parameters, such as satellite ephemeris, position and velocity parameters, drift parameters, etc., where the interpretation of values, bit width of values, etc., are understood based on standard specifications and / or configuration or signaling.

[0301] Note that the linear equation mentioned above is only one example and does not exclude parameter values ​​(e.g., N). TA The nonlinear relationship between () and the values ​​calculated based on it (e.g., TA).

[0302] In one embodiment, if the UE shares its antenna and RF front-end circuitry for GNSS measurements and communication with the NT-TRP, it may be unable to perform GNSS measurements and update location / timing information in RRC-connected mode. This could be evident, for example, in an aircraft with a continuous connection to the NT-TRP used to serve passenger devices.

[0303] In this scenario, the UE can be configured with measurement gaps to perform GNSS measurements in a timely manner. However, since measurement gaps for GNSS operation may not be guaranteed, the UE behavior for updating TA values ​​can be specified by standards and / or configured via the network.

[0304] In this embodiment, the UE is configured with measurement gaps to perform GNSS operations. The configuration of the measurement gaps may depend on the carrier frequency of the RRC connection and may depend on the UE's capabilities. For example, if the UE indicates that it cannot perform simultaneous GNSS operations and communicate with the TRP, then the UE can be configured with measurement gaps via the network to perform GNSS measurements. The measurement gaps can be configured by indicating the occurrence frequency and the length of each measurement gap. These configuration parameters can also be determined based on the UE's capabilities, which are signaled to the network by the UE.

[0305] If measurement gaps are not frequent enough, or if no measurement gaps for GNSS measurements are configured for the UE, the UE can employ a method to obtain new TA values, as previously described. For example, the network can configure both measurement gaps and a reference signal for Doppler measurements. Then, when the UE can use a measurement gap to perform GNSS operations, it can obtain updated position / timing information and use it to calculate new TA values. However, during the time intervals between measurement gaps, the UE can perform Doppler measurements and update the TA values, as previously explained. Parameters, such as the minimum or maximum time intervals used to employ a method to update TA values ​​(without performing GNSS measurements), can also be determined through configuration or specified by standards.

[0306] The following should be noted throughout this publication:

[0307] • The different steps described in the text and in the flowchart for example implementations can be replaced.

[0308] Each configuration can actually be provided by one or more configurations. An earlier configuration may provide a subset of parameters, while a subsequent configuration may provide another subset of parameters. Alternatively, a subsequent configuration may override values ​​provided by an earlier configuration or pre-configuration.

[0309] Configuration may be provided by Radio Resource Control (“RRC”) signaling, Media Access Control (“MAC”) signaling, Physical Layer signaling (e.g., Downlink Control Information (“DCI”) messages), a combination thereof, or other methods. Configuration may include pre-configured or semi-static configurations provided by standards, vendors, and / or network / operator. Each parameter value received by configuration or indication may override a previous value of a similar parameter.

[0310] • Parameter values ​​determined by standards, specifications, configurations, or control signaling are presented in units specified by the standards to save bit width and signaling overhead. For example, time parameters can be described / interpreted in units of time slots or frames, based on parameter configurations (e.g., subcarrier spacing) or reference parameter configurations, or by the number of time slots / frames specified by the standard or determined by configuration. Frequency parameters can be described / interpreted in units of MHz, GHz, the number of PRBs, carrier frequency divisions, etc., as specified by the standard or determined by configuration.

[0311] • Velocity is generally determined relative to the Earth; therefore, Earth-fixed entities, such as those that appear fixed from the perspective of an observer anywhere on Earth, are typically assigned zero velocity, regardless of whether the entity is terrestrial (e.g., a VSAT antenna) or non-terrestrial (e.g., a GEO satellite). Velocity can be described / interpreted in m / s or any other unit of velocity specified by a standard or configured via a network. Position and velocity values ​​can be expressed in a Cartesian system as triples (e.g., (x, y, z), (V ... x V y V z (or as may be specified by a standard or configured via a network) as described.

[0312] Figure 12 User equipment device 1200, which can be used for timing and frequency adjustment in non-terrestrial networks according to embodiments of the present disclosure, is depicted. In various embodiments, user equipment device 1200 is used to implement one or more of the solutions described above. User equipment device 1200 may be an embodiment of remote unit 105 and / or UE 205 described above. Furthermore, user equipment device 1200 may include processor 1205, memory 1210, input device 1215, output device 1220, and transceiver 1225.

[0313] In some embodiments, input device 1215 and output device 1220 are combined into a single device, such as a touchscreen. In some embodiments, user equipment device 1200 may not include any input device 1215 and / or output device 1220. In various embodiments, user equipment device 1200 may include one or more of processor 1205, memory 1210, and transceiver 1225, and may not include input device 1215 and / or output device 1220.

[0314] As depicted, transceiver 1225 includes at least one transmitter 1230 and at least one receiver 1235. In some embodiments, transceiver 1225 communicates with one or more cells (or wireless coverage areas) supported by one or more base station units 110. In various embodiments, transceiver 1225 may operate on unlicensed spectrum. Furthermore, transceiver 1225 may include multiple UE boards supporting one or more beams. Additionally, transceiver 1225 may support at least one network interface 1240 and / or application programming interface 1245. Application programming interface 1245 may support one or more APIs. Network interface 1240 may support 3GPP reference points, such as Uu, N1, PC5, etc. Other network interfaces 1240 may be supported, as will be understood by those skilled in the art.

[0315] In one embodiment, processor 1205 may include any known controller capable of executing computer-readable instructions and / or performing logical operations. For example, processor 1205 may be a microcontroller, microprocessor, central processing unit (“CPU”), graphics processing unit (“GPU”), auxiliary processing unit, field-programmable gate array (“FPGA”), or similar programmable controller. In some embodiments, processor 1205 executes instructions stored in memory 1210 to perform the methods and routines described herein. Processor 1205 is communicatively coupled to memory 1210, input device 1215, output device 1220, and transceiver 1225.

[0316] In various embodiments, processor 1205 controls user equipment device 1200 to perform the UE behaviors described above. In some embodiments, processor 1205 may include an application processor (also referred to as a "main processor") that manages application domains and operating system ("OS") functions, and a baseband processor (also referred to as a "baseband radio processor") that manages radio functions.

[0317] In one embodiment, processor 1205 determines a first frequency from one of a first reference signal received from the mobile wireless communication network and a configuration message received from the mobile wireless communication network. In one embodiment, processor 1205 determines a second frequency from a second reference signal received from the mobile wireless communication network. In one embodiment, processor 1205 calculates a second timing advance value based on a first timing advance value, the first determined frequency, and the second determined frequency, wherein the first timing advance value is received as part of a control message. In one embodiment, transceiver 1225 uses the second timing advance value to transmit uplink signals to the mobile wireless communication network.

[0318] In one embodiment, transceiver 1225 receives an indication that the second reference signal is not altered by Doppler precompensation, the Doppler precompensation including frequency shift in the transmitter.

[0319] In one embodiment, the processor 1205 calculates the second timing advance value by calculating the ratio of the second determined frequency to the first determined frequency. In another embodiment, the processor 1205 calculates the second timing advance value by calculating the difference between a first time and a second time, the first time being associated with the time when the first timing advance value is received and the second time being associated with the time when the uplink signal is transmitted.

[0320] In one embodiment, the processor 1205 calculates the second timing advance value based on the first timing advance value plus the differential timing advance value, wherein the differential timing advance value is equal to two times multiplied by a coefficient multiplied by a time difference, the coefficient including the ratio of the second frequency to the first frequency minus 1, and the time difference including the difference between a first time and a second time, the first time being associated with the time when the first timing advance value is received, and the second time being associated with the time when the uplink signal is transmitted.

[0321] In one embodiment, the processor 1205 calculates a second timing advance value based on a predefined time function that takes into account the first timing advance value, the first determined frequency, and the second determined frequency.

[0322] In one embodiment, the control message further includes an expiration timer value, such that transmitting the uplink signal using the second timing advance value is performed in response to determining that a first time associated with the time the control message is received, plus the expiration timer value, is greater than a second time associated with the time the uplink signal is transmitted.

[0323] In one embodiment, transceiver 1225 transmits the uplink signal using the second timing advance value in response to receiving at least one of the following: an indication of a quasi-conjunction relationship between the first reference signal and the second reference signal; an indication of a quasi-conjunction relationship between the first reference signal and the first timing advance value; and an indication of a quasi-conjunction relationship between the second reference signal and the first timing advance value.

[0324] In one embodiment, the first reference signal includes a first synchronization signal, and the second reference signal includes a second synchronization signal. In one embodiment, the first frequency includes at least one of a carrier frequency, a carrier frequency without Doppler precompensation, a carrier frequency with Doppler precompensation, and a Doppler precompensated frequency.

[0325] In one embodiment, at least a portion of the mobile wireless communication network includes a non-terrestrial network that provides wireless connectivity between the UE and a gateway of the terrestrial network.

[0326] In one embodiment, memory 1210 is a computer-readable storage medium. In some embodiments, memory 1210 includes volatile computer storage media. For example, memory 1210 may include RAM, including dynamic RAM (“DRAM”), synchronous dynamic RAM (“SDRAM”), and / or static RAM (“SRAM”). In some embodiments, memory 1210 includes non-volatile computer storage media. For example, memory 1210 may include a hard disk drive, flash memory, or any other suitable non-volatile computer storage device. In some embodiments, memory 1210 includes both volatile and non-volatile computer storage media.

[0327] In some embodiments, memory 1210 stores data related to timing and frequency adjustments in non-terrestrial networks. For example, memory 1210 may store various parameters, board / beam configurations, resource assignments, strategies, etc., as described above. In some embodiments, memory 1210 also stores program code and related data, such as an operating system or other controller algorithms operating on device 1200.

[0328] In one embodiment, input device 1215 may include any known computer input device, including a touchpad, button, keyboard, stylus, microphone, etc. In some embodiments, input device 1215 may be integrated with output device 1220 as, for example, a touchscreen or similar touch-sensitive display. In some embodiments, input device 1215 includes a touchscreen, enabling text input using a virtual keyboard displayed on the touchscreen and / or by handwriting on the touchscreen. In some embodiments, input device 1215 includes two or more different devices, such as a keyboard and a touchpad.

[0329] In one embodiment, the output device 1220 is designed to output visual, auditory, and / or tactile signals. In some embodiments, the output device 1220 includes an electronically controllable display or display device capable of outputting visual data to a user. For example, the output device 1220 may include (but is not limited to) a liquid crystal display (“LCD”), a light-emitting diode (“LED”) display, an organic LED (“OLED”) display, a projector, or a similar display device capable of outputting images, text, etc., to a user. As another non-limiting example, the output device 1220 may include a wearable display, such as a smartwatch, smart glasses, a head-up display, etc., which is separate from but communicatively coupled to the remainder of the user equipment device 1200. Furthermore, the output device 1220 may be a component of a smartphone, personal digital assistant, television, desktop computer, laptop computer, personal computer, vehicle dashboard, etc.

[0330] In some embodiments, the output device 1220 includes one or more speakers for generating sound. For example, the output device 1220 may generate an auditory alarm or notification (e.g., a beep or chime). In some embodiments, the output device 1220 includes one or more haptic devices for generating vibration, motion, or other haptic feedback. In some embodiments, the output device 1220 may be wholly or partially integrated with the input device 1215. For example, the input device 1215 and the output device 1220 may form a touchscreen or a similar touch-sensitive display. In other embodiments, the output device 1220 may be located near the input device 1215.

[0331] Transceiver 1225 communicates with one or more network functions of a mobile communication network via one or more access networks. Transceiver 1225 operates under the control of processor 1205 to transmit and receive messages, data, and other signals. For example, processor 1205 may selectively activate transceiver 1225 (or a portion thereof) at specific times to send and receive messages.

[0332] Transceiver 1225 includes at least a transmitter 1230 and at least one receiver 1235. One or more transmitters 1230 may be used to provide UL communication signals to base station unit 110, such as the UL transmission described herein. Similarly, one or more receivers 1235 may be used to receive DL communication signals from base station unit 110, as described herein. Although only one transmitter 1230 and one receiver 1235 are described, user equipment device 1200 may have any suitable number of transmitters 1230 and receivers 1235. Furthermore, transmitters 1230 and receivers 1235 may be of any suitable type. In one embodiment, transceiver 1225 includes a first transmitter / receiver pair for communicating with a mobile communication network via licensed radio spectrum and a second transmitter / receiver pair for communicating with a mobile optical communication network via unlicensed radio spectrum.

[0333] In some embodiments, a first transmitter / receiver pair for communicating with a mobile communication network via licensed radio spectrum and a second transmitter / receiver pair for communicating with a mobile communication network via unlicensed radio spectrum may be combined into a single transceiver unit, such as a single chip that performs functions for use with both licensed and unlicensed radio spectrum. In some embodiments, the first transmitter / receiver pair and the second transmitter / receiver pair may share one or more hardware components. For example, some transceivers 1225, transmitters 1230, and receivers 1235 may be implemented as physically separate components that access shared hardware and / or software resources, such as (for example) network interface 1240.

[0334] In various embodiments, one or more transmitters 1230 and / or one or more receivers 1235 may be implemented and / or integrated into a single hardware component, such as a multi-transceiver chip, a system-on-a-chip, an application-specific integrated circuit (“ASIC”), or other types of hardware components. In some embodiments, one or more transmitters 1230 and / or one or more receivers 1235 may be implemented and / or integrated into a multi-chip module. In some embodiments, other components of, such as network interface 1240 or other hardware components / circuits, may be integrated with any number of transmitters 1230 and / or receivers 1235 into a single chip. In this embodiment, transmitters 1230 and receivers 1235 may be logically configured as transceivers 1225 using one or more common control signals or as modular transmitters 1230 and receivers 1235 configured to be implemented in the same hardware chip or multi-chip module.

[0335] Figure 13A network equipment device 1300 for timing and frequency adjustment in non-terrestrial networks is depicted according to embodiments of the present disclosure. In one embodiment, the network equipment 1300 may be an implementation of a RAN node, such as base station unit 110 and / or RAN node 110 as described above. Furthermore, the base station network equipment 1300 may include a processor 1305, a memory 1310, an input device 1315, an output device 1320, and a transceiver 1325.

[0336] In some embodiments, input device 1315 and output device 1320 are combined into a single device, such as a touch screen. In some embodiments, network device 1300 may not include any input device 1315 and / or output device 1320. In various embodiments, network device 1300 may include one or more of processor 1305, memory 1310, and transceiver 1325, and may not include input device 1315 and / or output device 1320.

[0337] As depicted, transceiver 1325 includes at least one transmitter 1330 and at least one receiver 1335. Here, transceiver 1325 communicates with one or more remote units 105. Additionally, transceiver 1325 may support at least one network interface 1340 and / or application programming interface 1345. Application programming interface 1345 may support one or more APIs. Network interface 1340 may support 3GPP reference points, such as Uu, N1, N2, and N3. Other network interfaces 1340 may be supported, as will be understood by those skilled in the art.

[0338] In one embodiment, processor 1305 may include any known controller capable of executing computer-readable instructions and / or performing logical operations. For example, processor 1305 may be a microcontroller, microprocessor, CPU, GPU, auxiliary processing unit, FPGA, or similar programmable controller. In some embodiments, processor 1305 executes instructions stored in memory 1310 to perform the methods and routines described herein. Processor 1305 is communicatively coupled to memory 1310, input device 1315, output device 1320, and transceiver 1325.

[0339] In various embodiments, network device 1300 is a RAN node (e.g., gNB) communicating with one or more UEs, as described herein. In such embodiments, processor 1305 controls network device 1300 to perform the RAN behaviors described above. When operating as a RAN node, processor 1305 may include an application processor (also referred to as the "main processor") that manages application domains and operating system ("OS") functions, and a baseband processor (also referred to as the "baseband radio processor") that manages radio functions.

[0340] In various embodiments, processor 1305 and transceiver 1325 control network device 1300 to perform the embodiments described above. For example, in one embodiment, transceiver 1325 transmits one of a first reference signal and a configuration message to a user equipment (“UE”) device; transmits a second reference signal to the UE device; transmits a control message including a first timing advance value to the UE device; and receives an uplink signal transmitted using a second timing advance value from the UE device, the second timing advance value being determined based on: a first frequency determined from one of the first reference signal and the configuration message; a second frequency determined from the second reference signal; and the first timing advance value.

[0341] In one embodiment, memory 1310 is a computer-readable storage medium. In some embodiments, memory 1310 includes volatile computer storage media. For example, memory 1310 may include RAM, including dynamic RAM (“DRAM”), synchronous dynamic RAM (“SDRAM”), and / or static RAM (“SRAM”). In some embodiments, memory 1310 includes non-volatile computer storage media. For example, memory 1310 may include a hard disk drive, flash memory, or any other suitable non-volatile computer storage device. In some embodiments, memory 1310 includes both volatile and non-volatile computer storage media.

[0342] In some embodiments, memory 1310 stores data related to timing and frequency adjustments in non-terrestrial networks. For example, memory 1310 may store parameters, configurations, resource assignments, policies, etc., as described above. In some embodiments, memory 1310 also stores program code and related data, such as an operating system or other controller algorithms operating on device 1300.

[0343] In one embodiment, input device 1315 may include any known computer input device, including a touchpad, button, keyboard, stylus, microphone, etc. In some embodiments, input device 1315 may be integrated with output device 1320 as, for example, a touchscreen or similar touch-sensitive display. In some embodiments, input device 1315 includes a touchscreen, enabling text input using a virtual keyboard displayed on the touchscreen and / or by handwriting on the touchscreen. In some embodiments, input device 1315 includes two or more different devices, such as a keyboard and a touchpad.

[0344] In one embodiment, output device 1320 may be designed to output visual, auditory, and / or tactile signals. In some embodiments, output device 1320 includes an electronically controllable display or display device capable of outputting visual data to a user. For example, output device 1320 may include (but is not limited to) an LCD display, LED display, OLED display, projector, or similar display device capable of outputting images, text, etc., to a user. As another non-limiting example, output device 1320 may include a wearable display, such as a smartwatch, smart glasses, head-up display, etc., which is separate from but communicatively coupled to the remainder of network device 1300. Furthermore, output device 1320 may be a component of a smartphone, personal digital assistant, television, desktop computer, laptop computer, personal computer, vehicle dashboard, etc.

[0345] In some embodiments, the output device 1320 includes one or more speakers for generating sound. For example, the output device 1320 may generate an auditory alarm or notification (e.g., a beep or chime). In some embodiments, the output device 1320 includes one or more haptic devices for generating vibration, motion, or other haptic feedback. In some embodiments, the output device 1320 may be wholly or partially integrated with the input device 1315. For example, the input device 1315 and the output device 1320 may form a touchscreen or a similar touch-sensitive display. In other embodiments, the output device 1320 may be located near the input device 1315.

[0346] Transceiver 1325 includes at least a transmitter 1330 and at least one receiver 1335. Similarly, one or more transmitters 1330 can be used to communicate with a UE, as described herein. Similarly, one or more receivers 1335 can be used to communicate with network functions in a PLMN and / or RAN, as described herein. Although only one transmitter 1330 and one receiver 1335 are described, network device 1300 may have any suitable number of transmitters 1330 and receivers 1335. Furthermore, transmitters 1330 and receivers 1335 may be of any suitable type.

[0347] Figure 14 One embodiment of a method 1400 for timing and frequency adjustment in a non-terrestrial network according to embodiments of the present disclosure is described. In various embodiments, method 1400 is performed by a user equipment device in a mobile communication network, such as remote unit 105, UE 205, and / or user equipment device 1200 described above. In some embodiments, method 1400 is performed by a processor, such as a microcontroller, microprocessor, CPU, GPU, auxiliary processing unit, FPGA, etc.

[0348] In one embodiment, method 1400 begins by determining a first frequency 1405 from one of a first reference signal received from the mobile wireless communication network and a configuration message received from the mobile wireless communication network. In another embodiment, method 1400 determines a second frequency 1410 from a second reference signal received from the mobile wireless communication network.

[0349] In one embodiment, method 1400 calculates a second timing advance value 1415 based on a first timing advance value, a first determined frequency, and a second determined frequency, wherein the first timing advance value is received as part of a control message. In one embodiment, method 1400 uses the second timing advance value to transmit an uplink signal 1420 to the mobile wireless communication network, and method 1400 terminates.

[0350] Figure 15 One embodiment of a method 1500 for timing and frequency adjustment in a non-terrestrial network according to embodiments of the present disclosure is described. In various embodiments, method 1500 is performed by the network device 1300 described above. In some embodiments, method 1500 is performed by a processor, such as a microcontroller, microprocessor, CPU, GPU, auxiliary processing unit, FPGA, etc.

[0351] Method 1500 begins and transmits one of a first reference signal and a configuration message to a user equipment (“UE”) device at 1505. In one embodiment, method 1500 transmits a second reference signal to the UE device at 1510. In one embodiment, method 1500 transmits a control message including a first timing advance value to the UE device at 1515. In one embodiment, method 1500 receives an uplink signal transmitted using the second timing advance value from the UE device at 1520, and method 1500 ends.

[0352] This document discloses a first device for timing and frequency adjustment in a non-terrestrial network according to embodiments of the present disclosure. The first device may be implemented by a user equipment device in a mobile communication network, such as the remote unit 105, UE 205, and / or user equipment device 1200 described above.

[0353] In one embodiment, the first device includes a processor that determines a first frequency from one of a first reference signal received from the mobile wireless communication network and a configuration message received from the mobile wireless communication network. In one embodiment, the processor determines a second frequency from a second reference signal received from the mobile wireless communication network. In one embodiment, the processor calculates a second timing advance value based on a first timing advance value, the first determined frequency, and the second determined frequency, the first timing advance value being received as part of a control message. In one embodiment, the first device includes a transceiver that transmits an uplink signal to the mobile wireless communication network using the second timing advance value.

[0354] In one embodiment, the transceiver receives an indication that the second reference signal is not altered by Doppler precompensation, the Doppler precompensation including frequency shift in the transmitter.

[0355] In one embodiment, the processor calculates the second timing advance value by calculating the ratio of the second determined frequency to the first determined frequency. In another embodiment, the processor calculates the second timing advance value by calculating the difference between a first time and a second time, the first time being associated with the time when the first timing advance value is received, and the second time being associated with the time when the uplink signal is transmitted.

[0356] In one embodiment, the processor calculates the second timing advance value based on the first timing advance value plus a differential timing advance value, wherein the differential timing advance value is equal to two times multiplied by a coefficient multiplied by a time difference, the coefficient including the ratio of the second frequency to the first frequency minus 1, and the time difference including the difference between a first time and a second time, the first time being associated with the time when the first timing advance value is received, and the second time being associated with the time when the uplink signal is transmitted.

[0357] In one embodiment, the processor calculates a second timing advance value based on a predefined time function that takes into account the first timing advance value, the first determined frequency, and the second determined frequency.

[0358] In one embodiment, the control message further includes an expiration timer value, such that transmitting the uplink signal using the second timing advance value is performed in response to determining that a first time associated with the time the control message is received, plus the expiration timer value, is greater than a second time associated with the time the uplink signal is transmitted.

[0359] In one embodiment, the transceiver transmits the uplink signal using the second timing advance value in response to receiving at least one of the following: an indication of a quasi-conjunction relationship between the first reference signal and the second reference signal; an indication of a quasi-conjunction relationship between the first reference signal and the first timing advance value; and an indication of a quasi-conjunction relationship between the second reference signal and the first timing advance value.

[0360] In one embodiment, the first reference signal includes a first synchronization signal, and the second reference signal includes a second synchronization signal. In one embodiment, the first frequency includes at least one of a carrier frequency, a carrier frequency without Doppler precompensation, a carrier frequency with Doppler precompensation, and a Doppler precompensated frequency.

[0361] In one embodiment, at least a portion of the mobile wireless communication network includes a non-terrestrial network that provides wireless connectivity between the UE and a gateway of the terrestrial network.

[0362] This document discloses a first method for timing and frequency adjustment in a non-terrestrial network according to embodiments of the present disclosure. The first method can be performed by a user equipment device in a mobile communication network, such as the remote unit 105, UE 205, and / or user equipment device 1200 described above.

[0363] In one embodiment, the first method includes determining a first frequency from one of a first reference signal received from the mobile wireless communication network and a configuration message received from the mobile wireless communication network. In one embodiment, the method includes determining a second frequency from a second reference signal received from the mobile wireless communication network. In one embodiment, the method includes calculating a second timing advance value based on a first timing advance value, the first determined frequency, and the second determined frequency, wherein the first timing advance value is received as part of a control message. In one embodiment, the method includes transmitting an uplink signal to the mobile wireless communication network using the second timing advance value.

[0364] In one embodiment, the first method receives an indication that the second reference signal is not altered by Doppler precompensation, the Doppler precompensation including frequency shift in the transmitter.

[0365] In one embodiment, the first method calculates the second timing advance value by calculating the ratio of the second determined frequency to the first determined frequency. In another embodiment, the first method calculates the second timing advance value by calculating the difference between a first time and a second time, the first time being associated with the time when the first timing advance value is received, and the second time being associated with the time when the uplink signal is transmitted.

[0366] In one embodiment, the first method calculates the second timing advance value based on the first timing advance value plus a differential timing advance value, wherein the differential timing advance value is equal to two times multiplied by a coefficient multiplied by a time difference, the coefficient including the ratio of the second frequency to the first frequency minus 1, and the time difference including the difference between a first time and a second time, the first time being associated with the time when the first timing advance value is received, and the second time being associated with the time when the uplink signal is transmitted.

[0367] In one embodiment, the first method calculates a second timing advance value based on a predefined time function that takes into account the first timing advance value, the first determined frequency, and the second determined frequency.

[0368] In one embodiment, the control message further includes an expiration timer value, such that transmitting the uplink signal using the second timing advance value is performed in response to determining that a first time associated with the time the control message is received, plus the expiration timer value, is greater than a second time associated with the time the uplink signal is transmitted.

[0369] In one embodiment, the first method transmits the uplink signal using the second timing advance value in response to receiving at least one of the following: an indication of a quasi-conjunction relationship between the first reference signal and the second reference signal; an indication of a quasi-conjunction relationship between the first reference signal and the first timing advance value; and an indication of a quasi-conjunction relationship between the second reference signal and the first timing advance value.

[0370] In one embodiment, the first reference signal includes a first synchronization signal, and the second reference signal includes a second synchronization signal. In one embodiment, the first frequency includes at least one of a carrier frequency, a carrier frequency without Doppler precompensation, a carrier frequency with Doppler precompensation, and a Doppler precompensated frequency.

[0371] In one embodiment, at least a portion of the mobile wireless communication network includes a non-terrestrial network that provides wireless connectivity between the UE and a gateway of the terrestrial network.

[0372] This document discloses a second device for timing and frequency adjustment in a non-terrestrial network according to embodiments of the present disclosure. The second device may be implemented by a base station, such as the gNB and / or network device 1300 described above.

[0373] In one embodiment, the second device includes: a transceiver that transmits one of a first reference signal and a configuration message to a user equipment (“UE”) device; transmits a second reference signal to the UE device; transmits a control message including a first timing advance value to the UE device; and receives an uplink signal transmitted using the second timing advance value from the UE device, the second timing advance value being determined based on: a first frequency determined from the first reference signal and the configuration message; a second frequency determined from the second reference signal; and the first timing advance value.

[0374] This document discloses a second method for timing and frequency adjustment in a non-terrestrial network according to embodiments of the present disclosure. The second method can be performed by a base station, such as the gNB and / or network device 1300 described above.

[0375] In one embodiment, the second method includes: transmitting one of a first reference signal and a configuration message to a user equipment (“UE”) device; transmitting a second reference signal to the UE device; transmitting a control message including a first timing advance value to the UE device; and receiving an uplink signal transmitted using the second timing advance value from the UE device, the second timing advance value being determined based on: a first frequency determined from one of the first reference signal and the configuration message; a second frequency determined from the second reference signal; and the first timing advance value.

[0376] Several abbreviations and mathematical symbols were used in the preceding text. Brief explanations of some are provided below:

[0377] ·quantity:

[0378] iG ephemeris information or location information

[0379] ii.L-Position, such as 3D coordinates

[0380] iii. P - Position, such as 3D coordinates

[0381] iv. V - velocity, for example:

[0382] 1. Velocity in 3D coordinates, or

[0383] 2. Direction of travel plus speed (the magnitude of speed)

[0384] vT - associated with a time, timestamp, or time reference of...

[0385] vi. TA - Timing Advancement

[0386] • Subscript:

[0387] i.NW-Network

[0388] ii. UE - User Equipment (usually on the ground, but for general purposes, it can also be off-ground)

[0389] iii. GW - Gateway (usually located on the ground)

[0390] iv. TRP-NT-TRP (or, for general purposes, ground-based TRP)

[0391] The embodiments may be practiced in other specific forms. The described embodiments should be considered illustrative rather than limiting in all respects. The scope of the invention is therefore indicated by the appended claims rather than by the foregoing description. All variations within the equivalent meaning and scope of the claims should be covered within their scope.

Claims

1. A user equipment (UE) comprising: At least one memory; and At least one processor, coupled to the at least one memory and configured such that the UE: The first frequency is determined from one of a first reference signal received from the mobile wireless communication network and a configuration message received from the mobile wireless communication network; The second frequency is determined from a second reference signal received from the mobile wireless communication network; A second timing advance value is calculated based on a first timing advance value, a determined first frequency, and a determined second frequency. The first timing advance value is received as part of a control message. Calculating the second timing advance value includes calculating the difference between a first time and a second time. The first time is associated with the time when the first timing advance value is received, and the second time is associated with the time when an uplink signal is transmitted. and The uplink signal is transmitted to the mobile wireless communication network using the second timing advance value.

2. The UE of claim 1, wherein the at least one processor is configured such that the UE receives an indication that the second reference signal is not altered by Doppler precompensation, the Doppler precompensation including frequency shift in the transmitter.

3. The UE of claim 1, wherein the at least one processor is configured such that the UE calculates the second timing advance value by calculating the ratio of the determined second frequency to the determined first frequency.

4. The UE of claim 1, wherein the at least one processor is configured such that the UE calculates the second timing advance value based on the first timing advance value plus the differential timing advance value, wherein: The differential timing advance value is equal to two times the coefficient multiplied by the time difference; The coefficient includes the ratio of the second frequency to the first frequency minus 1; The time difference includes the difference between the first time and the second time; The first time is associated with the time when the first timing advance value is received; and The second time is associated with the time of transmitting the uplink signal.

5. The UE of claim 1, wherein the at least one processor is configured such that the UE calculates the second timing advance value based on a predefined time function taking into account the first timing advance value, the determined first frequency, and the determined second frequency.

6. The UE of claim 1, wherein the control message further includes an expiration timer value, such that transmitting the uplink signal using the second timing advance value is performed in response to determining that a first time associated with the time of receiving the control message plus the expiration timer value is greater than a second time associated with the time of transmitting the uplink signal.

7. The UE of claim 6, wherein the at least one processor is configured such that the UE transmits the uplink signal using the second timing advance value in response to receiving at least one of the following: An indication of the quasi-parallel relationship between the first reference signal and the second reference signal; An indication of the quasi-parallel relationship between the first reference signal and the first timing advance value; and An indication of the quasi-parallel relationship between the second reference signal and the first timing advance value.

8. The UE according to claim 1, wherein the first reference signal includes a first synchronization signal, and the second reference signal includes a second synchronization signal.

9. The UE according to claim 1, wherein the first frequency includes a carrier frequency.

10. The UE of claim 1, wherein the first frequency includes at least one of a carrier frequency without Doppler precompensation, a carrier frequency with Doppler precompensation, and a Doppler precompensated frequency.

11. The UE of claim 1, wherein at least a portion of the mobile wireless communication network includes a non-terrestrial network that provides wireless connectivity between the user equipment (UE) and a gateway of a terrestrial network.

12. A method performed by a user equipment (UE), comprising: The first frequency is determined from one of a first reference signal received from the mobile wireless communication network and a configuration message received from the mobile wireless communication network; The second frequency is determined from a second reference signal received from the mobile wireless communication network; A second timing advance value is calculated based on a first timing advance value, a determined first frequency, and a determined second frequency. The first timing advance value is received as part of a control message. Calculating the second timing advance value includes calculating the difference between a first time and a second time. The first time is associated with the time when the first timing advance value is received, and the second time is associated with the time when an uplink signal is transmitted. and The uplink signal is transmitted to the mobile wireless communication network using the second timing advance value.

13. The method of claim 12, further comprising receiving an indication that the second reference signal is not altered by Doppler precompensation, the Doppler precompensation including frequency shift in the transmitter.

14. The method of claim 12, further comprising calculating the second timing advance value by calculating the ratio of the determined second frequency to the determined first frequency.

15. The method of claim 12, further comprising calculating the second timing advance value based on the first timing advance value plus the differential timing advance value, wherein: The differential timing advance value is equal to two times the coefficient multiplied by the time difference; The coefficient includes the ratio of the second frequency to the first frequency minus 1; The time difference includes the difference between the first time and the second time; The first time is associated with the time when the first timing advance value is received; and The second time is associated with the time of transmitting the uplink signal.

16. The method of claim 12, further comprising calculating the second timing advance value based on a predefined time function taking into account the first timing advance value, the determined first frequency, and the determined second frequency.

17. The method of claim 12, wherein the control message further includes an expiration timer value, such that transmitting the uplink signal using the second timing advance value is performed in response to determining that a first time associated with the time of receiving the control message plus the expiration timer value is greater than a second time associated with the time of transmitting the uplink signal.

18. The method of claim 17, further comprising transmitting the uplink signal using the second timing advance value in response to receiving at least one of the following: An indication of the quasi-parallel relationship between the first reference signal and the second reference signal; An indication of the quasi-parallel relationship between the first reference signal and the first timing advance value; and An indication of the quasi-parallel relationship between the second reference signal and the first timing advance value.

19. A base station, comprising: At least one memory; and At least one processor, coupled to the at least one memory and configured such that the base station: Transmit one of a first reference signal and a configuration message to the user equipment (UE); Transmit a second reference signal to the UE; Transmit a control message including a first timing advance value to the UE; and The UE receives an uplink signal transmitted using a second timing advance value, which is determined based on the following: A first frequency determined from either the first reference signal or the configuration message; The second frequency determined from the second reference signal; and The first timing advance value, wherein the second timing advance value includes the difference between a first time and a second time, the first time being associated with the time of transmitting the first timing advance value, and the second time being associated with the time of receiving the uplink signal.

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