Enhanced method and apparatus for transmit-receive transition gap

Abstract

The present disclosure provides enhanced methods of transmit-receive transition gap and apparatuses thereof. Solutions are proposed related to enhanced support for transmit-receive (Tx-Rx) gap in non-terrestrial network (NTN) communications. An apparatus implemented in a UE receives, from a non-terrestrial (NT) network node of a network, an uplink (UL) grant or configuration scheduling a UL transmission (Tx). The apparatus performs the UL Tx to the NT network node within a transmit-receive (Tx-Rx) transition gap, where no downlink (DL) Tx from the NT network node is expected during the Tx-Rx transition gap. The Tx-Rx transition gap includes a UL Tx duration, a UL Tx pre-gap (Gap_start) before a start time (t_start) of the UL Tx duration, and a UL Tx post-gap (Gap_end) after an end time (t_end) of the UL Tx duration.

Description

[0001] Cross Reference to Related Applications

[0002] This disclosure is part of a non-provisional application claiming priority to U.S. Provisional Patent Application No. 63 / 087,933, filed on October 06, 2020, the contents of which are incorporated in their entirety. TECHNICAL FIELD

[0003] The present disclosure relates generally to mobile communications, and more particularly, to enhanced support of transmit-receive (Tx-Rx) transition gaps in non-terrestrial network (NTN) communications. BACKGROUND

[0004] Unless otherwise stated in this document, the methods described in this section are not prior art to the claims listed below, and are not admitted to be prior art by virtue of their inclusion in this section.

[0005] In wireless communications, such as mobile communications according to the 3rd Generation Partnership Project (3GPP) specifications, timing advance (TA) generally refers to the length of time it takes for a signal to arrive at a base station from a user equipment (UE). Thus, in NTN communications, the TA can be quite large. The value of the TA can be estimated by the base station as part of an initial access procedure, or reported by the UE to the base station. In any case, the base station can not have a complete understanding of the TA. For frequency-division-duplexing (FDD)-half-duplex systems and time-division-duplexing (TDD), unless the base station knows the TA used by the UE, the downlink (DL) and uplink (UL) scheduled by the base station can collide at the UE. Thus, there is a need to enhance the mechanisms currently defined in the 3GPP specifications for half-duplex (HD)-FDD and TDD UEs in which symbols, slots, and / or subframes are used for UE transition between DL and UL transmissions in order to support large TA in NTN systems. Accordingly, there is a need for a solution to provide enhanced support of Tx-Rx transition gaps in NTN communications. SUMMARY

[0006] The following summary is illustrative only and is not intended to be limiting in any way. That is, the following summary is provided to introduce some concepts, highlights, benefits and advantages of the novel and non-obvious technology described herein. Selected implementations are described further below in the DETAILED DESCRIPTION. Thus, the following summary is not intended to identify essential features of the claimed subject matter, nor is it intended for use in determining the scope of the claimed subject matter.

[0007] An object of the present disclosure is to propose a solution or a scheme to solve the above problems. More specifically, various schemes proposed in the present disclosure include enhanced support for Tx-Rx switching gap in NTN communication.

[0008] In one aspect, a method can include a UE performing UL transmission to a non-terrestrial (NT) network node of a network within a Tx-Rx switching gap during which no DL transmission Tx from the NT network node is expected. The Tx-Rx switching gap can include an UL Tx duration, an UL Tx pre-gap before a start time of the UL Tx duration, and an UL Tx post-gap after an end time of the UL Tx duration.

[0009] In another aspect, a method can include a UE acquiring an initial value of a TA. The method can further include the UE receiving an indication of a TA drift rate or function from an NTN. In a case that the initial value of the TA is determined by the network, the TA drift rate or function can be specific to the UE or common for a beam or a cell associated with the UE. In a case that the initial value of the TA is determined by the UE, the TA drift rate or function can be common for a beam or a cell associated with the UE.

[0010] In yet another aspect, an apparatus implemented in a user equipment includes a memory and a processor coupled to the memory. The processor is configured to acquire an initial value of a TA and receive an indication of a TA drift rate or function from an NTN. In a case that the initial value of the TA is determined by the network, the TA drift rate or function can be specific to the UE or common for a beam or a cell associated with the UE. In a case that the initial value of the TA is determined by the UE, the TA drift rate or function can be common for a beam or a cell associated with the UE.

[0011] The present disclosure proposes an enhanced method of transmission-reception switching gap in non-terrestrial network communication and an apparatus thereof, which achieves the beneficial effect of solving the downlink (DL) and uplink (UL) collision.

[0012] It is worth noting that although the description provided herein can be in the context of certain radio access technologies, networks, and network topologies, such as NTNs, the proposed concepts, solutions, and any variants / derivatives thereof can be implemented in or for other types of radio access technologies, networks, and network topologies, for example but not limited to Long Term Evolution (LTE), LTE-Advanced, LTE-Advanced Pro, Fifth Generation (5G), New Radio (NR), Internet of Things (IoT), Narrow Band-Internet of Things (NB-IoT), Industrial Internet of Things (IIoT), and implemented by the aforementioned other types of radio access technologies, networks, and network topologies. Therefore, the scope of the present disclosure is not limited to the examples described herein. BRIEF DESCRIPTION OF DRAWINGS

[0013] The accompanying drawings are included to provide a further understanding of the present disclosure, and are incorporated in and constitute a part of the present disclosure. The drawings illustrate embodiments of the present disclosure and, together with the specification, serve to explain principles of the present disclosure. It should be apparent to those skilled in the art that the drawings are not necessarily to scale, as the emphasis is generally placed upon illustrating the principles of the present disclosure.

[0014] Figure 1 is a schematic diagram of an example network environment in which various proposed solutions according to the present disclosure can be implemented.

[0015] Figure 2 is a schematic diagram of an example scenario under the proposed solutions according to the present disclosure.

[0016] Figure 3 is a schematic diagram of an example scenario under the proposed solutions according to the present disclosure.

[0017] Figure 4 is a block diagram of an example communication system according to an embodiment of the present disclosure.

[0018] Figure 5 is a flowchart of an example process according to an embodiment of the present disclosure.

[0019] Figure 6 is a flowchart of an example process according to an embodiment of the present disclosure. DETAILED DESCRIPTION

[0020] Detailed embodiments and implementations of the claimed subject matter are disclosed herein. It should be understood, however, that the disclosed embodiments and implementations are merely examples of the claimed subject matter that can be implemented in various forms. In fact, the disclosure can be implemented in numerous ways, including but not limited to the exemplary embodiments and implementations described in this document. However, the disclosure should not be construed as limited to the examples set forth herein. Rather, these examples are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the disclosure to those skilled in the art. In the following description, details of well-known features and techniques can be omitted to avoid unnecessarily obscuring the presented embodiments and implementations.

[0021] SUMMARY

[0022] Implementations in accordance with the present disclosure include various techniques, methods, schemes, and / or solutions related to enhanced support for Tx-Rx switch gap in NTN communications. In accordance with the present disclosure, a number of possible solutions can be implemented individually or jointly. That is, although these possible solutions can be described separately below, two or more of these possible solutions can be implemented in one combination or another combination.

[0023] Figure 1 An example network environment 100 in which various proposed schemes in accordance with the present disclosure can be implemented is illustrated. The network environment 100 can include a UE 110 and a wireless network 120 (e.g., an LTE network, a 5G network, an NR network, an IoT network, an NB-IoT network, an IIoT network, and / or an NTN network). The UE 110 can communicate with the wireless network 120 via a network node 125. In some cases, the network node 125 can be an NT network node (e.g., a satellite) of an NTN. In some cases, the network node 125 can be a ground network node (e.g., a base station such as a gNB, an eNB, or a transmission and reception point (TRP)). As described below, each of the UE 110 and the network node 125 can be configured to perform operations related to enhanced support for Tx-Rx switch gap in NTN communications under various proposed schemes in accordance with the present disclosure.

[0024] Under a first proposed scheme in accordance with the present disclosure, a guard period as a Tx-Rx switch gap can be utilized around the beginning and end of an UL transmission. Figure 2 An example scenario 200 under the proposed scheme is illustrated, and Figure 3 An example scenario 300 under the proposed scheme is illustrated. Reference is made to Figure 2 and Figure 3, the start and end of the UL transmission can correspond to the scheduled start time t_start - TA and the scheduled end time t_end - TA, respectively. Due to timing drift, the first TA applied by the UE 110 at the start of the UL transmission can potentially be different from the second TA applied by the UE 110 at the end of the UL transmission. As shown in FIG. 6, from the perspective of the base station (e.g., network node 125), the time of the UL transmission by the UE 110 can be after the time of the UL grant by a first duration (e.g., K0+K1) of slots, due to accounting for the DL propagation delay and the UL propagation delay. Figure 2 As shown in FIG. 6, from the perspective of the base station (e.g., network node 125), the time of the UL transmission by the UE 110 can be after the time of the UL grant by a first duration (e.g., K0+K1) of slots, due to accounting for the DL propagation delay and the UL propagation delay. offset As shown in FIG. 6, from the perspective of the base station (e.g., network node 125), the time of the UL transmission by the UE 110 can be after the time of the UL grant by a first duration (e.g., K0+K1) of slots, due to accounting for the DL propagation delay and the UL propagation delay. offset As shown in FIG. 6, from the perspective of the base station (e.g., network node 125), the time of the UL transmission by the UE 110 can be after the time of the UL grant by a first duration (e.g., K0+K1) of slots, due to accounting for the DL propagation delay and the UL propagation delay. Figure 2 As shown in FIG. 6, from the perspective of the base station (e.g., network node 125), the time of the UL transmission by the UE 110 can be after the time of the UL grant by a first duration (e.g., K0+K1) of slots, due to accounting for the DL propagation delay and the UL propagation delay.

[0025] Under the proposed scheme, UL Tx pre-gap (Gap_start) and UL Tx post-gap (Gap_end) of the guard period can be defined such that during the duration of the Tx-Rx switching gap from t_start - TA - Gap_start until t_end - TA + Gap_end (as shown in FIGs. 7 and 8), the UE 110 is expected to not receive any DL transmission (and thus should not be performed by the base station), especially since the UE 110 can perform the UL transmission (e.g., due to receiving the UL grant from the network node 125) during this Tx-Rx switching gap. Advantageously, the use of the guard period to provide the pre-UL span and the post-UL span can allow for radio frequency (RF) retuning and alignment of symbols / slots. Moreover, the use of the guard period as the pre-UL span and the post-UL span can account for the partial lack of knowledge of the base station of the actual TA. Figure 2 Figure 3 Under the proposed scheme, the values of Gap_start and Gap_end can be the same or different. Moreover, t_start - TA - Gap_start can be rounded down to the start of the first symbol, slot, or subframe of the UL transmission. Similarly, t_end - TA + Gap_end can be rounded up to the end of the last symbol, slot, or subframe of the UL transmission.

[0026] Under the proposed scheme, the values of Gap_start and Gap_end can be the same or different. Moreover, t_start - TA - Gap_start can be rounded down to the start of the first symbol, slot, or subframe of the UL transmission. Similarly, t_end - TA + Gap_end can be rounded up to the end of the last symbol, slot, or subframe of the UL transmission.

[0027] ​Under the proposed scheme, the use of the guard period around the start and end of UL transmission can be applied to the HD-FDD mode, the TDD mode, or both. In this case, the values of Gap_start and Gap_end can be the same or different for the HD-FDD mode or the TDD mode.

[0028] Under the proposed scheme, the values of Gap_start and Gap_end can be defined in the 3GPP specification on NTN. Alternatively, the values of Gap_start and Gap_end can be signaled to the UE 110 by the wireless network 120.

[0029] Under the proposed scheme, the values of Gap_start and Gap_end can depend on the frequency band, the frequency range, or the subcarrier spacing. For example, in NR, the frequency range 1 (FR1) and the frequency range 2 (FR2) can have different values of Gap_start and Gap_end, respectively.

[0030] Under the proposed scheme, the values of Gap_start and Gap_end can depend on the UE category or the UE capability. For example, depending on the category or the capability, the values of Gap_start and Gap_end used by a first UE can be different from the values of Gap_start and Gap_end used by a second UE in the case that the first UE and the second UE have different categories or capabilities.

[0031] Under the proposed scheme, the values of Gap_start and Gap_end can depend on the synchronization method and the TA reporting setting. For example, with respect to the synchronization method, the synchronization between the UE 110 and the wireless network 120 (or the network node 125) can be based on the Global Navigation Satellite System (GNSS) capability, or can be based on the determination of the network-driven TA. Therefore, the values of Gap_start and Gap_end can be different between those synchronization methods. With respect to the TA reporting setting, the UE 110 can report its TA to the network node 125 based on the triggering (e.g., by the UE 110 itself or by the network node 125) or based on the hysteresis value. Therefore, the values of Gap_start and Gap_end can be different between those TA reporting settings.

[0032] Under a second proposed solution in accordance with the present disclosure, TA drift rate can be reported by the network to the UE, as the actual value of the TA can change over time, the TA is estimated by the base station and indicated to the UE or reported by the UE to the base station. In the first case where the base station is the one determining the TA, the base station can indicate to the UE how the TA changes or drifts over time (e.g., TA drift rate). As the base station can communicate with multiple UEs, and the respective TA drift rate for each UE can be different, the indication can be specific to the UE. Alternatively, the TA drift rate can be beam or cell based, and thus the TA drift rate can be common for all UEs within the coverage of the beam or cell. For the first case, the UE (e.g., UE 110) can continuously update its TA based on the signaled initial TA and the TA drift rate (which can be in the form of a TA drift function). For example, UE 110 can determine or otherwise time the updated location of the guard period or Tx-Rx switching gap based on its own updated TA (e.g., t start - TA updated - Gap start and t end - TA updated + Gap end can be based on the UE’s updated TA).

[0033] In the second case where the UE is a UE that determines the TA and reports it to the base station, the base station can indicate to the UE a value of the estimated TA drift rate used by the base station to update its TA. In this case, the TA drift rate can be considered as a beam or cell based TA drift rate. For the second case, the UE (e.g., UE 110) can be able to determine two quantities, TA_used and TA_updated. The value of TA_used can be based on the TA calculated by the UE for UL synchronization, and the UE calculated TA can be based on UE location and satellite location or another method. The value of TA_updated can be based on the TA report already provided by the UE to the base station, and where the TA report is updated with a TA drift rate (or TA drift function). For example, UE 110 can calculate the difference TA_diff between TA_used and TA_updated as TA_diff = TA_used - TA_updated. UE 110 can determine a trigger for a TA report based on TA_diff crossing a threshold Thrd (e.g., the trigger can occur when abs(TA_diff) > Thrd). The value of threshold Thrd can be set by the base station or fixed in 3GPP specifications. In addition, UE 110 can account for the location of the Tx-Rx switching gap based on its own updated TA (e.g., t_start - TA_updated - Gap_start and t_end - TA_updated + Gap_end). Alternatively, UE 110 can account for the location of the Tx-Rx switching gap based on its own used TA (including the value of Thrd) (e.g., t_start - TA_used - Thrd - Gap_start and t_end - TA_used + Thrd + Gap_end). It is noted that alternative formulas can also be used to account for any mismatch between the TA used at the UE and the TA assumed by the base station.

[0034] Exemplary Embodiments

[0035] Figure 4 An example communication system 400 with an example communication device 410 and an example network device 420 according to embodiments of the present disclosure is illustrated. Each of the communication device 410 and the network device 420 can perform various functions to implement the schemes, techniques, procedures, and methods described herein related to enhanced support of Tx-Rx switching gap in NTN communications, including the scenarios / schemes described above and the flows described below.

[0036] Communication device 410 may be part of an electronic device, such as a portable or mobile device, a wearable device, a wireless communication device, or a computing device (UE). For example, communication device 410 may be implemented in a smartphone, smartwatch, personal digital assistant, digital camera, or computing device (such as a tablet, laptop, or notebook computer). Communication device 410 may also be part of a machine-type device, such as an IoT, NB-IoT, IIoT, or NTN device, such as a fixed or stationary device, a home device, a wired communication device, or a computing device. For example, communication device 410 may be implemented in a smart thermostat, smart refrigerator, smart door lock, wireless speaker, or home control center. Alternatively, communication device 410 may be implemented in the form of one or more integrated circuit (IC) chips, such as, but not limited to, one or more single-core processors, one or more multi-core processors, one or more Reduced Instruction Set Computing (RISC) processors, or one or more Complex Instruction Set Computing (CISC) processors. For example, communication device 410 may include... Figure 4 At least some of the components shown, such as processor 412. Communication device 410 may also include one or more other components unrelated to the scheme presented in this disclosure (e.g., internal power supply, display device, and / or user interface device), and therefore, for simplicity and brevity, such components of communication device 410 are not included in... Figure 4 It is shown in the text and is not described below.

[0037] Network device 420 may be part of an electronic device / station, which may be a network node such as a base station, small cell, router, gateway, or satellite. For example, network device 420 may be implemented in an eNodeB in LTE, in a gNB in ​​5G, NR, IoT, NB-IoT, IIoT, or in a satellite in an NTN network. Alternatively, network device 420 may be implemented as one or more IC chips, such as, but not limited to, one or more single-core processors, one or more multi-core processors, or one or more RISC or CISC processors. For example, network device 420 may include... Figure 4 At least some of the components shown, such as processor 422. Network device 420 may also include one or more other components (e.g., internal power supply, display device, and / or user interface device) unrelated to the proposed scheme of this disclosure, and therefore, for simplicity and brevity, such components of network device 420 are not included. Figure 4 It is shown in the text and is not described below.

[0038] In one aspect, each of the processor 412 and the processor 422 can be implemented in the form of one or more single-core processors, one or more multi-core processors, one or more RISC processors, or one or more CISC processors. That is, although the singular term “processor” is used herein to refer to the processor 412 and the processor 422, each of the processor 412 and the processor 422 can include multiple processors in some implementations, and can include a single processor in other implementations in accordance with the present disclosure. In another aspect, each of the processor 412 and the processor 422 can be implemented in the form of hardware having electronic components, including, for example and without limitation, one or more transistors, one or more diodes, one or more capacitors, one or more resistors, one or more inductors, one or more memristors, and / or one or more varactors configured and arranged to carry out the particular purposes of the present disclosure. In other words, in at least some implementations, each of the processor 412 and the processor 422 is a special purpose machine specially designed, arranged, and configured to perform particular tasks, including enhanced support for Tx-Rx switch gap in NTN communications in accordance with various implementations of the present disclosure.

[0039] In some implementations, the communication device 410 can further include a transceiver 416 coupled to the processor 412 and capable of wirelessly transmitting and receiving data. In some implementations, the communication device 410 can further include a memory 414 coupled to the processor 412 and accessible by the processor 412 and in which data can be stored. In some implementations, the network device 420 can further include a transceiver 426 coupled to the processor 422 and capable of wirelessly transmitting and receiving data. In some implementations, the network device 420 can further include a memory 424 coupled to the processor 422 and accessible by the processor 422 and in which data can be stored. Accordingly, the communication device 410 and the network device 420 can wirelessly communicate with each other via the transceiver 416 and the transceiver 426, respectively.

[0040] Each of the communication device 410 and the network device 420 can be a communication entity capable of communicating with each other using various proposed schemes according to the present disclosure. To help better understanding, the following description of the operation, function, and capability of each of the communication device 410 and the network device 420 is provided in the context of a mobile communication environment in which the communication device 410 is implemented in or as a communication device or UE (e.g., the UE 110) and the network device 420 is implemented in or as a network node or base station (e.g., the network node 125) of a communication network (e.g., the network 120). It is also worth noting that although the example implementations described below are provided in the context of an NTN, the same implementations can also be implemented in other types of networks.

[0041] Under some proposed schemes according to the present disclosure related to enhanced support of Tx-Rx switch gap in NTN communications, in which the communication device 410 is implemented in or as the UE 110 and the network device 420 is implemented in or as the network node 125 in the network environment 100, the processor 412 can receive, via the transceiver 416, a UL grant or configuration scheduling a UL Tx from the device 420 that is an NTN network node (e.g., the network node 125) of a network (e.g., the network 120). In addition, the processor 412 can perform, via the transceiver 416, a UL transmission to the device 420 within a Tx-Rx switch gap during which no DL Tx from the device 420 is expected.

[0042] In some implementations, the Tx-Rx switch gap can include a UL Tx duration, a UL Tx pre-gap (Gap_start) before a start time (t_start) of the UL Tx duration, and a UL Tx post-gap (Gap_end) after an end time (t_end) of the UL Tx duration. Further, the start timing of the Tx-Rx switch gap is expressed as t_start - TA - Gap_start from the perspective of the device 420. Further, the end time of the Tx-Rx switch gap is expressed as t_end - TA + Gap_end from the perspective of the device 420.

[0043] In some implementations, the start timing of the Tx-Rx switch gap can be rounded down to the start of the first symbol, slot, or subframe of the UL Tx. In addition, the end time of the Tx-Rx switch gap can be rounded up to the end of the last symbol, slot, or subframe of the UL Tx.

[0044] In some implementations, the value of the UL Tx before gap and the value of the UL Tx after gap can be the same. Alternatively, the value of the UL Tx before gap and the value of the UL Tx after gap can be different.

[0045] In some implementations, the UL grant can be received, and the UL Tx can be performed with HD-FDD, TDD, or both. In this case, the corresponding value of each of the Gap_start and the Gap_end can vary or remain fixed between the HD-FDD mode and the TDD mode.

[0046] In some implementations, the corresponding value of each of the Gap_start and the Gap_end can be fixed or signaled by the network.

[0047] In some implementations, the corresponding value of each of the Gap_start and the Gap_end can depend on a frequency band, a frequency range, or a subcarrier spacing.

[0048] In some implementations, the corresponding value of each of the Gap_start and the Gap_end can depend on a category or capability of the UE.

[0049] In some implementations, the corresponding value of each of the Gap_start and the Gap_end can depend on a synchronization method or a TA reporting setting.

[0050] In some implementations, the processor 412 can perform additional operations. For example, the processor 412 can obtain an initial value of the TA (e.g., by determining the initial value of the TA by the processor 412 or by receiving the initial value of the TA from the apparatus 420 or another network node of the network). Additionally, the processor 412 can receive an indication of a TA drift rate or function from the network via the transceiver 416.

[0051] In some implementations, in a case where the initial value of the TA is determined by the network, the TA drift rate or function can be specific to the UE or common for beams or cells associated with the UE. Further, in a case where the initial value of the TA is determined by the UE, the TA drift rate or function can be common for beams or cells associated with the UE.

[0052] In some implementations, in response to the initial value of the TA being determined by the network, the processor 412 can perform additional operations. For example, the processor 412 can update the TA based on the initial value of the TA and the TA drift rate or function to provide an updated TA (TA_updated). Further, the processor 412 can determine an updated location of the time Tx-Rx transition gap based on the TA_updated.

[0053] In some embodiments, in response to the initial value of the TA being determined by the UE, the processor 412 can perform additional operations. For example, the processor 412 can send, via the transceiver 416, a TA report to the network (e.g., via the apparatus 420 or another network node) indicating the value of the TA determined by the UE. In addition, the processor 412 can calculate a TA used for UL synchronization (TA_used) based on the location of the UE and the location of the NT network node. Further, the processor 412 can calculate an updated TA (TA_updated) based on the TA indicated in the TA report and a TA drift rate or function. Further, the processor 412 can calculate a differential TA (TA_diff) based on the difference between TA_used and TA_updated. Further, the processor 412 can determine whether the magnitude of TA_diff is greater than a threshold. Further, the processor 412 can send, via the transceiver 416, a TA report to the network in response to TA_diff being greater than the threshold.

[0054] In some embodiments, the processor 412 can perform additional operations. For example, the processor 412 can determine an updated location of the time Tx-Rx transition gap based on any of: (a) the TA_used and the threshold; or (b) the TA_updated.

[0055] In some proposed schemes according to the present disclosure related to support for enhancements to Tx-Rx transition gaps in NTN communications, in which the communication apparatus 410 is implemented in or as a UE 110 and the network apparatus 420 is implemented in or as a network node 125 in the network environment 100, the processor 412 can obtain an initial value of a TA. For example, the processor 412 can obtain the initial value of the TA by determining the initial value of the TA itself or by receiving the initial value of the TA from the apparatus 420 (as the network node 125) or another network node of the network (e.g., an NTN such as the network 120). In addition, the processor 412 can receive, via the transceiver 416, an indication of a TA drift rate or function from the NTN.

[0056] In some embodiments, in the case where the initial value of the TA is determined by the network, the TA drift rate or function can be specific to the UE or common to a beam or cell associated with the UE. In addition, in the case where the initial value of the TA is determined by the UE, the TA drift rate or function can be common to the beam or cell associated with the UE.

[0057] In some embodiments, in response to the initial value of the TA being determined by the network, the processor 412 can perform additional operations. For example, the processor 412 can update the TA based on the initial value of the TA and a TA drift rate or function to provide an updated TA (TA updated). Further, the processor 412 can determine an updated location of the Tx-Rx switching gap in time based on the TA updated.

[0058] In some embodiments, in response to the initial value of the TA being determined by the UE, the processor 412 can perform additional operations. For example, the processor 412 can transmit, via the transceiver 416, a TA report to the network indicating the value of the TA determined by the UE. Additionally, the processor 412 can calculate a TA used for UL synchronization (TA used) based on a location of the UE and a location of the NT network node. Further, the processor 412 can calculate an updated TA (TA updated) based on the TA indicated in the TA report and a TA drift rate or function. Moreover, the processor 412 can determine an updated location of the Tx-Rx switching gap in time based on any of: (a) the TA used and a threshold, or (b) the TA updated.

[0059] In some embodiments, the processor 412 can perform additional operations. For example, the processor 412 can calculate a differential TA (TA diff) based on a difference between the TA used and the TA updated. Further, the processor 412 can determine whether a magnitude of the TA diff is greater than a threshold. Moreover, the processor 412 can transmit, via the transceiver 416, a TA report to the network in response to the TA diff being greater than the threshold.

[0060] Exemplary flow

[0061] Figure 5 An example flow 500 is illustrated in accordance with an embodiment of the present disclosure. The flow 500 can be an example implementation of the approaches described above in part or in whole with respect to support for enhancements to Tx-Rx switching gaps in NTN communications, in accordance with the present disclosure. The flow 500 can be representative of aspects of implementing features of the communication apparatus 410 and / or the network apparatus 420. The flow 500 can include one or more operations, actions, or functions as illustrated in one or more of blocks 510 and 520. Although illustrated as discrete blocks, various blocks of the flow 500 can be divided into more blocks, combined into fewer blocks, or eliminated, depending on the intended implementation. Further, the blocks of the flow 500 can be performed in any order, including in parallel, depending on the intended implementation. Figure 5The illustrated order of execution or alternatively, the order of execution can be different. The flow 500 can be implemented by the communication apparatus 410 or any suitable UE or machine type device. For illustrative purposes only and not by way of limitation, the flow 500 is described below in the context of being implemented in or as the communication apparatus 410 of the UE 110 and the network apparatus 420 of the network node 125. The flow 500 can begin at block 510.

[0062] At block 510, the flow 500 can include the processor 412 of the apparatus 410 as the UE 110 receiving, via the transceiver 416, an UL grant or configuration scheduling a UL Tx from the apparatus 420 as the NT network node (e.g., the network node 125) of the network (e.g., the network 120). The flow 500 can proceed from block 510 to block 520.

[0063] At block 520, the flow 500 can include the processor 412 performing, via the transceiver 416, the UL transmission to the apparatus 420 within a Tx-Rx switching gap during which no DL Tx from the apparatus 420 is expected.

[0064] In some implementations, the Tx-Rx switching gap can include a UL Tx duration, a UL Tx pre-gap (Gap start) before a start time (t start) of the UL Tx duration, and a UL Tx post-gap (Gap end) after an end time (t end) of the UL Tx duration. Further, the start timing of the Tx-Rx switching gap is expressed as t start - TA - Gap start from the perspective of the apparatus 420. Further, the end time of the Tx-Rx switching gap is expressed as t end - TA + Gap end from the perspective of the apparatus 420.

[0065] In some implementations, the start timing of the Tx-Rx switching gap can be rounded down to the start of the first symbol, slot, or subframe of the UL Tx. Additionally, the end time of the Tx-Rx switching gap can be rounded up to the end of the last symbol, slot, or subframe of the UL Tx.

[0066] In some implementations, the value of the UL Tx pre-gap and the value of the UL Tx post-gap can be the same. Alternatively, the value of the UL Tx pre-gap and the value of the UL Tx post-gap can be different.

[0067] In some implementations, the UL grant can be received, and the UL Tx can be performed with HD-FDD, TDD, or both. In this case, the corresponding value of each of Gap_start and Gap_end can vary or remain fixed between the HD-FDD mode and the TDD mode.

[0068] In some implementations, the corresponding value of each of Gap_start and Gap_end can be fixed or signaled by the network.

[0069] In some implementations, the corresponding value of each of Gap_start and Gap_end can depend on a frequency band, a frequency range, or a subcarrier spacing.

[0070] In some implementations, the corresponding value of each of Gap_start and Gap_end can depend on a category or capability of the UE.

[0071] In some implementations, the corresponding value of each of Gap_start and Gap_end can depend on a synchronization method or a TA reporting setting.

[0072] In some implementations, the process 500 can include the processor 412 performing additional operations. For example, the process 500 can include the processor 412 obtaining an initial value of the TA (e.g., by the processor 412 determining the initial value of the TA or by receiving the initial value of the TA from the apparatus 420 or another network node of the network). Additionally, the process 500 can include the processor 412 receiving an indication of a TA drift rate or function from the network via the transceiver 416.

[0073] In some implementations, where the initial value of the TA is determined by the network, the TA drift rate or function can be specific to the UE or common to beams or cells associated with the UE. Further, where the initial value of the TA is determined by the UE, the TA drift rate or function can be common to beams or cells associated with the UE.

[0074] In some implementations, in response to the initial value of the TA being determined by the network, the process 500 can include the processor 412 performing additional operations. For example, the process 500 can include the processor 412 updating the TA based on the initial value of the TA and the TA drift rate or function to provide an updated TA (TA_updated). Further, the process 500 can include the processor 412 determining an updated location of the time Tx-Rx transition gap based on the TA_updated.

[0075] In some implementations, flow 500 can include processor 412 performing additional operations in response to the initial value of TA being determined by the UE. For example, flow 500 can include processor 412 transmitting, via transceiver 416, a TA report to the network (e.g., via apparatus 420 or another network node) indicating the value of TA determined by the UE. Additionally, flow 500 can include processor 412 calculating a TA used for UL synchronization (TA_used) based on the location of the UE and the location of the NT network node. Moreover, flow 500 can include processor 412 calculating an updated TA (TA_updated) based on the TA drift rate or function and the TA indicated in the TA report. Further, flow 500 can include processor 412 calculating a differential TA (TA_diff) based on a difference between TA_used and TA_updated. Further still, flow 500 can include processor 412 determining whether a magnitude of TA_diff is greater than a threshold. Further still, flow 500 can include processor 412 transmitting, via transceiver 416, a TA report to the network in response to TA_diff being greater than the threshold.

[0076] In some implementations, flow 500 can include processor 412 performing additional operations. For example, flow 500 can include processor 412 determining an updated location of the time Tx-Rx transition gap based on any of: (a) TA_used and the threshold; or (b) TA_updated.

[0077] Figure 6 An example flow 600 is illustrated in accordance with an implementation of the present disclosure. Flow 600 can be an example implementation of a scheme as described above in part or in whole with respect to support for enhancements to Tx-Rx transition gaps in NTN communications. Flow 600 can be representative of aspects of implementing features of communication apparatus 410 and / or network apparatus 420. Flow 600 can include one or more operations, actions, or functions as illustrated in one or more of blocks 610 and 620. Although illustrated as discrete blocks, various blocks of flow 600 can be divided into more blocks, combined into fewer blocks, or eliminated, depending on the intended implementation. Further, the blocks of flow 600 can be performed in the order shown or, alternatively, in a different order. Flow 600 can be implemented by communication apparatus 410 or any suitable UE or machine type device. For illustrative purposes only and not by way of limitation, flow 600 is described below in the context of communication apparatus 410 implemented in or as UE 110 and network apparatus 420 implemented in or as network node 125. Flow 600 can begin at block 610. Figure 6

[0078] ​At block 610, the process 600 can include the processor 412 of the apparatus 410, as a UE 110, acquiring an initial value of a TA. For example, the processor 412 can acquire the initial value of the TA by determining the initial value of the TA itself or by receiving the initial value of the TA from the apparatus 420 (as a network node 125) or another network node of the network (e.g., an NTN such as the network 120). The process 600 can proceed from block 610 to block 620.

[0079] At block 620, the process 600 can include the processor 412 receiving, via the transceiver 416, an indication of a TA drift rate or function from the NTN.

[0080] In some implementations, where the initial value of the TA is determined by the network, the TA drift rate or function can be specific to the UE or common to beams or cells associated with the UE. Further, where the initial value of the TA is determined by the UE, the TA drift rate or function can be common to beams or cells associated with the UE.

[0081] In some implementations, in response to the initial value of the TA being determined by the network, the process 600 can include the processor 412 performing additional operations. For example, the process 600 can include the processor 412 updating the TA based on the initial value of the TA and the TA drift rate or function to provide an updated TA (TA_updated). Further, the process 600 can include the processor 412 determining an updated location of the Tx-Rx switching gap in time based on the TA_updated.

[0082] In some implementations, in response to the initial value of the TA being determined by the UE, the process 600 can include the processor 412 performing additional operations. For example, the process 600 can include the processor 412 transmitting, via the transceiver 416, a TA report to the network indicating the value of the TA determined by the UE. Additionally, the process 600 can include the processor 412 calculating a TA used for UL synchronization (TA_used) based on a location of the UE and a location of the NTN node. Further, the process 600 can include the processor 412 calculating an updated TA (TA_updated) based on the TA drift rate or function and the TA indicated in the TA report. Further, the process 600 can include the processor 412 determining an updated location of the Tx-Rx switching gap in time based on any of: (a) the TA_used and a threshold value, or (b) the TA_updated.

[0083] In some implementations, the process 600 can include the processor 412 performing additional operations. For example, the process 600 can include the processor 412 calculating a differential TA (TA_diff) based on a difference between the TA_used and the TA_updated. Further, the process 600 can include the processor 412 determining whether a magnitude of the TA_diff is greater than a threshold. Further, the process 600 can include the processor 412 transmitting a TA report to the network via the transceiver 416 in response to the TA_diff being greater than the threshold.

[0084] Additional Description

[0085] The subject matter described herein is sometimes illustrated using different components contained within, or connected with, different other components. It is to be understood that the architectures depicted are merely examples, and that in fact many other architectures can be implemented which achieve the same functionality. In concept, any arrangement of components to achieve the same functionality is effectively "associated" such that the desired functionality is achieved. Hence, any two components herein combined to achieve a particular functionality can be seen as "associated with" each other such that the desired functionality is achieved, irrespective of architectures or intermediate components. Likewise, any two components so associated can also be viewed as being "operably connected", or "operably coupled", to each other to achieve the desired functionality, and any two components capable of being so associated can also be viewed as being "operably couplable", to each other to achieve the desired functionality. Specific examples of operably couplable include but are not limited to physically mateable and / or physically interacting components and / or wirelessly interactable and / or wirelessly interacting components and / or logically interacting and / or logically interactable components.

[0086] Further, with respect to the use of substantially any plural and / or singular terms herein, those having skill in the art can translate the concurrency and / or the singularity to the plural and / or the singularity as is appropriate to the context and / or application. And any singular / plural versions herein can be specifically recited herein for clarity.

[0087] Furthermore, those skilled in the art will understand that, generally, the terms used herein, and especially those used in the appended claims, such as the body of the appended claims, are generally intended as “open” terms; for example, the term “comprising” should be interpreted as “including but not limited to,” the term “having” should be interpreted as “at least having,” and the term “comprising” should be interpreted as “including but not limited to,” etc. Those skilled in the art will further understand that if it is intended to introduce a specific number of claim statements in a claim, such intention will be explicitly stated in the claim, and without such statements, such intention does not exist. For example, for ease of understanding, the appended claims may contain the introductory phrases “at least one” and “one or more” to introduce claim statements. However, the use of such phrases should not be construed as implying that a claim statement introduced by the indefinite article "a" or "an" limits any particular claim containing such an introduced claim statement to an implementation containing only one such statement, even when the same claim includes the introductory phrase "one or more" or "at least one" and indefinite articles such as "a" or "an" (e.g., "a" and / or "an" should be interpreted as meaning "at least one" or "one or more"); the same applies to the use of definite articles used to introduce claim statements. Furthermore, even if a specific number of introduced claim statements are explicitly stated, those skilled in the art will recognize that such a statement should be interpreted as meaning at least the number stated; for example, simply stating "two statements" without other modifiers means at least two statements, or two or more statements. Furthermore, in cases where conventions such as "at least one of A, B, and C" are used, the construction is generally intended to be understood by a person skilled in the art in the sense of the convention. For example, "a system having at least one of A, B, and C" will include, but is not limited to, systems having only A, only B, only C, A and B together, A and C together, B and C together, and / or A, B, and C together, etc. In cases where conventions such as "at least one of A, B, or C" are used, the construction is generally intended to be understood by a person skilled in the art in the sense of the convention. For example, "a system having at least one of A, B, or C" will include, but is not limited to, systems having only A, only B, only C, A and B together, A and C together, B and C together, and / or A, B, and C together, etc. A person skilled in the art will further understand that virtually any extractive word and / or phrase (whether in the specification, claims, or drawings) presenting two or more alternative terms should be understood to contemplate the possibility of including one, any, or both of the terms. For example, the phrase "A or B" will be understood to include the possibility of "A" or "B" or "A and B".

[0088] In light of the foregoing, it should be appreciated that the various embodiments of the present disclosure have been described herein for illustrative purposes, and that various modifications are possible without departing from the scope and spirit of the present disclosure. Accordingly, the various embodiments disclosed herein are not intended to be limiting, the true scope and spirit being indicated by the following claims.

Claims

1. An enhanced method of transmit receive transition gap, the method comprising: performing, by an apparatus implemented in a user equipment, an uplink transmission to a non-terrestrial network node of a network within a transmit-receive transition gap during which no downlink transmission from the non-terrestrial network node is expected, wherein the transmit-receive transition gap comprises an uplink transmission duration, an uplink transmission pre-gap preceding a start time of the uplink transmission duration, and an uplink transmission post-gap following an end time of the uplink transmission duration, wherein the start time of the uplink transmission duration is denoted as t start, the uplink transmission pre-gap preceding the start time of the uplink transmission duration is denoted as Gap start, the end time of the uplink transmission duration is denoted as t end, and the uplink transmission post-gap following the end time of the uplink transmission duration is denoted as Gap end, and wherein, from the perspective of the non-terrestrial network node: a start timing of the transmit-receive transition gap is denoted as: t start - timing advance - Gap start, and an end time of the transmit-receive transition gap is denoted as: t end - timing advance + Gap end.

2. The method of enhancing a transmit-receive transition gap according to claim 1, wherein, the start timing of the transmit-receive transition gap is rounded down to a start of a first symbol, slot or subframe of the uplink transmission, and wherein the end time of the transmit-receive transition gap is rounded up to an end of a last symbol, slot or subframe of the uplink transmission.

3. The method of enhancing a transmit-receive transition gap according to claim 1, wherein, a value of the uplink transmission pre-gap and a value of the uplink transmission post-gap are the same or different.

4. The method of enhancing a transmit-receive transition gap according to claim 1, wherein, an uplink grant is received, and the uplink transmission is performed with half duplex frequency division duplexing, time division duplexing or both.

5. The method of enhancing a transmit-receive transition gap according to claim 4, wherein, a corresponding value of each of the Gap start and the Gap end varies or remains fixed between a half duplex frequency division duplexing mode and a time division duplexing mode.

6. The method of enhancing a transmit-receive transition gap according to claim 1, wherein, a corresponding value of each of the Gap start and the Gap end is fixed or signaled by the network.

7. The method of enhancing a transmit-receive transition gap according to claim 1, wherein, a corresponding value of each of the Gap start and the Gap end depends on at least one of: a frequency band, a frequency range or a subcarrier spacing; a category or capability of the user equipment; and a synchronization method or a timing advance reporting setting.

8. The method of enhancing a transmit-receive transition gap according to claim 1, wherein, the method further comprises: obtaining an initial value of the timing advance; receiving, from the network, an indication of a timing advance drift rate or a drift function; and receiving, from the network, an uplink grant or a configuration scheduling the uplink transmission, wherein the step of performing the uplink transmission comprises performing the uplink transmission in response to receiving the uplink grant or the configuration.

9. The enhanced method of transmit receive transition gap according to claim 8, characterized in that, in case the initial value of the timing advance is determined by the network, the timing advance drift rate or drift function is specific to the user equipment or common for a beam or a cell associated with the user equipment, and in case the initial value of the timing advance is determined by the user equipment, the timing advance drift rate or drift function is common for the beam or the cell associated with the user equipment.

10. The enhanced method of transmit-receive transition gap according to claim 8, characterized in that, in response to the initial value of the timing advance being determined by the network, the method further comprises: updating the timing advance based on the initial value of the timing advance and the timing advance drift rate or drift function to provide an updated timing advance, wherein the updated timing advance is denoted as TA_updated; and determining an updated position in time of the transmission-reception transition gap based on the TA_updated.

11. The method of enhancing a transmit-receive transition gap according to claim 8, wherein, in response to the initial value of the timing advance being determined by the user equipment, the method further comprises: sending a timing advance report to the network indicating the value of the timing advance determined by the user equipment; calculating a used timing advance for uplink synchronization based on a position of the user equipment and a position of the non-terrestrial network node, wherein the used timing advance is denoted as TA_used; and calculating an updated timing advance based on the timing advance indicated in the timing advance report and the timing advance drift rate or drift function, wherein the updated timing advance is denoted as TA_updated.

12. The method of enhancing a transmit-receive transition gap according to claim 11, wherein, the method further comprises: calculating a differential TA TA_diff based on a difference between the TA_used and the TA_updated; determining whether a magnitude of the TA_diff is greater than a threshold value; and in response to the TA_diff being greater than the threshold value, sending a timing advance report to the network.

13. The method of enhancing a transmit-receive transition gap according to claim 11, wherein, the method further comprises: determining an updated position in time of the transmission-reception transition gap based on the TA_used and a threshold value; or determining an updated position in time of the transmission-reception transition gap based on the TA_updated.

14. An apparatus for enhanced transmission-reception transition gap, comprising: a memory; and a processor coupled to the memory, wherein the processor is configured to perform the method of any of claims 1-13.

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