WO2022193235A1

WO2022193235A1 - Method and apparatus for determining timing relationship between downlink reception and uplink transmission

Info

Publication number: WO2022193235A1
Application number: PCT/CN2021/081551
Authority: WO
Inventors: Hongmei Liu; Zhi YAN; Yuantao Zhang; Yingying Li; Haiming Wang
Original assignee: Lenovo (Beijing) Limited
Priority date: 2021-03-18
Filing date: 2021-03-18
Publication date: 2022-09-22

Abstract

Embodiments of the present application relate to a method and an apparatus for determining timing relationship between DL reception and UL reception. An exemplary method may include: receiving a first time domain offset; receiving signaling information associated with a second time domain offset between downlink reception and uplink transmission, wherein the signaling information indicates at least one of the following: a set of drift rates, each drift rate indicating the change rate of at least one part of the second time domain offset; coordinates of a set of positions, each position being associated with a cell or a coverage area; and a set of resource indexes; and determining the second time domain offset based on the first time domain offset and the received signaling information.

Description

METHOD AND APPARATUS FOR DETERMINING TIMING RELATIONSHIP BETWEEN DOWNLINK RECEPTION AND UPLINK TRANSMISSION

TECHNICAL FIELD

Embodiments of the present application generally relate to wireless communication technology, especially to a method and apparatus for determining the timing relationship between downlink (DL) reception and uplink (UL) transmission in a wireless communication system.

BACKGROUND

To extend the coverage and availability of wireless communication systems (e.g., 5G systems) , satellite and high-altitude platforms may be utilized as relay devices in communications related to ground devices such as user equipment (UE) . Network or segment of network using radio frequency (RF) resources on board a satellite or an airborne aircraft may be referred to as a non-terrestrial network (NTN) . In the NTN, some or all functions of a base station (BS) may be deployed in a satellite or an airborne aircraft.

However, there is large propagation delay in the NTN due to the high attitude of satellites. To enhance the timing relationship between DL reception and UL transmission, a value named "K-offset" is introduced in new radio (NR) release (R) 17, which is related to the round trip delay (RTD, also referred to as RTT) between a UE and a reference point (RP) where DL transmission and UL reception are aligned. It has been agreed that a cell-specific K-offset is used in an initial access procedure, and a K-offset can be updated after the initial access procedure. In addition, it has been discussed whether to support a beam-specific K-offset etc. However, there are still many items for further study, e.g., details on how to update K-offset.

Thus, it is desirable to provide a technical solution to improving the timing relationship between DL reception and UL transmission, especially in the NTN to adapt the industry trend.

SUMMARY OF THE DISCLOSURE

One objective of the present application is to provide a method and apparatus for determining the timing relationship between DL reception and UL transmission during wireless transmission, especially in the NTN.

According to an embodiment of the present application, a method may include: receiving a first time domain offset; receiving signaling information associated with a second time domain offset between downlink reception and uplink transmission, wherein the signaling information indicates at least one of the following: a set of drift rates, each drift rate indicating the change rate of at least one part of the second time domain offset; coordinates of a set of positions, each position being associated with a cell or a coverage area; and a set of resource indexes; and determining the second time domain offset based on the first time domain offset and the received signaling information.

According to another embodiment of the present application, a method may include: transmitting a first time domain offset; transmitting signaling information associated with a second time domain offset between downlink reception and uplink transmission, wherein the signaling information indicates at least one of the following: a set of drift rates, each drift rate indicating the change rate of at least one part of the second time domain offset; coordinates of a set of positions, each position being associated with a cell or a coverage area; and a set of resource indexes; and determining the second time domain offset based on the first time domain offset and the signaling information associated with the second time domain offset.

In some embodiments of the present application, at least one of the set of drift rates is determined based on a distance between a user equipment and a reference point between the user equipment and a satellite. In some other embodiments of the present application, at least one of the set of drift rates is determined based on a distance between a user equipment and a satellite. In some yet other embodiments of the present application, at least one of the set of drift rates is determined based on a distance between a satellite and a reference point between the satellite and a base station.

In some embodiments of the present application, transmitting the first time domain offset includes: determining a distance based on a coordinate of a position of the set of positions and the coordinate of a predefined position, and transmitting the coordinate of the position of the set of positions and the coordinate of the predefined position. Receiving the first time domain offset includes: receiving a coordinate of a position of the set of positions and of a coordinate of a predefined position, and determining a distance based on the coordinate of the position and the coordinate of the predefined position. The predefined position may be a position of a satellite. The method may further include: determining a subcarrier spacing (SCS) to determine the number of slots or symbols of the second time domain offset. The SCS may be indicated by at least one of radio resource control (RRC) signaling, medium access control (MAC) control element (CE) and downlink control information (DCI) . The SCS may be determined based on at least one of: a frequency band, the SCS of synchronization signal block (SSB) , the SCS of control resource set (CORESET) #0, the SCS of physical random access channel (PRACH) , the SCS of Msg 3, the SCS of active downlink bandwidth part (BWP) and the SCS of active uplink BWP.

In some embodiments of the present application, in the case that there is more than one drift rate in the set of drift rates, each drift rate is associated with a resource index of the set of resource indexes.

In some embodiments of the present application, in the case that there is more than one position in the set of positions, each position is associated with a resource index of the set of resource indexes.

In some embodiments of the present application, at least one of the set of resource indexes is at least one of a channel state information-reference signal (CSI-RS) resource index, an SSB index, and a sounding reference signal (SRS) resource index.

In some embodiments of the present application, the set of resource indexes is indicated by at least one of RRC signaling, MAC CE and DCI.

In some embodiments of the present application, the set of resource indexes is indicated by spatial quasi co-location (QCL) information of at least one of physical random access channel (PRACH) , random access response (RAR) , physical downlink shared channel (PDSCH) , physical uplink shared channel (PUSCH) , physical downlink control channel (PDCCH) and physical uplink control channel (PUCCH) . According to some embodiments of the present application, the method may further include: determining the spatial QCL information based on the spatial QCL information of a CORESET with a lowest index. According to some embodiments of the present application, the method may further include: determining the spatial QCL information based on the spatial QCL information of a PUCCH resource with a lowest index.

In some embodiments of the present application, the method may include: determining a resource index of the set of resource indexes based on a position of a satellite.

In some embodiments of the present application, determining the second time domain offset may further include: determining the second time domain offset based on a common timing offset indicated by a broadcasting signaling. A drift rate of the set of drift rate may be a drift rate of the common timing offset, and determining the second time domain offset may further include: determining the second time domain offset based on the drift rate of the common timing offset.

In some embodiments of the present application, the set of drift rate may be enabled or not. In the case that an indication of a drift rate of the set of drift rates is enabled or the drift rate is not set to 0, a beam generated by a corresponding satellite is determined to be an earth fixed beam. In the case that an indication of a drift rate of the set of drift rate is disabled or the drift rate is set to 0, a beam generated by a corresponding satellite is determined to be an earth moving beam.

In some embodiments of the present application, the first time domain offset is determined based on one of the following: a round trip delay between a user equipment and a reference point, and a round trip delay between a user equipment and a satellite.

In some embodiments of the present application, each position is a cell center or a coverage area center.

In some embodiments of the present application, the method may further include: determining whether the reference point is in a service link or a feeder link based on a value of a common timing offset.

In addition, some embodiments of the present application also provide an apparatus for performing a method according to an embodiment of the present application, e.g., a method as stated above. An exemplary apparatus may include: at least one non-transitory computer-readable medium having stored thereon computer-executable instructions; at least one receiving circuitry; at least one transmitting circuitry; and at least one processor coupled to the at least one non-transitory computer-readable medium, the at least one receiving circuitry and the at least one transmitting circuitry. The computer-executable instructions cause the at least one processor to implement any method according to an embodiment of the present application with the at least one receiving circuitry and the at least one transmitting circuitry.

Embodiments of the present application can solve the technical problems on determining the timing relationship between DL reception and UL transmission, especially in view of K-offset introduced in the NTN, and will facilitate the deployment and implementation of the NR.

BRIEF DESCRIPTION OF THE DRAWINGS

In order to describe the manner in which the advantages and features of the disclosure can be obtained, a description of the disclosure is rendered by reference to specific embodiments thereof, which are illustrated in the appended drawings. These drawings depict only exemplary embodiments of the disclosure and are not therefore to be considered limiting of its scope.

FIG. 1 is a schematic diagram illustrating an exemplary wireless communication system according to some embodiments of the present application;

FIG. 2 illustrates a flow chart of a method for determining timing relationship between DL reception and UL transmission according to some embodiments of the present application;

FIG. 3 illustrates an exemplary method on how to associate a position of a satellite with a beam according to some embodiments of the present application;

FIG. 4 illustrates an exemplary Scenario 1 of earth fixed beam with a reference point located between a UE and a satellite according to some embodiments of the present application;

FIG. 5 illustrates an exemplary Scenario 2 of earth fixed beam with a reference point located between a satellite and a territorial BS according to some embodiments of the present application;

FIG. 6 illustrates an exemplary Scenario 3 of earth moving beam with a reference point located between a UE and a satellite according to some embodiments of the present application;

FIG. 7 illustrates an exemplary Scenario 4 of earth moving beam with a reference point located between a satellite and a terrestrial BS according to some embodiments of the present application; and

FIG. 8 illustrates a block diagram of an exemplary apparatus according to some embodiments of the present application.

DETAILED DESCRIPTION

The detailed description of the appended drawings is intended as a description of the preferred embodiments of the present application and is not intended to represent the only form in which the present application may be practiced. It should be understood that the same or equivalent functions may be accomplished by different embodiments that are intended to be encompassed within the spirit and scope of the present application.

Reference will now be made in detail to some embodiments of the present application, examples of which are illustrated in the accompanying drawings. To facilitate understanding, embodiments are provided under specific network architecture and new service scenarios, such as 3rd generation partnership project (3GPP) 5G, 3GPP long term evolution (LTE) , and so on. It is contemplated that along with the developments of network architectures and new service scenarios, all embodiments in the present application are also applicable to similar technical problems. Moreover, the terminologies recited in the present application may change, which should not affect the principle of the present application.

FIG. 1 is a schematic diagram illustrating an exemplary wireless communication system according to some embodiments of the present application.

Referring to FIG. 1, the shown exemplary wireless communication system is an exemplary NTN 100 in which the techniques, processes and methods described herein can be implemented, according to various embodiments of the present application. In other embodiments of the present application, the wireless communication system may be other type of networks.

Generally, to extend the coverage and availability of wireless communication systems, some or all functions of a BS may be deployed in a satellite. That is, in the NTN, a satellite may be also referred to as a BS. For example, a satellite may generate multiple beams over a certain service area. The service area corresponding to a beam may be referred to a beam coverage area, and the service area corresponding to multiple beams (part or all of the beams generated by a satellite) may be referred to a cell coverage area. Each beam is generated by a spatial domain filter, and can be associated with a resource, such as CSI-RS, SSB, or SRS. For example, from the perspective of a UE, a DL beam may be associated with a spatial domain reception filter, and an uplink UL beam may be associated with a spatial domain transmission filter. Although the term "beam" has been commonly used in the work items of 3GPP, it has not been written into 3GPP standards or specifications. In the future, the term "beam" may develop into other wording, e.g., the term "beam" may be represented by spatial relation information etc. Such changes should not be used to limit the scope of the present application.

The concept of cell with respect to a terrestrial BS may similarly apply to a satellite serving as a BS. Such network or segment of network using RF resources on board a satellite or an airborne aircraft may be referred to as NTN. Hereafter, the BS(s) illustrated in the specification all cover any type of devices with the substantial function of a BS, including a satellite 120, a terrestrial BS 140 or the like.

As shown in FIG. 1, the NTN 100 includes at least one UE 110 and at least one satellite 120. The UE (s) 110 communicates with the satellite 120 over a service link 102, which has both an uplink from the UE 101 to the satellite 120 and a downlink from the satellite 120 to the UE 110. The UE (s) 110 may include computing devices, such as desktop computers, laptop computers, personal digital assistants (PDAs) , tablet computers, smart televisions (e.g., televisions connected to the Internet) , set-top boxes, game consoles, security systems (including security cameras) , vehicle on-board computers, network devices (e.g., routers, switches, and modems) , internet of things (IoT) devices, or the like. According to some embodiments of the present application, the UE (s) 110 may include a portable wireless communication device, a smart phone, a cellular telephone, a flip phone, a device having a subscriber identity module, a personal computer, a selective call receiver, or any other device that is capable of sending and receiving communication signals on a wireless network. In some embodiments of the present application, the UE (s) 110 includes wearable devices, such as smart watches, fitness bands, optical head-mounted displays, or the like. Moreover, the UE (s) 110 may be referred to as a subscriber unit, a mobile, a mobile station, a user, a terminal, a mobile terminal, a wireless terminal, a fixed terminal, a subscriber station, a user terminal, or a device, or described using other terminology used in the art.

Satellite (s) 120 may include low earth orbiting (LEO) satellites, medium earth orbiting (MEO) satellites, geostationary earth orbiting (GEO) satellites, as well as highly elliptical orbiting (HEO) satellites. In some embodiments of the present application, alternatively, a satellite 120 may be an unmanned aircraft systems (UAS) platform. The UAS platform (s) may include tethered UAS and lighter than air (LTA) UAS, heavier than air (HTA) UAS, and high altitude platform (HAP) UAS.

The satellite 120 may provide a plurality of geographic areas (footprint) 160 for serving UEs 110 located in one or more of the geographic areas. A geographic area 160 can be associated with a cell, and can also be associated with a beam. When the geographic area 160 is associated with a cell, it can be named as a "cell footprint. " When the geographic area 160 is associated with a beam, it can be named as a "beam footprint. " In FIG. 1, exemplary UE (s) may be a normal mobile terminal, which can wirelessly communicate with the satellite120 via a communication link, such as service link or radio link according to a NR access technology (e.g., a NR-Uu interface) or other technology. As also shown in FIG. 1, the satellite 120 may also communicates with a gateway 130 or an on earth (terrestrial) BS 140 via a communication link, which may be a feeder link 102 or radio link according to the NR access technology or other technology. According to various embodiments, the satellite 120 may be implemented with either a transparent or a regenerative payload. When the satellite 120 carries a "transparent" payload, it performs only radio frequency filtering, frequency conversion and/or amplification of signals on board. Hence, the waveform signal repeated by the satellite is un-changed. When a satellite carries a regenerative payload, in addition to performing radio frequency filtering, frequency conversion and amplification, it performs other signal processing functions such as demodulation/decoding, switching and/or routing, coding/decoding and modulation/demodulation on board as well. In other words, for a satellite with a regenerative payload, all or part of base station functions (e.g., a gNB, eNB, etc. ) are implemented on board.

The gateway 130 may be coupled to a data network 150 such as, for example, the Internet, terrestrial public switched telephone network, mobile telephone network, or a private server network, etc. The gateway 130 and the satellite 120 communicate over a feeder link 120, which has both a feeder uplink from the gateway to the satellite 120 and a feeder downlink from the satellite 120 to the gateway 130. Although a single gateway 130 is shown, some implementations will include more gateways, such as five, ten, or more.

One or more terrestrial BSs 140 (i.e., not airborne or spaceborne) are provided within a typical terrestrial communication network, which provides geographical radio coverage, wherein the UEs 110 that can transmit and receive data within the radio coverage (cell coverage) of the terrestrial BS 140. In the terrestrial communication network, a terrestrial BS 140 and a UE 110 can communicate with each other via a communication link, e.g., via a downlink radio frame from the terrestrial BS 140 to the UE 110 or via an uplink radio frame from the UE 110 to the terrestrial BS 140.

Although a limited number of UEs 110 and satellites 120 etc., are illustrated in FIG. 1, it is contemplated that the wireless communication system 100 may include any number of UEs 110, satellites 120, and/or other network components.

Due to the high attitude of satellites, there is large propagation delay in the NTN, especially, a propagation delay between a satellite (such as, the satellites 120 in FIG. 1) and a UE (such as, the UE 110) . Such a propagation delay will impact the scheduling delay between a DL channel and a UL channel (e.g., the delay between physical downlink control channel (PDCCH) and physical uplink shared channel PUSCH) ) , and the feedback delay between a DL channel and a UL channel (e.g., a delay between physical downlink shared channel (PDSCH) and physical uplink control channel (PUCCH) ) . To ensure the network side and the remote side have common understanding for efficient scheduling, K-offset should be set according to R17, which is related to the RTT between a UE and a reference point where DL transmission and UL reception are aligned. RAN1 agreement on K-offset indication has been achieved in RAN1#102e, 103e and 104e; and RAN1 agreement on common timing offset indication for UL timing synchronization has been achieved in RAN1#102e and 103e. However, to enhance the timing relationship between DL reception and UL transmission, there are still many work items for further study, e.g., details on how to update K-offset after an initial access procedure and details on additional information signalled from the network side for common timing offset etc.

Methods and apparatuses according to embodiments of the present application are proposed to at least solve the above technical problems.

FIG. 2 illustrates a flow chart of a method for determining timing relationship between DL reception and UL transmission according to some embodiments of the present application. Although the method is illustrated in a system level by a UE in the remote side (e.g., the UE 110 as illustrated and shown in FIG. 1) and a BS in the network side (e.g., the satellite 120 or the terrestrial BS 140 as illustrated and shown in FIG. 1) , persons skilled in the art should understand that the method implemented in the remote side and that implemented in the network side can be separately implemented and/or incorporated by other apparatus with the like functions.

As shown in FIG. 2, in step 201, the network side, e.g., the satellite 120 as shown in FIG. 1 may transmit a first time domain offset to the remote side, e.g., the UE 110 in FIG. 1. In some embodiments of the present application, the first time domain offset corresponds to a K-offset, e.g., a cell-specific K-offset for an initial access. Since K-offset has not been written into the 3GPP standards or specifications yet, it may evolve into another terminology in the future. Such a change should not be used to limit the scope of the present application.

In some embodiments of the present application, the first time domain offset, e.g., the K-offset is determined based on a RTT between a UE and a reference point or a RTT between a UE and a satellite. The reference point may be in a service link (i.e., the link between the UE and the satellite) or in a feeder link (i.e., the link between the satellite and the terrestrial BS, e.g., a gNB) . According to some embodiments of the present application, whether the reference point is in a service link or a feeder link may be determined based on a value of a common timing offset. In some embodiments of the present application, the first time domain offset corresponds to a distance determined based on a coordinate of a position and a coordinate of a predefined position. The position may be a cell center or a coverage area center (also referred to as a beam center) . The predefined position may be a position of a satellite. Accordingly, transmitting the first time domain offset includes: transmitting the coordinate of the position and the coordinate of the predefined position.

In the remote side, the first time domain offset will be received, e.g., by the UE 110 in FIG. 1 in step 202. For example, a cell-specific K-offset used for the initial access may be received in system information in some embodiments of the present application. In some other embodiments of the present application, receiving the first time domain offset may include: receiving a coordinate of a position of the set of positions and of a coordinate of a predefined position, and determining a distance based on the coordinate of the position and the coordinate of the predefined position. Being consistent with the network side, the position may be a cell center or a beam center. The predefined position may be a position of a satellite.

In step 203, the network side, e.g., the satellite 120 as shown in FIG. 1 may transmit signaling information associated with a second time domain offset between DL reception and UL transmission to the remote side, e.g., the UE 110 in FIG. 1. In some embodiments of the present application, the second time domain offset between DL reception and UL transmission is the time domain offset between DL reception and UL transmission, including: a first part based on the RTT between a UE and a reference point, a second part based on processing time for DL reception, a third part based on preparation time for UL transmission, etc. The reference point can be at the satellite, at the terrestrial BS, e.g., at a gNB, between the UE and the satellite, or between the satellite and the gNB. The signaling information may be at least one of broadcast signaling, RRC signaling, MAC CE and DCI etc. In some embodiments of the present application, the signaling information indicates at least one of the following: a set of drift rates, each drift rate indicating the change rate of at least one part of the second time domain offset, e.g., the first part based on the RTT between a UE and a reference point; coordinates of a set of positions, each position being associated with a cell or a coverage area; and a set of resource indexes. Herein (throughout the specification) , the wording "a set of" means "one or more" or the like.

Accordingly, in the remote side, signaling information associated with a second time domain offset between DL reception and UL transmission will be received, e.g., by the UE 110 in FIG. 1 in step 204. Being consistent with the network side, the signaling information indicates at least one of the following: a set of drift rates, each drift rate indicating the change rate of at least one part of the second time domain offset; coordinates of a set of positions, each position being associated with a cell or a coverage area; and a set of resource indexes.

In some embodiments of the present application, in the case that there is more than one drift rate in the set of drift rates, each drift rate is associated with a resource index of the set of resource indexes. In the case that there is more than one position in the set of positions, each position is associated with a resource index of the set of resource indexes. According to some embodiments of the present application, each position is a cell center or a coverage area center. A resource index of the set of resource indexes may be a CSI-RS resource index, an SSB index, or a SRS resource index. As stated above, a resource index can be associated with a beam of a satellite.

In step 205, the network side, e.g., the satellite 120 as shown in FIG. 1 may determine the second time domain offset based on the first time domain offset and the signaling information associated with the second time domain offset. Accordingly, in the remote side, the second time domain offset will be determined based on the first time domain offset and the received signaling information, e.g., by the UE 110 in FIG. 1 in step 206.

Considering that the position of a reference point may be different in difference application scenarios, the indication (and/or update) of the first time domain offset between DL reception and UL transmission may be different. Similarly, the drift rate of the time domain offset may be indicated (and/or updated) differently. Accordingly, the second time domain may be determined in different manners.

For example, in some embodiments of the present application, at least one of the set of drift rates is determined based on a distance between a UE and a reference point between the UE and a satellite. In some other embodiments of the present application, at least one of the set of drift rates is determined based on a distance between a UE and a satellite. In some yet other embodiments of the present application, at least one of the set of drift rates is determined based on a distance between a satellite and a reference point between the satellite and a base station.

In some embodiments of the present application, in the case that the first time domain offset corresponds to a distance determined based on the coordinate of the position and the coordinate of the predefined position, a SCS needs to be determined so that the number of slots or symbols of the second time domain offset is determined. The SCS may be indicated by at least one of RRC signaling, MAC CE and DCI. The SCS may be determined based on at least one of: a frequency band, the SCS of SSB, the SCS of CORESET#0, the SCS of PRACH, the SCS of Msg 3, the SCS of active downlink BWP and the SCS of active uplink BWP. For example, if the frequency band for at least one of DL and UL transmission is FR1 (<6GHz) , then the SCS is determined to be 15KHz; otherwise, if the frequency band is FR2 (>6GHz) , then the SCS is determined to be 60KHz.

There are two application scenarios where the timing relationship between DL reception and UL transmission needs to be determined in the NTN based on whether the beam generated by the satellite is an earth fixed beam or an earth moving beam. In an application scenario, a satellite generates an earth fixed beam, which means that with the satellite moving, the satellite for a UE will not change and the satellite's beam for the UE may not be changed. In the other application scenario, a satellite generates an earth moving beam, which means that with the satellite moving, the corresponding coverage area of the satellite's beam for a UE is also changed.

In addition, there are two application scenarios where the timing relationship between DL reception and UL transmission needs to be determined in the NTN based on the location of a reference point. In an application scenario, the reference point is located between a UE and a satellite, including in the satellite. In the other application scenario, the reference point is located between a satellite and a territorial BS, including in the satellite or territorial BS.

Accordingly, based on whether a satellite’s beam is an earth moving beam or earth fixed beam and the location of a reference point, there are four application scenarios where the timing relationship between DL reception and UL transmission needs to be determined in the NTN, i.e., earth fixed beam with a reference point located between a UE and a satellite (including in the satellite, hereafter, Scenario 1) ; earth fixed beam with a reference point located between a satellite and a territorial BS (including in the satellite or territorial BS, hereafter, Scenario 2) ; earth moving beam with a reference point located between a UE and a satellite (including in the satellite, hereafter, Scenario 3) ; and earth moving beam with a reference point located between a satellite and a territorial BS (including in the satellite or territorial BS, hereafter, Scenario 4) .

To differentiate different application scenarios, there are various solutions according to embodiments of the present application. In some embodiments of the present application, the network side will explicitly indicate the specific application scenario to the remote side. For example, the network side may explicitly configure whether it is earth fixed beam or earth moving beam via signaling (s) . In another example, the network side may explicitly configure the location of the reference point, e.g., whether the reference point is between a UE and a satellite or between a satellite and a territorial BS.

In some embodiments of the present application, the network side will not explicitly indicate the specific application scenario to the remote side, and will transmit implicit information on the application scenario. The remote side will determine the specific application scenario based on the related implicit information.

For example, the network side may broadcast a common timing offset, and the remote side receives the common timing offset indicated by broadcasting signaling (s) . The common timing offset is based on the RTT between the satellite and a reference point, and the reference point may be between UE and satellite or between satellite and gNB. The reference point can be determined based on the value of the common timing offset. Accordingly, determining the second time domain offset includes: determining the second time domain offset based on a common timing offset. According to some embodiments of the present application, in the case that the common timing offset is a positive value, the reference point is determined to be between a satellite and a territorial BS; in the case that the common timing offset is a negative value, the reference point is determined to be between a UE and a satellite, and vice versa. Moreover, according to some embodiments of the present application, a drift rate indicated to the remote side is a drift rate of the common timing offset. Accordingly, determining the second time domain offset further include: determining the second time domain offset based on the drift rate of the common timing offset.

For another example, the network side may indicate the state of the drift rate to the remote side, which may be enabled or not. An application scenario may be determined based on the state of the drift rate, e.g., whether the beam generated by the satellite is earth fixed beam or earth moving beam can be implicitly determined by whether an indication of the drift rate is enabled or not or by the value of the drift rate. According to some embodiments of the present application, in the case that an indication of drift rate is enabled or the drift rate is set to non-zero, a corresponding beam generated by the satellite is determined to be an earth fixed beam; in the case that an indication of drift rate is disabled or a drift rate is set to 0, a corresponding beam generated by the satellite is determined to be an earth moving beam, and vice versa.

In some application scenarios, e.g., a scenario of earth moving beam, there may be multiple beams in a cell coverage. The movement of the satellite will lead to the change of beams, e.g. beam center coordinate change, beam-specific K-offset change, or beam-specific drift rate change etc. Thus, the remote side needs to identify a specific beam for a UE at a specific time instance, so that information associated with timing relationship between DL reception and UL transmission, e.g., the beam center coordinate, K-offset, or drift rate etc., can be determined.

In some embodiments of the present application, the network side may explicitly indicate a set of beams or a set of resource indexes to the remote side by at least one of RRC signaling, MAC CE and DCI. For example, the network may indicate a set of beams, e.g., being represented by a set of CSI-RS resource index, a set of SSB index, or a set of SRS resource index via group common DCI.

In some other embodiments of the present application, the network may implicitly indicate a set of beams or a set of resource indexes, e.g., by spatial QCL information of at least one of PRACH, RAR, PDSCH, PUSCH, PDCCH and PUCCH. The spatial QCL information may be determined based on the spatial QCL information of a CORESET which is associated with the lowest index in some embodiments of the present application. In some other embodiments of the present application, the spatial QCL information may be determined based on the spatial QCL information of a PUCCH resource which is associated with the lowest index. When there is a common beam configured for the cell or BWP for the UE, the common beam identifier can be used to determine beam center coordinate, K-offset, or drift rate, which can be applied to only DL channels, only UL channels, or both DL and UL channels. For example, the beam identifier for determining beam center coordinate, K-offset, or drift rate can be the beam identifier of PDSCH or PUSCH, which is indicated in PDCCH. In another example, the beam identifier for determining beam center coordinate, K-offset, or drift rate can be the beam identifier of PDCCH, which is the beam identifier of the CORESET with the lowest index. In yet another example, the beam identifier for determining beam center coordinate, K-offset, or drift rate can be the beam identifier used in an initial access procedure, and it may be the SSB index used for RAR monitoring, or the uplink beam identifier used for PRACH transmission.

In some yet other embodiments of the present application, the beam identifier, or a resource index may be determined based on at least one of the satellite ephemeris and position information. For example, a beam identifier or resource index may be indicated or determined by the position of the satellite.

FIG. 3 illustrates an exemplary method on how to associate a position of a satellite with a beam identifier according to some embodiments of the present application.

As shown in FIG. 3, the estimated orbit of a satellite can be divided into several parts, i.e., position ranges as shown in FIG. 3, wherein each position range is associated with a beam identifier. The mapping between beam identifier and position range of the satellite should be predefined or indicated to a UE, e.g., in a UE specific way. For example, a first position range, e.g., Part#1 is mapped to a first beam; a second position range, e.g., Part#2 is mapped to a second beam; a third position range, e.g., Part#3 is mapped to a third beam; a fourth position range, e.g., Part#4 is mapped to a fourth beam; a fifth position range, e.g., Part#5 is mapped to a fifth beam; and so on. The position range of a satellite will be firstly identified based on the estimated orbit, and then the associated beam identifier will be determined. It should be noticed that the actual orbit of a satellite may be different from the estimated orbit. The reason is that the estimated orbit is calculated based on some theoretical models, and for the actual orbit there may be some impairments or there may be some kind of attraction. For the satellite, if it is not exactly on the estimated orbit of the satellite, a corresponding position range in the estimated orbit will be identified firstly, and then the corresponding beam identifier can be identified. For example, for Satellite#1 on the estimated orbit, it is in Part#3, and the third beam associated with Part#3 will be determined. For Satellite#2 in Position#A, which is not on the estimated orbit, a nearest position, e.g., Position#B on the estimated orbit will be identified firstly, and then the corresponding position range, i.e., Part#4 can be identified. Accordingly, the fourth beam associated with Part#4 will be determined.

Some exemplary application scenarios are illustrated in the following to help further understand the principle of the present application. Persons skilled in the art should understand that although some specific embodiments are illustrated in view of exemplary scenarios, the illustrated solutions may also be applicable to some other application scenarios and should not be limited to the exemplary application scenarios.

Scenario 1: Earth fixed beam with a reference point located between a UE and a satellite

FIG. 4 illustrates an exemplary Scenario 1 of earth fixed beam with a reference point located between a UE and a satellite according to some embodiments of the present application.

As shown in FIG. 4, a satellite, e.g., Satellite1, a UE, e.g., UE1 and a terrestrial BS, e.g., gNB1 are illustrated in exemplary Scenario 1. Satellite1 may generate a set of beams over a set of certain service areas. Each service area may also be referred to as a cell coverage area or a beam coverage area. When Satellite1 is in the first position, e.g., P1, UE1 is serviced by a beam 400 generated by Satellite1. Since the beam generated by Satellite1 is an earth fixed beam in Scenario 1, when Statellite1 moves from the first position P1 to the second position, e.g., P2, UE1 is still serviced by the same beam 400. Satellite1 may communicate with UE1 via a communication link, such as a service link or radio link according to a NR access technology (e.g., a NR-Uu interface) or other technology. Satellite1 may also communicate with gNB1 via a communication link, which may be a feeder link or radio link according to the NR access technology or other technology. A reference point, e.g., RP1 is located in the service link, i.e., between Statellite1 and UE1, wherein the reference point can also be located in the Satellite1.

According to some embodiments of the present application, in Scenario 1, the first time domain offset, e.g., K-offset corresponds to the RTT between the UE and the reference point, and the drift rate corresponds to the change rate of the distance between the UE and the reference point. Accordingly, the drift rate indicates the change on the service link only.

According to some other embodiments of the present application, in Scenario 1, the first time domain offset, e.g., K-offset corresponds to the RTT between a UE and a satellite, and the drift rate corresponds to the change rate of the distance between a UE and a satellite. The other part of the second time domain offset, which is based on the RTT between satellite and the reference point, is determined by common timing offset with or without its drift rate indicated from the network side by high layer signaling, which is similar to that for uplink synchronization.

According to some other embodiments of the present application, in Scenario 1, the first time domain offset, e.g., K-offset corresponds to the RTT between a UE and a satellite, and is implicitly determined based on a coordinate of a position, e.g., the cell center and the coordinate of the satellite. The other part of the second time domain offset, which is based on the RTT between the satellite and the reference point, is determined by common timing offset with or without its drift rate indicated from the network side by high layer signaling. That is similar to that for uplink synchronization. In addition, a SCS needs to be determined so that the number of slots or symbols of the second time domain offset is determined. The SCS may be indicated by at least one of RRC signaling, MAC CE and DCI. The SCS may be determined based on at least one of a frequency band and SCS used in an initial access procedure. The SCS used in an initial access procedure may be at least one of: the SCS of SSB, the SCS of CORESET#0, the SCS of PRACH, the SCS of Msg 3, the SCS of active downlink BWP and the SCS of active uplink BWP.

Scenario 2: Earth fixed beam with a reference point located between a satellite and a territorial BS

FIG. 5 illustrates an exemplary Scenario 2 of earth fixed beam with a reference point located between a satellite and a territorial BS according to some embodiments of the present application.

As shown in FIG. 5, a satellite, e.g., Satellite2, a UE, e.g., UE2 and a terrestrial BS, e.g., gNB2 are illustrated in exemplary Scenario 2. Satellite2 may generate a set of beams over a set of certain service areas. Each service area may also be referred to as a cell coverage area or a beam coverage area. When Satellite2 is in the first position, e.g., P3, UE2 is serviced by a beam 500 generated by Satellite2. Since the beam generated by Satellite2 is an earth fixed beam in Scenario 2, when Statellite2 moves from the first position P3 to the second position, e.g., P4, UE2 is still serviced by the same beam 500. Satellite2 may communicate with UE2 via a communication link, such as a service link or radio link according to a NR access technology (e.g., a NR-Uu interface) or other technology. Satellite2 may also communicate with gNB2 via a communication link, which may be a feeder link or radio link according to the NR access technology or other technology. A reference point, e.g., RP2 is located in the feeder link, i.e., between Statellite2 and gNB2, wherein the reference point can also be located in Statellite2 or gNB2.

According to some embodiments of the present application, in Scenario 2, the first time domain offset, e.g., K-offset corresponds to the RTT between a UE and a reference point, and the drift rate corresponds to the change rate of the distance between the UE and the reference point. Accordingly, the drift rate indicates the change on both the service link and feeder link, which can be expressed in a single value.

According to some other embodiments of the present application, in Scenario 2, the first time domain offset, e.g., K-offset corresponds to the RTT between a UE and a satellite, and the drift rate corresponds to the change rate of the distance between the UE and the satellite. The other part of the second time domain offset, which is based on the RTT between the satellite and the reference point, is determined by common timing offset with or without its drift rate indicated from the network side by high layer signaling. That is similar to that for uplink synchronization.

According to some other embodiments of the present application, in Scenario 2, the first time domain offset, e.g., K-offset corresponds to the RTT between a UE and a satellite. In an example, K-offset is implicitly determined based on a coordinate of a position, e.g., the cell center and the coordinate of the satellite. The other part of the second time domain offset, which is based on the RTT between the satellite and the reference point, is determined by common timing offset and with or without its drift rate indicated from the network side by high layer signaling. That is similar to that for uplink synchronization. In addition, a SCS needs to be determined so that the number of slots or symbols of the second time domain offset is determined. The SCS may be indicated by at least one of RRC signaling, MAC CE and DCI. The SCS may be determined based on at least one of a frequency band and SCS used in an initial access procedure. The SCS used in an initial access procedure may be at least one of: the SCS of SSB, the SCS of CORESET#0, the SCS of PRACH, the SCS of Msg 3, the SCS of active downlink BWP and the SCS of active uplink BWP.

Scenario 3: Earth moving beam with a reference point located between a UE and a satellite

FIG. 6 illustrates an exemplary Scenario 3 of earth moving beam with a reference point located between a UE and a satellite according to some embodiments of the present application.

As shown in FIG. 6, a satellite, e.g., Satellite3, a UE, e.g., UE3 and a terrestrial BS, e.g., gNB3 are illustrated in exemplary Scenario 3. Satellite3 may generate a set of beams over a set of certain service areas. Each service area may also be referred to as a cell coverage area or a beam coverage area. When Satellite3 is in the first position, e.g., P5, UE3 is serviced by a beam 600 generated by Satellite3. Since the beam generated by Satellite3 is an earth moving beam in Scenario 3, when Statellite3 moves from the first position P5 to the second position, e.g., P6, the beam for UE3 may change from beam 600 into beam 601. Satellite3 may communicate with UE3 via a communication link, such as a service link or radio link according to a NR access technology (e.g., a NR-Uu interface) or other technology. Satellite3 may also communicate with gNB3 via a communication link, which may be a feeder link or radio link according to the NR access technology or other technology. A reference point, e.g., RP3 is located in the service link, i.e., between Statellite3 and UE3, wherein the reference point can also be located in Statellite3.

According to some embodiments of the present application, in Scenario 3, the first time domain offset, e.g., K-offset corresponds to the RTT between a UE and a reference point, and the drift rate corresponds to the change rate of the distance between the UE and the reference point. In the case that the changed beam identifier is indicated, the updated beam-specific K-offset is determined. Accordingly, the drift rate is not needed. The indication of the drift rate can be disabled or the drift rate can be set to be 0.

According to some other embodiments of the present application, in Scenario 3, the first time domain offset, e.g., K-offset corresponds to the RTT between a UE and a satellite, and the drift rate corresponds to the change rate of the distance between the UE and the satellite. In the case that the changed beam identifier is indicated, the updated beam-specific K-offset is determined. The other part of the second time domain offset, which is based on the RTT between the satellite and the reference point, is determined by common timing offset and with or without its drift rate indicated from the network side by high layer signaling. That is similar to that for uplink synchronization.

According to some yet other embodiments of the present application, in Scenario 3, the first time domain offset, e.g., K-offset corresponds to the RTT between a UE and a satellite. In an example, K-offset is implicitly determined based on a coordinate of a position, e.g., the beam center and the coordinate of the satellite. The changed coordinate of the beam center will be determined based on the indication of the beam identifier. In this case, multiple beam center coordinates will be configured by signaling, e.g., RRC signaling. In some embodiments of the present application, the network may implicitly indicate a set of beams or a set of resource indexes, e.g., by spatial QCL information of at least one of PRACH, RAR, PDSCH, PUSCH, PDCCH and PUCCH. The spatial QCL information may be determined based on the spatial QCL information of a CORESET which is associated with the lowest index in some embodiments of the present application. In some other embodiments of the present application, the spatial QCL information may be determined based on the spatial QCL information of a PUCCH resource which is associated with the lowest index. When there is a common beam configured for the cell or BWP for the UE, the common beam identifier can be used to determine beam center coordinate, K-offset, or drift rate, which can be applied to only DL channels, only UL channels, or both DL and UL channels. For example, the beam identifier for determining beam center coordinate, K-offset, or drift rate can be the beam identifier of PDSCH or PUSCH, which is indicated in PDCCH. In another example, the beam identifier for determining beam center coordinate, K-offset, or drift rate can be the beam identifier of PDCCH, which is the beam identifier of the CORESET with the lowest index. In yet another example, the beam identifier for determining beam center coordinate, K-offset, or drift rate can be the beam identifier used in an initial access procedure, and it may be the SSB index used for RAR monitoring, or the uplink beam identifier used for PRACH transmission.

The other part of the second time domain offset, which is based on the RTT between the satellite and the reference point, is determined by common timing offset and with or without its drift rate indicated from the network side by high layer signaling. That is similar to that for uplink synchronization. In addition, a SCS needs to be determined so that the number of slots or symbols of the second time domain offset is determined. The SCS may be indicated by at least one of RRC signaling, MAC CE and DCI. The SCS may be determined based on at least one of a frequency band and SCS used in an initial access procedure. The SCS used in an initial access procedure may be at least one of: the SCS of SSB, the SCS of CORESET#0, the SCS of PRACH, the SCS of Msg 3, the SCS of active downlink BWP and the SCS of active uplink BWP.

Scenario 4: Earth moving beam with a reference point located between a satellite and a terrestrial BS

FIG. 7 illustrates an exemplary Scenario 4 of earth moving beam with a reference point located between a satellite and a terrestrial BS according to some embodiments of the present application.

As shown in FIG. 7, a satellite, e.g., Satellite4, a UE, e.g., UE4 and a terrestrial BS, e.g., gNB4 are illustrated in exemplary Scenario 4. Satellite4 may generate a set of beams over a set of certain service areas. Each service area may also be referred to as a cell coverage area or a beam coverage area. When Satellite4 is in the first position, e.g., P7, UE4 is serviced by a beam 700 generated by Satellite4. Since the beam generated by Satellite4 is an earth moving beam in Scenario 4, when Statellite4 moves from the first position P7 to the second position, e.g., P8, the beam for UE4 may change from the beam 700 into another beam 701. Satellite4 may communicate with UE4 via a communication link, such as a service link or radio link according to a NR access technology (e.g., a NR-Uu interface) or other technology. Satellite4 may also communicate with gNB4 via a communication link, which may be a feeder link or radio link according to the NR access technology or other technology. A reference point, e.g., RP4 is located in the feeder link, i.e., between Statellite4 and gNB4, wherein the reference point can also be located in Statellite4 or gNB4.

According to some embodiments of the present application, in Scenario 4, the second time domain offset corresponds to the RTT between a UE and a reference point, which is between the UE and the reference point contains the RTT between the UE and satellite and the RTT between the satellite and the reference point. The change on the distance between the UE and the satellite can be determined based on the corresponding beam identifier. A set of K-offsets corresponding to the RTT between the UE and the satellite will be configured previously, and the determined beam identifier is used to select one of the configured K-offset values corresponding to the RTT between UE and the satellite. Regarding the distance between the satellite and the reference point, it can be determined based on an initial value and a drift rate. The initial value is related to the distance between the satellite and the reference point, and the drift rate is also to reflect the change rate on the distance between the satellite and the reference point. In some embodiments of the present application, the network side may broadcast the common timing offset, which is corresponding to the RTT between the satellite and the reference point, and the drift rate indication is not necessary. There may also be a drift of the common timing offset, and the common timing offset at any time can be determined.

According to some other embodiments of the present application, in Scenario 4, the first time domain offset, e.g., K-offset corresponds to the RTT between a UE and a satellite, and the drift rate corresponds to the change rate of the distance between the UE and the satellite. In the case that the changed beam identifier is indicated, the updated beam-specific K-offset is determined. The other part of the second time domain offset, which is based on the RTT between the satellite and the reference point, is determined by common timing offset with or without its drift rate indicated from the network side by high layer signaling. That is similar to that for uplink synchronization.

According to some yet other embodiments of the present application, in Scenario 4, the first time domain offset, e.g., K-offset corresponds to the RTT between a UE and a satellite. In an example, K-offset is implicitly determined based on a coordinate of a position, e.g., the beam center and the coordinate of the satellite. The changed coordinate of the beam center will be determined based on the indication of the beam identifier. In this case, multiple beam center coordinates will be configured by signaling, e.g., RRC signaling. In some embodiments of the present application, the network may implicitly indicate a set of beams or a set of resource indexes, e.g., by spatial QCL information of at least one of PRACH, RAR, PDSCH, PUSCH, PDCCH and PUCCH. The spatial QCL information may be determined based on the spatial QCL information of a CORESET which is associated with the lowest index in some embodiments of the present application. In some other embodiments of the present application, the spatial QCL information may be determined based on the spatial QCL information of a PUCCH resource which is associated with the lowest index. When there is a common beam configured for the cell or BWP for the UE, the common beam identifier can be used to determine beam center coordinate, K-offset, or drift rate, which can be applied to only DL channels, only UL channels, or both DL and UL channels. For example, the beam identifier for determining beam center coordinate, K-offset, or drift rate can be the beam identifier of PDSCH or PUSCH, which is indicated in PDCCH. In another example, the beam identifier for determining beam center coordinate, K-offset, or drift rate can be the beam identifier of PDCCH, which is the beam identifier of the CORESET with the lowest index. In yet another example, the beam identifier for determining beam center coordinate, K-offset, or drift rate can be the beam identifier used in an initial access procedure, and it may be the SSB index used for RAR monitoring, or the uplink beam identifier used for PRACH transmission.

Embodiments of the present application also propose an apparatus for determining timing relationship between DL reception and UL transmission. For example, FIG. 8 illustrates a block diagram of an apparatus 800 for determining timing relationship between DL reception and UL transmission according to some embodiments of the present application.

As shown in FIG. 8, the apparatus 800 may include at least one non-transitory computer-readable medium 801, at least one receiving circuitry 802, at least one transmitting circuitry 804, and at least one processor 806 coupled to the non-transitory computer-readable medium 801, the receiving circuitry 802 and the transmitting circuitry 804. The apparatus 800 may be a network side apparatus (e.g., a BS) configured to perform a method illustrated in FIG. 2, or the like, or a remote unit (e.g., a UE) configured to perform a method illustrated in FIG. 2 or the like.

Although in this figure, elements such as the at least one processor 806, transmitting circuitry 804, and receiving circuitry 802 are described in the singular, the plural is contemplated unless a limitation to the singular is explicitly stated. In some embodiments of the present application, the receiving circuitry 802 and the transmitting circuitry 804 can be combined into a single device, such as a transceiver. In certain embodiments of the present application, the apparatus 800 may further include an input device, a memory, and/or other components.

For example, in some embodiments of the present application, the non-transitory computer-readable medium 801 may have stored thereon computer-executable instructions to cause a processor to implement the method with respect to the UE as described above. For example, the computer-executable instructions, when executed, cause the processor 806 interacting with receiving circuitry 802 and transmitting circuitry 804, so as to perform the steps with respect to the UE depicted in FIG. 2, 4, 5, 6, or 7.

In some embodiments of the present application, the non-transitory computer-readable medium 801 may have stored thereon computer-executable instructions to cause a processor to implement the method with respect to the BS as described above. For example, the computer-executable instructions, when executed, cause the processor 806 interacting with receiving circuitry 802 and transmitting circuitry 804, so as to perform the steps with respect to the BS depicted in FIG. 2, 4, 5, 6, or 7.

The method according to embodiments of the present application can also be implemented on a programmed processor. However, the controllers, flowcharts, and modules may also be implemented on a general purpose or special purpose computer, a programmed microprocessor or microcontroller and peripheral integrated circuit elements, an integrated circuit, a hardware electronic or logic circuit such as a discrete element circuit, a programmable logic device, or the like. In general, any device on which resides a finite state machine capable of implementing the flowcharts shown in the figures may be used to implement the processor functions of this application. For example, an embodiment of the present application provides an apparatus, including a processor and a memory. Computer programmable instructions for implementing a method are stored in the memory, and the processor is configured to perform the computer programmable instructions to implement the method. The method may be a method as stated above or other method according to an embodiment of the present application.

An alternative embodiment preferably implements the methods according to embodiments of the present application in a non-transitory, computer-readable storage medium storing computer programmable instructions. The instructions are preferably executed by computer-executable components preferably integrated with a network security system. The non-transitory, computer-readable storage medium may be stored on any suitable computer readable media such as RAMs, ROMs, flash memory, EEPROMs, optical storage devices (CD or DVD) , hard drives, floppy drives, or any suitable device. The computer-executable component is preferably a processor but the instructions may alternatively or additionally be executed by any suitable dedicated hardware device. For example, an embodiment of the present application provides a non-transitory, computer-readable storage medium having computer programmable instructions stored therein. The computer programmable instructions are configured to implement a method as stated above or other method according to an embodiment of the present application.

In addition, in this disclosure, relational terms such as "first, " "second, " and the like may be used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. The terms "includes, " "including, " or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that includes a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. An element proceeded by "a, " "an, " or the like does not, without more constraints, preclude the existence of additional identical elements in the process, method, article, or apparatus that includes the element. Also, the term "another" is defined as at least a second or more.

While this disclosure has been described with specific embodiments thereof, it is evident that many alternatives, modifications, and variations may be apparent to those skilled in the art. For example, various components of the embodiments may be interchanged, added, or substituted in the other embodiments. In addition, all of the elements of each figure are not necessary for the operation of the disclosed embodiments. For example, one of ordinary skill in the art of the disclosed embodiments would be enabled to make and use the teachings of the disclosure by simply employing the elements of the independent claims. Accordingly, embodiments of the disclosure as set forth herein are intended to be illustrative, not limiting. Various changes may be made without departing from the spirit and scope of the disclosure.

Claims

A method, comprising:

receiving a first time domain offset;

receiving signaling information associated with a second time domain offset between downlink reception and uplink transmission, wherein the signaling information indicates at least one of the following:

a set of drift rates, each drift rate indicating the change rate of at least one part of the second time domain offset;

coordinates of a set of positions, each position being associated with a cell or a coverage area; and

a set of resource indexes; and

determining the second time domain offset based on the first time domain offset and the received signaling information.
The method of Claim 1, wherein receiving the first time domain offset comprises:

receiving a coordinate of a position of the set of positions and of a coordinate of a predefined position; and

determining a distance based on the coordinate of the position and the coordinate of the predefined position.
The method of Claim 1, wherein in the case that there is more than one drift rate in the set of drift rates, each drift rate is associated with a resource index of the set of resource indexes.
The method of Claim 1, wherein in the case that there is more than one position in the set of positions, each position is associated with a resource index of the set of resource indexes.
The method of Claim 2, further comprising:

determining a subcarrier spacing (SCS) to determine the number of slots or symbols of the second time domain offset.
The method of Claim 5, wherein the SCS is indicated by at least one of radio resource control (RRC) signaling, medium access control (MAC) control element (CE) and downlink control information (DCI) .
The method of Claim 6, wherein the SCS is determined based on at least one of: a frequency band, the SCS of synchronization signal block (SSB) , the SCS of control resource set (CORESET) #0, the SCS of physical random access channel (PRACH) , the SCS of Msg 3, the SCS of active downlink bandwidth part (BWP) and the SCS of active uplink BWP.
The method of Claim 1, wherein at least one of the set of resource indexes is at least one of a channel state information-reference signal (CSI-RS) resource index, a synchronization signal block (SSB) index, and a sounding reference signal (SRS) resource index.
The method of Claim 1, wherein the set of resource indexes is indicated by at least one of radio resource control (RRC) signaling, medium access control (MAC) control element (CE) and downlink control information (DCI) .
The method of Claim 1, wherein the set of resource indexes is indicated by spatial quasi co-location (QCL) information of at least one of physical random access channel (PRACH) , random access response (RAR) , physical downlink shared channel (PDSCH) , physical uplink shared channel (PUSCH) , physical downlink control channel (PDCCH) and physical uplink control channel (PUCCH) .
The method of Claim 1, comprising: determining a resource index of the set of resource indexes based on a position of a satellite.
The method of Claim 1, wherein said determining the second time domain offset further comprises:

determining the second time domain offset based on a common timing offset indicated by a broadcasting signaling.
The method of Claim 1, wherein the set of drift rate is enabled or not, and in the case that an indication of a drift rate of the set of drift rates is enabled or the drift rate is set to non-0, a beam generated by a corresponding satellite is determined to be an earth fixed beam.
The method of Claim 1, wherein the set of drift rate is enabled or not, and in the case that an indication of a drift rate of the set of drift rate is disabled or the drift rate is set to 0, a beam generated by a corresponding satellite is determined to be an earth moving beam.
An apparatus, comprising:

at least one non-transitory computer-readable medium having stored thereon computer-executable instructions;

at least one receiving circuitry;

at least one transmitting circuitry; and

at least one processor coupled to the at least one non-transitory computer-readable medium, the at least one receiving circuitry and the at least one transmitting circuitry,

wherein the computer-executable instructions cause the at least one processor to implement the method of any of Claims 1-14 with the at least one receiving circuitry and the at least one transmitting circuitry.