PUSCH transmission based on srs trigger after ltm cell switch

Abstract

This disclosure relates to PUSCH transmission based on SRS triggering after LTM cell handover. Example embodiments of this disclosure relate to a method, apparatus, and computer-readable storage medium communication in a terminal device, the terminal device comprising: at least one processor; and at least one memory storing instructions, which, when executed by the at least one processor, cause the terminal device to at least: receive configuration from one or more network nodes, the configuration including at least: a configuration for transmitting a probe reference signal for mobility operation between a serving cell and at least one candidate cell; and transmit the probe reference signal to at least one candidate cell based on a trigger received from a target cell among the at least one candidate cell.

Description

Technical Field

[0001] Various exemplary embodiments of this disclosure are generally related to the telecommunications field, and particularly to methods, apparatuses, devices, and computer-readable storage media for cell handover procedures. Background Technology

[0002] When the UE (User Equipment) is powered on, it selects a cell in the PLMN (Public Land Mobile Network) to camp on. After camping on a cell, the UE monitors system information, performs measurements on the serving cell and neighboring cells based on measurement rules, and selects a better cell to camp on based on cell reselection criteria.

[0003] L1 / L2 triggered mobility, or low-layer triggered mobility (LTM), is a cell handover procedure in which the serving cell (PCell or PSCell) of a UE (User Equipment) is handed over by the network by sending an LTM cell handover command. Currently, it is assumed that the LTM handover command is delivered using MAC (Media Access Control) signaling via MAC CE (Media Access Control Element). Therefore, not using RRC (Radio Resource Control) signaling for L3 (Layer 3) based handover is one of the current methods used for handover between cells. LTM cell handover decisions are based on L1 (Layer 1) measurements performed and reported by the UE using L1 measurement reports. Measurements and reports are based on the LTM candidate cell configuration provided by the network for one or more LTM candidate cells. LTM candidate cells can be neighboring cells or the UE's current serving cell (e.g., SCell).

[0004] To maintain high data transmission efficiency during cell handover, Rel-19 LTM has agreed to acquire CSI based on downlink reference signals for candidate cells. Summary of the Invention

[0005] In a first aspect of this disclosure, a terminal device (510) for wireless communication is provided, the terminal device comprising: at least one processor (531); and at least one memory (532) storing instructions that, when executed by the at least one processor (531), cause the terminal device (510) to at least: receive (502) a configuration from one or more network nodes (515), the configuration comprising at least: a configuration (503) for transmitting a probe reference signal (513c) for mobility operations between a serving cell (520) and one or more candidate cells (530); and transmit (584) the probe reference signal (513c) to one or more candidate cells (530) based on trigger information (582a) received from at least one candidate cell (530a).

[0006] In a second aspect of this disclosure, a network node (515) for wireless communication is provided, the network node including at least one processor (534); and at least one memory (535) storing instructions that, when executed by the at least one processor, cause the network node (515) to at least: send (502) a configuration to a terminal device (510), the configuration including at least: a configuration (503) for causing the terminal device (510) to send (584) a probe reference signal (513c) for mobility operation between a serving cell (520) and one or more candidate cells (530); and send (578) a cell handover command (CSC) (514c) to the terminal device (510) before the terminal device (510) begins to send (584) the probe reference signal (513c) to the target cell (530a) based on trigger information (582a) received from the target cell (530a), wherein the target cell (530a) is from one or more candidate cells (530).

[0007] In a third aspect of this disclosure, a terminal device (510) for wireless communication is provided, the terminal device comprising: components for receiving (502) a configuration from one or more network nodes (515), the configuration comprising at least: a configuration (503) for transmitting a probe reference signal (513c) for mobility operation between a serving cell (520) and one or more candidate cells (530); and components for transmitting (584) the probe reference signal (513c) to at least one candidate cell (530) based on trigger information (582a) received from a target cell (530a) among at least one candidate cell (530a).

[0008] In a fourth aspect of this disclosure, a network node (515) for communication is provided, the network node comprising: components for transmitting (502) a configuration to a terminal device (510), the configuration comprising at least: a configuration (503) for causing the terminal device (510) to transmit (584) a probe reference signal (513c) for mobility operation between a serving cell (520) and one or more candidate cells (530); and components for transmitting (578) a cell handover command (CSC) (514c) to the terminal device (510) before the terminal device begins to transmit (584) the probe reference signal (513c) to one or more candidate cells (530) based on trigger information (582a) received from at least one candidate cell (530a), wherein the target cell (530a) is from one or more candidate cells (530).

[0009] In a fifth aspect of this disclosure, a method for wireless communication is provided, the method comprising: receiving (502) a configuration by a terminal device (510) from one or more network nodes (515), the configuration comprising at least: a configuration (503) for transmitting a probe reference signal (513c) for mobility operation between a serving cell (520) and one or more candidate cells (530); transmitting (512) a probe reference signal (513a) to one or more candidate cells (530) based on trigger information (509a) received from the serving cell (520) before receiving (514) a cell handover command (CSC) (514a) from the network node (515); and transmitting (584) a probe reference signal (513c) to at least one candidate cell (530) based on trigger information (582a) received from at least one candidate cell (530a).

[0010] In a sixth aspect of this disclosure, a method for wireless communication is provided, the method comprising: transmitting (502) a configuration from a network node (515) to a terminal device (510), the configuration comprising at least: a configuration (503) for causing the terminal device (510) to transmit (584) a probe reference signal (513c) for mobility operation between a serving cell (520) and one or more candidate cells (530); and transmitting (578) a cell handover command (CSC) (514c) to the terminal device (510) before the terminal device begins to transmit (584) the probe reference signal (513c) to a target cell (530a) based on trigger information (582a) received from at least one candidate cell (530a), wherein the target cell (530a) is from one or more candidate cells (530).

[0011] In a seventh aspect of this disclosure, a computer-readable medium is provided. The computer-readable medium includes instructions stored thereon for causing a terminal device (510) for wireless communication to at least perform the method according to the fifth aspect.

[0012] In an eighth aspect of this disclosure, a computer-readable medium is provided. The computer-readable medium includes instructions stored thereon for causing a network node (515) for wireless communication to perform at least the method according to the sixth aspect.

[0013] It should be understood that the summary portion is not intended to identify key or essential features of the embodiments of this disclosure, nor is it intended to limit the scope of this disclosure. Other features of this disclosure will become readily apparent from the following description. Attached Figure Description

[0014] Some exemplary embodiments will now be described with reference to the accompanying drawings, in which:

[0015] Figure 1 The diagram illustrates the signal flow of the L1 / L2 triggered mobility (LTM) process based on TS 38.300;

[0016] Figure 2 The diagram illustrates the process of acquiring CSI (Channel State Information) prior to handover in an LTM cell;

[0017] Figure 3 The diagram illustrates the LTM cell handover command MAC CE (Media Access Control element).

[0018] Figure 4A and Figure 4B Cell handover environments according to some example embodiments of this disclosure are described; and

[0019] Figure 5 The diagram illustrates a signal flow diagram of an L1 / L2 triggered mobility (LTM) detection reference signal process according to some example embodiments of the present disclosure.

[0020] Throughout the accompanying drawings, the same or similar reference numerals may denote the same or similar elements. Detailed Implementation

[0021] The principles of this disclosure will now be described with reference to some exemplary embodiments. It should be understood that these embodiments are described for illustrative purposes only and to assist those skilled in the art in understanding and implementing this disclosure, and do not constitute any limitation on the scope of this disclosure. The embodiments described herein can be implemented in various ways other than those described below. Where applicable, references may be used in various figures to illustrate different embodiments or implementations.

[0022] In the following description and claims, unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure pertains.

[0023] In this disclosure, references to "an embodiment," "embodiment," and "example embodiment," etc., indicate that the described embodiment may include a particular feature, structure, or characteristic, but not every embodiment must include that particular feature, structure, or characteristic. Furthermore, such phrases do not necessarily refer to the same embodiment. Moreover, when a particular feature, structure, or characteristic is described in connection with an embodiment, those skilled in the art will understand that, whether explicitly described or not, combining it with other embodiments to affect such a feature, structure, or characteristic is within the scope of their knowledge.

[0024] It should be understood that although the terms "first," "second," etc., preceding the nouns(s) herein may be used to describe various elements, these elements should not be limited by these terms. These terms are only used to distinguish one element from another and do not restrict the order of the nouns(s). For example, without departing from the scope of the exemplary embodiments, a first element may be referred to as a second element, and similarly, a second element may be referred to as a first element. As used herein, the term "and / or" includes any and all combinations of one or more of the listed terms.

[0025] As used herein, “one or more of the following: ” and “<at least one of the two or more elements>” and similar wording (where the list of two or more elements is connected by “and” or “or”) means at least any one of these elements, or at least any two or more of these elements, or at least all of these elements.

[0026] As used herein, unless explicitly stated otherwise, “responding to A” does not mean that the step must be performed immediately after “A” occurs, but rather allows for one or more intermediate steps.

[0027] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the exemplary embodiments. The singular forms “a,” “an,” and “the” used herein also include the plural forms unless the context clearly indicates otherwise. Further understanding is that the terms “comprising,” “including,” “having,” “containing,” and / or “containing,” as used herein, specify the presence of the stated features, elements, and / or components, but do not exclude the presence or addition of one or more other features, elements, components, and / or combinations thereof.

[0028] As used in this application, the term "circuit system" may refer to one or more or all of the following: (a) Pure hardware circuit implementation (such as implementations only in analog and / or digital circuit systems), and (b) A combination of hardware circuitry and software, such as (if applicable): (i) A combination of (multiple) analog and / or digital hardware circuits and software / firmware, and (ii) Any part of a hardware processor (including multiple digital signal processors), software, and memory (multiple processors) that works together to enable a device (such as a mobile phone or server) to perform various functions, and (c) (Multiple) hardware circuits and / or (multiple) processors, such as (multiple) microprocessors or portions of (multiple) microprocessors, which require software (e.g., firmware) to operate, but may be absent when operation is not required.

[0029] The definition of "circuit system" applies to all uses of the term in this application, including in any claim. As another example, as used in this application, the term "circuit system" also covers only hardware circuitry or a processor (or processors) or a portion of hardware circuitry or a processor and its accompanying software and / or firmware. For example, if applicable to a particular claim element, the term "circuit system" also covers baseband integrated circuits or processor integrated circuits for mobile devices, or similar integrated circuits in servers, cellular network devices, or other computing or network devices.

[0030] As used herein, the term "communication network" refers to a network that conforms to any suitable communication standard, such as New Radio (NR), Long Term Evolution (LTE), LTE-A Advanced (LTE-A), Wideband Code Division Multiple Access (WCDMA), High-Speed ​​Packet Access (HSPA), Narrowband Internet of Things (NB-IoT), etc. Furthermore, communication between terminal devices and network devices in a communication network can be performed according to any suitable generation of communication protocol, including but not limited to first-generation (1G), second-generation (2G), 2.5G, 2.75G, third-generation (3G), fourth-generation (4G), 4.5G, fifth-generation (5G), 5.5G, sixth-generation (6G) communication protocols and / or any other currently known or future-developed protocols. Embodiments of this disclosure can be applied to various communication systems. Given the rapid development of communications, there will naturally be communication technologies and systems that can be used to embody future types of communication technologies and systems. This should not be construed as limiting the scope of this disclosure to the systems described above.

[0031] As used herein, the term "network node" or "network device" refers to a node in a communication network through which terminal devices access the network and receive services. A network device can refer to a base station (BS) or access point (AP), such as a Node B (NodeB or NB), an evolved Node B (eNodeB or eNB), an NR NB (also known as a gNB), a Remote Radio Unit (RRU), a Radio Header (RH), a Remote Radio Header End (RRH), a relay, an Integrated Access and Backhaul (IAB) node, a low-power node (such as a femtosecond or picosecond), a non-terrestrial network (NTN), or a non-terrestrial network device (such as satellite network equipment, low Earth orbit (LEO) satellites and geostationary orbit (GEO) satellites, aircraft network equipment, etc.), depending on the terminology and technology applied. In some example embodiments, the Radio Access Network (RAN) split architecture includes a centralized unit (CU) and a distributed unit (DU) at the IAB donor node. An IAB node includes: a mobile terminal (IAB-MT) portion that behaves as a UE to its parent node, and a DU portion of the IAB node that behaves as a base station to the next-hop IAB node.

[0032] The term "serving cell" can refer to the "source cell".

[0033] The term "terminal device" refers to any terminal device capable of wireless communication. As an example and not a limitation, a terminal device may also be referred to as a communication device, user equipment (UE), subscriber station (SS), portable subscriber station, mobile station (MS), or access terminal (AT). Terminal devices can include, but are not limited to, mobile phones, cellular phones, smartphones, Voice over IP (VoIP) phones, wireless local loop phones, tablets, wearable terminal devices, personal digital assistants (PDAs), portable computers, desktop computers, image acquisition terminal devices (such as digital cameras), gaming terminal devices, music storage and playback devices, in-vehicle wireless terminal devices, wireless endpoints, mobile stations, laptop embedded devices (LEE), laptop mounted devices (LME), USB dongles, smart devices, wireless customer premises equipment (CPE), Internet of Things (IoT) devices, watches or other wearable devices, head-mounted displays (HMDs), vehicles, drones, medical devices and applications (e.g., remote surgery), industrial devices and applications (e.g., robots and / or other wireless devices operating in industrial and / or automated processing chain environments), consumer electronics devices, devices operating on commercial and / or industrial wireless networks, etc. The terminal device may also correspond to the mobile terminal (MT) portion of an IAB node (e.g., a relay node). In the following description, the terms "terminal device," "communication device," "terminal," "user equipment," and "UE" are used interchangeably.

[0034] As used herein, the terms “resource,” “transmission resource,” “resource block,” “physical resource block” (PRB), “uplink resource,” or “downlink resource” can refer to any resource used to perform communication, such as communication between a terminal device and a network device, including time-domain resources, frequency-domain resources, spatial-domain resources, code-domain resources, or any other combination of time-domain resources, frequency-domain resources, spatial-domain resources, and / or code-domain resources used to enable communication. In the following, unless explicitly stated otherwise, resources in both the frequency and time domains will be used as examples of transmission resources to describe some exemplary embodiments of this disclosure. It should be noted that the exemplary embodiments of this disclosure are equally applicable to other resources in other domains.

[0035] Figure 1 The diagram illustrates the signal flow of the L1 / L2 triggered mobility (LTM) procedure based on TS 38.300. In version 18, LTM measurements of neighboring candidate cells can be performed using synchronization signal blocks (SSBs) sent by the candidate cells, whose SSB configurations are provided to the user equipment (UE) (or terminal equipment) (110).

[0036] Before cell handover (i.e., before the handover from the serving cell (120) to the target cell (130a)), at least one network (115a, ..., 115n) (collectively referred to as network 115) may optionally activate one or more TCI states of one or more candidate cells (130a, ..., 130n) (see See Figure 1 (Step 4a). After the candidate cell TCI state is activated, the UE (110) can begin tracking time / frequency synchronization using reference signals associated with the activated TCI states(s). The UE can also perform early UL synchronization prior to cell handover if requested by the network node (see [link to relevant documentation]). Figure 1 (Step 4b).

[0037] The LTM process is referenced below (step numbers in section 9.2.3.5.2 of TS 38.300):

[0038] The UE (110) can be in the RRC_connected state with the serving cell (120) via a network node or gNB (115a) (at the initial preparation step of LTM (140) before cell handover).

[0039] Step 1. The UE (110) can send a message to the gNB (115a) in the serving cell (120). L3 RRC Measurement Report Message (142). gNB (115a) (i.e., the serving cell (120)) can decide to configure LTM and initiate LTM preparation.

[0040] Step 2. The serving cell (120) may send the LTM candidate configuration (146) to the UE (110). RRCReconfiguration Message (144).

[0041] Step 3. The UE (110) can store the LTM candidate configuration and send it to the serving cell (120). RRCReconfigurationComplete information.

[0042] During LTM execution (150), the following steps may be performed.

[0043] Step 5. In the first option, the UE (110) can perform L1 measurements on (multiple) configured LTM candidate cells and send an L1 measurement report (L1 CSI report) (142) to the serving cell (120).

[0044] In another option, the UE (110) can perform L3 measurements on (multiple) configured LTM candidate cells (130a to 130n) and send another RRC Measurement Report (142) Initiate LTM execution.

[0045] As long as RRC reconfiguration (step 2) applies, L1 and L3 (i.e., lower-level) measurements should be performed.

[0046] Step 4a. The UE (110) may perform early DL synchronization (152) with (multiple) LTM candidate cells (130a to 130n) before receiving the cell handover command (156). The UE (110) may activate and deactivate the TCI state of (multiple) LTM candidate cells, as triggered by the serving cell (120) through TCI state activation (MAC CE) (153).

[0047] Step 4b. After early DL synchronization (152) is completed, the UE may perform early UL synchronization (154) with (a plurality of) LTM candidate cells (130a to 130n) by using UE-based TA measurement (if configured) and / or by sending a preamble (310b) to candidate cells (130a to 130n), as triggered by network node 115a (i.e., or serving cell (120)). When UE-based TA measurement is configured, the UE (110) may acquire (a plurality of) TA values ​​of (a plurality of) candidate cells (130a to 130n) by measurement. Before receiving the cell handover command (156), the UE performs early TA acquisition for (a plurality of) candidate cells (130a to 130n) at the request of network node (115a), as specified in Clause 9.2.6 of TS 38.300. This is performed via a CFRA triggered by a PDCCH command downlink control information (DCI) from the source cell (120b), after which the UE (110) can send a preamble (310b) to a designated candidate cell (130a) as the target cell. To minimize data interruption in the source cell (120b) due to CFRAs with (multiple) candidate cells (130a to 130n), the UE (110) may not receive a random access response (RAR) from the network node (115a) to obtain the TA value, and the TA value of the candidate cell as the target cell (130a) is indicated in the cell handover command. The UE does not maintain a TA timer for the candidate cell, but relies on the network implementation to ensure TA validity.

[0048] Step 6. The gNB (115a) decides to perform a cell handover to the target cell (130a) and sends an LTM cell handover command (MAC CE) (156) that triggers the handover, including a target configuration ID (302b) indicating the candidate configuration of the target cell, a beam indicated by the TCI state (306a), or a beam indicated by the DL and ULTCI states (308a), and a timing advance command (304a) for the target cell (130a) (if available). The UE (110) may handover to the target cell (130a) and apply the candidate configuration indicated by the target configuration ID (302a).

[0049] Step 7. If the UE (110) does not have a valid TA for the target cell (130a), the UE (110) may perform a random access procedure (158) to the target cell (130a) as specified in Clause 5.18.35 of TS 38.321.

[0050] Step 8. The UE (110) can send a message to the target cell (130a). RRCReconfigurationCompleteThe message completes the LTM cell handover process. If the UE (110) performs a random access (RACH) procedure in step 7, the UE can consider the LTM cell handover to be successfully completed when the random access procedure is successfully completed. For LTM without RACH, the UE considers the LTM cell handover to be successfully completed when it determines that the network has successfully received its first UL data.

[0051] Steps 4-8 can be performed multiple times (i.e., repeated 314a) to allow subsequent LTM cell handover execution using the (multiple) LTM candidate configurations (146) provided in step 2.

[0052] The air interface (F1-C) procedures described in Figure 9.2.3.5.2-1 of TS 38.300 apply to both intra-gNB-DU LTM and inter-gNB-DU LTM. The overall LTM procedures on the F1-C interface are documented in TS 38.401.

[0053] Figure 2 The diagram illustrates the process of acquiring CSI (Channel State Information) prior to handover in an LTM cell.

[0054] Early TCI State Activation (Early DL Synchronization): When supported by the UE (110), the TCI states of one or more LTM candidate cells (130a to 130n) can be activated before sending a cell handover command (156). This early TCI activation allows the UE (110) to perform DL synchronization (152) with the cell associated with the activated TCI state, thereby facilitating a faster handover to one of these cells when a cell handover is triggered. If the TCI state of a candidate cell is not activated before the cell handover, the TCI state activation will occur along with the cell handover command. Then, since the UE (110) may require time for fine-grained time tracking in the candidate cells, an additional delay is added to the handover delay.

[0055] Early CSI (Channel State Information) Acquisition in Rel-19 LTM. Rel-19 considers NR mobility enhancements. One topic discussed is the CSI acquisition process before / during LTM cell handover. Three alternatives are investigated: - Alternative 1: CSI-RS (Channel State Information Reference Signal) measurement and CSI reporting operations (151) are performed before the reception of LTM cell handover command (CSC) MAC CE (156). - The report (147A) is sent to the serving cell (120) and transmitted to (multiple) candidate / target cells (130) (see See Figure 2 ). - Alternative Solution 2 (see Figure 2 ): CSI-RS measurement (151) can begin before the LTM CSC MAC CE is received, and CSI report (147B) operation is performed after the LTM CSC MAC CE (156) is received. - The report (147B) was sent directly to the target cell (130a). - Alternative 3: CSI-RS measurement (151) and CSI reporting operations are performed after the LTM CSC MAC CE (156) is received.

[0056] During RAN1#119, it was agreed to support the above alternatives 2 and 3, more specifically: as a baseline, CSI-RS measurements (151) and CSI reporting operations (147B) are performed after the receipt of LTM CSC MAC CE (156). - The report (147B) was sent directly to the target cell (130a). - The introduction of UE capability for CSI-RS measurement (151) can begin before the reception of LTM CSC MAC CE (156). ○ In addition to UE capabilities, avoid creating additional specification effects compared to the baseline (specify only one triggering mechanism).

[0057] Table 7.3.1.1.2-24 provides the SRS request in 38.212 for reference. Table 7.3.1.1.2-24: SRS Request

[0058] The SRS configuration provided in 38.331 is for reference only:

[0059] IE SRS-Config This configuration is used to configure the transmission of the probe reference signal. It defines the SRS-Resource list and the SRS-ResourceSet list. Each resource set defines an SRS resource set. The network triggers the transmission of the SRS resource set using the configured aperiodic SRS resource triggering (L1 DCI).

[0060] Figure 3The diagram illustrates the LTM cell handover command MAC CE (300) (Media Access Control element). Note 2: If the target configuration ID value (302b) of the LTM cell handover command MAC CE received by the UE (110) matches any configured... ltm- CandidateId The minus 1 mismatch, as specified in TS 38.331[5], does not apply to the process of handling LTM cell handover command MAC CE in Clause 5.18.35.

[0061] LTM cell handover command MAC CE (300)

[0062] The LTM cell handover command MAC CE is identified by a MAC subheader with eLCID, as shown in Table 6.2.1-1b. It has a variable size and contains the following fields (Figure 6.1.3.75-1): - R: Reserved bit, set to 0; - Target Configuration ID (302b): This field indicates the index of the candidate target configuration to be applied to LTM cell handover, corresponding to... ltm-CandidateId Subtract 1, as specified in TS 38.331[5]. The length of this field is 3 bits; - Timing Advance Command (304a): This field indicates whether the TA is valid for the LTM target cell (i.e., the SpCell corresponding to the target configuration indicated by the Target Configuration ID field). If the value of this field is set to FFF, this field indicates that there is no valid timing adjustment available for the LTM target cell's PTAG; otherwise, this field indicates the index value of the timing adjustment amount that the MAC entity must apply in TS38.213[6]. T A And the UE can skip the random access procedure for handover in this LTM cell. If tag-Id-ptr Configured to the TCI state indicated by the UL TCI state ID field (if present) or the TCI state ID field in the LTM target cell, and tag-Id-ptr Set as value n1 Then this field indicates the target cell of LTM. tag2-Id The field indicates the TA of the TAG; otherwise, it indicates the target cell's TA by LTM. tag-id The TA of the indicated TAG. This field is 12 bits long; - TCI Status ID (306a): This field indicates and activates the TCI status of the LTM target cell (i.e., the SpCell of the target configuration indicated by the Target Configuration ID field). The TCI status is determined by... ltm-DL-OrJointTCI-StateToAddModList In TCI-StateIdThe identifier, as specified in TS 38.331[5]. If the configuration is indicated by the target configuration ID field. ltm-TCI-Info middle unifiedTCI-StateType The value is joint If the condition is met, this field is used for the joint TCI status; otherwise, this field is used for the downlink TCI status. This field is 7 bits long. - UL TCI Status ID (308a): This field indicates and activates the uplink TCI status of the LTM target cell (i.e., the SpCell of the target configuration indicated by the Target Configuration ID field). The UL TCI status is determined by... ltm-UL-TCI- StateToAddModList In TCI-UL-StateId The identifier, as specified in TS 38.331[5]. If the configuration is indicated by the target configuration ID field. ltm-TCI-Info In unifiedTCI-StateType The value is separate If so, then the octet containing the field (i.e., the field and two reserved bits in the same octet) is included. The field is 6 bits long; - C (302a): This field indicates the presence of the contention-free random access resource field. If the value of this field is set to 1, the following fields are present: random access preamble index field, S / U field, SS / PBCH index field, PRACH mask index field, repetition count field, and reserved bits in the same octet. If the value of this field is set to 0, these fields are not present. - S / U: This field indicates which UL carrier is used to transmit PRACH for contention-free random access resources. If the value of this field is set to 1, SUL is used; otherwise, NUL is used. This field is 1 bit long. - Random Access Preamble Index (310b): This field indicates the random access preamble index of a contention-free random access resource. This field should not be set to 0b000000. This field is 6 bits long. - SS / PBCH Index (312b): This field indicates the SS / PBCH that should be used to determine the RACH timing for PRACH transmissions of contention-free random access resources. This field is 6 bits long; - PRACH Mask Index (312a): This field indicates the timing of (multiple) RACHs associated with the SS / PBCH indicated by the 'SS / PBCH Index' for PRACH transmissions on contention-free random access resources. It indicates the origin of... rach- ConfigDedicated A subset of the (multiple) RACH timings for the UL carrier (indicated by the S / U field), (if provided, otherwise it indicates) firstActiveUplinkBWP-Id UL BWP configuration from rach-ConfigCommonThe subset of (multiple) RACH timings for the UL carrier (indicated by the S / U field, as specified in TS 38.331[5]). The UE ignores the repetition count field when it is not set to 0. The field is 4 bits long; - Repetition Count (314a): This field indicates the number of Msg1 repetitions applied to contention-free random access. If this field is set to 0, the Msg1 repetition count is not applied. If this field is set to 1, the Msg1 repetition count is 2. If this field is set to 2, the Msg1 repetition count is 4. If this field is set to 3, the Msg1 repetition count is 8. This field is 2 bits long. Note 1: When the LTM target cell is configured with contention-based random access resources, and FeatureCombinationPreambles Having the same Msg1 repetition count and featureCombination Only indicate Msg1 repeats msg1-Repetition At that time, non-zero Msg1 duplicate values ​​can only be included in the LTM cell handover command MAC CE.

[0063] The technical issues to be addressed will be discussed below. Since link adaptation is crucial for achieving good spectral efficiency, appropriate modulation and coding rates for the data channel and the aggregation level of the control channel as the physical downlink control channel (PDCCH) can be determined based on channel parameters such as CRI, CQI, PMI, and RI, also known as CSI acquisition.

[0064] For Rel-19 LTM, it has been agreed that CSI acquisition is based on downlink reference signals (e.g., CSI-RS) of candidate cells, whereby the terminal device or UE (510) can acquire and report CSI parameters of one or more candidate cells (530a to 530n). These parameters are used for transmission and reception in the target cell (530a) after cell handover, thereby reducing the need for additional channel quality information measurements in the target cell (530a) during the initial transmission or reception.

[0065] To improve communication quality and avoid the need for the UE (510) to report any channel quality information measurements to one or more network nodes (515), a method for acquiring CSI based on the transmission of the Sounding Reference Signal (SRS) is proposed. SRS-based (i.e., UL-derived) DL MIMO has been widely used in 5G networks because it can provide higher spectral efficiency than DL MIMO operation based on DL CSI. For cell handover (LTM), SRS-based CSI acquisition can be triggered before or after the reception of the cell handover command.

[0066] This disclosure describes the configuration, signaling, and UE procedures for enabling SRS-based CSI acquisition for (a plurality of) mobility candidate cells (530a to 530n) after receiving a cell handover command (514c).

[0067] The proposed technical solution addresses the aforementioned problem (i.e., reducing the need for additional channel quality information measurements in the target cell (530a) during initial transmission or reception) because the physical uplink shared channel (PUSCH) transmission based on SRS transmission reflects the actual channel quality through the proposed signaling, thereby enabling higher communication quality (on the uplink, downlink, or both).

[0068] This disclosure proposes a framework (including configuration, signaling, and UE procedures) for enabling SRS-based CSI acquisition for one or more mobility candidate cells (530a to 530n) after receiving a cell handover command (514a). Specifically, LTM-SRS (513c) is triggered and sent to the target candidate cell (530a) after the reception of the LTM cell handover command (CSC) MAC CE (514c), wherein the target candidate cell (530a) triggers the UE (510) to send LTM-SRS (513c) to the target candidate cell (530a).

[0069] In one example, a terminal device such as a UE (510) can be configured to send an SRS (513c) for a PUSCH transmission (587) associated with an LTM cell handover process, which includes at least the following features: wherein the LTM-SRS (513c) is triggered by the target cell (530a) after the cell handover command is received. The LTM-SRS (513c) is configured by the LTM configuration, (i) wherein at least one PUSCH transmission (587, 593, 597) on the target candidate cell (530a) is associated with the triggered LTM-SRS (triggered by the target cell); (ii) wherein the SRS transmission parameters (583a, 592a) are determined based on the DCI indicated by the target cell, the DCI being associated with the LTM-SRS configuration; (ii) the LTM-SRS transmission is indicated by the DCI to schedule (585) PUSCH for the first uplink transmission (587) (RRCreconfiguration complete); (iii) prior to scheduling PUSCH for the first uplink transmission (587) on the candidate cell, the transmission is indicated by the DCI (RRCreconfiguration complete); (iv) the target cell DCI is indicated to schedule PUSCH for the uplink transmission on the target candidate cell (530a). The UE is configured to monitor LTM-SRS triggering in a DCI sent by the target cell (530a) (582a); (v) receive the DCI and schedule (585) SRS-based PUSCH transmissions on the candidate cell (587), where the SRS is the sent LTM-SRS (513c); (vi) send the PUSCH.

[0070] In one example, the PUSCH transport described herein may include at least one of the following aspects: 1. First aspect: SRS configuration for LTM cell handover operations; 2. Secondly, LTM SRS triggering is performed by the target cell DCI. 3. Thirdly, applying TA values ​​for LTM-SRS transmission. 4. Fourthly, regarding the spatial relationships for LTM-SRS transmission applications. 5. Fifthly, supply power control parameters for LTM-SRS. 6. Sixthly, PUSCH transmission based on the transmitted LTM-SRS scheduled by DCI.

[0071] Figure 4A and Figure 4B Some example embodiments according to this disclosure are depicted. Figure 5The cell handover environment (500) may include at least a terminal device (510) communicating with at least one network node (515a to 515n), which can provide services for a serving cell (520) and one or more candidate cells (530a to 530n). The one or more candidate cells (530a to 530n) may include at least a target cell (530a) and other candidate cells (530b to 530n). In one example, both the serving cell (520) and the target cell (530a) may be provided by the same network node (515a) (see [link to relevant documentation]). Figure 4A Alternatively, services can be provided by different individual network nodes (515b) (see [link]). Figure 4B For the purposes of discussion, at least one network node (515a to 515n) may be collectively referred to as at least one network node (515).

[0072] Figure 4A and Figure 4B Simplified block diagrams of a terminal device (510) and a network node (515) suitable for implementing exemplary embodiments of the present disclosure are also disclosed. The terminal device (510) may include one or more processors (531), one or more memories (532) coupled to the one or more processors (531), and the one or more processors (531) may be coupled to a transceiver communication module (533) including at least one antenna for bidirectional communication. The network node (515) may include one or more processors (534), one or more memories (535) coupled to the one or more processors (534), and the one or more processors (531) may be coupled to the transceiver communication module (533) including at least one antenna for bidirectional communication.

[0073] The processor (531) can be of any type suitable for a local technology network, and by way of non-limiting example, can include one or more of the following: a general-purpose computer, a special-purpose computer, a microprocessor, a digital signal processor (DSP), and a processor based on a multi-core processor architecture. The device (510) can have multiple processors, such as application-specific integrated circuit chips that are time-dependent on a clock synchronized with the main processor.

[0074] The memory (532) may include one or more non-volatile memories and one or more volatile memories. Examples of non-volatile memories include, but are not limited to, read-only memory (ROM), electrically programmable read-only memory (EPROM), flash memory, hard disk, compact disc (CD), digital video disc (DVD), optical disc, laser disc, and other magnetic and / or optical storage devices. Examples of volatile memories include, but are not limited to, random access memory (RAM) and other volatile memories that do not persist during power outages.

[0075] A computer program may include computer-executable instructions that are executed by an associated processor (531). The instructions of the program may include instructions for performing operations / actions of some example embodiments of this disclosure. The program may be stored in memory, such as ROM (532). The processor (531) may perform any suitable actions and processes by loading the program into RAM.

[0076] The exemplary embodiments of this disclosure can be implemented by a program, enabling the terminal device (510) to execute the commands shown in FIG4 to... Figure 5 Any process discussed in this disclosure. Exemplary embodiments of this disclosure may also be implemented using hardware or a combination of software and hardware.

[0077] In some example embodiments, the program may be tangibly contained in a computer-readable medium, which may be included in the terminal device (510) (such as in memory (532)) or in other storage devices accessible to the terminal device (510). The terminal device (510) may load the program from the computer-readable medium into RAM for execution. In some example embodiments, the computer-readable medium may include any type of non-transitory storage medium, such as ROM, EPROM, flash memory, hard disk, CD, DVD, etc. The term “non-transitory” as used herein refers to a limitation on the medium itself (i.e., tangible, not tactile), rather than a limitation on the persistence of data storage (e.g., RAM and ROM).

[0078] Generally, the various embodiments of this disclosure can be implemented using hardware or dedicated circuitry, software, logic, or any combination thereof. Some aspects can be implemented using hardware, while others can be implemented using firmware or software that can be executed by a controller, microprocessor, or other computing device. Although various aspects of the embodiments of this disclosure are illustrated and described as block diagrams, flowcharts, or using some other graphical representation, it should be understood that, as non-limiting examples, the blocks, apparatuses, systems, techniques, or methods described herein can be implemented using hardware, software, firmware, dedicated circuitry or logic, general-purpose hardware or controllers or other computing devices, or some combination thereof.

[0079] Some exemplary embodiments of this disclosure also provide at least one computer program product tangibly stored on a computer-readable medium, such as a non-transitory computer-readable medium. The computer program product includes computer-executable instructions, such as instructions included in a program module, which execute in a device on a target physical or virtual processor to perform any of the methods described above. Typically, a program module includes routines, programs, libraries, objects, classes, components, data structures, etc., that perform a particular task or implement a particular abstract data type. In various embodiments, the functionality of a program module can be combined or split among program modules as needed. The machine-executable instructions of a program module can execute within a local or distributed device. In a distributed device, a program module can reside on both local and remote storage media.

[0080] Program code used to perform the methods of this disclosure may be written in any combination of one or more programming languages. This program code may be provided to a processor or controller of a general-purpose computer, special-purpose computer, or other programmable data processing apparatus, such that, when executed by the processor or controller, the program code causes the functions / operations specified in the flowcharts and / or block diagrams to be implemented. The program code may be executed entirely on a machine, partially on a machine, as a stand-alone software package, partially on a machine and partially on a remote machine, or entirely on a remote machine or server.

[0081] In the context of this disclosure, computer program code or related data may be carried by any suitable carrier to enable a device, apparatus, or processor to perform the various processes and operations described above. Examples of carriers include signals, computer-readable media, etc.

[0082] Computer-readable media can be computer-readable signal media or computer-readable storage media. Computer-readable media can include, but is not limited to, electronic, magnetic, optical, electromagnetic, infrared, or semiconductor systems, apparatuses, or devices, or any suitable combination of the foregoing. More specific examples of computer-readable storage media will include electrical connections having one or more wires, portable computer floppy disks, hard disks, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), optical fibers, portable optical disc read-only memory (CD-ROM), optical storage devices, magnetic storage devices, or any suitable combination of the foregoing.

[0083] The proposed LTM-SRS transmission process illustrates Figure 5 The various aspects of the technical solution disclosed in the flowchart, Figure 5 Examples of methods according to some embodiments of this disclosure are shown. For the purposes of discussion, the description will be primarily from the perspective of the terminal device (510). Figure 5 The method in the middle.

[0084] With the proposed signaling, PUSCH transmission is based on SRS transmission, which reflects the actual channel quality and thus enables higher communication quality.

[0085] The proposed method offers several advantages, including: enabling higher communication quality immediately after cell handover; and allowing network nodes (515) to indicate PUSCH parameters (592a, 596a) reflecting actual channel quality in PUSCH messages (587a, 593a, 597a), thus avoiding scheduling using conservative MCS / layer numbers. Various aspects of this method can be further elaborated upon. Figure 5 The steps executed by the UE in the signal flow diagram are discussed.

[0086] The first aspect of the method relates to the configuration of the probe reference signal (SRS) for LTM cell handover operations.

[0087] The SRS configuration (503) may be included in the LTM configuration (502a). In some examples, the SRS configuration may be configured for mobility operations (i.e., for either or both of L3 / RRC level mobility or LTM). The SRS configuration for any of the candidate cells (530a to 530n) may be provided in the LTM configuration (502a) as part of the serving cell configuration or the cell group configuration of the candidate cells. The SRS configuration may be provided as part of an LTM candidate configuration (candidate configuration IE, information element). In some examples, this configuration may be associated with an LTM (candidate) configuration that may have common parameters for one or more candidate cells. The LTM candidate configuration may include RRC reconfiguration of the candidate cells. In some examples, the SRS configuration may be part of the serving cell configuration. In another example, the SRS configuration (503) may be part of a common configuration of one or more candidate cell configurations.

[0088] In any of the examples in this article, SRS or LTM-SRS can be used interchangeably.

[0089] In any of the examples in this article, SRS resources (sets) or LTM-SRS resources (sets) can be used interchangeably.

[0090] In any example in this document, SRS or LTM-SRS can refer to the SRS used for mobility operations (e.g., L3 handover and / or LTM cell handover) and can be used interchangeably.

[0091] In any example in this document, SRS resource(set) or LTM-SRS resource(set) can refer to an SRS resource(set) used for mobility operations (e.g., L3 handover and / or LTM cell handover) and can be used interchangeably.

[0092] In one example embodiment, the UE can be configured to send SRS to one or more candidate cells for LTM cell handover purposes (this may be referred to as LTM-SRS (513c)).

[0093] SRS configurations can be associated with certain candidate IDs.

[0094] In one example, the SRS configuration (503a) can be common to all candidates, meaning that the SRS resource set ID can be associated with an LTM transport to one or more candidate cells. For example, the SRS configuration can provide a common LTM configuration for all candidate cells (530a to 530n) outside of any LTM candidate IE.

[0095] In one example, SRS can be configured such that in the target cell (530a), one SRS transmission occurs before the cell handover command, while another SRS transmission (584, 594) occurs after the cell handover command (514c, 578). The SRS configuration (503) before and after CSC (514c) can be the same, or they can have separate configurations in terms of SRS characteristics, such as frequency hopping, SRS density, number of ports used by the SRS transmission, etc. For example, the SRS configuration to be used before CSC can be given in the LTM configuration outside the candidate cell's RRC configuration (i.e., outside the candidate cell's serving cell configuration or cell group configuration), while the SRS configuration to be used after CSC can be given in the candidate cell's ltm-CandidateConfig (which contains the candidate cell's associated RRCReconfiguration).

[0096] refer to Figure 5 In step 502, the UE (510) may be configured with an SRS configuration (503) associated with LTM cell handover / LTM operation. In some examples, the SRS configuration may be configured for mobility operations (i.e., for either or both of L3 / RRC level mobility or LTM). More specifically, the SRS configuration (503) may be included in the LTM configuration (502a). In one example, the SRS configuration (503) of a candidate cell (one of 530a to 530n) may be provided in the LTM configuration (502a) as part of the serving cell configuration.

[0097] The SRS configuration can be provided as part of an LTM candidate IE. In some examples, this configuration can be associated with an LTM (candidate) configuration, which may have common parameters for one or more candidate cells but is signaled in another information element. In another example, the SRS configuration (503) can be part of the serving cell (520) configuration. In yet another example, the SRS configuration (503) can be part of a common configuration of one or more candidate cell configurations.

[0098] In any example herein, SRS or LTM-SRS may be used interchangeably. In any example herein, SRS or LTM-SRS can refer to SRS used for mobility operations (e.g., L3 handover and / or LTM cell handover) and may be used interchangeably. In any example herein, LTM-SRS can refer to SRS transmissions used for mobility operations. LTM-SRS transmissions can refer to SRS transmissions used for mobility purposes during, before, and after cell handovers (from a source to at least one target candidate cell).

[0099] In step 504, the UE (510) may perform measurements and reports on at least one of the serving cell (520) and one or more candidate cells (530a to 530n).

[0100] In step 506, the UE (510) can receive candidate TCI state activation (511a) from the network node (515).

[0101] In step 576, the UE (510) may receive the candidate TCI activation state (511a) of at least one candidate cell (e.g., 530a).

[0102] In step 578, the UE (510) may receive a cell handover command (514c). In step 579, the UE (510) may monitor the DCI (525c) based on the cell handover command (514a) to obtain uplink authorization on the target candidate cell (530a).

[0103] In any example, the TCI status information signaled in the cell handover command can activate or indicate at least one TCI status (e.g., a combined uplink and downlink TCI status or individual uplink and downlink TCI status). In some examples, the activation and indication of at least one TCI status can be used interchangeably. The cell handover command can activate at least one TCI status or indicate at least one TCI status (which may have been activated previously).

[0104] In option 1 (580), an LTM-SRS request (received by the UE) is made prior to the DCI-scheduled uplink UL grant (579a). In step 582, the target cell (530a) may send a DCI trigger (582a) to the UE (510) to trigger an LTM-SRS transmission. In step (583), the UE (510) may apply the SRS-related parameters (583a) indicated by the DCI (525c). In step (583), the UE may apply the RS or the quasi-co-located source RS of the RS included in the indicated TCI state (in the cell handover command) as the spatial relationship for the LTM-SRS transmission. In some examples, the spatial relationship RS may refer to the spatial relationship between a reference RS and the target SRS. The reference RS may be an SSB / CSI-RS or an SRS.

[0105] In step 584, the UE (510) can send LTM-SRS (513c) to the target candidate cell (530a) according to the indicated / determined parameters.

[0106] In step 585, the target cell (530a) may send a DCI, which is a UL transmission scheduling uplink grant, including information related to the LTM-SRS (513a) being sent.

[0107] In step 586, the UE (510) may determine the transmission parameters for the PUSCH based on the indications in the LTM-SRS and DCI (525d) (521c).

[0108] In step 587, the UE (510) may send a PUSCH message (587a) according to the indicated or determined SRS related parameters (583a). The DCI (525d) may also indicate one or more PUSCH transmission parameters in the PUSCH transmission parameters: MCS, Transport Precoding Matrix Index (TPMI), and rank indicator.

[0109] Alternatively, the UE (510) may use an LTM_SRS request in the DCI that schedules the UL grant (579a) to perform option 2 (590). For example, in step 593, the UE (510) may send a first PUSCH message (593a) scheduled by the DCI (RRCreconfiguration_complete) to the target cell (530a).

[0110] In step 594, the UE may send LTM-SRS (513c) to the target cell (530a) according to the parameters indicated / determined by the DCI (525c).

[0111] In step 595, the UE (510) may receive a DCI for UL transmission scheduling uplink grant (579a), which includes information related to the transmitted LTM-SRS (513c).

[0112] In step 596, the UE (510) may determine the transmission parameters (596a) for the second (another) PUSCH message (597a) based on the indications (525c) in the LTM-SRS (513c) and DCI.

[0113] In step 597, the UE (510) can send a second PUSCH message (597a) according to the transmission parameters and LTM-SRS (513c) to complete the process.

[0114] The second aspect of the method involves LTM SRS triggering by the target cell DCI. In an example embodiment, the DCI format that triggers an SRS transmission to the target cell (530a) (in step 584) may include one or more fields associated with the LTM-SRS transmission or the triggering of an LTM-SRS transmission. For example, the DCI format may be the format used for scheduling UL transmissions (e.g., PUSCH transmissions (587, 593, 597)).

[0115] In one example embodiment, fields in the DCI (525c) may be associated with an LTM SRS configuration. Fields in the DCI may point to an SRS resource set ID configured for mobility purposes. The SRS resource set ID configured for mobility purposes may be provided by the RRC in the LTM configuration / LTM candidate configuration. In one example, a DCI field (code point) may refer to one or more SRS resource set IDs for a specific candidate cell ID used for LTM purposes. In one example, a DCI field (code point) may refer to an SRS resource set ID configured for LTM purposes. In one example embodiment, the DCI may include fields indicating whether the SRS resource set ID refers to an LTM configuration or a serving cell configuration. In one example, one or more SRS resource sets or one or more SRS resources may be candidate cell specific. SRS resource sets used for mobility purposes can be referenced using fields / information in the DCI. A DCI referencing an SRS may be sent by the target candidate cell. The DCI may indicate the triggering of an SRS transmission or reference an earlier transmitted SRS.

[0116] In some examples, the DCI may include a field indicating how the SRS-related information included in the DCI should be interpreted. When this field is set to a first value, it can indicate the serving cell configuration (i.e., the SRS associated with the serving cell). In one example, the UE interprets the SRS-related information as pointing to at least one SRS resource set ID in the serving cell configuration. When this field is set to a second value, the SRS-related information is mapped to an SRS resource set ID given in the LTM configuration. Fields in the DCI may point to an SRS resource set ID configured by the RRC in the LTM configuration / LTM candidate configuration. The SRS resource set ID may be associated with a candidate cell. The SRS-related information may be provided in the form of code points.

[0117] The relevant candidate cell for SRS transmission can be determined based on at least one of the following: the candidate cell ID based on the field that triggers SRS in the DCI, the active TCI state in the CSC, or the candidate identifier signaled in the cell handover command. The UE can determine the candidate cell ID based on the CSC (514c). In one example, the DCI may include a field indicating the candidate cell identifier. The candidate cell identifier indicates the target / candidate cell for the SRS transmission. The candidate cell ID can be used to determine the spatial relationship of the SRS transmission; that is, the UE can determine the spatial relationship based on the indication / active TCI state of the candidate cell. In some examples, if the target cell schedules the triggering of LTM SRS transmission, the candidate ID field or a field referencing the candidate ID is set to the candidate cell ID, or the candidate ID is implicitly determined based on the candidate cell handover scheduled by the DCI.

[0118] In one example, the UE may indicate its ability to support SRS transmissions to the target cell (transmissions performed after receiving a cell handover command). In another example, the UE may indicate its ability to support PUSCH transmissions based on SRS transmissions to the target cell (transmissions performed after receiving a cell handover command).

[0119] Alternatively or additionally, the UE may indicate its ability to support LTM-SRS transmissions triggered by DCI.

[0120] The third aspect of this method involves the timing advance (TA) value of the LTM-SRS. In one example embodiment, the spatial relationship configuration of the LTM-SRS can be determined based on the (candidate) TCI state indicated in the cell handover command.

[0121] In one example, if a separate TCI state is indicated, the UE applies the UL TCI state as the spatial relationship. In another example, if a combined TCI state is indicated, the UE applies the DL (or combined) TCI state as the spatial relationship. In yet another example, the DCI is used to schedule the triggering of the LTM SRS.

[0122] The fourth aspect of this method relates to the spatial relationships of LTM-SRS. In one example embodiment, the spatial relationship configuration of LTM-SRS can be determined based on the candidate TCI state indicated in the cell handover command. In one example, if a single TCI state is indicated, the UE applies the UL TCI state as the spatial relationship. In another example, if a combined TCI state is indicated, the UE applies the DL (or combined) TCI state as the spatial relationship.

[0123] In one example embodiment, the spatial relationships for LTM-SRS transmissions can be determined based on the DCI triggered for LTM-SRS scheduling. Quasi-colocation information can be determined based on the DCI (e.g., determining the reference signal of the QCL source used as the DCI transmission), and the QCL information RS is applied as the spatial relationships for LTM-SRS.

[0124] In any embodiment herein, spatial relation may refer to using a determined downlink reference signal as a reference for uplink transmission.

[0125] The fifth aspect of this method relates to the power control configuration of LTM-SRS.

[0126] In one example embodiment, the power control parameters of the LTM SRS can be determined based on the indicated TCI state, such as one or more of the Po value, alpha value, and downlink path loss estimate. In another example embodiment, the power control parameters of the LTM SRS (e.g., one or more of the Po value, alpha value, and downlink path loss estimate) can be determined based on a reference signal or a quasi-co-located source RS of the RS included in the indicated TCI state. In one instance, the power control parameters are provided as information elements in the DCI that triggers the LTM-SRS. In another example, the power control parameters are provided in the TCI state provided in the DCI that triggers the LTM-SRS. In yet another example, the power control parameters are provided via higher-layer signaling prior to the cell handover command, and the UE will apply the power control parameters in the target cell.

[0127] The sixth aspect of the method relates to PUSCH transmissions based on LTM-SRS transmissions scheduled by the DCI. In one example embodiment, the DCI transmitted by the target candidate cell includes the field LTM-SRI (SRS Resource Indicator), which indicates an SRS transmission by the UE to the candidate cell triggered by the DCI transmitted by the candidate cell. In one example embodiment, the LTM-SRI field indicates the latest SRS transmission by the UE to the candidate cell, triggered by the DCI transmitted by the candidate cell. In one example embodiment, the LTM-SRI field indicates a transmission of an SRS resource within the LTM-SRS resource set. In one example embodiment, the LTM-SRI field indicates the latest transmission of an SRS resource (ID) within the LTM SRS resource set.

[0128] In one example embodiment, the DCI that schedules PUSCH transmissions based on SRS transmissions may include a field indicating whether the SRI field indicates LTM-SRS or serving cell SRS resources.

[0129] If the field indicates an LTM-SRS resource, the UE interprets the SRI as an indicator of the SRS resource associated with the transmitted LTM-SRS resource set.

[0130] If the field indicates serving cell SRS resources, the UE interprets the SRI as an indicator of the SRS resources associated with the transmitted (serving cell) SRS resource set. In one example embodiment, the SRI (SRS Resource Indicator) field in the DCI refers to the latest SRS transmission made by the UE to the candidate cell.

[0131] If the latest transmission is LTM-SRS, then SRI refers to the most recently transmitted SRS associated with the LTM-SRS configuration. If the latest transmission is SRS (Serving Cell Configuration SRS), then SRI refers to the most recently transmitted SRS associated with the LTM-SRS configuration.

[0132] For example, LTM SRS and SRS share the same SRI field.

[0133] In one example, PUSCH transmissions to candidate cells based on LTM-SRS can be scheduled using a dedicated DCI format. By receiving a DCI format specifically designed for LTM-related / mobility-related scheduling, the UE can interpret one or more fields in the DCI as being associated with mobility operations (associated with the target cell).

[0134] In one example, PUSCH transfers to the target candidate cell can be performed on dynamically authorized UL resources.

[0135] In one example embodiment, the UE applies the PUSCH parameter indicated by the DCI and determines that the SRI (SRI information in the DCI) refers to an SRS transmission triggered by the target cell DCI.

[0136] In one example, the applied PUSCH parameters may include one or more of the (LTM-)SRI, TPMI-RI, and MCS indicated by the target candidate cell DCI authorized by the scheduling uplink. The UE may also determine, based on the DCI sent by the target cell, that one or more fields refer to the LTM-SRS sent to the target candidate cell.

[0137] In one example, the target cell's DCI can instruct the UE whether to apply the provided parameters to the PUSCH transmission based on the LTM SRS (or other SRS, such as the serving cell-triggered SRS).

[0138] In one example embodiment, the UE determines that the SRI field in the DCI scheduled by the target cell (which becomes the new serving cell) is a (latest) LTM SRS resource transmission pointing to the target cell.

[0139] In one example embodiment, the UE determines that the SRI field in the DCI scheduled by the target cell (current serving cell) refers to the (latest) LTM SRS resource transmission to the target cell until a new SRS is sent.

[0140] In an example of a terminal device (510) for communication, the terminal device includes: at least one processor (531); and at least one memory (532) storing instructions that, when executed by the at least one processor (531), cause the terminal device (510) to perform at least: receiving (502) a configuration from one or more network nodes (515), the configuration including at least: a configuration (503) for sending a probe reference signal (513c) for mobility operations between a serving cell (520) and one or more candidate cells (530); and sending (512) a probe reference signal (513c) to one or more candidate cells (530) based on trigger information (582a) received from at least one target cell (530a).

[0141] In an example of a terminal device (510) used for communication, the terminal device (510) is configured to receive (578) a cell handover command (514c) from one or more network nodes (515) before receiving trigger information from a target cell (530a) indicated in a cell handover command (514c), wherein the indicated target cell (530a) is from one or more candidate cells (530).

[0142] In the example of terminal device (510), at least one or two of the following are combined with terminal device (510): the serving cell (520) and one or more candidate cells (530) are served by the same or different network nodes among one or more network nodes (515); and mobility operations include terminal device (510) switching from serving cell (520) to target cell (530a).

[0143] In the example of terminal device (510), the transmission of a probe reference signal (513c) to one or more candidate cells (530) is triggered by the first downlink control information (DCI) (525c) received from the target cell (530a).

[0144] In the example of terminal device (510), terminal device (510) is also configured to perform at least one of the following: receive the Transmission Configuration Indicator (TCI) status activation (511a) of the target candidate cell (530a) in the cell handover command (514c) (506).

[0145] In the example of terminal device (510), after receiving the cell handover command (CSC) (514c), terminal device (510) is also configured to monitor (579) the first downlink control information (DCI) (525c) to obtain uplink grants (579a) for at least one candidate cell that is indicated as the target cell (530a) in the cell handover command (514c).

[0146] In the example of terminal device (510), terminal device (510) is configured to receive (582) first DCI (525c) from target cell (530a) to trigger (582a) a request to send probe reference signal (513c) before scheduling (585) uplink (UL) authorization (579a) using second DCI (525d).

[0147] In the example of the terminal device (510), the terminal device (510) is also configured to perform one or more of the following: apply (583) the probe reference signal related parameters (583a) indicated by the first downlink control information (DCI) (525c), apply the reference signal (RS) or the quasi-co-located source reference signal (RS) included in the TCI state (511a) indicated by the application as the spatial relation configuration of the probe reference signal (513c); and transmit (584) the probe reference signal (513c) according to the probe reference signal related parameters (583a) indicated by the first DCI (525c).

[0148] In the example of the terminal device (510), the terminal device (510) is also configured to perform one or more of the following: receive (585) a second DCI (525d) from the target cell (530a) for uplink transmission scheduling (581) and uplink (UL) authorization (579a), wherein the second DCI (525d) includes information related to a probe reference signal (513c) sent by the terminal device (510) to the target cell (530a); determine (586) transmission parameters (521c) of at least one physical uplink shared channel (PUSCH) based on the transmitted probe reference signal (513c) and the indication in the second DCI (525d); and send (587) at least one PUSCH according to the transmission parameters (521c) and the probe reference signal (513c).

[0149] In an example of a network node (515) for communication, the network node includes: at least one processor (534); and at least one memory (535) storing instructions that, when executed by the at least one processor (534), cause the network node (515) to at least: send (502) a configuration to a terminal device (510), the configuration including at least: a configuration (503) for causing the terminal device (510) to send (584) a probe reference signal (513c) for mobility operations between a serving cell (520) and one or more candidate cells (530); and before the terminal device (510) begins to send (584) the probe reference signal (513c) to the target cell (530a) based on trigger information (582a) received from the target cell (530a), a cell handover command (CSC) (514a) is sent to the terminal device (510), wherein the target cell (530a) is from one or more candidate cells (530).

[0150] In an example of a terminal device (510) for communication, the terminal device includes: a component for receiving (502) a configuration from one or more network nodes (515), the configuration including at least: a configuration (503) for transmitting a probe reference signal (513c) for mobility operations between a serving cell (520) and one or more candidate cells (530); and a component for transmitting (584) the probe reference signal (513c) to one or more candidate cells (530) based on trigger information (582a) received from at least one candidate cell (530a).

[0151] In an example of a network node (515) for communication, the network node includes: a component for sending (502) a configuration to a terminal device (510), the configuration including at least: a configuration (503) for causing the terminal device (510) to send (584) a probe reference signal (513c) for mobility operations between a serving cell (520) and one or more candidate cells (530); and a component for sending (578) a cell handover command (CSC) (514c) to the terminal device (510) before the terminal device starts sending (584) the probe reference signal (513c) to the target cell (530a) based on trigger information (582a) received from the target cell (530a), wherein the target cell (530a) is from one or more candidate cells (530).

[0152] In an example of a method for communication, the method includes: receiving (502) a configuration by a terminal device (510) from one or more network nodes (515), the configuration including at least: a configuration (503) for sending a probe reference signal (513c) for mobility operations between a serving cell (520) and one or more candidate cells (530); and sending (584) the probe reference signal (513c) to one or more candidate cells (530) based on trigger information (582a) received from at least one candidate cell (530a).

[0153] In an example of a method for communication, the method includes: a network node (515) sending (502) a configuration to a terminal device (510), the configuration including at least: a configuration (503) for causing the terminal device (510) to send (584) a probe reference signal (513c) for mobility operations between a serving cell (520) and one or more candidate cells (530); and a configuration (578) for sending a cell handover command (CSC) (514c) to the terminal device (510) before the terminal device begins to send (584) the probe reference signal (513c) to the target cell (530a) based on trigger information (582a) received from the target cell (530a), wherein the target cell (530a) is from one or more candidate cells (530).

[0154] In an example of a terminal device (510), a computer-readable medium includes instructions stored thereon for causing the terminal device (510) for wireless communication to at least perform the methods of the terminal device (510).

[0155] In an example of a terminal device (510), a computer-readable medium includes instructions stored thereon for causing a network node (515) for wireless communication to at least perform the methods of the network node.

[0156] Furthermore, although operations are described in a specific order, this should not be construed as requiring the operations to be performed in the specific order shown or sequentially, or to perform all of the shown operations to obtain the desired result. In some cases, multitasking and parallel processing may be advantageous. Similarly, while several specific implementation details are included in the foregoing discussion, these should not be construed as limiting the scope of this disclosure, but rather as descriptions of features that may be specific to particular embodiments. Unless explicitly stated otherwise, certain features described in the context of a single embodiment may also be implemented in combination in a single embodiment. Conversely, unless explicitly stated otherwise, various features described in the context of a single embodiment may also be implemented individually or in any suitable sub-combination in multiple embodiments.

[0157] Although this disclosure has been described in language specific to structural features and / or methodological actions, it should be understood that the disclosure as defined in the appended claims is not necessarily limited to the specific features or actions described above. Rather, the specific features or actions described above are disclosed as exemplary forms of implementing the claims.

Claims

1. A terminal device (510) for communication, comprising: At least one processor (531); as well as At least one memory (532) stores instructions that, when executed by the at least one processor, cause the terminal device (510) to at least: Receive (502) a configuration from one or more network nodes (515), the configuration including at least: a configuration (503) for sending a probe reference signal (513c) for mobility operation between the serving cell (520) and one or more candidate cells (530). as well as Based on the triggering information (582a) received from at least one candidate cell (530a), the probe reference signal (513c) is sent (584) to the one or more candidate cells (530).

2. The terminal device (510) according to claim 1, wherein the terminal device (510) is configured to: Before the terminal device (510) receives the trigger information from the target cell (530a) indicated in the cell handover command (514c), it receives (578) the cell handover command (514c) from the one or more network nodes (515), wherein the indicated target cell (530a) is from the one or more candidate cells (530).

3. The terminal device (510) according to claim 2, wherein at least one or both of the following are combined with the terminal device (510) for operation: The serving cell (520) and the one or more candidate cells (530) are served by the same or different network nodes among the one or more network nodes (515); and The mobility operation includes the terminal device (510) switching from the serving cell (520) to the target cell (530a).

4. The terminal device (510) according to claim 2, wherein sending (584) the probe reference signal (513c) to the at least one candidate cell (530) is triggered (582a) by the first downlink control information (DCI) (525c) received from the target cell (530a).

5. The terminal device (510) according to claim 2, wherein the terminal device (510) is further configured to perform at least one of the following: Receive (506) Transmission Configuration Indicator (TCI) status activation for the target candidate cell (530a) in the cell handover command (514c).

6. The terminal device (510) according to claim 2, wherein after receiving the cell handover command (CSC) (514c), the terminal device (510) is further configured to monitor (579) the first downlink control information (DCI) (525c) to obtain uplink grants (579a) for at least one candidate cell indicated as the target cell (530a) in the cell handover command (514c).

7. The terminal device (510) according to claim 6, wherein the terminal device (510) is configured to receive (582) the first DCI (525c) from the target cell (530a) before scheduling (585) uplink (UL) authorization (579a) using the second DCI (525d) to trigger (582a) a request to send the probe reference signal (513c).

8. The terminal device (510) according to claim 7, wherein the terminal device (510) is further configured to perform one or more of the following: The application (583) uses the detection reference signal related parameters (583a) indicated by the first downlink control information (DCI) (525c). The reference signal (RS) included in the indicated TCI state (511a) or the quasi-co-located source reference signal of the reference signal (RS) is used as the spatial relational configuration for the probe reference signal (513c); and The probe reference signal (513c) is transmitted (584) according to the probe reference signal related parameters (583a) indicated by the first DCI (525c).

9. The terminal device (510) according to claim 8, wherein the terminal device (510) is further configured to perform one or more of the following: A second DCI (525d) for uplink (UL) authorization (579a) for uplink transmission scheduling (581) is received (585) from the target cell (530a), wherein the second DCI (525d) includes: Information related to the detection reference signal (513c) sent by the terminal device (510) to the target cell (530a); Based on one or both of the transmitted probe reference signal (513c) and the indication in the second DCI (525d), determine (586) the transmission parameters (521c) for at least one Physical Uplink Shared Channel (PUSCH); and The at least one PUSCH is transmitted (587) according to the transmission parameters (521c) and the probe reference signal (513c).

10. A network node (515) for communication, comprising: At least one processor (534); as well as At least one memory (535) stores instructions that, when executed by the at least one processor (534), cause the network node (515) to at least: Send (502) a configuration to the terminal device (510), the configuration including at least: a configuration (503) for causing the terminal device (510) to send (584) a probe reference signal (513c) for mobility operation between the serving cell (520) and one or more candidate cells (530). as well as Before the terminal device (510) begins to send (584) the probe reference signal (513c) to the target cell (530a) based on the trigger information (582a) received from the target cell (530a), a cell handover command (CSC) (514c) is sent to the terminal device (510), wherein the target cell (530a) is from the one or more candidate cells (530).

11. A terminal device (510) for communication, comprising: Components for receiving (502) a configuration from one or more network nodes (515), the configuration including at least: a configuration (503) for transmitting a probe reference signal (513c) for mobility operation between the serving cell (520) and one or more candidate cells (530); and A component for sending (584) the probe reference signal (513c) to the one or more candidate cells (530) based on trigger information (582a) received from at least one candidate cell (530a).

12. A network node (515) for communication, comprising: Components for transmitting (502) a configuration to a terminal device (510), the configuration including at least: a configuration (503) for causing the terminal device (510) to transmit (584) a probe reference signal (513c) for mobility operation between a serving cell (520) and one or more candidate cells (530); and A component for sending (578) a cell handover command (CSC) (514c) to the terminal device (510) before the terminal device starts sending (584) the probe reference signal (513c) to the target cell (530a) based on trigger information (582a) received from the target cell (530a), wherein the target cell (530a) is from the one or more candidate cells (530).

13. A method for communication, comprising: The terminal device (510) receives (502) a configuration from one or more network nodes (515), the configuration including at least: a configuration (503) for transmitting a probe reference signal (513c) for mobility operation between the serving cell (520) and at least one candidate cell (530); and The terminal device (510) sends (584) the detection reference signal (513c) to the one or more candidate cells (530) based on the trigger information (582a) received from at least one candidate cell (530a).

14. A method for communication, comprising: A configuration (502) is sent from a network node (515) to a terminal device (510), the configuration including at least: a configuration (503) for causing the terminal device (510) to send (584) a probe reference signal (513c) for mobility operations between the serving cell (520) and one or more candidate cells (530); and Before the terminal device starts sending (584) the probe reference signal (513c) to the target cell (530a) based on the trigger (582a) TCI state received from the target cell (530a), a cell handover command (CSC) (514c) is sent to the terminal device (510), wherein the target cell (530a) is from the one or more candidate cells (530).

15. A computer-readable medium comprising instructions stored thereon, the instructions being configured to cause a terminal device (510) for wireless communication to perform at least the method according to claim 13.

16. A computer-readable medium comprising instructions stored thereon, the instructions being configured to cause a network node (515) for wireless communication to perform at least the method according to claim 14.

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