Processor and user equipment for enhanced SCell activation with auxiliary reference signals

Abstract

A user equipment is configured to receive a reference signal when a secondary cell (SCell) is to be activated. The UE receives an SCell activation indication for activating the SCell, receives an RS triggering indication for triggering a reference signal (RS) before an expected SCell activation time period, performs measurements on the triggered RS, and activates the SCell based on the RS measurements.

Description

Technical Field

[0001] This application generally relates to wireless communication systems, and more particularly to enhanced SCell activation with auxiliary reference signals. Background Art

[0002] A user equipment (UE) may be configured with a variety of different capabilities. For example, the UE may be capable of establishing a connection with a network such as a 5G New Radio (NR) network. When connected to a 5G NR network, the UE may utilize the capabilities associated with that network. For example, the UE may utilize carrier aggregation (CA) functionality, where data is transmitted over various NR frequency bands using a primary component carrier (PCC) and at least one secondary component carrier (SCC). The network component to which the UE has connected may be a next-generation node B (gNB) that acts as a primary cell (PCell) and provides the PCC. A second network component may act as a secondary cell (SCell) and provide at least one SCC.

[0003] In the current NR standard, an SCell may be activated or deactivated for a UE based on a Medium Access Control layer (MAC) control element (MAC-CE) configured by the network. When receiving a MAC-CE to activate an SCell, it is expected that the UE performs the configured activation 3 ms after transmitting a Hybrid Automatic Repeat reQuest acknowledgement (HARQ-ACK) on the UL for that MAC-CE. When the SCell is deactivated for a long duration, the UE may lose the timing and frequency tracking of the SCell. In addition, for FR2, the UE may also lose the correct beam for the SCell. Therefore, the UE may take much longer than 3 ms to become fully operational in the SCell. Summary of the Invention

[0004] Some exemplary embodiments relate to one or more processors configured to perform operations. The operations include: receiving an SCell activation indication for activating a secondary cell (SCell), receiving an RS trigger indication for triggering a reference signal (RS) before an expected SCell activation period, performing measurements on the triggered RS, and activating the SCell based on the RS measurements.

[0005] Other exemplary embodiments relate to a user equipment (UE) having: a transceiver configured to connect to a base station; and one or more processors communicatively coupled to the transceiver and configured to perform operations. The operations include: receiving an SCell activation indication for activating a secondary cell (SCell), receiving an RS trigger indication for triggering a reference signal (RS) before an expected SCell activation period, performing measurements on the triggered RS, and activating the SCell based on the RS measurements. Brief Description of the Drawings

[0006] Figure 1 An exemplary network arrangement according to various exemplary embodiments is shown.

[0007] Figure 2 An exemplary UE according to various exemplary embodiments is shown.

[0008] Figure 3 An exemplary network cell according to various exemplary embodiments is shown.

[0009] Figure 4 An existing Secondary Cell (SCell) activation / deactivation Medium Access Control Control Element (MAC-CE) is shown.

[0010] Figure 5a An illustration of SCell activation based on an existing MAC-CE is shown.

[0011] Figure 5b An illustration of SCell activation based on a MAC-CE and including a sounding reference signal (RS) according to various exemplary embodiments described herein is shown.

[0012] Figure 6a A new MAC-CE according to a first option is shown.

[0013] Figure 6b A new MAC-CE according to a second option is shown.

[0014] Figure 7 An illustration of RS-assisted SCell activation including a first timing offset and a second timing offset is shown.

[0015] Figure 8 An illustration of a set of multiple pairs of RSs configured with a Quasi-Co-Location (QCL) relationship for timing and frequency tracking is shown.

[0016] Figure 9 A method for RS-assisted SCell activation according to various exemplary embodiments described herein is shown. DETAILED DESCRIPTION

[0017] Exemplary embodiments may be further understood with reference to the following description and the related drawings, in which like elements are provided with the same reference numerals. The exemplary embodiments describe systems and methods for rapid activation of a secondary cell (SCell), the method including reference signal (RS) transmission prior to SCell activation to assist a user equipment (UE) in performing operations including timing and frequency error tracking, beam refinement, and other processes that affect the amount of time it takes for the UE to become fully operational within the activated SCell.

[0018] According to various exemplary embodiments described herein, a network cell may trigger the auxiliary RS, and the UE may monitor the auxiliary RS and perform measurements on the auxiliary RS before the expected SCell activation time period, which may reduce the activation delay of the SCell, especially after being in an inactive state for a long time. The exemplary embodiments also relate to specific implementation details of the auxiliary RS, including timing restrictions and quasi-co-location (QCL) configurations for the RS.

[0019] Network / Device

[0020] Figure 1 An exemplary network arrangement 100 according to various exemplary embodiments is shown. The exemplary network arrangement 100 includes a plurality of UEs 110, 112. Those skilled in the art will understand that a UE may be any type of electronic component configured to communicate via a network, such as components of a connected vehicle, a mobile phone, a tablet computer, a smart phone, a phablet, an embedded device, a wearable device, an Internet of Things (IoT) device, etc. It should also be understood that an actual network arrangement may include any number of UEs used by any number of users. Therefore, the example with two UEs 110, 112 is provided for illustrative purposes only. In some of the exemplary embodiments described below, a group of UEs may be used to perform corresponding channel measurements.

[0021] The UEs 110, 112 may communicate directly with one or more networks. In the example of the network configuration 100, the networks with which the UEs 110, 112 may communicate wirelessly are the 5G NR radio access network (5G NR-RAN) 120, the LTE radio access network (LTE-RAN) 122, and the wireless local area network (WLAN) 124. Thus, the UEs 110, 112 may include a 5G NR chipset for communicating with the 5G NR-RAN 120, an LTE chipset for communicating with the LTE-RAN 122, and an ISM chipset for communicating with the WLAN 124. However, the UEs 110, 112 may also communicate with other types of networks (e.g., traditional cellular networks), and the UE 110 may also communicate with the network via a wired connection. Referring to the exemplary embodiments, the UEs 110, 112 may establish a connection with the 5G NR-RAN 120 and / or the LTE-RAN 122.

[0022] 5G NR-RAN 120 and LTE-RAN 122 can be parts of cellular networks that can be deployed by cellular providers (e.g., Verizon, AT&T, T-Mobile, etc.). These networks 120, 122 can include, for example, cells or base stations (NodeB, eNodeB, HeNB, eNBS, gNB, gNodeB, macro base stations, micro base stations, small cell base stations, femto base stations, etc.) configured to send and receive traffic from UEs equipped with appropriate cellular chipsets. WLAN 124 can include any type of wireless local area network (WiFi, hotspots, IEEE 802.11x networks, etc.).

[0023] UEs 110, 112 can be connected to 5G NR-RAN 120 via at least one of next-generation node Bs (gNBs) 120A and / or gNB 120B. Exemplary embodiments can be applied to any suitable number of gNBs. For example, UEs 110, 112 can be connected to and exchange data with multiple gNBs simultaneously in a multi-cell CA configuration. UEs 110, 112 can also be connected to LTE-RAN 122 via either or both of eNBs 122A, 122B, or to any other type of RAN, as described above. In network arrangement 100, UE 110 is shown as having a connection to gNB 120A, while UE 112 is shown as having a connection to gNB 120B.

[0024] In addition to networks 120, 122, and 124, network arrangement 100 also includes a cellular core network 130, the Internet 140, an IP multimedia subsystem (IMS) 150, and a network service backbone 160. The cellular core network 130 (e.g., 5GC for NR) can be regarded as an interconnected collection of components that manage the operation and traffic of the cellular network. The cellular core network 130 also manages the traffic flowing between the cellular network and the Internet 140.

[0025] IMS 150 can generally be described as an architecture for delivering multimedia services to UE 110 using IP protocols. IMS 150 can communicate with the cellular core network 130 and the Internet 140 to provide multimedia services to UE 110. The network service backbone 160 communicates directly or indirectly with the Internet 140 and the cellular core network 130. The network service backbone 160 can generally be described as a set of components (e.g., servers, network storage arrangements, etc.) that implement a set of services that can be used to extend the functions for UE 110 to communicate with various networks.

[0026] Figure 2 An exemplary UE 110 is shown according to various exemplary embodiments. It will be referred to Figure 1The UE 110 is described with reference to the network arrangement 100. The UE 110 may represent any electronic device and may include a processor 205, a memory arrangement 210, a display device 215, an input / output (I / O) device 220, a transceiver 225, and other components 230. The other components 230 may include, for example, an audio input device, an audio output device, a battery providing a limited power source, a data acquisition device, a port for electrically connecting the UE 110 to other electronic devices, sensors for detecting the condition of the UE 110, etc. Figure 2 The UE 110 shown may also represent the UE 112.

[0027] The processor 205 may be configured to execute multiple engines of the UE 110. For example, these engines may include a SCell activation engine 235 for performing operations that include receiving SCell activation and reference signal (RS) triggers from the network, monitoring the triggered RS and performing measurements on the triggered RS, and performing fast SCell activation based on the RS measurements, which will be described in detail below.

[0028] The above engines are merely exemplary as applications (e.g., programs) executed by the processor 205. The functions associated with the engines may also be represented as independent integrated components of the UE 110 or may be modular components coupled to the UE 110, e.g., integrated circuits with or without firmware. For example, an integrated circuit may include an input circuitry for receiving signals and a processing circuitry for processing the signals and other information. The engines may also be embodied as one application or separate multiple applications. Additionally, in some UEs, the functionality described for the processor 205 is divided among two or more processors such as a baseband processor and an application processor. The exemplary embodiments may be implemented in any of these or other configurations of the UE.

[0029] The memory 210 may be a hardware component configured to store data related to operations performed by the UE 110. The display device 215 may be a hardware component configured to display data to a user, while the I / O device 220 may be a hardware component that enables a user to make inputs. The display device 215 and the I / O device 220 may be separate components or may be integrated together (such as a touchscreen). The transceiver 225 may be a hardware component configured to establish connections with a 5G-NR RAN 120, an LTE RAN 122, etc. Thus, the transceiver 225 may operate on various different frequencies or channels (e.g., contiguous frequency bands). For example, when NR-U is configured, for example, the transceiver 225 may operate on unlicensed spectrum.

[0030] Figure 3An exemplary network cell according to various exemplary embodiments is shown, in this example, as gNB 120A. As described above with reference to UE 110, gNB 120A may represent a cell that provides services as a PCell or SCell or is independently configured with UE 110. gNB 120A may represent any access node of a 5G NR network through which UE 110, 112 may establish connections and manage network operations. Figure 3 The illustrated gNB 120A may also represent gNB 120B.

[0031] gNB 120A may include a processor 305, a memory arrangement 310, an input / output (I / O) device 320, a transceiver 325, and other components 330. The other components 330 may include, for example, an audio input device, an audio output device, a battery, a data acquisition device, ports for electrically connecting gNB 120A to other electronic devices, etc.

[0032] The processor 305 may be configured to execute multiple engines of gNB 120A. For example, these engines may include an SCell activation engine 335 for performing operations that include configuring an auxiliary reference signal (RS) for a UE and sending an SCell activation indication to the UE such that the UE can measure the RS to assist the UE in performing fast SCell activation, which will be described in detail below.

[0033] Each of the above engines, as an application (e.g., program) executed by the processor 305, is merely exemplary. The functions associated with the engines may also be represented as independent integrated components of gNB 120A or may be modular components coupled to gNB 120A, e.g., integrated circuits with or without firmware. For example, an integrated circuit may include an input circuitry for receiving signals and a processing circuitry for processing the signals and other information. Additionally, in some gNBs, the functions described for the processor 305 are split among multiple processors (e.g., a baseband processor, an application processor, etc.). The exemplary embodiments may be implemented in any of these or other configurations of the gNB.

[0034] The memory 310 may be a hardware component configured to store data related to operations performed by UE 110, 112. The I / O device 320 may be a hardware component or port that enables a user to interact with gNB 120A. The transceiver 325 may be a hardware component configured to exchange data with UE 110, 112 and any other UE in the system 100. The transceiver 325 may operate at various different frequencies or channels (e.g., a set of contiguous frequencies). Thus, the transceiver 325 may include one or more components (e.g., radio components) to be able to exchange data with various networks and UEs.

[0035] SCell Activation Enhancement

[0036] Exemplary embodiments are described with reference to carrier aggregation that is performed at a 5G NR network and includes a secondary cell (SCell) activation mechanism. However, the use of a 5G NR network is merely exemplary. Exemplary embodiments may be modified and / or used with any network that supports carrier aggregation (CA) or substantially similar functionality where multiple component carriers (CCs) are used.

[0037] CA may include a primary component carrier (PCC) and at least one secondary component carrier (SCC), where the PCC and the at least one SCC correspond to the same radio access technology (RAT) used to facilitate communication with the network. Additionally, in 5G NR, in the case of establishing a connection to both 5G NR RAT and LTE RAT, Eutra NR dual connectivity (ENDC) may be enabled and exemplary embodiments may be used. The PCC may be partially used for control information such as scheduling requests, uplink grants, downlink grants, etc. CA functionality enables the PCC and the at least one SCC to combine bandwidths to exchange data with a user equipment (UE). Thus, with CA, the PCC may provide a first portion of the total bandwidth for data to be exchanged, while the SCC may provide a second portion of the total bandwidth. The combination of a PCC and a single SCC may be characterized as a CC combination that includes two carriers. To further increase the total available bandwidth of data to be exchanged with the UE, additional SCCs may be incorporated. For example, for CA used in LTE, there may be CC combinations that include, but are not limited to, two carriers, four carriers, five carriers, eight carriers, ten carriers, thirty-two carriers, etc. For CA used in 5G NR, there may be CC combinations that include, but are not limited to, two carriers, five carriers, ten carriers, twelve carriers, sixteen carriers, twenty carriers, twenty-five carriers, thirty-two carriers, sixty-four carriers, etc.

[0038] An exemplary system may be configured with CA functionality and include a primary cell (PCell) that provides the PCC and at least one SCell that correspondingly provides the SCC. The PCell may control how data is exchanged with the UE, such as how the PCC and any SCCs are used in the CA functionality. When the UE has CA capabilities, the CA functionality enables the PCell and additional SCells to combine bandwidths to exchange data with the UE, thereby increasing the rate of data exchange. Thus, with CA, the PCell may provide a first portion of the total bandwidth for data to be exchanged, while the SCell may provide a second portion of the total bandwidth. When additional SCells are used, the PCell may provide a first portion of the total bandwidth, the first SCell may provide a second portion of the total bandwidth, the second SCell may provide a third portion of the total bandwidth, and so on.

[0039] For a specific SCell, the UE and the SCell can be configured in a non-dormant (active), dormant (active), and deactivated state relative to the connection between them. In the non-dormant active state, the UE can be configured for the following functions: 1) monitoring of the physical downlink control channel (PDCCH), 2) transmission of sounding reference signals (SRS), radio access channels (RACH), physical uplink shared channels (PUSCH), and physical downlink shared channels (PDSCH), 3) beam management and CSI measurement, and 4) automatic gain control (AGC). In the dormant state, the UE can be configured for 3) beam management and CSI measurement and 4) AGC, but not for 1) PDCCH monitoring or 2) transmission as described above. In the deactivated state, the UE is not configured for any of the above functions 1) to 4).

[0040] In the current NR standard, SCell activation and deactivation can be based on MAC-CE, which is defined in Section 6.1.3.10, "SCell Activation / Deactivation MAC-CE" of TS 38.321. Figure 4 An existing SCell activation / deactivation MAC-CE 400 is shown, which includes four octets containing 31 C fields and one R field. A C field set to 1 indicates that the SCell with the corresponding SCell index should be activated, and a C field set to 0 indicates that the SCell with the corresponding SCell index should be deactivated. Thus, up to 31 SCell can be activated / deactivated using the MAC-CE 400. When receiving the MAC-CE 400 for activating an SCell, it is expected that the UE performs the configured activation / deactivation 3 ms after transmitting a HARQ acknowledgement (HARQ-ACK) on the UL for the corresponding MAC-CE. When an SCell is deactivated for a long duration, the UE may lose the timing and frequency tracking of the SCell. In addition, for FR2, the UE may also lose the correct beam for the SCell. Therefore, the UE may take much longer than 3 ms to become fully operational in the SCell because NR removes the "always-on" signal, such as the cell-specific reference signal (CRS) in LTE.

[0041] Figure 5a An illustration 500 of SCell activation based on the existing MAC-CE 400 is shown. As described above, the existing SCell activation scheme may result in a high activation delay (longer than 3 ms). It may be beneficial to provide an RS burst to the UE before SCell activation and after the MAC-CE, so that the UE can quickly perform timing and frequency tracking, beam refinement, etc. for the SCell for fast SCell activation.

[0042] According to various exemplary embodiments described herein, a secondary reference signal (RS) may be used to serve one or more or all of the following purposes before SCell activation. The secondary RS may provide for fast AGC adjustment, fast timing and frequency error tracking, fast beam refinement, and fast CSI measurement for the SCell to be activated. The secondary RS may be an aperiodic (AP) tracking reference signal (TRS), a periodic (P) TRS, a semi-persistent (SP) TRS, an AP CSI-RS, a P CSI-RS, or an SP CSI-RS. Figure 5b Illustrated is a diagram 550 of SCell activation based on a MAC-CE and including a secondary reference signal (RS) according to various exemplary embodiments described herein. As Figure 5b shown, the RS may be triggered before HARQ-ACK transmission such that the UE may monitor the RS during the period between HARQ-ACK transmission and SCell activation. Although the RS trigger is Figure 5b illustrated as occurring simultaneously with the reception of the MAC-CE, in some embodiments, the RS trigger may also occur before or after the MAC-CE, which will be described in further detail below.

[0043] According to some exemplary embodiments, an existing SCell activation MAC-CE 400 may be utilized to trigger the secondary RS. In this embodiment, the AP-TRS associated with the SCell is configured by the radio resource control (RRC) layer, and the configuration includes time domain and frequency domain resource allocation within a time slot and a time slot offset. When the time slot offset conflicts with an uplink (UL) symbol, the UE may assume that the AP-TRS is transmitted in the next available valid time slot without violating any duplex direction restrictions. When the MAC-CE activates the SCell, the UE may assume that the corresponding AP-TRS configured by the RRC will be transmitted. The corresponding AP-TRS may be released by the RRC or deactivated by the MAC-CE.

[0044] In other exemplary embodiments, a combination of existing MAC-Ces (e.g., a combination of an SCell activation / deactivation MAC-CE 400 and an SP CSI-RS / CSI-IM resource set activation / deactivation MAC-CE for performing interference measurement on the SCell) may be utilized to trigger the secondary RS. This embodiment allows the network to simultaneously activate the SCell and the SP-RS for fast SCell activation.

[0045] In a further exemplary embodiment, a new MAC-CE may be used simultaneously to activate the SCell and trigger the AP-TRS. Figure 6aShows the new MAC-CE 600 according to the first option. The first MAC-CE 600 includes 31 C fields and one R field, similar to the existing SCell activation / deactivation MAC-CE 400 discussed above, where the i-th SCell is activated when Ci = 1. For each Ci that is 1, in ascending order of i, the MAC-CE 600 also triggers the corresponding AP-TRS via a CSI request field, which has up to 6 bits to index one of 64 RRC-configured AP-TRSs. The bit width of the CSI request can also be changed based on the reportTriggerSize parameter configured by the RRC layer.

[0046] Figure 6b Shows the new MAC-CE 650 according to the second option. The second MAC-CE 650 includes a five-bit SCell index field and a six-bit CSI request field for each activated SCell. The SCell index indicates the SCell to be activated, and the CSI request indicates the AP-TRS to be triggered. Similar to above, the bit width of the CSI request can be changed based on the reportTriggerSize parameter configured by the RRC layer.

[0047] In a further exemplary embodiment, the scheduling DCI for the SCell activation / deactivation MAC-CE 400 can be used to trigger the AP-TRS. For example, the modified downlink (DL) DCI formats 1_0, 1_1, or 1_2 can include a CSI request field. The CSI request field can be any one of 0, 1, 2, 3, 4, 5, or 6 bits configurable by the reportTriggerSize parameter configured by the RRC layer.

[0048] In an additional exemplary embodiment, a slot offset can be set between the DCI that triggers the AP-TRS and the actual transmission of the AP-TRS. The slot offset can be indicated in the DCI or the SCell activation / deactivation MAC-CE.

[0049] In other exemplary embodiments, the uplink (UL) DCI can be used to trigger both the AP-TRS and activate the SCell. The AP-TRS trigger function is already supported by the current CSI request field in the UL DCI. To activate the SCell, a new field is introduced in the UL DCI for activating one SCell at a time or multiple SCells at a time.

[0050] Timing restrictions can be introduced into the embodiments discussed above for UE power saving. Figure 7Illustrated is an illustration 700 of RS-assisted SCell activation including a first timing offset and a second timing offset. The first timing offset 705 (timing offset A) can be defined from the triggering of the RS to the actual transmission of the RS. In one embodiment, the first timing offset can be configured such that the triggered RS cannot be transmitted before the time slot carrying the RS trigger command. In another embodiment, the first timing offset can be configured such that the triggered RS cannot be transmitted before the start of the transmission of the RS trigger command. In yet another embodiment, the timing offset can be configured such that the triggered RS cannot be transmitted before the end of the transmission of the RS trigger command.

[0051] The minimum timing offset A can be defined by a standard (e.g., 3GPP standard), potentially according to the subcarrier spacing (SCS), or reported as a UE capability.

[0052] The second timing offset 710 (timing offset B) can be defined from the end of the triggered RS to the expected activation of the SCell. Similar to timing offset A, the minimum timing offset B can be defined by a standard (e.g., 3GPP standard), potentially according to the SCS, or reported as a UE capability.

[0053] The triggered RS in the above embodiments can be defined as quasi-co-located (QCL) with a synchronization signal block (SSB) or P-TRS. The QCL relationship can be used to improve timing / frequency error tracking and beam refinement at the UE.

[0054] Multiple triggered RSs can be configured to achieve the above purposes. Figure 8 Illustrated is an illustration 800 of a set of multiple pairs of RSs configured with QCL relationships for timing and frequency tracking. Illustration 800 includes four pairs of RSs 805a-d, which have three symbols between the first and second RSs in each pair, similar to the TRS design. Multiple pairs can be configured, where each pair corresponds to the same transmission beam.

[0055] Figure 9 Illustrated is a method 900 for RS-assisted SCell activation according to various exemplary embodiments described herein. At 905, an SCell activation indication is sent from a base station (e.g., gNB) to a device (e.g., a user equipment (UE)). In some embodiments, as described above, SCell activation can be triggered by an SCell activation / deactivation MAC-CE, while in another embodiment, the SCell can be triggered by a UL DCI.

[0056] In 910, an auxiliary reference signal (RS) trigger indication is sent from a base station to a device such that the UE can determine when to monitor the auxiliary RS. The RS trigger can be sent before, at the same time as, or after the SCell activation indication discussed above in 905. For example, as described above, an existing SCell activation / deactivation MAC-CE, a new or modified SCell activation / deactivation MAC-CE, a DL DCI, or a UL DCI can be used to trigger the RS.

[0057] In 915, the triggered auxiliary RS is received at the UE. In some embodiments, as described above, the auxiliary RS is an AP-TRS. In some embodiments, the triggered RS is subject to timing constraints.

[0058] In 920, the UE measures the auxiliary RS and uses the measurement to quickly perform timing and frequency tracking, beam refinement, etc. for rapid SCell activation. The auxiliary RS can be configured to be QCL to an SSB or a P-TRS to further assist in the above operations.

[0059] Embodiment

[0060] In a first example, an exemplary embodiment includes one or more processors configured to perform operations including: sending an SCell activation indication for activating a secondary cell (SCell) for a user equipment (UE), and sending an RS trigger indication for triggering a reference signal (RS) before an expected SCell activation period, wherein the UE performs a measurement on the triggered RS and activates the SCell based on the RS measurement.

[0061] In a second example, the one or more processors according to the first example, wherein the SCell activation is indicated by a medium access control layer (MAC) control element (MAC-CE).

[0062] In a third example, the one or more processors according to the second example, wherein the operations further include: sending a radio resource control (RRC) configuration for the RS, the configuration including a resource allocation and a time slot offset for the RS, wherein the UE receives the MAC-CE SCell activation triggering the RS.

[0063] In a fourth example, the one or more processors according to the second example, wherein the operations further include sending another MAC-CE for channel state information (CSI) resource activation, wherein the UE receives the MAC-CE SCell activation and another MAC-CE CSI resource activation triggering the RS.

[0064] In a fifth example, one or more processors as described in the second example, wherein the MAC-CE includes multiple fields for indicating SCell and a field for triggering the RS for each of the indicated SCell.

[0065] In a sixth example, one or more processors as described in the second example, wherein the operation further includes sending scheduling downlink control information (DCI) for the MAC-CE, the DCI including a field for triggering the RS of the SCell.

[0066] In a seventh example, one or more processors as described in the sixth example, wherein a slot offset between the scheduling DCI and the RS transmission is indicated in the scheduling DCI or the MAC-CE.

[0067] In an eighth example, one or more processors as described in the first example, wherein the SCell activation and the RS trigger are indicated in an uplink (UL) DCI.

[0068] In a ninth example, one or more processors as described in the first example, wherein the operation further includes determining a first scheduling offset between the RS trigger indication and the RS transmission and a second scheduling offset between the RS transmission and the expected activation of the SCell.

[0069] In a tenth example, one or more processors as described in the first example, wherein the minimum scheduling offset is reported as UE capability or hard-coded in a standard.

[0070] In an eleventh example, one or more processors as described in the first example, wherein the triggered RS is configured with a quasi-co-location (QCL) relationship with a synchronization signal block (SSB) or a periodic tracking reference signal (P-TRS).

[0071] In a twelfth example, one or more processors as described in the first example, wherein the expected SCell activation period is 3 ms after the transmission of a hybrid automatic repeat request (HARQ) acknowledgement (HARQ-ACK) for the SCell activation indication.

[0072] In a thirteenth example, one or more processors as described in the first example, wherein the triggered RS is one of an aperiodic (AP) tracking reference signal (TRS), a periodic (P) TRS, a semi-persistent (SP) TRS, an AP CSI-RS, a P CSI-RS, or an SP CSI-RS.

[0073] In a fourteenth example, one or more processors as described in the first example, wherein the UE activates the SCell based on the RS measurement includes using the measurement for automatic gain control (AGC) adjustment, timing and frequency error tracking, beam refinement, and channel state information (CSI) measurement for the activated SCell.

[0074] In a fifteenth example, a base station includes: a transceiver configured to connect to a user equipment (UE), and one or more processors communicatively coupled to the transceiver and configured to perform operations including: sending an SCell activation indication for activating a secondary cell (SCell), and sending an RS trigger indication for triggering a reference signal (RS) before an expected SCell activation period, wherein the UE performs measurements on the triggered RS and activates the SCell based on the RS measurement.

[0075] In a sixteenth example, one or more processors as described in the fifteenth example, wherein the SCell activation is indicated by a medium access control layer (MAC) control element (MAC-CE).

[0076] In a seventeenth example, one or more processors as described in the sixteenth example, wherein the operations further include: sending a radio resource control (RRC) configuration for the RS, the configuration including resource allocation and time slot offset for the RS, wherein the UE receives the MAC-CE SCell activation triggering the RS.

[0077] In an eighteenth example, one or more processors as described in the sixteenth example, wherein the operations further include sending another MAC-CE for channel state information (CSI) resource activation, wherein the UE receives the MAC-CE SCell activation and another MAC-CE CSI resource activation triggering the RS.

[0078] In a nineteenth example, one or more processors as described in the sixteenth example, wherein the MAC-CE includes multiple fields for indicating the SCell and a field for triggering the RS for each of the indicated SCells.

[0079] In a twentieth example, one or more processors as described in the sixteenth example, wherein the operations further include sending scheduling downlink control information (DCI) for the MAC-CE, the DCI including a field for triggering the RS of the SCell, wherein the time slot offset between the scheduling DCI and the RS transmission is indicated in the scheduling DCI or the MAC-CE.

[0080] In a twenty - first example, one or more processors as described in the sixteenth example, wherein the SCell activation and the RS triggering are indicated in an uplink (UL) DCI.

[0081] Those skilled in the art will understand that the above - described exemplary embodiments can be implemented in any suitable software configuration or hardware configuration or a combination thereof. An exemplary hardware platform for implementing the exemplary embodiments may include, for example, an Intel x86 - based platform with a compatible operating system, Windows OS, Mac platform and MAC OS, mobile devices with operating systems such as iOS, Android, etc. In other examples, the exemplary embodiments of the above - described method may be embodied as a program including lines of code stored on a non - transitory computer - readable storage medium, which, when compiled, can be executed on a processor or a microprocessor.

[0082] Although this patent application describes various combinations of various aspects each having different features, those skilled in the art will understand that any feature of one aspect can be combined with the features of other aspects in any manner not negated by the disclosure, or with features that are not functionally or logically inconsistent with the operation of the devices of the aspects disclosed in the present invention or the said functions.

[0083] It is well known that the use of personally identifiable information should follow privacy policies and practices that are recognized as meeting or exceeding industry or government requirements for maintaining user privacy. Specifically, personally identifiable information data should be managed and processed to minimize the risk of inadvertent or unauthorized access or use, and the nature of the authorized use should be clearly explained to the user.

[0084] It will be apparent to those skilled in the art that various modifications can be made to the present disclosure without departing from the essence or scope of the disclosure. Accordingly, the present disclosure is intended to cover modifications and variations of the present disclosure, provided that these modifications and variations are within the scope of the appended claims and their equivalents.

Claims

1. A processor, the processor includes a secondary cell (SCell) activation engine, and the SCell activation engine is configured to perform operations including the following: Receive a media access control (MAC) control element (CE), i.e., a MAC-CE, the MAC-CE includes an SCell activation indication for activating the SCell and an RS trigger indication for triggering reference signal (RS) reception after the MAC-CE and before SCell activation, wherein the MAC-CE includes multiple fields for indicating multiple SCells and a field for triggering RS for each of the indicated multiple SCells; Perform measurements on the triggered RS; and Activate the SCell based on the RS measurement.

2. The processor according to claim 1, wherein the operations further include: Receive a radio resource control (RRC) configuration for the RS, the RRC configuration includes resource allocation and time slot offset for the RS.

3. The processor according to claim 1, wherein the operations further include: Receive another MAC-CE for channel state information (CSI) resource activation.

4. The processor according to claim 1, wherein the bit width of the field for triggering RS for each of the indicated multiple SCells changes based on a reportTriggerSize parameter configured by the radio resource control (RRC) layer.

5. The processor according to claim 1, wherein the operations further include: Receive scheduling downlink control information (DCI) for the MAC-CE, the scheduling DCI includes a field for triggering the RS of the SCell.

6. The processor according to claim 5, wherein a time slot offset between the scheduling DCI and the RS transmission is indicated in the scheduling DCI or the MAC-CE.

7. The processor according to claim 1, wherein the operations further include: Determine a first scheduling offset between the RS trigger indication and the RS transmission and a second scheduling offset between the RS transmission and the expected activation of the SCell.

8. The processor according to claim 7, wherein one of the first scheduling offset or the second scheduling offset is reported as the capability of a device including the processor or defined by a standard.

9. The processor according to claim 1, wherein the triggered RS is configured with a quasi-co-location (QCL) relationship with a synchronization signal block (SSB) or a periodic tracking reference signal (P-TRS).

10. The processor according to claim 1, wherein the expected SCell activation time period is 3 ms after the transmission of a hybrid automatic repeat request (HARQ) acknowledgement (HARQ-ACK) for the SCell activation indication.

11. The processor according to claim 1, wherein the triggered RS is one of an aperiodic (AP) tracking reference signal (TRS), a periodic (P) TRS, a semi-persistent (SP) TRS, an AP channel state information reference signal (CSI-RS), a P CSI-RS, or an SP CSI-RS.

12. The processor according to claim 1, wherein activating the SCell based on the RS measurement includes using the RS measurement for automatic gain control (AGC) adjustment, timing and frequency error tracking, beam refinement, and channel state information (CSI) measurement for the activated SCell.

13. A user equipment (UE) comprising: a transceiver configured to connect to a base station; and one or more processors communicatively coupled to the transceiver and configured to perform operations including: receiving a medium access control (MAC) control element (CE), i.e., a MAC-CE, the MAC-CE including an SCell activation indication for activating a secondary cell (SCell) and an RS trigger indication for triggering reference signal (RS) reception after the MAC-CE and before SCell activation, wherein the MAC-CE includes multiple fields for indicating multiple SCells and a field for triggering RS for each of the indicated multiple SCells; performing measurements on the triggered RS; and activating the SCell based on the RS measurement.

14. The UE according to claim 13, wherein the operations further include: receiving a radio resource control (RRC) configuration for the RS, the RRC configuration including resource allocation and time slot offset for the RS.

15. The UE according to claim 13, wherein the operations further include: receiving another MAC-CE for channel state information (CSI) resource activation.

16. The UE according to claim 13, wherein the bit width of the field for triggering RS for each of the indicated multiple SCells is changed based on a reportTriggerSize parameter configured by a radio resource control (RRC) layer.

17. The UE according to claim 13, wherein the operations further include: receiving scheduling downlink control information (DCI) for the MAC-CE, the scheduling DCI including a field for triggering RS of the SCell, wherein a time slot offset between the scheduling DCI and RS transmission is indicated in the scheduling DCI or the MAC-CE.

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