Apparatus and method for secondary cell enhancement in wireless communication

Abstract

The invention provides a method and a device for triggering activation of a secondary cell (SCell) and activating the SCell. A user equipment (UE) may receive an SCell activation command from a gNB, the SCell activation command instructing the UE to activate an SCell to communicate between the UE and the gNB on the SCell, and the user equipment receives a reference signal (RS) on the SCell. The RS is used for activating the SCell. The UE may, upon receiving the SCell activation command, perform SCell activation based at least on the RS to activate the SCell, and send a report to the gNB, the report indicating that the SCell is activated for the UE.

Description

[0001] This patent application is a divisional application of patent application number 202180073868.2, entitled "Apparatus and Method for Enhancing Secondary Cells (SCELL) in Wireless Communication," filed on October 27, 2021. Technical Field

[0002] The present invention generally relates to wireless communication, and in certain embodiments, to apparatus and methods for enhancing secondary cells (SCells) in wireless communication. Background Technology

[0003] Wireless communication systems include Long Term Evolution (LTE), LTE-A, LTE-A-beyond, 5G LTE, and 5G New Radio (NR). Modern wireless communication systems can include multiple NodeBs (NBs), which can also be called base stations, network nodes, communication controllers, cells, or enhanced NBs (eNBs). A NodeB can include one or more network points or network nodes using different radio access technologies (RATs), such as High-Speed ​​Packet Access (HSPA) NBs or WiFi access points. A NodeB can be associated with a single network point or multiple network points. A cell can include a single network point or multiple network points, each of which can have a single antenna or multiple antennas. A network point can correspond to multiple cells operating on multiple component carriers. Typically, each component carrier in carrier aggregation is a serving cell, which can be a primary cell (PCell) or a secondary cell (SCell).

[0004] A cell or NodeB can serve multiple users (also commonly referred to as user equipment (UE), mobile station, terminal, device, etc.) within a given period of time. The communication channel from the base station to the UE is typically called the downlink (DL) channel, and transmission from the base station to the UE is downlink transmission. The communication channel from the UE to the base station is typically called the uplink (UL) channel, and transmission from the UE to the base station is uplink transmission. Summary of the Invention

[0005] Technical advantages are generally achieved through embodiments of the invention, which describe apparatuses and methods for enhancing secondary cells (SCells) in wireless communications.

[0006] According to one aspect of the present invention, a method is provided, the method comprising: receiving a secondary cell (SCell) activation command from a gNB by a user equipment (UE), the secondary cell activation command instructing the UE to activate the SCell for communication between the UE and the gNB on the SCell; receiving a reference signal (RS) on the SCell from the gNB by the UE, wherein the RS is used to activate the SCell; performing SCell activation by the UE, at least based on the RS, to activate the SCell upon receiving the SCell activation command; and sending a report to the gNB indicating that the UE has activated the SCell.

[0007] Optionally, in any of the above aspects, the SCell activation command is received in a Media Access Control (MAC) control element (MAC CE) on an active cell serving the UE, wherein the active cell is different from the SCell.

[0008] Optionally, in any of the above aspects, the transmission of the RS is triggered by a trigger command sent on the active cell, and the trigger command is included in the MAC CE.

[0009] Alternatively, in any of the above aspects, the RS is one of a set of RSs for activating the SCell and is indicated by the trigger command.

[0010] Optionally, in any of the above aspects, the RS is an aperiodic RS and is triggered / transmitted during the activation of the SCell, and the time slot in which the RS is transmitted is determined according to the time slot in which the SCell activation command is transmitted and the time slot offset value sent to the UE by signal.

[0011] Optionally, in any of the above aspects, the UE performs at least one of AGC establishment, frequency tracking, time tracking, or fine timing based on the RS.

[0012] Optionally, in any of the above aspects, the RS includes at least a CSI-RS for tracking or a tracking reference signal (TRS) for the SCell.

[0013] Optionally, in any of the above aspects, the transmission of the RS includes one or more transmissions of the TRS in one or more time slots.

[0014] Optionally, in any of the above aspects, the method further includes: the UE receiving a channel state information-reference signal (CSI-RS) for the SCell after receiving the RS.

[0015] Alternatively, in any of the above aspects, the CSI-RS is associated with the RS.

[0016] Alternatively, in any of the above aspects, the CSI-RS is quasi-colocate (QCL) with the RS.

[0017] Optionally, in any of the foregoing aspects, the report includes a CSI report based on CSI-RS measurements, the CSI report including a valid channel quality indicator (CQI) indicating that the SCell is activated.

[0018] Optionally, in any of the above aspects, the method further includes: the UE sending a message to the gNB confirming receipt of the SCell activation command.

[0019] Optionally, in any of the foregoing aspects, the method further includes: the UE activating the bandwidth part (BWP) of the SCell associated with the RS.

[0020] Alternatively, in any of the foregoing aspects, the report indicates that the BWP of the SCell associated with the RS is active.

[0021] According to another aspect of the present invention, a method is provided, the method comprising: sending a secondary cell (SCell) activation command to a user equipment (UE) by a gNB, the secondary cell activation command instructing the UE to activate a SCell for communication between the UE and the gNB on the SCell; sending a reference signal (RS) to the UE on the SCell to be activated by the UE, the RS being used to activate the SCell; and receiving, in response to sending the SCell activation command and the RS, a report from the UE indicating that the UE has activated the SCell.

[0022] Optionally, in any of the foregoing aspects, the method further includes: the gNB determining, for the UE, to activate the deactivated SCell.

[0023] Optionally, in any of the above aspects, the SCell activation command is sent in a medium access control control element (MAC CE) on an active cell serving the UE, wherein the active cell is different from the SCell.

[0024] Optionally, in any of the foregoing aspects, the method further includes: the gNB sending a trigger command on the active cell to trigger the transmission of a temporary RS, the trigger command being included in the MAC CE.

[0025] Alternatively, in any of the above aspects, the RS is one of a set of RSs for activating the SCell and is indicated by the trigger command.

[0026] Alternatively, in any of the above aspects, the RS is an aperiodic RS and is triggered / sent during the activation of the SCell.

[0027] Optionally, in any of the above aspects, the RS includes at least a CSI-RS for tracking or a tracking reference signal (TRS) for the SCell.

[0028] Optionally, in any of the above aspects, the transmission of the RS includes one or more transmissions of the TRS in one or more time slots.

[0029] Optionally, in any of the above aspects, the method further includes: after transmitting the RS, the gNB transmits a channel state information-reference signal (CSI-RS) for the SCell.

[0030] Alternatively, in any of the above aspects, the CSI-RS is associated with the RS.

[0031] Alternatively, in any of the above aspects, the CSI-RS is quasi-colocate (QCL) with the RS.

[0032] Optionally, in any of the foregoing aspects, the report includes a CSI report based on CSI-RS measurements, the CSI report including a valid channel quality indicator (CQI) indicating that the SCell is activated.

[0033] Alternatively, in any of the foregoing aspects, the report indicates that the BWP of the SCell associated with the RS is active.

[0034] Optionally, in any of the foregoing aspects, the method further includes: the gNB receiving a message from the UE confirming receipt of the SCell activation command.

[0035] According to another aspect of the present invention, a method is provided, the method comprising: a user equipment (UE) receiving from a gNB a reference signal (RS) transmitted on a secondary cell (SCell) triggering a reference signal (RS); the UE receiving from the gNB the RS on the SCell, the RS being used to activate the SCell; the UE performing cell activation to activate the SCell using the RS upon receiving the RS triggering; and the UE sending a report to the gNB indicating that the SCell has been activated for the UE.

[0036] Optionally, in any of the above aspects, the RS trigger is received on an active cell serving the UE, the active cell being different from the SCell.

[0037] Optionally, in any of the above aspects, the RS trigger is received in the downlink control information (DCI).

[0038] Optionally, in any of the above aspects, the RS is a tracking reference signal (TRS) for the SCell, a channel state information-reference signal (CSI-RS) for activating the SCell, or a sounding reference signal (SRS) for the SCell.

[0039] Optionally, in any of the foregoing aspects, the method further includes: the UE receiving an RS from the gNB during cell activation of the SCell, the RS being quasi-co-located with the RS.

[0040] Optionally, in any of the foregoing aspects, the report includes a CSI report based on CSI-RS measurements, the CSI report including a valid channel quality indicator (CQI) indicating that the SCell is activated.

[0041] Alternatively, in any of the foregoing aspects, the report indicates that the BWP of the SCell associated with the RS is active.

[0042] According to another aspect of the present invention, a method is provided, the method comprising: a gNB sending a trigger reference signal (RS) to a user equipment (UE) to trigger a reference signal (RS) transmitted on a secondary cell (SCell) to be activated for the UE; the gNB transmitting a temporary RS on the SCell to the UE, the RS being used to activate the SCell; and in response to sending the RS trigger and transmitting the RS, the gNB receiving from the UE a report indicating that the SCell is activated for the UE.

[0043] Optionally, in any of the foregoing aspects, the method further includes: the gNB determining, for the UE, to activate the deactivated SCell.

[0044] Optionally, in any of the above aspects, the RS trigger is sent on an active cell serving the UE, the active cell being different from the SCell.

[0045] Optionally, in any of the above aspects, the RS trigger is sent in the downlink control information (DCI).

[0046] Optionally, in any of the above aspects, the RS is a tracking reference signal (TRS) for the SCell, a channel state information-reference signal (CSI-RS) for activating the SCell, or a sounding reference signal (SRS) for the SCell.

[0047] Optionally, in any of the foregoing aspects, the method further includes: the gNB sending an RS to the UE during the cell activation of the SCell, the RS being quasi-co-located with the RS.

[0048] Optionally, in any of the foregoing aspects, the report includes a CSI report based on CSI-RS measurements, the CSI report including a valid channel quality indicator (CQI) indicating that the SCell is activated.

[0049] Alternatively, in any of the foregoing aspects, the report indicates that the BWP of the SCell associated with the RS is active.

[0050] According to another aspect of the present invention, an apparatus is provided, the apparatus comprising: a non-transitory memory including instructions; and one or more processors communicating with the memory, wherein the instructions, when executed by the one or more processors, cause the apparatus to perform the method according to any of the preceding aspects.

[0051] According to another aspect of the present invention, a non-transitory computer-readable medium is provided, the non-transitory computer-readable medium storing computer instructions that, when executed by one or more processors of a device, cause the device to perform the method according to any of the preceding aspects.

[0052] The present invention offers the advantages of reducing SCell activation latency and providing enhanced SCell communication. By reducing SCell activation latency, SCells can be made available immediately upon arrival of traffic data, thereby significantly improving the user experience during data transmission. Reducing activation latency also reduces UE power consumption. The UE can be configured with a large number of SCells in a deactivated state, thereby typically minimizing UE power consumption, where some or all SCells can be deactivated and then activated as needed to provide high-speed communication. The network and UE can achieve a better balance between a better user experience and reduced power consumption. Attached Figure Description

[0053] To gain a more complete understanding of the invention and its advantages, reference is now made to the following description taken in conjunction with the accompanying drawings, in which:

[0054] Figure 1A A diagram illustrating an exemplary wireless communication system;

[0055] Figure 1B A diagram illustrating an exemplary use of carrier aggregation (CA);

[0056] Figure 2A A diagram illustrating an exemplary physical layer channel and signal is provided.

[0057] Figure 2B A diagram illustrating exemplary channels and signals multiplexed for more than one UE is provided.

[0058] Figure 2C A diagram illustrating an exemplary non-zero power (NZP) CSI-RS for channel estimation and interference measurement is provided.

[0059] Figure 3 A diagram illustrating the QCL assumption in the NR reference signal when using wide beams for communication;

[0060] Figure 4 A diagram illustrating the QCL assumption in the NR reference signal when using narrow beams for communication;

[0061] Figure 5 A diagram illustrating the composition of an embodiment for SCell activation according to an exemplary embodiment of the present invention;

[0062] Figure 6 A flowchart illustrating an embodiment configuration process for SCell activation according to an exemplary embodiment of the present invention is shown;

[0063] Figure 7 A diagram illustrating a first exemplary embodiment for SCell activation is shown;

[0064] Figure 8 A diagram illustrating a second exemplary embodiment for SCell activation is shown;

[0065] Figure 9 A diagram illustrating a third exemplary embodiment for SCell activation is shown;

[0066] Figure 10 A diagram illustrating a fourth exemplary embodiment for SCell activation is shown;

[0067] Figure 11 A diagram illustrating a fifth exemplary embodiment for SCell activation is shown;

[0068] Figure 12 A diagram illustrating a sixth exemplary embodiment for SCell activation is shown;

[0069] Figure 13 A diagram illustrating a seventh exemplary embodiment for SCell activation is shown;

[0070] Figure 14 A flowchart illustrating an embodiment of the wireless communication method;

[0071] Figure 15 A flowchart illustrating another embodiment of the wireless communication method;

[0072] Figure 16 A flowchart illustrating another embodiment of the wireless communication method;

[0073] Figure 17 A flowchart illustrating another embodiment of the wireless communication method;

[0074] Figure 18 A diagram of an exemplary communication system according to an exemplary embodiment of the present invention is shown;

[0075] Figure 19A and Figure 19B Exemplary device models that can be used to implement embodiments of the present invention are shown; and

[0076] Figure 20 A diagram of a computing system that can be used to implement embodiments of the present invention.

[0077] Unless otherwise indicated, corresponding numbers and symbols in different figures generally refer to corresponding parts. The figures are drawn to clearly illustrate relevant aspects of the embodiments and are therefore not necessarily drawn to scale. Detailed Implementation

[0078] The following section discusses in detail the making and use of embodiments of the present invention. However, it should be understood that the concepts disclosed herein can be embodied in various specific contexts, and the specific embodiments discussed herein are merely illustrative and not intended to limit the scope of the claims. Furthermore, it should be understood that various changes, substitutions, and modifications can be made to this document without departing from the spirit and scope of the invention as defined by the appended claims.

[0079] Embodiments of the present invention provide methods and apparatus for secondary cell (SCell) enhancement in wireless communication. According to some embodiments, methods for SCell activation triggering and SCell activation are provided. A deactivated SCell of a user equipment (UE) can be activated, enabling the UE to communicate with the network on the activated SCell. The latency incurred by SCell activation can affect communication performance, user experience, and user power consumption; therefore, it is necessary to reduce SCell activation latency. Typically, SCell activation latency can be caused by various factors / conditions, which may include, for example, that the information of the SCell to be activated is unknown to the UE (latency may be caused by processing that informs the UE of the SCell to be activated), or functions that need to be performed during SCell activation, such as AGC establishment, time / frequency tracking, channel state information (CSI) measurement / acquisition, etc.

[0080] The embodiment considers the transmission of one or more reference signals during SCell activation, and based on these reference signals, the UE and the network can obtain the information required for SCell activation. The one or more reference signals may include a tracking reference signal (TRS), a channel state information-reference signal (CSI-RS), a synchronization signal block (SSB), a sounding reference signal (SRS), or a combination thereof. SCell activation can be triggered by sending an SCell activation command or reference signal trigger to the UE. One or more reference signals can also be sent to the UE during SCell activation. The UE can use one or more reference signals to perform SCell activation. The embodiment reduces SCell activation latency and provides enhancements to SCell communication. In particular, by reducing SCell activation latency, the SCell can be made available immediately after burst traffic data arrives, thereby significantly improving the user experience when receiving data. The reduced activation latency itself can also reduce UE power consumption. Furthermore, the UE can be configured with more SCells in a deactivated state, which typically minimizes the UE's power consumption. Some or all of these SCells can be "standby" (deactivated) and can be used as needed to provide high-speed communication. In this way, the network and UE can achieve a better balance between a better user experience and reduced power consumption.

[0081] In some embodiments, the UE can receive a SCell activation command from the gNB, which instructs the UE to activate the SCell for communication between the UE and the gNB on the SCell. The UE can also receive a temporary reference signal (RS) on the SCell. The temporary RS is used to activate the SCell. Upon receiving the SCell activation command, the UE can perform SCell activation at least based on the temporary RS to activate the SCell. The UE can send a report to the gNB indicating that it has activated the SCell for the UE.

[0082] In some embodiments, the UE may receive a reference signal (RS) trigger transmitted on the secondary cell (SCell). The temporary RS is used to activate the SCell. Upon receiving the RS trigger, the UE may perform cell activation based on the temporary RS to activate the SCell and send a report indicating that the UE has activated the SCell.

[0083] Figure 1A An exemplary wireless communication system 100 is illustrated. The communication system 100 includes a base station 110 having a coverage area 101. The base station 110 serves multiple user equipment (UEs), including UE 120. Transmissions from the base station 110 to the UEs are referred to as downlink (DL) transmissions and occur on the downlink channel. Figure 1A (Seen as solid arrow 135 in the image), and the transmission from the UE to the base station 110 is called uplink (UL) transmission and occurs on the uplink channel (…). Figure 1A (Dashed arrow 130 shown in the image). Data carried over the uplink / downlink connection may include data transmitted between UEs 120 and data transmitted to and from a remote end (not shown) via the backhaul network 115. Exemplary uplink channels and signals include the physical uplink shared channel (PUSCH), the physical uplink control channel (PUCCH), the uplink sounding reference signal (SRS), or the physical random access channel (PRACH). A service provider connected to base station 110 via backhaul network 115 (e.g., the Internet) may provide services to multiple UEs. The wireless communication system 100 may include multiple distributed access nodes 110.

[0084] In typical communication systems, there are several operating modes. In cellular mode, communication between multiple UEs is routed through a base station, while in device-to-device communication modes, such as proximity service (ProSe) mode, direct communication between UEs is possible. As used herein, the term "base station" refers to any component (or set of components) used to provide radio access to a network. A base station may also be referred to as a NodeB, evolved NodeB (eNB), next-generation (NG) NodeB (gNB), primary eNB (MeNB), secondary eNB (SeNB), primary gNB (MgNB), secondary gNB (SgNB), network controller, control node, access node, access point (AP), transmission point (TP), transmission-reception point (TRP), cell, carrier, macro cell, femtocell, picocell, repeater, customer premises equipment (CPE), network side, network, etc. In this invention, unless otherwise stated, the terms "base station" and "TRP" are used interchangeably. As used herein, the term "UE" refers to any component (or set of components) capable of establishing a wireless connection with a base station. UE may also be commonly referred to as a mobile station, mobile device, mobile phone, terminal, user terminal, user, subscriber, site, communication equipment, CPE, repeater, Integrated Access and Backhaul (IAB) repeater, etc. It should be noted that when using relays (based on repeaters, picocells, CPEs, etc.), especially multi-hop relays, the boundary between the controller and the node controlled by the controller may become blurred, and a dual-node deployment (e.g., a controller or a node controlled by a controller) where the first node provides configuration or control information to the second node is considered the controller. Similarly, the concepts of UL and DL transmissions can also be extended.

[0085] A cell may include one or more bandwidth parts (BWPs) of a UL or DL ​​allocated to the UE. Each BWP may have its own BWP-specific parameters and configurations, such as the BWP bandwidth. It should be noted that not all BWPs need to be active for the UE simultaneously. A cell may correspond to one carrier, and in some cases, multiple carriers. Typically, a cell (e.g., a primary cell (PCell) or a secondary cell (SCell)) is a component carrier (e.g., a primary component carrier (PCC) or a secondary CC (SCC)). For some cells, each cell may include multiple carriers in the UL, one carrier referred to as a UL carrier with an associated DL or a non-supplementary UL (non-SUL, or simply UL) carrier, while other carriers are referred to as supplementary UL (SUL) carriers without an associated DL. Cells or carriers may be configured with time slot or subframe formats including DL and UL symbols, and the cell or carrier is considered to operate in time division duplex (TDD) mode. Typically, for unpaired spectrum, the cell or carrier operates in TDD mode, and for paired spectrum, the cell or carrier operates in frequency division duplex (FDD) mode. The transmission time interval (TTI) typically corresponds to a subframe (in LTE) or a time slot (in NR). Access nodes can provide radio access according to one or more wireless communication protocols such as Long Term Evolution (LTE), LTE-A Advanced, 5G, 5G LTE, 5G NR, future 5G NR versions, 6G, High Speed ​​Packet Access (HSPA), Wi-Fi 802.11a / b / g / n / ac, etc. While it should be understood that a communication system can employ multiple access nodes (or base stations) capable of communicating with multiple UEs, for simplicity... Figure 1A The image shows only one access node and two UEs.

[0086] One way to increase network resources is to utilize more available spectrum resources, including not only licensed spectrum resources of the same type as macro cells, but also licensed spectrum resources of different types (e.g., macro cells are FDD cells, but small cells can use both FDD and TDD carriers), as well as unlicensed spectrum resources and shared licensed spectrum; some spectrum resources are located in high-frequency bands, such as 6 GHz to 60 GHz. Unlicensed spectrum is generally available to any user, but is subject to regulatory requirements. Shared licensed spectrum is also not operator-exclusive. Traditionally, cellular networks do not use unlicensed spectrum because it is often difficult to ensure quality of service (QoS) requirements. Wireless local area networks (WLANs), such as Wi-Fi networks, primarily operate on unlicensed spectrum. Since licensed spectrum is generally scarce and expensive, cellular operators may consider utilizing unlicensed spectrum. It should be noted that TDD is typically used in high-frequency bands and unlicensed / shared licensed bands, thus allowing communication to take advantage of channel reciprocity.

[0087] In practical deployments, a gNB can control one or more cells. Multiple remote radio units (RF units) can be connected to the same baseband unit of the gNB via optical fiber, and the latency between the baseband unit and the remote RF units is very small. Therefore, the same baseband unit can handle coordinated transmission / reception for multiple cells. For example, the gNB can coordinate transmissions from multiple cells to the UE, which is called coordinated multiple point (CoMP) or multi-TRP (mTRP, M-TRP) transmission. The gNB can also coordinate reception from multiple cells to the UE, which is called CoMP / M-TRP reception. In this case, the backhaul links between these cells with the same gNB are fast, and the scheduling of data transmitted by the UE in different cells can be easily coordinated within the same gNB. Backhaul connections can also be connections with longer latency and lower transmission rates.

[0088] Figure 1B An exemplary use of carrier aggregation (CA) as another deployment strategy is shown. Figure 1BAs shown, system 150 is a typical wireless network configured with carrier aggregation (CA). The communication controller 160 communicates with wireless device 165 using wireless link 170 (solid line) and with wireless device 166 using wireless link 172 (dashed line) and wireless link 170. In some exemplary deployments, for wireless device 166, the carrier used by wireless link 170 can be called the primary component carrier (PCC), while the carrier used by wireless link 172 can be called the secondary component carrier (SCC). In some carrier aggregation deployments, the PCC can carry feedback from the UE device to the communication controller, while the SCC can only carry data traffic. In the 3GPP specification, component carriers are called cells. When multiple cells are controlled by the same eNB, cross-scheduling of multiple cells can be achieved, and a single scheduler within the same eNB can schedule multiple cells. Through CA, an eNB can operate and control several component carriers that form the primary cell (Pcell) and secondary cell (SCell).

[0089] Figure 2A This is a schematic diagram 200 illustrating exemplary physical layer channels and signals, which may include a primary synchronization signal / secondary synchronization signal (PSS / SSS), a physical broadcast channel (PBCH), and their associated demodulation reference signal (DMRS). The PSS / SSS / PBCH and the associated DMRS form an SSB. Figure 2B This is a schematic diagram 220 showing exemplary channels and signals multiplexed for more than one UE. Figure 2C This is a schematic diagram 240 illustrating an exemplary non-zero power (NZP) channel state information-reference signal (CSI-RS) for purposes such as channel estimation and interference measurement. The CSI-RS can be multiplexed with the PDSCH and used by one or more UEs. Physical layer channels and signals may include the PSS / SSS, PBCH, and their associated DMRS (see [link to diagram]). Figure 2AThe SS burst is embedded, i.e., multiplexed with its surrounding PBCH, the physical downlink shared channel (PDSCH) and its associated DMRS and phase tracking reference signal (PT-RS), the physical downlink control channel (PDCCH) and its associated DMRS (for some of these signals / channels, see [link to relevant documentation]). Figure 2B These signals / channels are multiplexed for more than one UE) and CSI-RS, which may also include those CSI-RS for CSI acquisition, beam management, and tracking (for some examples of NZP CSI-RS for channel estimation, interference measurement, etc., see...). Figure 2C These CSI-RS examples are multiplexed with PDSCH and used for one or more UEs. The CSI-RS used for tracking is also called the tracking reference signal (TRS).

[0090] The UE receives a timing advance (TA) command associated with a configured TA group (TAG) to adjust its uplink transmission timing to synchronize uplink transmission with the network, ensuring that uplink transmissions from multiple UEs arrive at the base station approximately simultaneously within the transmission time interval (TTI). Similarly, the UE needs to receive a DL reference signal (RS) or synchronization signal (SS) block, also known as an SS / PBCH block (SSB), to acquire and maintain DL synchronization, for example, by maintaining a DL timing tracking loop. The UE places the start of its FFT window within a cyclic prefix (CP) based on this DL timing tracking loop for its DL reception. Additionally, both the UL and DL signals / channels need to be associated with other signals to derive signal / channel properties, such as delay spread, Doppler shift, etc. DL timing, often referred to as time synchronization, can include coarse timing / coarse timing and fine timing, although sometimes they are not explicitly distinguished. Coarse timing is about the approximate time when a certain time slot / symbol might occur, while fine timing is usually about the time when the first arriving path begins or the time when the receiver's fast Fourier transform (FFT) window begins.

[0091] In wireless communication operations, the tracking functions performed by the UE may include fine time tracking, fine frequency tracking, delay spread estimation, and Doppler spread estimation.

[0092] In fine-time tracking, the UE can detect the first arrival path, and based on this, the UE can typically optimally position its FFT window to maximize the data signal-to-noise ratio plus inter-symbol interference ratio. In continuous operation, the FFT window position may drift due to UE mobility and residual oscillator errors between the transmitter and receiver. The UE can adjust its FFT window position based on changes in the detected path arrival time.

[0093] In fine-grained frequency tracking, the UE can detect the frequency offset between the transmitter and receiver and adjust its oscillator accordingly. During demodulation of data symbols, residual frequency errors can be estimated and compensated. Residual frequency error compensation can be critical, especially in high signal-to-noise ratio (SNR) and high code rate data transmission scenarios. Uncompensated frequency errors can introduce phase errors into modulated data symbols, leading to degraded decoding performance. Since temperature variations affect the oscillator's output accuracy and Doppler shift caused by UE motion, the UE can periodically track frequency offsets and make corresponding adjustments and compensations.

[0094] Delay spread determines the degree of dispersion of the wireless multipath channel experienced by the UE. The longer the delay spread, the greater the frequency selectivity of the channel. To maximize processing gain along the frequency domain in channel estimation based on received pilot signals, the UE can apply linear filters of the longest possible length if within the channel's coherence bandwidth. Coherence bandwidth is inversely proportional to channel selectivity. Therefore, delay spread estimation plays a crucial role in shaping the filter coefficients and length for channel estimation, thus affecting the performance of channel estimation and data demodulation.

[0095] Doppler spread is typically proportional to UE mobility and multipath spatial distribution. Larger Doppler spread corresponds to faster-changing radio multipath fading channels. If channel coherence time constraints exist, channel estimation often involves applying filtering in the time domain with longer filter lengths to suppress noise and interference. Therefore, Doppler spread estimation is another factor affecting UE channel estimation performance along the time domain.

[0096] The quasi-co-location (QCL) type corresponding to each DL RS (more specifically, the port or antenna port of the DL RS) is given by the higher-level parameter qcl-Type in QCL-Info and can take one of the following values: 1) 'QCL-TypeA': {Doppler shift, Doppler spread, average delay, delay spread}; 2) 'QCL-TypeB': {Doppler shift, Doppler spread}; 3) 'QCL-TypeC': {Doppler shift, average delay}; and 4) 'QCL-TypeD': {Spatial Rx parameter}. The QCL type can be configured / indicated in the RS's transmission configuration indication (TCI) state. QCL assumptions are primarily used for DL ​​RSs, but can be extended to UL RSs if the correlation between path loss RSs and spatial relationships is specified. The QCL assumption for RS, such as RS1, can be specified as: {RS1: QCL type C to RS2}, {RS1: QCL type C to RS2 and QCL type D to RS3}. Then, RS1 (sometimes called the target or destination RS) derives the attributes specified according to the QCL type from the associated RS (sometimes called the source RS, such as RS2). It should be noted that the source RS can be an SSB. It should also be noted that the source RS and destination RS can be on the same carrier or different carriers (i.e., cross-carrier QCL).

[0097] Figure 3 This is a schematic diagram 300 illustrating the QCL assumption in a new radio (NR) reference signal when wide beams are used for communication. For example, TRS, SS blocks, or broadcast DMRS can be transmitted using wide beams. Figure 3The QCL configurations of SS block 302, DMRS 304, CSI-RS 306, TRS 308, CSI-RS 310, and DMRS 312 are shown. DMRS 304 is used for the broadcast channel. That is, DMRS 304 is the DMRS used for demodulating system information block (SIB), radio resource control (RRC) signaling, paging, etc., prior to configuring TRS. CSI-RS 306 is transmitted for beamforming. CSI-RS 310 is transmitted for channel estimation. DMRS 312 is used for demodulating signals transmitted in the unicast channel. Arrows starting from a first reference signal (e.g., SS block 302) and ending at a second reference signal (e.g., DMRS 304) indicate that the second reference signal has a QCL relationship with the first reference signal in terms of one or more QCL parameters. One or more QCL parameters (e.g., average delay, Doppler shift, delay spread, and spatial RX) are shown on the arrow, indicating that one or more QCL parameters required for the second reference signal can be derived from the first reference signal.

[0098] As shown in the figure, DMRS 304 is configured to have a QCL relationship with SS block 302. The average delay, Doppler shift, delay spread, and spatial RX of DMRS 304 can be derived based on SS block 302. Similarly, CSI-RS 306 and TRS 308 have QCL relationships with SS block 302, respectively. The average delay, Doppler shift, and coarse spatial RX required for CSI-RS 306 can be derived based on SS block 302. The average delay, Doppler shift, and spatial RX required for TRS 308 can also be derived based on SS block 302. CSI-RS 310 has QCL relationships with both CSI-RS 306 and TRS 308. CSI-RS 310 can be received using the spatial RX derived from CSI-RS 306 and the average delay, Doppler shift, and delay spread from TRS 308. DMRS 312 has QCL relationships with both TRS 308 and CSI-RS 310, respectively. The DMRS 312 can receive spatial RX data derived from CSI-RS 310. The DMRS 312 can also receive average delay, Doppler shift, Doppler spread, and delay spread data derived from TRS 308.

[0099] Figure 4 This is a schematic diagram 400 illustrating the QCL assumption in the NR reference signal when a narrow beam is used for communication. Figure 4The QCL configurations in SS block 402, DMRS 404, CSI-RS 406, TRS 408, CSI-RS 410, and DMRS 412 are shown. Similar to... Figure 3 DMRS 404 is used to demodulate signals transmitted in a broadcast channel, such as a physical broadcast channel (PBCH), before TRS configuration. CSI-RS 406 is used for beamforming. CSI-RS 410 is used for channel estimation. DMRS 412 is used to demodulate signals transmitted in a unicast channel. An arrow starting with a first reference signal and ending with a second reference signal indicates that the second reference signal has a QCL relationship with the first reference signal in terms of one or more QCL parameters. The one or more QCL parameters indicated on the arrow indicate that one or more QCL parameters required for the second reference signal can be derived from the first reference signal. Figure 4 It shows that, in addition to TRS, the reference signal has the same characteristics as... Figure 3 The QCL configuration shown is similar to the QCL configuration. Figure 4 In this configuration, TRS 408 has QCL relationships with SS block 402 and CSI-RS 406, respectively. TRS 408 can be received using the Doppler frequency shift derived from SS block 402, and can be received using the average delay and spatial RX derived from CSI-RS 406. Data transmission can use multiple narrow beams, and tracking may require multiple narrow TRS beams. To support both scenarios, the configuration of TRS and its QCL assumptions or relationships should be flexible.

[0100] A sounding reference signal (SRS) is a reference signal transmitted in the uplink by the user equipment (UE) to achieve uplink channel estimation within a certain bandwidth. Therefore, the network can perform communication with the UE based on the uplink channel estimation. Furthermore, due to the channel reciprocity between the uplink and downlink in time division duplex (TDD) communication systems, the network can utilize SRS to perform dynamic scheduling. That is, the network can utilize channel-dependent scheduling. In this case, time-frequency resources are dynamically scheduled considering different traffic priorities and quality-of-service requirements. Typically, the UE monitors several PDCCHs to obtain scheduling decisions, which are signaled to the UE by the network. When a valid PDCCH is detected, the UE follows the scheduling decision and receives (or transmits) data.

[0101] The configuration of SRS-related parameters for the SRS to be transmitted in the uplink (e.g., SRS transmission port, SRS transmission bandwidth, SRS resource set, transmission comb, and cyclic shift, etc.) is inherently semi-static and can be provided by higher-layer signaling, such as radio resource control (RRC) signaling. Furthermore, the correlation between downlink reference signals such as CSI-RS or DMRS and the uplink SRS can be transmitted to the UE to accurately reflect interference conditions and perform optimal beamforming. Therefore, there is a need for apparatus and methods for signaling control information that accurately indicates a more dynamic (not semi-static) configuration of the aforementioned parameters, for example, using a subset of transmission ports associated with a specific downlink reference signal set to transmit a portion of the required transmission bandwidth for a subset of the SRS resource set (thus implicitly indicating the transmission comb and cyclic shift). Signaling control information can be closely correlated with actual data transmission. SRS transmission can be periodic (i.e., periodic SRS, P-SRS, or P SRS) configured by Layer 3 RRC configuration signaling in the PDCCH, semi-static (i.e., semi-static SRS, SP-SRS, or SP SRS) activated / deactivated via Layer 2 MAC CE, or aperiodic (i.e., aperiodic SRS, A-SRS, AP-SRS, A SRS, or AP SRS) indicated by Layer 1 DCI. As used herein, "AP" followed by RS (e.g., TRS, SRS) refers to "aperiodic". 3GPP has investigated network adaptive or adaptive transmissions, such as cell on / off, fast SCell activation / deactivation, SCell Layer-1 sleep, etc., to achieve efficient network adaptation for various purposes such as network / UE power saving, interference management, and network / UE complexity reduction. It has been widely observed that NR Rel-15 SCell activation latency is typically in the range of tens to hundreds of milliseconds, and in many cases even longer than LTE. Therefore, it is desirable to reduce SCell activation latency. The significant latency in SCell activation is primarily driven by the time slots associated with the SSB measurement timing configuration (SMTC), which configures the UE to typically monitor and process the SSB every tens of milliseconds. Based on the SSB, the UE obtains the necessary information to set its automatic gain control (AGC), acquire timing, and perform frequency synchronization. In contrast, in LTE SCell activation, these operations are based on the always-on common reference signal (CRS) and can therefore be completed much faster. To reduce SCell activation latency, it is crucial to minimize or avoid relying on the SSB to obtain the necessary information for these operations during SCell activation.

[0102] The entire text is referenced and incorporated herein by section 5.9 of 3GPP TS 38.321, V16.2.1 (September 2020):

[0103] If a MAC entity is configured with one or more SCells, the network can activate and deactivate the configured SCells. When a SCell is configured, it will be deactivated unless the upper layer sets the SCell's parameter sCellState to active.

[0104] Configured Scells are activated and deactivated in the following ways:

[0105] - Receive SCell activation / deactivation MAC CE as described in section 6.1.3.10;

[0106] - Each configured SCell (except for SCells configured with PUCCH, if any) is configured with an sCellDeactivationTimer timer: the associated SCell is deactivated when it expires;

[0107] - sCellState configuration for each SCell configuration: If configured, the associated SCell is activated when the SCell configuration is performed.

[0108] 3GPP TS 38.321, Section 5.9 also specifies:

[0109] 1> If SCell is deactivated:

[0110] 2> Do not transmit SRS on SCell;

[0111] 2> Do not report CSI for SCell;

[0112] 2> Not transmitted on the UL-SCH of the SCell;

[0113] 2> Do not transmit on the RACH on the SCell;

[0114] 2> Do not monitor the PDCCH on the SCell;

[0115] 2> Do not monitor the PDCCH of SCell;

[0116] 2> Do not transmit PUCCH on SCell.

[0117] The HARQ feedback of the MAC PDU containing the SCell activation / deactivation MAC CE should not be affected by the interruption of PCell, PSCell and PUCCH SCell due to the SCell activation / deactivation of TS 38.133

[11] .

[0118] When a SCell is deactivated, any ongoing random access procedures on the SCell are aborted.

[0119] 3GPP TS 38.321 specifies that a SCell in FR1 is known if the following conditions are met:

[0120] - Before receiving the SCell activation command, at max(5) equal to FR1 measCycleSCell, 5 During the time period of the DRX loop:

[0121] -The UE has sent a valid measurement report to the active SCell, and

[0122] - The measured SSB remains detectable in accordance with the cell identification conditions specified in Articles 9.2 and 9.3.

[0123] -According to the cell identification conditions specified in Articles 9.2 and 9.3, when equal to max(5 measCycleSCell, 5 SSB measured during the DRX cycle also remains detectable during the SCell activation delay.

[0124] Otherwise, the SCell in FR1 is unknown.

[0125] The requirement for FR1 unknown SCell activation as specified in this clause applies when one of the following conditions is met.

[0126] -'ssb-PositionInBurst' indicates that only one SSB is actually transmitted, or

[0127] -'ssb-PositionInBurst' indicates multiple SSBs and TCI indicates that they are provided in the same MAC PDU that activates the SCell.

[0128] For the first SCell activation in the FR2 band, the SCell is known if the following conditions are met:

[0129] - Before the UE receives the final activation command (if applicable) for PDCCH TCI, PDSCH TCI, and semi-static CSI-RS (if applicable) for CQI reporting, during a period of 4 seconds for UEs supporting power levels 1 / 5 and 3 seconds for UEs supporting power levels 2 / 3 / 4:

[0130] - The UE has sent a valid L3-RSRP measurement report with an SSB index.

[0131] - After L3-RSRP reporting and no later than the time the UE receives the MAC-CE command to activate TCI, the SCell activation command is received.

[0132] - During the period from L3-RSRP reporting to valid CQI reporting, the reported indexed SSBs remain detectable according to the cell identification conditions specified in Articles 9.2 and 9.3, and the TCI status is selected according to one of the latest reported SSB indices.

[0133] Otherwise, the first SCell in the FR2 segment is unknown. The requirement for an unknown SCell applies if the activation command for PDCCH TCI, PDSCH TCI (if applicable), the configuration message for semi-static CSI-RS for CQI reporting (if applicable), and the TCI for periodic CSI-RS for CQI reporting (if applicable) are reported based on the latest valid L1-RSRP. The extent to which cell activation latency can be reduced depends on the scenario and mechanism applied to SCell activation. The following exemplary aspects can be considered. First, if the UE has no information about the SCell at all (UE does not know the SCell), the potential reduction in activation latency depends on how the UE becomes aware of the SCell, for example, by providing SCell SSB-related information. When the SCell is deactivated for the UE, the SCell becomes an unknown SCell to the UE, and the UE does not have SCell information to transmit on the SCell. Information about the SCell, such as the SSB, can be provided to the UE, allowing the UE to activate the SCell with less latency. Secondly, and more generally, even if the UE knows the SCell, other functions may still be needed during SCell activation, such as AGC establishment / setting (the process from AGC establishment to update settings), time / frequency tracking, CSI measurement / acquisition, etc. For these purposes, it is generally advisable to transmit one or more RSs during SCell activation so that the UE / network can obtain the information required for activation. These RSs used for cell activation can be called temporary RSs. After the SCell is activated, various RSs can be transmitted on the SCell, as is known to those skilled in the art. Thirdly, according to the Rel-15 mechanism, if the UE already knows a great deal of information about the SCell but has not yet fully utilized this information, the expected latency reduction achieved by utilizing information about the SCell through embodiments of the present invention will be more significant. Information about the SCell can be obtained by the UE from past activation times before deactivating the SCell, such as timing (e.g., DL timing). This information may drift slowly after deactivation but can still be used as a reference. Such information can be called pre-deactivation information, etc. Information can also be obtained from another cell, as described later. In any case, the UE can obtain necessary information that it cannot obtain in order to shorten the activation delay. This can be based on network information signaling to the UE or on network signals sent specifically for the purpose of effective activation (e.g., reference signals, and sometimes PSS / SSS).

[0134] Reference signals used for SCell activation and during the SCell activation process can be referred to as temporary RSs (tempRS, or temp RS, or tRS). Temporary RSs are specifically used for SCell activation. As used herein, temporary RSs can also be referred to as "temporary RS configuration," "temporary RS resource," or "temporary RS resource configuration." Temporary RSs can include TRS, CSI-RS, SSB, SRS, etc. Any reference signal used for SCell activation can be referred to as a temporary RS. For example, TRS, CSI-RS, SSB, and / or SRS configured or triggered on demand for SCell activation and transmitted for SCell activation can be referred to as temporary RSs, while TRS, CSI-RS, SSB, and / or SRS not used for SCell activation are not temporary RSs. Some embodiments of the present invention use TRS as temporary RSs, which are the primary candidates for temporary RSs. In this case, the temporary RS used for SCell activation can be referred to as an AP TRS-based temporary RS. Some of these embodiments can also be applied to situations where other RSs, such as CSI-RS, SSB, or SRS, are used as temporary RSs for SCell activation. It should be noted that "transmit / receive RS resources" or "transmit / receive RS" can also be used to refer to or describe "temporary RS". The terms "cell activation procedure" and "cell activation process" are used interchangeably in this invention. The cell activation process may include initiating cell activation, performing cell activation, and determining and / or indicating whether a cell is activated. The cell activation process may also include, for example, transmitting and processing one or more reference signals according to one or more functional requirements, such as AGC establishment, time / frequency tracking, fine timing, CSI measurement / acquisition, etc. The terms "cell activation" and "activation" are used interchangeably in this invention.

[0135] Therefore, as mentioned above, different scenarios may exist for SCell activation, and different functionalities may be required during SCell activation. Consequently, different temporary RSs may be needed during and for SCell activation. For example, scenarios include known SCells (UE knows the SCell) and unknown SCells (UE does not know the SCell), meaning the SCell activation process may or may not require an SSB. As another example, AGC setup (or establishment) during SCell activation may require TRS and / or CSI-RS. For example, TRS may be needed for time / frequency tracking. For example, CSI measurement / acquisition may require CSI-RS and CSI reporting and / or SRS. However, due to the high overhead and processing complexity of RSs, forcing the transmission and processing of some or all of these RSs during SCell activation may be impractical. This indicates that different RSs and different activation procedures are needed in different situations. Therefore, it is desirable to provide a flexible framework for configuring and triggering temporary RSs with reasonable overhead and complexity during SCell activation.

[0136] In some embodiments, where the UE knows which SCell to be activated, a temporary RS can be supported during the activation process of both FR1 and FR2 SCells. This may help speed up the SCell activation process and improve SCell activation efficiency. In one example, the temporary RS can provide at least AGC setup or establishment and time / frequency tracking functionality during SCell activation. Therefore, the temporary RS may include a TRS and / or a CSI-RS. The TRS may also have the potential functionality of CSI measurement / acquisition and cell search. As used herein, RS providing or supporting functionality means that RS transmission enables the performance of functions based on the RS.

[0137] The TRS can be selected as the temporary RS for SCell activation. Other RS ​​candidates can also be considered, such as aperiodic CSI-RS, P / SP-CSI RS, SRS, and SSS / PSS-based RS. The TRS can be triggered on demand by downlink control information (DCI) or medium access control-control element (MAC-CE). The UE can receive, process, measure, or adjust TRS settings / parameters based on the triggered temporary RS during SCell activation no earlier than a certain time slot, for example, in time slot n+k in one of the embodiments below.

[0138] Providing the UE with appropriate network-aided information and / or the UE's assumptions about common attributes of multiple serving cells can lead to efficient SCell activation and can be considered for standardization. Depending on network configuration and standard specifications, the UE can assume some common attributes across multiple serving cells, thus deriving a wealth of information about the SCell to be activated, which may not be fully utilized under the Rel-15 mechanism. In practice, one reason multiple serving cells share some common attributes is that these cells may be co-located and associated with the same hardware, such as the same set of antennas, the same RF components, etc. This is especially true if the cell carriers are located in the same frequency band (e.g., in-band CA) or in close proximity to each other. 3GPP has defined several types of quasi-co-located (QCL) relationships between antenna ports of different signals so that attributes derived from one signal can be extended to another. This concept can be utilized and generalized to effectively reduce SCell activation latency in applicable scenarios.

[0139] Two quasi-co-located serving cells can share one or more of the following attributes, and the UE can use each attribute to obtain side information about the SCell to be activated, thereby reducing the latency of SCell activation. Attributes may include:

[0140] ● Path loss, coupling loss, or RSRP

[0141] If the carriers of two cells are close in the frequency domain, for example, in in-band CA (continuous or discontinuous), the path loss and shadow fading values ​​of the two cells may be the same. Furthermore, if the same set of antennas is used, the antenna gain, and therefore the coupling loss and RSRP values, may also be very close for the two cells. For cells whose carriers are not so close but not too far apart and are highly uncorrelated, the difference between the path loss values ​​can be a predictable value that can be derived from the UE and / or gNB.

[0142] Side information about the path loss, coupling loss, or referenced signal received power (RSRP) of the SCell to be activated can be used to set the (initial) AGC, which can help accelerate activation.

[0143] ●Frequency / Timing Offset

[0144] Frequency / timing information about the cell to be activated can be inferred from another cell. Even if this information is insufficient for fine-grained tracking, it can still be used to reduce the latency involved in achieving frequency / timing tracking. For example, if the symbol boundaries of the two cells are roughly aligned, such as within the CP length (or with a fixed offset), the UE can be able to set its FFT window for one cell based on the other cell, and can further refine it based on the temporary RS.

[0145] It should be noted that SCell, which does not have an SSB, already utilizes this mechanism, as specified in TS38.213 V16.3.0 (September 2020), which incorporates the full text of this paper:

[0146] For a serving cell that does not send SS / PBCH blocks, the UE obtains time and frequency synchronization with the serving cell based on the reception of SS / PBCH blocks on the PCell or PSCell of the serving cell's cell group.

[0147] However, without network assistance or standardized UE behavior, a UE cannot assume common attributes on the serving cell. Network signaling can be sent to the UE indicating side information and UE assumptions with that side information. This network signaling can be specified in standards such as Rel-17. Some methods supporting this are described below (without mutual exclusion).

[0148] ● Introducing a new QCL type for obtaining cross-carrier path loss, RSRP, and frequency / time synchronization.

[0149] Existing QCL types can be extended to define attributes that the UE can assume when signaled by the network. QCL relationships can be signaled based on references to cell indices, SSBs, or RSs. For example, the SSB of cell 1 can be configured as a QCL with the SSB of cell 2. Since this relationship is reversible between cell 1 and cell 2, it is not necessary to configure relationships that the UE can assume in the opposite direction.

[0150] ● Introducing community clusters with shared public attributes

[0151] More generally, the aforementioned common attributes can be shared among multiple cells, such as intra-band cells or cells in adjacent frequency bands. Therefore, it may be useful to introduce a set of cells with common attributes. This can be implemented similarly to a timing advance group (TAG), where cells are configured with multiple TAGs, and cells within the same TAG share the same TA.

[0152] ●Introducing offset values

[0153] Even if two cells have different attributes, there may be a fixed offset (or an offset with an upper limit) between them that is known to the network or can be derived by the UE. The network can signal the fixed offset value to the UE. For example, if the symbol boundary of cell 1 is x ms earlier than the symbol boundary of cell 2, the value of x can be signaled to the UE, and the UE can use it to obtain coarse timing. As another example, if the path loss of cell 1 is y dB higher than the path loss of cell 2, the value of y can be signaled to the UE to estimate its initial AGC setting. Alternatively, the UE can derive the offset value, for example, based on the carrier frequency separation of the cells.

[0154] According to some embodiments, it is proposed to support effective SCell activation through enhanced UE assumptions to reduce the latency associated with estimated path loss, coupling loss, RSRP, frequency / timing offset, and / or initial UL TA on the SCell to be activated. Examples may include one or more of the following embodiments.

[0155] ● Utilize the cross-carrier QCL assumption. For example, the SCell to be activated can rely on the activated QCL cell for initial path loss and / or RSRP estimation.

[0156] ● Utilize a set of cells with shared attributes. For example, cells in one or more frequency bands that are close to each other can be configured in a set of cells with similar path loss and / or timing.

[0157] ● Utilize specified cross-carrier offset values. For example, the network can specify path loss offset and / or timing offset between two cells or between two sets of cells.

[0158] In cases where the UE cannot derive all the necessary information for SCell activation based on available UE assumptions, one or more temporary RSs can be reused to support effective SCell activation by providing the UE with information that cannot be derived based on available UE assumptions.

[0159] The triggering configuration, triggering command, and triggering procedure for SCell activation are described below. The current SCell activation procedure uses L2 signaling. This is referred to herein as L2 activation. With the various enhancements proposed in Rel-17 that can significantly reduce latency, further reduction of the latency caused by L2 signaling is meaningful. In one embodiment, the low latency of L1 signaling is considered. L1 signaling can be used for SCell activation. This is referred to herein as L1 activation. It should be noted that L1 activation in this document does not necessarily mean or require newly designed L1 signaling or L1 procedures; instead, existing L1 signaling can be reused as existing aperiodic RS, and the L2 activation procedure begins once the UE receives the L1 signaling associated with the deactivated SCell. Therefore, if the activation procedure involves aperiodic CSI-RS resource triggering and / or aperiodic CSI reporting triggering, the network and UE can use one or more of these triggers associated with the deactivated SCell as the SCell activation command. This not only reduces the latency caused by L2 signaling and potentially multiple signalings completing a single activation, but also limits control channel overhead. L1 signaling carries instructions / information that can be sent via downlink control information (DCI). However, in some embodiments, the same instructions / information can be sent via MAC CE. A potential problem with this approach is the reliability of DCI, as it lacks acknowledgement / non-acknowledgement / hybrid automatic repeat request (ACK / NACK / HARQ), unlike MAC commands. Therefore, if DCI is lost or incorrectly decoded, the network and UE may temporarily become out of sync until the network / UE detects and corrects the problem. However, the probability of such an error is small (generally <1%), and the DCI-based approach is likely still beneficial in most scenarios.

[0160] It should be noted that when using L1 activation, MAC signaling may not be necessary for activation. For proposals to continue using MAC signaling, MAC signaling can also accompany L1 signaling; however, this makes MAC signaling unnecessary.

[0161] According to an exemplary embodiment, an enhanced activation process can be used to support effective SCell activation via existing L1 aperiodic (AP) RS (e.g., temporary RS based on TRS / CSI-RS / SRS, if supported) triggering, and the SCell activation process can be initiated when the UE receives a temporary RS trigger associated with the SCell. An L1 AP RS triggering can trigger or indicate the transmission or reception of a temporary RS. For example, an AP TRS (or AP CSI-RS) triggering can trigger a receiver to receive an associated AP TRS (or CSI-RS). An AP SRS triggering can trigger the triggered receiver to transmit the associated AP TRS.

[0162] Examples of SCell activation triggering (i.e., activation command) configuration and temporary RS configuration are provided. The examples provide a configuration for triggering SCell activation, and a configuration of temporary RS to be transmitted during the SCell activation process. For the configured SCell to be activated, a TRS can be configured, and optionally, AP CSI-RS and / or APSRS can be configured. These RSs will be very useful during the SCell activation process. According to some embodiments, for various methods of triggering SCell activation, at least the TRS can always be transmitted during SCell activation: via MAC signaling, via AP TRS L1 triggering via the TRS, via AP CSI-RS L1 triggering via the CSI-RS associated with the SCell and therefore associated with the TRS, or via AP SRS L1 triggering via the SRS associated with the SCell and therefore associated with the TRS. References are provided below. Figure 5 This provides some implementations and possible methods for SCell activation. Figure 5 A schematic diagram 500 showing the configuration of an embodiment for SCell activation is shown.

[0163] In some embodiments, the essential components for SCell activation may include:

[0164] ● It can always support the MAC activation command 512 sent on the active cell to activate the SCell 502. This can be configurable or not.

[0165] ●AP TRS 514 can always be configured with SCell, so it is always transmitted during SCell activation.

[0166] In other words, to activate SCell 502, a MAC activation command 512 can be sent to trigger activation, and an AP TRS 514 for activation can be sent during SCell activation. The MAC activation command 512 instructs / instructs / triggers the UE to activate SCell 502. Upon receiving the MAC activation command 512, the UE can begin monitoring SCell 502 and perform cell activation, for example, at least based on the received AP TRS 514. The UE can perform at least one of AGC establishment, frequency tracking, time tracking, or fine timing based on the AP TRS 514. The activation command 512 can be sent on an active cell serving the UE, which is different from the SCell to be activated. The transmission of AP TRS 514 can be triggered by a trigger command sent on the active cell. The trigger command can be included in a MAC CE carrying the MAC activation command 512, or it can be included in another MAC CE sent simultaneously in the same PDSCH. AP TRS 514 can be one of a set of TRSs for SCell activation and can be indicated by the trigger command. The transmission of AP TRS 514 may include one or more transmissions of AP TRS 514 on one or more time slots.

[0167] In some embodiments, optional components for SCell activation may include one or more of the following:

[0168] ● AP TRS trigger 516 (sent on a different cell than the SCell to be activated (e.g., the active cell serving the UE)) to trigger AP TRS 514 configured with SCell 502. Upon receipt, SCell activation can begin without receiving MAC activation command 512. AP TRS trigger 516 triggers / instructs the UE to receive AP TRS 514. The UE can be triggered to begin SCell activation without receiving MAC activation command 512, upon receiving AP TRS 514. In this case, it is not necessary to send MAC activation command 512 to the UE to trigger SCell 502 activation.

[0169] ● The AP CSI-RS 518 can be configured with SCell 502. If SCell activation begins, the AP CSI-RS 518 will also be sent to the UE.

[0170] ● AP CSI-RS trigger 520 (sent on a different cell than the SCell to be activated (e.g., the active cell serving the UE)) triggers AP CSI-RS 518 configured with SCell 502. Upon receipt, SCell activation can begin without a MAC activation command. The received AP CSI-RS trigger 520, which triggers / instructs AP CSI-RS 518, can trigger / instruct the UE to begin SCell activation. In this case, it is not necessary to send a MAC activation command 512 to the UE to trigger SCell 502 activation.

[0171] ● AP SRS 522 can be configured with SCell 502. If SCell activation begins, AP SRS 522 will also be sent.

[0172] ● AP SRS trigger 524 (sent on a different cell than the SCell to be activated (e.g., the active cell serving the UE)) triggers AP SRS 522 configured with SCell 502. Upon receipt, SCell activation can begin without a MAC activation command. AP SRS trigger 524, which triggers / indicates the transmission of AP SRS 522, can trigger / indicate the UE to begin SCell activation. In this case, it is not necessary to send a MAC activation command 512 to the UE to trigger SCell 502 activation.

[0173] In some embodiments, essential components can be used to trigger SCell activation. For example, the gNB sends a SCell activation command in the MAC CE to trigger SCell activation, and a TRS as a temporary RS is used to activate the SCell. In another embodiment, one of the optional components can be used to trigger SCell activation. For example, the gNB can send a TRS trigger that triggers TRS transmission to the UE to trigger SCell activation, where the TRS is used for SCell activation. As another example, a CSI-RS trigger that triggers CSI-RS transmission can be sent to trigger SCell activation, where the CSI-RS is used for SCell activation. As another example, an SRS trigger that triggers SRS transmission can be sent to trigger SCell activation, where the SRS is used for SCell activation. In any case, TRS, CSI-RS, SRS, or any combination thereof can be used for SCell activation and sent during SCell activation. CSI-RS and SRS can be associated with or quasi-co-located with TRS. SCell activation triggered by a MAC command can be referred to as L2 command-initiated activation. SCell activation triggered by a temporary RS can be referred to as L1 RS-initiated activation.

[0174] Figure 6 A flowchart 600 illustrates an embodiment configuration process for SCell activation. The gNB can configure a TRS for SCell activation (block 602). Optionally, the gNB can configure an aperiodic CSI-RS for SCell activation (block 604). Optionally, the gNB can configure an aperiodic SRS for SCell activation (block 606). The UE can perform SCell activation using at least the TRS for SCell activation (block 608).

[0175] Examples for SCell activation triggering and activation procedures are provided. In one embodiment, an aperiodic (AP) TRS can be transmitted during SCell activation. SCell activation can be initiated by a MAC command (L2 signaling), during which an AP TRS is transmitted. SCell activation can be initiated by a DCI (L1 signaling), during which an AP TRS is transmitted. AP TRS triggering is not required. Since SCell activation is associated with an AP TRS, the AP TRS can be configured for the SCell for its activation. The AP TRS can be configured independently of the SCell BWP, i.e., the same AP TRS is transmitted regardless of which BWP of the SCell is activated, which simplifies activation design. Alternatively, the AP TRS can be specific to the SCell BWP, and the triggering of the AP TRS results in the activation of the associated BWP. If an explicit signaling for an AP TRS or BWP is not sent, a default BWP and its associated default AP TRS can be sent. References are provided below. Figures 7 to 13 Seven embodiments for SCell activation are provided.

[0176] Figure 7 A schematic diagram 700 is shown for a first exemplary embodiment of SCell activation triggering and activation. Figure 7 Four implementation procedures for activating or deactivating a SCell are shown. Figure 7As shown, the SCell is in a deactivated state for the UE (box 702). When the gNB determines that the UE is activating the deactivated SCell, the gNB can trigger the activation of the SCell. In the first embodiment, the gNB can send a MAC activation command to the UE to activate the deactivated SCell. This will initiate an SCell activation process / procedure between the UE and the gNB. The UE receives the MAC activation command from the gNB (box 712). The UE can optionally send a response to the gNB indicating that the MAC activation command has been correctly received and decoded. The UE can initiate the SCell activation process (box 714), during which the UE monitors the SCell and can receive the AP TRS for SCell activation (box 716). During the SCell activation process, the UE can optionally receive the AP CSI-RS associated with the AP TRS or transmit the SRS associated with the AP TRS (box 716). For example, the UE can send a message indicating that the SCell is activated to the gNB by reporting a valid downlink (DL) channel state indicator (CSI) (box 704). The UE can measure the AP CSI-RS to generate a CSI report that includes the measurement results of the AP CSI-RS. The measurement results can include CSIs, such as the channel quality indicator (CQI). Measurement results are valid when they meet conditions, such as exceeding a threshold or having a non-zero CQI value. A CSI report including a valid CSI or CQI indicates that the SCell is activated for the UE. The CSI report can also indicate that the SCell's BWP is active. If the measurement results do not meet the conditions, the SCell is not activated for the UE. The UE may send a message indicating that the SCell is not activated. In one example, the UE may not send such a message, and the gNB will know from this message that the SCell is not activated for the UE.

[0177] A SCell can be configured with default AP TRS, and optionally, default AP CSI-RS and / or AP SRS. The MAC activation command can use an existing design where information about the TRS / CSI-RS / SRS is not provided, but the associated default TRS / CSI-RS / SRS configured by RRC signaling is automatically triggered. There may be more than one AP TRS (or CSI-RS / SRS) for a SCell or SCell activation procedure, but one is configured as the default. The default value can be explicitly configured or implicitly configured via BWPs; for example, multiple AP TRSs are associated with multiple BWPs for the SCell, and one BWP signals the default value for activation of this SCell. Therefore, the default AP TRS associated with the default BWP is triggered. This reduces MAC / DCI signaling overhead and avoids the need for a new design for the MAC activation command. In another embodiment, the MAC activation command can use an enhanced design, such as including one or more fields to trigger one or more of the TRS / CSI-RS / SRS or one of the BWPs. This requires more MAC overhead but provides more flexibility to the network. For example, if two or more TRSs are associated with an SCell (for the SCell), a MAC command can activate / select one of them (e.g., a TRS is associated with a BWP, and by selecting the TRS or selecting the BWP, the associated BWP / TRS is also activated / selected) or more of them. Then, after the AP TRS transmission, associated RSs (CSI-RS / SRS) can also be transmitted / received / processed according to network configuration / activation. CSI-RS, SRS, and TRS can be associated with the same BWP, and one can be quasi-co-located with another. For example, a CSI-RS can be quasi-co-located with a TRS having QCL type A, and the SRS uses the TRS and / or CSI-RS as its path loss RS. Valid DL CSIs can be reported from the UE to the gNB, and these valid DL CSIs typically include at least a valid channel quality indicator (CQI) value (e.g., a non-zero CQI value, or a CQI value that meets a standard). Some embodiments of this will be discussed further later. Afterward, SCell activation is completed and the SCell is activated.

[0178] Figure 7A second embodiment process is also illustrated, in which the gNB sends an L1 AP TRS trigger associated with the deactivated SCell. Even without receiving an L2 MAC activation command, the UE can still understand that receiving an L1 AP TRS trigger will initiate / trigger the SCell activation process / procedure. The UE receives the L1 AP TRS trigger associated with the SCell (box 722) and initiates the SCell activation process (box 724), during which the UE monitors the SCell and may receive AP TRS for activating the SCell (box 716). During the SCell activation process, the UE may optionally receive an AP CSI-RS associated with the AP TRS or transmit an SRS associated with the AP TRS (box 716). As described above, for example, by reporting validity (CSI), the UE may send a message to the gNB indicating that the SCell is activated (box 704).

[0179] The AP TRS associated with an L1 AP TRS trigger can be either the default AP TRS or a non-default AP TRS, providing the network with greater flexibility in selecting which AP TRS to transmit or which BWP to activate. For example, the default TRS (TRS1) can be associated with the default BWP1, and the L1 AP TRS trigger is for both TRS2 and BWP2. The UE then understands that this SCell activation is for the purpose of activating BWP2. Following the AP TRS transmission, associated RSs (CSI-RS / SRS) can also be transmitted / received / processed depending on the network configuration / activation. CSI-RS, SRS, and TRS can be associated with the same BWP, and one can be quasi-co-located with another. For example, a CSI-RS can be quasi-co-located with a TRS having QCL type A, and an SRS can use a TRS and / or a CSI-RS as its path loss RS. Valid DL CSIs can be reported from the UE to the gNB, and these valid DL CSIs typically include at least a valid CQI value. Some embodiments of this will be discussed further later. Afterward, SCell activation is complete and the SCell is activated.

[0180] Figure 7A third embodiment is also illustrated, in which the gNB sends an L1 AP CSI-RS trigger associated with the deactivated SCell. Even without receiving an L2 MAC activation command, the UE can still understand that receiving an L1 AP CSI-RS trigger initiates / triggers the SCell activation process / procedure. The UE receives the L1 AP CSI-RS trigger associated with the SCell (box 732) and initiates the SCell activation process (box 734), during which the UE monitors the SCell and may receive the associated AP TRS and associated AP CSI-RS for activating the SCell (box 736). During the SCell activation process, the UE may optionally transmit an SRS associated with the AP TRS of the SCell (box 736). As described above, for example, by reporting validity (CSI), the UE may send a message to the gNB indicating that the SCell is activated (box 704). The AP CSI-RS associated with the L1 AP CSI-RS trigger may or may not be the default AP CSI-RS. It can be associated with a specific default TRS and optionally a default SRS and BWP, providing the network with greater flexibility in selecting which AP CSI-RS / TRS / SRS to transmit or which BWP to activate. For example, a default TRS (TRS1) can be associated with default BWP1 and default CSI-RS1, and an L1 AP CSI-RS trigger is for CSI-RS2, which is associated with BWP2 and TRS2. The UE then understands that this SCell activation is to activate BWP2 and anticipates TRS2 and CSI-RS2. AP CSI-RS2 is sent and received after AP TRS2 transmission. Optionally, APSRS can be transmitted according to configuration / activation, and optionally, a valid DL CSI can be reported from the UE to the gNB, which typically includes at least a valid CQI value. CSI-RS, SRS, and TRS can be associated with the same BWP, and one can be quasi-co-located with another. For example, a CSI-RS can be quasi-co-located with a TRS having QCL type A, and an SRS can use a TRS and / or a CSI-RS as its path loss RS. Some embodiments in this regard will be discussed further later. Afterwards, SCell activation is complete and the SCell is activated.

[0181] Figure 7A fourth embodiment is also illustrated, in which the gNB sends an L1 AP SRS trigger associated with the deactivated SCell. Even without receiving an L2 MAC activation command, the UE can still understand that receiving an L1 AP SRS trigger initiates / triggers the SCell activation process / procedure. The UE receives the L1 AP SRS trigger associated with the SCell (box 742) and initiates the SCell activation process (box 744). During this process, the UE monitors the SCell and may receive the associated AP TRS for activating the SCell, and transmits the associated AP SRS (triggered by the L1 AP SRS trigger) (box 746). During the SCell activation process, the UE may optionally receive the associated AP CSI-RS (box 746). As described above, for example, by reporting validity (CSI), the UE may send a message to the gNB indicating that the SCell is activated (box 704). The AP SRS associated with the L1 AP SRS trigger may or may not be the default AP SRS. It can be associated with a specific default TRS and optionally a default CSI-RS and BWP, which provides the network with more flexibility in selecting which AP CSI-RS / TRS / SRS to transmit or which BWP to activate. For example, a default TRS (TRS1) can be associated with default BWP1 and default SRS1, and an L1 AP SRS trigger is for SRS2, which is associated with BWP2 and TRS2. The UE then understands that this SCell activation is to activate BWP2 and anticipates TRS2 and will transmit SRS2. Then, after receiving AP TRS2, AP SRS2 is transmitted. Optionally, AP CSI-RS is transmitted according to configuration / activation, and optionally, a valid DL CSI is reported from the UE to the gNB, which typically includes at least a valid CQI value. Some embodiments of this will be discussed further later. Afterward, SCell activation is completed and the SCell is activated.

[0182] Figure 8 A schematic diagram 800 is shown for a second exemplary embodiment of SCell activation triggering and activation. Figure 8In the example, the gNB sends a MAC activation command (L2 SCell activation command) to the UE in time slot n for deactivating the SCell, and the UE receives the L2 SCell activation command in time slot n of the MAC CE (box 802). The MAC CE is carried in the PDSCH transmitted on the UE's active serving cell. The UE needs to send an ACK / NACK for the PDSCH carrying the MAC CE on, for example, one of the UE's active serving cells. If the PDSCH carrying the MAC CE is successfully decoded, an ACK is sent, and this initiates the UE's SCell activation process; otherwise, if the PDSCH is not successfully decoded, a NACK is sent, and the gNB will have to transmit another PDSCH carrying the MAC CE command on, for example, one of the UE's active serving cells, and the SCell activation process will begin in the time slot in which the ACK for the other PDSCH is sent. It may take t time slots from receiving the PDSCH carrying the MAC CE to sending the ACK. In some cases, t=3, that is, the time required for the UE to decode the MAC signaling is 3 time slots. The value t can also be other UE capability-related values, which can be determined before the UE sends the ACK. The value t may include additional delays required for the UE to process the MAC CE and take action in Layer 1. In any case, both the network and the UE require a common reference timing for transmitting / receiving the remaining signals without other signaling. One embodiment of this common reference timing is the ACK time slot, and another embodiment is the time slot following the ACK time slot, making the UE Layer 1 ready. As shown in the figure, the UE transmits an ACK message acknowledging receipt of the L2 activation command (box 804).

[0183] Then, the gNB can transmit the AP TRS to the UE on the SCell to be activated, and the UE receives the AP TRS in slot n + t + k_trs (box 806), where k_trs is the trigger offset associated with the UE receiving the AP TRS in terms of the number of slots. In this example, the TRS is used as a temporary RS for SCell activation. The trigger offset can indicate the duration (e.g., the number of slots) from the receive RS trigger to the receive / transmit trigger. A trigger offset of 0 indicates the same slot. This may be related to UE capabilities, and the gNB configures the AP TRS trigger offset after the UE reports its capabilities. This gives the UE sufficient time to prepare to receive the AP TRS. AP TRS is pre-configured for SCell activation. In this example, triggering the TRS is not required, thus reducing signaling overhead and latency. If multiple AP TRSs are used for SCell activation, one of them is configured as the default and the default AP TRS is transmitted without the others. Some embodiments of this have been previously described in this invention. MACCE can also be enhanced to include the triggering of one of the selected AP TRSs. Based on the received AP TRS, the UE can perform AGC establishment, time / frequency tracking, etc. The AP TRS can be repeated within a time slot or across different time slots.

[0184] In some embodiments, at least one of the default AP CSI-RS and the default AP SRS can be used for SCell activation. In one example, the SCell activation process can be configured with a default AP CSI-RS having a trigger offset k_csi-rs, and the AP CSI-RS can be transmitted to the UE on the SCell to be activated, and the UE receives the AP CSI-RS in time slot n + t + k_csi-rs (box 808). The CSI-RS and / or SRS transmitted to the UE can be considered as temporary RSs for this SCell activation process of the UE if they are configured and triggered in an on-demand manner specifically for SCell activation. The AP CSI-RS used as a temporary RS during the SCell activation process can be triggered as needed for SCell activation and differs from the regular CSI-RS during SCell activation. The regular CSI-RS is typically periodic (sent according to a pre-configured slot periodicity and slot offset without triggering, which may require a longer reception time for the UE) or semi-static (sent once activated by a command according to a pre-configured slot periodicity and slot offset; the command only enables it but does not control the slot position for transmission, which may also require a longer reception time for the UE). The default AP CSI-RS can be identified based on whether it is the default AP CSI-RS of the BWP associated with the triggered AP TRS. In this case, triggering the CSI-RS is unnecessary, thus reducing signaling overhead and latency. For example, the CSI-RS can preferably be received after the TRS so that AGC / tracking implemented from the TRS can be applied to the reception and processing of the CSI-RS; therefore, the network should generally ensure k_csi-rs > k_trs. As another example, AP CSI-RS can be transmitted in time slot n + t + k_trs + k_csi-rs, ensuring that CSI-RS is later than TRS. If TRS is transmitted in multiple time slots, AP CSI-RS can be transmitted in time slot n + t + k_trs + k + k_csi-rs, where k is the number of time slots with AP TRS transmission (k is an integer greater than 1), and k can be specified in the RRC configuration or standard, such as k=2, 4, etc., ensuring sufficient time-domain samples of TRS for CSI-RS. Based on CSI-RS, the UE can generate an (AP)CSI report, which can include at least a valid CQI indicating successful SCell activation. The UE then causes the CSI to send the report (with at least a valid CQI) to the gNB on the SCell (box 810). The time slot for sending the report with a valid CQI can be considered as the time when SCell activation is complete, i.e., when the SCell is activated (box 812). If the CSI measurement does not include a valid CQI, then no SCell is activated.The UE can also send a CSI report including an invalid CQI (e.g., CQI=0), based on which the network knows that the SCell was not activated for the UE, for example, due to poor channel conditions. It should be noted that if a default AP SRS is also configured / identified during SCell activation, the UE should send an AP SRS, which can be after the TRS and before or after the CSI-RS. This eliminates the need to trigger an SRS, thereby reducing signaling overhead and latency. Embodiments of AP SRS transmission will be described further later in this invention.

[0185] Furthermore, the AP TRS is typically not an independent RS; that is, it depends on the P / SP TRS. The AP and P / SP TRS can be quasi-co-located with each other, and in particular, the AP TRS can depend on the P / SP TRS. However, for a deactivated SCell, the AP TRS cannot depend on the P / SP TRS on the deactivated SCell. Several embodiments are provided. One embodiment is that the AP TRS depends on a cross-carrier signal, for example, the AP TRS is quasi-co-located with a cross-carrier SSB or cross-carrier P / SP TRS having QCL types A and D (for FR2). The cross-carrier SSB or P / SP TRS should be on the active carrier / cell, typically an in-band carrier, and should be configured for or received by the UE before the activation process begins. In another embodiment, if the cross-carrier SSB or P / SP TRS is not configured for the UE or is not transmitted to the UE (e.g., the carrier is also deactivated), the AP TRS can be repeatedly transmitted in consecutive time slots after n + t + k_trs so that the UE can derive sufficient tracking information from the AP TRS. The AP TRS may still be quasi-co-located with the SCell's P / SP TRS, and if the P / SP TRS is configured with an AP TRS, the P / SP TRS may be automatically activated after the SCell activation is complete. The UE can then receive the P / SP TRS associated with the AP TRS (box 814).

[0186] Figure 9 A schematic diagram 900 illustrates a third exemplary embodiment for SCell activation triggering and activation. Figure 9In the example, the gNB sends a MAC activation command (L2 SCell activation command) to the UE in time slot n for deactivating the SCell, and the UE receives the L2 SCell activation command in time slot n of the MAC CE (box 902). The MAC CE is carried in the PDSCH transmitted on the UE's active serving cell. The UE needs to send an ACK / NACK for the PDSCH carrying the MAC CE on one of the UE's active serving cells. If the PDSCH carrying the MAC CE is successfully decoded, an ACK is sent (box 904), and this initiates the UE's SCell activation process; otherwise, if the PDSCH is not successfully decoded, a NACK is sent, and the gNB will have to transmit another PDSCH carrying the MAC CE on one of the UE's active serving cells, and the SCell activation process will begin in the time slot where the ACK for the other PDSCH is sent. It may take t time slots from receiving the PDSCH with the MAC CE to sending the ACK. The value t may also include additional delays required for the UE to process the MAC CE and take action at the L1 layer.

[0187] The gNB can transmit AP TRS to the UE in time slot n + t + k_trs, and the UE receives AP TRS in time slot n + t + k_trs (box 906), where k_trs is the trigger offset associated with the UE receiving the AP TRS in terms of the number of time slots. AP TRS is transmitted on the SCell to be activated. In this example, TRS is used as a temporary RS for SCell activation. AP TRS can be pre-configured for SCell activation, thus eliminating the need to trigger TRS, thereby reducing signaling overhead and latency. If multiple AP TRS are used for SCell activation, one is configured as the default and the default AP TRS is transmitted without the others. Some embodiments of this have been previously described in this invention. The MAC CE can also be enhanced to include the triggering of one of the AP TRS to be selected. AP TRS can be transmitted repeatedly within a time slot or across different time slots.

[0188] If the SCell activation procedure is also configured with a default AP SRS with a trigger offset k_srs, the UE will also transmit the AP SRS in slot n + t + k_srs on the SCell to be activated (box 908). The AP SRS can be considered a temporary RS for the SCell activation procedure because it is configured and triggered on demand for the SCell activation procedure. The default AP SRS can be identified based on the fact that it is the default AP SRS of the BWP associated with the triggered AP TRS. Triggering the SRS is not required, thus reducing signaling overhead and latency. In one example, the SRS can preferably be transmitted after the TRS so that the tracking implemented from the TRS can be applied to the SRS transmission; therefore, the network should generally ensure k_srs > k_trs. In another example, the AP SRS can be transmitted in slot n + t + k_trs + k_srs, which ensures that the SRS is later than the TRS. If the TRS is transmitted in multiple time slots, the AP SRS can be sent in time slots n + t + k_trs + k + k_srs, where k is the number of time slots with AP TRS transmission (k is an integer greater than 0), and k can be specified in the RRC configuration or standard, such as k = 2, 4, etc. This ensures that the SRS has sufficient temporal samples based on the TRS, for example, for path loss estimation purposes discussed later. However, in either case, the time gap between receiving the TRS and sending the SRS can be shorter than the time gap between receiving the TRS and receiving the AP CSI-RS, because the SRS can be sent without waiting for AGC establishment (which is typically required for receiving CSI-RS). The UE is ready to send the SRS as soon as it obtains tracking from the AP TRS. Therefore, in one embodiment, the AP SRS time slot can be n + t + k_trs + t_srs, where t_srs < k_srs, and can be a value specified by the network. For example, t_srs can be a single time slot, meaning that if the frame structure allows (e.g., it is a UL time slot or a flexible time slot with UL symbols), SRS can be transmitted in a time slot exactly after the TRS time slot. Based on SRS, the gNB can derive partial DL MIMO CSI for FDD systems, full DL MIMO CSI for TDD systems, and full UL MIMO CSI and UL power control / timing advance information for FDD / TDD systems. If no default AP CSI-RS is configured for SCell activation, the time slot for transmitting SRS can be considered as the time when SCell activation is complete, i.e., the time when the SCell is activated (box 910).

[0189] It should be noted that if the default AP CSI-RS is also configured / identified during SCell activation, the UE should also receive APCSI-IM resources. These AP CSI-IM resources can be received after TRS, before CSI-RS, or after SCell activation, but SCell activation is completed before the APCSI report is sent. That is, SRS-based CSI acquisition and SCell activation may be faster than CSI-RS-based CSI acquisition and SCell activation. However, in some cases, UL slots / symbols are sparse in time, and SRS-based activation may be slower. Depending on how slots / parameters are configured and when the activation command is sent, comparing SRS-based and CSI-RS-based activation, one may be faster than the other, which is known to the gNB and selectable by the gNB. Additionally, if the gNB requires CQI and / or DL ​​interference information, CSI-RS-based activation can provide and utilize this information. If the gNB requires DL full MIMO CSI, UL CSI / TA / power control information, but not DL interference information, SRS-based activation can provide and utilize this information; activation is completed after the SRS is transmitted, but CSI reports may still be transmitted after activation. AP TRS can rely on cross-carrier signals; for example, AP TRS can be quasi-co-located with cross-carrier SSBs or cross-carrier P / SP TRS with QCL types A and D (for FR2). Cross-carrier SSBs or P / SP TRS should be on the active carrier, typically an in-band carrier, and should be configured for or received by the UE before the activation process begins. In another embodiment, if cross-carrier SSBs or P / SP TRS are not configured or transmitted due to the possibility of deactivation, AP TRS can be repeatedly transmitted in consecutive time slots after time slot n + k_trs so that the UE can derive sufficient tracking information from the AP TRS. If AP TRS is quasi-co-located with P / SP TRS, the P / SP TRS may automatically activate after SCell activation is complete, considering that the P / SP TRS is configured with AP TRS. Then, the UE can receive the P / SP TRS associated with the AP TRS (box 912).

[0190] Figure 10 A schematic diagram 1000 illustrates a fourth exemplary embodiment for SCell activation triggering and activation. Figure 10In this example, the gNB sends an AP TRS trigger for SCell (deactivation) to the UE in slot n, and the UE receives the AP TRS trigger (triggering AP TRS) in slot n (box 1002). In this example, the TRS is used as a temporary RS for SCell activation. AP TRS and their triggering information can be pre-configured for SCell. If multiple AP TRSs are used for SCell activation and a default AP TRS is configured, the AP TRS trigger can indicate an AP TRS different from the default. The AP TRS trigger can be carried in the PDCCH transmitted on the active serving cell. If the PDCCH with the AP TRS trigger is successfully decoded, the UE understands that this TRS is located on the deactivated SCell, which means that the gNB initiates the SCell activation process from slot n. The gNB can then transmit the AP TRS to the UE in slot n + k_trs on the SCell to be activated, and the UE receives the AP TRS in slot n + k_trs (box 1004), where k_trs is the trigger offset associated with the UE receiving the AP TRS in terms of the number of slots. This may be related to UE capabilities, and the gNB can configure the AP TRS trigger offset after the UE reports its capabilities. This allows the UE sufficient time to prepare to receive AP TRS. AP TRS triggers can be carried in L1 or L2 signaling. Although the SCell activation process is typically an L2 process, the reception of the AP TRS trigger, the interpretation of the trigger information, and the reception of the AP TRS during the SCell activation process can be prepared by the UE in L1, and the UE does not have to wait for L2 to be ready. However, if the AP TRS trigger is in L1 signaling, the UE's L1 must notify L2 of the reception of the trigger, which may take some time, and the notification can occur in parallel with the execution of the AP TRS trigger process. That is, the TRS trigger offset may overlap with the L1 to L2 processing (notification), and the latter may not cause any additional delay in the L1 processing of RS transmission / reception / processing. Based on the received AP TRS, the UE can perform AGC establishment, time / frequency tracking, and other functions. AP TRS can be transmitted repeatedly within a time slot or across different time slots.

[0191] If the SCell activation process is also configured with a default AP CSI-RS with a trigger offset k_csi-rs, then the AP CSI-RS will also be transmitted to the UE in slot n + k_csi-rs (on the SCell to be activated), and the UE receives the AP and the AP CSI-RS in slot n + k_csi-rs (box 1006). There is no need to trigger the CSI-RS, thus reducing signaling overhead and latency. The AP CSI-RS can be considered a temporary RS for the SCell activation process because it is configured and triggered on demand for the SCell activation process. In the example, the CSI-RS can preferably be received after the TRS so that AGC / tracking implemented from the TRS can be applied to CSI-RS reception and processing; therefore, the network should generally ensure k_csi-rs > k_trs. In another example, the AP CSI-RS can be sent in slot n + k_trs + k_csi-rs, which ensures that the CSI-RS is later than the TRS. If TRS is transmitted in multiple time slots, AP CSI-RS can be sent in time slots n + t + k_trs + k + k_csi-rs, where k is the number of time slots with AP TRS transmission (k is an integer greater than 1), and k can be specified in the RRC configuration or standard, such as k=2, 4, etc., which ensures sufficient time-domain samples of CSI-RS based on TRS.

[0192] If the SCell activation procedure is also configured with a default AP SRS with a trigger offset k_srs, the UE will also transmit the AP SRS on the SCell in slot n + k_srs. The AP SRS can be considered a temporary RS for the SCell activation procedure because it is configured and triggered on demand for the SCell activation procedure. No SRS triggering is required, thus reducing signaling overhead and latency. The SRS can preferably be transmitted after the TRS so that the tracking implemented from the TRS can be applied to the SRS transmission, and generally the network should ensure k_srs > k_trs. The AP SRS can also be transmitted in slot n + k_trs + k_srs, which ensures the SRS is later than the TRS. In the case of both configurations, the CSI-RS can be transmitted before or after the SRS, depending on the parameters. Based on the CSI-RS, the UE can generate an AP CSI report, which can at least include a valid CQI indicating successful SCell activation. The UE can then send a report to the gNB (box 1008). The time slot for sending a report with a valid CQI can be considered as the time when SCell activation is complete, i.e., the time when the SCell is activated (box 1010). One embodiment is that the AP TRS relies on a cross-carrier signal, for example, the APTRS is quasi-co-located with a cross-carrier SSB or cross-carrier P / SP TRS having QCL types A and D (for FR2). The cross-carrier SSB or P / SP TRS should be on an active carrier, typically an in-band carrier, and should be configured for or received by the UE before the activation process begins. In another embodiment, if the cross-carrier SSB or P / SP TRS is not configured or transmitted because it can also be deactivated, the AP TRS can be repeated in consecutive time slots after time slot n + k_trs so that the UE can derive sufficient tracking information from the APTRS. The AP TRS may still be quasi-co-located with the P / SP TRS, and considering that the P / SP TRS is configured with the APTRS, the P / SP TRS is automatically activated after SCell activation is complete. The UE can then receive the P / SP TRS associated with the AP TRS (box 1012).

[0193] Figure 11 A schematic diagram 1100 illustrates a fifth exemplary embodiment for SCell activation triggering and activation. Figure 11In this example, the gNB sends an AP CSI-RS trigger (triggered AP CSI-RS) to the UE in slot n for deactivating the SCell, and the UE receives the AP CSI-RS in slot n (box 1102). In this example, the CSI-RS is used as a temporary RS for SCell activation. AP CSI-RS and their triggering information can be pre-configured for the SCell. If multiple AP CSI-RS are used for SCell activation and a default AP CSI-RS is configured, the AP CSI-RS trigger can indicate an AP CSI-RS different from the default. The AP CSI-RS trigger can be carried in the PDCCH transmitted on the active serving cell. If the PDCCH with the AP CSI-RS trigger is successfully decoded, the UE understands that this CSI-RS is located on the deactivated SCell, and this means that the gNB initiates the SCell activation procedure from slot n. Then, the gNB can transmit the AP TRS to the UE in time slot n + k_trs on the SCell to be activated, and the UE receives the AP TRS in time slot n + k_trs (box 1104), where k_trs is the trigger offset associated with the number of time slots for the UE receiving the AP TRS, and the AP TRS is pre-configured for the SCell. The AP TRS is also a temporary RS for the SCell activation process. No TRS triggering is required, thus reducing signaling overhead and latency. The AP CSI-RS trigger can be carried in L1 signaling or L2 signaling. It can exist in the above-mentioned... Figure 10 Some L1-to-L2 processing is discussed, but L1-to-L2 processing can be performed in parallel with L1 steps and may not cause any additional delay in the L1 processing of RS transmission / reception / processing. Based on the received AP TRS, the UE can perform AGC establishment, time / frequency tracking, etc. AP TRS can repeat within a single time slot or across different time slots.

[0194] AP CSI-RS can be transmitted to the UE in time slot n + k_csi-rs on the SCell (box 1106). It is preferable to receive the CSI-RS after the TRS so that AGC / tracking implemented from the TRS can be applied to CSI-RS reception and processing; therefore, the network should generally ensure k_csi-rs > k_trs. AP CSI-RS can also be transmitted in time slot n + k_trs + k_csi-rs, which ensures that the CSI-RS is later than the TRS. If the TRS is transmitted in multiple time slots, the AP CSI-RS can be transmitted in time slot n + t + k_trs + k + k_csi-rs, where k is the number of time slots with AP TRS transmission (k is an integer greater than 1), and k can be specified in the RRC configuration or standard, e.g., k = 2, 4, etc., which ensures sufficient time-domain samples of the CSI-RS based on the TRS.

[0195] If the SCell activation procedure is also configured with a default AP SRS with a trigger offset k_srs, the AP SRS will also be transmitted by the UE on the SCell in slot n + k_srs (box 1108). The AP SRS can be considered a temporary RS for the SCell activation procedure because it is configured and triggered on demand for the SCell activation procedure. No SRS triggering is required, thus reducing signaling overhead and latency. The SRS can preferably be sent after the TRS so that the tracking implemented from the TRS can be applied to the SRS transmission; therefore, the network should generally ensure k_srs > k_trs. The AP SRS can also be sent in slot n + k_trs + k_srs, which ensures that the SRS is later than the TRS. In the case where both are configured, the CSI-RS can be sent before or after the SRS, depending on the parameters. Based on the CSI-RS, the UE can generate an AP CSI report, which can at least include a valid CQI indicating that the SCell is activated. The UE can then send the report to the gNB (box 1110). The time slot for sending a report with a valid CQI can be considered the time when SCell activation is complete, i.e., when the SCell is activated (box 1112). It should be noted that even if the SRS is sent before the CSI-RS, in the case of SCell activation triggered by the APCSI-RS (such as... Figure 11As shown in this example, it is only activated after the CSI report is sent. One embodiment is that the AP TRS relies on a cross-carrier signal; for example, the AP TRS can be quasi-co-located with a cross-carrier SSB or cross-carrier P / SP TRS having QCL types A and D (for FR2). The cross-carrier SSB or P / SP TRS should be on the active carrier, typically an in-band carrier, and should be configured for or received by the UE before the activation process begins. In another embodiment, if the cross-carrier SSB or P / SP TRS is not configured or transmitted due to the possibility of deactivation, the AP TRS can be repeated in consecutive time slots after n + k_trs so that the UE can derive sufficient tracking information from the AP TRS. The AP TRS may still be quasi-co-located with the P / SP TRS, and given that the P / SP TRS is configured with the AP TRS, the P / SP TRS may be automatically activated after SCell activation is complete. The UE can then receive the P / SP TRS associated with the AP TRS (box 1114).

[0196] Figure 12 A schematic diagram 1200 illustrates a sixth exemplary embodiment for SCell activation triggering and activation. Figure 12 In this example, the gNB sends an AP SRS trigger (triggered AP SRS) to the UE in slot n for deactivating the SCell, and the UE receives the AP SRS in slot n (box 1202). In this example, the AP SRS is used as a temporary RS for SCell activation. AP SRS and their triggering information can be pre-configured for the SCell. If multiple AP SRSs are used for SCell activation and a default AP SRS is configured, the AP SRS trigger can indicate an AP SRS different from the default. The AP SRS trigger can be carried in the PDCCH transmitted on the active serving cell. If the PDCCH carrying the AP SRS trigger is successfully decoded, the UE understands that this SRS is located on the deactivated SCell, and this means that the gNB initiates the SCell activation process from slot n. Then, the gNB can transmit the AP TRS to the UE in time slot n + k_trs on the SCell to be activated, and the UE receives the AP TRS in time slot n + k_trs (box 1204), where k_trs is the trigger offset associated with the number of time slots for the UE receiving the AP TRS, and the AP TRS is pre-configured for the SCell. The AP TRS is also a temporary RS for the SCell activation process. No TRS triggering is required, thus reducing signaling overhead and latency. The AP TRS trigger can be carried in L1 signaling or L2 signaling. It can exist in the above-mentioned... Figure 10Some L1-to-L2 processing is discussed, but L1-to-L2 processing can be performed in parallel with L1 steps and may not cause any additional delay in the L1 processing of RS transmission / reception / processing. Based on the received AP TRS, the UE can perform AGC establishment, time / frequency tracking, etc. AP TRS can be repeatedly transmitted within a single time slot or across different time slots.

[0197] The UE can transmit AP SRS in slot n + k_srs on the SCell (box 1206). It is preferable to transmit the SRS after the TRS so that the tracking implemented from the TRS can be applied to the SRS transmission; therefore, the network should generally ensure k_srs > k_trs. AP SRS can also be transmitted in slot n + k_trs + k_srs, which ensures that the SRS is later than the TRS. If the TRS is transmitted in multiple slots, the AP SRS can be transmitted in slot n + t + k_trs + k + k_srs, where k is the number of slots with AP TRS transmission (k is an integer greater than 1), and k can be specified in the RRC configuration or standard, e.g., k = 2, 4, etc. This ensures that the SRS has sufficient temporal samples based on the TRS, for example, for path loss estimation purposes discussed later.

[0198] If the SCell activation procedure is also configured with a default AP CSI-RS with a trigger offset k_csi-rs, then the AP CSI-RS will also be transmitted to the UE on the SCell in time slot n + k_csi-rs. The AP CSI-RS can be considered a temporary RS for the SCell activation procedure. It is preferable to receive the CSI-RS after the TRS so that AGC / tracking implemented from the TRS can be applied to CSI-RS reception and processing; therefore, the network should generally ensure k_csi-rs > k_trs. The AP CSI-RS can also be transmitted in time slot n + k_trs + k_csi-rs, which ensures that the CSI-RS is later than the TRS. In the case of both configurations, the CSI-RS can be transmitted before or after the SRS, depending on the parameters. Based on the CSI-RS, the UE will generate an AP CSI report, which may include at least a valid CQI indicating that the SCell is activated. The UE then sends the report to the gNB. The time slot for transmitting the AP SRS can be considered as the time when SCell activation is complete, i.e., when the SCell is activated. Therefore, when the AP SRS is sent, the SCell is activated (box 1206). It should be noted that even if the SRS is sent after the CSI-RS, in the case of SCell activation triggered by the AP SRS, it will only be activated after the SRS is sent.

[0199] One embodiment is that the AP TRS relies on a cross-carrier signal; for example, the AP TRS can be quasi-co-located with a cross-carrier SSB or cross-carrier P / SP TRS having QCL type A and QCL type D (for FR2). The cross-carrier SSB or P / SP TRS should be on an active carrier, typically an in-band carrier, and should be configured for or received by the UE before the activation process begins. In another embodiment, if the cross-carrier SSB or P / SP TRS is not configured or transmitted because it can also be deactivated, the AP TRS can be repeated in consecutive time slots after n + k_trs so that the UE can derive sufficient tracking information from the AP TRS. The AP TRS may still be quasi-co-located with the P / SP TRS, and given that the P / SP TRS is configured with the AP TRS, the P / SP TRS may be automatically activated after SCell activation is complete. The UE can then receive the P / SP TRS associated with the AP TRS (box 1208).

[0200] Table 1 below shows the criteria for considering a deactivated SCell as activated in the above embodiments. Table 1 shows four different activation signaling methods that can be used to trigger SCell activation: MAC CE, AP TRS trigger, AP CSI-RS trigger, and AP SRS trigger, listed in four columns. Each column has four possibilities, listed as subcolumns, corresponding to whether the default AP CSI-RS is configured for SCell activation and whether the default AP SRS is configured for SCell activation. "N / A" indicates an invalid configuration. The last row shows the content sent to indicate SCell activation. It should be noted that AP temporary RS triggers may or may not indicate the default RS.

[0201]

[0202] An example of the first sub-column shown in Table 1 is:

[0203] If the activation signaling is: MAC CE

[0204] And is the default AP CSI-RS configured for SCell activation? Yes

[0205] And is the default AP SRS configured for SCell activation? Yes

[0206] Then SCell is activated when this message is sent: CQI.

[0207] The other sub-columns can be understood in the same way.

[0208] The following provides some embodiments of CSI reporting associated with SCell activation. In one embodiment, the CSI report includes at least a valid CQI report, as is the case with conventional designs. In another embodiment, the CSI report includes at least a valid L1SINR report, but not necessarily a CQI. Determining the L1 SINR is simpler and faster than determining the CQI value, thus reducing activation latency. Both the CQI and L1 SINR reports must rely on CSI-RS (and CSI-IM resources), as described below. SCell activation is complete when the L1SINR is sent. To distinguish between sending CQI and sending L1 SINR, one embodiment requires L1 SINR for all Rel-17 enhanced activations but not CQI; alternatively, for activations initiated by an L2 command, CQI is sent, and for activations triggered by an L1 RS trigger, L1 SINR is sent. In another embodiment, the CSI report includes a valid L1 RSRP report, but not necessarily SINR or CQI. This is particularly useful for FR2 beam-based operations. Determining the L1 RSRP is simpler and faster than determining the L1 SINR value, thus further reducing activation latency. L1 RSRP reporting relies on CSI-RS, not CSI-IM resources. Therefore, if no default CSI-IM is configured or if CSI-IM is not signaled during AP RS triggering, the UE can assume that L1 RSRP will be reported, and SCell activation is complete when L1 RSRP is sent. Similarly, for activation initiated by an L2 command, CQI will be sent, and for activation initiated by an L1 RS trigger, L1 RSRP will be sent if no CSI-IM is available, but L1 SINR will be sent if CSI-IM is also available.

[0209] SRS transmissions may require an appropriate TA offset. In some embodiments, the TA offset can be determined or obtained for SRS transmissions used for SCell activation. For example, if the TA is valid for a TAG, the TA offset can be based on the TAG in which the SCell resides. If no valid TA is available for a TAG, an initial TA offset can be obtained from another TAG, which may be signaled from the network for timing differences estimated by the network between TAGs.

[0210] SRS transmission may also require appropriate transmission power. In some embodiments, the path loss RS of SRS can be configured as SSB, CSI-RS, or TRS. If SSB is available and configured as the path loss RS of SRS, the path loss can be estimated from the SSB. If CSI-RS is available as AP CSI-RS and configured as the path loss RS of SRS transmission, the path loss can be estimated from the AP CSI-RS. In the example, the network can configure the path loss (or associated RSRP measurement) based on at least k transmission opportunities of the AP CSI-RS. Depending on its configuration and slot configuration, the k transmission opportunities can be over k OFDM symbols, k time slots, or less or more than k time slots, and the AP SRS trigger offset can start from the time slot where the kth transmission occurs. If APTRS is configured as the path loss RS of SRS, the path loss can be estimated from the AP TRS. In another example, the network can configure the path loss (or associated RSRP measurement) based on at least k transmission opportunities of the AP TRS. Depending on its configuration and time slot configuration, the k transmission opportunities can occur over k OFDM symbols, k time slots, or less or more than k time slots, and the AP SRS trigger offset can begin from the time slot where the kth transmission occurs. In one embodiment, even if the SRS is configured with another path loss RS, the AP TRS can be the default path loss RS for the SRS during activation; this is because the AP TRS is guaranteed to be transmitted, while the CSI-RS can be optional, and the AP TRS provides better broadband information than the SSB for path loss estimation purposes. In another embodiment, information from other carriers can be used to set the transmission power of the SRS. For example, the path loss of SCell 1 can be derived from the path loss of another cell, where the offset is signaled to the UE or derived by the UE. If SCell 1 is in a TAG with an active serving cell, then in addition to obtaining TA information from the active serving cell, the UE can also obtain the initial path loss / RSRP value from the active serving cell via appropriate signaling from the network. As an example, if the offset for path loss / RSRP between the first and second cells is signaled and one of the cells is activated, the UE can apply the offset for path loss / RSRP to estimate the path loss / RSRP of the other cell, thereby estimating the initial SRS power control. As another example, network signaling may not have an offset, but it can allow the path loss / RSRP to be derived from the activated serving cell (possibly using the offset estimated by the UE).

[0211] In some embodiments, fast SCell activation can be implemented using existing L2 signaling with an enhanced activation process, which may be a variation of the embodiments described above or in combination with them. For example, when the UE receives L2 signaling, it initiates the SCell activation process. The temporary RS is triggered by L2 signaling, wherein the offset is triggered in a time slot according to the required MAC decoding time (typically n+3), or wherein the offset is triggered in a time slot in which an ACK for the PDSCH carrying the MAC command is sent. The temporary RS may include at least an AP TRS configured for SCell activation and at least one (or both) of AP CSI-RS and APSRS.

[0212] In some embodiments, fast SCell activation can be implemented via L1 or L2 signaling. In any case, the AP TRS is always triggered. In one exemplary embodiment, the gNB sends a MAC activation command for SCell activation, which is configured with a default AP TRS plus a default AP CSI-RS and / or a default AP SRS. The trigger offset for the AP RS can begin in a time slot based on the required MAC decoding time (typically n+3); or the trigger offset can begin in a time slot when the UE sends an ACK associated with the MAC activation command.

[0213] In another exemplary embodiment, for example, the gNB's network (NW) sends an L1 AP TRS trigger for deactivated SCell, which may be configured together with the default AP CSI-RS and / or the default AP SRS. The triggered AP TRS may or may not be the default AP TRS configured for SCell activation.

[0214] In another exemplary embodiment, the NW sends an L1 AP CSI-RS trigger for the deactivated SCell. This L1 AP CSI-RS trigger can be configured together with the default AP TRS, and the triggering AP CSI-RS can be different from the default AP CSI-RS configured for activation of the SCell. The SCell can also be configured with a default SRS, and the default SRS is also transmitted.

[0215] In another exemplary embodiment, the NW sends an L1 AP SRS trigger for the deactivated SCell. This L1 AP SRS trigger can be configured together with the default AP TRS, and the triggered AP SRS can be different from the default AP SRS configured for activation of the SCell. The SCell can also be configured with a default CSI-RS, and the triggered AP SRS is also transmitted there.

[0216] In some embodiments, L1 AP trigger activation deactivation SCell is used to prevent UE and network asynchrony. If the PDCCH is correctly decoded, an ACK for the L1-triggered PDCCH (i.e., L1-triggered signaling) can be sent from the UE. The ACK can be carried in the PUCCH in the immediately following time slot, which has a UL symbol for accommodating the PUCCH. In this case, the trigger offset start time (of the triggering RS) can be the time slot of the PUCCH. In this example, the L1 triggering process may be prolonged because it may have to wait for the flexible / UL time slot in TDD.

[0217] In addition to the TRS already agreed upon as a temporary RS, the following candidate RSs may also be considered:

[0218] ● Deactivate SCell's cycle CSI-RS

[0219] Essentially, periodic CSI-RS (or similarly, SP CSI-RS) function similarly to LTE CRS, thus reducing activation latency. Advantages include their fully predictable occurrence, which can help reduce PDCCH monitoring and overhead and simplify UE design. However, setting the period can be challenging. If the period is too long, the latency reduction is not significant, while if the period is too short, overhead and power consumption are high. Long-period CSI-RS (including long-period TRS) with a period of at least 100 TTIs can be configured for deactivated SCells to reduce power consumption. P / SP TRS configured for deactivated SCells can also be used as source RSs for AP TRSs during activation. If multiple AP TRSs are configured for SCell activation, the AP TRS associated with the P / SP TRS transmitted before activation can be assumed as the default AP TRS and transmitted during activation.

[0220] ●Non-periodic CSI-RS of deactivated SCell during activation period

[0221] Aperiodic CSI-RS is more flexible and can be triggered immediately at the start of the activation process. Multiple aperiodic CSI-RS can be triggered if one transmission is insufficient (e.g., by triggering once if overhead reduction is considered). The energy consumption associated with receiving aperiodic CSI-RS is lower than that of receiving periodic CSI-RS, especially when the deactivation duration is long and the period is short. With a sufficient trigger offset, the UE does not need to be constantly prepared to receive and generate aperiodic CSI-RS reports. The trigger offset provides the UE with sufficient time to respond to aperiodic triggers. However, additional PDCCH monitoring and overhead may be required in another serving cell. If many SCells are deactivated, PDCCH monitoring of those active serving cells may become important.

[0222] ● Deactivate the P / AP CSI-RS combination in SCell

[0223] This provides the network with maximum flexibility / capability, but the complexity can be high. Comparing CSI-RS and TRS, it should be noted that CSI-RS is needed for CSI measurements, while TRS is used for tracking. CSI measurements and reporting are required in almost all cases of SCell activation, and CSI-RS is still needed even when TRS is used as a temporary RS for activation. Therefore, at least one of AP CSI-RS and P / SP CSI-RS may need to be supported as a temporary RS. A combination of long-cycle P / SP CSI-RS and AP CSI-RS may achieve the best trade-off between fast activation and reduced UE power consumption.

[0224] ● Deactivate the SRS of the SCell during the activation process

[0225] As is well known, SRS can be used to provide DL full MIMO CSI in TDD systems, ULCSI in TDD / FDD systems, maintain UL TA, UL power control, and UL / DL beamforming. Therefore, SRS is crucial for an activating SCell to reacquire CSI, TA, power control, and beamforming. Even with the path loss of SRS in the active cell, the UE can transmit SRS on the activating SCell without waiting for the DL AGC of the activating SCell to be established. A SCell may not be fully usable as a "fully active" SCell until its UL is also ready, which can be achieved through SRS transmission. Furthermore, utilizing SRS during activation allows some processing to be offloaded from the UE to the network, reducing UE processing complexity. Therefore, it is recommended that SRS also be considered a temporary RS.

[0226] ●RS based on SSS / PSS during activation

[0227] The SCell to be activated can be known to the UE or unknown to the UE. If known, using a TRS as a temporary RS can provide the UE with at least the functionality associated with the TRS, such as time / frequency tracking during activation. However, if the SCell is unknown, a TRS may not be sufficient and an SSS / PSS-based RS may be required. Therefore, an SSS / PSS-based RS may need to be considered as a temporary RS for the unknown cell to be activated.

[0228] To prevent SCells from becoming unknown to the UE, periodic RS based on SSS / PSS can be configured for deactivated SCells. Alternatively, if power consumption is desired, long-period RS based on SSS / PSS with a period of at least 100 TTIs can be configured for deactivated SCells.

[0229] In some embodiments, when a deactivated SCell becomes unknown to the UE, an aperiodic trigger of an SSS / PSS-based RS can be sent. However, due to timing uncertainties, the precise timing of the SSS / PSS-based RS may be unknown to the UE. Therefore, a search time window for the SSS / PSS-based RS can be configured or signaled to the UE to activate the unknown SCell. For example, if the search time window is x OFDM symbols, x time slots, or x microseconds, and the RS trigger offset is k time slots, the UE can perform a search for the RS after receiving the RS trigger, and the search begins after k time slots and ends before k+x time slots. Depending on the UE configuration, the RS can be repeated multiple times in one time slot or multiple times in multiple time slots. After the SSS / PSS-based RS is sent l times, where l is a value configured for the UE, the remaining activation process begins similarly to the above embodiments for known cells.

[0230] Therefore, AP CSI-RS, P / SP CSI-RS, SRS, and SSS / PSS-based RS can be configured as temporary RSs. It should be noted that activation may not always require temporary RSs, and whether a particular temporary RS is supported / used may depend on network configuration / UE capabilities.

[0231] In embodiments that transmit AP CSI-RS, each AP CSI-RS may also be configured with AP CSI-IM resources, and AP CSI-IM resources may also be transmitted during the transmission of AP CSI-RS. Therefore, AP CSI-IM resources can be considered as part of temporary RS or temporary RS resources. In some embodiments, L1 AP CSI-RS triggering may be replaced by L1 AP CSI triggering. APCSI triggering triggers a combination of AP CSI-RS and AP CSI-IM resources and will report CQI and / or L1 SINR based on CSI-RS / CSI-IM. The timing relationship among AP CSI triggering, AP CSI-RS, AP CSI-IM, and AP CSI reporting is generally the same as conventionally known timing relationships; however, in some embodiments, to ensure that AP CSI-RS / CSI-IM follows AP TRS, the trigger offset of APCSI-RS / CSI-IM may start from the first or last AP TRS slot.

[0232] Figure 13 A schematic diagram 1300 is shown for a seventh exemplary embodiment of SCell activation triggering and activation. Figure 13 In the example, the gNB sends an AP CSI report trigger for the SCell (which is deactivated) to the UE in time slot n, and the UE receives the AP CSI report trigger (a combination of triggering AP CSI-RS and AP CSI-IM resources) in time slot n (box 1302). In this example, CSI-RS is used as a temporary RS for SCell activation. The AP CSI reporting trigger can be carried in L1 signaling or L2 signaling. AP CSI-RS and AP CSI-IM resources, along with associated triggering information, can be pre-configured for the SCell. The gNB can transmit the AP TRS to the UE in time slot n + k_trs, and the UE receives the AP TRS in time slot n + k_trs (box 1304), where k_trs is the trigger offset associated with the UE receiving the AP TRS in terms of the number of time slots. The UE receives the AP CSI-RS and AP CSI-IM resources in time slot n + k_trs + k_csi-rs (box 1306). k_csi-rs is the trigger offset of the CSI-RS. Based on CSI-RS, the UE can perform CSI measurements and generate an AP CSI report, which may include at least a valid CQI indicating successful SCell activation. The UE can then send the report to the gNB (box 1308). The time slot for sending the report with the valid CQI can be considered the time when SCell activation is complete. The SCell is then activated (box 1310). The UE can also receive P / SP TRS associated with the AP TRS (box 1312).

[0233] As mentioned above, the TRS has been selected as the temporary RS for SCell activation. The design of the Rel-15 / 16 TRS structure and configuration appears to be generally sufficient and can be reused for Rel-17 as much as possible. When using the TRS for SCell activation, the network needs to ensure that the RS / SSB quasi-co-located with the TRS (i.e., the source RS of the TRS) should exist and be valid for UE use. For example, if the source RS of the TRS is an SSS / PSS, and the SCell is unknown to the UE, the network should ensure that the SSS / PSS is transmitted to the UE before the TRS is sent. With proper network implementation / configuration, the existing TRS design should be able to activate the SCell well. As previously mentioned, TRS triggering can also be used as the SCell activation command, which may not require a new trigger command design. Some embodiments of AP TRS have been previously provided in this invention. Alternatively, the AP TRS can also be a cross-carrier TRS for the SCell to be activated. In this case, the P / SP / AP TRS is on the active serving cell, and the P / SP TRS is being continuously monitored by the UE. The period may be long (e.g., longer than 100 TTIs) to reduce overhead, and the AP TRS is on the active cell based on the MAC command used for activation or the L1RS trigger used for activation. The previous embodiment process still works, except that when using the L1 AP TRS trigger, the UE may need additional information to determine whether the L1 AP TRS trigger is used for cross-carrier SCell activation. If the AP TRS is also used for cross-carrier SCell activation, additional indication of the SCell ID can be provided along with the additional information. Advantages of using cross-carrier TRS for activation include: when the UE monitors the P / SP TRS, the TRS can be repeated in less time so that the UE obtains sufficient information about tracking and / or path loss estimates, thus reducing the delay between the TRS and CSI-RS / SRS in subsequent steps. However, AGC information may not be available from the cross-carrier TRS. Therefore, subsequent transmissions of the CSI-RS may require more repetitions, or the cross-carrier TRS can be used primarily with AP SRS that does not require AGC. In other words, an AP SRS trigger is sent to the UE for SCell activation, and the triggered SRS can be associated with the AP TRS on the activated SCell. The AP TRS is sent after the AP SRS trigger with the TRS trigger offset without any additional duplication. The UE updates the path loss estimate based on this, and the AP SRS is sent on the SCell to be activated. The SCell is then considered active.

[0234] Figure 14This is a flowchart of an embodiment of wireless communication method 1400. Method 1400 can instruct the UE to perform operations. As shown, the UE can receive a secondary cell (SCell) activation command from the gNB, which instructs the UE to activate the SCell to communicate between the UE and the gNB on the SCell (box 1402). The UE can receive a reference signal (RS) on the SCell from the gNB (box 1404). The RS is used to activate the SCell. The UE can perform SCell activation based at least on the RS to activate the SCell upon receiving the SCell activation command (box 1406). The UE can send a report to the gNB indicating that the SCell has been activated for the UE (box 1408).

[0235] Figure 15 This is a flowchart of another embodiment of the wireless communication method 1500. Method 1500 can instruct the gNB to perform operations. As shown, the gNB can send a secondary cell (SCell) activation command to the user equipment (UE), the secondary cell activation command instructing the UE to activate the SCell to communicate between the UE and the gNB on the SCell (box 1502). The gNB can send a reference signal (RS) to the UE on the SCell to be activated by the UE (box 1504). The RS is used to activate the SCell. In response to sending the SCell activation command and the RS, the gNB can receive a report from the UE indicating that the SCell has been activated for the UE (box 1506).

[0236] Figure 16 This is a flowchart of another embodiment of the wireless communication method 1600. Method 1600 can instruct the UE to perform operations. As shown, the UE can receive a reference signal (RS) trigger transmitted on the secondary cell (SCell) from the gNB (box 1602). The UE receives the RS on the SCell from the gNB (box 1604). The RS is used to activate the SCell. The UE performs cell activation upon receiving the RS trigger to activate the SCell using the RS (box 1606). The UE can send a report to the gNB indicating that the SCell has been activated for the UE (box 1608).

[0237] Figure 17This is a flowchart of another embodiment of wireless communication method 1700. Method 1700 can instruct the gNB to perform operations. As shown, the gNB can send a trigger reference signal (RS) to the user equipment (UE) to trigger a reference signal (RS) transmitted on the secondary cell (SCell) to be activated for the UE (box 1702). The gNB transmits the RS on the SCell to the UE (box 1704). The RS is used to activate the SCell. In response to sending the RS trigger and transmitting the RS, the gNB receives a report from the UE indicating that the SCell has been activated for the UE (box 1706).

[0238] Figure 18 An exemplary communication system 1800 is illustrated. Generally, system 1800 enables multiple wireless or wired users to transmit and receive data and other content. System 1800 may implement one or more channel access methods, such as code division multiple access (CDMA), time division multiple access (TDMA), frequency division multiple access (FDMA), orthogonal FDMA (OFDMA), single-carrier FDMA (SC-FDMA), or non-orthogonal multiple access (NOMA).

[0239] In this example, the communication system 1800 includes electronic devices (EDs) 1810a to 1810c, radio access networks (RANs) 1820a to 1820b, a core network 1830, a public switched telephone network (PSTN) 1840, the Internet 1850, and other networks 1860. Although Figure 18 A certain number of these components or elements are shown, but the system 1800 may include any number of these components or elements.

[0240] EDs 1810a to 1810c are used for operation or communication within system 1800. For example, EDs 1810a to 1810c are used for transmission or reception via wireless or wired communication channels. Each ED 1810a to 1810c represents any suitable end-user equipment and may include (or be referred to as) devices such as: user equipment (UE), wireless transmit or receive unit (WTRU), mobile station, fixed or mobile subscriber unit, cellular phone, personal digital assistant (PDA), smartphone, laptop computer, computer, touchpad, wireless sensor, or consumer electronic device.

[0241] In this document, RAN 1820a to 1820b include base stations 1870a to 1870b, respectively. Each base station 1870a to 1870b is used to establish a wireless connection with one or more of ED 1810a to 1810c to enable access to the core network 1830, PSTN 1840, Internet 1850, or other networks 1860. For example, base stations 1870a to 1870b may include one or more of several well-known devices, such as a base transceiver station (BTS), NodeB (NodeB), evolved NodeB (eNodeB), next-generation (NG) NodeB (gNB), home NodeB, home eNodeB, site controller, access point (AP), or wireless router. ED 1810a to 1810c are used for connection and communication with the Internet 1850 and can access the core network 1830, PSTN 1840 or other networks 1860.

[0242] exist Figure 18 In the illustrated embodiment, base station 1870a forms part of RAN 1820a, which may include other base stations, components, or devices. Similarly, base station 1870b forms part of RAN 1820b, which may include other base stations, components, or devices. Each base station 1870a to 1870b is used to transmit or receive radio signals within a specific geographical area or region, sometimes referred to as a "cell." In some embodiments, multiple-input multiple-output (MIMO) technology may be used to enable each cell to have multiple transceivers.

[0243] Base stations 1870a to 1870b communicate with one or more of ED 1810a to 1810c via one or more air interfaces 1890 using a wireless communication link. Air interface 1890 may use any suitable wireless access technology.

[0244] It is conceivable that System 1800 can use multi-channel access capabilities, including the schemes described above. In specific embodiments, the base station and ED implement 5G New Radio (NR), LTE, LTE-A, or LTE-B. Of course, other multiple access schemes and radio protocols can also be used.

[0245] RANs 1820a to 1820b communicate with the core network 1830 to provide voice, data, application, voice over internet protocol (VoIP), or other services to EDs 1810a to 1810c. It is understood that RANs 1820a to 1820b or the core network 1830 can communicate directly or indirectly with one or more other RANs (not shown). The core network 1830 can also serve as a gateway access for other networks (e.g., PSTN 1840, Internet 1850, and other networks 1860). Additionally, some or all of EDs 1810a to 1810c may include the ability to communicate with different wireless networks via different wireless links using different wireless technologies or protocols. Instead of wireless communication (or other than wireless communication), EDs can also communicate with service providers or switches (not shown) and with the Internet 1850 via wired communication channels.

[0246] Although Figure 18 An example of a communication system is shown, but it is possible to... Figure 18 Various modifications can be made. For example, in any suitable configuration, the communication system 1800 can include any number of EDs, base stations, networks, or other components.

[0247] Figure 19A and Figure 19B Exemplary apparatuses are shown that can implement various methods and teachings according to the present invention. Specifically, Figure 19A An exemplary ED 1910 is shown, while Figure 19B An exemplary base station 1970 is shown. These components can be used in system 1800 or any other suitable system.

[0248] like Figure 19AAs shown, ED 1910 includes at least one processing unit 1900. The processing unit 1900 implements various processing operations of ED 1910. For example, the processing unit 1900 may perform signal encoding, data processing, power control, input / output processing, or any other function that enables ED 1910 to operate within system 1900. The processing unit 1900 also supports the methods and teachings described in more detail above. Each processing unit 1900 includes any suitable processing or computing device for performing one or more operations. Each processing unit 1900 may include, for example, a microprocessor, microcontroller, digital signal processor, field-programmable gate array, or application-specific integrated circuit.

[0249] ED 1910 also includes at least one transceiver 1902. Transceiver 1902 is used to modulate data or other content for transmission via at least one antenna or network interface controller (NIC) 1904. Transceiver 1902 is also used to demodulate data or other content received by at least one antenna 1904. Each transceiver 1902 includes any suitable structure for generating signals for wireless or wired transmission or for processing signals received wirelessly or wiredly. Each antenna 1904 includes any suitable structure for transmitting or receiving wireless or wired signals 1990. One or more transceivers 1902 may be used in ED 1910, and one or more antennas 1904 may be used in ED 1910. Although transceiver 1902 is shown as a single functional unit, it can also be implemented using at least one transmitter and at least one separate receiver.

[0250] ED 1910 also includes one or more input / output devices 1906 or interfaces (such as a wired interface connected to the Internet 1850). Input / output devices 1906 facilitate interaction with users or other devices on the network (network communication). Each input / output device 1906 includes any suitable structure for providing or receiving information from a user, including network interface communication, such as a speaker, microphone, keypad, keyboard, display, or touchscreen.

[0251] Furthermore, ED 1910 includes at least one memory 1908. Memory 1908 stores instructions and data used, generated, or collected by ED 1910. For example, memory 1908 may store software or firmware instructions executed by one or more processing units 1900, as well as data for reducing or eliminating interference in incoming signals. Each memory 1908 includes any suitable one or more volatile or non-volatile storage and retrieval devices. Any suitable type of memory can be used, such as random access memory (RAM), read-only memory (ROM), hard disk, optical disk, subscriber identity module (SIM) card, memory stick, secure digital (SD) memory card, etc.

[0252] like Figure 19B As shown, base station 1970 includes: at least one processing unit 1950, at least one transceiver 1952 including transmitter and receiver functions, one or more antennas 1956, at least one memory 1958, and one or more input / output devices or interfaces 1966. A scheduler, as will be understood by those skilled in the art, is coupled to processing unit 1950. The scheduler may be included within base station 1970 or may operate separately from base station 1970. Processing unit 1950 implements various processing operations of base station 1970, such as signal encoding, data processing, power control, input / output processing, or any other functions. Processing unit 1950 may also support the methods and teachings described in detail above. Each processing unit 1950 includes any suitable processing or computing device for performing one or more operations. Each processing unit 1950 may include, for example, a microprocessor, microcontroller, digital signal processor, field-programmable gate array, or application-specific integrated circuit.

[0253] Each transceiver 1952 includes any suitable structure for generating signals for wireless or wired transmission with one or more EDs or other devices. Each transceiver 1952 also includes any suitable structure for processing signals received wirelessly or wiredly from one or more EDs or other devices. Although shown as a transceiver 1952, the transmitter and receiver may be separate components. Each antenna 1956 includes any suitable structure for transmitting or receiving wireless or wired signals 1990. Although a shared antenna 1956 coupled to a transceiver 1952 is shown herein, one or more antennas 1956 may be coupled to one or more transceivers 1952, such that separate antennas 1956 are coupled to the transmitter and receiver when the transmitter and receiver are configured as separate components. Each memory 1958 includes any suitable one or more volatile or non-volatile storage and retrieval devices. Each input / output device 1966 facilitates interaction with users or other devices in the network (network communication). Each input / output device 1966 includes any suitable structure for providing or receiving information from a user, including network interface communication.

[0254] Figure 20 This is a block diagram of a computing system 2000 that can be used to implement the devices and methods disclosed herein. For example, the computing system can be any entity of a UE, access network (AN), mobility management (MM), session management (SM), user plane gateway (UPGW), or access stratum (AS). A particular device may use all of the components shown or only a subset of these components, and the degree of integration may vary between different devices. Furthermore, the device may contain multiple instances of components, such as multiple processing units, multiple processors, multiple memories, multiple transmitters, multiple receivers, etc. The computing system 2000 includes a processing unit 2002. The processing unit includes a central processing unit (CPU) 2014, memory 2008, and may also include a mass storage device 2004, a video adapter 2010, and an I / O interface 2012 connected to a bus 2020.

[0255] Bus 2020 can be one or more of several bus architectures of any type, including a memory bus or memory controller, a peripheral bus, or a video bus. CPU 2014 can include any type of electronic data processor. Memory 2008 can include any type of non-transitory system memory, such as static random access memory (SRAM), dynamic random access memory (DRAM), synchronous DRAM (SDRAM), read-only memory (ROM), or combinations thereof. In one embodiment, memory 2008 can include ROM used at startup and DRAM used to store programs and data during program execution.

[0256] Mass storage 2004 may include any type of nontransitory storage device for storing data, programs, and other information and making such data, programs, and other information accessible via bus 2020. Mass storage 2004 may include one or more of, for example, solid-state drives, hard disk drives, disk drives, or optical disk drives.

[0257] Video adapter 2010 and I / O interface 2012 provide interfaces for coupling external input and output devices to processing unit 2002. As shown, examples of input and output devices include a monitor 2018 coupled to video adapter 2010 and a mouse, keyboard, or printer 2016 coupled to I / O interface 2012. Other devices may be coupled to processing unit 2002, and more or fewer interface cards may be used. For example, a serial interface such as Universal Serial Bus (USB) (not shown) can be used to provide interfaces for external devices.

[0258] The processing unit 2002 also includes one or more network interfaces 2006, which may include a wired link (e.g., an Ethernet cable) or a wireless link to an access node or a different network. The network interface 2006 enables the processing unit 2002 to communicate with remote units over a network. For example, the network interface 2006 may provide wireless communication via one or more transmitter / transmit antennas and one or more receiver / receive antennas. In one embodiment, the processing unit 2002 is coupled to a local area network 2022 or a wide area network to perform data processing and communication with remote devices (e.g., other processing units, the Internet, or remote storage facilities).

[0259] It should be understood that one or more steps in the methods of the embodiments provided herein can be performed by corresponding units or modules. For example, a signal can be transmitted by a transmission unit or transmission module. A signal can be received by a receiving unit or receiving module. A signal can be processed by a processing unit or processing module. Other steps can be performed by a configuration unit / module, activation unit / module, command unit / module, indication unit / module, measurement unit / module, reference signal triggering unit / module, cell activation triggering unit / module, confirmation unit / module, determination unit / module, and / or communication unit / module. The corresponding units / modules can be hardware, software, or a combination thereof. For example, one or more units / modules can be integrated circuits, such as field-programmable gate arrays (FPGAs) or application-specific integrated circuits (ASICs).

[0260] It is also conceivable that embodiments of the present invention can be implemented in various ways. For example, in some embodiments, a method is disclosed that contemplates means for transmitting a reference signal (RS) triggering transmitted on a secondary cell (SCell) to be activated for a UE; means for transmitting a temporary RS on the SCell for activating the SCell; and means for receiving a report indicating that the SCell has been activated for the UE.

[0261] The following references are relevant to the subject of this invention and are incorporated herein by reference in their entirety as if copied in full:

[0262] ●TS 38.213, V16.3.0 (September 2020).

[0263] https: / / www.3gpp.org / ftp / Specs / 2020-09 / Rel-16 / 38_series / 38213-g30.zip

[0264] ●TS 38.321, V16.2.1 (September 2020).

[0265] https: / / www.3gpp.org / ftp / Specs / 2020-09 / Rel-16 / 38_series / 38321-g21.zip

[0266] ●TS 38.133, V16.5.0 (September 2020).

[0267] https: / / www.3gpp.org / ftp / Specs / 2020-09 / Rel-16 / 38_series / 38133-g50.zip

[0268] Despite the detailed description, it should be understood that various changes, substitutions, and modifications can be made to this document without departing from the spirit and scope of the invention as defined by the appended claims. Furthermore, the scope of the invention is not intended to be limited to the specific embodiments described herein, and those skilled in the art will readily appreciate from the invention that processes, machines, articles of manufacture, compositions of matter, components, methods, or steps (including those currently existing or to be developed hereafter) can perform substantially the same functions or achieve substantially the same effects as the corresponding embodiments described herein. Therefore, the appended claims are intended to encompass such processes, machines, articles of manufacture, compositions of matter, components, methods, or steps within their scope.

Claims

1. A communication method, characterized in that, include: The user equipment (UE) receives a secondary cell SCell activation command from the gNB, the secondary cell activation command instructing the UE to activate the SCell to communicate between the UE and the gNB on the SCell; The UE receives a reference signal RS on the SCell from the gNB, the RS including channel state information reference signal CSI-RS; When the UE receives the SCell activation command, it performs SCell activation to activate the SCell; as well as The UE sends a valid CSI report of the SCell to the gNB, and the valid CSI report indicates that the UE has activated the SCell.

2. The method according to claim 1, characterized in that, The SCell activation command is received in the Media Access Control (MAC) CE on the active cell serving the UE.

3. The method according to claim 2, characterized in that, The transmission of the RS is triggered by a trigger field sent on the active cell, and the trigger field is included in the MAC CE.

4. The method according to claim 3, characterized in that, The RS is indicated by the trigger command.

5. The method according to claim 1, characterized in that, The RS is a non-periodic RS and is triggered / transmitted during the activation of the SCell, and the time slot in which the RS is transmitted is determined based on the time slot in which the SCell activation command is transmitted and the time slot offset value sent to the UE by signal.

6. The method according to claim 1, characterized in that, Also includes: The UE performs at least one of AGC establishment, frequency tracking, or time tracking based on the RS.

7. The method according to any one of claims 1 to 6, characterized in that, The RS includes at least a CSI-RS or a tracking reference signal (TRS) for the SCell.

8. The method according to claim 1, characterized in that, The transmission of the RS includes one or more transmissions of the TRS in one or more time slots.

9. The method according to any one of claims 1 to 8, characterized in that, The method further includes: After receiving the RS, the UE receives the Channel State Information-Reference Signal (CSI-RS) for the SCell.

10. The method according to claim 9, characterized in that, The CSI-RS and the RS are quasi-co-located (QCL).

11. The method according to any one of claims 1 to 7, characterized in that, The report includes a CSI report based on the CSI-RS measurement, and the CSI report includes a valid channel quality indicator (CQI) indicating that the SCell is activated.

12. The method according to any one of claims 1 to 7, characterized in that, The method further includes: The UE sends a message to the gNB confirming receipt of the SCell activation command.

13. The method according to any one of claims 1 to 7, characterized in that, The method further includes: The UE activates the bandwidth portion (BWP) of the SCell associated with the RS.

14. The method according to any one of claims 1 to 7, characterized in that, The report indicates that the BWP of the SCell associated with the RS is active.

15. A communication method, characterized in that, include: The gNB sends a secondary cell SCell activation command to the user equipment (UE), the secondary cell activation command instructing the UE to activate the SCell to communicate between the UE and the gNB on the SCell; The gNB sets the reference signal RS, which includes the channel state information reference signal CSI-RS; The gNB sends the RS to the UE; as well as In response to sending the SCell activation command and the RS, the gNB receives a valid CSI report for the SCell from the UE that has performed SCell activation, the valid CSI report indicating that the UE has activated the SCell.

16. A communication device, characterized in that, include: Includes non-transitory memory for instructions; as well as One or more processors communicating with the memory, wherein the instructions, when executed by the one or more processors, cause the device to perform the method of any one of claims 1 to 15.

17. A non-transitory computer-readable medium for storing computer instructions, characterized in that, The computer instructions, when executed by one or more processors of the device, cause the device to perform the method of any one of claims 1 to 15.

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