Wireless communication method and apparatus

Abstract

Provided are a wireless communication method and apparatus. The method comprises: a terminal device receiving a reference signal sent by a first cell, wherein the sending of the reference signal is triggered by the terminal device and / or a primary cell.

Description

Wireless communication method and device Technical Field

[0001] The present application relates to the field of communication technology, and more specifically, to a wireless communication method and apparatus. Background Art

[0002] Currently, a cell can periodically send a reference signal, and a terminal device can communicate with the cell by receiving the reference signal. However, periodically sending a reference signal is not conducive to saving power.

[0003] Summary of the Invention

[0004] The present application provides a wireless communication method and apparatus. The following introduces various aspects of the present application.

[0005] In a first aspect, a wireless communication method is provided, comprising: a terminal device receiving a reference signal sent by a first cell, wherein the sending of the reference signal is triggered by the terminal device and / or a primary cell.

[0006] In a second aspect, a terminal device is provided, comprising: a receiving unit, configured to receive a reference signal sent by a first cell, wherein the sending of the reference signal is triggered by the terminal device and / or a primary cell.

[0007] In a third aspect, a terminal device is provided, comprising a processor, a memory, and a communication interface, wherein the memory is used to store one or more computer programs, and the processor is used to call the computer program in the memory so that the terminal device executes some or all of the steps in the method of the first aspect.

[0008] In a fourth aspect, an embodiment of the present application provides a computer-readable storage medium, which stores a computer program, and the computer program enables a communication device (for example, a terminal device) to execute some or all of the steps in the method of the first aspect above.

[0009] In a fifth aspect, embodiments of the present application provide a computer program product, wherein the computer program product includes a non-transitory computer-readable storage medium storing a computer program, wherein the computer program is operable to cause a communication device (e.g., a terminal device) to perform some or all of the steps of the method of the first aspect described above. In some implementations, the computer program product can be a software installation package.

[0010] In a sixth aspect, an embodiment of the present application provides a chip comprising a memory and a processor, wherein the processor can call and run a computer program from the memory to implement some or all of the steps described in the method of the first aspect above.

[0011] In the present application, the terminal device and / or the main cell triggers the first cell to send a reference signal, so that the first cell can send a reference signal after being triggered. Compared with the method of periodically sending a reference signal, the solution of the embodiment of the present application can save power. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] FIG1 is a wireless communication system 100 used in an embodiment of the present application.

[0013] FIG2 is a schematic diagram of an SSB burst set provided in an embodiment of the present application.

[0014] FIG3 shows a structure of an SSB.

[0015] FIG4 is a schematic flowchart of a primary cell selecting a secondary cell.

[0016] FIG5 is a schematic flowchart of a wireless communication method provided in an embodiment of the present application.

[0017] FIG6 is a schematic flowchart of indicating a first resource provided in an embodiment of the present application.

[0018] FIG7 is a schematic diagram of time domain resources for transmitting a reference signal provided in an embodiment of the present application.

[0019] FIG8 is a schematic diagram of another time domain resource for transmitting a reference signal provided in an embodiment of the present application.

[0020] FIG9 is a schematic flowchart of instructing a first cell to stop sending a reference signal according to an embodiment of the present application.

[0021] FIG10 is a schematic diagram of an indication frequency provided by an embodiment of the present application.

[0022] FIG11 is a schematic diagram of another frequency indication provided by an embodiment of the present application.

[0023] FIG12 is a schematic flowchart of a method for obtaining TA provided in an embodiment of the present application.

[0024] Figure 13 is a schematic flowchart of triggering the sending of a reference signal by a terminal device provided in an embodiment of the present application.

[0025] FIG14 is a schematic block diagram of a terminal device provided in an embodiment of the present application.

[0026] FIG15 is a schematic structural diagram of a communication device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0027] The technical solution in this application will be described below with reference to the accompanying drawings.

[0028] Figure 1 illustrates a wireless communication system 100 used in an embodiment of the present application. The wireless communication system 100 may include a network device 110 and a terminal device 120. The network device 110 may be a device that communicates with the terminal device 120. The network device 110 may provide communication coverage for a specific geographic area and may communicate with the terminal device 120 within the coverage area.

[0029] FIG1 exemplarily shows a network device and two terminals. Optionally, the wireless communication system 100 may include multiple network devices and each network device may include other numbers of terminal devices within its coverage area, which is not limited in the embodiments of the present application.

[0030] Optionally, the wireless communication system 100 may further include other network entities such as a network controller and a mobility management entity, which is not limited in the embodiment of the present application.

[0031] It should be understood that the technical solutions of the embodiments of the present application can be applied to various communication systems, such as: fifth generation (5G) system or new radio (NR), long term evolution (LTE) system, LTE frequency division duplex (FDD) system, LTE time division duplex (TDD), etc. The technical solutions provided in this application can also be applied to future communication systems, such as the sixth generation mobile communication system, satellite communication system, etc.

[0032] The terminal device in the embodiments of the present application may also be referred to as user equipment (UE), access terminal, user unit, user station, mobile station, mobile station (MS), mobile terminal (MT), remote station, remote terminal, mobile device, user terminal, terminal, wireless communication device, user agent or user device. The terminal device in the embodiments of the present application may refer to a device that provides voice and / or data connectivity to a user and can be used to connect people, objects and machines, such as a handheld device with wireless connection function, a vehicle-mounted device, etc. The terminal device in the embodiments of the present application can be a mobile phone, a tablet computer, a laptop computer, a PDA, a mobile internet device (MID), a wearable device, a virtual reality (VR) device, an augmented reality (AR) device, a wireless terminal in industrial control, a wireless terminal in self-driving, a wireless terminal in remote medical surgery, a wireless terminal in a smart grid, a wireless terminal in transportation safety, a wireless terminal in a smart city, a wireless terminal in a smart home, etc. Optionally, the UE can be used to act as a base station. For example, the UE can act as a scheduling entity that provides sidelink signals between UEs in V2X or D2D, etc. For example, a cellular phone and a car communicate with each other using sidelink signals. The cellular phone and smart home devices communicate without relaying the communication signal through the base station.

[0033] The network device in the embodiments of the present application may be a device for communicating with a terminal device, and may also be referred to as an access network device or a radio access network device. For example, the network device may be a base station. The network device in the embodiments of the present application may refer to a radio access network (RAN) node (or device) that connects a terminal device to a wireless network. A base station can broadly cover various names as follows, or be replaced with the following names, such as: NodeB, evolved NodeB (eNB), next generation NodeB (gNB), relay station, access point, transmission point (TRP), transmission point (TP), master station MeNB, secondary station SeNB, multi-standard radio (MSR) node, home base station, network controller, access node, wireless node, access point (AP), transmission node, transceiver node, baseband unit (BBU), remote radio unit (RRU), active antenna unit (AAU), remote radio head (RRH), central unit (CU), distributed unit (DU), positioning node, etc. A base station can be a macro base station, a micro base station, a relay node, a donor node or the like, or a combination thereof. A base station can also refer to a communication module, modem or chip used to be set in the aforementioned device or apparatus. The base station can also be a mobile switching center and a device that performs base station functions in device-to-device D2D, vehicle-to-everything (V2X), and machine-to-machine (M2M) communications, a network-side device in a 6G network, or a device that performs base station functions in future communication systems. The base station can support networks with the same or different access technologies. The embodiments of this application do not limit the specific technology and specific device form used by the network equipment.

[0034] Base stations can be fixed or mobile. For example, a helicopter or drone can be configured to act as a mobile base station, and one or more cells can move based on the location of the mobile base station. In other examples, a helicopter or drone can be configured to act as a device that communicates with another base station.

[0035] In some deployments, the network device in the embodiments of the present application may refer to a CU or a DU, or the network device may include a CU and a DU. The gNB may also include an AAU.

[0036] The network equipment and terminal devices can be deployed on land, including indoors or outdoors, handheld or vehicle-mounted; they can also be deployed on water; they can also be deployed in the air on aircraft, balloons, and satellites. The embodiments of this application do not limit the scenarios in which the network equipment and terminal devices are located.

[0037] It should be understood that all or part of the functions of the communication device in this application can also be implemented through software functions running on hardware, or through virtualization functions instantiated on a platform (such as a cloud platform).

[0038] Multi-beam systems in NR systems

[0039] Communication systems (e.g., NR) are designed to provide wide-bandwidth communications in high-frequency bands (e.g., bands above 6 GHz). As the operating frequency increases, path loss during transmission increases, impacting the coverage capabilities of high-frequency systems. Therefore, to effectively ensure high-frequency coverage, an effective technical solution is to use massive multiple-in-multiple-out (MIMO) antenna arrays (MMIMO). This creates shaped beams with greater gain, overcomes propagation loss, and ensures the coverage of the communication system.

[0040] In some communication systems (such as 2G, 3G, or 4G systems), a cell (or sector) uses a wide beam to cover the entire cell. Therefore, at every moment, terminal devices within the cell coverage area have the opportunity to obtain resources allocated by the system.

[0041] Some communication systems (such as NR or 5G systems) can cover the entire cell through different beams. That is, each beam covers a smaller range, and the effect of multiple beams covering the entire cell is achieved by temporal sweeping.

[0042] Different beams can be identified by the differences in the signals carried on the beams. For example, the synchronization signal and physical broadcast channel block (SS block, also called SS / PBCH block or SSB) transmitted on different beams are different, and the terminal device can identify different beams through different SS blocks. For another example, the channel state information reference signal (CSI-RS) transmitted on different beams is different, and the terminal device can identify different beams through CSI-RS and / or CSI-RS resources.

[0043] For different communication systems, downlink signals or downlink channels (such as physical downlink control channel (PDCCH), physical downlink shared channel (PDSCH)) can be transmitted through different downlink beams. For example, for communication systems below 6G, terminal devices generally do not have analog beams, so the terminal devices can use omnidirectional antennas (or nearly omnidirectional antennas) to receive downlink signals sent by network devices. The network device can send downlink signals to the terminal device through different downlink transmit beams. For another example, for a millimeter wave system, the terminal device may have an analog beam, and the terminal device can receive signals using a downlink receive beam corresponding to the downlink transmit beam. In this case, the terminal device can determine the transmit beam-related information on the network device side or the receive beam-related information corresponding to the terminal device side based on the beam indication information.

[0044] In some embodiments, the beam indication information may not directly indicate the beam itself, but rather through quasi co-location (QCL) information (or QCL assumption) between signals. The terminal device can determine the corresponding received signal or channel based on the QCL information, where the QCL information can be indicated by the TCI state. QCL information and TCI state are described in detail below.

[0045] Generally, the beam used by the transmitting end to transmit signals is called a "transmitting beam", and the beam used by the receiving end to receive signals is called a "receiving beam".

[0046] In some cases, the transmit beam may also be referred to as a spatial domain transmission filter, and accordingly, the receive beam may also be referred to as a spatial domain reception filter. In other cases, the transmit beam may also be referred to as a spatial domain transmission parameter, and accordingly, the receive beam may also be referred to as a spatial domain reception parameter. For ease of understanding, the embodiments of the present application are mainly described using beams as an example.

[0047] In some communication systems (such as 5G systems), network equipment can periodically transmit reference signals, and terminal devices can communicate with the cell by receiving the reference signals. In some embodiments, the terminal device can measure the reference signals and communicate with the cell based on the signal measurement results. In other embodiments, the terminal device can receive the reference signals to achieve downlink synchronization.

[0048] The following describes the solution involved in the embodiment of the present application using a reference signal including SSB.

[0049] Network devices can periodically send SSBs, and terminal devices can receive SSBs to synchronize downlink with the cell. In addition, terminal devices can read the master information block (MIB) to access the network.

[0050] Figure 2 illustrates the transmission resources for SSBs. (a) in Figure 2 illustrates the transmission beams for SSBs. A network device can transmit SSBs to a terminal device using different beams. Correspondingly, a terminal device can receive SSBs using different beams. (b) in Figure 2 illustrates the transmission times for SSBs. A network device can transmit SSBs to a terminal device at different times. One SSB cycle can be used to transmit one SSB burst set. An SSB burst set contains SSBs corresponding to multiple beams.

[0051] Figure 3 shows the structure of an SSB. The SSB may include a primary synchronization signal (PSS), a secondary synchronization signal (SSS), and a physical broadcast channel (PBCH). The SSB may occupy 4 symbols in the time domain and 240 subcarriers (i.e., 20 resource blocks (RBs)) in the frequency domain, numbered 0 to 239. The PSS is located in the middle 127 subcarriers of symbol 0. The SSS is located in the middle 127 subcarriers of symbol 2. In order to protect the PSS and SSS, different subcarriers are set at 0 at both ends of them. The PBCH is located in symbols 1, 2, and 3, where the PBCH occupies all subcarriers from 1 to 239 in symbols 1 and 3, and occupies all subcarriers except the subcarriers occupied by the SSS and the subcarriers protecting the SSS in symbol 2.

[0052] An SSB burst takes up 5 ms in the time domain. The number of SSBs contained in an SSB burst depends on the cell frequency. When the cell frequency is below 3 GHz, an SSB burst contains 4 SSBs. When the cell frequency is between 3 GHz and 6 GHz, an SSB burst contains 8 SSBs (as shown in Figure 2). When the cell frequency is above 6 GHz, an SSB burst contains 64 SSBs.

[0053] The terminal device can obtain the SSB sequence number (or SSB index), that is, the order in which the current SSB is located in the SSB burst set, through the demodulation reference signal (DM-RS) in the PBCH and the information in the MIB, so as to know the starting time of the 5ms (i.e., half-frame) where the current SSB burst set is located. The terminal device can determine whether the time domain position of the current SSB is the first half-frame or the second half-frame through the half-frame indication in the MIB. In addition, the terminal device can obtain the current system frame number based on the SFN indication in the MIB, thereby achieving downlink synchronization.

[0054] A terminal device can access the network by accessing a cell. The first cell accessed by a terminal device is called a primary cell (PCell). When the amount of data a terminal device has is large, the terminal device can transmit data through carrier aggregation (CA). The network device can configure or activate one or more secondary cells (SCells) for the terminal device, and the terminal device can transmit data through one or more of the primary and secondary cells.

[0055] It should be noted that the roles of primary cell and secondary cell are for terminal devices. Taking cell 1 and cell 2 as an example, for terminal device A, the primary cell is cell 1 and the secondary cell is cell 2. However, for terminal device B, the primary cell can be cell 2 and the secondary cell can be cell 1.

[0056] Each cell can independently send a reference signal (such as SSB) for terminal devices to perform initial access.

[0057] If a terminal device needs to send data through multiple cells, the primary cell can select a secondary cell for the terminal device, allowing the terminal device to transmit data through the primary and secondary cells. However, with the introduction of the network energy saving (NES) feature, some cells will reduce or not transmit reference signals to save power. In this case, the primary cell can autonomously determine the secondary cell and configure or activate the secondary cell for the terminal device, as shown in Figure 4.

[0058] 4 , in step S410 , the primary cell indicates the secondary cell to the terminal device.

[0059] The primary cell indicates the secondary cell to the terminal device, which may include the primary cell configuring the secondary cell for the terminal device or the primary cell activating the secondary cell.

[0060] When configuring or activating a secondary cell, the primary cell may select a cell that is co-sited with the primary cell and / or a cell that belongs to the same timing advance group (TAG) as the primary cell as the secondary cell.

[0061] In step S420, the primary cell allocates uplink resources to the terminal device. The uplink resources are uplink resources of the secondary cell, or in other words, the uplink resources are used by the terminal device to send uplink data to the secondary cell.

[0062] In step S430, the terminal device sends uplink data to the secondary cell through uplink resources.

[0063] The secondary cell may be one that does not transmit a reference signal. In this case, the terminal device cannot obtain the timing advance (TA) by measuring the reference signal transmitted by the secondary cell. When transmitting data, the terminal device may assume that the downlink subframe boundary of the secondary cell is aligned with the downlink subframe boundary of the primary cell, and infer the uplink transmission time of the secondary cell based on the downlink subframe boundary of the primary cell.

[0064] In addition, the terminal device may also determine the uplink transmission power on the secondary cell according to the signal measurement result (such as path loss) measured on the primary cell.

[0065] If, according to the solution shown in Figure 4, the primary cell directly configures or activates a secondary cell for a terminal device, the configured or activated secondary cell may not be suitable for the terminal device. For example, the radio signal strength of the secondary cell configured or activated by the primary cell for the terminal device may be low, resulting in poor data transmission performance between the terminal device and the secondary cell.

[0066] To address the above issues, a terminal device can measure the reference signals transmitted by one or more cells to obtain signal measurement results. Based on the signal measurement results, the primary cell can configure or activate a secondary cell for the terminal device. For example, the primary cell can select a cell with a good signal measurement result and configure that cell as the secondary cell for the terminal device. For another example, the primary cell can configure multiple candidate secondary cells for the terminal device and then activate one or more of the multiple candidate secondary cells based on the signal measurement results.

[0067] However, as mentioned above, in order to save power, some cells may not send reference signals. In this case, there is currently no clear regulation on how these cells send reference signals.

[0068] The above example only uses the selection of a secondary cell as an example. In other scenarios, other cells (other than the primary cell) may also be required to send reference signals. For example, in a multi-beam scenario, when selecting a beam, the terminal device needs to measure the reference signal sent by the cell to select the appropriate beam for communication with the cell.

[0069] In response to the above problem, an embodiment of the present application proposes that the terminal device and / or the main cell can trigger the first cell to send a reference signal, thereby proposing a clear solution for the first cell to send a reference signal, so that the first cell can send a reference signal only when it is needed, thereby saving power.

[0070] In conjunction with 5 below, the wireless communication method provided in the embodiment of the present application is described in detail.

[0071] Referring to Figure 5, in step S510, the terminal device receives a reference signal sent by the first cell. The sending of the reference signal can be triggered by the terminal device and / or the primary cell. In some embodiments, the sending of the reference signal can be triggered by the terminal device. The terminal device can send a trigger message to the first cell to trigger the first cell to send the reference signal. After receiving the trigger message, the first cell sends the reference signal. In other embodiments, the sending of the reference signal can be triggered by the primary cell. The primary cell can send a trigger message to the first cell to trigger the first cell to send the reference signal. After receiving the trigger message, the first cell sends the reference signal.

[0072] The primary cell may be a serving cell of a terminal device, and the primary cell may be a cell that the terminal device accesses for the first time after accessing the network. The first cell may be any cell other than the primary cell. For example, the primary cell and the first cell may share a station, and communication between the primary cell and the first cell may be performed inside the base station. For another example, the primary cell and the first cell may not share a station, and information exchange between the primary cell and the first cell is performed between base stations. In some embodiments, the first cell and the primary cell may belong to the same TAG or different TAGs, and the embodiments of the present application do not specifically limit this.

[0073] The embodiment of the present application does not specifically limit the type of reference signal. For example, the reference signal may include one or more of the following: SSB, CSI-RS, tracking reference signal (TRS), etc.

[0074] In some embodiments, the first cell may send a reference signal on a first resource, or in other words, the resource for sending the reference signal is the first resource. The first resource may include one or more of the following: a time domain resource, a frequency domain resource, and a beam.

[0075] The embodiments of the present application do not specifically limit the method for determining the first resource. As an example, the first resource may be autonomously determined by the first cell. As another example, the first resource may be a preconfigured resource, which may be, for example, a resource specified in a protocol. As yet another example, the first resource may be determined based on the first indication information. In some implementations, the first indication information may also be referred to as the first configuration information. The following describes a method for determining the first resource based on the first indication information.

[0076] In some implementations, the first cell may determine the first resource based on the first indication information. The first indication information may be sent by a terminal device to the first cell, as in step S502 in Figure 6 , or the first indication information may be sent by a primary cell to the first cell, as in step S504 in Figure 6 . By sending the first indication information to the first cell to indicate the first resource, the first cell can accurately determine the resource for sending a reference signal and send the reference signal on the corresponding first resource, thereby avoiding blindly sending the reference signal by the first cell, thereby achieving power conservation.

[0077] Taking the example of the first resource including a time domain resource, the time domain resource may be determined based on one or more of the following: a reference signal transmission period, a start time for transmitting the reference signal, an end time for transmitting the reference signal, a time unit in which the reference signal is located, a position of the reference signal in the time unit, the number of times the reference signal is transmitted, and a duration for transmitting the reference signal. The above information may be specified in the protocol or indicated by the first indication information.

[0078] The reference signal may be sent periodically or aperiodically, which is not specifically limited in the embodiments of the present application. For a reference signal sent periodically, the first indication information may include the transmission period of the reference signal.

[0079] The starting time of transmitting the reference signal may refer to the time when the reference signal is first transmitted. There are various ways to express the starting time, which are not specifically limited in the embodiments of the present application. As an example, the starting time may be an absolute time. As another example, the starting time may also be expressed in time units. For example, the starting time may be expressed by a frame number. In another example, the starting time may be expressed by a subframe number. In another example, the starting time may be expressed by a frame number + a subframe number.

[0080] The end time of transmitting the reference signal may refer to the time of the last reference signal transmission. There are various ways to express the end time, which are not specifically limited in the embodiments of the present application. As an example, the end time may be an absolute time. As another example, the end time may also be expressed in time units. For example, the end time may be expressed by a frame number. In another example, the end time may be expressed by a subframe number. In another example, the end time may be expressed by a frame number + a subframe number.

[0081] The time unit may include one or more of the following: system frame (or radio frame), half frame, subframe, time slot, symbol, etc. Taking the time unit as a radio frame as an example, the time unit where the reference signal is located may refer to the radio frame (or system frame number) where the reference signal is located. The time unit where the reference signal is located may be directly indicated by the first indication information, or the time unit where the reference signal is located may be determined based on other information. For example, the time unit where the reference signal is located may be determined based on the starting time of the reference signal and the period of the reference signal. For another example, the time unit where the reference signal is located may be determined based on the period of the reference signal and the first rule. For another example, the time unit where the reference signal is located may be determined by a bit map. The first indication information may include a bit map, which may indicate whether a reference signal needs to be sent on each time unit.

[0082] The position of the reference signal in the time unit may refer to which half-frame of the system frame the reference signal is located in, for example, whether the reference signal is located in the first half-frame or the second half-frame of the radio frame.

[0083] In some embodiments, the time domain resources can be determined based on the reference signal transmission period, the starting time of transmitting the reference signal, and the position of the reference signal in the time unit. Based on the above information, the first cell can determine the time domain resources for transmitting the reference signal. Taking the time unit as a radio frame as an example, assuming that the reference signal transmission period is 80ms, the system frame number SFN=360 for transmitting the reference signal for the first time, and the reference signal is transmitted in the first half frame of the system frame, then the time domain resources for transmitting the reference signal for the first time in the first cell are the first half frame of SFN=360, the time domain resources for transmitting the reference signal for the second time are the first half frame of SFN=368, the time domain resources for transmitting the reference signal for the third time are the first half frame of SFN=376, and so on, as shown in Figure 7.

[0084] In some embodiments, the time domain resources can be determined based on the transmission period of the reference signal and the position of the reference signal in the time unit. Based on the above information, the first cell can determine the time domain resources for sending the reference signal. If the first indication information does not indicate the starting time of sending the reference signal or the protocol does not specify the starting time of sending the reference signal, the first cell can determine the starting time of sending the reference signal based on a preset rule. Taking the time unit as a radio frame as an example, assuming that the transmission period of the reference signal is 80ms and the reference signal is sent in the first half frame of the system frame, the first cell can determine that the reference signal is sent when the system frame with SFN mod SSB period = 0. The first cell can use the system frame with the most recent SFN mod SSB period = 0 as the starting frame. For example, based on the above information, the first cell can determine that when SFN = 0, 8, 16, 24..., the reference signal needs to be sent in the first half frame. Assuming that the current SFN = 356, the next most recent reference signal transmission opportunity is the first half frame of SFN = 364.

[0085] In some embodiments, the reference signal may not be sent periodically. In this case, the time unit where the reference signal is located can be determined by a bit map. In some implementations, the time domain resource can be determined based on the starting time of sending the reference signal, the time unit where the reference signal is located, and the position of the reference signal in the time unit. The first indication information includes a bit map, and the time unit where the reference signal is located can be determined based on the starting time unit of sending the reference signal and the bit map. Taking the time unit as an example of a radio frame, assuming that the starting system frame number SFN for sending the reference signal is SFN=360, the reference signal is sent in the first half frame of the system frame, and the bit map is 11010110, then the first cell can send the reference signal in the first half frame of the system frames of SFN=360, 361, 363, 365, and 366. In some implementations, the bit map can also be cyclic. For example, the first cell can also send the reference signal in the first half frame of the system frames of SFN=368, 369, 371, 373, and 374.

[0086] The above is an example of the first half frame, and the embodiments of the present application are not limited to this. As an example, the first indication information may also indicate that the position of the reference signal in the system frame is sent in the second half frame. As another example, the first indication information may also indicate that the reference signal is sent in the first half frame of some system frames and in the second half frame of some system frames. As another example, the first indication information may also indicate that the reference signal is sent in both the first half frame of the system frame and the second half frame of the system frame. In this way, for the scenario where the reference signal is sent to obtain the signal measurement result, the reference signal is sent intensively, so that the terminal device can obtain the signal measurement result as soon as possible. The above is explained by taking the example of the first indication information indicating the position of the reference signal in the system frame. It can be understood that the position of the reference signal in the system frame can also be specified in the protocol.

[0087] In some implementations, the time domain resources may include a first time period during which the first cell transmits a reference signal. In some implementations, the time domain resources may be determined based on a starting time instant for transmitting the reference signal. The starting time instant for transmitting the reference signal may, for example, include a starting time unit within which the reference signal is transmitted. The first cell may transmit the reference signal throughout the entire time period after the starting time instant. For example, the first cell may transmit the reference signal in all half-frames starting from SFN=360, as shown in FIG8 .

[0088] In some implementations, the first indication information may not indicate the end time of sending the reference signal, or the end time of sending the reference signal is not specified in the protocol. Taking the first indication information as an example, the first indication information may instruct the first cell to send the reference signal starting from the first moment, without indicating the end time of sending the reference signal. In this case, the primary cell may instruct the first cell to stop sending the reference signal through other messages. For example, the primary cell may send indication information to the first cell, and the indication information is used to instruct the first cell to stop sending the reference signal, see step S530 in Figure 9. After receiving the indication information, the first cell stops sending the reference signal. For another example, the primary cell may send indication information to the first cell, and the indication information is used to indicate the end time of sending the reference signal. After receiving the indication information, the first cell stops sending the reference signal after the end time arrives.

[0089] Of course, in some embodiments, the terminal device may also instruct the first cell to stop transmitting reference signals. For example, the terminal device may send indication information to the first cell, where the indication information is used to instruct the first cell to stop transmitting reference signals. For another example, the terminal device may send indication information to the first cell, where the indication information is used to indicate the end time of transmitting reference signals. After receiving the indication information, the first cell stops transmitting reference signals after the end time arrives.

[0090] There are various ways to express the end time, which are not specifically limited in the embodiments of the present application. As an example, the end time can be an absolute time. As another example, the end time can also be expressed in time units. For example, the end time can be expressed by a frame number. For another example, the end time can be expressed by a subframe number. For another example, the end time can be expressed by a frame number + a subframe number.

[0091] In some implementations, the first resource may include a frequency domain resource. The first cell may send a reference signal on the frequency domain resource. In some embodiments, the frequency domain resource may be determined based on an absolute frequency value for sending the reference signal or a reference frequency point for sending the reference signal.

[0092] For example, if the first indication information indicates an absolute frequency value for sending a reference signal, the first cell may determine the frequency domain resource based on the absolute frequency value. The absolute frequency value may be, for example, 786 MHz. Indicating the frequency domain resource by indicating the absolute frequency value is relatively simple in implementation.

[0093] For another example, if the first indication information indicates a reference frequency for sending a reference signal, the first cell may determine the frequency domain resources based on the reference frequency. By indicating the reference frequency to indicate the frequency domain resources, the signaling overhead may be reduced. The reference frequency may be a frequency corresponding to the first cell (i.e., the frequency actually exists on the primary cell), or it may not be a frequency corresponding to the first cell (i.e., the frequency does not actually exist on the primary cell). This embodiment of the present application does not specifically limit this. An example is given below with reference to FIG10.

[0094] 10 , the primary cell occupies 100 physical resource blocks (PRBs), and the corresponding PRBs are numbered from 1 to 100. The first indication information may instruct the first cell to send a reference signal at PRB=150, or the first indication information may instruct the first cell to send a reference signal at PRB=50.

[0095] In some implementations, the reference frequency may be the starting frequency of the reference signal, or may be the center frequency of the reference signal, or may be the ending frequency of the reference signal. Taking Figure 11 as an example, Figure 11 illustrates an example where the reference signal is an SSB. The reference frequency indicated by the first indication information may be the starting frequency of the SSB or the center frequency of the SSB.

[0096] If the reference frequency is the starting frequency of the reference signal, the first cell may determine the ending frequency based on the sum of the starting frequency and the first offset value. If the reference frequency is the center frequency of the reference signal, the first cell may determine the starting frequency based on the difference between the center frequency and the second offset value, and determine the ending frequency based on the sum of the center frequency and the second offset value.

[0097] In some implementations, the first cell may send a response message to the terminal device or the primary cell after receiving the first indication information. Taking the primary cell sending the first indication letter to the first cell as an example, after the first cell receives the first indication information sent by the primary cell, it may send a response message to the primary cell. In some embodiments, the response message may include confirmation information. For example, if the first cell agrees to use the resources indicated in the first indication information to send a reference signal, the response message may include confirmation information. In some embodiments, if the first cell does not agree to use the resources indicated in the first indication information to send a reference signal, but uses other resources to send a reference signal, the first cell may indicate the updated resources to the primary cell through a response message. If the first cell updates the reference signal sending resources, the actual sending resources shall be based on the updated resources.

[0098] Of course, in some embodiments, after receiving the first indication information, the first cell may not send a response message. If the first cell does not send a response message, the primary cell may default that the first cell uses the first resource indicated by the first indication information to send a reference signal.

[0099] In some implementations, if the transmission of the reference signal is triggered by a primary cell, the primary cell may further send second indication information to the terminal device, where the second indication information is used to indicate the second resource, as shown in step S508 of Figure 12. The second resource is used to receive the reference signal sent by the first cell. In other words, the terminal device can use the second resource to receive the reference signal sent by the first cell.

[0100] In some implementations, the second resource may include time domain resources and / or frequency domain resources. If the second resource includes a time domain resource, the second indication information may be used to indicate one or more of the following: a reference signal transmission period, a start time for transmitting the reference signal, an end time for transmitting the reference signal, a time unit in which the reference signal is located, a position of the reference signal within the time unit, the number of times the reference signal is transmitted, and a duration for transmitting the reference signal. In some implementations, the second indication information may indicate the above information in the same manner as the first indication information, and for the sake of brevity, this is not further described here.

[0101] It can be understood that, for the terminal device, the sending period of the above-mentioned reference signal can be understood as the receiving period of the reference signal, the starting time of sending the reference signal can be understood as the starting time of receiving the reference signal, the end time of sending the reference signal can be understood as the end time of receiving the reference signal, and the number of times the reference signal is sent can be understood as the number of times the reference signal is received.

[0102] In some embodiments, the second resource may be the same as the first resource, or the second resource may be different from the first resource. For example, the second resource may be a subset of the first resource. For example, if the primary cell instructs the first cell to start sending reference signals from SFN=360, and when the primary cell sends the second indication information to the terminal device, the SFN has already exceeded SFN=360, then the primary cell may notify the terminal device to immediately receive (or measure) the reference signal without instructing the terminal device to start receiving the reference signal from SFN=360.

[0103] In some implementations, the primary cell may not indicate the second resource to the terminal device. If the primary cell does not send the second indication information to the terminal device, or in other words, the primary cell does not indicate the second resource to the terminal device, the terminal device may receive the reference signal sent by the first cell according to the default rule. The default rule may, for example, include a cell search rule during initial access. The default rule may, for example, include a period of 20ms, and the terminal device may receive and measure the reference signal sent by the first cell every 20ms.

[0104] The embodiment of the present application does not specifically limit the carrying method of the second indication information. For example, the second indication information can be carried in a radio resource control (RRC) message, that is, the primary cell can send the second indication information to the terminal device through the RRC message. For another example, the second indication information can be carried in a media access control control element (MAC CE), that is, the primary cell can send the second indication information to the terminal device through the MAC CE.

[0105] In some implementations, the primary cell may send third indication information to the terminal device, where the third indication information is used to instruct the terminal device to measure the reference signal sent by the first cell. After receiving the third indication information, the terminal device may receive the reference signal sent by the first cell and measure the reference signal.

[0106] The embodiments of the present application do not specifically limit the manner in which the third indication information is carried. For example, the third indication information may be carried in an RRC message, that is, the primary cell may send the third indication information to the terminal device via an RRC message. For another example, the third indication information may be carried in a MAC CE, that is, the primary cell may send the third indication information to the terminal device via a MAC CE.

[0107] In some implementations, the primary cell may instruct the terminal device to measure the reference signal of one cell through an indication message, or may instruct the terminal device to measure the reference signals of multiple cells through an indication message. In some implementations, the primary cell may indicate the reference signal measurement rules of multiple cells to the terminal device through an RRC message, and then instruct the terminal device to measure the reference signals of one or more cells through a MAC CE. The measurement rules may include resources for measuring reference signals. In some implementations, the primary cell may instruct the terminal device not only to measure the reference signal sent by the first cell through the third indication message, but may also instruct the terminal device to measure the reference signals sent by other cells (such as the second cell). In some implementations, the primary cell may not only indicate the resources for sending reference signals by the first cell through the second indication message, but may also indicate the resources for sending reference signals by other cells (such as the second cell).

[0108] In some implementations, the second indication information and the third indication information are the same indication information, that is, the primary cell can instruct the terminal device to measure the reference signal of the first cell and instruct the terminal device to receive the second resource of the reference signal through one indication information.

[0109] In some implementations, if the RF system of a terminal device supports simultaneous measurement of multiple cells, the terminal device may measure the reference signals transmitted by multiple cells simultaneously, or may measure the reference signals transmitted by multiple cells separately in different time periods. Whether the terminal device measures the reference signals transmitted by multiple cells simultaneously may be indicated by the primary cell or determined autonomously by the terminal device. If the RF system of the terminal device does not support simultaneous measurement of multiple cells, the terminal device may measure the reference signals transmitted by multiple cells separately in different time periods.

[0110] If the RF system of a terminal device does not support simultaneous measurement of reference signals transmitted by multiple cells, the primary cell can only configure the terminal device to measure reference signals transmitted by multiple cells separately in time periods. For example, if the primary cell configures the terminal device to measure reference signals transmitted by cell 1 and cell 2 separately in time periods, in this case, the terminal device can support carrier aggregation between the primary cell and cell 1, and can also support carrier aggregation between the primary cell and cell 2, but does not support carrier aggregation between the primary cell, cell 1, and cell 2.

[0111] After the terminal device measures the reference signal, it obtains a signal measurement result. The signal measurement result can also be called a measurement report. The terminal device can send (or report) the signal measurement result to the primary cell. In some embodiments, the signal measurement result can be used by the primary cell to select a secondary cell for the terminal device. As in the solution described above, when the terminal device needs to transmit data through the primary cell and the secondary cell, the primary cell can select a secondary cell for the terminal device. However, in the traditional solution, since the secondary cell does not send a measurement reference signal, the selection of the secondary cell does not take into account the signal measurement result, but is blindly selected by the primary cell, which may cause poor data transmission performance between the terminal device and the secondary cell. In the solution of the embodiment of the present application, by triggering the first cell to send a reference signal, the terminal device can report the signal measurement result for the first cell to the primary cell, and the primary cell can select a secondary cell for the terminal device based on the signal measurement result, so as to ensure the data transmission performance between the terminal device and the secondary cell. For scenarios where the primary cell needs to select a secondary cell for the terminal device based on the signal measurement result, or where the primary cell needs to determine whether the first cell needs to stop sending the reference signal based on the signal measurement result, the terminal device needs to send the signal measurement result regardless of the signal measurement result.

[0112] The signal measurement result may include one or more of the following: reference signal receiving power (L1-RSRP), reference signal receiving quality (RSRQ), and received signal strength indicator (RSSI).

[0113] The timing for transmitting the signal measurement results can be determined autonomously by the terminal device or by the primary cell. The present embodiment of the application does not specifically limit the timing for the terminal device to transmit the signal measurement results. As an example, the terminal device can transmit the signal measurement results to the primary cell after obtaining the signal measurement results. As another example, the terminal device can transmit the signal measurement results to the primary cell only if the first condition is met. The first condition is explained below.

[0114] In some implementations, the first condition may be related to the measurement duration. The measurement duration may refer to the duration for the terminal device to measure the reference signal. In some embodiments, the duration for the terminal device to measure the reference signal may also be understood as the duration for the terminal device to receive the reference signal. In some implementations, the first condition may include that the measurement duration is greater than or equal to the first duration. For example, if the measurement duration is greater than or equal to the first duration, the terminal device may send the signal measurement result to the primary cell. The first duration may be predefined in the protocol, or may be indicated to the terminal device by the primary cell, or may be determined autonomously by the terminal device. For example, the primary cell may indicate to the terminal device that the signal measurement result shall be reported after the first duration. By setting the first duration, the terminal device can report the signal measurement result in a timely manner, so that the primary cell can select a suitable secondary cell for the terminal device, thereby reducing the data transmission delay of the terminal device.

[0115] The embodiments of the present application do not specifically limit the moment when the measurement duration starts. For example, if the primary cell sends the third indication information through an RRC message, the measurement duration starts from the time the RRC message is received. For another example, if the primary cell sends the third indication information through a MAC CE, the measurement duration starts from the time the MAC CE is received. For another example, if the primary cell configures the measurement rules for multiple cells through an RRC message, and instructs the terminal device to start measuring the reference signal sent by the first cell through a MAC CE, the measurement duration starts from the time the MAC CE is received.

[0116] In some implementations, the first condition may be related to a signal measurement result. In some implementations, the first condition may include that the signal measurement result is greater than or equal to a first threshold. The first threshold may be predefined in the protocol, or may be indicated to the terminal device by the primary cell, or may be determined autonomously by the terminal device. When the signal measurement result is greater than or equal to the first threshold, the terminal device reports the signal measurement result, so that the primary cell can learn about the cell with better signal measurement results as soon as possible, thereby being able to configure or activate the secondary cell for the terminal device as soon as possible, thereby reducing the data transmission delay of the terminal device.

[0117] The above-mentioned first condition can be implemented independently or in combination, and is not specifically limited in the embodiments of the present application. For example, if the signal measurement result is greater than or equal to the first threshold, the terminal device can send the signal measurement result. For another example, if the signal measurement result is always less than the first threshold, such as after the measurement duration has reached the first duration, the signal measurement result is still less than the first threshold, the terminal device can still send the signal measurement result.

[0118] In some implementations, the primary cell may further send indication information to the first cell to instruct the first cell to stop sending reference signals. For example, if the first indication information does not indicate the time to stop sending reference signals, the primary cell may further send indication information to the first cell to instruct the first cell to stop sending reference signals. If the first indication information has already indicated the time to stop sending reference signals, the primary cell may not send indication information to the first cell to instruct the first cell to stop sending reference signals. Of course, in some embodiments, if the first indication information has already indicated the time to stop sending reference signals, the primary cell may also send indication information to the first cell to cause the first cell to stop sending reference signals in advance.

[0119] The embodiments of the present application do not specifically limit the timing at which the primary cell instructs the first cell to stop sending reference signals. For example, if the primary cell instructs multiple terminal devices to measure the reference signals sent by the first cell, the primary cell may instruct the first cell to stop sending reference signals after the multiple terminal devices have obtained signal measurement results. For another example, the primary cell may instruct the first cell to stop sending reference signals if the signal measurement duration of the terminal device is greater than or equal to a preset threshold.

[0120] In some scenarios, after the primary cell configures the first cell as a secondary cell, it may also need to trigger the first cell to send a reference signal. For example, the primary cell may not belong to the same TAG as the first cell, that is, the TA corresponding to the primary cell is different from the TA corresponding to the first cell. In this case, the first cell needs to send a reference signal to facilitate random access by the terminal device to obtain the TA. For another example, after the primary cell configures the first cell as a secondary cell, it does not activate the secondary cell. When the amount of service data of the terminal device increases, the primary cell hopes to activate the secondary cell so that the terminal device can transmit data through the secondary cell. In this case, the first cell needs to send a reference signal for the terminal device to perform signal measurement. The primary cell can instruct the first cell to send a reference signal. The way in which the primary cell instructs the first cell to send a reference signal is similar to the way described above. For the sake of brevity, it will not be repeated here. The following only describes the behavior of the terminal device after receiving the reference signal.

[0121] As mentioned above, in some communication systems, the first cell may support multi-beam transmission. In this case, the first cell may send a reference signal through multiple beams, or in other words, the reference signal may be sent through multiple beams. The terminal device may measure the reference signals sent on multiple beams, and the terminal device may determine the target beam based on the signal measurement results, or in other words, the target beam may be determined based on the signal measurement results of the reference signals carried on multiple beams. The target beam may be a beam with a better signal measurement result. For example, the target beam may be the beam with the best signal measurement result among multiple beams, such as the target beam may be the beam with the strongest signal strength among multiple beams. For another example, the target beam may be a beam among multiple beams whose signal measurement result is greater than or equal to a preset threshold. The target beam may include one beam or multiple beams, and the embodiments of the present application do not specifically limit this.

[0122] In some implementations, the terminal device may send fourth indication information to the primary cell, where the fourth indication information is used to indicate a target beam among multiple beams, as shown in step S540 in FIG12 .

[0123] The embodiment of the present application does not specifically limit the manner in which the fourth indication information indicates the target beam. For example, the fourth indication information may indicate the index of the target beam. For another example, the fourth indication information may indicate the index of a reference signal (e.g., the index of an SSB), and the target beam may be determined by the SSB index. For another example, the fourth indication information may indicate the index of a reference signal resource, and the target beam may be determined by the reference signal resource index.

[0124] The embodiment of the present application does not specifically limit the carrying manner of the fourth indication information. For example, the fourth indication information may be carried in an RRC message, or the fourth indication information may be carried in a MAC CE, or the fourth indication information may be carried in uplink control information (UCI), or the fourth indication information may be carried in a physical uplink control channel (PUCCH).

[0125] The target beam can be used for random access. For example, the target beam can be used for the terminal device to send a preamble code. Through random access, the terminal device can obtain uplink synchronization with the first cell. For example, in some scenarios, the primary cell and the first cell may not belong to the same TAG, that is, the TA corresponding to the primary cell and the TA corresponding to the first cell are different. Therefore, when the terminal device needs to send data through the primary cell and the first cell, it needs to obtain the TA corresponding to the first cell before sending data to the first cell. In the above scenario, the terminal device can obtain the TA corresponding to the first cell through the random access process.

[0126] In some implementations, the primary cell may determine a first physical random access channel (PRACH) opportunity based on the target beam. The primary cell may indicate the first PRACH opportunity to the terminal device, as shown in step S550 of Figure 12. The first PRACH opportunity may be used for the terminal device to send a preamble. In other words, the terminal device may send a preamble on the first PRACH opportunity, as shown in step S560 of Figure 12. The first PRACH opportunity may be a PRACH opportunity for the first cell, and the terminal device may send a preamble to the first cell on the first PRACH opportunity.

[0127] There are multiple ways to determine the first PRACH opportunity, which is not specifically limited in the embodiments of the present application. As an example, the primary cell can autonomously determine the first PRACH opportunity, or in other words, the primary cell can randomly determine the first PRACH opportunity. For example, if the primary cell cannot obtain the correspondence between the beam of the first cell and the PRACH opportunity, the primary cell can autonomously determine the first PRACH opportunity.

[0128] As another example, the primary cell may determine the first PRACH opportunity based on the correspondence between the beam of the first cell and the PRACH opportunity. The first PRACH opportunity may be the PRACH opportunity corresponding to the target beam. The correspondence between the beam of the first cell and the PRACH opportunity may be indicated by the first cell to the primary cell.

[0129] In some implementations, if the primary cell autonomously determines the first PRACH opportunity, the primary cell may further send an indication to the primary cell, indicating the first PRACH opportunity and the target beam. Based on the indication, the primary cell may adjust its receiving antenna on the first PRACH opportunity to match the target beam for optimal reception.

[0130] In some implementations, the primary cell may send fifth indication information to the terminal device, where the fifth indication information may be used to indicate the first PRACH opportunity. The terminal device may send a preamble to the first cell through the first PRACH opportunity.

[0131] In some implementations, the first cell may measure the TA after receiving the preamble sent by the terminal device. The first cell may send the TA to the terminal device. After the terminal device obtains the TA, it may achieve uplink synchronization with the first cell. The first cell sending the TA to the terminal device may refer to the first cell directly sending the TA to the terminal device, or the first cell sending the TA to the terminal device through the main cell. For example, for a scenario where the first cell is only used for uplink reception, the first cell is not used for downlink transmission, that is, no downlink signal is sent, and the first cell may not set the downlink PDCCH configuration. In this case, the first cell may send the TA through the main cell. As shown in Figure 12, in step S570, the first cell may send the TA to the main cell. In step S580, after the main cell receives the TA sent by the first cell, it may forward the TA of the first cell to the terminal device.

[0132] In the solution described above, the transmission of the reference signal may be triggered by the primary cell, ie, the primary cell transmits first indication information to the first cell to instruct the first cell to transmit the reference signal. The following describes a solution in which the reference signal is triggered by the terminal device.

[0133] In some scenarios, after the terminal device and the first cell have started data transmission, it may still be necessary to measure the reference signal sent by the first cell. For example, the signal quality of the first cell changes, or the TA of the first cell changes. If the signal quality of the first cell changes, the terminal device can re-determine the appropriate beam by measuring the reference signal. If the TA of the first cell changes, the terminal device can determine the uplink transmission time by receiving the reference signal and using the reference signal as a benchmark. For example, the terminal device can determine the downlink subframe boundary information based on the reception time of the reference signal, and then determine the uplink transmission time based on the downlink subframe boundary information.

[0134] In some implementations, the terminal device may send a first request message, where the first request message is used to request the first cell to send a reference signal. The first request message may be sent by the terminal device to the primary cell, or the first request message may be sent by the terminal device to the first cell. For example, the terminal device may send a first request message to the primary cell to request the first cell to send a reference signal, see step S503 in Figure 13. By sending the first request message to the primary cell, the carrying method of the first request message is made more flexible, such as the first request message may be carried in a PUCCH (such as a special scheduling request (SR)), because only the primary cell may have a PUCCH. For another example, the terminal device may send a first request message to the first cell to request the first cell to send a reference signal, see step S505 in Figure 13. By sending the first request message directly to the first cell, the terminal device does not need to indicate the cell that needs to send a reference signal in the first request message, thereby reducing signaling overhead. If the first cell and the primary cell are co-located, it can be considered that there is no delay in communication between the first cell and the primary cell. The terminal device requests the first cell to send a reference signal by sending a first request message to the primary cell, which does not affect the communication delay.

[0135] In some implementations, if multiple cells are required to transmit reference signals, the terminal device may send a first request message to a first cell to instruct the first cell and other cells to transmit reference signals. For example, the terminal device may send a first request message to the first cell to request a second cell to transmit a reference signal.

[0136] The embodiment of the present application does not specifically limit the carrying method of the first request message. For example, the first request message can be carried in an RRC message, or the first request message can be carried in a MAC CE, or the first request message can be carried in a UCI, or the first request message can be carried in a PUCCH.

[0137] In some implementations, if the terminal device sends a first request message to the primary cell, the first request message may include sixth indication information, and the sixth indication information is used to indicate the cell that needs to send a reference signal. The cell that needs to send a reference signal may include the first cell. Through the sixth indication information, the primary cell can clearly identify which cells send reference signals and trigger the corresponding cells to send reference signals. The cells that need to send reference signals may include one cell or multiple cells, and the embodiments of the present application do not specifically limit this. The cells that need to send reference signals may include cells without reference signals (such as cells without SSB). The cells without reference signals may be configured by the network device to the terminal device. In some implementations, if there are multiple cells that need to send reference signals, the first request message includes the sixth indication information; if there is only one cell that needs to send a reference signal, the first request message may not include the sixth indication information to reduce signaling overhead.

[0138] In some embodiments, the terminal device may instruct one cell to send a reference signal, or may instruct multiple cells to send reference signals through the first request message.

[0139] There are many ways to indicate the sixth indication information, and the embodiments of the present application do not specifically limit this. As an example, the sixth indication information may include an identifier or index of a cell. For example, the terminal device may directly indicate the index (index) of the first cell through a MAC CE. As another example, the sixth indication information may include a bitmap, where one bit corresponds to one cell, and the value of the bit may indicate whether the corresponding cell needs to send a reference signal. For example, if the value of the bit is 1, it indicates that a reference signal needs to be sent; if the value of the bit is 0, it indicates that a reference signal does not need to be sent.

[0140] In some implementations, when sending the first request message, the terminal device may have already transmitted data with the first cell. Therefore, the terminal device may have learned about some or all of the beam conditions of the first cell. For example, the terminal device may know which beam or beams of the first cell have better signal transmission quality. In this case, the terminal device can indicate the target beam to the first cell. That is, the first request message can be used to indicate the target beam. The target beam may include one beam or multiple beams. By indicating the target beam to the first cell, the first cell can send reference signals only on part of the beams (such as the first cell can only send part of the SSB set), thereby reducing the power consumption of the first cell.

[0141] In some implementations, the first indication information may be carried in the first request message. Of course, the first indication information may also be carried in other messages, which is not specifically limited in the embodiments of the present application.

[0142] In some implementations, the parameters for sending the reference signal by the first cell may be preconfigured parameters. After the first cell receives the first request message, the first cell may send the reference signal according to the preconfigured parameters. The preconfigured parameters may include one or more of the following: the frequency for sending the reference signal, the position of the reference signal in the time unit, the time unit where the reference signal is located, the length of the time period for sending the reference signal, the number of times the reference signal is sent, and the transmit power of the reference signal. In this case, the first request message may only indicate whether the first cell sends the reference signal without carrying other information.

[0143] In some implementations, the parameters used by the first cell to send the reference signal may not be preconfigured parameters. The terminal device indicates to the first cell, via a first request message, the parameters used to send the reference signal. For example, the first request message may include a reference signal index, a reference signal transmission duration, and the like.

[0144] In some implementations, some of the parameters used to send the reference signal are preconfigured parameters, and some of the parameters are indicated by the first request message. For example, the reference signal index and the reference signal transmission duration can be indicated by the first request message.

[0145] In some implementations, the terminal device may send the first request message if a second condition is met. The second condition may be related to one or more of the following: a signal measurement result for the first cell, and synchronization between the terminal device and the first cell.

[0146] In some embodiments, the second condition may include that the signal measurement result for the first cell is less than or equal to a second threshold. That is, the terminal device may send the first request message when the signal quality of the first cell is poor.

[0147] In some embodiments, the second condition may include a change in the TA for the first cell. That is, the terminal device may send the first request message when the TA for the first cell changes. The change in the TA for the first cell may include the terminal device being unable to determine downlink subframe boundary information of the first cell. For example, if the terminal device is unable to determine the downlink subframe boundary information of the first cell, the terminal device may send the first request message.

[0148] In some implementations, if a third condition is met, the terminal device is unable to determine the downlink subframe boundary information of the first cell. The third condition includes: the time interval between the current moment and the first moment is greater than or equal to a third threshold. The first moment is the moment of the last data transmission between the terminal device and the first cell. In other words, if there has been no data transmission between the terminal device and the first cell for a long period of time, the terminal device may be unable to determine the downlink subframe boundary of the first cell.

[0149] The time of the last data transmission may refer to the time of the last uplink data transmission or the time of the last downlink data transmission.

[0150] In some implementations, after the terminal device sends the first request message, it may receive the reference signal sent by the first cell after a second duration has passed. The second duration may be a duration predefined by the protocol, or the second duration may be configured by the primary cell.

[0151] The method embodiment of the present application is described in detail above in conjunction with Figures 1 to 13. The device embodiment of the present application is described in detail below in conjunction with Figures 14 and 15. It should be understood that the description of the method embodiment corresponds to the description of the device embodiment. Therefore, for parts not described in detail, reference can be made to the above method embodiment.

[0152] FIG14 is a schematic block diagram of a terminal device provided in an embodiment of the present application. The terminal device 1400 shown in FIG14 can be any of the terminal devices described above. The terminal device 1400 shown in FIG14 can include a receiving unit 1410.

[0153] The receiving unit 1410 is configured to receive a reference signal sent by a first cell, where the sending of the reference signal is triggered by the terminal device and / or the primary cell.

[0154] In some possible implementations, the resource for sending the reference signal is a first resource, the first resource is determined based on first indication information, or the first resource is a preconfigured resource.

[0155] In some possible implementations, the first indication information is sent by the terminal device and / or the primary cell to the first cell.

[0156] In some possible implementations, the first resources include one or more of the following: time domain resources, frequency domain resources, and beams.

[0157] In some possible implementations, the first resource includes a time domain resource, and the time domain resource is determined based on one or more of the following: a reference signal sending period, a start time for sending a reference signal, an end time for sending a reference signal, a time unit in which the reference signal is located, a position of the reference signal in the time unit, the number of times the reference signal is sent, and a duration for sending the reference signal.

[0158] In some possible implementations, the first resource includes a frequency domain resource, and the frequency domain resource is determined based on an absolute frequency value of a sent reference signal or a reference frequency point of a sent reference signal.

[0159] In some possible implementations, the sending of the reference signal is triggered by the primary cell, and the receiving unit is further used to: receive second indication information sent by the primary cell, the second indication information is used to indicate a second resource, and the second resource is used to receive the reference signal sent by the first cell.

[0160] In some possible implementations, the second resources include time domain resources and / or frequency domain resources.

[0161] In some possible implementations, the second resource includes a time domain resource, and the second indication information is used to indicate one or more of the following: a reference signal sending period, a start time for sending a reference signal, an end time for sending a reference signal, a time unit in which the reference signal is located, a position of the reference signal in the time unit, the number of times the reference signal is sent, and a duration for sending the reference signal.

[0162] In some possible implementations, the second resource includes a frequency domain resource, and the second configuration information includes an absolute frequency value for sending a reference signal or a reference frequency point for sending a reference signal.

[0163] In some possible implementations, the time unit includes a system frame.

[0164] In some possible implementations, the system frame is a system frame number of the primary cell.

[0165] In some possible implementations, the reference frequency point is one of the following: a starting frequency point, a center frequency point, and an ending frequency point.

[0166] In some possible implementations, the receiving unit is further used to: receive third indication information sent by the primary cell, where the third indication information is used to instruct the terminal device to measure the reference signal sent by the first cell.

[0167] In some possible implementations, the terminal device further includes: a sending unit, configured to send a signal measurement result of a reference signal to the primary cell when a first condition is met, wherein the first condition is related to the measurement duration and / or the signal measurement result.

[0168] In some possible implementations, the first condition includes one or more of the following: a measurement duration is greater than or equal to a first duration; a signal measurement result is greater than or equal to a first threshold.

[0169] In some possible implementations, the reference signal is sent through multiple beams, and the terminal device also includes a sending unit for: sending fourth indication information to the primary cell, wherein the fourth indication information is used to indicate a target beam among the multiple beams, and the target beam is the beam with the best signal measurement result among the multiple beams.

[0170] In some possible implementations, the receiving unit is further used to: receive fifth indication information sent by the primary cell, where the fifth indication information is used to indicate a first PRACH opportunity; and the sending unit is further used to: send a preamble code to the first cell through the first PRACH opportunity.

[0171] In some possible implementations, the sending of the reference signal is triggered by the terminal device, and the terminal device also includes a sending unit, which is used to: send a first request message, where the first request message is used to request the first cell to send a reference signal, and the first request message is sent by the terminal device to the primary cell, or the first request message is sent by the terminal device to the first cell.

[0172] In some possible implementations, the first request message includes sixth indication information, where the sixth indication information is used to indicate a cell that needs to send a reference signal, and the cell that needs to send a reference signal includes the first cell.

[0173] In some possible implementations, the sending unit is further used to: send the first request message when a second condition is met, and the second condition includes one or more of the following: the signal measurement result for the first cell is less than or equal to a second threshold; the terminal device cannot determine the downlink subframe boundary information of the first cell.

[0174] In some possible implementations, when a third condition is met, the terminal device cannot determine the downlink subframe boundary information of the first cell, and the third condition includes: the time interval between the current moment and the first moment is greater than or equal to a third threshold, and the first moment is the moment of the last data transmission between the terminal device and the first cell.

[0175] In some possible implementations, the reference signal includes one or more of the following: SSB, CSI-RS, TRS.

[0176] In some possible implementations, the primary cell and the first cell are co-located.

[0177] In an optional embodiment, the receiving unit 1410 and the sending unit may be a transceiver 1530. The terminal device 1400 may further include a processor 1510 and a memory 1520, as specifically shown in FIG15 .

[0178] Figure 15 is a schematic block diagram of a communication device according to an embodiment of the present application. The dashed lines in Figure 15 indicate that the unit or module is optional. Apparatus 1500 may be used to implement the method described in the above method embodiment. Apparatus 1500 may be a chip, a terminal device, or a network device.

[0179] The device 1500 may include one or more processors 1510. The processor 1510 may support the device 1500 to implement the method described in the method embodiment above. The processor 1510 may be a general-purpose processor or a special-purpose processor. For example, the processor may be a central processing unit (CPU). Alternatively, the processor may be another general-purpose processor, a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field programmable gate array (FPGA) or other programmable logic device, discrete gate or transistor logic device, discrete hardware component, etc. The general-purpose processor may be a microprocessor or the processor may be any conventional processor, etc.

[0180] The apparatus 1500 may further include one or more memories 1520. The memories 1520 store programs that can be executed by the processor 1510, causing the processor 1510 to perform the methods described in the above method embodiments. The memories 1520 may be independent of the processor 1510 or integrated into the processor 1510.

[0181] The apparatus 1500 may further include a transceiver 1530. The processor 1510 may communicate with other devices or chips via the transceiver 1530. For example, the processor 1510 may transmit and receive data with other devices or chips via the transceiver 1530.

[0182] The present application also provides a computer-readable storage medium for storing a program. The computer-readable storage medium can be applied to a terminal or network device provided in the present application, and the program enables a computer to execute the method performed by the terminal or network device in each embodiment of the present application.

[0183] The present application also provides a computer program product. The computer program product includes a program. The computer program product can be applied to a terminal or network device provided in the present application, and the program causes a computer to execute the method performed by the terminal or network device in each embodiment of the present application.

[0184] The embodiments of the present application also provide a computer program. The computer program can be applied to the terminal or network device provided in the embodiments of the present application, and the computer program enables a computer to execute the method performed by the terminal or network device in each embodiment of the present application.

[0185] It should be understood that the terms "system" and "network" in this application can be used interchangeably. In addition, the terms used in this application are only used to explain the specific embodiments of this application and are not intended to limit this application. The terms "first", "second", "third", and "fourth" in the specification and claims of this application and the accompanying drawings are used to distinguish different objects rather than to describe a specific order. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions.

[0186] In the embodiments of this application, the term "indication" may refer to a direct indication, an indirect indication, or an indication of an association. For example, "A indicates B" may refer to a direct indication of B, e.g., B can obtain information through A; it may refer to an indirect indication of B, e.g., A indicates C, e.g., B can obtain information through C; or it may refer to an association between A and B.

[0187] In the embodiment of the present application, "B corresponding to A" means that B is associated with A and B can be determined based on A. However, it should be understood that determining B based on A does not mean determining B based solely on A, but B can also be determined based on A and / or other information.

[0188] In the embodiments of the present application, the term "corresponding" may indicate a direct or indirect correspondence between the two, or an association relationship between the two, or a relationship between indication and indication, configuration and configuration, etc.

[0189] In the embodiments of the present application, "pre-definition" or "pre-configuration" may be implemented by pre-storing corresponding codes, tables, or other methods that can be used to indicate relevant information in a device (e.g., a terminal device and a network device). The present application does not limit the specific implementation method. For example, pre-definition may refer to information defined in a protocol.

[0190] In the embodiments of the present application, the “protocol” may refer to a standard protocol in the communications field, for example, it may include an LTE protocol, an NR protocol, and related protocols used in future communication systems, and the present application does not limit this.

[0191] In the embodiments of this application, the term "and / or" is simply a description of the association relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in this document generally indicates that the related objects are in an "or" relationship.

[0192] In various embodiments of the present application, the size of the serial numbers of the above-mentioned processes does not mean the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present application.

[0193] In the several embodiments provided in this application, it should be understood that the disclosed systems, devices and methods can be implemented in other ways. For example, the device embodiments described above are merely schematic. For example, the division of the units is merely a logical function division. In actual implementation, there may be other division methods, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of devices or units, which can be electrical, mechanical or other forms.

[0194] The units described as separate components may or may not be physically separate, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed across multiple network units. Some or all of these units may be selected to achieve the purpose of this embodiment according to actual needs.

[0195] In addition, each functional unit in each embodiment of the present application may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit.

[0196] In the above embodiments, it can be implemented in whole or in part by software, hardware, firmware or any combination thereof. When implemented using software, it can be implemented in whole or in part in the form of a computer program product. The computer program product includes one or more computer instructions. When the computer program instructions are loaded and executed on a computer, the process or function described in the embodiment of the present application is generated in whole or in part. The computer can be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device. The computer instructions can be stored in a computer-readable storage medium or transmitted from one computer-readable storage medium to another computer-readable storage medium. For example, the computer instructions can be transmitted from one website, computer, server or data center to another website, computer, server or data center via a wired (e.g., coaxial cable, optical fiber, digital subscriber line (DSL)) or wireless (e.g., infrared, wireless, microwave, etc.) method. The computer-readable storage medium can be any available medium that can be read by a computer or a data storage device such as a server or data center that includes one or more available media integrated therein. The available medium may be a magnetic medium (eg, a floppy disk, a hard disk, a magnetic tape), an optical medium (eg, a digital versatile disc (DVD)), or a semiconductor medium (eg, a solid state disk (SSD)).

[0197] The above description is merely a specific embodiment of the present application, but the scope of protection of the present application is not limited thereto. Any changes or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in this application should be included in the scope of protection of the present application. Therefore, the scope of protection of the present application should be based on the scope of protection of the claims.

Claims

1. A wireless communication method, characterized in that, Including: The terminal device receives a reference signal sent by a first cell, and the transmission of the reference signal is triggered by the terminal device and / or a primary cell.

2. The method according to claim 1, wherein The transmission resource of the reference signal is a first resource, and the first resource is determined based on first indication information, or the first resource is a pre-configured resource.

3. The method according to claim 2, wherein The first indication information is sent from the terminal device and / or the primary cell to the first cell.

4. The method according to claim 2 or 3, characterized in that, The first resource includes one or more of the following: time domain resource, frequency domain resource, and beam.

5. The method according to claim 4, characterized in that, The first resource includes a time domain resource, and the time domain resource is determined based on one or more of the following: the first indication information is used to indicate one or more of the following: the transmission period of the reference signal, the start time of transmitting the reference signal, the end time of transmitting the reference signal, the time unit where the reference signal is located, the position of the reference signal in the time unit, the number of times of transmitting the reference signal, and the duration of transmitting the reference signal.

6. The method according to claim 4, characterized in that, The first resource includes a frequency domain resource, and the frequency domain resource is determined based on the absolute frequency value of transmitting the reference signal or the reference frequency point of transmitting the reference signal.

7. The method according to any one of claims 1 to 6, characterized in that, The transmission of the reference signal is triggered by the primary cell, and the method further includes: The terminal device receives second indication information sent by the primary cell, and the second indication information is used to indicate a second resource, and the second resource is used to receive the reference signal sent by the first cell.

8. The method according to claim 7, wherein The second resource includes a time domain resource and / or a frequency domain resource.

9. The method according to claim 8, wherein The second resource includes a time domain resource, and the second indication information is used to indicate one or more of the following: the transmission period of the reference signal, the start time of transmitting the reference signal, the end time of transmitting the reference signal, the time unit where the reference signal is located, the position of the reference signal in the time unit, the number of times of transmitting the reference signal, and the duration of transmitting the reference signal.

10. The method according to claim 8, characterized in that, The second resource includes a frequency domain resource, and the second configuration information includes the absolute frequency value of transmitting the reference signal or the reference frequency point of transmitting the reference signal.

11. The method according to claim 5 or 9, characterized in that The time unit includes a system frame.

12. The method according to claim 11, wherein The system frame is the system frame number of the primary cell.

13. The method according to claim 6 or 10, characterized in that, The reference frequency point is one of the following: start frequency point, center frequency point, and end frequency point.

14. The method according to any one of claims 7-10, characterized in that, The method further includes: The terminal device receives third indication information sent by the primary cell, and the third indication information is used to indicate that the terminal device measures the reference signal sent by the first cell.

15. The method according to any one of claims 1-14, characterized in that, The method further includes: When a first condition is met, the terminal device sends a signal measurement result of the reference signal to the primary cell, where the first condition is related to the measurement duration and / or the signal measurement result.

16. The method according to claim 15, characterized in that, The first condition includes one or more of the following: The measurement duration is greater than or equal to a first duration; The signal measurement result is greater than or equal to a first threshold.

17. The method according to any one of claims 1-14, characterized in that, The reference signal is sent through multiple beams, and the method further includes: The terminal device sends fourth indication information to the primary cell, and the fourth indication information is used to indicate a target beam among the multiple beams, and the target beam is the beam with the best signal measurement result among the multiple beams.

18. The method according to claim 17, characterized in that The method further includes: The terminal device receives fifth indication information sent by the primary cell, where the fifth indication information is used to indicate a first Physical Random Access Channel (PRACH) occasion; The terminal device sends a preamble to the first cell through the first PRACH occasion.

19. The method according to any one of claims 1-7, characterized in that, The transmission of the reference signal is triggered by the terminal device, and the method further includes: The terminal device sends a first request message, where the first request message is used to request the first cell to send a reference signal. The first request message is sent by the terminal device to the primary cell, or the first request message is sent by the terminal device to the first cell.

20. The method according to claim 19, wherein The first request message includes sixth indication information, where the sixth indication information is used to indicate the cell for which a reference signal needs to be sent, and the cell for which a reference signal needs to be sent includes the first cell.

21. The method according to claim 19 or 20, characterized in that, The terminal device sending the first request message includes: When a second condition is met, the terminal device sends the first request message, and the second condition includes one or more of the following: The signal measurement result for the first cell is less than or equal to a second threshold; The terminal device cannot determine the downlink subframe boundary information of the first cell.

22. The method according to claim 21, wherein When a third condition is met, the terminal device cannot determine the downlink subframe boundary information of the first cell, and the third condition includes: the time interval between the current moment and a first moment is greater than or equal to a third threshold, and the first moment is the moment of the last data transmission between the terminal device and the first cell.

23. The method according to any one of claims 1-22, characterized in that, The reference signal includes one or more of the following: Synchronization Signal and Physical Broadcast Channel Block (SSB), Channel State Information Reference Signal (CSI-RS), Tracking Reference Signal (TRS).

24. The method according to any one of claims 1-23, characterized in that, The primary cell and the first cell are co-located.

25. A terminal device, characterized in that, including: a receiving unit, configured to receive a reference signal sent by the first cell, where the transmission of the reference signal is triggered by the terminal device and / or the primary cell.

26. The terminal device according to claim 25, wherein, The transmission resource of the reference signal is a first resource, where the first resource is determined based on first indication information, or the first resource is a pre-configured resource.

27. The terminal device according to claim 26, characterized in that, The first indication information is sent by the terminal device and / or the primary cell to the first cell.

28. The terminal device according to claim 26 or 27, characterized in that, The first resource includes one or more of the following: time domain resource, frequency domain resource, and beam.

29. The terminal device according to claim 28, characterized in that, The first resource includes a time domain resource, and the time domain resource is determined based on one or more of the following: the transmission period of the reference signal, the start moment of sending the reference signal, the end moment of sending the reference signal, the time unit where the reference signal is located, the position of the reference signal in the time unit, the number of times of sending the reference signal, the duration of sending the reference signal.

30. The terminal device according to claim 28, wherein, The first resource includes a frequency domain resource, and the frequency domain resource is determined based on the absolute frequency value of sending the reference signal or the reference frequency point of sending the reference signal.

31. The terminal device according to any one of claims 25 - 30, characterized in that, When the transmission of the reference signal is triggered by the primary cell, the receiving unit is further configured to: receive second indication information sent by the primary cell, where the second indication information is used to indicate a second resource, and the second resource is used to receive the reference signal sent by the first cell.

32. The terminal device according to claim 31, characterized in that, The second resource includes a time domain resource and / or a frequency domain resource.

33. The terminal device according to claim 32, wherein The second resource includes time domain resources, and the second indication information is used to indicate one or more of the following: the transmission period of the reference signal, the starting time of transmitting the reference signal, the ending time of transmitting the reference signal, the time unit where the reference signal is located, the position of the reference signal in the time unit, the number of times of transmitting the reference signal, and the duration of transmitting the reference signal.

34. The terminal device according to claim 32, wherein The second resource includes frequency domain resources, and the second configuration information includes the absolute frequency value of transmitting the reference signal or the reference frequency point for transmitting the reference signal.

35. The terminal device according to claim 29 or 33, characterized in that, The time unit includes system frames.

36. The terminal device according to claim 35, wherein The system frame is the system frame number of the primary cell.

37. The terminal device according to claim 30 or 34, characterized in that, The reference frequency point is one of the following: the starting frequency point, the center frequency point, and the ending frequency point.

38. The terminal device according to any one of claims 31-34, characterized in that, The receiving unit is further configured to: Receive third indication information sent by the primary cell, where the third indication information is used to indicate that the terminal device measures the reference signal sent by the first cell.

39. The terminal device according to any one of claims 25-38, characterized in that, The terminal device further includes: A sending unit, configured to send a signal measurement result of the reference signal to the primary cell when a first condition is met, where the first condition is related to the measurement duration and / or the signal measurement result.

40. The terminal device according to claim 39, characterized in that, The first condition includes one or more of the following: The measurement duration is greater than or equal to a first duration; The signal measurement result is greater than or equal to a first threshold.

41. The terminal device according to any one of claims 25-40, characterized in that, The reference signal is sent through multiple beams, and the terminal device further includes a sending unit, configured to: Send fourth indication information to the primary cell, where the fourth indication information is used to indicate a target beam among the multiple beams, and the target beam is the beam with the best signal measurement result among the multiple beams.

42. The terminal device according to claim 41, wherein The receiving unit is further configured to: receive fifth indication information sent by the primary cell, where the fifth indication information is used to indicate a first physical random access channel (PRACH) opportunity; The sending unit is further configured to: send a preamble to the first cell through the first PRACH opportunity.

43. The terminal device according to any one of claims 25-31, characterized in that, The transmission of the reference signal is triggered by the terminal device, and the terminal device further includes a sending unit, configured to: Send a first request message, where the first request message is used to request the first cell to send a reference signal, and the first request message is sent by the terminal device to the primary cell, or the first request message is sent by the terminal device to the first cell.

44. The terminal device according to claim 43, wherein The first request message includes sixth indication information, where the sixth indication information is used to indicate the cell that needs to send the reference signal, and the cell that needs to send the reference signal includes the first cell.

45. The terminal device according to claim 43 or 44, characterized in that, The sending unit is further configured to: Send the first request message when a second condition is met, where the second condition includes one or more of the following: The signal measurement result for the first cell is less than or equal to a second threshold; The terminal device cannot determine the downlink subframe boundary information of the first cell.

46. The terminal device according to claim 45, characterized in that, When the third condition is satisfied, the terminal device cannot determine the downlink subframe boundary information of the first cell, and the third condition includes: the time interval between the current moment and the first moment is greater than or equal to a third threshold, and the first moment is the moment of the last data transmission between the terminal device and the first cell.

47. The terminal device according to any one of claims 25-46, characterized in that, The reference signal includes one or more of the following: synchronization signal and physical broadcast channel block SSB, channel state information reference signal CSI-RS, tracking reference signal TRS.

48. The terminal device according to any one of claims 25-47, characterized in that, The primary cell and the first cell share the same site.

49. A terminal device, characterized in that, It includes a memory, a processor and a transceiver. The memory is used to store one or more computer programs, and the processor is used to call the computer programs in the memory, so that the terminal device executes the method according to any one of claims 1-24.

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