Downlink carrier handover method, communication apparatus, and storage medium

Abstract

A downlink carrier handover method, a communication apparatus, and a storage medium. Downlink control information dynamically indicates a target secondary cell where a downlink transmission occurs, and when secondary cell handover occurs, a terminal simply needs to hand over a corresponding downlink radio frequency receiver to the target secondary cell, and the handover delay is short. Therefore, when the terminal is enabled to use limited capabilities to dynamically use preferred carrier resources, dynamic and fast handover is achieved, the handover delay is shortened, and thus the dynamic change of channels and loads of different carriers can be quickly adapted.

Description

Downlink carrier switching method, communication device and storage medium

[0001] This application claims priority to the Chinese patent application filed with the State Intellectual Property Office of China on October 30, 2023, with application number 202311428220.X and invention name “Downlink carrier switching method, communication device and storage medium”, the entire contents of which are incorporated by reference into this application. Technical Field

[0002] The present application relates to the field of communications, and in particular to a downlink carrier switching method, a communication device, and a storage medium. Background Art

[0003] In carrier aggregation (CA) scenarios, network equipment can activate multiple serving cells for a single terminal. However, due to cost constraints, the number of cells a terminal can simultaneously support is limited. Therefore, it is necessary to enable the terminal's limited capabilities to flexibly utilize optimal carrier resources, allowing the carrier used for terminal data transmission to dynamically adapt to dynamic changes in channels and loads on different carriers.

[0004] Summary of the Invention

[0005] The present application provides a downlink carrier switching method, a communication device, and a storage medium to achieve dynamic and rapid switching of carriers, so that the carrier performing data transmission can dynamically adapt to the dynamic changes of channels and loads on different carriers.

[0006] In a first aspect, a downlink carrier switching method is provided, wherein the method is implemented by a terminal, or a circuit or chip used for a terminal.

[0007] The method includes: receiving downlink control information on the primary cell in a first time unit, the downlink control information being used to schedule the transmission of a physical downlink shared channel on the target secondary cell; and switching from the source secondary cell to the target secondary cell to receive the physical downlink shared channel in a second time unit according to the downlink control information, wherein the second time unit is the Nth time unit after the first time unit, and N is an integer greater than or equal to 0.

[0008] By adopting this method, the target secondary cell for downlink transmission is dynamically indicated through downlink control information. When a secondary cell switching occurs, the terminal only needs to switch the corresponding downlink RF receiver to the target secondary cell, and the switching delay is short. Therefore, while enabling the terminal to dynamically use the preferred carrier resources with limited capabilities, dynamic fast switching is achieved, the switching delay is shortened, and it is possible to quickly adapt to the dynamic changes of channels and loads of different carriers.

[0009] In one possible implementation, the method further includes: sending first information, where the first information includes a cell switching interval, where the cell switching interval is used to indicate the time required to switch from the source secondary cell to the target secondary cell, and the cell switching interval is based on the hardware capability of the terminal.

[0010] With this implementation, the terminal can report the cell switching interval supported by itself to the network device, so that the network device can calculate the time unit of the physical downlink shared channel of the target secondary cell according to the cell switching interval.

[0011] In another possible implementation, the N is an integer greater than 0, the second time unit includes the cell switching interval, and the N is associated with at least one of the following: the cell switching interval, the index of the time slot where the downlink control information is located, the numerology number of the carrier or part of the bandwidth where the physical downlink shared channel is located, the numerology number of the carrier or part of the bandwidth where the physical downlink control channel carrying the downlink control information is located, and the K0 corresponding to the target secondary cell; wherein the K0 corresponding to the target secondary cell is greater than the K0 corresponding to the source secondary cell, wherein the K0 is the time slot interval between the physical downlink control channel and the physical downlink shared channel scheduled by it.

[0012] With this implementation, network equipment can schedule downlink transmissions for secondary cells across time units. The time interval between the second time unit and the first time unit can be accurately determined, enabling accurate carrier switching. By setting the K0 corresponding to the target secondary cell to be greater than the K0 corresponding to the source secondary cell, the source cell has already stopped transmitting when the terminal switches its RF receiver to receive signals from the target secondary cell.

[0013] In another possible implementation, the N is an integer greater than 0, the first time unit includes the cell switching interval, and the N is associated with at least one of the following: the index of the time slot where the downlink control information is located, the numerology number of the carrier or part of the bandwidth where the physical downlink shared channel is located, the numerology number of the carrier or part of the bandwidth where the physical downlink control channel carrying the downlink control information is located, and the K0 corresponding to the target secondary cell; wherein the K0 corresponding to the target secondary cell is greater than the K0 corresponding to the source secondary cell, wherein the K0 is the time slot interval between the physical downlink control channel and the physical downlink shared channel scheduled by it.

[0014] With this implementation, the network device can schedule downlink transmissions for the secondary cell across time units. The time interval between the second time unit and the first time unit can be accurately determined, enabling accurate carrier switching. By setting the K0 corresponding to the target secondary cell to be greater than the K0 corresponding to the source secondary cell, the source cell has already stopped transmitting when the terminal switches its RF receiver to receive signals from the target secondary cell. The downlink transmission resources indicated by the downlink control information of the source secondary cell are empty.

[0015] In another possible implementation, N=0, the second time unit includes the cell switching interval, the downlink control information also includes the start and length indication values ​​of the physical downlink shared channel, the start and length indication values ​​are greater than a first threshold, and the first threshold is associated with the cell switching interval.

[0016] With this implementation, the network device can schedule downlink transmissions of the secondary cell within the same time unit. By setting the start and length indicator values ​​to be greater than a first threshold, and the first threshold being associated with the cell handover interval, the terminal's RF receiver has sufficient time to perform blind detection and parse downlink control information.

[0017] In another possible implementation, the downlink control information includes an identifier of the target secondary cell.

[0018] In another possible implementation, the number of the target secondary cells is less than or equal to the maximum number of physical downlink shared channels that can be processed by the terminal.

[0019] In a second aspect, another downlink carrier switching method is provided, which is implemented by a network device, or a circuit or chip used for a network device.

[0020] The method includes: sending downlink control information on the primary cell in a first time unit, wherein the downlink control information is used to schedule the transmission of a physical downlink shared channel on the target secondary cell; and sending the physical downlink shared channel on the target secondary cell in a second time unit according to the downlink control information, wherein the second time unit is the Nth time unit after the first time unit, and N is an integer greater than or equal to 0.

[0021] By adopting this method, the target secondary cell for downlink transmission is dynamically indicated through downlink control information. When a secondary cell switching occurs, the terminal only needs to switch the corresponding downlink RF receiver to the target secondary cell, and the switching delay is short. Therefore, while enabling the terminal to dynamically use the preferred carrier resources with limited capabilities, dynamic fast switching is achieved, the switching delay is shortened, and it is possible to quickly adapt to the dynamic changes of channels and loads of different carriers.

[0022] In one possible implementation, the method further includes: receiving first information, where the first information includes a cell switching interval, where the cell switching interval is used to indicate the time required to switch from the source secondary cell to the target secondary cell, and the cell switching interval is based on the hardware capability of the terminal.

[0023] In another possible implementation, the N is an integer greater than 0, the second time unit includes the cell switching interval, and the N is associated with at least one of the following: the cell switching interval, the index of the time slot where the downlink control information is located, the numerology number of the carrier or part of the bandwidth where the physical downlink shared channel is located, the numerology number of the carrier or part of the bandwidth where the physical downlink control channel carrying the downlink control information is located, and the K0 corresponding to the target secondary cell; wherein the K0 corresponding to the target secondary cell is greater than the K0 corresponding to the source secondary cell, wherein the K0 is the time slot interval between the physical downlink control channel and the physical downlink shared channel scheduled by it.

[0024] In another possible implementation, the N is an integer greater than 0, the first time unit includes the cell switching interval, and the N is associated with at least one of the following: the index of the time slot where the downlink control information is located, the numerology number of the carrier or part of the bandwidth where the physical downlink shared channel is located, the numerology number of the carrier or part of the bandwidth where the physical downlink control channel carrying the downlink control information is located, and the K0 corresponding to the target secondary cell; wherein the K0 corresponding to the target secondary cell is greater than the K0 corresponding to the source secondary cell, wherein the K0 is the time slot interval between the physical downlink control channel and the physical downlink shared channel scheduled by it.

[0025] In another possible implementation, N=0, the second time unit includes the cell switching interval, the downlink control information also includes the start and length indication values ​​of the physical downlink shared channel, the start and length indication values ​​are greater than a first threshold, and the first threshold is associated with the cell switching interval.

[0026] In another possible implementation, the downlink control information includes an identifier of the target secondary cell.

[0027] In another possible implementation, the number of the target secondary cells is less than or equal to the maximum number of physical downlink shared channels that can be processed by the terminal.

[0028] The method of the first aspect described above may be executed by a terminal, or by a module applied to the terminal (such as a processor, chip, or chip system, etc.), or by a logical node, logical module, or software that can implement all or part of the terminal functions.

[0029] The method of the second aspect mentioned above can be executed by a network device, or by a module applied to the network device (such as a processor, chip, or chip system, etc.), or by a logical node, logical module or software that can realize all or part of the network device functions.

[0030] In a third aspect, a communication device is provided for implementing the downlink carrier switching method in the first aspect or any one of the implementations of the first aspect. The device may be a terminal, a module applied to a terminal (e.g., a processor, a chip, or a chip system), or a logical node, a logical module, or software that implements all or part of the terminal's functions.

[0031] In a fourth aspect, a communication device is provided for implementing the downlink carrier switching method in the second aspect or any one of the implementations of the second aspect. The device can be a network device, a module applied to a network device (such as a processor, chip, or chip system), or a logical node, logic module, or software that can implement all or part of the network device functions.

[0032] In a possible implementation, the communication device in the third to fourth aspects includes a module for respectively executing the method in any one of the first to second aspects or any one of the implementations.

[0033] In another possible implementation, the communication device in the third and fourth aspects includes a processor coupled to a memory; the processor is configured to enable the device to perform the corresponding functions in the downlink carrier switching method. The memory is coupled to the processor and stores the necessary programs (instructions) and / or data for the device. Optionally, the communication device may further include a communication interface for enabling communication between the device and other network elements. Optionally, the memory may be located inside or outside the communication device.

[0034] In another possible implementation, the communication device in the third to fourth aspects includes a processor and a transceiver, the processor being coupled to the transceiver, and the processor being used to execute a computer program or instruction to control the transceiver to receive and send information; when the processor executes the computer program or instruction, the processor is also used to implement the above method through a logic circuit or executing code instructions. The transceiver may be a transceiver, a transceiver circuit, or an input / output interface, configured to receive signals from other communication devices other than the communication device and transmit them to the processor, or to send signals from the processor to other communication devices other than the communication device. When the communication device is a chip, the transceiver is a transceiver circuit or an input / output interface.

[0035] When the communication device in the third and fourth aspects above is a chip, the sending unit may be an output unit, such as an output circuit or a communication interface; the receiving unit may be an input unit, such as an input circuit or a communication interface. When the communication device is a terminal, the sending unit may be a transmitter or a transmitter; and the receiving unit may be a receiver or a receiver.

[0036] In a fifth aspect, a computer-readable storage medium is provided, in which a computer program or instruction is stored. When the computer program or instruction is executed, the methods described in the above aspects are implemented.

[0037] In a sixth aspect, a computer program product comprising instructions is provided, which, when executed on a communication device, causes the communication device to execute the methods described in the above aspects.

[0038] In a seventh aspect, a communication system is provided, which includes the communication device described in the third aspect and the communication device described in the fourth aspect. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] FIG1 is a schematic diagram of the architecture of a communication system 1000 used in an embodiment of the present application;

[0040] FIG2 is a schematic diagram of carrier aggregation;

[0041] FIG3 is a schematic diagram of a cell handover based on a layer 1-2 mobility technology;

[0042] FIG4 is a schematic diagram of an uplink carrier switching technology;

[0043] FIG5 is a schematic flow chart of a downlink carrier switching method provided in an embodiment of the present application;

[0044] FIG6 is a schematic diagram of a PCell scheduling an SCell across time units according to an embodiment of the present application;

[0045] FIG7 is a schematic diagram of data scheduling according to an embodiment of the present application;

[0046] FIG8 is a schematic diagram of another example of a PCell scheduling an SCell across time units according to an embodiment of the present application;

[0047] FIG9 is a schematic diagram of a PCell scheduling an SCell within the same time unit according to an embodiment of the present application;

[0048] FIG10 is a schematic diagram of another data scheduling example according to an embodiment of the present application;

[0049] FIG11 is a schematic structural diagram of a communication device provided in an embodiment of the present application;

[0050] FIG12 is a schematic structural diagram of another communication device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0051] The solution provided in this application is further described below with reference to the accompanying drawings.

[0052] The downlink carrier switching method provided in the embodiment of the present application can be applied to wireless communication systems such as 5G, 6G, and satellite communications. The communication system 1000 includes a radio access network (RAN) 100, wherein the RAN 100 includes at least one RAN node (such as 110a and 110b in Figure 1, collectively referred to as 110), and may also include at least one terminal (such as 120a-120j in Figure 1, collectively referred to as 120). The RAN 100 may also include other RAN nodes, such as wireless relay equipment and / or wireless backhaul equipment (not shown in Figure 1). The terminal 120 is connected to the RAN node 110 wirelessly. Terminals and RAN nodes can be connected to each other by wired or wireless means. The communication system 1000 may also include a core network 200. The RAN node 110 is connected to the core network 200 by wireless or wired means. The core network devices in the core network 200 and the RAN nodes 110 in the RAN 100 may be independent and different physical devices, or may be the same physical device that integrates the logical functions of the core network devices and the logical functions of the RAN nodes.

[0053] RAN100 can be an evolved universal terrestrial radio access (E-UTRA) system, a new radio (NR) system, and a future radio access system defined in the 3rd Generation Partnership Project (3GPP). RAN100 can also include two or more different radio access systems mentioned above. RAN100 can also be an open RAN (O-RAN). RAN nodes, also known as radio access network equipment, RAN entities, or access nodes, are used to help terminals access the communication system wirelessly. In an application scenario, a RAN node can be a base station, an evolved NodeB (eNodeB), a transmission reception point (TRP), a next generation NodeB (gNB) in a fifth generation (5G) mobile communication system, a next generation base station in a sixth generation (6G) mobile communication system, or a base station in a future mobile communication system. The RAN node may be a macro base station (such as 110a in FIG1 ), a micro base station or an indoor station (such as 110b in FIG1 ), or a relay node or a donor node.

[0054] In another application scenario, multiple RAN nodes can collaborate to help terminals achieve wireless access, with different RAN nodes implementing portions of the base station's functions. For example, a RAN node can be a centralized unit (CU), a distributed unit (DU), or a radio unit (RU). The CU implements the base station's radio resource control protocol and packet data convergence protocol (PDCP) functions, as well as the service data adaptation protocol (SDAP) functions. The DU implements the base station's radio link control layer and medium access control (MAC) layer functions, as well as some or all of the physical layer functions. For detailed descriptions of each of the above protocol layers, please refer to the relevant 3GPP technical specifications. The RU can be used to implement the transmission and reception of radio frequency signals. The CU and DU can be two independent RAN nodes, or they can be integrated into the same RAN node, such as in a baseband unit (BBU). The RU can be included in radio frequency equipment, such as a remote radio unit (RRU) or an active antenna unit (AAU). The CU can be further divided into two types of RAN nodes: CU-control plane and CU-user plane.

[0055] In different systems, RAN nodes may have different names. For example, in an O-RAN system, a CU may be called an open CU (O-CU), a DU may be called an open DU (O-DU), and a RU may be called an open RU (O-RU). The RAN node in the embodiments of the present application may be implemented by a software module, a hardware module, or a combination of a software module and a hardware module. For example, the RAN node may be a server loaded with the corresponding software module. The embodiments of the present application do not limit the specific technology and specific device form adopted by the RAN node. For ease of description, the following description takes a base station as an example of a RAN node.

[0056] A terminal is a device with wireless transceiver capabilities that can send signals to a base station or receive signals from a base station. A terminal may also be referred to as a terminal device, user equipment (UE), mobile station, mobile terminal, etc. Terminals can be widely used in various scenarios, such as device-to-device (D2D), vehicle-to-everything (V2X) communication, machine-type communication (MTC), Internet of Things (IoT), virtual reality, augmented reality, industrial control, autonomous driving, telemedicine, smart grid, smart furniture, smart office, smart wearable, smart transportation, smart city, etc. A terminal can be a mobile phone, tablet computer, computer with wireless transceiver capabilities, wearable device, vehicle, airplane, ship, robot, robotic arm, smart home device, etc. The embodiments of this application do not limit the specific technology and specific device form adopted by the terminal.

[0057] Base stations and terminals can be fixed or mobile. They can be deployed on land, indoors or outdoors, handheld or vehicle-mounted; on water; or on aircraft, balloons, and satellites. The embodiments of this application do not limit the application scenarios of base stations and terminals.

[0058] The roles of base stations and terminals can be relative. For example, the helicopter or drone 120i in Figure 1 can be configured as a mobile base station. To terminals 120j accessing the wireless access network 100 via 120i, terminal 120i is a base station. However, to base station 110a, 120i is a terminal, meaning that communication between 110a and 120i occurs via a wireless air interface protocol. Of course, communication between 110a and 120i can also occur via a base station-to-base station interface protocol. In this case, 120i is also a base station relative to 110a. Therefore, base stations and terminals can be collectively referred to as communication devices. 110a and 110b in Figure 1 can be referred to as communication devices with base station functionality, while 120a-120j in Figure 1 can be referred to as communication devices with terminal functionality.

[0059] In the embodiments of the present application, a base station is also referred to as a network device. The device for implementing the functions of the network device may be a network device; it may also be a device capable of supporting the network device to implement the functions, such as a chip system, a hardware circuit, a software module, or a hardware circuit plus a software module. The device may be installed in the network device or used in conjunction with the network device. In the embodiments of the present application, only the device for implementing the functions of the network device is used as an example for description, and does not constitute a limitation on the embodiments of the present application.

[0060] It is understandable that the present application can be applied between network devices and terminals.

[0061] The communication between network devices and terminals follows a certain protocol layer structure. This protocol layer structure may include a control plane protocol layer structure and a user plane protocol layer structure. For example, the control plane protocol layer structure may include the functions of protocol layers such as the radio resource control (RRC) layer, the PDCP layer, the radio link control (RLC) layer, the MAC layer, and the physical layer. For example, the user plane protocol layer structure may include the functions of protocol layers such as the PDCP layer, the RLC layer, the MAC layer, and the physical layer. In one possible implementation, an SDAP layer may also be included above the PDCP layer.

[0062] Optionally, the protocol layer structure between the network device and the terminal may also include an artificial intelligence (AI) layer for transmitting data related to AI functions.

[0063] Taking data transmission between network devices and terminals as an example, data transmission needs to pass through the user plane protocol layers, such as the SDAP layer, PDCP layer, RLC layer, MAC layer, and physical layer. The SDAP layer, PDCP layer, RLC layer, MAC layer, and physical layer can also be collectively referred to as the access layer. Data transmission is divided into sending or receiving based on the direction of transmission, and each of these layers is further divided into a sending part and a receiving part. Taking downlink data transmission as an example, after the PDCP layer obtains data from the upper layer, it transmits the data to the RLC layer and MAC layer. The MAC layer then generates a transport block, which is then wirelessly transmitted through the physical layer. Data is encapsulated accordingly in each layer. For example, data received by a layer from the layer above it is considered a service data unit (SDU) of that layer. After encapsulation by that layer, it becomes a protocol data unit (PDU) and is then passed to the next layer.

[0064] For example, a terminal may also have an application layer and a non-access layer. The application layer can be used to provide services to applications installed in the terminal. For example, downlink data received by the terminal can be sequentially transmitted from the physical layer to the application layer, and then provided to the application by the application layer. For another example, the application layer can obtain data generated by the application and sequentially transmit the data to the physical layer for transmission to other communication devices. The non-access layer can be used to forward user data, such as forwarding uplink data received from the application layer to the SDAP layer, or forwarding downlink data received from the SDAP layer to the application layer.

[0065] It should be understood that the number and type of each device in the communication system shown in Figure 1 are for illustration only, and the present application is not limited to this. In actual applications, the communication system may also include more terminals, more network devices, and other network elements, such as core network devices, and / or network elements for implementing artificial intelligence functions.

[0066] It is understandable that all or part of the functions implemented by one or more of the terminals, network devices, core network devices, or network elements for implementing artificial intelligence functions can be virtualized, that is, implemented by one or more of the proprietary processors or general-purpose processors and the corresponding software modules. Among them, since the terminals and network devices involve interfaces for air interface transmission, the transceiver functions of the interfaces can be implemented by hardware. Core network devices, such as operation administration and maintenance (OAM) network elements, can be virtualized. Optionally, one or more functions of the virtualized terminals, network devices, core network devices, or network elements for implementing artificial intelligence functions can be implemented by cloud devices, such as cloud devices in over the top (OTT) systems.

[0067] First, the concept of carrier aggregation involved in the embodiments of the present application is introduced:

[0068] Carrier aggregation is a key technology for addressing the limited bandwidth of a single carrier. It aggregates two or more component carriers to serve users, enabling greater transmission bandwidth. Figure 2 shows a schematic diagram of carrier aggregation, which aggregates the primary component carrier (PCC), secondary component carriers (SCC) 1, and SCC 2 to serve users.

[0069] In carrier aggregation, there may be multiple cells providing services for a single UE, that is, a UE may have multiple serving cells, including a primary cell (PCell) and one or more secondary cells (SCells).

[0070] The PCell is the cell where the UE establishes an initial connection, reestablishes an RRC connection, or is designated as the primary cell during a handover. The PCell is responsible for RRC communication with the UE. The carrier component corresponding to the PCell is called the primary carrier. The downlink carrier of the PCell is called the downlink primary carrier (DL PCC), and the uplink carrier of the PCell is called the uplink primary carrier (UL PCC).

[0071] An SCell is added by the UE during RRC reconfiguration to provide additional radio resources. No RRC communication occurs between the SCell and the UE. The carrier component corresponding to the SCell is called a secondary carrier. The downlink carrier of the SCell is called a downlink secondary carrier (DL SCC), and the uplink carrier of the SCell is called an uplink secondary carrier (UL SCC).

[0072] A serving cell may include only one downlink carrier, one downlink carrier and one uplink carrier, or one downlink carrier and two uplink carriers. Therefore, a serving cell may correspond one-to-one with a downlink carrier, and the concepts of carrier (referring to a downlink carrier unless otherwise specified) and cell in this application may be interchangeable.

[0073] Currently, the network's carrier resources mostly range from four to five component carriers (CCs), and more frequency bands are expected in the future. For example, there are currently five CCs: two 2.6GHz CCs, two 4.9GHz CCs, and one 700Mbps CC. With the opening of one 1.8GHz CC, one F-band CC, one A-band CC, and several U6G CCs, even more carrier resources are expected.

[0074] However, due to cost constraints, terminals are limited in the number of cells that can be scheduled simultaneously (or the maximum number of physical downlink shared channels (PDSCHs) that the terminal's baseband can process). This limits the number of carriers that can be supported simultaneously. Specifically, each PDSCH requires independent baseband processing units, such as FFT and post-FFT data buffering. The more cells that can be scheduled simultaneously (or the more PDSCHs that can be processed simultaneously), the greater the baseband implementation cost. Most current terminals only have two CCs capable of CA, or even no CA support at all.

[0075] In summary, the number of cells configured in the current network is much greater than the number of cells that can be scheduled simultaneously by terminals. In order to maximize user experience, it is necessary to enable limited terminal capabilities to flexibly use preferred carrier resources.

[0076] One cell scheduling technology is L1 / L2-triggered mobility (LTM). In this technology, the network configures multiple serving cells for the terminal. The number of configured serving cells is greater than the number of cells that can be simultaneously scheduled by the terminal. Only activated serving cells are counted towards the terminal's capacity consumption. As shown in Figure 3, a cell switching diagram based on LTM technology shows that the network configures four serving cells, CC1 to CC4, for the terminal, while the number of cells that can be simultaneously scheduled by the terminal is two. When the network uses LTM technology and Layer 2 signaling to indicate a cell switch, the CC corresponding to the PCell switches. In Figure 3, the CC corresponding to the PCell switches from CC1 to CC3. When the CC corresponding to the PCell switches, the CC corresponding to the SCell may or may not change. In Figure 3, the CC corresponding to the SCell switches from CC2 to CC4. Layer 2 signaling is used to indicate cell switching, and the switching time is approximately 10ms. This layer 2 signaling includes the medium access control-control element (MAC CE) activation signal, which takes approximately 5ms; the ASN.1 decoding time and Layer 2 / Layer 3 reconfiguration (L2 / 3re-cfg.) time, which takes approximately 1-6ms; and the baseband adjustment time (BB retuning) and radio frequency adjustment time (RF retuning), which take approximately 1-2ms. However, as can be seen above, for this LTM technology, PCell switching must be performed when performing cell switching, and the scenario of only SCell switching is not supported.

[0077] Another cell switching indication technology can support SCell switching only, which is performed through the Layer 3 (L3) signaling process, including radio resource control reconfiguration signaling (RRC re-configuration signaling), secondary cell activation (SCell activation) and radio resource control completion signaling (RRC complete signaling), with a delay of about 50ms, which is relatively large.

[0078] Another technology is uplink transmit switching (UL Tx switching). As shown in Figure 4, the network configures and activates multiple uplink serving cells for the terminal. The number of activated uplink serving cells is greater than or equal to the number of the terminal's transmit antennas. This technology uses Layer 1 signaling to schedule and instruct the terminal's transmit antennas to switch between different cells, enabling dynamic switching of the terminal's limited number of transmit antennas between multiple cells. This interruption lasts for approximately several hundred microseconds. However, this technology is essentially designed to address the issue of a limited number of uplink transmit antennas for the terminal, and does not yet support cell switching when the number of cells that can be simultaneously scheduled by the terminal during downlink transmission is limited.

[0079] It can be seen that the above technologies are unable to fully and dynamically utilize downlink spectrum resources, and thus cannot enable limited terminal capabilities to flexibly use preferred carrier resources.

[0080] To this end, the present application provides a downlink carrier switching solution, which dynamically indicates the target secondary cell for downlink transmission through downlink control information. When a secondary cell switching occurs, the terminal only needs to switch the corresponding downlink RF receiver to the target secondary cell, and the switching delay is short. This enables the terminal to dynamically use the preferred carrier resources with limited capabilities, thereby achieving dynamic and fast switching, shortening the switching delay, and enabling rapid adaptation to dynamic changes in channels and loads of different carriers.

[0081] The downlink carrier switching method provided by the embodiment of the present application is described in detail below.

[0082] As shown in Figure 5, a flowchart of a downlink carrier switching method provided in an embodiment of the present application is provided. Exemplarily, the method may include the following steps:

[0083] S501. A network device sends downlink control information (DCI) to a terminal on a primary cell in a first time unit. Correspondingly, the terminal receives the DCI on the primary cell in the first time unit.

[0084] In carrier aggregation, the network equipment can configure one or more serving cells for a single terminal, that is, a terminal can have multiple serving cells, including one PCell and one or more SCells. Among them, PCell is also called a special cell (SpCell). The number of cells configured by the network equipment is much larger than the number of cells that the terminal can be scheduled simultaneously, or the number of cells that the terminal can be scheduled simultaneously is much smaller than the number of cells configured by the network equipment, that is, the terminal cannot be scheduled at the same time in all the cells configured by the network equipment. The number of cells that the terminal can be scheduled simultaneously can also be called the maximum number of PDSCHs that the terminal can process. Among them, the serving cell represents the wireless coverage area that works on a specific carrier to serve the terminal.

[0085] The network device can instruct the terminal to switch carriers based on the channel and load of the carrier. In this embodiment, the network device does not switch the PCell, but indicates the switching of the SCell on the PCell. Therefore, it can also be called the PCell indicating the switching of the SCell. For example, the network device sends a DCI to the terminal on the PCell in the first time unit. The DCI is used to schedule the transmission of the PDSCH on the target secondary cell, that is, to instruct the terminal to switch from the source SCell to the target SCell and receive the PDSCH on the target SCell. Among them, the source SCell can also be called the SCell before the switch; the target SCell can also be called the SCell after the switch.

[0086] Furthermore, the DCI may include an identifier of the target SCell. Each SCell has a unique identifier.

[0087] S502. The network device sends a PDSCH to the terminal in the target secondary cell at a second time unit according to the DCI. Correspondingly, the terminal receives the PDSCH in the target secondary cell at a second time unit according to the DCI.

[0088] After receiving the above-mentioned DCI, the terminal receives the PDSCH on the target SCell in the second time unit according to the instruction of the DCI.

[0089] The second time unit is the Nth time unit after the first time unit, and N is an integer greater than or equal to 0.

[0090] Depending on the scheduling scenario, there are several switching methods:

[0091] One implementation is that the PCell schedules the downlink transmission of the SCell across time units, where the PCell is scheduled in a first time unit, and the scheduling target SCell transmits the PDSCH in a second time unit. Cross-time unit scheduling means that the time interval N between the second time unit and the first time unit is an integer greater than 0. The time unit can be any of a subframe, a time slot, a mini-time slot, a symbol, etc., and the following description will use the time unit as a time slot.

[0092] As shown in Figure 6, a schematic diagram of a PCell scheduling SCell across time units in an example embodiment of the present application is shown. In this implementation, in addition to scheduling the downlink transmission of its own cell, the PCell can also schedule the downlink transmission of the SCell. In Figure 6, the network device configures the PCell and SCell1 to SCell3 for the terminal. The number of service cells scheduled by the PCell at the same time does not exceed the maximum number of PDSCHs that the terminal can process. In Figure 6, the number of cells that the terminal can schedule simultaneously is 2. In particular, in one or more time slots before carrier switching occurs, the PCell will not only schedule the transmission of the SCell in the current time slot (i.e., the SCell before switching or the source SCell in this embodiment), but will also schedule the transmission of the SCell after switching (i.e., the target SCell in this embodiment) across time slots. The PCell can schedule the downlink transmission on the SCell by sending DCI signaling. After the terminal receives the DCI for cross-time slot scheduling sent by the network device, it will switch the RF receiver (Rx) to the carrier indicated by the cross-time slot scheduling DCI after the corresponding time slot, and demodulate the downlink data on the corresponding time-frequency resources indicated by the cross-time slot scheduling DCI.

[0093] Since it takes time for the terminal to switch the downlink (DL) Rx, this time is called the cell switching gap (switching gap, abbreviated as Gap), which is used to indicate the time required to switch from the source secondary cell to the target secondary cell. From the perspective of frame timing, in this implementation, the switching gap occurs on the carrier (SCell2) after switching, that is, the second time unit includes the cell switching gap. Exemplarily, the terminal can report the above-mentioned cell switching interval supported by itself to the network device, such as 210us. For example, the terminal sends first information to the network device, wherein the first information includes the cell switching interval. The cell switching interval is based on the hardware capabilities of the terminal.

[0094] When the PCell schedules the SCell across time slots, the network equipment and terminal calculate the number of time slots N across time slots using the switching gap. This determines the time slot in which the PDSCH of the carrier after the switch occurs. N is associated with at least one of the following: the cell switching interval, the index of the time slot containing the downlink control information, the numerology index of the carrier or bandwidth portion containing the physical downlink shared channel, the numerology index of the carrier or bandwidth portion containing the physical downlink control channel carrying downlink control information, and K0 corresponding to the target secondary cell.

[0095] In one example, the time slot K of the PDSCH of the carrier after switching is S Satisfies the following formula 1:

[0096] Where n is the timeslot index where the DCI is located; μPDSCH is the numeric index of the carrier / bandwidth part (BWP) where the PDSCH is located; μPDCCH is the numeric index of the carrier / BWP where the physical downlink control channel (PDCCH) is located; The time slot index n of DCI is converted into the corresponding time slot index under PDSCH numerology; T SwichingGap is the cell switching interval mentioned above; K0 is the time slot interval between the PDCCH and the PDSCH it schedules. Figure 7 shows a schematic diagram of data scheduling in an embodiment of the present application. When K0 = 0, it means that the PDCCH schedules the PDSCH in the same time slot; when K0 = 1, it means that the PDCCH schedules the PDSCH in the next time slot.

[0097] The K0 of the target SCell (SCell2) is greater than or equal to the K0 of the source SCell (SCell1), thereby ensuring that the source SCell (SCell1) has stopped transmitting when the Rx is switched off.

[0098] Another implementation is that the PCell schedules the downlink transmission of the SCell across time units, where the PCell is scheduled in a first time unit, and the scheduling target SCell transmits the PDSCH in a second time unit. Cross-time unit scheduling means that the time interval N between the second time unit and the first time unit is an integer greater than 0. The time unit can be any of a subframe, a time slot, a mini-time slot, a symbol, etc., and the following description will use the time unit as a time slot.

[0099] As shown in Figure 8, it is a schematic diagram of another embodiment of the present application of PCell scheduling SCell across time units. Similar to the above implementation, in this implementation, in addition to scheduling the downlink transmission of its own cell, the PCell can also schedule the downlink transmission of the SCell. In Figure 8, the network device configures the PCell and SCell1 to SCell3 for the terminal. The number of service cells scheduled by the PCell at the same time does not exceed the maximum number of PDSCHs that the terminal can process. In Figure 8, the number of cells that the terminal can schedule simultaneously is 2. In particular, in one or more time slots before the carrier switching occurs, the PCell will not only schedule the transmission of the SCell in the current time slot (i.e., the SCell before switching or the source SCell in this embodiment), but also schedule the transmission of the SCell after switching (i.e., the target SCell in this embodiment) across time slots. The PCell can schedule the downlink transmission on the SCell by sending DCI signaling. After the terminal receives the DCI for cross-time slot scheduling sent by the network device, it will switch the Rx to the carrier indicated by the cross-time slot scheduling DCI after the corresponding time slot, and demodulate the downlink data on the corresponding time-frequency resources indicated by the cross-time slot scheduling DCI.

[0100] Since it takes time for the terminal to switch DLRx, this time is called the switching gap, which is used to indicate the time required to switch from the source secondary cell to the target secondary cell. From the perspective of frame timing, unlike the above implementation, in this implementation, the switching gap occurs on the carrier (SCell1) before the switch, that is, the first time unit includes the switching gap. At this time, the PDSCH resource indicated by the DCI of the carrier (SCell1) before the scheduling switch is empty. Exemplarily, the terminal can report the above-mentioned cell switching interval supported by itself to the network device, such as 210us. For example, the terminal sends first information to the network device, where the first information includes the cell switching interval. The cell switching interval is based on the hardware capabilities of the terminal.

[0101] When the PCell schedules the SCell across time slots, the network and terminal calculate the number of time slots N using the switching gap, which determines the time slot in which the PDSCH of the carrier after switching is located. N is associated with at least one of the following: the index of the time slot in which the DCI is located, the numerology index of the carrier or bandwidth portion in which the PDSCH is located, the numerology index of the carrier or bandwidth portion in which the PDCCH carrying the DCI is located, and K0 corresponding to the target secondary cell.

[0102] In one example, the time slot K of the PDSCH of the carrier after switching is S Satisfies the following formula 2:

[0103] Where n is the timeslot index where the DCI is located; μPDSCH is the numerology index of the carrier / BWP where the PDSCH is located; μPDCCH is the numerology index of the carrier / BWP where the PDCCH is located; The time slot index n of the DCI is converted into the corresponding time slot index under PDSCH numerology; K0 is the time slot interval between the PDCCH and the PDSCH it schedules.

[0104] The K0 of the target SCell (SCell2) is greater than or equal to the K0 of the source SCell (SCell1), thereby ensuring that the source SCell (SCell1) has stopped transmitting when the Rx is switched off.

[0105] Another implementation is that PCell schedules downlink transmission of SCell in the same time unit, where PCell is scheduled in the first time unit, and the scheduling target SCell transmits PDSCH in the second time unit, and the time interval N between the second time unit and the first time unit is 0, that is, the first time unit = the second time unit.

[0106] As shown in Figure 9, a schematic diagram of a PCell scheduling SCell within the same time unit is shown in an example of an embodiment of the present application. In this implementation, in addition to scheduling the downlink transmission of its own cell, the PCell can also schedule the downlink transmission of the SCell. In Figure 8, the network device configures the terminal with PCell and SCell1 to SCell3. The number of service cells scheduled by the PCell at the same time does not exceed the maximum number of PDSCHs that the terminal can process. In Figure 6, the number of cells that can be scheduled simultaneously by the terminal is 2. In particular, the DCI schedules the downlink transmission on the target SCell within the time unit, and the DCI also includes the start and length indicator value (SLIV) of the PDSCH. As shown in Figure 10, another schematic diagram of data scheduling is shown in an example of an embodiment of the present application. SLIV refers to the start and length indicator value. The terminal can calculate the index value S of the starting OFDM symbol of the PDSCH in the time slot and the time domain length L of the PDSCH based on the SLIV value. In this implementation, the SLIV is greater than the first threshold, so that the terminal's Rx has sufficient time to perform blind detection and parse the DCI. In this case, the first threshold is associated with the cell switching interval. The meaning of the cell switching interval can be referred to the above description.

[0107] The downlink carrier switching method provided in the embodiments of this application dynamically indicates the SCell for PDSCH transmission via DCI signaling. When an SCell switch occurs, the terminal only needs to switch the corresponding DLRx to the target SCell. The switching gap can be as short as several hundred microseconds, enabling dynamic and rapid switching, better adapting to dynamic changes in carrier channels and loads, and improving the user experience. Compared to existing technologies, this method uses Layer 1 DCI signaling to indicate the SCell. The terminal dynamically switches the carrier where the DLRx resides based on this indication, thus achieving dynamic SCell switching.

[0108] It is understandable that this application uses network devices and terminals as examples of the execution entities of the interactive diagrams, but this application does not limit the execution entities of the interactive diagrams. For example, the network device in the method provided by this application may also be a chip, chip system, or processor applied to the network device, or a logical node, logic module, or software that can implement all or part of the network device; the terminal in the method provided by this application may also be a chip, chip system, or processor applied to the terminal, or a logical node, logic module, or software that can implement all or part of the terminal functions.

[0109] In this application, when entity A sends information to entity B, it can be done directly from A to B or indirectly through another entity. Similarly, when entity B receives information from entity A, it can be done directly from entity B or indirectly through another entity. Entities A and B herein can be RAN nodes or terminals, or modules within a RAN node or terminal. The sending and receiving of information can be information exchange between a RAN node and a terminal, for example, between a base station and a terminal; the sending and receiving of information can also be information exchange between two RAN nodes, for example, between a CU and a DU; the sending and receiving of information can also be information exchange between different modules within a device, for example, between a terminal chip and other modules in the terminal, or between a base station chip and other modules within the base station.

[0110] It can be understood that in the above embodiments, the methods and / or steps implemented by the network device can also be implemented by components (such as chips or circuits) that can be used for the network device; the methods and / or steps implemented by the terminal can also be implemented by components (such as chips or circuits) that can be used for the terminal.

[0111] The above description primarily describes the solutions provided by the embodiments of the present application from the perspective of interaction between various network elements. Accordingly, the embodiments of the present application also provide a communication device for implementing the various methods described above. The communication device may be a network device or a component usable in a network device in the above method embodiments; alternatively, the communication device may be a terminal or a component usable in a terminal in the above method embodiments. It will be understood that, to implement the aforementioned functions, the communication device includes hardware structures and / or software modules corresponding to the respective functions. Those skilled in the art will readily appreciate that, in conjunction with the various exemplary units and algorithm steps described in the embodiments disclosed herein, the present application can be implemented in hardware or a combination of hardware and computer software. Whether a function is implemented in hardware or in a hardware-driven manner by computer software depends on the specific application and design constraints of the technical solution. Professionals and technicians may use different methods to implement the described functions for each specific application, but such implementations should not be considered beyond the scope of this application.

[0112] In the embodiment of the present application, the functional modules of the communication device can be divided according to the above method embodiment. For example, each functional module can be divided according to each function, or two or more functions can be integrated into one processing unit. The above integrated modules can be implemented in the form of hardware or in the form of software functional modules. It should be noted that the division of modules in the embodiment of the present application is schematic and is only a logical functional division. In actual implementation, there may be other division methods.

[0113] Based on the same concept of the above-mentioned downlink carrier switching method, the present application also provides the following communication device:

[0114] As shown in FIG11 , a schematic diagram of the structure of a communication device provided in an embodiment of the present application is shown. The communication device 1100 includes a transceiver unit 1101 and a processing unit 1102 .

[0115] When the communication device is used to implement the functions of the terminal in the above method embodiment, the transceiver unit 1101 can be used to execute the operations of the terminal in steps S501 and S502 in the embodiment shown in FIG5 .

[0116] When the communication device is used to implement the functions of the network device in the above method embodiment, the transceiver unit 1101 can be used to execute the operations of the network device in steps S501 and S502 in the embodiment shown in FIG5 .

[0117] For the specific implementation of the above-mentioned transceiver unit 1101 and the processing unit 1102, reference may be made to the description in the above-mentioned method embodiment.

[0118] As shown in Figure 12, it is a structural diagram of another communication device provided in an embodiment of the present application, and the communication device 1200 includes a processor 1201. Optionally, the communication device 1200 may further include an interface circuit 1202 (represented by a dotted line in the figure), and the processor 1201 and the interface circuit 1202 are coupled to each other. It will be understood that the interface circuit 1202 can be a transceiver or an input and output interface. Optionally, the communication device 1200 may further include a memory 1203 (represented by a dotted line in the figure), and the memory 1203 is used to store instructions executed by the processor 1201, or to store input data required for the processor 1201 to run the instructions, or to store data generated after the processor 1201 runs the instructions. Among them, the processor 1201 is used to implement the function of the processing unit 1102 in the embodiment shown in Figure 11 above; and the interface circuit 1202 is used to implement the function of the transceiver unit 1101 in the embodiment shown in Figure 11 above.

[0119] When the communication device is a chip used in a network device, the chip implements the functions of the network device in the above method embodiments. The chip receives information from other modules in the network device (such as a radio frequency module or antenna), and the information is sent by the terminal to the network device; or the chip sends information to other modules in the network device (such as a radio frequency module or antenna), and the information is sent by the network device to the terminal.

[0120] When the communication device is a chip used in a terminal, the chip implements the terminal functions in the above method embodiments. The chip receives information from other modules in the terminal (such as a radio frequency module or antenna), which is information sent by the network device to the terminal; or the chip sends information to other modules in the terminal (such as a radio frequency module or antenna), which is information sent by the terminal to the network device.

[0121] In addition, it should be noted that the aforementioned transceiver unit and / or processing unit may be implemented through virtual modules, for example, the processing unit may be implemented through a software function unit or a virtual device, and the transceiver unit may be implemented through a software function or a virtual device. Alternatively, the processing unit or transceiver unit may also be implemented through a physical device, for example, if the device is implemented using a chip / chip circuit, the transceiver unit may be an input / output circuit and / or a communication interface, performing input operations (corresponding to the aforementioned receiving operations) and output operations (corresponding to the aforementioned sending operations); the processing unit is an integrated processor or microprocessor or integrated circuit.

[0122] The division of modules in this application is illustrative and represents only a logical functional division. In actual implementation, other division methods may be used. Furthermore, the functional modules in the examples of this application may be integrated into a single processor, exist physically as separate modules, or two or more modules may be integrated into a single module. The aforementioned integrated modules may be implemented in either hardware or software functional modules.

[0123] It is understood that the processor in the embodiments of the present application may be a central processing unit (CPU), or may be other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), field programmable gate arrays (FPGA), or other programmable logic devices, transistor logic devices, hardware components, or any combination thereof. The general-purpose processor may be a microprocessor or any conventional processor.

[0124] An embodiment of the present application further provides a computer-readable storage medium, in which a computer program or instruction is stored. When the computer program or instruction is executed, the method in the above embodiment is implemented.

[0125] An embodiment of the present application further provides a computer program product comprising instructions, which, when executed on a computer, enables the computer to execute the method in the above embodiment.

[0126] An embodiment of the present application also provides a communication system, including the above-mentioned communication device.

[0127] The present application also provides a circuit, which is coupled to a memory and is used to execute the method shown in the above embodiment. The circuit may include a chip circuit.

[0128] When the above-mentioned communication device is a module applied to a base station, the base station module implements the functions of the base station in the above-mentioned method embodiment. The base station module receives information from other modules in the base station (such as a radio frequency module or an antenna), and the information is sent by the terminal to the base station; or, the base station module sends information to other modules in the base station (such as a radio frequency module or an antenna), and the information is sent by the base station to the terminal. The base station module here can be a baseband chip of a base station, or a CU, DU or other module, or a device under an open radio access network (O-RAN) architecture, such as an open CU, open DU or other devices.

[0129] It should be noted that the above units or one or more of the units can be implemented by software, hardware, or a combination of the two. When any of the above units or units is implemented by software, the software exists in the form of computer program instructions and is stored in a memory, and a processor can be used to execute the program instructions and implement the above method flow.

[0130] In this application, a processor may be a general-purpose processor, a digital signal processor, an application-specific integrated circuit, a field-programmable gate array or other programmable logic device, a discrete gate or transistor logic device, or a discrete hardware component, and may implement or execute the methods, steps, and logic block diagrams disclosed in this application. A general-purpose processor may be a microprocessor or any conventional processor. The steps of the methods disclosed in this application may be directly executed by a hardware processor, or by a combination of hardware and software modules within the processor.

[0131] When the above units or units are implemented in hardware, the hardware can be any one or any combination of a CPU, a microprocessor, a DSP, a microcontroller unit (MCU), an artificial intelligence processor, an ASIC, a SoC, an FPGA, a PLD, a dedicated digital circuit, a hardware accelerator or a non-integrated discrete device, which can run the necessary software or not rely on the software to execute the above method flow.

[0132] Optionally, an embodiment of the present application further provides a chip system, comprising: at least one processor and an interface, wherein the at least one processor is coupled to a memory via the interface, and when the at least one processor executes a computer program or instruction in the memory, the chip system executes the method in any of the above method embodiments. Optionally, the chip system may be composed of a chip, or may include a chip and other discrete devices, which is not specifically limited in the embodiments of the present application.

[0133] The memory in the present application may also be a circuit or any other device capable of implementing a storage function for storing program instructions and / or data. A memory is any other medium that can be used to carry or store a desired program code in the form of an instruction or data structure and can be accessed by a computer, but is not limited thereto. For example, the memory may be a non-volatile memory, such as a digital versatile disc (DVD), a hard disk drive (HDD), or a solid-state drive (SSD), or a volatile memory, such as a random-access memory (RAM).

[0134] The at least one (item) involved in this application indicates one (item) or more (items). More than one (item) refers to two (items) or more than two (items). "And / or" describes the association relationship of associated objects, indicating that three relationships may exist. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. The character " / " generally indicates that the previous and next associated objects are in an "or" relationship. In addition, it should be understood that although the terms first, second, etc. may be used to describe each object in this application, these objects should not be limited to these terms. These terms are only used to distinguish each object from each other.

[0135] The terms "including" and "having" mentioned above and any variations thereof are intended to cover non-exclusive inclusions. For example, a process, method, system, product or device that includes a series of steps or units is not limited to the listed steps or units, but may optionally include other steps or units that are not listed, or may optionally include other steps or units that are inherent to these processes, methods, products or devices. It should be noted that, in this application, words such as "exemplary" or "for example" are used to indicate examples, illustrations or explanations. Any method or design described in this application as "exemplary" or "for example" should not be interpreted as being more preferred or more advantageous than other methods or designs. Specifically, the use of words such as "exemplary" or "for example" is intended to present related concepts in a concrete way.

[0136] A network element in a communication system can send signals to or receive signals from another network element. The signals may include information, signaling, or data. The network element can also be replaced by an entity, a network entity, a device, a terminal, a communication module, a node, a communication node, etc. The network element is used as an example for description in this application. For example, a communication system may include at least one terminal and at least one network device. The network device can send downlink signals to the terminal, and / or the terminal can send uplink signals to the network device. In addition, it is understood that if the communication system includes multiple terminals, the multiple terminals can also send signals to each other, that is, the signal sending network element and the signal receiving network element can both be terminals.

[0137] In the above embodiments, it can be implemented in whole or in part by software, hardware, firmware or any combination thereof. When implemented using a software program, 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 wired (e.g., coaxial cable, optical fiber, digital subscriber line (DSL)) or wireless (e.g., infrared, wireless, microwave, etc.) means.

[0138] Although the present application is described herein in conjunction with various embodiments, in the process of implementing the claimed application, those skilled in the art can understand and implement other changes to the disclosed embodiments by reviewing the drawings, the disclosure, and the appended claims. In the claims, the word "comprising" does not exclude other components or steps, and "a" or "an" does not exclude multiple situations. A single processor or other unit can implement several functions listed in the claims. Certain measures are recorded in different dependent claims, but this does not mean that these measures cannot be combined to produce good results.

[0139] It is understood that the various numbers used in the embodiments of this application are merely for ease of description and are not intended to limit the scope of the embodiments of this application. The order of the sequence numbers of the above-mentioned processes does not necessarily imply a specific order of execution; the order of execution of the processes should be determined by their functions and inherent logic.

[0140] In the above embodiments, the description of each embodiment has its own focus. For parts that are not described in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0141] The components in the device of the embodiment of the present application can be merged, divided, or deleted according to actual needs. Those skilled in the art can combine or combine the different embodiments and features of the different embodiments described in this specification.

[0142] In this application, under the premise of no logical contradiction, the examples can reference each other, for example, the methods and / or terms between method embodiments can reference each other, for example, the functions and / or terms between device embodiments can reference each other, for example, the functions and / or terms between device examples and method examples can reference each other.

Claims

1. A downlink carrier switching method, characterized in that: The method comprises: Receiving downlink control information on a primary cell in a first time unit, where the downlink control information is used to schedule transmission of a physical downlink shared channel on a target secondary cell; According to the downlink control information, the source secondary cell switches to the target secondary cell to receive the physical downlink shared channel in a second time unit, wherein the second time unit is the Nth time unit after the first time unit, and N is an integer greater than or equal to 0.

2. The method according to claim 1, characterized in that The method further comprises: First information is sent, where the first information includes a cell switching interval, where the cell switching interval is used to indicate a time required for switching from the source secondary cell to the target secondary cell, and the cell switching interval is based on a hardware capability of the terminal.

3. The method according to claim 2, characterized in that The N is an integer greater than 0, the second time unit includes the cell switching interval, and the N is associated with at least one of the following: the cell switching interval, the index of the time slot where the downlink control information is located, the number of the numerology of the carrier or part of the bandwidth where the physical downlink shared channel is located, the number of the numerology of the carrier or part of the bandwidth where the physical downlink control channel carrying the downlink control information is located, and the K0 corresponding to the target secondary cell; The K0 corresponding to the target secondary cell is greater than the K0 corresponding to the source secondary cell, wherein the K0 is a time slot interval between a physical downlink control channel and a physical downlink shared channel scheduled by the channel.

4. The method according to claim 2, characterized in that The N is an integer greater than 0, the first time unit includes the cell switching interval, and the N is associated with at least one of the following: the index of the time slot where the downlink control information is located, the number of the numerology of the carrier or part of the bandwidth where the physical downlink shared channel is located, the number of the numerology of the carrier or part of the bandwidth where the physical downlink control channel carrying the downlink control information is located, and the K0 corresponding to the target secondary cell; The K0 corresponding to the target secondary cell is greater than the K0 corresponding to the source secondary cell, wherein the K0 is a time slot interval between a physical downlink control channel and a physical downlink shared channel scheduled by the channel.

5. The method according to claim 2, characterized in that The N=0, the second time unit includes the cell switching interval, the downlink control information also includes the start and length indication values ​​of the physical downlink shared channel, the start and length indication values ​​are greater than a first threshold, and the first threshold is associated with the cell switching interval.

6. The method according to any one of claims 1 to 5, characterized in that The downlink control information includes an identifier of the target secondary cell.

7. The method according to any one of claims 1 to 6, characterized in that The number of the target secondary cells is less than or equal to the maximum number of physical downlink shared channels that can be processed by the terminal.

8. A downlink carrier switching method, characterized in that: The method comprises: Sending downlink control information on a primary cell in a first time unit, where the downlink control information is used to schedule transmission of a physical downlink shared channel on a target secondary cell; The physical downlink shared channel is sent in the target secondary cell in a second time unit according to the downlink control information, wherein the second time unit is the Nth time unit after the first time unit, and N is an integer greater than or equal to 0.

9. The method according to claim 8, characterized in that The method further comprises: First information is received, where the first information includes a cell switching interval, where the cell switching interval is used to indicate a time required for switching from the source secondary cell to the target secondary cell, and the cell switching interval is based on a hardware capability of a terminal.

10. The method according to claim 9, characterized in that The N is an integer greater than 0, the second time unit includes the cell switching interval, and the N is associated with at least one of the following: the cell switching interval, the index of the time slot where the downlink control information is located, the number of the numerology of the carrier or part of the bandwidth where the physical downlink shared channel is located, the number of the numerology of the carrier or part of the bandwidth where the physical downlink control channel carrying the downlink control information is located, and the K0 corresponding to the target secondary cell; The K0 corresponding to the target secondary cell is greater than the K0 corresponding to the source secondary cell, wherein the K0 is a time slot interval between a physical downlink control channel and a physical downlink shared channel scheduled by the channel.

11. The method according to claim 9, characterized in that The N is an integer greater than 0, the first time unit includes the cell switching interval, and the N is associated with at least one of the following: the index of the time slot where the downlink control information is located, the number of the numerology of the carrier or part of the bandwidth where the physical downlink shared channel is located, the number of the numerology of the carrier or part of the bandwidth where the physical downlink control channel carrying the downlink control information is located, and the K0 corresponding to the target secondary cell; The K0 corresponding to the target secondary cell is greater than the K0 corresponding to the source secondary cell, wherein the K0 is a time slot interval between a physical downlink control channel and a physical downlink shared channel scheduled by the channel.

12. The method according to claim 9, characterized in that The N=0, the second time unit includes the cell switching interval, the downlink control information also includes the start and length indication values ​​of the physical downlink shared channel, the start and length indication values ​​are greater than a first threshold, and the first threshold is associated with the cell switching interval.

13. The method according to any one of claims 8 to 12, characterized in that The downlink control information includes an identifier of the target secondary cell.

14. The method according to any one of claims 8 to 13, characterized in that The number of the target secondary cells is less than or equal to the maximum number of physical downlink shared channels that can be processed by the terminal.

15. A communication device, characterized in that: The method comprises a unit for implementing the method according to any one of claims 1 to 7, or comprises a unit for implementing the method according to any one of claims 8 to 14.

16. A communication device, characterized in that: The method comprises a processor and an interface circuit, wherein the interface circuit is used to receive signals from other communication devices and transmit them to the processor or send signals from the processor to other communication devices, and the processor is used to implement the method as claimed in any one of claims 1 to 7 or to implement the method as claimed in any one of claims 8 to 14 through a logic circuit or by executing code instructions.

17. A computer-readable storage medium, characterized in that: The storage medium stores a computer program or instruction, and when the computer program or instruction is executed by the communication device, the method according to any one of claims 1 to 14 is implemented.

18. A computer program product, characterized in that The computer program product comprises program instructions, and when the program instructions are executed, the method according to any one of claims 1 to 14 is implemented.

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