Communication method and communication apparatus

Abstract

Provided in the present application are a communication method and a communication apparatus. The communication method comprises: if a condition for determining a first slot to be a downlink slot is met, determining the first slot to be the downlink slot, wherein the first slot comprises a first symbol configured with a synchronization signal block (SSB), and frequency-domain resources in two transmission directions are configured on the first symbol; or, determining a first slot in a subband full duplex (SBFD) period and a second slot before or after the first slot to be downlink slots, wherein the second slot comprises a first symbol, and the first symbol comprised in the second slot is not configured with an SSB; or, if there are N non-consecutive first slots in an SBFD period, determining the N non-consecutive first slots and a second slot between the N non-consecutive first slots to be downlink slots, wherein N is a positive integer greater than or equal to 2; and performing communication on the basis of the determined first slot(s).

Description

Communication methods and communication devices

[0001] This application claims priority to Chinese Patent Application No. 202411017241.7, filed on July 26, 2024, entitled "Communication Method and Communication Apparatus", the entire contents of which are incorporated herein by reference. Technical Field

[0002] This application relates to the field of communications, and more particularly to a communication method and a communication device. Background Technology

[0003] To further reduce latency and enhance uplink coverage in Time Division Duplex (TDD) systems, the concept of Subband Full Duplex (SBFD) is introduced. SBFD refers to the simultaneous allocation of frequency domain resources for uplink and downlink transmission on certain symbols. These symbols are often referred to as SBFD symbols, and the frequency domain resources allocated for uplink transmission on these symbols can be called, for example, uplink subband (UL subband, UL SB), while the frequency domain resources allocated for downlink transmission can be called, for example, downlink subband (DL subband, DL SB).

[0004] To enable terminal devices to access the cell, network devices send parameters to the terminal devices for configuring the SSB. These parameters include, but are not limited to, the position of the symbol occupied by the SSB and the frequency domain position occupied by the SSB.

[0005] However, there may be instances where the configured SSB occupies symbols including SBFD symbols. In such cases, how network devices and terminal devices communicate becomes a pressing technical problem that needs to be solved. Summary of the Invention

[0006] This application provides a communication method and a communication apparatus to enable communication between network devices and terminal devices when the symbols occupied by the configured SSB include SBFD symbols.

[0007] Firstly, this application provides a communication method, which can be executed by a terminal device, or by a component (such as a chip, chip system, etc.) configured in the terminal device, or by a logic module or software capable of implementing all or part of the functions of the terminal device; this application does not limit this. In this application, a terminal device is used as an example for description.

[0008] For example, the communication method includes: determining the first time slot as a downlink time slot if the condition for determining the first time slot as a downlink time slot is met, wherein the first time slot includes a first symbol configured with a synchronization signal block (SSB), and the first symbol is configured with frequency domain resources for two transmission directions; or,

[0009] The first time slot within a sub-band full-duplex SBFD cycle and the second time slot before or after the first time slot are defined as downlink time slots, wherein the second time slot includes the first symbol and the first symbol included in the second time slot is not configured with the SSB; or...

[0010] If there are N discontinuous first time slots within an SBFD cycle, then the N discontinuous first time slots and the second time slots between the N discontinuous first time slots are determined as downlink time slots, where N is a positive integer greater than or equal to 2;

[0011] Communication is based on a determined first time slot.

[0012] In this application, if the condition for determining the first time slot as a downlink time slot is met, then the first time slot is determined as a downlink time slot. This can also be interpreted as: if the condition for switching the first time slot as a downlink time slot is met, then the first time slot is switched to a downlink time slot.

[0013] Similarly, defining the first time slot and the second time slot before or after the first time slot within a sub-band full-duplex SBFD cycle as the downlink time slot can also be interpreted as: switching the first time slot and the second time slot before or after the first time slot within a sub-band full-duplex SBFD cycle to the downlink time slot.

[0014] Similarly, if there are N discontinuous first time slots within an SBFD cycle, then the N discontinuous first time slots and the second time slot between the N discontinuous first time slots are determined as downlink time slots. This can also be interpreted as: if there are N discontinuous first time slots within an SBFD cycle, then the N discontinuous first time slots and the second time slot between the N discontinuous first time slots are switched to downlink time slots.

[0015] In this application, the first symbol is also referred to as the SBFD symbol. Both the first time slot and the second time slot include the SBFD symbol; therefore, both the first time slot and the second time slot are also referred to as SBFD time slots. However, it is understood that the difference between the first time slot and the second time slot is that the first time slot is a time slot with an SSB configured on the SBFD symbol, while the second time slot is a time slot without an SSB configured on the SBFD symbol.

[0016] In this application, a downlink time slot refers to a time slot that consists only of downlink symbols. That is, a time slot composed solely of downlink symbols is called a downlink time slot.

[0017] Understandably, if the conditions for switching the first time slot to a downlink time slot are met, then the first time slot will be designated as a downlink time slot. In another interpretation, if the conditions for designating the first time slot as a downlink time slot are not met, then the terminal device will not designate the first time slot as a downlink time slot.

[0018] Optionally, if the first time slot is determined as a downlink time slot based on satisfying the condition that the first time slot is determined as a downlink time slot, the condition includes the condition that the number of first symbols in the first time slot satisfies.

[0019] For example, the number of first symbols in the first time slot may satisfy one or more of the following conditions: the number of first symbols in the first time slot is less than a first threshold, the ratio of the number of first symbols in the first time slot to the number of downlink symbols in the first time slot is less than a second threshold, and the ratio of the number of first symbols in the first time slot to the number of symbols other than the first symbols in the first time slot is less than a third threshold.

[0020] For example, the number of first symbols in the first time slot may satisfy one or more of the following conditions: the number of first symbols in the first time slot is less than or equal to a first threshold, the ratio of the number of first symbols in the first time slot to the number of downlink symbols in the first time slot is less than or equal to a second threshold, and the ratio of the number of first symbols in the first time slot to the number of symbols other than the first symbols in the first time slot is less than or equal to a third threshold.

[0021] Optionally, if the first time slot is determined as a downlink time slot based on satisfying the condition that the first time slot is determined as a downlink time slot, the condition includes the condition that the number of first symbols in the first time slot that are not configured with the SSB is satisfied.

[0022] For example, the number of first symbols without configured SSBs in the first time slot may satisfy one or more of the following conditions: the number of first symbols without configured SSBs in the first time slot is less than a fourth threshold, and the ratio of the number of first symbols with configured SSBs to the number of first symbols without configured SSBs in the first time slot is greater than a fifth threshold.

[0023] For example, the number of first symbols without configured SSBs in the first time slot may satisfy one or more of the following conditions: the number of first symbols without configured SSBs in the first time slot is less than or equal to a fourth threshold, and the ratio of the number of first symbols with configured SSBs to the number of first symbols without configured SSBs in the first time slot is greater than or equal to a fifth threshold.

[0024] Optionally, if the first time slot is determined as a downlink time slot based on satisfying the conditions for determining the first time slot as a downlink time slot, the conditions include the condition that the number of symbols configuring the SSB in the first time slot satisfies the condition.

[0025] For example, the number of symbols of the configuration SSB in the first time slot may satisfy the following conditions: the number of symbols of the configuration SSB in the first time slot is greater than the eighth threshold, or the number of symbols of the configuration SSB in the first time slot is greater than or equal to the eighth threshold.

[0026] Optionally, if the first time slot is determined as a downlink time slot based on satisfying the conditions for determining the first time slot as a downlink time slot, the conditions include the condition that the number of first symbols configured in the first time slot for the SSB is satisfied.

[0027] For example, the number of first symbols of the configuration SSB in the first time slot satisfies the following conditions: the number of symbols of the configuration SSB in the first time slot is greater than the ninth threshold, or the number of first symbols of the configuration SSB in the first time slot is greater than or equal to the ninth threshold.

[0028] Understandably, when determining whether to switch based on the condition that the number of first symbols in the first time slot meets the condition and / or the condition that the number of first symbols in the first time slot without the SSB meets the condition and / or the condition that the number of symbols in the first time slot with the SSB meets the condition and / or the condition that the number of first symbols in the first time slot with the SSB meets the condition, the number of SBFD time slots determined as downlink time slots can be reduced, thereby ensuring the gain of the SBFD system.

[0029] Optionally, if the first time slot is determined as a downlink time slot based on the condition that the first time slot is determined as a downlink time slot, the condition includes the condition that all symbols in the first time slot are of the downlink symbol type in the first configuration message, and the first configuration message is a message used to configure TDD.

[0030] The first configuration message is also called the TDD configuration message. Understandably, this implementation ensures that the type of the symbols in the original TDD configuration is not corrupted after the first time slot is determined as a downlink time slot, thus guaranteeing the consistency of the SBFD system.

[0031] Optionally, if the first time slot is determined as a downlink time slot based on satisfying the conditions for determining the first time slot as a downlink time slot, the conditions include that the number of switching points within one SBFD cycle remains unchanged after the first time slot is determined as a downlink time slot.

[0032] Understandably, this implementation method can ensure the gain of the SBFD system without affecting the number of switching points within the SBFD cycle, and without affecting the complexity of terminal and network devices.

[0033] Optionally, when the terminal device determines a first time slot and a preceding second time slot within an SBFD cycle as downlink time slots, the method further includes: receiving second information, the second information indicating that the second time slot is located before the first time slot.

[0034] Optionally, when the terminal device determines the first time slot and the subsequent second time slot within an SBFD cycle as downlink time slots, the method further includes: receiving third information, the third information being used to indicate that the second time slot is located after the first time slot.

[0035] Optionally, when the terminal device determines the first time slot and the preceding second time slot within an SBFD cycle as downlink time slots, it includes: determining the first time slot and the preceding second time slot within an SBFD cycle as downlink time slots when the number of preceding second time slots is less than a sixth threshold.

[0036] Optionally, when the terminal device determines the first time slot within an SBFD cycle and the second time slot preceding the first time slot as downlink time slots, it includes: when the number of subsequent second time slots is less than a seventh threshold, switching the first time slot within an SBFD cycle and the subsequent second time slots to downlink time slots.

[0037] Optionally, the sixth and seventh thresholds are the same.

[0038] Optionally, the method further includes: sending first information, the first information being used to indicate whether there is the capability to determine a first time slot as a downlink time slot, or the first information being used to indicate whether there is the capability to determine a first symbol configured with an SSB as a downlink symbol.

[0039] The first information is used to indicate whether there is the capability to determine the first time slot as a downlink time slot, or, the first information is used to indicate whether there is the capability to determine the first symbol configured with an SSB as a downlink symbol. It can also be interpreted as: the first information is used to indicate whether there is the capability to switch the first time slot to a downlink time slot, or, the first information is used to indicate whether there is the capability to switch the first symbol configured with an SSB to a downlink symbol.

[0040] In other words, the terminal device has the ability to report the handover through the first information. Optionally, the first information may also carry information about the duration of the handover.

[0041] Secondly, this application provides a communication method, which can be executed by a terminal device, or by a component (such as a chip, chip system, etc.) configured in the terminal device, or by a logic module or software capable of implementing all or part of the functions of the terminal device; this application does not limit this. In this application, a terminal device is used as an example for description.

[0042] For example, the communication method includes:

[0043] If the frequency domain resources for transmitting the SSB on the first symbol configured with the synchronization signal block SSB are not included in the downlink available PRB, discard the second configuration message, which is a message used to configure the SSB; or,

[0044] If the frequency domain resources for transmitting the SSB on the first symbol configured with a synchronization signal block (SSB) include frequency domain resources located outside the downlink available PRB, downlink signals are received only within the downlink available PRB on the first symbol configured with the SSB, and uplink signals are not transmitted on the uplink available PRB; or,

[0045] If the frequency domain resources for transmitting the SSB on the first symbol configured with a synchronization signal block (SSB) include frequency domain resources located outside the downlink available PRB, then on the first symbol configured with the SSB, downlink signals are received within the downlink available PRB or uplink signals are transmitted on the uplink available PRB; or,

[0046] If the frequency domain resources for transmitting the SSB on the first symbol configured with the synchronization signal block SSB include frequency domain resources located outside the downlink available PRB, the SSB is received on the frequency domain resources outside the downlink available PRB on the first symbol configured with the SSB, but downlink signals other than the SSB are not received.

[0047] This communication method specifically defines the behavior of a terminal device on a first symbol configured with an SSB, thereby enabling the terminal device to communicate with network devices based on this behavior.

[0048] Thirdly, this application provides a communication method, including:

[0049] If the number of switching points within a sub-band full-duplex SBFD cycle remains unchanged after the first symbol configured with the synchronization signal block SSB is determined as the downlink symbol, then the first symbol configured with the synchronization signal block SSB will be determined as the downlink symbol; or...

[0050] The first symbol configured with an SSB within an SBFD cycle, as well as the first symbol before or after it that is not configured with an SSB, are identified as downlink symbols; or,

[0051] If there are M discontinuous symbol groups within an SBFD period, the symbols included in each of the M symbol groups and the first symbol without an SSB between the M symbol groups are determined as downlink symbols. Each of the M symbol groups includes the first symbol with an SSB configured, and M is a positive integer greater than or equal to 2.

[0052] The first symbol is configured with frequency domain resources for two transmission directions;

[0053] Communication is based on the determined first symbol.

[0054] It should be noted that each of the M groups of discontinuous symbols here contains 4 symbols.

[0055] Understandably, this implementation method can ensure the gain of the SBFD system without affecting the number of switching points within the SBFD cycle, and without affecting the complexity of terminal and network devices.

[0056] Fourthly, this application provides an apparatus comprising modules or units for implementing the methods of the first aspect and any possible implementation thereof, or modules or units for implementing the methods of the second aspect, or modules or units for implementing the methods of the third aspect. It should be understood that each module or unit may implement its corresponding function by executing a computer program.

[0057] Fifthly, an apparatus is provided, comprising a processor and a storage medium storing instructions which, when executed by the processor, cause a method as described in the first aspect or any possible implementation thereof to be implemented, or cause a method as described in the second aspect to be implemented, or cause a method as described in the third aspect to be implemented.

[0058] A sixth aspect provides an apparatus comprising a processing circuit for processing data and / or information such that a method as in the first aspect or any possible implementation thereof is implemented, or a method as in the implementation of the second aspect is implemented, or a method as in the implementation of the third aspect is implemented.

[0059] The processing circuit may include one or more processors, or all or part of the circuitry in one or more processors used for control or processing functions.

[0060] Optionally, the apparatus may further include a memory for storing programs or instructions, and the processor for running the programs or instructions to implement the methods as in the first aspect or any possible implementation of the first aspect, or to implement the methods as in the second aspect, or to implement the methods as in the third aspect.

[0061] Optionally, the device may also include the transceiver circuit, or an input / output interface.

[0062] In a seventh aspect, a chip is provided, including processing circuitry for running a program or instructions to implement a method as described in the first aspect or any possible implementation thereof, or to implement a method as described in the second aspect, or to implement a method as described in the third aspect.

[0063] Optionally, the chip may further include a memory for storing programs or instructions.

[0064] Optionally, the chip may also include transceiver circuitry, or input / output interfaces.

[0065] Eighthly, an apparatus is provided, comprising one or more processors and communication circuitry, the communication circuitry being used by the apparatus to perform at least one of signal input or output; the one or more processors being used to implement the method as described in the first aspect or any possible implementation thereof, or to implement the method as described in the second or third aspect.

[0066] A ninth aspect provides a computer-readable storage medium comprising instructions that, when executed by a processor, cause the method as described in the first aspect or any possible implementation thereof to be implemented, or cause the method as described in the second or third aspect to be implemented.

[0067] In a tenth aspect, a computer program product is provided, the computer program product comprising computer program code or instructions that, when the computer program code or instructions are executed, cause the method as described in the first aspect and any possible implementation thereof to be implemented, or cause the method as described in the second or third aspect to be implemented. Attached Figure Description

[0068] Figure 1 shows a schematic diagram of the architecture of a communication system to which the communication method of this application can be applied;

[0069] Figure 2 shows a schematic diagram of BWP switching;

[0070] Figure 3 shows a schematic diagram of FDD, TDD, and SBFD;

[0071] Figure 4 illustrates a configuration method for the time-frequency resources of an SBFD;

[0072] Figure 5 shows a schematic diagram of the frequency domain resource location of SBFD;

[0073] Figure 6 shows a schematic diagram of an available PRB for a downlink subband and an uplink subband;

[0074] Figure 7 shows a schematic diagram of the subcarrier positions occupied by PSS, SSS and PBCH in an SSB;

[0075] Figure 8 is a schematic flowchart of a communication method provided in an embodiment of this application;

[0076] Figure 9 is a schematic flowchart of a communication method provided in another embodiment of this application;

[0077] Figure 10 is a schematic flowchart of a communication method provided in another embodiment of this application;

[0078] Figure 11 is a structural schematic diagram of a communication device provided in an embodiment of this application;

[0079] Figure 12 is a structural schematic diagram of a communication device provided in another embodiment of this application. Detailed Implementation

[0080] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the embodiments of this application will be further described in detail below with reference to the accompanying drawings.

[0081] Before introducing the communication method and related apparatus provided in the embodiments of this application, the following points should be made first.

[0082] First, in the embodiments of this application, the use of prefixes such as "first" and "second" is merely for the purpose of distinguishing and describing different things belonging to the same name category, and does not constrain the order, size, or quantity of things. For example, "first information" and "second information" are simply different pieces of information, and there is no temporal sequence, size, or priority relationship between them.

[0083] Second, in the embodiments of this application, "send" and "receive" indicate the direction of signal transmission. For example, "send first information to a terminal device" can be understood as the destination of the first information being the terminal device, which may include direct transmission via the air interface or indirect transmission via the air interface by other units or modules. "Receive second information from a network device" can be understood as the source of the second information being the network device, which may include direct reception from the network device via the air interface or indirect reception from the network device via the air interface by other units or modules. "Send" can also be understood as the "output" of the chip interface, and "receive" can also be understood as the "input" of the chip interface.

[0084] In other words, sending and receiving can occur between devices, such as between network devices and terminal devices; or they can occur within a device, such as between components, modules, chips, software modules, or hardware modules within a device via a bus, wiring, or interface.

[0085] It is understandable that information may undergo necessary processing, such as encoding and modulation, before being sent from the source to the destination. After receiving information from the source, the destination can also perform corresponding processing, such as decoding and demodulation, to interpret the valid information from the source.

[0086] Third, in the embodiments of this application, "at least one" refers to one or more, and "more than one" refers to two or more. "And / or" describes the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A alone, A and B simultaneously, or B alone, where A and B can be singular or plural. The character " / " generally indicates an "or" relationship between the preceding and following related objects, but does not exclude the possibility of an "and" relationship. The specific meaning can be understood in conjunction with the context. "At least one of the following" or similar expressions refer to any combination of these items, including any combination of single or plural items. For example, at least one of a, b, or c can represent: a, b, c; a and b; a and c; b and c; or a and b and c. Here, a, b, and c can be single or multiple.

[0087] Fourth, in the embodiments of this application, "instruction" can include direct instruction and indirect instruction, as well as explicit instruction and implicit instruction. The information indicated by a certain piece of information (as described below, the instruction information) is called the information to be instructed. In the specific implementation process, there are many ways to indicate the information to be instructed, such as, but not limited to, directly indicating the information to be instructed, such as the information to be instructed itself or its index. It can also indirectly indicate the information to be instructed by indicating other information, where there is a correlation between the other information and the information to be instructed; or it can only indicate a part of the information to be instructed, while the other parts of the information to be indicated are known or pre-agreed upon. For example, the instruction of specific information can be achieved by using a pre-agreed (e.g., protocol predefined) arrangement of various pieces of information, thereby reducing the instruction overhead to a certain extent. This application does not limit the specific method of instruction.

[0088] It is understandable that, for the sender of the instruction information, the instruction information can be used to indicate the information to be indicated, and for the receiver of the instruction information, the instruction information can be used to determine the information to be indicated.

[0089] Fifth, in the embodiments of this application, descriptions such as "when," "under the circumstances," "if," and "if" all refer to the device making corresponding processing under certain objective circumstances, and are not limited to a time, nor do they require the device to make a judgment action when implementing it, nor do they imply any other limitations.

[0090] The technical solutions provided in this application can be applied to various communication systems, such as: 5th generation (5G) or new radio (NR) systems, long term evolution (LTE) systems, LTE frequency division duplex (FDD) systems, LTE time division duplex (TDD) systems, wireless local area network (WLAN) systems, satellite communication systems, etc. Among them, 5G mobile communication systems can include non-standalone (NSA) and / or standalone (SA) networks.

[0091] The technical solutions provided in this application can also be applied to future communication systems, such as sixth-generation (6G) mobile communication systems. This application does not limit this application.

[0092] For example, Figure 1 is a schematic diagram of the architecture of a communication system to which the communication method of this application can be applied. As shown in Figure 1, the communication system 1000 includes a radio access network (RAN) 100 and a core network 200. Optionally, the communication system 1000 may also include an Internet 300. The RAN 100 may include at least one RAN node (110a and 110b in Figure 1, collectively referred to as 110), and may also include at least one terminal (120a-120j in Figure 1). The terminal is wirelessly connected to the RAN device, and the RAN device is wirelessly or wiredly connected to the core network. The core network device and the RAN device may be independent physical devices, or the functions of the core network device and the logical functions of the RAN device may be integrated on the same physical device, or a single physical device may integrate some of the functions of the core network device and some of the functions of the RAN device. Terminals and RAN devices may be interconnected via wired or wireless means. Figure 1 is just a schematic diagram. The communication system may also include other network devices, such as wireless relay devices and wireless backhaul devices, which are not shown in Figure 1.

[0093] RAN 100 can be a 3GPP-related cellular system, such as a 4G or 5G mobile communication system, or a future-oriented evolution system (such as a 6G mobile communication system). RAN 100 can also be an open access network (open RAN, O-RAN, or ORAN), a cloud radio access network (CRAN), or a wireless fidelity (WiFi) system. RAN 100 can also be a communication system that integrates two or more of the above systems.

[0094] RAN node 110, sometimes also referred to as access network equipment, RAN entity, or access node, constitutes part of the communication system and is used to help terminals achieve wireless access. Multiple RAN nodes 110 in communication system 1000 can be of the same type or different types. In some scenarios, the roles of RAN node 110 and terminal 120 are relative. For example, network element 120i in Figure 1 can be a helicopter or drone, which can be configured as a mobile base station. For terminals 120j accessing RAN 100 through network element 120i, network element 120i is a base station; but for base station 110a, network element 120i is a terminal. RAN node 110 and terminal 120 are sometimes both referred to as communication devices. For example, network elements 110a and 110b in Figure 1 can be understood as communication devices with base station functions, and network elements 120a-120j can be understood as communication devices with terminal functions.

[0095] In one possible scenario, the RAN node can be a base station, an evolved NodeB (eNodeB), an access point (AP), a transmission reception point (TRP), a next-generation NodeB (gNB), a next-generation base station in a 6th-generation (6G) mobile communication system, a base station in a future mobile communication system, or an access node in a WiFi system. The RAN node can be a macro base station (as shown in Figure 1, 110a), a micro base station or indoor station (as shown in Figure 1, 110b), a relay node or donor node, or a radio controller in a CRAN scenario. Optionally, the RAN node can also be a server, wearable device, vehicle, or in-vehicle equipment. For example, the access network equipment in vehicle-to-everything (V2X) technology can be a roadside unit (RSU). All or part of the functions of the RAN node in this application can also be implemented through software functions running on hardware, or through virtualization functions instantiated on a platform (e.g., a cloud platform). The RAN node in this application can also be a logical node, logical module, or software that can implement all or part of the functions of the RAN node.

[0096] In another possible scenario, multiple RAN nodes collaborate to assist the terminal in achieving wireless access, with each RAN node performing a portion of the base station's functions. For example, RAN nodes can be central units (CUs), distributed units (DUs), CU-control plane (CPs), CU-user plane (UPs), or radio units (RUs), etc. CUs and DUs can be separate entities or included in the same network element, such as a baseband unit (BBU). RUs can be included in radio frequency equipment or radio frequency units, such as remote radio units (RRUs), active antenna units (AAUs), or remote radio heads (RRHs).

[0097] In different systems, CU (or CU-CP and CU-UP), DU, or RU may have different names, but those skilled in the art will understand their meaning. For example, in an ORAN system, CU can also be called O-CU (open CU), DU can also be called O-DU, CU-CP can also be called O-CU-CP, CU-UP can also be called O-CU-UP, and RU can also be called O-RU. For ease of description, this application uses CU, CU-CP, CU-UP, DU, and RU as examples. Any of the units among CU (or CU-CP, CU-UP), DU, and RU in this application can be implemented through software modules, hardware modules, or a combination of software and hardware modules.

[0098] A terminal is a device with wireless transceiver capabilities, capable of sending signals to or receiving signals from a base station. Terminals can also be called terminal equipment, 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 grids, smart furniture, smart offices, smart wearables, smart transportation, smart cities, etc. Terminals can be mobile phones, tablets, computers with wireless transceiver capabilities, wearable devices, vehicles, airplanes, ships, robots, robotic arms, smart home devices, etc. The embodiments of this application do not limit the specific technology or device form used in the terminal.

[0099] Base stations and terminals can be fixed or mobile. They can be deployed on land, including indoors or outdoors, handheld or vehicle-mounted; they can also be deployed on water; and they can be deployed on aircraft, balloons, and satellites. The embodiments of this application do not limit the application scenarios of the base stations and terminals.

[0100] 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. For terminals 120j that access the wireless access network 100 through 120i, terminal 120i is a base station; however, for base station 110a, 120i is a terminal, meaning that 110a and 120i communicate via a wireless air interface protocol. Of course, 110a and 120i can also communicate via a base station-to-base station interface protocol. In this case, relative to 110a, 120i is also a base station. Therefore, both base stations and terminals can be collectively referred to as communication devices. 110a and 110b in Figure 1 can be called communication devices with base station functions, and 120a-120j in Figure 1 can be called communication devices with terminal functions.

[0101] Communication between base stations and terminals, between base stations, and between terminals can be conducted using licensed spectrum, unlicensed spectrum, or both simultaneously. Communication can be conducted using spectrum below 6 GHz, spectrum above 6 GHz, or both simultaneously. The embodiments of this application do not limit the spectrum resources used for wireless communication.

[0102] In the embodiments of this application, the functions of the base station can be executed by modules (such as chips) within the base station, or by a control subsystem that includes base station functions. This control subsystem, including base station functions, can be a control center in the aforementioned application scenarios such as smart grids, industrial control, intelligent transportation, and smart cities. Similarly, the functions of the terminal can be executed by modules (such as chips or modems) within the terminal, or by a device that includes terminal functions.

[0103] It is understood that the number of terminal devices shown in Figure 1 is merely an example. In practice, the number of terminal devices can be other than that shown. It should be noted that the specific forms of network devices and terminal devices are not limited in this embodiment.

[0104] To facilitate understanding of the content of this solution, some terms used in the embodiments of this application are explained below. This part is only for the purpose of understanding and should not be regarded as a specific limitation of this application.

[0105] 1. Data transmission in NR

[0106] Data transmission in NR can be divided into uplink and downlink transmission based on the data transmission direction, and into dynamic scheduling and pre-allocation based on the scheduling method.

[0107] Uplink transmission refers to the process where the terminal device sends data and the network device receives it; downlink transmission refers to the process where the network device sends data and the terminal device receives it.

[0108] Dynamic scheduling refers to the distribution of downlink control information (DCI) by network devices. The DCI carries scheduling information (including time-frequency resource allocation, coding and modulation schemes, and transport block size for data transmission). Network devices can send DCI to terminal devices via downlink control channels, such as the physical downlink control channel (PDCCH). A PDCCH can carry a DCI scrambled with a radio network temporary identifier (RNTI) in one format. The information carried by the DCI can vary depending on the DCI format and / or the configuration of higher-layer signaling (e.g., RRC signaling). The DCI can indicate cell-level information, such as control information scrambled with system information RNTI (SI-RNTI), paging RNTI (P-RNTI), or random access RNTI (RA-RNTI). DCI can also indicate terminal device-level information, such as control information scrambled with cell RNTI (C-RNTI), configured scheduling RNTI (CS-RNTI), or semi-persistent channel state information RNTI (SP-CSI-RNTI) used by the terminal device.

[0109] Pre-allocation refers to network devices issuing scheduling information (including time-frequency resource allocation, coding and modulation scheme, and transport block size) through higher-layer signaling (such as RRC signaling, MAC CE, etc.). Under the pre-allocation scheduling method, it usually corresponds to periodic data transmission, that is, periodic time-frequency resources, while information such as coding and modulation scheme and transport block size remains unchanged.

[0110] 2. Bandwidth section

[0111] NR introduces the concept of bandwidth part (BWP), which refers to a continuous common resource block (CRB) within a given subcarrier spacing. It can be understood that a carrier can contain multiple BWPs, and the frequency domain resources corresponding to any two BWPs may or may not overlap, and different BWPs can be activated at different times.

[0112] Figure 2 illustrates a schematic diagram of BWP handover. As shown in Figure 2, the terminal device begins operating within BWP1 on a carrier from time T1. The network device can instruct the terminal device to perform BWP handover through the bandwidth part indicator field in the DCI. After the handover time T2, the terminal device begins to switch to operating within BWP2.

[0113] When the index of the BWP indicated by the bandwidth part indicator is different from the index of the currently active BWP, it means that the network device instructs the terminal device to perform a BWP handover; conversely, if the index of the BWP indicated by the bandwidth part indicator is the same as the index of the currently active BWP, it means that the network device instructs the terminal device not to perform a BWP handover and to receive or send data on the currently active BWP.

[0114] 3. Sub-belt full-duplex

[0115] Currently, NR includes frequency division duplex (FDD) and time division duplex (TDD).

[0116] For example, Figure 3(a) shows a schematic diagram of an FDD. As shown in Figure 3(a), downlink transmission can be performed on the downlink (DL) BWP in slot 0, and uplink transmission can also be performed on the uplink (UL) BWP in slot 0. The DL BWP and UL BWP are located on different carriers and are separated in the frequency domain.

[0117] For example, Figure 3(b) illustrates a schematic diagram of TDD. As shown in Figure 3(b), the DL BWP and UL BWP have the same center frequency. The bandwidths of the DL BWP and UL BWP can be the same or different. At the same time (in the same time slot), the terminal device can only perform uplink or downlink transmission. For example, in slot 0, only downlink transmission can be performed; in slot 4, only uplink transmission can be performed; slot 3 is a flexible (F) time slot, which can be used for either uplink or downlink transmission, but not both simultaneously.

[0118] For flexible time slots, the smallest granularity of uplink / downlink transmission switching is a symbol. For example, slot 3 is a flexible time slot, consisting of 14 or 12 orthogonal frequency division multiplexing (OFDM) symbols. The first P1 symbols are downlink symbols, the last P2 symbols are uplink symbols, and the middle 14-P1-P2 (or 12-P1-P2) symbols are flexible symbols, where 0 <= P1 <= 14, 0 <= P2 <= 14, and P1 + P2 <= 14. Downlink symbols are used for downlink transmission, uplink symbols are used for uplink transmission, and flexible symbols can be used for both uplink and downlink. The specific transmission direction is notified to the terminal device by the network device through RRC signaling or DCI scheduling.

[0119] Compared to FDD, TDD occupies less frequency domain resources. However, because uplink and downlink transmissions cannot be performed simultaneously in TDD (for example, only downlink transmission can be performed in slot 0, and uplink transmission cannot be performed), uplink transmission latency will increase.

[0120] To further reduce latency and enhance uplink coverage in Time Division Duplex (TDD) systems, flexible duplexing, also known as complementary TDD (C-TDD), full duplex, or other names such as subband full duplex (SBFD), is being discussed in standards. The core idea of ​​SBFD is to simultaneously configure uplink and downlink transmission resources on a specific symbol or time slot in a TDD system. The frequency domain resources configured on these symbols for uplink transmission can be called uplink subbands (UL subband, UL SB), and the frequency domain resources for downlink transmission can be called downlink subbands (DL subband, DL SB). These symbols can be understood as SBFD symbols, while other symbols can be understood as non-SBFD symbols. In other words, an SBFD symbol contains both DL SB and UL SB. SBFD symbols support bidirectional transmission. However, non-SBFD symbols only support unidirectional transmission. Additionally, a guard band can exist between the DL SB and UL SB.

[0121] For example, Figure 3(c) shows a schematic diagram of SBFD. As shown in Figure 3(c), there is a frequency domain resource in the downlink BWP on slot 0, on which uplink transmission can be performed. This frequency domain resource is the uplink sub-band mentioned above. Thus, uplink transmission can be performed on slot 0, reducing uplink latency. Simultaneously, downlink transmission can also be performed on slot 0. That is, network devices can perform uplink and downlink transmissions simultaneously on slot 0. For full-duplex terminal devices, uplink and downlink transmissions can be performed simultaneously on slot 0; for half-duplex terminal devices, either uplink or downlink transmission can be performed on slot 0. It can be seen that SBFD, compared to TDD, increases uplink resources, thereby increasing uplink coverage.

[0122] Network devices will send TDD and SBFD configurations to the terminals.

[0123] The TDD configuration includes, but is not limited to, the following parameters: the slot index of downlink slots, uplink slots and flexible slots; the symbol index of uplink symbols, downlink symbols and flexible symbols in flexible slots; downlink symbols in downlink slots and flexible slots are used for downlink data transmission; uplink symbols in uplink slots and flexible slots are used for uplink data transmission; and flexible symbols in flexible slots can be used for both uplink and downlink data transmission.

[0124] The SBFD configuration includes, but is not limited to, the following parameters: SBFD slot / symbol position and SBFD subband position within the SBFD slot. The SBFD slot / symbol position refers to some or all of the DL slots / symbols or flexible slots / symbols configured in the TDD configuration, i.e., converting some or all downlink slots / symbols or flexible slots / symbols into SBFD symbols. The SBFD subband position can be the frequency domain position of the UL subband and / or DL ​​subband.

[0125] 4. SBFD Time / Frequency Domain Configuration

[0126] For terminal devices in RRC connected state, network devices can configure the time and frequency domain positions of SBFD sub-bands within a TDD carrier through RRC parameters.

[0127] In one implementation, when configuring time-domain locations, network devices can semi-statically configure SBFD subband time-domain locations using RRC parameters (e.g., TDD-UL-DL-Pattern). For example, Figure 4 illustrates a configuration method for SBFD time-domain resources. As shown in Figure 4, the network device configures DL symbols, UL symbols, and flexible symbols using the TDD-UL-DL-ConfigCommon parameter. SBFD symbols can be configured on DL symbols and / or flexible symbols. A configured SBFD symbol can start or end at any symbol within a slot. It is understood that the SBFD subband time-domain period can be the same as the period configured in dl-UL-TransmissionPeriodicity within the TDD-UL-DL-Pattern, or an integer multiple of the period configured in dl-UL-TransmissionPeriodicity within the TDD-UL-DL-Pattern. A time slot can contain SBFD symbols and non-SBFD symbols.

[0128] In one implementation, when configuring frequency domain location, network devices can explicitly configure the frequency domain location of an intra-carrier UL subband and DL subband in a semi-static manner at the RRC parameter resource block level (RB-level).

[0129] For example, Figure 5 shows a schematic diagram of the frequency domain resource location of SBFD. As shown in Figure 5, the frequency domain location of the subband is the same on different SBFD symbols within a TDD carrier. Only one UL subband can be configured within one TDD carrier. The UL subband can be located in the middle of the carrier (as shown in Figure 5(a)) or on one side of the carrier (as shown in Figure 5(b)).

[0130] Currently, the UL / DL usable PRB discussed in the standard has two indication methods:

[0131] Method 1: The terminal device takes the intersection of the physical resource blocks (PRBs) contained in the semi-statically configured UL subband and the PRBs of the active UL BWP on the SBFD symbol to obtain the UL-usable PRBs. Similarly, the terminal device takes the intersection of the PRBs contained in the semi-statically configured DL subband and the PRBs of the active DL BWP on the SBFD symbol to obtain the DL-usable PRBs.

[0132] For example, Figure 6 illustrates a schematic diagram of usable PRBs for a downlink subband and an uplink subband. As shown in Figure 6, the SBFD symbol includes both uplink and downlink usable PRBs, and a guard band exists between the uplink and downlink usable PRBs.

[0133] Method 2: The network device is explicitly configured via signaling to activate the UL / DL available PRB on the UL / DL BWP on the SBFD symbol. Explicit configuration can be understood as direct instruction; the terminal device directly determines the UL / DL available PRB on the SBFD symbol based on the signaling, without any other operations.

[0134] Here, BWP is a continuous common resource block (CRB) under a given subcarrier spacing value.

[0135] It is understandable that a single carrier may include multiple BWPs, and different BWPs may be activated at different times.

[0136] 5. Switching points in SBFD systems

[0137] Network devices may employ different antenna arrays for SBFD and non-SBFD symbols, or terminal devices may use different transmit / receive filters for SBFD and non-SBFD symbols. Therefore, at the switching points between SBFD and non-SBFD symbols (switch from non-SBFD to SBFD, or vice versa), network devices and / or terminal devices may need time to adjust components or filters, thus interrupting normal data transmission. Such switching points cause both system performance degradation and increased complexity for network and terminal devices. Therefore, in the research phase of SBFD systems, current discussions focus on a maximum of two switching points within an SBFD cycle: one switching point from non-SBFD to SBFD, and the other switching point from SBFD to non-SBFD.

[0138] 6. Synchronization signal block (SSB) in NR

[0139] SSB can also be called synchronization signal and PBCH block. Specifically, SSB consists of three parts: primary synchronization signals (PSS), secondary synchronization signals (SSS), and physical broadcasting channel block (PBCH), and can be used for downlink synchronization.

[0140] For example, Figure 7 illustrates the subcarrier positions occupied by the PSS, SSS, and PBCH within an SSB. As shown in Figure 7, one SSB occupies four orthogonal frequency division multiplexing (OFDM) symbols in the time domain and 20 consecutive resource blocks (RBs) in the frequency domain, i.e., 240 consecutive subcarriers. The first symbol of the SSB is the PSS, and the third symbol is the SSS, both occupying 127 subcarriers. The PBCH is distributed across the second to fourth symbols of the SSB, occupying 240 subcarriers in the second and fourth symbols. Additionally, as shown in Figure 7, there are some unused resource elements (REs) on both sides of the SSS in the third symbol.

[0141] The frequency domain bandwidth of the SSB under different subcarriers is shown in Table 1:

[0142] Table 1

[0143] An SS burst set represents a set of one or more SSBs. An SS burst set is located in the first or second half of a radio frame. The period of an SSB can also be considered the period of the SS burst set. The maximum number of SSBs included in an SS burst set, Lmax, represents the number of SSBs that a network device may transmit in an SS burst set. The actual number of SSBs transmitted in an SS burst set is less than or equal to Lmax. Lmax is related to the frequency range. For example, when the carrier frequency is FR1 and less than or equal to 3 GHz, Lmax = 4; when the carrier frequency is FR1 and greater than 3 GHz, Lmax = 8; and when the carrier frequency is FR2, Lmax = 64. SSBs in an SS burst set can be distributed across one or more time slots, with a maximum of 2 SSBs per time slot, occupying a total of 8 symbols, with a symbol interval between the two SSBs.

[0144] The primary function of the SSB is cell access: by receiving the master information block (MIB) information through the SSB, one can obtain the system information block (SIB)1 associated with the SSB to access the cell. Since the SSB includes the PSS, SSS, and PBCH, and the PBCH includes the PBCH DMRS (demodulation reference signal), the SSB can also be used by terminal equipment to perform time-frequency tracking (or time-frequency synchronization), beam management, radio resource management (RRM) measurements, radio link monitoring (RLM) measurements, and channel state information (CSI) measurements.

[0145] In existing NR standards, symbols for transmitting SSBs are configured for TDD systems, and these symbols are also called SSB symbols. Specifically, the following rules apply when configuring SSBs: 1) SSBs cannot be configured on semi-static UL symbols; 2) Uplink transmission is not allowed on semi-static flexible symbols, including the physical uplink shared channel (PUSCH), physical uplink control channel (PUCCH), physical random access channel (PRACH), and sounding reference signal (SRS).

[0146] Currently, research has begun on transmitting SSBs on SBFD symbols. Regarding SSBs on SBFD symbols, the following conclusions have been drawn:

[0147] 1) Reuse the conflict handling principles in TDD, with SSB taking precedence over configured UL transmissions and dynamically scheduled UL transmissions.

[0148] 2) For further study (FFS): A slot containing an SSB symbol is considered a full DL slot, or an SSB symbol configured with an SBFD subband is an SBFD symbol and downlink reception is only performed on a DL usable PRB.

[0149] However, analysis revealed that if "slots containing SSB symbols are considered full DL slots," the following technical problems would arise:

[0150] a) Other SBFD symbols in this slot will also be switched to DL symbols, which will reduce the number of SBFD symbols and thus reduce the SBFD gain;

[0151] b) The slot containing the SSB symbol may not have originally been a full DL slot. For example, it may have been a DL symbol + flexible symbol, or a DL symbol + flexible symbol + UL symbol, or a flexible symbol + UL symbol, or it may have been all flexible symbols. However, if the slot containing the SSB symbol is switched to a full DL slot, it is equivalent to changing the original TDD configuration.

[0152] c) After a slot containing an SSB symbol is considered a "full DL slot", the number of switching points in one SBFD cycle may exceed two, which does not meet the requirements of the SBFD system configuration.

[0153] On the other hand, if the rule is adopted that "the SSB symbol configured with the SBFD subband is an SBFD symbol and downlink reception is only performed on the DL usable PRB", the behavior of the network side and the terminal side is unclear because it is not specified whether the SSB symbol can appear on frequency domain resources outside the range of the DL usable PRB.

[0154] In view of this, this application provides a communication method and related apparatus so that network devices and terminal devices can accurately determine the type of each time slot in order to realize communication between network devices and terminal devices.

[0155] The communication method and communication device provided in this application will now be described in detail with reference to the accompanying drawings.

[0156] Figure 8 is a schematic flowchart of the communication method provided in an embodiment of this application. Figure 8 only illustrates the method from the perspective of interaction between network devices and terminal devices, and should not be construed as limiting the embodiments of this application in any way. The network device in Figure 8 can be replaced by components configured in the network device (such as chips, chip systems, processors, etc.), or by logic modules or software capable of implementing all or part of the functions of the network device; the terminal device in Figure 8 can be replaced by components configured in the terminal device (such as chips, chip systems, processors, etc.), or by logic modules or software capable of implementing all or part of the functions of the terminal device.

[0157] The following details each step in method 800.

[0158] S801, if the condition for determining the first time slot as a downlink time slot is met, the terminal device determines the first time slot as a downlink time slot. The first time slot includes a first symbol configured with an SSB, and the first symbol is configured with frequency domain resources for two transmission directions.

[0159] S802, the terminal device communicates with the network device based on the determined first time slot.

[0160] Here, the first symbol refers to a symbol that is configured with both uplink frequency domain resources for uplink transmission and downlink frequency domain resources for downlink transmission. That is, the first symbol can be considered as the SBFD symbol described above.

[0161] In this embodiment, a time slot including SBFD symbols is also referred to as an SBFD time slot. In some examples, every symbol included in an SBFD time slot is a first symbol. In other examples, some symbols in an SBFD time slot are first symbols; this embodiment does not impose any limitations.

[0162] In this context, a downlink time slot refers to a time slot that consists only of downlink symbols. That is, a time slot composed solely of downlink symbols is called a downlink time slot.

[0163] In this embodiment, the first time slot refers to an SBFD time slot that includes a first symbol configured with an SSB. In some examples, an SSB is configured on every first symbol included in the first time slot; in other examples, some of the first symbols included in the first time slot are configured with SSBs, while others are not. In some examples, all symbols configured with SSBs included in the first time slot are first symbols; in other examples, some of the symbols configured with SSBs included in the first time slot are first symbols, while others are not. The symbols that are not first symbols can be downlink symbols or flexible symbols.

[0164] In this embodiment, when the condition for determining the first time slot as a downlink time slot is met, the terminal device will determine the first time slot as a downlink time slot. That is, the terminal device will re-determine the first time slot from the SBFD time slot as a downlink time slot. Alternatively, if the condition for determining the first time slot as a downlink time slot is not met, the terminal device will not determine the first time slot as a downlink time slot.

[0165] In this embodiment, the terminal device re-determines the first time slot from an SBFD time slot to a downlink time slot, which can also be interpreted as switching the time slot type of the first time slot from an SBFD time slot to a downlink time slot. That is, the SBFD time slot and the downlink time slot are considered to be different time slot types.

[0166] In a first implementation, the condition for determining the first time slot as a downlink time slot includes a condition that the number of first symbols within the first time slot meets a certain requirement. For example, when the number of first symbols within the first time slot meets the requirement, the terminal device switches the first time slot from the SBFD time slot to the downlink time slot; when the number of first symbols within the first time slot does not meet the requirement, the terminal device does not switch the first time slot from the SBFD time slot to the downlink time slot.

[0167] For example, the condition for the number of first symbols in the first time slot to be satisfied includes condition 1. Condition 1 is that the number of first symbols in the first time slot is less than a first threshold. For example, when the number of first symbols in the first time slot is less than the first threshold, the terminal device determines the first time slot from the SBFD time slot as a downlink time slot; when the number of first symbols in the first time slot is greater than or equal to the first threshold, the terminal device does not determine the first time slot from the SBFD time slot as a downlink time slot. Or,

[0168] Condition 1 is that the number of first symbols in the first time slot is less than or equal to a first threshold. For example, when the number of first symbols in the first time slot is less than or equal to the first threshold, the terminal device switches the first time slot from the SBFD time slot to the downlink time slot; when the number of first symbols in the first time slot is greater than the first threshold, the terminal device does not switch the first time slot from the SBFD time slot to the downlink time slot.

[0169] For example, the condition that the number of first symbols in the first time slot meets includes condition 2. Condition 2 is that the ratio of the number of first symbols in the first time slot to the number of downlink symbols in the first time slot is less than a second threshold. That is, the ratio of the number of SBFD symbols in the first time slot to the number of downlink symbols in the first time slot is less than the second threshold. For example, when the ratio of the number of first symbols in the first time slot to the number of downlink symbols in the first time slot is less than the second threshold, the terminal device switches the first time slot from the SBFD time slot to the downlink time slot; when the ratio of the number of SBFD symbols in the first time slot to the number of downlink symbols in the first time slot is greater than or equal to the second threshold, the terminal device does not switch the first time slot from the SBFD time slot to the downlink time slot. Or,

[0170] Condition 2 is that the ratio of the number of first symbols in the first time slot to the number of downlink symbols in the first time slot is less than or equal to a second threshold. That is, the ratio of the number of SBFD symbols in the first time slot to the number of downlink symbols in the first time slot is less than or equal to the second threshold. For example, when the ratio of the number of first symbols in the first time slot to the number of downlink symbols in the first time slot is less than or equal to the second threshold, the terminal device switches the first time slot from the SBFD time slot to the downlink time slot. When the ratio of the number of SBFD symbols in the first time slot to the number of downlink symbols in the first time slot is greater than the second threshold, the terminal device does not switch the first time slot from the SBFD time slot to the downlink time slot.

[0171] For example, the condition that the number of first symbols in the first time slot meets includes condition 3. Condition 3 is that the ratio of the number of first symbols in the first time slot to the number of symbols other than the first symbol in the first time slot is less than a third threshold. That is, the ratio of the number of SBFD symbols in the first time slot to the number of non-SBFD symbols in the first time slot is less than the third threshold. For example, when the ratio of the number of SBFD symbols in the first time slot to the number of non-SBFD symbols in the first time slot is less than the third threshold, the terminal device switches the first time slot from the SBFD time slot to the downlink time slot; when the ratio of the number of SBFD symbols in the first time slot to the number of non-SBFD symbols in the first time slot is greater than or equal to the third threshold, the terminal device does not switch the first time slot from the SBFD time slot to the downlink time slot. Or,

[0172] Condition 3 is that the ratio of the number of first symbols in the first time slot to the number of symbols other than the first symbol in the first time slot is less than or equal to a third threshold. That is, the ratio of the number of SBFD symbols in the first time slot to the number of non-SBFD symbols in the first time slot is less than or equal to the third threshold. For example, when the ratio of the number of SBFD symbols in the first time slot to the number of non-SBFD symbols in the first time slot is less than or equal to the third threshold, the terminal device switches the first time slot from the SBFD time slot to the downlink time slot. When the ratio of the number of SBFD symbols in the first time slot to the number of non-SBFD symbols in the first time slot is greater than the third threshold, the terminal device does not switch the first time slot from the SBFD time slot to the downlink time slot.

[0173] In the second implementation, the condition for determining the first time slot as a downlink time slot includes: satisfying a condition regarding the number of first symbols without configured SSBs within the first time slot. For example, when the number of first symbols without configured SSBs within the first time slot satisfies the condition, the terminal device switches the first time slot from the SBFD time slot to the downlink time slot; when the number of first symbols without configured SSBs within the first time slot does not satisfy the condition, the terminal device does not switch the first time slot from the SBFD time slot to the downlink time slot.

[0174] For example, the condition that the number of first symbols without configured SSBs in the first time slot meets includes condition 4. Condition 4 is that the number of first symbols without configured SSBs in the first time slot is less than a fourth threshold. That is, condition 4 is that the number of SBFD symbols without configured SSBs in the first time slot is less than the fourth threshold. For example, when the number of SBFD symbols without configured SSBs in the first time slot is less than the fourth threshold, the terminal device switches the first time slot from the SBFD time slot to the downlink time slot; when the number of SBFD symbols without configured SSBs in the first time slot is greater than or equal to the fourth threshold, the terminal device does not switch the first time slot from the SBFD time slot to the downlink time slot. Or,

[0175] Condition 4 is that the number of first symbols without configured SSBs in the first time slot is less than or equal to the fourth threshold. That is, condition 4 is that the number of SBFD symbols without configured SSBs in the first time slot is less than or equal to the fourth threshold. For example, when the number of SBFD symbols without configured SSBs in the first time slot is less than or equal to the fourth threshold, the terminal device switches the first time slot from the SBFD time slot to the downlink time slot; when the number of SBFD symbols without configured SSBs in the first time slot is greater than the fourth threshold, the terminal device does not switch the first time slot from the SBFD time slot to the downlink time slot.

[0176] For example, the number of first symbols without SSB configuration in the first time slot satisfies condition 5. Condition 5 is that the ratio of the number of first symbols with SSB configuration to the number of first symbols without SSB configuration in the first time slot is greater than a fifth threshold. That is, condition 5 is that the ratio of the number of SBFD symbols with SSB configuration to the number of SBFD symbols without SSB configuration in the first time slot is greater than the fifth threshold. For example, when the ratio of the number of SBFD symbols with SSB configuration to the number of SBFD symbols without SSB configuration in the first time slot is greater than the fifth threshold, the terminal device switches the first time slot from the SBFD time slot to the downlink time slot; when the ratio of the number of SBFD symbols with SSB configuration to the number of SBFD symbols without SSB configuration in the first time slot is less than or equal to the fifth threshold, the terminal device does not switch the first time slot from the SBFD time slot to the downlink time slot. Or,

[0177] Condition 5 is that the ratio of the number of first symbols configured with SSB to the number of first symbols not configured with SSB in the first time slot is greater than or equal to the fifth threshold. That is, Condition 5 is that the ratio of the number of SBFD symbols configured with SSB to the number of SBFD symbols not configured with SSB in the first time slot is greater than or equal to the fifth threshold. For example, when the ratio of the number of SBFD symbols configured with SSB to the number of SBFD symbols not configured with SSB in the first time slot is greater than or equal to the fifth threshold, the terminal device switches the first time slot from the SBFD time slot to the downlink time slot. When the ratio of the number of SBFD symbols configured with SSB to the number of SBFD symbols not configured with SSB in the first time slot is less than the fifth threshold, the terminal device does not switch the first time slot from the SBFD time slot to the downlink time slot.

[0178] In the third implementation, the condition for determining the first time slot as a downlink time slot includes: the condition that the number of symbols configured with an SSB in the first time slot meets the requirement. For example, when the number of symbols configured with an SSB in the first time slot meets the requirement, the terminal device switches the first time slot from the SBFD time slot to the downlink time slot; when the number of symbols configured with an SSB in the first time slot does not meet the requirement, the terminal device does not switch the first time slot from the SBFD time slot to the downlink time slot.

[0179] For example, the condition that the number of SSB symbols configured in the first time slot meets includes condition 7. Condition 7 is that the number of SSB symbols configured in the first time slot is greater than an eighth threshold. That is, condition 7 is that the number of SSB symbols configured in the first time slot is greater than an eighth threshold. For example, when the number of SSB symbols configured in the first time slot is greater than the eighth threshold, the terminal device switches the first time slot from the SBFD time slot to the downlink time slot; when the number of SSB symbols configured in the first time slot is less than or equal to the eighth threshold, the terminal device does not switch the first time slot from the SBFD time slot to the downlink time slot. Or,

[0180] Condition 7 is that the number of SSB symbols configured in the first time slot is greater than or equal to the eighth threshold. In other words, condition 7 is that the number of SSB symbols configured in the first time slot is greater than or equal to the eighth threshold. For example, when the number of SSB symbols configured in the first time slot is greater than or equal to the eighth threshold, the terminal device switches the first time slot from the SBFD time slot to the downlink time slot; when the number of SSB symbols configured in the first time slot is less than the eighth threshold, the terminal device does not switch the first time slot from the SBFD time slot to the downlink time slot.

[0181] In the fourth implementation, the condition for determining the first time slot as a downlink time slot includes: satisfying a condition regarding the number of first symbols of the configured SSB within the first time slot. For example, when the number of first symbols of the configured SSB within the first time slot satisfies the condition, the terminal device switches the first time slot from the SBFD time slot to the downlink time slot; when the number of first symbols of the configured SSB within the first time slot does not satisfy the condition, the terminal device does not switch the first time slot from the SBFD time slot to the downlink time slot.

[0182] For example, the condition that the number of first symbols of a configured SSB in the first time slot satisfies includes condition 8. Condition 8 is that the number of symbols of a configured SSB in the first time slot is greater than a ninth threshold. That is, condition 8 is that the number of first symbols of a configured SSB in the first time slot is greater than the ninth threshold. For example, when the number of first symbols of a configured SSB in the first time slot is greater than the ninth threshold, the terminal device switches the first time slot from the SBFD time slot to the downlink time slot; when the number of first symbols of a configured SSB in the first time slot is less than or equal to the ninth threshold, the terminal device does not switch the first time slot from the SBFD time slot to the downlink time slot. Or,

[0183] Condition 8 is that the number of first symbols of the configured SSB within the first time slot is greater than or equal to the ninth threshold. In other words, condition 8 is that the number of first symbols of the configured SSB within the first time slot is greater than or equal to the ninth threshold. For example, when the number of first symbols of the configured SSB within the first time slot is greater than or equal to the ninth threshold, the terminal device switches the first time slot from the SBFD time slot to the downlink time slot; when the number of first symbols of the configured SSB within the first time slot is less than the ninth threshold, the terminal device does not switch the first time slot from the SBFD time slot to the downlink time slot.

[0184] Understandably, conditions 1, 2, 3, 4, 5, 7, and 8 can be combined. For example, if conditions 1 and 4 are met to determine the first time slot as a downlink time slot, then the terminal device will only switch the first time slot from the SBFD time slot to the downlink time slot if both the number of first symbols in the first time slot is less than a first threshold and the number of SBFD symbols without configured SSBs in the first time slot is less than a fourth threshold.

[0185] Optionally, one or more of the first, second, third, fourth, fifth, eighth, and ninth thresholds mentioned above may be predefined or configured by the network device for the terminal device. This embodiment does not impose any restrictions on this.

[0186] In one implementation, the terminal device determines whether the conditions for designating a first timeslot as a downlink timeslot are met based on a first configuration parameter for configuring TDD, a second configuration parameter for configuring SSB, and a third configuration parameter for configuring SBFD. The first configuration parameter is also called a TDD parameter or a first configuration message; the second configuration parameter is also called an SSB configuration parameter or a second configuration message; and the third configuration parameter is also called an SBFD parameter or a third configuration message. Correspondingly, the terminal device determines whether the handover conditions are met based on the first, second, and third configuration parameters, thereby determining whether to perform a handover. That is, the terminal device determines whether to perform a handover based on the first, second, and third configuration parameters. For example, the terminal device determines the first timeslot based on the TDD and SBFD parameters, and then further determines whether to switch the first timeslot from an SBFD timeslot to a downlink timeslot based on whether the number of SBFD symbols within the first timeslot meets the conditions.

[0187] For example, TDD configuration parameters include, but are not limited to: the slot index of the downlink slot, the slot index of the uplink slot, and the slot index of the flexible slot; the symbol index of the uplink symbol in the flexible slot; the symbol index of the downlink symbol in the flexible slot; and the symbol index of the flexible symbol in the flexible slot. The downlink symbols in the downlink slot and the flexible slot are used for downlink data transmission, the uplink symbols in the uplink slot and the flexible slot are used for uplink data transmission, and the flexible symbols in the flexible slot can be used for both uplink and downlink data transmission.

[0188] For example, SBFD configuration parameters include, but are not limited to: the location of the SBFD time slot, the location of the SBFD symbol, and the location of the SBFD subband within the SBFD time slot. The location of the SBFD time slot / SBFD symbol can be some or all of the DL time slots / symbols or flexible time slots / symbols configured in the TDD configuration, that is, converting some or all of the downlink time slots / symbols or flexible time slots / symbols into SBFD symbols. The SBFD subband can be the frequency domain location of the UL subband and / or DL ​​subband.

[0189] For example, SSB configuration parameters include, but are not limited to: the position of the symbol occupied by the SSB, and the frequency domain position occupied by the SSB. In this embodiment, the symbol occupied by the SSB is also referred to as the SSB symbol.

[0190] Optionally, as shown in Figure 8, method 800 further includes S801-b: the network device sends a first configuration parameter, a second configuration parameter, and a third configuration parameter to the terminal device.

[0191] Therefore, it is understandable that determining whether to perform a handover through the first and second implementation schemes helps to reduce the number of handovers to DL slots, thereby ensuring the gain of the SBFD system.

[0192] In the fifth implementation scheme, the condition for determining the first time slot as a downlink time slot includes condition 6: all symbols within the first time slot must be downlink symbols in the first configuration parameters. That is, in this implementation scheme, the terminal device needs to satisfy the condition that all symbols in the first time slot are downlink symbols in the TDD configuration parameters before switching the first time slot from the SBFD time slot to the downlink time slot. It can be understood that this implementation scheme ensures that the symbol types in the original TDD configuration are not disrupted after switching the first time slot from the SBFD time slot to the downlink time slot, thereby guaranteeing the consistency of the SBFD system.

[0193] In the fifth implementation scheme, the condition for determining the first time slot as a downlink time slot includes: the number of handover points within one sub-band full-duplex SBFD cycle remains unchanged after the first time slot is determined as a downlink time slot. That is, in this implementation scheme, whether the first time slot is switched from an SBFD time slot to a downlink time slot is determined based on whether the handover of the first time slot affects the number of handover points (a non-SBFD symbol switching to an SBFD symbol, or an SBFD symbol switching to a non-SBFD symbol). For example, if the handover of the first time slot does not affect the number of handover points, the terminal device will switch the first time slot from an SBFD time slot to a downlink time slot; however, if the handover of the first time slot affects the number of handover points, the terminal device will not switch the first time slot from an SBFD time slot to a downlink time slot.

[0194] Optionally, the number of switching points within a sub-band full-duplex SBFD cycle remains unchanged after the first time slot is determined as the downlink time slot, including: the first symbol configured with SSB within the first time slot is located at the beginning (i.e., the boundary between non-SBFD and SBFD) or the end (i.e., the boundary between SBFD and non-SBFD) of the SBFD region.

[0195] Optionally, the number of switching points within one sub-band full-duplex SBFD cycle after the first time slot is determined as a downlink time slot remains unchanged, including: satisfying the boundary where the first symbol configured with SSB in the first time slot switches from non-SBFD to SBFD, or satisfying the boundary where the first symbol configured with SSB in the first time slot switches from SBFD to non-SBFD.

[0196] For example, the terminal device communicates with the network device based on a determined first time slot, which can be interpreted as the terminal device communicating with the network device based on the first time slot after the handover. This includes, for example, the terminal device sending uplink data to the network device based on the first time slot after the handover, or the terminal device receiving downlink data sent by the network device based on the first time slot after the handover.

[0197] Understandably, this fourth implementation scheme can ensure the gain of the SBFD system without affecting the number of switching points within the SBFD cycle, and without affecting the complexity of terminal and network devices.

[0198] Optionally, as shown in Figure 8, it may also include S801-a: the terminal device sends first information to the network device, the first information indicating whether it has the capability to determine the first timeslot as a downlink timeslot, or the first information indicating whether it has the capability to determine the first symbol configured with an SSB as a downlink symbol. This can also be interpreted as: the first information indicating whether it has the capability to switch the first timeslot to a downlink timeslot, or the first information indicating whether it has the capability to switch the first symbol configured with an SSB to a downlink symbol.

[0199] The communication method and communication device provided in this application will now be described in detail with reference to the accompanying drawings.

[0200] Figure 9 is a schematic flowchart of the communication method provided in an embodiment of this application. Figure 9 only illustrates the method from the perspective of interaction between network devices and terminal devices, and should not be construed as limiting the embodiments of this application in any way. The network device in Figure 9 can be replaced by components configured in the network device (such as chips, chip systems, processors, etc.), or by logic modules or software that can implement all or part of the functions of the network device; the terminal device in Figure 9 can be replaced by components configured in the terminal device (such as chips, chip systems, processors, etc.), or by logic modules or software that can implement all or part of the functions of the terminal device.

[0201] The following details each step in method 900.

[0202] S901 defines the first time slot within an SBFD cycle and the second time slot before or after the first time slot as the downlink time slot.

[0203] S902, the terminal device communicates with the network device based on a determined first time slot.

[0204] The concept of the first time slot can be referred to the description in the embodiment shown in Figure 8, which will not be repeated here.

[0205] For a detailed description of the SBFD cycle, please refer to the relevant technical documentation; it will not be elaborated upon here.

[0206] In this embodiment, the second time slot includes the first symbol, and no SSB is configured on the first symbol included in the second time slot. That is, the second time slot is also an SBFD time slot, but the difference between the second time slot and the first time slot is that the first time slot is a time slot with an SSB configured on the SBFD symbol, while the second time slot is a time slot without an SSB configured on the SBFD symbol.

[0207] In this embodiment, the terminal device determines the first time slot and the second time slot before or after the first time slot within one SBFD cycle as the downlink time slot. This can also be interpreted as the terminal device precisely switching the first time slot and the second time slot before or after the first time slot within one SBFD cycle to the downlink time slot.

[0208] In this embodiment, the terminal device communicates with the network device based on a determined first time slot, including: the terminal device communicating with the network device based on a determined first time slot and a determined second time slot. This can also be interpreted as: the terminal device communicating with the network device based on the first time slot and the second time slot after the handover. For example, the terminal device communicating with the network device based on the first and second time slots after the handover includes: the terminal device sending uplink data to the network device based on the first and second time slots after the handover, or the terminal device receiving downlink data sent by the network device based on the first time slot after the handover.

[0209] For example, the terminal device may designate the first time slot and the preceding second time slot (SBFD slot) within an SBFD cycle as downlink time slots.

[0210] For example, the terminal device designates the first time slot and the subsequent second time slot (SBFD slot) within an SBFD cycle as downlink time slots.

[0211] Optionally, the network device can instruct the terminal device whether to designate the previous or subsequent second timeslot as the downlink timeslot.

[0212] For example, the method further includes: the network device sending second information to the terminal device, and correspondingly, the terminal device receiving the second information, which indicates that the second time slot is located before the first time slot. Further, the terminal device determines both the first time slot within one SBFD cycle and the preceding second time slot (SBFD slot) as downlink time slots.

[0213] For example, the method further includes: the network device sending third information to the terminal device, and correspondingly, the terminal device receiving the third information, which indicates that the second time slot is located after the first time slot. Further, the terminal device determines both the first time slot within one SBFD cycle and the subsequent second time slot (SBFD slot) as downlink time slots.

[0214] Optionally, the terminal device compares the number of first time slots and preceding second time slots within a single SBFD cycle with the number of second time slots following the first time slot, and identifies the SBFD time slot with the smaller number of times slots as downlink time slots. For example, if the number of second time slots before the first time slot within a single SBFD cycle is less than the number of second time slots following the first time slot, then both the first time slot and the preceding second time slot (SBFD slot) within that single SBFD cycle are identified as downlink time slots. Similarly, if the number of second time slots following the first time slot within a single SBFD cycle is less than the number of second time slots before the first time slot, then both the first time slot and the following second time slot (SBFD slot) within that single SBFD cycle are identified as downlink time slots.

[0215] Optionally, when the terminal device determines the first time slot and the preceding second time slot within a SBFD cycle as downlink time slots, it includes: the terminal device only determines the first time slot and the preceding second time slot within a SBFD cycle as downlink time slots when the number of the preceding second time slots within a SBFD cycle is less than the sixth threshold N1.

[0216] Optionally, when the terminal device determines the first time slot and the subsequent second time slot within a SBFD cycle as downlink time slots, it includes: the terminal device only determines the first time slot and the subsequent second time slot within a SBFD cycle as downlink time slots when the number of second time slots following the first time slot within a SBFD cycle is less than a seventh threshold N2. Optionally, N1 equals N2.

[0217] Optionally, the method further includes: the terminal device sending first information to the network device, the first information indicating whether it has the capability to determine the first time slot as a downlink time slot, or the first information indicating whether it has the capability to determine the first symbol configured with an SSB as a downlink symbol.

[0218] Optionally, one or more of the sixth and seventh thresholds appearing in this embodiment may be predefined, or they may be configured by the network device to the terminal device. This embodiment does not impose any restrictions on this.

[0219] Optionally, the method further includes: the network device sending a first configuration parameter, a second configuration parameter, and a third configuration parameter to the terminal device. The concepts of the first configuration parameter, the second configuration parameter, and the third configuration parameter can be referred to the description in the embodiment of Figure 8, and will not be repeated here. Correspondingly, the terminal device determines whether the handover conditions are met based on the first configuration parameter, the second configuration parameter, and the third configuration parameter, thereby determining whether to perform a handover. That is, the terminal device determines whether to perform a handover based on the first configuration parameter, the second configuration parameter, and the third configuration parameter. For example, this includes: the terminal device determining a first time slot and a second time slot based on the first configuration parameter, the second configuration parameter, and the third configuration parameter, and then, based on the determined first time slot and second time slot, determining the first time slot within one SBFD cycle and the second time slot before or after it as downlink time slots.

[0220] Optionally, as shown in Figure 9, it may further include S901-a: the terminal device sends first information to the network device, the first information indicating whether it has the capability to determine the first timeslot as a downlink timeslot, or the first information indicating whether it has the capability to determine the first symbol configured with an SSB as a downlink symbol. This can also be interpreted as: the first information indicating whether it has the capability to switch the first timeslot to a downlink timeslot, or the first information indicating whether it has the capability to switch the first symbol configured with an SSB to a downlink symbol.

[0221] Understandably, the communication method provided in this embodiment can maintain the number of switching points within one SBFD cycle, ensuring the gain of the SBFD system and not affecting the complexity of terminal devices and network devices.

[0222] Figure 10 is a schematic flowchart of the communication method provided in an embodiment of this application. Figure 10 only illustrates the method from the perspective of interaction between network devices and terminal devices, and should not be construed as limiting the embodiments of this application in any way. The network device in Figure 10 can be replaced by components configured in the network device (such as chips, chip systems, processors, etc.), or by logic modules or software capable of implementing all or part of the functions of the network device; the terminal device in Figure 10 can be replaced by components configured in the terminal device (such as chips, chip systems, processors, etc.), or by logic modules or software capable of implementing all or part of the functions of the terminal device.

[0223] The following details each step in Method 1000.

[0224] S1001, if there are N discontinuous first time slots within an SBFD cycle, the terminal device determines the N discontinuous first time slots and the second time slots between the N discontinuous first time slots as downlink time slots, where N is a positive integer greater than or equal to 2.

[0225] S1002, the terminal device communicates with the network device based on the determined first time slot.

[0226] The concept of the first time slot can be referred to the description in the embodiment of Figure 8, and the concept of the second time slot can be referred to the description in the embodiment of Figure 9, which will not be repeated in this embodiment.

[0227] For a detailed description of the SBFD cycle, please refer to the relevant technical documentation; it will not be elaborated upon here.

[0228] If there are N discontinuous first time slots within an SBFD cycle, then the N discontinuous first time slots and the second time slots between the N discontinuous first time slots are determined as downlink time slots. In other words, if there are two or more discontinuous SBFD time slots configured with SSB within an SBFD cycle, then the multiple SBFD time slots configured with SSB and the adjacent SBFD time slots without SSB are determined together as downlink time slots.

[0229] Optionally, the N discontinuous first time slots and the second time slots between the N discontinuous first time slots are determined as downlink time slots, including: when the number of second time slots between the N discontinuous first time slots is less than the threshold N3, the terminal device determines the N discontinuous first time slots and the second time slots between the N discontinuous first time slots as downlink time slots; otherwise, when the number of second time slots between the N discontinuous first time slots is greater than or equal to the threshold N3, only the SBFD time slot of the first configured SSB is switched, or no switching is performed.

[0230] Optionally, the method further includes: the terminal device sending first information to the network device, the first information indicating whether it has the capability to determine the first timeslot as a downlink timeslot, or the first information indicating whether it has the capability to determine the first symbol configured with an SSB as a downlink symbol. This can also be interpreted as: the first information indicating whether it has the capability to switch the first timeslot to a downlink timeslot, or the first information indicating whether it has the capability to switch the first symbol configured with an SSB to a downlink symbol.

[0231] Optionally, the method further includes: the network device sending a first configuration parameter, a second configuration parameter, and a third configuration parameter to the terminal device. The concepts of the first configuration parameter, the second configuration parameter, and the third configuration parameter can be referred to the description in the embodiment of Figure 8, and will not be repeated here. Correspondingly, the terminal device determines whether the handover conditions are met based on the first configuration parameter, the second configuration parameter, and the third configuration parameter, thereby determining whether to perform a handover. That is, the terminal device determines whether to perform a handover based on the first configuration parameter, the second configuration parameter, and the third configuration parameter. For example, this includes: the terminal device determining a first time slot and a second time slot based on the first configuration parameter, the second configuration parameter, and the third configuration parameter, and then, based on the determined first time slot and second time slot, determining N discontinuous first time slots and the second time slot between the N discontinuous first time slots as downlink time slots.

[0232] For example, the terminal device communicates with the network device based on the first time slot after the handover, including: the terminal device sending uplink data to the network device based on the first time slot after the handover, or the terminal device receiving downlink data sent by the network device based on the first time slot after the handover.

[0233] Understandably, the communication method provided in this embodiment can maintain the number of switching points within one SBFD cycle, ensuring the gain of the SBFD system and not affecting the complexity of terminal devices and network devices.

[0234] Optionally, switching can also be performed at the symbol level. For example, switching at the symbol level includes: if the number of switching points within one SBFD cycle remains unchanged after the first symbol configured with SSB is determined as the downlink symbol, then the terminal device will determine the first symbol configured with SSB as the downlink symbol. The first symbol is a symbol configured with frequency domain resources for both transmission directions. That is, the first symbol configured with SSB will be determined as the downlink symbol without affecting the number of switching points; otherwise, no switching will occur. This can also be interpreted as: if the number of switching points within one SBFD cycle remains unchanged after the first symbol configured with SSB is switched to the downlink symbol, then the terminal device will switch the first symbol configured with SSB as the downlink symbol. The first symbol is a symbol configured with frequency domain resources for both transmission directions. That is, the first symbol configured with SSB will be switched to the downlink symbol without affecting the number of switching points; otherwise, no switching will occur.

[0235] Optionally, the conditions that ensure the number of switching points remains constant within an SBFD cycle include: the first symbol configured with SSB is located at the beginning (i.e., the boundary between non-SBFD and SBFD) or the end (i.e., the boundary between SBFD and non-SBFD) of the SBFD region.

[0236] Optionally, the conditions that satisfy the requirement that the number of switching points remains unchanged within an SBFD cycle include: the first symbol configured with SSB switching to SBFD across the boundary of non-SBFD, or the first symbol configured with SSB switching to non-SBFD within the first time slot.

[0237] For example, the first symbol configured with an SSB and the first symbol before or after it without an SSB within an SBFD cycle are switched to downlink symbols. In other words, within an SBFD cycle, the terminal device switches all SBFD symbols configured with an SSB, as well as the SBFD symbols before or after it, to downlink symbols to keep the number of switching points constant.

[0238] Optionally, the network device can instruct the terminal device whether to switch the first symbol of the previous or subsequent unconfigured SSB to the downlink symbol.

[0239] For example, the method further includes: the network device sending fourth information to the terminal device, and correspondingly, the terminal device receiving the fourth information, which is used to instruct the switching of the first symbol that is not configured with an SSB preceding the first symbol. Further, the terminal device switches both the first symbol within one SBFD cycle and the previous first symbols without configured SSBs to downlink symbols.

[0240] For example, the method further includes: the network device sending fifth information to the terminal device, and correspondingly, the terminal device receiving the fifth information, which is used to instruct the switching of the first symbol without a configured SSB following the first symbol. Further, the terminal device switches the first symbol within one SBFD cycle and subsequent first symbols without configured SSBs to downlink symbols.

[0241] Optionally, the terminal device compares the number of first symbols without SSB configuration within a single SBFD cycle, including the number of first symbols without SSB configuration preceding the first symbol, with the number of first symbols without SSB configuration following the first symbol. The first symbol with the smaller number of SSB configurations is then switched to a downlink symbol. For example, if the number of first symbols without SSB configuration preceding the first symbol within a single SBFD cycle is less than the number of first symbols without SSB configuration following the first symbol, then both the first symbol within the single SBFD cycle and the first symbols without SSB configuration preceding it are switched to downlink symbols. Similarly, if the number of first symbols without SSB configuration following the first symbol within a single SBFD cycle is less than the number of first symbols without SSB configuration preceding the first symbol, then both the first symbol within the single SBFD cycle and the first symbols without SSB configuration following it are switched to downlink symbols.

[0242] Optionally, when the terminal device switches the first symbol in one SBFD cycle and the first symbol before it that was not configured with an SSB to the downlink symbol, it includes: the terminal device switches the first symbol in one SBFD cycle and the first symbol before it that was not configured with an SSB to the downlink symbol only when the number of first symbols before the first symbol in one SBFD cycle is less than a threshold N4.

[0243] Optionally, when the terminal device switches the first symbol within an SBFD cycle and subsequent first symbols without configured SSBs to downlink symbols, the following procedure is followed: the terminal device switches the first symbol within an SBFD cycle and subsequent first symbols without configured SSBs to downlink symbols only when the number of first symbols without configured SSBs following the first symbol within an SBFD cycle is less than a threshold N5. Optionally, N4 equals N5.

[0244] Optionally, when there are M discontinuous symbol groups within an SBFD cycle, the symbols included in each of the M symbol groups, as well as the first symbol without an configured SSB between the M symbol groups, are switched to downlink symbols, where M is a positive integer greater than or equal to 2. For example, each of the M symbol groups here is a symbol group containing 4 symbols, and each symbol group includes a first symbol configured with an SSB. That is, it can be interpreted as: for two or more discontinuous SBFD symbol groups with configured SSBs within an SBFD cycle, each symbol, along with the adjacent SBFD symbols without configured SSBs, are switched to downlink symbols.

[0245] Optionally, switching the symbols included in each symbol group in the M symbol groups and the first symbol without an configured SSB between the M symbol groups to downlink symbols includes: when the number of the first symbols without a configured SSB between the M symbol groups is less than the threshold N6, the terminal device switches the symbols included in each symbol group in the M symbol groups and the first symbol without a configured SSB between the M symbol groups to downlink symbols; otherwise, only the first SBFD symbol group with an configured SSB is switched, or no switching is performed.

[0246] Understandably, this implementation method can ensure the gain of the SBFD system without affecting the number of switching points within the SBFD cycle, and without affecting the complexity of terminal and network devices.

[0247] The following describes another embodiment provided by this application. This embodiment includes: the terminal device performing any of the following actions on a first symbol configured with an SSB:

[0248] Action 1: If the frequency domain resources for transmitting the SSB on the first symbol configured with the SSB are not included in the downlink available PRB, discard the second configuration message, which is a message used to configure the SSB.

[0249] That is, if the second configuration message received by the terminal device does not conform to the requirement that the frequency domain resources for transmitting the SSB on the first symbol configured with the SSB are included in the DL usable PRB, the terminal device considers the second configuration message to be erroneous and discards the second configuration message.

[0250] Optionally, if the second configuration message received by the terminal device does not conform to the requirement that the frequency domain resources for transmitting the SSB on the first symbol configured with the SSB are included in the DL usable PRB, the terminal device considers the third configuration message to be erroneous, i.e., the SBFD configuration message is erroneous, and discards the third configuration message.

[0251] Optionally, if the second configuration message received by the terminal device does not conform to the requirement that the frequency domain resources for transmitting the SSB on the first symbol configured with the SSB are included in the DL usable PRB, the terminal device considers the first configuration message, the second configuration message, and the third configuration message to be erroneous and discards the first configuration message, the second configuration message, and the third configuration message.

[0252] It should be noted that when the terminal device transmits data on the first symbol occupied by the SSB in behavior 1, the network device must ensure that when transmitting the SSB on the first symbol configured with the SSB, the frequency domain resource of the SSB is located within the DL usable PRB on the first symbol configured with the SSB. That is, the network device ensures that the SSB on the SBFD symbol is configured within the DL usable PRB.

[0253] Behavior 2: When the network device configures frequency domain resources for SSB transmission on the first symbol configured with SSB that include frequency domain resources located outside the downlink usable PRB (i.e., the network device configures the frequency domain resources occupied by the SSB on the SBFD symbol outside the DL usable PRB), the terminal device only receives downlink signals within the downlink usable PRB and does not transmit uplink signals on the uplink usable PRB on the first symbol configured with SSB. Alternatively, it can be interpreted as: when the network device configures the frequency domain resources occupied by the SSB on the SBFD symbol outside the DL usable PRB, the terminal device can only receive downlink signals within the DL usable PRB on the SBFD symbol configured with SSB and cannot transmit uplink signals on the UL usable PRB.

[0254] In one scenario, the network device configures the frequency domain resources occupied by the SSB on the SBFD symbol outside the DL usable PRB, including: the network device configuring all the frequency domain resources occupied by the SSB on the SBFD symbol outside the DL usable PRB; in another scenario, the network device configures part of the frequency domain resources occupied by the SSB on the SBFD symbol outside the DL usable PRB.

[0255] Behavior 3: When the network device configures frequency domain resources for SSB transmission on the first symbol configured with SSB, including frequency domain resources located outside the downlink usable PRB (i.e., the network device configures the frequency domain resources occupied by the SSB on the SBFD symbol outside the DL usable PRB), the terminal device receives downlink signals within the downlink usable PRB or transmits uplink signals on the uplink usable PRB on the first symbol configured with SSB. Alternatively, it can be interpreted as: when the network device configures the frequency domain resources occupied by the SSB on the SBFD symbol outside the DL usable PRB, the terminal device can perform uplink transmission on the UL usable PRB on the first symbol configured with SSB. Understandably, in this behavior, the corresponding SSB on the first symbol configured with SSB is invalid; that is, the first symbol configured with SSB can be considered a regular SBFD symbol. Furthermore, it is understandable that the mapping between SSB and RO remains unchanged, but the terminal device does not use the RO corresponding to the invalid SSB.

[0256] Optionally, when the network device configures the frequency domain resources occupied by the SSB on the SBFD symbol outside the DL usable PRB, the network device can indicate to the terminal device whether uplink transmission can be performed on the UL usable PRB. If the network device indicates to the terminal device that uplink transmission cannot be performed on the UL usable PRB, then the terminal device performs action 2; if the network device indicates to the terminal device that uplink transmission can be performed on the UL usable PRB, then the terminal device performs action 3.

[0257] Behavior 4: When the network device configures frequency domain resources for SSB transmission on the first symbol configured with SSB, including frequency domain resources located outside the downlink usable PRB (i.e., the network device configures the frequency domain resources occupied by the SSB on the SBFD symbol outside the DL usable PRB), the terminal device receives the SSB on the first symbol configured with SSB, but does not receive downlink signals other than the SSB, on the frequency domain resources outside the downlink usable PRB. In other words, on the first symbol configured with SSB, the terminal device receives the SSB outside the DL usable PRB but does not receive other downlink signals. Understandably, in this case, the terminal device obviously cannot perform uplink transmission on the UL usable PRB, but can receive PDSCH, PDCCH, CSI-RS, etc., on the DL usable PRB.

[0258] Optionally, in this embodiment, the downlink available PRB can also be replaced with the downlink available PRB + the PRB corresponding to the guard sideband. The concept of the guard sideband can be referred to the previous introduction, and will not be repeated here.

[0259] Optionally, when the terminal device does not determine the SBFD time slot / symbol where the SSB is configured as a downlink time slot / symbol, the terminal device executes the method in this embodiment.

[0260] Optionally, the network device sends a first configuration parameter, a second configuration parameter, and a third configuration parameter to the terminal device. Correspondingly, after receiving the first, second, and third configuration parameters, the terminal device determines the first symbol configured with the SSB based on these parameters, and then determines the behavior on the first symbol configured with the SSB. Detailed descriptions of the first, second, and third configuration parameters can be found in the preceding descriptions and will not be repeated here.

[0261] As can be seen, this embodiment provides configuration restrictions when the SBFD symbol configured with SSB is still an SBFD symbol, and gives a clear definition of the behavior of network devices and terminal devices at this time, thus improving the SBFD system design.

[0262] The transmission method of the embodiments of this application has been described in detail above. The transmission device provided by the embodiments of this application will be described in detail below with reference to FIG11 and FIG12.

[0263] Figure 11 is a structural schematic diagram of the communication device provided in an embodiment of this application. Specifically, as shown in Figure 11, the device 1100 includes: a processing module 1101 and a transceiver module 1102.

[0264] For example, in one embodiment, the processing module 1101 is configured to determine the first time slot as a downlink time slot if the conditions for determining the first time slot as a downlink time slot are met. The first time slot includes a first symbol configured with a synchronization signal block (SSB), and the first symbol is configured with frequency domain resources for two transmission directions; or,

[0265] The first time slot within a sub-band full-duplex SBFD cycle and the second time slot before or after the first time slot are defined as downlink time slots, wherein the second time slot includes the first symbol and no SSB is configured on the first symbol included in the second time slot; or,

[0266] If there are N discontinuous first time slots within an SBFD cycle, then the N discontinuous first time slots and the second time slots between the N discontinuous first time slots are determined as downlink time slots, where N is a positive integer greater than or equal to 2;

[0267] The first time slot includes a first symbol configured with a synchronization signal block (SSB), and the first symbol is configured with frequency domain resources for two transmission directions. The second time slot includes the first symbol, but the first symbol included in the second time slot is not configured with an SSB.

[0268] The transceiver module 1102 is used for communication based on the first time slot after the handover is performed.

[0269] Optionally, if the first time slot is determined as a downlink time slot based on satisfying the condition that the first time slot is determined as a downlink time slot, the condition includes the condition that the number of first symbols in the first time slot satisfies.

[0270] Optionally, the number of the first symbols in the first time slot may satisfy one or more of the following conditions: the number of the first symbols in the first time slot is less than a first threshold, the ratio of the number of the first symbols in the first time slot to the number of downlink symbols in the first time slot is less than a second threshold, and the ratio of the number of the first symbols in the first time slot to the number of symbols other than the first symbols in the first time slot is less than a third threshold.

[0271] Optionally, if the first time slot is determined as a downlink time slot based on satisfying the condition that the first time slot is determined as a downlink time slot, the condition includes the condition that the number of first symbols without configured SSBs in the first time slot satisfies the condition.

[0272] Optionally, the number of first symbols without configured SSBs in the first time slot may satisfy one or more of the following conditions: the number of first symbols without configured SSBs in the first time slot is less than a fourth threshold, and the ratio of the number of first symbols with configured SSBs to the number of first symbols without configured SSBs in the first time slot is greater than a fifth threshold.

[0273] Optionally, if the first time slot is determined as a downlink time slot based on the condition that the first time slot is determined as a downlink time slot, the condition includes the condition that all symbols in the first time slot are of the downlink symbol type in the first configuration message, and the first configuration message is a message used to configure TDD.

[0274] Optionally, if the first time slot is determined as a downlink time slot based on satisfying the condition that the first time slot is determined as a downlink time slot, the condition includes the condition that the number of switching points in one sub-band full-duplex SBFD cycle remains unchanged after the first time slot is determined as a downlink time slot.

[0275] Optionally, the transceiver module 1102 is further configured to: send first information, the first information being used to indicate whether it has the capability to determine the first time slot as a downlink time slot, or the first information being used to indicate whether it has the capability to determine the first symbol configured with an SSB as a downlink symbol.

[0276] For example, in the second embodiment, the processing module 1101 is configured to: discard the second configuration message, which is a message for configuring the SSB, if the frequency domain resources for transmitting the SSB on the first symbol configured with the synchronization signal block SSB are not included in the downlink available PRB; or,

[0277] If the frequency domain resources for transmitting the SSB on the first symbol configured with a synchronization signal block (SSB) include frequency domain resources located outside the downlink available PRB, downlink signals are received only within the downlink available PRB on the first symbol configured with the SSB, and uplink signals are not transmitted on the uplink available PRB; or,

[0278] If the frequency domain resources for transmitting the SSB on the first symbol configured with a synchronization signal block (SSB) include frequency domain resources located outside the downlink available PRB, then on the first symbol configured with the SSB, downlink signals are received within the downlink available PRB or uplink signals are transmitted on the uplink available PRB; or,

[0279] If the frequency domain resources for transmitting the SSB on the first symbol configured with a synchronization signal block SSB include frequency domain resources located outside the downlink available PRB, the SSB is received on the frequency domain resources outside the downlink available PRB on the first symbol configured with the SSB, but downlink signals other than the SSB are not received.

[0280] Figure 12 is a structural schematic diagram of another data transmission apparatus provided in an embodiment of this application. The apparatus shown in Figure 12 can be used to perform the method described in any of the foregoing embodiments.

[0281] As shown in Figure 12, the device 1200 of this embodiment includes a memory 1201 and a processor 1202. In one implementation, the device 1200 further includes a communication interface 1203 and a bus 1204. The memory 1201, processor 1202, and communication interface 1203 are interconnected via the bus 1204.

[0282] The memory 1201 may be a read-only memory (ROM), a static storage device, a dynamic storage device, or a random access memory (RAM). The memory 1201 may store a program, and when the program stored in the memory 1201 is executed by the processor 1202, the processor 1202 is used to perform the various steps of the method shown in the foregoing embodiments.

[0283] The processor 1202 may be a general-purpose central processing unit (CPU), a microprocessor, an application-specific integrated circuit (ASIC), or one or more integrated circuits, used to execute relevant programs to implement the methods shown in the foregoing embodiments.

[0284] The processor 1202 can also be an integrated circuit chip with signal processing capabilities. In implementation, each step of the method in FIG9 of this application embodiment can be completed by the integrated logic circuitry in the processor 1202 or by software instructions.

[0285] For example, processor 1202 includes a transmission direction determination circuit for determining whether to designate the SBFD time slot / SBFD symbol containing the SSB as a downlink time slot / downlink symbol based on first configuration parameters, second configuration parameters, third configuration parameters, and preset conditions issued by the network device, thereby controlling the transmit / receive chain through communication and processing circuitry. The function of the transmission direction determination circuit can also be processed on a computer-readable medium.

[0286] The processor 1202 described above can also be a general-purpose processor, a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA), or other programmable logic devices, discrete gate or transistor logic devices, or discrete hardware components. It can implement or execute the methods, steps, and logic block diagrams disclosed in the embodiments of this application. The general-purpose processor can be a microprocessor or a conventional processor, etc.

[0287] The steps of the method disclosed in the embodiments of this application can be directly implemented by a hardware decoding processor, or implemented by a combination of hardware and software modules in the decoding processor. The software modules can reside in random access memory, flash memory, read-only memory, programmable read-only memory, electrically erasable programmable memory, registers, or other mature storage media in the art. This storage medium is located in memory 1201. The processor 1202 reads information from memory 1201 and, in conjunction with its hardware, performs the functions required by the units included in the device of this application. For example, it can execute the various steps / functions of the foregoing embodiments.

[0288] The communication interface 1203 can use, but is not limited to, transceivers to enable communication between the device 1200 and other devices or communication networks.

[0289] Bus 1204 may include a pathway for transmitting information between various components of device 1200 (e.g., memory 1201, processor 1202, communication interface 1203).

[0290] It should be understood that the device 1200 shown in the embodiments of this application can be an electronic device, or it can be a chip configured in an electronic device. The device 1200 can be deployed in a terminal device, or it can be deployed in a network device.

[0291] The above embodiments can be implemented, in whole or in part, by software, hardware, firmware, or any other combination thereof. When implemented using software, the above embodiments can be implemented, in whole or in part, as a computer program product. The computer program product includes one or more computer instructions or computer programs. When the computer instructions or computer programs are loaded or executed on a computer, all or part of the processes or functions described in the embodiments of this application are generated. 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. 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., infrared, wireless, microwave, etc.) means. The computer-readable storage medium can be a usable medium accessible to a computer or a data storage device such as a server or data center containing one or more sets of usable media. The usable medium can be a magnetic medium (e.g., floppy disk, hard disk, magnetic tape), an optical medium (e.g., DVD), or a semiconductor medium. A semiconductor medium can be a solid-state drive.

[0292] It should be understood that the term "and / or" in this article is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. A and B can be singular or plural. Additionally, the character " / " in this article generally indicates an "or" relationship between the preceding and following related objects, but it can also represent an "and / or" relationship. Please refer to the context for a more accurate understanding.

[0293] In this application, "at least one" means one or more, and "more than one" means two or more. "At least one of the following" or similar expressions refer to any combination of these items, including any combination of single or multiple items. For example, at least one of a, b, or c can mean: a, b, c, ab, ac, bc, or abc, where a, b, and c can be single or multiple.

[0294] It should be understood that in the various embodiments of this application, the order of the above-mentioned processes does not imply the order of execution. The execution order of each process should be determined by its function and internal logic, and should not limit the implementation process of the embodiments of this application.

[0295] Those skilled in the art will recognize that the units and algorithm steps of the various examples described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this application.

[0296] Those skilled in the art will understand that, for the sake of convenience and brevity, the specific working processes of the systems, devices, and units described above can be referred to the corresponding processes in the foregoing method embodiments, and will not be repeated here.

[0297] In the several embodiments provided in this application, it should be understood that the disclosed systems, apparatuses, and methods can be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative; for instance, the division of units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be through some interfaces; the indirect coupling or communication connection between apparatuses or units may be electrical, mechanical, or other forms.

[0298] The units described as separate components may or may not be physically separate. 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 the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0299] In addition, the functional units in the various embodiments of this application can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit.

[0300] If the aforementioned functions are implemented as software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, or a portion of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of this application. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory, random access memory, magnetic disks, or optical disks.

Claims

1. A communication method characterized by comprising: comprise: determining a first slot as a downlink slot if a condition for determining a first slot as a downlink slot is met, the first slot comprising a first symbol in which a synchronization signal block (SSB) is configured, and the first symbol comprising frequency domain resources configured for two transmission directions; or, determining the first slot and a second slot before or after the first slot in a sub-band full duplex (SBFD) period as downlink slots, the second slot comprising the first symbol and the first symbol in the second slot being free of the SSB; or, if there are N discontinuous first slots in an SBFD period, determining the N discontinuous first slots and a second slot between the N discontinuous first slots as downlink slots, N being a positive integer greater than or equal to 2; communicating based on the determined first slot.

2. The method of claim 1, wherein, If the first slot is determined as a downlink slot based on the condition for determining a first slot as a downlink slot, the condition comprises a condition that a number of the first symbols in the first slot meets.

3. The method of claim 2, wherein, The condition that the number of the first symbols in the first slot meets comprises one or more of: the number of the first symbols in the first slot being less than a first threshold, a ratio of the number of the first symbols in the first slot to a number of downlink symbols in the first slot being less than a second threshold, and a ratio of the number of the first symbols in the first slot to a number of symbols in the first slot other than the first symbols being less than a third threshold.

4. The method according to any one of claims 1 to 3, characterized in that, If the first slot is determined as a downlink slot based on the condition for determining a first slot as a downlink slot, the condition comprises a condition that a number of the first symbols in the first slot that are free of the SSB meets.

5. The method of claim 4, wherein, The condition that the number of the first symbols in the first slot that are free of the SSB meets comprises one or more of: the number of the first symbols in the first slot that are free of the SSB being less than a fourth threshold, and a ratio of a number of the first symbols in the first slot in which the SSB is configured to a number of the first symbols in the first slot that are free of the SSB being greater than a fifth threshold.

6. The method according to any one of claims 1 to 5, characterized in that, If the first slot is determined as a downlink slot based on the condition for determining a first slot as a downlink slot, the condition comprises a condition that all symbols in the first slot are downlink symbols in a first configuration message used to configure a time division duplex (TDD).

7. The method according to any one of claims 1 to 6, characterized in that, If the first slot is determined as a downlink slot based on the condition for determining a first slot as a downlink slot, the condition comprises a condition that a number of switching points in a SBFD period after the first slot is unchanged.

8. The method according to any one of claims 1 to 7, characterized in that, The method further comprises: sending first information indicating whether a capability of determining the first slot as a downlink slot is present, or indicating whether a capability of determining the first symbol in which the SSB is configured as a downlink symbol is present.

9. A communication method characterized by comprising: comprise: if frequency domain resources for transmitting a synchronization signal block (SSB) on a first symbol of the SSB are not contained in downlink available PRBs, discarding a second configuration message, the second configuration message being a message for configuring the SSB; or, if frequency domain resources for transmitting a synchronization signal block (SSB) on a first symbol of the SSB contain frequency domain resources outside downlink available PRBs, only receiving a downlink signal within the downlink available PRBs on the first symbol of the SSB and not transmitting an uplink signal on uplink available PRBs; or, if frequency domain resources for transmitting a synchronization signal block (SSB) on a first symbol of the SSB contain frequency domain resources outside downlink available PRBs, receiving a downlink signal within the downlink available PRBs or transmitting an uplink signal on uplink available PRBs on the first symbol of the SSB; or, if frequency domain resources for transmitting a synchronization signal block (SSB) on a first symbol of the SSB contain frequency domain resources outside downlink available PRBs, receiving the SSB on the frequency domain resources outside the downlink available PRBs but not receiving a downlink signal other than the SSB on the first symbol of the SSB.

10. A communications device, characterized by comprising means for performing the method of any one of claims 1 to 9.

11. A communications device, characterized by comprising: a processor, the processor being configured to cause the communication device to perform the method of any one of claims 1 to 9 by executing a computer program and / or by logic circuitry.

12. A computer program product, characterised in that, the computer program product comprising computer program code which, when the computer program code is run on a computer, causes the computer to perform the method of any one of claims 1 to 9.

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