Uplink signal transmission method and apparatus

Abstract

An uplink signal transmission method and apparatus are disclosed, which relate to the field of wireless communications. The method includes: when a terminal accesses at least two cells deployed in a non-colocated manner and obtains multiple timing advance groups, adjacent PUSCH slots on different uplink carriers are not aligned because different uplink carriers correspond to different timing advances; and when the terminal performs a switch between two different uplink carriers, the terminal omits transmitting an uplink signal during a first period and transmits an uplink signal on a second uplink carrier whose uplink radio frequency chain has been switched from the first uplink carrier. This avoids service interruptions caused by misalignment of frame boundaries of uplink carriers before and after the uplink carrier switch when the terminal starts uplink transmission after the uplink radio frequency chain switch time but before the uplink radio frequency chain switch is completed. Additionally, this helps achieve higher uplink transmission rates, higher spectrum utilization, and larger uplink capacity by utilizing dynamic spectrum selection during uplink radio frequency chain switch in non-colocated deployments.

Description

[Technical Field]

[0001] This application claims priority to Chinese Patent Application No. 202211215709.4, entitled "Uplink Signal Transmission Method and Apparatus," filed with the State Intellectual Property Office of the People's Republic of China on September 30, 2022, which is incorporated herein by reference in its entirety.

[0002] TECHNICAL FIELD Embodiments of the present application relate to the field of wireless communication, and in particular to an uplink signal transmission method and apparatus. [Background technology]

[0003] With the development and evolution of technology, radio frequency chain switching technology has been introduced into the fifth generation (5G) mobile communication technology. For example, a terminal supports radio frequency chain switching between the 3.5 GHz frequency band and the 1.8 GHz frequency band to occupy different frequency band resources for uplink signal transmission. For more flexible spectrum use, radio frequency chain switching in frequency band combinations including three or four frequency bands is supported. However, in non-colocated deployments, the distances from two network devices to a terminal may be different, and the timing advances delivered by the two network devices for the terminal may be different, resulting in service interruptions due to radio frequency chain switching. Summary of the Invention [Means for solving the problem]

[0004] The present application provides an uplink signal transmission method and apparatus to solve the problem of service interruption caused by radio frequency chain switching in non-colocated deployments.

[0005] According to a first aspect, an uplink signal transmission method is provided. The method may be applied to a terminal, or may be applied to a communication device capable of assisting the terminal in performing the method. For example, the communication device may include a chip system. The method includes: transmitting capability information to a first network device on a first uplink carrier, so that the first network device determines a switching time of an uplink radio frequency chain of the terminal; obtaining first signaling indicating an uplink carrier switch when a first uplink signal is transmitted to the first network device on the first uplink carrier; omitting to transmit the uplink signal during a first period; and transmitting a second uplink signal to the second network device on a second uplink carrier after the first period. The first uplink carrier belongs to a first frequency band, and the first uplink carrier belongs to a first Timing Advance Group (TAG). The second uplink carrier belongs to a second frequency band and a second TAG. The first period is longer than an uplink radio frequency chain switching time. The first frequency band is different from the second frequency band, and the first TAG is different from the second TAG.

[0006] When a terminal accesses at least two cells deployed in a non-colocated manner and obtains multiple timing advance groups, adjacent physical uplink shared channel (PUSCH) slots on different uplink carriers are not aligned because different uplink carriers correspond to different timing advances. Thus, when switching between two different uplink carriers, the terminal omits transmitting an uplink signal during a first period. Specifically, the terminal transmits an uplink signal on a second uplink carrier whose uplink radio frequency chain has been switched from the first uplink carrier after waiting for a period longer than an uplink radio frequency chain switching time indicated by the terminal's capabilities. This avoids service interruptions caused by misalignment of frame boundaries between uplink carriers before and after the uplink carrier switching when the terminal starts uplink transmission after the uplink radio frequency chain switching time but before the uplink radio frequency chain switching is completed. Additionally, this helps achieve higher uplink transmission rates, higher spectrum utilization, and greater uplink capacity by utilizing dynamic spectrum selection during uplink radio frequency chain switching in non-colocated deployments.

[0007] In one possible implementation, the first period is equal to or greater than the sum of the switching time and the maximum transmission timing difference, which is a preconfigured maximum offset of the uplink carriers with misaligned frame boundaries. To ensure that the uplink signal is successfully transmitted on the second uplink carrier to which the uplink radio frequency chain is switched from the first uplink carrier, the uplink signal is transmitted during the period equal to the sum of the switching time and the maximum transmission timing difference.

[0008] In another possible implementation, the first period is equal to or greater than the sum of the switching time, the maximum transmission timing difference, and a first value predefined in the protocol. In this way, another first value predefined in the protocol is added to the first period to further ensure that an uplink signal is successfully transmitted on the second uplink carrier after the uplink radio frequency chain is switched from the first uplink carrier.

[0009] In another possible implementation, the first period is a period corresponding to symbols overlapping with an uplink radio frequency chain switching time of a terminal on a first uplink carrier and / or symbols overlapping with an uplink radio frequency chain switching time of a terminal on a second uplink carrier.

[0010] In another possible implementation, the first period is greater than or equal to the sum of the switching time, twice the maximum transmission timing difference, and a first value predefined in the protocol.

[0011] According to a second aspect, an uplink signal reception method is provided. The method may be applied to a network device or a communication device capable of assisting the network device in performing the method. For example, the communication device may include a chip system. The method includes receiving capability information on a first uplink carrier, determining an uplink radio frequency chain switching time of the terminal, transmitting first signaling instructing the terminal to perform uplink switching, omitting to receive uplink signals during a first period, and receiving a second uplink signal on a second uplink carrier. The first uplink carrier belongs to a first frequency band, and the first uplink carrier belongs to a first TAG. The second uplink carrier belongs to a second frequency band, and the second uplink carrier belongs to a second TAG. The first period is longer than the uplink radio frequency chain switching time.

[0012] When a terminal accesses at least two cells deployed in a non-colocated manner and obtains multiple timing advance groups, adjacent PUSCH slots on different uplink carriers are not aligned because different uplink carriers correspond to different timing advances. Therefore, when performing a switch between two different uplink carriers, the terminal omits transmitting an uplink signal during a first period. Specifically, the network device omits receiving an uplink signal during the first period, and after waiting for a period longer than an uplink radio frequency chain switching time indicated by the terminal's capabilities, the network device receives an uplink signal on a second uplink carrier whose uplink radio frequency chain has been switched from the first uplink carrier. This avoids service interruptions caused by misalignment of frame boundaries of uplink carriers before and after the uplink carrier switch when the terminal starts uplink transmission after the uplink radio frequency chain switching time but before the uplink radio frequency chain switch is completed. Additionally, this helps achieve higher uplink transmission rates, higher spectrum utilization, and greater uplink capacity by utilizing dynamic spectrum selection during uplink radio frequency chain switching in non-colocated deployments.

[0013] In one possible implementation, the first period is equal to or greater than the sum of the switching time and the maximum transmission timing difference, which is a preconfigured maximum offset of the uplink carriers with misaligned frame boundaries. To ensure that the uplink signal is successfully transmitted on the second uplink carrier to which the uplink radio frequency chain is switched from the first uplink carrier, the uplink signal is transmitted during the period equal to the sum of the switching time and the maximum transmission timing difference.

[0014] In another possible implementation, the first period is equal to or greater than the sum of the switching time, the maximum transmission timing difference, and the error, where the error includes at least one of a measurement error of the terminal and thermal noise, and in this case, another error is added to the first period to further ensure that the uplink signal is successfully transmitted on the second uplink carrier after the uplink radio frequency chain is switched from the first uplink carrier.

[0015] In another possible implementation, the first period is a period corresponding to symbols overlapping with an uplink radio frequency chain switching time of a terminal on a first uplink carrier and / or symbols overlapping with an uplink radio frequency chain switching time of a terminal on a second uplink carrier.

[0016] In another possible implementation, the first period is greater than or equal to the sum of the switching time, twice the maximum transmission timing difference, and the error.

[0017] According to a third aspect, a communication device is provided. For beneficial effects, please refer to the description of the first aspect. Details will not be described again here. The communication device has a function of implementing the behavior of an embodiment of the method of the first aspect. The function may be implemented by hardware or by hardware executing corresponding software. The hardware or software includes one or more modules corresponding to the aforementioned functions. In one possible design, the communication device includes a transceiver unit and a processing unit. The transceiver unit is configured to transmit capability information so that the network device determines a switching time of an uplink radio frequency chain of the terminal; obtain first signaling indicating uplink switching when a first uplink signal is transmitted to the first network device on a first uplink carrier; omit transmitting an uplink signal during the first period; and transmit a second uplink signal to the second network device on a second uplink carrier. The first uplink carrier belongs to a first frequency band, and the first uplink carrier belongs to a first TAG. The second uplink carrier belongs to a second frequency band, and the second uplink carrier belongs to a second TAG. The first period is longer than an uplink radio frequency chain switching time. The processing unit is configured to determine, based on the first signaling, not to transmit an uplink signal during the first period. These modules can perform corresponding functions in the method example of the first aspect. For details, please refer to the detailed description of the method example. Details will not be described again here.

[0018] According to a fourth aspect, a communication device is provided. For beneficial effects, please refer to the description of the second aspect. Details will not be described again here. The communication device has a function of implementing the behavior of an embodiment of the method of the second aspect. The function may be implemented by hardware or by hardware executing corresponding software. The hardware or software may include one or more modules corresponding to the aforementioned functions. In one possible design, the communication device includes a transceiver unit and a processing unit. The transceiver unit is configured to receive capability information, determine a switching time of an uplink radio frequency chain of the terminal, transmit first signaling instructing the terminal to perform uplink switching when a first uplink signal is received on a first uplink carrier, omit receiving uplink signals during the first period, and receive a second uplink signal on a second uplink carrier. The first uplink carrier belongs to a first frequency band, and the first uplink carrier belongs to a first TAG. The second uplink carrier belongs to a second frequency band, and the second uplink carrier belongs to a second TAG. The first period is longer than an uplink radio frequency chain switching time. The processing unit is configured to determine, based on the first signaling, that no uplink signal is received during the first period. These modules can perform corresponding functions in the method example of the second aspect. For details, please refer to the detailed description of the method example. Details will not be described again here.

[0019] According to a fifth aspect, there is provided a communication device. The communication device may be a terminal or a chip within the terminal in the aforementioned method embodiments. The communication device includes a communication interface and a processor, and optionally further includes a memory. The memory is configured to store computer programs or instructions. The processor is coupled to the memory and the communication interface. When the processor executes the computer programs or instructions, the communication device is capable of performing the method performed by the terminal in the aforementioned method embodiments.

[0020] According to a sixth aspect, there is provided a communication device. The communication device may be a network device or a chip within the network device in the aforementioned method embodiments. The communication device includes a communication interface and a processor, and optionally further includes a memory. The memory is configured to store computer programs or instructions. The processor is coupled to the memory and the communication interface. Execution of the computer programs or instructions by the processor enables the communication device to perform the method performed by the network device in the aforementioned method embodiments.

[0021] According to a seventh aspect, there is provided a computer program product, the computer program product comprising computer program code which, when executed, performs the terminal-executed method of the aforementioned aspect.

[0022] According to an eighth aspect, there is provided a computer program product, the computer program product comprising computer program code that, when executed, performs the method performed by the network device in the aforementioned aspect.

[0023] According to a ninth aspect, a chip system is provided. The chip system includes a processor configured to perform the functions of a terminal according to the method of the previous aspect. In one possible design, the chip system further includes a memory configured to store program instructions and / or data. The chip system may include a chip, or may include a chip and other discrete components.

[0024] According to a tenth aspect, a chip system is provided. The chip system includes a processor configured to perform the functions of a network device in the manner of the previous aspect. In one possible design, the chip system further includes a memory configured to store program instructions and / or data. The chip system may include a chip, or may include a chip and other discrete components.

[0025] According to an eleventh aspect, there is provided a computer-readable storage medium storing a computer program which, when executed, performs the method executed by the terminal in the aforementioned aspect.

[0026] According to a twelfth aspect, there is provided a computer-readable storage medium storing a computer program which, when executed, performs the method performed by the network device in the aforementioned aspect.

[0027] According to a thirteenth aspect, there is provided a communication system, the communication system including a terminal according to the third aspect or a communication apparatus that assists the terminal in performing the method according to the first aspect, and a network device according to the fourth aspect or a communication apparatus that assists the network device in performing the method according to the second aspect.

[0028] Alternatively, the communication system includes a terminal according to the fifth aspect or a communication apparatus that assists the terminal in performing the method according to the first aspect, and a network device according to the sixth aspect or a communication apparatus that assists the network device in performing the method according to the second aspect.

[0029] In this application, the names of terminals, network devices, and communication devices are not intended to limit the devices. In actual implementation, the devices may have other names. However, if the functions of the devices are similar to those of this application, the devices fall within the scope of the claims of this application and their equivalent technologies. [Brief explanation of the drawings]

[0030] [Figure 1] 1 is a diagram of the architecture of a mobile communication system to which an embodiment of the present application applies; [Figure 2] 1 is a diagram of a radio frequency chain according to the present application; [Figure 3] 2 is a flowchart of an uplink signal transmission method according to the present application; [Figure 4] FIG. 1 is a diagram of multi-TAG uplink carrier switching according to the present application. [Figure 5] 1 is an exemplary diagram of a configuration of a communication device according to the present application; [Figure 6] FIG. 2 is an exemplary diagram of another communication device configuration according to the present application. DETAILED DESCRIPTION OF THE INVENTION

[0031] Hereinafter, implementations of the embodiments of the present application will be described in detail with reference to the accompanying drawings.

[0032] FIG. 1 is an architecture diagram of a communication system 1000 to which an embodiment of the present application is applied. As shown in FIG. 1, the communication system includes a radio access network 100 and a core network 200. Optionally, the communication system 1000 may further include the Internet 300. The radio access network 100 may include at least one radio access network device (e.g., 110a and 110b in FIG. 1) and may further include at least one terminal (e.g., 120a to 120j in FIG. 1). The terminal is connected to the radio access network device wirelessly, and the radio access network device is connected to the core network wirelessly or by a wired method. The core network device and the radio access network device may be separate physical devices, or the functions of the core network device and the logical functions of the radio access network device may be integrated into the same physical device, or some functions of the core network device and some functions of the radio access network device may be integrated into one physical device. The connection between the terminal and the radio access network device may be wired or wireless. FIG. 1 is merely a diagram. The communication system may further include other network devices, for example, wireless relay devices and wireless backhaul devices not shown in FIG.

[0033] A radio access network device is an access device for a terminal to wirelessly access a communication system. The radio access network device may be a base station, an evolved NodeB (eNodeB), a transmission reception point (TRP), a next-generation base station (next-generation NodeB (gNB)) for a fifth-generation (5G) mobile communication system, a next-generation base station for a sixth-generation (6G) mobile communication system, a base station for a future mobile communication system, an access node for a Wi-Fi system, etc. Alternatively, the radio access network device may be a module or unit that completes some functions of a base station, such as a central unit (CU) or a distributed unit (DU). Here, the CU completes the functions of the radio resource control protocol and packet data convergence protocol (PDCP) of the base station and may also complete the function of the service data adaptation protocol (SDAP). The DU completes the functions of the radio link control layer and medium access control (MAC) layer of the base station, and may also complete some or all of the functions of the physical layer. For a specific description of the aforementioned protocol layers, please refer to the relevant technical specifications of the 3rd generation partnership project (3GPP). The radio access network device may be a macro base station (e.g., 110a in FIG. 1), a micro base station or an indoor base station (e.g., 110b in FIG. 1), or a relay node, a donor node, etc. The specific technology and specific device form adopted by the radio access network device are not limited by the embodiments of this application.For ease of explanation, the following description will be given using an example in which the radio access network device is a base station.

[0034] A terminal is a device with wireless transceiver capabilities that can transmit signals to or receive signals from a base station. A terminal may also be referred to as a terminal device, user equipment (UE), mobile station, or mobile terminal. Terminals can be widely used in various scenarios, such as device-to-device (D2D), vehicle-to-everything (V2X) communications, machine-type communications (MTC), the Internet of Things (IoT), virtual reality, augmented reality, industrial control, autonomous driving, telemedicine, smart grids, smart furniture, smart offices, smart wearables, smart transportation, and smart cities. Terminals may be mobile phones, tablet computers, computers with wireless transceiver capabilities, wearable devices, vehicles, airplanes, ships, robots, robotic arms, smart home devices, and the like. The specific technologies and device configurations employed by the terminals are not limited by the embodiments of this application.

[0035] The base station and the terminal may be fixed or mobile. The base station and the terminal may be deployed on land, including indoor or outdoor devices, handheld devices, or vehicle-mounted devices, or may be deployed on water, or may be deployed on airplanes, balloons, or satellites. The application scenarios of the base station and the terminal are not limited by the embodiments of the present application.

[0036] The roles of a base station and a terminal may be relative. For example, helicopter or unmanned aerial vehicle 120i in FIG. 1 may be configured as a mobile base station. To terminal 120j accessing wireless access network 100 via 120i, terminal 120i is a base station. However, to base station 110a, 120i is a terminal. In other words, communication between 110a and 120i is performed based on a wireless air interface protocol. It is clear that communication between 110a and 120i may instead be performed based on an interface protocol between base stations. In this case, to base station 110a, 120i is also a base station. Therefore, both the base station and the terminal may be collectively referred to as a communication device. 110a and 110b in FIG. 1 may each be referred to as a communication device having the functionality of a base station, and 120a to 120j in FIG. 1 may each be referred to as a communication device having the functionality of a terminal.

[0037] Communication between a base station and a terminal, between base stations, or between terminals may be performed on a licensed spectrum, an unlicensed spectrum, or both licensed and unlicensed spectrum. Communication may be performed on a spectrum below 6 gigahertz (GHz), or above 6 GHz, or both below and above 6 GHz. Spectral resources used for wireless communication are not limited in the embodiments of this application.

[0038] In an embodiment of the present application, the functions of the base station may alternatively be performed by a module (e.g., a chip) within the base station, or by a control subsystem including the functions of the base station. The control subsystem including the functions of the base station here may be a control center in the aforementioned application scenarios such as smart grid, industrial control, smart transportation, and smart city. The functions of the terminal may alternatively be performed by a module (e.g., a chip or modem) within the terminal, or by a device including the functions of the terminal.

[0039] In this application, a base station transmits downlink signals or downlink information to a terminal, where the downlink information is carried on a downlink channel, and the terminal transmits uplink signals or uplink information to the base station, where the uplink information is carried on an uplink channel. To communicate with the base station, the terminal needs to establish a radio connection to a cell controlled by the base station. The cell that establishes a radio connection to the terminal is called the serving cell of the terminal. When communicating with the serving cell, the terminal is further interfered with by signals from neighboring cells.

[0040] In the embodiments of the present application, the time-domain symbols may be orthogonal frequency division multiplexing (OFDM) symbols or Discrete Fourier Transform-spread-OFDM (DFT-s-OFDM) symbols. Unless otherwise specified, the symbols in the embodiments of the present application are time-domain symbols.

[0041] In an embodiment of the present application, a timing advance (TA) is a timing advance that a network device instructs a terminal to transmit an uplink signal, and is used to compensate for propagation delay. It should be understood that an important feature of uplink transmission is that different terminals perform orthogonal multiple access in the time and frequency domains, in other words, that uplink transmissions of different terminals in the same cell do not interfere with each other. To ensure the orthogonality of uplink transmissions and avoid intra-cell interference, a network device requires that signals from different terminals on different frequency domain resources (different resource blocks (RBs)) within the same time domain resource (e.g., slot) arrive at the network device at essentially aligned times. If the network device receives uplink data transmitted by a terminal within a cyclic prefix (CP) range, the network device can correctly decode the uplink data. Therefore, uplink synchronization requires that the times at which signals from different terminals in the same time domain resource arrive at the network device all fall within the CP. The network device can control the time at which uplink signals from different terminals arrive at the network device by appropriately controlling the timing offset of each terminal. Terminals that are relatively far from the network device have relatively long transmission delays. Therefore, terminals that are relatively far from the network device transmit uplink data earlier than terminals that are relatively close to the network device.

[0042] A network device determines the value of a terminal's timing advance by measuring the terminal's uplink transmission. In theory, any uplink signal transmitted by the terminal can be used to measure the timing advance. For example, uplink signals include a sounding reference signal (SRS), a demodulation reference signal (DMRS), and a channel quality indicator (CQI).

[0043] In the random access procedure, the network device determines the timing advance by measuring the received random access preamble and delivers the initial timing adjustment in a timing advance command within the RAR. In a Radio Resource Control (RRC) connected state, the timing at which an uplink signal arrives at the network device may change over time. Reasons include: a change in the distance between a fast-moving terminal and the network device causes a change in the transmission delay between the terminal and the network device; terminal offsets cause long-term offset accumulation, further causing uplink timing errors; and transmission path switching and terminal movement cause Doppler frequency shifts. Therefore, the network device needs to send dynamic signaling to adjust the terminal's timing advance.

[0044] To increase uplink capacity, a terminal supports radio frequency chain switching between two different frequency bands (e.g., 3.5 GHz and 1.8 GHz) to occupy different frequency band resources for transmitting uplink signals. For example, as shown in FIG. 2, a terminal includes two radio frequency chains. A first radio frequency chain supports the 3.5 GHz frequency band, and a second radio frequency chain supports the 3.5 GHz frequency band and the 1.8 GHz frequency band. The terminal can transmit uplink signals based on the 3.5 GHz frequency band supported by the first radio frequency chain and the second radio frequency chain, or the terminal can transmit uplink signals in the 1.8 GHz frequency band supported by the second radio frequency chain. Radio frequency chain switching (Tx switching) of the second radio frequency chain of the terminal between the 3.5 GHz frequency band and the 1.8 GHz frequency band includes at least hardware phase-locked loop switching, power amplifier (PA) switching, etc. Therefore, there is a radio frequency chain switching time when the terminal performs radio frequency chain switching.

[0045] It should be understood that one carrier corresponds to one timing advance group, and different carriers correspond to different timing advance groups.

[0046] When a terminal accesses at least two cells deployed in a non-colocated manner and obtains multiple timing advance groups, the timing advances of the multiple uplink carriers are distributed separately by the cells of the multiple non-colocated network devices, so that the frame boundaries of the two corresponding uplink carriers are not aligned. In this case, when the terminal performs a radio frequency chain switch, uplink transmission is started before the uplink radio frequency chain switch is completed, resulting in a service interruption.

[0047] To solve the problem of service interruption caused by radio frequency chain switching in non-colocated deployments, the present application provides an uplink signal transmission method. Specifically, a terminal transmits capability information, which allows a network device to determine the terminal's uplink radio frequency chain switching time. When a first uplink signal is transmitted to a first network device on a first uplink carrier, the terminal receives first signaling indicating an uplink carrier switch, omits transmitting an uplink signal during a first period, and transmits a second uplink signal to a second network device on a second uplink carrier. The first uplink carrier belongs to a first frequency band, and the first uplink carrier belongs to a first TAG. The second uplink carrier belongs to a second frequency band, and the second uplink carrier belongs to a second TAG. The first period is longer than the uplink radio frequency chain switching time. In this way, when a terminal performs a switch between two different uplink carriers, after waiting for a period longer than the uplink radio frequency chain switching time indicated by the terminal's capabilities, the terminal transmits an uplink signal on the second uplink carrier whose uplink radio frequency chain has been switched from the first uplink carrier. This avoids service interruptions caused by misalignment of frame boundaries of the uplink carrier before and after the uplink carrier switch when the terminal starts uplink transmission after the uplink radio frequency chain switching time but before the uplink radio frequency chain switch is completed. In addition, this helps achieve higher uplink transmission rates, higher spectrum utilization, and larger uplink capacity by utilizing dynamic spectrum selection during uplink radio frequency chain switching in non-colocated deployments.

[0048] Next, Fig. 3 is a flowchart of an uplink signal transmission method according to the present application. Here, an example in which a terminal performs radio frequency chain switching in multiple timing advance groups is used for description. As shown in Fig. 3, the method may include the following steps:

[0049] Step 310: The terminal transmits capability information on a first uplink carrier. The capability information indicates a switching period of the terminal's uplink radio frequency chain. For example, the value of the uplink radio frequency chain switching period may be 140 microseconds (μs), 35 μs, or 210 μs.

[0050] The terminal reports to the network device that the terminal has radio frequency chain switching capability, and the first time period indicates that the terminal omits transmitting an uplink signal during the first time period. The first network device receives capability information on the first uplink carrier, or the second network device receives capability information on the first uplink carrier.

[0051] A terminal accesses cell #1 of a first network device and cell #2 of a second network device, and these two cells belong to network devices in different locations. Cell #1 belongs to a first TAG, and cell #2 belongs to a second TAG.

[0052] Step 320: The terminal transmits a first uplink signal on a first uplink carrier to a first network device.

[0053] After the terminal accesses the cell #1 deployed by the first network device, the terminal transmits a first uplink signal to the first network device on a first uplink carrier provided by the cell #1 based on the first TAG, where the first uplink carrier belongs to a first frequency band.

[0054] Step 330: A first network device receives a first uplink signal on a first uplink carrier.

[0055] Step 340: The first network device or the second network device sends a first signaling, which indicates an uplink carrier switch.

[0056] Step 350: The terminal receives a first signaling.

[0057] The terminal receives first signaling transmitted by a first network device or a second network device. For example, the first instruction may be downlink control information (DCI). The network device instructs the terminal to switch an uplink from a first carrier to a second carrier. The first signaling further indicates a second time interval, and the second time interval indicates an interval between an end symbol of a physical downlink control channel carrying the first signaling and a start symbol of an uplink channel. The uplink channel may be a physical uplink shared channel, a physical uplink control channel, or an uplink sounding reference signal.

[0058] Step 360: The terminal omits transmitting an uplink signal during the first period, and transmits a second uplink signal to the second network device on the second uplink carrier after the first period. It should also be understood that the terminal does not expect the second time interval to be less than the first period. If the second time interval indicated by the first signaling received by the terminal is less than the first period, the terminal discards the first signaling.

[0059] The terminal triggers an uplink radio frequency chain switch after receiving the first command. Because the first network device and the second network device are non-co-located, the first TAG corresponding to the first network device and the second TAG corresponding to the second network device are also different.

[0060] If the frame boundaries of the first uplink carrier and the second uplink carrier are not aligned and the slot boundaries and orthogonal frequency division multiplexing (OFDM) symbol boundaries are also not aligned, the terminal omits transmitting an uplink signal for a first period longer than an uplink radio frequency chain switching time. After waiting the first period to ensure that the radio frequency chain is switched from the first uplink carrier to the first uplink carrier, the terminal device can transmit an uplink signal on the second uplink carrier. The second uplink carrier belongs to a second frequency band, and the second uplink carrier belongs to a second TAG. The first frequency band is different from the second frequency band. For example, the first frequency band may be a 3.5 GHz frequency band, and the second frequency band may be a 1.8 GHz frequency band. The first frequency band and the second frequency band form a first frequency band pair. The first frequency band pair is included in a first frequency band combination, and the first frequency band combination includes three or four uplink frequency bands that can be used to transmit uplink transmissions. Optionally, for a second frequency band pair belonging to the first frequency band combination, if the two frequency bands corresponding to the second frequency band pair correspond to the first TAG and the second TAG, respectively, the first time period applied to the uplink radio frequency chain switching interruption of the first frequency band pair also applies to the second frequency band pair.

[0061] In a first possible implementation, the first period is a period during which uplink radio frequency chain switching is performed, and the terminal device omits transmitting uplink signals during the first period, including but not limited to PUSCH, a physical uplink control channel (PUCCH), and SRS. The first period is equal to or longer than the radio frequency chain switching time. The terminal device completes the uplink radio frequency chain switching during the first period. The first period satisfies the following equation (1): T'=T1+T os or T'=ceil(T1 / T os )+1 formula (1)

[0062] T' represents the first period, specifically the interruption time during which the terminal performs uplink radio frequency chain switching. T1 represents the uplink radio frequency chain switching time. os represents the duration of a symbol. The duration of a symbol may be determined based on various subcarrier spacings. For example, if the subcarrier spacing is 15 kilohertz (kHz), the slot contains 12 or 14 time-domain symbols and the corresponding duration is 1 millisecond (ms), and if the subcarrier spacing is 60 kHz, the slot has a corresponding duration reduced to 0.25 ms.

[0063] In a second possible implementation, the value of the first period is related to a maximum transmission timing difference (MTTD) predefined in a protocol. MTTD indicates the maximum value of the transmission timing difference that can be handled by a terminal. For example, the value of MTTD is 34.6 μs. When triggering an uplink radio frequency chain switch, the terminal can determine the first period based on the switch time and the maximum transmission timing difference. For example, the first period is equal to or greater than the sum of the switch time and the maximum transmission timing difference. The first period satisfies the following equation (2): T'=ceil{(T1+T MTTD ) / T os} Formula (2)

[0064] T' represents the first period. ceil represents rounding up. T1 represents the uplink radio frequency chain switching time. T MTTD represents the maximum transmission timing difference. os represents the duration of an OFDM symbol.

[0065] [Table 1]

[0066] In a third possible implementation, the first period is equal to or greater than the sum of the switching time, the maximum transmission timing difference, and a first value predefined in the protocol, which may alternatively be expressed as a margin or a first value predefined in the protocol for TA adjustment. The first period satisfies the following equation (3): T'=ceil{(T1+T MTTD +Terror) / T os} Formula (3)

[0067] T' represents the first period. ceil represents rounding up. T1 represents the uplink radio frequency chain switching time. T MTTD represents the maximum transmission timing difference. Terror represents a first value predefined by the protocol. os represents the duration of the symbol.

[0068] In a fourth possible implementation, the first period is equal to or greater than the sum of the switching time, twice the maximum transmission timing difference, and a first value predefined in the protocol, which may alternatively be expressed as a margin or a first value predefined in the protocol for TA adjustment. The first period satisfies the following equation (4): T'=ceil{(T1+2*T MTTD +Terror) / Tos} Formula (4)

[0069] In this way, when a terminal performs a switch between two different uplink carriers, after waiting for a period longer than the uplink radio frequency chain switching time indicated by the terminal's capabilities, the terminal transmits an uplink signal on the second uplink carrier whose uplink radio frequency chain has been switched from the first uplink carrier. This avoids service interruptions caused by misalignment of frame boundaries of the uplink carrier before and after the uplink carrier switch when the terminal starts uplink transmission after the uplink radio frequency chain switching time but before the uplink radio frequency chain switch is completed. In addition, this helps achieve higher uplink transmission rates, higher spectrum utilization, and larger uplink capacity by utilizing dynamic spectrum selection during uplink radio frequency chain switching in non-colocated deployments.

[0070] In a fifth possible implementation, the UE omits sending an uplink transmission during a first period of time, the first period of time being represented as symbols overlapping with an uplink radio frequency chain switching time on a first uplink carrier and / or symbols overlapping with an uplink radio frequency chain switching time on a second uplink carrier.

[0071] For example, as shown in FIG. 4(a), the subcarrier spacing of the first uplink carrier is the same as the subcarrier spacing of the second uplink carrier, and the duration of a symbol included in the first uplink carrier is the same as the duration of a symbol included in the second uplink carrier. Because the first TAG is different from the second TAG, the frame boundaries and symbol boundaries of the two uplink carriers are not aligned. The terminal switches the uplink radio frequency chain from the second uplink carrier to the first uplink carrier. The uplink radio frequency chain switching time starts in symbol 4 of the first slot, and ends in symbol 8 of the first slot. The first period includes symbol 4 to symbol 8, i.e., a duration of five symbols on the first uplink carrier.

[0072] The terminal begins transmitting an uplink signal at symbol 9 in the first slot of the first uplink carrier. The terminal switches the uplink radio frequency chain from the first uplink carrier to the second uplink subcarrier. The start of the uplink radio frequency chain switching time is at symbol 13 in the first slot of the second uplink carrier, and the end of the uplink radio frequency chain switching time is at symbol 3 in the second slot of the second uplink carrier. The first period covers symbol 13 to symbol 3, i.e., a duration of five symbols on the second uplink carrier.

[0073] As shown in Figure 4(b), the subcarrier spacing of the first uplink carrier is 60 kHz, the subcarrier spacing of the second uplink carrier is 30 kHz, and the duration of a symbol included in the first uplink carrier is different from the duration of a symbol included in the second uplink carrier. The uplink radio frequency chain switching time starts in symbol 7 of the first slot of the first uplink carrier, and ends in symbol 1 of the second slot. The first period includes symbol 7 of the first slot to symbol 1 of the second slot, i.e., a duration of nine symbols on the first uplink carrier.

[0074] The terminal begins transmitting an uplink signal at symbol 1 in the second slot of the first uplink carrier. The terminal switches from the first uplink carrier to the second uplink subcarrier. The start of the uplink radio frequency chain switching time is at symbol 12 in the first slot of the second uplink carrier, and the end of the uplink radio frequency chain switching time is at symbol 2 in the second slot of the second uplink carrier. The first period covers symbol 12 to symbol 2, i.e., a duration of five symbols on the second uplink carrier.

[0075] In some other embodiments, the terminal reporting the uplink radio frequency chain switching time in the mTAG to the network device may be independent from the terminal reporting the uplink radio frequency chain switching time in a single TAG to the network device. For example, the terminal triggers the uplink radio frequency chain switching in the mTAG, and the uplink radio frequency chain switching time is determined based on the uplink radio frequency chain switching time in the single TAG and the duration of the symbol. For example, the uplink radio frequency chain switching time in the mTAG satisfies Equation (5). T”=T2+T os Formula (5)

[0076] T" represents the uplink radio frequency chain switching time in the mTAG. T2 represents the uplink radio frequency chain switching time in a single TAG. T os represents the duration of the symbol.

[0077] It should be understood that, to implement the functions of the foregoing embodiments, the base station and the terminal include corresponding hardware structures and / or software modules that perform various functions. Those skilled in the art should easily realize, with reference to the example units and method steps described in the embodiments disclosed in the present application, that the present application can be implemented by hardware or a combination of hardware and computer software. Whether the functions are performed by hardware or by hardware driven by computer software depends on the specific application scenario and design constraints of the technical solutions.

[0078] 5 and 6 are diagrams of possible communication device structures according to embodiments of the present application. These communication devices may be configured to implement the functions of a terminal or a base station in the above-described method embodiments, and thus may also achieve the beneficial effects of the above-described method embodiments. In the embodiments of the present application, the communication device may be one of the terminals 120a to 120j shown in FIG. 1, or may be the base station 110a or 110b shown in FIG. 1, or may be a module (such as a chip) used in the terminal or the base station.

[0079] 5, the communication device 500 includes a processing unit 510 and a transceiver unit 520. The communication device 500 is configured to perform the functions of a terminal or a base station in the embodiment of the method shown in FIG.

[0080] When the communications apparatus 500 is configured to perform the functions of the terminal in the embodiment of the method shown in FIG. 3 , the transceiver unit 520 is configured to: transmit capability information on a first uplink carrier so that the network device determines a switching time of the terminal's uplink radio frequency chain; obtain first signaling indicating an uplink carrier switching when a first uplink signal is transmitted to the first network device on the first uplink carrier; omit transmitting an uplink signal during a first period; and transmit a second uplink signal to the second network device on the second uplink carrier after the first period; and perform, for example, steps 310, 320, 330, and 360 shown in FIG. 3 .

[0081] The processing unit 510 is configured to determine the first period of time.

[0082] When the communications device 500 is configured to perform the functions of a base station in the embodiment of the method shown in FIG. 3, the transceiver unit 520 is configured to receive capability information on a first uplink carrier, transmit first signaling instructing the terminal to perform uplink carrier switching, omit receiving an uplink signal during a first period of time, and receive a second uplink signal on a second uplink carrier after the first period of time, for example, perform steps 340 and 350 shown in FIG. 3.

[0083] The processing unit 510 is configured to determine a switching time of an uplink radio frequency chain of the terminal.

[0084] For a more detailed description of the processing unit 510 and the transceiver unit 520, please refer to the relevant description of the method embodiment shown in FIG.

[0085] 6, the communication device 600 includes a processor 610 and an interface circuit 620. The processor 610 and the interface circuit 620 are coupled to each other. It will be understood that the interface circuit 620 may be a transceiver or an input / output interface. Optionally, the communication device 600 may further include a memory 630 configured to store instructions to be executed by the processor 610, to store input data required by the processor 610 to execute the instructions, or to store data generated after the processor 610 executes the instructions.

[0086] When the communications device 600 is configured to perform the method shown in FIG. 3, the processor 610 is configured to perform the functions of the processing unit 510, and the interface circuit 620 is configured to perform the functions of the transceiver unit 520.

[0087] If the communication device is a chip used in a terminal, the chip in the terminal implements the functions of the terminal in the above-mentioned method embodiment. The chip in the terminal receives information from another module (e.g., a radio frequency module or an antenna) in the terminal, and this information is transmitted to the terminal by the base station, or the chip in the terminal transmits information to another module (e.g., a radio frequency module or an antenna) in the terminal, and this information is transmitted to the base station by the terminal.

[0088] If the communication device is a module used in a base station, the module in the base station performs the functions of the base station in the above-mentioned method embodiment. The module in the base station receives information from another module (e.g., a radio frequency module or an antenna) in the base station, and this information is transmitted to the base station by a terminal, or the module in the base station transmits information to another module (e.g., a radio frequency module or an antenna) in the base station, and this information is transmitted to the terminal by the base station. The module in the base station here may be a baseband chip in the base station, or may be a DU or another module. The DU here may be a DU in an open radio access network (O-RAN) architecture.

[0089] It will be understood that the processor in embodiments of the present application may be a Central Processing Unit (CPU), or may be another general-purpose processor, a Digital Signal Processor (DSP), an Application Specific Integrated Circuit (ASIC), a Field Programmable Gate Array (FPGA) or other programmable logic device, a transistor logic device, a hardware component, or any combination thereof. The general-purpose processor may be a microprocessor or any conventional processor.

[0090] The method steps in the embodiments of the present application may be implemented in hardware or software instructions that can be executed by a processor. The software instructions may include corresponding software modules. The software modules may be stored in random access memory, flash memory, read-only memory, programmable read-only memory, erasable programmable read-only memory, electrically erasable programmable read-only memory, registers, hard disk, removable hard disk, CD-ROM, or any other form of storage medium well known in the art. For example, the storage medium may be coupled to the processor such that the processor can read information from and write information to the storage medium. The storage medium may instead be a component of the processor. The processor and the storage medium may be located in an ASIC. In addition, the ASIC may be located in a base station or a terminal. The processor and the storage medium may instead reside as separate components within the base station or terminal.

[0091] All or part of the above-described embodiments may be implemented by software, hardware, firmware, or any combination thereof. When software is used to implement an embodiment, all or part of the embodiment may be implemented in the form of a computer program product. The computer program product includes one or more computer programs or instructions. When the computer programs or instructions are loaded and executed on a computer, the procedures or functions of the embodiments of the present application are performed in whole or in part. The computer may be a general-purpose computer, a special-purpose computer, a computer network, a network device, a user terminal, or another programmable device. The computer program or instructions may be stored in a computer-readable storage medium or transmitted from one computer-readable storage medium to another. For example, the computer program or instructions may be transmitted from one website, computer, server, or data center to another website, computer, server, or data center via a wired or wireless method. The computer-readable storage medium may be any available medium that can be accessed by a computer, or a data storage device, such as a server or data center that integrates one or more available media. The available media may be magnetic media such as floppy disks, hard disks, or magnetic tapes, or optical media such as digital video disks, or semiconductor media such as solid-state drives. The computer-readable storage media may be volatile or non-volatile storage media, or may include two types of storage media: volatile and non-volatile storage media.

[0092] In the embodiments of the present application, unless otherwise stated or there is no logical contradiction, the terms and / or descriptions of different embodiments are consistent and may be cross-referenced, and the technical features of different embodiments may be combined based on their internal logical relationships to form new embodiments.

[0093] It should be understood that various numbers in the embodiments of the present application are used only for distinction to facilitate description, and are not used to limit the scope of the embodiments of the present application. The sequential numbers of the above processes do not imply an execution order, and the execution order of the processes should be determined based on the functions and internal logic of the processes. [Explanation of symbols]

[0094] 100 Wireless Access Network 110a Radio Access Network Devices 110b Radio Access Network Devices 120a~120j terminals 120i terminal, helicopter or unmanned aerial vehicle 200 Core Network 300 Internet 500 Communication Equipment 510 Processing Unit 520 Transceiver Unit 600 Communication Equipment 610 processor 620 Interface Circuit 630 memory 1000 Communication Systems

Claims

1. 1. An uplink signal transmission method performed by a terminal or a module used in a terminal, comprising: transmitting capability information to a first network device on a first uplink carrier, the capability information indicating a switching time of an uplink radio frequency chain of the terminal; transmitting a first uplink signal to the first network device on the first uplink carrier, wherein the first uplink carrier belongs to a first frequency band and the first uplink carrier belongs to a first timing advance group (TAG); receiving first signaling from the first network device, the first signaling instructing the terminal to perform an uplink carrier switch; omitting transmitting an uplink signal during a first period of time; and transmitting a second uplink signal on a second uplink carrier to a second network device after the first period of time, wherein the second uplink carrier belongs to a second frequency band, the second uplink carrier belongs to a second TAG, the first period of time is longer than the uplink radio frequency chain switching time, the first frequency band is different from the second frequency band, and the first TAG is different from the second TAG; A method comprising:

2. The method of claim 1 , wherein the first period is greater than or equal to the sum of the switching time and a maximum transmission timing difference.

3. The method of claim 1 , wherein the first period is greater than or equal to the sum of the switching time, a maximum transmission timing difference, and a first value predefined in a protocol.

4. 2. The method of claim 1, wherein the first period corresponds to a symbol that overlaps with the uplink radio frequency chain switching time of the terminal on the first uplink carrier and / or a symbol that overlaps with the uplink radio frequency chain switching time of the terminal on the second uplink carrier.

5. The method of claim 1 , wherein the first period is greater than or equal to the sum of the switching time, twice the maximum transmission timing difference, and a first value predefined in a protocol.

6. 6. A communication device comprising a processor and an interface circuit, wherein the interface circuit is configured to receive signals from another communication device and transmit said signals to the processor or transmit signals from the processor to another communication device, and wherein the processor is configured to perform the method of any one of claims 1 to 5 by using logic circuits or by executing code instructions.

7. 6. A computer-readable storage medium having stored thereon a computer program or instructions which, when executed by a communication device, perform the method of any one of claims 1 to 5.

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