Communication method, communication device, and communication system

Abstract

Implementations of the present application provide a communication method and a communication apparatus. The method comprises: transmitting first data on a first time division duplex (TDD) carrier, while transmitting corresponding HARQ feedback on a second carrier different from the first TDD carrier. According to the method, the corresponding HARQ feedback can be transmitted in time, so that another data transmission or retransmission can also be performed in time.

Description

[0001] This application claims priority to U.S. Provisional Application No. 63 / 565,431, filed March 14, 2024, entitled “Method, Apparatus, and System for Cross-carrier Transmission of Feedback for TDD Carriers,” the entire contents of which are incorporated herein by reference. Technical Field

[0002] This disclosure generally relates to wireless communication. Specifically, this disclosure relates to communication methods, communication apparatus, and communication systems. Background Technology

[0003] Wireless communication between communication devices can be performed on time-frequency resources constrained by frame structures. There are several types of frame structures: frequency division duplex (FDD), time division duplex (TDD), and full duplex (FD).

[0004] Hybrid Automatic Repeat Request (HARQ) is a mechanism that provides reliable wireless transmission. This mechanism combines forward error correction (FEC) and automatic repeat request (ARQ). During HARQ, the receiver can send HARQ feedback, which either confirms successful data decoding (called ACK) or indicates unsuccessful data decoding (called NCK).

[0005] Currently, for TDD frame structures, after receiving and decoding data, the receiver needs to wait for a suitable time unit to send HARQ feedback. This results in significant transmission delays for both HARQ feedback and potential data retransmissions.

[0006] Therefore, how to reduce the feedback latency in the HARQ process is a problem that this application needs to solve. Summary of the Invention

[0007] This disclosure provides a communication method and communication apparatus for reducing feedback latency in the HARQ process.

[0008] According to a first aspect, a communication method is provided. The method can be applied to a first device, such as the first device or a module within the first device, a circuit or chip in the first device that has communication functionality (e.g., a modem chip (also called a baseband chip), or a system-on-a-chip (SoC) chip or system-in-package (SIP) chip including a modem core). For example, the method is applied to the first device.

[0009] In the method, the first device transmits a first data transmission in a first time unit on a first time division duplex (TDD) carrier. The first device receives a hybrid automatic repeat request (HARQ) feedback corresponding to the first data transmission in a second time unit on a second carrier.

[0010] In the above method, the first data transmission is carried on a first TDD carrier, while the corresponding HARQ feedback is carried on a different carrier. Compared to the first data transmission and the corresponding HARQ feedback being carried on the same TDD carrier, this reduces the time the first device waits to receive the feedback. This can be achieved by having the HARQ feedback corresponding to the first data transmission be sent back to the first device on a second TDD carrier, different from the first TDD carrier. The first device can obtain the HARQ feedback in a timely manner, allowing another data transmission or retransmission to occur promptly as well.

[0011] In one possible design, the first TDD carrier and the second TDD carrier are in different frequency bands.

[0012] In one possible design, the second carrier is a TDD carrier.

[0013] In one possible design, the first device also sends a first indication message indicating the frequency domain resources of the second carrier.

[0014] Therefore, the first indication information helps the receiver determine the second carrier used to send the HARQ feedback.

[0015] In one possible design, the first device also sends a second indication message, which indicates the time interval for determining the second time unit.

[0016] Therefore, the second indication information helps the receiver determine the second time unit for sending the HARQ feedback.

[0017] In one possible design, the time interval is located between the first time unit and the second time unit.

[0018] In one possible design, the time interval is located between a third time unit and a second time unit, wherein the third time unit is used to send control information.

[0019] Therefore, different time intervals will provide more diverse methods for determining the second time unit used to send the HARQ feedback.

[0020] In one possible design, the first indication information is carried on a first downlink control information (DCI) and / or a first radio resource control (RRC) configuration; the second indication information is carried on a second DCI and / or a second RRC configuration; the first DCI or the second DCI is used to schedule the first data transmission and the HARQ feedback.

[0021] In some implementations, the first indication information and the second indication information may be carried on the same DCI or the same RRC configuration. The first DCI is the same as the second DCI. The first RRC configuration is the same as the second RRC configuration. Alternatively, the first indication information and the second indication information may be carried on different DCIs or different RRC configurations. The first DCI is different from the second DCI. The first RRC configuration is different from the second RRC configuration.

[0022] In one possible design, the first DCI or the second DCI is carried on any one of the first TDD carrier, the second carrier, and a third carrier different from the first TDD carrier and the second carrier.

[0023] In one possible design, the first time unit overlaps with the second time unit.

[0024] Therefore, the first data transmission and the corresponding HARQ feedback can be sent at different parts of the same time unit. This further reduces the HARQ feedback latency.

[0025] In one possible design, after transmitting a first data transmission in a first time unit on a first time division duplex (TDD) carrier, the first device also transmits a second data transmission in a fourth time unit on the first TDD carrier, wherein the fourth time unit is adjacent to the first time unit. The second data transmission is a retransmission of the same data block as the first data transmission.

[0026] Therefore, the first data transmission and the second data transmission can be progressive. This will reduce the overall latency of the data transmission and the corresponding HARQ feedback.

[0027] In one possible design, after transmitting a first data transmission in a first time unit on a first time division duplex (TDD) carrier, the first device also transmits a third data transmission in a fifth time unit on the first TDD carrier. The first data transmission and the third data transmission correspond to different transport blocks. The first device also transmits HARQ feedback corresponding to the third data transmission in a second time unit on a second carrier.

[0028] Therefore, multiple HARQ feedbacks corresponding to different data transmissions in different transport blocks can be sent within the same time unit. This will further reduce the latency of the different data transmissions and the corresponding multiple HARQ feedbacks.

[0029] In one possible design, the first TDD carrier and the second carrier have one or more different sub-carrier spacings (SCS).

[0030] According to a second aspect, a communication method is provided. The method can be applied to a second device, such as a second device or a module within the second device, a circuit or chip in the second device that has communication functionality (e.g., a modem chip (also called a baseband chip), or a system-on-a-chip (SoC) chip or system-in-package (SIP) chip including a modem core). For example, the method is applied to a second device.

[0031] In the method, the second device receives the first data transmission in a first time unit on a first time division duplex (TDD) carrier. The second device then sends a hybrid automatic repeat request (HARQ) feedback corresponding to the first data transmission in a second time unit on a second carrier.

[0032] In the above method, the first data transmission is carried on a first TDD carrier, while the corresponding HARQ feedback is carried on a different carrier. Compared to the first data transmission and the corresponding HARQ feedback being carried on the same TDD carrier, this reduces the time the first device waits to receive the feedback. This can be achieved by the second device not having to wait a suitable time unit on the same TDD carrier to send the HARQ feedback back to the first device, even though the same TDD carrier also carries the data transmission. This helps the first device obtain the HARQ feedback in a timely manner, allowing other data transmissions or retransmissions to also be performed promptly.

[0033] In one possible design, the first TDD carrier and the second TDD carrier are in different frequency bands.

[0034] In one possible design, the second carrier is a TDD carrier.

[0035] In one possible design, the second device also receives first indication information, which indicates the frequency domain resources of the second TDD carrier.

[0036] Therefore, the first indication information helps the second device determine the second TDD carrier used to transmit the HARQ feedback.

[0037] In one possible design, the second device also receives second indication information, which indicates the time interval for determining the second time unit.

[0038] Therefore, the second indication information helps the second device determine the second time unit for sending the HARQ feedback.

[0039] In one possible design, the time interval is located between the first time unit and the second time unit.

[0040] In one possible design, the time interval is located between a third time unit and a second time unit, wherein the third time unit is used to receive control information.

[0041] In one possible design, the unit of the time interval is consistent with that of the second time unit, and the second device further determines a first corresponding time of the first time unit in the second carrier. The second device also determines the second time unit based on the first corresponding time and the time interval.

[0042] In one possible design, the unit of the time interval is consistent with that of the second time unit, and the second device further determines a second corresponding time of the third time unit within the second carrier. The second device also determines the second time unit based on the second corresponding time and the time interval.

[0043] In one possible design, the unit of the time interval is consistent with the first time unit, and the second device further determines a sixth time unit by combining the time interval and the first time unit. The second device also determines the corresponding time of the sixth time unit in the second carrier. The second time unit is the corresponding time of the sixth time unit in the second carrier.

[0044] In one possible design, the unit of the time interval is consistent with that of the third time unit, and the second device further determines a seventh time unit by combining the time interval and the third time unit. The second device also determines the corresponding time of the seventh time unit in the second carrier. The second time unit is the corresponding time of the seventh time unit in the second carrier.

[0045] Therefore, the second time unit on different carriers and the first time unit will be aligned, making it easier for the second device to determine the second time unit on the second carrier, especially in scenarios where the first TDD carrier and the second TDD carrier have different subcarrier spacing.

[0046] In one possible design, the first indication information is carried on a first downlink control information (DCI) and / or a first radio resource control (RRC) configuration; the second indication information is carried on a second DCI and / or a second RRC configuration; the first DCI or the second DCI is used to schedule the first data transmission and the HARQ feedback.

[0047] In one possible design, the first DCI or the second DCI is carried on any one of the first TDD carrier, the second carrier, and a third carrier different from the first TDD carrier or the second carrier.

[0048] In one possible design, the first time unit overlaps with the second time unit.

[0049] Therefore, the first data transmission and the corresponding HARQ feedback can be sent at different parts of the same time unit. This further reduces the HARQ feedback latency.

[0050] In one possible design, after receiving the first data transmission in a first time unit on a first time division duplex (TDD) carrier, the second device also receives the second data transmission in a fourth time unit on the first TDD carrier. The fourth time unit is adjacent to the first time unit. The second data transmission is a retransmission of the same data block as the first data transmission.

[0051] Therefore, the first data transmission and the second data transmission can be progressive. This will reduce the overall latency of the data transmission and the corresponding HARQ feedback.

[0052] In one possible design, after receiving a first data transmission in a first time unit on a first time division duplex (TDD) carrier, the second device also receives a third data transmission in a fifth time unit on the first TDD carrier, wherein the first data and the third data correspond to different transport blocks. The second device then transmits a HARQ feedback corresponding to the third data transmission in the second time unit on the second carrier.

[0053] Therefore, multiple HARQ feedbacks corresponding to different data transmissions in different transport blocks can be sent within the same time unit. This will further reduce the latency of the different data transmissions and the corresponding multiple HARQ feedbacks.

[0054] In one possible design, the first TDD carrier and the second TDD carrier have one or more different sub-carrier spacings (SCS).

[0055] According to a third aspect, a communication device is provided. The communication device has the functions of the first aspect. For example, the communication device includes corresponding modules, units, or means for performing the operations in the first aspect. The modules, units, or means can be implemented in software, in hardware, or a combination of software and hardware.

[0056] According to a fourth aspect, a communication device is provided. The communication device has the functions of the second aspect. For example, the communication device includes corresponding modules, units, or means for performing the operations in the second aspect. The modules, units, or means can be implemented in software, in hardware, or a combination of software and hardware.

[0057] According to the fifth aspect, another communication device is provided. The communication device includes a memory and one or more processors. The memory is used to store some or all of the computer programs or instructions necessary for implementing the functions in the first aspect. The one or more processors can execute the computer programs or instructions, which, when executed, enable the communication device to implement the methods in any possible design or implementation of the first aspect.

[0058] In some implementations, the communication device may further include an interface circuit, through which the processor communicates with another device or component.

[0059] In some implementations, the communication device may also include the memory.

[0060] The communication device may be a base station, a module in a base station, or a chip in a base station that has communication functions (e.g., a modem chip (also known as a baseband chip), a SoC chip including a modem module, or a SIP chip).

[0061] According to the sixth aspect, another communication device is provided. The communication device includes a memory and one or more processors. The memory is used to store some or all of a computer program or instructions necessary for implementing the functions in the second aspect. The one or more processors can execute the computer program or instructions, which, when executed, enable the communication device to implement the methods in any possible design or implementation of the second aspect.

[0062] In some implementations, the communication device may further include an interface circuit, through which the processor communicates with another device or component.

[0063] In some implementations, the communication device may also include the memory.

[0064] The communication device may be user equipment (UE), a module in the UE, or a chip in the UE that has communication functions (e.g., a modem chip (also known as a baseband chip), a SoC chip including a modem module, or a SIP chip).

[0065] According to a seventh aspect, a communication system is provided. The system includes a first means enabling the implementation of the method in any possible design or implementation of the first aspect, and a second means enabling the implementation of the method in any possible design or implementation of the second aspect.

[0066] According to an eighth aspect, a computer-readable storage medium is provided. The computer-readable storage medium stores computer-readable instructions that, when read and executed by a computer, enable the computer to perform any of the possible methods in the designs of the first and second aspects.

[0067] According to a ninth aspect, this application provides a computer program product. When a computer reads and executes the computer program product, the computer is enabled to perform any of the possible methods in the design of the first and second aspects. Attached Figure Description

[0068] Figure 1 An example of a communication system 100 is shown; Figure 2 Another example of the communication system 100 is shown; Figure 3 Another example of ED 110 and base stations 170a, 170b and / or 170c is shown; Figure 4 This shows the units or modules in the device; Figure 5 An example of the HARQ process in TDD DL-UL transmission is shown; Figure 6 A schematic flowchart of a communication method 600 according to one implementation of this application is shown; Figure 7 A schematic flowchart of a communication method 700 according to another implementation of this application is shown; Figure 8 This illustrates one implementation of a cross-carrier HARQ feedback scheme; Figure 9 Another implementation of the cross-carrier HARQ feedback scheme is shown; Figure 10 Another implementation of the cross-carrier HARQ feedback scheme is shown; Figure 11 Another implementation of the cross-carrier HARQ feedback scheme is shown; Figure 12 Another implementation of the cross-carrier HARQ feedback scheme is shown; Figure 13 Another implementation of the cross-carrier HARQ feedback scheme is shown; Figure 14 Another implementation of the cross-carrier HARQ feedback scheme is shown; Figure 15 Another implementation of the cross-carrier HARQ feedback scheme is shown; Figure 16 Another implementation of the cross-carrier HARQ feedback scheme is shown; Figure 17 A schematic flowchart of a communication method 1700 according to another implementation of this application is shown; Figure 18 This illustrates a scenario of timing alignment; Figure 19 This illustrates another scenario of timing alignment; Figure 20 A schematic block diagram of a communication device 1000 according to some implementations of this application is shown; Figure 21 A schematic block diagram of a communication device according to some implementations of this application is shown. Detailed Implementation

[0069] The technical solution of this application will now be described with reference to the accompanying drawings.

[0070] Figure 1 An example of a communication system 100 is shown. (Reference) Figure 1 As a non-limiting illustrative example, a simplified schematic diagram of a communication system is provided. Communication system 100 includes a radio access network 120. Radio access network 120 may be a next-generation radio access network or a traditional (e.g., 5G, 4G, 3G, or 2G) radio access network. One or more electronic devices (EDs) 110a, 110b, 110c, 110d, 110e, 110f, 110g, 110h, 110i, 110j (generally referred to as 110) may interconnect with each other or be connected to one or more network nodes (170a, 170b, generally referred to as 170) in radio access network 120. Core network 130 may be part of the communication system and may depend on or be independent of the radio access technology used in communication system 100. Furthermore, communication system 100 includes a public switched telephone network (PSTN) 140, the Internet 150, and other networks 160.

[0071] Figure 2Another example of a communication system 100 is shown. Typically, the communication system 100 enables multiple wireless or wired components to transmit data and other content. The purpose of the communication system 100 may be to provide content such as voice, data, video, and / or text via broadcast, multicast, unicast, etc. The communication system 100 can operate by sharing resources (e.g., carrier spectrum bandwidth) among its constituent components. The communication system 100 may include terrestrial communication systems and / or non-terrestrial communication systems. The communication system 100 can provide a wide range of communication services and applications (e.g., earth monitoring, remote sensing, passive sensing and positioning, navigation and tracking, autonomous delivery, and mobility). The communication system 100 can provide high availability and robustness through the joint operation of terrestrial and non-terrestrial communication systems. For example, integrating a non-terrestrial communication system (or components thereof) into a terrestrial communication system can create a heterogeneous network that can be viewed as comprising multiple layers. Compared to traditional communication networks, heterogeneous networks can achieve better overall performance through efficient multi-link joint operation, more flexible function sharing, and faster physical layer link switching between terrestrial and non-terrestrial networks.

[0072] Terrestrial communication systems and non-terrestrial communication systems can be subsystems of a communication system. Figure 2 In the example shown, communication system 100 includes electronic devices (EDs) 110a, 110b, 110c, and 110d (collectively referred to as ED110), radio access networks (RANs) 120a and 120b, a non-terrestrial communication network 120c, a core network 130, a public switched telephone network (PSTN) 140, the Internet 150, and other networks 160. RANs 120a and 120b include corresponding base stations (BSs) 170a and 170b, which may be collectively referred to as terrestrial transmit and receive points (T-TRPs) 170a and 170b. As mentioned herein, the terms “TRP” and “base station” are used interchangeably unless explicitly stated otherwise in a given example or section. For the sake of brevity, this disclosure may refer primarily to base stations; however, without explicit limitation, references to TRPs are merely non-limiting examples of interchangeable use. The non-terrestrial communication network 120c includes an access node 172, which can be collectively referred to as a non-terrestrial transmit and receive point (NT-TRP) 172.

[0073] ED 110a to 110d and TRPs 170a, 170b, and 172 are examples of communication devices that can be used to implement some or all of the operations and / or implementations described herein. TRP 170a forms part of RAN 120a, which may include other TRPs and / or other devices. Furthermore, TRP 170b forms part of RAN 120b, which may include other TRPs and / or devices. Each TRP 170a and 170b can transmit and / or receive radio signals within a specific geographic area or region, sometimes referred to as a “cell” or “coverage area.” TRPs 170a and 170b can be responsible for allocating and / or configuring resources and transmitting and / or receiving within a set of cells. A cell can be a radio network object, which can be uniquely identified by a (cell) identifier broadcast over the geographic area or region from the base station associated with the cell. A cell can operate in either frequency division duplex (FDD) or time division duplex (TDD) mode. A cell can also refer to a carrier frequency within the DL / UL carrier bandwidth resources of a component carrier in a single independent carrier or carrier aggregation mode. A cell can be further divided into cell sectors, and base stations 170a and 170b can, for example, employ multiple transceivers to provide services to multiple sectors. In some implementations, there may be established picocells or femtocells supported by radio access technologies. In some implementations, for example, multiple-input multiple-output (MIMO) technology can be used to utilize multiple transceivers for each cell. The number of RANs 120a and 120b shown is merely exemplary. Any number of RANs can be envisioned when designing the communication system 100.

[0074] Any base station can be a single element, as shown in the figure, or multiple elements distributed across a corresponding RAN, and so on. In some implementations, multiple RAN nodes coordinate to assist the ED 110 in achieving radio access, and different RAN nodes implement different functions of the base station. For example, a RAN node can be a central unit (CU), a distributed unit (DU), a CU-control plane (CP), a CU-user plane (UP), or a radio unit (RU), etc. CU and DU can be deployed separately or included in the same element (i.e., a baseband unit (BBU)). RU can be included in radio equipment or radio units (i.e., remote radio unit (RRU), active antenna unit (AAU), or remote radio head (RRH)). In different systems, CU (or CU-CP and CU-UP), DU, or RU may also have different names, but their meanings will be understood by those skilled in the art. For example, in an Open Radio Access Network (ORAN) system, a CU can also be called an Open CU (O-CU), a DU can also be called an Open DU (O-DU), and a CU-CP can also be called an Open CU-CP (O-CU-CP). A CU-UP can also be called an Open CU-UP (O-CU-UP), and a RU can also be called an Open RU (O-RU). Any of the CU (or CU-CP, CU-UP), DU, and RU can be implemented using software modules, hardware modules, or a combination of software and hardware modules.

[0075] Furthermore, in various implementations of this application, one or more communications between different devices / apparatus can refer to direct communication between different devices / apparatus (i.e., without the need for forwarding by another device / apparatus), or it can refer to one or more communications between different devices / apparatus via another device / apparatus (i.e., requiring forwarding by another device / apparatus). Alternatively, such one or more communications can refer to a functional unit within a device / apparatus using another functional unit within the device / apparatus to communicate with another device / apparatus. In other words, "sending (or transmitting) information to... (ED or base station)" in this application can be understood as the destination endpoint of the information being the ED or base station. This can include sending / transmitting information directly or indirectly to the ED or base station. Similarly, "receiving information from... (ED or base station)" can be understood as the source endpoint of the information being the ED or base station, and can include receiving information directly or indirectly from the ED or base station. Necessary processing such as format conversion, digital-to-analog conversion, amplification, and filtering can be performed on the information between the source endpoint and the destination endpoint. However, the destination endpoint can understand the valid information from the source endpoint. Similar descriptions in this application can be understood similarly. Further details are omitted here. In this disclosure, the terms “send” and “transmit” may be used interchangeably in implementations of this application.

[0076] Each ED 110 connected to TRP 170a and 170b and / or TRP 172 can be dynamically or semi-statically started (i.e., established, activated, or enabled), shut down (i.e., released, deactivated, or disabled), and / or configured in response to one or more of connectivity availability and connectivity necessity.

[0077] Any ED 110 can be used alternatively or additionally to interface, access, or communicate with any T-TRP 170a, 170b, and NT-TRP 172, Internet 150, Core Network 130, PSTN 140, other network 160, or any combination thereof. In some examples, ED 110a can communicate with T-TRP 170a via uplink (UL) and / or downlink (DL) transmissions through terrestrial air interface 190a. In some examples, ED 110a, 110b, 110c, and 110d can also communicate directly with each other via one or more sidelink air interfaces 190b. In some examples, ED 110d can communicate with NT-TRP 172 via non-terrestrial air interface 190c for uplink and / or downlink transmissions.

[0078] Air interfaces 190a and 190b can employ similar communication technologies, such as any suitable wireless access technology. For example, communication system 100 can implement one or more channel access methods in air interfaces 190a and 190b, such as code division multiple access (CDMA), space division multiple access (SDMA), time division multiple access (TDMA), frequency division multiple access (FDMA), orthogonal FDMA (OFDMA), or single-carrier FDMA (SC-FDMA) (also known as discrete Fourier transform spread OFDMA (DFT-s-OFDMA)). Air interfaces 190a and 190b can employ other higher-dimensional signal spaces, which may involve combinations of orthogonal and / or non-orthogonal dimensions.

[0079] The non-terrestrial air interface 190c enables communication between the ED 110d and one or more NT-TRP 172s via a wireless link or simply via a link. For some examples, the link is a dedicated connection for unicast transmission, a connection for broadcast transmission, or a connection between a group of ED 110s and one or more NT-TRP 172s for multicast transmission.

[0080] RANs 120a and 120b communicate with the core network 130 to provide various services, such as voice, data, and other services, to EDs 110a, 110b, and 110c. RANs 120a and 120b and / or the core network 130 may communicate directly or indirectly with one or more other RANs (not shown), which may or may not be directly served by the core network 130, and may or may not use the same radio access technology as RANs 120a, RAN 120b, or both. The core network 130 may also serve as a gateway access between (i) RANs 120a and 120b or EDs 110a, 110b, and 110c, or both, and (ii) other networks (e.g., PSTN 140, Internet 150, and other networks 160). Furthermore, some or all of EDs 110a, 110b, and 110c may include the ability to communicate with different wireless networks via different radio links using different radio technologies and / or protocols. Instead of wireless communication (or other than wireless communication), ED 110a, 110b, and 110c can also communicate with service providers or exchanges (not shown) via wired communication channels and with the Internet 150. PSTN 140 may include a circuit-switched telephone network for providing plain old telephone service (POTS). The Internet 150 may include a network of computers and / or subnets (intranets) and incorporate protocols such as Internet Protocol (IP), Transmission Control Protocol (TCP), and User Datagram Protocol (UDP). ED 110a, 110b, and 110c may be multimode devices capable of operating under various wireless access technologies, and may incorporate multiple transceivers required to support such wireless access technologies.

[0081] Figure 3Another example of an ED 110 and base stations 170a, 170b, and / or 170c is shown. The ED 110 is used to connect people, objects, machines, etc. The ED 110 can be widely used in various scenarios, including, for example, cellular communication, device-to-device (D2D), vehicle-to-everything (V2X), peer-to-peer (P2P), machine-to-machine (M2M), machine-type communication (MTC), Internet of Things (IoT), virtual reality (VR), augmented reality (AR), mixed reality (MR), metaverse, digital twins, industrial control, autonomous driving, telemedicine, smart grids, smart furniture, smart offices, smart wearable devices, smart transportation, smart cities, drones, robots, remote sensing, passive sensing, positioning, navigation and tracking, autonomous delivery, and mobility services.

[0082] Each ED 110 represents any suitable end-user equipment for wireless operation and may include (or be referred to as) devices such as: user equipment / device (UE), wireless transmit / receive unit (WTRU), mobile station, fixed or mobile subscriber unit, cellular phone, station (STA), machine type communication (MTC) device, personal digital assistant (PDA), smartphone, laptop, computer, tablet, wireless sensor, consumer electronics device, smartbook, vehicle, automobile, truck, bus, train, or IoT device, wearable device (such as watch, glasses, head-mounted device, etc.), industrial equipment, or means comprising or including the foregoing devices (such as communication modules, modems, or chips), etc. Future generations of ED 110 may be referred to using other terms. When ED 110 performs (or is used to perform) the methods described herein, it can be interpreted that the ED, one or more modules (or units) within the ED, circuitry or chips, or combinations thereof, can perform the method. For example, the circuit or chip may include a modem chip (also known as a baseband chip), a system-on-a-chip (SoC) including a modem core, or a system-in-package (SIP), and may be responsible for one or more communication functions in the ED. Base stations 170a and 170b are T-TRPs and will be referred to as T-TRP 170 below. Similarly... Figure 3 As shown, NT-TRP will be referred to as NT-TRP 172 below. Each ED 110 connected to T-TRP 170 and / or NT-TRP 172 can be dynamically or semi-statically started (i.e., established, activated, or enabled), shut down (i.e., released, deactivated, or disabled), and / or configured in response to one or more of connectivity availability and connectivity necessity.

[0083] ED 110 includes a transmitter 201 and a receiver 203 coupled to one or more antennas 204. Only one antenna 204 is shown in the figures to avoid congestion. Alternatively, one, some, or all of the antennas 204 may be panels. The transmitter 201 and receiver 203 may, for example, be integrated as a transceiver. The transceiver is used to modulate data or other content for transmission by at least one antenna 204 or a network interface controller (NIC). The transceiver may also be used to demodulate data or other content received through at least one antenna 204. Each transceiver includes any suitable structure for generating signals for wireless or wired transmission and / or processing signals received wirelessly or wiredly. Each antenna 204 includes any suitable structure for transmitting and / or receiving wireless or wired signals. In this disclosure, the transceiver (or transmitter 201 and / or receiver 203) may be considered as interface circuitry.

[0084] ED 110 includes at least one memory 208. Memory 208 stores instructions and data used, generated, or collected by ED 110. For example, memory 208 may store software instructions or modules for implementing some or all of the functions and / or implementations described herein and executed by one or more processing units (e.g., processor 210). Each memory 208 includes any suitable one or more volatile and / or non-volatile storage and retrieval devices. Any suitable type of memory can be used, such as random access memory (RAM), read-only memory (ROM), hard disk, optical disk, subscriber identity module (SIM) card, memory stick, secure digital (SD) memory card, and on-processor cache, etc.

[0085] ED 110 may also include one or more input / output devices (not shown) or interfaces (e.g., connected to...). Figure 1 (Wired interface of Internet 150 in the network). Input / output devices or interfaces support interaction with users or other devices in the network. Each input / output device or interface includes any suitable structure for providing or receiving information from the user and / or for network interface communication. Suitable structures include, for example, speakers, microphones, keypads, keyboards, displays, touchscreens, etc.

[0086] ED 110 includes a processor 210 for performing operations including: operations related to preparing uplink transmissions to NT-TRP 172 and / or T-TRP 170; operations related to processing downlink transmissions received from NT-TRP 172 and / or T-TRP 170; and operations related to processing sidelink transmissions to and from another ED 110. Processing operations related to preparing uplink transmissions may include operations such as encoding, modulation, transmit beamforming, and generating symbols for transmission. Processing operations related to processing downlink transmissions may include operations such as receive beamforming, demodulation, and decoding of received symbols. Depending on the implementation, the downlink transmissions may be received by receiver 203 using receive beamforming, and processor 210 may extract signaling from the downlink transmissions (e.g., by detecting and / or decoding signaling). Examples of signaling may be reference signals transmitted by NT-TRP 172 and / or T-TRP 170. In some implementations, processor 210 performs transmit beamforming and / or receive beamforming based on beam direction indications (e.g., beam angle information (BAI)) received from T-TRP 170. In some implementations, processor 210 can perform operations related to network access (e.g., initial access) and / or downlink synchronization, such as operations related to detecting synchronization sequences, decoding, and obtaining system information. In some implementations, processor 210 can perform channel estimation, for example, using reference signals received from NT-TRP 172 and / or from T-TRP 170.

[0087] Although not shown, processor 210 may be part of transmitter 201 and / or receiver 203. Although not shown, memory 208 may be part of processor 210.

[0088] The processor 210, the processing components of the transmitter 201, and the processing components of the receiver 203 may each be implemented by the same or different one or more processors for executing instructions stored in memory (e.g., memory 208). Alternatively, some or all of the processing components of the processor 210, the transmitter 201, and the receiver 203 may each be implemented using dedicated circuitry, such as a programmable field-programmable gate array (FPGA), an application-specific integrated circuit (ASIC), or a graphics processing unit (GPU) or an artificial intelligence (AI) accelerator, etc.

[0089] In some implementations, the T-TRP 170 can use other names, such as base station, basetransceiver station (BTS), wireless base station, network node, network device, network-side device, transmit / receive node, NodeB, evolved NodeB (eNodeB or eNB), home eNodeB, next-generation NodeB (gNB), transmission point (TP), site controller, access point (AP), wireless router, relay station, ground node, ground network device, ground base station, base band unit (BBU), remote radio unit (RRU), active antenna unit (AAU), remote radio head (RRH), central unit (CU), distributed unit (DU), location node, etc. The T-TRP 170 can be a macro BS, pico BS, relay node, or host node, or a combination thereof. T-TRP 170 may refer to the aforementioned device or to a component within the aforementioned device (e.g., a communication module, modem, or chip). When T-TRP 170 (also referred to as a base station) performs (or is used to perform) the methods described herein, it can be interpreted that the base station, one or more modules (or units) within the base station, circuitry or chips, or combinations thereof, can perform the methods. For example, the circuitry or chips may include a modem chip (also referred to as a baseband chip), a system-on-a-chip (SoC) including a modem core, a system-in-package (SIP), etc., and may be responsible for one or more communication functions within the base station.

[0090] In some implementations, the various parts of T-TRP 170 can be distributed. For example, some of the modules of T-TRP 170 may be located remotely from the device housing the antenna 256 for T-TRP 170, and may be coupled to the device housing the antenna 256 via a communication link (not shown) sometimes referred to as a fronthaul (e.g., a common public radio interface (CPRI)). Therefore, in some implementations, the term "T-TRP 170" may also refer to network-side modules that perform processing operations such as determining the location of ED 110, resource allocation (scheduling), message generation, and encoding / decoding, and are not necessarily part of the device housing the antenna 256 of T-TRP 170. These modules may also be coupled to other T-TRPs. In some implementations, T-TRP 170 may actually be multiple T-TRPs operating together to serve ED 110, for example, through cooperative multicast transmission.

[0091] T-TRP 170 includes at least one transmitter 252 and at least one receiver 254 coupled to one or more antennas 256. Only one antenna 256 is shown in the figures to avoid congestion. Alternatively, one, some, or all of the antennas 256 may be panels. The transmitter 252 and receiver 254 may be integrated as a transceiver. T-TRP 170 also includes a processor 260 for performing operations including operations related to: preparing downlink transmissions to be transmitted to ED 110, processing uplink transmissions received from ED 110, preparing backhaul transmissions to be transmitted to NT-TRP 172, and processing transmissions received from NT-TRP 172 via backhaul. Processing operations related to preparing downlink or backhaul transmissions may include operations such as encoding, modulation, precoding (e.g., multiple-input multiple-output (MIMO) precoding), transmit beamforming, and generating symbols for transmission. Processing operations related to receiving or backhauling transmissions in the uplink may include receive beamforming, demodulating received symbols, and decoding received symbols. Processor 260 may also perform operations related to network access (e.g., initial access) and / or downlink synchronization, such as generating the contents of a synchronization signal block (SSB) and generating system information. In some implementations, processor 260 also generates an indication of beam direction (e.g., BAI), which scheduler 253 can schedule for transmission. Processor 260 performs other network-side processing operations described herein, such as determining the location of ED 110 and the location for deploying NT-TRP 172. In some implementations, processor 260 may generate signaling, for example, to configure one or more parameters of ED 110 and / or one or more parameters of NT-TRP 172. Any signaling generated by processor 260 is transmitted by transmitter 252. It should be noted that "signaling" as used herein may alternatively be referred to as control signaling. Signaling can be transmitted in physical layer control channels such as the physical downlink control channel (PDCCH). In this case, the signaling can be called dynamic signaling. Signaling transmitted in the downlink physical layer control channel can be called downlink control information (DCI). Signaling transmitted in the uplink physical layer control channel can be called uplink control information (UCI). Signaling transmitted in the sidelink physical layer control channel can be called sidelink control information (SCI).Signaling can be included in higher-layer (e.g., above the physical layer) packets transmitted in physical layer data channels such as the physical downlink shared channel (PDSCH). In this case, the signaling can be referred to as higher-layer signaling, static signaling, or semi-static signaling. Higher-layer signaling can also refer to Radio Resource Control (RRC) protocol signaling or Media Access Control-Control Element (MAC-CE) signaling.

[0092] Scheduler 253 may be coupled to processor 260. Scheduler 253 may be included within T-TRP 170 or may operate separately from it. Scheduler 253 may schedule uplink, downlink, lateral link, and / or backlink transmissions, including issuing scheduling grants and / or configuring schedule-free (e.g., "configuration grants") resources. T-TRP 170 also includes memory 258 for storing information and data. Memory 258 stores instructions and data used, generated, or collected by T-TRP 170. For example, memory 258 may store software instructions or modules for implementing some or all of the functions and / or implementations described herein and executed by processor 260.

[0093] Although not shown, processor 260 may form part of transmitter 252 and / or receiver 254. Furthermore, although not shown, processor 260 may implement scheduler 253. Although not shown, memory 258 may form part of processor 260.

[0094] The processing components of processor 260, scheduler 253, transmitter 252, and receiver 254 may each be implemented by the same or different one or more processors for executing instructions stored in memory (e.g., memory 258). Alternatively, some or all of the processing components of processor 260, scheduler 253, transmitter 252, and receiver 254 may be implemented using dedicated circuitry, such as a programmed FPGA, hardware accelerator (e.g., GPU or AI accelerator), or ASIC.

[0095] Although the NT-TRP 172 is shown as an example of a drone only, it can be implemented in any suitable non-terrestrial form, such as satellites and high-altitude platforms including international mobile telecommunications base stations and unmanned aerial vehicles. Furthermore, in some implementations, the NT-TRP 172 may use other names, such as non-terrestrial node, non-terrestrial network device, or non-terrestrial base station. The NT-TRP 172 includes a transmitter 272 and a receiver 274 coupled to one or more antennas 280. Only one antenna 280 is shown in the figures to avoid congestion. One, some, or all of the antennas may alternatively be panels. The transmitter 272 and receiver 274 may be integrated as a transceiver. The NT-TRP 172 also includes a processor 276 for performing operations including operations related to: preparing downlink transmissions to ED 110, processing uplink transmissions received from ED 110, preparing return transmissions to T-TRP 170, and processing transmissions received from T-TRP 170 via return. Processing operations related to preparing downlink or backhaul transmissions may include encoding, modulation, precoding (e.g., MIMO precoding), transmit beamforming, generating symbols for transmission, etc. Processing operations related to processing transmissions received in the uplink or received via backhaul may include receive beamforming, demodulating received symbols, and decoding received symbols, etc. In some implementations, processor 276 performs transmit beamforming and / or receive beamforming based on beam direction information (e.g., BAI) received from T-TRP 170. In some implementations, processor 276 may generate signaling, for example, to configure one or more parameters of ED 110. In some implementations, NT-TRP 172 implements physical layer processing but not higher-layer functions, such as medium access control (MAC) or radio link control (RLC) layer functions. Since this is only an example, more generally, NT-TRP 172 may implement higher-layer functions in addition to physical layer processing.

[0096] The NT-TRP 172 also includes a memory 278 for storing information and data. Although not shown, a processor 276 may form part of the transmitter 272 and / or the receiver 274. Although not shown, the memory 278 may form part of the processor 276.

[0097] The processing components of processor 276, transmitter 272, and receiver 274 can each be implemented using one or more processors, which may be the same or different, to execute instructions stored in memory (e.g., memory 278). Alternatively, some or all of the processing components of processor 276, transmitter 272, and receiver 274 can be implemented using dedicated circuitry, such as a programmed FPGA, hardware accelerator (e.g., GPU or AI accelerator), or ASIC. In some implementations, NT-TRP 172 may actually be multiple NT-TRPs operating together to serve ED 110, for example, through cooperative multicast.

[0098] T-TRP 170, NT-TRP 172 and / or ED 110 may include other components, but these components have been omitted for clarity.

[0099] according to Figure 4 One or more steps of the implementation method provided in this paper can be executed by the corresponding unit or module. Figure 4 Units or modules in devices such as ED 110, T-TRP 170, or NT-TRP 172 are illustrated. For example, signals can be transmitted or output by a transmitting unit or transmitting module. Signals can be received or input by a receiving unit or receiving module. Signals can be processed by a processing unit or processing module. Other steps can be performed by an artificial intelligence (AI) module or a machine learning (ML) module. The corresponding units or modules can be implemented using hardware, one or more components or devices executing software, or a combination thereof. For example, one or more of these units or modules can be circuits such as integrated circuits. Examples of integrated circuits include programmed FPGAs, GPUs, or ASICs. For example, one or more of these units or modules can be logical, such as logical functions executed by software instructions executed by a circuit, a portion of an integrated circuit, or a processor. It should be understood that if these modules are implemented using software executed by a processor, etc., then these modules can be retrieved by the processor, wholly or partially, individually or collectively, for processing as needed, in single or multiple instances, and these modules themselves can include instructions for further deployment and instantiation.

[0100] Although not shown, the transmitting module and the receiving module can be part of or combined into a transceiver module. The transceiver module can also be called an interface module, or simply an interface, and is used for input and output operations.

[0101] Further details regarding ED 110, T-TRP 170, and NT-TRP 172 are known to those skilled in the art. Therefore, these details are omitted herein.

[0102] To facilitate understanding of the implementation of this application, the following is a brief description of several terms used in this application.

[0103] 1) Frame structure Frame structure is a feature of the physical layer of wireless communication that defines the time-domain signal transmission structure to, for example, implement timing references and timing alignment of basic time-domain transmission units. Wireless communication between communication devices can be performed on time-frequency resources constrained by the frame structure. Alternatively, frame structure may sometimes be referred to as wireless frame structure.

[0104] Depending on the frame structure and / or the frame configuration within the frame structure, frequency division duplex (FDD) and / or time division duplex (TDD) and / or full duplex (FD) communication can be implemented. FDD communication refers to transmissions in different directions (e.g., uplink and downlink) occurring in different frequency bands. TDD communication refers to transmissions in different directions (e.g., uplink and downlink) occurring for different durations. FD communication refers to transmission and reception occurring on the same time-frequency resources; that is, the device can simultaneously transmit and receive on the same frequency resources in time.

[0105] An example of a frame structure is that in Long-Term Evolution (LTE) with the following specifications: each frame lasts for 10 ms; each frame has 10 subframes, each lasting for 1 ms; each subframe includes two time slots, each lasting for 0.5 ms; each time slot is used to transmit 7 OFDM symbols (assuming a conventional CP); each OFDM symbol has a symbol duration and a specific bandwidth (or partial bandwidth or bandwidth splitting) associated with the number of subcarriers and subcarrier spacing; the frame structure is based on OFDM waveform parameters, such as subcarrier spacing and CP length (where the CP has a fixed length or finite length option); the handover interval between the uplink and downlink in TDD must be an integer multiple of the OFDM symbol duration.

[0106] Another example of a frame structure is that in New Radio (NR) with the following specifications: support for multiple subcarrier spacings, each corresponding to a specific parameter set; the frame structure depends on the parameter set, but in any case, the frame length is set to 10 ms, consisting of ten subframes, each 1 ms long; and time slots are defined as 14 OFDM symbols, with the slot length depending on the parameter set. For example, the NR frame structure for a standard CP 15 kHz subcarrier spacing (“Parameter Set 1”) and the NR frame structure for a standard CP 30 kHz subcarrier spacing (“Parameter Set 2”) are different. For the 15 kHz subcarrier spacing, the slot length is 1 ms; for the 30 kHz subcarrier spacing, the slot length is 0.5 ms. The NR frame structure can be more flexible than the LTE frame structure.

[0107] 2) Subcarrier spacing (SCS) SCS is a parameter in a scalable set of parameters that may support values ​​ranging from 15 kHz to 480 kHz. SCS can vary with spectral frequency and / or maximum UE speed to minimize the effects of Doppler shift and phase noise. In some examples, separate transmit and receive frames may exist, and the SCS of symbols in the receive frame structure can be configured independently of the SCS of symbols in the transmit frame structure. The SCS in the receive frame can differ from the SCS in the transmit frame. In some examples, the SCS of each transmit frame can be half the SCS of each receive frame. If there is a difference in the SCS between the receive and transmit frames, this difference does not necessarily have to be scaled by a factor of two; for example, using the inverse discrete Fourier transform (IDFT) instead of the fast Fourier transform (FFT) can provide more flexible symbol duration. Additional examples of frame structures can be used with different SCS.

[0108] 3) Cell / Carrier / Bandwidth Part (BWP) / Occupied Bandwidth: Base stations and other equipment can provide cell coverage. Wireless communication with the equipment can be conducted via one or more carrier frequencies. These carrier frequencies will be referred to as carriers. Carriers can also be referred to as component carriers (CCs). A carrier can be characterized by its bandwidth and reference frequency (e.g., the center frequency, minimum frequency, or maximum frequency of the carrier). Carriers can be in licensed or unlicensed spectrum. Wireless communication with the equipment can also, or alternatively, be conducted on one or more bandwidth parts (BWPs). For example, a carrier can have one or more BWPs. More generally, wireless communication with the equipment can be conducted via a spectrum. A spectrum can include one or more carriers and / or one or more BWPs.

[0109] A cell may include one or more downlink resources and optionally one or more uplink resources, or a cell may include one or more uplink resources and optionally one or more downlink resources, or a cell may include one or more downlink resources and one or more uplink resources simultaneously. As an example, a cell may include only one downlink carrier / BWP, or only one uplink carrier / BWP, or multiple downlink carriers / BWP, or multiple uplink carriers / BWP, or one downlink carrier / BWP and one uplink carrier / BWP, or one downlink carrier / BWP and multiple uplink carriers / BWP, or multiple downlink carriers / BWP and one uplink carrier / BWP, or multiple downlink carriers / BWP and multiple uplink carriers / BWP.

[0110] 2) PDCCH In the downlink, control signaling can be transmitted in a control channel, which may be called the PDCCH. Specifically, the PDCCH is a physical downlink channel used to carry bit strings (e.g., downlink control information (DCI) bits). For example, the PDCCH can be formed by a string of encoded DCI bits plus cyclic redundancy check (CRC) bits.

[0111] In some implementations, the signal carried on the PDCCH can also be called the PDCCH. Specifically, sending / receiving the PDCCH means sending / receiving the signal carried by the PDCCH.

[0112] 3) DCI DCI can be used to schedule data transmission or provide feedback on data transmission. For example, DCI may include information for scheduling data transmission (e.g., for downlink / uplink data transmission or sidelink (SL) data transmission) and / or power control (e.g., uplink power control, sidelink power control, or downlink power control).

[0113] In view of this, the implementation of this application provides a scheme in which control signal transmission (e.g., downlink control signal transmission or sidelink control signal transmission) can use multiple transport layers and the control signal transmission is for a single UE. In other words, for a single UE, its control signals can be transmitted on multiple transport layers. When multiple transport layers are available, the control signals of a single UE (e.g., PDCCH) can be transmitted simultaneously on multiple transport layers, that is, one or more transport layers are added on top of a single transport layer for time-frequency resources used for control signal transmission. That is, more time-frequency resources can be utilized to send and / or receive control signals. Compared with single-layer control signal transmission, this can greatly improve the performance and capacity of control signal transmission.

[0114] 5) Hybrid Automatic Repeat Request (HARQ) HARQ is a mechanism for providing reliable wireless transmission. It combines forward error correction (FEC) and automatic repeat request (ARQ). In HARQ, the initial transmission is an FEC codeword with CRC bits to support error detection at the receiver. If a decoding error is detected, the receiver sends back NCK signaling to notify the transmitter of the error and request a retransmission. The retransmitted bits can be selected directly from the initial transmission bits or from incrementally generated code bits, which, together with the initial transmission bits, form a longer codeword. The former is called chase-combining HARQ (CC-HARQ), and the latter is called incremental-redundancy HARQ (IR-HARQ). Generally, IR-HARQ outperforms CC-HARQ in performance due to the additional coding gain from incremental redundancy.

[0115] The UL-DL transmission direction configuration indication can be dynamic or semi-static. This direction indication is used to configure transmission resources in the UL or DL ​​direction. Semi-static is defined relative to dynamic options operating in each time slot. For example, semi-static can mean periodic over a given time period (e.g., 200 or more time slots). Semi-static can also mean configured once and updated only occasionally. Sometimes, semi-static configuration refers to configuration signaling that is not part of dynamic signaling; for example, the signaling could be broadcast signaling, RRC signaling, higher-layer signaling, or non-DCI signaling. Communication between the network and the UE can be time-slot based. Such time slots are based on time division duplexing (TDD), where uplink transmissions occur at times different from downlink transmissions. In a specific example, each time slot has 14 OFDM symbols. Time slots can include one or a combination of the following: downlink (DL) symbols; uplink (UL) symbols; protection symbols; flexible, unknown, or reserved symbols.

[0116] Alternatively, a time slot may include one or a combination of DL symbols, UL symbols, and other symbols that are neither DL symbols nor UL symbols for a particular UE, i.e., on which no transmissions to or from the UE occur. From the perspective of the UE receiving information, these other symbols are typically referred to as "flexible" symbols or "unknown" symbols. One or more of the indicated "flexible" or "unknown" symbols may serve as a protection period or interval between one or more DL symbols and one or more UL symbols; that is, no one or more "protection" symbols may be identified in the time slot. Instead, some symbols may typically be referred to as "flexible" or "unknown" symbols, one or more of which may serve as intervals or be overridden as DL symbols or UL symbols by other dynamic signaling. For this purpose, a time slot may include one or a combination of the following: downlink (DL) symbols; uplink (UL) symbols; flexible or unknown symbols.

[0117] User equipment (UE) can be semi-statically configured via higher-layer signaling, such as system information block (SIB) or radio resource control (RRC) signaling indicating the allocation of UL and DL symbols for different time slots. Examples of such higher-layer signaling can include TDD UL-DL configuration, UL-DL-configuration-common (also known as common TDD UL-DL configuration), and UL-DL-configuration-dedicated (also known as dedicated TDD UL-DL configuration). This type of semi-static configuration can be periodic. The semi-static UL-DL transmission direction configuration provides a time slot format for each of multiple time slots. The configuration can be repeated in different periods. The UE considers symbols in a time slot indicated as downlink by the semi-static UL-DL transmission direction configuration (e.g., via the higher-layer parameter UL-DL-configuration-common or via the higher-layer parameter UL-DL-configuration-dedicated) as available for reception. The UE considers symbols in a time slot that are indicated as uplink by the semi-static UL-DL transmission direction configuration (i.e., by the higher-layer parameter UL-DL-configuration-common or by the higher-layer parameter UL-DL-configuration-dedicated) as available for transmission. UL-DL-configuration-dedicated may only be able to cover the flexible symbols indicated in UL-DL-configuration-common. In some implementations, unlicensed UEs can detect the dynamic slot format indication (SFI) and follow both dynamic and semi-static UL-DL configurations.

[0118] For DL ​​transmissions, the UE can send HARQ feedback, which confirms successful data decoding (ACK) or indicates unsuccessful data decoding (NCK). HARQ feedback can be sent in the UL PUCCH or PUSCH resources. If an NCK is received, the BS can schedule a retransmission for HARQ merging. HARQ feedback can also be referred to as HARQ-ACK or ACK / NCK.

[0119] 5G NR supports flexible configuration of TDD frame structures, where each symbol can be an uplink symbol, a downlink symbol, or a flexible symbol. During transmission scheduling, HARQ feedback indicating ACK or NCK can help the transmitter decide whether to retransmit. For DL ​​data transmission, ACK / NCK is sent by the UE as a UCI, which needs to be transmitted in one or more UL symbols.

[0120] However, for a given TDD carrier, waiting for an available UL symbol to send an ACK or NCK can be too long for some communication scenarios that require fast HARQ feedback. Since waiting for the next UL channel on the same carrier to send HARQ feedback can result in significant delays, this is undesirable for many applications.

[0121] Figure 5 An example of the HARQ process in TDD DL-UL transmission is shown. Figure 5 As shown, a carrier in the time domain comprises a set of transmission time units. The abbreviations D, F, and U represent the downlink time unit, flexible time unit, and uplink time unit, respectively. In related technologies, the base station can send a DCI to the UE in the downlink time unit to schedule downlink data. The downlink data can then be sent to the UE in one or more other downlink time units. The UE can decode the downlink data and generate an indication, also known as HARQ feedback, to indicate whether the downlink data decoding was successful or unsuccessful. However, according to... Figure 5 The carrier shown can carry the uplink time unit for HARQ feedback, or the flexible time unit can be located at the end of the time domain. Therefore, the UE must wait for the appropriate time unit to send the HARQ feedback. This will result in a relatively large delay for the base station to receive the HARQ feedback. In scenarios where the HARQ feedback indicates a request for retransmission, even greater delays will occur depending on the relevant technology. The time unit can be a symbol, a time slot, multiple symbols, a micro-time slot, or any time unit. Figure 5 The time unit in the time slot is a symbol, and there are 14 symbols in the time slot.

[0122] If HARQ feedback is transmitted on the same carrier, the UE needs to wait at least until the UL symbol at the end of the time slot before it can transmit HARQ feedback, which may result in excessive delays for both feedback and potential data retransmissions.

[0123] Therefore, reducing latency in the HARQ process is a challenge.

[0124] The main technical solution to the above-mentioned technical problems is that data transmission and HARQ feedback may be carried on different TDD carriers. This solution can be applied to different scenarios, such as the HARQ process between the base station and the UE, or the HARQ process between UEs (e.g., downlink HARQ process including downlink data transmission and uplink HARQ feedback, uplink HARQ process including uplink data transmission and downlink HARQ feedback, and sidelink HARQ process including sidelink data transmission and sidelink HARQ feedback).

[0125] More specifically, as an example, in a HARQ process that includes downlink data transmission and uplink HARQ feedback, some implementations of this disclosure involve a mechanism for ACK / NCK feedback, where the BS or network can schedule DL transmissions on a first carrier, and the ACK / NCK for that transmission can be transmitted on a second carrier. Both the first and second carriers can be TDD carriers. DL data transmissions can be transmitted on one or more DL symbols or flexible symbols of the first TDD carrier, while the ACK / NCK for the transmission can be transmitted on one or more UL symbols or flexible symbols of the second TDD carrier. The two TDD carriers can be configured with different TDD configurations such that the UL symbol of the second TDD carrier can be found immediately after or within a short delay following the DL symbol for the DL transmission on the first TDD carrier, minimizing the ACK / NCK delay. This mechanism can be considered a virtual full-duplex scheme for HARQ feedback.

[0126] The implementation of this application will be described in detail below with reference to the accompanying drawings. For ease of description, the following text will use a line-by-line transmission as an example.

[0127] In the implementation of this application, time-frequency resources may be referred to as any of the following: resources, time-frequency domain resources, time-frequency resource sets, or time-frequency resource blocks.

[0128] In the implementation of this application, "and / or" describes the association relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent the following three cases: only A exists, both A and B exist, and only B exists. The character " / " generally indicates an "OR" relationship between related objects. "At least one" means one or more. "At least one of A and B" is similar to "A and / or B" in describing the association relationship between related objects, indicating that three relationships can exist. For example, at least one of A and B can represent the following three cases: only A exists, both A and B exist, and only B exists.

[0129] refer to Figure 6 , Figure 6A schematic flowchart of a communication method 600 according to one implementation of this application is shown. The communication method 600 can be executed between a first device and a second device, or by a chip, circuit, or processing system configured in the first and second devices. The communication method 600 uses the first and second devices as examples of execution entities.

[0130] The communication method 600 can be applied to either a downlink HARQ process or an uplink HARQ process. In a downlink HARQ process, the first device can be a base station, and the second device can be a UE. In an uplink HARQ process, the first device can be a UE, and the second device can be a base station. Alternatively, the communication method 600 can be applied to a sidelink HARQ process, where both the first and second devices are UEs.

[0131] In step 601, the first device transmits the first data transmission on the first TDD carrier in the first time unit, and the second device receives the first data transmission accordingly.

[0132] For a TDD carrier, physical resources in the time domain can include one or more of the UL time unit, DL time unit, and flexible time unit. For example, UL data can be transmitted in the UL time unit or flexible time unit of a TDD carrier. Similarly, DL data transmission can be transmitted in the DL time unit or flexible time unit of a TDD carrier.

[0133] The first TDD carrier can use a specific frequency band. First data can be transmitted in a first time unit in the time domain at a frequency belonging to the frequency band of the first TDD carrier in the frequency domain. The time unit can be a symbol, a time slot, multiple symbols, a micro-time slot, or any time unit. Implementations of this application do not limit the type of time unit.

[0134] In step 602, the second device transmits HARQ feedback corresponding to the first data transmission on the second carrier in the second time unit, and the first device receives the HARQ feedback accordingly.

[0135] In some implementations, the second carrier is a TDD carrier.

[0136] It should be noted that the second TDD carrier is used as an example below.

[0137] A time unit can be interpreted as a unit such as a symbol, a time slot, multiple symbols, a micro-time slot, or any other time unit. Alternatively, the first time unit, second time unit, or other time units described below can also refer to a time location, such as a second time slot, a third symbol, etc.

[0138] The first TDD carrier and the second carrier are in different frequency bands.

[0139] In other words, if physical resources are divided into several frequency bands in the frequency domain, then the first TDD carrier corresponds to one frequency band, and the second carrier corresponds to another frequency band.

[0140] The first TDD carrier can be the UE's primary cell, and the second TDD carrier can be the UE's secondary cell, and vice versa.

[0141] For example, for a downlink HARQ procedure, the first data will be transmitted in the DL / flexible time unit on the first TDD carrier, and the HARQ feedback will be transmitted in the UL / flexible time unit on the second TDD carrier.

[0142] For example, in the uplink HARQ process, the first data will be transmitted in the UL / flexible time unit on the first TDD carrier, and the HARQ feedback will be transmitted in the DL / flexible time unit on the second TDD carrier.

[0143] If the communication method is performed by a chip, circuit, or processing system configured in the first and second devices, then step 601 can also be described as the first device outputting the first data transmission on a first TDD carrier in a first time unit, and the second device correspondingly inputting the first data transmission. Furthermore, step 602 can also be described as the second device outputting HARQ feedback of the first data transmission on a second carrier in a second time unit, and the first device correspondingly inputting HARQ feedback of the first data transmission. It should be noted that similar alternative descriptions can be used for the sending or receiving steps described below, and will not be repeated hereafter.

[0144] In the above technical solution of this application, the first data transmission is carried on a first TDD carrier, while the corresponding HARQ feedback is carried on a different carrier. Compared to the first data transmission and corresponding HARQ feedback carried on the same TDD carrier, this reduces the time the first device waits to receive feedback. This can be achieved by the following method: the second device does not need to wait for a suitable time unit on the same TDD carrier to send the HARQ feedback back to the first device, even though the same TDD carrier also carries data transmission. The first device can obtain HARQ feedback in a timely manner, allowing another data transmission or retransmission to occur promptly.

[0145] To support data transmission carried on different carriers and corresponding HARQ feedback, some implementation methods of this application are as follows.

[0146] The following non-limiting examples illustrate various implementations of this disclosure.

[0147] refer to Figure 7 , Figure 7A schematic flowchart of a communication method 700 according to another implementation of this application is shown. The communication method 700 can be executed between a base station and a UE, or by a chip, circuit, or processing system configured in the base station and the UE. The communication method 700 uses the base station and the UE as examples of execution entities. The communication method 700 uses a second TDD carrier as an example.

[0148] In step 701, the base station sends first indication information for indicating the frequency domain resources of the second TDD carrier, and the UE receives the first indication information accordingly.

[0149] Optionally, the base station may also send a third indication information, and the UE may also receive the third indication information, which is used to indicate that the second TDD carrier is different from the first TDD carrier.

[0150] To support this type of cross-carrier HARQ feedback scheduling, some signaling may be required to indicate the carrier used for HARQ feedback. The second TDD carrier in this first indication information can be transmitted in the DCI, for example, via a carrier ID. Additional signaling may exist to indicate that HARQ feedback is transmitted on different carriers; for example, additional bits indicating this configuration may be indicated in the DCI or RRC configuration.

[0151] Optionally, the base station may also send a fourth indication information, and the UE may also receive the fourth indication information, which is used to schedule the first data transmission and indicate the resources used for the first data transmission.

[0152] In other words, the fourth indication information is used to indicate the frequency resource allocation and the first time unit in the time domain for the first data transmission on the first TDD carrier.

[0153] For example, for DL ​​transmission, a DCI is transmitted on the PDCCH channel to schedule downlink transmission. The DCI is transmitted within a specific search area and typically occupies part or all of the downlink time unit. The DCI schedules DL data transmission and indicates the resources used for DL ​​data transmission on the PDSCH. A fourth indication information can indicate the time interval between the PDCCH carrying the DCI and the start of DL data transmission carried at the PDSCH. The time interval can be indicated by a timeslot, symbol, microtimeslot, or any transmission time unit or combination of different time units. In this example, DL data transmission at the PDSCH begins in the next transmission time unit after the DCI transmission on the PDCCH, but in many scenarios, there is a time interval between the PDCCH and PDSCH. DCI and DL data transmission can be transmitted on the same carrier or different carriers.

[0154] Optionally, in step 702, the base station sends second indication information to indicate the time interval for determining the second time unit, and the UE receives the second indication information accordingly.

[0155] In other words, the second indication information is used to indicate the time interval, which is used to determine the time-domain resources of the HARQ feedback of the first data transmission on the second TDD carrier.

[0156] In some implementations of this application, the time interval is located between PDSCH and PUSCH or between PDSCH and PUCCH, wherein the first data transmission is carried in PDSCH, and the HARQ feedback of the first data transmission is carried in PUSCH or PUCCH.

[0157] In other words, the time interval lies between the first time unit and the second time unit. The first time unit is used to transmit the first data related to the PDSCH. The second time unit is used to transmit the corresponding HARQ feedback related to the PUSCH or PUCCH.

[0158] In some implementations of this application, the time interval is located between the DCI and HARQ feedback, or between the PDCCH and HARQ feedback.

[0159] In other words, the time interval lies between the third and second time units. The third time unit is used to transmit scheduling information related to DCI or PDCCH. The second time unit is used to transmit corresponding HARQ feedback related to PUSCH or PUCCH.

[0160] For example, in a downlink HARQ procedure, the timing of the HARQ feedback transmission can be indicated in the transmission of the same DCI-scheduled DL data (example of the first data). For instance, the time interval between the PDSCH and the PUCCH or PUSCH used to send the HARQ feedback can be indicated in the DCI. In other scenarios, the indicated time interval lies between the DCI / PDCCH and HARQ-ACK timings. The indicated time interval can be in units of time slots, symbols, multiple symbols, micro-slots, any other time unit, or a combination of different time units.

[0161] In some implementations of this application, the time interval can be derived based on a predefined interval.

[0162] As an alternative to step 702, the time interval for determining the second time unit can be derived from the fourth indication information and the predefined interval, which indicates the resources used for the first data transmission.

[0163] For example, in some other scenarios, the timing of HARQ feedback can be derived based on a predefined interval, such as the first slot or symbol after a given interval of DL data transmission (e.g., a given processing time). The given interval of DL data transmission can be obtained from the fourth indication information.

[0164] In some implementations of this application, the first instruction information and the second instruction information may be carried on DCI, RRC configuration, or a combination of DCI and RRC configuration.

[0165] In other words, the resources used for HARQ feedback (including frequency domain resources (e.g., frequency domain allocation on the second TDD carrier or the second TDD carrier) and time domain resources (e.g., the second time unit)) can also be indicated by DCI, or configured in advance in RRC, or a combination of both.

[0166] It should be noted that the first indication information and the second indication information may be carried on the same DCI or the same RRC configuration. Alternatively, the first indication information and the second indication information may be carried on different DCIs or different RRC configurations.

[0167] For example, in some scenarios, the timing or time intervals used for PDSCH and HARQ-ACK indications are indicated in a combination of RRC and DCI signaling. RRC can be configured with a set of possible time interval selections, and DCI can indicate which selection from this set of possibilities to use. The timing or time intervals used for PDSCH and HARQ-ACK (an example of HARQ feedback) are included in the second indication information.

[0168] It should be noted that if the first indication information and / or the second indication information are configured by DCI, then DCI can be transmitted on the first TDD carrier, the second TDD carrier, or the third carrier, and the third carrier is different from the first TDD carrier and the second TDD carrier. Figure 7 An example is shown, and the carrier carrying DCI is not limited in the implementation of this application.

[0169] In some implementations, the third carrier can be a TDD carrier. The following section uses a third TDD carrier as an example.

[0170] In step 703, the base station and the UE can perform the first data transmission in the first time unit and on the first TDD carrier.

[0171] In step 704, the base station and the UE can transmit HARQ feedback corresponding to the first data transmission on the second time unit and on the second TDD carrier.

[0172] As an example, in a downlink HARQ procedure, the base station transmits a first data transmission on a first TDD carrier in a first time unit, and the UE receives the first data transmission accordingly. The UE then transmits a HARQ feedback on a second TDD carrier in a second time unit, and the base station receives the HARQ feedback accordingly.

[0173] More specifically, after the UE receives DL data (referred to as first data) transmission on the PDSCH and performs DL data decoding, the UE can send HARQ feedback (ACK / NCK) as uplink control information (UCI) on the PUCCH or PUSCH. This HARQ feedback can be sent on UL cells (one or more UL symbols) in a different carrier, which can be the second TDD carrier as described above.

[0174] As another example, for the uplink HARQ procedure, the UE transmits a first data transmission on a first TDD carrier in a first time unit, and the base station receives the first data transmission accordingly. The base station then transmits HARQ feedback on a second TDD carrier in a second time unit, and the UE receives the HARQ feedback accordingly.

[0175] The first data transmission carried on different TDD carriers and the HARQ feedback of the first data transmission can also be called cross-carrier HARQ feedback. This allows the UE to transmit on multiple carriers. In multiple carriers (e.g., two TDD carriers), one TDD carrier is used for the first data transmission, and the other TDD carrier is used for transmitting the HARQ feedback of the first data transmission. Each carrier can also be called a component carrier. Each carrier can correspond to a frequency band, and each carrier can also correspond to a cell.

[0176] In this example, the UE transmits on at least two carriers, labeled f1 (representing the first TDD carrier used for the first data transmission) and f2 (representing the second TDD carrier used for the HARQ feedback of the first data transmission), corresponding to two different frequency bands / carriers. Carrier f1 can be the UE's primary cell, while carrier f2 can be the UE's secondary cell, or vice versa, but it is not limited to this scenario. D, F, and U refer to downlink transmission unit, flexible transmission unit, and uplink transmission unit, respectively, in terms of time. Each transmission unit can be a symbol, time slot, multiple symbols, micro-time slot, or any time unit. When the transmission unit is a symbol, D, F, and U can directly refer to a DL symbol, flexible symbol, or uplink symbol. When the transmission is a time slot, D and U can respectively refer to a DL-dominated time slot (i.e., most symbols in the time slot are used for DL ​​transmission) and a UL-dominated time slot (i.e., most symbols in the time slot are used for UL transmission).

[0177] There are several ways to implement this type of cross-carrier HARQ feedback. The following section will combine... Figures 8 to 15 This section describes different scenarios for cross-carrier HARQ feedback.

[0178] It should be noted that, Figures 8 to 15 This is an example of a downlink HARQ procedure.

[0179] In some implementations of this application, the DCI is carried on a first TDD carrier, a second TDD carrier, or a third TDD carrier, wherein the third TDD carrier is different from the first TDD carrier and the second TDD carrier.

[0180] In the first scenario, DCI is carried on the first TDD carrier. Figure 8 and Figure 9 An example of DCI carried on a first TDD carrier is shown.

[0181] In one possible implementation, the transmission of the first data and the retransmission of the first data are scheduled in different DCIs.

[0182] refer to Figure 8 , Figure 8 One implementation of the cross-carrier HARQ feedback scheme is shown.

[0183] Figure 8 The example illustrates a HARQ transmission and retransmission process using a cross-carrier HARQ feedback scheduling scheme. For ease of illustration, it is assumed that the time units in the figure are symbols, and the figure will show all 14 symbols of the time slot. The figure shows a TDD configuration of the first TDD carrier f1 and the second TDD carrier f2 on the same time slot, where a DL-dominated time slot is configured for carrier f1 and a UL-dominated time slot is configured for carrier f2. The BS first transmits the scheduled DCI in the first symbol, and the initial transmission of DL data (referred to as the first data) is scheduled to be transmitted in the two symbols immediately following the scheduled DCI. Other intervals (e.g., AGC or handover intervals) may exist before or after the DCI and before or after the DL data transmission, which are not shown in the figure. The HARQ-ACK for DL ​​data transmission can be transmitted shortly after the DL data transmission (e.g., in this example, assuming the UE processing time is less than one symbol, it is transmitted one symbol after the DL transmission). If the UE provides HARQ feedback with an NCK, the BS can quickly schedule a retransmission, such as Figure 8 As shown. In Figure 8 In this context, the BS can optionally send another DCI to schedule the retransmission of DL data and the HARQ feedback resources used for that retransmission. And using a similar mechanism, the UE can send another HARQ feedback shortly after the retransmission (in...). Figure 8 The example sends a HARQ response with an ACK.

[0184] Therefore, compared with the traditional scheduling scheme in which ACK / NCK are transmitted on the same TDD carrier, the feedback delay and the overall transmission delay are much shorter.

[0185] In one possible implementation, the transmission and retransmission of the first data are scheduled in the same DCI.

[0186] refer to Figure 9 , Figure 9 Another implementation of the cross-carrier HARQ feedback scheme is shown.

[0187] like Figure 9 As shown, in some scenarios, retransmissions and corresponding HARQ-ACKs may already be scheduled in the initial DCI of the initial transmission of DL data. Other processes are similar to... Figure 8 Similar to the descriptions in the text, I will not repeat them here.

[0188] DCI and data transmission / retransmission may be carried on the same TDD carrier. For example... Figure 8 and Figure 9 As shown, the first TDD carrier carries DCI and data transmission / retransmission.

[0189] In the second scenario, DCI is carried on the second TDD carrier. Figure 10 An example of DCI carried on a second TDD carrier is shown.

[0190] In some examples, the HARQ feedback on the DCI and UL units that schedule DL data transmission can be on the same carrier, while the data transmission is on a different carrier. In this case, it is cross-carrier scheduling, but the HARQ feedback is still transmitted on a different carrier than the DL data transmission.

[0191] refer to Figure 10 , Figure 10 Another implementation of the cross-carrier HARQ feedback scheme is shown.

[0192] like Figure 10 As shown, this example is similar to Figure 8 Similarly, but DCI and HARQ feedback are sent in f2, while DL data transmission is sent in f1. Other processes are the same. Figure 8 Similar to the descriptions in the text, I will not repeat them here.

[0193] In the third scenario, DCI is carried on a third TDD carrier, which is different from the first TDD carrier and the second first TDD carrier. Figure 11 An example of DCI carried on a third TDD carrier is shown.

[0194] refer to Figure 11 , Figure 11 Another implementation of the cross-carrier HARQ feedback scheme is shown.

[0195] In the above Figures 8 to 10 In the example described, only two carriers are used. In some scenarios, the carriers used to transmit DCI, DL data, and HARQ feedback can all be different. Figure 11 An example of this is shown, where DCI is transmitted on a third TDD carrier labeled f3, DL data is transmitted on a first TDD carrier f1, and HARQ feedback of the data is transmitted by the UE in a UL time unit on a second TDD carrier f2. Other processes are similar. Figures 8 to 10 Similar to the descriptions in the text, I will not repeat them here.

[0196] In some implementations of this application, the first data transmission and the HARQ feedback of the first data transmission are scheduled by the DCI in the eighth time unit prior to the first time unit.

[0197] For example, the eighth time unit is an earlier time slot than the time slot used for the first data transmission. Or, the eighth time unit is a symbol earlier than the symbol used for the first data transmission, and the eighth time unit and the first time unit are in the same time slot.

[0198] refer to Figure 12 , Figure 12 Another implementation of the cross-carrier HARQ feedback scheme is shown.

[0199] exist Figure 12 In this context, DCI is used to schedule data transmission and the corresponding HARQ-ACK. DCI is carried in an earlier time slot than the time slot carrying the data transmission. Alternatively, DCI is carried in a symbol earlier than the symbol carrying the data transmission, and both symbols are in the same time slot.

[0200] In some implementations of this application, the first time unit overlaps with the second time unit.

[0201] refer to Figure 13 , Figure 13 Another implementation of the cross-carrier HARQ feedback scheme is shown.

[0202] Figure 13 A similar HARQ transmission example using the proposed cross-carrier HARQ feedback scheme is shown. Figure 13In the accompanying diagram, the time unit can be a time slot, where D refers to the DL-dominated time slot and U refers to the UL-dominated time slot. DCI can indicate a first time interval indicated by the fourth indication information as described above and a second time interval indicated by the second indication information as described above, the first time interval being located between the PDCCH and PDSCH, and the second time interval being located between the PDSCH and the PUCCH used for sending HARQ feedback, or between the PDSCH and the PUSCH used for sending HARQ feedback. The time interval can be indicated in time slots. Due to this mechanism, HARQ feedback can be sent shortly after the DL transmission. If the DL data transmission and HARQ feedback transmission occupy only a portion of the time slots, for example, within one or more symbols within a time slot, then... Figure 12 As shown, UL feedback can be sent in the same time slot as DL data transmission, provided there is sufficient interval (e.g., multiple symbols) for the UE to process the transmission and prepare to send HARQ feedback.

[0203] In some implementations of this application, the first device also transmits the second data transmission on the first TDD carrier in the fourth time unit, and the second device receives the second data transmission accordingly, wherein the fourth time unit is adjacent to the first time unit, and the second data transmission is a retransmission of the same data block as the first data transmission.

[0204] During downlink HARQ, the first device can be a base station, and the second device can be a UE.

[0205] refer to Figure 14 , Figure 14 Another implementation of the cross-carrier HARQ feedback scheme is shown.

[0206] Figure 14 Another application example of the proposed cross-carrier HARQ feedback scheme is shown. In this example, the BS can perform continuous retransmission or repetition of data blocks, or it can employ a progressive transmission scheme, where each subsequent transmission adds additional redundancy to the previous transmission on the first TDD carrier f1. Figure 14 As shown, the second data transmission of the data block will be transmitted in the fourth time unit after the first data transmission of the data block and on the first TDD carrier. The second data transmission can be a repetition of the first data transmission, and additional redundancy of the data block can be added in the second data transmission. Using the proposed scheme, the ACK / NCK feedback of the data block can be transmitted very quickly in the uplink time units of different TDD carriers, for example... Figure 14The second TDD carrier f2 is shown. After processing the first data transmission of the data block, the UE begins decoding and sends ACK / NCK feedback. If decoding is unsuccessful, after sending NCK feedback, the UE can continue to attempt to decode the data and send ACK / NCK feedback again after receiving more transmissions of the data block. If the BS receives an ACK from the UE, the BS can stop any further repetition / retransmission or progressive transmission of the data block. The timing or resources of HARQ feedback can be indicated in the DCI or follow predefined intervals or rules. That is, frequency domain resources and time domain resources can be obtained according to the first indication information and the second indication information, respectively.

[0207] In some implementations of this application, the first device further transmits a third data transmission on a first TDD carrier in a fifth time unit, and correspondingly, the second device also receives the third data transmission, wherein the first data transmission and the third data transmission correspond to different data blocks or different transport blocks. The second device further transmits HARQ feedback corresponding to the third data transmission on a second TDD carrier in a second time unit, and the first device also receives the HARQ feedback.

[0208] During downlink HARQ, the first device can be a base station, and the second device can be a UE.

[0209] refer to Figure 15 , Figure 15 Another implementation of the cross-carrier HARQ feedback scheme is shown.

[0210] Figure 15 An example is shown where multiple ACK / NCKs can be multiplexed on a single PUCCH or PUSCH resource. These multiple ACK / NCKs can be sent and multiplexed together using multiple HARQ-ACK codebooks. Figure 15 In the example, the DCI schedules DL transmissions of two data blocks, which can be two transport blocks (TBs), two codeblock groups (CBGs), or any other data block unit. These two data blocks can be scheduled by the same DCI or by two separate DCIs. A single DCI or multiple DCIs can indicate the timing of HARQ feedback (e.g., the time interval between DL data transmission and HARQ feedback), thereby generating the same PUCCH or PUSCH resource on the same UL transmission unit. Multiple ACKs / NCKs for feedback of multiple data blocks can be multiplexed together on the same PUCCH or PUSCH resource using different HARQ-ACK codebooks. These ACKs / NCKs can be transmitted on a different TDD carrier (e.g., a second TDD carrier f2) than the TDD carrier used for data transmission (e.g., a first TDD carrier f1).

[0211] In some implementations of this application, the first TDD carrier and the second TDD carrier have one or more different sub-carrier spacings (SCS).

[0212] refer to Figure 16 , Figure 16 Another implementation of the cross-carrier HARQ feedback scheme is shown.

[0213] For example, in some scenarios, the two carriers used for cross-carrier HARQ feedback schemes can have different subcarrier spacing (SCS) or parameter sets. Figure 16 An example is shown. In this case, the SCS of the second TDD carrier f2 is twice that of the first TDD carrier f1, so the symbol duration is half that of the first TDD carrier f1. For example, the first TDD carrier f1 could have a 30 kHz SCS, while the second TDD carrier f2 could have a 60 kHz SCS.

[0214] Figures 8 to 15 The implementation shown is a scenario where the first TDD carrier and the second TDD carrier have the same SCS. Figure 16 The implementation shown can also be applied to scenarios where the first TDD carrier and the second TDD carrier correspond to one or more different SCSs, which will not be elaborated here. For example, DL data transmission and DL data retransmission can be scheduled in the same DCI or different DCIs.

[0215] Combining Figures 17 to 19 Describe the scenario of the downlink HARQ process.

[0216] refer to Figure 17 , Figure 17 A schematic flowchart of a communication method 1700 according to another implementation of this application is shown. The communication method 1700 can be executed between a base station and a UE, or by a chip, circuit, or processing system configured in the base station and the UE. The communication method 1700 uses the base station and the UE as examples of execution entities. Figure 17 A diagram illustrating the basic steps of a cross-carrier fast feedback scheme is shown.

[0217] In step 1701, the base station and UE transmit RRC configuration.

[0218] More specifically, the BS or network first configures the UE with the information required for multi-carrier scheduling or simply carrier aggregation information, which can be done through RRC signaling.

[0219] For example, the RRC configuration may also include the configuration of PUCCH or PUSCH resources for HARQ feedback, and the selection of a potential time interval (labeled k1) for determining the time interval of the second time unit, for example, the time interval being between the PDSCH carrying the first data transmission and the channel carrying the HARQ feedback (which may be PUCCH or PUSCH).

[0220] In step 1702, the base station sends the DCI, and the UE receives the DCI accordingly.

[0221] In some implementations, DCI includes the first indication information and / or the second indication information as described above.

[0222] After configuration, when the UE's DL service arrives, the BS or network can send a DCI to the UE on the first TDD carrier to schedule DL data transmission in the PDSCH (e.g., the first data transmission) and schedule HARQ-ACK feedback transmission. The DCI can indicate one of the potential time interval selections k1 configured in the RRC.

[0223] Therefore, the UE will obtain both the frequency domain resources and the time domain resources of the first data transmission and the HARQ feedback of the first data transmission through RRC configuration and / or DCI.

[0224] DCI signaling: The DCI used to schedule PDSCH transmissions may need to indicate information about the carriers used to transmit HARQ feedback (this information may be referred to as the first indication information as described above), the timing of the HARQ feedback (this information may be referred to as the second indication information as described above), and an indication that the HARQ feedback will be transmitted on different carriers (this indication may be referred to as the third indication information as described above). For example, the indication of HARQ feedback resources may include at least some of the following: timing indication, time-frequency resource indication, and HARQ-ACK codebook indication.

[0225] The following are possible examples of fields used for indications (referred to as the first indication information as described above) in the DCI, and these examples may include, but are not limited to, the following. Indications in the DCI can also be configured by RRC signaling or a combination of DCI and RRC signaling.

[0226] Tables 1 and 2 show more specific examples of the first and second indication information during the downlink HARQ process.

[0227] It should be noted that the HARQ-ACK feedback in Tables 1 and 2 can be either ACK or NCK. HARQ feedback may be carried on channels such as PUCCH or PUSCH.

[0228] Table 1

[0229] As shown in Table 1, the field including the carrier ID used for HARQ-ACK feedback is a specific form of the first indication information.

[0230] The field indicating the PDSCH-HARQ-ACK feedback timing, which includes the time interval from PDSCH to HARQ-ACK, is a specific form of the second indication information. The time interval from PDSCH to HARQ-ACK is referred to as the time interval from PDSCH to the PUCCH carrying the HARQ-ACK, or the time interval from PDSCH to the PUSCH carrying the HARQ-ACK. The time interval is merely an example here; as mentioned above, the time interval could also be from PDCCH to the PUCCH carrying the HARQ-ACK, or from PDCCH to the PUSCH carrying the HARQ-ACK.

[0231] As shown in the table, the field including the carrier ID used for data transmission is optional.

[0232] Table 2

[0233] The time interval for the PDSCH or PDCCH to HARQ-ACK feedback timing indication can be in units of time slots, symbols, sub-time slots, multiple symbols, any time unit, or a combination of different time units.

[0234] In step 1703, the UE determines the resources for HARQ feedback based on the first indication information and / or the second indication information.

[0235] More specifically, the UE determines the frequency domain resources for HARQ feedback based on the first indication information.

[0236] For example, if the first indication information is carried in the DCI shown in Table 1, the UE can directly determine the second TDD carrier based on the carrier ID used for HARQ-ACK feedback.

[0237] For example, if the first indication information is carried in the DCI shown in Table 2, the UE can obtain the carrier ID field and determine whether the second TDD carrier used for HARQ feedback is the same as the carrier corresponding to the carrier ID.

[0238] More specifically, the UE determines the time-domain resources for HARQ feedback based on the second indication information.

[0239] If the SCS of the first TDD carrier and the second TDD carrier are the same, the UE can determine the second time unit based on the first time unit and the time interval.

[0240] If the first TDD carrier and the second TDD carrier have one or more different SCSs, the UE needs to align the second time unit and the first time unit. It should be noted that during uplink HARQ, the data receiver is the base station. Therefore, aligning the second time unit and the first time unit is also necessary for the base station.

[0241] In some implementations of this application, the second instruction information includes the time interval between the third time unit and the second time unit, and the third time unit is used to send control information.

[0242] If the third time unit is used to transmit control information (e.g., DCI), the time interval can also be referred to as the time interval between the PDCCH and the channel carrying HARQ feedback (e.g., PUCCH or PUSCH).

[0243] In some implementations of this application, the second indication information includes the time interval between the first time unit and the second time unit. In this case, the time interval may also be referred to as the time interval between the PDSCH and the channel carrying HARQ feedback (e.g., PUCCH or PUSCH).

[0244] As mentioned earlier, for example, the timing of HARQ-ACK resources can be indicated by the time interval between PDSCH and HARQ-ACK feedback. PDSCH transmission and HARQ-ACK can be sent on different carriers, and therefore can have different parameter sets.

[0245] Regarding the time interval, there are several possibilities. In one case, the unit of the time interval is the same as the second time unit. In another case, the unit of the time interval is the same as the first time unit.

[0246] In this case, the unit of the time interval is the same as that of the second time unit.

[0247] In some implementations of this application, the UE determines the first corresponding time of the first time unit in the second TDD carrier, and determines the second time unit based on the first corresponding time and the time interval.

[0248] In some implementations of this application, the UE determines the second corresponding time of the third time unit in the second TDD carrier, and determines the second time unit based on the second corresponding time and the time interval.

[0249] There are two examples where the second time unit and the first time unit are aligned.

[0250] refer to Figure 18 , Figure 18 This illustrates a scenario involving timing alignment.

[0251] Figure 18 An example of this timing alignment is shown. For instance, in a DCI that schedules DL data transmission, the DCI can indicate the time interval between the PDSCH and the channel carrying HARQ-ACK as a k1 unit. Without loss of generality and for ease of representation, the time unit is considered as a time slot in this example; however, if the time unit is a symbol, multiple symbols, micro-slots, or sub-slots, the same mechanism and formula can be applied. As previously mentioned, k1 can be obtained from the DCI or a combination of DCI signaling and RRC configuration.

[0252] If the PDSCH transmission ends at slot n, the time interval can indicate the interval between the last PDSCH slot and the HARQ-ACK slot. Two carriers may require a reference point to align slots or time units. This is likely the case in many practical scenarios if the frame boundaries of the two carriers are aligned. The start point of the same frame with the same frame number (e.g., the same system frame number (SFN) for both carriers) can be considered as the reference point. The slot number within the same frame can then be determined.

[0253] Since the two TDD carriers f1 and f2 can have different parameter sets, their time slots can be different. In this case, k1 can indicate the number of time slots in units of the second TDD carrier f2. Furthermore, the UE can send HARQ feedback in the time slot corresponding to the time slot number given by the following formula on the second TDD carrier f2:

[0254] It can be the number or index of the third time unit on the first TDD carrier. This is used to convert an index on a first TDD carrier (such as a PDSCH carrying the first data transmission) to another index on a second TDD carrier (such as a PUCCH carrying HARQ feedback), where the SCS (and thus symbol duration and time unit) of the two subcarriers are different. It is a function used to determine the corresponding time of the third time unit in the second TDD carrier. The corresponding time of the third time unit in the second TDD carrier is the number or index of the third time unit in the second TDD carrier. k1 can indicate the time interval in terms of the time unit defined by the second TDD carrier f2.

[0255] These are the parameter set indices used for HARQ-ACK carriers or BWP and PDSCH carriers or BWP, respectively. Examples of parameter set indices are shown in Table 3 below: Table 3

[0256] When the two carriers have the same parameter set, the division becomes 1, and the equation becomes... The slot index n of PDSCH can also be determined based on an indication of the interval between PDCCH and PDSCH.

[0257] In some other scenarios, if there are multiple time units (e.g., time slots) for PDSCH transmission, then n It can refer to the beginning of PDSCH rather than the end of PDSCH.

[0258] refer to Figure 19 , Figure 19 This illustrates another scenario of timing alignment.

[0259] In some other scenarios, the timing alignment used to calculate the HARQ-ACK timing between two carriers may not be entirely based on the slot number or symbol number in the frame. Alignment can be based on the actual timing of the slot, symbol, or time unit boundaries. Figure 18 An example of this is shown, based on the timing of actual PDSCH transmissions. For example, such as... Figure 19 As shown, the slot or time unit (referred to as the second time unit) used for HARQ-ACK in the second TDD carrier f2 is numbered by the following formula.

[0260] in It is the first (earliest) time slot in TDD carrier f2 that appears slightly after the end of PDSCH transmission, or the first (earliest) time slot that appears afterward and does not overlap with PDSCH. In other words, It can be the number or index of the time unit after the corresponding time of the third time unit in the second TDD carrier. The corresponding time of the third time unit on the second TDD carrier is the actual time, not the number or index of the time unit.

[0261] Furthermore, for all schemes of HARQ-ACK timing indication, if the time slot or time unit obtained through the above calculation is not a UL time slot or cannot be used for HARQ-ACK transmission, the UE can use the first available UL time slot or the first UL time slot after which HARQ-ACK feedback can be performed.

[0262] In this case, the unit of the time interval is the same as that of the first time unit.

[0263] In some implementations of this application, the UE determines the sixth time unit by combining the time interval with the first time unit, and determines the corresponding time of the sixth time unit on the second TDD carrier. The second time unit is the corresponding time of the sixth time unit on the second carrier.

[0264] There are two examples where the second time unit and the first time unit are aligned.

[0265] For an example, the UE can send HARQ feedback in the slot corresponding to the slot number given by the following formula on the second TDD carrier f2:

[0266] Here, k1 can refer to the time interval measured with respect to the time unit of the first TDD carrier. It can be the number or index of the sixth time unit on the first TDD carrier. It is a function used to determine the corresponding time of the sixth time unit on the second TDD carrier. The corresponding time of the sixth time unit on the second TDD carrier is the number or index of the sixth time unit on the second TDD carrier.

[0267] For example, the second time unit carrying HARQ feedback on the second TDD carrier f2 can be the index or number of the time unit on the second TDD carrier that is after the corresponding time of the sixth time unit. In this example, the corresponding time for the sixth time unit on the second TDD carrier is the actual time, not the time unit number or index.

[0268] Similarly, if the time interval is defined between PDCCH and HARQ-ACK, a similar mechanism can be used.

[0269] More specifically, the unit of the time interval is consistent with that of the third time unit. The UE determines the seventh time unit by combining the time interval with the third time unit, and determines the corresponding time of the seventh time unit on the second TDD carrier. The second time unit is the corresponding time of the seventh time unit on the second carrier.

[0270] In step 1704, the base station transmits a PDSCH carrying the first data transmission on the first TDD carrier, and the UE receives the PDSCH accordingly.

[0271] Optionally, the UE decodes the first data.

[0272] In step 1705, the UE transmits HARQ feedback corresponding to the first data transmission on the second TDD carrier, and the base station receives the HARQ feedback accordingly.

[0273] Then, DL data transmission is sent via PDSCH on the downlink resources of the first TDD carrier. After decoding the data, the UE can send HARQ feedback (ACK or NCK) on the uplink PUCCH or PUSCH resources of the second TDD carrier.

[0274] The first TDD carrier and the second TDD carrier can both be TDD carriers with different TDD configurations. The first TDD carrier can be the primary cell, and the second TDD carrier can be the secondary cell.

[0275] The communication method proposed in the implementation of this application has been described in detail above. The communication device provided by this application will be described below.

[0276] Figure 20 This is a schematic block diagram of a communication device 1000 according to some implementations of this application. The device may be a communication equipment, or a device implemented within a communication equipment capable of performing the corresponding functions of any implementation of this application. For example, the device implemented in the communication equipment may be an integrated circuit, which may have other names in some cases, such as chip, modem, modem chip, baseband chip, or baseband processor. In some implementations, one or more integrated circuits may be packaged as a system-on-a-chip, system-in-package, or multi-chip module. The device may include one or more integrated circuits, or it may include one or more integrated circuits and other discrete components. The communication equipment may be a signal transmitter, a signal receiver, or a device implemented in any of these communication devices.

[0277] The communication device 1000 includes a communication module 1200. The communication module 1200 is used to implement sending and / or receiving operations. The communication module 1200 may also be referred to as a transceiver module, transceiver, or transceiver device, etc., and is used to implement receiving (which may be called input) and / or sending (which may be called output) operations.

[0278] The communication device 1000 may further include a processing module 1100. The processing module 1100 may be a processor, processing circuit, processing board, processing unit, or processing device, etc. The processing module 1100 is used to implement processing and / or operations implemented within the communication device, other than sending and / or receiving operations.

[0279] For example, if communication device 1000 corresponds to Figure 6In the first device, the communication module 1200 is used to transmit the first data transmission in the first time unit and on the first time division duplex (TDD) carrier. The communication module 1200 is also used to receive a hybrid automatic repeat request (HARQ) feedback corresponding to the first data transmission in the second time unit and on the second TDD carrier.

[0280] For example, if communication device 1000 corresponds to Figure 6 The second device in the process is configured to receive the first data transmission in the first time unit and on the first time division duplex (TDD) carrier. The communication module 1200 is also configured to send a hybrid automatic repeat request (HARQ) feedback corresponding to the first data transmission in the second time unit and on the second carrier.

[0281] Briefly, the operation and / or functions of the communication device 1000 are designed to implement the corresponding steps of the above-described method implementation.

[0282] Figure 21 A schematic block diagram of a communication device according to some implementations of this application is shown. The communication device 2000 includes at least one communication interface 2300 for inputting and / or outputting information or data. Optionally, the device 2000 may further include at least one processor 2100. The at least one processor 2100 is coupled to at least one memory 2200. The at least one memory 2200 is used to store one or more instructions and / or executable computer code. The at least one processor 2100 is used to invoke one or more instructions and / or executable computer code to cause the communication device 2000 to implement the methods provided in the implementations of this application. Optionally, the device 2000 may further include at least one memory 2200.

[0283] In one implementation, the communication device 2000 can be any type of communication device in the method implementation. For example, the communication device 2000 can be a first device (e.g., a base station) or a second device (e.g., a UE). In this implementation, the processor 2100 can be a baseband device, and the communication interface 2300 can be a radio frequency device.

[0284] In another implementation, the communication device 2000 can be implemented in communication equipment such as a sending sensing node and a receiving sensing node. In this case, the device can be an integrated circuit, which in some contexts can be other names, such as a chip, modem, modem chip, baseband chip, or baseband processor. In some implementations, one or more integrated circuits can be packaged as a system-on-a-chip, system-in-package, or multi-chip module. The device may include one or more integrated circuits, or it may include one or more integrated circuits and other discrete components. In this implementation, the processor 2100 can be a logic module or circuitry that is part of an integrated circuit. The communication interface 2300 can be a transceiver, interface circuitry, input / output interface, bus, module, pin, or other type of interface.

[0285] This application also provides a communication system. The communication system may include the first device and the second device introduced in the above implementation. For example, such as... Figure 6 , Figure 7 or Figure 17 As shown, the communication system may include a base station and a UE.

[0286] This application also provides a computer storage medium that can store one or more instructions for performing any of the methods described above.

[0287] This application also provides a computer program product that can store one or more instructions for performing any of the methods described above.

[0288] In the implementation of this application, "and / or" describes the association relationship between related objects, indicating that three relationships can exist. For example, A and / or B may represent the following three cases: only A exists, both A and B exist, and only B exists. The character " / " generally indicates an "OR" relationship between related objects. "At least one" means one or more. "At least one of A and B" is similar to "A and / or B" in describing the association relationship between related objects, indicating that three relationships can exist. For example, at least one of A and B can represent the following three cases: only A exists, both A and B exist, and only B exists.

[0289] Furthermore, unless the context clearly indicates otherwise, the singular forms of “a” and “the” used in the implementation of this application and in the appended claims are also intended to include the plural forms.

[0290] Those skilled in the art will recognize that, in conjunction with the examples described in the implementations disclosed herein, the units and algorithm steps can be implemented by electronic hardware or a combination of computer software and electronic hardware. Whether the function is executed via 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 should not consider such implementations to be beyond the scope of this application.

[0291] Those skilled in the art will understand that, for convenience and brevity, the detailed working process of the above-described systems, devices, and units can be referred to the corresponding process in the above-described method implementation, and will not be repeated here.

[0292] Among the several implementations provided in this application, the disclosed systems, apparatuses, and methods can be implemented in other ways. For example, the described apparatus implementations are merely examples. For instance, unit partitioning is a logical functional partitioning, and other partitioning methods can be used in actual implementations. For example, multiple units or components can be merged or integrated into another system, or some features can be ignored or not performed. Furthermore, the mutual coupling or direct coupling or communication connections shown or discussed can be implemented through various communication interfaces. Indirect coupling or communication connections between devices or units can be implemented electronically, mechanically, or otherwise.

[0293] Furthermore, the functional units in the implementation of this application can be integrated into a processing unit. Each of these units can exist physically independently, or two or more units can be integrated into one unit.

[0294] When these functions are implemented as software functional units and sold or used as independent products, these functions can be stored in a computer-readable storage medium. The technical solution of this application can be implemented in the form of a software product. This software product is stored in a storage medium and includes several instructions for instructing a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the method described in the implementation of this application. The aforementioned storage medium includes any medium capable of storing program code, such as a USB flash drive, external hard drive, ROM, RAM, magnetic disk, or optical disk.

[0295] The units described as independent components may or may not be physically independent, and the components shown as units may or may not be physical units; they may be located in one place or distributed across multiple network units. Some or all of the units can be selected based on actual needs to achieve the purpose of this implementation. Furthermore, the functional units in the implementation of this application may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit.

[0296] The above description is merely a specific implementation of this application and is not intended to limit the scope of protection of this application. Any variations or substitutions that would be readily conceived by a person skilled in the art within the scope of the technology disclosed in this application should be within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A communication method, characterized in that, include: The first data transmission is transmitted in the first time unit and on the first time division duplex (TDD) carrier. In the second time unit and on the second carrier, a hybrid automatic repeat request (HARQ) feedback corresponding to the first data transmission is received.

2. The method according to claim 1, characterized in that, The first TDD carrier and the second carrier are in different frequency bands.

3. The method according to claim 1 or 2, characterized in that, The second carrier is a TDD carrier.

4. The method according to any one of claims 1 or 3, characterized in that, The method further includes: Send a first indication message, which indicates the frequency domain resources of the second carrier.

5. The method according to any one of claims 1 to 4, characterized in that, The method further includes: Send a second indication message, which indicates the time interval used to determine the second time unit.

6. The method according to claim 5, characterized in that, The time interval is located between the first time unit and the second time unit.

7. The method according to claim 5, characterized in that, The time interval is located between the third time unit and the second time unit, wherein the third time unit is used to send control information.

8. The method according to any one of claims 4 to 7, characterized in that, The first indication information is carried on the first downlink control information (DCI) and / or the first radio resource control (RRC) configuration; the second indication information is carried on the second DCI and / or the second RRC configuration; the first DCI or the second DCI is used to schedule the first data transmission and the HARQ feedback.

9. The method according to claim 8, characterized in that, The first DCI or the second DCI is carried on any one of the first TDD carrier, the second carrier, and a third carrier different from the first TDD carrier and the second carrier.

10. The method according to any one of claims 1 to 9, characterized in that, The first time unit overlaps with the second time unit.

11. The method according to any one of claims 1 to 9, characterized in that, After transmitting the first data in the first time unit and on the first time division duplex (TDD) carrier, the method further includes: In the fourth time unit, a second data transmission is transmitted on the first TDD carrier, wherein the fourth time unit is adjacent to the first time unit; wherein the second data transmission is a retransmission of the same data block as the first data transmission.

12. The method according to any one of claims 1 to 9, characterized in that, After transmitting the first data in the first time unit and on the first time division duplex (TDD) carrier, the method further includes: In the fifth time unit, a third data transmission is transmitted on the first TDD carrier, wherein the first data transmission and the third data transmission correspond to different transport blocks; In the second time unit and on the second carrier, HARQ feedback corresponding to the third data transmission is transmitted.

13. The method according to any one of claims 1 to 12, characterized in that, The first TDD carrier and the second carrier have one or more different sub-carrier spacings (SCS).

14. A communication method, characterized in that, include: The first data transmission is received in the first time unit and on the first time division duplex (TDD) carrier. In the second time unit and on the second carrier, a hybrid automatic repeat request (HARQ) feedback corresponding to the first data transmission is sent.

15. The method according to claim 14, characterized in that, The first TDD carrier and the second carrier are in different frequency bands.

16. The method according to claim 14 or 15, characterized in that, The second carrier is a TDD carrier.

17. The method according to any one of claims 14 to 16, characterized in that, The method further includes: Receive first indication information, which indicates the frequency domain resources of the second TDD carrier.

18. The method according to any one of claims 14 to 17, characterized in that, The method further includes: Receive second indication information, which indicates the time interval used to determine the second time unit.

19. The method according to claim 18, characterized in that, The time interval is located between the first time unit and the second time unit.

20. The method according to claim 18, characterized in that, The time interval is located between the third time unit and the second time unit, wherein the third time unit is used to receive control information.

21. The method according to claim 19, characterized in that, The unit of the time interval is consistent with that of the second time unit, and the method further includes: Determine the first corresponding time of the first time unit in the second carrier; The second time unit is determined based on the first corresponding time and the time interval.

22. The method according to claim 20, characterized in that, The unit of the time interval is consistent with that of the second time unit, and the method further includes: Determine the second corresponding time of the third time unit in the second carrier; The second time unit is determined based on the second corresponding time and the time interval.

23. The method according to claim 19, characterized in that, The unit of the time interval is the same as that of the first time unit, and the method further includes: By combining the time interval and the first time unit, the sixth time unit is determined; Determine the corresponding time of the sixth time unit in the second carrier, wherein the second time unit is the corresponding time of the sixth time unit in the second carrier.

24. The method according to claim 20, characterized in that, The unit of the time interval is consistent with that of the third time unit, and the method further includes: By combining the aforementioned time interval and the third time unit, the seventh time unit is determined; Determine the corresponding time of the seventh time unit in the second carrier, wherein the second time unit is the corresponding time of the seventh time unit in the second carrier.

25. The method according to any one of claims 14 to 18, characterized in that, The first indication information is carried on the first downlink control information (DCI) and / or the first radio resource control (RRC) configuration; the second indication information is carried on the second DCI and / or the second RRC configuration; the first DCI or the second DCI is used to schedule the first data transmission and the HARQ feedback.

26. The method according to claim 25, characterized in that, The first DCI or the second DCI is carried on any one of the first TDD carrier, the second carrier, and a third carrier different from the first TDD carrier or the second carrier.

27. The method according to any one of claims 14 to 26, characterized in that, The first time unit overlaps with the second time unit.

28. The method according to any one of claims 14 to 26, characterized in that, After receiving the first data transmission in the first time unit and on the first time division duplex (TDD) carrier, the method further includes: The second data transmission is received in the fourth time unit on the first TDD carrier, wherein the fourth time unit is adjacent to the first time unit; wherein the second data transmission is a retransmission of the same data block as the first data transmission.

29. The method according to any one of claims 14 to 26, characterized in that, After receiving the first data transmission in the first time unit and on the first time division duplex (TDD) carrier, the method further includes: In the fifth time unit, a third data transmission is received on the first TDD carrier, wherein the first data and the third data correspond to different transport blocks; In the second time unit and on the second carrier, HARQ feedback corresponding to the third data transmission is transmitted.

30. The method according to any one of claims 14 to 29, characterized in that, The first TDD carrier and the second carrier have one or more different sub-carrier spacings (SCS).

31. A communication device, characterized in that, Used to perform the method according to any one of claims 1 to 13 or any one of claims 14 to 30.

32. The communication device according to claim 31, characterized in that, include: The transmitting unit is configured to transmit the first data transmission in the first time unit and on the first time division duplex (TDD) carrier; The receiving unit is configured to receive, in the second time unit and on the second carrier, a hybrid automatic repeat request (HARQ) feedback corresponding to the first data transmission.

33. The communication device according to claim 31, characterized in that, include: A receiving unit is configured to receive a first data transmission in a first time unit and on a first time division duplex (TDD) carrier. The transmitting unit is configured to transmit a hybrid automatic repeat request (HARQ) feedback corresponding to the first data transmission in the second time unit and on the second carrier.

34. The communication device according to claim 31, characterized in that, include: One or more processors are configured to perform the processing steps according to any one of claims 1 to 13 or any one of claims 14 to 30; An interface circuit for performing a transmitting or receiving step according to any one of claims 1 to 13 or any one of claims 14 to 30.

35. The communication device according to claim 34, characterized in that, The interface circuit includes one or more transceivers.

36. An apparatus, characterized in that, include: One or more processors; A memory storing instructions that, when executed by the one or more processors, cause the apparatus to perform the method according to any one of claims 1 to 13 or 14 to 30.

37. A communication system, characterized in that, The communication system includes a first communication device for performing the method according to any one of claims 1 to 13 and a second communication device for performing the method according to any one of claims 14 to 30.

38. A computer-readable storage medium having instructions stored thereon, characterized in that, When executed by the device, the instructions cause the device to perform the method according to any one of claims 1 to 13 or any one of claims 14 to 30.

39. A computer program product storing instructions, characterized in that, When the instruction is executed, it causes the device to perform the method according to any one of claims 1 to 13 or any one of claims 14 to 30.

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