Communication method, apparatus, and medium

Abstract

Exemplary embodiments of the present disclosure relate to a method, an apparatus, and a computer storage medium for communication. A terminal device receives DCI for scheduling a plurality of PDSCHs on a plurality of cells from a network device, determines a reference cell for generating a HARQ-ACK codebook including a plurality of bit groups corresponding to the plurality of cells from the plurality of cells, and within a first bit group for a first cell among the plurality of cells, based on a reference bit position for a reference PDSCH on the reference cell within a reference bit group for the reference cell, determines a first bit position for a first PDSCH having the same TDRA row index as the reference PDSCH on the first cell, thereby generating the HARQ-ACK codebook, and transmits the HARQ-ACK codebook to the network device. For this reason, when MC-DCI is applied, the bit length in the HARQ-ACK codebook within a slot may be determined based on a reference cell. Therefore, the processing complexity for generating the HARQ-ACK codebook can be reduced.

Description

Technical Field

[0001] Exemplary embodiments of the present disclosure generally relate to the field of communication technologies, and more particularly, to methods, apparatuses, and computer-readable media for communication.

Background Art

[0002] To improve the reliability of transmission, the mechanism of hybrid automatic repeat request (HARQ) is widely used in communication systems. According to the HARQ mechanism, the receiver transmits HARQ feedback information indicating whether the data transmission from the transmitter has been successfully detected to the transmitter.

[0003] In Release 15, it is possible to schedule the physical downlink shared channel (PDSCH) on the serving cell using the downlink control information (DCI) on the physical downlink control channel (PDCCH). In Release 17, the DCI is enhanced to schedule multiple PDSCHs in different slots in the time domain on the serving cell. The HARQ codebook can be used for the HARQ feedback information of the PDSCH on the serving cell.

[0004] It has been proposed to further enhance the DCI to schedule multiple PDSCHs on multiple cells. However, it is necessary to discuss how to transmit the HARQ feedback information for the multiple PDSCHs on multiple cells.

Summary of the Invention

Problems to be Solved by the Invention

[0005] Generally, exemplary embodiments of the present disclosure provide a method, an apparatus, and a computer storage medium for communication.

Means for Solving the Problems

[0006] In a first aspect, a method of communication is provided. The method includes, at a terminal device, receiving, from a network device, downlink control information (DCI) for scheduling a plurality of physical downlink shared channels (PDSCHs) on a plurality of cells, where one or more of the plurality of PDSCHs are scheduled for a cell among the plurality of cells; determining, from the plurality of cells, a reference cell for generating a hybrid automatic repeat request (HARQ)-acknowledgement (ACK) codebook for the plurality of PDSCHs, the HARQ-ACK codebook including a plurality of bit groups corresponding to the plurality of cells; generating the HARQ-ACK codebook by determining a first bit position for a first PDSCH having the same time domain resource allocation (TDRA) row index as the reference PDSCH on the first cell, within a first bit group for the first cell among the plurality of cells, based on a reference bit position for the reference PDSCH on the reference cell within a reference bit group for the reference cell; and transmitting the HARQ-ACK codebook to the network device.

[0007] In a second aspect, a communication method is provided. The method includes, at a terminal device, receiving, from a network device, DCI that schedules a plurality of PDSCHs on a plurality of cells, wherein one or more of the plurality of PDSCHs are scheduled for a cell among the plurality of cells; determining a plurality of subsets of slot offset values, each slot offset value indicating a gap between a slot of one of the plurality of PDSCHs and a slot of a HARQ-ACK codebook; determining a plurality of merged TDRA tables based on the plurality of subsets; generating the HARQ-ACK codebook based on the plurality of subsets and the plurality of merged TDRA tables; and transmitting the HARQ-ACK codebook to the network device.

[0008] In a third aspect, a communication method is provided. The method includes, at a terminal device, receiving, from a network device, DCI that schedules a plurality of PDSCHs on a plurality of cells, wherein one or more of the plurality of PDSCHs are scheduled for a cell among the plurality of cells; determining a reference cell for generating a HARQ-ACK codebook for the plurality of PDSCHs from the plurality of cells; generating the HARQ-ACK codebook including bits in ascending order of the start time of PDSCH reception on the reference cell; and transmitting the HARQ-ACK codebook to the network device.

[0009] In a fourth aspect, a communication method is provided. The method includes, in a network device, transmitting, to a terminal device, DCI for scheduling a plurality of PDSCHs on a plurality of cells, where one or more of the plurality of PDSCHs are scheduled for a cell among the plurality of cells, and receiving, from the terminal device, a HARQ-ACK codebook for the plurality of PDSCHs, the HARQ-ACK codebook including a plurality of bit groups corresponding to the plurality of cells. A first bit position in a first bit group for a first PDSCH on a first cell among the plurality of cells is based on a reference bit position for a reference PDSCH on a reference cell in a reference bit group for the reference cell, and the first PDSCH and the reference PDSCH have the same time domain resource allocation (TDRA) row index.

[0010] In a fifth aspect, a communication method is provided. The method includes, in a network device, transmitting, to a terminal device, DCI for scheduling a plurality of PDSCHs on a plurality of cells, where one or more of the plurality of PDSCHs are scheduled for a cell among the plurality of cells, and receiving, from the terminal device, a HARQ-ACK codebook for the plurality of PDSCHs based on a plurality of subsets of slot offset values and a plurality of merged TDRA tables, where the plurality of merged TDRA tables are determined based on the plurality of subsets, and each slot offset value is used to indicate a gap between a slot of one of the plurality of PDSCHs and a slot of the HARQ-ACK codebook.

[0011] In a sixth aspect, a communication method is provided. The method includes, in a network device, transmitting, to a terminal device, DCI for scheduling a plurality of PDSCHs on a plurality of cells, wherein one or more of the plurality of PDSCHs are scheduled for a cell among the plurality of cells, and receiving, from the terminal device, a HARQ-ACK codebook for the plurality of PDSCHs, the HARQ-ACK codebook including bits in ascending order of the start time of PDSCH reception of a reference cell.

[0012] In a seventh aspect, a terminal device is provided. The terminal device includes a processor and a memory. The memory is coupled to the processor and stores instructions. When the instructions are executed by the processor, the terminal device is caused to execute the method described in the first aspect above.

[0013] In an eighth aspect, a network device is provided. The network device includes a processor and a memory. The memory is coupled to the processor and stores instructions. When the instructions are executed by the processor, the network device is caused to execute the method described in the second aspect above.

[0014] In a ninth aspect, a computer-readable medium storing instructions for causing at least one processor to execute the method described in the first aspect or the second aspect above when executed on the at least one processor is provided.

[0015] It should be understood that the summary part of the invention is not intended to identify important or essential features of the embodiments of the present disclosure, nor to limit the scope of the present disclosure. Other features of the present disclosure should be easily understood from the following description.

Brief Description of the Drawings

[0016] Some exemplary embodiments of the present disclosure will be described in more detail in the accompanying drawings, making the above and other objects, features, and advantages of the present disclosure more apparent.

[0017]

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[0033] In the figure, the same or similar reference numerals represent the same or similar elements.

Embodiments for Carrying Out the Invention

[0034] Here, the principles of the present disclosure will be described with reference to some exemplary embodiments. It should be understood that these embodiments are described for illustrative purposes only and are intended to assist those skilled in the art in understanding and implementing the present disclosure, and do not imply any limitation on the scope of the present disclosure. The embodiments described herein can be implemented in various ways different from the methods described below.

[0035] In the following description and claims, unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure pertains.

[0036] References to "one embodiment", "an embodiment", "exemplary embodiment", etc. in the present disclosure indicate that the described embodiment can include a particular feature, structure, or characteristic, but each embodiment does not necessarily include that particular feature, structure, or characteristic. Furthermore, such phrases do not necessarily refer to the same embodiment. Moreover, when describing a particular feature, structure, or characteristic in relation to an embodiment, it is considered within the knowledge of those skilled in the art that such feature, structure, or characteristic can affect other embodiments, whether explicitly described or not.

[0037] The terms "first", "second", etc. can be used in this specification to describe various elements, but it should be understood that these elements should not be limited by these terms. These terms are only used to distinguish one element from another. For example, without departing from the scope of the exemplary embodiments, the first element may be named the second element, and similarly, the second element may be named the first element. As used in this specification, the term "and / or" includes any and all combinations of one or more of the recited terms.

[0038] The terms used in this specification are used only for the purpose of describing a particular embodiment and are not intended to limit the exemplary embodiments. As used in this specification, the singular forms "a", "an", and "the" also include the plural forms unless explicitly stated otherwise in the context. When used in this specification, the terms "comprise", "comprising", "include", "including", "have", "having", "possess", "possessing", "be provided with", and / or "with" specify the presence of the recited features, elements, and / or components, etc., but do not preclude the presence or addition of one or more other features, elements, components, and / or combinations thereof.

[0039] In some instances, values, procedures, or devices are referred to as "best", "lowest", "highest", "minimum", "maximum", etc. Such descriptions are intended to indicate that a selection can be made from among a number of available functional alternatives, and it should be understood that such a selection need not be better, smaller, higher, or otherwise more preferred than other selections.

[0040] As used herein, the term "communication network" means a network that complies with any suitable communication standard, such as New Radio (NR), Long Term Evolution (LTE), LTE-Advanced (LTE-A), Wideband Code Division Multiple Access (WCDMA (registered trademark)), High-Speed Packet Access (HSPA), Narrow Band Internet of Things (NB-IoT), and the like. Further, the communication between the terminal device and the network device in the communication network may be realized according to any suitable generation of communication protocol, including but not limited to the first generation (1G), second generation (2G), 2.5G, 2.75G, third generation (3G), fourth generation (4G), 4.5G, fifth generation (5G), 5.5G, 5G-Advanced network or sixth generation (6G) communication protocol, and / or any other protocol currently known or to be developed in the future. Embodiments of the present disclosure are applicable to various communication systems. In view of the rapid development of communication, there will naturally be future types of communication technologies and systems in which the present disclosure can be implemented. This should not be regarded as limiting the scope of the present disclosure to only the aforementioned systems.

[0041] As used herein, the term "terminal device" refers to any device having a wireless or wired communication function. Examples of terminal devices include user equipment (UE), personal computers, desktops, mobile phones, cellular phones, smartphones, personal digital assistants (PDA), portable computers, tablets, wearable devices, Internet of Things (IoT) devices, Ultra-reliable and Low Latency Communications (URLLC) devices, Internet of Everything (IoE) devices, machine type communications (MTC) devices, vehicle-mounted devices for vehicle-to-everything (V2X) communication (where X means pedestrian, vehicle, or infrastructure / network), devices for Integrated Access and Backhaul (IAB), spacecraft or aircraft in non-terrestrial networks (NTN) including High Altitude Platforms (HAP) and satellites that include Unmanned Aircraft Systems (UAS), Extended Reality (XR) devices including different types of reality such as Augmented Reality (AR), Mixed Reality (MR), Virtual Reality (VR), unmanned aerial vehicles (UAV), which are generally known as drones and are aircraft that do not require a human pilot, devices on high speed trains (HST), imaging devices such as digital cameras, sensors, gaming devices, music storage / playback devices, or Internet devices that enable wireless / wired Internet access and browsing, etc., but are not limited thereto.The "terminal device" can further have a multicast / broadcast function and support public safety, mission-critical, V2X applications, transparent IPv4 / IPv6 multicast delivery, IPTV, smart TV, wireless services, wireless software delivery, group communication, and IoT applications. Also, one or more subscriber identity modules (SIMs), known as multi-SIM, may be incorporated. The term "terminal device" can be used interchangeably with UE, mobile station, subscriber equipment, mobile terminal, user terminal, or wireless device.

[0042] As used herein, the term "network device" means a device that can provide or host a cell or coverage with which a terminal device can communicate. Examples of network devices include, but are not limited to, satellites, unmanned aerial systems (UAS) platforms, Node B (NodeB or NB), evolved Node B (eNodeB or eNB), next-generation Node B (gNB), transmission reception point (TRP), remote radio unit (RRU), radio head (RH), remote radio head (RRH), IAB node, femto node, low-power nodes such as pico nodes, reconfigurable intelligent surface (RIS), etc.

[0043] In one embodiment, the terminal device may be connected to a first network device and a second network device. One of the first network device and the second network device may be used as a master node, and the other may be used as a secondary node. The first network device and the second network device may use different radio access technologies (RATs). In one embodiment, the first network device may be a first RAT device, and the second network device may be a second RAT device. In one embodiment, the first RAT device is an eNB, and the second RAT device is a gNB. Information regarding different RATs may be transmitted from at least one of the first network device and the second network device to the terminal device. In one embodiment, the first information may be transmitted from the first network device to the terminal device, and the second information may be transmitted from the second network device directly or via the first network device to the terminal device. In one embodiment, information regarding the settings of the terminal device set by the second network device may be transmitted from the second network device via the first network device. Information regarding the re - settings of the terminal device set by the second network device may be transmitted from the second network device directly or via the first network device to the terminal device.

[0044] The communication described in this specification may conform to any suitable standard, including but not limited to New Radio access (NR), Long Term Evolution (LTE), LTE-Evolution, LTE-Advanced (LTE-A), Wideband Code Division Multiple Access (WCDMA), Code Division Multiple Access (CDMA), cdma2000, and Global System for Mobile Communications (GSM) for mobile communication. Further, the communication may be performed according to any generation of communication protocol known currently or developed in the future. Examples of communication protocols include, but are not limited to, the first generation (1G), second generation (2G), 2.5G, 2.85G, third generation (3G), fourth generation (4G), 4.5G, fifth generation (5G), and sixth generation (6G) communication protocols. The technology described in this specification can be used in the above-mentioned wireless networks and wireless technologies, as well as other wireless networks and wireless technologies. Embodiments of the present disclosure may be performed according to any generation of communication protocol known currently or developed in the future. Examples of communication protocols include, but are not limited to, the first generation (1G), second generation (2G), 2.5G, 2.75G, third generation (3G), fourth generation (4G), 4.5G, fifth generation (5G) communication protocols, 5.5G, 5G-Advanced network, or sixth generation (6G) network.

[0045] The terminal device or network device may have the ability of artificial intelligence (AI) or machine learning. Generally, a trained model is included from a large number of data collected for a specific function and can be used to predict some information.

[0046] The terminal device or network device may operate, for example, in several frequency ranges such as FR1 (410 MHz to 7125 MHz), FR2 (24.25 GHz to 71 GHz), frequency bands greater than 100 GHz, and terahertz (THz). Furthermore, it can operate on licensed / unlicensed / shared spectrum. The terminal device may have two or more connections with the network device under a multi-radio dual connectivity (MR-DC) application scenario. The terminal device or network device can operate in full-duplex, flexible-duplex, cross-split duplex modes.

[0047] Embodiments of the present disclosure may be implemented in test equipment such as, for example, a signal generator, a signal analyzer, a spectrum analyzer, a network analyzer, a test terminal device, a test network device, or a channel emulator.

[0048] Embodiments of the present disclosure may be executed according to any generation of communication protocol known currently or developed in the future. Examples of communication protocols include, but are not limited to, the first generation (1G), the second generation (2G), 2.5G, 2.75G, the third generation (3G), the fourth generation (4G), 4.5G, the fifth generation (5G) communication protocol, 5.5G, 5G-Advanced network, or the sixth generation (6G) network.

[0049] As used herein, the term "circuit" may mean a hardware circuit and / or a combination of a hardware circuit and software. For example, a circuit may be a combination of analog and / or digital hardware circuits and software / firmware. As yet another example, a circuit may be any portion of a hardware processor with software that includes a digital signal processor, software, and one or more memories that cooperate to cause a device such as a terminal device or a network device to perform various functions. In yet another example, a circuit may be a hardware circuit and / or a processor such as a microprocessor or a portion thereof that requires software / firmware for operation, but the software may not be present if not required for operation. As used herein, the term "circuit" also includes the implementation of only a hardware circuit or one or more processors, or a portion of a hardware circuit or one or more processors and their (or their) accompanying software and / or firmware.

[0050] As used herein, the singular forms "a", "an", and "the" include the plural forms as well, unless the context clearly dictates otherwise. The terms "comprising" and variations thereof are to be understood as open-ended terms meaning "including, but not limited to". The term "based on" is to be understood as "based at least in part on". The terms "one embodiment" and "an embodiment" are to be understood as "at least one embodiment". The term "another embodiment" is to be understood as "at least one other embodiment". Terms such as "first", "second", etc. may refer to different or the same object. There may be other explicit and implicit definitions below.

[0051] In some examples, a value, procedure, or device is referred to as "best," "lowest," "highest," "minimum," "maximum," etc. Such descriptions are intended to indicate that a selection can be made from among a number of available functional alternatives, and it should be understood that such a selection need not be better, smaller, higher, or otherwise preferable to other selections.

[0052] In the context of the present disclosure, the terms "acknowledgment response," "positive acknowledgment," "ACK," "HARQ," "hybrid automatic repeat request acknowledgment response," "HARQ-ACK," "negative acknowledgment," "NACK," "NAK," "ACK / NACK," and "ACK / NAK" may be used interchangeably. In the context of the present disclosure, the terms "DCI," "DCI format carrying information," and "DCI format" may be used interchangeably.

[0053] As described above, in Release 18, in order to further improve scheduling efficiency, one DCI is permitted to schedule multiple PDSCHs on multiple cells, and in some scenarios, the multiple cells may be referred to as multiple component carriers (CCs). Fallback DCIs, such as DCI formats 0_0 and 1_0, are proposed not to support multi-cell scheduling, and DCI formats 0-X or 1-X are considered. In some examples, the DCI format 0-X / 1-X on the scheduling cell may be used to schedule multiple physical uplink shared channels (PUSCHs) or PDSCHs on multiple cells including the scheduling cell. In some examples, the DCI format 0-X / 1-X on the scheduling cell may be used to schedule multiple PUSCHs / PDSCHs on multiple cells excluding the scheduling cell.

[0054] In the present disclosure, the term "multi-carrier DCI (MC-DCI)" may refer to one DCI scheduling for a plurality of carriers, one DCI scheduling for a plurality of cells, etc. In the present disclosure, the term "slot" may refer to a dynamic scheduling unit. The slot used in this specification may refer to a normal slot including a predetermined number of symbols, or may refer to a sub-slot including fewer symbols than the predetermined number of symbols.

[0055] Embodiments of the present disclosure provide a communication solution. In this solution, the HARQ-ACK codebook for a plurality of PDSCHs on a plurality of cells scheduled by one DCI may be determined based on a reference cell. Therefore, MC-DCI can be supported and communication efficiency can be improved. Hereinafter, with reference to the accompanying drawings, the principle and embodiments of the present disclosure will be described in detail.

[0056] FIG. 1 shows an exemplary communication system 100 in which some embodiments of the present disclosure can be implemented. The communication system 100, which is part of a communication network, includes a network device 110 and a terminal device 120.

[0057] The network device 110 provides services to the terminal device 120, and the network device 110 and the terminal device 120 may communicate data and control information with each other. In some embodiments, the network device 110 and the terminal device 120 may communicate using a direct link / channel.

[0058] In system 100, the link from network device 110 to terminal device 120 is referred to as the downlink (DL), and the link from terminal device 120 to network device 110 is referred to as the uplink (UL). In the downlink, network device 110 is a transmitting (TX) device (or transmitter), and terminal device 120 is a receiving (RX) device (or receiver). In the uplink, terminal device 120 is a transmitting TX device (or transmitter), and network device 110 is an RX device (or receiver). It should be understood that network device 110 may provide one or more serving cells. In some embodiments, network device 110 can provide multiple cells.

[0059] Communication in communication system 100 may conform to any suitable standard, including but not limited to Long Term Evolution (LTE), LTE-Evolution, LTE-Advanced (LTE-A), Wideband Code Division Multiple Access (WCDMA), Code Division Multiple Access (CDMA), and Global System for Mobile Communications (GSM). Further, the communication may be performed according to any generation of communication protocol known currently or developed in the future. Examples of communication protocols include, but are not limited to, the first generation (1G), second generation (2G), 2.5G, 2.75G, third generation (3G), fourth generation (4G), 4.5G, fifth generation (5G), 5.5G, 5G-Advanced network, or sixth generation (6G) communication protocol.

[0060] It should be understood that the number of devices and their connection relationships and types as shown in FIG. 1 are used for illustrative purposes only and do not imply any limitation. Communication system 100 may include any suitable number of devices suitable for implementing the embodiments of the present disclosure.

[0061] In some embodiments, the network device 110 can provide a plurality of cells. In some embodiments, the DCI may be used to schedule the PDSCH. In some exemplary embodiments, the DCI may be used to schedule one or more PDSCHs on one serving cell. In some embodiments, the DCI may be used to schedule a plurality of PDSCHs on a plurality of cells, and at least one PDSCH is scheduled for any one of the plurality of cells.

[0062] In some embodiments, the HARQ-ACK codebook may be used for the scheduled PDSCH. In some examples, the HARQ-ACK may be transmitted via the PUCCH. In some embodiments, the type of the HARQ codebook may be set for the terminal device 120. For example, the type may be at least one of type 1 (e.g., static or semi-static), type 2 (e.g., dynamic), and type 3 (one-time feedback). Also, the type may be set via, for example, RRC, MAC CE, or DCI. In some embodiments, the DCI is received / detected in the PDCCH.

[0063] In some embodiments, when MC-DCI is configured, i.e., when one DCI scheduling is configured for multi-cells, all HARQ-ACK codebook types (i.e., type 1, type 2, and type 3) are applicable. The type 1 HARQ-ACK codebook may also be referred to as the type 1 codebook, and the number of bits therein may be regarded as a static codebook that is static regardless of the actual scheduling. One bit in the type 1 codebook corresponds to the ACK / NACK result of PDSCH reception. All possible PDSCH opportunities in the time domain on all configured cells have corresponding positions in the codebook. Since all possible positions are included in the codebook, i.e., the maximum possible length, the bit length of the type 1 codebook is static. When the PDSCH is not scheduled to be received, the feedback information may be set to "NACK".

[0064] To enable the feedback of PDSCH, the terminal device 120 may be configured with a time domain resource allocation (TDRA) table and a value (denoted as K1) indicating the slot gap between the PDSCH reception slot and the PUCCH HARQ-ACK transmission slot. For example, the TDRA table and K1 may be configured via RRC. In some examples, the TDRA table may also be referred to as TDRA configuration or simply TDRA for short. It should be understood that the configured TDRA and K1 are associated with a specific cell, e.g., a primary cell (PCell).

[0065] In some embodiments, the row index of the set TDRA table may be indicated to the terminal device 120 via DCI. Since it is not assumed that the PDSCH overlaps even partially in the time domain, it should be understood that there is a limit to the maximum number of possible TDRA indications, i.e., the maximum number of possible PDSCHs in a slot. In some examples, the possible allocations in a slot may depend on the set TDRA.

[0066] FIG. 2A shows an exemplary TDRA table 210 according to some exemplary embodiments of the present disclosure. The set TDRA 210 has four rows from row 0 to row 3. And it is determined that there are at most two possible allocations for slots where the PDSCHs cannot overlap with each other. For example, the DCI may indicate only one row, for example, any one of rows 0, 1, 2, and 3. For example, the DCI may indicate row 0 and row 3 simultaneously. For example, the DCI may indicate row 1 and row 2 simultaneously. For example, the DCI may indicate row 1 and row 3 simultaneously. In this case, based on the set TDRA 210 shown in FIG. 2A, the maximum number of possible PDSCHs in a slot is 2.

[0067] In some embodiments, the sequence of bits in the type 1 codebook is first arranged in all possible allocations in a slot, and then in all possible slot opportunities in ascending order based on the set K1 value. For example, assume that the terminal device 120 is set with a K1 set {3, 4, 6}. FIG. 2B shows an exemplary transmission occasion 220 for PDSCH and PUCCH according to some exemplary embodiments of the present disclosure. If the PUCCH HARQ-ACK transmission slot (i.e., the slot for HARQ-ACK transmission) is slot 8, it may be determined that PDSCH reception on slots 2, 4, and 5 is possible for scheduling.

[0068] It should be understood that as long as a TDRA table and a K1 set are set for a cell (e.g., a PCell), it is possible to determine the number of bits in the type 1 codebook. For example, according to FIGS. 2A to 2B, it is determined that the number of bits in the type 1 codebook is 6. The first 2 bits are used for K1 = 6, the middle 2 bits are used for K1 - 4, and the last 2 bits are used for K1 = 3.

[0069] When MC-DCI is set, one DCI may be used to set multiple PDSCHs on multiple cells. According to embodiments of the present disclosure, a solution for determining a HARQ-ACK codebook is provided. In this solution, the terminal device may determine a reference cell from multiple cells, and the number of bits in the HARQ-ACK codebook is determined based on the reference cell.

[0070] First, referring to FIG. 3, FIG. 3 is a signaling chart showing a communication process 300 according to some exemplary embodiments of the present disclosure. For the sake of explanation, the process 300 will be described with reference to FIG. 1. The process 300 may involve the terminal device 120 and the network device 110.

[0071] In some embodiments of the present disclosure, the terminal device 120 is set to have a TDRA table associated with each cell and a K1 set. The setting may be transmitted from the network device 110 to the terminal device 120 via RRC.

[0072] For example, there may be a first TDRA table and a first set of K1 associated with a first cell. For example, there may be a second TDRA table and a second set of K1 associated with a second cell. In some examples, the first set of K1 is associated with (or corresponds to) the first TDRA table, and the second set of K1 is associated with (or corresponds to) the second TDRA table. It should be understood that the first set of K1 includes at least one K1 value, and the second set of K1 also includes at least one K1 value. It should be understood that the first set of K1 and the second set of K1 may be set independently, the first value in the first set of K1 may be equal to the second value in the second set of K1, or may not be equal, and the present disclosure does not limit this aspect.

[0073] The network device 110 transmits (310) the DCI 312 to the terminal device 120, and the DCI 312 schedules a plurality of PDSCHs on a plurality of cells. It should be understood that one or more PDSCHs may be scheduled for one of the plurality of cells. As an exemplary and non-limiting embodiment, the plurality of PDSCHs includes PDSCH 1 on cell 1, and PDSCHs 2 and 3 on cell 2. In some embodiments, the DCI 312 may indicate at least one row index.

[0074] On the other side of the communication, the terminal device 120 receives (314) the DCI 312. In some embodiments, the terminal device 120 may blindly detect the PDCCH from the network device 110 and receive the DCI 312. The terminal device 120 determines (320) a reference cell from the plurality of cells. The reference cell may be used to generate a HARQ-ACK codebook for a plurality of PDSCHs scheduled by the DCI 312.

[0075] In some exemplary embodiments, the reference cell may be indicated or set by the network device 110. For example, among the plurality of cells, the first scheduled cell or the last scheduled cell may be indicated as the reference cell. In some exemplary embodiments, the terminal device 120 may determine the number of bits required for each cell of the plurality of cells, and the number of required bits indicates the maximum number of possible PDSCHs within a slot for the cell. Thus, for the plurality of cells, a plurality of required bit numbers may be determined respectively. The number of bits required for a cell within a slot may be determined based on a type 1 codebook generation procedure, which is not repeated redundantly herein in the present disclosure.

[0076] For a specific cell within a plurality of cells, its associated TDRA table may be used to determine the number of bits required for the specific cell. Assuming that the cell has an associated TDRA table shown in FIG. 2A, since PDSCH is not even allowed to partially overlap in the time domain, the number of bits required for the cell is determined to be 2.

[0077] Specifically, the row with the minimum number of last symbols (which may be referred to as the bit-0-row) is determined. For example, it is row 1 as shown in FIG. 2A, and the last symbol in row 1 is symbol 3. Further, one or more rows that overlap with the bit-0-row may be determined. For example, row 0 overlaps with row 1. Therefore, the bit-0-row and the one or more rows that overlap with the bit-0-row all correspond to bit 0. Additionally, among the remaining rows (e.g., row 2 and row 3), the row with the minimum number of last symbols (which may be referred to as the bit-1-row) is determined. For example, it is row 2 as shown in FIG. 2A, and the last symbol in row 2 is symbol 10. Further, one or more of the remaining rows that overlap with the bit-1-row may be determined. For example, row 3 overlaps with row 2. Therefore, the bit-1-row and the one or more rows that overlap with the bit-1-row all correspond to bit 1. Further, if there are several other rows, more bits may be determined, and it should be understood that the present disclosure does not limit this aspect.

[0078] In some exemplary embodiments, the terminal device 120 may determine the minimum number among the plurality of required bit numbers, and the cell having the minimum number may be determined as the reference cell. In some examples, there may be two or more cells each having the minimum number. In this case, among the two or more cells, the cell having the lowest or highest index may be determined as the reference cell.

[0079] As a specific example, assume that the plurality of cells include cell 1, cell 2, and cell 3. If the required bit numbers for cells 1, 2, and 3 are 2, 3, and 3 respectively, cell 1 may be determined as the reference cell. If the required bit numbers for cells 1, 2, and 3 are 2, 2, and 3 respectively, and the index of cell 1 is smaller than the index of cell 2, cell 1 (or cell 2) may be determined as the reference cell.

[0080] The terminal device 120 generates (330) a HARQ-ACK codebook for the plurality of PDSCHs on the plurality of cells. In some embodiments, the HARQ-ACK codebook includes a plurality of bit groups corresponding to the plurality of cells, and each bit group has the same number of bits equal to the number of bits required for the reference cell as described above. As a specific example, if the number of bits required for the reference cell is 2 and there are 3 cells scheduled by DCI 312, the generated HARQ-ACK codebook may include 6 bits. In some embodiments, the HARQ-ACK codebook generated by the terminal device 120 is a type 1 codebook.

[0081] In some embodiments, the bits in the HARQ-ACK codebook may be associated with the row index of the TDRA table. The HARQ-ACK codebook may include a plurality of bit groups corresponding to the plurality of cells. Assume that the plurality of bit groups include a first bit group corresponding to a first cell and a reference bit group corresponding to the reference cell. In some embodiments, the first bit in the first bit group corresponds to a first PDSCH having a first row index, the reference bit in the reference bit group corresponds to a reference PDSCH having a reference row index, and the first row index is equal to the reference row index. In some embodiments, the position of the first bit in the first bit group is the same as the position of the reference bit in the reference bit group.

[0082] The terminal device 120 may determine a first bit position for a first PDSCH on the first cell based on a reference bit position for a reference PDSCH on the reference cell, where the first bit position is the position of a first bit within a first bit group for the first cell, the reference bit position is the position of a reference bit within a reference bit group, the first PDSCH corresponds to a first row index within a first TDRA associated with the first cell, the reference PDSCH corresponds to a reference row index within a reference TDRA associated with the reference cell, and it should be understood that the first row index is the same as the reference row index.

[0083] In other words, after removing the row index of the TDRA of the first cell based on the TDD-UL-DL setting where the allocated PDSCH overlaps with the UL symbol, the position of the first row index of the allocated PDSCH on the first cell is the same as the position of the same first index of the allocated PDSCH on the reference cell.

[0084] The terminal device 120 transmits (340) the HARQ-ACK codebook 342 to the network device 110. In some embodiments, the terminal device 120 may determine a slot for the PUCCH based on the DCI 312, and the terminal device 120 may transmit the HARQ-ACK codebook 342 within the slot for the PUCCH. On the other side of the communication, the network device 110 receives (344) the HARQ-ACK codebook.

[0085] For better understanding, refer to FIGS. 4A to 4B which show exemplary scenarios in which some embodiments of the present disclosure can be implemented. As shown in FIG. 4A, there is a first TDRA table 410 associated with a first cell and a second TDRA table 420 associated with a second cell. The terminal device 120 may determine that the number of required bits for the first cell is 2 based on the first TDRA table 410, and the terminal device 120 may also determine that the number of required bits for the second cell is 3 based on the second TDRA table 420. Since 2 < 3, the terminal device 120 may determine that the first cell is the reference cell.

[0086] As shown in FIG. 4B, the association between the bits and the row indexes may be determined based on the association for the reference cell, i.e., the first cell. Specifically, as shown in FIG. 4B, for both the first cell and the second cell, bit 0 is associated with rows 0 / 0' and 1 / 1', and bit 1 is associated with rows 2 / 2' and 3 / 3'. Therefore, when MC-DCI is applied, the bit length in the type 1 HARQ-ACK codebook within the slot may be determined based on the reference cell. Thus, the processing complexity for generating the type 1 HARQ-ACK codebook can be reduced. Alternatively, in some other exemplary embodiments, an exhaustive search method may be used by the terminal device 120 to find the maximum number of sets of row indexes based on the plurality of TDRA tables associated with the plurality of cells.

[0087] In some embodiments, within the remaining TDRA on all cells, after removing the row index of the TDRA on a specific cell based on the UL symbol setting of the specific cell, the terminal device 120 can find the maximum number of sets of row indexes where the corresponding PDSCH does not overlap in the time domain in any cell. In some examples, if two or more sets are found, the terminal device 120 may select one of these sets, for example, the set with the minimum / maximum total index. It should be understood that the exhaustion method in the present disclosure may be any feasible method, and the present disclosure does not limit this aspect. In some embodiments, a graph having nodes and edges is considered.

[0088] Refer to FIGS. 5A - 5B, which show exemplary scenarios in which some embodiments of the present disclosure can be implemented. FIG. 5A shows an exemplary TDRA table 510 associated with two cells respectively. In some examples, each row index in the TDRA table 510 may be considered as a node in the graph. If the PDSCH of one row index and the PDSCH of another row index overlap in the time domain in any cell, an edge is added between the node representing the row index and the node representing the other row index. FIG. 5B shows an exemplary graph 520 having nodes and edges related to the TDRA table 510 of FIG. 5A. In FIG. 5B, the dashed line may indicate the overlap of the PDSCH based on rows 0 - 3 of FIG. 5A, and the solid line may indicate the overlap of the PDSCH based on rows 0 - 3 of FIG. 5B.

[0089] In some embodiments, the terminal device 120 can find (or determine) the maximum number of nodes in a subset that have no edges between any of the nodes in the subset. The subset may be referred to as an independent set, and in some cases, this problem may be considered as the well-known "clique problem", which is an NP-hard problem. Therefore, according to the exhaustive method, it is possible to determine the optimal bit length in the HARQ-ACK codebook of type 1 within the slot, so that the best performance can be maintained.

[0090] Further, refer to FIG. 6, which is a signaling chart showing the communication process 600 according to some exemplary embodiments of the present disclosure. For the sake of explanation only, the process 600 will be described with reference to FIG. 1. The terminal device 120 and the network device 110 may be involved in the process 300.

[0091] In some embodiments of the present disclosure, a TDRA table associated with each cell and a K1 set are set in the terminal device 120. This setting may be transmitted from the network device 110 to the terminal device 120 via RRC.

[0092] For example, there may be a first TDRA table and a first K1 set associated with the first cell. For example, there may be a second TDRA table and a second K1 set associated with the second cell. In some examples, the first K1 set is associated with (or corresponds to) the first TDRA table, and the second K1 set is associated with (or corresponds to) the second TDRA table. The first cell and the second cell may be the same cell. In this case, it should be understood that for the first cell, both the first TDRA (and / or the corresponding first K1 set) and the second TDRA (and / or the corresponding second K1 set) are set.

[0093] It should be understood that the first set of K1 includes at least one K1 value, and the second set of K1 also includes at least one K1 value. The first set of K1 and the second set of K1 may be set independently, and the first value in the first set of K1 may be equal to or not equal to the second value in the second set of K1. It should be understood that the present disclosure does not limit this aspect.

[0094] The network device 110 transmits DCI 612 to the terminal device 120 (610), and DCI 612 schedules a plurality of PDSCHs on a plurality of cells. It should be understood that one or more PDSCHs may be scheduled for one of the plurality of cells. As an illustrative and non-limiting embodiment, the plurality of PDSCHs includes PDSCH 1 on cell 1, and PDSCHs 2 and 3 on cell 2. In some embodiments, DCI 612 may indicate at least one row index.

[0095] On the other side of the communication, the terminal device 120 receives DCI 612 (614). In some embodiments, the terminal device 120 may blindly detect the PDCCH from the network device 110 and receive DCI 612. The terminal device 120 determines a plurality of subsets of slot offset values, which may be referred to as a plurality of K1 subsets (620). In some embodiments, each K1 subset may include one or more K1 values, and the K1 value may indicate a slot gap between the slot of the PDSCH and the slot of the HARQ-ACK codebook. The terminal device 120 determines a plurality of merged TDRA tables based on the plurality of subsets of slot offset values (i.e., the plurality of K1 subsets) (630).

[0096] In some exemplary embodiments, the plurality of K1 subsets may be set by the network device 110. In some examples, the network device 110 may send a setting indicating the plurality of K1 subsets to the terminal device 120. In this case, the terminal device 120 may determine the plurality of K1 subsets based on the setting. In some embodiments, when the first K1 subset contains only one value and the one value belongs only to the first K1 set associated with the first TDRA table, the terminal device 120 may determine that the merged TDRA table corresponding to the first K1 subset is the first TDRA table.

[0097] In some embodiments, when the second K1 subset contains one (or more) values and the one value belongs to both the second K1 set and the third K1 set, the terminal device 120 may determine that the merged TDRA table corresponding to the second K1 subset is generated by merging the second TDRA table associated with the second K1 set and the third TDRA table associated with the third K1 set.

[0098] In some embodiments, when the third K1 subset contains two (or more) values, one value belongs to the fourth K1 set, and another value belongs to the fifth K1 set, the terminal device 120 may determine that the merged TDRA table corresponding to the third K1 subset is generated by merging the fourth TDRA table associated with the fourth K1 set and the fifth TDRA table associated with the fifth K1 set.

[0099] The terminal device 120 generates a HARQ-ACK codebook (640) based on a plurality of merged TDRA tables and a plurality of subsets of slot offset values (i.e., a plurality of K1 subsets). In some exemplary embodiments, for slots corresponding to K1 values within a K1 subset, the terminal device 120 may determine a HARQ-ACK sub-codebook based on the merged TDRA table corresponding to the K1 subset. Further, the HARQ-ACK codebook can be generated based on all HARQ-ACK sub-codebooks associated with all slots within all K1 subsets.

[0100] The terminal device 120 transmits the HARQ-ACK codebook 652 to the network device 110 (650). In some embodiments, the terminal device 120 may determine a slot for PUCCH based on DCI 612, and the terminal device 120 may transmit the HARQ-ACK codebook 652 within the slot for PUCCH. On the other side of the communication, the network device 110 receives the HARQ-ACK codebook 652 (654).

[0101] For better understanding, refer to FIGS. 7A to 7D showing exemplary scenarios in which some embodiments of the present disclosure can be implemented. Assume that a first TDRA table and a first K1 set are set, and a second TDRA table and a second K1 set are also set. For example, the first TDRA table is shown in FIG. 7A and the second TDRA table is shown in FIG. 7B. Assume that the first K1 set includes K1 values 3, 4, and 6 represented as {3, 4, 6}, and the second K1 set includes K1 values 2 and 4 represented as {2, 4}.

[0102] In some examples, two K1 subsets are configured. The first K1 subset includes K1 values 3 and 6 represented as {3, 6}, and the second K1 subset includes K1 values 2 and 4 represented as {2, 4}. Since both K1 values 3 and 6 are in the first K1 set and neither is in the second K1 set, the first merged TDRA table associated with the first K1 subset is the same as the first TDRA table shown in FIG. 7A. Since both K1 values 2 and 4 are in the second K1 set and K1 value 4 is also in the first K1 set, the second merged TDRA table associated with the second K1 subset is generated by merging the first TDRA table and the second TDRA table. For example, the second merged TDRA table is shown in FIG. 7C. Based on the merged TDRA table, it is determined that the maximum possible length is 3, for example, rows 1, 3, and 2' shown in FIG. 7C.

[0103] When the PUCCH HARQ-ACK transmission slot (i.e., the slot for HARQ-ACK transmission) is slot 8, as shown in FIG. 7D, it may be determined that PDSCH reception on slots 2, 4, 5, and 6 is possible for scheduling based on all K1 values. For example, the bits of the HARQ-ACK sub-codebook in slot 2 and the bits of the HARQ-ACK sub-codebook in slot 5 are determined based on the first merged TDRA table, and the bits of the HARQ-ACK sub-codebook in slot 4 and the bits of the HARQ-ACK sub-codebook in slot 6 are determined based on the second merged TDRA table.

[0104] It is determined that the maximum possible length of the first merged table as shown in FIG. 7A is 2, and the maximum possible length of the second merged table as shown in FIG. 7C is 3. Therefore, the terminal device 120 may determine that the HARQ-ACK codebook includes 13 bits consisting of 2 bits for slot 2, 3 bits + 3 bits for slot 4, 2 bits for slot 5, and 3 bits for slot 6.

[0105] In some other exemplary embodiments, it has been proposed that DCI format 1-0 (or 1-1, 1-2) may not support MC-DCI, and DCI format 1-X may support MC-DCI. For ease of explanation, in the following embodiments, DCI format 1-0 and DCI format 1-X are considered. In some exemplary embodiments, for a specific cell, the TDRA table and / or K1 set configured for DCI format 1-X may be different from those configured for DCI 1-0.

[0106] Considering a specific cell among a plurality of cells, for example, the first cell, the TDRA table and / or K1 set may be configured for DCI 1-X, and another TDRA table and / or K1 set may be configured for DCI 1-0. In some exemplary embodiments, the TDRA table and / or K1 set may be configured for DCI 1-X for the first cell, but either the TDRA table or the K1 set may be configured for DCI 1-0. In this case, the TDRA table and / or K1 set configured for DCI 1-0 for the first cell may be determined based on the TDRA table and / or K1 set configured for DCI 1-X for the first cell.

[0107] In some cases, if the first cell is configured with a TDRA table and / or K1 set for DCI format 1-X (MC-DCI), but not with a TDRA table or K1 set for DCI format 1-0, the TDRA table configured for DCI format 1-X may be used as the TDRA table for DCI format 1-0.

[0108] In some examples, there is an indicated offset value of a slot gap between a slot of a PDSCH (e.g., the last scheduled PDSCH) and a slot of a PUCCH, and for example, the indicated offset value may be represented as K1. In some examples, the indicated offset value may be associated with a cell (e.g., the same as or different from the first cell, e.g., referred to as a primary cell) based on a subcarrier spacing (SCS) unit of a scheduled PDSCH of the cell. For example, there is an indicated offset value of a slot gap between a slot of a PDSCH on a cell and a slot of a PDCCH (DCI) that schedules the PDSCH, and for example, the indicated offset value may be represented as K0. When the SCS of the primary cell is different from that of the first cell, K0 for the first cell is aligned with the SCS of the primary cell. Further, the K1 value within the set of K1 for the first cell may be determined as the indicated offset value (K1) plus a delta slot value, where the delta slot value is determined based on the difference between the number of slots of the PDSCH for the primary cell (K0 for the primary cell) and the number of slots of the PDSCH for the first cell (K0 for the first cell). Thus, it is possible to determine the set of K1 for DCI 1-0 for the first cell. Thus, it is possible to determine K1 for DCI 1-X for the first cell for a type 1 codebook.

[0109] In some embodiments, three K1 subsets may be set for the particular cell (e.g., the first cell). For example, K1 subset 1 is associated with the TDRA table for DCI 1-X, K1 subset 2 is associated with the TDRA table for DCI 1-0, and K1 subset 3 is associated with the merged TDRA table for DCI 1-X and DCI 1-0, and the merged TDRA table may be a combined TDRA table formed by merging the TDRA table for DCI 1-X and the TDRA table for DCI 1-0. Therefore, it is possible to generate three HARQ-ACK sub-codebooks. For example, sub-codebook 1 is generated based on K1 subset 1 and the TDRA table for DCI 1-X, sub-codebook 2 is generated based on K1 subset 2 and the TDRA table for DCI 1-0, and sub-codebook 3 is generated based on K1 subset 3 and the combined TDRA table. Since it is possible to generate three HARQ-ACK sub-codebooks for each cell among the plurality of cells according to a similar procedure, it is possible to generate a HARQ-ACK codebook for the plurality of cells.

[0110] Further, refer to FIG. 8 which is a signaling chart showing a communication process 800 according to some exemplary embodiments of the present disclosure. For the sake of explanation only, the process 800 will be described with reference to FIG. 1. The terminal device 120 and the network device 110 may be involved in the process 800. The network device 110 transmits DCI 812 to the terminal device 120 (810), and DCI 812 schedules a plurality of PDSCHs on a plurality of cells. It should be understood that one or more PDSCHs may be scheduled for one of the plurality of cells. As an exemplary but non-limiting embodiment, the plurality of PDSCHs includes PDSCH 1 on cell 1, and PDSCHs 2 and 3 on cell 2. In some embodiments, DCI 812 may indicate a downlink assignment index (DAI) value.

[0111] On the other side of the communication, the terminal device 120 receives the DCI 812 (814). In some embodiments, the terminal device 120 may blindly detect the PDCCH from the network device 110 and receive the DCI 812. The terminal device 120 determines a reference cell from the plurality of cells (820). The reference cell may be used to generate a HARQ-ACK codebook for a plurality of PDSCHs scheduled by the DCI 812.

[0112] In some exemplary embodiments, the reference cell may be indicated or set by the network device 110. For example, among the plurality of cells, the first scheduled cell or the last scheduled cell may be indicated as the reference cell. In some exemplary embodiments, the reference cell may be the cell with the lowest index among the plurality of cells. In some exemplary embodiments, the reference cell may be the cell with the highest index among the plurality of cells. In some exemplary embodiments, the reference cell may be the cell having the last slot of the plurality of scheduled PDSCHs. In some embodiments, the HARQ-ACK codebook described in process 800 may be a type 2 HARQ-ACK codebook, or simply a type 2 codebook.

[0113] The terminal device 120 generates a HARQ-ACK codebook for the plurality of PDSCHs on the plurality of cells (830). In some embodiments, the HARQ-ACK codebook includes a plurality of bits in ascending order of the start time of PDSCH reception on the reference cell. In some embodiments, the type 2 HARQ-ACK codebook is generated based on the DAI value indicated by the DCI 812.

[0114] In some exemplary embodiments, the type 2 HARQ-ACK codebook includes a plurality of bits, and the order of these bits is as follows: (1) First, when one DCI schedules a plurality of PDSCHs on a plurality of cells, or when two or more DCIs (and thus one PDSCH) are scheduled from the same PDCCH monitoring occasion, in ascending order of the start time of PDSCH reception on the reference cell for the same {serving cell, PDCCH monitoring occasion} pair; (2) Second, in ascending order of the serving cell index; (3) Third, in ascending order of the PDCCH monitoring occasion index m, where 0 ≤ m < M and M represents the total number of PDCCH monitoring occasions.

[0115] It should be understood that different PDSCHs on the same cell may have different start times, and different PDSCHs on different cells may also have the same start time. According to the present disclosure, the reference cell is considered to have a unique start time so that the order of the bits can be determined. The DCI does not have to schedule the actual PDSCH reception on the reference cell. In other words, the reference cell used to determine the start time is not scheduled. In this case, the virtual PDSCH allocation can be determined, for example, based on the indicated row index of the TDRA table associated with the reference cell.

[0116] The terminal device 120 transmits (840) the HARQ-ACK codebook 842 to the network device 110. Accordingly, the network device 110 receives (844) the HARQ-ACK codebook 842. Therefore, since the reference cell has a unique start time, the type 2 HARQ-ACK codebook may be generated in a deterministic order.

[0117] According to the embodiments described with reference to FIGS. 3 to 8, since the terminal device can generate a HARQ-ACK codebook for a plurality of PDSCHs on a plurality of cells, it can support MC-DCI and improve communication efficiency.

[0118] FIG. 9 is a flowchart of an exemplary method 900 implemented in a terminal device according to some embodiments of the present disclosure. For the sake of explanation, method 900 will be described with reference to FIG. 1 from the perspective of terminal device 120.

[0119] In block 910, the terminal device 120 receives from the network device 110 DCI for scheduling a plurality of PDSCHs on a plurality of cells, and one or more PDSCHs are scheduled for a cell among the plurality of cells. In block 920, the terminal device 120 determines, from the plurality of cells, a reference cell for generating a HARQ-ACK codebook for the plurality of PDSCHs, and the HARQ-ACK codebook includes a plurality of bit groups corresponding to the plurality of cells. In block 930, the terminal device 120 generates the HARQ-ACK codebook by determining, within a first bit group for a first cell among the plurality of cells, a first bit position for a first PDSCH having the same TDRA row index as the reference PDSCH on the reference cell based on a reference bit position on the reference cell within a reference bit group for the reference cell. In block 940, the terminal device 120 transmits the HARQ-ACK codebook to the network device 110.

[0120] In some exemplary embodiments, the first bit position is the same as the reference bit position. In some exemplary embodiments, each of the plurality of bit groups includes the same number of bits determined based on a TDRA table for the reference cell.

[0121] In some exemplary embodiments, the reference cell among the plurality of cells is a cell having a minimum required number of bits for a corresponding bit group, the lowest index among cells having the same minimum required number of bits for a corresponding bit group, the highest index among cells having the same minimum required number of bits for a corresponding bit group, or any combination thereof.

[0122] In some exemplary embodiments, each of the plurality of bit groups includes the same number of bits equal to the minimum required number of bits.

[0123] FIG. 10 is a flowchart of an exemplary method 1000 implemented in a terminal device according to some embodiments of the present disclosure. For the sake of explanation, method 1000 will be described with reference to FIG. 1 from the perspective of the terminal device 120.

[0124] In block 1010, the terminal device 120 receives, from the network device 110, DCI for scheduling a plurality of PDSCHs on a plurality of cells, and one or more PDSCHs are scheduled for a cell among the plurality of cells. In block 1020, the terminal device 120 determines a plurality of subsets of slot offset values, where each slot offset value indicates a gap between a slot of one of the plurality of PDSCHs and a slot of the HARQ-ACK codebook. In block 1030, the terminal device 120 determines a plurality of merged TDRA tables based on the plurality of subsets. In block 1040, the terminal device 120 generates the HARQ-ACK codebook based on the plurality of subsets and the plurality of merged TDRA tables. In block 1050, the terminal device 120 transmits the HARQ-ACK codebook to the network device 110.

[0125] In some exemplary embodiments, when the terminal device 120 determines that a first subset of the plurality of subsets includes a plurality of values, a first set of values corresponding to a first TDRA table includes one of the plurality of values, and a second set of values corresponding to a second TDRA table includes another one of the plurality of values, the terminal device 120 generates a merged TDRA table among the plurality of merged TDRA tables by merging the first TDRA table and the second TDRA table.

[0126] In some exemplary embodiments, when the terminal device 120 determines that a second subset of the plurality of subsets contains one value, and both a first set of values corresponding to a first TDRA table and a second set of values corresponding to a second TDRA table contain the value, the terminal device 120 generates a merged TDRA table among the plurality of merged TDRA tables by merging the first TDRA table and the second TDRA table.

[0127] In some exemplary embodiments, the terminal device 120 obtains the slot offset value indicated by the DCI, determines a plurality of slot offset values corresponding to the plurality of cells based on the slot offset value indicated by the DCI, and generates a plurality of subsets each containing one of the plurality of slot offset values.

[0128] FIG. 11 is a flowchart of an exemplary method 1100 implemented in a terminal device according to some embodiments of the present disclosure. For the sake of explanation, method 1100 will be described with reference to FIG. 1 from the perspective of the terminal device 120.

[0129] In block 1110, the terminal device 120 receives from the network device 110 a DCI that schedules a plurality of PDSCHs on a plurality of cells, and one or more PDSCHs are scheduled for a cell among the plurality of cells. In block 1120, the terminal device 120 determines, from the plurality of cells, a reference cell for generating a HARQ-ACK codebook for the plurality of PDSCHs. In block 1130, the terminal device 120 generates a HARQ-ACK codebook including bits in ascending order of the start time of PDSCH reception on the reference cell. In block 1140, the terminal device 120 transmits the HARQ-ACK codebook to the network device 110.

[0130] In some exemplary embodiments, the reference cell among the plurality of cells is a cell having the last slot of the scheduled PDSCH, the lowest index, the highest index, or any combination thereof.

[0131] FIG. 12 is a flowchart of an exemplary method 1200 implemented in a network device according to some embodiments of the present disclosure. For the sake of explanation, method 1300 will be described with reference to FIG. 1 from the perspective of network device 110.

[0132] In block 1210, network device 110 transmits DCI that schedules a plurality of PDSCHs on a plurality of cells to terminal device 120, and one or more of the plurality of PDSCHs are scheduled for a cell among the plurality of cells. In block 1220, network device 110 receives a HARQ-ACK codebook for the plurality of PDSCHs from terminal device 120, the HARQ-ACK codebook includes a plurality of bit groups corresponding to the plurality of cells, and a first bit position in a first bit group for a first PDSCH on a first cell among the plurality of cells is based on a reference bit position for a reference PDSCH on a reference cell in a reference bit group for the reference cell, and the first PDSCH and the reference PDSCH have the same TDRA row index.

[0133] In some exemplary embodiments, the first bit position is the same as the reference bit position. In some exemplary embodiments, each of the plurality of bit groups includes the same number of bits determined based on the TDRA table of the reference cell.

[0134] In some exemplary embodiments, the reference cell among the plurality of cells is a cell having the minimum required number of bits for a corresponding bit group, the lowest index among cells having the same minimum required number of bits for the corresponding bit group, or the highest index among cells having the same minimum required number of bits for the corresponding bit group, or any combination thereof.

[0135] In some exemplary embodiments, each of the plurality of bit groups includes the same number of bits equal to the minimum required number of bits.

[0136] FIG. 13 is a flowchart of an exemplary method 1300 implemented in a network device according to some embodiments of the present disclosure. For the sake of explanation, method 1300 will be described with reference to FIG. 1 from the perspective of network device 110.

[0137] In block 1310, network device 110 transmits DCI for scheduling a plurality of PDSCHs on a plurality of cells to terminal device 120, and one or more of the plurality of PDSCHs are scheduled for a cell among the plurality of cells. In block 1320, network device 110 receives a HARQ-ACK codebook for the plurality of PDSCHs from terminal device 120 based on a plurality of subsets of slot offset values and a plurality of merged TDRA tables, the plurality of merged TDRA tables being determined based on the plurality of subsets, and each slot offset value being used to indicate a gap between a slot of one of the plurality of PDSCHs and a slot of the HARQ-ACK codebook.

[0138] FIG. 14 is a flowchart of an exemplary method 1400 implemented in a network device according to some embodiments of the present disclosure. For the sake of explanation, method 1400 will be described with reference to FIG. 1 from the perspective of network device 110.

[0139] In block 1410, the network device 110 transmits DCI for scheduling a plurality of PDSCHs on a plurality of cells to the terminal device 120, and one or more of the plurality of PDSCHs are scheduled for a cell among the plurality of cells. In block 1420, the network device 110 receives, from the terminal device 120, a HARQ-ACK codebook for the plurality of PDSCHs, the HARQ-ACK codebook including bits in ascending order of the start time of PDSCH reception of a reference cell.

[0140] In some exemplary embodiments, the reference cell among the plurality of cells is a cell having the last slot, the lowest index, the highest index, or any combination thereof of the scheduled PDSCH.

[0141] Details of some embodiments according to the present disclosure have been described with reference to FIGS. 1 to 14. Next, exemplary realizations of the terminal device and the network device will be described below.

[0142] In some exemplary embodiments, the terminal device includes a circuit, and the circuit receives DCI for scheduling a plurality of PDSCHs on a plurality of cells from a network device, one or more of the PDSCHs are scheduled for a cell among the plurality of cells, determines a reference cell for generating a HARQ-ACK codebook for the plurality of PDSCHs from the plurality of cells, the HARQ-ACK codebook including a plurality of bit groups corresponding to the plurality of cells, and determines a first bit position for a first PDSCH having the same TDRA row index as the reference PDSCH on the reference cell within a first bit group for a first cell among the plurality of cells based on a reference bit position for the reference PDSCH on the reference cell within a reference bit group for the reference cell, thereby generating the HARQ-ACK codebook, and is set to transmit the HARQ-ACK codebook to the network device 110.

[0143] In some exemplary embodiments, the first bit position is the same as the reference bit position. In some exemplary embodiments, each of the plurality of bit groups includes the same number of bits determined based on a TDRA table for the reference cell.

[0144] In some exemplary embodiments, the reference cell among the plurality of cells is a cell having at least one of a minimum number of bits for a corresponding bit group, the lowest index among cells having the same minimum number of bits for the corresponding bit group, or the highest index among cells having the same minimum number of bits for the corresponding bit group.

[0145] In some exemplary embodiments, each of the plurality of bit groups includes the same number of bits equal to the minimum number of bits.

[0146] In some exemplary embodiments, the terminal device includes a circuit that receives, from the network device, DCI for scheduling a plurality of PDSCHs on a plurality of cells, one or more PDSCHs are scheduled for cells among the plurality of cells, determines a plurality of subsets of slot offset values, each slot offset value indicating a gap between a slot of one of the plurality of PDSCHs and a slot of a HARQ-ACK codebook, determines a plurality of merged TDRA tables based on the plurality of subsets, generates the HARQ-ACK codebook based on the plurality of subsets and the plurality of merged TDRA tables, and is configured to transmit the HARQ-ACK codebook to the network device.

[0147] In some exemplary embodiments, the terminal device comprises a circuit, and the circuit is configured to generate a merged TDRA table among the plurality of merged TDRA tables by merging the first TDRA table and the second TDRA table when it is determined that a first subset of the plurality of subsets includes a plurality of slot offset values, a first set of slot offset values corresponding to the first TDRA table includes one of the plurality of values, and a second set of slot offset values corresponding to the second TDRA table includes another one of the plurality of slot offset values.

[0148] In some exemplary embodiments, the terminal device comprises a circuit, and the circuit is configured to generate a merged TDRA table among the plurality of merged TDRA tables by merging the first TDRA table and the second TDRA table when it is determined that a second subset of the plurality of subsets includes one slot offset value and both a first set of slot offset values corresponding to the first TDRA table and a second set of slot offset values corresponding to the second TDRA table include the slot offset value.

[0149] In some exemplary embodiments, the terminal device comprises a circuit, and the circuit is configured to obtain the slot offset value indicated by the DCI, determine a plurality of slot offset values corresponding to the plurality of cells based on the slot offset value indicated by the DCI, and generate the plurality of subsets each including one of the plurality of slot offset values.

[0150] In some exemplary embodiments, the terminal device comprises a circuit, the circuit receives from the network device a DCI that schedules a plurality of PDSCHs on a plurality of cells, one or more PDSCHs are scheduled for a cell among the plurality of cells, determines from the plurality of cells a reference cell for generating a HARQ-ACK codebook for the plurality of PDSCHs, generates the HARQ-ACK codebook including bits in ascending order of the start time of PDSCH reception on the reference cell, and is configured to transmit the HARQ-ACK codebook to the network device.

[0151] In some exemplary embodiments, the reference cell among the plurality of cells is a cell having at least one of the last slot, the lowest index, or the highest index of the scheduled PDSCH.

[0152] In some exemplary embodiments, the network device comprises a circuit, the circuit transmits to the terminal device a DCI that schedules a plurality of PDSCHs on a plurality of cells, one or more of the plurality of PDSCHs are scheduled for a cell among the plurality of cells, is configured to receive from the terminal device a HARQ-ACK codebook for the plurality of PDSCHs, the HARQ-ACK codebook including a plurality of bit groups corresponding to the plurality of cells, and a first bit position in a first bit group for a first PDSCH on a first cell among the plurality of cells is based on a reference bit position for a reference PDSCH on a reference cell in a reference bit group for the reference cell, and the first PDSCH and the reference PDSCH have the same TDRA row index.

[0153] In some exemplary embodiments, the first bit position is the same as the reference bit position. In some exemplary embodiments, each of the plurality of bit groups includes the same number of bits determined based on the TDRA table of the reference cell.

[0154] In some exemplary embodiments, the reference cell among the plurality of cells is a cell having at least one of the minimum number of bits for a corresponding bit group, the lowest index among the cells having the same minimum number of bits for the corresponding bit group, or the highest index among the cells having the same minimum number of bits for the corresponding bit group.

[0155] In some exemplary embodiments, each of the plurality of bit groups includes the same number of bits equal to the minimum number of bits.

[0156] In some exemplary embodiments, a network device includes a circuit, the circuit is configured to transmit DCI for scheduling a plurality of PDSCHs on a plurality of cells to a terminal device, one or more of the plurality of PDSCHs are scheduled for a cell among the plurality of cells, and the circuit is configured to receive, from the terminal device, a HARQ-ACK codebook for the plurality of PDSCHs based on a plurality of subsets of slot offset values and a plurality of merged TDRA tables, the plurality of merged TDRA tables are determined based on the plurality of subsets, and each slot offset value is used to indicate a gap between a slot of one of the plurality of PDSCHs and a slot of the HARQ-ACK codebook.

[0157] In some exemplary embodiments, a network device includes a circuit, the circuit is configured to transmit DCI for scheduling a plurality of PDSCHs on a plurality of cells to a terminal device, one or more of the plurality of PDSCHs are scheduled for a cell among the plurality of cells, and the circuit is configured to receive, from the terminal device, the HARQ-ACK codebook for the plurality of PDSCHs, the HARQ-ACK codebook including bits in ascending order of the PDSCH reception start time of the reference cell.

[0158] In some exemplary embodiments, the reference cell among the plurality of cells is a cell having at least one of the last slot of the scheduled PDSCH, the lowest index, or the highest index.

[0159] FIG. 15 is a schematic block diagram of an apparatus 1500 suitable for implementing embodiments of the present disclosure. The apparatus 1500 can be considered as another exemplary embodiment of the terminal device 120 and / or the network device 110 as shown in FIG. 1. Therefore, the apparatus 1500 may be implemented in the terminal device 120 or the network device 110, or as at least a part thereof.

[0160] As shown, the apparatus 1500 includes a processor 1510, a memory 1520 coupled to the processor 1510, a suitable transmitter (TX) and receiver (RX) 1540 coupled to the processor 1510, and a communication interface coupled to the TX / RX 1540. The memory 1510 stores at least a part of the program 1530. The TX / RX 1540 is used for bidirectional communication. The TX / RX 1540 has at least one antenna for facilitating communication, although the access nodes mentioned in the present disclosure may actually have a plurality of antennas. The communication interface may represent any interface required for communication with other network elements, such as an X2 interface for bidirectional communication between eNBs, an S1 interface for communication between a mobility management entity (MME) / serving gateway (S-GW) and an eNB, a Un interface for communication between an eNB and a relay node (RN), or a Uu interface for communication between an eNB and a terminal device.

[0161] As described herein with reference to FIGS. 3-14, program 1530 is assumed to include program instructions that, when executed by an associated processor 1510, enable device 1500 to operate in accordance with embodiments of the present disclosure. Embodiments herein may be implemented by computer software executable by processor 1510 of device 1500, or by hardware, or by a combination of software and hardware. Processor 1510 may be configured to implement various embodiments of the present disclosure. Further, the combination of processor 1510 and memory 1520 may form processing means 1550 suitable for implementing various embodiments of the present disclosure.

[0162] Memory 1520 may be of any type suitable for a local technology network and may be implemented using any suitable data storage technology, by way of non-limiting example, a non-transitory computer-readable storage medium, a semiconductor-based memory device, a magnetic memory device and system, an optical memory device and system, a fixed memory and a removable memory, etc. Although only one memory 1520 is shown within device 1500, there may be several physically different memory modules within device 1500. Processor 1510 may be of any type suitable for a local technology network and may include, by way of non-limiting example, one or more of a general-purpose computer, a dedicated computer, a microprocessor, a digital signal processor (DSP), and a processor based on a multi-core processor architecture. Device 1500 may have an application-specific integrated circuit chip that is temporally dependent on a clock that synchronizes a plurality of processors, e.g., a main processor.

[0163] In short, embodiments of the present disclosure are capable of providing the following solutions.

[0164] The present disclosure provides a communication method. The method includes, at a terminal device, receiving downlink control information (DCI) from a network device for scheduling a plurality of physical downlink shared channels (PDSCHs) on a plurality of cells, where one or more of the plurality of PDSCHs are scheduled for a cell among the plurality of cells; determining, from the plurality of cells, a reference cell for generating a hybrid automatic repeat request (HARQ)-acknowledgement (ACK) codebook for the plurality of PDSCHs, the HARQ-ACK codebook including a plurality of bit groups corresponding to the plurality of cells; generating the HARQ-ACK codebook by determining, within a first bit group for a first cell among the plurality of cells, a first bit position for a first PDSCH having the same time domain resource allocation (TDRA) occasion index as the reference PDSCH on the reference cell based on a reference bit position within a reference bit group for the reference cell on the reference cell; and transmitting the HARQ-ACK codebook to the network device.

[0165] In one embodiment, in the above method, the first bit position is the same as the reference bit position.

[0166] In one embodiment, in the above method, each of the plurality of bit groups includes the same number of bits determined based on a TDRA table for the reference cell.

[0167] In one embodiment, in the above method, the reference cell among the plurality of cells is a cell having at least one of the minimum number of bits for the corresponding bit group, the lowest index among the cells having the same minimum number of bits for the corresponding bit group, or the highest index among the cells having the same minimum number of bits for the corresponding bit group.

[0168] In one embodiment, in the above method, each of the plurality of bit groups includes the same number of bits equal to the minimum number of bits.

[0169] The present disclosure provides a method of communication. The method includes, at a terminal device, receiving, from a network device, downlink control information (DCI) for scheduling a plurality of physical downlink shared channels (PDSCHs) on a plurality of cells, where one or more of the plurality of PDSCHs are scheduled for a cell among the plurality of cells; determining a plurality of subsets of slot offset values indicating a gap between a slot of one of the plurality of PDSCHs and a slot of a hybrid automatic repeat request (HARQ)-acknowledgement (ACK) codebook; determining a plurality of merged time domain resource allocation (TDRA) tables based on the plurality of subsets; generating the HARQ-ACK codebook based on the plurality of subsets and the plurality of merged TDRA tables; and transmitting the HARQ-ACK codebook to the network device.

[0170] In one embodiment, in the above method, determining the plurality of merged TDRA tables includes determining that a first subset of the plurality of subsets includes a plurality of slot offset values, and determining that a first set of slot offset values corresponding to a first TDRA table includes one of the plurality of slot offset values and a second set of slot offset values corresponding to a second TDRA table includes another one of the plurality of slot offset values, and generating a merged TDRA table among the plurality of merged TDRA tables by merging the first TDRA table and the second TDRA table according to the determination.

[0171] In one embodiment, in the above method, determining the plurality of merged TDRA tables includes determining that a second subset of the plurality of subsets includes one slot offset value, and determining that both a first set of slot offset values corresponding to a first TDRA table and a second set of slot offset values corresponding to a second TDRA table include the slot offset value, and generating a merged TDRA table among the plurality of merged TDRA tables by merging the first TDRA table and the second TDRA table according to the determination.

[0172] In one embodiment, in the above method, determining the plurality of subsets includes obtaining the slot offset value indicated by the DCI, determining a plurality of slot offset values corresponding to the plurality of cells based on the slot offset value indicated by the DCI, and generating the plurality of subsets each including one of the plurality of slot offset values.

[0173] The present disclosure provides a communication method, the method comprising: at a terminal device, receiving downlink control information (DCI) for scheduling a plurality of physical downlink shared channels (PDSCHs) on a plurality of cells from a network device, wherein one or more of the plurality of PDSCHs are scheduled for a cell among the plurality of cells; determining, from the plurality of cells, a reference cell for generating a hybrid automatic repeat request (HARQ)-acknowledgement (ACK) codebook for the plurality of PDSCHs; generating the HARQ-ACK codebook including bits in ascending order of the start time of PDSCH reception on the reference cell; and transmitting the HARQ-ACK codebook to the network device.

[0174] In one embodiment, in the above method, the reference cell among the plurality of cells is a cell having at least one of the last slot, the lowest index, or the highest index of the scheduled PDSCH.

[0175] The present disclosure provides a communication method, which includes, in a network device, transmitting downlink control information (DCI) for scheduling a plurality of physical downlink shared channels (PDSCHs) on a plurality of cells to a terminal device, where one or more of the plurality of PDSCHs are scheduled for a cell among the plurality of cells, and receiving, from the terminal device, a hybrid automatic repeat request (HARQ)-acknowledgement (ACK) codebook for the plurality of PDSCHs, the HARQ-ACK codebook including a plurality of bit groups corresponding to the plurality of cells. A first bit position in a first bit group for a first PDSCH on a first cell among the plurality of cells is based on a reference bit position for a reference PDSCH on a reference cell in a reference bit group for the reference cell, and the first PDSCH and the reference PDSCH have the same time domain resource allocation (TDRA) row index.

[0176] In one embodiment, in the above method, the first bit position is the same as the reference bit position.

[0177] In one embodiment, in the above method, each of the plurality of bit groups includes the same number of bits determined based on a TDRA table of the reference cell.

[0178] In one embodiment, in the above method, the reference cell among the plurality of cells is a cell having at least one of a minimum number of bits for a corresponding bit group, the lowest index among cells having the same minimum number of bits for the corresponding bit group, or the highest index among cells having the same minimum number of bits for the corresponding bit group.

[0179] In one embodiment, in the above method, each of the plurality of bit groups includes the same number of bits equal to the minimum number of bits.

[0180] The present disclosure provides a method of communication, the method comprising, in a network device, transmitting downlink control information (DCI) for scheduling a plurality of physical downlink shared channels (PDSCHs) on a plurality of cells to a terminal device, wherein one or more of the plurality of PDSCHs are scheduled for a cell among the plurality of cells, and receiving, from the terminal device, a hybrid automatic repeat request (HARQ)-acknowledgement (ACK) codebook for the plurality of PDSCHs based on a plurality of subsets of slot offset values and a plurality of merged time domain resource allocation (TDRA) tables, wherein the plurality of merged TDRA tables are determined based on the plurality of subsets, and each slot offset value is used to indicate a gap between a slot of one of the plurality of PDSCHs and a slot of the HARQ-ACK codebook.

[0181] The present disclosure provides a communication method, the method comprising: in a network device, transmitting downlink control information (DCI) for scheduling a plurality of physical downlink shared channels (PDSCHs) on a plurality of cells to a terminal device, wherein one or more of the plurality of PDSCHs are scheduled for a cell among the plurality of cells; and receiving, from the terminal device, a hybrid automatic repeat request (HARQ)-ACK (acknowledgement) codebook for the plurality of PDSCHs, the HARQ-ACK codebook including bits in ascending order of the start time of PDSCH reception of a reference cell.

[0182] In one embodiment, in the above method, the reference cell among the plurality of cells is a cell having at least one of the last slot, the lowest index, or the highest index of the scheduled PDSCH.

[0183] The present disclosure provides a terminal device comprising a processor and a memory storing computer program code, the memory and the computer program code being configured, together with the processor, to cause the terminal device to execute the above method implemented in the terminal device.

[0184] The present disclosure provides a network device comprising a processor and a memory storing computer program code, the memory and the computer program code being configured, together with the processor, to cause the network device to execute the above method implemented in the network device.

[0185] The present disclosure discloses a computer-readable medium that stores instructions which, when executed by a processor of a device, cause the device to execute the above-described method implemented in a terminal device or a network device.

[0186] Overall, various embodiments of the present disclosure may be implemented in hardware or dedicated circuitry, software, logic, or any combination thereof. Some aspects may be implemented in hardware, and other aspects may be implemented in firmware or software executable by a controller, a microprocessor, or other computing device. Although various aspects of the embodiments of the present disclosure are illustrated and described using block diagrams, flowcharts, or other pictorial representations, it should be understood that the blocks, devices, systems, techniques, or methods described herein may be implemented, by way of non-limiting example, in hardware, software, firmware, dedicated circuitry or logic, general-purpose hardware or controllers or other computing devices, or any combination thereof.

[0187] The present disclosure also provides at least one computer program product tangibly stored on a non-transitory computer-readable storage medium. The computer program product includes computer-executable instructions, such as instructions included in program modules, that are executed within a device on a target physical processor or a virtual processor to perform the processes or methods described above with reference to FIGS. 6-20. Generally, program modules include routines, programs, libraries, objects, classes, components, data structures, etc. that perform particular tasks or implement particular abstract data types. In various embodiments, the functions of the program modules may be combined or divided among the program modules as needed. The machine-executable instructions of the program modules may be executed within a local or distributed device. In a distributed device, the program modules may be located in both local and remote storage media.

[0188] The program code for executing the method of the present disclosure may be described in any combination of one or more programming languages. These program codes are provided to a processor or a controller of a general-purpose computer, a dedicated computer, or other programmable data processing devices, and when executed by the processor or the controller, the program codes implement the functions / operations specified in the flowchart and / or block diagram. The program code may be executed entirely on the machine, partially on the machine, as an independent software package, partially on the machine and partially on a remote machine, or entirely on a remote machine or server.

[0189] The above program code may be implemented on a machine-readable medium, and the machine-readable medium may be any tangible medium that can be used by or associated with an instruction execution system, apparatus, or device and that can contain or store a program for these. The machine-readable medium may be a machine-readable signal medium or a machine-readable storage medium. The machine-readable medium may include, but is not limited to, an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any suitable combination of the foregoing media. More specific examples of the machine-readable storage medium may include an electrical connection having one or more wires, a portable computer disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber, a portable compact disc read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the foregoing.

[0190] Although the operations have been described in a particular order, it should be understood that in order to obtain the desired results, these operations need not be performed in the particular order shown or in a sequential order, nor is it required that all of the operations described be performed. In some cases, multitasking and parallel processing may be advantageous. Similarly, although some specific implementation details are included in the above discussion, these should not be construed as limitations on the scope of the present disclosure, but rather as descriptions of features that may be specific to particular embodiments. Some of the features described in the context of individual embodiments may be combined and implemented in a single embodiment. Conversely, the various features described in the context of a single embodiment may be implemented separately in multiple embodiments or in any suitable sub-combination.

[0191] Although the present disclosure has been described in language specific to structural features and / or methodological acts, it should be understood that the present disclosure as defined in the appended claims is not necessarily limited to the specific features or acts described above. Rather, the specific features and acts described above are disclosed as exemplary forms of implementing the claims.

Claims

1. A method of communication, comprising: at a terminal device, receiving downlink control information (DCI) for scheduling a plurality of physical downlink shared channels (PDSCHs) on a plurality of cells from a network device, wherein one or more of the plurality of PDSCHs are scheduled for a cell among the plurality of cells; determining, from the plurality of cells, a reference cell for generating a hybrid automatic repeat request (HARQ)-acknowledgment (ACK) codebook for the plurality of PDSCHs, the HARQ-ACK codebook including a plurality of bit groups corresponding to the plurality of cells; generating the HARQ-ACK codebook by determining a first bit position for a first PDSCH having a time domain resource allocation (TDRA) row index identical to that of the reference PDSCH on the reference cell in a first bit group for a first cell among the plurality of cells, based on a reference bit position of the reference PDSCH on the reference cell in a reference bit group for the reference cell; transmitting the HARQ-ACK codebook to the network device. A method comprising the above steps.

2. The method according to claim 1, wherein the first bit position is the same as the reference bit position. The method according to claim 1.

3. The method according to claim 1, wherein each of the plurality of bit groups includes the same number of bits determined based on a TDRA table for the reference cell. The method according to claim 1.

4. The reference cell among the plurality of cells is a cell having at least one of: a minimum number of bits for a corresponding bit group; the lowest index among cells having the same minimum number of bits for a corresponding bit group; or the highest index among cells having the same minimum number of bits for a corresponding bit group. The method according to claim 1. The method according to claim 1.

5. The method according to claim 4, wherein each of the plurality of bit groups includes the same number of bits equal to the minimum number of bits. The method according to claim 4.

6. A method of communication, comprising: at a terminal device, receiving downlink control information (DCI) for scheduling a plurality of physical downlink shared channels (PDSCHs) on a plurality of cells from a network device, wherein one or more of the plurality of PDSCHs are scheduled for a cell among the plurality of cells; determining a plurality of subsets of slot offset values, each slot offset value indicating a gap between a slot of one of the plurality of PDSCHs and a slot of a hybrid automatic repeat request (HARQ)-acknowledgment (ACK) codebook; determining a plurality of merged time domain resource allocation (TDRA) tables based on the plurality of subsets; generating the HARQ-ACK codebook based on the plurality of subsets and the plurality of merged TDRA tables; transmitting the HARQ-ACK codebook to the network device. A method as described above.

7. The determining of the plurality of merged TDRA tables comprises: determining that a first subset of the plurality of subsets includes a plurality of slot offset values; merging a first TDRA table and a second TDRA table according to a determination that a first set of slot offset values corresponding to the first TDRA table includes one of the plurality of slot offset values and a second set of slot offset values corresponding to the second TDRA table includes another one of the plurality of slot offset values, thereby generating a merged TDRA table among the plurality of merged TDRA tables; The method according to claim 6, comprising the above.

8. The determining of the plurality of merged TDRA tables comprises: determining that a second subset of the plurality of subsets includes one slot offset value; Generating a merged TDRA table among the plurality of merged TDRA tables by merging the first TDRA table and the second TDRA table according to the determination that both the first set of slot offset values corresponding to the first TDRA table and the second set of slot offset values corresponding to the second TDRA table include the slot offset value; The method according to claim 6, comprising: **Claim 9** A communication method, comprising: In a terminal device, receiving downlink control information (DCI) for scheduling a plurality of physical downlink shared channels (PDSCHs) on a plurality of cells from a network device, wherein one or more of the plurality of PDSCHs are scheduled for a cell among the plurality of cells; Determining a reference cell for generating a hybrid automatic repeat request (HARQ) acknowledgment (ACK) codebook for the plurality of PDSCHs from the plurality of cells; Generating the HARQ-ACK codebook including bits in ascending order of the start time of PDSCH reception on the reference cell; Transmitting the HARQ-ACK codebook to the network device; The method comprising: **Claim 10** The reference cell among the plurality of cells is a cell having at least one of the last slot of the scheduled PDSCH, the lowest index, or the highest index. The method according to claim 9. **Claim 11** A communication method, comprising: In a network device, transmitting downlink control information (DCI) for scheduling a plurality of physical downlink shared channels (PDSCHs) on a plurality of cells to a terminal device, wherein one or more of the plurality of PDSCHs are scheduled for a cell among the plurality of cells; Receiving, from the terminal device, a hybrid automatic repeat request (HARQ) - acknowledgement (ACK) codebook for the plurality of physical downlink shared channels (PDSCHs), the HARQ-ACK codebook including a plurality of bit groups corresponding to the plurality of cells, wherein a first bit position within a first bit group for a first PDSCH on a first cell among the plurality of cells is based on a reference bit position for a reference PDSCH on a reference cell within a reference bit group for the reference cell, and the first PDSCH and the reference PDSCH have the same time domain resource allocation (TDRA) row index Method. **Claim 12** The first bit position is the same as the reference bit position The method according to claim 11. **Claim 13** Each of the plurality of bit groups includes the same number of bits determined based on a TDRA table of the reference cell The method according to claim 11. **Claim 14** The reference cell among the plurality of cells is The minimum number of bits for the corresponding bit group, The lowest index among cells having the same minimum number of bits for the corresponding bit group, or The highest index among cells having the same minimum number of bits for the corresponding bit group, And is a cell having at least one of them The method according to claim 11. **Claim 15** A communication method, comprising In a network device, transmitting, to a terminal device, downlink control information (DCI) for scheduling a plurality of physical downlink shared channels (PDSCHs) on a plurality of cells, wherein one or more of the plurality of PDSCHs are scheduled for a cell among the plurality of cells Receiving, from the terminal device, a hybrid automatic repeat request (HARQ)-acknowledgment (ACK) codebook for the plurality of physical downlink shared channels (PDSCHs) based on a plurality of subsets of slot offset values and a plurality of merged time domain resource allocation (TDRA) tables, wherein the plurality of merged TDRA tables are determined based on the plurality of subsets, and each slot offset value is used to indicate a gap between a slot of one of the plurality of PDSCHs and a slot of the HARQ-ACK codebook Method. **Claim 16** A method of communication, comprising: In a network device, transmitting downlink control information (DCI) for scheduling a plurality of physical downlink shared channels (PDSCHs) on a plurality of cells to a terminal device, wherein one or more of the plurality of PDSCHs are scheduled for a cell among the plurality of cells Receiving, from the terminal device, a hybrid automatic repeat request (HARQ)-acknowledgment (ACK) codebook for the plurality of PDSCHs, the HARQ-ACK codebook including bits in ascending order of the reception start time of the PDSCH of a reference cell The method as described above. **Claim 17** The reference cell among the plurality of cells is A cell having at least one of the last slot of the scheduled PDSCH, The lowest index, or The highest index The method according to claim 16. **Claim 18** A terminal device comprising a processor and a memory storing computer program code, The memory and the computer program code are configured to cause the terminal device to execute the method according to any one of claims 1 to 10 in conjunction with the processor Terminal device. **Claim 19** A network device comprising a processor and a memory storing computer program code, wherein the memory and the computer program code are configured, with the processor, to cause the network device to execute the method according to any one of claims 11 to 17 network device. **Claim 20** A computer-readable medium storing instructions which, when executed by a processor of a device, cause the device to execute the method according to any one of claims 1 to 17 computer-readable medium.

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