Method and apparatus for determining Type-1 HARQ-ACK codebook

Abstract

[0003] Embodiments of the present disclosure relate to methods and apparatus for determining a type-1 (semi-static) Hybrid Automatic Repeat Request-Acknowledgement (HARQ-ACK) codebook. According to some embodiments of the present disclosure, a UE may receive a first downlink control information (DCI) format that schedules a first set of physical downlink shared channels (PDSCHs) on a first set of cells of the UE, generate a HARQ-ACK codebook comprising HARQ-ACK feedback associated with candidate PDSCH reception opportunities on the first set of cells and HARQ-ACK feedback for the first set of PDSCHs, and transmit the HARQ-ACK codebook.

Description

[Technical Field]

[0001] FIELD Embodiments of the present disclosure relate generally to wireless communication technologies, and more particularly to determining a type-1 (semi-static) Hybrid Automatic Repeat Request-Acknowledgement (HARQ-ACK) codebook. [Background technology]

[0002] Wireless communications are widely deployed to provide various telecommunication services such as telephony, video, data, messaging, broadcasting, and so on. Wireless communication systems may utilize multiple access technologies capable of supporting communication with multiple users by sharing available system resources (e.g., time, frequency, and power). Examples of wireless communication systems may include fourth-generation (4G) systems, such as long-term evolution (LTE) systems, LTE-advanced (LTE-A) systems, or LTE-A Pro systems, and fifth-generation (5G) systems, sometimes referred to as new radio (NR) systems.

[0003] In a wireless communication system, a user equipment (UE) may monitor a physical downlink control channel (PDCCH) in one or more search spaces. The PDCCH may carry downlink control information (DCI), which may schedule an uplink channel, such as a physical uplink shared channel (PUSCH), or a downlink channel, such as a physical downlink shared channel (PDSCH). If the DCI schedules a PDSCH, the UE may transmit HARQ-ACK feedback (e.g., HARQ-ACK information bits) for the PDSCH over the PUSCH or physical uplink control channel (PUCCH). For example, the PUCCH may carry a HARQ-ACK codebook including HARQ-ACK information bits for the PDSCH. Summary of the Invention [Problem to be solved by the invention]

[0004] It is necessary to address the determination of HARQ-ACK codebooks in wireless communication systems. [Means for solving the problem]

[0005] Some embodiments of the present disclosure provide a user equipment (UE). The UE may include a transceiver and a processor coupled to the transceiver. The processor may be configured to receive a first downlink control information (DCI) format that schedules a first set of physical downlink shared channels (PDSCHs) on a first set of cells of the UE, generate a hybrid automatic repeat request-acknowledgement (HARQ-ACK) codebook comprising HARQ-ACK feedback associated with candidate PDSCH reception opportunities on the first set of cells and the HARQ-ACK feedback for the first set of PDSCHs, and transmit the HARQ-ACK codebook.

[0006] In some embodiments of the present disclosure, generating the HARQ-ACK codebook may include generating HARQ-ACK information bits for each cell of the first set of cells and concatenating the generated HARQ-ACK information bits for each cell of the first set of cells in order of associated serving cell index.

[0007] In some embodiments of the present disclosure, generating a HARQ-ACK information bit for each cell of the first set of cells may include generating a HARQ-ACK information bit for a candidate PDSCH reception opportunity of the corresponding cell, and generating a HARQ-ACK information bit for a first PDSCH of the first set of PDSCHs that is received on the corresponding cell and is located outside the candidate PDSCH reception opportunity of the corresponding cell.

[0008] In some embodiments of the present disclosure, the HARQ-ACK information bits for the PDSCH reception opportunity candidates of the corresponding cell and the HARQ-ACK information bits for the first PDSCH are ordered according to the PDSCH reception opportunity on the corresponding cell.

[0009] In some embodiments of the present disclosure, generating a HARQ-ACK information bit for each cell of the first set of cells may include generating a HARQ-ACK information bit for a candidate PDSCH reception opportunity of the corresponding cell and generating a HARQ-ACK information bit for a first PDSCH that may potentially be scheduled on the corresponding cell by the first DCI format.

[0010] In some embodiments of the present disclosure, the HARQ-ACK information bits for the first PDSCH are placed after or before the HARQ-ACK information bits for the PDSCH reception opportunity candidates of the corresponding cell. In some embodiments of the present disclosure, the HARQ-ACK information bits for the PDSCH reception opportunity candidates of the corresponding cell are ordered according to the PDSCH reception opportunities on the corresponding cell.

[0011] In some embodiments of the present disclosure, if the first PDSCH is actually scheduled on the corresponding cell by the first DCI format, the HARQ-ACK information bit for the first PDSCH is ACK or Negative ACK (NACK) according to the decoding result of the first PDSCH. In some embodiments of the present disclosure, if the first PDSCH is not scheduled on the corresponding cell by the first DCI format, the HARQ-ACK information bit for the first PDSCH is NACK.

[0012] In some embodiments of the present disclosure, the HARQ-ACK codebook may include a first portion and a second portion, and generating the HARQ-ACK codebook may include generating the first portion including HARQ-ACK information bits for candidate PDSCH reception opportunities for each cell of the first set of cells, and generating the second portion including HARQ-ACK information bits for all cells that may potentially be scheduled by the first DCI format with one PDSCH on each cell.

[0013] In some embodiments of the present disclosure, if a cell that may potentially be scheduled by the first DCI format is not included in the first set of cells, the HARQ-ACK information bit in the second part for the cell is a negative ACK (NACK). In some embodiments of the present disclosure, the HARQ-ACK information bit in the second part for a cell in the first set of cells that are scheduled by the first DCI format is an ACK or a NACK.

[0014] In some embodiments of the present disclosure, if a second PDSCH in the first set of PDSCHs is scheduled on a cell in the first set of cells and is included in the candidate PDSCH reception opportunities for that cell, the HARQ-ACK information bit for the second PDSCH in the first portion for that cell is an ACK or a negative ACK (NACK), or is a NACK, depending on the decoding result of the second PDSCH.

[0015] In some embodiments of the present disclosure, the HARQ-ACK codebook may include a first portion and a second portion, and generating the HARQ-ACK codebook may include generating a first portion including HARQ-ACK information bits for a candidate PDSCH reception opportunity for each cell of the first set of cells, and generating a second portion including HARQ-ACK information bits for one or more PDSCHs of the first set of PDSCHs that are received on one or more cells of the first set of cells and that are located outside the candidate PDSCH reception opportunity for the one or more cells of the first set of cells.

[0016] In some embodiments of the present disclosure, the HARQ-ACK information bits in the first portion for the PDSCH reception opportunity candidate for each cell in the first set of cells are ordered according to the associated PDSCH reception opportunity candidate, and in some embodiments of the present disclosure, the HARQ-ACK information bits in the second portion are ordered according to the associated cell index.

[0017] In some embodiments of the present disclosure, the HARQ-ACK information bits in the second portion are ordered first according to the associated PDSCH start timing and then according to the associated cell index.

[0018] In some embodiments of the present disclosure, generating the HARQ-ACK codebook may include: for each cell of the first set of cells, generating a first portion including HARQ-ACK information bits for candidate PDSCH reception opportunities of the corresponding cell; if a first PDSCH of the first set of PDSCHs is received on the corresponding cell and is outside the candidate PDSCH reception opportunities of the corresponding cell, generating a second portion including HARQ-ACK information bits for the first PDSCH; and concatenating the first portion and the second portion to generate HARQ-ACK feedback for the corresponding cell.

[0019] In some embodiments of the present disclosure, the HARQ-ACK information bits for each cell of the first set of cells are ordered according to the associated serving cell index.

[0020] In some embodiments of the present disclosure, the processor is further configured to receive a second DCI format that schedules a second set of PDSCHs on a second set of cells of the UE, wherein the HARQ-ACK feedback for the second set of PDSCHs is to be multiplexed in a HARQ-ACK codebook.

[0021] In some embodiments of the present disclosure, each of the first and second sets of cells is a subset of a respective set of cells configured for multi-cell scheduling or is a subset of the same set of cells configured for multi-cell scheduling.

[0022] In some embodiments of the present disclosure, generating a HARQ-ACK codebook may include generating HARQ-ACK feedback for each cell of the first and second sets of cells, which may include generating HARQ-ACK information bits for candidate PDSCH reception opportunities of a corresponding cell in the first and second sets of cells, and generating HARQ-ACK information bits for a first PDSCH received on the corresponding cell and located outside the candidate PDSCH reception opportunities of the corresponding cell.

[0023] In some embodiments of the present disclosure, generating a HARQ-ACK codebook may include generating HARQ-ACK feedback for each cell of the first and second sets of cells, which may include generating HARQ-ACK information bits for candidate PDSCH reception opportunities for corresponding cells of the first and second sets of cells, and generating HARQ-ACK information bits for first PDSCHs that may potentially be scheduled on the corresponding cell by the first DCI format or the second DCI format.

[0024] In some embodiments of the present disclosure, the HARQ-ACK codebook may include a first portion and a second portion, and generating the HARQ-ACK codebook may include generating the first portion including HARQ-ACK information bits for candidate PDSCH reception opportunities for each cell of the first set and the second set of cells, and generating the second portion including HARQ-ACK information bits for all cells that may potentially be scheduled by the first DCI format and the second DCI format with one PDSCH on each cell.

[0025] In some embodiments of the present disclosure, the HARQ-ACK information bits in the second portion are ordered according to cell indices of the first and second sets of cells. In some embodiments of the present disclosure, the HARQ-ACK information bits in the second portion are ordered first according to an associated cell set index and then according to an associated serving cell index within the corresponding set of the first and second sets of cells.

[0026] In some embodiments of the present disclosure, the HARQ-ACK codebook may include a first portion including HARQ-ACK information bits for candidate PDSCH reception opportunities for each cell in the first and second sets of cells, and a second portion including HARQ-ACK information bits for one or more PDSCHs in the first and second sets of PDSCHs that are received on one or more cells in the first and second sets of cells and that are outside the candidate PDSCH reception opportunities for the one or more cells in the first and second sets of cells.

[0027] In some embodiments of the present disclosure, generating a HARQ-ACK codebook may include generating HARQ-ACK feedback for each cell of the first and second sets of cells, which may include a first portion including HARQ-ACK information bits for a candidate PDSCH reception opportunity of a corresponding cell of the first and second sets of cells, and a second portion including HARQ-ACK information bits for a first PDSCH of the first and second sets of PDSCHs in response to the first PDSCH being received on the corresponding cell and falling outside the candidate PDSCH reception opportunity of the corresponding cell.

[0028] In some embodiments of the present disclosure, the first DCI format includes an indicator that indicates the same slot-level offset for each of the first set of PDSCHs relative to the slot in which the first DCI format is received, and the HARQ-ACK feedback for the first set of PDSCHs is included in the HARQ-ACK feedback associated with the candidate PDSCH reception opportunities on the first set of cells.

[0029] In some embodiments of the present disclosure, the first DCI format includes a first indicator indicating a distinct slot-level offset for each of the first set of PDSCHs relative to the slot in which the first DCI format is received, and a second indicator indicating the slot in which the HARQ-ACK codebook is transmitted, under the constraints that the first set of PDSCHs are included in the candidate PDSCH reception opportunity on an associated cell of the first set of cells and that the HARQ-ACK feedback for the first set of PDSCHs is included in the HARQ-ACK feedback associated with the candidate PDSCH reception opportunity on the first set of cells.

[0030] Some embodiments of the present disclosure provide a base station (BS). The BS may include a transceiver and a processor coupled to the transceiver. The processor may be configured to transmit, to a user equipment (UE), a first downlink control information (DCI) format that schedules a first set of physical downlink shared channels (PDSCHs) on a first set of cells of the UE, and to receive, from the UE, hybrid automatic repeat request-acknowledgement (HARQ-ACK) feedback associated with candidate PDSCH reception opportunities on the first set of cells and a HARQ-ACK codebook including HARQ-ACK feedback for the first set of PDSCHs.

[0031] In some embodiments of the present disclosure, the HARQ-ACK codebook may include a HARQ-ACK information bit for each cell of the first set of cells ordered according to the associated serving cell index.

[0032] In some embodiments of the present disclosure, the HARQ-ACK information bits for each cell of the first set of cells may include HARQ-ACK information bits for the PDSCH reception opportunity candidates of the corresponding cell and HARQ-ACK information bits for a first PDSCH of the first set of PDSCHs transmitted on the corresponding cell and located outside the PDSCH reception opportunity candidates of the corresponding cell.

[0033] In some embodiments of the present disclosure, the HARQ-ACK information bits for the PDSCH reception opportunity candidates of the corresponding cell and the HARQ-ACK information bits for the first PDSCH are ordered according to the PDSCH reception opportunity on the corresponding cell.

[0034] In some embodiments of the present disclosure, the HARQ-ACK information bits for each cell of the first set of cells may include HARQ-ACK information bits for candidate PDSCH reception opportunities of the corresponding cell and HARQ-ACK information bits for a first PDSCH that may potentially be scheduled on the corresponding cell by the first DCI format.

[0035] In some embodiments of the present disclosure, the HARQ-ACK information bits for the first PDSCH are placed after or before the HARQ-ACK information bits for the candidate PDSCH reception opportunities of the corresponding cell, and the HARQ-ACK information bits for the candidate PDSCH reception opportunities of the corresponding cell are ordered according to the PDSCH reception opportunities on the corresponding cell.

[0036] In some embodiments of the present disclosure, if the first PDSCH is actually scheduled on the corresponding cell by the first DCI format, the HARQ-ACK information bit for the first PDSCH is ACK or Negative ACK (NACK) according to the decoding result of the first PDSCH. In some embodiments of the present disclosure, if the first PDSCH is not scheduled on the corresponding cell by the first DCI format, the HARQ-ACK information bit for the first PDSCH is NACK.

[0037] In some embodiments of the present disclosure, the HARQ-ACK codebook may include a first portion and a second portion, where the first portion may include HARQ-ACK information bits for candidate PDSCH reception opportunities for each cell of the first set of cells, and the second portion may include HARQ-ACK information bits for all cells that may potentially be scheduled by the first DCI format with one PDSCH on each cell.

[0038] In some embodiments of the present disclosure, if a cell that may potentially be scheduled by the first DCI format is not included in the first set of cells, the HARQ-ACK information bit in the second part for that cell is a negative ACK (NACK), and the HARQ-ACK information bit in the second part for a cell in the first set of cells that is scheduled by the first DCI format is an ACK or a NACK.

[0039] In some embodiments of the present disclosure, if a second PDSCH in the first set of PDSCHs is scheduled on a cell in the first set of cells and is included in the candidate PDSCH reception opportunities for that cell, the HARQ-ACK information bit for the second PDSCH in the first portion for that cell is an ACK or a negative ACK (NACK), or is a NACK, depending on the decoding result of the second PDSCH.

[0040] In some embodiments of the present disclosure, the HARQ-ACK codebook may include a first portion and a second portion, where the first portion may include HARQ-ACK information bits for a candidate PDSCH reception opportunity for each cell in the first set of cells, and the second portion may include HARQ-ACK information bits for one or more PDSCHs in the first set of PDSCHs that are transmitted on one or more cells in the first set of cells and that are outside the candidate PDSCH reception opportunity for the one or more cells in the first set of cells.

[0041] In some embodiments of the present disclosure, the HARQ-ACK information bits in the first portion for each cell's PDSCH reception opportunity candidate of the first cell are ordered according to the associated PDSCH reception opportunity candidate, and in some embodiments of the present disclosure, the HARQ-ACK information bits in the second portion are ordered according to the associated cell index.

[0042] In some embodiments of the present disclosure, the HARQ-ACK information bits in the second portion are ordered first according to the associated PDSCH start timing and then according to the associated cell index.

[0043] In some embodiments of the present disclosure, the HARQ-ACK codebook may include, for each cell of the first set of cells, a first portion including HARQ-ACK information bits for a candidate PDSCH reception opportunity of the corresponding cell, and a second portion including HARQ-ACK information bits for a first PDSCH of the first set of PDSCHs in response to the first PDSCH being transmitted on the corresponding cell and being outside the candidate PDSCH reception opportunity of the corresponding cell.

[0044] In some embodiments of the present disclosure, the HARQ-ACK information bits for each cell of the first set of cells are ordered according to the associated serving cell index.

[0045] In some embodiments of the present disclosure, the processor is further configured to send, to the UE, a second DCI format that schedules a second set of PDSCHs on a second set of cells of the UE, wherein HARQ-ACK feedback for the second set of PDSCHs is to be multiplexed in a HARQ-ACK codebook.

[0046] In some embodiments of the present disclosure, each of the first and second sets of cells is a subset of a respective set of cells configured for multi-cell scheduling or is a subset of the same set of cells configured for multi-cell scheduling.

[0047] In some embodiments of the present disclosure, the HARQ-ACK codebook may include HARQ-ACK feedback for each cell of the first and second sets of cells, which may include HARQ-ACK information bits for PDSCH reception opportunity candidates of the corresponding cell in the first and second sets of cells and HARQ-ACK information bits for the first PDSCH transmitted on the corresponding cell and located outside the PDSCH reception opportunity candidates of the corresponding cell.

[0048] In some embodiments of the present disclosure, the HARQ-ACK codebook may include HARQ-ACK feedback for each cell of the first and second sets of cells, which may include HARQ-ACK information bits for candidate PDSCH reception opportunities of corresponding cells of the first and second sets of cells and HARQ-ACK information bits for first PDSCHs that may potentially be scheduled on the corresponding cells by the first DCI format or the second DCI format.

[0049] In some embodiments of the present disclosure, the HARQ-ACK codebook may include a first portion and a second portion, where the first portion may include HARQ-ACK information bits for candidate PDSCH reception opportunities for each cell of the first and second sets of cells, and the second portion may include HARQ-ACK information bits for all cells that may potentially be scheduled by the first and second DCI formats with one PDSCH on each cell.

[0050] In some embodiments of the present disclosure, the HARQ-ACK information bits in the second portion are ordered according to cell indices of the first and second sets of cells. In some embodiments of the present disclosure, the HARQ-ACK information bits in the second portion are ordered first according to associated cell set indices and then according to associated serving cell indices within the corresponding sets of the first and second sets of cells.

[0051] In some embodiments of the present disclosure, the HARQ-ACK codebook may include a first portion including HARQ-ACK information bits for candidate PDSCH reception opportunities for each cell in the first and second sets of cells, and a second portion including HARQ-ACK information bits for one or more PDSCHs in the first and second sets of PDSCHs that are transmitted on one or more cells in the first and second sets of cells and that are outside the candidate PDSCH reception opportunities for the one or more cells in the first and second sets of cells.

[0052] In some embodiments of the present disclosure, the HARQ-ACK codebook may include a HARQ-ACK feedback for each cell of the first and second set of cells, which may include a first portion including HARQ-ACK information bits for a candidate PDSCH reception opportunity of a corresponding cell of the first and second sets of cells, and a second portion including HARQ-ACK information bits for a first PDSCH of the first and second sets of PDSCHs in response to the first PDSCH being transmitted on the corresponding cell and falling outside the candidate PDSCH reception opportunity of the corresponding cell.

[0053] In some embodiments of the present disclosure, the first DCI format includes an indicator that indicates the same slot-level offset for each of the first set of PDSCHs relative to the slot in which the first DCI format is transmitted, and the HARQ-ACK feedback for the first set of PDSCHs is included in the HARQ-ACK feedback associated with the candidate PDSCH reception opportunities on the first set of cells.

[0054] In some embodiments of the present disclosure, the first DCI format includes a first indicator indicating a distinct slot-level offset for each of the first set of PDSCHs relative to the slot in which the first DCI format is transmitted, and a second indicator indicating the slot in which the HARQ-ACK codebook is transmitted, under the constraints that the first set of PDSCHs are included in the candidate PDSCH reception opportunity on an associated cell of the first set of cells and that the HARQ-ACK feedback for the first set of PDSCHs is included in the HARQ-ACK feedback associated with the candidate PDSCH reception opportunity on the first set of cells.

[0055] Some embodiments of the present disclosure provide a method implemented by a user equipment (UE), which may include receiving a first downlink control information (DCI) format that schedules a first set of physical downlink shared channels (PDSCHs) on a first set of cells of the UE, generating a Hybrid Automatic Repeat Request Acknowledgement (HARQ-ACK) codebook comprising HARQ-ACK feedback associated with candidate PDSCH reception opportunities on the first set of cells and HARQ-ACK feedback for the first set of PDSCHs, and transmitting the HARQ-ACK codebook.

[0056] Some embodiments of the present disclosure provide a method implemented by a base station (BS), which may include transmitting, to a user equipment (UE), a first downlink control information (DCI) format that schedules a first set of physical downlink shared channels (PDSCHs) on a first set of cells of the UE, and receiving, from the UE, hybrid automatic repeat request-acknowledgement (HARQ-ACK) feedback associated with candidate PDSCH reception opportunities on the first set of cells and a HARQ-ACK codebook comprising the HARQ-ACK feedback for the first set of PDSCHs.

[0057] Some embodiments of the present disclosure provide an apparatus. According to some embodiments of the present disclosure, the apparatus may include at least one non-transitory computer-readable medium having computer-executable instructions stored thereon, at least one receiving circuit, at least one transmitting circuit, and at least one processor coupled to the at least one non-transitory computer-readable medium, the at least one receiving circuit, and the at least one transmitting circuit, wherein the at least one non-transitory computer-readable medium and the computer-executable instructions, together with the at least one processor, may be configured to cause the apparatus to perform a method according to some embodiments of the present disclosure.

[0058] To explain the manner in which the advantages and features of the present disclosure may be obtained, the disclosure will be described with reference to specific embodiments thereof, which are illustrated in the accompanying drawings. These drawings depict only exemplary embodiments of the disclosure and therefore should not be considered limiting of its scope. [Brief explanation of the drawings]

[0059] [Figure 1] 1 is a schematic diagram of a wireless communication system according to some embodiments of the present disclosure. [Figure 2] FIG. 2 is a schematic diagram of a PDSCH transmission according to some embodiments of the present disclosure. [Figure 3] 1 is a flowchart of an exemplary procedure for wireless communication according to some embodiments of the present disclosure. [Figure 4] FIG. 1 is a schematic diagram of determining a HARQ-ACK codebook according to some embodiments of the present disclosure. [Figure 5] FIG. 1 is a schematic diagram of determining a HARQ-ACK codebook according to some embodiments of the present disclosure. [Figure 6] FIG. 2 is a schematic diagram of a PDSCH transmission according to some embodiments of the present disclosure. [Figure 7] FIG. 1 is a schematic diagram of determining a HARQ-ACK codebook according to some embodiments of the present disclosure. [Figure 8]FIG. 1 is a schematic diagram of determining a HARQ-ACK codebook according to some embodiments of the present disclosure. [Figure 9] FIG. 1 is a schematic diagram of determining a HARQ-ACK codebook according to some embodiments of the present disclosure. [Figure 10] 1 is a schematic diagram of a PDSCH transmission according to some embodiments of the present disclosure. [Figure 11] FIG. 1 is a schematic diagram of determining a HARQ-ACK codebook according to some embodiments of the present disclosure. [Figure 12] 1 is a flowchart of an exemplary procedure for wireless communication according to some embodiments of the present disclosure. [Figure 13] FIG. 1 is a block diagram of an exemplary apparatus according to some embodiments of the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0060] The detailed description of the accompanying drawings is intended as an illustration of preferred embodiments of the present disclosure and is not intended to represent the only form in which the present disclosure may be practiced. It should be understood that the same or equivalent function may be accomplished by different embodiments which are intended to be encompassed without departing from the spirit and scope of the present disclosure.

[0061] Reference will now be made in detail to several embodiments of the present disclosure, examples of which are illustrated in the accompanying drawings. For ease of understanding, embodiments are provided under specific network architectures and new service scenarios, such as Third Generation Partnership Project (3GPP) 5G (NR), 3GPP long-term evolution (LTE) Release 8, etc. With the development of network architectures and new service scenarios, all embodiments in the present disclosure may also be applicable to similar technical problems, and the terms described in the present disclosure may change, which is not considered to affect the principles of the present disclosure.

[0062] FIG. 1 illustrates a schematic diagram of a wireless communication system 100 in accordance with some embodiments of the present disclosure.

[0063] 1, the wireless communication system 100 may include several UEs 101 (e.g., UE 101a and UE 101b) and base stations (e.g., BS 102). Although a particular number of UEs 101 and BSs 102 are shown in FIG. 1, it is contemplated that any number of UEs and BSs may be included in the wireless communication system 100.

[0064] The UE 101 may include computing devices such as desktop computers, laptop computers, personal digital assistants (PDAs), tablet computers, smart televisions (e.g., televisions connected to the Internet), set-top boxes, game consoles, security systems (including security cameras), in-vehicle computers, network devices (e.g., routers, switches, and modems). According to some embodiments of the present disclosure, the UE 101 may include portable wireless communication devices, smartphones, mobile phones, flip phones, devices with subscriber identity modules, personal computers, selective call receivers, or any other devices capable of transmitting and receiving communication signals over a wireless network. In some embodiments of the present disclosure, the UE 101 includes wearable devices such as smart watches, fitness bands, and optical head-mounted displays. Moreover, the UE 101 may be referred to as a subscriber unit, mobile, mobile station, user, terminal, mobile terminal, wireless terminal, fixed terminal, subscriber station, user terminal, or device, or may be described using other terms used in the art. The UE 101 may communicate with the BS 102 via uplink (UL) communication signals.

[0065] The BSs 102 may be dispersed over a geographic region. In some embodiments of the present disclosure, the BSs 102 may also be referred to as access points, access terminals, bases, base units, macrocells, Node-Bs, evolved Node Bs (eNBs), gNBs, Home Node-Bs, relay nodes, or devices, or may be described using other terms used in the art. The BSs 102 are generally part of a radio access network, which may include one or more controllers communicatively coupled to one or more corresponding BSs 102. The BSs 102 may communicate with the UEs 101 via downlink (DL) communication signals.

[0066] The wireless communication system 100 may be compatible with any type of network capable of transmitting and receiving wireless communication signals. For example, the wireless communication system 100 may be compatible with a wireless communication network, a cellular network, a time division multiple access (TDMA)-based network, a code division multiple access (CDMA)-based network, an orthogonal frequency division multiple access (OFDMA)-based network, an LTE network, a 3GPP-based network, a 3GPP 5G network, a satellite communication network, a high altitude platform network, and / or other communication networks.

[0067] In some embodiments of the present disclosure, the wireless communication system 100 conforms to the 3GPP protocol 5G NR. For example, the BS 102 may transmit data on the DL using an Orthogonal Frequency Division Multiplexing (OFDM) modulation scheme, and the UE 101 may transmit data on the UL using a Discrete Fourier Transform-Spread-Orthogonal Frequency Division Multiplexing (DFT-S-OFDM) or Cyclic Prefix OFDM (CP-OFDM) scheme. However, more generally, the wireless communication system 100 may implement some other open or proprietary communication protocol, such as WiMAX, among other protocols.

[0068] In some embodiments of the present disclosure, the BS 102 and the UE 101 may communicate using other communication protocols, such as the IEEE 802.11 family of wireless communication protocols. Additionally, in some embodiments of the present disclosure, the BS 102 and the UE 101 may communicate over a licensed spectrum, while in some other embodiments, the BS 102 and the UE 101 may communicate over an unlicensed spectrum. This disclosure is not limited to any particular wireless communication system architecture or protocol implementation.

[0069] For example, multiple types of HARQ-ACK codebooks may be defined for HARQ-ACK multiplexing for multiple received PDSCHs, including a Type-1 HARQ-ACK codebook (also called a "quasi-static HARQ-ACK codebook"). The definition of the Type-1 HARQ-ACK codebook is specified in the 3GPP specifications.

[0070] For example, in some embodiments of the present disclosure, the size of the Type-1 HARQ-ACK codebook (e.g., the number of HARQ-ACK information bits included therein) may be independent of the actual scheduling situation. For example, the number of HARQ-ACK information bits may be determined based on a list of parameters including, for example, a PDSCH-to-HARQ timing value (also referred to as a “HARQ-ACK feedback timing set” or “K1 set”), the maximum number of code block groups (CBGs) per transport block (TB), and the number of configured component carriers (CCs). The K1 set may be configured for the UE via an RRC signaling message or may be predetermined in a standard. For example, the UE may determine a time for transmitting the Type-1 HARQ-ACK codebook based on a PDSCH-to-HARQ_feedback timing indicator (hereinafter “k1”) in the scheduling DCI format, and may determine candidate PDSCH reception opportunities based on the time for transmitting the codebook and the K1 set. The codebook may include HARQ-ACK information bits for these candidate PDSCH reception opportunities, regardless of whether a PDSCH is actually scheduled within the PDSCH reception opportunity.

[0071] Communication technologies (e.g., NR) may support a wide range of spectrum in different frequency ranges. For example, in the market for 5G Advanced, increased spectrum availability is expected, which may be due to the realignment of bands originally used for previous cellular generation networks. For example, in some low-frequency bands in Frequency Range 1 (FR1), the available spectrum bands tend to be more fragmented and scattered, with narrower bandwidths. Additionally, in bands in Frequency Range 2 (FR2) and some bands in FR1, the available spectrum may be wider, necessitating intra-band multicarrier operation.

[0072] To meet the various spectrum demands, it is important to ensure that these fragmented or sparse spectrum bands, or wider bandwidth spectrum, are utilized in a more spectrally and power-efficient and flexible manner, thereby providing higher throughput and adequate coverage in the network.

[0073] For example, one motivation is to increase spectral / power efficiency and flexibility in scheduling data across multiple cells, including intra-band and inter-band cells. In some examples, scheduling mechanisms may only allow scheduling a single PUSCH or PDSCH on a single cell per scheduling DCI. As more sparse spectrum bands or wider spectrum becomes available, it is prudent to allow simultaneous scheduling of multiple cells. To reduce control overhead, it is beneficial to extend from single-cell scheduling to multi-cell PUSCH / PDSCH scheduling using a single scheduling DCI. For example, a single DCI may schedule multiple PDSCHs or PUSCHs on multiple carriers configured for a UE, which is referred to as multi-cell or multi-carrier scheduling in the context of this disclosure. Meanwhile, a trade-off between reduced signaling overhead and scheduling constraints may need to be considered. A communication system (e.g., NR) may be designed to support up to 16 component carriers (CCs) in the case of carrier aggregation (CA) and up to 32 CCs in the case of dual connectivity (DC).

[0074] In the context of this disclosure, for brevity, a DC format that schedules multiple PUSCHs on multiple cells is referred to as DCI format 0_X, and a DCI format that schedules multiple PDSCHs on multiple cells is referred to as DCI format 1_X. In some embodiments of the present disclosure, DCI format 0_X / 1_X may schedule a single PDSCH per cell.

[0075] In some embodiments of the present disclosure, when DCI format 0_X / 1_X is transmitted to jointly schedule multiple PUSCHs / PDSCHs on multiple cells, a single time domain resource allocation (TDRA) field in DCI format 0_X / 1_X may indicate one row of a TDRA table, where each row of the TDRA table is configured with a separate start and length indication value (SLIV), mapping type, and scheduling offset (e.g., K0 / K2 as specified in the 3GPP specifications) for each of the jointly scheduled PUSCHs / PDSCHs.

[0076] In some embodiments of the present disclosure, to determine the timing of a PUCCH carrying HARQ-ACK information corresponding to a set of co-scheduled PDSCHs by DCI format 1_X, the reference PDSCH is the last terminating PDSCH of the set of co-scheduled PDSCHs as indicated in DCI format 1_X.

[0077] Therefore, in DCI format 1_X, which jointly schedules a set of cells and is accompanied by a TDRA field indicating a separate K0 value for each of the jointly scheduled PDSCHs, when the last-terminating PDSCH among the jointly scheduled PDSCHs as indicated in DCI format 1_X is used as a reference PDSCH for determining, by DCI format 1_X, the timing of the PUCCH carrying HARQ-ACK information corresponding to the set of jointly scheduled PDSCHs, the k1 value indicated by the PDSCH-to-HARQ_feedback timing indicator field in DCI format 1_X is associated with the reference PDSCH among the jointly scheduled PDSCHs, so that the jointly scheduled PDSCHs on non-reference cells may be outside the PDSCH reception opportunity candidates determined by the respective K1 sets of the non-reference cells, where the reference cell is defined as the cell to which the reference PDSCH is transmitted. Therefore, corresponding HARQ-ACK information for PDSCHs outside the PDSCH reception opportunity candidates cannot be reported in the Type-1 HARQ-ACK codebook.

[0078] FIG. 2 shows a schematic diagram of PDSCH transmission according to some embodiments of the present disclosure.

[0079] Referring to Figure 2, multiple CCs (e.g., including but not limited to CCs 231 to 234 in Figure 2) may be configured for a UE. It should be understood that the subcarrier spacings (SCSs) of the carriers configured for the UE may be the same or different. Each of the multiple CCs may correspond to a respective cell (e.g., serving cell) or carrier of the UE. Each carrier (serving cell) may be associated with a (serving) cell index.

[0080] In Figure 2, BS may send DCI210 to UE on CC231 in slot n. DCI210 is assumed to schedule four cells, namely CC231 to 234 together. For simplicity, it is assumed that the serving cell indexes of CC231 to 234 are CC231 < CC232 < CC233 < CC234. DCI210 may indicate a specific row in the TDRA table. This specific row is assumed to indicate the K0 values of {1, 6, 5, 2}. Based on the indicated K0 values, UE can determine that DCI210 schedules PDSCH221 on CC231 in slot n+1, schedules PDSCH222 on CC232 in slot n+6, schedules PDSCH223 on CC233 in slot n+5, and schedules PDSCH224 on CC234 in slot n+2. Since PDSCH222 is the newest PDSCH among the four scheduled PDSCHs together, it is used as the reference PDSCH, and cell 232 is regarded as the reference cell. Assume that the PDSCH-to-HARQ_feedback timing indicator field in DCI210 indicates a k1 value of 3, and it is assumed that the PUCCH carrying the HARQ-ACK feedback for the four scheduled PDSCHs together is transmitted in slot n+9 (i.e., (slot n+6) + 3 slots).

[0081] Assuming that the K1 set is {1, 2, 3, 4} for each of CC231 - 234, based on slot n+9, the PDSCH reception opportunity candidates on each cell are determined in slots n+5 to n+8 according to the reverse order of the k1 values in the K1 set (e.g., (slot n+9) - 4, (slot n+9) - 3, (slot n+9) - 2, and (slot n+9) - 1). As shown in Figure 2, PDSCH221 on CC231 and PDSCH224 on CC234 are not included in the range of PDSCH reception opportunity candidates on their respective cells. In that sense, the Type-1 HARQ-ACK codebook does not include the HARQ-ACK information bits for PDSCH221 and PDSCH224.

[0082]

[0013] Embodiments of the present disclosure provide a strategy for determining a Type-1 HARQ-ACK codebook that can solve at least the above problems. For example, embodiments of the present disclosure provide a strategy for including HARQ-ACK information bits for PDSCHs located outside PDSCH reception opportunity candidates in the HARQ-ACK codebook. For example, embodiments of the present disclosure provide a strategy for avoiding a scenario in which a PDSCH scheduled by a DCI format is located outside PDSCH reception opportunity candidates. Further details about embodiments of the present disclosure are provided in the following text in combination with the accompanying drawings.

[0083] 3 illustrates a flowchart of an exemplary procedure 300 for wireless communication according to some embodiments of the present disclosure. Details described in all of the above-described embodiments of the present disclosure are applicable to the embodiment illustrated in FIG. 3. In some examples, the procedure may be performed by a UE, for example, the UE 101 of FIG. 1.

[0084] In some embodiments of the present disclosure, a UE may be configured with a Type-1 HARQ-ACK codebook and a set of cells for multi-cell scheduling using DCI format 1_X. In some embodiments, all DCI formats 1_X are configured or predetermined with the same set of cells for multi-cell scheduling. For example, different DCI formats 1_X may schedule respective subsets of the same set of cells for multi-cell scheduling. In some embodiments, multiple sets of cells may be configured or predetermined for multi-cell scheduling. A cell included in one cell set of the multiple sets of cells may not be included in another cell set of the multiple sets of cells. A single set of cells or multiple sets of cells may or may not include all serving cells of the UE. For example, DCI format 1_X may schedule a subset of cells in one cell set of the multiple sets of cells, and another DCI format 1_X may schedule a subset of cells in another cell set of the multiple sets of cells.

[0085] 3, in operation 311, the UE may receive a first DCI format (e.g., DCI format 1_X as described above) that schedules a first set of PDSCHs on a first set of cells of the UE. In some embodiments, the first set of cells may be a subset of the cell set (hereinafter the first cell set) as described above.

[0086] The TDRA field in the first DCI format may indicate a separate K0 value for each of the jointly scheduled PDSCHs. The slot in which the PUCCH carrying HARQ-ACK feedback for the jointly scheduled PDSCHs is transmitted is determined according to the last-ending PDSCH among the jointly scheduled PDSCHs as indicated by the TDRA field in the first DCI format and the HARQ-ACK feedback timing value indicated by the PDSCH-to-HARQ_feedback timing indicator field in the first DCI format. The PDSCH reception opportunity candidates on the first set of cells or each cell of the first cell set are determined according to the K1 set configured for the corresponding cell and the slot in which the PUCCH is transmitted. In some embodiments, separate K1 sets may be configured or predetermined for different cells. In some embodiments, the same K1 set may be configured or predetermined for different cells.

[0087] At operation 313, the UE may generate a HARQ-ACK codebook including HARQ-ACK feedback associated with candidate PDSCH reception opportunities on the first set of cells and HARQ-ACK feedback for the first set of PDSCHs. At operation 315, the UE may transmit the HARQ-ACK codebook, for example, the HARQ-ACK codebook in the slot in which the PUCCH is transmitted, as determined above.

[0088] As described in the following text, various methods for determining the HARQ-ACK codebook may be utilized.

[0089] In some embodiments of the present disclosure, a strategy is provided for including HARQ-ACK information bits for PDSCHs located outside PDSCH reception opportunity candidates in the HARQ-ACK codebook (hereinafter, Strategy #1). As described in the following text, various methods can be used to achieve Strategy #1.

[0090] Method #1 In some embodiments of the present disclosure, generating the HARQ-ACK codebook may include generating HARQ-ACK information bits for each cell of the first set of cells and concatenating the generated HARQ-ACK information bits for each cell of the first set of cells in order of associated serving cell index (e.g., a predetermined order such as ascending or descending).

[0091] In some embodiments of the present disclosure, generating a HARQ-ACK information bit for each cell of the first set of cells may include generating a HARQ-ACK information bit for a PDSCH reception opportunity candidate of the corresponding cell, and generating a HARQ-ACK information bit for a PDSCH of the first set of PDSCHs (denoted as PDSCH #1A) that is received on the corresponding cell and is located outside the PDSCH reception opportunity candidate of the corresponding cell.

[0092] In some embodiments, for example, when a PDSCH of the first set of PDSCHs scheduled on a particular cell of the first set of cells falls within a corresponding PDSCH reception opportunity candidate of the particular cell, such PDSCH #1A may not exist, and therefore, the HARQ-ACK information bits for the particular cell may include only HARQ-ACK information bits for the PDSCH reception opportunity candidate of the particular cell.

[0093] In some embodiments of the present disclosure, the HARQ-ACK information bits for the PDSCH reception opportunity candidates of the corresponding cell and the HARQ-ACK information bits for PDSCH #1A (if any) are ordered according to the PDSCH reception opportunities on the corresponding cell (e.g., a predetermined order thereof, such as ascending or descending order of the PDSCH reception opportunity candidates on the corresponding cell).

[0094] In some examples, when a PDSCH is actually scheduled on a cell within a certain PDSCH reception opportunity candidate for the cell, the HARQ-ACK information bit for this PDSCH reception opportunity candidate is the HARQ-ACK information bit for this PDSCH, i.e., an ACK or NACK depending on the decoding result of the PDSCH. In some examples, when a PDSCH is not actually scheduled on a cell within a certain PDSCH reception opportunity candidate for the cell, the HARQ-ACK information bit for this PDSCH reception opportunity candidate is a NACK.

[0095] In some embodiments, the first set of cells may be a subset of a set of cells configured for multi-cell scheduling. Generating the HARQ-ACK codebook may include generating HARQ-ACK information bits for each cell of the set of cells and sorting them in order of associated serving cell index (e.g., ascending or descending order). and concatenating the generated HARQ-ACK information bits for each cell of the cell set in a predetermined order, such as descending order.

[0096] For example, the first DCI format may schedule a set of cells but may not actually schedule all cells in the set of cells. The HARQ-ACK codebook may include HARQ-ACK information bits for cells in the set of cells that are not actually scheduled by the first DCI format. The HARQ-ACK information bits for these cells may include HARQ-ACK information bits for candidate PDSCH reception opportunities for these cells. When no PDSCH is actually scheduled on this cell, the HARQ-ACK information bits for each candidate PDSCH reception opportunity for this cell may indicate a NACK.

[0097] For example, referring again to Figure 2, the UE may generate a HARQ-ACK codebook to be transmitted in slot n+9. An exemplary HARQ-ACK codebook 450 according to Method #1 is shown in Figure 4. HARQ-ACK codebook 450 may include HARQ-ACK information bits for each cell of CCs 231-234. For example, as shown in Figure 4, HARQ-ACK codebook 450 may include HARQ-ACK information bits a1 through a4, which respectively represent HARQ-ACK information bits for CCs 231-234 and are ordered in HARQ-ACK codebook 450 according to ascending order of their associated cell indexes.

[0098] 2 is not included in the range of PDSCH reception opportunity candidates for CC 231, HARQ-ACK information bit a1 in Figure 4 includes HARQ-ACK information bits for PDSCH reception opportunity candidates for CC 231 and HARQ-ACK information bits for PDSCH 221, which may be ordered according to the associated PDSCH reception opportunity candidates. For example, assuming that an ascending order of PDSCH reception opportunity candidates is used, and the HARQ-ACK information bits for the four PDSCH reception opportunity candidates for CC 231 in Figure 2 are denoted as a1-1, a1-2, a1-3, and a1-4, and the HARQ-ACK information bit for PDSCH 221 in Figure 2 is denoted as a1-0, HARQ-ACK information bit a1 in Figure 4 may be denoted as {a1-0, a1-1, a1-2, a1-3, a1-4}. In some examples, a1-1, a1-2, a1-3, and a1-4 may be NACKs when there is no PDSCH actually scheduled on the corresponding PDSCH reception opportunity candidate.

[0099] 2 is included in the range of PDSCH reception opportunity candidates for CC 232, HARQ-ACK information bit a2 in FIG. 4 includes the HARQ-ACK information bit for the PDSCH reception opportunity candidate for CC 232, and the HARQ-ACK information bit for the PDSCH reception opportunity candidate for CC 232 in slot n+6 in FIG. 2 refers to the HARQ-ACK information bit for PDSCH 222. In some examples, if the HARQ-ACK information bits for the PDSCH reception opportunity candidates in slots n+5, n+7, and n+8 of CC 231 in FIG. 2 are denoted as a2-1, a2-3, and a2-4, and the HARQ-ACK information bit for PDSCH 222 in FIG. 2 is denoted as a2-0, then HARQ-ACK information bit a2 in FIG. 4 may be denoted as {a2-1, a2-0, a2-3, a2-4}. In some examples, a2-1, a2-3, and a2-4 may be NACKs when there is no PDSCH actually scheduled on the corresponding PDSCH reception opportunity candidate.

[0100] 2 is included in the range of PDSCH reception opportunity candidates of CC 233, HARQ-ACK information bit a3 in FIG. 4 includes the HARQ-ACK information bit for the PDSCH reception opportunity candidate of CC 233, and the HARQ-ACK information bit for the PDSCH reception opportunity candidate of CC 233 in slot n+5 in FIG. 2 refers to the HARQ-ACK information bit for PDSCH 223. In some examples, if the HARQ-ACK information bits for the PDSCH reception opportunity candidates in slots n+6, n+7, and n+8 of CC 231 in FIG. 2 are denoted as a3-2, a3-3, and a3-4, and the HARQ-ACK information bit for PDSCH 223 in FIG. 2 is denoted as a3-0, then the HARQ-ACK information bit a3 in FIG. 4 may be denoted as {a3-0, a3-2, a3-3, a3-4}. In some examples, a3-2, a3-3, and a3-4 may be NACKs when there is no PDSCH actually scheduled on the corresponding PDSCH reception opportunity candidate.

[0101] 2 is not included in the range of PDSCH reception opportunity candidates for CC 234, HARQ-ACK information bit a4 in Figure 4 includes HARQ-ACK information bits for PDSCH reception opportunity candidates for CC 234 and HARQ-ACK information bits for PDSCH 224, which may be ordered according to the ascending order of PDSCH reception opportunity candidates as assumed above. If the HARQ-ACK information bits for the four PDSCH reception opportunity candidates for CC 234 in Figure 2 are denoted as a4-1, a4-2, a4-3, and a4-4, and the HARQ-ACK information bit for PDSCH 224 in Figure 2 is denoted as a4-0, then HARQ-ACK information bit a4 in Figure 4 may be denoted as {a4-0, a4-1, a4-2, a4-3, a4-4}. In some examples, a4-1, a4-2, a4-3, and a4-4 may be NACKs when there is no PDSCH actually scheduled on the corresponding PDSCH reception opportunity candidate.

[0102] From the UE perspective, the following steps may be implemented to generate a Type-1 HARQ-ACK codebook according to Method #1. (1-1) The UE checks the K0 value for each of the co-scheduled PDSCHs as indicated by the TDRA field, and finds the reference PDSCH that terminates last among the co-scheduled PDSCHs. (1-2) The UE determines the slot in which the PUCCH carrying the HARQ-ACK feedback for the co-scheduled PDSCH is transmitted. (1-3) The UE identifies PDSCH reception opportunity candidates for each cell of the co-scheduled cells (or the configured cell set) according to the respective K1 sets of each cell of the co-scheduled cells (or the configured cell set) and the slots in which the PUCCH is transmitted. (1-4) For each cell in the cell (or cell set) that is scheduled together The UE generates a HARQ-ACK information bit for each PDSCH reception opportunity candidate in the cell; The UE checks whether there are one or more PDSCHs scheduled by a multi-cell scheduling DCI format (e.g., DCI format 1_X or a first DCI format) and located outside of a PDSCH reception opportunity candidate on the cell; If only a single PDSCH scheduled by the multi-cell scheduling DCI format is located outside the PDSCH reception opportunity candidates in the cell, the UE generates a HARQ-ACK information bit for the single PDSCH; If there are multiple PDSCHs scheduled by multiple multi-cell scheduling DCI formats outside of the PDSCH reception opportunity candidates in a cell, the UE generates HARQ-ACK information bits for the multiple PDSCHs. (1-5) The UE concatenates the HARQ-ACK information bits for each cell of the co-scheduled cell (or configured cell set) as a Type-1 HARQ-ACK codebook for transmission on the PUCCH.

[0103] From the BS perspective, the BS may send a DCI format that schedules multiple PDSCHs to the UE and may receive a Type-1 HARQ-ACK codebook from the UE, such as that generated above.

[0104] Method #2 In some embodiments of the present disclosure, generating the HARQ-ACK codebook may include generating HARQ-ACK information bits for each cell of the first set of cells and concatenating the generated HARQ-ACK information bits for each cell of the first set of cells in order of associated serving cell index (e.g., a predetermined order such as ascending or descending).

[0105] In some embodiments of the present disclosure, generating a HARQ-ACK information bit for each cell of the first set of cells may include generating a HARQ-ACK information bit for a candidate PDSCH reception opportunity of the corresponding cell and generating a HARQ-ACK information bit for a PDSCH (denoted as PDSCH #1B) that may potentially be scheduled on the corresponding cell by the first DCI format.

[0106] In some examples, when a PDSCH is actually scheduled on a cell within a certain PDSCH reception opportunity candidate for the cell, the HARQ-ACK information bit for this PDSCH reception opportunity candidate is the HARQ-ACK information bit for this PDSCH, i.e., an ACK or NACK according to the decoding result of the PDSCH. In some examples, when a PDSCH is not actually scheduled on the cell within a certain PDSCH reception opportunity candidate for the cell, the HARQ-ACK information bit for this PDSCH reception opportunity candidate is a NACK.

[0107] In some other examples, the HARQ-ACK information bit for a PDSCH reception opportunity candidate is always NACK. For example, even when a PDSCH is actually scheduled on a cell within a PDSCH reception opportunity candidate of a cell, the HARQ-ACK information bit for this PDSCH reception opportunity candidate is NACK. This is because the HARQ-ACK information bit for this PDSCH within that PDSCH reception opportunity candidate of a cell can be indicated by the HARQ-ACK information bit for PDSCH #1B.

[0108] The HARQ-ACK information bit for PDSCH #1B may always be included in the HARQ-ACK information bit for the corresponding cell, regardless of whether the PDSCH is actually scheduled by the first DCI format on the corresponding cell. For example, if the corresponding cell or PDSCH #1B is not scheduled by the first DCI format, a NACK bit may be generated (i.e., the HARQ-ACK information bit for PDSCH #1B is NACK). If the corresponding cell or PDSCH #1B is actually scheduled by the first DCI format, an ACK or NACK bit may be generated depending on the decoding result of PDSCH #1B scheduled on the corresponding cell (i.e., the HARQ-ACK information bit for PDSCH #1B is ACK or NACK).

[0109] In some embodiments of the present disclosure, the HARQ-ACK information bits for the PDSCH reception opportunity candidates of the corresponding cell are ordered according to the PDSCH reception opportunities on the corresponding cell (e.g., a predetermined order thereof, such as ascending or descending order of the PDSCH reception opportunity candidates on the corresponding cell), and the HARQ-ACK information bits for PDSCH #1B on the corresponding cell are placed after or before the HARQ-ACK information bits for the PDSCH reception opportunity candidates of the corresponding cell.

[0110] In some embodiments, the first set of cells may be a subset of a set of cells configured for multi-cell scheduling. Generating the HARQ-ACK codebook may include generating HARQ-ACK information bits for each cell of the set of cells and concatenating the generated HARQ-ACK information bits for each cell of the set of cells in order of associated serving cell index (e.g., a predetermined order such as ascending or descending).

[0111] For example, a first DCI format may schedule a set of cells but may not actually schedule all cells in the set of cells. The HARQ-ACK codebook may include HARQ-ACK information bits for a cell in the set of cells that is not actually scheduled by the first DCI format. The HARQ-ACK information bits for this cell may include HARQ-ACK information bits for candidate PDSCH reception opportunities for this cell and HARQ-ACK information bits for assumed PDSCH #1B on this cell, all of which may be NACKs when no PDSCH is actually scheduled on this cell.

[0112] For example, referring again to Figure 2, the UE may generate a HARQ-ACK codebook to be transmitted in slot n+9. An exemplary HARQ-ACK codebook 550 according to Method #2 is shown in Figure 5. HARQ-ACK codebook 550 may include a HARQ-ACK information bit for each cell of CCs 231-234. For example, as shown in Figure 5, HARQ-ACK codebook 550 may include HARQ-ACK information bits b1 through b4, which respectively represent HARQ-ACK information bits for CCs 231-234, ordered in HARQ-ACK codebook 550 according to ascending order of associated cell index.

[0113] Since PDSCH221 is scheduled on CC231 in FIG. 2, HARQ-ACK information bits b1 in FIG. 5 include HARQ-ACK information bits for PDSCH reception opportunity candidates of CC231, which may be ordered according to the associated PDSCH reception opportunity candidates, and HARQ-ACK information bits for PDSCH221, which may be placed before or after the HARQ-ACK information bits for PDSCH reception opportunity candidates of CC231.

[0114] For simplicity, it is assumed that for each cell, an ascending order of PDSCH reception opportunity candidates is utilized and / or HARQ-ACK information bits for potentially scheduled PDSCHs are placed before HARQ-ACK information bits for PDSCH reception opportunity candidates.

[0115] For example, if the HARQ-ACK information bits for the four PDSCH reception opportunity candidates of CC 231 in Figure 2 are denoted as b1-1, b1-2, b1-3, and b1-4, and the HARQ-ACK information bit for PDSCH 221 in Figure 2 is denoted as b1-0, then the HARQ-ACK information bit b1 in Figure 5 may be denoted as {b1-0, b1-1, b1-2, b1-3, b1-4}. In some examples, b1-1, b1-2, b1-3, and b1-4 may be NACKs.

[0116] Since PDSCH222 is scheduled on CC232 in FIG. 2, HARQ-ACK information bits b2 in FIG. 5 include HARQ-ACK information bits for PDSCH reception opportunity candidates of CC232, which may be ordered according to the associated PDSCH reception opportunity candidates, and HARQ-ACK information bits for PDSCH222, which may be placed before the HARQ-ACK information bits for PDSCH reception opportunity candidates of CC232 (as assumed above).

[0117] The HARQ-ACK information bit for the PDSCH reception opportunity candidate of CC 232 in slot n+6 in Figure 2 may refer to the HARQ-ACK information bit for PDSCH 222 or may always be NACK. In some embodiments, when there is no PDSCH actually transmitted in a PDSCH reception opportunity candidate of a cell, the HARQ-ACK information bit for this PDSCH reception opportunity candidate indicates NACK. For example, if the HARQ-ACK information bit for PDSCH 222 in Figure 2 is denoted as b2-0, the HARQ-ACK information bit b2 in Figure 5 may be denoted as {b2-0, NACK, b2-0, NACK, NACK} or {b2-0, NACK, NACK, NACK, NACK}.

[0118] In Figure 2, PDSCH223 is scheduled on CC233, so HARQ-ACK information bits b3 in Figure 5 include HARQ-ACK information bits for PDSCH reception opportunity candidates of CC233, which may be ordered according to the associated PDSCH reception opportunity candidates, and HARQ-ACK information bits for PDSCH223, which may be placed before the HARQ-ACK information bits for PDSCH reception opportunity candidates of CC233 (as assumed above).

[0119] The HARQ-ACK information bit for the PDSCH reception opportunity candidate of CC 233 in slot n+5 of Figure 2 may refer to the HARQ-ACK information bit for PDSCH 223 or may always be NACK. In some embodiments, when there is no PDSCH actually transmitted in a PDSCH reception opportunity candidate of a cell, the HARQ-ACK information bit for this PDSCH reception opportunity candidate indicates NACK. For example, if the HARQ-ACK information bit for PDSCH 223 in Figure 2 is denoted as b3-0, the HARQ-ACK information bit b3 in Figure 5 may be denoted as {b3-0, b3-0, NACK, NACK, NACK} or {b3-0, NACK, NACK, NACK, NACK}.

[0120] Since PDSCH224 is scheduled on CC234 in FIG. 2, HARQ-ACK information bits b4 in FIG. 5 include HARQ-ACK information bits for PDSCH reception opportunity candidates of CC234, which may be ordered according to the associated PDSCH reception opportunity candidates, and HARQ-ACK information bits for PDSCH224, which may be placed before the HARQ-ACK information bits for PDSCH reception opportunity candidates of CC234 (as assumed above).

[0121] In some embodiments, when there is no PDSCH actually transmitted in a PDSCH reception opportunity candidate for a cell, the HARQ-ACK information bit for this PDSCH reception opportunity candidate indicates NACK. For example, if the HARQ-ACK information bit for PDSCH 224 in Figure 2 is denoted as b4-0, the HARQ-ACK information bit b4 in Figure 5 may be denoted as {b4-0, NACK, NACK, NACK, NACK}.

[0122] From the UE perspective, the following steps may be implemented to generate a Type-1 HARQ-ACK codebook according to Method #2. (2-1) The UE checks the K0 value for each of the co-scheduled PDSCHs as indicated by the TDRA field, and finds the reference PDSCH that terminates last among the co-scheduled PDSCHs. (2-2) The UE determines the slot in which the PUCCH carrying the HARQ-ACK feedback for the co-scheduled PDSCH is transmitted. (2-3) The UE identifies PDSCH reception opportunity candidates for each cell of the co-scheduled cells (or configured cell set) according to the respective K1 sets of each cell of the co-scheduled cells (or configured cell set) and the slot in which the PUCCH is transmitted. (2-4) For each cell in the set of cells (or cells that are scheduled together) The UE generates a HARQ-ACK information bit for each PDSCH reception opportunity candidate in the cell; · Generate HARQ-ACK information bits for PDSCHs (e.g., PDSCH #1B) that the UE may be scheduled on cells with a multi-cell DCI format (e.g., DCI format 1_X). (2-5) The UE concatenates the HARQ-ACK information bits for each cell of the co-scheduled cell (or configured cell set) as a Type-1 HARQ-ACK codebook for transmission on the PUCCH.

[0123] From the BS perspective, the BS may send a DCI format that schedules multiple PDSCHs to the UE and may receive a Type-1 HARQ-ACK codebook from the UE, such as that generated above.

[0124] Method #3 In some embodiments of the present disclosure, the HARQ-ACK codebook may include two parts (denoted as Part #1C and Part #2C for clarity). Generating the HARQ-ACK codebook may include generating Part #1C including HARQ-ACK information bits for candidate PDSCH reception opportunities for each cell of the first set of cells, and generating Part #2C including HARQ-ACK information bits for all cells that may potentially be scheduled by the first DCI format with one PDSCH on each cell.

[0125] Regarding portion #1C, in some examples, when a PDSCH is actually scheduled on a cell within a PDSCH reception opportunity candidate of the cell, the HARQ-ACK information bit for this PDSCH reception opportunity candidate is the HARQ-ACK information bit for this PDSCH, i.e., is ACK or NACK according to the decoding result of the PDSCH. For example, if a PDSCH from the first set of PDSCHs is scheduled on a cell from the first set of cells and is included in the PDSCH reception opportunity candidate of the cell, the HARQ-ACK information bit for this PDSCH reception opportunity candidate in portion #1C refers to the HARQ-ACK information bit for this PDSCH. In some examples, when a PDSCH that is actually scheduled within a PDSCH reception opportunity candidate of the cell is not on the cell, the HARQ-ACK information bit for this PDSCH reception opportunity candidate is NACK.

[0126] In some other examples, for portion #1C, the HARQ-ACK information bit for a PDSCH reception opportunity candidate is always NACK. For example, even when a PDSCH is actually scheduled on a cell within a PDSCH reception opportunity candidate of the cell, the HARQ-ACK information bit for this PDSCH reception opportunity candidate is NACK. For example, if a PDSCH from the first set of PDSCHs is scheduled on a cell from the first set of cells and is included in the PDSCH reception opportunity candidate of the cell, the HARQ-ACK information bit for this PDSCH reception opportunity candidate in portion #1C is NACK. This is because the HARQ-ACK information bit for this actually scheduled PDSCH can be indicated by portion #2C.

[0127] In some embodiments of the present disclosure, the HARQ-ACK information bits in portion #1C may first be ordered according to the PDSCH reception opportunity candidates for each of the first set of cells (e.g., in a predetermined order such as ascending or descending order of the PDSCH reception opportunity candidates), and then ordered according to the serving cell index of the first set of cells (e.g., in a predetermined order such as ascending or descending order of the serving cell index).

[0128] In some embodiments, the first set of cells may be a subset of a set of cells configured for multi-cell scheduling. Generating portion #1C may include generating HARQ-ACK information bits for PDSCH reception opportunity candidates for each cell of the set of cells (which may be ordered according to a predetermined order, such as ascending or descending order of PDSCH reception opportunity candidates for the corresponding cell), and concatenating the generated HARQ-ACK information bits according to associated serving cell indices (e.g., in a predetermined order, such as ascending or descending order of serving cell indices for the set of cells).

[0129] For example, the first DCI format may schedule a set of cells but may not actually schedule all cells in the set of cells, and portion #1C may include HARQ-ACK information bits for candidate PDSCH reception opportunities for cells in the set of cells that are not actually scheduled by the first DCI format.

[0130] As previously mentioned, in the context of this disclosure, cells that may potentially be scheduled by a multi-cell DCI format may refer to cells in the corresponding configured cell set. Part #2C may include HARQ-ACK information bits for all cells that may potentially be scheduled by the first DCI format with one PDSCH on each cell, regardless of whether any of such cells are actually scheduled by the first DCI format.

[0131] In some embodiments of the present disclosure, a cell that may potentially be scheduled by the first DCI format is not included in the first set of cells (i.e., is not actually scheduled), and the HARQ-ACK information bit in part #2C for this cell is NACK. The HARQ-ACK information bit in part #2C for a cell in the first set of cells scheduled by the first DCI format is ACK or NACK depending on the decoding result of the PDSCH scheduled on this cell.

[0132] In some embodiments of the present disclosure, the HARQ-ACK information bits in portion #2C may be ordered according to the associated cell index (e.g., a predetermined order such as ascending or descending order of the serving cell index of the configured cell set).

[0133] In some embodiments of the present disclosure, part #1C and part #2C may be arranged in the HARQ-ACK codebook according to a predetermined order. For example, part #1C is placed first in the HARQ-ACK codebook, followed by part #2C. For example, part #2C is placed first in the HARQ-ACK codebook, followed by part #1C.

[0134] In some embodiments of the present disclosure, when at least one cell of a configured cell set associated with DCI format 1_X (e.g., the first DCI format) is configured with a maximum of two codewords per PDSCH without spatial bundling, the number of HARQ-ACK information bits in portion #2C (i.e., the size of portion #2C) may be based on (e.g., equal to) M, where M indicates the maximum number of transport blocks (TBs) that can be jointly scheduled by DCI format 1_X (e.g., the first DCI format) in a PUCCH group for the UE.

[0135] In some embodiments of the present disclosure, when none of the cells in the configured cell set are configured with a maximum of two codewords per PDSCH, or when one or more cells in the configured cell set are configured with a maximum of two codewords per PDSCH and configured with spatial bundling, the number of HARQ-ACK information bits in portion #2C (i.e., the size of portion #2C) may be based on (e.g., equal to) N, where N is the maximum number of cells that can be scheduled together by DCI format 1_X (e.g., the first DCI format) in a PUCCH group for the UE.

[0136] An example of determining the HARQ-ACK codebook according to Method #3 is shown in FIG. 6 and FIG.

[0137] Referring to FIG. 6, the UE may be configured with a set of cells including CC631 to CC634 for multi-cell scheduling by DCI format 1_X. For simplicity, it is assumed that the serving cell indexes of CC631 to CC634 are CC631 < CC632 < CC633 < CC634.

[0138] The UE may receive DCI610 on CC631 in slot n from the BS. It is assumed that DCI610 schedules three cells, namely CC631 to CC633 together. DCI610 may indicate a specific row of the TDRA table, which indicates a K0 value of {1, 6, 5, 2}. Based on the indicated K0 value and the number of cells scheduled together (e.g., assumed to be 3), the UE can determine that DCI610 schedules PDSCH621 on CC631 in slot n+1, schedules PDSCH622 on CC632 in slot n+6, and schedules PDSCH623 on CC633 in slot n+5. Since PDSCH622 is the newest PDSCH among the three scheduled PDSCHs together, it is used as the reference PDSCH, and cell 632 is regarded as the reference cell. The PDSCH-to-HARQ_feedback timing indicator field in DCI610 indicates a k1 value of 3, and thus it is assumed that the PUCCH carrying the HARQ-ACK feedback for the three scheduled PDSCHs together is transmitted in slot n+9 (i.e., (slot n+6) + 3 slots).

[0139] Assuming that the K1 set is {1, 2, 3, 4} for each of CC631 to CC634, based on slot n+9, the PDSCH reception opportunity candidates on each cell are determined in slots n+5 to n+8 in the reverse order of the k1 values in the K1 set.

[0140] The UE may generate a HARQ-ACK codebook 750 as shown in FIG. 7 according to method #3 for transmission in slot n+9 (eg, on a PUCCH 760 as shown in FIG. 7).

[0141] 7, HARQ-ACK codebook 750 includes portion 751 and portion 752. Part 751 includes HARQ-ACK information bits for PDSCH reception opportunity candidates on each of the configured cell set for multi-cell scheduling. Part 752 includes HARQ-ACK information bits for all cells of the configured cell set with one PDSCH on each cell.

[0142] For simplicity, it is assumed that an ascending order of cell indexes is used. For example, if the HARQ-ACK information bits for the PDSCH reception opportunity candidates on CCs 631 to 634 in FIG. 6 are denoted as c1 to c4, respectively, then portion 751 in FIG. 7 may be arranged as {c1, c2, c3, c4}. For example, if the HARQ-ACK information bits for PDSCHs 621 to 623 in FIG. 6 are denoted as c5 to c7, respectively, and the HARQ-ACK information bit for a PDSCH that may be scheduled on CC 634 in FIG. 6 is denoted as c8, then portion 752 in FIG. 7 may be arranged as {c5, c6, c7, c8}. In some examples, c8 may indicate a NACK when no PDSCH is actually scheduled on CC 634 in FIG. 6.

[0143] HARQ-ACK information bit c1 in Figure 7 includes HARQ-ACK information bits for four PDSCH reception opportunity candidates of CC 631 in Figure 6, which may be ordered according to the associated PDSCH reception opportunity candidates. Similarly, HARQ-ACK information bit c2, c3, or c4 in Figure 7 includes HARQ-ACK information bits for four PDSCH reception opportunity candidates of CC 632, 633, or 634 in Figure 6, which may be ordered according to the associated PDSCH reception opportunity candidates.

[0144] For simplicity, it is assumed that for each cell, an ascending order of PDSCH reception opportunity candidates is utilized.

[0145] For example, if the HARQ-ACK information bits for the four PDSCH reception opportunities of CC631 in FIG. 6 are denoted as c1-1, c1-2, c1-3, and c1-4, the HARQ-ACK information bit c1 in FIG. 7 can be denoted as {c1-1, c1-2, c1-3, c1-4}.

[0146] In some embodiments, when there is no PDSCH actually transmitted in a PDSCH reception opportunity candidate of a cell, the HARQ-ACK information bit for this PDSCH reception opportunity candidate indicates a NACK. For example, c1-1, c1-2, c1-3, and c1-4 may be a NACK.

[0147] In some embodiments, when a PDSCH is actually transmitted in a PDSCH reception opportunity candidate of a cell, the HARQ-ACK information bit for this PDSCH reception opportunity candidate refers to the HARQ-ACK information bit for this PDSCH. In some other embodiments, the HARQ-ACK information bit for a PDSCH reception opportunity candidate of a cell may always indicate a NACK.

[0148] For example, the HARQ-ACK information bit for the PDSCH reception opportunity candidate of CC 632 in slot n+6 in Figure 6 may refer to the HARQ-ACK information bit for PDSCH 622 (e.g., c6) or may always be NACK because PDSCH 622 is scheduled in slot n+6 on CC 632. For example, the HARQ-ACK information bit c2 in Figure 7 may be denoted as {NACK, c6, NACK, NACK} or {NACK, NACK, NACK, NACK}.

[0149] Similarly, the HARQ-ACK information bit for the PDSCH reception opportunity candidate of C633 in slot n+5 in Figure 6 may refer to the HARQ-ACK information bit for PDSCH 623 (e.g., c7) or may always be a NACK since PDSCH 623 is scheduled in slot n+5 on CC 633. For example, the HARQ-ACK information bit c3 in Figure 7 may be denoted as {c7,NACK,NACK,NACK} or {NACK,NACK,NACK,NACK}.

[0150] For example, DCI 610 does not schedule CC 634, and HARQ-ACK information bit c4 in FIG. 7 may be represented as {NACK, NACK, NACK, NACK}.

[0151] From the UE perspective, the following steps may be implemented to generate a Type-1 HARQ-ACK codebook according to Method #3. (3-1) The UE checks the K0 value for each of the co-scheduled PDSCHs as indicated by the TDRA field, and finds the reference PDSCH that terminates last among the co-scheduled PDSCHs. (3-2) The UE determines the slot in which the PUCCH carrying the HARQ-ACK feedback for the co-scheduled PDSCH is transmitted. (3-3) The UE identifies PDSCH receiving opportunity candidates for each of the configured cell sets according to the respective K1 sets of each cell of the configured cell sets and the slots in which the PUCCH is transmitted. (3-4) The UE generates part #1C comprising HARQ-ACK information bits for each PDSCH reception opportunity candidate for each cell of the co-scheduled cells (configured cell set), and orders the generated HARQ-ACK information bits first according to the PDSCH reception opportunity candidate for each cell of the co-scheduled cells (or configured cell set) (e.g., in ascending order), and then according to the serving cell index of the co-scheduled cells (or configured cell set) (e.g., in ascending order). (3-5) The UE generates portion #2C comprising HARQ-ACK information bits for the configured cell set. In one embodiment, the UE orders the HARQ-ACK information bits for the configured cell set according to (e.g., in ascending order of) the serving cell index of the configured cell set. In another embodiment, the HARQ-ACK information bits for the configured cell set are ordered according to (e.g., in ascending order of) the PDSCH start timing, and if there are two or more PDSCHs with the same start timing, the HARQ-ACK information bits for two or more PDSCHs with the same start timing are ordered according to (e.g., in ascending order of) the associated serving cell index. (3-6) The UE concatenates parts #1C and #2C as a HARQ-ACK codebook for transmission on the PUCCH.

[0152] From the BS perspective, the BS may send a DCI format that schedules multiple PDSCHs to the UE and may receive a Type-1 HARQ-ACK codebook from the UE, such as that generated above.

[0153] Method #4 In some embodiments of the present disclosure, the HARQ-ACK codebook may include two portions (denoted as portion #1D and portion #2D for clarity). Generating the HARQ-ACK codebook may include generating portion #1D including HARQ-ACK information bits for candidate PDSCH reception opportunities for each cell of the first set of cells, and generating portion #2D including HARQ-ACK information bits for one or more PDSCHs of the first set of PDSCHs that are received on one or more cells of the first set of cells and that are outside the candidate PDSCH reception opportunities for the one or more cells of the first set of cells.

[0154] In some embodiments of the present disclosure, part #1D and part #2D may be arranged in the HARQ-ACK codebook according to a predetermined order. For example, part #1D is placed in the HARQ-ACK codebook first, followed by part #2D. For example, part #2D is placed in the HARQ-ACK codebook first, followed by part #1D.

[0155] The description regarding part #1C in method #3 may also apply to part #1D of method #4, except that in part #1D, when a PDSCH is actually scheduled on a cell within a PDSCH reception opportunity candidate of the cell, the HARQ-ACK information bit for this PDSCH reception opportunity candidate is the HARQ-ACK information bit for this PDSCH, i.e., ACK or NACK depending on the PDSCH decoding result. In other words, the HARQ-ACK information bit for such a PDSCH reception opportunity candidate may not always indicate NACK.

[0156] For example, similar to part #1C in method #3, in some embodiments of the present disclosure, the HARQ-ACK information bits in part #1D for the PDSCH reception opportunity candidates for each cell in the first set of cells may be ordered according to the associated PDSCH reception opportunity candidate.

[0157] For example, similar to part #1C in method #3, in some embodiments of the present disclosure, part #1D may include HARQ-ACK information bits for candidate PDSCH reception opportunities of a cell in the configured cell set that is not actually scheduled by the first DCI format.

[0158] In some embodiments of the present disclosure, the HARQ-ACK information bits in portion #2D are ordered according to the associated cell index. In some embodiments of the present disclosure, the HARQ-ACK information bits in portion #2D are ordered first according to the associated PDSCH start timing and then according to the associated cell index.

[0159] For example, referring again to Figure 2, the UE may generate a HARQ-ACK codebook to be transmitted in slot n+9. An example HARQ-ACK codebook 850 according to method #4 is shown in Figure 8 and may be transmitted on the PUCCH 860.

[0160] 8, HARQ-ACK codebook 850 includes portion 851 and portion 852. Portion 851 includes HARQ-ACK information bits for candidate PDSCH reception opportunities on each of CCs 231-234 (e.g., cells scheduled by DCI 210, or configured cell sets for multi-cell scheduling). Portion 852 includes HARQ-ACK information bits for PDSCHs 221 and 224 among PDSCHs that are scheduled by DCI 210 of FIG. 2 and are outside the candidate PDSCH reception opportunities of CCs 231 and 234, which are received on CCs 231 and 234.

[0161] For simplicity, it is assumed that an ascending order of cell index is used to arrange the HARQ-ACK information bits in portion 851 and portion 852. For example, if the HARQ-ACK information bits for the PDSCH reception opportunity candidates for CCs 231-234 in Figure 2 are denoted as d1 to d4, respectively, then portion 851 may be arranged as {d1, d2, d3, d4}. For example, if the HARQ-ACK information bits for PDSCHs 221 and 224 in Figure 2 are denoted as d5 and d6, respectively, then portion 852 in Figure 8 may be arranged as {d5, d6}.

[0162] HARQ-ACK information bit d1 in Figure 8 includes HARQ-ACK information bits for four PDSCH reception opportunity candidates of CC231 in Figure 2, which may be ordered according to the associated PDSCH reception opportunity candidates. Similarly, HARQ-ACK information bit d2, d3, or d4 in Figure 8 includes HARQ-ACK information bits for four PDSCH reception opportunity candidates of CC232, 233, or 234 in Figure 2, which may be ordered according to the associated PDSCH reception opportunity candidates.

[0163] For simplicity, it is assumed that for each cell, an ascending order of PDSCH reception opportunity candidates is utilized.

[0164] For example, if the HARQ-ACK information bits for the four PDSCH reception opportunity candidates of CC231 in FIG. 2 are denoted as d1-1, d1-2, d1-3, and d1-4, the HARQ-ACK information bit d1 in FIG. 8 can be denoted as {d1-1, d1-2, d1-3, d1-4}.

[0165] In some embodiments, when there is no PDSCH actually transmitted in a PDSCH reception opportunity candidate of a cell, the HARQ-ACK information bits for this PDSCH reception opportunity candidate indicate a NACK. For example, d1-1, d1-2, d1-3, and d1-4 may be NACKs. That is, the HARQ-ACK information bit d1 in FIG. 8 may be written as {NACK, NACK, NACK, NACK}. For example, the HARQ-ACK information bit d4 in FIG. 8 may be written as {NACK, NACK, NACK, NACK}.

[0166] In some embodiments, when a PDSCH is actually transmitted in a PDSCH reception opportunity candidate of a cell, the HARQ-ACK information bit for this PDSCH reception opportunity candidate refers to the HARQ-ACK information bit for this PDSCH.

[0167] For example, the HARQ-ACK information bit for the PDSCH reception opportunity candidate of CC 232 in slot n+6 in Figure 2 may refer to the HARQ-ACK information bit for PDSCH 222 because PDSCH 222 is scheduled in slot n+6 on CC 632. For example, if the HARQ-ACK information bit for PDSCH 222 is denoted as d2-0, then the HARQ-ACK information bit d2 in Figure 8 may be denoted as {NACK, d2-0, NACK, NACK}. Similarly, if the HARQ-ACK information bit for PDSCH 223 in slot n+5 on CC 633 is denoted as d3-0, then the HARQ-ACK information bit d3 in Figure 8 may be denoted as {d3-0, NACK, NACK, NACK}.

[0168] From the UE perspective, the following steps may be implemented to generate a Type-1 HARQ-ACK codebook according to Method #4. (4-1) The UE checks the K0 value for each of the co-scheduled PDSCHs as indicated by the TDRA field, and finds the reference PDSCH that terminates last among the co-scheduled PDSCHs. (4-2) The UE determines the slot in which the PUCCH carrying the HARQ-ACK feedback for the co-scheduled PDSCH is transmitted. (4-3) The UE identifies PDSCH reception opportunity candidates for each of the co-scheduled cells (or configured cell sets) according to the respective K1 sets of each of the co-scheduled cells (or configured cell sets) and the slots in which the PUCCH is transmitted. (4-4) The UE generates part #1D comprising HARQ-ACK information bits for each PDSCH reception opportunity candidate for each cell of the co-scheduled cells (or configured cell set), and orders the generated HARQ-ACK information bits first according to the PDSCH reception opportunity candidate for each of the co-scheduled cells (or configured cell set) (e.g., in ascending order), and then according to the serving cell index of the co-scheduled cells (or configured cell set) (e.g., in ascending order). (4-5) The UE checks whether there are one or more PDSCHs located outside the PDSCH reception opportunity candidates for each cell of the cells that are scheduled together by the multi-cell scheduling DCI format (e.g., DCI format 1_X or the first DCI format). If there is only one PDSCH scheduled by the DCI format and located outside the PDSCH reception opportunity candidates for the associated cell, the UE generates part #2D containing HARQ-ACK information bits for that single PDSCH. If there are multiple PDSCHs scheduled by the DCI format and located outside the PDSCH reception opportunity candidates in each cell, the UE generates part #2D including HARQ-ACK information bits for the multiple PDSCHs and orders the HARQ-ACK information bits for the multiple PDSCHs. i. In one embodiment, the HARQ-ACK information bits for multiple PDSCHs are ordered according to (eg, in ascending order of) the associated serving cell index. ii. In another embodiment, the HARQ-ACK information bits for the multiple PDSCHs are ordered according to (e.g., in ascending order of) the PDSCH start timing. If there are two or more PDSCHs with the same start timing among the multiple PDSCHs, the HARQ-ACK information bits for those two or more PDSCHs are ordered according to (e.g., in ascending order of) the associated serving cell index. (4-6) The UE concatenates Part #1D and Part #2D as a Type-1 HARQ-ACK codebook for transmission on the PUCCH.

[0169] From the BS perspective, the BS may send a DCI format scheduling multiple PDSCHs to the UE and may receive a Type-1 HARQ-ACK codebook from the UE as described above.

[0170] Method #5 In some embodiments of the present disclosure, generating the HARQ-ACK codebook may include generating, for each cell of the first set of cells, a portion (denoted as Part 1E) including HARQ-ACK information bits for candidate PDSCH reception opportunities of the corresponding cell, where the HARQ-ACK information bits for the candidate PDSCH reception opportunities in Part 1E are ordered according to the associated PDSCH reception opportunities (e.g., a predetermined order, such as ascending or descending order of candidate PDSCH reception opportunities on the corresponding cell).

[0171] In some embodiments of the present disclosure, if a PDSCH (denoted as PDSCH #1E) from the first set of PDSCHs is received on a cell from the first set of cells and is outside the PDSCH reception opportunity candidate for that cell, generating a HARQ-ACK codebook may further include generating another portion (denoted as Part #2E) for that cell, where Part #2E includes HARQ-ACK information bits for PDSCH #1E.

[0172] The UE may concatenate Part #1E and Part #2E for this cell to form the HARQ-ACK feedback for this cell. In some embodiments of the present disclosure, Part #1E and Part #2E may be concatenated according to a predetermined order. For example, Part #1E is placed before Part #2E. For example, Part #2E is placed before Part #1E.

[0173] In some embodiments of the present disclosure, the HARQ-ACK information bits for each cell of the first set of cells are ordered according to the associated serving cell index (e.g., in a predetermined order, such as ascending or descending order of the serving cell index of the first set of cells).

[0174] In some embodiments, the first set of cells may be a subset of the configured cell set for multi-cell scheduling. Generating the HARQ-ACK codebook may further include, for a cell in the configured cell set that may be scheduled by the first DCI format but is not actually scheduled, generating a Part #1E for such cell. The HARQ-ACK information bits for each cell in the configured cell set are ordered according to an associated serving cell index (e.g., in a predetermined order, such as ascending or descending order of the serving cell index of the configured cell set).

[0175] For example, referring again to Figure 2, the UE may generate a HARQ-ACK codebook to be transmitted in slot n+9. An exemplary HARQ-ACK codebook 950 according to Method #5 is shown in Figure 9. In the example of Figure 9, it is assumed that Part #1E is placed before Part #2E, and that ascending serving cell index order is utilized to order the HARQ-ACK information bits for each cell.

[0176] 9, HARQ-ACK codebook 950 may include HARQ-ACK information bit e1 and HARQ-ACK information bit f1 for CC 231 in Figure 2, HARQ-ACK information bit e2 for CC 232 in Figure 2, HARQ-ACK information bit e3 for CC 233 in Figure 2, and HARQ-ACK information bit e4 and HARQ-ACK information bit f4 for CC 234 in Figure 2. HARQ-ACK information bits e1 to e4 indicate HARQ-ACK information bits for PDSCH reception opportunity candidates for CCs 231 to 234 in Figure 2, respectively. HARQ-ACK information bits f1 and f4 indicate HARQ-ACK information bits for PDSCHs 221 and 224 in Figure 2, respectively.

[0177] In some embodiments, when a PDSCH is actually transmitted in a PDSCH reception opportunity candidate of a cell, the HARQ-ACK information bit for this PDSCH reception opportunity candidate refers to the HARQ-ACK information bit for this PDSCH. In some embodiments, when there is no PDSCH actually transmitted in a PDSCH reception opportunity candidate of a cell, the HARQ-ACK information bit for this PDSCH reception opportunity candidate indicates a NACK.

[0178] For example, if the HARQ-ACK information bits for PDSCHs 222 and 223 are denoted as f2 and f3, respectively, then HARQ-ACK information bits e1 to e4 may be denoted as {NACK,NACK,NACK,NACK}, {NACK,f2,NACK,NACK}, {f3,NACK,NACK,NACK}, and {NACK,NACK,NACK,NACK}, respectively.

[0179] From the UE perspective, the following steps may be implemented to generate a Type-1 HARQ-ACK codebook according to Method #5. (5-1) The UE checks the K0 value for each of the co-scheduled PDSCHs as indicated by the TDRA field, and finds the reference PDSCH that terminates last among the co-scheduled PDSCHs. (5-2) The UE determines the slot in which the PUCCH carrying the HARQ-ACK feedback for the co-scheduled PDSCH is transmitted. (5-3) The UE identifies PDSCH reception opportunity candidates for each of the co-scheduled cells (or configured cell sets) according to the respective K1 sets of each of the co-scheduled cells (or configured cell sets) and the slots in which the PUCCH is transmitted. (5-4) For each cell in the set of cells (or cells that are scheduled together), The UE generates a portion #1E including HARQ-ACK information bits for each PDSCH reception opportunity candidate on the cell; The UE checks whether there are one or more PDSCHs scheduled by a multi-cell scheduling DCI format (e.g., DCI format 1_X or a first DCI format) that are located outside of the PDSCH reception opportunity candidates on the cell; If there is only one PDSCH scheduled by the multi-cell scheduling DCI format outside the PDSCH reception opportunity candidates in the cell, the UE generates part #2E including HARQ-ACK information bits for the single PDSCH; If there are multiple PDSCHs scheduled by multiple multi-cell scheduling DCI formats outside the PDSCH reception opportunity candidates in the cell, the UE generates part #2E containing HARQ-ACK information bits for those multiple PDSCHs. (5-5) The UE concatenates the HARQ-ACK information bits for each cell of the co-scheduled cell (or configured cell set) as a Type-1 HARQ-ACK codebook for transmission on the PUCCH.

[0180] From the BS perspective, the BS may send a DCI format scheduling multiple PDSCHs to the UE and may receive a Type-1 HARQ-ACK codebook from the UE as described above.

[0181] As noted above, in some embodiments, all DCI format 1_X are configured or predetermined with the same set of cells for multi-cell scheduling, and in some other embodiments, multiple sets of cells may be configured or predetermined for multi-cell scheduling. The methods described above with respect to Strategy #1 (e.g., Methods #1 through #5) are applicable to both cases.

[0182] For example, referring to Figure 3, the UE may receive a second DCI format that schedules a second set of PDSCHs on a second set of cells of the UE, and the HARQ-ACK feedback for the second set of PDSCHs will be multiplexed in the HARQ-ACK codebook. In some embodiments of the present disclosure, each of the first and second sets of cells is a subset of a respective set of cells configured for multi-cell scheduling or is a subset of the same set of cells configured for multi-cell scheduling.

[0183] In some embodiments of the present disclosure, Method #1 is utilized. For example, generating a HARQ-ACK codebook may include generating HARQ-ACK feedback for each cell of the first set and the second set of cells, which may include generating HARQ-ACK information bits for PDSCH reception opportunity candidates of corresponding cells among the first set and the second set of cells, and generating HARQ-ACK information bits for a PDSCH (denoted as PDSCH #1A′) received on the corresponding cell and located outside the PDSCH reception opportunity candidate of the corresponding cell.

[0184] For example, referring to FIG. 10, the UE may be configured with a plurality of cells (e.g., CC1031 to 1038) and a plurality of sets of cells (e.g., cell set 1070 and cell set 1071) for multi-cell scheduling. Cell set 1070 may include CC1031 to 1034, and cell set 1071 may include CC1035 and 1036. CC1037 and 1038 may not be used for multi-cell scheduling. For simplicity, it is assumed that the serving cell indexes of CC1031 to 1038 are CC1031 < CC1032 < CC1033 < CC1034 < CC1035 < CC1036 < CC1037 < CC1038.

[0185] The DCI1010 transmitted in slot n on CC1031 may schedule PDSCH1021 in slot n + 1 on CC1031, schedule PDSCH1022 in slot n + 6 on CC1032, and schedule PDSCH1023 in slot n + 5 on CC1033. That is, DCI1010 does not schedule CC1034 in cell set 1070. The DCI1011 transmitted in slot n on CC1035 may schedule PDSCH1024 in slot n + 5 on CC1035 and schedule PDSCH1025 in slot n + 3 on CC1036. The UE may determine that the HARQ-ACK information bits for PDSCH1021 to 1025 are multiplexed in the same PUCCH in slot n + 9, and that the PDSCH reception opportunity candidates for each of the cells CC1031 to 1038 are within slots n + 5 to n + 8. The HARQ-ACK information bits for PDSCH1021 to 1025 are denoted as h1 to h5, respectively.

[0186] When Method #1 is utilized, in some embodiments, the UE may generate the following HARQ-ACK codebook: {{h1,NACK,NACK,NACK,NACK}, {NACK,h2,NACK,NACK}, {h3,NACK,NACK,NACK}, {NACK,NACK,NACK,NACK}, {h4,NACK,NACK,NACK}, {h5,NACK,NACK,NACK,NACK,NACK}, {NACK,NACK,NACK,NACK}, {NACK,NACK,NACK,NACK}}.

[0187] In some embodiments of the present disclosure, Method #2 is utilized. For example, generating a HARQ-ACK codebook may include generating HARQ-ACK feedback for each cell of the first set and the second set of cells, which may include generating HARQ-ACK information bits for candidate PDSCH reception opportunities for corresponding cells of the first set and the second set of cells, and generating HARQ-ACK information bits for PDSCHs (denoted as PDSCH #1B′) that may potentially be scheduled on the corresponding cells by the first DCI format or the second DCI format.

[0188] For example, and still referring to Figure 10, it is assumed that Method #2 is utilized. In some embodiments, the UE may generate the following HARQ-ACK codebook: {{h1,NACK,NACK,NACK,NACK}, {h2,NACK,NACK,NACK,NACK}, {h3,NACK,NACK,NACK,NACK,NACK}, {NACK,NACK,NACK,NACK,NACK}, {h4,NACK,NACK,NACK,NACK}, {h5,NACK,NACK,NACK,NACK}, {NACK,NACK,NACK,NACK}, {NACK,NACK,NACK,NACK}, {NACK,NACK,NACK,NACK}}. In some embodiments, the UE may generate the following HARQ-ACK codebook: {{h1,NACK,NACK,NACK,NACK}, {h2,NACK,h2,NACK,NACK}, {h3,h3,NACK,NACK,NACK}, {NACK,NACK,NACK,NACK,NACK,NACK}, {h4,h4,NACK,NACK,NACK}, {h5,NACK,NACK,NACK,NACK,NACK}, {NACK,NACK,NACK,NACK}, {NACK,NACK,NACK,NACK}}.

[0189] In some embodiments of the present disclosure, method #3 is utilized. For example, the HARQ-ACK codebook may include a portion #1C' and a portion #2C'. Generating the HARQ-ACK codebook may include generating a portion #1C' including HARQ-ACK information bits for candidate PDSCH reception opportunities for each cell of the first and second sets of cells, and generating a portion #2C' including HARQ-ACK information bits for all cells that may potentially be scheduled by the first and second DCI formats with one PDSCH on each cell.

[0190] In some embodiments of the present disclosure, the HARQ-ACK information bits in portion #2C' are ordered according to the cell indexes of the first and second sets of cells. In some embodiments of the present disclosure, the HARQ-ACK information bits in portion #2C' are ordered first according to the associated cell set index and then according to the associated serving cell index within the corresponding cell in the first and second sets of cells.

[0191] When multiple cell sets are configured or predetermined for multi-cell scheduling, in some embodiments of the present disclosure, when at least one cell of the multiple cell sets is configured with a maximum of two codewords per PDSCH without spatial bundling, the number of HARQ-ACK information bits in portion #2C' may be based on (e.g., equal to) M'*Z, where M' is the maximum number of TBs that can be scheduled together by DCI format 1_X in a PUCCH group for the UE, and Z is the number of cell sets configured for the UE in the same PUCCH group.

[0192] In some other embodiments of the present disclosure, when at least one cell of the plurality of cell sets is configured with at most two codewords per PDSCH without spatial bundling, the number of HARQ-ACK information bits in portion #2C′ is M1+M2+...M Z may be based on (e.g., equal to) M1, M2, ..., M Z is the respective maximum number of TBs of each cell in multiple cell sets in the same PUCCH group for the UE, and Z is the number of cell sets configured for the UE in the same PUCCH group. For example, M'=max(M1,M2,...,M Z )

[0193] In some embodiments of the present disclosure, if none of the cells in the multiple cell sets are configured with a maximum of two codewords per PDSCH, or if one or more cells in the multiple cell sets are configured with a maximum of two codewords per PDSCH and configured with spatial bundling, the number of HARQ-ACK information bits in portion #2C' may be based on (e.g., equal to) N'*Z, where N' is the maximum number of cells that can be scheduled together with DCI format 1_X in a PUCCH group for the UE (e.g., the total number of cells in the multiple cell sets), and Z is the number of cell sets configured for the UE in the same PUCCH group.

[0194] In some other embodiments of the present disclosure, if no cell in the plurality of cell sets is configured with at most two codewords per PDSCH, or if one or more cells in the plurality of cell sets are configured with at most two codewords per PDSCH and configured with spatial bundling, the number of HARQ-ACK information bits in portion #2C′ is N1 + N2 + ... N Z may be based on (e.g., equal to) N1, N2, ..., N Z is the number of cells in each of the cell sets in the same PUCCH group for the UE, and Z is the number of cell sets configured for the UE in the same PUCCH group. For example, N'=max(N1,N2,...,N Z )

[0195] For example, and still referring to Figure 10, it is assumed that Method #3 is utilized. In some embodiments, the UE may generate a HARQ-ACK codebook 1150 as shown in Figure 11 for transmission on the PUCCH 1160. The HARQ-ACK codebook 1150 may include two parts, namely, part 1151 (e.g., part #1C') may be written as {g1, g2, g3, g4, g5, g6, g7, g8}, and part 1152 (e.g., part #2C') may be written as {h1, h2, h3, NACK, h4, h5}, where g1, g2, g3, g4, g5, g6, g7, and g8 respectively indicate HARQ-ACK information bits for PDSCH reception opportunity candidates of cells in the configured cell sets (e.g., cell sets 1070 and 1071) corresponding to DCI 1010 and DCI 1011, and HARQ-ACK information bits for PDSCH reception opportunity candidates of cells 1037 and 1038.

[0196] In some embodiments of the present disclosure, method #4 is utilized. For example, the HARQ-ACK codebook may include a portion #1D′ including HARQ-ACK information bits for candidate PDSCH reception opportunities for each cell in the first and second sets of cells, and a portion #2D′ including HARQ-ACK information bits for one or more PDSCHs in the first and second sets of PDSCHs that are received on one or more cells in the first and second sets of cells and that are outside the candidate PDSCH reception opportunities for one or more cells in the first and second sets of cells.

[0197] For example, and still referring to Figure 10, it is assumed that method #4 is utilized. In some embodiments, the UE may generate a HARQ-ACK codebook of {{i1, i2, i3, i4, i5, i6, i7, i8}, {h1, h5}}, where i1, i2, i3, i4, i5, i6, i7, and i8 indicate HARQ-ACK information bits for candidate PDSCH reception opportunities of cells in the configured cell sets corresponding to DCI 1010 and DCI 1011 (e.g., cell sets 1070 and 1071), and for candidate PDSCH reception opportunities of cells 1037 and 1038, respectively.

[0198] In some embodiments of the present disclosure, method #5 is utilized. For example, generating a HARQ-ACK codebook may include generating HARQ-ACK feedback for each cell of the first and second sets of cells, comprising: a portion #1E′ including HARQ-ACK information bits for a candidate PDSCH reception opportunity of a corresponding cell among the first and second sets of cells; and a portion #2E′ including HARQ-ACK information bits for a PDSCH (denoted as PDSCH #1E′) among the first and second sets of PDSCHs in response to PDSCH #1E′ being received on the corresponding cell and located outside the candidate PDSCH reception opportunity of the corresponding cell.

[0199] For example, and still referring to Figure 10, it is assumed that method #5 is utilized. In some embodiments, the UE may generate a HARQ-ACK codebook of {{h1,j1},j2,j3,j4,j5,{h5,j6},j7,j8}, where j1, j2, j3, j4, j5, j6, j7, and j8 indicate HARQ-ACK information bits for candidate PDSCH reception opportunities of cells in the configured cell sets corresponding to DCI 1010 and DCI 1011 (e.g., cell sets 1070 and 1071) and for candidate PDSCH reception opportunities of cells 1037 and 1038, respectively.

[0200] In some embodiments of the present disclosure, both the BS and the UE should synchronize the same reference PDSCH for the UE to determine the slot in which HARQ-ACK feedback for a co-scheduled PDSCH is transmitted, the same candidate PDSCH reception opportunities on each cell of the co-scheduled cell or configured cell set, and the same understanding of the HARQ-ACK information bits for the candidate PDSCH reception opportunities on all cells of the co-scheduled cell or configured cell set.

[0201] In some embodiments of the present disclosure, a strategy is provided to avoid a scenario in which a PDSCH scheduled by a DCI format is located outside of a PDSCH reception opportunity candidate (hereinafter, Strategy #2). As described in the following text, various methods can be used to achieve Strategy #2.

[0202] Method #6 In some embodiments of the present disclosure, when a Type-1 HARQ-ACK codebook is configured for a UE and a set of cells is configured for multi-cell scheduling using DCI format 1_X, when DCI format 1_X for jointly scheduling multiple cells of the set of cells is received, the TDRA field in DCI format 1_X should indicate the same K0 value for each of the jointly scheduled PDSCHs, i.e., the jointly scheduled PDSCHs should be scheduled in the same slot. The UE does not expect to be indicated different K0 values ​​for each of the jointly scheduled PDSCHs. In other words, the BS should ensure that the TDRA field in DCI format 1_X should indicate the same K0 value for each of the jointly scheduled PDSCHs.

[0203] For example, the first DCI format received in operation 311 of FIG. 3 may include an indicator indicating the same slot-level offset for each of the first set of PDSCHs relative to the slot in which the first DCI format is received, and HARQ-ACK feedback for the first set of PDSCHs may be included in the HARQ-ACK feedback associated with the candidate PDSCH reception opportunities on the first set of cells.

[0204] Method #7 For a UE, when a Type-1 HARQ-ACK codebook is configured and a set of cells is configured for multi-cell scheduling using DCI format 1_X, when DCI format 1_X is received to jointly schedule multiple cells of the set of cells, the jointly scheduled PDSCHs should be included in the candidate PDSCH reception opportunities on the associated cells.

[0205] In some embodiments of the present disclosure, the K0 value configuration for each co-scheduled cell and the K1 set for each co-scheduled cell in the TDRA table, as well as the k1 value indicated by the PDSCH-to-HARQ_feedback timing indicator in DCI format 1_X, may be set in a manner to achieve this objective, for example, they may satisfy the following conditions: For cell X of cells that are scheduled together, n-(A max -K 0,X )>=n+kB max,X , i.e., k<=B max,X -(A max -K 0,X ) where A max is the maximum K0 value for cells that are scheduled together, and B max,X is the largest k1 value in the K1 set for cell X, and K 0,Xis the K0 value for cell X, k is the k1 value indicated by the PDSCH-to-HARQ_feedback timing indicator in DCI format 1_X, n is the slot in which the reference PDSCH is transmitted, and the reference PDSCH is the PDSCH with the largest K0 value among the co-scheduled PDSCHs.

[0206] At the UE side, for cells in the co-scheduled cell, the UE determines whether k<=B max,X -(A max -K 0,X ) is not expected to be presented in DCI format 1_X.

[0207] For example, assume that the K1 set is {1,2,3,4} for each cell of cells that are co-scheduled by DCI format 1_X, and the maximum k1 value is 4, as shown in Table 1 below.

[0208] In some examples, when row index 0 is indicated by the TDRA field in DCI format 1_X, the maximum K0 value is 6. If the indicated k1 value is 3, then 3<=4-(6-K 0,X ) is satisfied, K 0,X should be >= 5. Therefore, the PDSCHs on cell 1 and cell 4 are outside the PDSCH reception opportunity candidates on cell 1 and cell 4.

[0209] In some examples, when row index 1 is indicated by the TDRA field in DCI format 1_X, the maximum K0 value is 5. If the indicated k1 value is 3, then 3<=4-(5-K 0,X ) is satisfied, K 0,X should be >= 4. Therefore, the PDSCHs on cell 2, cell 3, and cell 4 are outside the candidate PDSCH reception opportunities on cell 2, cell 3, and cell 4.

[0210] [Table 1]

[0211] As can be seen, the configuration of the K0 value, the configuration of the K1 set, and the k1 value in the TDRA table are k<=B max,X -(A max -K 0,X ) should be set appropriately to satisfy the condition. An example that satisfies this condition is shown in Table 2.

[0212] [Table 2]

[0213]

[0043] Note that the above conditions and tables are for illustrative purposes only. The gist of this method is that when DCI format 1_X is transmitted to jointly schedule multiple PDSCHs on multiple cells, it should ensure that the jointly scheduled PDSCHs are included in the PDSCH reception opportunity candidates on the associated cells. For example, the first DCI format received in operation 311 of Figure 3 may include a first indicator indicating a separate slot-level offset for each of the first set of PDSCHs relative to the slot in which the first DCI format is received, and a second indicator indicating the slot in which the HARQ-ACK codebook is transmitted, under the constraints that the first set of PDSCHs are included in the PDSCH reception opportunity candidates on the associated cells of the first set of cells and that HARQ-ACK feedback for the first set of PDSCHs is included in the HARQ-ACK feedback associated with the PDSCH reception opportunity candidates on the first set of cells.

[0214] It should be understood by those skilled in the art that the order of the operations in the exemplary procedure 300 may be changed and that some of the operations in the exemplary procedure 300 may be omitted or modified without departing from the spirit and scope of the present disclosure.

[0215] 12 shows a flowchart of an exemplary procedure 1200 for wireless communication in accordance with some embodiments of the present disclosure. Details described in all of the above-described embodiments of the present disclosure are applicable to the embodiment shown in FIG. 12. In some examples, the procedure may be performed by a BS, for example, BS 102 of FIG. 1.

[0216] 12 , in operation 1211, the BS may send to the UE a first DCI format that schedules a first set of PDSCHs on a first set of cells of the UE. The description above regarding the first DCI format and DCI format 1_X may apply to the first DCI format in operation 1211.

[0217] In operation 1213, the BS may receive from the UE a HARQ-ACK codebook including HARQ-ACK feedback associated with candidate PDSCH reception opportunities on the first set of cells and HARQ-ACK feedback for the first set of PDSCHs. The HARQ-ACK codebook may be generated by the UE according to one of methods #1 through #7 as described above.

[0218] For example, in some embodiments of the present disclosure, according to Method #1, the HARQ-ACK codebook may include HARQ-ACK information bits for each cell of the first set of cells ordered according to an associated serving cell index. In some embodiments, the HARQ-ACK information bits for each cell of the first set of cells may include HARQ-ACK information bits for candidate PDSCH reception opportunities of the corresponding cell and HARQ-ACK information bits for a first PDSCH of the first set of PDSCHs transmitted on the corresponding cell and located outside the candidate PDSCH reception opportunities of the corresponding cell. In some embodiments, the HARQ-ACK information bits for the candidate PDSCH reception opportunities of the corresponding cell and the HARQ-ACK information bits for the first PDSCH are ordered according to the PDSCH reception opportunities on the corresponding cell.

[0219] For example, in some embodiments of the present disclosure, according to Method #2, the HARQ-ACK codebook may include HARQ-ACK information bits for each cell of the first set of cells ordered according to an associated serving cell index. In some embodiments, the HARQ-ACK information bits for each cell of the first set of cells may include HARQ-ACK information bits for candidate PDSCH reception opportunities of the corresponding cell and HARQ-ACK information bits for first PDSCHs that may potentially be scheduled on the corresponding cell by the first DCI format.

[0220] In some embodiments, the HARQ-ACK information bits for the first PDSCH are placed after or before the HARQ-ACK information bits for the candidate PDSCH reception opportunities of the corresponding cell. In some embodiments, the HARQ-ACK information bits for the candidate PDSCH reception opportunities of the corresponding cell are ordered according to the PDSCH reception opportunities on the corresponding cell.

[0221] In some embodiments, if the first PDSCH is actually scheduled on the corresponding cell according to the first DCI format, the HARQ-ACK information bit for the first PDSCH is ACK or NACK according to the decoding result of the first PDSCH. In some embodiments, if the first PDSCH is not scheduled on the corresponding cell according to the first DCI format, the HARQ-ACK information bit for the first PDSCH is NACK.

[0222] For example, in some embodiments of the present disclosure, according to Method #3, the HARQ-ACK codebook may include a first part and a second part, where the first part may include HARQ-ACK information bits for candidate PDSCH reception opportunities for each cell of the first set of cells, and the second part may include HARQ-ACK information bits for all cells that may potentially be scheduled by the first DCI format with one PDSCH on each cell.

[0223] In some embodiments, if a cell that may potentially be scheduled by the first DCI format is not included in the first set of cells, the HARQ-ACK information bit in the second part for that cell is a NACK. In some embodiments, the HARQ-ACK information bit in the second part for a cell in the first set of cells that are scheduled by the first DCI format is an ACK or a NACK.

[0224] In some embodiments, if a second PDSCH of the first set of PDSCHs is scheduled on a cell of the first set of cells and is included in the candidate PDSCH reception opportunities for that cell, the HARQ-ACK information bit for the second PDSCH in the first portion for that cell is ACK or NACK, or is NACK, depending on the decoding result of the second PDSCH.

[0225] In some embodiments, the HARQ-ACK information bits in the first portion for the PDSCH reception opportunity candidate for each cell in the first set of cells are ordered according to the associated PDSCH reception opportunity candidate, and in some embodiments, the HARQ-ACK information bits in the second portion are ordered according to the associated cell index.

[0226] For example, in some embodiments of the present disclosure, according to Method #4, the HARQ-ACK codebook may include a first part and a second part, where the first part may include HARQ-ACK information bits for candidate PDSCH reception opportunities for each cell of the first set of cells, and the second part may include HARQ-ACK information bits for one or more PDSCHs of the first set of PDSCHs that are transmitted in one or more cells of the first set of cells and are located outside the candidate PDSCH reception opportunities for the one or more cells of the first set of cells.

[0227] In some embodiments, the HARQ-ACK information bits in the first portion for the PDSCH reception opportunity candidate for each cell in the first set of cells are ordered according to the associated PDSCH reception opportunity candidate. In some embodiments, the HARQ-ACK information bits in the second portion are ordered according to the associated cell index. In some embodiments, the HARQ-ACK information bits in the second portion are ordered first according to the associated PDSCH start timing and then according to the associated cell index.

[0228] For example, in some embodiments of the present disclosure, according to method #5, the HARQ-ACK codebook may include, for each cell of the first set of cells, a first portion comprising HARQ-ACK information bits for the PDSCH reception opportunity candidates of the corresponding cell, and a second portion comprising HARQ-ACK information bits for a first PDSCH of the first set of PDSCHs in response to the first PDSCH being transmitted on the corresponding cell and being outside the PDSCH reception opportunity candidates of the corresponding cell.

[0229] In some embodiments, the HARQ-ACK information bits for each cell of the first set of cells are ordered according to the associated serving cell index.

[0230] In some embodiments of the present disclosure, the BS may further transmit to the UE a second DCI format that schedules a second set of PDSCHs on a second set of cells of the UE, and the HARQ-ACK feedback for the second set of PDSCHs is to be multiplexed in the HARQ-ACK codebook.

[0231] In some embodiments of the present disclosure, each of the first and second sets of cells is a subset of a respective set of cells configured for multi-cell scheduling. In some embodiments of the present disclosure, each of the first and second sets of cells is a subset of the same set of cells configured for multi-cell scheduling.

[0232] In some embodiments of the present disclosure, the HARQ-ACK codebook may include HARQ-ACK feedback for each cell of the first and second sets of cells, which may include HARQ-ACK information bits for PDSCH reception opportunity candidates of the corresponding cell in the first and second sets of cells and HARQ-ACK information bits for the first PDSCH transmitted on the corresponding cell and located outside the PDSCH reception opportunity candidates of the corresponding cell.

[0233] In some embodiments of the present disclosure, the HARQ-ACK codebook may include HARQ-ACK feedback for each cell of the first and second sets of cells, which may include HARQ-ACK information bits for candidate PDSCH reception opportunities of the corresponding cell in the first and second sets of cells and HARQ-ACK information bits for the first PDSCH that may potentially be scheduled on the corresponding cell by the first DCI format or the second DCI format.

[0234] In some embodiments of the present disclosure, the HARQ-ACK codebook may include a first portion and a second portion, where the first portion may include HARQ-ACK information bits for candidate PDSCH reception opportunities for each cell of the first and second sets of cells, and the second portion may include HARQ-ACK information bits for all cells that may potentially be scheduled by the first and second DCI formats with one PDSCH on each cell.

[0235] In some embodiments, the HARQ-ACK information bits in the second portion are ordered according to cell indices of the first and second sets of cells. In some embodiments, the HARQ-ACK information bits in the second portion are ordered first according to associated cell set indices and then according to associated serving cell indices within corresponding sets of the first and second sets of cells.

[0236] In some embodiments of the present disclosure, the HARQ-ACK codebook may include a first portion comprising HARQ-ACK information bits for candidate PDSCH reception opportunities for each cell in the first and second sets of cells, and a second portion comprising HARQ-ACK information bits for one or more PDSCHs in the first and second sets of PDSCHs that are transmitted on one or more cells in the first and second sets of cells and that are outside the candidate PDSCH reception opportunities for the one or more cells in the first and second sets of cells.

[0237] In some embodiments of the present disclosure, the HARQ-ACK codebook may include a HARQ-ACK feedback for each cell of the first and second sets of cells, which may include a first portion comprising HARQ-ACK information bits for a PDSCH reception opportunity candidate of the corresponding cell of the first and second sets of cells, and a second portion comprising HARQ-ACK information bits for a first PDSCH of the first and second sets of PDSCHs in response to the first PDSCH being transmitted on the corresponding cell and falling outside the PDSCH reception opportunity candidate of the corresponding cell.

[0238] In some embodiments of the present disclosure, the first DCI format may include an indicator that indicates the same slot-level offset for each of the first set of PDSCHs relative to the slot in which the first DCI format is transmitted, and the HARQ-ACK feedback for the first set of PDSCHs is included in the HARQ-ACK feedback associated with the candidate PDSCH reception opportunities on the first set of cells.

[0239] In some embodiments of the present disclosure, the first DCI format may include a first indicator indicating a distinct slot-level offset for each of the first set of PDSCHs relative to the slot in which the first DCI format is transmitted, and a second indicator indicating the slot in which the HARQ-ACK codebook is transmitted, under the constraints that the first set of PDSCHs are included in the candidate PDSCH reception opportunity on an associated cell of the first set of cells and that the HARQ-ACK feedback for the first set of PDSCHs is included in the HARQ-ACK feedback associated with the candidate PDSCH reception opportunity on the first set of cells.

[0240] It should be understood by those skilled in the art that the order of the operations in the exemplary procedure 1200 may be changed and some of the operations in the exemplary procedure 1200 may be deleted or modified without departing from the spirit and scope of the present disclosure.

[0241] 13 illustrates a block diagram of an exemplary apparatus 1300 according to some embodiments of the present disclosure. As shown in FIG. 13, the apparatus 1300 may include at least one processor 1306 and at least one transceiver 1302 coupled to the processor 1306. The apparatus 1300 may be a UE or a BS.

[0242] In this figure, elements such as at least one transceiver 1302 and processor 1306 are described in the singular, but the plural is contemplated unless limitation to the singular is explicitly stated. In some embodiments of the present application, the transceiver 1302 may be separated into two devices, such as a receiving circuit and a transmitting circuit. In some embodiments of the present application, the apparatus 1300 may further include an input device, a memory, and / or other components.

[0243] In some embodiments of the present application, the apparatus 1300 may be a UE. The transceiver 1302 and the processor 1306 may interact with each other to perform operations related to a UE described in Figures 1-12. In some embodiments of the present application, the apparatus 1300 may be a BS. The transceiver 1302 and the processor 1306 may interact with each other to perform operations related to a BS described in Figures 1-12.

[0244] In some embodiments of the present application, the apparatus 1300 may further include at least one non-transitory computer-readable medium.

[0245] For example, in some embodiments of the present disclosure, a non-transitory computer-readable medium may store computer-executable instructions for causing the processor 1306 to perform methods related to a UE, such as those described above. For example, the computer-executable instructions, when executed, cause the processor 1306, interacting with the transceiver 1302, to perform operations related to a UE, as described in FIGS. 1-12.

[0246] In some embodiments of the present disclosure, a non-transitory computer-readable medium may store computer-executable instructions to cause the processor 1306 to perform methods related to the BS as described above. For example, the computer-executable instructions, when executed, cause the processor 1306, interacting with the transceiver 1302, to perform operations related to the BS described in FIGS. 1-12.

[0247] Those skilled in the art will understand that the operations or steps of the methods described in connection with the aspects disclosed herein may be embodied directly in hardware, in software modules executed by a processor, or in a combination of the two. The software modules may reside in RAM memory, flash memory, ROM memory, EPROM memory, EEPROM memory, registers, a hard disk, a removable disk, a CD-ROM, or any other form of storage medium known in the art. Additionally, in some aspects, the operations or steps of the methods may reside as one or any combination or set of codes and / or instructions on a non-transitory computer-readable medium, which may be incorporated into a computer program product.

[0248] While the present disclosure has been described with specific embodiments thereof, it is apparent that many alternatives, modifications, and variations may be apparent to those skilled in the art. For example, various components of the embodiments may be interchanged, added, or substituted in other embodiments. Also, not all elements in each figure are necessary for the operation of the disclosed embodiments. For example, one skilled in the art of the disclosed embodiments will be enabled to make and use the teachings of the present disclosure by simply utilizing the elements of the independent claims. Accordingly, the embodiments of the present disclosure described herein are intended to be illustrative, not limiting. Various changes may be made without departing from the spirit and scope of the present disclosure.

[0249] As used herein, the terms "includes," "including," or any other variations thereof are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that includes a list of elements does not include only those elements, but may include other elements not expressly listed or inherent in such process, method, article, or apparatus. The use of an element preceded by "a," "an," etc., without further constraints, does not exclude the presence of additional identical elements in the process, method, article, or apparatus that includes that element. Also, the term "another" is defined as at least a second or more. Terms such as "having" are defined herein as "comprising." Phrases such as "A and / or B" or "at least one of A and B" may include any and all combinations of the words listed with that phrase. For example, the phrase "A and / or B" or "at least one of A and B" may include A, B, or both A and B. Phrases such as "first," "second," etc. are used only to clearly illustrate embodiments of the present application and are not used to limit the scope of the present application. [Explanation of symbols]

[0250] 100 Wireless Communication System 101UE 102 BS 231 CC 232 CC 233 CC 234 CC 450 HARQ-ACK codebook 550 HARQ-ACK codebook 631 CC 632 CC 633 CC 634 CC 750 HARQ-ACK codebook 751 parts 752 parts 760 PUCCH 850 HARQ-ACK codebook 851 parts 852 parts 860 PUCCH 950 HARQ-ACK codebook 1031 CC 1032 CC 1033 CC 1034 CC 1035 CC 1036 CC 1037 CC 1038 CC 1070 Cell Set 1071 Cell Set 1150 HARQ-ACK codebook 1151 parts 1152 parts 1160 PUCCH 1302 Transceiver 1306 processor

Claims

1. A transceiver; a processor coupled to the transceiver, the processor comprising: receiving a first downlink control information (DCI) format that schedules a first set of physical downlink shared channels (PDSCHs) on a first set of cells for the UE; generating a hybrid automatic repeat request acknowledgement (HARQ-ACK) codebook comprising HARQ-ACK feedback associated with candidate PDSCH reception opportunities on the first set of cells and HARQ-ACK feedback for the first set of PDSCHs; Send the HARQ-ACK codebook The UE is configured as follows.

2. 2. The UE of claim 1, wherein generating the HARQ-ACK codebook comprises generating a HARQ-ACK information bit for each cell of the first set of cells and concatenating the generated HARQ-ACK information bits for each cell of the first set of cells in order of associated serving cell index.

3. generating a HARQ-ACK information bit for each cell of the first set of cells; generating a HARQ-ACK information bit for a PDSCH receiving opportunity candidate of the corresponding cell; and generating a HARQ-ACK information bit for a first PDSCH of the first set of PDSCHs that is received on the corresponding cell and that is located outside the PDSCH reception opportunity candidates of the corresponding cell.

4. generating a HARQ-ACK information bit for each cell of the first set of cells; generating a HARQ-ACK information bit for a PDSCH receiving opportunity candidate of the corresponding cell; and generating a HARQ-ACK information bit for a first PDSCH that may be scheduled on the corresponding cell according to the first DCI format.

5. 2. The UE of claim 1, wherein the HARQ-ACK codebook comprises a first portion and a second portion, and wherein generating the HARQ-ACK codebook comprises: generating the first portion comprising HARQ-ACK information bits for candidate PDSCH reception opportunities for each cell of the first set of cells; and generating the second portion comprising HARQ-ACK information bits for all cells that may potentially be scheduled by the first DCI format with one PDSCH on each cell.

6. 2. The UE of claim 1, wherein the HARQ-ACK codebook comprises a first portion and a second portion, and generating the HARQ-ACK codebook comprises: generating the first portion comprising HARQ-ACK information bits for a candidate PDSCH reception opportunity for each cell of the first set of cells; and generating the second portion comprising HARQ-ACK information bits for one or more PDSCHs of the first set of PDSCHs that are received on one or more cells of the first set of cells and that are outside the candidate PDSCH reception opportunity for the one or more cells of the first set of cells.

7. The step of generating a HARQ-ACK codebook comprises, for each cell of the first set of cells: generating a first portion comprising HARQ-ACK information bits for PDSCH reception opportunity candidates of the corresponding cell; generating a second portion comprising HARQ-ACK information bits for a first PDSCH of the first set of PDSCHs when the first PDSCH is received on the corresponding cell and is located outside the PDSCH reception opportunity candidate of the corresponding cell; and concatenating the first portion and the second portion to generate a HARQ-ACK feedback for the corresponding cell.

8. 10. The UE of claim 1, wherein the processor is further configured to receive a second DCI format that schedules a second set of PDSCHs on a second set of cells of the UE, and wherein HARQ-ACK feedback for the second set of PDSCHs is to be multiplexed in the HARQ-ACK codebook.

9. generating a HARQ-ACK codebook comprises generating a HARQ-ACK feedback for each cell of the first and second sets of cells, the generating comprising: generating HARQ-ACK information bits for PDSCH reception opportunity candidates of corresponding cells in the first and second sets of cells; and generating a HARQ-ACK information bit for a first PDSCH received on the corresponding cell and located outside the PDSCH reception opportunity candidates of the corresponding cell.

10. generating a HARQ-ACK codebook comprises generating a HARQ-ACK feedback for each cell of the first and second sets of cells, the generating comprising: generating HARQ-ACK information bits for PDSCH reception opportunity candidates of corresponding cells in the first and second sets of cells; and generating a HARQ-ACK information bit for a first PDSCH that may be scheduled on the corresponding cell by the first DCI format or the second DCI format.

11. 9. The UE of claim 8, wherein the HARQ-ACK codebook comprises a first portion and a second portion, and wherein generating the HARQ-ACK codebook comprises: generating the first portion comprising HARQ-ACK information bits for a candidate PDSCH reception opportunity for each cell of the first and second sets of cells; and generating the second portion comprising HARQ-ACK information bits for all cells that may potentially be scheduled by the first and second DCI formats with one PDSCH on each cell.

12. 9. The UE of claim 8, wherein the HARQ-ACK codebook comprises: a first portion comprising HARQ-ACK information bits for a candidate PDSCH reception opportunity for each cell in the first and second sets of cells; and a second portion comprising HARQ-ACK information bits for one or more PDSCHs in the first and second sets of PDSCHs that are received on one or more cells in the first and second sets of cells and that are outside the candidate PDSCH reception opportunity for the one or more cells in the first and second sets of cells.

13. generating a HARQ-ACK codebook comprises generating a HARQ-ACK feedback for each cell of the first and second sets of cells, the generating comprising: a first portion comprising HARQ-ACK information bits for PDSCH reception opportunity candidates of corresponding cells in the first and second sets of cells; and a second portion comprising HARQ-ACK information bits for a first PDSCH of the first and second sets of PDSCHs in response to the first PDSCH being received on the corresponding cell and being outside the PDSCH reception opportunity candidates of the corresponding cell.

14. 2. The UE of claim 1, wherein the first DCI format includes: a first indicator indicating a distinct slot-level offset for each of the first set of PDSCHs relative to the slot in which the first DCI format is received; and a second indicator indicating the slot in which the HARQ-ACK codebook is transmitted, under constraints that the first set of PDSCHs are included in the candidate PDSCH reception opportunity on an associated cell of the first set of cells and that the HARQ-ACK feedback for the first set of PDSCHs is included in the HARQ-ACK feedback associated with the candidate PDSCH reception opportunity on the first set of cells.

15. A transceiver; a processor coupled to the transceiver, the processor comprising: transmitting, to a user equipment (UE), a first downlink control information (DCI) format that schedules a first set of physical downlink shared channels (PDSCHs) on a first set of cells of the UE; receive, from the UE, a hybrid automatic repeat request acknowledgement (HARQ-ACK) codebook comprising HARQ-ACK feedback associated with candidate PDSCH reception opportunities on the first set of cells and HARQ-ACK feedback for the first set of PDSCHs; A base station (BS) configured to:

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