WO2024109113A1

WO2024109113A1 - Method and apparatus for harq-ack codebook determination based on downlink assignment index

Info

Publication number: WO2024109113A1
Application number: PCT/CN2023/107491
Authority: WO
Inventors: Haipeng Lei
Original assignee: Lenovo (Beijing) Limited
Priority date: 2023-07-14
Filing date: 2023-07-14
Publication date: 2024-05-30

Abstract

Embodiments of the present disclosure relate to method and apparatus for HARQ-ACK codebook determination based on downlink assignment index. According to some embodiments of the disclosure, a UE may: receive, from a BS, a plurality of DCI formats for scheduling a plurality of PDSCHs on a plurality of serving cells of the UE, wherein the plurality of DCI formats indicates a same slot for transmitting HARQ-ACK feedback, and each of the plurality of DCI formats comprises a counter DAI and a total DAI; generate a HARQ-ACK codebook comprising HARQ-ACK information bits for the plurality of PDSCHs; and transmit, to the BS, the HARQ-ACK codebook.

Description

METHOD AND APPARATUS FOR HARQ-ACK CODEBOOK DETERMINATION BASED ON DOWNLINK ASSIGNMENT INDEX

TECHNICAL FIELD

Embodiments of the present disclosure generally relate to wireless communication technology, and more particularly to hybrid automatic repeat request acknowledgement (HARQ-ACK) codebook determination.

BACKGROUND

A wireless communication system may include one or multiple network communication devices, such as base stations, which may support wireless communication for one or multiple user communication devices, which may be otherwise known as user equipment (UE) , or other suitable terminology. The wireless communication system may support wireless communication with one or multiple user communication devices by utilizing resources of the wireless communication system (e.g., time resources (e.g., symbols, slots, subframes, frames, or the like) or frequency resources (e.g., subcarriers, carriers, or the like) . Additionally, the wireless communication system may support wireless communication across various radio access technologies including third generation (3G) radio access technology, fourth generation (4G) radio access technology, fifth generation (5G) (which is also known as new radio (NR) ) radio access technology, among other suitable radio access technologies beyond 5G (e.g., sixth generation (6G) ) .

In a wireless communication system, a base station (BS) and a UE may communicate via downlink (DL) channels and uplink (UL) channels. For example, a 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 uplink channels, such as a physical uplink shared channel (PUSCH) , or downlink channels, such as a physical downlink shared channel (PDSCH) . The UE may transmit HARQ-ACK feedback (e.g., included in a HARQ-ACK codebook) for the scheduled PDSCH to the BS.

Carrier aggregation (CA) technology may be used in a wireless communication system to, for example, increase data rates. For example, CA technology may refer to aggregating spectrum resources (e.g., carriers or cells) from the same frequency band or different frequency bands. In a CA scenario, multiple cells may be configured for a UE and DL or UL channels may be carried on one or more cells of the multiple cells.

The industry desires technologies for handling HARQ-ACK feedback determination in a CA scenario.

SUMMARY

An article “a” before an element is unrestricted and understood to refer to “at least one” of those elements or “one or more” of those elements. The terms “a, ” “at least one, ” “one or more, ” and “at least one of one or more” may be interchangeable. As used herein, including in the claims, “or” as used in a list of items (e.g., a list of items prefaced by a phrase such as “at least one of” or “one or more of” or “one or both of” ) indicates an inclusive list such that, for example, a list of at least one of A, B, or C means A or B or C or AB or AC or BC or ABC (i.e., A and B and C) . Also, as used herein, the phrase “based on” shall not be construed as a reference to a closed set of conditions. For example, an example step that is described as “based on condition A” may be based on both a condition A and a condition B without departing from the scope of the present disclosure. In other words, as used herein, the phrase “based on” shall be construed in the same manner as the phrase “based at least in part on. ” Further, as used herein, including in the claims, a “set” may include one or more elements.

Some embodiments of the present disclosure provide a UE. The UE may include at least one memory; and at least one processor coupled with the at least one memory and configured to cause the UE to: receive, from a BS, a plurality of DCI formats for scheduling a plurality of PDSCHs on a plurality of serving cells of the UE, wherein the plurality of DCI formats indicates a same slot for transmitting HARQ-ACK feedback, and each of the plurality of DCI formats comprises a counter downlink assignment indicator (DAI) and a total DAI; generate a HARQ-ACK codebook comprising HARQ-ACK information bits for the plurality of PDSCHs; and transmit, to the BS, the HARQ-ACK codebook.

Some embodiments of the present disclosure provide a processor. The processor may include at least one controller coupled with at least one memory and configured to cause the processor to: receive, from a BS, a plurality of DCI formats for scheduling a plurality of PDSCHs on a plurality of serving cells of the UE, wherein the plurality of DCI formats indicates a same slot for transmitting HARQ-ACK feedback, and each of the plurality of DCI formats comprises a counter DAI and a total DAI; generate a HARQ-ACK codebook comprising HARQ-ACK information bits for the plurality of PDSCHs; and transmit, to the BS, the HARQ-ACK codebook.

Some embodiments of the present disclosure provide a BS. The BS may include: at least one memory; and at least one processor coupled with the at least one memory and configured to cause the BS to: transmit, to a UE, a plurality of DCI formats for scheduling a plurality of PDSCHs on a plurality of serving cells of the UE, wherein the plurality of DCI formats indicates a same slot for transmitting HARQ-ACK feedback, and each of the plurality of DCI formats comprises a counter DAI and a total DAI; transmit, to the UE, the plurality of PDSCHs based on the plurality of DCI formats; and receive, from the UE, a HARQ-ACK codebook comprising HARQ-ACK information bits for the plurality of PDSCHs.

In some embodiments of the present disclosure, the counter DAI is updated first in a predefined order of serving cell index and then in a predefined order of PDCCH monitoring occasion index. In some embodiments of the present disclosure, the total DAI is updated from PDCCH monitoring occasion to PDCCH monitoring occasion.

Some embodiments of the present disclosure provide a method for wireless communication. The method may include: receiving, from a BS, a plurality of DCI formats for scheduling a plurality of PDSCHs on a plurality of serving cells of a UE, wherein the plurality of DCI formats indicates a same slot for transmitting HARQ-ACK feedback, and each of the plurality of DCI formats comprises a counter DAI and a total DAI; generating a HARQ-ACK codebook comprising HARQ-ACK information bits for the plurality of PDSCHs; and transmitting, to the BS, the HARQ-ACK codebook.

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 stored thereon computer-executable instructions; at least one receiving circuitry; at least one transmitting circuitry; and at least one processor coupled to the at least one non-transitory computer-readable medium, the at least one receiving circuitry and the at least one transmitting circuitry, wherein the at least one non-transitory computer-readable medium and the computer executable instructions may be configured to, with the at least one processor, cause the apparatus to perform a method according to some embodiments of the present disclosure.

BRIEF DESCRIPTION OF THE DRAWINGS

In order to describe the manner in which the advantages and features of the disclosure can be obtained, a description of the disclosure is rendered by reference to specific embodiments thereof, which are illustrated in the appended drawings. These drawings depict only exemplary embodiments of the disclosure and are not therefore to be considered limiting of its scope.

FIG. 1 illustrates a schematic diagram of a wireless communication system in accordance with some embodiments of the present disclosure;

FIG. 2 illustrates a schematic diagram of a DCI format scheduling a plurality of PDSCHs in accordance with some embodiments of the present disclosure;

FIGs. 3 and 4 illustrate schematic diagrams of a plurality of DCI formats scheduling a plurality of PDSCHs in accordance with some embodiments of the present disclosure;

FIGs. 5 and 6 illustrate flowcharts of methods for wireless communication in accordance with some embodiments of the present disclosure;

FIG. 7 illustrates a block diagram of an exemplary apparatus in accordance with some embodiments of the present disclosure;

FIG. 8 illustrates an example of a UE in accordance with some embodiments of the present disclosure;

FIG. 9 illustrates an example of a processor in accordance with some embodiments of the present disclosure; and

FIG. 10 illustrates an example of a network equipment (NE) in accordance with some embodiments of the present disclosure.

DETAILED DESCRIPTION

The detailed description of the appended drawings is intended as a description of the 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 functions may be accomplished by different embodiments that are intended to be encompassed within the spirit and scope of the present disclosure.

Reference will now be made in detail to some embodiments of the present disclosure, examples of which are illustrated in the accompanying drawings. To facilitate understanding, embodiments are provided under a specific network architecture (s) and new service scenarios, such as the 3rd generation partnership project (3GPP) 5G NR or 6G, 3GPP LTE, and so on. It is contemplated that along with the developments of network architectures and new service scenarios, all embodiments in the present disclosure are also applicable to similar technical problems; and moreover, the terminologies recited in the present disclosure may change, which should not affect the principles of the present disclosure.

Currently, in a communication system, a single DCI format can schedule a single PDSCH or PUSCH on a single cell, or can schedule one or multiple PDSCHs or PUSCHs on a single cell, or can schedule a single PDSCH or PUSCH on one or multiple cells. These scheduling mechanisms have drawbacks, such as requires much signaling overhead and cannot exploit the scheduling benefit from FR1 to FR2.

It would be beneficial if a single DCI can schedule a plurality of cells with one or multiple PDSCHs or PUSCHs per cell. Various issues may need to be addressed when such scheduling mechanism is supported. For example, when a DCI format scheduling a plurality of PDSCHs on one or multiple cells is missed by a UE, the UE cannot know how many PDSCHs are scheduled by the BS for the UE. In this case, the HARQ-ACK codebook may be mismatched between the UE and the BS. That is, the HARQ-ACK codebook generated by the UE may not match what the BS expects. As a result, downlink performance will be degraded. The present disclosure provides solutions to solve the above issues while supporting such scheduling mechanism. The solutions thus provided ensure that the understandings of the HARQ-ACK codebook at the UE and the BS are synchronized and that the HARQ-ACK information bits for the received PDSCHs are correctly ordered in the HARQ-ACK codebook.

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

The wireless communication system 100 may include one or more NEs 102 (e.g., one or more BSs) , one or more UEs 104, and a core network (CN) 106. The wireless communication system 100 may support various radio access technologies. In some implementations, the wireless communication system 100 may be a 4G network, such as an LTE network or an LTE-Advanced (LTE-A) network. In some other implementations, the wireless communication system 100 may be a NR network, such as a 5G network, a 5G-Advanced (5G-A) network, or a 5G ultra-wideband (5G-UWB) network. In other implementations, the wireless communication system 100 may be a combination of a 4G network and a 5G network, or other suitable radio access technology including Institute of Electrical and Electronics Engineers (IEEE) 802.11 (Wi-Fi) , IEEE 802.16 (WiMAX) , and IEEE 802.20. The wireless communication system 100 may support radio access technologies beyond 5G, for example, 6G. Additionally, the wireless communication system 100 may support technologies, such as time division multiple access (TDMA) , frequency division multiple access (FDMA) , or code division multiple access (CDMA) , etc.

The one or more NEs 102 may be dispersed throughout a geographic region to form the wireless communication system 100. One or more of the NEs 102 described herein may be or include or may be referred to as a network node, a base station, a network element, a network function, a network entity, a radio access network (RAN) , a NodeB, an eNodeB (eNB) , a next-generation NodeB (gNB) , or other suitable terminology. An NE 102 and a UE 104 may communicate via a communication link, which may be a wireless or wired connection. For example, an NE 102 and a UE 104 may perform wireless communication (e.g., receive signaling, transmit signaling) over a Uu interface.

An NE 102 may provide a geographic coverage area for which the NE 102 may support services for one or more UEs 104 within the geographic coverage area. For example, an NE 102 and a UE 104 may support wireless communication of signals related to services (e.g., voice, video, packet data, messaging, broadcast, etc. ) according to one or multiple radio access technologies. In some implementations, an NE 102 may be moveable, for example, a satellite associated with a non-terrestrial network (NTN) . In some implementations, different geographic coverage areas 112 associated with the same or different radio access technologies may overlap, but the different geographic coverage areas may be associated with a different NE 102.

The one or more UEs 104 may be dispersed throughout a geographic region of the wireless communication system 100. A UE 104 may include or may be referred to as a remote unit, a mobile device, a wireless device, a remote device, a subscriber device, a transmitter device, a receiver device, or some other suitable terminology. In some implementations, the UE 104 may be referred to as a unit, a station, a terminal, or a client, among other examples. Additionally, or alternatively, the UE 104 may be referred to as an Internet-of-Things (IoT) device, an Internet-of-Everything (IoE) device, or machine-type communication (MTC) device, among other examples.

A UE 104 may be able to support wireless communication directly with other UEs 104 over a communication link. For example, a UE 104 may support wireless communication directly with another UE 104 over a device-to-device (D2D) communication link. In some implementations, such as vehicle-to-vehicle (V2V) deployments, vehicle-to-everything (V2X) deployments, or cellular-V2X deployments, the communication link 114 may be referred to as a sidelink. For example, a UE 104 may support wireless communication directly with another UE 104 over a PC5 interface.

An NE 102 may support communication with the CN 106, or with another NE 102, or both. For example, an NE 102 may interface with another NE 102 or the CN 106 through one or more backhaul links (e.g., S1, N2, N2, or network interface) . In some implementations, the NE 102 may communicate with each other directly. In some other implementations, the NE 102 may communicate with each other or indirectly (e.g., via the CN 106. In some implementations, one or more NEs 102 may include subcomponents, such as an access network entity, which may be an example of an access node controller (ANC) . An ANC may communicate with the one or more UEs 104 through one or more other access network transmission entities, which may be referred to as radio heads, smart radio heads, or transmission-reception points (TRPs) .

The CN 106 may support user authentication, access authorization, tracking, connectivity, and other access, routing, or mobility functions. The CN 106 may be an evolved packet core (EPC) , or a 5G core (5GC) , which may include a control plane entity that manages access and mobility (e.g., a mobility management entity (MME) , an access and mobility management functions (AMF) ) and a user plane entity that routes packets or interconnects to external networks (e.g., a serving gateway (S-GW) , a Packet Data Network (PDN) gateway (P-GW) , or a user plane function (UPF) ) . In some implementations, the control plane entity may manage non-access stratum (NAS) functions, such as mobility, authentication, and bearer management (e.g., data bearers, signal bearers, etc. ) for the one or more UEs 104 served by the one or more NEs 102 associated with the CN 106.

The CN 106 may communicate with a packet data network over one or more backhaul links (e.g., via an S1, N2, N2, or another network interface) . The packet data network may include an application server. In some implementations, one or more UEs 104 may communicate with the application server. A UE 104 may establish a session (e.g., a protocol data unit (PDU) session, or the like) with the CN 106 via an NE 102. The CN 106 may route traffic (e.g., control information, data, and the like) between the UE 104 and the application server using the established session (e.g., the established PDU session) . The PDU session may be an example of a logical connection between the UE 104 and the CN 106 (e.g., one or more network functions of the CN 106) .

In the wireless communication system 100, the NEs 102 and the UEs 104 may use resources of the wireless communication system 100 (e.g., time resources (e.g., symbols, slots, subframes, frames, or the like) or frequency resources (e.g., subcarriers, carriers) ) to perform various operations (e.g., wireless communication) . In some implementations, the NEs 102 and the UEs 104 may support different resource structures. For example, the NEs 102 and the UEs 104 may support different frame structures. In some implementations, such as in 4G, the NEs 102 and the UEs 104 may support a single frame structure. In some other implementations, such as in 5G and among other suitable radio access technologies, the NEs 102 and the UEs 104 may support various frame structures (i.e., multiple frame structures) . The NEs 102 and the UEs 104 may support various frame structures based on one or more numerologies.

One or more numerologies may be supported in the wireless communication system 100, and a numerology may include a subcarrier spacing and a cyclic prefix. A first numerology (e.g., μ=0) may be associated with a first subcarrier spacing (e.g., 15 kHz) and a normal cyclic prefix. In some implementations, the first numerology (e.g., μ=0) associated with the first subcarrier spacing (e.g., 15 kHz) may utilize one slot per subframe. A second numerology (e.g., μ=1) may be associated with a second subcarrier spacing (e.g., 30 kHz) and a normal cyclic prefix. A third numerology (e.g., μ=2) may be associated with a third subcarrier spacing (e.g., 60 kHz) and a normal cyclic prefix or an extended cyclic prefix. A fourth numerology (e.g., μ=3) may be associated with a fourth subcarrier spacing (e.g., 120 kHz) and a normal cyclic prefix. A fifth numerology (e.g., μ=4) may be associated with a fifth subcarrier spacing (e.g., 240 kHz) and a normal cyclic prefix.

A time interval of a resource (e.g., a communication resource) may be organized according to frames (also referred to as radio frames) . Each frame may have a duration, for example, a 10 millisecond (ms) duration. In some implementations, each frame may include multiple subframes. For example, each frame may include 10 subframes, and each subframe may have a duration, for example, a 1 ms duration. In some implementations, each frame may have the same duration. In some implementations, each subframe of a frame may have the same duration.

Additionally or alternatively, a time interval of a resource (e.g., a communication resource) may be organized according to slots. For example, a subframe may include a number (e.g., quantity) of slots. The number of slots in each subframe may also depend on the one or more numerologies supported in the wireless communication system 100. For instance, the first, second, third, fourth, and fifth numerologies (i.e., μ=0, μ=1, μ=2, μ=3, μ=4) associated with respective subcarrier spacings of 15 kHz, 30 kHz, 60 kHz, 120 kHz, and 240 kHz may utilize a single slot per subframe, two slots per subframe, four slots per subframe, eight slots per subframe, and 16 slots per subframe, respectively. Each slot may include a number (e.g., quantity) of symbols (e.g., orthogonal frequency-division multiplexing (OFDM) symbols) . In some implementations, the number (e.g., quantity) of slots for a subframe may depend on a numerology. For a normal cyclic prefix, a slot may include 14 symbols. For an extended cyclic prefix (e.g., applicable for 60 kHz subcarrier spacing) , a slot may include 12 symbols. The relationship between the number of symbols per slot, the number of slots per subframe, and the number of slots per frame for a normal cyclic prefix and an extended cyclic prefix may depend on a numerology. It should be understood that reference to a first numerology (e.g., μ=0) associated with a first subcarrier spacing (e.g., 15 kHz) may be used interchangeably between subframes and slots.

In the wireless communication system 100, an electromagnetic (EM) spectrum may be split, based on frequency or wavelength, into various classes, frequency bands, frequency channels, etc. By way of example, the wireless communication system 100 may support one or multiple operating frequency bands, such as frequency range designations FR1 (410 MHz –7.125 GHz) , FR2 (24.25 GHz –52.6 GHz) , FR3 (7.125 GHz –24.25 GHz) , FR4 (52.6 GHz –114.25 GHz) , FR4a or FR4-1 (52.6 GHz –71 GHz) , and FR5 (114.25 GHz –300 GHz) . In some implementations, the NEs 102 and the UEs 104 may perform wireless communication over one or more of the operating frequency bands. In some implementations, FR1 may be used by the NEs 102 and the UEs 104, among other equipment or devices for cellular communication traffic (e.g., control information, data) . In some implementations, FR2 may be used by the NEs 102 and the UEs 104, among other equipment or devices for short-range, high data rate capabilities.

FR1 may be associated with one or multiple numerologies (e.g., at least three numerologies) . For example, FR1 may be associated with a first numerology (e.g., μ =0) , which includes 15 kHz subcarrier spacing; a second numerology (e.g., μ =1) , which includes 30 kHz subcarrier spacing; and a third numerology (e.g., μ=2) , which includes 60 kHz subcarrier spacing. FR2 may be associated with one or multiple numerologies (e.g., at least 2 numerologies) . For example, FR2 may be associated with a third numerology (e.g., μ=2) , which includes 60 kHz subcarrier spacing; and a fourth numerology (e.g., μ=3) , which includes 120 kHz subcarrier spacing.

A UE 104 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) , vehicle on-board computers, network devices (e.g., routers, switches, and modems) , or the like. According to some embodiments of the present disclosure, a UE 104 may include a portable wireless communication device, a smart phone, a cellular telephone, a flip phone, a device having a subscriber identity module, a personal computer, a selective call receiver, or any other device that is capable of sending and receiving communication signals on a wireless network. In some embodiments of the present disclosure, a UE 104 includes wearable devices, such as smart watches, fitness bands, optical head-mounted displays, or the like. Moreover, a UE 104 may be referred to as a subscriber unit, a mobile, a mobile station, a user, a terminal, a mobile terminal, a wireless terminal, a fixed terminal, a subscriber station, a user terminal, or a device, or described using other terminology used in the art. A UE 104 may communicate with an NE 102 (e.g., a BS) via uplink (UL) communication signals. An NE 102 may communicate with a UE 104 via downlink (DL) communication signals.

In some embodiments of the present disclosure, an NE 102 and a UE 104 may communicate over licensed spectrums, whereas in some other embodiments, an NE 102 and a UE 104 may communicate over unlicensed spectrums. The present disclosure is not intended to be limited to the implementation of any particular wireless communication system architecture or protocol.

In some embodiments of the present disclosure, the wireless communication system 100 may be designed to support a maximum of 16 component carriers (CCs) in the case of carrier aggregation (CA) or a maximum of 32 CCs in the case of dual connectivity (DC) . In some embodiments of the present disclosure, in the case of CA, one DCI format can schedule at most one cell (e.g., carrier) by cross-cell (or cross-carrier) scheduling or self-scheduling. This requires much signaling overhead for PDCCHs to schedule DL transmissions (e.g., PDSCHs) or UL transmissions (e.g., PUSCHs) when the number of cells configured for a UE is large. To reduce signaling overhead, it would be beneficial to use a single DCI format to schedule multiple PDSCHs or PUSCHs on multiple cells (or carriers) configured for the UE. In the context of the present disclosure, the term "cell" may be used interchangeably with the term "carrier. "

In some embodiments of the present disclosure, a single DCI can schedule at most 4 cells with one PDSCH or one PUSCH per cell. However, it is important to acknowledge that such scheduling scheme has a certain restriction. For example, when one cell (e.g., the DCI is transmitted on this scheduling cell) in FR1 schedules multiple cells (e.g., the PDSCHs or PUSCHs are transmitted on these scheduled cells) in FR2, a slot in the scheduling cell may be, for example, 4 or 8 times longer than a slot in scheduled cells, such that a majority of the slots on scheduled cells cannot be scheduled.

FIG. 2 illustrates a schematic diagram of a DCI format scheduling a plurality of PDSCHs in accordance with some embodiments of the present disclosure.

In some embodiments of the present disclosure, a plurality of cells (e.g., including but not limited to CCs 231-234 in FIG. 2) may be configured for a UE by a BS. Each of the plurality of CCs may correspond to a respective cell (e.g., serving cell) or carrier of the UE. Each cell (serving cell) may be associated with a (serving) cell index. The sub-carrier spacing (SCS) of CCs 231-234 may be different. For example, CC 231 may be on FR1 with a 15kHz SCS and CCs 232-234 may be on FR2 with 120kHz SCS. Therefore, one slot on CC 231 (e.g., slot 0 on CC 231 as shown in FIG. 2) may occupy 1ms and eight slots on each of CCs 232-234 (e.g., slot 0 to slot 7 on CCs 232-234 as shown in FIG. 2) may occupy 1ms.

A BS may transmit a single DCI format to schedule a plurality of PDSCH on a plurality of cells. For example, DCI format 211 on CC 231 may schedule a single PDSCH on each of CCs 232-234. For example, as shown in FIG. 2, each of PDSCHs 221-223 may be scheduled in a single slot (e.g., slot 5) on each of CCs 232-234. However, the remaining 7 slots (e.g., slot 0 to slot 4, slot 6 and slot 7) cannot be scheduled within the 1ms duration due to different SCSs among the scheduled cells and scheduling cell. As a result, performance will be greatly degraded.

In some embodiments of the present disclosure, to fully exploit the scheduling benefit from FR1 to FR2, a single DCI can schedule a plurality of cells with one or multiple PDSCHs or PUSCHs per cell. In this way, all the slots on the scheduled cells can be scheduled. For example, referring to FIG. 2, DCI 211 can schedule a PDSCH in each of slot 0 to slot 7 on CC 232. However, various issues can arise when a single DCI schedules a plurality of cells with one or multiple PDSCHs or PUSCHs per cell.

For example, when a UE is configured to monitor a DCI format scheduling a plurality of PDSCHs on one or multiple cells with one or multiple PDSCHs per cell, one issue is how to determine the number of PDSCHs scheduled by a DCI format in the case that the DCI format is missed by the UE. In this sense, the HARQ-ACK codebook may be mismatched between the UE and the BS. That is, the HARQ-ACK codebook comprising the HARQ-ACK information bits for the scheduled PDSCHs generated by the UE may not match what the BS expects.

FIG. 3 illustrates a schematic diagram of a plurality of DCI formats scheduling a plurality of PDSCHs in accordance with some embodiments of the present disclosure. In some embodiments of the present disclosure, a plurality of cells (e.g., including but not limited to CCs 331-335 in FIG. 3) may be configured for a UE by a BS. Each of the plurality of CCs may correspond to a respective cell (e.g., serving cell) or carrier of the UE. Each cell (serving cell) may be associated with a (serving) cell index.

As shown in FIG. 3, the BS may transmit a plurality of DCI formats (e.g., DCI formats 311-314) scheduling a plurality of PDSCHs (e.g., PDSCHs 321-328) on a plurality of cells (e.g., CCs 331-335) to the UE. For example, DCI format 311 on CC 331 may schedule PDSCH 321 on CC 331, DCI format 312 on CC 332 may schedule PDSCHs 322 and 323 on CC 332 and PDSCH 324 on CC 333, DCI format 313 on CC 334 may schedule PDSCHs 325-327 on CC 334, and DCI format 314 on CC 335 may schedule PDSCH 328 on CC 335. The BS may indicate HARQ-ACK feedback for PDSCHs 321-328 to be transmitted in the same slot (e.g., in the same physical uplink control channel (PUCCH) ) .

Each of DCI formats 311-314 may include downlink assignment index information to facilitate HARQ-ACK feedback for the PDSCH (s) scheduled by the corresponding DCI format. For example, each of DCI formats 311-314 may include a counter DAI and total DAI.

For example, the counter DAI may denote the accumulative number of {serving cell, PDCCH monitoring occasion} -pairs in which a PDSCH reception (s) or semi-persistent scheduling (SPS) PDSCH release associated with a DCI format is present, up to the current serving cell and current PDCCH monitoring occasion. The total DAI may denote the total number of {serving cell, PDCCH monitoring occasion} -pairs in which a PDSCH reception (s) or SPS PDSCH release associated with a DCI format is present, up to the current PDCCH monitoring occasion. According to the above definitions, the {counter DAI, total DAI} values in DCI formats 311-314 in FIG. 3 may be {1, 4} , {2, 4} , {3, 4} and {4, 4} , respectively.

From the perspective of the UE, when no DCI format is missed, the UE can clearly know that eight PDSCHs (i.e., PDSCHs 321-328) are scheduled by the four DCI formats (i.e., DCI formats 311-314) and transmit corresponding HARQ-ACK feedback for the eight PDSCHs in one HARQ-ACK codebook. Assuming that for each of the scheduled PDSCHs, a single HARQ-ACK information bit is required, the UE may generate eight HARQ-ACK information bits (denoted as b1 to b8) for PDSCHs 321-328 in one HARQ-ACK codebook, according to, for example, the respective decoding results of PDSCHs 321-328.

When a DCI format, such as DCI format 312, is missed by the UE, the UE can identify that there is one DCI format missed based on the counter DAIs in DCI formats 311 and 313. However, the UE cannot know how many PDSCHs are scheduled by the missed DCI format based on the DAI information (e.g., based on the total DAIs in DCI formats 311 and 313) . Hence, from the UE’s perspective, if the UE assumes that a single PDSCH is scheduled by the missed DCI format, the UE may transmit the HARQ-ACK codebook (e.g., {b1, NACK, b5, b6, b7, b8} ) for PDSCH 321, the assumed single PDSCH scheduled by the missed DCI 312, and PDSCH 325, PDSCH 326, PDSCH 327 and PDSCH 328, respectively. On the other hands, the BS may expect a HARQ-ACK feedback corresponding to the eight transmitted PDSCHs (e.g., {b1, b2, b3, b4, b5, b6, b7, b8} . As a result, the misunderstanding of the HARQ-ACK codebook may happen between the BS and the UE.

As shown above, when the number of actually transmitted PDSCHs is not known to the UE, the misunderstanding of the HARQ-ACK codebook between the UE and the BS seems to be inevitable. Since the BS cannot receive the HARQ-ACK feedback for the transmitted PDSCHs due to the misunderstanding, the BS has to retransmit all the transmitted PDSCHs (in the case of FIG. 3, eight PDSCHs has to be retransmitted) , which would result in a degradation of downlink performance.

Embodiments of the present disclosure propose solutions for solving the above issues. For example, methods for avoiding the above misunderstanding of the HARQ-ACK codebook between the UE and the BS are provided. For example, DAI information in a DCI format are designed to avoid the above misunderstanding. More details on the embodiments of the present disclosure will be illustrated in the following text in combination with the appended drawings.

In some embodiments of the present disclosure, the DAIs in a DCI format can be designed to identify the number of missed PDSCHs, if any.

For example, in some embodiments, a counter DAI in a DCI format may indicate the accumulative number of {serving cell, PDCCH monitoring occasion} -pairs in which a PDSCH reception (s) with HARQ-ACK feedback enabled or a DCI format (s) with HARQ-ACK feedback required is present, up to the current serving cell and current PDCCH monitoring occasion. The counter DAI may be updated (e.g., incremented) first in a predefined order (e.g., ascending or descending) of the serving cell index and then in a predefined order (e.g., ascending or descending) of the PDCCH monitoring occasion index.

A total DAI in the DCI format may indicate the total number of PDSCH receptions with HARQ-ACK feedback enabled and DCI formats with HARQ-ACK feedback required, up to the current PDCCH monitoring occasion. The total DAI may be updated (e.g., incremented) from one PDCCH monitoring occasion to the next PDCCH monitoring occasion.

In the context of the present disclosure, a PDSCH reception with HARQ-ACK feedback disabled (e.g., disabled by a radio resource control (RRC) configuration or disabled by an indicator (e.g., the HARQ-ACK feedback enabling/disabling indicator) in the scheduling DCI format) is not counted during counter DAI updating. That is, such PDSCH reception does not belongs to "PDSCH receptions with HARQ-ACK feedback enabled" in the above definition for the counter DAI or total DAI.

In the context of the present disclosure, a DCI format indicating an SPS PDSCH release or secondary cell (SCell) dormancy indication requires HARQ-ACK feedback. That is, such DCI format belongs to "DCI formats with HARQ-ACK feedback required" in the above definition for the counter DAI or total DAI.

In the context of the present disclosure, a DCI format for SPS activation does not require HARQ-ACK feedback. That is, such DCI format does not belong to "DCI formats with HARQ-ACK feedback required" in the above definition for the counter DAI or total DAI.

According to the above definitions for the counter DAI and total DAI, when a plurality of DCI formats is transmitted by a BS to a UE to schedule a plurality of PDSCHs on a plurality of serving cells of the UE and indicates the same slot for transmitting HARQ-ACK feedback, the value of the total DAI in the last (transmitted) DCI format may be larger than the value of the counter DAI in this DCI format.

The UE may generate HARQ-ACK information bits for the plurality of PDSCHs in the same HARQ-ACK codebook based on the counter DAIs and total DAIs in the plurality of DCI formats. The positions of the HARQ-ACK information bits in the HARQ-ACK codebook can be determined based on the counter DAIs (e.g., according to a predefined order (e.g., ascending or descending) of the value of the counter DAIs) . The UE can determine whether a DCI format among the plurality of DCI formats is missed or not based on the counter DAIs and total DAIs in the plurality of DCI formats. In the case that at least one DCI format is determined to be missed, the UE may generate HARQ-ACK information bits in the HARQ-ACK codebook for the PDSCH (s) scheduled by the at least one DCI format based on the counter DAIs and total DAIs in the plurality of DCI formats.

An example is described in the following text with respect to FIG. 3.

Referring to FIG. 3, it is assumed that the serving cell indices of CCs 331-335 satisfy CC 331<CC 332<CC 333<CC 334<CC 335, the counter DAI is updated first in an ascending order of the serving cell index and then in an ascending order of the PDCCH monitoring occasion index and for each of the scheduled PDSCHs, a single HARQ-ACK information bit is required.

According to the above definitions for counter DAI and total DAI, since there are a total of 8 PDSCHs transmitted, the value of the total DAI in each of DCI formats 311-314 is set to 8. In addition, since there are a total of 4 PDCCHs (four DCI formats, i.e., DCI formats 311-314) transmitted, the counter DAI values in DCI formats 311-314 are set to 1, 2, 3 and 4, respectively. That is, the {counter DAI, total DAI} values in DCI formats 311-314 are set as {1, 8} , {2, 8} , {3, 8} and {4, 8} , respectively.

From the perspective of the UE, when no DCI format is missed, the UE can clearly know that eight PDSCHs (i.e., PDSCHs 321-328) are scheduled by the four DCI formats (i.e., DCI formats 311-314) and transmit corresponding HARQ-ACK feedback for the eight PDSCHs in one HARQ-ACK codebook. The UE may generate eight HARQ-ACK information bits (e.g., b1 to b8) for PDSCHs 321-328 in one HARQ-ACK codebook.

When a DCI format, such as DCI format 312, is missed by the UE, the UE can identify that there is one DCI format missed based on the counter DAIs in DCI formats 311 and 313. The UE can also determine that the missed DCI format schedules three PDSCHs based on the numbers of PDSCHs scheduled by DCI formats 311, 313 and 314, and the total DAI in any of DCI formats 311, 313 and 314. For example, the UE can determine a total of eight PDSCHs are scheduled based on the total DAI, and one PDSCH, three PDSCHs and one PDSCH are respectively scheduled by DCI formats 311, 313 and 314. Then, the UE can determine that the missed DCI format schedules three (i.e., 8-1-3-1) PDSCHs. The UE can generate “NACK” bits for the three PDSCHs scheduled by the missed DCI format. For example, the HARQ-ACK codebook can include HARQ-ACK information bits {b1, NACK, NACK, NACK, b5, b6, b7, b8} for PDSCHs 321-328, respectively.

In this way, the HARQ-ACK codebook sizes between a UE and a BS are synchronized, and the HARQ-ACK information bits for the received PDSCHs are correctly ordered in a HARQ-ACK codebook.

In some embodiments, a counter DAI in a DCI format may indicate the accumulative number of PDSCH receptions with HARQ-ACK feedback enabled and DCI formats with HARQ-ACK feedback required, up to the current serving cell and current PDCCH monitoring occasion. The counter DAI may be updated (e.g., incremented) first in a predefined order (e.g., ascending or descending) of the serving cell index and then in a predefined order (e.g., ascending or descending) of the PDCCH monitoring occasion index.

According to the above definition, the value of a counter DAI counts a DCI format if this DCI format requires HARQ-ACK feedback or counts the PDSCH (s) scheduled by a DCI format if the HARQ-ACK feedback for the PDSCH (s) is enabled.

In some examples, a PDSCH reception with HARQ-ACK feedback disabled (e.g., disabled by an RRC configuration or disabled by an indicator (e.g., the HARQ-ACK feedback enabling/disabling indicator) in the scheduling DCI format) is not counted during counter DAI updating. In some examples, a DCI format indicating an SPS PDSCH release or SCell dormancy indication requires HARQ-ACK feedback. In some examples, a DCI format for SPS activation does not require HARQ-ACK feedback.

According to the above definitions for the counter DAI and total DAI, when a plurality of DCI formats is transmitted by a BS to a UE to schedule a plurality of PDSCHs on a plurality of serving cells of the UE and indicates the same slot for transmitting HARQ-ACK feedback, from the perspective of the BS, the value of the total DAI in the last (transmitted) DCI format may be equal to the value of the counter DAI in this DCI format. From the perspective of the UE, the value of the total DAI in the last DCI format may be equal to the value of the counter DAI in this DCI format in the case the last DCI format transmitted by the BS is not missed by the UE.

An example is described in the following text with respect to FIG. 3.

According to the above definitions for counter DAI and total DAI, since there are a total of 8 PDSCHs transmitted, the value of the total DAI in each of DCI formats 311-314 is set to 8. In addition, since there is only a single PDSCH (i.e., PDSCH 321) accumulatively scheduled up to the monitoring occasion of DCI format 311, the value of the counter DAI in DCI format 311 is set to 1. Since there are 4 PDSCHs (i.e., PDSCHs 321-324) accumulatively scheduled up to the monitoring occasion of DCI format 312, the value of the counter DAI in DCI format 312 is set to 4. Since there are 7 PDSCHs (i.e., PDSCHs 321-327) accumulatively scheduled up to the monitoring occasion of DCI format 313, the value of the counter DAI in DCI format 313 is set to 7. Since there are 8 PDSCHs (i.e., PDSCHs 321-328) accumulatively scheduled up to the monitoring occasion of DCI format 314, the value of the counter DAI in DCI format 314 is set to 8. That is, the {counter DAI, total DAI} values in DCI formats 311-314 are set as {1, 8} , {4, 8} , {7, 8} and {8, 8} , respectively.

When a DCI format, such as DCI format 312, is missed by the UE, the UE can identify that there are three PDSCHs missed (i.e., due to the miss of a DCI format (s) ) based on the counter DAIs in DCI formats 311 and 313. The UE can generate “NACK” bits for the three missed PDSCHs. For example, the HARQ-ACK codebook can include HARQ-ACK information bits {b1, NACK, NACK, NACK, b5, b6, b7, b8} for PDSCHs 321-328, respectively.

In some embodiments, a counter DAI in a DCI format may indicate the ordering of HARQ-ACK information bits in the HARQ-ACK codebook for a start HARQ-ACK information bit of HARQ-ACK information bit (s) for PDSCH (s) scheduled by a DCI format with HARQ-ACK feedback enabled or for HARQ-ACK information bit (s) for a DCI format with HARQ-ACK feedback required.

For example, a DCI format may schedule a set of PDSCHs. The HARQ-ACK information bit (s) for the set of PDSCHs may be ordered in the HARQ-ACK codebook according to a certain manner. Denoting the ordered HARQ-ACK information bits for the set of PDSCHs as {a1, a2, …, an} , the counter DAI in the DCI format may indicate the ordering of HARQ-ACK information bits in a HARQ-ACK codebook for bit a1. Based on the counter DAI, the UE can determine the position of bit a1 in the HARQ-ACK codebook as well as the positions of the remaining HARQ-ACK information bits (e.g., a2 to an) for the set of PDSCHs which immediately follow bit a1.

Or put another way, the counter DAI in a DCI format may indicate the ordering of HARQ-ACK information bits in the HARQ-ACK codebook for the specific PDSCH scheduled by the DCI format with HARQ-ACK feedback enabled or for the DCI format with HARQ-ACK feedback required.

For example, a DCI format may schedule a set of PDSCHs, and the HARQ-ACK information bit (s) for the set of PDSCHs may be ordered in the HARQ-ACK codebook according to a certain manner. The specific PDSCH may refer to a PDSCH among the set of PDSCHs with its corresponding HARQ-ACK information bit (s) placed at a predefined position after the ordering. For example, the specific PDSCH may refer to the PDSCH among the set of PDSCHs with its corresponding HARQ-ACK information bit (s) placed at the start of all HARQ-ACK information bits for the set of PDSCHs.

For example, the set of PDSCHs may include PDSCH #B1, PDSCH#B2 and so on. The HARQ-ACK information bit (s) for PDSCH #B1 may be placed at the start of all HARQ-ACK information bits for the set of PDSCHs, followed by HARQ-ACK information bit (s) for the remaining scheduled PDSCH (s) in the set of PDSCHs. The counter DAI in the DCI format may indicate the ordering of HARQ-ACK information bits in a HARQ-ACK codebook for PDSCH #B1. The HARQ-ACK information bit (s) for the remaining scheduled PDSCH (s) in the set of PDSCHs may be placed in the HARQ-ACK codebook immediately following the HARQ-ACK information bit for PDSCH #B1.

In the case that a DCI format schedules a single PDSCH, the counter DAI in this DCI format may indicate the ordering of HARQ-ACK information bits in the HARQ-ACK codebook for the single PDSCH.

The counter DAI may be updated (e.g., incremented) first in a predefined order (e.g., ascending or descending) of the serving cell index and then in a predefined order (e.g., ascending or descending) of the PDCCH monitoring occasion index.

An example is described in the following text with respect to FIG. 3.

According to the above definitions for counter DAI and total DAI, since there are a total of 8 PDSCHs transmitted, the value of the total DAI in each of DCI formats 311-314 is set to 8. DCI format 311 schedules a single PDSCH (i.e., PDSCH 321) . The value of the counter DAI in DCI format 311 may be set to 1, indicating that the HARQ-ACK information bit for PDSCH 321 is located in the first bit in the HARQ-ACK codebook.

DCI format 312 schedules 3 PDSCHs (i.e., PDSCHs 322-324) . The value of the counter DAI in DCI format 311 may be set to 2, indicating that the start HARQ-ACK information bit of the three HARQ-ACK information bits for PDSCHs 322-324 is located in the second bit in the HARQ-ACK codebook. The remaining two HARQ-ACK information bits immediately follow the start HARQ-ACK information bit, that is, are located in the third and fourth bits in the HARQ-ACK codebook.

DCI format 313 schedules 3 PDSCHs (i.e., PDSCHs 325-327) . The value of the counter DAI in DCI format 313 may be set to 5, indicating that the start HARQ-ACK information bit of the three HARQ-ACK information bits for PDSCHs 325-327 is located in the fifth bit in the HARQ-ACK codebook. The remaining two HARQ-ACK information bits immediately follow the start HARQ-ACK information bit, that is, are located in the sixth and seventh bits in the HARQ-ACK codebook.

DCI format 314 schedules a single PDSCH (i.e., PDSCH 328) . The value of the counter DAI in DCI format 314 may be set to 8, indicating that the HARQ-ACK information bit for PDSCH 324 is located in the eighth bit in the HARQ-ACK codebook.

That is, the {counter DAI, total DAI} values in DCI formats 311-314 may be set as {1, 8} , {2, 8} , {5, 8} and {8, 8} , respectively.

In some embodiments, a counter DAI in a DCI format may indicate the accumulative number of PDSCH receptions with HARQ-ACK feedback enabled and DCI formats with HARQ-ACK feedback required, before the current serving cell and current PDCCH monitoring occasion. The counter DAI may be updated (e.g., incremented) first in a predefined order (e.g., ascending or descending) of the serving cell index and then in a predefined order (e.g., ascending or descending) of the PDCCH monitoring occasion index.

According to the above definitions for the counter DAI and total DAI, when a plurality of DCI formats is transmitted by a BS to a UE to schedule a plurality of PDSCHs on a plurality of serving cells of the UE and indicates the same slot for transmitting HARQ-ACK feedback, from the perspective of either the BS or the UE, the value of the total DAI in the last DCI format may be larger than the value of the counter DAI in this DCI format since the last DCI format does not count the PDSCH reception (s) scheduled by the last DCI format with HARQ-ACK feedback enabled or itself if it requires HARQ-ACK feedback.

An example is described in the following text with respect to FIG. 3.

According to the above definitions for counter DAI and total DAI, since there are a total of 8 PDSCHs transmitted, the value of the total DAI in each of DCI formats 311-314 is set to 8. In addition, since there is no PDSCH accumulatively scheduled before the monitoring occasion of DCI format 311, the value of the counter DAI in DCI format 311 is set to 0. Since there is a single PDSCH (i.e., PDSCH 321) accumulatively scheduled before the monitoring occasion of DCI format 312, the value of the counter DAI in DCI format 312 is set to 1. Since there are 4 PDSCHs (i.e., PDSCHs 321-324) accumulatively scheduled before the monitoring occasion of DCI format 313, the value of the counter DAI in DCI format 313 is set to 4. Since there are 7 PDSCHs (i.e., PDSCHs 321-327) accumulatively scheduled before the monitoring occasion of DCI format 314, the value of the counter DAI in DCI format 314 is set to 7. That is, the {counter DAI, total DAI} values in DCI formats 311-314 are set as {0, 8} , {1, 8} , {4, 8} and {7, 8} , respectively.

In some embodiments of the present disclosure, counter DAIs in DCI formats each scheduling a single PDSCH may be counted separately from counter DAIs in DCI formats each scheduling more than one PDSCH. Total DAIs in DCI formats each scheduling a single PDSCH may be counted separately from total DAIs in DCI formats each scheduling more than one PDSCH. A DCI format with HARQ-ACK feedback required may be regarded as a DCI format scheduling a single PDSCH.

According to the above definitions, there may be two loops for DAI counting: a first loop (denoted as loop #A1) is used for updating (e.g., incrementing) the counter DAI and total DAI in a DCI format (denoted as type #A1 DCI) which schedules a single PDSCH or requires HARQ-ACK feedback; and a second loop (denoted as loop #A2) is used for updating (e.g., incrementing) the counter DAI and total DAI in a DCI format (denoted as type #A2 DCI) which schedules more than one PDSCH.

For example, the counter DAI in a type #A1 DCI may indicate the accumulative number of {serving cell, PDCCH monitoring occasion} -pairs in which a PDSCH reception (s) with HARQ-ACK feedback enabled or a DCI format (s) with HARQ-ACK feedback required is present, up to the current serving cell and current PDCCH monitoring occasion. The counter DAI may be updated (e.g., incremented) first in a predefined order (e.g., ascending or descending) of the serving cell index and then in a predefined order (e.g., ascending or descending) of the PDCCH monitoring occasion index.

For example, the total DAI in a type #A1 DCI may indicate the total number of {serving cell, PDCCH monitoring occasion} -pair (s) in which a PDSCH reception (s) with HARQ-ACK feedback enabled or a DCI format (s) with HARQ-ACK feedback required are present, up to the current PDCCH monitoring occasion. The total DAI may be updated (e.g., incremented) from one PDCCH monitoring occasion to the next PDCCH monitoring occasion.

For example, the counter DAI in a type #A2 DCI may indicate the accumulative number of {serving cell, PDCCH monitoring occasion} -pairs in which a PDSCH reception (s) with HARQ-ACK feedback enabled is present, up to the current serving cell and current PDCCH monitoring occasion. The counter DAI may be updated (e.g., incremented) first in a predefined order (e.g., ascending or descending) of the serving cell index and then in a predefined order (e.g., ascending or descending) of the PDCCH monitoring occasion index.

For example, the total DAI in a type #A2 DCI may indicate the total number of {serving cell, PDCCH monitoring occasion} -pair (s) in which PDSCH receptions with HARQ-ACK feedback enabled, up to the current PDCCH monitoring occasion. The total DAI may be updated (e.g., incremented) from one PDCCH monitoring occasion to the next PDCCH monitoring occasion.

According to the above definitions for the counter DAI and total DAI, a plurality of DCI formats transmitted by a BS to a UE for scheduling a plurality of PDSCHs on a plurality of serving cells of the UE may indicate the same slot for transmitting HARQ-ACK feedback, and may be divided into two sets of DCI formats (denoted as DCI set #A1 and DCI set #A2) . DCI set #A1 includes all type #A1 DCIs in the plurality of DCI formats, that is, each DCI format in DCI set #A1 schedules a single PDSCH of the plurality of PDSCHs or requires HARQ-ACK feedback. DCI set #A2 includes all type #A2 DCIs in the plurality of DCI formats, that is, each DCI format in DCI set #A2 schedules more than one PDSCH of the plurality of PDSCHs. The counter DAI (s) of the DCI format (s) in DCI set #A1 are counted separately from the counter DAI (s) of the DCI format (s) in DCI set #A2. The total DAI (s) of the DCI format (s) in DCI set #A1 are counted separately from the total DAI (s) of the DCI format (s) in DCI set #A2.

An example is described in the following text with respect to FIG. 4.

FIG. 4 illustrates a schematic diagram of a plurality of DCI formats scheduling a plurality of PDSCHs in accordance with some embodiments of the present disclosure. In some embodiments of the present disclosure, a plurality of cells (e.g., including but not limited to CCs 431-435 in FIG. 4) may be configured for a UE by a BS. Each of the plurality of CCs may correspond to a respective cell (e.g., serving cell) or carrier of the UE. Each cell (serving cell) may be associated with a (serving) cell index.

As shown in FIG. 4, the BS may transmit a plurality of DCI formats (e.g., DCI formats 411-416) scheduling a plurality of PDSCHs (e.g., PDSCHs 421-4213) on a plurality of cells (e.g., CCs 431-435) to the UE. For example, DCI format 411 on CC 431 may schedule PDSCH 421 on CC 431, DCI format 412 on CC 432 may schedule PDSCHs 422-424 on CC 432 and PDSCHs 425 and 426 on CC 433, DCI format 413 on CC 434 may schedule PDSCHs 427-329 on CC 434, DCI format 414 on CC 435 may schedule PDSCH 4210 on CC 435, DCI format 415 on CC 431 may schedule PDSCH 4211 on CC 431, and DCI format 416 on CC 435 may schedule PDSCHs 4212 and 4213 on CC 435. The BS may indicate that HARQ-ACK feedback for PDSCHs 421-4213 to be transmitted in the same slot (e.g., in the same PUCCH) . Each of DCI formats 411-416 may include a counter DAI and total DAI.

It is assumed that the serving cell indices of CCs 431-435 satisfy CC 431<CC 432<CC 433<CC 434<CC 435, the counter DAI is updated first in an ascending order of serving cell index and then in an ascending order of PDCCH monitoring occasion index and for each of the scheduled PDSCHs, a single HARQ-ACK information bit is required.

According to the above definitions for counter DAI and total DAI, DCI formats 411-416 can be divided into two sets of DCI formats, a first set including DCI formats 411, 414 and 415, each of which schedules a single PDSCH, and a second set including DCI formats 412, 413 and 416, each of which schedules more than one PDSCH. Separate DAI counting is performed in the first and second sets. For example, the {counter DAI, total DAI} values in DCI formats 411, 414 and 415 are set as {1, 2} , {2, 2} and {3, 3} , respectively. The {counter DAI, total DAI} values in DCI formats 412, 413 and 416 are set as {1, 2} , {2, 2} and {3, 3} , respectively.

From the perspective of the UE, when no DCI format is missed, the UE can clearly know that 13 PDSCHs (i.e., PDSCHs 421-4213) are scheduled by the six DCI formats (i.e., DCI formats 411-416) and transmit corresponding HARQ-ACK feedback for the PDSCHs in one HARQ-ACK codebook. For example, the HARQ-ACK codebook may include two sub-codebooks corresponding to the two sets of DCI formats. Denoting the actual HARQ-ACK information bits for PDSCHs 421-4213 as c1 to c13, respectively, the sub-codebook corresponding to the first set of DCI formats can include HARQ-ACK information bits {c1, c10, c11} .

Denoting the number of HARQ-ACK information bits corresponding to the PDSCHs co-scheduled by a type #A2 DCI as X, the UE may generate X bits for each type #A2 DCI. Assuming that X=5, the UE may generate HARQ-ACK information bits {c2, c3, c4, c5, c6} for DCI format 412, HARQ-ACK information bits {c7, c8, c9, NACK, NACK} for DCI format 413, and HARQ-ACK information bits {c12, c13, NACK, NACK, NACK} for DCI format 416, wherein "NACK" bits are padding bits. The sub-codebook corresponding to the second set of DCI formats can include HARQ-ACK information bits { {c2, c3, c4, c5, c6} , {c7, c8, c9, NACK, NACK} , {c12, c13, NACK, NACK, NACK} } .

When a DCI format scheduling a single PDSCH, such as DCI format 414, is missed by the UE, the UE can identify that there is one DCI format scheduling a single PDSCH missed based on the counter DAIs or total DAIs in DCI formats 411 and 415. The UE can also determine that there is a single PDSCH missed (i.e., due to the miss of DCI format 414) . The UE can generate a “NACK” bit for the missed PDSCH. For example, a sub-codebook corresponding to the first set of DCI formats can include HARQ-ACK information bits {c1, NACK, c11} for PDSCHs 421, 4210 and 4211, respectively.

When a DCI format scheduling more than one PDSCH, such as DCI format 413, is missed by the UE, the UE can identify that there is one DCI format scheduling a single PDSCH missed based on the counter DAIs or total DAIs in DCI formats 412 and 416. The UE can also determine that there is more than one PDSCH missed (i.e., due to the miss of DCI format 413) . The UE can generate “NACK” bits for the missed PDSCHs.

For example, the UE may generate HARQ-ACK information bits {c2, c3, c4, c5, c6} for DCI format 412, HARQ-ACK information bits {NACK, NACK, NACK, NACK, NACK} for the missed DCI format (i.e., DCI format 413) , and HARQ-ACK information bits {c12, c13, NACK, NACK, NACK} for DCI format 416. The sub-codebook corresponding to the second set of DCI formats may include HARQ-ACK information bits { {c2, c3, c4, c5, c6} , {NACK, NACK, NACK, NACK, NACK} , {c12, c13, NACK, NACK, NACK} } .

In some embodiments of the present disclosure, counter DAIs in DCI formats each scheduling a single PDSCH, counter DAIs in DCI formats each scheduling more than one PDSCH on the same cell, and counter DAIs in DCI formats each scheduling more than one PDSCH on more than one cell are counted separately from each other. Total DAIs in DCI formats each scheduling a single PDSCH, total DAIs in DCI formats each scheduling more than one PDSCH on the same cell, and total DAIs in DCI formats each scheduling more than one PDSCH on more than one cell are counted separately from each other. A DCI format with HARQ-ACK feedback required may be regarded as a DCI format scheduling a single PDSCH.

According to the above definitions, there may be three loops for DAI counting: a first loop (denoted as loop #B1) is used for updating (e.g., incrementing) the counter DAI and total DAI in a DCI format (denoted as type #B1 DCI) which schedules a single PDSCH or requires HARQ-ACK feedback; a second loop (denoted as loop #B2) is used for updating (e.g., incrementing) the counter DAI and total DAI in a DCI format (denoted as type #B2 DCI) which schedules more than one PDSCH on a single cell; and a third loop (denoted as loop #B3) is used for updating (e.g., incrementing) the counter DAI and total DAI in a DCI format (denoted as type #B3 DCI) which schedules more than one PDSCH on more than one cell.

For example, the counter DAI in a type #B1 DCI may indicate the accumulative number of {serving cell, PDCCH monitoring occasion} -pairs in which a PDSCH reception (s) with HARQ-ACK feedback enabled or a DCI format (s) with HARQ-ACK feedback required is present, up to the current serving cell and current PDCCH monitoring occasion. The counter DAI may be updated (e.g., incremented) first in a predefined order (e.g., ascending or descending) of the serving cell index and then in a predefined order (e.g., ascending or descending) of the PDCCH monitoring occasion index.

For example, the total DAI in a type #B1 DCI may indicate the total number of {serving cell, PDCCH monitoring occasion} -pair (s) in which PDSCH receptions with HARQ-ACK feedback enabled or DCI formats with HARQ-ACK feedback required are present, up to the current PDCCH monitoring occasion. The total DAI may be updated (e.g., incremented) from one PDCCH monitoring occasion to the next PDCCH monitoring occasion.

For example, the counter DAI in a type #B2 DCI may indicate the accumulative number of {serving cell, PDCCH monitoring occasion} -pairs in which a PDSCH reception (s) with HARQ-ACK feedback enabled is present, up to the current serving cell and current PDCCH monitoring occasion. The counter DAI may be updated (e.g., incremented) first in a predefined order (e.g., ascending or descending) of the serving cell index and then in a predefined order (e.g., ascending or descending) of the PDCCH monitoring occasion index.

For example, the total DAI in a type #B2 DCI may indicate the total number of {serving cell, PDCCH monitoring occasion} -pair (s) in which PDSCH receptions with HARQ-ACK feedback enabled, up to the current PDCCH monitoring occasion. The total DAI may be updated (e.g., incremented) from one PDCCH monitoring occasion to the next PDCCH monitoring occasion.

For example, the counter DAI in a type #B3 DCI may indicate the accumulative number of {serving cell, PDCCH monitoring occasion} -pairs in which a PDSCH reception (s) with HARQ-ACK feedback enabled is present, up to the current serving cell and current PDCCH monitoring occasion. The counter DAI may be updated (e.g., incremented) first in a predefined order (e.g., ascending or descending) of the serving cell index and then in a predefined order (e.g., ascending or descending) of the PDCCH monitoring occasion index.

For example, the total DAI in a type #B3 DCI may indicate the total number of {serving cell, PDCCH monitoring occasion} -pair (s) in which PDSCH receptions with HARQ-ACK feedback enabled, up to the current PDCCH monitoring occasion. The total DAI may be updated (e.g., incremented) from one PDCCH monitoring occasion to the next PDCCH monitoring occasion.

According to the above definitions for the counter DAI and total DAI, a plurality of DCI formats transmitted by a BS to a UE for scheduling a plurality of PDSCHs on a plurality of serving cells of the UE may indicate the same slot for transmitting HARQ-ACK feedback, and may be divided into three sets of DCI formats (denoted as DCI set #B1, DCI set #B2 and DCI set #B3) . DCI set #B1 includes all type #B1 DCIs in the plurality of DCI formats, that is, each DCI format in DCI set #B1 schedules a single PDSCH of the plurality of PDSCHs or requires HARQ-ACK feedback. DCI set #B2 includes all type #B2 DCIs in the plurality of DCI formats, that is, each DCI format in DCI set #B2 schedules more than one PDSCH of the plurality of PDSCHs on a single cell. DCI set #B3 includes all type #B3 DCIs in the plurality of DCI formats, that is, each DCI format in DCI set #B3 schedules more than one PDSCH of the plurality of PDSCHs on more than one cell. The counter DAI (s) of the DCI format (s) in DCI set #B1, DCI set #B2 and DCI set #B3 are counted separately from each other (e.g., counted within each set) . The total DAI (s) of the DCI format (s) in DCI set #B1, DCI set #B2 and DCI set #B3 are counted separately from each other (e.g., counted within each set) .

An example is described in the following text with respect to FIG. 4.

Referring to FIG. 4, it is assumed that the serving cell indices of CCs 431-435 satisfy CC 431<CC 432<CC 433<CC 434<CC 435, the counter DAI is updated first in an ascending order of serving cell index and then in an ascending order of PDCCH monitoring occasion index and for each of the scheduled PDSCHs, a single HARQ-ACK information bit is required.

According to the above definitions for counter DAI and total DAI, DCI formats 411-416 can be divided into three sets of DCI formats, a first set including DCI formats 411, 414 and 415, each of which schedules a single PDSCH, a second set including DCI formats 413 and 416, each of which schedules more than one PDSCH on a single cell, and a third set including DCI format 412, which schedules more than one PDSCH on more than one cell. Separate DAI counting is performed in the three sets of DCI formats. For example, the {counter DAI, total DAI} values in DCI formats 411, 414 and 415 are set as {1, 2} , {2, 2} and {3, 3} , respectively. The {counter DAI, total DAI} values in DCI formats 413 and 416 are set as {1, 1} and {2, 2} , respectively. The {counter DAI, total DAI} values in DCI format 412 is set as {1, 1} .

From the perspective of the UE, when no DCI format is missed, the UE can clearly know that 13 PDSCHs (i.e., PDSCHs 421-4213) are scheduled by the six DCI formats (i.e., DCI formats 411-416) and transmit corresponding HARQ-ACK feedback for the PDSCHs in one HARQ-ACK codebook. For example, the HARQ-ACK codebook may include three sub-codebooks corresponding to the three sets of DCI formats. Denoting the actual HARQ-ACK information bits for PDSCHs 421-4213 as c1 to c13, respectively, the sub-codebook corresponding to the first set of DCI formats can include HARQ-ACK information bits {c1, c10, c11} .

Denoting the number of HARQ-ACK information bits corresponding to the PDSCHs co-scheduled by a type #B2 DCI as Y, the UE may generate Y bits for each type #B2 DCI. Assuming that Y=4, the UE may generate HARQ-ACK information bits {c7, c8, c9, NACK} for DCI format 413 and HARQ-ACK information bits {c12, c13, NACK, NACK} for DCI format 416, wherein "NACK" bits are padding bits. The sub-codebook corresponding to the second set of DCI formats can include HARQ-ACK information bits { {c7, c8, c9, NACK} , {c12, c13, NACK, NACK} } .

Denoting the number of HARQ-ACK information bits corresponding to the PDSCHs co-scheduled by a type #B3 DCI as Z, the UE may generate Z bits for each type #B3 DCI. Assuming that Z=5, the UE may generate HARQ-ACK information bits {c2, c3, c4, c5, c6} for DCI format 413. The sub-codebook corresponding to the third set of DCI formats can include HARQ-ACK information bits {c2, c3, c4, c5, c6} .

When a DCI format scheduling more than one PDSCH on a single cell, such as DCI format 413, is missed by the UE, the UE can identify that there is one DCI format scheduling more than one PDSCH on a single cell missed based on the counter DAIs or total DAIs in DCI format 416. The UE can also determine that there is more than one PDSCH missed (i.e., due to the miss of DCI format 413) . The UE can generate “NACK” bits for the missed PDSCHs.

For example, the UE may generate HARQ-ACK information bits {NACK, NACK, NACK, NACK} for the missed DCI format (i.e., DCI format 413) and HARQ-ACK information bits {c12, c13, NACK, NACK} for DCI format 416. The sub-codebook corresponding to the second set of DCI formats may include HARQ-ACK information bits { {NACK, NACK, NACK, NACK} , {c12, c13, NACK, NACK} } .

FIG. 5 illustrates a flowchart of method 500 for wireless communication in accordance with some embodiments of the present disclosure. Details described in all of the foregoing embodiments of the present disclosure are applicable for the embodiments shown in FIG. 5. In some examples, method 500 may be performed by a UE, for example, UE 104 as described with reference to FIG. 1. In some embodiments, the UE may execute a set of instructions to control the functional elements of the UE to perform the described functions or operations.

At 511, the UE may receive, from a BS, a plurality of DCI formats for scheduling a plurality of PDSCHs on a plurality of serving cells of the UE, wherein the plurality of DCI formats indicates a same slot for transmitting HARQ-ACK feedback, and each of the plurality of DCI formats comprises a counter DAI and a total DAI.

At 513, the UE may generate a HARQ-ACK codebook comprising HARQ-ACK information bits for the plurality of PDSCHs. At 515, the UE may transmit, to the BS, the HARQ-ACK codebook.

The descriptions regarding the counter DAI and the total DAI as mentioned above may apply here.

For example, in some embodiments, the total DAI may indicate a total number of PDSCH receptions with HARQ-ACK feedback enabled and DCI formats with HARQ-ACK feedback required, up to the current PDCCH monitoring occasion.

In some embodiments, the counter DAI may indicate one of the following: an accumulative number of {serving cell, PDCCH monitoring occasion} -pairs in which a PDSCH reception (s) with HARQ-ACK feedback enabled or a DCI format (s) with HARQ-ACK feedback required is present, up to the current serving cell and current PDCCH monitoring occasion; an accumulative number of PDSCH receptions with HARQ-ACK feedback enabled and DCI formats with HARQ-ACK feedback required, up to the current serving cell and current PDCCH monitoring occasion; an ordering in the HARQ-ACK codebook for a start HARQ-ACK information bit of HARQ-ACK information bit (s) for PDSCH (s) scheduled by a DCI format with HARQ-ACK feedback enabled or for HARQ-ACK information bit (s) for a DCI format with HARQ-ACK feedback required; and an accumulative number of PDSCH receptions with HARQ-ACK feedback enabled and DCI formats with HARQ-ACK feedback required, before the current serving cell and current PDCCH monitoring occasion.

In some embodiments, the plurality of DCI formats may include a first set of DCI formats and a second set of DCI formats, each DCI format in the first set of DCI formats schedules a single PDSCH of the plurality of PDSCHs, and each DCI format in the second set of DCI formats schedules more than one PDSCH of the plurality of PDSCHs. The counter DAI (s) of the DCI format (s) in the first set of DCI formats may be counted separately from the counter DAI (s) of the DCI format (s) in the second set of DCI formats. The total DAI (s) of the DCI format (s) in the first set of DCI formats may be counted separately from the total DAI (s) of the DCI format (s) in the second set of DCI formats.

In some embodiments, the plurality of DCI formats may include a first set of DCI formats, a second set of DCI formats and a third set of DCI formats, each DCI format in the first set of DCI formats schedules a single PDSCH of the plurality of PDSCHs, each DCI format in the second set of DCI formats schedules more than one PDSCH of the plurality of PDSCHs on a single cell of the plurality of serving cells, and each DCI format in the third set of DCI formats schedules more than one PDSCH of the plurality of PDSCHs on more than one cell of the plurality of serving cells. The counter DAI (s) of the DCI format (s) in the first set of DCI formats, the counter DAI (s) of the DCI format (s) in the second set of DCI formats and the counter DAI (s) of the DCI format (s) in the third set of DCI formats may be counted separately from each other. The total DAI (s) of the DCI format (s) in the first set of DCI formats, the total DAI (s) of the DCI format (s) in the second set of DCI formats and the total DAI (s) of the DCI format (s) in the third set of DCI formats may be counted separately from each other.

In some embodiments, the counter DAI in each DCI format in the first, second or third set of DCI formats may indicate an accumulative number of {serving cell, PDCCH monitoring occasion} -pairs in which a PDSCH reception (s) with HARQ-ACK feedback enabled or a DCI format (s) with HARQ-ACK feedback required is present, up to the current serving cell and current PDCCH monitoring occasion.

In some embodiments, the total DAI in each DCI format in the first, second or third set of DCI formats may indicate a total number of {serving cell, PDCCH monitoring occasion} -pairs in which a PDSCH reception (s) with HARQ-ACK feedback enabled or a DCI format (s) with HARQ-ACK feedback required is present, up to the current PDCCH monitoring occasion.

In some embodiments, the UE may determine whether a DCI format is missed based on the counter DAIs and total DAIs in the plurality of DCI formats. In response to at least one DCI format being missed, the UE may generate HARQ-ACK information bits in the HARQ-ACK codebook for PDSCH (s) scheduled by the at least one DCI format based on the counter DAIs and total DAIs in the plurality of DCI formats.

In some embodiments, the counter DAI may be updated first in a predefined order of serving cell index and then in a predefined order of PDCCH monitoring occasion index. In some embodiments, the total DAI may be updated from PDCCH monitoring occasion to PDCCH monitoring occasion.

It should be appreciated by persons skilled in the art that the sequence of the operations in exemplary method 500 may be changed and some of the operations in exemplary method 500 may be eliminated or modified, without departing from the spirit and scope of the disclosure.

FIG. 6 illustrates a flowchart of method 600 for wireless communication in accordance with some embodiments of the present disclosure. Details described in all of the foregoing embodiments of the present disclosure are applicable for the embodiments shown in FIG. 6. In some examples, method 600 may be performed by a BS or an NE (for example, NE 106 as described with reference to FIG. 1) . In some embodiments, the BS or the NE may execute a set of instructions to control the functional elements of the BS or the NE to perform the described functions or operations.

At 611, a BS may transmit, to a UE, a plurality of DCI formats for scheduling a plurality of PDSCHs on a plurality of serving cells of the UE, wherein the plurality of DCI formats may indicate a same slot for transmitting HARQ-ACK feedback, and each of the plurality of DCI formats may include a counter DAI and a total DAI.

At 613, the BS may transmit, to the UE, the plurality of PDSCHs based on the plurality of DCI formats. At 615, the BS may receive, from the UE, a HARQ-ACK codebook comprising HARQ-ACK information bits for the plurality of PDSCHs.

For example, in some embodiments, the total DAI may indicate a total number of PDSCH transmissions with HARQ-ACK feedback enabled and DCI formats with HARQ-ACK feedback required, up to the current PDCCH monitoring occasion.

In some embodiments, the counter DAI may indicate one of the following: an accumulative number of {serving cell, PDCCH monitoring occasion} -pairs in which a PDSCH transmission (s) with HARQ-ACK feedback enabled or a DCI format (s) with HARQ-ACK feedback required is present, up to the current serving cell and current PDCCH monitoring occasion; an accumulative number of PDSCH transmissions with HARQ-ACK feedback enabled and DCI formats with HARQ-ACK feedback required, up to the current serving cell and current PDCCH monitoring occasion; an ordering in the HARQ-ACK codebook for a start HARQ-ACK information bit of HARQ-ACK information bit (s) for PDSCH (s) scheduled by a DCI format with HARQ-ACK feedback enabled or for HARQ-ACK information bit (s) for a DCI format with HARQ-ACK feedback required; and an accumulative number of PDSCH transmissions with HARQ-ACK feedback enabled and DCI formats with HARQ-ACK feedback required, before the current serving cell and current PDCCH monitoring occasion.

In some embodiments, the plurality of DCI formats may include a first set of DCI formats, a second set of DCI formats and a third set of DCI formats, each DCI format in the first set of DCI formats schedules a single PDSCH of the plurality of PDSCHs, each DCI format in the second set of DCI formats schedules more than one PDSCH of the plurality of PDSCHs on a single cell of the plurality of serving cells, and each DCI format in the third set of DCI formats schedules more than one PDSCH of the plurality of PDSCHs on more than one cell of the plurality of serving cells. The counter DAI (s) of the DCI format (s) in the first set of DCI formats, the counter DAI (s) of the DCI format (s) in the second set of DCI formats and the counter DAI (s) of the DCI format (s) in the third set of DCI formats are counted separately from each other. The total DAI (s) of the DCI format (s) in the first set of DCI formats, the total DAI (s) of the DCI format (s) in the second set of DCI formats and the total DAI (s) of the DCI format (s) in the third set of DCI formats are counted separately from each other.

In some embodiments, the counter DAI in each DCI format in the first, second or third set of DCI formats may indicate an accumulative number of {serving cell, PDCCH monitoring occasion} -pairs in which a PDSCH transmission (s) with HARQ-ACK feedback enabled or a DCI format (s) with HARQ-ACK feedback required is present, up to the current serving cell and current PDCCH monitoring occasion.

In some embodiments, the total DAI in each DCI format in the first, second or third set of DCI formats may indicate a total number of {serving cell, PDCCH monitoring occasion} -pairs in which a PDSCH transmission (s) with HARQ-ACK feedback enabled or a DCI format (s) with HARQ-ACK feedback required is present, up to the current PDCCH monitoring occasion.

In some embodiments, the HARQ-ACK information bits in the HARQ-ACK codebook may be generated based on the counter DAIs and total DAIs in the plurality of DCI formats.

It should be appreciated by persons skilled in the art that the sequence of the operations in exemplary method 600 may be changed and some of the operations in exemplary method 600 may be eliminated or modified, without departing from the spirit and scope of the disclosure.

FIG. 7 illustrates a block diagram of exemplary apparatus 700 according to some embodiments of the present disclosure. As shown in FIG. 7, the apparatus 700 may include at least one processor 706 and at least one transceiver 702 coupled to the processor 706. The apparatus 700 may be a UE or an NE (e.g., a BS) .

Although in this figure, elements such as the at least one transceiver 702 and processor 706 are described in the singular, the plural is contemplated unless a limitation to the singular is explicitly stated. In some embodiments of the present disclosure, the transceiver 702 may be divided into two devices, such as a receiving circuitry and a transmitting circuitry. In some embodiments of the present disclosure, the apparatus 700 may further include an input device, a memory, and/or other components.

In some embodiments of the present disclosure, the apparatus 700 may be a UE. The transceiver 702 and the processor 706 may interact with each other so as to perform the operations with respect to the UE described in FIGs. 1-6. In some embodiments of the present disclosure, the apparatus 700 may be an NE (e.g., a BS) . The transceiver 702 and the processor 706 may interact with each other so as to perform the operations with respect to the BS or NE described in FIGs. 1-6.

In some embodiments of the present disclosure, the apparatus 700 may further include at least one non-transitory computer-readable medium.

For example, in some embodiments of the present disclosure, the non-transitory computer-readable medium may have stored thereon computer-executable instructions to cause the processor 706 to implement the method with respect to the UE as described above. For example, the computer-executable instructions, when executed, cause the processor 706 interacting with transceiver 702 to perform the operations with respect to the UE described in FIGs. 1-6.

In some embodiments of the present disclosure, the non-transitory computer-readable medium may have stored thereon computer-executable instructions to cause the processor 706 to implement the method with respect to the BS or NE as described above. For example, the computer-executable instructions, when executed, cause the processor 706 interacting with transceiver 702 to perform the operations with respect to the BS or NE described in FIGs. 1-6.

FIG. 8 illustrates an example of a UE 800 in accordance with aspects of the present disclosure. The UE 800 may include a processor 802, a memory 804, a controller 806, and a transceiver 808. The processor 802, the memory 804, the controller 806, or the transceiver 808, or various combinations thereof or various components thereof may be examples of means for performing various aspects of the present disclosure as described herein. These components may be coupled (e.g., operatively, communicatively, functionally, electronically, electrically) via one or more interfaces.

The processor 802, the memory 804, the controller 806, or the transceiver 808, or various combinations or components thereof may be implemented in hardware (e.g., circuitry) . The hardware may include a processor, a digital signal processor (DSP) , an application-specific integrated circuit (ASIC) , or other programmable logic device, or any combination thereof configured as or otherwise supporting a means for performing the functions described in the present disclosure.

The processor 802 may include an intelligent hardware device (e.g., a general-purpose processor, a DSP, a CPU, an ASIC, an FPGA, or any combination thereof) . In some implementations, the processor 802 may be configured to operate the memory 804. In some other implementations, the memory 804 may be integrated into the processor 802. The processor 802 may be configured to execute computer-readable instructions stored in the memory 804 to cause the UE 800 to perform various functions of the present disclosure.

The memory 804 may include volatile or non-volatile memory. The memory 804 may store computer-readable, computer-executable code including instructions when executed by the processor 802 cause the UE 800 to perform various functions described herein. The code may be stored in a non-transitory computer-readable medium such as the memory 804 or another type of memory. Computer-readable media includes both non-transitory computer storage media and communication media including any medium that facilitates transfer of a computer program from one place to another. A non-transitory storage medium may be any available medium that may be accessed by a general-purpose or special-purpose computer.

In some implementations, the processor 802 and the memory 804 coupled with the processor 802 may be configured to cause the UE 800 to perform one or more of the functions described herein (e.g., executing, by the processor 802, instructions stored in the memory 804) . For example, the processor 802 may support wireless communication at the UE 800 in accordance with examples as disclosed herein. For example, the UE 800 may be configured to support means for performing the operations as described with respect to FIG. 5.

For example, the UE 800 may be configured to support a means for receiving, from a BS (or an NE) , a plurality of DCI formats for scheduling a plurality of PDSCHs on a plurality of serving cells of a UE, wherein the plurality of DCI formats indicates a same slot for transmitting HARQ-ACK feedback, and each of the plurality of DCI formats comprises a counter DAI and a total DAI; a means for generating a HARQ-ACK codebook comprising HARQ-ACK information bits for the plurality of PDSCHs; and a means for transmitting, to the BS, the HARQ-ACK codebook.

The controller 806 may manage input and output signals for the UE 800. The controller 806 may also manage peripherals not integrated into the UE 800. In some implementations, the controller 806 may utilize an operating system such as or other operating systems. In some implementations, the controller 806 may be implemented as part of the processor 802.

In some implementations, the UE 800 may include at least one transceiver 808. In some other implementations, the UE 800 may have more than one transceiver 808. The transceiver 808 may represent a wireless transceiver. The transceiver 808 may include one or more receiver chains 810, one or more transmitter chains 812, or a combination thereof.

A receiver chain 810 may be configured to receive signals (e.g., control information, data, packets) over a wireless medium. For example, the receiver chain 810 may include one or more antennas for receive the signal over the air or wireless medium. The receiver chain 810 may include at least one amplifier (e.g., a low-noise amplifier (LNA) ) configured to amplify the received signal. The receiver chain 810 may include at least one demodulator configured to demodulate the receive signal and obtain the transmitted data by reversing the modulation technique applied during transmission of the signal. The receiver chain 810 may include at least one decoder for decoding the processing the demodulated signal to receive the transmitted data.

A transmitter chain 812 may be configured to generate and transmit signals (e.g., control information, data, packets) . The transmitter chain 812 may include at least one modulator for modulating data onto a carrier signal, preparing the signal for transmission over a wireless medium. The at least one modulator may be configured to support one or more techniques such as amplitude modulation (AM) , frequency modulation (FM) , or digital modulation schemes like phase-shift keying (PSK) or quadrature amplitude modulation (QAM) . The transmitter chain 812 may also include at least one power amplifier configured to amplify the modulated signal to an appropriate power level suitable for transmission over the wireless medium. The transmitter chain 812 may also include one or more antennas for transmitting the amplified signal into the air or wireless medium.

It should be appreciated by persons skilled in the art that the components in exemplary UE 800 may be changed, for example, some of the components in exemplary UE 800 may be omitted or modified or a new component (s) may be added to exemplary UE 800, without departing from the spirit and scope of the disclosure. For example, in some embodiments, the UE 800 may not include the controller 806.

FIG. 9 illustrates an example of a processor 900 in accordance with aspects of the present disclosure. The processor 900 may be an example of a processor configured to perform various operations in accordance with examples as described herein. The processor 900 may include a controller 902 configured to perform various operations in accordance with examples as described herein. The processor 900 may optionally include at least one memory 904, which may be, for example, an L1/L2/L3 cache. Additionally, or alternatively, the processor 900 may optionally include one or more arithmetic-logic units (ALUs) 906. One or more of these components may be in electronic communication or otherwise coupled (e.g., operatively, communicatively, functionally, electronically, electrically) via one or more interfaces (e.g., buses) .

The processor 900 may be a processor chipset and include a protocol stack (e.g., a software stack) executed by the processor chipset to perform various operations (e.g., receiving, obtaining, retrieving, transmitting, outputting, forwarding, storing, determining, identifying, accessing, writing, reading) in accordance with examples as described herein. The processor chipset may include one or more cores, one or more caches (e.g., memory local to or included in the processor chipset (e.g., the processor 900) or other memory (e.g., random access memory (RAM) , read-only memory (ROM) , dynamic RAM (DRAM) , synchronous dynamic RAM (SDRAM) , static RAM (SRAM) , ferroelectric RAM (FeRAM) , magnetic RAM (MRAM) , resistive RAM (RRAM) , flash memory, phase change memory (PCM) , and others) .

The controller 902 may be configured to manage and coordinate various operations (e.g., signaling, receiving, obtaining, retrieving, transmitting, outputting, forwarding, storing, determining, identifying, accessing, writing, reading) of the processor 900 to cause the processor 900 to support various operations in accordance with examples as described herein. For example, the controller 902 may operate as a control unit of the processor 900, generating control signals that manage the operation of various components of the processor 900. These control signals include enabling or disabling functional units, selecting data paths, initiating memory access, and coordinating timing of operations.

The controller 902 may be configured to fetch (e.g., obtain, retrieve, receive) instructions from the memory 904 and determine a subsequent instruction (s) to be executed to cause the processor 900 to support various operations in accordance with examples as described herein. The controller 902 may be configured to track memory address of instructions associated with the memory 904. The controller 902 may be configured to decode instructions to determine the operation to be performed and the operands involved. For example, the controller 902 may be configured to interpret the instruction and determine control signals to be output to other components of the processor 900 to cause the processor 900 to support various operations in accordance with examples as described herein. Additionally, or alternatively, the controller 902 may be configured to manage flow of data within the processor 900. The controller 902 may be configured to control transfer of data between registers, ALUs, and other functional units of the processor 900.

The memory 904 may include one or more caches (e.g., memory local to or included in the processor 900 or other memory, such RAM, ROM, DRAM, SDRAM, SRAM, MRAM, flash memory, etc. In some implementations, the memory 904 may reside within or on a processor chipset (e.g., local to the processor 900) . In some other implementations, the memory 904 may reside external to the processor chipset (e.g., remote to the processor 900) .

The memory 904 may store computer-readable, computer-executable code including instructions that, when executed by the processor 900, cause the processor 900 to perform various functions described herein. The code may be stored in a non-transitory computer-readable medium such as system memory or another type of memory. The controller 902 and/or the processor 900 may be configured to execute computer-readable instructions stored in the memory 904 to cause the processor 900 to perform various functions. For example, the processor 900 and/or the controller 902 may be coupled with or to the memory 904, the processor 900, the controller 902, and the memory 904 may be configured to perform various functions described herein. In some examples, the processor 900 may include multiple processors and the memory 904 may include multiple memories. One or more of the multiple processors may be coupled with one or more of the multiple memories, which may, individually or collectively, be configured to perform various functions herein.

The one or more ALUs 906 may be configured to support various operations in accordance with examples as described herein. In some implementations, the one or more ALUs 906 may reside within or on a processor chipset (e.g., the processor 900) . In some other implementations, the one or more ALUs 906 may reside external to the processor chipset (e.g., the processor 900) . One or more ALUs 906 may perform one or more computations such as addition, subtraction, multiplication, and division on data. For example, one or more ALUs 906 may receive input operands and an operation code, which determines an operation to be executed. One or more ALUs 906 be configured with a variety of logical and arithmetic circuits, including adders, subtractors, shifters, and logic gates, to process and manipulate the data according to the operation. Additionally, or alternatively, the one or more ALUs 906 may support logical operations such as AND, OR, exclusive-OR (XOR) , not-OR (NOR) , and not-AND (NAND) , enabling the one or more ALUs 906 to handle conditional operations, comparisons, and bitwise operations.

The processor 900 may support wireless communication in accordance with examples as disclosed herein.

For example, the processor 900 may be configured to support means for performing the operations as described with respect to FIG. 5. For example, the processor 900 may be configured to or operable to support a means for receiving, from a BS (or an NE) , a plurality of DCI formats for scheduling a plurality of PDSCHs on a plurality of serving cells of a UE, wherein the plurality of DCI formats indicates a same slot for transmitting HARQ-ACK feedback, and each of the plurality of DCI formats comprises a counter DAI and a total DAI; a means for generating a HARQ-ACK codebook comprising HARQ-ACK information bits for the plurality of PDSCHs; and a means for transmitting, to the BS, the HARQ-ACK codebook.

For example, the processor 900 may be configured to support means for performing the operations as described with respect to FIG. 6. For example, the processor 900 may be configured to support a means for transmitting, to a UE, a plurality of DCI formats for scheduling a plurality of PDSCHs on a plurality of serving cells of the UE, wherein the plurality of DCI formats indicates a same slot for transmitting HARQ-ACK feedback, and each of the plurality of DCI formats comprises a counter DAI and a total DAI; a means for transmit, to the UE, the plurality of PDSCHs based on the plurality of DCI formats; and a means for receive, from the UE, a HARQ-ACK codebook comprising HARQ-ACK information bits for the plurality of PDSCHs.

It should be appreciated by persons skilled in the art that the components in exemplary processor 900 may be changed, for example, some of the components in exemplary processor 900 may be omitted or modified or a new component (s) may be added to exemplary processor 900, without departing from the spirit and scope of the disclosure. For example, in some embodiments, the processor 900 may not include the ALUs 906.

FIG. 10 illustrates an example of an NE 1000 in accordance with aspects of the present disclosure. The NE 1000 may include a processor 1002, a memory 1004, a controller 1006, and a transceiver 1008. The processor 1002, the memory 1004, the controller 1006, or the transceiver 1008, or various combinations thereof or various components thereof may be examples of means for performing various aspects of the present disclosure as described herein. These components may be coupled (e.g., operatively, communicatively, functionally, electronically, electrically) via one or more interfaces.

The processor 1002, the memory 1004, the controller 1006, or the transceiver 1008, or various combinations or components thereof may be implemented in hardware (e.g., circuitry) . The hardware may include a processor, a DSP, an ASIC, or other programmable logic device, or any combination thereof configured as or otherwise supporting a means for performing the functions described in the present disclosure.

The processor 1002 may include an intelligent hardware device (e.g., a general-purpose processor, a DSP, a CPU, an ASIC, an FPGA, or any combination thereof) . In some implementations, the processor 1002 may be configured to operate the memory 1004. In some other implementations, the memory 1004 may be integrated into the processor 1002. The processor 1002 may be configured to execute computer-readable instructions stored in the memory 1004 to cause the NE 1000 to perform various functions of the present disclosure.

The memory 1004 may include volatile or non-volatile memory. The memory 1004 may store computer-readable, computer-executable code including instructions when executed by the processor 1002 cause the NE 1000 to perform various functions described herein. The code may be stored in a non-transitory computer-readable medium such as the memory 1004 or another type of memory. Computer-readable media includes both non-transitory computer storage media and communication media including any medium that facilitates transfer of a computer program from one place to another. A non-transitory storage medium may be any available medium that may be accessed by a general-purpose or special-purpose computer.

In some implementations, the processor 1002 and the memory 1004 coupled with the processor 1002 may be configured to cause the NE 1000 to perform one or more of the functions described herein (e.g., executing, by the processor 1002, instructions stored in the memory 1004) . For example, the processor 1002 may support wireless communication at the NE 1000 in accordance with examples as disclosed herein. For example, the NE 1000 may be configured to support means for performing the operations as described with respect to FIG. 6.

For example, the NE 1000 may be configured to support a means for transmitting, to a UE, a plurality of DCI formats for scheduling a plurality of PDSCHs on a plurality of serving cells of the UE, wherein the plurality of DCI formats indicates a same slot for transmitting HARQ-ACK feedback, and each of the plurality of DCI formats comprises a counter DAI and a total DAI; a means for transmit, to the UE, the plurality of PDSCHs based on the plurality of DCI formats; and a means for receive, from the UE, a HARQ-ACK codebook comprising HARQ-ACK information bits for the plurality of PDSCHs.

The controller 1006 may manage input and output signals for the NE 1000. The controller 1006 may also manage peripherals not integrated into the NE 1000. In some implementations, the controller 1006 may utilize an operating system such as or other operating systems. In some implementations, the controller 1006 may be implemented as part of the processor 1002.

In some implementations, the NE 1000 may include at least one transceiver 1008. In some other implementations, the NE 1000 may have more than one transceiver 1008. The transceiver 1008 may represent a wireless transceiver. The transceiver 1008 may include one or more receiver chains 1010, one or more transmitter chains 1012, or a combination thereof.

A receiver chain 1010 may be configured to receive signals (e.g., control information, data, packets) over a wireless medium. For example, the receiver chain 1010 may include one or more antennas for receive the signal over the air or wireless medium. The receiver chain 1010 may include at least one amplifier (e.g., an LNA) configured to amplify the received signal. The receiver chain 1010 may include at least one demodulator configured to demodulate the receive signal and obtain the transmitted data by reversing the modulation technique applied during transmission of the signal. The receiver chain 1010 may include at least one decoder for decoding the processing the demodulated signal to receive the transmitted data.

A transmitter chain 1012 may be configured to generate and transmit signals (e.g., control information, data, packets) . The transmitter chain 1012 may include at least one modulator for modulating data onto a carrier signal, preparing the signal for transmission over a wireless medium. The at least one modulator may be configured to support one or more techniques such as AM, FM, or digital modulation schemes like PSK or QAM. The transmitter chain 1012 may also include at least one power amplifier configured to amplify the modulated signal to an appropriate power level suitable for transmission over the wireless medium. The transmitter chain 1012 may also include one or more antennas for transmitting the amplified signal into the air or wireless medium.

It should be appreciated by persons skilled in the art that the components in exemplary NE 1000 may be changed, for example, some of the components in exemplary NE 1000 may be omitted or modified or a new component (s) may be added to exemplary NE 1000, without departing from the spirit and scope of the disclosure. For example, in some embodiments, the NE 1000 may not include the controller 1006.

Those having ordinary skill in the art would understand that the operations or steps of the methods described in connection with the aspects disclosed herein may be embodied directly in hardware, in a software module executed by a processor, or in a combination of the two. A software module 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.

While this disclosure has been described with specific embodiments thereof, it is evident that many alternatives, modifications, and variations may be apparent to those skilled in the art. The disclosure is not limited to the examples and designs described herein but is to be accorded with the broadest scope consistent with the principles and novel features disclosed herein. For example, various components of the embodiments may be interchanged, added, or substituted in other embodiments. Also, all of the elements of each figure are not necessary for the operation of the disclosed embodiments. For example, one of ordinary skill in the art of the disclosed embodiments would be enabled to make and use the teachings of the disclosure by simply employing the elements of the independent claims. Accordingly, embodiments of the disclosure as set forth herein are intended to be illustrative, not limiting. Various changes may be made without departing from the spirit and scope of the disclosure.

In this document, the terms "includes, " "including, " or any other variation 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 to such process, method, article, or apparatus. An element proceeded by "a, " "an, " or the like does not, without more constraints, preclude the existence of additional identical elements in the process, method, article, or apparatus that includes the element. Also, the term "another" is defined as at least a second or more. The term "having" or the like, as used herein, is defined as "including. " Expressions such as "A and/or B" or "at least one of A and B" may include any and all combinations of words enumerated along with the expression. For instance, the expression "A and/or B" or "at least one of A and B" may include A, B, or both A and B. The wording "the first, " "the second" or the like is only used to clearly illustrate the embodiments of the present disclosure, but is not used to limit the substance of the present disclosure.

Claims

A user equipment (UE) , comprising:

at least one memory; and

at least one processor coupled with the at least one memory and configured to cause the UE to:

receive, from a base station (BS) , a plurality of downlink control information (DCI) formats for scheduling a plurality of physical downlink shared channels (PDSCHs) on a plurality of serving cells of the UE, wherein the plurality of DCI formats indicates a same slot for transmitting hybrid automatic repeat request acknowledgement (HARQ-ACK) feedback, and each of the plurality of DCI formats comprises a counter downlink assignment indicator (DAI) and a total DAI;

generate a HARQ-ACK codebook comprising HARQ-ACK information bits for the plurality of PDSCHs; and

transmit, to the BS, the HARQ-ACK codebook.
The UE of claim 1, wherein the total DAI indicates a total number of PDSCH receptions with HARQ-ACK feedback enabled and DCI formats with HARQ-ACK feedback required, up to current physical downlink control channel (PDCCH) monitoring occasion.
The UE of claim 1, wherein the counter DAI indicates one of the following:

an accumulative number of {serving cell, physical downlink control channel (PDCCH) monitoring occasion} -pairs in which a PDSCH reception (s) with HARQ-ACK feedback enabled or a DCI format (s) with HARQ-ACK feedback required is present, up to current serving cell and current PDCCH monitoring occasion;

an accumulative number of PDSCH receptions with HARQ-ACK feedback enabled and DCI formats with HARQ-ACK feedback required, up to current serving cell and current PDCCH monitoring occasion;

an ordering in the HARQ-ACK codebook for a start HARQ-ACK information bit of HARQ-ACK information bit (s) for PDSCH (s) scheduled by a DCI format with HARQ-ACK feedback enabled or for HARQ-ACK information bit (s) for a DCI format with HARQ-ACK feedback required; and

an accumulative number of PDSCH receptions with HARQ-ACK feedback enabled and DCI formats with HARQ-ACK feedback required, before current serving cell and current PDCCH monitoring occasion.
The UE of claim 1, wherein the plurality of DCI formats comprises a first set of DCI formats and a second set of DCI formats, each DCI format in the first set of DCI formats schedules a single PDSCH of the plurality of PDSCHs, and each DCI format in the second set of DCI formats schedules more than one PDSCH of the plurality of PDSCHs,

wherein the counter DAI (s) of the DCI format (s) in the first set of DCI formats are counted separately from the counter DAI (s) of the DCI format (s) in the second set of DCI formats, and

wherein the total DAI (s) of the DCI format (s) in the first set of DCI formats are counted separately from the total DAI (s) of the DCI format (s) in the second set of DCI formats.
The UE of claim 1, wherein the plurality of DCI formats comprises a first set of DCI formats, a second set of DCI formats and a third set of DCI formats, each DCI format in the first set of DCI formats schedules a single PDSCH of the plurality of PDSCHs, each DCI format in the second set of DCI formats schedules more than one PDSCH of the plurality of PDSCHs on a single cell of the plurality of serving cells, and each DCI format in the third set of DCI formats schedules more than one PDSCH of the plurality of PDSCHs on more than one cell of the plurality of serving cells,

wherein the counter DAI (s) of the DCI format (s) in the first set of DCI formats, the counter DAI (s) of the DCI format (s) in the second set of DCI formats and the counter DAI (s) of the DCI format (s) in the third set of DCI formats are counted separately from each other, and

wherein the total DAI (s) of the DCI format (s) in the first set of DCI formats, the total DAI (s) of the DCI format (s) in the second set of DCI formats and the total DAI (s) of the DCI format (s) in the third set of DCI formats are counted separately from each other.
The UE of claim 4 or 5, wherein the counter DAI in each DCI format in the first set of DCI formats indicates an accumulative number of {serving cell, physical downlink control channel (PDCCH) monitoring occasion} -pairs in which a PDSCH reception (s) with HARQ-ACK feedback enabled or a DCI format (s) with HARQ-ACK feedback required is present, up to current serving cell and current PDCCH monitoring occasion; and

wherein the counter DAI in each DCI format in the second or third set of DCI formats indicates an accumulative number of {serving cell, physical downlink control channel (PDCCH) monitoring occasion} -pairs in which a PDSCH reception (s) with HARQ-ACK feedback enabled is present, up to current serving cell and current PDCCH monitoring occasion.
The UE of claim 4 or 5, wherein the total DAI in each DCI format in the first set of DCI formats indicates a total number of {serving cell, physical downlink control channel (PDCCH) monitoring occasion} -pairs in which a PDSCH reception (s) with HARQ-ACK feedback enabled or a DCI format (s) with HARQ-ACK feedback required is present, up to current PDCCH monitoring occasion; and

wherein the total DAI in each DCI format in the second or third set of DCI formats indicates a total number of {serving cell, physical downlink control channel (PDCCH) monitoring occasion} -pairs in which a PDSCH reception (s) with HARQ-ACK feedback enabled is present, up to current PDCCH monitoring occasion.
The UE of any of claims 1-5, wherein the at least one processor is further configured to cause the UE to:

determine whether a DCI format is missed based on the counter DAIs and total DAIs in the plurality of DCI formats; and

in response to at least one DCI format being missed, generate HARQ-ACK information bits in the HARQ-ACK codebook for PDSCH (s) scheduled by the at least one DCI format based on the counter DAIs and total DAIs in the plurality of DCI formats.
The UE of any of claims 1-5, wherein the counter DAI is updated first in a predefined order of serving cell index and then in a predefined order of physical downlink control channel (PDCCH) monitoring occasion index.
The UE of any of claims 1-5, wherein the total DAI is updated from physical downlink control channel (PDCCH) monitoring occasion to PDCCH monitoring occasion.
A processor, comprising:

at least one controller coupled with at least one memory and configured to cause the processor to:

receive, from a base station (BS) , a plurality of downlink control information (DCI) formats for scheduling a plurality of physical downlink shared channels (PDSCHs) on a plurality of serving cells of a user equipment (UE) , wherein the plurality of DCI formats indicates a same slot for transmitting hybrid automatic repeat request acknowledgement (HARQ-ACK) feedback, and each of the plurality of DCI formats comprises a counter downlink assignment indicator (DAI) and a total DAI;

generate a HARQ-ACK codebook comprising HARQ-ACK information bits for the plurality of PDSCHs; and

transmit, to the BS, the HARQ-ACK codebook.
A base station (BS) , comprising:

at least one memory; and

at least one processor coupled with the at least one memory and configured to cause the BS to:

transmit, to a user equipment (UE) , a plurality of downlink control information (DCI) formats for scheduling a plurality of physical downlink shared channels (PDSCHs) on a plurality of serving cells of the UE, wherein the plurality of DCI formats indicates a same slot for transmitting hybrid automatic repeat request acknowledgement (HARQ-ACK) feedback, and each of the plurality of DCI formats comprises a counter downlink assignment indicator (DAI) and a total DAI;

transmit, to the UE, the plurality of PDSCHs based on the plurality of DCI formats; and

receive, from the UE, a HARQ-ACK codebook comprising HARQ-ACK information bits for the plurality of PDSCHs.
The BS of claim 12, wherein the total DAI indicates a total number of PDSCH transmissions with HARQ-ACK feedback enabled and DCI formats with HARQ-ACK feedback required, up to current physical downlink control channel (PDCCH) monitoring occasion.
The BS of claim 12, wherein the counter DAI indicates one of the following:

an accumulative number of {serving cell, physical downlink control channel (PDCCH) monitoring occasion} -pairs in which a PDSCH transmission (s) with HARQ-ACK feedback enabled or a DCI format (s) with HARQ-ACK feedback required is present, up to current serving cell and current PDCCH monitoring occasion;

an accumulative number of PDSCH transmissions with HARQ-ACK feedback enabled and DCI formats with HARQ-ACK feedback required, up to current serving cell and current PDCCH monitoring occasion;

an ordering in the HARQ-ACK codebook for a start HARQ-ACK information bit of HARQ-ACK information bit (s) for PDSCH (s) scheduled by a DCI format with HARQ-ACK feedback enabled or for HARQ-ACK information bit (s) for a DCI format with HARQ-ACK feedback required; and

an accumulative number of PDSCH transmissions with HARQ-ACK feedback enabled and DCI formats with HARQ-ACK feedback required, before current serving cell and current PDCCH monitoring occasion.
The BS of claim 12, wherein the plurality of DCI formats comprises a first set of DCI formats and a second set of DCI formats, each DCI format in the first set of DCI formats schedules a single PDSCH of the plurality of PDSCHs, and each DCI format in the second set of DCI formats schedules more than one PDSCH of the plurality of PDSCHs,

wherein the counter DAI (s) of the DCI format (s) in the first set of DCI formats are counted separately from the counter DAI (s) of the DCI format (s) in the second set of DCI formats, and

wherein the total DAI (s) of the DCI format (s) in the first set of DCI formats are counted separately from the total DAI (s) of the DCI format (s) in the second set of DCI formats.
The BS of claim 12, wherein the plurality of DCI formats comprises a first set of DCI formats, a second set of DCI formats and a third set of DCI formats, each DCI format in the first set of DCI formats schedules a single PDSCH of the plurality of PDSCHs, each DCI format in the second set of DCI formats schedules more than one PDSCH of the plurality of PDSCHs on a single cell of the plurality of serving cells, and each DCI format in the third set of DCI formats schedules more than one PDSCH of the plurality of PDSCHs on more than one cell of the plurality of serving cells,

wherein the counter DAI (s) of the DCI format (s) in the first set of DCI formats, the counter DAI (s) of the DCI format (s) in the second set of DCI formats and the counter DAI (s) of the DCI format (s) in the third set of DCI formats are counted separately from each other, and

wherein the total DAI (s) of the DCI format (s) in the first set of DCI formats, the total DAI (s) of the DCI format (s) in the second set of DCI formats and the total DAI (s) of the DCI format (s) in the third set of DCI formats are counted separately from each other.
The BS of claim 15 or 16, wherein the counter DAI in each DCI format in the first set of DCI formats indicates an accumulative number of {serving cell, physical downlink control channel (PDCCH) monitoring occasion} -pairs in which a PDSCH transmission (s) with HARQ-ACK feedback enabled or a DCI format (s) with HARQ-ACK feedback required is present, up to current serving cell and current PDCCH monitoring occasion; and

wherein the counter DAI in each DCI format in the second or third set of DCI formats indicates an accumulative number of {serving cell, physical downlink control channel (PDCCH) monitoring occasion} -pairs in which a PDSCH reception (s) with HARQ-ACK feedback enabled is present, up to current serving cell and current PDCCH monitoring occasion.
The BS of claim 15 or 16, wherein the total DAI in each DCI format in the first set of DCI formats indicates a total number of {serving cell, physical downlink control channel (PDCCH) monitoring occasion} -pairs in which a PDSCH transmission (s) with HARQ-ACK feedback enabled or a DCI format (s) with HARQ-ACK feedback required is present, up to current PDCCH monitoring occasion; and

wherein the total DAI in each DCI format in the second or third set of DCI formats indicates a total number of {serving cell, physical downlink control channel (PDCCH) monitoring occasion} -pairs in which a PDSCH reception (s) with HARQ-ACK feedback enabled is present, up to current PDCCH monitoring occasion.
The BS of any of claims 12-16, wherein the HARQ-ACK information bits in the HARQ-ACK codebook are generated based on the counter DAIs and total DAIs in the plurality of DCI formats.
A method for wireless communication, comprising:

receiving, from a base station (BS) , a plurality of downlink control information (DCI) formats for scheduling a plurality of physical downlink shared channels (PDSCHs) on a plurality of serving cells of a user equipment (UE) , wherein the plurality of DCI formats indicates a same slot for transmitting hybrid automatic repeat request acknowledgement (HARQ-ACK) feedback, and each of the plurality of DCI formats comprises a counter downlink assignment indicator (DAI) and a total DAI;

generating a HARQ-ACK codebook comprising HARQ-ACK information bits for the plurality of PDSCHs; and

transmitting, to the BS, the HARQ-ACK codebook.