WO2021042091A2

WO2021042091A2 - Apparatus and method of performing a hybrid-automatic repeat request-acknowledgement codebook selection process

Info

Publication number: WO2021042091A2
Application number: PCT/US2020/063833
Authority: WO
Inventors: Yuanye WANG
Original assignee: Zeku, Inc.
Priority date: 2020-10-13
Filing date: 2020-12-08
Publication date: 2021-03-04
Also published as: WO2021042091A3; CN116325583A

Abstract

Embodiments of the present disclosure include an apparatus of a user equipment (UE). The apparatus may include at least one processor, and memory storing instructions that, when executed by the at least one processor cause the apparatus to perform operations. In certain aspects, the apparatus may receive one or more code block groups (CBGs) from a base station. In certain other aspects, the apparatus may perform a hybrid automatic repeat request (HARQ)-acknowledgement (ACK) codebook selection process to determine a smaller HARQ-ACK codebook by calculating a first codebook size associated with the one or more CBGs, calculating a second codebook size associated with the one or more CBGs, and determining whether the first HARQ-ACK codebook or the second HARQ-ACK codebook is a smaller HARQ-ACK codebook by comparing the first codebook size and the second codebook size. In certain other aspects, the apparatus may transmit the smaller HARQ-ACK codebook to the base station.

Description

APPARATUS AND METHOD OF PERFORMING A HYBRID-

AUTOMATIC REPEAT REQUEST-ACKNOWLEDGEMENT CODEBOOK

SELECTION PROCESS

CROSS-REFERENCE TO RELATED APPLICATION

[0001] This application claims the benefit of priority to U. S. Provisional Patent Application

No. 63/091,182, filed October 13, 2020, entitled “A NEW HARQ-ACK CODEBOOK DETERMINATION TYPE,” which is hereby incorporated by reference in its entirety.

BACKGROUND

[0002] Embodiments of the present disclosure relate to apparatus and method for wireless communication.

[0003] Wireless communication systems are widely deployed to provide various telecommunication services such as telephony, video, data, messaging, and broadcasts. In cellular communication, such as the 4th-generation (4G) Long Term Evolution (LTE) and the 5th-generation (5G) New Radio (NR), the 3rd Generation Partnership Project (3GPP) defines various mechanisms for error correction, e.g., such as hybrid automatic repeat request (HARQ) feedback.

SUMMARY

[0004] Embodiments of the present disclosure include an apparatus of a user equipment

(UE). The apparatus may include at least one processor. In certain aspects, the apparatus may further include memory storing instructions that, when executed by the at least one processor, cause the apparatus to receive one or more code block groups (CBGs) from a base station. In certain other aspects, the memory storing instructions that, when executed by the at least one processor, further cause the apparatus to perform a hybrid-automatic repeat request (HARQ)- acknowledgement (ACK) codebook selection process to determine a smaller HARQ-ACK codebook by calculating a first codebook size associated with the one or more CBGs, the first codebook size being associated with a first HARQ-ACK codebook of the first type, calculating a second codebook size associated with the one or more CBGs, the second codebook size being associated with a second HARQ-ACK codebook of a second type, and determining whether the first HARQ-ACK codebook or the second HARQ-ACK codebook is a smaller HARQ- ACK codebook by comparing the first codebook size and the second codebook size. In certain other aspects, the memory storing instructions that, when executed by the at least one processor, further cause the apparatus to transmit the smaller HARQ-ACK codebook to the base station.

[0005] Embodiments of the present disclosure include an apparatus of a base station. The apparatus may include at least one processor. In certain aspects, the apparatus may further include memory storing instructions that, when executed by the at least one processor, cause the apparatus to configure a UE to perform a HARQ-ACK codebook selection process to determine a smaller HARQ-ACK codebook from a first HARQ-ACK codebook of a first type and a second HARQ-ACK codebook of a second type. In certain other aspects, the memory storing instructions that, when executed by the at least one processor, further cause the apparatus to transmit one or more CBGs to the UE. In certain other aspects, the memory storing instructions that, when executed by the at least one processor, further cause the apparatus to receive the smaller HARQ-ACK codebook from the UE the smaller HARQ-ACK codebook from the UE in response to transmitting the one or more CBGs.

[0006] Embodiments of the present disclosure include a method of a UE. In certain aspects, the method may include receiving one or more CBGs from a base station. In certain other aspects, the method may further include performing a HARQ-ACK codebook selection process to determine a smaller HARQ-ACK codebook by calculating a first codebook size associated with the one or more CBGs, the first codebook size being associated with a first HARQ-ACK codebook of the first type, calculating a second codebook size associated with the one or more CBGs, the second codebook size being associated with a second HARQ-ACK codebook of a second type, and determining whether the first HARQ-ACK codebook or the second HARQ- ACK codebook is a smaller HARQ-ACK codebook by comparing the first codebook size and the second codebook size. In certain other aspects, the method may further include transmitting the smaller HARQ-ACK codebook to the base station.

[0007] Embodiments of the present disclosure include a method of a base station. In certain aspects, the method may include configuring a UE to perform a HARQ-ACK codebook selection process to determine a smaller HARQ-ACK codebook from a first HARQ-ACK codebook of a first type and a second HARQ-ACK codebook of a second type. In certain other aspects, the method may further include transmitting one or more CBGs to the UE. In certain other aspects, the method may include receiving the smaller HARQ-ACK codebook from the UE in response to transmitting the one or more CBGs. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] The accompanying drawings, which are incorporated herein and form a part of the specification, illustrate embodiments of the present disclosure and, together with the description, further serve to explain the principles of the present disclosure and to enable a person skilled in the pertinent art to make and use the present disclosure.

[0009] FIG. 1 illustrates an exemplary wireless network, according to some embodiments of the present disclosure.

[0010] FIG. 2 illustrates a block diagram of an apparatus including a baseband chip, a radio frequency (RF) chip, and a host chip, according to some embodiments of the present disclosure. [0011] FIG. 3 illustrates an exemplary data flow for performing a HARQ-ACK codebook selection process, according to some embodiments of the present disclosure.

[0012] FIG. 4 illustrates a diagram of a HARQ-ACK codebook time span, according to certain aspects of the present disclosure.

[0013] FIG. 5 illustrates a flow chart of an exemplary method for performing a HARQ- ACK codebook selection process of a UE, according to some embodiments of the present disclosure.

[0014] FIG. 6 illustrates a flow chart of an exemplary method for configuring a UE to perform a HARQ-ACK codebook selection process, according to some embodiments of the present disclosure. [0015] FIG. 7 illustrates a block diagram of an exemplary node, according to some embodiments of the present disclosure.

[0016] Embodiments of the present disclosure will be described with reference to the accompanying drawings.

DETAILED DESCRIPTION [0017] Although specific configurations and arrangements are discussed, it should be understood that this is done for illustrative purposes only. A person skilled in the pertinent art will recognize that other configurations and arrangements can be used without departing from the spirit and scope of the present disclosure. It will be apparent to a person skilled in the pertinent art that the present disclosure can also be employed in a variety of other applications. [0018] It is noted that references in the specification to “one embodiment,” “an embodiment,” “an example embodiment,” “some embodiments,” “certain embodiments,” etc., indicate that the embodiment described may include a particular feature, structure, or characteristic, but every embodiment may not necessarily include the particular feature, structure, or characteristic. Moreover, such phrases do not necessarily refer to the same embodiment. Further, when a particular feature, structure, or characteristic is described in connection with an embodiment, it would be within the knowledge of a person skilled in the pertinent art to effect such feature, structure, or characteristic in connection with other embodiments whether or not explicitly described.

[0019] In general, terminology may be understood at least in part from usage in context.

For example, the term “one or more” as used herein, depending at least in part upon context, may be used to describe any feature, structure, or characteristic in a singular sense or may be used to describe combinations of features, structures or characteristics in a plural sense. Similarly, terms, such as “a,” “an,” or “the,” again, may be understood to convey a singular usage or to convey a plural usage, depending at least in part upon context. In addition, the term “based on” may be understood as not necessarily intended to convey an exclusive set of factors and may, instead, allow for existence of additional factors not necessarily expressly described, again, depending at least in part on context.

[0020] Various aspects of wireless communication systems will now be described with reference to various apparatus and methods. These apparatus and methods will be described in the following detailed description and illustrated in the accompanying drawings by various blocks, modules, units, components, circuits, steps, operations, processes, algorithms, etc. (collectively referred to as “elements”). These elements may be implemented using electronic hardware, firmware, computer software, or any combination thereof. Whether such elements are implemented as hardware, firmware, or software depends upon the particular application and design constraints imposed on the overall system.

[0021] The techniques described herein may be used for various wireless communication networks, such as code division multiple access (CDMA) system, time division multiple access (TDMA) system, frequency division multiple access (FDMA) system, orthogonal frequency division multiple access (OFDMA) system, single-carrier frequency division multiple access (SC-FDMA) system, and other networks. The terms “network” and “system” are often used interchangeably. A CDMA network may implement a radio access technology (RAT), such as Universal Terrestrial Radio Access (UTRA), evolved UTRA (E-UTRA), CDMA 2000, etc. A TDMA network may implement a RAT, such as GSM. An OFDMA network may implement a RAT, such as LTE or NR. The techniques described herein may be used for the wireless networks and RATs mentioned above, as well as other wireless networks and RATs.

[0022] A transport block in 5G NR may include a payload which is passed between the

MAC Layer and PHY Layer, specifically for a shared data channel, e.g., such as physical downlink shared channel (PDSCH) and physical uplink shared channel (PUSCH). A transport block may undergo PHY layer processing at the transmitter of a base station before being mapped onto the PDSCH for transmission in a time slot over the air interface to a UE. Once at the PHY layer of the base station, a cyclic redundancy check (CRC) may be appended to the transport block to facilitate error detection by the UE. The CRC may allow for UE-side detection of errors in the decoded transport block. In certain implementations, the CRC may^¬ be used by the hybrid-automatic repeat request (HARQ) protocol at the UE as a trigger for requesting retransmissions. Following the attachment of the CRC, the transport block may be segmented into multiple code blocks. Each code block may be low-density parity-check (LDPC)-eneoded and rate matched separately, including PFIY layer FIARQ processing, and the resulting bits may be concatenated to form the sequence of bits representing the coded transport block, which may be sent to the UE.

[0023] In certain implementations, a transport block may be segmented into hundreds of code blocks in a transport block. If only one or a few of the code blocks are in error, retransmitting the entire transport block to the UE may result in low spectral efficiency as compared to retransmitting only the erroneous code blocks. To reduce the control signaling overhead, multiple code blocks may be grouped together into code block groups (CBG). In case of an error in one code block, only the CBG to which the erroneous code block belongs may be retransmitted instead of the entire transport block, which may use fewer resources than retransmitting the entire transport block.

[0024] Furthermore, 5GNR supports very high bitrates and multiple simultaneous carriers.

A UE may be configured to use one or more of carrier aggregation, spatial multiplexing, and/or dual connectivity at the same time. This means that the UE should be able to concurrently report to the base station the success or failure of the transmission of multiple transport blocks (e.g., multiple CBGs per transport block). In certain implementations, the UE may send a single transmission that includes the HARQ feedback for each CBG transmitted to the UE during a time span across multiple carriers. This may be accomplished using a HARQ-ACK codebook that includes the HARQ feedback for multiple CBGs and/or transport blocks across multiple carriers. By combining the HARQ feedback into a HARQ-ACK codebook that is transmitted in a single region of an uplink channel, uplink signaling overhead may be reduced.

[0025] Conventional systems contemplate two types of HARQ-ACK codebooks that may be used to accomplish HARQ feedback by a UE. Namely, a UE may use either a type-1 HARQ-ACK codebook (e.g., semi-static codebook) or a type-2 HARQ-ACK codebook (e.g., dynamic codebook) to accomplish HARQ feedback in the uplink.

[0026] A type-1 HARQ-ACK codebook may be fixed in size, such that its number of bits is related to the number of CBGs and/or transport blocks within the time span. That is, a type-

1 HARQ-ACK codebook indicates HARQ feedback for all CBGs across all carriers within a time span regardless of whether the CBG was properly decoded. In certain instances, however, using a HARQ-ACK codebook of a fixed size may be undesirable. This may be especially true if discontinuous transmission (DTX) is used by the base station. When using DTX, the base station may not transmit to the UE in every CBG, transport block, and/or time slot within a time span. However, because type-1 HARQ-ACK codebook has a fixed size, the UE must include HARQ feedback for each CBG in the time span regardless of whether that CBG included a transmission from the base station. That is, the UE must still include a negative ACK (NACK) for the CBGs in which there was no transmission due to DTX to ensure that the UE and base station are aligned with respect to transmissions. This is undesirable in terms of both signaling overhead and power consumption.

[0027] For this reason, type-2 HARQ-ACK codebook was designed to reduce the codebook size as compared to type-1 HARQ-ACK codebook. More specifically, a type-2 HARQ-ACK codebook may include HARQ feedback for only those CBGs in which a transmission was sent by the base station to the UE. Hence, type-2 HARQ-ACK codebook was adopted as the default codebook type used in NR. However, in certain scenarios, a type-

2 HARQ-ACK codebook may be larger in size than a type-1 HARQ-ACK codebook. For example, in the case of an imbalanced number of CBGs per transport block across carriers, the base station transmits to the UE in all CBGs within the timespan across all carriers, and when the miss detection rate is low, the type-2 HARQ-ACK codebook may be larger than the type- 1 HARQ-ACK codebook. This is because a type-2 HARQ-ACK codebook must provide HARQ feedback for a maximum number of CBGs per transport block across all carriers to be sure the HARQ feedback is aligned at the UE and the base station. Consequently, it may be beneficial to use a type-1 HARQ-ACK codebook in certain instances. Thus, there is an unmet need for a flexible HARQ-ACK codebook selection process that ensures the smallest HARQ- ACK codebook is used for HARQ feedback by the UE.

[0028] The present disclosure provides a solution by enabling a UE to perform a HARQ-

ACK codebook selection process. The HARQ-ACK codebook selection process may enable the UE to generate either a type-1 HARQ-ACK codebook or a type-2 HARQ-ACK codebook, depending on which is smaller. In this way, the techniques of the present disclosure reduced signaling overhead and power consumption as compared to conventional NR HARQ feedback techniques, e.g., as described below in connection with FIGs. 1-7.

[0029] FIG. 1 illustrates an exemplary wireless network 100, in which certain aspects of the present disclosure may be implemented, according to some embodiments of the present disclosure. As shown in FIG. 1, wireless network 100 may include a network of nodes, such as a UE 102, an access node 104, and a core network element 106. UE 102 may be any terminal device, such as a mobile phone, a desktop computer, a laptop computer, a tablet, a vehicle computer, a gaming console, a printer, a positioning device, a wearable electronic device, a smart sensor, or any other device capable of receiving, processing, and transmitting information, such as any member of a vehicle to everything (V2X) network, a cluster network, a smart grid node, or an Intemet-of-Things (IoT) node. It is understood that UE 102 is illustrated as a mobile phone simply by way of illustration and not by way of limitation.

[0030] Access node 104 may be a device that communicates with user equipment 102, such as a wireless access point, a base station, a Node B, an enhanced Node B (eNodeB or eNB), a next-generation NodeB (gNodeB or gNB), a cluster master node, or the like. Access node 104 may have a wired connection to user equipment 102, a wireless connection to user equipment 102, or any combination thereof. Access node 104 may be connected to user equipment 102 by multiple connections, and user equipment 102 may be connected to other access nodes in addition to access node 104. Access node 104 may also be connected to other user equipments. It is understood that access node 104 is illustrated by a radio tower by way of illustration and not by way of limitation.

[0031] Core network element 106 may serve access node 104 and user equipment 102 to provide core network services. Examples of core network element 106 may include a home subscriber server (HSS), a mobility management entity (MME), a serving gateway (SGW), or a packet data network gateway (PGW). These are examples of core network elements of an evolved packet core (EPC) system, which is a core network for the LTE system. Other core network elements may be used in LTE and in other communication systems. In some embodiments, core network element 106 includes an access and mobility management function (AMF) device, a session management function (SMF) device, or a user plane function (UPF) device, of a core network for the NR system. It is understood that core network element 106 is shown as a set of rack-mounted servers by way of illustration and not by way of limitation.

[0032] Core network element 106 may connect with a large network, such as the Internet

108, or another Internet Protocol (IP) network, to communicate packet data over any distance. In this way, data from user equipment 102 may be communicated to other user equipments connected to other access points, including, for example, a computer 110 connected to Internet 108, for example, using a wired connection or a wireless connection, or to a tablet 112 wirelessly connected to Internet 108 via a router 114. Thus, computer 110 and tablet 112 provide additional examples of possible user equipments, and router 114 provides an example of another possible access node.

[0033] A generic example of a rack-mounted server is provided as an illustration of core network element 106. However, there may be multiple elements in the core network including database servers, such as a database 116, and security and authentication servers, such as an authentication server 118. Database 116 may, for example, manage data related to user subscription to network services. A home location register (HLR) is an example of a standardized database of subscriber information for a cellular network. Likewise, authentication server 118 may handle authentication of users, sessions, and so on. In the NR system, an authentication server function (AUSF) device may be the specific entity to perform user equipment authentication. In some embodiments, a single server rack may handle multiple such functions, such that the connections between core network element 106, authentication server 118, and database 116, may be local connections within a single rack.

[0034] Each element in FIG. 1 may be considered a node of wireless network 100. More detail regarding the possible implementation of a node is provided by way of example in the description of a node 700 in FIG. 7. Node 700 may be configured as user equipment 102, access node 104, or core network element 106 in FIG. 1. Similarly, node 700 may also be configured as computer 110, router 114, tablet 112, database 116, or authentication server 118 in FIG. 1. As shown in FIG. 7, node 700 may include a processor 702, a memory 704, and a transceiver 706. These components are shown as connected to one another by a bus, but other connection types are also permitted. When node 700 is UE 102, additional components may also be included, such as a user interface (UI), sensors, and the like. Similarly, node 700 may be implemented as a blade in a server system when node 700 is configured as core network element 106. Other implementations are also possible.

[0035] Transceiver 706 may include any suitable device for sending and/or receiving data.

Node 700 may include one or more transceivers, although only one transceiver 706 is shown for simplicity of illustration. An antenna 708 is shown as a possible communication mechanism for node 700. Multiple antennas and/or arrays of antennas may be utilized. Additionally, examples of node 700 may communicate using wired techniques rather than (or in addition to) wireless techniques. For example, access node 104 may communicate wirelessly to UE 102 and may communicate by a wired connection (for example, by optical or coaxial cable) to core network element 106. Other communication hardware, such as a network interface card (NIC), may be included as well.

[0036] As shown in FIG. 7, node 700 may include processor 702. Although only one processor is shown, it is understood that multiple processors can be included. Processor 702 may include microprocessors, microcontrollers (MCUs), digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), programmable logic devices (PLDs), state machines, gated logic, discrete hardware circuits, and other suitable hardware configured to perform the various functions described throughout the present disclosure. Processor 702 may be a hardware device having one or more processing cores. Processor 702 may execute software. Software shall be construed broadly to mean instructions, instruction sets, code, code segments, program code, programs, subprograms, software modules, applications, software applications, software packages, routines, subroutines, objects, executables, threads of execution, procedures, functions, etc., whether referred to as software, firmware, middleware, microcode, hardware description language, or otherwise. Software can include computer instructions written in an interpreted language, a compiled language, or machine code. Other techniques for instructing hardware are also permitted under the broad category of software.

[0037] As shown in FIG. 7, node 700 may also include memory 704. Although only one memory is shown, it is understood that multiple memories can be included. Memory 704 can broadly include both memory and storage. For example, memory 704 may include random- access memory (RAM), read-only memory (ROM), static RAM (SRAM), dynamic RAM (DRAM), ferro-electric RAM (FRAM), electrically erasable programmable ROM (EEPROM), CD-ROM or other optical disk storage, hard disk drive (HDD), such as magnetic disk storage or other magnetic storage devices, Flash drive, solid-state drive (SSD), or any other medium that can be used to carry or store desired program code in the form of instructions that can be accessed and executed by processor 702. Broadly, memory 704 may be embodied by any computer-readable medium, such as a non-transitory computer-readable medium.

[0038] Processor 702, memory 704, and transceiver 706 may be implemented in various forms in node 700 for performing wireless communication functions. In some embodiments, processor 702, memory 704, and transceiver 706 of node 700 are implemented (e.g., integrated) on one or more system-on-chips (SoCs). In one example, processor 702 and memory 704 may be integrated on an application processor (AP) SoC (sometimes known as a “host,” referred to herein as a “host chip”) that handles application processing in an operating system (OS) environment, including generating raw data to be transmitted. In another example, processor 702 and memory 704 may be integrated on a baseband processor (BP) SoC (sometimes known as a “modem,” referred to herein as a “baseband chip”) that converts the raw data, e.g., from the host chip, to signals that can be used to modulate the carrier frequency for transmission, and vice versa, which can run a real-time operating system (RTOS). In still another example, processor 702 and transceiver 706 (and memory 704 in some cases) may be integrated on an RF SoC (sometimes known as a “transceiver,” referred to herein as an “RF chip”) that transmits and receives RF signals with antenna 708. It is understood that in some examples, some or all of the host chip, baseband chip, and RF chip may be integrated as a single SoC. For example, a baseband chip and an RF chip may be integrated into a single SoC that manages all the radio functions for cellular communication.

[0039] Referring back to FIG. 1, in some embodiments, any suitable node of wireless network 100 (e.g., UE 102 or access node 104) may perform the HARQ-ACK selection process and/or configure the UE 102 to perform the HARQ-ACK selection process described below in connection with FIGs. 2-6. As a result, compared with conventional NR HARQ feedback, the techniques of the present disclosure provide reduced signaling overhead and power consumption.

[0040] FIG. 2 illustrates a block diagram of an apparatus 200 including a baseband chip

202, an RF chip 204, and a host chip 206, according to some embodiments of the present disclosure. Apparatus 200 may be an example of any suitable node of wireless network 100 in FIG. 1, such as user equipment 102 or access node 104. As shown in FIG. 2, apparatus 200 may include baseband chip 202, RF chip 204, host chip 206, and one or more antennas 210. In some embodiments, baseband chip 202 is implemented by processor 702 and memory 704, and RF chip 204 is implemented by processor 702, memory 704, and transceiver 706, as described above with respect to FIG. 7. Besides the on-chip memory (also known as “internal memory,” e.g., registers, buffers, or caches) on each chip 202, 204, or 206, apparatus 200 may further include an external memory 208 (e.g., the system memory or main memory) that can be shared by each chip 202, 204, or 206 through the system/main bus. Although baseband chip 202 is illustrated as a standalone SoC in FIG. 2, it is understood that in one example, baseband chip 202 and RF chip 204 may be integrated as one SoC; in another example, baseband chip 202 and host chip 206 may be integrated as one SoC; in still another example, baseband chip 202, RF chip 204, and host chip 206 may be integrated as one SoC, as described above.

[0041] In the uplink, host chip 206 may generate raw data and send it to baseband chip 202 for encoding, modulation, and mapping. Baseband chip 202 may also access the raw data generated by host chip 206 and stored in external memory 208, for example, using the direct memory access (DMA). Baseband chip 202 may first encode (e.g., by source coding and/or channel coding) the raw data and modulate the coded data using any suitable modulation techniques, such as multi-phase pre-shared key (MPSK) modulation or quadrature amplitude modulation (QAM). Baseband chip 202 may perform any other functions, such as symbol or layer mapping, to convert the raw data into a signal that can be used to modulate the carrier frequency for transmission. In the uplink, baseband chip 202 may send the modulated signal to RF chip 204. RF chip 204, through the transmitter (Tx), may convert the modulated signal in the digital form into analog signals, i.e., RF signals, and perform any suitable front-end RF functions, such as filtering, up-conversion, or sample-rate conversion. Antenna 210 (e.g., an antenna array) may transmit the RF signals provided by the transmitter of RF chip 204.

[0042] In the downlink, antenna 210 may receive RF signals and pass the RF signals to the receiver (Rx) of RF chip 204. RF chip 204 may perform any suitable front-end RF functions, such as filtering, down-conversion, or sample-rate conversion, and convert the RF signals into low-frequency digital signals (baseband signals) that can be processed by baseband chip 202. In the downlink, baseband chip 202 may demodulate and decode the baseband signals to extract raw data that can be processed by host chip 206. Baseband chip 202 may perform additional functions, such as error checking, de-mapping, channel estimation, descrambling, etc. The raw data provided by baseband chip 202 may be sent to host chip 206 directly or stored in external memory 208.

[0043] In some embodiments, one or more of the component of apparatus 200 (e.g., baseband chip 202, RF chip 204, host chip 206, external memory 208, etc.) may perform the HARQ-ACK selection process and/or configure the UE 102 to perform the HARQ-ACK selection process described below in connection with FIGs. 3-6. As a result, compared with conventional NR HARQ feedback, the techniques of the present disclosure provide reduced signaling overhead and power consumption.

[0044] FIG. 3 illustrates a data flow 300 for performing a HARQ-ACK codebook selection process, according to some embodiments of the present disclosure. FIG. 4 illustrates a diagram 400 of a HARQ-ACK codebook time span 404, according to certain aspects of the present disclosure. In FIG. 4, the time span 404 may include a single time slot with one transport block 406 in each of ten carriers 402. Furthermore, carrier #0 includes eight CBGs 408 per transport block 406, and each of carrier #1 -carrier #9 include two CBGs 408 per transport block 406. In other words, there is an imbalance in the number of CBGs 408 in carrier #0 as compared to carriers #1 -carrier #9. However, the present techniques for HARQ-ACK codebook selection are not limited to the configurations illustrated in FIG. 4. In other words, the HARQ-ACK codebook selection may be performed for any number of carriers 402, transport blocks 406 per carrier, and CBGs per transport block 406 without departing from the scope of the present disclosure. FIGs. 3 and 4 will now be described together.

[0045] Referring to FIG. 3, the base station 120 may configure the UE 102 to perform a

HARQ-ACK codebook selection process. For example, the base station 120 may generate control information that may configure the UE 102 to perform the HARQ-ACK codebook selection process. In certain implementations, the control information may include an indication of the HARQ-ACK codebook type that configures the UE to perform the HARQ- ACK codebook selection process. The indication included in the control signaling may be different than the indication for HARQ feedback associated with either type-1 HARQ-ACK codebook (e.g., “semi-static”) or type-2 HARQ-ACK codebook (e.g., “dynamic”). By way of example and not limitation, the indication that configures the UE 102 to perform the HARQ- ACK selection process (e.g., type-4 HARQ-ACK codebook) of the present disclosure may include a “dynamic2” indication. However, the indication of the present disclosure is not limited to “dynamic2.” On the contrary, the indication used to configure the UE 102 to perform HARQ-ACK codebook selection may be any type of indicator without departing from the scope of the present disclosure.

[0046] By way of example and not limitation, the control information that includes the indicator (e.g., PDSCH-HARQ-ACK-Codebook=“dynamic2”) of the present disclosure may be included in, e.g., RRC information (e.g., RRC message) or MAC information (e.g., MAC control element). The control information may include a, e.g., PhysicalCellGroupConfig information element. However, the indication may be included in any type of signaling that is sent from the base station 120 to the UE 102 without departing from the scope of the present disclosure.

[0047] In certain implementations, the control information may indicate the number of time slots, carriers, transport blocks per time slot, and/or CBGs per transport block for which the UE provides HARQ feedback. Table 1 set forth below provides an example configuration for HARQ-ACK codebook generation that may be included in the control information or other signaling sent to the UE 102.

Table 1: Configurations for HARQ-ACK Codebook Generation [0048] As seen in Table 1, the UE 102 may be configured to generate a HARQ-ACK codebook for CBGs received in slot [n-2] across ten carriers. In this example, the number of transport blocks per carrier is one. There are eight CBGs in the transport block 406 in carrier #0, and there are two CBGs in each of the transport blocks in each of carrier #l-carrier #9. Furthermore, the base station 120 indicates that there will be no DTX. Namely, Table 1 indicates that transmissions will be sent to the UE 102 in each of the CBGs across all carriers. An illustration of the configurations for HARQ-ACK codebook generation in Table 1 can be seen in FIG. 4. [0049] Still referring to FIG. 3, in certain other implementations, the control information and/or other control signaling may indicating the timing and/or resource allocation (e.g., physical uplink control channel (PUCCH) and/or physical uplink shared channel (PUSCH)) for use by the UE 102 in transmitting the HARQ-ACK codebook. Once generated, the base station 120 may transmit (at 301) the control information that configures the UE 102 to perform the HARQ-ACK selection process described herein.

[0050] In certain other implementations, the UE 102 may be preconfigured to perform the

HARQ-ACK selection process without receiving an indicator and/or control information from the base station 120. When the UE 102 is preconfigured to perform the HARQ-ACK selection process, operation 301 in FIG. 3 may be omitted.

[0051] In either implementation, the UE 102 may be configured (at 303) to perform the

HARQ-ACK selection process for one or more CBGs transmitted (at 305) by the base station 120. The one or more CBGs may be transmitted (at 305) across one or more carriers in a time span (e.g., slot [n-2]) associated with a HARQ-ACK codebook, a non-limiting example of which is illustrated in FIG. 4.

[0052] For example, referring to FIG. 4, the base station 120 may transmit a plurality of

CBGs 408 across a plurality of carriers 402. In the present non-limiting example, the HARQ- ACK codebook time span 404 may be one transport block 406 (e.g., time slot [n-2]). Furthermore, the CBGs 408 may be transmitted across ten carriers 402 (e.g., carrier #0, carrier #1, carrier #2, carrier #3, carrier #4, carrier #5, carrier #6, carrier #7, carrier #8, carrier #9). In carrier #0, the transport block 406 may include eight CBGs 408. For each of carriers #1 - carrier #9, each transport block 406 may include two CBGs 408. In other words, the number of CBGs per transport block across the carriers is imbalanced in this example.

[0053] Referring again to FIG. 3, the UE 102 may perform (at 307) the HARQ-ACK codebook selection process to determine whether a type-1 HARQ-ACK codebook or a type-2 HARQ-ACK codebook associated with the one or more CBGs 408 is smaller.

[0054] For example, the UE 102 may calculate a first codebook size (e.g., O_ACKI ) of type-

1 HARQ-ACK codebook associated with the one or more CBGs 408. The calculated codebook size may include a number of bits. The size of a type-1 HARQ-ACK codebook may be calculated as a sum of all CBGs 408 transmitted during the time span 404. Using the example illustrated in FIG. 4 and Table 1, the codebook size of a type-1 HARQ-ACK codebook is 26 bits, which is the total number of CBGs 408 across all carriers 402. [0055] Furthermore, the UE 102 may calculate a second codebook size (e.g., OACK2) of a type-2 HARQ-ACK codebook associated with the one or more CBGs 408. As mentioned above, a type-2 HARQ-ACK codebook may include HARQ feedback for a maximum number of CBGs 408 per transport block 406 multiplied by the number of carriers 402. This may ensure the HARQ feedback is aligned at the UE 102 and the base station 120. Again, using the example illustrated in FIG. 4 and Table 1, the codebook size of a type-2 HARQ-ACK codebook is 80 bits, which is the maximum number of CBGs per transport block (e.g., 8 CBGs) multiplied by the total number of carriers (e.g., 10 carriers).

[0056] In this example, the type-1 HARQ-ACK codebook is smaller. Hence, the UE 102 may generate the type-1 HARQ-ACK codebook and append a first bit (e.g., 0) to the codebook to indicate that the HARQ-ACK codebook is type-1. The UE 102 may then transmit (at 309) the type-1 HARQ-ACK codebook to the base station 120. However, when the type-2 HARQ- ACK codebook is smaller, the UE 102 may generate the type-2 HARQ-ACK codebook and append a second bit (e.g., 1) to the codebook to indicate that the HARQ-ACK codebook is type-2. Again, the UE 102 may transmit (at 309) the type-2 HARQ-ACK codebook to the base station 120 when the type-2 HARQ-ACK codebook is smaller.

[0057] Using the techniques described above in connection with FIGs. 3 and 4, the smallest

HARQ-ACK codebook may be sent to the base station 120, thereby reducing signaling overhead and power consumption, as compared to conventional NR HARQ feedback techniques.

[0058] FIG. 5 illustrates a flow chart of an exemplary method 500 of a UE for performing a HARQ-ACK codebook selection process, according to some embodiments of the present disclosure. It is understood that the operations shown in method 500 are not exhaustive and that other operations can be performed as well before, after, or between any of the illustrated operations. Further, some of the operations may be performed simultaneously, or in a different order than shown in FIG. 5. Furthermore, one or more of the operations shown in FIG. 5 may be optional or omitted.

[0059] Referring to FIG. 5, at 502, the UE may receive one or more CBGs from a base station. For example, referring to FIG. 4, the base station 120 may transmit a plurality of CBGs 408 across a plurality of carriers 402 to the UE 102. In the present non-limiting example, the HARQ-ACK codebook time span 404 may be one transport block 406 (e.g., time slot [n-2]). Furthermore, the CBGs 408 may be transmitted across ten carriers (e.g., carrier #0, carrier #1, carrier #2, carrier #3, carrier #4, carrier #5, carrier #6, carrier #7, carrier #8, carrier #9). In carrier #0, the transport block 406 may include eight CBGs 408. For each of carriers #1 - carrier #9, each transport block 406 may include two CBGs 408. In other words, the number of CBGs per transport block across the carriers is imbalanced in this example.

[0060] At 504, the UE may perform a HARQ-ACK codebook selection process to determine a smaller HARQ-ACK codebook. For example, referring to FIGs. 3 and 4, Referring again to FIG. 3, the UE 102 may perform (at 307) the HARQ-ACK codebook selection process to determine whether a type-1 HARQ-ACK codebook or a type-2 HARQ-ACK codebook associated with the one or more CBGs is smaller.

[0061] At 506, the UE may perform the HARQ-ACK codebook selection process by calculating a first codebook size associated with the one or more CBGs, the first codebook size being associated with a first HARQ-ACK codebook of the first type. For example, the UE 102 may calculate a first codebook size (e.g., OACKI ) of type-1 HARQ-ACK codebook associated with the one or more CBGs. The calculated codebook size may include a number of bits. The size of a type-1 HARQ-ACK codebook may be calculated as a sum of all CBGs transmitted during the time span. Using the example illustrated in FIG. 4 and Table 1, the codebook size of a type-1 HARQ-ACK codebook is 26 bits, which is the total number of CBGs.

[0062] At 508, the UE may perform the HARQ-ACK codebook selection process by calculating a second codebook size associated with the one or more CBGs, the second codebook size being associated with a second HARQ-ACK codebook of a second type. For example, referring to FIG. 3, the UE 102 may calculate a second codebook size (e.g., OACK2) of a type-2 HARQ-ACK codebook associated with the one or more CBGs. As mentioned above, a type-2 HARQ-ACK codebook must include HARQ feedback for a maximum number of CBGs per transport block across all carriers to be sure the HARQ feedback is aligned at the UE and the base station. Again using the example illustrated in FIG. 4 and Table 1, the codebook size of a type-2 HARQ-ACK codebook is 80 bits, which is the maximum number of CBGs per transport block (e.g., 8 CBGs) times the total number of carriers (e.g., 10 carriers).

[0063] At 510, the UE may perform the HARQ-ACK codebook selection process by determining whether the first HARQ-ACK codebook or the second HARQ-ACK codebook is a smaller HARQ-ACK codebook by comparing the first codebook size and the second codebook size. In the example described in connection with FIGs. 3 and 4, OACKI < OACKI , and, hence, the type-1 HARQ-ACK codebook is smaller. [0064] At 512, the UE may transmit the smaller HARQ-ACK codebook to the base station.

For example, referring to FIG. 3, the UE 102 may then transmit (at 309) the type-1 HARQ- ACK codebook to the base station 120. However, when the type-2 HARQ-ACK codebook is smaller, the UE 102 may generate the type-2 HARQ-ACK codebook and append a second bit (e.g., 1) to the codebook to indicate to the base station 120 that the HARQ-ACK codebook is type-2. Again, the UE 102 may transmit (at 309) the type-2 HARQ-ACK codebook to the base station 120.

[0065] FIG. 6 illustrates a flow chart of an exemplary method 600 of a base station to configure a UE to performing a HARQ-ACK codebook selection process, according to some embodiments of the present disclosure. It is understood that the operations shown in method 500 are not exhaustive and that other operations can be performed as well before, after, or between any of the illustrated operations. Further, some of the operations may be performed simultaneously, or in a different order than shown in FIG. 6. Furthermore, one or more operations shown in FIG. 6 may optional or omitted.

[0066] Referring to FIG. 6, at 602, the base station may configure a UE to perform a HARQ codebook selection process. For example, referring to FIG. 3, the base station 120 may configure the UE to perform a HARQ-ACK codebook selection process. For example, the base station 120 may generate control information that may configure the UE 102 to perform the HARQ-ACK codebook selection process. In certain implementations, the control information may include an indication of HARQ-ACK codebook type that configures the UE to perform the HARQ-ACK codebook selection process. The indication included in the control signaling may be different than the indication for HARQ feedback using either type-1 HARQ-ACK codebook (e.g., “semi-static”) or type-2 HARQ-ACK codebook (e.g., “dynamic”). By way of example and not limitation, the indication that configures the UE 102 to perform the HARQ- ACK selection process of the present disclosure may include a “dynamic2” indication. However, the indication of the present disclosure is not limited to “dynamic2.” On the contrary, the indication used to configure the UE 102 to perform HARQ-ACK codebook selection may be any type of indicator without departing from the scope of the present disclosure. By way of example and not limitation, the control information that includes the indicator (e.g., PDSCH- HARQ-ACK-Codebook=“dynamic2”) of the present disclosure may be included in, e.g., RRC information (e.g., RRC message) or MAC information (e.g., MAC control element). The control information may include a, e.g., PhysicalCellGroupConfig information element or any other type of information element. Once generated, the base station 120 may transmit (at 301) the control signaling that configures the UE 102 to perform the HARQ-ACK selection process described herein.

[0067] At 604, the base station may transmit one or more CBGs to the UE. For example, referring to FIG. 3, the one or more CBGs may be transmitted (at 305) across one or more carriers in a time span associated with a HARQ-ACK codebook, a non-limiting example of which is illustrated in FIG. 4.

[0068] At 606, the base station may receive the smaller HARQ-ACK codebook from the

UE the smaller HARQ-ACK codebook from the UE in response to transmitting the one or more CBGs. For example, referring to FIG. 3, the UE may then transmit (at 309) the type-1 HARQ- ACK codebook to the base station 120. However, when the type-2 HARQ-ACK codebook is smaller, the UE 102 may generate the type-2 HARQ-ACK codebook and append a second bit (e.g., 1) to the codebook to indicate to the base station 120 that the HARQ-ACK codebook is type-2. Again, the UE 102 may transmit (at 309) the type-2 HARQ-ACK codebook to the base station 120.

[0069] In various aspects of the present disclosure, the functions described herein may be implemented in hardware, software, firmware, or any combination thereof. If implemented in software, the functions may be stored on or encoded as instructions or code on a non-transitory computer-readable medium. Computer-readable media includes computer storage media. Storage media may be any available media that can be accessed by a computing device, such as node 700 in FIG. 7. By way of example, and not limitation, such computer-readable media can include RAM, ROM, EEPROM, CD-ROM or other optical disk storage, HDD, such as magnetic disk storage or other magnetic storage devices, Flash drive, SSD, or any other medium that can be used to carry or store desired program code in the form of instructions or data structures and that can be accessed by a processing system, such as a mobile device or a computer. Disk and disc, as used herein, includes CD, laser disc, optical disc, DVD, and floppy disk where disks usually reproduce data magnetically, while discs reproduce data optically with lasers. Combinations of the above should also be included within the scope of computer- readable media.

[0070] Embodiments of the present disclosure include an apparatus of a UE. The apparatus may include at least one processor. In certain aspects, the apparatus may further include memory storing instructions that, when executed by the at least one processor, cause the apparatus to receive one or more code block groups (CBGs) from a base station. In certain other aspects, the memory storing instructions that, when executed by the at least one processor, further cause the apparatus to perform a hybrid-automatic repeat request (HARQ)- acknowledgement (ACK) codebook selection process to determine a smaller HARQ-ACK codebook by calculating a first codebook size associated with the one or more CBGs, the first codebook size being associated with a first HARQ-ACK codebook of the first type, calculating a second codebook size associated with the one or more CBGs, the second codebook size being associated with a second HARQ-ACK codebook of a second type, and determining whether the first HARQ-ACK codebook or the second HARQ-ACK codebook is a smaller HARQ- ACK codebook by comparing the first codebook size and the second codebook size. In certain other aspects, the memory storing instructions that, when executed by the at least one processor, further cause the apparatus to transmit the smaller HARQ-ACK codebook to the base station.

[0071] In certain other aspects, in response to determining that the first HARQ-ACK codebook is the smaller HARQ-ACK codebook, execution of the instructions may further cause the apparatus to generate the first HARQ-ACK codebook associated with the one or more CBGs. In certain other aspects, in response to determining that the first HARQ-ACK codebook is the smaller HARQ-ACK codebook, execution of the instructions may further cause the apparatus to append a first bit to the first HARQ-ACK codebook, the first bit indicating to the base station that the first HARQ-ACK codebook is of the first type.

[0072] In certain other aspects, in response to determining that the second HARQ-ACK codebook is the smaller HARQ-ACK codebook, execution of the instructions may further cause the apparatus to generate the second HARQ-ACK codebook associated with the one or more CBG. In certain other aspects, in response to determining that the second HARQ-ACK codebook is the smaller HARQ-ACK codebook, execution of the instructions may further cause the apparatus to append a second bit to the second HARQ-ACK codebook, the second bit indicating to the base station that the second HARQ-ACK codebook is of the second type.

[0073] In certain other aspects, execution of the instructions may further cause the apparatus to receive, from the base station, control information that configures the apparatus of the UE to perform the HARQ-ACK codebook selection process.

[0074] In certain other aspects, the control information may include an indication of a

HARQ-ACK codebook type that configures the UE to perform the HARQ-ACK codebook selection process. [0075] In certain other aspects, the indication of the HARQ-ACK codebook type may comprise a dynamic2 indication.

[0076] In certain other aspects, the control information may comprise radio resource control (RRC) information or medium access control (MAC) information.

[0077] Embodiments of the present disclosure include an apparatus of a base station. The apparatus may include at least one processor. In certain aspects, the apparatus may further include memory storing instructions that, when executed by the at least one processor, cause the apparatus to configure a user equipment (UE) to perform a hybrid-automatic repeat request (HARQ)-acknowledgement (ACK) codebook selection process to determine a smaller HARQ- ACK codebook from a first HARQ-ACK codebook of a first type and a second HARQ-ACK codebook of a second type. In certain other aspects, the memory storing instructions that, when executed by the at least one processor, further cause the apparatus to transmit one or more code block groups (CBGs) to the UE. In certain other aspects, the memory storing instructions that, when executed by the at least one processor, further cause the apparatus to receive the smaller HARQ-ACK codebook from the UE the smaller HARQ-ACK codebook from the UE in response to transmitting the one or more CBGs.

[0078] In certain other aspects, execution of the instructions may further cause the apparatus to configure the UE to perform the HARQ-ACK codebook selection process by transmitting control information that configures the UE to perform the HARQ-ACK codebook selection process.

[0079] In certain other aspects, the control information may include an indication of

HARQ-ACK codebook type that configures the UE to perform the HARQ-ACK codebook selection process.

[0080] In certain other aspects, the indication of the HARQ-ACK codebook type may comprise a dynamic2 indication.

[0081] In certain other aspects, the control information may comprise radio resource control (RRC) information or medium access control (MAC) information.

[0082] Embodiments of the present disclosure include a method of a user equipment (UE).

In certain aspects, the method may include receiving one or more code block groups (CBGs) from a base station. In certain other aspects, the method may further include performing a hybrid-automatic repeat request (HARQ)-acknowledgement (ACK) codebook selection process to determine a smaller HARQ-ACK codebook by calculating a first codebook size associated with the one or more CBGs, the first codebook size being associated with a first HARQ-ACK codebook of the first type, calculating a second codebook size associated with the one or more CBGs, the second codebook size being associated with a second HARQ-ACK codebook of a second type, and determining whether the first HARQ-ACK codebook or the second HARQ-ACK codebook is a smaller HARQ-ACK codebook by comparing the first codebook size and the second codebook size. In certain other aspects, the method may further include transmitting the smaller HARQ-ACK codebook to the base station.

[0083] In certain other aspects, in response to determining that the first HARQ-ACK codebook is the smaller HARQ-ACK codebook, the method may further include generating the first HARQ-ACK codebook associated with the one or more CBGs. In certain other aspects, in response to determining that the first HARQ-ACK codebook is the smaller HARQ-ACK codebook, the method may further include appending a first bit to the first HARQ-ACK codebook, the first bit indicating to the base station that the first HARQ-ACK codebook is of the first type.

[0084] In certain other aspects, in response to determining that the second HARQ-ACK codebook is the smaller HARQ-ACK codebook, the method may further comprise generating the second HARQ-ACK codebook associated with the one or more CBGs. In certain other aspects, in response to determining that the second HARQ-ACK codebook is the smaller HARQ-ACK codebook, the method may further comprise appending a second bit to the second HARQ-ACK codebook, the second bit indicating to the base station that the second HARQ- ACK codebook is of the second type.

[0085] In certain other aspects, the method may further comprise receiving, from the base station, control information that configures the UE to perform the HARQ-ACK codebook selection process.

[0086] In certain other aspects, the control information may include an indication of a

[0087] In certain other aspects, the indication of the HARQ-ACK codebook type may comprise a dynamic2 indication.

[0088] In certain other aspects, the control information may comprise radio resource control (RRC) information or medium access control (MAC) information. [0089] Embodiments of the present disclosure include a method of a base station. In certain aspects, the method may include configuring a user equipment (UE) to perform a hybrid- automatic repeat request (HARQ)-acknowledgement (ACK) codebook selection process to determine a smaller HARQ-ACK codebook from a first HARQ-ACK codebook of a first type and a second HARQ-ACK codebook of a second type. In certain other aspects, the method may further include transmitting one or more code block groups (CBGs) to the UE. In certain other aspects, the method may include receiving the smaller HARQ-ACK codebook from the UE in response to transmitting the one or more CBGs.

[0090] In certain aspects, the configuring the UE to perform the HARQ-ACK codebook selection process may further comprise transmitting control information that configures the UE to perform the HARQ-ACK codebook selection process.

[0091] In certain aspects, the control information may include an indication of HARQ-

ACK codebook type that configures the UE to perform the HARQ-ACK codebook selection process.

[0092] In certain other aspects, the indication of HARQ-ACK codebook type may comprise a dynamic2 indication.

[0093] In certain other aspects, the control information comprises radio resource control

(RRC) information or medium access control (MAC) information.

[0094] In some embodiments, to provide each set of the commands, the respective set of the commands are stored into a corresponding command queue in memory. In some embodiments, to receive each set of the result statuses, the respective set of the result statuses are retrieved from a corresponding status queue in the memory.

[0095] The foregoing description of the specific embodiments will so reveal the general nature of the present disclosure that others can, by applying knowledge within the skill of the art, readily modify and/or adapt for various applications such specific embodiments, without undue experimentation, without departing from the general concept of the present disclosure. Therefore, such adaptations and modifications are intended to be within the meaning and range of equivalents of the disclosed embodiments, based on the teaching and guidance presented herein. It is to be understood that the phraseology or terminology herein is for the purpose of description and not of limitation, such that the terminology or phraseology of the present specification is to be interpreted by the skilled artisan in light of the teachings and guidance. [0096] Embodiments of the present disclosure have been described above with the aid of functional building blocks illustrating the implementation of specified functions and relationships thereof. The boundaries of these functional building blocks have been arbitrarily defined herein for the convenience of the description. Alternate boundaries can be defined so long as the specified functions and relationships thereof are appropriately performed.

[0097] The Summary and Abstract sections may set forth one or more but not all exemplary embodiments of the present disclosure as contemplated by the inventor(s), and thus, are not intended to limit the present disclosure and the appended claims in any way.

[0098] Various functional blocks, modules, and steps are disclosed above. The particular arrangements provided are illustrative and without limitation. Accordingly, the functional blocks, modules, and steps may be re-ordered or combined in different ways than in the examples provided above. Likewise, certain embodiments include only a subset of the functional blocks, modules, and steps, and any such subset is permitted.

[0099] The breadth and scope of the present disclosure should not be limited by any of the above-described exemplary embodiments, but should be defined only in accordance with the following claims and their equivalents.

Claims

WHAT IS CLAIMED IS:

1. An apparatus of a user equipment (UE), comprising: at least one processor; and memory storing instructions that, when executed by the at least one processor, cause the apparatus at least to: receive one or more code block groups (CBGs) from a base station; perform a hybrid-automatic repeat request (HARQ)-acknowledgement (ACK) codebook selection process to determine a smaller HARQ-ACK codebook, comprising: calculating a first codebook size associated with the one or more CBGs, the first codebook size being associated with a first HARQ-ACK codebook of a first type; calculating a second codebook size associated with the one or more CBGs, the second codebook size being associated with a second HARQ-ACK codebook of a second type; and determining whether the first HARQ-ACK codebook or the second HARQ- ACK codebook is a smaller HARQ-ACK codebook by comparing the first codebook size and the second codebook size; and transmit the smaller HARQ-ACK codebook to the base station.

2. The apparatus of claim 1, wherein in response to determining that the first HARQ-ACK codebook is the smaller HARQ-ACK codebook, execution of the instructions further causes the apparatus to: generate the first HARQ-ACK codebook associated with the one or more CBGs; and append a first bit to the first HARQ-ACK codebook, the first bit indicating to the base station that the first HARQ-ACK codebook is of the first type.

3. The apparatus of claim 2, wherein in response to determining that the second HARQ-ACK codebook is the smaller HARQ-ACK codebook, execution of the instructions further causes the apparatus to: generate the second HARQ-ACK codebook associated with the one or more CBGs; and append a second bit to the second HARQ-ACK codebook, the second bit indicating to the base station that the second HARQ-ACK codebook is of the second type.

4. The apparatus of claim 1, wherein execution of the instructions further causes the apparatus to: receive, from the base station, control information that configures the apparatus of the UE to perform the HARQ-ACK codebook selection process.

5. The apparatus of claim 4, wherein the control information includes an indication of a HARQ-ACK codebook type that configures the UE to perform the HARQ-ACK codebook selection process.

6. The apparatus of claim 5, wherein the indication of the HARQ-ACK codebook type comprises a dynamic2 indication.

7. The apparatus of claim 4, wherein the control information comprises radio resource control (RRC) information or medium access control (MAC) information.

8. An apparatus of a base station, comprising: at least one processor; and memory storing instructions that, when executed by the at least one processor, cause the apparatus at least to: configure a user equipment (UE) to perform a hybrid-automatic repeat request (HARQ)-acknowledgement (ACK) codebook selection process to determine a smaller HARQ-ACK codebook from a first HARQ-ACK codebook of a first type and a second HARQ-ACK codebook of a second type; transmit one or more code block groups (CBGs) to the UE; and receive the smaller HARQ-ACK codebook from the UE in response to transmitting the one or more CBGs.

9. The apparatus of claim 8, wherein execution of the instructions further causes the apparatus to configure the UE to perform the HARQ-ACK codebook selection process by: transmitting control information that configures the UE to perform the HARQ-ACK codebook selection process.

10. The apparatus of claim 9, wherein the control information includes an indication of HARQ- ACK codebook type that configures the UE to perform the HARQ-ACK codebook selection process.

11. The apparatus of claim 10, wherein the indication of HARQ-ACK codebook type comprises a dynamic2 indication.

12. The apparatus of claim 9, wherein the control information comprises radio resource control (RRC) information or medium access control (MAC) information.

13. A method of a user equipment (UE), comprising: receiving one or more code block groups (CBGs) from a base station; performing a hybrid-automatic repeat request (HARQ)-acknowledgement (ACK) codebook selection process to determine a smaller HARQ-ACK codebook, comprising: calculating a first codebook size associated with the one or more CBGs, the first codebook size being associated with a first HARQ-ACK codebook of a first type; calculating a second codebook size associated with the one or more CBGs, the second codebook size being associated with a second HARQ-ACK codebook of a second type; and determining whether the first HARQ-ACK codebook or the second HARQ-ACK codebook is a smaller HARQ-ACK codebook by comparing the first codebook size and the second codebook size; and transmitting the smaller HARQ-ACK codebook to the base station.

14. The method of claim 13, wherein in response to determining that the first HARQ-ACK codebook is the smaller HARQ-ACK codebook, the method further comprises: generating the first HARQ-ACK codebook associated with the one or more CBGs; and appending a first bit to the first HARQ-ACK codebook, the first bit indicating to the base station that the first HARQ-ACK codebook is of the first type.

15. The method of claim 14, wherein in response to determining that the second HARQ-ACK codebook is the smaller HARQ-ACK codebook, the method further comprises: generating the second HARQ-ACK codebook associated with the one or more CBGs; and appending a second bit to the second HARQ-ACK codebook, the second bit indicating to the base station that the second HARQ-ACK codebook is of the second type.

16. The method of claim 13, further comprising: receiving, from the base station, control information that configures the UE to perform the HARQ-ACK codebook selection process.

17. The method of claim 16, wherein the control information includes an indication of a HARQ-ACK codebook type that configures the UE to perform the HARQ-ACK codebook selection process.

18. The method of claim 17, wherein the indication of the HARQ-ACK codebook type comprises a dynamic2 indication.

19. The method of claim 16, wherein the control information comprises radio resource control (RRC) information or medium access control (MAC) information.

20. A method of a base station, comprising: configuring a user equipment (UE) to perform a hybrid-automatic repeat request (HARQ)- acknowledgement (ACK) codebook selection process to determine a smaller HARQ-ACK codebook from a first HARQ-ACK codebook of a first type and a second HARQ-ACK codebook of a second type; transmitting one or more code block groups (CBGs) to the UE; and receiving the smaller HARQ-ACK codebook from the UE in response to transmitting the one or more CBGs.

21. The method of claim 20, wherein the configuring the UE to perform the HARQ-ACK codebook selection process further comprises: transmitting control information that configures the UE to perform the HARQ-ACK codebook selection process.

22. The method of claim 21, wherein the control information includes an indication of HARQ- ACK codebook type that configures the UE to perform the HARQ-ACK codebook selection process.

23. The method of claim 22, wherein the indication of HARQ-ACK codebook type comprises a dynamic2 indication.

24. The method of claim 21, wherein the control information comprises radio resource control (RRC) information or medium access control (MAC) information.