PATENT DOCUMENT

Publication Number: US-12068859-B2
Application Number: US-202017593333-A
Country: US
Kind Code: B2

Title: HARQ codebook determination in wireless communications

Abstract:
A user equipment (UE) and a network agree on the use of a hybrid automatic repeat request (HARQ) codebook. The UE receives a plurality of downlink control information (DCI) transmissions during a corresponding plurality of physical downlink control channel (PDCCH) monitoring occasions from the base station, wherein each DCI transmission schedules multiple physical downlink shared channel (PDSCH) transmissions on a corresponding one of a plurality of component carriers (CCs), receives a time domain resource allocation (TDRA) table configuration from the base station, determines a maximum number of PDSCH transmissions per CC based on the TDRA table configuration, groups the plurality of CCs together and determines a hybrid automatic repeat request (HARQ)-acknowledgement (ACK) codebook size based on a number of the multiple PDSCH transmissions, the maximum number of PDSCH transmissions, and a resulting ACK or negative acknowledgement (NACK) for each of the multiple PDSCH transmissions.

Claims:
What is claimed: 
     
       1. A user equipment (UE), comprising:
 a transceiver configured to communicate with a base station; and 
 a processor communicatively coupled to the transceiver and configured to perform operations comprising:
 receiving a plurality of downlink control information (DCI) transmissions during a corresponding plurality of physical downlink control channel (PDCCH) monitoring occasions from the base station, wherein each DCI transmission schedules multiple physical downlink shared channel (PDSCH) transmissions on a corresponding one of a plurality of component carriers (CCs); 
 receiving a time domain resource allocation (TDRA) table configuration from the base station; 
 determining a maximum number of PDSCH transmissions per CC based on the TDRA table configuration; 
 grouping the plurality of CCs together, wherein CCs having the same maximum number of PDSCH transmissions per CC are grouped together, and wherein a maximum number of PDSCH transmissions per group is equivalent to the maximum number of PDSCH transmissions per CC; 
 determining a hybrid automatic repeat request (HARQ)-acknowledgement (ACK) codebook size based on a number of the multiple PDSCH transmissions, the maximum number of PDSCH transmissions, and a resulting ACK or negative acknowledgement (NACK) for each of the multiple PDSCH transmissions; and 
 generating a plurality of HARQ bits for each of the multiple PDSCH transmissions, wherein the plurality of HARQ bits is equal to the maximum number of PDSCH transmissions per group. 
 
 
     
     
       2. The UE of  claim 1 , wherein DCI transmission comprises:
 a counter downlink assignment indicator (C-DAI) indicating a cumulative number of PDCCH monitoring occasions in a CC group up to a current C-DAI; and 
 a total DAI (T-DAI) indicating a total number of PDCCH monitoring occasions in a CC group. 
 
     
     
       3. The UE of  claim 1 , wherein the plurality of HARQ bits includes a decoding acknowledgement for each of the multiple PDSCH transmissions and one or more NACK bits corresponding to the difference between the plurality of multi-PDSCH transmission and the maximum number of PDSCH transmissions per group. 
     
     
       4. The UE of  claim 3 , wherein the HARQ-ACK codebook size is the product of a total DAI (T-DAI) indicating a total number of PDCCH monitoring occasions in a CC group of a last PDCCH monitoring occasion and the maximum number of PDSCH transmissions per group. 
     
     
       5. The UE of  claim 1 , wherein the operations further comprise:
 performing a HARQ compression on the plurality of HARQ bits based on a HARQ compression scheme. 
 
     
     
       6. The UE of  claim 5 , wherein the HARQ compression scheme includes applying a compression factor to the maximum number of PDSCH transmissions per group to determine a bundling window size. 
     
     
       7. The UE of  claim 6 , wherein if the bundling window is greater than or equal to a number of PDSCH transmissions scheduled by the DCI transmission, the plurality of HARQ bits include a decoding acknowledgement for each of the multiple PDSCH transmissions and one or more NACK bits corresponding to the difference between the number of multiple PDSCH transmissions and the bundling window size. 
     
     
       8. The UE of  claim 6 , wherein if the bundling window is less than a number of PDSCH transmissions scheduled by the DCI transmission, the operations further comprise:
 determining a HARQ bit for each of the multiple PDSCH transmissions to obtain multiple HARQ bits, wherein the HARQ bit is based on a result of decoding a corresponding one of the multiple PDSCH transmissions; 
 determining a first sub-window corresponding to a first subset of the multiple HARQ bits and a second sub-window corresponding to a second subset of the multiple HARQ bits. 
 
     
     
       9. A processor configured to perform operations comprising:
 receiving a plurality of downlink control information (DCI) transmissions during a corresponding plurality of physical downlink control channel (PDCCH) monitoring occasions from a base station, wherein each DCI transmission schedules multiple physical downlink shared channel (PDSCH) transmissions on a corresponding one of a plurality of component carriers (CCs); 
 receiving a time domain resource allocation (TDRA) table configuration from the base station; 
 determining a maximum number of PDSCH transmissions per CC based on the TDRA table configuration; 
 grouping the plurality of CCs together, wherein CCs having the same maximum number of PDSCH transmissions per CC are grouped together, and wherein a maximum number of PDSCH transmissions per group is equivalent to the maximum number of PDSCH transmissions per CC; 
 determining a hybrid automatic repeat request (HARQ)-acknowledgement (ACK) codebook size based on a number of the multiple PDSCH transmissions, the maximum number of PDSCH transmissions, and a resulting ACK or negative acknowledgement (NACK) for each of the multiple PDSCH transmissions; and 
 generating a plurality of HARQ bits for each of the multiple PDSCH transmissions, wherein the plurality of HARQ bits is equal to the maximum number of PDSCH transmissions per group. 
 
     
     
       10. The processor of  claim 9 , wherein DCI transmission comprises:
 a counter downlink assignment indicator (C-DAI) indicating a cumulative number of PDCCH monitoring occasions in a CC group up to a current C-DAI; and 
 a total DAI (T-DAI) indicating a total number of PDCCH monitoring occasions in a CC group. 
 
     
     
       11. The processor of  claim 9 , wherein the plurality of HARQ bits includes a decoding acknowledgement for each of the multiple PDSCH transmissions and one or more NACK bits corresponding to the difference between the plurality of multi-PDSCH transmission and the maximum number of PDSCH transmissions per group. 
     
     
       12. The processor of  claim 9 , wherein the operations further comprise:
 performing a HARQ compression on the plurality of HARQ bits based on a HARQ compression scheme. 
 
     
     
       13. The processor of  claim 12 , wherein the HARQ compression scheme includes applying a compression factor to the maximum number of PDSCH transmissions per group to determine a bundling window size. 
     
     
       14. The processor of  claim 13 , wherein if the bundling window is greater than or equal to a number of PDSCH transmissions scheduled by the DCI transmission, the plurality of HARQ bits include a decoding acknowledgement for each of the multiple PDSCH transmissions and one or more NACK bits corresponding to the difference between the number of multiple PDSCH transmissions and the bundling window size. 
     
     
       15. The processor of  claim 13 , wherein if the bundling window is less than a number of PDSCH transmissions scheduled by the DCI transmission, the operations further comprise:
 determining a HARQ bit for each of the multiple PDSCH transmissions to obtain multiple HARQ bits, wherein the HARQ bit is based on a result of decoding a corresponding one of the multiple PDSCH transmissions; 
 determining a first sub-window corresponding to a first subset of the multiple HARQ bits and a second sub-window corresponding to a second subset of the multiple HARQ bits. 
 
     
     
       16. The processor of  claim 11 , wherein the HARQ-ACK codebook size is the product of a total DAI (T-DAI) indicating a total number of PDCCH monitoring occasions in a CC group of a last PDCCH monitoring occasion and the maximum number of PDSCH transmissions per group. 
     
     
       17. A method, comprising:
 receiving a plurality of downlink control information (DCI) transmissions during a corresponding plurality of physical downlink control channel (PDCCH) monitoring occasions from the base station, wherein each DCI transmission schedules multiple physical downlink shared channel (PDSCH) transmissions on a corresponding one of a plurality of component carriers (CCs); 
 receiving a time domain resource allocation (TDRA) table configuration from the base station; 
 determining a maximum number of PDSCH transmissions per CC based on the TDRA table configuration; 
 grouping the plurality of CCs together, wherein CCs having the same maximum number of PDSCH transmissions per CC are grouped together, and wherein a maximum number of PDSCH transmissions per group is equivalent to the maximum number of PDSCH transmissions per CC; 
 determining a hybrid automatic repeat request (HARQ)-acknowledgement (ACK) codebook size based on a number of the multiple PDSCH transmissions, the maximum number of PDSCH transmissions, and a resulting ACK or negative acknowledgement (NACK) for each of the multiple PDSCH transmissions; and 
 generating a plurality of HARQ bits for each of the multiple PDSCH transmissions, wherein the plurality of HARQ bits is equal to the maximum number of PDSCH transmissions per group. 
 
     
     
       18. The method of  claim 17 , wherein the plurality of HARQ bits includes a decoding acknowledgement for each of the multiple PDSCH transmissions and one or more NACK bits corresponding to the difference between the plurality of multi-PDSCH transmission and the maximum number of PDSCH transmissions per group. 
     
     
       19. The method of  claim 18 , wherein the HARQ-ACK codebook size is the product of a total DAI (T-DAI) indicating a total number of PDCCH monitoring occasions in a CC group of a last PDCCH monitoring occasion and the maximum number of PDSCH transmissions per group. 
     
     
       20. The method of  claim 17 , wherein the DCI transmission comprises:
 a counter downlink assignment indicator (C-DAI) indicating a cumulative number of PDCCH monitoring occasions in a CC group up to a current C-DAI; and 
 a total DAI (T-DAI) indicating a total number of PDCCH monitoring occasions in a CC group.

Description:
BACKGROUND 
     In 5G new radio (NR) wireless communications, the 5G NR network configures a physical downlink control channel (PDCCH) with downlink channel information (DCI) to schedule a physical downlink shared channel (PDSCH). A user equipment (UE) receives the PDCCH and decodes the DCI so that the UE can determine when to monitor the PDSCH. If the UE successfully decodes the PDSCH, the UE transmits an acknowledgement (ACK) to the network. If the UE does not successfully decode the PDSCH, the UE transmits a negative ACK (NACK) to the network. 
     SUMMARY 
     Some exemplary embodiments are related to a user equipment (UE) having a transceiver configured to communicate with a network and a processor communicatively coupled to the transceiver and configured to perform operations. The operations include receiving a plurality of downlink control information (DCI) transmissions during a corresponding plurality of physical downlink control channel (PDCCH) monitoring occasions from the base station, wherein each DCI transmission schedules multiple physical downlink shared channel (PDSCH) transmissions on a corresponding one of a plurality of component carriers (CCs), receiving a time domain resource allocation (TDRA) table configuration from the base station, determining a maximum number of PDSCH transmissions per CC based on the TDRA table configuration, grouping the plurality of CCs together and determining a hybrid automatic repeat request (HARQ)-acknowledgement (ACK) codebook size based on a number of the multiple PDSCH transmissions, the maximum number of PDSCH transmissions, and a resulting ACK or negative acknowledgement (NACK) for each of the multiple PDSCH transmissions. 
     Other exemplary embodiments are related to a processor configured to perform operations. The operations include receiving a plurality of downlink control information (DCI) transmissions during a corresponding plurality of physical downlink control channel (PDCCH) monitoring occasions from a base station, wherein each DCI transmission schedules multiple physical downlink shared channel (PDSCH) transmissions on a corresponding one of a plurality of component carriers (CCs), receiving a time domain resource allocation (TDRA) table configuration from the base station, determining a maximum number of PDSCH transmissions per CC based on the TDRA table configuration, grouping the plurality of CCs together and determining a hybrid automatic repeat request (HARQ)-acknowledgement (ACK) codebook size based on a number of the multiple PDSCH transmissions, the maximum number of PDSCH transmissions, and a resulting ACK or negative acknowledgement (NACK) for each of the multiple PDSCH transmissions. 
     Still further exemplary embodiments are related to a base station having a transceiver configured to communicate with a user equipment (UE) and a processor communicatively coupled to the transceiver and configured to perform operations. The operations include transmitting, to the UE, a plurality of downlink control information (DCI) transmissions during a corresponding plurality of physical downlink control channel (PDCCH) monitoring occasions from the base station, wherein each DCI transmission schedules multiple physical downlink shared channel (PDSCH) transmissions on a corresponding one of a plurality of component carriers (CCs), transmitting, to the UE, a time domain resource allocation (TDRA) table configuration, determining a maximum number of PDSCH transmissions per CC based on the TDRA table configuration, transmitting the multiple PDSCH transmissions to the UE, wherein the UE determines a hybrid automatic repeat request (HARQ)-acknowledgement (ACK) codebook size based on a number of the multiple PDSCH transmissions, the maximum number of PDSCH transmissions, and a resulting ACK or negative acknowledgement (NACK) for each of the multiple PDSCH transmissions. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG.  1    shows an exemplary network arrangement according to various exemplary embodiments. 
         FIG.  2    shows an exemplary UE according to various exemplary embodiments. 
         FIG.  3    shows an exemplary base station configured to establish a connection with a user equipment according to various exemplary embodiments. 
         FIG.  4    shows a method of determining a hybrid automatic repeat request (HARQ) codebook size according to various exemplary embodiments. 
         FIG.  5    shows exemplary tables of time domain resource allocation (TDRA) tables according to various exemplary embodiments. 
         FIG.  6    shows a diagram illustrating an exemplary multi-PDSCH reception scenario according to various exemplary embodiments. 
         FIGS.  7 A- 7 C  show diagrams illustrating exemplary HARQ-ACK compression schemes according to various exemplary embodiments. 
         FIG.  8    shows a diagram illustrating exemplary HARQ-ACK compression schemes according to various exemplary embodiments. 
         FIG.  9 A  shows pseudocode illustrating a Type I HARQ codebook determination process according to various exemplary embodiments. 
         FIG.  9 B  shows a diagram illustrating a Type I HARQ codebook determination process according to various exemplary embodiments. 
     
    
    
     DETAILED DESCRIPTION 
     The exemplary embodiments may be further understood with reference to the following description and the related appended drawings, wherein like elements are provided with the same reference numerals. The exemplary embodiments describe a device, system and method for a user equipment (UE) of a 5G new radio (NR) network to determine a hybrid automatic repeat request (HARQ) codebook size for multi-PDSCH scheduling. 
     The exemplary embodiments are described with regard to a network that includes 5G new radio NR radio access technology (RAT). However, the exemplary embodiments may be implemented in other types of networks using the principles described herein. 
     The exemplary embodiments are also described with regard to a UE. However, the use of a UE is merely for illustrative purposes. The exemplary embodiments may be utilized with any electronic component that may establish a connection with a network and is configured with the hardware, software, and/or firmware to exchange information and data with the network. Therefore, the UE as described herein is used to represent any electronic component. 
     There is currently a need in 5G NR to address the critical power capability of reduced capability (RedCap) UEs. One function that has a significant effect on a RedCap UE&#39;s power consumption is the numerous times that it monitors the PDCCH. 
     According to some exemplary embodiments, a multi-PDSCH scheduling downlink control information (DCI) format may be used to increase the PDCCH monitoring periodicity, thus reducing power consumption at the UE. In addition, to avoid discrepancies between the UE and g-NodeB (gNB) regarding the payload size of a HARQ-ACK in response to the multi-PDSCH scheduling DCI, the UE is configured to determine a HARQ codebook size so that both the UE and the base station (e.g., next generation Node B (gNB)) are in agreement regarding the HARQ-ACK payload size, especially when the UE does not successfully decode a DCI of a PDCCH monitoring occasion. 
       FIG.  1    shows an exemplary network arrangement  100  according to various exemplary embodiments. The exemplary network arrangement  100  includes a UE  110 . It should be noted that any number of UEs may be used in the network arrangement  100 . Those skilled in the art will understand that the UE  110  may alternatively be any type of electronic component that is configured to communicate via a network, e.g., mobile phones, tablet computers, desktop computers, smartphones, phablets, embedded devices, wearables, Internet of Things (IoT) devices, etc. It should also be understood that an actual network arrangement may include any number of UEs being used by any number of users. Thus, the example of a single UE  110  is merely provided for illustrative purposes. 
     The UE  110  may be configured to communicate with one or more networks. In the example of the network configuration  100 , the networks with which the UE  110  may wirelessly communicate are a 5G New Radio (NR) radio access network (5G NR-RAN)  120 , an LTE radio access network (LTE-RAN)  122  and a wireless local access network (WLAN)  124 . However, it should be understood that the UE  110  may also communicate with other types of networks and the UE  110  may also communicate with networks over a wired connection. Therefore, the UE  110  may include a 5G NR chipset to communicate with the 5G NR-RAN  120 , an LTE chipset to communicate with the LTE-RAN  122  and an ISM chipset to communicate with the WLAN  124 . 
     The 5G NR-RAN  120  and the LTE-RAN  122  may be portions of cellular networks that may be deployed by cellular providers (e.g., Verizon, AT&amp;T, T-Mobile, etc.). These networks  120 ,  122  may include, for example, cells or base stations (Node Bs, eNodeBs, HeNBs, eNBS, gNBs, gNodeBs, macrocells, microcells, small cells, femtocells, etc.) that are configured to send and receive traffic from UE that are equipped with the appropriate cellular chip set. The WLAN  124  may include any type of wireless local area network (WiFi, Hot Spot, IEEE 802.11x networks, etc.). 
     The UE  110  may connect to the 5G NR-RAN  120  via the gNB  120 A and/or the gNB  120 B. During operation, the UE  110  may be within range of a plurality of gNBs. Thus, either simultaneously or alternatively, the UE  110  may connect to the 5G NR-RAN  120  via the gNBs  120 A and  120 B. Further, the UE  110  may communicate with the eNB  122 A of the LTE-RAN  122  to transmit and receive control information used for downlink and/or uplink synchronization with respect to the 5G NR-RAN  120  connection. 
     Those skilled in the art will understand that any association procedure may be performed for the UE  110  to connect to the 5G NR-RAN  120 . For example, as discussed above, the 5G NR-RAN  120  may be associated with a particular cellular provider where the UE  110  and/or the user thereof has a contract and credential information (e.g., stored on a SIM card). Upon detecting the presence of the 5G NR-RAN  120 , the UE  110  may transmit the corresponding credential information to associate with the 5G NR-RAN  120 . More specifically, the UE  110  may associate with a specific base station (e.g., the gNB  120 A of the 5G NR-RAN  120 ). 
     In addition to the networks  120 ,  122  and  124  the network arrangement  100  also includes a cellular core network  130 , the Internet  140 , an IP Multimedia Subsystem (IMS)  150 , and a network services backbone  160 . The cellular core network  130  may be considered to be the interconnected set of components that manages the operation and traffic of the cellular network, e.g. the 5GC for NR. The cellular core network  130  also manages the traffic that flows between the cellular network and the Internet  140 . 
     The IMS  150  may be generally described as an architecture for delivering multimedia services to the UE  110  using the IP protocol. The IMS  150  may communicate with the cellular core network  130  and the Internet  140  to provide the multimedia services to the UE  110 . The network services backbone  160  is in communication either directly or indirectly with the Internet  140  and the cellular core network  130 . The network services backbone  160  may be generally described as a set of components (e.g., servers, network storage arrangements, etc.) that implement a suite of services that may be used to extend the functionalities of the UE  110  in communication with the various networks. 
       FIG.  2    shows an exemplary UE  110  according to various exemplary embodiments. The UE  110  will be described with regard to the network arrangement  100  of  FIG.  1   . The UE  110  may represent any electronic device and may include a processor  205 , a memory arrangement  210 , a display device  215 , an input/output (I/O) device  220 , a transceiver  225  and other components  230 . The other components  230  may include, for example, an audio input device, an audio output device, a battery that provides a limited power supply, a data acquisition device, ports to electrically connect the UE  110  to other electronic devices, one or more antenna panels, etc. For example, the UE  110  may be coupled to an industrial device via one or more ports. 
     The processor  205  may be configured to execute a plurality of engines of the UE  110 . For example, the engines may include a HARQ management engine  235 . The HARQ management engine  235  may perform various operations related to determining a HARQ codebook size for multi-PDSCH scheduling scenarios. Examples of this process will be described in greater detail below. 
     The above referenced engine being an application (e.g., a program) executed by the processor  205  is only exemplary. The functionality associated with the engine may also be represented as a separate incorporated component of the UE  110  or may be a modular component coupled to the UE  110 , e.g., an integrated circuit with or without firmware. For example, the integrated circuit may include input circuitry to receive signals and processing circuitry to process the signals and other information. The engines may also be embodied as one application or separate applications. In addition, in some UE, the functionality described for the processor  205  is split among two or more processors such as a baseband processor and an applications processor. The exemplary embodiments may be implemented in any of these or other configurations of a UE. 
     The memory arrangement  210  may be a hardware component configured to store data related to operations performed by the UE  110 . The display device  215  may be a hardware component configured to show data to a user while the I/O device  220  may be a hardware component that enables the user to enter inputs. The display device  215  and the I/O device  220  may be separate components or integrated together such as a touchscreen. The transceiver  225  may be a hardware component configured to establish a connection with the 5G NR-RAN  120 , the LTE-RAN  122 , the WLAN  124 , etc. Accordingly, the transceiver  225  may operate on a variety of different frequencies or channels (e.g., set of consecutive frequencies). 
       FIG.  3    shows an exemplary network cell, in this case gNB  120 A, according to various exemplary embodiments. The gNB  120 A may represent any access node of the 5G NR network through which the UEs  110  may establish a connection. The gNB  120 A illustrated in  FIG.  3    may also represent the gNB  120 B. 
     The gNB  120 A may include a processor  305 , a memory arrangement  310 , an input/output (I/O) device  320 , a transceiver  325 , and other components  330 . The other components  330  may include, for example, a power supply, a data acquisition device, ports to electrically connect the gNB  120 A to other electronic devices, etc. 
     The processor  305  may be configured to execute a plurality of engines of the gNB  120 A. For example, the engines may include a PDSCH management engine  335  for performing operations including configuring a multi-PDSCH scheduling DCI for the UE  110 . Examples of this process will be described in greater detail below. 
     The above noted engine being an application (e.g., a program) executed by the processor  305  is only exemplary. The functionality associated with the engines may also be represented as a separate incorporated component of the gNB  120 A or may be a modular component coupled to the gNB  120 A, e.g., an integrated circuit with or without firmware. For example, the integrated circuit may include input circuitry to receive signals and processing circuitry to process the signals and other information. In addition, in some gNBs, the functionality described for the processor  305  is split among a plurality of processors (e.g., a baseband processor, an applications processor, etc.). The exemplary aspects may be implemented in any of these or other configurations of a gNB. 
     The memory  310  may be a hardware component configured to store data related to operations performed by the UEs  110 ,  112 . The I/O device  320  may be a hardware component or ports that enable a user to interact with the gNB  120 A. The transceiver  325  may be a hardware component configured to exchange data with the UE  110  and any other UE in the system  100 . The transceiver  325  may operate on a variety of different frequencies or channels (e.g., set of consecutive frequencies). Therefore, the transceiver  325  may include one or more components (e.g., radios) to enable the data exchange with the various networks and UEs. 
       FIG.  4    shows a method  400  of determining a HARQ codebook size according to various exemplary embodiments. At  405 , the UE  110  receives a DCI during a PDCCH monitoring occasion. In some embodiments, the UE  110  receives multiple DCIs corresponding to multiple PDCCH monitoring occasions. Each DCI schedules multiple PDSCHs. At  410 , the UE  110  receives a time domain resource allocation (TDRA) for up to a maximum number of PDSCHs or transport blocks (TBs) (N cc,i   TB,max ) on serving cell or component carrier(CC) index ‘i’. In some embodiments, the TDRA is indicated in the pdsch-Conf information element (IE) of a pdsch-TimeDomainAllocationList configuration. At  415 , the UE  110  determines the value of N cc,i   TB,max  based on the TDRA table configured by RRC signal for the UE&#39;s serving cell or CC index ‘i’. In some embodiments, different CCs may be configured with different TDRA tables by the RRC signaling. The time domain resource allocation for a given PDSCH reception on a CC is indicated by the received DCI based on the RRC_configured TDRA. 
       FIG.  5    shows examples of TDRA tables for four different serving cells or CCs i.e. CC0, CC1, CC2, CC3. In some embodiments, the number of actually scheduled transport blocks (TBs)  504  by a single DCI is signaled by the selected row index  502  of the TDRA table configured by RRC for the corresponding CC. In some embodiments, a different row index  502  may be selected on a per PDCCH occasion basis and then signaled by the DCI. Based on each TDRA table, the maximum number of TBs for each TDRA table of each serving cell/CC is determined as the N cc,i   TB,max    506 . 
     In some embodiments, the gNB  120 A may alternatively configure the UE  110  with one or more groups of serving cells via a radio resource control (RRC) configuration. In some embodiments, each group is configured a maximum number of N group,j   TB,max  PDSCHs for a single DCI. In some embodiments, the UE  110  alternatively determines N group,j   TB,max  based on the maximum number of TDRAs/TBs (e.g.,  504 ) associated with a single TDRA row (e.g.,  502 ) for multi-PDSCH scheduling. 
     Returning to  FIG.  4   , at  420 , for a HARQ-ACK bit determination, the UE  110  may group together different CCs that have the same N cc,i   TB,max  value. In such a scenario, the maximum number of PDSCHs in a given CC group (N group,k   TB,max ) is equal to N cc,i   TB,max . In some embodiments, CC grouping may alternatively be configured by RRC signaling from the gNB  120 A. In such a scenario, the maximum number of PDSCHs in a given CC group (N group,k   TB,max ) is equal to the maximum number of PDSCHs (N cc,i   TB,max ) in any of the CCs of the group. 
     In some embodiments, the DCI received during the PDCCH monitoring occasion includes two downlink assignment indicators (DAIs) specific to each CC group: a counter DAI (C-DAI) and a total DAI (T-DAI). The C-DAI indicates the cumulative number of PDCCH monitoring occasions in a CC group up to the current CC and current PDSCH monitoring occasion. The C-DAI is first counted by ascending CC index number and, subsequently, by ascending monitoring occasion index number. The T-DAI indicates the total number of PDCCH monitoring occasions in a CC group. In some embodiments, the T-DAI may be updated from one PDCCH monitoring occasion to the next. For example, although the DCI of one PDSCH monitoring occasion may indicate that the T-DAI is 3, the T-DAI may be updated in a later PDCCH monitoring occasion to reflect a different number (e.g., 4), which includes all PDCCH scheduling across CCs up to the current slot where the T_DAI is transmitted. 
     At  425 , the UE  110  determines the HARQ codebook size. In some embodiments, for each multi-PDSCH scheduling DCI received, the UE  110  designates N group,k   TB,max  information bits for the HARQ-ACK response. The UE  110  then generates an ACK or NACK based on the result of decoding each scheduled PDSCH. If N group,k   TB,max  is greater than the number of actually scheduled PDSCHs, then the UE  110  generates NACKs for the difference to ensure that the codebook size for each multi-PDSCH transmission is constant. For example, if a DCI schedules 2 PDSCHs and N group,k   TB,max =4, then the UE  110  will generate 4 information bits for the HARQ-ACK response for this multi-PDSCH scheduling occasion. The first 2 bits are ACK/NACK depending on the result of decoding each of the 2 scheduled PDSCHs. The second 2 bits are NACKs because N group,k   TB,max  is greater than the 2 scheduled PDSCHs. If, for example, the UE  110  successfully decodes both PDSCHs, then the resulting HARQ-ACK response would be ACK, ACK, NACK, NACK. 
       FIG.  6    shows a diagram illustrating an exemplary multi-PDSCH reception scenario according to various exemplary embodiments.  FIG.  6    assumes four CCs and that the TDRA tables of  FIG.  5    apply to these four CCs. Since the largest N cc,i   TB,max  of these tables is 4, then N group,k   TB,max =4. As such, for each successfully received DCI, the UE  110  will generate 4 HARQ-ACK bits. As illustrated in  FIG.  6   , the UE  110  successfully receives/decodes the multi-PDSCH scheduling DCIs of PDCCH monitoring occasions  602   a ,  604   a ,  606   a ,  608   a , and  612   a . As explained above, since N group,k   TB,max =4, then the UE will generate 4 HARQ-ACK bits regardless of how many PDSCHs are actually scheduled to ensure that there is no mismatch between the UE  110  and the gNB  120 A regarding the number of HARQ-ACK bits in case of a missed DCI detection at the UE side. The difference between N group,k   TB,max  and the actually scheduled PDSCHs will result in a NACK for each extra HARQ-ACK bit. As such, the UE  110  will generate ACK, ACK, NACK, NACK for the PDSCHs  602   b  and  602   c , ACK, ACK, ACK, ACK for the PDSCHs  604   b - 604   e , ACK, ACK, ACK, NACK for the PDSCHs  606   b - 606   d , ACK, ACK, ACK, ACK for the PDSCHs  608   b - 608   e , and ACK, ACK, NACK, NACK for the PDSCHs  612   b  and  612   c.    
     Although the UE  110  successfully processes the multi-PDSCH transmissions  602 ,  604 ,  606 ,  608 , and  612 , the UE  110  does not successfully receive/process/detect the PDCCH  610   a . Because each PDCCH monitoring occasion includes the C-DAI and T-DAI, the UE  110  understands that it did not receive a DCI. For example, as illustrated in  FIG.  6   , the C-DAI and T-DAI of PDCCH monitoring occasions  602   a - 606   a  are (1,3), (2,3), and (3,3), respectively. As such, when the UE  110  receives the DCI at PDCCH monitoring occasion  602   a , the UE  110  knows that this is the first of a total of three monitoring occasions. Similarly, the second PDCCH monitoring occasion  604   a  is the second of a total of three monitoring occasions. The T-DAI of PDCCH monitoring occasion  608   a  was updated to 4. As such, the C-DAI and T-DAI of PDCCH monitoring occasion  608   a  is (4,4). As noted above, the C-DAI is counted by CC index first (C0-C3) and then by PSCCH monitoring occasion. In other words, referring to  FIG.  6   , the C-DAI is counted from top to bottom first (by CC index) and then from left to right (by PDCCH monitoring occasion). 
     When the UE  110  receives the DCI of PDCCH monitoring occasion  612   a , the UE  110  similarly knows that this PDCCH monitoring occasion is the second of a total of two monitoring occasions. Since the UE  110  has not received the DCI of a PDCCH monitoring occasion having a C-DAI and T-DAI of (1,2) (the first of the total of two indicated in PDCCH monitoring occasion  612   a ), the UE  110  knows that it missed a DCI. 
     The HARQ-ACK codebook size may be determined based on the T-DAI of the last detected PDCCH monitoring occasion and N group,k   TB,max ; specifically, the product of these two parameters. In the scenario depicted in  FIG.  6   , the last T-DAI of the last detected PDCCH monitoring occasion  612   a  is 2. However, because the UE  110  previously detected a T-DAI value of 4 in CC1, the UE  110  determines that it has missed a DCI and that the T-DAI used to determine the HARQ-ACK codebook size is actually 6 (4+2). As noted earlier N group,k   TB,max =4. Therefore, the codebook size is 24 bits. As a result of this process, both the UE  110  and the gNB  120 A agree on a 24-bit HARQ-ACK codebook size. The gNB  120 A configures 6 PDCCH monitoring occasions. Knowing that N group,k   TB,max  is 4, the gNB  120 A will expect a 24-bit HARQ-ACK payload. Although the UE  110  missed a DCI of one of the PDCCH monitoring occasions, the C-DAI and T-DAI apprise the UE  110  of this failure and the UE  110  is still able to determine the correct 24-bit HARQ-ACK payload size. 
     Also shown in  FIG.  6    is the PUCCH transmission  614 . In the example shown in  FIG.  6   , it is assumed that the UE  110  is configured with a set of K1 values for HARQ-ACK feedback where K1 can be 2, 3, 4, 6, 7, 8. The K1 value indicates how many TBs from the last TB of the multi-PDSCH transmission the PUCCH  614  is sent (e.g., for multi-PDSCH transmission  602 , K1=8). 
     In some embodiments, in addition to the CC grouping of  420 , the UE  110  may perform a HARQ-ACK compression.  FIGS.  7 A- 7 C  show diagrams illustrating exemplary HARQ-ACK compression schemes according to various exemplary embodiments. In some embodiments, the UE  110  may utilize a compression window having a size W, where W=N group,k   TB,max * α group,k  and α group,k  is a compression factor of (¼, ½, 1). A compression factor of α group,k =1 means there is no compression. In some embodiments, the value of α group,k  may be configured via RRC signaling by the gNB  120 A on a per UE basis. In the following description, M cc,m   TB  will denote the number of TBs/PDSCHs that are scheduled by the gNB  120 A at PDCCH monitoring occasion ‘m.’ 
     If M cc,m   TB  is less than or equal to W, then the HARQ-ACK bit sequence generated by the UE  110  will include M cc,m   TB  HARQ-ACK bits based on the decoding results of the PDSCHs plus (W−M cc,m   TB ) bits, each of which have a NACK value. For example, as shown in  FIG.  7 A , a PDCCH monitoring occasion  702  with two scheduled PDSCHs  704   a  and  704   b  (M cc,m   TB =2) is scheduled for the UE  110 . Assuming the window  710  has a size of W=4, the HARQ-ACK bit sequence  706  includes ACK, ACK (assuming successful decoding of both PDSCHs  704   a ,  704   b ) and a padding  708  of two NACKs (W−M cc,m   TB ). 
     If, however, M cc,m   TB  is greater than W, then the UE  110  may divide the M cc,m   TB  into a first sub-window having a size of S=(M cc,m   TB /W) bits and a second sub-window having bits corresponding to the remaining (M cc,m   TB −S) scheduled PDSCHs. For example, as shown in  FIG.  7 B , a PDCCH monitoring occasion  712  with 5 scheduled PDSCHs  714   a - 714   e  (M cc,m   TB =5) is scheduled for the UE  110 . Assuming the window has a size of W=2, the sub-window size S would be (5/2=3) (rounded up to the nearest whole number). As a result, a first sub-window  720   a  includes 3 bits, which correspond to scheduled PDSCHs  714   a - 714   c , and a second sub-window  720   b  includes 2 bits corresponding to the remaining scheduled PDSCHs  714   d  and  714   e .  FIG.  7 B  assumes that PDSCH  714   d  was not properly decoded. As a result, the HARQ-ACK bit sequence  716  is ACK, ACK, ACK, NACK, ACK. The compression scheme in this example yields an ACK for the first sub-window  720   a  and a NACK for the second sub-window  720   b  (due to the presence of a NACK in sub-window  720   b ). As a result, the gNB  120   a  would retransmit both PDSCHs  714   d  and  714   e  that are associated with the second sub-window  720   b.    
     In some embodiments, the UE  110  may alternatively group j PDSCHs together in a first sub-group, where j is less than W, and the remaining (W−j) PDSCHs together in a second sub-group. The motivation behind this grouping is that there is a tight correlation of the decoding of the PDSCHs in the time domain due to the channel correlation property in time. For example, as shown in  FIG.  7 C , a PDCCH monitoring occasion  722  with 5 scheduled PDSCHs  724   a - 724   e  (M cc,m   TB =5) is scheduled for the UE  110 . Assuming the window has a size of W=2, a first sub-window  730   a  includes 1 bit corresponding to scheduled PDSCH  724   a  and the second sub-window  730   b  includes 4 bits corresponding to scheduled PDSCHs  724   b - 724   e .  FIG.  7 C  also assumes that PDSCH  724   d  was not properly decoded. As a result, the HARQ-ACK bit sequence  726  is ACK, ACK, ACK, NACK, ACK. The compression scheme in this example yields an ACK for the first sub-window  730   a  and a NACK for the second sub-window  730   b  (due to the presence of a NACK in sub-window  730   b ). As a result, the gNB  120   a  would retransmit PDSCHs  714   b ,  714   c ,  714   d , and  714   e  that are associated with the second sub-window  730   b.    
     In some embodiments, a HARQ-ACK Codebook may indicate the number of continuous PDSCH receptions scheduled by a single multi-PDSCH DCI Format and successfully decoded at the UE side. One example of 2-bit HARQ-ACK code states is provided in the table below. This codebook advantageously indicates to the gNB  120 A how many PDSCHs, beginning with the first scheduled PDSCH with DAI=1, have been successfully decoded by the UE and, therefore, how many failed PDSCHs should be retransmitted. 
     
       
         
           
               
               
               
             
               
                   
                   
               
               
                   
                 HARQ-ACK states (PDSCH decoding results) 
                 Mapped  
               
               
                   
                 HARQ_ACK(1), HARQ_ACK(2), . . . ,  
                 HARQ-ACK 
               
               
                   
                 HARQ_ACK(N group,k   TB,max ) 
                 states 
               
               
                   
                   
               
             
            
               
                   
                 DTX, any, . . . 
                 DRX 
               
               
                   
                 ACK, NACK/DTX, any, . . . (1 ACK) 
                 State_1 
               
               
                   
                 ACK, ACK, NACK/DTX, any, . . .  
                 State_2 
               
               
                   
                 (2 Consecutive ACKs) 
                   
               
               
                   
                 ACK, ACK, ACK, NACK/DTX, any, . . .  
                 State_3 
               
               
                   
                 (3 Consecutive ACKs) 
                   
               
               
                   
                 . . .  
                   
               
               
                   
                 ACK, ACK, ACK, ACK, . . . ACK  
                 State_N 
               
               
                   
                 (N Consecutive ACKs) 
               
               
                   
                   
               
            
           
         
       
     
       FIG.  8    shows a diagram illustrating exemplary HARQ-ACK compression schemes according to various exemplary embodiments. As shown in  FIG.  8   , a PDCCH monitoring occasion  802  with 5 scheduled PDSCHs  804   a    804   e  (M cc,m   TB =5) is scheduled for the UE  110 . Assuming the window has a size of W=2, the sub-window size S would be (5/2=3) (rounded up to the nearest whole number).  FIG.  8    assumes that PDSCHs  804   c  and  804   d  were not properly decoded. As a result, the HARQ-ACK bit sequence  806  is ACK, ACK, NACK, NACK, ACK. Compressed HARQ-ACK bit sequence  810  is based on the compression scheme described above with respect to  FIG.  7 B . As a result of compression scheme  810 , the gNB  120   a  would retransmit all five PDSCHs  804   a - 804   e . Compressed HARQ-ACK bit sequence  820  is based on the compression scheme described above with respect to  FIG.  7 C . As a result of compression scheme  820 , the gNB  120   a  would retransmit the last four PDSCHs  804   b - 804   e.    
     Based on the table above, the UE  110  uses a compression scheme  830  to group the first two PDSCHs in a first sub-window having 2 bits, which correspond to the 2 consecutive ACKS for PDSCHs  804   a  and  804   b , and the last three PDSCHs in a second sub-window having 3 bits, which correspond to the remaining scheduled PDSCHs  804   c - 804   e . The compression scheme  830  yields an ACK for the first sub-window and a NACK for the second sub-window (due to the presence of two NACKs in the second sub-window). As a result of compression scheme  830 , the gNB  120   a  would retransmit PDSCHs  804   c - 804   e . It should be noted that although one scheme may seem to yield better results than another scheme, the results discussed above are based primarily on the assumed values of the variables explained above (N group,k   TB,max , α group,k , W, S, etc.) and that the results are, therefore, dictated by the value of these variable. 
       FIG.  9 A  shows pseudocode illustrating a Type I HARQ codebook determination process according to various exemplary embodiments.  FIG.  9 B  shows a diagram illustrating a Type I HARQ codebook determination process according to various exemplary embodiments. In some embodiments, the UE  110  is configured with a plurality of K1 values. The UE then uses the configured K1 values and the pseudocode shown in  FIG.  9 A  to determine the PDCCH monitoring occasions and the maximum scheduled TBs corresponding to different multi-PDSCH transmissions. For example, as illustrated in  FIG.  9 B , the UE  110  may be configured with K1 values of (8, 6, 5, 3, 2) corresponding to PUCCH transmission  908 . Based on these K1 values, the UE determines a first multi-PDSCH transmission  902  corresponding to K1=8, a second multi-PDSCH transmission  904  corresponding to K1=6, and a third multi-PDSCH transmission  906  corresponding to K1=3.  FIG.  9 B  assumes that there are no valid TDRAs for K1=5 and K1=2. The Type I HARQ codebook excludes overlapping between the scheduled multi-PDSCHs. As shown in  FIG.  9 B , only the 2 TBs after the end of the first multi-PDSCH transmission  902  are shown. Similarly, only the 2 TBs after the K1=5 is shown. As a result, the resulting HARQ-ACK payload size (codebook size) is 12 bits (8 from the first multi-PDSCH transmission  902 , 2 from the second multi-PDSCH transmission  904 , and 2 from the third multi-PDSCH transmission  906 ). 
     Those skilled in the art will understand that the above-described exemplary embodiments may be implemented in any suitable software or hardware configuration or combination thereof. An exemplary hardware platform for implementing the exemplary embodiments may include, for example, an Intel x86 based platform with compatible operating system, a Windows OS, a Mac platform and MAC OS, a mobile device having an operating system such as iOS, Android, etc. In a further example, the exemplary embodiments of the above described method may be embodied as a program containing lines of code stored on a non-transitory computer readable storage medium that, when compiled, may be executed on a processor or microprocessor. 
     Although this application described various aspects each having different features in various combinations, those skilled in the art will understand that any of the features of one aspect may be combined with the features of the other aspects in any manner not specifically disclaimed or which is not functionally or logically inconsistent with the operation of the device or the stated functions of the disclosed aspects. 
     It is well understood that the use of personally identifiable information should follow privacy policies and practices that are generally recognized as meeting or exceeding industry or governmental requirements for maintaining the privacy of users. In particular, personally identifiable information data should be managed and handled so as to minimize risks of unintentional or unauthorized access or use, and the nature of authorized use should be clearly indicated to users. 
     It will be apparent to those skilled in the art that various modifications may be made in the present disclosure, without departing from the spirit or the scope of the disclosure. Thus, it is intended that the present disclosure cover modifications and variations of this disclosure provided they come within the scope of the appended claims and their equivalent.

Metadata:
Filing Date: 20201015
Publication Date: 20240820
Grant Date: 20240820
Priority Date: 20201015
Inventors: HE, HONG
YAO, CHUNHAI
YE, CHUNXUAN
ZHANG, DAWEI
SUN, HAITONG
NIU, HUANING
CUI, JIE
OTERI, OGHENEKOME
YE, SIGEN
ZENG, WEI
YANG, WEIDONG
TANG, YANG
ZHANG, YUSHU
Assignee: APPLE INC
CPC Classifications: [{"code": "H04W72/23", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04L5/001", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04L1/1896", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04L5/0044", "inventive": false, "first": false, "tree": "[]"}, {"code": "H04L5/0094", "inventive": false, "first": false, "tree": "[]"}, {"code": "H04L5/001", "inventive": false, "first": false, "tree": "[]"}, {"code": "H04L1/1812", "inventive": true, "first": true, "tree": "[]"}, {"code": "H04L1/1614", "inventive": true, "first": true, "tree": "[]"}, {"code": "H04W72/23", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04L5/001", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04L1/1812", "inventive": true, "first": true, "tree": "[]"}]
Family ID: 81208742